First United States
Conference on
Municipal Solid
Waste Management
Solutions for the 90s
Proceedings
Volume II
June 13 -16, 1990
(Wednesday p.m. - Saturday p.m.)

Ramada Renaissance Tech World
Washington, D.C.
Sponsored by
The U.S. Environmental
Protection Agency

Office of Solid Waste	


S-EPA
Printed on recycled paper

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RECYCLING AND
 COMPOSTING

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           ADVANCES IN COLLECTING PLASTICS
                     Janet  Keller
      RI Department of Environmental Management
                  Presentated  at the

First U.S. Conference on Municipal Solid Waste Management

                  June  13-16,  1990
                       491

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Acknowledgment








     Much  of the  material in  this paper  was presented  at  the



American  Institute  of  Chemical  Engineers  Conference  in  San



Francisco  in November 1990.   Partial  funding for  the  original



presentation  and  paper was provided  by the Center  for  Plastics



Recycling Research at Rutgers University.
                               492

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ADVANCES  IN  COLLECTING PLASTICS
INTRODUCTION



     Plastic  soda bottles and milk  jugs  are increasingly common



components  of municipal' recycling  programs,  and  recyclers are



examining the feasibility of recycling different  types of plastics



such  as colored  HDPE bottles and  other rigid  plastic bottles.



However,  it is  still unclear whether  plastics, with  their low



weight  to  volume ratios, are  cost  effective to  recycle.   Thus,



there  has  been  much interest  in  methods to   densify  plastic



materials  onboard  recycling  vehicles.     This   paper  discusses



curbside collection costs, evaluates several on-truck systems for



densifying plastics and concludes that perforator  compactor systems



warrant further study.







IMPACT OF PLASTICS ON RECYCLING SYSTEMS



     The low  density  of  plastics and the high number  of serving



units  involved  can raise  the costs  of  collecting, sorting and



processing plastics.   And although plastic  soda  bottles and milk



jugs  command  relatively high  prices on  a  per  ton basis,  they



contribute little to  recycling program revenue due to  their low



density.  Plastic soda bottles and milk jugs  account for only 4 per



cent of the weight  while making up  36 per  cent  of  the  volume of



material collected in Rhode Island.
                           493

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      Mixed rigid  plastic bottles  are present  in most  American
municipal waste streams  in  amounts  equal to or slightly  greater
than  the  amounts  of  plastic  soda  bottles  and milk  jugs.   However,
revenue will  be lower for this less desirable feedstock  than  for
soda  and milk  bottles.   As discussed below,  in  certain cases,
adding  plastic  containers  can  raise   collection  costs  by a
significant margin.
                   Revenue RI Recycling Facility
                          Four Months —
                   January  1990 through April 1990
Material          Revenue          % of Total            $/Ton
newspaper
corrugated
clear glass
brown glass
green glass
pi milk j
pi soda b
mixed piste
tin metal
aluminum
other
$ 15,222.36
       0.00
  57,348.12
  16,237.00
  16,483.00
  26,056.40
  51,538.00
       0.00
   6,039.00
 189,767.55
       0.00
  4.02
  0.00
 15.14
  4.29
  4.35
  6.88
 13.61
  0.00
  1.59
 50.11
  0.00
   0.5-7
    0.00
   50-65
   30-50
   20-40
 120-180
 160-240
 110-160
    0-10
850-1000
      NA
total
$378,691.43
100.00
                            494

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COLLECTION COSTS
The following discussion of collection costs is provided to provide
a context for understanding the potential of on-truck densification
for reducing  costs.

     The  cost of putting a truck  and  driver on the  road  is the
largest component of recycling collection costs.  The truck fleet
sizing  model  used  in  Rhode  Island  shows  how  various  inputs
influence the size of  the  fleet and  therefore the  cost  of the
program.

     The model has three main parts: drive time,  pickup  time and
haul time.  Of these, only pickup time and haul time are  affected
by the  amount and type of materials collected  and  therefore the
amount of plastic materials present.  Drive time is independent of
these factors.

                          SIZING TRUCK FLEETS
           units served                 housing density
                I                            i
           materials x volume           road & traffic conditions
                j,                            J,  '             .
           participation rate           drive time
      	4:	
   truck cap.       time/pickup
     4-                   4
   # hauls          pickup time
   haul time
                               495

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      The greater number of serving units and the increased volume
 of plastics lead to more full boxes, which in turn can lead to more
 setouts,  requiring  more pickups  and possibly  overtime.    These
 factors  also  mean additional  time to make more hauls,  requiring
 more  money  to  pay  for  overtime and  increased  operating  and
 maintenance costs (tires, fuel, repairs,  etc.)-  The greater volume
 can   mean that   larger,   more  costly   trucks   are required to
 accommodate plastics.

      In  most  cases,  the  combined effect  of all  these  factors
 produces  only  marginal  increases in costs  for overtime and larger
 trucks.  However, in certain circumstances, such as when long hauls
 are involved,  the  increased volume and  greater number of  serving
 units means that an additional  truck is required.  In that case the
 cost  of  adding plastic  is  high —  about $65,000 per year  (annual
 cost to own and operate a dedicated recycling vehicle).

     The  cost  of  collecting  recyclables  is   already  high in
 comparison to  the cost  of  solid waste collection due to  the  lack
 of compaction  and the need to do  at least one  curbside sort to
 separate  paper  from bottles  and   cans.    The  average  cost of
collecting recyclables  in  Rhode  Island is  $70 to  85  per  ton
compared to $35 to 40 per  ton  for  solid waste even for  efficient
recycling  collection systems  that use  one operator,  dedicated
recycling trucks in order to keep costs  down.
                          496

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Collection Systems



     Before  looking at  how  compaction and  augmentation devices



could work, a brief look at  recyclables collection systems is in



order.  Recycling trucks generally hold from  15  to  30 cubic yards.



Truck  types include trailers  and  dedicated  recycling trucks.



Manually loaded recycling trucks come in either low or high profile



versions, with low profile trucks being easier to load.







     Semi-automatic trucks are easier  to  load than manual trucks



but are  available  only  in high profile  versions.  Trucks  come



equipped with from  one to  six  compartments which may be fixed or



moveable.  Moveable compartments are preferred because  they allow



adjustments for differing mixes of materials.







                   Low Profile Recycling Truck
             Semi-automatic Top Loading Recycling Truck
                             497

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                              Manual Truck
                     rrrrr    rr
      When a recycling facility is available,  then  the number of



 curbside  sorts and the time  taken  for sorting can be  kept to a



 minimum  — one for paper,  another  for bottles and cans.   If no



 recycling facility is available,  then further sorting by residents



 and/or  operators  is  necessary to prepare materials  for market.







      Some programs  report  up  to six  curbside  sorts.    Based on



 information collected from programs around the country, it appears



 that  each additional sort  after the  first  one would  take  four



 additional  seconds  for the manual-  truck and  three  and a  half



 additional seconds for the semi-automatic truck.  (Don Fish, RIDEM,



 June 1989.)







     In programs without a  recycling facility,  densification  may



be more feasible since additional  sorting time will not be required



 in order to separate materials for densification.
                               498

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 DEKSIFICATION METHODS



           Manufacturers  and  recyclers  are  trying to  fit  more



 material in  recycling trucks  either by  densifying material  or



 augmenting the space available.   Numerous  projects to  develop on-



 truck  compactors  or granulators, or to add  space on  recycling



 trucks have been conducted in the last two years. Of these,  eleven



 were reviewed for  this paper  (see appendix).   Most of  the devices



 did not  work.   However, several warrant  further  study.   A general



 discussion  of each  type  of  device   and   the  advantages   and



 disadvantages  of each are provided,







     Methods  for  making  room for plastics  include granulation,



 heavy compaction with or without perforation, light compaction,  and



 augmentation of space on trucks either by adding  bubblebacks or by



 adding wire baskets  to the tops or sides of low  profile  vehicles.







     Determining whether a device  provides a benefit is  a  balancing



 act. Do  the gains from increased capacity  or reduced  pickup and



haul time outweigh the losses from the space taken up by the device



 (one to  two cubic yards  for compactors  or  densifiers);  the time



needed for  extra sorting, and revenue lost due to increased glass



breakage?  (Glass breakage increases when plastics are  sorted and



placed  in  a   separate  compartment  for  densification,  and  the



cushioning  effect of the plastics is lost.)







     The degree to  which a densifier provides a benefit also varies



according to certain program characteristics.   The densifier will
                             499

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provide  more benefit  in programs  that  have smaller  trucks,  longer


hauls,  more  material that  can be  densified, and/or  where  the


residents  or operators  are already sorting materials.




      In  general  on-board  densification  device have  not  worked


because  the size reduction achieved is  not enough  to offset  the

disadvantages:  extra space consumed by the device itself,  the time

                                                       x
required for feeding and cycling, the time needed for extra sorting


in programs that use  recycling facilities, the extra cost of  the


devices  (from $4000 to 20000),  and the increase in broken glass  due

to loss  of cushioning from the plastics when plastics are sorted

into  the compaction chamber.




Granulators

      Granulation is unworkable despite high size reduction ratios

(15:1) due to a host of specific problems in  addition  to  those

cited above:  high cost  ($20,000 each); high contamination levels;

and frequent  breakdowns.  Moreover,  granulators can be used with

only  one resin  at a time.   Therefore  in  order to granulate soda

bottles, milk jugs and  rigid plastic  bottles,  three granulators

would be needed at a cost of $20,000  each for a  total  cost  of

$60,000  added to the initial  cost of the vehicle (between $45 and


72K) .




Light Compactors

     Light compactors, such as a sheet metal wedge installed  under

the roof of a semi-automatic truck in Rhode Island, are inexpensive
                           5OO

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 (less than $1000), and provided up to 20 percent size reduction in



 stationary  trials.  They can  handle  mixed recyclables  so  they



 require no extra  sorting, and did not  result in more broken glass



 since plastics were not separated out.  However, the size reduction



 achieved in the stationary trials could not be  replicated  in field



 studies.







 Heavy Compactors



     Heavy Compactors have yielded up to threefold  size reductions



 in  field trials;  up  to fivefold  reductions  are  theoretically



 possible.  And compactors can be used to densify both plastics and



 aluminum.   However,  the disadvantages  of heavy  compaction are



 daunting:   relatively high cost  ($4000 to 10000) ;  time  lost to



 sort, feed and cycle (cycle time 8  — 15 seconds);  and more broken



 glass.  Moreover,  those compactors that do  not perforate materials



 have a fatal flaw  — the plastic springs back to its original shape



 once the material is ejected from the compaction chamber.







     Nonetheless,  heavy on-board compactors that employ perforation



deserve  further  study to  determine  whether   higher levels  of



densification can be achieved; whether the time required  to feed



and cycle the devices can be reduced; and whether the time needed



for sorting  is offset by  the gains in capacity.    A compaction



device that can be installed in a top loading semi-automatic truck



is under development by the Labrie Corporation.  Lummus Corporation



is also conducting trials of a smaller, less expensive version of



its side loading compactor-perforator in Louisiana.
                             501

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 wire Baskets



      In the  meantime,   some  recyclers  are making  do with  wire



 baskets attached to the  sides  and  tops of low profile trucks  or



 with bubbleback trucks.   Wire baskets can increase capacity by  up



 to  16 cubic yards at very low cost  (about $1000).







      The disadvantage of the  baskets  is the time required  to sort



 material.  One company is developing a wire basket system to use  on



 high profile trucks  as well as  low profile vehicles.   However,  at



 least one hauler reports mixed  results  in using wire baskets.







 Flattening by Residents



      Rhode Island is also experimenting  with  having homeowners



 flatten material despite  fears that participation  and recovery



 rates will drop when residents  are asked  to perform extra work  in



 order to recycle.  A single observation of material collected  in



 West Warwick during a previous trial of homeowner flattening showed



 that residents   did  flatten material  and that  approximately  30



 percent of the soda bottles and  50 percent of the milk bottles were



 flattened on arrival  at the interim recycling facility.  Flattening



 rates were much lower for  food  and beverage cans.







CONCLUSION



     If manufacturers can produce smaller, more powerful compactor-



perforators,  with either  larger,  lower,  feed  hoppers for  side



loading vehicles; or  top  loading models  for semi-automatic trucks;



and  provide fullness indicators so that drivers would know how
                             502

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often to cycle the devices, we may see real advances in plastics



collection technology.
                             503

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                             APPENDIX







 Perforator  —~ compactors







 Labrie  Equipment Company



 302 Rue du  Fleuve



 Beaumont, Quebec



 Canada  GOR  ICO



 Contact:  Dominique Dubois 418-837-3606







 Prodeva  Inc.



 100 Jerry Drive



 Jackson  Center OH 45334-0817



 Contact:  Fred Bunke 513-596-6713







 Tri-State Trucking Equipment



 Contact:  Neil Buckman 215-657-1583







Lummus Development Corporation



PO Box 2326



Columbus, GA 31902



Contact: James Renfroe
                               504

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COMPACTORS (without perforation at time of  data collection in Fall



1989)







Impact Products



281 East Haven



New Lenox IL 60451



Contact: Tom Pawlak 815-485-1808







Rudco



Contact: Sal Marizio 609-692-1314







Nu-Way Occupational Rehabilitation Center  (ORC)



Wisconsin



Contact:  Ryan Squires, ORC



          Bea Hoffman, Winona County MN







Jurek Manufacturing



2975 Soffel Avenue



Melrose Park IL 60160



Contact: Bill Rock 312-345-0200







Perkins Manufacturing Company (still under  development, Fall 1989)



3220 West 31 Street



Chicago IL 60623



Contact:  Richard Berman 312-927-0200
                                505

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GRANOLATORS








Shred-Tech Ltd.



PO Box 2526



Cambridge Ontario NIR 7G8



Contact:  Vince Catania 519-621-3560








Foremost



Contact:  Bill Turner 201-277-0700
                          506

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 SOURCES








 Richard Berman, Perkins Manufacturing  Company



 Neil Buckman, Tri-State Trucking  Equipment



 Fred Bunke, Prodera  Incorporated



 Gretchen Brewer,



 Vince Catania, Shred-Tech Limited



 Dominique Dubois, LaBrie Equipment Company



 Rea Hoffman, Winona  Country, MN



 Tom Kimmerly, General Engineers,  Company, Inc.



 Sal Marizio, Rudco



 Patti Moore, Moore Recycling Associates



 Tom Pawlak, Impact Products



 James Renfroe, Lummus Development Corporation



 Bill Rock, Jurek Manufacturing Company



Richard Sherer, General Engineers Company, Inc.



John Snellen, Waste Management Incorporated



Ryan Squires,  Nu-Way Occupational  Rehabilitation Center, Wisconsin



Bill Turner, Foremost
                                 507

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CO-MARKETING IN DUPAGE COUNTY, ILLINOIS
                 Miriam C. Foshay
             Recycling Management, Inc.
                  Presented at the

First U.S. Congerence on Municipal Solid Waste Management

                June 13-16,1990
                    509

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             CO-MARKETING IN DUPAGE COUNTY, ILLINOIS
                                              by
                                       Miriam C. Foshay

        Co-marketing to improve marketability is a method pioneered by Gary Olson and the New
Hampshire Resource Recovery Association. But co-marketing has been identified with rural situations
remote from markets. DuPage Cpounty's recycling centers are distinctly urban, part of the metropolitan
area of the nation's third largest city. The Chicago area has markets for every material. Yet co-marketing
is just as applicable here, although for slightly different reasons.

        DuPage County currently has ten recycling centers. All but one of these is a small, severely
underfunded operation manned largely by volunteers. All are short on storage space and many do not
have a shelter or electric power. Brokers are available to help them market newspaper, glass, and
aluminum. But plastic presents a special problem: because it has such a low density, it requires a
tremendous amount of storage space, and it must be densifled to make it marketable.

        The largest of the recycling centers is Napervillle Area Recycling Center in the southwest corner
of the county. NARC became involved in recycling high-density polyethylene (HOPE) in 1987 when the
State of Illinois provided grant money to help purchase a baler. The baler was quickly outgrown, and in
1988 NARC proposed to the County that in exchange for a grant to purchase a plastics granulator, NARC
would provide marketing services for HDPE for the county's recycling centers.

        Since none of the other recycling centers had the volume or the space to justify the purchase of
this piece of equipment, this arrangement seemed ideal. The services NARC provides include:
o       Supplying woven polyester bags with a 2.2 cubic yard capacity for storing the plastic,
o       Transporting the bags of plastic in a truck with a 22-foot box to the center in Naperville;
o       Sorting the plastic by color and granulating it;
o       Shipping the granulated plastic to Eaglebrook Plastics in Chicago.

        NARC charges the recycling centers S.04 per pound for supplying the bags and granulating the
plastic Transport costs S12 per hour for labor and payroll taxes and S1.2S per mile for use of the truck.
NARC has agreed to charge only to cover its direct costs and none of the overhead. These charges are
subtracted from the revenue paid to each recycling center from the sale of its HDPE.
                                            510

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       As a result of this program, plastics recycling in DuPage County has increased tremendously. As
of January, 1990, NARC was collecting 20 tons per month from participating centers. Recycling centers
in surrounding counties have also joined, in spite of the fact that transportation costs can exceed the
revenue from sale of plastic. The accompanying graphs show how volume has changed over time.
           o
           c_
                 35
                 30 -
           0.
           ^-g   acH
           "5s
                 15 -
                 10 -
                 5 -
                         Total HDPE Marketed  for All Centers
                                   OcL 198* through Dec. 1989	
          77s
                             A
  WamnilU  Gl«
           Blys
                                    clear
                                              VIII,  V,'t*tm,mt
                                              r.rk
                                                  colored
                                                               L»Gr..(c Wh««i»
        Cd
        C-
         o
        1  1
         o
        a.
16
15
14
13
12
11
10
 9
 8
 7
 6
 5
 4
 3
 2
 1
 0
                      Total HDPE  Co-marketednper Month
                                     All Centers—Ocl 88-Decl9^
                                                                 v
                                                                         \

                                                                             /.
                                                                      0   N
                EZ1 Clear
                                                      colored
                                           511

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         One interesting sidebar of the data we collected was a reading of the volume of colored HOPE
that can be captured by a recycling program. Not all programs advertised that colored HDPE was
accepted; most, however, accepted the colored HDPE that showed up at their doors. The following table
shows the percentage of colored HDPE collected by each center during the period from May through
December, 1989:


Center

Hinsdale
Villa Park
Westmont
Wood ridge
Wheaton
Naperville
La Grange Park
% of colored
HDPE in a
mixed-HDPE
waste stream
23.5%
10.9%
7.7%
8.0%
10.1%
23.6%
28.4%
Even in Naperville, where colored plastic has been collected for over a year, many recyclers don't realize
that their detergent bottles can be recycled, too. One must assume that the lower figures reflect
incomplete dissemination of knowledge that colored plastics can also be recycled. The higher figures,
then, would approach the maximum level of colored HDPE recovery. It would appear from this table that
colored HDPE constitutes one-quarter to perhaps as much as 30% of all household HDPE.

In addition to allowing small recycling centers to handle plastic economically, co-marketing has provided
us with power in the marketplace. NARC found that their granulator had a difficult time handling
colored plastics because the detergent residues would cause plastic flakes to adhere to the grinding
chamber, clogging the screen and requiring extensive cleanup.  This problem was solved by increasing the
hole diameter of the screen from the standard 3/8" to 5/8", which also allowed faster processing of HDPE.
Our buyer, however, refused to accept this coarser product, so we found another market.  At 30 tons of
plastic a month, we are a major supplier of post-consumer regrind, and it only took two shipments  before
our original market ate crow and agreed to accept our 5/8" material.
                                            512

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        Co-marketing of materials is a technique with a number of advantages. It allows pooling of
resources to allow maximum use of the resources available. It gives power in the marketplace, allowing
more control over price and specifications. And it allows the recycling of materials which would
otherwise be uneconomical to handle.
                                           513

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              COMPOSTING OF HSU  IN THE USA
          Luis  F. Diaz and Clarence G. Golueke
                Cal Recovery Systems,  Inc.
                     Presented at the
First U.S. Conference on Municipal  Solid Waste Management
                     June  13-16, 1990
                        515

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INTRODUCTION
     The convening of this Conference is ample evidence of the public's
awareness of the magnitude of the solid waste managment problem and of the
challenge to do something about it.  Nevertheless, at the risk of stres-
sing the obvious, we begin with a few words about the causes of the prob-
lem and the nature of the challenge so as to provide a setting for the
subject of our paper.
     Three factors share responsibility for much of the problem and the
challenges.  They are: 1) the continuing migration of the urban population
to the suburbs; 2) the unceasing generation of large quantities of wastes;
and 3) a serious shortage of professionals specifically capable of relying
upon alternatives other than the land for the disposal  of municipal  solid
waste (MSW).  The shortage is critical for a rapidly increasing number of
municipalities, inasmuch as for them, landfilling is no longer a viable
alternative because of public pressure,  cost, and intensification of re-
source conservation.
     The nature and dimensions of the problem are such that each and every
solution proposed for it and adopted by the community must not only be
politically and environmentally acceptable, but also be economically fea-
sible.  A solution that sufficiently meets these requirements is to sup-
plement sanitary landfilling with resource recovery (i.e., recycling).
One of the more important forms of resource recovery is biological stabil-
ization ("biostabilization").  Of the biostabilization methods, composting
has much to offer, and moreover has been demonstrated as being eco-
nomically feasible.
     The main theme of our presentation is the past, present, and
projected status of composting as a means of biologically stabilizing MSW
                             516

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in the U.S.A.  We close with a discussion of the status of yard, leaf, and
garden waste composting.

STATUS OF MSW COMPOSTING
Past
     Chronologically, the status of composting MSW in the past can be
divided into the two periods:  "Early" and "Intermediate" (or "Dormant").
Broadly speaking, the early period began in the 1940s and continued until
the onset of the intermediate period in the late 1960s.  The intermediate
period continued until the onset of the present or modern period in the
mid-1970s.   (The time frames are only approximate.)
Early Period
     The compost record during this period would be best summarized by the
adjective "mixed."  Thus, through research and development, great strides
were made in the advancement of understanding and knowledge of principles
and parameters  of the compost process.  The progress and accomplishments
were such as to raise composting from the status of an  art to that of a
science.
     In sharp contrast, the record compiled by composting, when used as  an
option on a practical  (municipal) scale in municipal solid waste manage-
ment, was far from  impressive.  A very likely reason for the mediocrity  of
the early record was that at the time, composting was 3 to 4 decades
 "ahead of its time."  Open dumping was only beginning to give way to the
 early  and rather primitive versions of sanitary landfilling.  Moreover,
 the prevailing  illusion  at the time was that not only was an abundance of
 land  available  for  the  disposal of wastes, but that the abundance would
 continue  into  the dim,  distant future.  These and other factors  (e.g.,
                                 517

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public apathy towards resource recovery, little concern about the quality
of the environment) combined to render disposal via the land economically
much more attractive than composting.  The situation was rendered almost
hopelessly grim by an unwarranted and certainly not-fulfilled expectation
of profits to be obtained from the sale of the compost product.
     We conclude our discussion of the early status of composting with
brief descriptions of a few of the compost operations that attracted
attention at the time.
     Sacramento. California
     A refuse composting facility, operated as a demonstration facility
and based on the use of a "Dano" reactor was designed and built in
Sacramento in 1956.  Having served its purpose, the facility was closed
after having been  in operation for about five years.
     The Sacramento facility was operated in the following manner:  Un-
sorted (mixed) waste brought to the facility in conventional waste col-
lection vehicles was discharged onto a conveyor system.  Noncompostable
items, along with  recyclable items (e.g., bottles, rags, cardboard), were
removed manually.  The non-compostable items were discarded.  Ferrous
material was removed with the use of a magnetic drum.   Refuse remaining
after the removal  of objectionable items was primarily organic in nature.
This organic residue was passed through a shredder, in which it was size
reduced to a particle size that ranged from less than 1 inch to about 5
inches.  The shredded material was discharged into a Dano reactor.  Resi-
dence time in the  reactor was on the order of 14 days.  The final volume
of the composted refuse varied from 60% to 70% of that of the incoming raw
material. The Dano reactor used in the demonstration was much the same in
design and operation as the modern Dano reactor.  The Dano reactor was a
                                 518

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closed, horizontally oriented cylinder that had a 100-ton capacity and was
rotated at 0.8 rpm.  The interior of the cylinder was equipped with vanes
to impart a tumbling motion to the rotating wastes.  Air was introduced
into the cylinder to aerate the composting mass.  Moisture content of the
material was adjusted by means of water jets distributed along the side of
the cylinder.
     Chandler, Arizona
     In the Chandler operation, a few oversize items and rags were grossly
sorted from the incoming refuse.  Ferrous metals were removed by means of
an electromagnet (60% efficiency).  The sorted refuse was shredded in a
hammermill equipped with coarse grates.  Moisture content was adjusted by
adding either sewage sludge or water at the bottom of the primary elevator
conveyor.
     The shredded material was transferred to outdoor concrete slabs,
where it was either piled into 4-ft high windrows that were about 6-ft
wide at the base, or was placed in bins formed of hardware cloth.  During
the first 14 days ("active" stage), the material was aerated by way of
"turning," and moisture was added when required.  The active stage was
followed by the "curing" stage (about 14 additional days).  Apparently the
quality of the compost was adversely affected by the inefficiency of the
sorting process.
     Phoenix. Arizona
     The Phoenix refuse composting facility was owned and operated by the
Arizona Biochemical Company.  The company had a contract with the city to
accept refuse for a tipping fee of $1.25 per ton for the first year and
for $1.10 per ton thereafter.  Operation of the facility was begun in
1962.
                                519

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     In the operation, refuse was manually sorted, followed by magnetic
separation.  The sorted residue was shredded and then introduced into a
Dano drum.  Two additional drums were expected to be put into operation
about 5 to 6 months after start-up.  Unfortunately, after seven months of
operation the facility closed because of lack of financial support.
     Johnson City. Tennessee
     The construction and operation of the Johnson City compost facility
was a part of a joint project conducted by the U.S. EPA and the TVA.  The
project was begun in 1967 and was terminated in 1971.   The main objective
of the project was to evaluate the feasibility of windrow composting for
managing municipal solid waste.  However, the scope of the study embraced
a wide range of investigations, among which were: 1) the composting of
mixtures of refuse and sewage sludge; 2) the evaluation of public health
problems; 3) an assessment of economic benefits from using compost for
agricultural, horticultural, or soil amendment purposes; and 4) the deter-
mination of permissible rates of compost loading on the soil.
     The plant had a nominal capacity of 60 tons per day for an 8-hr
shift.  Incoming wastes were sorted manually and ferrous materials were
removed by means of magnets.  The sorted residue was either passed through
a hammermill or through a rasping machine. Moisture was adjusted to a
level of 50% to 60% by adding either water or sludge to the refuse.   The
size reduced material was stacked into 4- to 4.5-ft windrows that were
about 9-ft wide at the base and as long as 230 feet.  The material was
aerated 8 or more times using a turning machine.  The active composting
period varied from 35 to 44 days.  After composting, the material was
cured, dried, shredded, and screened.
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     Other Facilities
     Time and space permit only a brief mention of two other facilities,
namely, the 35-ton per day plant at Norman, Oklahoma and the 70 ton per
day plant (design capacity - 150 tons/day) at San Fernando, California.
Both employed the "Naturizer" system.
     The two principal features of the Naturizer system were the "pul-
verator" and two vertical 3-tiered digesters.  The pulverator was a large
diameter cylinder revolving slowly on a longitudinal axis with heavy bar
hammers.  It was followed by a horizontal hammermill with studded shells.
Each digester consisted of 3 rectangular cells tiered one above the
other.  Slowly moving slat bottoms advanced refuse from the receiving end
of the top cell to the discharge end.  The discharged refuse was passed
through the middle cell and then through the bottom cell.  At this stage,
the material was reground and then passed through a second tier of cells
(the second digester).
Intermediate (Dormant) Period
     The intermediate period is appropriately termed "dormant," since at
the time, excepting by a dedicated few, composting was not regarded as
being a viable option in municipal solid waste management.  Despite this
temporary loss of favor, the interest and research regarding composting as
a treatment method persisted.  This persistence paved the way for compost-
ing to become the candidate of choice when a viable alternative to land-
filling and incineration had to be found for sewage sludge disposal in the
late 1970s.
PRESENT AND FUTURE STATUS
     Toward the end of the 1970s, the situation, hitherto so unfavorable
to the compost option, began to change rapidly and drastically, to the
                                521

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extent that composting no longer was ahead of its time.  On the contrary,
its time had come.  The change began with sewage sludge, then progressed
to yard and garden debris, and now is making inroads on the entire organic
fraction of the municipal solid waste stream.  The magnitude of the transi-
tion from the low status of MSW composting in the late 1960s and early
1970s is emphasized by the fact that now composting is one of the more
publicly accepted options for treating important components of the
municipal waste stream, namely, yard wastes and sewage sludge.
     Several factors have and are combining to bring about the remarkable
rise in the status of composting to the level of being the popularly ac-
cepted option of choice for treating and disposing of organic municipal
waste.  Although the importance of the favorable economic situation re-
sulting from the change in circumstances must not be overlooked, other
factors come into play.  Those factors include landfill shortages, high
disposal fees, and legislation that prohibits the disposal of "unprocessed
waste."  Those factors, combined with the federal and state regulatory
constraints imposed on the two principal competing options (sanitary land-
fill, incineration), and the higher costs of the two have substantially
raised the status of MSW composting.  In addition, financial assistance
programs established in several states (e.g., Massachussetts, Minnesota,
Iowa) are also having a positive impact on the growth of MSW composting.
     Not to be underestimated is the legislative impetus.  Recently, sev-
eral states have enacted legislation in which priorities are established
regarding alternatives for managing solid wastes.  Typically, the laws
assign top priorities to reduction of generation rates and volumes, ex-
pansion in recycling and composting, followed by incineration and land-
filling.  If put into effect, new regulations recently proposed by the
                                522

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U.S. Environmental Protection Agency for landfills undoubtedly would raise
the cost of landfill ing.  As it is, landfill costs are major incentives
for the strenuous efforts now being directed to the reduction of the
amount of wastes destined for land disposal.  Composting has the advantage
of fitting well with many of the approaches to waste reduction and
recycling.
Potential Danger
     A potential danger to the continued success of modern composting.is
in the uncritical attitude that could be an undesired offshoot of the
present interest in MSW composting.  The interest could be so intense as
to engender an uncritical attitude; which in turn could lead to the selec-
tion of the composting option without having made a thorough analysis of
alternative options and their costs.  The uncritical attitude could take
the form of failing to realize that composting MSW usually is an under-
taking, the complexity of which is a function of the extent and type of
separation required.  Although manual separation can be and is success-
fully used for smaller operations, it is inadequate for coping with the
massive quantities of refuse that must be sorted in the larger opera-
tions.  Mechanical processing must be incorporated in designs for dealing
with those quantitites.  Consequently, with the exception of some particu-
larly unusual set of circumstances, a combination of manual and mechanical
sorting is the only practical means of accomplishing the degree of separa-
tion needed to render MSW a satisfactory feedstock for the compost pro-
cess.  The importance of doing so rests on the fact that the quality of
the finished compost product depends heavily upon the effectiveness of the
separation process  [3,4].  The problem is that providing a satisfactory
mechanical separation is a difficult task.
                                523

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Modern Status — Specifics
     Operating Facilities
     Judging from personal observations and information gained from dis-
cussions with their designers and operators, existing plants in the U.S.
generally are characterized by a relatively low throughput and capital
investment, and an over-simplification of design.  Insufficient attention
is given to the segregation of organic from inorganic matter in the
refuse.
     The status of MSW compost projects in the U.S. is summarized in Table
1.  The location, capacity, year of establishement, and other pertinent
information regarding MSW composting plants in operation in the U.S. in
May, 1990 are listed in Table 2.  The collective range of capacities was
from about 15 to 350 tons/day.  The table further indicates that with its
capacity of 700 tons/day  (design capacity - 1000 tons/day), the Wilmington
(Delaware) plant was much larger than the other four plants in operation.
The respective capacities of the latter four were only 15-20, 30, 50, and
65-70 tons/day.  Moreover, the designs of the four were relatively simple
and had been made operational within the preceding two years.
     Wilmington Facility  -- The Wilmington facility is designed to process
about 1000 tons of municipal and commercial solid waste per day into ref-
use derived fuel and compost.  It incorporates size reduction, air clas-
sification, magnetic separation, and screening to recover metals and
glass.  This sorting set-up results in the production of about 250 tons of
highly organic residue each day.  Sewage sludge  (about 20% solids) is
added to this residue, and the resulting mixture is introduced into one of
four digesters, each of which has a holding capacity of 175 tons.  Each
digester is equipped such that its contents can  be mixed and aerated while
                               524

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          Table 1.   Summary of MSW Compost Projects


      Status                                 Number

    Operation                                   7
    Pilot                                       7
    Design                                     17
    Permit                                      8
    Feasibility                                21
      Total                                     60

Source:  BioCvcle and Cal  Recovery Systems,  Inc.  [8]
                          525

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              Table 2.   Operational  Municipal  Solid Waste  Composting  Facilities  in the U.S. (1990)
Location
Lake of the Woods, Minnesota
Fillmore County, Minnesota
en J
o> Portage, Wisconsin
St. Cloud, Minnesota
Sumter County, Florida
Wilmington, Delaware3)
Skamania County, Washington
Capacity
(tons/day)
5 to 10
15 to 20
30
50
65 to 70
-700
70
Year
Established
1989
1987
1986
1988
1988
1984
1988
Type of System
Windrow
Windrow
In-vessel/drum
In-vessel/drum
Windrow
In-vessel/silo
Windrow
Material
Added
..
--
Sewage sludge
Sewage sludge
--
Sewage sludge

Markets
None
None
None
None
None
Yes
Yes
a) This facility was designed to process about 1,000 TPD of MSW to recover RDF,  glass, and metals.  An organic
   residue is mixed with sludge and composted in an in-vessel  system.

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in the digester.  At the completion of a 5-day retention period in the
digester, the material is removed and is stacked in a pile and is allowed
to mature for 30 to 45 days.  The matured material is screened.  By virtue
of a permit, the fines are used for horticulture.  The rejects are mixed
with top soil in a 1:1 ratio, and the mixture is used for erosion control
at landfills.
     Sumter County -- Since mid-1988, a windrow composting facility has
been in operation in Sumter County, Florida.  According to the operators
of the facility, from 65 to 70 tons of residential waste and commercial
waste are processed at the facility each day.
     In the operation, incoming waste is introduced into a unit designed
to open the bags and discharge the contents onto a conveyor belt.  The
belt passes the contents by a magnetic device such that ferrous metals are
removed.  Aluminum and some inerts are removed manually.  The waste, now
free of ferrous and aluminum metals and some inerts, is size reduced to an
approximate 2 x 2 in. particle size.  The size reduced material is stacked
in 6 ft high by 10 ft wide windrows and is dosed with a proprietary
bacterial inoculum.  The operators claim that the compost is ready after
six weeks.  The operators hope to market the product as soon as the
Florida Department of Environmental Regulation grants permission.
Market for the Compost Product
     At present, information on product characteristics, expected quanti-
ties, and consistency of production is too uncertain and fragmentary to
permit a firm definition of the present and hoped-for market for the MSW
compost product.  Apparently, no MSW composting facility is routinely
marketing its product.  The absence of marketing  is to be expected,
                                527

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inasmuch as most MSW compost facilities are as yet in the testing and
permitting stage.
     The very little quantity of available MSW compost product makes it
difficult or even impossible to collect needed information.  Moreover,
projections made on the basis of available information would be highly
uncertain.  It is unlikely that the characteristics of the product
presently available would be the same as those of material routinely
produced after full production is reached.
HSW as a Bulking Agent
     Refuse has many shortcomings that would make it less effective than
wood chips as a bulking agent in the composting of sewage sludge.  How-
ever, the shortcomings can be lessened or even avoided by resorting to a
combination of careful preprocessing, avoidance of excessive moisture,
following suitable mixing, and aeration procedures.
     Potential benefits from the use of MSW as a bulking agent could in-
clude significant cost savings, possible (but very unlikely) sale of the
co-compost product, and the utility of the product in soil reclamation.
The economic justification of the substitution of refuse for wood chips as
a bulking agent in sewage sludge composting obviously would be determined
by way of a careful analysis of the shortcomings of refuse versus the
benefits of using it as a substitute for wood chips [5].
Future
     The future of the implementation of MSW facilities seems bright.  If
it can be done successfully, the implementation would greatly lighten the
management and disposal burden.  Composting lends itself to integration
into many material-recycling schemes -- including those that involve
incineration.  For example, the use of suitably processed MSW as a bulking
                                 528

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agent for composting sewage sludge (i.e., co-composting) would ease the
task of treating and disposing two major wastes.
     Before the routine success of co-composting can be assured, certain
requirements must be met.  Among the more important are these:  1) as-
suredly reliable mechanical equipment; 2) advancement of the knowledge and
understanding had by designers and system vendors; 3) means of removing or
counteracting the toxic content of the sludge fraction; and 4) development
of an outlet large enough to accommodate all or most of the resulting
co-compost product.

STATUS OF YARD WASTE, LEAF, AND PARK DEBRIS COMPOSTING
     Unless otherwise specified, the term "yard waste" refers to the three
wastes collectively.  The concept of reducing the size of the municipal
waste stream destined for treatment and disposal by separately treating
yard waste not only is becoming increasingly attractive, but also is being
implemented throughout the country.  Moreover, the usual method of treat-
ment is composting.
     Judging from information gained in various MSW characterization
studies, 5% to 30% (by weight) of the municipal solid waste stream may be
in the form of yard debris.  Quantities of yard debris generated and its
resulting proportion of the MSW stream not unexpectedly vary seasonly, as
well as from region to region.  Thus, generation is at its lowest during
the winter season in those parts of the country that have such a season,
and during the rainy season in the other parts.  A precipitous influx of
leaves into the waste stream occurs in autumn in the temperate zone--- as
much as 95% of the MSW stream in some communities.
                               529

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     Because of the relative ease with which yard waste can be diverted
from the landfill, hundreds of municipalities have established programs
for utilizing the waste.  Additionally, the diversion is encouraged by
legislative measures.  Some of the measures even prohibit the disposal of
yard debris in landfills:  In 1988, the State of New Jersey banned the
disposal of leaves in landfills; other states include Minnesota,
Wisconsin, and Illinois.
Collection of Yard Waste
     Because yard waste is an excellent substrate for the compost process,
the waste should not be permitted to be contaminated with other wastes,
especially not with undesirable wastes.  Prevention can be accomplished
through appropriate collection strategies.  For example, establish pub-
licized drop-off sites and institute curbside collection.
     The use of drop-off sites is, perhaps, the simplest and least expen-
sive of the yard waste collection strategies.  Large containers are placed
in one or more strategic locations, and the public is encouraged to de-
posit its yard waste in the containers.  Some public officials regard the
dependence upon the public to both segregate the material and transport it
to the drop-off site as being a weakness of the strategy.  Thus far,
public participation has been at a modest level.
     Curbside collection has been more successful in terms of public
participation,  Curbside collection is carried on in many ways.  One way
is to impose a regulation that demands that the homeowner segregate and
place the yard waste at a designated collection point.  For example, have
the yard waste piled curbside for either manual or mechanical collection.
An alternative is to have the homeowner use a container (can, box, or bag)
instead of simply piling the yard waste at the curb.  The task of
                                530

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collecting the mass of leaves that accumulate in the autumn is accom-
plished in several  communities through the use of vacuum trucks.  However,
the cost of collecting leaves via vacuum can be more than $80/ton of
leaves collected.
Yard Haste Compost Technology
     A few communities use an extremely low-technology approach that they
unjustifiably label "composting."  Their so-called "composting" makes mini-
mal use, if any,  of processing.  The material is simply stacked in piles
as high as 10 to 20 ft, which are not disturbed over periods of longer
than 18 months.  Because the wastes consist mostly of plant residues, and
of shrub and tree trimmings ranging from twigs to large branches, the
experience had by those communities has been far from satisfactory and has
been marred by the development of fire hazards during the dry season.
     The windrow system is the one of choice for communities interested in
pursuing a satisfactory approach to composting yard waste.  Aeration is
accomplished either by mechanical turning, by forced aeration, or by a
combination of the two.  The general experience has been that forced
aeration leads to an excessive drying and cooling of the composting mass,
especially when the substrate consists largely of tree trimmings and dried
vegetation (leaves, straw).  The very porous nature of the waste mass
permits a relatively unimpeded movement of air and diminishes the moisture
holding capacity of the windrowed mass as a whole.  The lowered "water
holding capacity" is due to the rapid percolation of water to the bottom
and out of the windrow.
     As with mixed yard wastes, a minimal approach is used by some com-
munities in the composting of leaves.  Basically, the leaves are stacked
in piles and are allowed to decompose without being given further
                                531

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attention.  Decomposition may take as long as 18 or more months, and
usually is accompanied by the development of unpleasant odors which are
especially pronounced on the rare occasions on which the mass is turned.
This approach is used in situations in which there is available land area.
     A more positive approach is followed when available land is expen-
sive.  The approach is the windrow method described for mixed yard waste
(i.e., aeration either by mechanical turning or by way of blowers).  Mois-
ture content and other parameters are maintained at levels that permit
shortening the compost process to four or five weeks.  The process may be
further optimized through the addition of nitrogen.
     Equipment
     The unsatisfactory performance of many yard waste compost operations
usually can be traced to the lack of a reliable shredder.  A shredder has
an adequate capacity if it can size reduce fairly large branches and
brush, twigs, tree clippings, and other woody material to a particle size
small enough to permit easy manipulation and promote biological break-
down.  Moreover, the shredder must be sufficiently sturdy to deal with
occasional contaminants such as rocks, bricks, and pieces of metal.  An
indicator of an inadequate shredder is an accumulation of branches and
other woody debris.  Eventually the accumulation reaches unmanageable
proportions, becomes unsightly, and could well constitute a serious fire
hazard.  Other indicators are excessive downtime and high O&M costs.
     Turning the piles in small operations can be adequately accomplished
by means of a front-end loader or a bulldozer equipped with a standard
blade.  Exceptions might be the occasions when yard waste consists mostly
or exclusively of grass clippings.  Because of the matting tendency of
grass clippings, a bulldozer or front-end loader might not be capable of
                                532

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dealing with the tendency of grass clippings to mat or form clumps.  A
machine specifically designed for the turning would be needed for large
operations [6].
Moisture Problem
     Neglect of moisture maintenance in the composting mass is an all too
common occurrence in yard waste compost operations.  Insufficient moisture
can seriously inhibit the compost process and thereby lower the efficiency
of the operation.  A more serious consequence is the intensification of
the fire hazard.  The usual reason for the failing is the absence of an
accessible water source.  The absence generally is due to the high cost of
providing the water source.  Unfortunately, the high cost has no effect on
lowering the minimum moisture content required for satisfactory compost-
ing.  Some communities confronted with such a dilemma resort to an alter-
native, but doubtfully acceptable, approach.  They simply allow the piles
to remain undisturbed until the arrival of the rainy season, at which time
they start or resume the compost program, as the case may be.
The Yard Waste Compost Product
     Yard waste compost operations in which the feedstock is consistently
free of objectionable contaminants, and the compost process is conducted
satisfactorily, almost invariably produce a product that simultaneously is
an excellent soil amendment and a partial source of fertilizer elements.
Properly screened, the product could be safely used in the more demanding
landscaping activities.

SUMMARY AND CONCLUSIONS
     The many positive past and present developments in yard waste and MSW
composting warrant the objective conclusion that the current status of
                                533

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composting as a waste management and disposal alternative is quite
favorable in the United States.
     The status of yard waste composting is steadily improving.  Within
the span of the past five years, the yard waste compost activity in the
U.S. has expanded from a few scattered operations, to the hundreds of
known operations distributed throughout the nation.  Despite the un-
fortunate tendency of some communities and developers to oversimplify the
operation to the extent that management disappears, the yard waste compost
movement will continue to grow unabated, particularly in the role of
diverting the waste from landfills.
     MSW composting is experiencing a period of growth that, barring
unforeseen reverses, will continue for some time to come.  The rate of
growth, although far slower than that of yard waste composting, neverthe-
less is respectable.
     An unfortunate occurrence in MSW composting is the failure of most of
the present and planned MSW composting programs to include source separa-
tion.  The failure very likely will prove to be a substantial impediment
to the attainment of design performance by the compost facility.  Other
major impediments to the success of the MSW compost movement include:  1)
insufficient basic design data; 2) failure to establish standards for the
finished product; 3) insufficiency of experience on the part of many
designers, vendors, and clients; and 4) overly optimistic expectations
regarding markets and uses for the material  [4,6,7].
REFERENCES
  1.  Anonymous, "Composting Saves Landfill Space," World Wastes.
     28(12):29,31 (1985).
                                534

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2.  Goldstein,  N.,  "Steady Growth for Sludge Composting," BioCvcle.
    29(10):27-36 (November-December 1988).
3.  Savage,  G.M.,  and L.F. Diaz, "Key Issues Concerning Waste Processing
    Design," Proceedings of the 1986 ASME National Waste Processing
    Conference. Denver, Colorado, June 1986.
4.  Diaz, L.F., G.M. Savage, and C.G. Golueke, "Production of Refuse-
    Derived Fuel from Municipal Solid Waste," presented at the 79th Air
    Pollution Control Association Annual Meeting, Minneapolis, Minnesota,
    June 1986.
5.  Savage, G.M. and C.G. Golueke, "Major Cost Elements in Co-Compost-
    ing," BioCvcle. 27(l):33-35 (January 1986).
6.  Savage, G.M., et al_, Engineering Design Manual for Solid Waste
    Reduction Equipment. Report by Cal Recovery Systems, Inc. under U.S.
    EPA  Contract No. 68-03-2972, 1982.
7.  Diaz, L.F., G.M. Savage, and C.G. Golueke, Resource Recovery from
    Municipal Solid Waste. Vol. I. Primary  Processing. CRC Press,  Inc.,
    Boca Raton, Florida, 1982.
8.  Goldstein,  N.,  "Solid Waste Composting  in the U.S.," BioCvcle.
    30(H):32-37 (Novmeber 1989).
                               535

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             THE COMPOSTING PLANTS IN MEXICO
                   A STATE OF THE ART

                  ARTURO DAVILA, M.Sc.
    PRESIDENT OF THE MEXICAN SOCIETY FOR THE CONTROL
              OF SOLID AND  HAZARDOUS WASTES

                    PRESENTED AT THE

FIRST U.S.  CONFERENCE  ON MUNICIPAL SOLID WASTE  MANAGEMENT
                   JUNE 13-16, 1990
                            537

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                           ABSTRACT


THE  RECYCLING  AND UTILIZATION OF MUNICIPAL SOLID  WASTE  IS AN
OLD  PRACTICE  IN MEXICO,  SOME  TIME  AGO,  THIS  PRACTICE  WAS
CARRIED  ONLY   BY SCAVENGERS  IN  THE DISPOSAL  SITES,  IN 1972,
HOWEVER, THE FIRST COMPOSTING  PLANT IN MEXICO WAS  BUILT  IN THE
CITY OF  GUADALAJARA, WITH swiss TECHNOLOGY,

PRESENTLY  THERE  ARE  six COMPOSTING PLANTS, OF  WHICH  ONLY TWO
ARE  IN  OPERATION,  ONE  MORE  WILL BEGIN OPERATION  BY  1990,  THE
TENDENCY TO PUT  MORE OF  THESE  PLANTS  IN  OPERATION IS UNKNOWN,
BECAUSE  IT  DEPENDS  ON  ,POLITICAL  DECISSIONS,   RATHER  THAN
TECHNICAL  AND   ECONOMICAL   FACTORS,   IN   THIS  RESPECT  OUR
ASOCIATION IS  PROMOTING A REAL EVALUATION  OF  PROJECTS  BEFORE
GRANTING LOANS FOR THIS PURPOSE.

FOR THE  PEOPLE  WHO  WORK IN THE FIELD OF  CONTROL  OF  MUNICIPAL
SOLID WASTE, THE COMPOSTING PLANTS INSTALLED, DO NOT REPRESENT
A SOLUTION FOR  RECYCLING IN  MEXICO, WE ARE PRESENTLY WORKING
IN THE DEVELOPMENT  OF  NATIONAL TECHNOLOGY  AND  ALSO  TRYING TO
STOP THE ACQUISITION  OF CONVENTIONAL  PLANTS   WHICH  MIGHT BE
USEFUL IN DEVELOPED COUNTRIES  BUT NOT IN OUR COUNTRIES,

AS A RESULT WE CAN RESUME THE  FOLLOWING RESULTS:

1.- THE PLANTS REPRESENTS A LOSS OF HARD CURRENCY

2.- THE PLANTS PRESENTS NO SOLUTION TO THE  PROBLEM

3,- THERE  is  LACK  OF  EXPERIENCE  OF  PERSONNEL OPERATING  THE
    PLANTS

4.- THE  PLANTS REPRESENTS TECHCNICAL AND ECONOMICAL PROBLEMS
                           538

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5,- THERE is  A LOW DEMAND FOR THE COMPOST

6,- TOO  WIDE  VARIATIONS  IN  THE  PRICES  OF  THE  RECOVERED
    MATERIALS COMPLICATE THE  ADMINISTRATION OF THE PLANTS,

7,- LOW OR NO AVAILABILITY OF  SPARE PARTS,  MAKES MAINTENANCE
    EXPENSIVE AND SLOW,

8,- SCAVENGING IN  THE  COLLECTION VEHICLES,  MAKES THE  WASTES
    THAT ARRIVE TO THE  PLANTS VERY POOR,

THIS  PAPER  PRESENTS  THE  PAST,   PRESENT   AND  FUTURE  OF  THE
COMPOSTING AND RECYCLING PLANTS   IN  MEXICO,  AND  ANALIZES  THE
MAIN TECHNICAL, POLITICAL, SOCIAL AND ECONOMICAL PROBLEMS THAT
HAVE OCCURED, AS  WELL AS PRESENT  CONDITIONS,
                              539

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                        I.-  INTRODUCTION
    HUMAN  ACTIVITIES  PRODUCE,  AMONG  OTHER  THINGS,  WASTES;
MAINLY  GASES,  LIQUIDS  AND  SOLIDS,   IN  GENERAL  MAN'S  CHOSEN
ENVIRONS  HAVE  A  LIMITED  CAPACITY  TO  ACCEPT,  MODIFY  AND
INTEGRATE  THESE  WASTES  INTO  ITS  ECOSYSTEM  WITHOUT  CAUSING
MAJOR PROBLEMS, WHEN NATURE'S THRESHOLD LIMITS AND CAPACITY TO
ADAPT ARE EXCEEDED, IRREVERSIBLE ECOLOGICAL PROBLEMS ARE TO BE
EXPECTED, AND  THE  RESULTING  ECOSYSTEMS  MAY NOT  BE  AMIABLE TO
MANKIND SURVIVAL,

    OUR  SOCIETY  IS  A  WASTEFUL  ONE,  MANUFACTURERS  AND  THE
MERCHANTS WRAP THEIR PRODUCTS WITH EXCESSIVE SUMPTUOUSNESS FOR
THE SOLE  PURPOSE OF CALLING  THE ATTENTION OF  THE  BUYER;  IN
MANY INSTANCES THE WRAPPING MAY EXCEED THE VOLUME AND VALUE OF
THE PRODUCT  BEING  SOLD,  THE  FINAL DESTINATION  AND  PURPOSE OF
ALL THIS WRAPPING  IS  THE  GARBAGE  CAN,  AND VERY  LIKELYT OPEN
DUMPS.

    IN ORDER TO  TRY  TO SOLVE THE  INCREASING PROBLEM  OF  SOLID
WASTE,  IN SOME PARTS OF MEXICO, MAINLY  IN  THE  BIG CITIES,  THE
AUTORITIES  LOOK,  AMONG   OTHER   THINGS,   FOR   RECYCLING  AND
COMPOSTING PLANTS, IN 1972 THE  FIRST  COMPOSTING AND RECYCLING
PLANT IN  THE COUNTRY WAS  BUILT IN THE CITY  OF  GUADALAJARA;
AFTER THAT  PLANT,  FIVE  MORE  PLANTS  WERE  CONSTRUCTED  AND  ONE
MORE IS UNDER STUDY,

    NOW, AFTER  18  YEARS, ONLY  TWO  PLANTS ARE  WORKING  WITH  A
LOT OF PROBLEMS,  THIS  PAPER  PRESENTS  THE  STATE  OF  THE  ART OF
THE  COMPOSTING  AND  RECYCLING  PLANTS  IN  MEXICO,  MAKING  AN
EVALUATION OF THE TECHNICAL  AND ECONOMICAL PROBLEMS THAT HAVE
OCURRED  IN  THE  PAST  18  YEARS, IN ORDER  TO  ARRIVE TO  SOME
CONCLUSIONS AND RECOMENDATIONS FOR DEVELOPING COUNTRIES.
                             540

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    I  HOPE  THIS PAPER  WILL BE  OF  HELP  TO  THOSE  PEOPLE  IN
POSITIONS WHERE DECISSIONS  ARE TAKEN,  SO  THAT  THEY  BE  VERY
CAREFUL   WITH  THE   IMPORTED  TECNOLOGIES  OFFERED  BY  DEVELOPED
COUNTRIES,
             II.- THE COMPOSTING PLANTS IN MEXICO
    As I MENTIONED/ THERE ARE SIX COMPOSTING PLANTS IN MEXICO/
IN FIGURE NO,I/ THEIR LOCATION IS SHOWN,

    THE PLANTS IN GUADALAJARA/ MONTERREY AND MEXICO CITY, HAVE
THE BULHER MlAG  PROCESS,  THE MEXICO CITY  PLANT,  HOWEVER,  THE
FEEDLINE  IS  IN  THE  OPPOSITE  DIRECTION AS  IN  THE  OTHER  TWO
PLANTS, ACAPULCO AND  OAXACA HAVE A  COPY OF THE  SAME PROCESS
WITH LITTLE CHANGES BEFORE THE MILLS, THE  LAST  ONE IS LOCATED
IN TOLUCA, AND HAD A TOLLEMACHI PROCESS,

    PRESENTLY/ ONLY THE GUADALAJARA AND MEXICO CITY PLANTS ARE
STILL WORKING,

    IN  THE  VE.RY  NEAR   FUTURE/  POSSIBLY  THIS  YEAR/  A  NEW
RECYCLING  AND  COMPOSTING  PLANT  WILL   BE  BUILT  IN  MERIDA,
YUCATAN,  WITH  A CREDIT  OF  THE WORLD  BANK,  IN THIS  PART  OF
MEXICO THERE  IS  NO COVER SOIL/ BECAUSE  THE  YUCATAN  PENINSULA
IS  CONSTITUTED BY  CALCAROUS  ROCK,  As  USUAL  THE   EXPECTATIVES
ARE  FABULOUS/  AS  BEFORE THE  OPERATION OF  THE  OTHER  PLANTS
BUILT/  HOWEVER/  I  EXPECT THE  SAME  RESULTS  AS  IN  THE  OTHER
PLANTS,

    THE PLANT'S  PROCESSES CONSIST BASICALLY  IN  THE  FOLLOWING
ACTIVITIES! FIRST  THE COLECCTION  VEHICLES  DISCHARGE THE SOLID
                            541

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               LOCATION   OF   THE   COMPOSTING   PLANTS
                                                                   1r GUADALAJARA




                                                                  2 .-MONTERREY




                                                                  3r MEXICO, D.F.




                                                                  4r TOLUCA




                                                                  5 r ACAPULCO




                                                                  6 r OAXACA
FIG No. 1

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WASTES  IN  STORAGE PITS/  LOCATED  BETWEEN  THE  CONVEYORS  THAT
FEED THE BELTS  WHERE THE  SALVAGE MATERIALS  ARE  SELECTED  BY
SCAVENGERS  MANUALY; AFTER THAT/  AND  BEFORE GOING  THROUGH THE
HAMMERMILLS THERE IS  A MAGNETIC SEPARATOR/ AFTER THE MILL'S THE
WASTES  ARE  DEPOSITED  IN  A  VIBRATING   SCREEN/   IN  ORDER  TO
SEPERATE THE WASTE NOT SUITABLE FOR COMPOSTING/ WHICH CONSISTS
                   n
MAINLY OF PARTICLES GREATER THAN FOUR INCHES,
                     »

    THE  WASTES  ARE  THAN  PASSED  THROUGH  THE   SCREEN AND THE
DISTRIBUTION  BRIDGE   IN  THE   PRE'DIGESTI ON   FIELD  TO  FORM
WINDROWS,  AFTER  THREE  MONTHS  THE COMPOST  is  FORMED  BY  AN
AEROBIC  PROCESS,  AFTER  THAT/   AND DEPENDING   ON  THE  MARKET,
THERE  IS ANOTHER MILL FOR  FINE MILLING  TO  GET  COMPOST  WITH
VERY GOOD PRESENTATION,
          III.- SOLID WASTE CHARACTERISTIC IN MEXICO
    IN MEXICO/  THE SOLID  WASTE  GENERATED  VARIES/  BUT  IT IS
POSSIBLE TO PUT IT INTO THREE MAIN GROUPS:  ONE/  THE REGION IN
THE BORDER WITH THE UNITED STATES OF  AMERICA,  WITH ALMOST ONE
KILOGRAM PER CAPITA;  THE  CENTRAL PART  OF  THE COUNTRY  WITH A
GENERATION PER  CAPITA OF  AROUND  650 GRAMS  AND  THE SOUTHEAST
WITH ABOUT 550 GRAMS PER CAPITA,

    THE  AVERAGE  COMPOSITION  IN THE  SOLID  WASTE  GENERATED IN
MEXICO FOR THE  THREE  GROUPS  IS PRESENTED  IN TABLE  No,  I/ IN
THIS TABLE  IT  IS  POSSIBLE  TO SEE  THE GREAT DIFERENCE  IN THE
COMPOSITION  OF  THE   SOLID  WASTE   GENERATED   IN  DEVELOPING
COUNTRIES  AND   IN  DEVELOPING  COUNTRIES,  MAINLY  THE  ORGANIC
MATTER VARIES  FROM 45 UP  TO  60 PERCENT  BY  WEIGHT/  AND  IT IS
ONLY  POSIBLE TO GET 25 TO 30 PERCENT OF SALVAGE MATERIAL/ THE
                             543

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    TABLE No,  1.-  AVERAGE  COMPOSITION  OF  THE  MEXICAN REFUSE
RECUPERATED               PERCENTAJE      PERCENTAJE
MATERIAL                  BY WEIGHT       OF RECOVERING

CARDBOARD                  4.10               70
PAPER                      9.63               45
COLOR GLASS                3.40               75
WHITE GLASS                4.25               71
CANS                       2.52               60
FERROUS MATERIAL           0.76               60
NON FERROUS MATERIAL       0.60               40
TETRAPACK                  1.66               50
BONES                      0.80               50
PLASTIC FILM               3.42               55
RIGID PLASTIC              2,28               55
DIAPERS                    3.66
RAGS                       1.94               60
ORGANIC MATTER            44.70               60
OTHER                     16.28
                              544

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REST IS MATERIAL WITH NO POSIBIL'ITY OF RECUPERATION BECAUSE OF
ITS CHARACTERISTICS OR THE DIFICULTY TO RECOVER THEM,
 IV,- ANALYSIS AND EVALUATION OF THE RECYCLING AND COMPOSTING
                       PLANTS  IN MEXICO,
    THE  MAIN  PROBLEMS  DETECTED  IN   THE  DIFERENT  PLANTS  IN
MEXICO CAN BE RESUMED IN THE FOLLOWING:
4,1,- FEASIBILITY STUDIES
    A,- POOR  JUDGMENT  IN  DIFINING  THE   WASTE   LOAD  AND  ITS
        CHARACTERISTICS, INCLUDING THEIR  SEASONAL QUALITATIVE
        AND CUANTITATIVE CHANGES,

    B,- THE INADEQUACY OF SAMPLING PROGRAMS USED HAVE RESULTED
        IN AN UNREAL FORECAST OF THE RECOVERY POTENTIAL OF THE
        SOLID WASTE,

    C,- THE  QUALITY,  QUANTITY  AND  MARKETABILITY  OF  SALVAGE
        MATERIALS WERE PREDICTED OUT  OF  THE SAMPLING PROGRAMS
        WITH   THE   APPLICATION  OF   FICTITIOUS   FACTORS  OF
        EFFICIENCY,

    D.- THE FLUCTUATION'OF THE  SECONDARY MATERIALS MARKET WAS
        UNDERESTIMATED,

    E.- NO ATTEMP WAS  MADE TO CREATE A MARKET FOR THE COMPOST,
        THE ASSUMPTION WAS THAT THIS WAS  NOT AN  ISSUE,
                              545

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     F,-  THE  REDUCED  MARKET AND VALUE OF WET OR DIRTY  RECOVERED
         MATERIALS    WAS   NO   CONSIDERED   IN   THE   REVENUE
         PROJECTIONS,

     G,~  THE  GREAT  IMPACT OF  ON-ROUTE  SCAVENGING -SPECIALLY
         VALUABLE  PRODUCTS  AS  CARDBOARD,   GLASS   BOTTLES  AND
         ALUMINIUM  CANS-  WASNOT CONSIDERED  IN  THE PROJECTIONS
         OF RECLAMATION AND SALES OF SALVAGED MATERIALS,

     H,~  AT THE  FIRST PLANT,  THE  LACK  OF  EXPERIENCE  WAS  NOT
         CONTEMPLATED/ THE PEOPLE GOT  EXPERIENCE  BY THEIR OWN
         EFFORT AND VARIOUS COSTLY MISTAKES WERE MADE,

     I,-  THE  OPENING  OF  IMPORTS FROM  USA  FOR USED  COMPUTER
         PAPER/ PAPER/ CARDBOARD  AND METALS, LOWER THE PRICES
         IN MEXICO FOR THIS TYPE OF SALVAGED MATERIALS,

    j,-  THE  DECISSION  TAKERS BELIVED  ALL  THE  PLANT  SALESMEN
         SAID. EXPERIENCE SAYS THAT ALMOST ALL WAS  FALSE,

    K,~  NO COMERCIALIZATION PROGRAMS WERE MADE,
4,2,- COMPOST PLANT DESIGN
    A,- THE STORAGE PITS WERE BUILT  IN  SUCH  MANNER THAT IT IS
        ALMOST  IMPOSSIBLE  TO  MANTAIN   THEM  IN  A  GOOD  AND
        SANITARY CONDITION,
    B,- IN THE MEXICO  CITY COMPOSTING PLANT, THE  ONLY  WAY TO
        FEED THE CONVEYORS IS BY  THE  CLAM  CRANE,  IF  THIS IS
        OUT OF WORK THE PLANT STOPS,
                             546

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c,- AFTER  THE  FIRST  PLANT  IN  GUADALAJARA,  VERY  LITTLE
    EXPERIENCIE WAS  PUT  IN THE CORRECTION OF  THE  DESIGN
    DEFECTS OF  THE PLANTS,

D,~ THE CLAM CRANE  SYSTEM  BEING  USED TO  FEED  THE  PLANTS
    HAS PROVEN  INEFFECTIVE  AND UNRELIABLE,

E,- THE  PITS  FOR THE  CONVEYOR  THAT  FEEDS  THE  SELECTION
    AREA PRESENTS DEFICIENCIES FOR  THE  CHARACTERISTICS OF
    THE MEXICAN WASTE/ AS THE WASTE TENDS  TO FORM  AN ARCH
    AND IT IS ALMOST IMPOSSIBLE  TO FEED,

F,- THE  AUTOMATED  FEED  CONTROL   SYSTEM  ON  THE   FEEDER
    CONVEYOR AND THE FEED CONTROL  SYSTEM FOR THE SELECTION
    BELT  DON'T  GIVE   POSITIVE  RESULTS  FOR  THE  MEXICAN
    REFUSE,

G,- THE  BELT  CONVEYOR  IN  THE  SEPARATION  AREA  TENDS  TO
    BUCKLE, AND  IS  TOO WIDE  FOR  THE MANUAL  SELECTION OF
    MATERIALS,

H,~ THE  SPEED  OF  THE  CONVEYOR  IN THE  SELECTION AREA, AS
    DELIVERED  BY  THE  MANUFACTURER/ WAS  TOO FAST FOR  THE
    SCAVENGERS  TO PROPERLY  SELECT  RECYCLABLE MATERIALS,

I,- THE BELT IN THE SELECTION AREA DID NOT HAVE THE LENGTH
    TO  GIVE   THE   NECESARY   TIME  TO   GET   THE  SALVAGE
    MATERIALS,

j,- THE PLANT'S TWO VERTICAL  HAMMERMILLS ARE A  SOURCE OF
    CONSTANT  MAINTENANCE  PROBLEMS   AND  VERY   EXPENSIVE
    REPAIR COSTS, THE HAMMERS WEAR OUT VERY QUICKLY DUE TO
    THE HIGH ABRASSIVENESS  OF MEXICAN REFUSE, AND  HAVE TO
    BE REPLACED OR REVITALIZED ALMOST EVERY SHIFT,
                         547

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    K,- MECHANICAL FAILURES OF THE DISTRIBUTION  BRIDGE  IN THE
        PRE-DIGESTION FIELD CAUSES  THE CONDITIONED  REFUSE  TO
        RUN OUT OF CONTROL MAKING IT DIFFICULT TO MANAGE,

    L,~ THE FINE  MILLING  MILL IS  TOO SMALL  FOR THE  PLANT'S
        PRODUCTION.
4.3,- OPERATION
    A,- THE PLANT, NOT BEING DESIGNED  FOR MEXICAN  REFUSE,  IS
        HARD  TO   MAINTAIN,   GENERATING   SEVERE   OPERATION
        PROBLEMS,  MAINLY  IN CONVEYOR BELTS AND HAMMERMILLS,

    B,~ THE ABSENCE  OF  A  PROGRAM OF  INCENTIVES FOR  THE  PEOPLE
        IN THE  SEPARATION BELT,  CAUSES  LOW EFFICIENCIES  IN THE
        SEPARATION OF  THE MATERIALS,

    C,~ THE  HANDLING   OF  RECOVERED  MATERIALS  WAS  NOT  DONE
        EFFICIENTLY,   LOWERING   THE  PRICE  OF   THE  SALVAGED
        MATERIALS  (DUE  TO MIXING),  AND  INCREASING THE COSTS OF
        OPERATION.

    D.- NOISE LEVELS  ARE  HIGH  IN THE SEPARATION AREA, PARTIALY
        DUE TO  THE  KNOCKING OF  THE MATERIAL  WITH  THE  STEEL
        HOPPERS  AND WHEN  THEY  FALL  TO  THE LOWER  FLOOR,  ALSO
        BECAUSE  THE  LACK  OF ISOLATION ON THE HAMMERMILLS.

    E,- THE  LACK   OF  LABORATORY   FACILITIES   PRECLUDES   THE
        ADEQUATE CONTROL  OF THE  COMPOSTING PROCESS,  (EXCEPTION
        MEXICO  CITY).
                            548

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              V,- CONCLUSIONS AND RECOMENDATIONS
5,1,- CONCLUSIONS
    A,- THE  COMPOSTING  PLANTS  IN  MEXICO  HAVE  NOT  HAD  THE
        SUCCESS SALESMEN CLAIM,

    B,- THE PART  RELATED  WITH THE  SEPARATION OF  RECOVERABLE
        MATERIAL  OUT  OF THE  REFUSE SHOW  THAT  WE  NEED  MORE
        RESEARCH AND DEVELOPMENT TO  IMPROVE  A SEMI  MECHANIZED
        SEPARATION MORE  IN ACCORDANCE WITH  THE CHARACTERISTICS
        OF MEXICAN WASTES.

    c,- THE USE OF COMPOST AS A SOIL IMPROVEMENT AGENT IN SOME
        OF SOILS FOUND IN MEXICO HAS GIVEN  GOOD RESULTS,

    D,~ THE OFFER OF COMPOST IS GREATER THAN  THE DEMAND,

    E,- THE SEPARATION OF MATERIAL  ON  ROUTE  IN THE  COLLECTION
        TRUCKS  HAVE  A SERIOUS  IMPACT  IN  THE  ECONOMY OF  THE
        PLANTS,

    F,~ THE HAMMERMILLS  HAVE  SERIOUS  MAITENANCE  PROBLEMS  DUE
        TO THE GREAT CONTENT OF ORGANIC MATTER,

    G,~ THE LACK OF MARKETS MECHANISMS OF COMPOST DERIVED IN A
        FAILURE OF SALES.

    H,- THE  ADMINISTRATION  BY  MUNICIPALITIES  HAS  NOT  BEEN
        EFFICIENT,
                              549

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5,2,- RECOMENDATIONS
    A,- THE DECISSION  TO  INSTALL  COMPOSTING  PLANTS  MUST  BE
        ASSESED BY EXPERTS ON THE BASIS OF REALISTIC TECHNICAL
        AND ECONOMICAL  FEASIBILITY STUDIES,  AND NOT BECAUSE OF
        SALESMEN BLUFF  AND POLITICAN's DECISSIONS,

    B,- A   TRAINING   PROGRAM   MUST   BE   PROVIDED   BY   THE
        MANUFACTURER  PRIOR TO STARTING PLANT OPERATION.

    C.~ THE SALVAGED  MATERIAL MUST BE  SEPARATED AND CLEANED TO
        GET BETTER PRICES IN  SALES,

    D,- THE COMPOST MUST BE PRODUCED ACCORDING TO DEMAND.

    E,- A GOOD PROGRAM OF  MAINTENANCE  AND INCENTIVES FOR  THE
        PERSONNEL  IS  A  MUST,  THE EXPERIENCE  OF OTHER  PLANTS
        EXISTING UNDER  SIMILAR CONDITIONS MUST BE  TAKEN  INTO
        ACCOUNT,

    F,~ IF  IT  IS  IMPOSSIBLE TO AVOID  THE  PRESELECCION  ON  THE
        COLLECTION TRUCKS  DUE  TO  LABOR  UNION  PRESSURES  OR
        OTHER  FACTORS,  THE ADMINISTRATION OF  THE   PLANT  MUST
        BUY THE  PRESELECTED MATERIALS.

    G,- ONLY FOR  REMARKS, THE  COMPOST  is NOT  A  FERTILIZER,  IT
        IS  ONLY  A SOIL  IMPROVEMENT AGENT,

    H.- THE COMPOSTING  PLANTS ARE NO PANACEA,  NO ONE IN  MEXICO
        HAS HAD  ECONOMICAL BENEFITS,  AS  NOT  EVEN  OPERATION
        COSTS  HAVE BEEN RECOVERED.

    I.- THE RECYCLING PROGRAMS IN MEXICO ARE  INCREASING,
                             550

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J,- THE ECOLOGICAL CULTURE IS GROWING INTO THE POPULATION,
    THIS DEMANDS THAT PUBLIC  OPINION BE  INFORMED  OF  REAL
    ALTERNATIVES  TO  SOLVE  PROBLEMS/  IN  ORDER  TO  AVOID
    FUTURE FIASCOS,

K,- THE  GROWTH  OF  ECOLOGICAL  CULTURE   MUST  BE  TAKEN
    ADVANTAGE OF,  IN ORDER  TO  INCREASE THE  PARTICIPATION
    OF PEOPLE IN RECYCLING PROGRAMS,

L,- THE PLANTS  COULD BE  MANAGED AS AN  ENTERPRISE,  IF  THE
    DESIGN  IS  IN ACCORDANCE   WITH  THE  KIND  OF  REFUSE
    GENERATED IN MEXICO  AND WITH  TECHNOLOGIES  THAT  ADAPT
    TO  THE   SOCIAL  AND  ECONOMICAL  CONDITIONS   OF   THE
    COUNTRY,
                          551

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       A CRITICAL EXAMINATION OF THE RELATIONSHIP
         BETWEEN CONVENIENCE AND RECOVERY RATES
            IN RESIDENTIAL RECYCLING PROGRAMS

               Mack  Rugg and Sanjay Kharod
                Camp Dresser & McKee Inc.
                    Edison,  New Jersey
                    Presented at the

First U.S.  Conference on Municipal  Solid Waste Management

                    June 13-16, 1990
                         553

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     It is almost universally assumed that if participation in a recycling
program is made more convenient, a higher rate of recovery will result.  In
fact, this "convenience assumption" is so compelling that people readily
accept it without asking for supporting evidence.  It is not surprising,
therefore, that very little evidence of the validity of the convenience
assumption has been developed.  What is surprising, perhaps, is that when
quantitative analysis of recovery rates is performed, some of the results
cast doubt on the validity of the convenience assumption rather than
confirming it.

BACKGROUND FDR THIS PAPER

     During 1989 Camp Dresser & McKee was retained by Morris County, New
Jersey to evaluate the recycling system in the county and recommend County
initiatives to optimize the system.  The authors of this paper had primary
responsibility for the technical aspects of the Morris County study.  One
of the issues in the study was whether households served by a countywide
collection system should be required to set out each targeted material  in
separate containers.  Another issue was how often the materials should be
picked up.  This paper grew out of the Morris County study.

     Sorted materials set out in multiple containers generally cost more to
collect than commingled materials set out in a single container.   However,
sorted materials are worth much more than commingled materials.  The value
gained by having residents sort their recyclable materials may be
substantially greater than the additional cost of collecting sorted
materials.  With respect to collection frequency, cost per ton generally
decreases as collection becomes less frequent.  This is because more
material is picked up for the same distance travelled.  Therefore, the most
economical recycling program could be one in which completely separated
materials are picked up infrequently.

     A major question is whether people will participate in such a program.
In an attempt to answer this question, the experience of the municipal
recycling programs in Morris County was evaluated.

     Morris County is an affluent suburban county in north-central New
Jersey with a population of just over 400,000 persons.  Essentially all
residential solid waste generated in the county passes through two transfer
stations with identical  tipping fees of approximately $120 per ton.
Therefore, the economic incentive to recycle is similar throughout the
county.

     A broad range of recycling programs is found among the 39
municipalities of Morris County.  Collection frequency ranges from monthly
to twice weekly.   Some municipal programs that provide collection of
recyclables require complete separation of materials at the curb, including
clear, brown and  green glass.  Other municipal programs allow complete
commingling of materials.  Still other programs provide no pickup, relying
on residents to bring recyclable materials to dropoff centers.

     Residential  recovery rates for aluminum beverage cans and glass food
and beverage containers  achieved by the municipal recycling programs in the
county were examined.  Commercial recycling was excluded from this analysis
because (1) more  than one approach to source separation is used by the

                                   554

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 private haulers serving the commercial sector in many municipalities, and
 (2) even if only one approach is used in the commercial sector, it may not
 be the same approach used in the residential sector.  Aluminum cans and
 glass containers were chosen for analysis because they are collected in all
 municipalities in the county.  Newspaper is also collected in every
 municipality, but was excluded from the analysis because it is kept
 separate from glass and aluminum in all programs.

 RECOVERY RATES USING DIFFERENT APPROACHES TO SOURCE SEPARATION

     Table 1 shows the combined recovery rates for glass containers and
 aluminum cans achieved by groups of Morris County municipalities in 1988
 using different approaches to source separation.  All averages shown in
 this table and in the other tables in this paper are weighted by
 population.  Boonton Borough has been excluded because its reported per-
 capita residential recycling rate for glass and aluminum is almost twice as
 high as the second highest municipality in the county.  This indicates that
 the recycling rate for Boonton Borough is so strongly influenced by factors
 other than its approach to source separation that its inclusion in the
 analysis would make the results less meaningful.  Mount Arlington and Mine
 Hill have been excluded for the opposite reason:  the recovery rates in
 these municipalities are so low that they cannot be considered reflective
 of the approach to source separation used.

     Table 1 indicates that, on average, Morris County municipalities
 providing curbside collection achieved approximately the same residential
 recovery rate whether they required complete sorting, partial  sorting,  or
 no sorting by residents.  The municipalities providing dropoff centers  but
 no curbside collection achieved an average recovery rate approximately  20
 percent lower than those providing curbside collection.   As shown  by the
 "highest recovery rate" column,  individual  municipalities  achieved high
 recovery rates using all four approaches.   The high standard  deviations
 reflect the great variability within source separation categories.

     It has been suggested that people higher on the socio-economic scale
 are more likely to participate in recycling programs,  and  may also be more
 willing to keep the various  recyclable materials separate.  Therefore,
 according to this argument,  the success of  municipal  programs  requiring
 complete sorting of materials may be a reflection of the affluence of the
 residents of the municipalities  that have  implemented those programs.

     As shown by table 1,  the municipalities  in  Morris County that  required
 complete sorting of glass  and aluminum by residents  in 1988 have an average
 per-capita income approximately  10  percent  higher than that of the
municipalities that allowed  their residents  to  commingle glass and
aluminum.   However,  both groups  of  municipalities are highly  affluent.

     Residential  recovery  rates  were also examined  in Middlesex County, a
mixed urban,  suburban  and  rural  county in central New Jersey with an
average income per capita  20 percent  lower  than  that  in  Morris County.
Table 2 shows  the residential  recovery rates achieved by groups of
Middlesex County municipalities  in  1988  using three different  approaches to
source separation:   curbside pickup of commingled materials, curbside
pickup of sorted materials,  and dropoff centers with no curbside pickup.
Piscataway and South Brunswick were excluded from this analysis because

                                  555

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                                                       TABLE 1

                         COMBINED GLASS AND ALUMINUM RECOVERY RATES ACHIEVED IN MORRIS COUNTY
                             IN  1988 USING DIFFERENT APPROACHES TO SOURCE SEPARATION (a)

01
Cfl
0)

Approach to
source separation
Curbslde, commingled
Curbslde, semi-sorted (b)
Curbslde, sorted (c)
Drop-off center only
Number
of
munici-
palities
6
4
14
12
Population
represented
(1988
estimate)
122,103
37,595
165,560
79,698
Average
income
per capita
(1985)
$17,462
$12,840
$19,220
$18,733
Average
recovery
rate
(Ib/cap/yr)
49.4
53.3
50.1
41.2
Highest
recovery
w* a 4- £j
(lb/cap/yr)
79.3
76.7
86.4
91.3
Lowest
recovery
rate
(lb/cap/yr)
34.4
39.9
29.4
20.8
Standard
deviation
14.9
13.8
17.2
19.3
(a)  From residential  sources  only.  Boonton  Borough, Mt. Arlington, and Mine Hill not included.

(b)  Mixed glass separated  from  aluminum.

(c)  Glass separated from aluminum and  sorted by  color.

Sources:  For source separation  methods  and amounts recovered—Morris County Municipal Utilities Authority and
municipal officials.  For population estimates, New Jersey Department of Labor.  For per-capita income, U.S.
Bureau of the Census.

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                                                        TABLE  2

                        COMBINED GLASS AND ALUMINUM RECOVERY RATES  ACHIEVED  IN MIDDLESEX COUNTY
                              IN 1988 USING DIFFERENT  APPROACHES  TO SOURCE SEPARATION  (a)




Ul
01
-3


Approach to
source separation
Curbside, commingled
Curbslde, sorted (b)
Drop-off center only
Number
of
munici-
palities
9
7
7
Population
represented
(1988
estimate)
400,438
111,010
72,203
Average
income
per capita
(1985)
$13,059
$13,380
$15,019
Average
recovery
rate
(Ib/cap/yr)
33.7
39.9
32.2
Highest
recovery
rate
(Ib/cap/yr)
54.5
68.2
76.3
Lowest
recovery
rate
(Ib/cap/yr)
12.5
28.4
5.9

Standard
deviation
14.3
12.7
21.9
(a)  From non-commercial  sources  only.   Piscataway  and South Brunswick not included.

(b)  In six programs,  glass  was separated  from aluminum and sorted by color.  In one program,
     glass was mixed but  separated  from  aluminum.

Sources:  For source separation methods  and  amounts recovered—Middlesex County Department of Solid Waste Management
For population estimates,  New Jersey  Department of  Labor.  For per-capita income, U.S. Bureau of the Census.

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they each used two different approaches to source separation during
significant parts of the year.  In addition, aluminum recovery by Cranbury
was excluded because it represents 19 percent of the aluminum recovered in
the county even though Cranbury has less than 0.5 percent of the county
population.  This indicates that Cranbury's aluminum recycling is primarily
the result of factors other than its approach to source separation.

     As indicated by table 2, the Middlesex County municipalities that
required their residents to sort glass and aluminum achieved a slightly
higher average recovery rate than the municipalities that allowed residents
to commingle these materials.  As in Morris County, the municipal programs
that did not provide curbside collection achieved the lowest average
recovery rate.  However, also as in Morris County, the highest of all  the
municipal recovery rates was reported by a municipality not providing
curbside collection.  The high standard deviations reflect the great
variability within each source separation category.

     In Middlesex County, the average income per capita is essentially the
same for municipalities that required sorting in 1988 and for those that
allowed commingling.  Therefore, the higher average recovery rate achieved
by the municipalities requiring sorting cannot be explained based on
greater affluence in these communities.

     Per-capita income is substantially lower in Middlesex County.than in
Morris County, and the average recovery rates are also substantially lower.
However, it would be a mistake to conclude without further analysis that
the difference in recovery rates can be explained by the difference in
incomes.  In Middlesex County, residential  solid waste is disposed of  in
two in-county landfills where the tipping fees are approximately half  the
tipping fee at the Morris County transfer stations.  Lacking a landfill  of
their own, Morris County residents are particularly mindful  of the need  to
develop alternatives to landfill ing.

     To the south and east of Middlesex County lies Monmouth County, a
suburban and rural area with an average per-capita income slightly higher
than Middlesex but still significantly lower than Morris.  An analysis of
the recovery rates achieved in Monmouth County using different approaches
to source separation was performed by Scott McGrath when he was with the
Monmouth County Planning Board (Mr.  McGrath is now with Gannett Fleming,
Inc.,  King of Prussia,  Pennsylvania).   McGrath identified four degrees of
separation required by municipalities  providing curbside collection of
glass  containers, aluminum cans, and tin cans:

     •   Complete commingling, a one-container system.

     •   Commingling of  glass with separation of aluminum and tin
        cans,  a three-container system.

     •   Commingling of  aluminum and  tin cans with separation of
        glass  by color,  a four-container system.

    •   Complete separation of aluminum and tin cans and glass by
        color,  a five-container system.
                                      558

-------
     In analyzing data from the second,  third and fourth quarters of 1988,
McGrath found that the greater the number of containers required, the
higher was the average per-capita recovery rate.   When all  four approaches
to source separation were compared using analysis of variance, the
differences among the average recovery rates were not found to be
statistically significant.  However,  statistical  analysis (a two-sample "Z"
test) indicated that the average recovery rate achieved by the
municipalities using the five-container system was significantly higher
than the combined average recovery rate achieved  by the municipalities
using the other three approaches.

     It should be noted that McGrath  was able to  exclude only a portion of
the materials recovered from commercial  sources from his analysis.
Therefore, it is reasonable to assume that some of the material credited to
each source separation system was actually recovered through different
systems used by private haulers in the same municipalities.

     The year 1988 was the first full  year in which recycling programs were
fully implemented in a large number of New Jersey municipalities.
Therefore, data from 1989 and subsequent years will  be very significant to
the issues addressed in this paper.  However, data from 1989 are still
preliminary if they are available at  all.

     Table 3 shows the same information as table  1,  but based on
preliminary Morris County data for 1989.  The preliminary data show the
commingling municipalities with an average recovery rate approximately 11
percent higher than the municipalities requiring  complete separation.   The
average per-capita incomes for these  two groups of municipalities are quite
similar.  The very low numbers for commingling and complete sorting in the
"lowest recovery rate" column indicate that the data may be incomplete.  As
in 1988, individual municipalities in each source separation category
achieved high recovery rates.

RECOVERY RATES WITH DIFFERENT COLLECTION FREQUENCIES

     The second major convenience factor examined in the Morris County
study was frequency of pickup.  Table 4 shows average recovery rates
achieved by groups of Morris County municipalities using different
collection frequencies.  Zero collections per month indicates that  a
dropoff center is available but no curbside collection is provided.

     The pattern of recovery rates is very similar to that  in table 1.
Municipalities providing curbside pickup achieved essentially the same
average recovery rates whether pickup was weekly, monthly,  or in between.
Municipal programs with no curbside collection recovered approximately 20
percent less material.  Again, the high standard  deviations reflect the
great variability within categories.   Curiously,  the municipalities
providing only one pickup per month had  the highest average per-capita
income.

     Table 5 shows the same information  for Middlesex County.  Here, the
two municipalities providing weekly pickup achieved  a substantially higher
average recovery rate than the municipalities in  the other  three
categories.  These two municipalities  also have a somewhat  higher average
                                    559

-------
                                                       TABLE 3
                         COMBINED  GLASS AND ALUMINUM RECOVERY RATES ACHIEVED IN MORRIS COUNTY
                             IN  1989  USING DIFFERENT APPROACHES TO SOURCE SEPARATION (a)
Wl
8
•

Approach to
source separation
Curbslde, commingled
Curbslde, semi-sorted (b)
Curbslde, sorted (c)
Drop-off center only
Number
of
munici-
palities
10
2
17
7
Population
represented
(1988
estimate)
159,858
15,074
177,496
52,528
Average
income
per capita
(1985)
$16,798
$11,970
$17,764
$22,297
Average
recovery
rate
(Ib/cap/yr)
50.7
70.8
45.5
43.2
Highest
recovery
rate
(Ib/cap/yr)
88.7
83.9
93.6
84.1
Lowest
recovery
rate
(Ib/cap/yr)
17.2
69.8
8.9
29.6
Standard
deviation
19.6
7.0
20.4
18.7
(a)   From residential  sources only.  Boonton Borough, Mt. Arlington, and Mine Hill not included.
(b)   Mixed glass  separated  from  aluminum.
(c)   Glass separated  from aluminum and  sorted by color.
Sources:   For source  separation  methods and amounts  recovered—Morris County Municipal Utilities Authority.
For  population estimates, New Jersey Department of Labor.  For per-capita income, U.S. Bureau of the Census.

-------
                                                        TABLE 4

                          COMBINED GLASS AND ALUMINUM RECOVERY RATES ACHIEVED  IN  MORRIS  COUNTY
                                   IN 1988 USING DIFFERENT COLLECTION FREQUENCIES (a)


Ol
p


Collections
per
month
*
0"

1
2
4
Number
of
munici-
palities
12

13
4
7
Population
represented
(1988
estimate)
79,698

152,588
53,606
119,064
Average
income
per capita
(1985)
$18,733

$19,256
$16,249
$15,697
Average
recovery
rate
(Ib/cap/yr)
41.2

49.8
51.6
50.0
Highest
recovery
rate
(Ib/cap/yr)
91.3

76.4
76.7
86.4
Lowest
recovery
rate
(Ib/cap/yr)
20.8

29.4
39.9
32.2
Standard
deviation
19.3

15.3
13.2
18.6
(a)  From residential 'sources  only.   Boonton  Borough, Mt. Arlington, and Mine Hill not included.
            «    ! ect1?n  f recluen<:jes  and  amounts recovered-Morris County Municipal Utilities Authority and
Buea  of the Census      P°Pulat1on  estimates, New Jersey Department of Labor. HFor per-capita income; U.S.

-------
                                                       TABLE 5

                       COMBINED GLASS AND ALUMINUM RECOVERY RATES ACHIEVED IN MIDDLESEX COUNTY
                                  IN 1988 USING DIFFERENT COLLECTION FREQUENCIES (a)





01
05
(0



Collections
per
month
0

1
2
4
Number
of
munici-
palities
6

4
11
2
Population
represented
(1988
estimate)
70,930

80,008
370,113
62,600
Average
Income
per capita
(1985)
$15,724

$12,353
$13,045
$14,540
Average
recovery
rate
(Ib/cap/yr)
32.3

39.5
31.7
49.3
Highest
recovery
rate
(Ib/cap/yr)
76.3

52.2
68.2
54.5
Lowest
recovery
rate
(Ib/cap/yr)
5.9

25.1
12.5
42.5


Standard
deviation
22.7

11.2
15.6
6.0
(a)  From non-commercial  sources  only.   Plscataway and South Brunswick not included.

Sources:   For collection  frequencies  and amounts recovered—Middlesex County Department of Solid Waste Management.
For population estimates,  New Jersey  Department of Labor.  For per-capita income, U.S. Bureau of the Census.

-------
per-capita income than the municipalities providing one and two pickups per
month.

     Table 6, like table 3, is based on preliminary Morris County data from
1989.  Frequency of pickup is still inversely proportional to average
.income, the opposite of the pattern in Middlesex County.  The six
municipalities providing at least weekly pickup achieved higher average
recovery rates than the other groups of municipalities despite having lower
average incomes.  Nonetheless, the most affluent group achieved a
comparable average recovery rate with only one pickup per month.  This
group also included the municipality with the highest recovery-rate in the
county.

     The standard deviations in tables 3 and 6 are particularly high
because of very low recovery rates for some municipalities.  This is
probably an indication of incomplete data.

CONCLUDING DISCUSSION

     The Morris County and Middlesex County data evaluated in this paper do
not  indicate that allowing residents to commingle recyclable materials
increases recovery rates.  The data contain a suggestion that frequent
pickup may tend to increase recovery rates, but are far from conclusive on
this point.  Individual municipalities in Morris County have achieved high
recovery rates using a variety of approaches to source separation and the
full range of collection frequencies.

     If there is a message for recycling planners in the data from Morris
and  Middlesex counties, it is that they should give serious consideration
to the less convenient but more economical forms their programs could take.
Local, county, and regional officials should continue to design programs
that reflect the specific circumstances of the municipalities they serve.
They should not narrow their options by assuming that a recycling program
must be convenient to succeed.
                                    563

-------
                                                       TABLE 6

                          COMBINED GLASS  AND  ALUMINUM  RECOVERY RATES ACHIEVED IN MORRIS COUNTY
                                   IN  1989  USING  DIFFERENT COLLECTION FREQUENCIES (a)


Ul
2



Collections
per
month
0
1
2
4
8
Number
of
munici-
palities
5
17
8
5
1
Population
represented
(1988
estimate)
37,558
162,414
110,997
91,541
2,446
Average
Income
per capita
(1985)
$19,167
$19,523
$16,573
$15,096
$14,211
Average
recovery
rate
(Ib/cap/yr)
43.8
49.0
43.6
54.2
51.1
Highest
recovery
rate
(Ib/cap/yr)
84.1
93.6
75.6
88.7
51.1
Lowest
recovery
rate
(Ib/cap/yr)
29.6
11.0
8.9
35.0
51.1
Standard
deviation
19.0
20.5
19.1
22.1
0.0
(a)  From residential  sources  only.   Boonton Borough, Mt. Arlington, and Mine H111 not included.

Sources:   For collection  frequencies  and  amounts recovered—Morris County Municipal Utilities Authority.
For population estimates,  New  Jersey  Department of Labor.  For per-capita income, U.S. Bureau of the Census.

-------
CUYAHOGA FALLS, OHIO'S INTEGRATION OF RECYCLING
          INTO SOLID WASTE COLLECTION

               Patricia J. Smith
           President, Waste Options
             Presented at the the

First U.S. Conference on Municipal Solid Waste

               June 13-16, 1990
                     565

-------
       CUYAHOGA FALLS OHIO'S INTEGRATION OF RECYCLING
                 INTO SOLID WASTE COLLECTION
     In Cuyahoga Falls, Ohio, like many other municipalities,
we are changing our solid waste system to minimize the impact
of skyrocketing disosal costs and to simultaneously protect
the environment.
     At the cornerstone of our new solid waste system is a
voluntary, aggressive recycling comprehensive program that is
integrated with the City's regular solid waste collection
program.
     Our successful recycling programs are not a panacea for
the problems associated with solid waste disposal, but are
ones that we can leave behind to make a better quality life
for future generations.
     Over 70% of Cuyahoga Falls residents now participate in
recycling efforts and our City has diverted over 2,000 tons
of recyclables from the waste stream in one year's time.  The
City has avoided paying over $70,000 in disposal costs!
     In Cuyahoga Falls we don't want to be remembered as the
throw-away generation that left our children a legacy of over
indulgence and wasteful practices.  But rather we have chosen
to be remembered as the residents who sacrificed short-
term convenience for long-term protection of the health and
environment of the future.
                            566

-------
                           OUTLINE





I.    Overview of Solid Waste Dilemma



II.   Discussion on landfill/waste-to-energy options



III.  Reasons for integrating recycling into comprehensive



      solid waste management plans



IV.   Overview of successful, aggressive public



      awareness/education campaign



      a.   media blitz;  brochures,  flyers, door-hangers



      b.   costumed characters; puppet shows



      c.   door-to-door efforts



      d.   school skits, assemblies,  film strips, videos



      e.   recycling Olympics
                             567

-------
DESIGN OF MATERIALS RECOVERY FACILITIES (MRFs)
                 George M. Savage
              Cal Recovery Systems, Inc.
                  Presented at the
First U.S. Conference on Municipal Solid Waste Management
                  June 13-16,1990
                      569

-------
Abstract

       The explosion in the demand for materials recovery facilities (MRFs) is straining the
solid waste industry in terms of supplying reliable, efficient, and cost-effective recyclables
processing systems.  The design of MRFs is discussed, including the design criteria for th«
facilities, the available equipment, and system performance. The topic is approached in a
broad context, addressing the processing of feedstocks in the form of singular recyclabte
components, of commingled recyclables, and of mixed municipal solid wastes.
                                      570

-------
Introduction

      The design of a materials recovery facility (MRP) follows a series of basic considera-
tions, which generally include the following:

1.     Identifying the characteristics of the wastes to be processed.

2.     Maximizing recovered product quality.
3.     Maximizing diversion of wastes from landfill.

4.     Utilizing proven system concepts.

5.     Provision for receipt of municipal solid waste (MSW), based on the types and fre-
      quency of vehicles delivering the material.

6.     Utilizing manual labor for those operations where current automation technology is
      lacking, unproven, or but marginally effective.
7.     Establishing the throughput capacity, required availability, and desired redundancy
      for the system.

       Materials recovery facilities can be classified into two general types based on the
characteristics of the input municipal solid waste; namely source-separated or mixed.
Taken here, source-separated wastes refer to those that are collected in singular (i.e., seg-
regated) components or in commingled form (a mixture of several components, e.g.,  metal
and glass containers). Mixed wastes are not separated prior to collection and obviously
such a mixture contains numerous components.

       Source-separated recyclables do not suffer from the higher degree of contamination
from food wastes and other contaminants exhibited by recyclables in mixed  MSW.  Thus,

                                      571

-------
the percentage  recovery  of recyclables from  source-separated wastes is substantially
greater than that from mixed wastes.
       The following discussion considers first the design of a MRF for processing source-
separated materials. Subsequently, the design of a MRF for processing mixed MSW is
considered.

Source-Separated MSW
       Process flow diagrams for a 120TPD materials recovery facility project are shown in
Figures 1 and 2, respectively, for a paper processing line and a container processing line.
Each of these flow diagrams is also a mass balance showing the tonnages of the various
recyclables as they enter and exit the system.
       The process design in this example  assumes that 25% of the available recyclables
arrive at the facility in pre-segregated, singular form (e.g., tin cans)  and that the remaining
75% is commingled. Each of the flow diagrams shows provision for redundancy in receiv-
ing, sorting, and processing.

       Breakage and contamination generally amount to approximately 7 to 10% of the in-
feed total.  Glass breakage during collection and material handling at the facility results in
the loss of small particles of glass as residue, if markets for mixed colored cullet are not
available.  Contamination must be removed within the ranges dictated by the market speci-
fications.  Common contaminants include corrugated and magazines included with resi-
dential newspaper collections, and low-grade  paper (such as envelopes with windows) in
commercial high-grade paper collections.
                                    572

-------
         FROM       54.9.
      MIXED PftPER  	1
      COLLECTION
      COMMINGLED

         PAPER
tn
-j
GO
1.8
                     4.3
      O.C.C.




        NEWS




        MAG.
                                                               t
                                             REJECTS
                                                                  7.32

                                                                 REJECTS
SORTING STATION
0. C. C.
MAG.
NEWS
                                                                           1 ' 52.29
O.C.C. | MAG.
SORTING STATION
HEWS
                                                    REJECTS
                                         t
                                                                        10.97
                                                                               15.39
                          Figure  1.   Paper Processing Line / Design Capacity  =  75 TPD

                                      75X CoHMingled Collection
                                      25x Segregated Collection

-------
Oi
-3
                                                       2.62

                                                      REJECTS
        SEGREGATED
          GLASS
       8.60
       SORTING STATION


REJ. |  GRN  |  AI1B  |  FLT   |  MXD
1
1
i
f
i
^
1 i
L J
' 1

L J
f 1


k .
1

L*
l>
k
REJ. I GRN | AMB I FLT I hXD j*T
SORTING STATION
      0.10
I
                                                                    GRANULATOR
         LASS
      CRUSHERS
                                                                                                          7.8
                                                                                                         »• AM
                                                                                                          6.48
                                                                                                           MXD
          PRODUCTS


REJ.

SORTING STATION
PET

GRN CLR
HDPE

MILK N/M

ALUM.

                                         1.48

                                         ALUM,
                                                                .08  1.33   .81  Tl-21


                                                                 EH   d3     EH  EU   GAV LORDS
                                                                 GRN CLR    MILK N/M
                                                                   PET        HDPE

-------
      Figure 3 is an example plan view of a facility matching the flow diagrams described
above. The facility is designed to provide a high level of redundancy, both in paper pro-
cessing and in container processing.

      For the paper line, two receiving pits are shown and each line is capable of handling
either the maximum anticipated mixed paper waste or the maximum anticipated segregated
paper waste.

      Similarly, for the container line, three receiving pits are shown.  Two of the lines are
totally redundant, with  each capable of  handling either the maximum  anticipated  mixed
container waste or the maximum anticipated segregated container waste.  The third line is
provided to handle segregated plastic and aluminum containers exclusively.

      The tipping floor and product storage areas are sized for a minimum of one day's
storage of all materials.

      This particular design provides for a facility with a minimum risk of downtime  result-
ing from equipment failure.  However, the provision of extensive redundancy is expensive.
Substantial economies may be realized by eliminating redundant processing capability and
operating on at least a two-shift basis. However, in any plant, machinery can and will break
down. In the case of a  plant with little or no redundancy, plans must be in place  regarding
how to meet anticipated breakdowns to minimize the effect of an outage.

Mixed MSW

      Recyclable materials can be recovered in a mixed MSW processing facility.  Such
materials recovery facilities segregate and recover the recyclable components from the het-
erogeneous-mixture MSW.  As opposed to MRFs processing commingled and segregated
                                     575

-------
             r  I
        200'
CJl
-J
0)

                   CONTAINER
                     TIPPING
                      FLOOR
                      PAPER
                    TIPPING
                      FLOOR
ires
                                                    240'
II OFFICE
FE
t
RES 11
i
>UE
L
LCKR.fl
                                                =    I
                                                  GLASS
                                                 STORAGE
                                                       SORT IN6
                                                       PLATFORM
4O
FT

T
R
A
I
L
E
R
                                                  DENS IFIER


                                                    D D GAVLORDS

                                                    D D
                                                             BALER
                                                                                     BALER
            FT
                                                                                                  TRA1LERS


                                                                                                    DOCK
                                                                                                    LOADING
                                                                                       =  1.   J

-------
components wherein 90% or more of the input materials are recovered in the form of mar-
ketable end-products, MRFs processing mixed MSW can recover approximately 10 to 20%
of the  input in the form  of marketable  grades of metals, glass, plastics,  and  paper.
Additional resource  recovery can be achieved by integrating into the facility design addi-
tional processing operations to recover refuse-derived fuel (RDF) or a compostable feed-
stock. These options for integration can increase the total diversion to within the range of
75 to 85% if markets for the other materials exist.

      An example of a materials recovery facility design  configured for the primary pur-
pose of processing and recovering  recyclable materials from mixed municipal solid  waste,
including ferrous, HOPE, PET, aluminum, and  several grades of paper, is presented in
Figure 4.  The processing  capacity  is assumed to be 50 TPH. The processing system in-
corporates both mechanical and manual separation  processes in order to optimize  the re-
covery of marketable secondary materials. The design recovers approximately 15% of the
input mixed waste in the form of marketable grades of recyclables.

      Wastes are assumed delivered to the facility  via transfer trailers or refuse collection
vehicles.  A description of the facility design follows.

      Wheel loaders and a picking crane are employed to remove large, heavy objects
and other nonprocessibles from the waste stream prior to the waste entering the process-
ing equipment.

      Provision is made in the facility to segregate corrugated and other marketable waste
paper grades by wheel  loader that arrive in loads of  waste composed predominantly of pa-
per materials.  When sufficient corrugated or other  paper grades are removed on  the tip
                                     577

-------
CD
                      PRESORTED OCC «  HQ
        -t
                 INFEED
-t
                                                CORRUGATED
          NONPROCESSIBLE
              HASTE
                                              SORT
                                                Fe
                                                u
                                                             MPERF IN-
4*2




^*3





k

1
JP IT i v»nn.
CAN
PRO-
CESS


' ^


a r
t
>..

i

ll
SORT
«2
*
r ^
^
r
                                                                            M
                                                                               PAPER
                                  OTHER    Fe
                                    Fe
                                                          GLASS   REJECTS
                                                         REJECTS
                                           1. 4
                                           1. 0
0. 4
41. 4
 BALED
PRODUCTS

  5. 8

-------
ping floor by wheel loader and accumulated, the materials are transported directly to a
baler, bypassing the mixed waste processing equipment.

      Mixed MSW is introduced to a two-stage primary trommel, with the first stage under-
size material passing by a magnetic separator for ferrous extraction.  The resulting process
residue is routed to the output residue stream.

      The primary trommel second-stage unders pass through a magnetic separator,
where the ferrous is removed and conveyed to a sorting station. At the sorting station, fer-
rous from the trommel oversize material extracted by a magnetic separator joins the ferrous
extracted from the second-stage trommel unders.  Ferrous cans are  sorted from other fer-
rous and sent to a can processing subsystem to provide a product with minimal contami-
nation.

      After passing through a magnetic separator, the primary trommel overs are con-
veyed to a second sorting station where HOPE, PET, aluminum, cardboard, and various
paper grades are manually separated. When sufficient quantities of these materials are ac-
cumulated, they are processed by one of two balers. The second baler serves as a compo-
nent of processing redundancy for the facility.

      A third sorting station receives undersize from the second  stage  of the primary
trommel after ferrous removal.  HOPE and  PET containers are manually sorted at this sta-
tion, as  well as aluminum and some high-grade paper.   The remaining waste joins the
waste from the sorting station processing the trommel oversize stream.

      Substantial manual sorting is utilized for segregation of plastics and aluminum be-
cause manual sorting is efficient for recovering the various plastic polymers and aluminum
beverage containers and  because  of  the opportunity  for employment  development.

                                     579

-------
Additionally, mechanical and electro-mechanical separation systems for plastic polymers
and aluminum materials are developmental for waste processing applications.

       Process residues account for about 85% of the incoming solid waste.  Much of the
process residues are combustible and biodegradable organic materials. These materials
require landfill disposal  unless  processed for  energy  recovery or  converted to a com-
postable feedstock for subsequent composting. For example, if refuse-derived fuel recov-
ery is integrated with materials recovery, the residue stream could be reduced to 15 to 25%
of the input MSW.

Conclusions

       The design of materials recovery facilities is dependent upon a number of consider-
ations. One key consideration in the selection of appropriate facility designs is the form of
the delivered feedstock, i.e., source-separated recyclables or mixed municipal solid waste.
A second key consideration is the level of recycling or waste diversion that is required.
Source separation programs (i.e., collection and processing) may achieve 20 to 30% diver-
sion, while mixed waste processing may be required  if diversion goals are 30% or greater.
Of course, markets must be available for the recovered products in either case.
       The impetus toward greater rates of waste diversion from landfills places a greater
burden on the designer to efficiently  and cost-effectively process and  recover additional
components of the waste stream. This paper has  presented the rationale of process de-
sign and examples of facility designs to illustrate the variety  of processing means available
to achieve waste diversion.
                                       580

-------
   THE DEVELOPING ROAD OF MATERIAL RECOVERY
           FACILITIES IN MUNICIPAL SOLID
               WASTE MANAGEMENT
        Mitchell Kessler, Eastern Regional Director
            Resource Integration Systems Ltd.
                    Presented at the

First U. S. Conference on Municipal Solid Waste Management

                 June 13 - June 16,1990
                         581

-------
TAKE ADVANTAGE OF ECONOMIES OF
 SCALE:
    - Collect large volumes from
     various generators
    - Increase processing efficiency

• PRODUCE LARGE VOLUMES OF HIGH
  QUALITY, HIGH VALUE PROCESSED
  MATERIALS
 SECURE STABLE, LONG-TERM
 MARKETS
              582

-------
FACILITIES DESIGNED AND EQUIPPED TO

 • ACCEPT COMMINGLED AND SOURCE-
  SEPARATE RECYCLABLES

• ACCEPT RECYCLABLES FROM VARIOUS
 GENERATORS

•SEPARATE AND/OR PROCESS
  RECYCLABLES

• UPGRADE RECYCLABLES TO MEET
  MARKET SPEC IFICATIONS

• MARKET PROCESSED MATERIALS
            583

-------
 SITE AVAILABILITY
 VEHICLE ACCESS
INDUSTRIAL LOCATION
AESTHETICS
           584

-------
>  BUILDING

> PROCESSING CAPACITY

 -  Fibre
 -  Commingled Containers

•RECEIVE MATERIALS AS COLLECTED:
 -  Fibre
 -  Commingled Containers
 -  Source Separated

TIPPING AREAS

•  PROCESSING LINES

>  STORAGE

»  SHIPPING
            585

-------
PUBLICLY OWNED AND OPERATED
PUBLICLY OWNED AND
 PRIVATELY OPERATED
PRIVATELY OWNED & OPERATED
            586

-------
• RESPONSIBLITY &
  ACCOUNTABILITY
  RISK AND REVENUE
  CONSTRAINTS &
   OPPORTUNITIES
           587

-------
  LEGISLATIVE POLICY
- Mandatory Programs
- Taxes/Bans
- Deposit Laws
- Waste Management Hierarchy

 MARKETS & PRICES
- Supply & Demand
- Import & Export
- Regional Marketing
- Procurement

  TECHNOLpGICAL DEVELOPMENT
- Recyclability
- Rapid Evolution
- Mixed Waste Recycling
- Packaging

 TRANSPORTATION  &  DISPOSAL
 COST
- Tipping Fees
- Long Haul
- Environmental Impacts
              588

-------
ECONOMIC FEASIBILITY OF RECYCLING IN THE MIDWEST:
        RECYCLING ALTERNATIVES IN OKLAHOMA

       Robert E. Deyle and Bernd F. Schade
              University of Oklahoma
        Science and Public Policy Program
                 Presented at the

  First U.S.  Conference on Municipal Solid Waste
       U.S.  Environmental Protection Agency

                 June 13-16,  1990
                      589

-------
Introduction

     EPA's  Agenda for Action proposes a national goal of
reducing  municipal solid waste by 25 percent through source
reduction and recycling.1  This goal is reflected  in  recently
proposed  amendments to the federal Resource Conservation and
Recovery  Act (RCRA) ,2 but it is not yet clear how  this  goal
will be operationalized through federal mandates or incentives
to  states or municipalities.  It is likely, however,  that the
costs  of  achieving such reductions could vary substantially
among  regions of the country.

      In most municipalities in the Northeast, the added costs
of  recycling are more than balanced by recycling revenues and
the avoided costs of diverting wastes from landfills and
 incinerators.  Tipping fees in this region average $45  per ton
 and range as high as $120 per ton.3  Outside  the densely
 populated eastern states, however, the cost-effectiveness of
 recycling is less obvious.  Average land disposal costs range
 from $13 to $16 per ton  in states such as California, Texas,
 and Colorado, and suitable sites for additional landfills are
 more plentiful.

      If  federal legislation requires all states to adopt a 25
 percent  waste reduction goal and mandate recycling programs at
 the municipal level, political opposition could be substantial
 in municipalities where  a substantial increase in solid waste
 management  costs will result.  If the federal law exempts
 municipalities that can  show that recycling is less cost-
 effective  than other means of solid waste management,
 achieving  a 25 percent waste reduction goal may be very
 difficult.  Under  either approach, substantial financial
 incentives  may be  necessary to offset some of the initial
 costs  of municipal recycling programs if waste reduction goals
 are to be  achieved at the national level.

      This  paper offers a basis for assessing how achievable
 such a national goal might be in western and midwestern
 states.  We present the  results of a comparative assessment of
 the cost-effectiveness of curbside recycling and yard waste
 composting versus  current land disposal systems in four
 communities in Oklahoma.  The results also offer a means of
 estimating the level of  financial subsidy that might be
 required as an incentive for promoting recycling in
 communities where  land disposal remains more cost-effective.

       Analyses were also  conducted of municipal recycling
 options  that rely  on voluntary drop-off sites or buy-back
 centers.  These typically achieve very low diversion rates on
 the order  of 0.5  to  3.3  percent of the total municipal  solid
 waste stream.  Results of these analyses are not discussed
 here because of  space limitations and the relatively low
  impact they are  likely to have on achieving waste reduction
                            590

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goals.   For details,  see Deyle and Schade (forthcoming).A


Methodology

     This study uses 20-year "life cycle" costs, or net
present values,  to compare the cost-effectiveness of curbside
recycling and yard waste composting with continued operation
of the current solid waste management system in each of the
four case communities.5   Community-specific  data on current
solid waste management systems are analyzed along with data
from curbside recycling and yard waste composting programs in
other communities across the country.  Values for many of the
cost and revenue variables extend over a substantial range.
Therefore, base analyses were conducted using mid-range
values, and sensitivity analyses were performed to assess the
effects of varying individual variables.


                    Case Study Communities

     The case study communities were selected to represent the
range in conditions that characterize municipal solid waste
management in Oklahoma.  As shown in Table I, they range in
size from the rural town of Fairview, with a population of
3,200, to Oklahoma City, the state's largest metropolitan
area.  Land disposal costs range from less than $8.00 per ton
to about $12.50 per ton.  Each of the communities has
municipal collection of residential solid waste, with the
exception of a portion of Oklahoma City that is served by a
private hauler.  Three of the communities use commercial
landfills to dispose of their wastes.  Fairview uses a
regional facility operated by a public authority.


                    The Recycling Scenarios

     For each of the communities, the life cycle cost  of
operating the existing municipal collection and land disposal
system over a 20-year period, beginning in 1990, is compared
with the life cycle costs of two recycling options:

 (1)  adding a municipal curbside recycling program to  the
     existing solid waste management system and processing the
     recovered materials at a municipal materials  recovery
     facility  (MRF), and

 (2)  adding a separate curbside collection program for yard
     waste and composting the yard waste  at a municipal
     facility.
                               591

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  Table  I.   Case study communities.
                                                      Name of community
                                     Oklahoma  City
  Norman
Owasso
Fairviev
 Population of the service area         447,850

 Number of households in the
   service area                         130,000

 Annual waste generation (tons)         428,000

 Proportion of residential waste
   in the total waste stream              41.6%

 Salary of collection workers
   including fringe benefits            $20,400
   ($/year)

 Average distance travelled per
   collection vehicle (once weekly
   pickup)  (miles)                         7,982

 Number of garbage  trucks  used               33

 Unit  costs  of waste  collection          $38.20
   ($/ton)

 Remaining landfill capacity
   (years)                                    12

 Landfill ownership                      private

 Average round trip time from  a
  waste generation district to the
  processing facility (minutes)              45

Tipping fee in 1990  ($/ton)
  (if private landfill)                  $7.69

Unit costs of waste  disposal
  ($/ton)(if public  landfill)            $0.00
  79,500
12,000
  18,550      3,500

  65,800     18,607
   36.0%
     35
 24.1%
  2,919      8,060

     19          2

 $81.78     $71.00



      9         12

private    private
   10
 $12.48     $12.00
  3,200


  1,308

  3,276


  71.01
$23,300     $16,433      $23,000
             5,200

                 1

            $27.84
  $0.00
$0.00
           public
     50
            $0.00
 $8.79
                                        592

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     Twenty years was selected as the period of analysis to
account for the savings that will result by diverting wastes
from disposal and extending the capacity of a municipally-
owned landfill.  The materials included in the curbside
recycling scenario are aluminum cans, glass containers, and
newspapers.  Plastics and tin cans were excluded because of
the current lack of firm markets in this region.  It is
assumed the curbside program involves weekly collection of
commingled materials using dedicated recycling vehicles
operated by a one-person crew.  The city provides single
recycling containers to each household served by the
residential MSW collection system.  Processing at the
municipally owned and operated MRF includes crushing of
aluminum cans and color-separated glass, and baling of
newspapers.

     The composting scenario assumes that yard wastes,
including grass, leaves, and prunings, are picked up weekly on
a separate day from other household refuse using existing
packer trucks.  Yard wastes are assumed to be placed at the
curb in plastic bags that must be opened manually prior to
composting.  The composting operation is assumed to be a low-
technology system that uses a front-end loader to create and
turn windrows.
                    Life Cycle  Cost Analysis

     Life cycle cost analyses were conducted using a Lotus
program designed for the project.  The life cycle cost of a
solid waste management  system is the sum of the discounted net
annual costs over the period of analysis.  The net annual
costs are the sum of the annualized capital and operating
costs minus revenues.   Costs and revenues in years beyond the
base year are inflated  using specific inflation rates for such
cost components as  labor, vehicles, fuel, and utilities.  The
formula for calculating life cycle cost can be represented as
follows:


LCC =   S [A + PC * fl+c,)(n'1> - REV * fl+c..l
-------
     The annualized capital  costs  (A)  are the sum of costs to
 retire the debt for initial  capital  expenditures and payments
 to  a reserve fund for replacing equipment.   It was assumed
 that municipalities issue general  obligation bonds to pay for
 the initial capital costs of recycling.   For a more detailed
 explanation of how these cost components  were calculated, see
 Schade and Deyle (in preparation).6
                        Cost Components

     The individual cost components  for  a  solid waste
management system include the  following:

        - MSW collection and transport
        - MSW disposal
        - curbside  collection of recyclables or yard waste
        - processing recyclables or composting yard waste
        - revenues  from recovered materials.

Cost components for the existing municipal  solid waste
management system only include MSW collection  and transport
and MSW disposal.  The recycling and composting scenarios
include these costs, adjusted to account for the diversion of
materials into the recycling system, plus  costs for curbside
collection of recyclables or yard waste, operation of the
processing or composting facility, and promotion of the
collection program.  The recycling and composting systems also
include revenues from the sale of recovered materials.

     The individual variables employed in  the  analysis are
listed in Table II.  For some variables a  range of values was
used, either because the values are subject to fluctuation
over time (for example market prices for recovered materials)
or because  it was not possible to generate  a single value from
the available data (for example the unit costs of operating a
MRF).  Data on the solid waste management  systems in the four
communities were obtained through interviews with municipal
officials.   Data for the cost components of the recycling and
composting  options were obtained through interviews with
private-sector recyclers, MRF operators, officials in
communities in Oklahoma and other states with  existing
recycling and yard waste programs, and equipment vendors.
Some cost and operational data were derived from published
literature.7   For a  detailed discussion of data sources see
Schade (1989) .8
                              594

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Table II.    Life cycle cost variables.
Variable Description
     Range
Waste Diversion Rate Factors

Residential waste composition
  (% by weight)
     Aluminum cans
     Glass containers
     Newspaper
     Yard waste

Recycling rates (%)
     Aluminum cans
     Glass containers
     Newspaper
     Yard waste

Processing losses at the MRF (%)
     Aluminum cans
     Glass containers
     Newspapers
   1.1
   7.7
   9.0
   7.7
     3
    10
    15
    70
 3.9 %
12.9 %
15.0 %
19.3 %
 7
32
58
95
       5 %
      30 %
       5 %
MSW Collection Costs

Annual waste generation  (tons)

Proportion of residential waste in
  the municipal waste stream  (%)

Unit costs of collection  ($/ton)

Collection cost savings from recycling
  (% of waste diversion rate)

Collection cost increase with separate
  yard waste collection
community-specific1

community-specific


community-specific

     0, 70, 90 %


       0 - 25 %
MSW Disposal Costs

Private landfill: 1990 tipping fee
  ($/ton)

Public landfill: 1990 annualized
  capital and operating costs  ($)
community-specific
community-specific
       See Table I.
                              595

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 Table  II.
continued
Variable  Description
                                      Range
Unit cost  of  disposal  after
  Subtitle D  regulations in effect
  ($/ton)
                                    $18 - $21/ton
Costs of Curbside Collection of Recvclables

Weekly set-out rate  (%)

Density of recycled materials (tons  per
  cubic yard)
     Aluminum cans
     Glass containers
     Newspaper

Public promotion costs  ($ per
  household per year)

Workhours per week (hours)

Break time per week (minutes)

Capacity of recycling truck
  (cubic yards)

Price of recycling truck

Fuel consumption of recycling truck
  (miles/gallon)

Diesel fuel price ($/gallon)

Maintenance costs for recycling truck
  ($/year)

Productivity of recycling
  truck (stops passed per hour)

Useful life of recycling truck
  (years)

Capacity of pickup truck-trailer
  (cubic yards)

Price of pickup truck-trailer

Fuel consumption of pickup truck-
  trailer (miles/gallon)
                                     20 - 70
                                   0.037 tons/cy
                                   0.500 tons/cy
                                   0.275 tons/cy

                                   $0.75 - $1.50
                                       40  hrs

                                      150  min

                                       15  cy


                                      $37,000

                                       3.8 mpg


                                      $0.65/gal

                                      $5/200/yr


                                  85,100,165 stps/hr


                                       9  yrs


                                      14.25 cy


                                      $11,000

                                       18 mpg
                              596

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Table II.
continued
Variable Description
                                      Range
Gasoline price ($/gallon)

Maintenance costs for pickup truck-
  trailer ($/year)

Productivity of pickup truck-
  trailer recycling vehicle

Useful life of pickup truck-
  trailer (years)

Unloading time of recycling
  vehicle (minutes per trip)

Price of recycling container

Useful life of recycling container

Bond term for recycling equipment


Processing of Recyclables

Unit capital costs ($ per ton
  of daily capacity)

Unit costs of operation  ($/ton)

Minimum MRF size  (tons per day)

MRF design life  (years)


Yard Waste Composting

Unit capital costs ($ per ton
  of daily capacity)

Unit costs of operation  ($/ton)

Minimum facility  size  (tons per day)

Debagging costs  ($/bag)

Compost weight reduction  (%)
                                      $0.73/gal

                                       $850/yr


                                  69,78,113 stps/hr


                                        9 yrs


                                       10 min


                                       $4.50

                                        9 yrs

                                        9 yrs




                                $10,000 - $38,500


                                    $20 - $30/ton

                                      5 tpd

                                  10, 17, 25 yrs




                                 $7,600 - $13,800


                                  $3.60 - $22.50

                                      7 tpd

                                  $0.02 - $0.04

                                     30 - 50%
                              597

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Table II.   continued
Variable Description                               Range


Recovered Materials Revenues

Materials sales prices ($/ton)
     Aluminum cans                             $ 800 - 1,514
     Glass containers                          $  70 - .   80
     Newspaper                                 $  15 -    65
     Compost                                   $   0 -     4


Financial Variables

Interest and discount rate                   8.00,  8.25,  9.25 %

Inflation rate (gross national product)            3 - 4  %

Inflation rate (labor)                           3.6 - 4.6 %

Inflation rate (vehicles and equipment)          2.4 - 3.4 %

Inflation rate (machinery and equipment)         3.0 - 4.0 %

Inflation rate (fuel and utilities)              3.7 - 4.7 %

Backup factor for labor                             1.2

Overhead (percent of total annual costs)            15 %
                                598

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     Waste Diversion Rates.   The amount of waste that is
diverted from the waste stream through recycling is dependent
on three variables: (1) waste composition, (2) recycling
rates, and (3) processing losses at the MRF.  Estimates of the
composition of residential waste were derived from recent
studies in Missouri and several other states in the absence of
data for any communities in Oklahoma.   Recycling rates are
defined as the proportion of the total amount of a material in
the waste stream that  is collected from the public.  This
parameter is dependent on participation rates and recovery
rates, i.e. the percent of recyclables actually set at the
curb by a participating household.  Processing losses at a MRF
result from contamination of a portion of the collected
materials and, in the  case of glass, losses from breakage
during collecting and  handling.

     The amount of each material that is finally diverted from
the residential waste  stream is calculated by multiplying the
total tonnage of residential waste by the proportion of the
commodity in the residential waste stream and the recycling
rate, and then subtracting the estimated processing loss.  The
total waste diversion  rate for the composite municipal solid
waste stream  is calculated by dividing the tons of all
materials diverted from the waste stream by the total tonnage
of residential and commercial waste managed in the municipal
system.

     MSW collection costs  are the product of the total amount
of residential MSW generated in the service area and the unit
cost  of collection.   If a  proportion of the waste is diverted
through recycling, the MSW collection costs may be reduced.
This  collection cost  savings is calculated  as a proportion of
the waste  diversion rate.  Data from studies  in Rhode  Island
suggest that  collection costs decrease  in an  amount ranging
from  70 to 90 percent of the diversion  rate.    A lower bound
of  zero  is included  for a  worst-case assumption.  This may
apply in smaller  communities where the  net  reduction  in waste
volume is  insufficient to  eliminate  at  least  one  truck and
crew  from  the collection  system.  For yard  waste  collection
programs,  there  is typically a  net  increase in  total  MSW
collection costs,  on  the  order  of 8  to  25 percent, with the
 addition of separate  yard  waste collection  service.   Under
 optimal  conditions,  it may be possible  to break even.

      MSW disposal costs  are  calculated  differently for private
 and public landfills.  For a private landfill,  disposal costs
 are the product of the tipping  fee  paid by  the municipality
 and the amount of residential  waste disposed.   No extension of
 landfill capacity is  assumed to result  from recycling where
 the landfill is privately owned.   We assume that private
 operators would compensate for reductions in waste disposal
 from one source by seeking additional wastes from other
                                599

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 sources, since their earnings are a function of the volumes  of
 waste they handle.

      Where the community operates its own landfill,  we assume
 the annual operating costs are fixed and that recycling does
 not result in immediate reductions in disposal costs.
 However, reduced waste disposal is assumed to extend capacity,
 thus postponing the higher unit costs of constructing and
 operating a new landfill or landfill cell in compliance with
 the more stringent  standards to be imposed under the federal
 Subtitle D regulations.11  The new landfill is also assumed to
 be designed to handle a lower daily volume of waste that
 reflects the waste  diversion accomplished through recycling.

      Costs for curbside collection of recyclables include
 capital costs for collection vehicles and containers (for
 commingled recyclables),  payments to a reserve fund to replace
 that equipment,  labor,  fuel,  and vehicle maintenance costs,
 and the costs of an ongoing public promotion program.   The
 number of dedicated recycling vehicles needed for the curbside
 program is calculated using an iterative method described by
 Garrison (1988).12  The tonnage of recyclables collected is a
 function of the composition of the residential waste stream,
 the recycling rate  by residences within the service area,  and
 the density of individual materials.

      The costs of yard waste collection were not calculated
 separately since we assume that yard wastes are collected
 using existing collection equipment and personnel under a
 revised collection  schedule.   The net effect of a separate
 yard waste collection program are reflected in a factor
 described above under MSW collection costs: "collection cost
 increase with separate yard waste collection."

      The costs of processing recvclables or composting yard
 waste include capital costs for land and construction of a MRF
 or composting facility,  initial equipment costs, equipment
 replacement costs,  and operating costs.

      Revenue estimates from the sale of recovered newspaper,
 color-sorted glass,  and aluminum cans include ranges that
 reflect markets  for these commodities in Oklahoma during the
 past three years.   Prices are those paid by end-users, at the
 MRF dock.   Total  revenues reflect the amount of recyclables
 collected minus  processing losses.   Revenues from the sale of
 composted yard waste range from zero to $8 per ton.
 Commercial markets  tend to be local because it is generally
 not economical to transport compost long distances.   In many
 communities,  composted yard waste is not sold commercially but
 is  used  instead by  the municipality as a substitute for soil
 amendments that would otherwise be purchased by their parks  or
highway  departments.   The revenue range includes the avoided
                              600

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cost of making such substitutions.


                           Analyses

     For each of the four case study communities, three base
analyses were conducted:  (1) no recycling,  (2) curbside
recycling, and (3) curbside collection and composting of yard
waste.  The no-recycling option reflects the current solid
waste management system.  For variables in Table II with a
range of values, mid-points were used in the base analyses of
the recycling options; best and worst cases were defined to
reflect the highest possible range of variation.  Sensitivity
analyses were conducted to test the impact of varying
individual variables.

     For the two larger cities, Oklahoma City and Norman, the
curbside recycling collection vehicles were assumed to be 15-
cubic yard dedicated recycling trucks.  Sensitivity analyses
were performed for each of these communities substituting a
14.25-cubic yard recycling trailer hauled by a pickup truck.
For the smaller communities of Fairview and Owasso, the base
analysis assumed use of a pickup truck-trailer collection
vehicle.  In these two cases, only one collection vehicle is
needed to serve the community, and the decreased collection
efficiency of the truck-trailer system is offset by much lower
capital and maintenance costs.  In the Fairview case, the
truck-trailer rig is assumed to be shared with other
municipalities  in the  regional solid waste  management
authority.  Fairview would  only need to operate the vehicle
one day a week  to collect recyclables  from  its 1,308
households.

      The  base analyses for  Oklahoma City  and  Norman also
assumed that the  municipality  owns and operates  the MRF  for
processing  recyclables.   A  minimum capacity of 5 tons per day
 (tpd)  was assumed based on  interviews  with  MRF vendors.  The
Fairview  analysis assumes the  MRF is  regionally  owned, with
Fairview  responsible for 31 percent of the  capital  and
 operating costs,  which is equivalent  to  its proportion of the
wastes currently handled by the  regional  solid waste  system.
A scenario was also analyzed where Fairview only used that
 portion of a regional  MRF that it actually  would need for  its
 recyclables.   Such an option would require  extending  the size
 of the regional system to include other municipalities  to
 fully utilize the capacity of a 5-tpd MRF.   A similar scenario
 served as the base case- for Owasso,  which operates its  own
 solid waste management system at present but would utilize
 only about 18 percent of a 5-tpd MRF.
                               601

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   Results
                          Diversion Rates
       Waste diversion rates  for the  curbside recycling and yard
   waste composting options depend  on  assumptions about waste
   composition, recycling rates, and,  in the case of curbs ide
   recycling, processing losses at  the MRF.  The range in
   potential diversion rates for the residential waste stream are
   summarized in Table III.  Total  diversion rates for the
   composite MSW stream will vary with the mix of residential and
   commercial wastes managed by a municipal system.   As shown in
   Table I, the proportion of  residential waste varies
   substantially among the four communities studied,  from 71
   percent in Fairview to 24.1 percent in Owasso.  As a result,
   the total diversion rates for these four communities also vary
   considerably as shown in Table IV.
Table III.   Residential diversion rates.
Recycling
Option
curbs ide
composting
Best
Case
11.41%
44.07%
Base
Case
5.79%
30.96%
Worst
Case
1.85%
12.99%
combined
    55.48%
36.75%
14.84%
Table IV.    Composite diversion rate ranges.
Recycling
Option
curbs ide
composting
Best
Case
4.1 - 8.1%
10.6 - 31.2%
Base
Case
1.4 - 4.1%
7.5 - 22.0%
Worst
Case
0.5 -
3.1 -
1.
9.
3%
2%
combined
13.4 - 39.4%   8.9  -  26.1%
             3.6 - 10.5%
                               602

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                       Cost Effectiveness

     Comparison of the 20-year life cycle costs of the current
solid waste management systems and those for a curbside
recycling program suggests that curbside recycling would be
marginally cost-effective in the four communities under
conditions somewhat more favorable than the base cases.
Composting programs, however, represent a substantial increase
in costs except under  the most optimistic assumptions.

     Figure 1 portrays the life cycle cost differentials for
curbside recycling and yard waste collection and composting
for the four communities under the base-case assumptions.  The
bars indicate the percent difference between no recycling and
the two recycling options.  The curbside programs would entail
net increases of two to three percent in 20-year life cycle
costs for all but Fairview.  If Fairview were able to
participate in a regional MRF system where it only paid for
the proportion of a 5-tpd MRF that it actually needed, it's
life cycle cost differential for curbside recycling would be
in the same range, 2.6 percent.  The life cycle cost
differentials for yard waste collection and composting
programs are substantially higher, in the range of 11.5 to 13
percent.

     Figures 2 and 3  show the range of possible life cycle
cost differentials for the best-case and worst-case scenarios
for a curbside collection program and a composting program in
the four communities.  The best-case scenarios  for both
recycling  options yield  lower life cycle costs  than the
present solid waste management  system for all four
communities, but the  worst-case scenarios represent
substantial  cost  increases,  especially  for the  composting
option.  Tables V  and VI list the assumptions used to  define
the best and worst  cases for the two recycling  options.

      In Table VII,  a  more conventional  cost  figure is  used,
cost  per household per month.   These  figures  only show the
 first-year net  systems costs,  so the  effects  of landfill
capacity  savings  and paying off initial bonds are not
reflected.   Thus  while the best-case  scenarios  for yard waste
 composting all  show a net reduction in  life  cycle costs,
 first-year costs are only reduced  for Norman and Owasso.   For
 the best-case curbside option,  both the life cycle costs  and
 first-year net costs are lower for all  four communities.

      Under the best-case scenarios,  all four communities  would
 save money from a combined curbside recycling and  composting
 program.   The combined first-year net costs for the  base-
 caseanalyses of curbside recycling and yard waste  composting
 range from $1.50 to $2.00 per household.   These costs are
 within the range that municipalities in other parts  of the


                              603

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   14
        of life cycle cost
   12 -




   10




     8




     6




     4




     2
        Oklahoma City      Norman         Owasso        Fairview




              SB curbside recycling   I   I  yard waste compost




Figure 1.   Life cycle cost differentials compared to no recycling.
                                  604

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   20




   15




   10




    5




    0




   -5




  -10




  -15
        of life cycle cost
       Oklahoma City      Norman         Owasso         Fairview





             !SiM worst case   I   I base case   HH best case





 Figure 2.  LCC differentials - curbside compared to no recycling.
   30
   20
    10
      % of life cycle cost
  -10
       Oklahoma City      Norman
                 worst case
       Owasso
      Fairview
base case
best case
Figure 3.  LCC differentials - composting compared to no recycling.
                             605

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Table V.   Best and worst case scenarios for curbside recycling.
Variable
Waste composition (propor-
tion of recyclables)
Recycling rates
Collection cost savings
Productivity of recycling
vehicle
Processing costs*
MRF design life
Materials sales prices
Best Case
high
high
high
high
low
long
high
Worst Case
low
low
low
low
high
short
low
  Combined unit capital costs and operating costs.
Table VI.    Best and worst  case scenarios for composting.
Variable
Waste composition (propor-
tion of yard waste)
Recycling rates
Collection cost increase
Composting costs*
Debagging costs
Compost weight reduction
Compost sales prices
Best Case
high
high
low
low
low
low
high
Worst Case
low
low
high
high
high
high
low
 Combined unit capital costs and operating costs.





                             6O6

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8
      Table VII.   First-year net costs In dollars per household per month compared to no recycling.
Oklahoma City
Program
Option
curb side
composting
Worst
Case
$0.83
1.84
Base
Case
$0.28
1.22
Best
Case
-$0.98
0.02
Worst
Case
$1.10
3.03
Norman
Base
Case
$0.25
1.69
Owasso
Best
Case
-$1.41
-0.29
Worst
Case
$0.89
3.27
Base
Case
$0.25
1.75
Best
Case
-$1.10
-0.43
Fairview
Worst
Case
$1.69
2.13
Base
Case
$0.55
1.44
Best
Case
-$1.00
0.38
      combined
$2.67   $1.50   -$0.96     $4.13    $1.94   -$1.70     $4.16    $2.00  -$1.53     $3.82   $1.99  -$0.62

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 country have been willing to pay for the noneconomic benefits
 of recycling such as  energy conservation,  improved
 environmental quality,  and less  waste of natural resources.
 However,  under the worst-case scenarios,  combined costs would
 range from $2.67 to $4.16 per household per month.  It is
 likely that cost increases of this magnitude would generate
 political and public  opposition  in some communities.


            Importance of Different  Cost Components

      Examination of the individual cost components for the
 different systems shows that collection costs dominate the
 outcomes  for  both the curbside and composting programs.  Total
 life  cycle costs of curbside collection of recyclables account
 for 45 to 68  percent of the  total costs of a curbside
 recycling program in the  base cases.   Costs of yard waste
 collection are responsible  for 60 to 80 percent of the costs
 of  a  composting program under base-case assumptions.

      Under best-case assumptions, the reduced costs of
 collecting regular household waste compensate for the
 increased  costs of a separate curbside collection system for
 recyclables in all of the communities except Fairview.  In the
 worst-case  scenario, we assumed  no savings in collecting MSW
 which  is more likely in the  two  smaller communities, and
 possibly  in Norman as well,  since significant savings will
 only occur where at least one truck  and crew and can be
 eliminated.

     The best-case assumption for the composting option was
that the increased costs of  a separate yard waste collection
are completely offset by the reduced costs of collecting the
remaining MSW from residences.   In the worst-case scenario
there is a 25 percent increase in net collection costs.

     Processing costs account for 23  to 29 percent of the
costs of a curbside recycling program in  all of the
communities except Fairview.   In Fairview,  processing accounts
for 47 percent because of under-utilization of the city's
share of a  5-tpd MRF.  If Fairview were able to participate in
a regional  system where it only  paid for  the proportion of a
MRF that  it actually required, processing  costs would
represent  a proportion of total  costs comparable to that for
the other  cities.  In the base-case  composting scenarios,
composting  costs account  for 19  to 36 percent of total program
 costs.

      Program  promotion and public education costs are
 relatively insignificant  for both the curbside and composting
 programs.   They range from  8 to  10 percent for curbside
 recycling and from 2 to 5 percent for composting programs.
                              6O8

-------
     Revenues cover 31 to 40 percent of program life cycle
costs under the base-case scenarios for curbside recycling.
Under best-case assumptions, revenues equal or exceed costs
for curbside recycling in all of the communities except Owasso
where they cover about 84 percent of program costs.  Revenues
are much lower for yard waste compost, covering only 2 to 13
percent of program costs under base-case assumptions ($4/ton).
Under best-case assumptions, the range increases to 6 to 12
percent, but under the worst-case scenarios we assume no
revenues are generated through compost sales or substitution
for soil amendments used by municipal agencies.


                      Sensitivity Analyses

     In addition to assessing the effects of best-case and
worst-case assumptions, analyses were run to assess the impact
on life cycle costs of varying individual variables.  The
range of variation in life cycle cost differentials associated
with the value ranges for the individual variables tested are
summarized in Table VIII for the two recycling options.

     In the curbside recycling scenarios, results were most
sensitive to variation in recycling rates, collection cost
savings, set-out rate, waste composition, sales prices, and
processing costs.  The relative sensitivity of the program
life cycle costs to individual factors varied among the
communities, primarily because of differences in the unit
costs of collecting MSW.  Variations in processing costs had a
greater impact in Fairview because of its under-utilization of
a regional 5-tpd MRF.

     In the yard waste composting scenarios, variations in
assumed collection cost increases and processing costs have
the greatest impacts on life cycle costs.  This is due to
thegreater extent to which these costs overshadow the
potential revenues from compost sales or avoided costs from
compost use by the municipality or waste diversion.


Conclusions

     Analysis of these four communities in Oklahoma
demonstrates that in many municipalities recycling programs
must be extended to commercial wastes as well as residential
wastes to achieve a 25 percent reduction in MSW through
recycling.  This study also indicates that curbside recycling
programs will probably require some increase in total solid
waste management service fees, although these increases are
within a range that has been politically acceptable in many
communities throughout the nation.  The additional costs of
                              609

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Table VIII.    Range of variation in life cycle cost differentials
for individual variables.
Variable
Waste composition
Recycling rates
Materials sales prices
Collection cost savings
Collection cost increase
Processing costs
Debagging costs
Compost weight reduction
MRF lifetime
Set-out rate
Truck productivity
Collection vehicle type
Landfill lifetime
Landfill ownership
Discount/interest rate
Inflation rates
Recycling
Curbs ide
3-5%
6-7%
2-5%
3-4%
n/a
1-6%
n/a
n/a
0-2%
3-6%
2-3%
1-2%
0-1%
0-1%
<1%
<1%
Option
Composting
0-1%
<1%
1-2%
n/a
15-21%
7-12%
<1%
<1%
n/a
n/a
n/a
n/a
<1%
2-3%
<1%
<1%
                              610

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yard waste collection and composting may entail a substantial
increase in waste management costs, especially if combined
with the costs of a curbside recycling program in an effort to
achieve a 25 percent recycling goal.

     Because solid waste disposal costs are considerably lower
in this region of the country, the life cycle costs of
recycling or composting are primarily determined by collection
and processing costs.  The reduced savings that can be
realized from the avoided costs of waste diversion and
extended landfill capacity also make net costs for recycling
options more vulnerable to shifts in markets for recovered
materials.  Net costs are also more sensitive to such factors
as waste composition and variables that affect net recycling
rates including participation rates, recovery rates, and set-
out rates.

     Assessing the cost-effectiveness of recycling in
communities such as those analyzed here will, therefore,
require very careful examination of opportunities to minimize
collection costs and maximize savings from diverting wastes
from the regular MSW collection and disposal systems.
Particular care must be given to assessing potential markets,
and continued effort will be required to maintain high
participation and recovery rates through ongoing public
education programs.  In smaller communities, such as Owasso
and Fairview, regional processing facilities, and in some
cases, shared collection equipment, may be essential to making
curbside recycling and composting programs as nearly cost-
effective as possible.  Communities of this size, i.e. less
than 15,000, account for 25 percent of the total population in
Oklahoma and 33 percent of the population living in
incorporated municipalities.  Another 23 percent of the total
population of the state lives in unincorporated areas where
curbside collection is not currently provided and where
recycling would most likely require use of drop-off centers.

     The marginal cost-effectiveness of these recycling
options suggests that financial subsidies from states or the
federal government may be required to overcome political
opposition to the increased costs of municipal recycling
programs.  Some measure of willingness to pay is needed to
assess the cost thresholds beyond which communities are not
willing to go for the less tangible benefits of recycling.
The computer program designed for this project has the
capability to assess the impacts of public grants on first-
year net costs and life cycle costs.  We expect to conduct
such an analysis in the near future.
                               611

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 Acknowledgements

      Support for this work was provided  from the  federal  Exxon
 Oil  Overcharge Settlement Fund through a contract administered
 by the Oklahoma State Department of Commerce.
 References

1.   The Solid Waste Dilemma; An Agenda  for Action. United
     States Environmental Protection Agency, Washington,  DC,
     1989.

2.   K. Meade, "Recycling bill aims for  25%-50%, calls  for
     •hard look1 at waste," Recycling Times 1(8):  1; K. Meade,
     "RCRA draft highlights recycling,"  Recycling  Times 1(14):
     3  (1989).

3.   C.L. Petit, "Tip fees up more than  30% in annual NSWMA
     survey," Waste Age 20: 101 (1989).

4.   R.E. Deyle and B.F. Schade, Municipal buy-back recycling:
     economic feasibility in Oklahoma, Proceedings ASTSWMO
     1990 National Solid Waste Forum on  Integrated Municipal
     Waste Management. Association of State and Territorial
     Solid Waste Management Officials, Washington, DC,
     forthcoming.

5.   S.H. Russell, Resource Recovery Economics. Marcel  Dekker,
     New York, 1982.

6.   B.F. Schade and R.E. Deyle, "Recycling in the land of
     plenty: the cost effectiveness of curbside programs  in
     Oklahoma," in preparation.

7.   See for example The BioCycle Guide  to Collecting.
     Processing, and Marketing Recyclables. BioCycle Journal
     of Waste Recycling, JG Press, Emmaus, PA, 1990; 1990-91
     Materials Recovery and Recycling Yearbook. Governmental
     Advisory Associates, New York, NY,  1990; A.C. Taylor and
     R.M. Kashmanian, Yard Waste Composting A Study of  Eight
     Programs. U.S. Environmental Protection Agency,
     Washington, DC, 1988; Management Strategies for Landscape
     Waste. Illinois Department of Energy and Natural
     Resources, Springfield, ILL,  1989.

8.   B.F. Schade, Solid Waste Management and Recycling  in
     Oklahoma: An Economic Analysis, master's thesis,
     University of Oklahoma, 1989, p.106-130.
                              612

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9.   R.E.  Deyle,  T.E.  James,  T.M.  Coffman,  N.N.  Hanks,  G.
     Lawn-Day,  D.  Penn,  B.F.  Schade.  Solid Waste Management
     and Recycling in  Oklahoma.  Univ. of Oklahoma,  Norman,  OK,
     in preparation.

10.  Collection Cost Savings  Study.  Resource Integration
     Systems,  Inc., Toronto,  Ont., 1988.

 11.  Camp  Dresser and  McKee,  Inc., Economic Impact  Study of
     Landfill  Regulations (R88-7). Illinois Dept. of Energy
     and Natural Resources, Office of Research and  Planning,
     Springfield,  IL,  1990;   E.  Cowhey Sheliga,  Browning
     Ferris Industries,  Inc., personal communication,  November
     20, 1989;   R.T. Glebs,  "Subtitle D: How Will it Affect
     Landfills?" Waste Alternatives 1: 56-64 (1988);  E.  Knox,
     Laidlaw Waste Systems, Inc.,  personal communication,
     November  13,  1988;   G. McDonald, USA Waste Services,
     Inc., personal communication, November 13,  1988;
     National  Solid Waste Management Association, How Much
     Will  a State-of-the-Art  Landfill Cost?. NSWMA,
     Washington,  DC,  1988.

 12.  R. Garrison,  "Curbside Collection Service:  Estimating
     Equipment Needs," Resource Recycling 7: 30-32  (1988).
                               613

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                                  I 0 1990
                  FEDERAL FACILITIES RECYCLING

                   Gail Miller Wray,  Moderator
                    EPA Recycling Coordinator

                           Jim Nelson
       Assistant General Council, Toxic Substances Branch

                         Elaine Suraino
           Coordinator, Toxic Chemical Assesment Desk

                          Ruth Yender
               Environmental  Protection Specialist

   I.  EPA's Success

        A.   Sierra Club's Acceptable Six—EPA singled out for
             praise (Washington Post, New  York Times).

        B.   Federal Executive January  issue.

        C.   Federal Times issue.

  II.  EPA Recycling staff

      A.  Office of Solid Waste—Muncipal Solid Waste Office
          1.   Policy
          2.   Public/Community Outreach

      B.   Office  of Administration and  Resources  Management -
          Facilities Management and  Services  Division.
            1.   Administration of Internal Recycling program.
            2.   Assistance to Federal Agencies.

      C.  Recycling Workgroup
          1.   Advisory
          2.   Actual working arm of  program

      D.  AA Coordinators
          1.   Monitoring
            >
III.  EPA logistics (detailed on blue  handout)
      A.  8000  employees
      B.  Three buildings
      C.  1.2 million square  feet
                            615

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 IV.  EPA program history
     A.   "Use  it Again  Sam!"—1977  campaign.
         1.  Failure  of 1970's movement
            a.   Markets
            b.   Slow technological movement and procurement
                 problems
         2.  Sluggish continuation  of program throughout
            1980s.
            a.  GAO Report  (GAO/GGD-90-3)
                1.  Source  preparation
                2.  Procurement Guidelines

     B.   Resurgence of  concern—1988
         1.  Recycling  Workgroup
         2.  Agency Coordinator
         3.  August Kick-off
 V.  EPA Waste Stream Analysis
     A.   Conducted to survey contents of  recyclables  in waste
        stream.   Concrete  figures  are needed to entice vendor
        interest.   (Overhead 1)
        1.  Composite of EPA's three  HQ building sites
            a.  Paper by far the largest  is  73  % (weight).
            b.  Glass comes in 2nd at 11% (weight).
        [Overhead  2 is  a more visual representation  of these
        numbers]
        2.    [Overhead  3]  details  EPA's 1988 disposal  and
            recycling figures.
        3.   [Overhead 4]  details  FY 1989's—you can  see  the
            tremendous growth in our paper collection program.
        4.  [Overhead 5] gives current  FY 1990  statistics, we
            are currently 77% of last years collection figures
            (this does include the lower  grades of paper).

VI.  EPA's Program

     A.  Methods of Collection
        1.  EPA  Region  5 has a box  latched onto the  side of
            their waste bins.
        2.  EPA Region 7 developed the two-sort grey boxes.
        3.  EPA-HQ continued with the cardboard box.

     B.  Expansion of HQ Paper program
        l.  Three sorts
            a.   High grade
            b.   Low grade
            c.   Newspaper
                            816

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           2.   HQ adopted the Region 7 grey box—rationale.
               a.   small
               b.   asthetically pleasing
               c.   large enough for clear labeling
               d.    desire to  remove  "recycle"  image  away from
                    "garbage" image
           3.   HQ organized "central collections bins"
               a.   Rational for choosing plastic bins.
                    1.   durability
                    2.   strength
                    3.   Health and safety of Labor/Services
                        personnel.
           4.   Location of storage
               a.   Gaylords
                   1.   Size
               b.   Building and Fire codes

           5.   Marketing of recyclables
               a.   Paper—General Services Administration
               b.   Glass—
               c.   Aluminum—

       C.   Methods of  Procurement
           1.   In-House Printing
           2.   Agency  policy
               a.  Transmittal on Submission all contractor reports
                   on  recycled paper (1/24/90).
           3.   Working with the Joint Committee on Printing (JCP),
               the General Services  Administration  (GSA), and the
               Government Printing Office (GPO).

 VII.  Expansion  to include Glass and  metals  (D. C.  Solid Waste
       Management and  Multi-Material Recycling Act  of 1988).
           A.   Igloos  (provided by Glass Packaging  Institute and
               D.  C. Council of Churches).
           B.   Aluminum In-house program.

VIII.  Recycle—
       A.   Education
       B.   Collection
       C.   Marketing
       D.   Procurement
       E.   Monitoring  and Evaluation

Visual Aids:   Overhead graphs
               3-part  grey boxes
               1  red bin

Handouts:      EPA In-House Handout (Blue)
               OARM Recycling Update (White w/blue  ink)
                               617

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       FINANCING A RECYCLING PROGRAM:
          LANDFILL DIVERSION CREDITS

                 by Miriam Foshay
             Recycling Management, Inc.

                 Presented at the
                          s

First U.S. Conference on Municipal Solid Waste Management

                 June 13-16,1990
                      619

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                     FINANCING A RECYCLING PROGRAM:
                        LANDFILL DIVERSION CREDITS

                                  Miriam Foshay

       Whenever a municipality is analyzing the cost of a recycling or composting
 program, one of the factors it must consider is the amount of money saved by diverting
 waste from the landfill. This saving is called a "diversion credit," and it can often be a
 significant amount of money. If the municipality is providing both refuse and recycling
 services  with its own staff, then the city recovers this money directly.  But very few cities
 work this way.  Most either contract with a private hauler (who may or may not also
 handle the recycling or yard waste collection) or the citizens themselves contract with
 several different haulers. How, then, can a municipality recover the savings that comes
 from diverting waste from the landfill?

      The City of Naperville solved this problem in a unique way.  Refuse collection is
 handled by a single hauler in an exclusive contract with the city.  When Naperville signed
 its last five-year contract with its hauler, the local recycling center was beginning a pilot
 curbside collection of recyclable materials. Written into the contract was a clause
 requiring that after a period of one year, the hauler, the recycling center, and the city
would negotiate a rebate from the hauler based upon the volume of material diverted
from the landfill by the recycling center.1

      In this case, the refuse hauler acquires savings in many areas when waste is
diverted from his program. Every ton of material not collected by his trucks saves him
tipping fees at the landfill, but there are other savings as well: he makes fewer trips to
11 The text of the contract reads:

      39.  PILOT CURBSIDE COLLECTION PROGRAM
      It is understood between the City and Contractor that the City has entered into an agreement
      with the Naperville Area Recycling Center (NARC) in which NARC will conduct a Pilot
      Curbside Collection Program for collection of recyclable solid waste materials from certain areas
      of Naperville. Contractor agrees to cooperate and assist the City and NARC to evaluate the Pilot
      Program, and, if renewed or extended, the Contractor agrees to negotiate in good faith with the
      City to determine a reasonable reduction in the cost per stop per month charge in Section 14
      hereof.
                                      620

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the landfill, saving labor and vehicle costs; and he spends less time collecting trash,
saving labor costs. The negotiation between the City of Naperville, its refuse hauler, and
Naperville Area Recycling Center (NARC) yielded a three-part formula to calculate
each of these cost savings.

       Before we could develop a formula for a credit, we had to establish equivalent
values. For instance, refuse is measured in compacted cubic yards, but recyclable
materials are measured in tons. How many tons of recyclables equals one compacted
cubic yard of trash? For lack of a better measure, we agreed upon the value of three
compacted cubic yards to one ton which is used by the local landfill. In fact, this value
would depend upon what materials are collected: newspaper, one of the densest items,
might have a density of 3-4.5 cu yd/T, but plastic and corrugated have a much lower
density.^ This and other equivalency assumptions we made are listed in Table 1.
                                     Table 1
                                 ASSUMPTIONS

                1 ton = 3 compacted cubic yards = 12 loose cubic yards
                   one garbage truck = 25 compacted cubic yards
                     time to load one loose cu yd = 135 seconds
       Tipping fees saved. Having established that one ton of recyclables equals three
cubic yards of refuse, we can easily calculate tipping fees saved:

                                   Sj = 3 x (tipping fee/cu yd)

where Sj is savings per ton of recyclables collected.  As the tipping fee changes, the
value of Si also adjusts.
2Franklin Associates has just completed a study comparing density of materials in the landfill which
should be available soon from The Council for Solid Waste Solutions.
                                      621

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       Trips to landfill saved. In order to calculate trips to the landfill saved, one must
 know the volume of a garbage truck. The hauler's trucks all have a rated capacity of 25
 cubic yards. Therefore, using the 3 cu yd = 1T formula, every 8.33 T of recyclables
 collected would save one trip to the landfill.

       But what is a trip to the landfill worth? There are two factors to be considered:
             labor saved
             truck expenses saved
 Labor saved depends upon the average round trip time to drive to the landfill plus the
 average time to unload times the driver's wage plus payroll taxes. In this calculation,
 benefits were excluded because the refuse company maintained that the benefits paid
 did not depend upon the number of hours worked, so shaving a few hours of driving time
 would save hourly wages but not benefit  costs. In fact, the recycling program has grown
 so much that the refuse company's labor requirements have been reduced by nearly two
 full-time employees, which certainly produces a savings in benefits paid.

       Truck expenses saved relate directly to how far the truck must drive in one round
 trip to the landfill. Truck costs include fuel, oil and maintenance only. Depreciation and
 insurance costs were not included, because the truck accrues depreciation and requires
 insurance whether it is driven full-time or not. In fact, the recycling program currently
 replaces the need for two garbage trucks, reducing the capital outlay required of the
 refuse hauler.

      The savings for each truckload which does not go to the landfill (S2a) can be
 calculated as follows:

$2a - [(driving time saved)x(hourly wage + taxes + benefits)]
                                       + [(RT distance)x(truck cost/mi)]

In order to get savings per ton (instead of per truckload), this number must be divided by
8.33 T/truckload:
                                    622

-------
                            S2 = S2a/8.33 T/truckload
Trips to landfill saved (82) adjusts as labor and fuel costs change.

       Collection time saved was the most difficult figure to calculate. The hauler must
drive by every house whether the homeowner puts out trash or not; therefore, there is no
savings in vehicle costs. Is there a savings if the homeowner only puts out one bag
instead of two? Will the homeowner put out trash less often if he recycles? We finally
agreed to calculate how much time it took to load each bag of trash.

       First of all, the hauler collects loose material, not compacted. How many loose
cubic yards equal one ton? We established that a garbage truck compacts its load to
one-fourth of the original volume. Therefore:

             1 ton  = 3 compacted  cubic yards = 12 loose cubic yards

If we assume that the typical set-out consists of full 30-gallon plastic bags, then every 6.5
bags equals one loose cubic yard. It takes about 20 seconds to load each 30-gallon bag,
or 135 seconds per loose cubic yard. This amounts to about one-half hour per ton or
four hours to load one 25-yd packer truck.

       As above, marginal labor costs including benefits were not included in the
calculation; but since the labor savings amounts to two full-time employees, these costs
should have been included. Collection time saved (83) can be written as follows:

                  83 = (12 loose cu yd/T) x 135 sec x (labor cost/hrl
                                      3600 sec/hr

As for trips to landfill saved (82), collection time saved varies with labor costs.

       Items not covered. NARC collects certain items that the refuse hauler did not
include in his contract:  used motor  oil and white goods.  Analysis of NARC's loads
revealed that these two classes comprised 1.6% of the total collection by weight.
.Therefore, the total tonnage collected by NARC had to be reduced by 1.6%.
                                      623

-------
       The total savings accrued by the waste hauler (and payable to the City) can be
calculated by summing the above savings per ton and multiplying by the tonnage of
recyclables collected, adjusted for oil and white goods not included in the contract:

          Total savings = (tons of recyclables collected) x Fa x (Sj + 82 + 83)

where Fa is the adjustment factor for items not covered.

       Currently, tipping fees are $6.55/cu yd and the City receives about S35/T from its
waste hauler in landfill diversion credits. If this figure were adjusted for density of
materials, vehicle depreciation and benefits, it could be much higher.

       In Illinois and elsewhere, cities are negotiating with haulers not for a single trash
collection but often for three separate collections:  yard waste, recyclable materials, and
refuse. Whether they choose to contract with a single hauler to handle all three services
or with separate haulers, city officials should bear in mind the savings that a refuse firm
realizes when some of the material it formerly collected is diverted from the landfill.
This landmark contract negotiated by the City of Naperville establishes a precedent
which should help other cities to establish a similar credit from their waste hauler.
                                       624

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INNOVATIVE COMMERCIAL & APARTMENT
            RECYCLING PROGRAMS
                     Craig H. Benton
                     Planning Director
             Sound Resource Management Group, Inc.
    7220 Ledroit Court SW, Seattle, Washington 98136 • 206/281-5952
                      Presented at the
 First U.S. Conference on Municipal Solid Waste Management
                     June 13 -16,1990
                             625

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City of Tukwila Recycling  Pilot Project Summary
INTRODUCTION

This report summarizes activities undertaken by Sound Resource Management Group. Inc. (SRMG) in
planning, developing, implementing and evaluating a Recycling Pilot Project for the City of Tukwila,
Washington. The pilot project, conducted from June to August, 1989, was intended mainly to gather data
on commercial and apartment recycling within Tukwila, and to test the ability of Tukwila's primary solid
waste hauling firm to provide recycling services. A secondary purpose was to assess the feasibility of
operating a commingled system in which all recyclables are placed into one container for collection.

This document presents results of the quantities of materials recycled during the project, assesses participa-
tion levels, and analyzes costs and savings. It concludes with a discussion of some of the challenges the
City of Tukwila will likely face in implementing a full-scale recycling program.
ACTIVITIES

Summarized below are the activities SRMG completed to implement Tukwila's pilot recycling project

Planning
     •  Developed project plan.
     •  Selected the following two multi-family complexes and four commercial areas as pilot participants:
          1. San Juan Apartments, 6250 S. 153rd Street
          2. Canyon Estates Condominiums, 15138 65th Ave. S.
          3. Small Retail Mall, 16828 South Center Parkway
         4. Office Building, Southcenter Plaza, 14900 Interurban Ave S.
          5. Gateway Corporate Center, 12886 Interurban Ave. S.
          6. Small Manufacturer, Racon, Inc., 12128 Interurban Ave. S.

Development
     •  Obtained cooperation of property managers and owners.
     •  Negotiated pilot program terms with Sea-Tac Disposal Company, Inc. (Sea-Tac).
     •  Designed collection system (type of equipment, and size and location of containers).
     •  Developed instructional brochures and container labels.

Implementing
     •  Coordinated timing and placement of collection containers.
     «  Distributed instructional brochures to participants twice in the first month of the 3-month project.

Tukwia RecyeSng Pilot Project Summary
                                    626

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     •  Distributed deskside boxes to commercial participants.
     •  Coordinated activities with janitors when necessary.
     •  Modified a hand can for hauling cardboard for an office building tenant
     •  Wrote and distributed a news release to local and regional newspapers.

Monitoring & Evaluation
     •  Monitored garbage and recycling bins on a weekly basis. If excessive amounts of recyclables were
       found in the garbage bin, or if the recycling bin was contaminated with trash, then the appropriate
       business tenants or employees were revisited, talked to, and issued another instruction flyer.
     •  Photographed project and used pictures in a presentation to the Tukwila City Council.
     •  Developed and distributed a flyer, thank-you note and feedback form to participants.
     •  Produced a display map showing pilot project locations.
     •  Summarized data and findings (in  this report).
WEIGHT, VOLUME & COMPOSITION OF COLLECTED MATERIALS

The table below (Fig. 1) summarizes the volume reduction achieved by each pilot project participant and
for the project as a whole. The first column lists the pilot participants. The second column totals the weekly
garbage capacity of each participant by volume. The third and fourth columns list the size and hence the
designed weekly capacity for collecting recyclables. The fifth column estimates an average fullness factor
for each participant's recycling containers, based on Sea-Tac's collection route summary forms. The sixth
column lists the actual volume reduction each participant achieved, which was derived by multiplying the
design capacity by the fullness factor. The last column translates the actual volume of recovered waste (in
cubic yards) into a percentage figure that represents a volume reduction value.
 Volume Reduction Summary for Pilot Recycling Project
Fig. 1
Project
Participant
San Juan Apts.
Canyon Estates Condos
Retail Mall
Southcenter Office Plaza
Racon Manufacturing
Gateway Corporate Ctr.
Total
Average
Garbage
Capacity/Week
CUBIC YDS.
12
60
21
24
16
28
161
—
Recyclables
Capacity/Week
CU.YDS.
4
10
6
8
2
8
38
—
%
33
16
28
33
12.5
28.6
100
24
Fullness
Factor*
%
50
50
75
100.
75
75
—
—
Actual Volume
Reduction
CU.YDS.
2
5
4
8
1.5
6
26.5
—
%
16.6
8.3
19.0
33.3
9.3
21.5
100
16.5
 ; Based on Sea-Tac Disposal collection route summary forms.
                                            627
                                                              Sound Resource Management Group. Inc.

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Recyclables Collected by Tukwila's Pilot Recycling Project
Fig. 2
Collection
Date
6/20
6/27
7/4
7/11
7/18
7/25
8/1
8/8
8/15
8/22
• 8/29
Total
Average
Pounds
Collected
1,310
1.600
1,640
1.750
1,240
2,230
2,020
2.150
2,490
2,880
4,950
24,260
2,205
Lbs/CuYd
34.5
42.1
43.2
46.0
32.6
58.7
53.2
56.6
65.5
75.8
130.2
—
58.0
% Reduction
in Weight
6.76
8.26
8.46
9.03
6.40
11.51
10.42
11.01
12.85
14.86
25.55
—
11.4
                                                         Note: Percent Reduction in Weight is based on
                                                         19.375 Ibs/week of solid waste generated by the
                                                         six pilot participants. This figure was arrived at by
                                                         multiplying 155 cubic yards of solid waste collec-
                                                         tion capacity by 125 Ibs/cubic yard (supplied by
                                                         Sea-Tac as an average industry figure for volume-
                                                         to-weight conversion).
                                                                                The table and
                                                                          chart above (Fig. 2)
                                                                     shows the amounts of recy-
                                                                clables collected each week from
                                                          the six project participants. The data was
                                                     taken from the forms Sea-Tac Disposal devel-
                                               oped and used to record the amounts of recyclables
                                          collected from each participant as well as by the project as a
                                    whole. In summary, a total of 12 tons of recyclables was collected
                               during the entire project, amounting to an average of just over one ton
                         per week, and representing an average solid waste stream weight reduction of
                    11 percent. Weekly tonnage increased from week to week but varied slightly due to a
              mix-up in collection on July 18. The unusually large amount collected in the final week
         was due to the fact that all deskside boxes from offices were collected and emptied.

Tukwila Recycling Pilot Project Summary
                                          628

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The pilot project was designed to reduce solid waste volumes by 24 percent. In fact, because not all
recycling containers were full when they were collected, the pilot project actually reduced solid waste
volumes by approximately 16.5 percent

In summary, paper of some sort constituted about three-quarters of all material collected during the pilot
project This was especially true for the commercial participants, whose recovered materials included a
significant fraction of cardboard and mixed paper. The multi-family project recovered a mix of materials,
including cardboard, newspaper, glass containers, cans and plastic bottles.
COST/SAVINGS ANALYSIS

Sea-Tac Disposal completed a cost/savings analysis for each of the six pilot participants. (Attached to the
original report were copies of Sea-Toe's work sheets.) Their analysis indicated:
      1. The cost of garbage service for each participant prior to the recycling pilot project.
      2. The cost of the level of service offered during the pilot project
      3. The cost of service that accounted for the reduction in garbage service as a result of the amount of
        materials recycled during the pilot

Generally, solid waste collection costs increase when recycling services are added because additional con-
tainers and pick-ups are needed to collect the recyclables. But recycling can decrease disposal costs. A
break-even point occurs when savings from not having to pay for disposal equals the extra cost of provid-
ing recycling services. From Sea-Tac's data it can be estimated that the break-even point for recycling
services occurs when about 30 percent of the waste collected is recycled by volume. In other words, if an
apartment or business recycles less than 30 percent of its waste, the added recycling service will cost more
than the savings in dump fees, resulting in added costs. If a business or apartment complex recycles more
than 30 percent then the recycling program will cost less than the savings in dump fees, resulting in a net
savings. This break-even point can decrease if recycling containers are substituted for garbage containers.
 PARTICIPATION RATES

 Exact numerical participation rates are difficult to estimate for this project because apartment and business
 tenants shared a common recycling collection container, rather than each business or residential unit having
 its own container (as is basically the case with, for instance, single-family residential curbside collection
 programs). Participation rates in this project are therefore categorized as "low," "medium" and "high."
 Participation rates were evaluated using the following criteria:
      • How full the recycling containers and garbage dumpsters were over the pilot project period.
      • What materials were in the recycling container and garbage dumpsters. If large amounts of
        recyclables were found in garbage dumpsters, then participation in the recycling program was low.
        Conversely, if very few recyclables were found in the garbage, participation was high.


                                                                Sound Resource Management Group, Inc.
                                                629

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     • Regular visits to business and multi-family complexes. By visiting participants, SRMG personnel
       could determine if businesses were using their deskside boxes and whether apartment managers
       were working with their tenants. Personnel inquired about "how the participants felt the program
       was going." then used the feedback to make changes to encourage and sustain participation.

The following chart (Fig. 3) indicates the participation rate associated with each project participant:

     Recycling Participation Rates                      Fig. 3
Location
1. Office Building
2. Racon, Inc.
3. San Juan Apartments
4. Small Retail Mall
5. Gateway Corporate Center
6. Canyon Estates Condominiums
Participation
high
high
medium
medium
medium
low
1
       '///////////////////M^^^

In general, participation by multi-family residents was lower than participation by commercial employees.
The overall low participation rates for multi-family dwellers may be explained by the following factors:
     • They did not receive as much personalized one-on-one attention by SRMG personnel as did the
       commercial participants.
     • They did not receive a collection container for use inside their apartment units (the commercial
       participants received deskside boxes to collect office paper).
     • Apartment dwellers have little financial incentive to reduce waste because their garbage fees are
       typically included in their rent.

The point about apartment dwellers and financial incentives deserves further discussion. The pilot project
tested recycling in both an apartment and a condominium. In apartments, utilities are usually included in
the rent. In condominiums, most people own their units, and utilities (i.e., solid waste, water and sewer) are
included in an additional maintenance fee. It would seem logical that condominium dwellers or owners
would have a greater financial incentive to reduce and recycle than apartment dwellers. However, the pilot
project results indicate that there was less participation from the condominium dwellers than the apartment
participants. Thus, financial incentives alone are apparently not enough to get people to participate.
Manager involvement is an essential element to obtaining high participation rates.

Participation in the commercial projects was generally high because:
     • Convenient deskside boxes for collecting office paper were provided to commercial participants.
     • Janitors were often used to empty the deskside boxes and place the materials into the recycling bin.
       This made the recycling program even more convenient for some commercial participants.
     • The materials, mostly office paper and cardboard, were easy to separate at the source.
     • In some cases, the commercial participants had a financial incentive to reduce. This was the case
       with Racon, which paid its own solid waste collection bills.

Tukwila Recycling Piiot Protect Summary

                                           630

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Participation in the commercial projects was good overall, but there were also some low spots. Some man-
agers did not want to bother their employees with separating materials, since it was not part of their "jobs."
Others did not like the "big, unsightly" deskside boxes. Some participants ignored instructions for collec-
tion. For example, many businesses would not break down their cardboard because "it took too much
time." Unfortunately, the unflattened cardboard also filled the collection containers rapidly, at times
discouraging others from participating. Once this problem was identified and SRMG staff revisited partici-
pants, most cardboard was broken down by participants so that more materials could be collected.
SUMMARY: FUTURE CHALLENGES

Listed below are some of the challenges the City of Tukwila will face as it develops and implements a
citywide recycling program for apartment dwellers and businesses:
      •  Overcoming current throw-away attitudes and habits.
      •  Motivating renters and business tenants to participate even in the absence of a direct financial
        incentive. Or, developing a mechanism that provides a financial incentive for renters to recycle.
      • Making people aware of the solid waste disposal problem and about how to contribute to less cosdy
        and more environmentally sound ways of managing waste instead of burying it in landfills.
      • Working with the large number of actors or decisionmakers in apartment and commercial projects.
        For the commercial locations, cooperation from the property owners, building managers, janitors
        and business tenants is necessary for the project to be successful. This is opposed to working with
        just renters or owners of single-family homes who might participate in a curbside recycling
        collection program. For apartments, cooperation from the owner, manager and tenants is vital for
        the project to have any significant impact
      • Integrating legislative, educational and technical assistance activities with  a citywide collection
        program to maximize participation and waste reduction.
  PROMOTIONAL MATERIALS

  The following pages contain reduced images of promotional materials developed for this project, including:
       •  The pilot project collection container label and instruction sticker.
       •  Instructional flyer that was handed out to all project participants. (Not shown are all variations
         which had different site maps and slightly different text)
       •  Participant thank-you note and response card.
                                                                 Sound Resource Management Group. Inc.

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   RECYCLING
            ONLY
Fig. 4: Collection container identification label. Red on white vinyl. (36' x 18")
 Commercial
 Recycling
 Service
               Recycling Bin Instructions
            PteOM put only tto Mowing W*d md*riol* into th« recycling collection container.
            tyou ho»» CTiy <3J9*torv about r«cycQ off^r riaj«««ji not fat«d >*•*•.
               o> carryng ytxr wcyctaD*!. cai you Cx*dng mcrv^M or S*o-Toc Otootd.
           ALL PAPER CARDBOARD  CLASS   METALS  PLASTICS
torwnow* al
   toad

  toMHtmon
                                   » Slyn^ovn cux md

             DQ NOT put the following materials Into the recycling collection bin:

           Liquids • Food Waste • Waxed Paper Products • Fabrics • Wood • Styrafoam
Fig. 5: Collection container instruction label. Red on white vinyl. (15* x 10")
Tukwila Recycling Pilot Project Summary
                   632

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        W bated. •» vdl •• •
                       (Xl*« map
                        Oudc (mud
                 SISOTiSt
      I
      I
• PIT
 hoU hu»nh>u» >ue. csD the Sade-Kxc County
 Dcpvtnmt c< Public Hutth Hm4» Uae •> ICT-sa
                                                       CITY"  OF TLTKW7LA
                                                        PHOT RECYCLING PROGRAM
                                                        Owner1! Guide
   Apartment &
   Commercial
   Pilot Recycling
   Project
                      T
                    fir rmj *JTHnata > jilmitrt m

                    0«K uffl »ffer raey
                      •ucrf ronmngtedl racydofeit mottrtolj
                      uMOi iteyvt nOMcd to bun «r bojx Mo a
                      floe* of biomen. The ofUncra ud be
                                   Mart •njkwl. IBSm
                      irfT Imrfa flff ilnil TV n » iTtvcBnj bn. Dm MM
                                                                     TteJUbuto; e*K«  utat mnuto uffl be
                                                                     In Ms pn^ram mi taw Ouy rtajd te pnpa
                                                                     tfiey areput Mo the ecrtfral caOecdon CDrOMne
                                                                                    1. farrlfmi mrf Ay
                                                                                   da not
                                                                                                x  • F«Ww • Wood • Stra
Fig. 6:  Instruction flyer delivered to all pilot program participants: outside (top); inside (bottom). Six
versions printed. Black on blue paper. (11" x 8-1/2*)
                                                      633
                                                                        Sound Resource Management Group. Inc.

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     •out) aVaaiaMrad, or MM my comma/is you on.
                    (WJon*j-
                                                           c/rr  OF  TC/KWILA
                                                            HLOT RECYCLING PROGRAM
                                                                        D**i Pi« PTOIKI Partcpam.

                                                                        The City of Tukwb would »• to
                                                                        thank you lor pancpimg n our
                                                                        3-montn p*x racyctng protect w«
                                                                        v»ra aw* to iMm • futeantial
                                                                        amount atmut racydng in our dry.
                                                                        and am gong to be uuig ths ntor-
                                                                        mxnon to maw o*oa«xts nan yaar
                                                                        about now to ntaoran racyding nio
                                                                        our tutura iokd wasia mmagatnam
Tna racyang cantamrfs) that ow*
instakM at your location wil t»
ramovK]«tn» and of August, and
your gart>ag« vanno* «n8 ratum to
•hat t wa» bBlora Bin preset
began Houwvvr. ( you oouU *« to
contnua racychnrj. you may can
1 -80O-R£CYd£ to Und out wtwra
Bwn ar» ncyotng opporlundM in
yourama-

Snowaty.
Th« City of Tukw«a
                                                                         THAWS POR PMTKtPXnNG!
Fig. 7:  Thank-you note and response card: front (right); back (left). Black on yellow paper.

(5-1 /2'x 8-1/2")
Tukwila Recycling Pilot Project Summary
                                                         634-

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INTEGRATING CURBSIDE COLLECTION COST-EFFECTIVELY
                      Ronald A. Perkins
                  Waste Control Systems, Inc.
                       Presented at the

    First U.S. Conference on Municipal Solid Waste Management

                       June 13-16, 1990
                           635

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        INTEGRATING CURBSIDE COLLECTION COST-EFFECTIVELY
                               Ronald A. Perkins
                           Waste Control Systems, Inc.
 INTRODUCTION

 Municipal officials nationwide are confronted with increasing competition for limited tax
 dollars. Recycling advocates should not take for granted that taxpayers will always look upon
 curbside collection programs as sacred and untouchable. (Although environmentally uncon-
 scionable, solid waste management programs can exist without recycling.) Thus, those of us who
 are responsible for the design and operation of curbside collection systems must continuously
 search for more cost-effective ways to do our jobs. This presentation purports to provide the
 audience  with some proven techniques to achieve the objective of integrating collection of
 recyclables cost-effectively into existing refuse collection systems.

The ideas promulgated here are based upon the presenter's successful operation of curbside
programs over the past five years. "Success" here is measured by waste reduction achieved and
program cost; in this case 23-31 percent reduction and a positive economic impact on the total
solid waste management program. The particulars associated with these programs are set forth
in Table 1.
                                    636

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PURPOSE OF PRESENTATION

1.     Identify aspects of system design critical for cost-effectiveness.

       • Political and municipal administrative support.
       • Maximum convenience for residents within limits established by market con-
        straints.
       • Integrate operational plan to maximize positive economic impact on total solid
        waste system.
       • Identify optimal equipment/crew size, policies and collection frequency using
        simulation models.
       • Adjust refuse collection system resource requirements (equipment/labor) to reap
        rewards of refuse volume reduction.
       • Monitor refuse/recyclables ratio and adjust resources accordingly.
       • Provide feedback to public for positive reinforcement.

2.     Provide useful tips/based upon "real world" operational experience.

       • Give strong consideration to collecting corrugated; high volume/weight ratio
        positively impacts refuse density and landfill space usage. (There's more than you
        think!)
       • Whenever practically possible consider collecting one material (either source
        separated or commingled) at a time to allow utilization of conventional refuse
        collection equipment. This increases collection rate and ability to  swap trucks from
        recycling to refuse routes.
                                      637

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       • Collection of a single material at a time also totally eliminates problem of under
        utilizing full capacity of truck which occurs in multi-material collection when one
        bin typically fills before other.
       • Simulation models can be used to accurately estimate collection rates and corre-
        sponding crew and equipment requirements.
       • Do NOT believe equipment salesmen; visit existing systems for truth/problems.
       • Investment in equipment operator training is well worth it. The biggest budget item
        in collection of recyclables is labor; therefore state of the art equipment (stand up
        dual drive; mechanical loading) is worth the investment.

3.     Stimulate program planners to give sincere open minded consideration to com-
        peting ideas, policies and techniques and TRUTH.

       • Can materials be added/deleted which will have a net positive impact on total
        system costs?
       • Are our collection vehicles consuming more energy than they are ostensibly saving
        due to too frequent collection?
       • Can we justify making collection of recycling a "jobs" program?
       • What are the true costs of my program?
       • Could the program be operated more cost-effectively  by municipal crews or private
        contractors?
       • Are our publicized participation (% of households), productivity (households
        serviced/hr), and diversion (% of municipal waste stream) rates truthful?
                                      638

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CONCLUSIONS
        Curbside programs can be implemented at no extra cost to a municipality if



        properly integrated into existing solid waste management systems.



        Unbending adherence to the goal of minimizing labor is essential to attain program



        cost-effectiveness.



        Everything else being equal, commingled programs will achieve higher waste



        reduction rates than those "inconveniencing" residents by required "separation



        work".



        Program designers and managers must remain totally open minded to new ideas,



        policies and techniques which will increase program impact and reduce program



        cost.
                                       639

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TABLE 1.


Recyclable Material Curbside Collection Program
Operated by
Waste Control Systems, Inc.

Population
Households
Program Cost
Material Collected
Annual Tonnage



Cost per ton collected
Collection Frequency
Average Participation

E. Longmeadow
13,000
4,000
60,770
Mixed paper
1,000
Bottles/cans
285
_ _

$47.29
Once/4wks
90-95%
Municipality
Longmeadow
16,000
5,200
80,040
Newspaper
1,300
Corrugated
260
- .

$51.31
Once/2wks
90-95%

Montague
8,000
2,600
41,600
Newspaper
416
Corrugated
• 80
Clear Glass
80
$61.54
Weekly
50-60%
Waste Stream Reduction
     31%
    23.5%
         17%
P.RTEducation Budget
    <$500
    <$500
        <$200
Enforcement
Recycling coordinator
  Mandatory


     No
  Mandatory
     No
      Voluntary
         No
Collection Equipment
Sideload packer
   RH drive
   17 cu. yd.
Sideload packer
   RH drive
   17 cu. yd.
Specialized recycle truck
       RH drive
      31 cu. yd.
Collection Crew Size
                                              640

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"INVOLVING THE CORPORATE CITIZEN IN RECYCLING"
                   By Dale  Gubbels
         Resource  Integration  Systems,  Ltd.
                    Presented  at the
 First U.S. Conference on Municipal Solid Waste Management
                   June 13-16,  1990
                         641

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      With rare exception,  communities  rushing to implement
 recycling programs  immediately  set out  to  target  the  residential
 sector.   There are several explanations,  but  I suspect a major  reason
 is that  we have been conditioned to accept  that people  are  the  root
 cause of the  garbage problem  and therefore, we must  seek  them  out
 in their  burrows to  make them recycle.     Of  course, ultimately it is
 the individual  who  must be taught to  recycle, but  I think the issue ~
 and thus our responses  to solve  the problem ~ require  us to
 scrutinize  in  what capacity  and  exactly  where individuals are
 contributing to  the waste stream.   Given that   perspective,
 government ~ local, state and federal ~ would be better advised  to
 first target the corporate citizen  before  targeting citizens  in their
 homes.
      There are  numerous reasons  for this  suggestion.   An  important
 one  surely is that the American  workforce  generates  a  lot of waste.
 I'll come back to that in a second, but I  want to stress that  an  even
 more compelling justification  is  that unless  the private  sector  adopts
 packaging  and  product  design parameters which adhere  to  the
 hierarchy of resource conservation, those objectives will  never  be
 achieved  fully.
      I  think  anyone who has  dealt with the problems  of finding
 markets for the recyclables  they  collected, or has  had to  cope  with
 contamination restrictions  which  result in belying  any  claims that a
 material  is recyclable, will  agree with  that view.    Therefore I  won't
 dwell on  why we should  target the private  sector  in recycling
 programs, but  rather I  prefer  to  relate some examples  as  to how
 governments  can and have  accomplished that  goal.
       But first, referring back  to  the waste reduction  potential by
focusing on nonresidential wastes, our experience at RIS  is  that most
communities  will find that 40 percent and  higher  of what enters
their local waste disposal systems  comes from the
commercial/industrial sector.  This can include  offices,  stores,
institutions, factories  and construction demolition  wastes.
                             642

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      Let me give you  a little personal perspective on  that point.   For
Earth Day,  our office participated in a  contest with RIS's other three
offices  to see  which one could achieve the greatest  landfill  diversion
rate.  We weighed all of our office's trash -  there were  14 of us  ~
for a week.      We practice waste  reduction  and reuse strategies ~
such  as  copying all  internal forms and  communiques on the backs of
discarded documents,   making  scratch  pads  from  used paper,
providing mugs rather  than disposal  cups and using  a cloth towel
linen service for  rest rooms ~  so I suspected our numbers were  not
typical.
      With  these  practices, we  generated a per  person weekly
generation rate of 3.12  Ibs, a weekly total of  43.7  Ibs.  That  compares
quite favorably with the National Solid Waste Management
Association's typical  office  estimate of  1  Ib.  per 100 square  feet per
day.   Based on our office square footage and NSWMA's estimate,  we
would generate 100  pounds of  garbage per day.
      Of our office's waste stream, a little less than half  -- 17  Ibs.  -
was high grade paper.     Low grade paper, corrugated  and
commingled recyclable  containers accounted  for another  12.5  Ibs.
Kitchen  wastes were another 8.7  Ibs.    Because  we have markets and
an  on site compost  bin,  we were  able to divert all  of the above,
leaving 5.5  Ibs. of mixed  waste for an  overall waste diversion rate of
87.4%.    I  should add that we won the competition.
      But not  all  businesses are likely  to  be  as psyched  for waste
diversion as a recycling  consulting firm.  But with the right  types  of
incentives and direction provided by the  local waste authorities  — in
some cases, shoves and heavy  sticks  — the  business community will
respond  very  favorably  to waste diversion.
      Actually, I  think   the  communities which have  developed
commercial  recycling programs are  usually  pleasantly surprised  at
how well received recycling is by businesses.   In  fact,  one of the
major reasons  I believe they should be targeted  before  tackling the
residential sector  is  that commercial recycling can be  much  easier to
implement.
                                643

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       Most businesses will gladly cooperate with  recycling programs;
 the savings  from avoided  disposal costs alone  are  very tangible
 incentives,  plus  firms can enhance their public  image  and employees'
 morale.    Allow me to share a few anecdotal examples.
       Broome  County in south central New York has established a 44
 percent waste  reduction goal by 1992.   One  of  the  first things it did
 to  achieve that goal was to  raise  its landfill  tipping  fees which had
 been supported in  part  by the general  tax  base and  also did  not
 include provisions  for closing and monitoring the site.   Consequently,
 the fees went  from $12 to $38 per ton.    A three hundred percent
 disposal fee increase  got a lot of people's  attention.
       One person's whose attention  was grabbed immediately was
 the grounds  manager  for a local factory.  His annual disposal costs
 could  have easily  increased by  $160,000.    To  this  gentlemen's and
 his  company's  credit,  he had contacted  us  to help  develop  a recycling
 strategy prior  to even learning of the  county's intentions.
      The  next thing  the county did  was to  pass  an ordinance
 banning certain materials  from  the landfill,  beginning in December
 this year.   The materials  include:
      • suitable paper  products
      • recyclable  metal, plastic and glass  food  and beverage
        containers
      • large  appliances
      • yard wastes,  including leaves,  grass  clippings  and  brush
      • demolition  debris
      • tires
      • wet  and dry  cell  batteries.
      The  disposal  ban may not  necessarily  mean that these
materials must be  recycled at the source by  the generator.   For  some
materials, such as  tires and demolition debris,  the  generator  may
simply pay a premium above the  tipping fee at a disposal  facility for
certain  discarded  materials  that the  county  may  later attempt to
recycle.
                                644

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      The legislation covers  the commercial/institutional  sector  as
well as  the  residential  sector.   Since commercial/institutional solid
waste  constitutes approximately  half  of the county's total  solid  waste,
the waste disposal  practices of this  sector  will be  targeted, and
companies can  expect to encounter greater scrutiny.  The county is
anticipating  an  "adjustment and  education" period  of one  year,
during which time  violations  will not be  subject to  enforcement and
penalties.
      The county has hired a  staff person  to work directly  with  small
businesses to help  them  locate  markets and  meet  the  new
requirements.    It has also contracted  with us to hold a  workshop
this  fall  for further technical  assistance.
      The city of San Jose, California, was one of the first
municipalities to hire  a full-time  staffer to provide  technical
assistance to local  businesses.    The  city provides a  free inspection  —
or waste  audit  -- to businesses.    These onsite  visits are  a very
practical  and cost  effective means  to motivate  businesses to recycle.
States, also  offer advise and  information to businesses  for  little or no
charge.   Rhode Island  is a very good example,  and I will  touch on it
again  in  regards  to its legislation requiring businesses  to  recycle.
      One means for encouraging a  win-win situation  for  businesses
and  local waste authorities intent  on waste reduction would be for
the authority to sponsor  a loan  program whereby it  would  pay the
up front  costs  for  any  business  wishing to implement a recycling
program.    Balers,  carts, crushers --  consulting services ~  would  be
just  a  few examples of some of the types of expenses eligible for
coverage.
      The repayment for these loans could  be  accomplished by
adding the charge  to the  businesses  tipping fee.   Where private
haulers provide collection, the  waste authority  could compensate  the
private haulers  for  serving as  the collection agency by giving them a
small  percentage for facilitating the transactions.
                                  645

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      Once the recycling effort  is up  and running, the business should
 experience a drop in its disposal fees.    That  savings  would be
 applied towards  the  repayment  of the loan.
      The initial seed money for starting the  loan program could be  a
 number of sources:
      • a  tipping fee surcharge to finance recycling programs
      • state grants (not just recycling or solid  waste, but economic
        development and  energy  agencies' monies  should similarly
        be sought)
     . • foundations
      • bonds
      • businesses and  trade groups  themselves
      • banks  and lending  institutions.
      The latter  ones may  strike some as bordering on the  ridiculous:
 why  would banks  want to  help  fund  recycling  programs?
      For  sound  economic reasons I assure you.   If  a  business  can
 show that it will reduce its  operating  costs by recycling and reducing
 its  wastes, why  wouldn't a  bank consider putting  up some of the
 money?    If the local  landfill  authority agrees to collect payments
 and assist in  finding markets for participating businesses, it seems
 plausible  that  given  such assurances  for  repayment,  the  lending
 industry  would see the  merits  of providing gap measure  funding.
      I mentioned  Rhode  Island's legislation.   It  requires  that
 businesses with  250  or  more employees develop  recycling plans for
 the state's  approval.     Maine has similar legislation, but in  Rhode
 Island, the state  also will  serve  as  the  market  of last resort.  That is
 to say if a hauler can't find   ways to market the office paper, OCC and
 other recyclables  targeted by the state, the materials  can be  disposed
 of at the  state's Materials  Recovery Facility in Johnstown.   To date, no
 commercial wastes have had to  go to  the facility.
      Let's focus again on what local jurisdictions can do,  because,  in
 spite  of what many  may think, this level of  government  can  garner
significant contributions and support from the private sector  for
solving the solid waste problem.

                                  646

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      Since markets  are  the  foundations  stones  of  any recycling
program,  local jurisdictions  should  diligently  pursue  strategies which
identify and strengthen outlets  for  their collected materials.    Again,
the private  sector  should be viewed as partners in  that effort.
      We generally recommend  to  our  clients  that  they  form a
market  development committee  whose  members would  include
representatives from  both private and public sectors.   Their charge
would be  to  review and continually recommend measures designed
to increase the recyclability  and marketability  of  the area's waste
stream.   Both area government and private sector  practices should be
reviewed  by  the  committee.
      Deanna Ruffer will address the importance of involving  local
recycling  firms  in  a  community recycling  plan, but  my focus includes
those businesses not necessarily involved in the solid waste industry.
      Prime  candidates for serving on  the  committee  are local
brokers  and  end users  of recyclables,  but I think it just  as  important
to include the large  and small  generators of solid  wastes, bankers,
and  public  relations  firms  and  any  other  business that has a genuine
interest to help find or  improve local  markets.
      I  alluded  earlier  to one reason why these firms would want to
get involved  ~ enhanced company  efficiency  — but then there  are
important  considerations.
      In these days  of heightened public concern for  the
environment,  everyone  seems to be jumping on the recycling
bandwagon.  Let's  face it, the environment help sell  soup  to nuts.    I
don't think  we need  to dwell on why the private sector is  getting
involved;  I think  we should  just be thankful that  they are.
      Some examples of the objectives, questions and issues  which
the committee should address   include:

•   Reviews of government  procurement  practices.

    Is stationery printed  on recycled paper?  Are  public parks using
    compost?    Can  the  bids that are let for road construction  projects

                                647

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require the use  of reclaimed asphalt,  glassphalt, rubberized
asphalt, and cellulose mulches and compost for right of way re-
sodding?  Do bid specifications for traffic signs and barriers
require the use recycled plastics?   Do county-sponsored  energy
assistance  programs  encourage the use  of cellulose insulation?
Can the bid for printing  of public notices specify that they be
printed on recycled paper?

Encourage local  businesses  to use  recycled products.

Could area manufacturers  replace  primary  resources  with
secondary  resources  (recyclables)  in  any  of their  operations?
Examples  include modest low-tech efforts  such  as using  shredded
mixed paper or reclaimed  plastic  "peanuts" for packaging,
retrofitting  equipment —  e.g., plastic injection  molders  —  to  use
recycled  resins.

I think we too often forget  that recyclables  are  resources and  that
our  local businesses themselves  use resources.    An inventory of
their needs and your community's ability  to  fill  those  needs with
its reclaimed resources  is a natural.   In Broome  County, a local
landscaper set  up a  composting operation to handle its yard
waste.  It soon began helping other  businesses by accepting their
food processing  residues.

Work  with economic development agencies  to encourage market
development  opportunities.

Chamber of commerces,  local, regional  and state economic
agencies,  utility  companies  and  business associations are  all
potential allies.  Do they  understand  that  your  community's
recycling  program  will  be "mining" resources  which industries
need?   Perhaps  these  agencies  would  sponsor market  research
                             648

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    efforts for various troublesome  materials, such  as  tires or used
    oil.

Financial  Commitment

      These  efforts  need not be  costly.   For example,  advising
vendors  of one's  preferences for recycled items may in and  of itself
lead to options for  purchasing less  expensive products.    Some
agencies  have found  in  their  review of procurement practices  that
bid specifications required all products  be  made  of "virgin  materials."
This  stipulation  often reflects outdated  prejudices  based  on
misinformation.
      Further support  for using  recycled products  can be  shown  by
stipulating  that  procurement  agents purchase  recycled items  even
when their costs  exceed  that of  virgin products  made.  Five  to  10
percent price preferences are used  by several jurisdictions.  One way
to  give  such products preference,  but demonstrate fiscal
responsibility,  is  to dedicate  the revenues  from office paper recycling
programs to offset  the price  difference for using recycled paper.
      The purchasing  power  of  governments  and businesses can  be
applied even more  directly to secure markets  for  their  recyclables.
For example, oil suppliers for the  county's vehicles could be required
to  accept the county's used  oil.     Similar  stipulations could  be  made
for asphalt removed  as  part of  road work  and construction
demolition/   Several  of the firms  we developed recycling plans for
adopted  this recommendation, with  excellent results.   One client in
particular  found  that  its vendor  not only willing  to start hauling back
its  empty  plastic spools, but it could rebate  our client since  the
vendor was  allowed  to reuse the item.
      The voluntary  nature of your local  committee  assures that the
only  tangible costs  for the effort would be  administration costs for
coordinating  the committee's  meetings.
       I  should  point out  another major reason for businesses to want
to  get involved locally in this issue, and it  ties  back to the point

                               649

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 concerning  the design for recyclability.    Industry is  getting involved
 in  recycling like never  before  for fear that they may otherwise be
 banned from the  marketplace.
      Contra Costa County, California  has  a plastics recycling
 committee,  the  members of  which  include  representatives of Proctor
 and Gamble, Del Monte, the Council for Solid Waste Solutions and
 Dow.   These businesses are highly  visible in the area and they are all
 good corporate citizens,  but I don't  think anyone is so naive to think
 that the county's review of legislation to  limit  non-recyclable
 materials  did not motivate these firms to  action.

      I am  not  recommending  that communities threaten  anyone
 with bans, fines, taxes or  any other  punitive  actions.   Far  from it.
 Gaining attention with bans  is  one  thing, but I think there are  only so
 many times  you  can throw a  brick  through  a window before you  are
 labeled  a  vandal.    I  think industry has gotten the message  to  get
 involved in recycling.  Now  society needs to develop constructive
 ways to  channel industry's involvement.
      Some positive examples  for how companies  might collectively
 get involved exist already.    In the  Northeast, the Coalition of
 Northeast  Governors' Source  Reduction Council  created  last
 September is an excellent  example.    Representatives of major
 industry and nonprofit organizations  has joined with CONEG, a nine
 state regional group of governors, to focus on the  means  to reduce,
 minimize, return, reuse, refill and  recycle  packaging.
      Across our border  to  the north, the  Ontario Multi-material
 Recycling Industries,  OMMRI, is a program funded solely  by the
 private sector to  help  Ontario achieve its 50% waste diversion  goal by
 2000.   OMMRI's initial members are  Ontario Soft  Drink Association,
 the Grocery Products  Manufactures, the Ontario Printing  Papers
Users Group, the Packaging  Association,  the Council of Grocery
Distributors  and the Society of the Plastics Industry (all of Canada).
Its  goal is to take  a proactive, cooperative stance with the
                               650

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government to achieve  the opportunity  to  recycle for 80% of all
Ontario households by  1995.
      It intends to invest $45  million over the next  five years,
making this  money available to  local municipalities  on  a matching
grant  basis.
      A  similar group has formed  in  Europe ~ the  European
Recycling and Recovery Association.   It is studying the OMRRI
system as  its model of operation.
      Back in this country, such cooperative coalitions  have  been
slow, to develop, but  the makings of such efforts are there.   Witness
EPA's and the National Recycling Coalition's formation of the
Recycling Advisory Council.    While its  purpose  is advisory, I have
hopes that, because this group  involves major CEOs   and top
environmental and public sector  leaders, it can be the  genesis for
much  more  tangible support for recycling  than the  advisory  role  it
has currently adopted.   If not  the  RAC itself,  surely it  will be
exposed  to  the idea  for  a  broad,  multi-faceted  and  multi-material
coalition of  industries  which works  for  a common goal  to bring about
sensible  recycling,  and resource conservation  policies.
       If  the  RAC doesn't discuss this  idea,  perhaps you  can put it  on
the first agenda of your  local business and industry recycling
committee.
                                 651

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LOCAL GOVERNMENT RECYCLING PROGRAM DESIGN
        INTEGRATING EXISTING RECYCLERS
           Deanna L. Ruffer and Susan Schaefer
                  Roy F. Weston, Inc.
                 6021 Live Oak Parkway
                Norcross, Georgia  30093
                     404/448-0644
                     Presented at

 First U. S. Conference on Municipal Solid Waste Management

                    June 13-16, 1990
                        653

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Abstract

Markets are essential partners with local governments in recycling programs.  While
local governments typically  focus on  determining what markets exist,  too  often, the
existing capability of local  recyclers  has been overlooked.   As a  result,  recycling
programs are designed and,  in many instances,  material recovery facilities constructed
when they may not be needed, costing both time and money, and ultimately competing
for the materials that have kept private recyclers in business for many years.

While typically it will be unlikely that  existing firms will be providing the materials
collection  services  needed  for  many  local  government  recycling  programs,  the
consideration of existing recyclers to address processing requirements of the recycling
programs can be crucial to the successful, fast track development of recycling programs.
Local recyclers can, if considered, be valuable partners with local governments and
provide an  important component to  successful municipal recycling  and composting
programs while  at  the same   time  saving   the  municipality  capital  costs  and
implementation time.

This paper focuses on the questions about capacity, capabilities, and project interest to
consider when  assessing local  recyclers.  Discussion is given to approaches to use in
"winning" the support and cooperation of private recyclers given a natural reticence to
share business information.   Ways to  begin  fostering relationships between local
governments and recyclers early  on in the program planning and definition  process is
examined.  An outline  of practical information to request in an RFP  which gives
preference to existing local recyclers yet seeks certain guarantees of service is presented
based on experience with both local governments and processors.  Contract provisions
with a single  processor processing materials from  multiple programs and multiple
jurisdictions (i.e., curbside,  drop-off,  commercial, etc.) and equitable  treatments  of
multiple recyclers is discussed.

All of these ideas are brought together in an innovative approach of demonstrated
success. Benefits can include relative ease and timeliness of implementation, low capital
costs, relative ease to manage, program flexibility and a spirit of cooperation with the
private sector and local  business community. All of these are crucial to the success of
local government recycling and composting programs in an integrated approach to solid
waste management.
                                     654

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                  Local Government Recycling Program Design
                          Integrating Existing Recyclers
 I. Introduction
 n. Private Sector - The backbone of recycling efforts

   A.    Family Affair

   B.    "Brokers" "Dealers" and "Processors"

   C.    Independent Entrepreneurs

         1.     A strength
         2.     A weakness


III. Local Government - The new kid on the "recycling" block.

   A.    Mandates, Goals and Policies

   B.    The Results

         1.     Surveys
         2.     Curbside, MRFs, etc.
         3.     Markets?


 IV.      The "fit" with private sector.

   A.    Services Needed

   B.    Government Partnerships

   C.    Contractual Requirements

   D.    Costs and Implementation


  V.     Identifying Capabilities

   A.    What to look for
                                  /
   B.    How to get information, support and cooperation
                                     655

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                   Local Government Recycling Program Design
                          Integrating Existing Recyclers
   C.     Realistic Assessments

   D.     Fostering relationships early

   E.     Public-private partnership foundation building


 VI.      Contracting for Services

   A.     Structuring the  procurement

          1.     Separation of responsibilities

                       collection
                       processing
                       material/revenue

          2.     Preferential criteria without sacrificing

                       reliability
                       cost of service
   B.     Providing for

          1.     Security
          2.     Control
          3.     Flexibility
   C.     Monitoring provision of service


VII.       Benefits/Weakness

   A.     Entrepreneurial spirit/reticence to share information

          1.     During information gathering
          2.     During procurement
          3.     During contract

   B.     Ease and timeliness of implementation
                                     656

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                   Local Government Recycling Program Design
                           Integrating Existing Recyclers


   C.     Costs

   D.     Program Restrictions/Flexibility

   E.     Spirit of Cooperation

   F.     Responsibilities matched to capabilities


VIII.      Conclusions


   A.     Not for everyone - but should be considered by  all

   B.     Needs to be thoroughly thought out and contractually defined

   C.     Integration/partnership "attitude" is critical to success

   D.     Early identification of capabilities 'and program monitoring are critical to
          success
                                      657

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        MAKING  IT  WORK:   TRENDS FOR HANDLING LANDSCAPE  WASTE  IN ILLINOIS
                                       by
                       Deborah  Havenar and Allen  Bonini,
           Illinois  Department  of Energy and Natural  Resources (DENR)
                325  West Adams, Room 300, Springfield,  IL   62704
          (Session:   Recycling  and Composting  - Composting/Yard Waste)
In Illinois, landscape waste is  generated at an estimated annual  rate of
nearly 2.8 million tons.   By law,  landscape waste,  which  includes leaves,
grass clippings and brush, must  be diverted from landfill  disposal by July 1,
1990.  Management alternatives to  be in compliance  under  this  new law include
composting and agricultural use.
The Illinois Department of Energy  & Natural Resources  has taken  the  lead in
providing technical and financial  assistance necessary to carry  out  composting
programs in communities throughout Illinois.  To date, over 100  local and
regional landscape waste programs  are well on their way in an  effort to meet
the landscape waste challenge.
Close to $5 million will be used to assist these programs through grants which
can be used for equipment to collect landscape waste separately  from refuse
and also for compost facility equipment that process landscape waste into
finished compost.  Emphasis is placed on funding those programs  which provide
a comprehensive approach to managing yard waste - collection,  composting and
marketing.
Valuable information can be obtained from funding composting programs.  Trends
can be identified  in all aspects of the composting process.  Among  the  trends
are collection schemes in a rural  setting vs. a metropolitan area.   Also,
which composting  technology - high, medium, or low -  is most appropriate for a
particular area?   Finally, what are the most viable markets for the  finished
compost  -  giveaway programs vs. bag & sell  programs;  residential markets vs.
commercial  markets?
                                      659

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          MARKET DEVELOPMENT AND BUYING RECYCLED PRODUCTS;
                 PROSPECTS FOR THE 1990s

                        Richard Keller
       Northeast Maryland Waste Disposal Authority
                    Presented at the

First U.S. Conference on Municipal Solid Waste Management

                    June  13-16, 1990
                            661

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                   MARKET DEVELOPMENT AND BUYING RECYCLED
                    PRODUCTS:  PROSPECTS FOR THE 1990's
                      RICHARD KELLER, PROJECT MANAGER
                NORTHEAST MARYLAND WASTE DISPOSAL AUTHORITY
   Recycling involves three distinct steps: collection, manufacturing and

use.  These steps are represented by the three arrows in the traditional

recycling symbol.  The three arrows must be in balance if we are to fully

realize recycling's potential for waste management, energy conservation and

resource conservation.  Merely collecting recyclables is not recycling.

Recycling does not occur until a product made from recycled materials is

actually used by a final consumer.



   In order for the United States to achieve maximum recycling in the

1990's, state and local governments must make sure that markets are

available to absorb the new supplies.  For some materials, markets will

naturally grow as new supplies become available.  For other materials, the

public and private sector must work together to promote growth in

industries that can rely on secondary materials in their production

processes.



   State and local governments must be concerned about existing and future

markets for recyclable materials.  We must take steps now to plan for

future markets.



   One of the most important roles that public officials can play in market

development is to ensure that materials collected are clean, separated and
                                   662

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meet industry specifications.  They should also let potential markets know




about the timing and availability of new supplies.








   There are a wide variety of market development tools available to public




and private agencies to increase the markets for recyclables.  The majority




of these tools are activities that must be undertaken by the state and




local economic development agencies.  Recycling must be understood as an




economic activity, not as an environmental activity.








   The National Recycling Coalition has recently adopted a policy regarding




market development.  The policy emphasizes the importance of reliable




markets and the need for public / private cooperation to expand markets.




The policy includes the following market development instruments:








   *     material processing facilities;




   *     contracts between suppliers and manufacturers;




   *     economic development programs  (including financial assistance and




         assistance with facility siting and permit review);




   *     regional cooperative brokerage and transportation management




         programs;




   *     preferential  procurement of recycled products;




   *     information and research programs  (such as information




         clearinghouses, and public, private and university R&D consortia)




         to  develop new recycled products and expand the use of recovered




         materials  in existing products;
                                   663

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   *     investments in transportation infrastructure and marketing




         programs to facilitate increased use of recovered materials




         domestically and overseas;




   *     reassessment of material and product standards and specifications




         and consumer and business education programs to expand demand for




         recycled products;




   *     revisions in the tax codes, including differential packaging or




         materials taxes that favor recycled materials; and




   *     additional market development instruments as innovation and change




         within the recycling industry require.








PROCUREMENT OF RECYCLED PRODUCTS








   According to the National Institute of Governmental Purchasing, ~




government purchases represent approximately 20-21% of the Gross National




Product (GNP).  This breaks down to 7-8% federal and 12-13% state and




local.  Governments also have an important role in influencing private




purchases,  both through leadership by example and through their standards




and specifications.  Thus, government can influence private groups, from




non-profits to Fortune 500 companies, to use recycled products.








   At the federal level, the U.S. Environmental Protection Agency (EPA) has




published five guidelines (paper and paper products, rerefined oil, retread




tires, building insulation products and fly ash in cement and concrete) to




provide guidance to federal agencies, and state and local agencies and




contractors using appropriated federal funds.  The guidelines include
                                   664

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information on specifications, minimum content standards,  and




recommendations on establishing a procurement program.  EPA is also




examining the feasibility of guidelines for building and construction




materials, rubber products, asphalt rubber and yard waste compost.




Information on the guidelines and federal implementation can be obtained by




contacting the EPA guideline hotline at (703) 941-4452.








   At the state and local level, the National Recycling Coalition has




identified 38 states, the District of Columbia and 16 local governments




that favor recycled products.  The 37 states and the District of Columbia




represent approximately 221 million Americans, or about 90% of the U.S.




population.  Just 3 years ago, only 13 states (representing 46% of the




population) had been  identified.  These programs include general statements




favoring recycled products, goals, set-asides, price preferences,




specification review  and other methods to favor recycled products.




Regional efforts are  also beginning, such as those by the Northeast




Recycling Council,  the Metropolitan Washington Council of Governments and




the  States of Minnesota and Wisconsin.








KEY  ELEMENTS IN BUYING RECYCLED  PRODUCTS








   In order  to establish  a good  program for buying recycled products,




organizations  should include  the following elements:








   *     commitment to buy;




   *     review purchasing specifications;
                                    665

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   *     common definitions and percentages;




   *     variety of products;




   *     testing products;




   *     phased-in program;




   *     price incentives;




   *     cooperation between solid waste and purchasing officials;




   *     cooperation among manufacturers, vendors and users




   *     cooperative purchasing;




   *     data collection;




   *     waste reduction and recyclability;




   *     source separation to ensure adequate supplies.








CONCLUSION








   Market forces alone are not sufficient to create adequate demand for




recyclable materials.  Government recycling programs must include efforts




by economic development agencies,  procurement agencies, and the private




sector to create markets for recyclable materials.
   Richard Keller is a Project Manager with the Northeast Maryland Waste




Disposal Authority.  He is also Vice-Chairman of the Program Committee and




Chair of the Market Development Subcommittee for the National Recycling




Coalition.  He has been involved in promoting programs for recycled




products since 1975.  He is a frequent author and lecturer on procurement
                                  666

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and market development.  Mr. Keller also manages the Coalition's peer match




efforts.  He can be reached at (301) 333-2730.
 1083.RK
                                     667

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    MUNICIPAL SOLID WASTE COMPOSTING IN WEST GERMANY
                   THREE CASE STUDIES

          Henry R.  Boucher,  Principal Engineer
                Camp Dresser & McKee Inc.
                   Edison, New Jersey
                    Presented at the

First U.S. Conference on Municipal Solid Waste Management

                    June 13-16, 1990
                         669

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             MUNICIPAL SOLID WASTE COMPOSTING IN WEST GERMANY



                            THREE CASE STUDIES








                   Henry R. Boucher, Principal Engineer



                         Camp Dresser & McKee Inc.




                            Edison, New Jersey








    This is a presentation of a fact-finding tour in 1989 of three muni-



 cipal solid waste (MSW) composting plants in West Germany.  The three



 plants visited process between 80 and 200 tons a day of mixed municipal



 solid waste (residential waste only at one plant), producing three basic



 output streams:  compost, recyclables, and residue.  The tour pointed out a



 number of important factors to consider when evaluating a solid waste



 composting plant, including composition of the incoming waste, recovery of



 non-compostable recyclables, end uses of the compost product, and residue



 and reject disposal.








    The three solid waste composting plants visited are located in



Duisburg, Aurich, and Bad Kreuznach, West Germany.  All three plants employ



 the DANO drum in the composting process.   We now look at each one.








DUISBURG, WEST GERMANY, COMPOSTING PLANT








    In operation since 1958, the Duisburg composting plant is a 2-drum



system which for the last four years has been composting domestic MSW from



a select area of the City of Duisburg comprised of about 95,000 residents



in single-family and two-family dwellings with relatively large gardens.
                                   670

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The input waste is collected in 120 liter  (32 gallon) and 240 liter (63



gallon) containers only.  17,000 to 20,000 tons per year are processed.



The plant is operated Monday-Friday with one 8-hour shift.  The labor force



is 9.








    To keep heavy metal concentrations down, household-only MSW is com-



posted.  The rest of the City of Duisburg's (pop. 550,000) solid waste is



incinerated.  Plant management noted  that  the composting plant was but one



part of the city's overall municipal  waste management system, whose primary



purpose is not necessarily to produce compost but to process a portion of




the city's waste.








    From November through January, the plant stops composting household



refuse and composts the leaves collected throughout the city (about 19,000



cubic yards per year, or about 9,400  tons).








    Other wastes processed at the  plant are stable manures from the city



zoo and a slaughterhouse (about 1100  tons  per year) and grass clippings.



Because the service area has small lawns and because backyard composting is



widely practiced, the quantity of  grass clippings is small (about 2200 tons




per year).








    The plant  is situated near residential areas, an in-city location.  A



sewage  treatment plant  also  exists on the  site.








     Plant management  noted  that  their main emphasis  is on marketing the



compost.  Major  markets for  the  compost are farmers, nurseries, and as a
                                   671

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 bio-filter for odor  control at  other waste  treatment plants (about 60 to 70



 percent of the compost  is marketed as a  biofilter).   To maintain market-



 ability, much time is spent on  process adjustments to ensure that the com-




 post products suit their markets.  Storage  space equivalent to two years'



 processing capacity  is  available onsite.  In  the years selling compost



 products made from household MSV, plant  management reports that there has



 never been a time When  composting was stopped  due to lack of sales.








     It should be noted  that this plant processes household refuse only;



 wastes from commercial  sources  such as corrugated cardboard,  office paper,



 mixed paper are not  composted here.  Plant  management said the DANO drum



 can process cardboard and other larger pieces  but would do so not to



 produce compost but  to  pretreat the material for incineration (homogenizing



 step).   This  issue relates to collection container size.   Limiting con-



 tainer size has been found to be important  to  successful composting opera-



 tions because waste  from larger containers  (e.g.,  300 gallons) contains



 more  bulky  material which lowers the overall organic content  and dictates



 more  sorting  before  the drum.








 Process  Description








    Incoming waste is weighed and is conveyed  past a magnetic separator.  A



 hand-picking operation  then removes relatively large and/or non-decompos-



 able  items such as bottles,  tin cans, and plastic bags.








    After hand-picking,  the waste is conveyed  into the 3.5 m  x 26 m DANO



drum.  Residence time is 36 hours.  Recently,  according to plant manage-
                                  672

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ment, sludge has ceased being added to the waste because of concern for



dioxins in the compost. To replace sludge, nitrogen is added to the waste




(the source of nitrogen being added is discarded fire extinguisher



contents).








    After the drum the waste passes through two screens, a 16 mm (coarse)



and a 8 mm (fine) screen.








    The fresh compost is stored in an aerated static pile curing area.  The



source of air for the aeration system is plant air including the drum.



Air passing through the compost is cleansed of odors while maintaining the



piles in an aerobic condition.  After 3 weeks of curing, the compost is



transferred to storage.  In storage, augur holes are drilled into the



compost piles to create a stack effect and eliminate the need for turning



the piles over.








Mass Balance








    For 100 tpd in 5 tpd is removed in pre-sorting.  95 tpd into the DANO



drum plus 28.5 tpd water addition at 30% minus 28.5 tpd decomposition loss



equals 95 tpd out of drum after 36 hours.  38 tpd of rejects from the 16 mm



screen leaves 57 tpd to go to compost curing.








    Processing cost is approximately $28/ton (including residue disposal).



Compost revenue is about $5/ton.  (1989 figures).
                                    673

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 Comments








     o  The plant is both a research and testing facility and a




        component of the city's solid waste management system.








     o  The success of the plant in producing marketable compost  is




        due to: (1) a pre-selected waste stream (household waste




        characterized by little bulky waste, high organic content,




        little cardboard, office paper and other paper products);  (2)




        constant efforts by plant management to adjust process so  that




        compost produced remains marketable; (3) and the marketing and




        composting expertise of the plant manager.








AURICH, VEST GERMANY, COMPOSTING PLANT








    The Aurich plant, which is located in rural northern Germany,  is a




materials recovery and composting plant serving a population of 175,000.




Current throughput is 50,000 tons per year.  The labor force is 20.  Site




size is about 5 acres.








Process Description








    MSW from residential, commercial and institutional sources is  processed




by the plant.   Incoming MSW is deposited on a tipping floor and pushed onto




a conveyor.   The waste is conveyed past a magnetic separator to the hand-




sorting area.   Here ferrous and non-ferrous metals, glass, mixed paper,




light plastics, rubber/leather/textiles and household hazardous waste con-
                                   674

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tainers are manually sorted.  Except for the rubber/leather/textiles and



household hazardous vaste fractions, the hand-sorted materials are



recycled.  A rotating screen before the DANO drum removes over 100 mm



material (about 15% of input) as reject.








    After the drum, the material is separated into over and under 20 mm



fractions.  The under 20 mm material is further separated into under 8 mm




and 8-20 mm fractions (fine and coarse compost).  About 25 percent of the



input waste is 20 to 100 mm size and about 50 percent of the input waste is



less than 20 mm.








    The compost is stored for 2 months and then put on an aeration slab for



filtering.








Quantities and Marketing








    For 50,000 tons per year input, compost production is 25,000 tons per



year.  12,500 tons per year of 8 mm (fine) compost is sold in bulk to



nurseries and landscapers ($10-157ton) and 12,500 tons per year of 20 mm



(coarse) compost is sold in bulk to landscapers for soil loosening and



conditioning.  A small amount is mixed with peat (necessary to meet heavy



metal limits) and sold in bags to area consumers.  The plant has long-term



contracts for coarse compost sales.  Sludge addition has been reduced from



40 tpd to 5 tpd because of heavy metal concerns.
                                  675

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 Economics








     Overall cost  (incl. capitalization, transportation,  collection,  pro-



 cessing and residue disposal) is about $30-38 per  ton.   Average revenues



 are less than $5/ton.  The construction cost (1982)  was  about  $7 million.








 Bad Kreuznach, Vest Germany, Composting Plant








     Located in an industrial sector of the city of Bad Kreuznach,  the  new



 DANO composting plant in Bad Kreuznach went into operation  in  1987 and was



 designed to operate as a continuous, highly mechanized facility with



 several  hand-sorting stations for separation of recyclables prior  to com-



 posting.  However, at the time of the plant visit, numerous plant  mechan-



 isms  were not operating and the plant process train  was  not functioning as



 originally  designed.








    The  plant employs a single 4.25 meter x 40 meter DANO drum with a



 design capacity of 220 tons per day.  The service area population  is




 145,000.  The facility is publicly owned but privately operated.   MSW  from



 residential and commercial sources is processed.








 Process Description








    MSW is deposited on an enclosed tipping floor where  the material is



pushed onto a steel plate conveyor.  The waste is separated by a trommel



screen into two sizes:  under and over 15 mm.  The under 15 mm material is



sent directly to landfill (about 18 percent by weight of incoming
                                   676

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material).  This step was implemented because it was  thought that the



smaller particles were largely responsible for high heavy metal concen-



trations.  This has since been found not  to be true and government



permission is being sought to eliminate this step since a significant



amount of compostable material exists in  the under 15 mm fraction.  The




over 15 mm MSW is then conveyed past a magnetic separator and then past 3




hand sorters who manually remove glass, large pieces and plastic.  (The



original design called for separating the over 110 mm fraction from the 15



to 110 mm fraction.  Each fraction was to go to separate manual sorting



stations, plastics, paper and cardboard hand sorting on the over 110 mm



line and glass sorting on the 15 to 110 mm line).   At the time of the



plant visit there was only one sorting line with three sorters manually



removing large objects from  the waste stream.








    After the sorting and magnetic separation, the waste enters the DANO



drum.  Residence time is 24  hours.  At the end of the drum, a rotating 80



mm screen separates the material into over and under 80 mm fractions.  The



over 80 mm material is landfilled.  The under 80 mm material passes through



another screen which produces under and over 18 mm fractions.  The over 18



mm fraction is landfilled.   The under 18  mm fraction  is conveyed to a



ballistic separator, a device for removing hard material (glass, metal,



etc.)  from the compost.  The ballistic separator was  down on the day of the



tour and had not worked well in the past  (40£ efficiency of separation of



hard material).  The under 18 mm material represents  the final product



which  is  transported  to  the  storage area  for three months of storage.  A



short  curing step  on aerated slabs is not practiced.  Storage area onsite



is inadequate; as  a result compost piles  are 3 meters high instead of the



recommended 2 meters.





                                   677

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    One third of the input becomes compost;  another third is landfilled;



and the remaining third consists of decomposition loss and metal and glass




recyclables.








    Operating cost is about $33/ton;  capital cost vas about $16 million.




The labor force numbers 18.








    The compost product was relatively coarse (18 mm) and the product



contained bits and pieces of metals,  glass,  plastic, etc.








    The Bad Kreuznach operation is basically designed for the unique market



it has always had—an erosion control product for the German vineyards (the



plant is in a wine-growing region), sold for about $5/ton.  For this end



use 100% pathogen removal is not required.   The product is not approved,



nor aesthetically suitable, for household use.   To produce clean salable



metal, the over 110 mm material removed by the magnetic separator must be



re-sent past the magnetic separator.   Sorted glass has been difficult to



recycle because of high broken glass content.








Findings and Conclusions Based on the Three Plants








     o  Compost marketing is the most important challenge for plant



        operators.  (One operator reported that the majority of his



        time is spent on product marketing).








     o  The Vest German solid waste undergoing composting exhibited



        important differences from typical Northeast U.S. waste.



        Based on observations, the following differences were noted:
                                 678

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       Less newspaper



       Fewer aluminum cans and glass bottles



       Substantially less paper and plastic packaging material



       Little bulky waste



       Less junk mail




       More food waste (no kitchen food disposers)



       Little corrugated and office paper in compost plant waste



       streams








o  On average, forty to fifty percent, by weight, of material entering



   the plants was screened out be landfilled or incinerated.








o  Since the DANO composting plants visited in V. Germany are pro-



   cessing a different waste stream than typical U.S. MSW, caution



   should be exercised about transferring the results achieved at



   these Vest German plants to the U.S. situation.








o  The hand-sorting materials recovery process was not producing



   a large, high quality recyclables stream.  Substantial amounts



   of recyclables were not being removed by the sorting step



   before the drum.








o  Odors were not a major nuisance during the plant visits.



   Odor controls such as biofilters are used to control odors.
                              679

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     o  Provisions for leachate control vere not  evident  at  the



        plants.








     o  Substantial site area is devoted to compost  storage.
(337/LH)
                                   680

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                                         SUMMARY

                           CONFERENCE  ON MUNICIPAL SOLID WASTE

                         NEW JERSEY MARKET DEVELOPMENT PROGRAMS

BUSINESS RECYCLING LOANS

      Business recycling loans, ranging  from a  minimum of $50,000 to a
maximum of $500,000 or higher for certain projects that  are deemed
necessary by the Department, are available to qualified  businesses.  The
maximum term of the loan is 10 years  at  fixed rate of 3  points below the
prime rate.  A minimum 10 percent equity contribution of the total cost
of the project is required from the businesses.

      New Jersey businesses which collect, separate, process and convert
post-consumer waste materials into new or marketable products are
eligible for these loans.  Recyclable materials include:  paper, metal,
glass,-plastics, textiles, tires, food waste, motor oil. leaves, wood and
wood products, asphalt, brick and concrete.

RECYCLING EQUIPMENT TAX CREDIT CERTIFICATIONS

      The Recycling Act provides for  the availability of a 50 percent tax
credit to corporations operating in New  Jersey  that purchase recycling
equipment.  The recycling equipment tax  credit  is applied directly
(dollar for dollar) against the NJ State Corporate Business Tax.  To be
eligible:

      1.    Recyclable materials must be post-consumer  in origin;

      2.    Recycling equipment must  be  purchased as of  October 1, 1987, or
            thereafter, and used exclusively in NJ;

      3.    Equipment purchased must  be  certified as eligible by the
            Department; and

      4.    Not more than 20 percent  of  the total tax credit can be applied
            in any one year.

STATE PROCUREMENT OF RECYCLED PAPER AND  PAPER PRODUCTS

      The Recycling Act required that not less  that 45 percent of the
dollar amount of paper and paper products purchased by  the State after
July 1, 1989 be spent for recycled products.  Priority purchasing must be
given to products with the highest post-consumer material content.  In
1988, 59 percent of State expenditures  for paper and paper products were
for recycled products.  State expenditures for  paper prorincts containing
50 percent recycled content or more was  $1,997,641.43.
                                     681

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RECOVERY AND RECYCLING OF

 POST-CONSUMER PLASTIC FILM
                John B. Nutter
          American Recovery Corporation
               Presented at the

 First U.S. Conference on Municipal Solid Waste Management

              June 13 - 16, 1990
                   683

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       RECOVERY AND RECYCLING OF POST-CONSUMER PLASTIC FILM






 INTRODUCTION




       One of the most visible issues in the world of MSW management is the need to




 recycle plastics. Programs to collect plastic bottles are proliferating rapidly and several




 facilities for reprocessing these bottles have been built. However, the recycling opportunity




 that is being neglected in the push to recycle plastics is the potential to also recycle plastic




 film.









       Plastic  film production is currently much higher than plastic bottle production -




 approximately  7.2  billion Ibs./yr compared to around 4.5 billion Ibs./yr.  Essentially all of this




 film is discarded after a single use, significantly adding to  the volume of MSW. This paper




 presents a brief summary of how much film is being produced, current recycling efforts,




 processes available for recycling post-consumer film, and barriers to increased recycling.









 PLASTIC FILM PRODUCTION AND USE




       Domestic consumption of plastic resins in 1987 was around 44 billion pounds, and




 approximately  16 percent of this was used in  manufacturing film.  As shown in Figure 1, film




 production is dominated by low density polyethylene (LDPE)  and linear low density




polyethylene (LLDPE), which account for over three-fourths of the  film produced.




Consequently,  the discussion of film recycling must focus  primarily on LDPE and  LLDPE




(which are referred to as LDPE in the balance of  the discussion).
                                         684

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       Figure 2 illustrates how LDPE film is used.  Half of this film is used for packaging,




which includes non-food (industrial liners, shipping sacks, etc.) and food (produce, bread,




etc.) applications. Trash bags, at 19 percent of total consumption, represent the next largest




category followed by shrink or stretch film at 10 percent.  The remaining film  is used for




construction, agriculture, or other non-packaging applications.









FILM RECYCLING




       Film recycling rates are highest for scraps generated in manufacturing processes,




which are also known as "home" or "prompt" scrap.  While nearly 100 percent of this scrap




is recycled in many  facilities,  it is estimated that overall recycling rate is only 60 to 80




percent.  Factors influencing  how much a processor recycles include whether coatings are




used in the manufacturing process,  how much space is available to store scraps, whether the




film is laminated to other materials, and equipment  capabilities.









       Recycling of post-consumer film scrap, in contrast, is very low.  This is particularly




true if it is dirty or if the  supply contains a mixture of different resins.  It is estimated that




the average recycling rates for film discarded by large  users (i.e., large industrial or




commercial firms and agricultural sources) is between  5 and 20 percent, but the rates for




small firms and individuals is under  1 percent.  Note that at present most of the post-




consumer film that  is recovered for recycling is exported  rather than processed in the U.S.









        Recyclers of post-consumer plastic film are most interested in low density and high




density polyethylene. When  the film is used to produce  mixed plastic products (e.g., lumber,
                                           685

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playground or parks equipment, pallets, traffic control barriers), the polyethylene serves

largely as the "glue" that holds the mix together. In these applications, a small amount of

dry dirt or other types of resins are generally acceptable.



       To generate a higher value product from the recycled film, it must be cleansed to

remove dirt, organic material, and other  types of resins such as polypropylene  and PVC.

The resulting clean blend of recovered LDPE and HDPE can be used to manufacture film

products (for trash bags, agricultural,  construction use) or extrusions (pipe, conduit,  gutters,

etc.). The balance of this discussion will focus on these higher value applications.



RECYCLING PROCESS

       The five basic steps in the recycling process used to generate high value plastic resin

are:


       o      Collecting  the material

                    Purchase bundles or bales of film from high-volume generators or
                    materials recovery facilities (MRFs)

                    Extract it from the mixed waste stream

       o      Cleaning and Separating

                    Wash to remove dirt, product residues, paper scraps, organic material,
                    and other contaminants

                    Separate  the materials by resin type and possibly color

                    Dry the cleaned material

       o      Melting -  to generate a liquid, homogeneous material in an extruder

       o      Filtering — which may be required to remove contaminants missed in washing
                                         686

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       o      Pelletizing - to produce cleaned pellets for blending or direct use


       While most users prefer pelletized resin, it may be possible to bypass the melting,

homogenizing, and filtering steps if the feedstock is only lightly contaminated.  In these

cases, the clean shredded scrap would be fed directly to the end users extrusion system in

which the final screening would occur.



AVAILABLE SYSTEMS

       Several manufacturers offer systems  for processing post-consumer film and several

systems are in operation in Europe.  In addition, several firms are processing post-consumer

film in the U.S. or have announced plans to do so.  Figure 3  lists a few of the leading.

equipment vendors and processors.



       While the systems produced by these firms are largely similar, they do differ in some

significant ways.  The first of these is the film collection method.  All of the manufacturers

can process baled film,  but only Sorain Cecchini can extract film from the mixed waste

stream1. The second way they vary is in the use of proprietary equipment.  Each process

includes some proprietary components, most commonly in the areas of washing, separating

different types of resins, drying, and filtering.



       In practice, all manufacturers  configure their systems to meet  the specific

requirements of each application.  For instance, a line dedicated to processing only lightly
    1   A brief Description of the Sorain Cecchini technology which can recover plastic film
        from mixed municipal waste is enclosed as attachment 1.


                                          687

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contaminated commercial/industrial scrap may not require a heavy duty washing and filtering

systems.



BARRIERS TO POST-CONSUMER FILM PROCESSING

       The most significant remaining barriers to expanded recycling of post consumer film

plastics are:
       o     Lack of domestic processing capacity — only a few firms are processing (or
             plan to process) post-consumer film, and most of these will only process
             relatively clean scrap.
       o     Fluctuating resin prices and demand -- as illustrated in Figure 4, virgin resin
             prices (and corresponding recycled resin  prices) have fluctuated considerably
             over the last several years.

       o     Cleaning cost — to produce material that can replace virgin resin, it is
             necessary to remove:

                    Dirt and grit - soil, metals, glass, ceramic.

                    Organic material — food wastes, paper.

                    Other contaminants such as adhesives, coatings, labels and non-
                    polyethylene plastics.

       o     High collection cost

                    If selling directly to brokers/processors, users with low generation rales
                    must provide considerable space  to store the material until a large
                    enough volume  is generated.

                    Equipment required to extract film from mixed MSW.

       o     Need for a stable supply of feedstock —  the value of the product will be
             higher if fluctuations in composition and availability can be eliminated.

       o     Potential  contamination with photo- or bio-degradable materials - which is
             cause for rejection by most users.
                                        688

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CONCLUSIONS

       The capability to regenerate film-grade resin from post consumer plastic film exists

and has been fully demonstrated.  Given that plastics  is a significant contributor to the

growing solid waste disposal problem, it is essential that U.S. efforts to recycle plastic film

be expanded. Recommendations for increasing recycling of film include:


       o      Construct facilities to recover and reprocess post-consumer film -- existing
              capacity is limited and most facilities are only processing clean  film.

       o      Stop production of bio- or photo-degradable films

       o      Establish purchasing  preferences for products containing recycled plastics

       o      Expand  public education efforts  - to increase awareness of the potential  to
              recycle film
                                           689

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     Figure 1
Plastic Film Production

1988 Total -7.2 Billion Lbs.
Source: 1989 Facts & Figures of the Plastics Industry
     Figure 2
 LOPE Film Uses
                     Source: 1989 Facts & Figures of the Plastics Industry
Construction/"
 Agriculture
                         690

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         Figure 3
Him Regeneration from
Dirty Scrap
Equipment Vendors

   Sorain Cecchini
  American Leistritz
    Extruder Corp.
Herbold Granulators USA
     Transplastek
            Domestics Processors

                 Union Carbide*
                    Mobil
               Polysource (AKW)*
                Sonoco Graham*
                 Selected small
                  Processors
'Planned but not yet operating
         Figure 4
Resin Price Trends
Source: Plastics World, Composite index for
PE, PS, PP,and PVC
            1987
     1988
1989
                            691

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                                  ATTACHMENT 1

                            SUMMARY DESCRIPTION OF
                SORA1N SOLID WASTE RECYCLING TECHNOLOGIES
                                   INTRODUCTION

       American Recovery Corporation's Sorain technologies have a proven track record in solving
 the problems associated with waste handling, processing and disposal  Sorain has been involved hi
 the field of Municipal Solid  Waste (MSW) management for over 45 years.  Development of the
 Sorain MSW processing and recycling systems began in the early 1960s and the first facility using
 this technology was placed in service hi 1964.  Sorain presently owns and operates municipal waste
 collection equipment, street cleaning equipment, transfer stations, composting facilities and one of
 the largest landfills in Europe (Rome) with a daily capacity of 4000-5000 metric tons per day.  The
 knowledge obtained through actual operating experience has played a key role  in the development
 of the current state of the an Sorain technologies.
                                          DESCRIPTION

       The proven Sorain systems are capable of processing waste  materials  from residential,
commercial and light industrial sources. Each facility is specifically designed to meet the customer's
requirements, based on the following parameters:

             Waste composition
             Materials to be recovered
             Availability of a domestic or international market for the recovered materials
             Current cost of alternative disposal methods

       All Sorain processing  plants require  a waste receiving area and the  primary processing
system, while the recovery systems are determined by the site-specific parameters described above.

       Should the site have the ability, both physically and economically, to support a full-scale
Sorain facility, the plant would have the following processing and recovery systems:

             Waste Receiving
             Primary Processing System
             Plastic Film (Polyethylene) Recovery
             Corrugated Recovery
             Newsprint Recovery
             Mixed Paper Recovery
             Office/Computer Paper Recovery
             Aluminum Recovery
             Ferrous Recovery
             Organic Materials Recovery
             Combustible Material Recovery
                                  692

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      In addition, the following processing and refining lines could be installed:

             Fully automated Composting Systems  for the composting of the mixed organic
             fraction  and/or yard waste.
             Plastics Regeneration Systems for the processing of the Low Density Polyethylene
             (LDPE) and High Density Polyethylene  (HDPE) plastics  into LDPE and HOPE
             plastic pellets.
             Ferrous  Refining System for cleaning and  densifying the recovered ferrous materials
             Aluminum System for densifying the recovered aluminum materials.
             Baling System for the recovered paper materials.

       The recovered  components and products listed  above can be recycled and used in the
following manner:

             Newsprint, mixed paper, office, computer  and corrugated materials as feedstock for
             the paper industry.
             Plastic  pellets  for the  production of plastic trash bags, pipe,  conduit or molded
             objects
             Compost material as a soil conditioner in parks and gardens
             Ferrous metals in the steel industry
             Aluminum material  in the aluminum industry

                                 PROCESS DESCRIPTION
WASTE RECEIVING AREA

              Municipal waste can be brought to the facility by truck or rail. It is weighed as it
       enters the facility, and then proceeds to the tipping area.  The tipping area can consist of
       either a conventional tipping floor or a pit.

              When a tipping floor is used the material is handled and moved to the infeed
       conveyor with the use of front end loaders.  A tipping floor director is  responsible for
       instructing  the truck drivers  where to place their loads and for initial screening  and
       inspection of the load for non-processible materials. The  front end loader operator then
       moves the processible waste over to the infeed area of the primary processing system and
       directs the  non-processible material to the reject area for  landfill disposal.

              When a pit is used the material is segregated by the pit's overhead grapple crane
       operator.  Reject material is directed by the grapple crane operator  to a reject area and
       the processible waste is placed in the infeed area for subsequent loading into the primary
       processing system.

PRIMARY PROCESSING SYSTEM

              The primary processing system is the basis for  each Sorain facility.  This system
       takes the raw waste from  the  receiving area and processes  it for  subsequent material
       recovery.  The system is modular, with each module capable of processing 50  short tons of
       waste per hour.
                                            693

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             The infeed conveyor delivers the processible material to the bag breaker.  The bag
       breaker, a patented and  time proven device, has  the function of opening up the waste
       containers and of providing preliminary sizing of large pieces of cardboard and other bulky
       items.  This sizing function, and the method by which it  is accomplished, allows easier
       recovery of the recyclable materials, without the contamination experienced with shredding
       systems.

             The waste material leaving the bag breaker is then mechanically sorted by its physical
       characteristics (size and weight) using a patented  self-cleaning trommel and patented air
       classifier. This mechanical sorting operation  concentrates materials into specific materials
       streams which allow for subsequent material recovery.
FERROUS RECOVERY AND REFINING SYSTEMS

             Ferrous is  recovered  using a magnetic  conveyor  system.  Raw ferrous material
       recovered from MSW by magnetic separation contains a degree of contamination which can
       affect  the marketability of the  recovered material  Therefore a Sorain ferrous cleanup
       system is recommended for refining this raw material into a quality product.  This system
       economically cleans the raw ferrous and produces a high grade product, with  a nominal 2
       inch diameter, that is clean of paper, plastics and other contaminants.
ALUMINUM RECOVERY SYSTEM

             Aluminum is recovered using either hand picking or a fully mechanical eddy current
       system.  Recovered aluminum enjoys one of the highest recovered materials marketing
       prices.  The recovered material is densified or baled for market
PLASTICS RECOVERY AND REFINING SYSTEM

             Plastic film, Low Density Polyethylene (LDPE) is mechanically recovered from the
       waste stream using unique, patented equipment and can. then be processed by the plastics
       refining system.  The patented refining system will shred, wash, dry, extrude and filter the
       recovered Low Density Polyethylene material into a high grade plastic pellet.  The pellets
       produced by the  process are of such a high grade that they can be refilmed into new plastic
       trash bags. The plastics refining system can  also be configured to allow the direct infeed
       of agricultural and other industrial film plastic into the plastics washing line without first
       sending it through the primary processing equipment  High Density Polyethylene (HDPE)
       can also be processed separately to produce HDPE pellets. The system produces a nominal
       1/4 inch  pellet which can be marketed  in either bagged or bulk form.

             Sorain also has experience in the use of this recovered Low Density Polyethylene
       plastic in the manufacture of new plastic bags, piping and conduit  Sorain currently owns
       and operates separate plastic bag and pipe production facilities located in Pomezia, Italy.
                                         694

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PAPER RECOVERY SYSTEM

              Paper is usually recovered in the form of corrugated, newsprint and/or mixed paper.
       Newsprint and corrugated paper recovery is  accomplished by hand picking, after initial
       mechanical processing has concentrated the paper material Mixed paper is recovered by
       mechanical process.  These products are then baled and marketed.  Sorain can also provide
       a paper pulping system  if a market exists for a pulped product
PREPARED FUEL SYSTEM

              The system can be configured to produce a fuel product which can be burned in
       mass burn, Refuse Derived Fuel (RDF), kilns or fluidized bed boilers for steam and/or
       energy production.   The  type  of burner used will determine the  processing system's
       configuration.  Fuel heating values can be controlled through the process to accommodate
       the very specific fuel properties required for the type of combustion method used. Sorain
       also has experience with the production of palletized and semi-densified fuel products.
COMPOSTING SYSTEM

              The composting system is a self-contained process which can accept organic material
       separated from the MSW by the primary processing system or from direct outside sources
       such as segregated yard wastes. The current Sorain composting system (fourth generation)
       represents over twenty years of research and operating experience with MSW composting,
       and is covered by two  patents. The composting process takes 28 days, and the bed reaches
       a temperature of over 150° F during that period.  This provides a material that is clean of
       bacteria.  The material leaving the composting bed is sent through a final refining process
       where  glass, small plastic and paper fragments, and other contaminants are removed.

              The composting system is computer controlled and can be operated with a minimum
       of staffing. This system provides for significant weight and volume reduction of the amount
       of material entering the landfill  The compost material can be used for landscaping or can
       be enhanced with chemicals for use as a fertilizer and soil conditioner.
 DENSIFICATION SYSTEM

              Depending on the final processing system configuration, a densification system can
        be installed to enhance the volume reduction capabilities of the facility.  After material
        recovery,  the remaining material  is processed through  a  densifier, which  provides a
        significant reduction in volume of the reject material to be landfilled.
                                           695-

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          STIMULATING  MARKETS FOR RECYCLED PRODUCTS
                    Joan  Bradford, Manager
                      Education  Section
      Illinois Department of Energy  &  Natural Resources
         Office of Solid  Waste & Renewable  Resources
                         Presented  at

The First U.S. Conference on  Municipal  Solid Waste Management

                   "Solutions for the 90's"

                        June  16,  1990

                       Washington,  D.C.
                               697

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      It  is  government's  responsibility  to  set an example for the public
 and private  sectors by purchasing recycled  products.   The  most  important
 point  to remember  is that the demand for recycled products is what drives
 the markets  for the materials being  recovered.   Not  enough  attention  is
 given  to the  market  issue.   This  morning  I  will describe some of the
 successes we have experienced in Illinois regarding recycled products.

      Our  accomplishments are the result of a lot  of  hard  work,  research,
 and  substantial   staff  commitment.   Following  is  an  overview  of  our
 activities.  Central Management  Services  (CMS),  Illinois'  administrative
 agency,   is  purchasing recycled bond paper, tissue and toweling, corrugated
 and has an open contract for FSC stock  forms.   The  1989  Illinois  income
 tax  booklets,  1990 state phone directory, and budget books are all  printed
 on  recycled paper.  Illinois is working  on  incorporating  USEPA  standards
 into our  state  definition  for  recycled  paper.   Illinois  is  the only
 midwestern state represented on the ASTM project to develop  national   state
 purchasing  standards.   The  Illinois  Department of Transportation will  be
 testing recycled plastic products manufactured  by  OuPont.   Our  education
 outreach  includes  planning  a  technical   workshop  for  state  purchasing
 personnel   on  buying  recycled  paper  and  paper  products.   We  will   be
 developing  a  corporate waste reduction program for Illinois companies.   In
 Illinois,  as elsewhere, increasing attention is  being  directed  to  source
 reduction.   As you can see, our efforts are varied.  Our approach has been
 to  identify  opportunity  and  need,  then  pursuing  a  results   oriented
strategy.
                                     698

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I.   We are here today to better understand  and  to  stimulate  demand   for
     products   made   from   recycled  materials.   Increasing  volumes   of
     discarded waste material, coupled with  increased  efforts  to   recover
     recyclables  mean  there   must  be  increased  demand for  products made
     from these materials.
II.  Legislation is traditionally passed in response to  a  problem.    Solid
     waste  is  clearly  one of those public policy issues that has received
     substantial  attention  in  Illinois  and  elsewhere.    Illinois   law
     provides  the  basis  and framework upon which our solid  waste programs
     have been developed.

     A.   Illinois Solid Waste Management Act of 1986

          1.   Established hierarchy of disposal options:
               waste reduction, recycling, incineration, landfill ing.

          2.   Called for  recycling  market  development  efforts  by  ENR.
               This   mandate  is  the  basis  for  our  market  development
               efforts which includes "buy recycled" programs.

     B.   The past couple of legislative sessions in Illinois  set a  record
          in  the  number  of bills introduced to address the  issue of  solid
          waste, many of them  controversial  and  most  don't  become  law.
          However,  this  activity  clearly  points  to  the fact that  solid
          waste is a major public policy issue.
                                     699

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 III.  I'll briefly describe the procurement legislation that has  passed  and
      become law.

      HB  1085   (PA  86-452)   While  not  procurement legislation,  this  law
 will  provide for eventual  availability of products or fuel   sources   derived
 from  tires.   It  calls  for  the  recycling and development of markets  for
 tire-based  products  and   provides  financial   assistance.   (The   funding
 source  is  a  50£  increase in vehicle titles, deposited into the Used Tire
 Management Fund beginning  Jan. 1, 1990.)

      HB 1692 (PA 86-777)   Amends  the  Solid  Waste  Planning  & Recycling
 Act.   As  part  of  the  planning  process,   requires  counties  to develop
 programs for promoting the use of products made from recycled  materials   to
 county  businesses,  newspapers  and local governments.  (The law states that
 recycling goals mandated in the county plan are subject  to  viable markets.)

      HB 2326 (PA 86-246) Amends  Purchasing  and  State   Printing Contracts
 Act.    Requires  buying  and  using  recyclable  paper   whenever possible,
 including not using colored paper that is not recyclable.

     HB 3389 (PA 85-1196)  requires all state agencies to maximize  the  use
 of  recycled  paper  products.   The total volume of recycled paper  is to be
 10% by June 1989 (that goal was exceeded with a  13%  level),  25%  by June
1992,  and  40%  by  June   1996.   Procurement  consideration is to  be given
products with the highest  percentage of post-consumer waste  material.   It
requires  the  use of compost on state owned lands where feasible.  (Another
law bans landscape waste from being deposited in landfills   as  of  July   1,
1990).
                                     700

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     This  summary  does  not  include  legislation under consideration this
session, which ends June 30, 1990.
VI.  Regardless of any laws, buying recycled  products  and  examining  ways
     to  reduce  the  amount  of  solid waste we generate in our offices and
     schools is gaining increasing momentum:

     A.   Government, at all levels  needs  to  set  an  example:    federal,
          state   and  local  government;  school  districts,  colleges  and
          universities.  Private businesses have a major  role  to  play  as
          well.  There are 3 reasons why we should do this.

          1.   This  combined  buying.power is substantial and will  make the
               difference in making recycling programs successful.

          2.   We  cannot  expect  to   establish   recycling   (collection)
               programs    in   our   government   offices,   colleges   and
               universities or company offices without looking  at  ways  to
               close the recycling loop by purchasing recycled products.

          3.   Our  vision  is  short-sighted  if  we  look  only  at office
               paper,  i.e.,  fine  and  writing   grade   papers   in   our
               procurement  policies.   Certainly  that  is  a noble pursuit
               and a very visible display of our  recycling  ethic.   But  we
               must  not  stop  there.  There are other recycled products to
               consider as well.
                                      701

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B.   Common myths  for not buying  recycled:

     1.  Recycled  products don't  exist

     2.  Too few sources

     3.  Quality is  inferior

     4.  Costs  are too high

     I have observed that lack of information is a major deterrent.

C.   Some action and explanation  is  in  order  to  dispel!  the  above
     myths.

     1.   Recycled  products  do  exist, refer to the Recycled Products
          Guide available on  an  annual  subscription   basis   from
          American Recycling Markets.  Product listings are free.

     2.   Too  few  sources?   This  may be the case for some products,
          but competition has  been  increasing.   Many  companies  are
          monitoring  state  procurement laws and general buying trends
          to assess  how serious we are in buying recycled.

     3.   The  quality is not   inferior.   True,  for  some  recycled
          papers,  the brightness  may not be as  high  as  virgin  paper
          for  example.   The  question  is,  do  some of the standards
          need  to  be modified?
                                702

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          The benefits,  I  believe,   outweigh  the  faults.    For  recycled
          paper  and  other  recycled  products,  it  is  the  end  use,  the
          application that we  need  to  address.   If  products   serve   the
          intended  use,  are readily available from reliable vendors  and at
          a reasonable cost, then buy them.

          Regarding cost, some recycled products are  less expensive,  last
          longer   or  reduce  our  landfill   disposal   costs.    Life  cycle
          costing (or full cost accounting)  is not receiving   the  attention
          it  should.   In fact, we are working with the Illinois Department
          of Conservation where they will  do  a life cycle  costing  analysis
          on  recycled  plastic  lumber  used to build  park benches, outdoor
          toilets and boat docks.  Funding is provided   through  our market
          development program.
VII,, Lack  of  information  is  one  of the biggest barriers  to the  problem.
     Some ways to overcome this:

     1.   Statewide recycled product  procurement  sessions.    We  sponsored
          the  first  one  during  the  Spring  of 1989 in Illinois  with 250
          state and local government procurement officials  attending   along
          with  recycled  product vendors who had the opportunity  to display
          their products.  Other states have since duplicated that program.

     2.   Subscribe to the Recycled Products  Guide  and  if  you  have the
          funds, make it available to procurement officials.
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3.   Target  potential   high  volume purchasers of recycled products and
     conduct a testing  program for  the products,   which   we  have  done
     in  Illinois  State  Government.    We  tested  continuous  computer
     stock forms made from recycled  newsprint  by  an   Illinois mill,
     FSC.   We  have also tested   recycled  fine  and   writing  grade
     paper.   The  intent  of  the   testing program is to help  overcome
     institutional  barriers.

4.   Target  agencies  and organizations   that   indicate   a    strong
     interest   in   buying recycled.    Remember,   it only  takes   one
     individual  to  get  something  started.   If  you  can   identify  that
     individual   and provide  assistance,  you are well  on your way to
     success.

5.   Get testimonials from users  of  recycled  products   and  publicize
     heavily.

6.   Conduct  a   promotional  campaign  that ties in with  Recycling Week,
     for example.  Last fall  we  co-sponsored  a   Fall   Recycled Paper
     Promotional    which   included   presentations  at   various state
     government  subcabinet meetings.   Agency  directors   were  given  a
     hands-on experience, trying   to  guess  which paper  sample was
     recycled.    We   also   provided   information  on  appropriate
     applications of recycled paper for each  agency and  how   to   buy
     it.   We coordinated the  promotional  with  the Governor's Office
     and Central  Management Services.
                                704

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VIII Recycling Market Development Program.

     Low interest loans are available for:

     1.   Manufacturing operations that utilize  recycled  material   in  the
          production   of  new  products.   It  is  important  to  stimulate
          markets for the increasing volumes of  materials  being  collected
          which will result in useful products for purchase.

     2.   Marketing of recycled products

     Grants and loans are available for:

     3.   Procurement  and  testing  of recycled products.  We are providing
          funds  to  the  Illinois  Department  of  .Conservation   for   the
          purchase   of   recycled  plastic  lumber.   The  Department  will
          construct picnic benches, boat  docks and  outdoor  privies.   They
          will  then  test  them for their resistance to animal destruction.
          If  the project proves successful, they  will  expand  the  project
          and  save   substantial   man   hours    in   annual  repairs  and
          replacements.
      Closing the loop—government  procurement   plays  a  critical  role  in
 this public policy issue.
                                      705

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     Your  participation  here today can make  a  difference.   You  can  be  part
of the driving  force to make recycling, "buying   recycled"   and   buying   for
source  reduction  part  of  the  mainstream,  the   norm   in  our purchasing
decisions.
                                   706

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          UK MARKET BARRIERS AND OPPORTUNITIES FOR RECYCLING MATERIALS
                              FROM DOMESTIC WASTE

                                  John Barton
                            Warren Spring Laboratory

                                  Introduction

       As a  manufacturing country with  limited indigenous  material  resources,
the UK has  always  had a thriving reclamation industry geared to recovery values
from wastes whenever economically feasible.

       However, reclamation  activities have  tended  to centre  on  arisings  from
the industrial,  trade and  commercial sectors rather  than the waste  materials
discarded by the householder.   Where materials from domestic  wastes  have  been
recovered,  this  has largely  been due to  the efforts of  charity  and voluntary
groups  (eg  scout  collecting  paper,  clothes  sent  to  Oxfam)  rather  than  a
systematic or integrated approach to place recycling as a fundamental  element in
the management of domestic refuse.

       Obviously there have  been exceptions to this general picture,  the UK has
a number  of nationally available recycling schemes, eg bottle  banks  for glass,
and many local  authorities  (eg  Leeds Save  Waste  and Prosper) have  developed
facilities  for the public.   In  addition  a  limited number  of  pilot  collection
schemes  (eg Sheffield recycling  city) have  been implemented to  study separate
collection  of recyclables directly  from households.   However, at the  present
time, not more than 5% of dustbin type  household waste finds its way back into
the recycling loop through these activities.

       Once  in the  dustbin  and collected  as mixed waste,  some of  the waste
management  treatment  systems recover values,  eg  energy  from  mass  burn
incineration plant and  fuel  and materials  (mainly metal, some  compost)  from
waste  sorting/refuse  derived fuel plant.   Again less than 5%  of mixed waste is
so  treated, the remainder is either  incinerated without energy recovery  (8%) or
landfilled  (87%).
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       Frankly, in today's world  this  is simply not  good enough.  Whilst there
 are technical/financial/geographic  factors  which go  some  way to  explain the
 current position, few .would  argue that the UK was making best use of resources
 or  that  recycling  levels  from  the domestic  waste were at optimum  levels in
 broader economic/environmental terms.

       Neither  is  this  situation acceptable  politically,   a  point  clearly
 recognised in the summer of 89 when our Prime Minister commended a target of 50%
 recovery  of recyclables on  domestic  waste  by the  end  of  this  decade.   This
 target  calls for a  dramatic change in  attitude and  direction for the wastes
 management industry, for industries concerned with converting scrap to reusable
 and marketable products and the purchase of these products at the  manufacturing,
 retail and consumer levels.

       In the UK,  our Department of Industry has  the leading, co-ordinating role
 in  material  resources  and recycling but obviously our  Environment Department,
 with  responsibility  for local authorities, wastes management  and environmental
 quality has  a major  role in terms of  unlocking  the  gate.  Essentially the task
 is  to transform the dilute,  diverse   and  widely dispersed  state materials are
 found at  the household  level to the concentrated, high  volume and high quality
 flows needed for industry  to effectively reuse these  materials as feedstock to
 the processes and products  required by  the economy.

       In order  to  assess  the  requirements needed   for  a rapid  expansion of
 recycling in the UK  to  meet the Prime Minister's  target, DTI and DoE initiated
 the UK strategy group  for  recycling.   This group was drawn together from across
 the various  sectors  and included local and  central   government,  the  voluntary
 sector, environmental groups, the reclamation and primary industries, retailers,
 fillers/bottlers,  trade 'organisations,  economists  and  leading   academics  and
 researchers  working  in the  environmental and recycling field.

       The remit  for the group was clear; for each main commodity in domestic
 refuse, eg paper,  plastics, textiles etc, review the current practices, identify
barriers,  propose solutions  for  overcoming the barriers and arrive at commodity
 recycling targets  considered  achievable  over  the next decade.    The  group's
recommendations were then to be forwarded to Ministers in order to inform their
thinking  and policies,  with  particular  reference to  the new Environment White
Paper due to be published this Autumn  (1990).
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                                 The Potential

       To assist the strategy group in their task. Warren Spring Laboratory, the
UK's  government owned  Environmental Technology Agency,  prepared a  series of
'fact  sheet1  reports covering  the main  commodities.   As  most will  be aware,
'facts'  in the waste and reclamation industries are not easy  to  come by.   Not
only  are  weight  and  compositional  flows  frequently  estimated rather  than
measured, but definitions of what constitutes  'domestic waste1  are many and data
from  the  reclamation  and primary  industries  frequently fail  to differentiate
sufficiently with regard to the source of  'recycled' feedstocks and materials.

       Despite  these problems,  by considering commodity production and use data
and comparing  these with the limited but  specific weight and compositional data
for domestic wastes available from research institutes such as Harren Spring, a
broad picture  of the loss of potentially  recoverable materials was drawn up.  A
waste generation  figure  of  approximately 600  kg per  houeshold per  year for
dustbin  waste  was  used  (ie excluding  large items  such  as  fridges, cookers,
furniture  and  garden wastes which are normally  collected/delivered for disposal
separately).    This equates to  -16 million tonnes*  per year  for the UK  as a
whole.

       The 'typical*  composition of UK dustbin  waste  was known and furthermore
estimates  could be made of the quality and contamination levels associated with
the materials.   These  are reported  elsewhere1  and,  excluding options such as
energy and compost recovery, it  was estimated  that some 40%  of the UK dustbin
could in  theory  be recovered as  a  'clean  recyclable1  material.    How this
'amount' compares with  UK consumption, production and  current scrap use for each
commodity  is  very illuminating.  Table 1  provides the estimates and a number of
simple points  can be noted.

       *  For  some  commodities,  UK  consumption  significantly  differs   from
           production, eg  UK imports  over half  her paper  and board  materials  from
           abroad.
    note, weight  as received,  ie  with associated moisture content of -30%,  dry
    weight -11 million tonnes.
                                       709

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                 TABLE 1.  - UK Scrap Use and Potential Effect of Recovering Clean Recyclables from Domestic  Refuse
UK Consumption UK Production Current Scrap* Export of Potential*** Current Scrap
tonnes tonnes tonnes Scrap Available from Use as % of
x 10f x 10» Use tonnes Domestic Refuse Production
x 10* x 10* tonnes x 10s
Paper and 9.97 4.32 2.45 0.42 2.5 - 3.0 57
Board
Steel/iron 15.86 20.36 8.86** 3.61 0.8 - 1.0 44
Aluminium 0.53 0.41 0.13 0.11 0.09 - 0.11 32
Glass (containers) 1.75 1.73 0.28 <.01 0.6 - 0.8 16
Plastics 3.25 1.91 0.15 <.01 0.3 - 0.4 8
Factor Increase
Resulting from
Recovery of
Domestic Recyclable
x 2.2

x 1.1
x 1.8
x 4.8
x 6
*    includes imported scrap
**   includes in-house scrap (not post consumer)
***  'clean recyclable'  estimate

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       *  Some industries,  eg paper,  steel and  aluminium,  are well  aquainted
          with using scrap materials  (albeit  mainly from non domestic  sectors),
          other industries,  particularly plastics, are not.

       *  The  size  of  the  production  industry  has  a  direct  bearing on home
          market capacity to reuse scrap but for higher value materials, UK also
          exports scrap and provides a market for scrap collected abroad.

       *  For  all  commodities  other  than  steel,  the  effect of recovering
          recyclables  from domestic waste  significantly  increases  amount
          currently available/used.  For paper  and aluminium by a  factor of 2,
          for glass and plastics by 4 to 6  times.

       If nothing else,  these data clearly illustrate that  even at  50% recovery
of recyclables,  major infrastructure  changes  are needed within UK industry to
accommodate such  flows  and  a major impact  on import/export  of commodities would
result.   When it  is  also considered  that in addition to current  scrap flows,
unrecovered potential  exists in  other non domestic but  similar waste streams
(particularly   commercial  and  retail  trade  sectors)  then  the  need  for
direction/co-ordination  and  promotion  at a national level is readily  apparent.
Switching on  the  system cannot occur overnight,  the barriers and problems need
thorough analysis and positive action.

       In the above comments  the definition 'recyclable' has so far  only been
applied to materials,  the majority of domestic refuse is not suited to reuse as
a commodity.  For these residues treatment plant for composting, fuel and energy
recovery  will be additional  tools for recovering values from  domestic refuse.
Such process  guarantee  significant weight  and volume reductions and ensure the
remaining solid  residues'are stabilised prior to  landfilling.   Thus the effect
of upstream materials  recycling and the requirements for more widespread use of
such  systems  were also  topics covered by the strategy  group.   However it is
beyond  the  scope  of this  paper to  comment  in detail on the role of  such
systems.
                                       711

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 The Problem

       Although  the initial  report by  Warren  Spring identified  many  of the
 market  barriers  to reuse, the  experts  on the recycling  groups  provided a more
 focused  view of  the issues as well as new or amended information based on more
 recent development either within the UK or abroad.

       Common  to  all  commodities  was  the  issue of  collecting materials  in
 merchantable  quality and  quantities at  an affordable  cost.   Industry viewed an
 assured  supply as an  essential prerequisite to investing in  the transport and
 processing  capacity infrastructure required to reuse the materials, irrespective
 of the  need to resolve the technical and marketing problem they would encounter
 in completing the recycling  loop.   Local authorities, with the statutory duty
 for providing  the  householder with a cost effective waste disposal system, were
 clearly  anxious  to ensure that  revenues and avoided  disposal  costs would fully
 justify  instituting the collection systems that might be required.

       Both were well  aware  that although the traditional  'bring systems' such
 as bottle banks  and paper igloos were affordable  due to reliance on the public
 to bear  the cost  of  first stage  separation and  concentration,  they were also
 unlikely to achieve the high recovery rates across the full spectrum of material
 types.   They were  also clear that  in terms  of existing UK waste collection and
 disposal costs,  collection at the household, in simple cash terms, did not look
 attractive  for all but  a small  number  of authorities.   However,  putting the
 financial   issues  to   one  side,  as  these  were critically dependent  on
 environmental standards and costs of disposal which were undoubtedly increasing,
 for most materials the  groups agreed that household based collection systems for
 recyclables  were  the  practical  way  forward  and  set   about   considering  the
 technical and market barriers to reuse.

       At this point  the issues  and problems  facing the various commodities
began to become much more industry specific.  Table 2 attempts to group and list
the  issues  for each commodity  in  broader terms  and  provide  a  star rating in
terms  of priority/seriousness  of  the  problem.   Low  start ratings indicate
relatively few problem, high star ratings indicate more severe difficulties were
anticipated.  Considering the headings used;
                                      712

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TABLE 2. - Barriers to High Recycling Rates for the Recyclables in Domestic Refuse
Identification Collection UK Technical Problems UK Market Non UK
or Grading Storage Production in Reprocessing for Reclaimed Market
Handling Capacity Material
Commodity
Paper and
Board
Ferrous metal
Aluminium
Glass
Plastics
** * ** * ** **
* *
* * * *
* * ** * ** ***
*** ** *** ** ** **

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        *  Identification or grading  problems  are concerned with the preliminary
           stage  of  achieving  a  recognised merchantable  quality,  for example
           there  are  11  different  grades of waste paper, most household waste is
           of lower  fibre  quality and  to  maximise reuse  and revenues,  quite
           strict sorting and grading is required, hence a two star rating.

        *  Collection/storage/handling  problems  are  concerned  with  achieving
           merchantable quantities, plastics with very low bulk densities and low
           weight arisings per polymer type per household have more problems than
           most.

        *  DK production capacity  covers scale of new plant investment needed to
           process  the  reclaimed  material  and  experience  of  the  industry  in
           building such plant.

        *  Technical  problems  in  reprocessing reflect  industries  expertise  at
           reusing such scrap arising and includes problems such as degradation,
           achieving high specification, residual contamination build up.

        *  Market  for products  made  with reclaim  reflects perceived  consumer
           resistance to  recycled  material,  degree  of   change  necessary  in
           purchasing perference, institutional or health and safety barriers.

        *  Non UK market options indicate degree to which a commodity is traded
           on  the international  markets, for example, high  star  rating indicate
          market undeveloped due to low value.

        In  this paper I will  take only one material,  glass,  to  illustrate the
type of problems highlighted by the working groups.

       Glass is excellent  example because,  on the surface at least, most people
would  consider  it  to be  one  of the  most easily recyclable;  it is  easy  to
identify,  containers  are  simple  in  construction with only limited  amounts  of
'other'  materials  associated with them,  glass  melts  and  can  be reformed with
minimal  degradation  of  physical/chemical properties and  the industry worldwide
has plenty of experience  in  using  post  consumer  cullet,  in  fact  a  number  of
countries  in Europe achieved 50% recycling rates last year.
                                     714

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       For the UK. the recycling rate  was  17% in  1989 and, although the rate is
currently running at -22%, some significant problems are on the horizon.

       From Table  1 it can  be noted that  'consumption1 of  glass is broadly in
line with 'production' at about 1.7 million tonnes, however UK production is 69%
by weight  clear glass,  16% by weight green and  15% by  weight  brown or amber
whereas  the  cullet collected  from bottle  banks,  fillers and  waste from float
glass  production (total -310,000  tonne in 1989)  was 25% clear, 37% green, 6%
amber and 32% mixed (mainly  green and amber).  This difference in colour balance
reflects export/import of filled containers, predominantly clear  for UK products
abroad  (eg  whisky, gin)  mainly green  for imported products  (eg wine, lager).
This is  compounded by higher  returns of bottles (mainly coloured) as opposed to
jars   (mainly  clear).   Obviously  the  existence  of mixed colour  collection
(usually from commercial premises but also  for many bottle bank systems operated
for  the  public) does not help as  this mixed  glass can  only be used in green
glass production.  Amber glass is less tolerant than green to other colours  (due
to  chemical  incompatibility with  green and clear) and  for  clear glass, colour
contamination  must  be  strictly  controlled.    The  net  effect  of  the colour
imbalance problem  can be seen by considering the  amount of cullet used for each
colour,  last  year  clear  glass production  contained only  10%,  amber glass less
than  10% whereas green glass  made  in the UK already contains  in excess of 50%
cullet.

       While  improvements  in  colour separation  at the  collection  point  and
better returns  of jars will enable  overall recycling rate of perhaps 35% to be
achieved, rates beyond this will require  measures such  as  export of  coloured
cullet  or changes  in colour purchasing policy by UK fillers (eg bottling more
production in  green,  particularly for export).  Even at current  recovery rates,
the  distribution of glass making capacity  in the  UK, particularly the existence
of  only one green glass  furnace  in the South East  (the most populated area of
the  country)  is starting to require  long haul transportation of  green cullet to
Northern furnaces  and hence  is reducing the financial incentive for recovery.

       Given  their  own high  recycling rates,  the likelihood of our  European
neighbours  having excess  capacity to accept  green cullet  is  very low (though
perhaps, not  as  low as  expecting French red wines  to be  bottled in clear glass!)
and thus  I  suspect  a  significant change  in colour  purchasing and marketing
policy will  be  needed  by  UK fillers if UK glass recycling rates  are  to  match or
exceed the 50% level.
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       The recycling strategy  group also identified a number of other problems,
some technical,  some institutional, some economic but concluded that these were
all surmountable  given  the  commitment.   However  it  was  not just a 'collection1
and a  'glass  industry problem',  all sectors of the economy needed to adjust and
change to ensure success.

                               Routes to Success

       The last  section gave  a broad overview of the  problems illustrating the
different nature of these problems for the  different  commodities,  particularly
in the  technical and market areas.  Furthermore,  as for any other country, the
UK has her own specific issues to resolve.

       Of  major  importance  is  the  lack  of  financial  incentive;  for  the
collection of recyclables the methods that ensure the highest recovery rates, eg
separate  collection at  the household  for  the main commodities,  are the  most
expensive.  Experience  to date in the UK suggests costs of £50 to £150 per tonne
of recyclable material  collected and sorted and  these data  are not in variance
with reported experience  abroad, what is in variance with reported costs abroad
are the avoided  disposal costs of implementing such a scheme.  For most of the
UK transport  and disposal costs  are less than £15 per tonne for domestic refuse
(albeit rising fast).   These are much  lower  than the  £50-£100/tonne quoted for
some parts of the USA or the £30-£60 tonne for many parts of Germany.  Obviously
there are some savings  to be made  by reduced collection costs for the residual
refuse  (typically 70% remains  for collection) but clearly markets  and revenues
from the  sale of the  materials  collected  are very important for  a household
based scheme  to  be  financially viable in the  UK.  For 'recyclables' separately
collected from the  household,  it can be estimated that  the maximum theoretical
revenue, assuming materials meet merchantable quality, would be between £30 and
£40 per tonne.
                                       716

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       A  compositional breakdown  of  the  'tonne*  and merchant  prices  are as
follows:
   Commodity
Paper and board
Plastics
Glass
Ferrous
Aluminium
TOTAL
Weight
kg
515
70
280
120
15
1000
Estimated Price
£/tonne
15-25
25-75
20-30
20-30
600-800
-
Revenue
£
7.70-12.90
1.75- 5.30
5.60- 8.40
2.40- 3.60
9.00-12.00
26 -A2
       Clearly paper,  glass and aluminium provide  the  main revenue sources and
stable markets and prices  for these materials are a minimum requirement.  If too
rapid  an  introduction of  collect schemes  is  attempted  without corresponding
development  of the  industrial  capacity to use  the materials  the effect of the
inevitable price reductions, possibly to negative levels if materials have to be
put onto world markets or  simply dumped/stored,  will leave the collection scheme
unviable  unless/until disposal costs  savings rise  significantly above current
levels.    While  it  can  be argued that this situation  can be tolerated  for a
period  if  it  ensured/stimulated industrial  capacity  to use  caught  up with
supply,  it is obviously better to co-ordinate and balance supply and demand for
these  commodities as  far  as possible.   It was to this  end that many of the
recommendations  and  suggestions  were targetted  over  and above  the  specific
commodity  based requirements or  the general need  to ensure careful evaluation
and development  of collection systems  to identify where improved efficiency and
cost reductions could be realised.

       The following list gives some of  the more general conclusions  and ideas
suggested  by the strategy  group,  some  were widely held, some had  only minority
support.

        *  Waste  collection and  disposal cost  saving must be fully credited  to
           the recycling system.

        *  Detailed  and comprehensive  recycling  plans  must form an  integral
           feature in  waste management plans  drawn up by the responsible local
           authority body.
                                        717

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        *  Purchasing  policies,  particularly  in  the  public  sector,  should be
           geared to buying products with a high recycled material content.

        *  Review  and  elimination  of  unreasonable  specification  requirements
           which prevent  use of reclaimed materials - adequate  for the purpose
           definitions needed.

        *  Consideration  to  be   given  to assisting  investment  in  industrial
           processing  capacity  designed  to accept  reclaimed materials  (eg tax
           breaks, grants).

        *  Consideration  be  given  to  supporting  'buffer  stocks'  to  assist in
           stabilising markets/prices.

        *  Consideration  to  using  differential  taxes  for  virgin as  opposed to
           recycled materials.

        *  Consideration of legislation/regulation targetted  to assist recycling
           eg  mandatory  facility  provision   for  collection,  minimum  recycled
           content for certain products.

        *   Use of deposit systems for certain  products  to ensure return.

        In  this paper  I  do not intend to make predictions with regard to actions
that  might  be  taken  or how  and  with  what  impact   such  actions  might  be
implemented.   The  proposals do  however illustrate a recognition that existing
market  forces alone were not considered sufficient to  achieve the high recycling
levels  considered  necessary in a  world acutely conscious of the environmental
degradation and resource  depletion problems  caused be waste.  On the other hand
following  the experience  of  undertaking and  being involved  in the studies, few
were arguing  for  blanket mandatory measures or  blanket and  arbitory targets.
There  was  a  general  recognition  that  these  could  well  result  in  a  net
resource/environmental losses.   It is a simple truth that attempting to achieve
'IOCS'   efficiency in  one element  of a chain  inevitably leads to inefficiencies
elsewhere.  It is generally accepted that the major environmental problems faced
by the world today illustrate the failings of trying to maximise material wealth
at  the expense  of sustainable development.    Similarly,  recycling is  but one
element  in the  effective use  of  materials  and  energy starting  with primary
extraction of materials  and ending in ultimate disposal of waste.  Furthermore,
                                     TIB

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household waste is but one potential source of such materials and little benefit
would be achieved if they merely displaced materials recovered from other waste
sources.  Recycling has been an undervalued element in that chain for many years
but  this  does not  mean  that  optimum  recycling rates  in  environmental  and
resource terms are the  same  for different materials or products,  the same for
different  localities  or countries,  the same over time.   Bearing  this in mind,
there  was  no  doubt that  the  overall conclusion was  that positive  action to
significantly  increase  recycling rates from domestic waste  could  and  should be
taken.

       The  recycling  strategy  group  has gone  some  way  in the process  of
formulating  action plans, for  many sub divisions within  a  given  commodity (eg
newsprint  within  the  broad heading paper  and board,  plastic bottles  within
plastics)  and  for some  commodities in total  (eg  glass  containers, ferrous and
aluminium  can  stock)  recycling levels in  excess of  50% recovery and reuse from
households were deemed  eminently achievable  within  a 5 to  10  year time frame.
Identifying  the  problems in  achieving  these  levels  provide the  basis  for
effective  action  to  resolve  them,  not  an acceptance of the status  quo.  For
materials still discarded to household refuse, methods of treatment and recovery
of  energy  and  other waste derived products (eg composts, aggregates) will still
have a significant, and  for the UK, growing role to play in reducing the weight,
volume and environmental impact of domestic refuse disposal.

       The UK  Government has  a vital role  to play in setting the  framework for
this to  happen, but it  is society  as  a whole, business and consumers which has
to  be  involved and committed to ensuring recycling of materials and energy from
domestic waste takes  its proper place  in  an  integrated and structural approach
to  resource conservation and wastes management.

1.     Barton,  J.R.   Recycling for  Packaging;  Source Separation or Centralised
                     Treatment.

                     IWM  Seminar  "Packaging  and  Waste  Management and  the
                     Consumer" 4 October 1989, London.
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     THE  USE  OF INCENTIVES IN SOLID WASTE PLANNING;
                 SEATTLE AS A CASE STUDY
                 Diana H. Gale, Director
               Seattle Solid Waste Utility
                     Presented at the

First U.S. Conference on Municipal Solid Waste Management

                     June 13-16,  1990
                             721

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 Over the past three  years,  Seattle  has  redesigned its  solid
 waste system.   The system was redesigned to  be based on  the
 local and state  hierarchy of  planning goals which make  waste
 reduction  first   priority,   then   recycling,   then  use   of
 incineration  or  landfill.   In redesigning  its waste  system,
 decision  makers  wanted to concentrate on providing voluntary
 programs  and taking advantage  of incentives  in  order to change
 customer  behavior.    This paper  will  describe the  types  of
 incentives  that  were  used  to convert  the vast  majority  of
 Seattle customers to  a recycling-based solid waste collection
 system.

 OVERVIEW  OF SEATTLE'S PROGRAMS

 Seattle's Solid Waste Utility (SWU)  is an enterprise fund  which
 means that  it  is run like a small  business and revenues from
 rates and other  sources  cover all  expenses.  Programs  are  not
 supported by the City's general fund.  Having a rate structure
 has  been  a benefit to the Utility in designing programs  because
 it  has been possible to  give  customers  an economic signal  to
 encourage changes  in  behavior.   The SWU  is  responsible  for
 collection and transfer of waste.   Currently Seattle hauls  its
 waste 30 miles to a county landfill.  Seattle had two landfills
 which are now  closed  and being cleaned up as Superfund sites.
 Seattle has  a  population of 490,000  and  a collection base  of
 150,000 customer  units.    Our transfer  stations accept  resi-
 dential  and commercial  self-haul  waste.   In  addition,  the
 commercial  haulers  collect  225,000 commercial  tons  per year
 which are taken to  private transfer stations.    These tonnages
 have been dropping  dramatically as  a result of a total set  of
 solid waste programs.   The SWU is a  division of  the  Engineering
 Department with an annual budget of $60 million for operations
 and  an additional $5-10 million for capital  expenses depending
 on what aspect of the landfill is currently under construction.


As a result of a comprehensive planning  process in 1988,  the
City made  a  decision to establish a  goal of 60%  for recycling by
1998.  In order  to achieve  this overall goal,   specific  goals
were  established fpr  a  series  of City  recycling programs.
Curbside recycling was to achieve 7.8%; the self-haul dump-and-
pick  program,  a  reduction  of 4.8%;  curbside   yard  waste,  a
reduction of  4.8%;  apartment  recycling,  a reduction  of  2.4%;
source reduction  programs,  a reduction  of 1%;  and  backyard
composting a reduction of 2%.  In addition, in order to  achieve
the  60% recycling,  the City  had to  hold on to  the  24%  private
recycling which had been going on previous to the time curbside
recycling was initiated; and, has to achieve an additional  10%
of new commercial sector recycling.
                         722

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When decision makers were reviewing options for achieving levels
of recycling reduction, a decision was made first to try volun-
tary programs.  If voluntary programs did not succeed,  then the
City was willing to move to mandatory programs.  The decision to
try voluntary first came primarily because the City does charge
rates  for garbage  collection.   The  City's  rate structure  is
volume-based, which means the more garbage you produce  the more
you  pay.    People  have  an  option of  choosing  a mini-can  for
weekly garbage pickup  service  for  $10.70  per month  or  they can
go up to a three-can service (a 90-gallon container)  that would
cost  $31.75 a month.   The types  of  incentives that the  City
considered  in trying to change public behavior were:    giving
customers a choice,  making programs convenient, and giving  an
economic  signal that by changing behavior customers  could save
money.

The use of incentives seems  to  be working.  Now,  two years after
having started its  curbside  recycling  program,  Seattle  has 80%
of its customers voluntarily signed up for recycling.   62% are
signed  up  for  yard  waste  collection  services.    Seattle  is
currently recycling  36% of  its wastestream,  and last year the
tonnage to  the  landfill was reduced  by 22%  from the  previous
year.  Programs that have already been initiated are 76% of the
way to achieving their  1998 levels.

TYPES OF  INCENTIVES

A.   Choice

     Both the rate  structure and the service structure  of the
     Seattle  system  were  designed  around   the  belief  that
     customers -would be happier if they could select their own
     services and, therefore,  set  their own  bill.   The premise
     behind the integrated  garbage  collection and recycling
     service is that by having volume-based rates customers are
     encouraged  to have less garbage.    Therefore,  if  other
     services such as  recycling  and  yard waste which  divert
     tonnage  out  of the garbage can  are provided at a  low  or
     reduced cost price,  customers will select  those services.
     If fact, the system has worked.  Seattle now has 86% of its
     customers  on  one  can  or  less of  garbage  pickup  a  week.
     Over 80% of  those customers  are  using  recycling  services
     regularly; over 62% are using yard  waste  set-out  service
     regularly.

     For the garbage system, customers are given a choice of the
     size can they will use. The types of choices they  have are
     a'mini-can  (20  gallon), one-can  (30-gallon),  two-can (60-
     gallon), three-cans (90-gallon).   As  they increase the size


                             723

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 of their can the cost  of  their weekly pickup  increases.
 Another  choice customers have in customizing their garbage
 service  is  to  decide if they want curb/alley or  backyard
 service.  Previous to 1989, the entire City of Seattle was
 on backyard pickup  service.   In  1989,  with the  new  rate
 structure and garbage system, customers were encouraged to
 move  to the  curb  or alley,  but were  offered  backyard
 service.   However,  backyard service  is  offered at a  40%
 premium.   The  effect of this  choice is  that  97% of  the
 customers have chosen curb/alley service.

 For  the  yard waste  program, starting in 1989, the  City
 required separation  of yard  waste out of  the garbage  can.
 In other words, you  were no longer allowed to  put any of
 your yard waste into your garbage can.  However,  there  were
 three different methods  customers could use to divert their
 yard waste.   First  they  were  offered  a curbside pickup
 service  where yard  waste would be picked up regularly at
 their home  at  the curb.   Secondly,  they could take  yard
 waste at a reduced fee to  the  transfer station.   Thirdly,
 they could  compost  yard waste  in the backyard.    The  City
 offers a backyard compost  program where it  will deliver a
 customer a  free  compost   bin  and give  an  hour  of  free
 instruction  in  effective   methods  of  composting.     In
 addition, customers  still  have  options for  managing their
 yard waste such as choosing  a  gardener or cementing their
 entire yard in  order not to have yard waste.   Our recent
 garbage  composition  analyses are indicating that  now  less
 than 1%  of waste left in a garbage can is yard  debris.   A
 year ago yard waste  was  up  to 20% of the waste in a garbage
 can.

 Seattle,  working  with the region,  has  also developed  a
 comprehensive household hazardous  waste  management plan.
At the same  time that household hazardous wastes  are banned
 from  the garbage  can,  options  are  being planned   for
disposing of  those  wastes.    The  region  started with  a
number of  roundups.   A roundup is  a one  day  collection
where  all  household hazardous  wastes  are collected  at
centralized sites.   Now the region  is  moving  to having
permanent  sites  in reasonable  locations,  and mobile
collection  vehicles  that  can  move  from  site  to site.
Seattle  currently   has  one  household   hazardous  waste
collection  site and  is siting a second  one.   Household
hazardous waste materials  are  collected  at the  transfer
station at a subsidized  fee in order to encourage people to
bring their materials to that site.
                         724

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     The theory in a waste reduction/recycling based concept  of
     solid waste  management is  that for all  elements of the
     waste stream  you  provide customers with  a  way to manage
     that waste  other than place  it  in the  garbage stream.
     Consequently, the City has spawned a number  of programs  to
     handle specific elements of the waste stream.  Again, the
     purpose of these  programs  is  to give customers a choice.
     We believe that if customers have a choice they will make
     the  right  decision  about  how to dispose of a material.
     Bulky items (such as white goods —  refrigerators, stoves,
     etc.) can be picked up at the  curb  for a small fee.  They
     may  also  be  delivered to  the transfer station.   At the
     transfer station mercury switches or capacitors are removed
     from white goods  so they can  be  recycled for  metal.    In
     addition at  the transfer stations,  customers can deliver
     mattresses, waste oil, wood waste,  lawn mowers, cardboard,
     motor oil. All of these items  can be delivered free to the
     transfer station where they are sold as recyclables.

B.   Convenience

     A second major belief in  an incentive-based  system is that
     for customers to change behavior programs need to be easy
     and convenient.  We believe that if programs are  designed
     to be "user  friendly" more people will participate.   For
     the curbside recycling program, this means that we provide
     all  customers  with  bins  and  we give  frequent  pickup  of
     those bins.  Bins were all delivered to a customer's door
     with a packet of  information on how to use the materials.
     For garbage collection all customers were provided wheeled
     containers for curb  service.  The belief was  that if it was
     easy to manage a wheeled container, people would not object
     to wheeling it to the curb.  To encourage participation  in
     the compost program,  customers  are given a free compost bin
     and  a free hour of education.   Yard  waste  programs were
     designed so that people could put materials out  on the curb
     in  plastic bags knowing that that was the preferred method
     customers already have of disposing of yard waste.  Seattle
     is now  reconsidering  the  use  of plastic bags and looking
     for possible alternatives, one of which would be providing
     customers  for  a  wheeled  bin that would  be  used  for yard
     waste.

     One fear of having high garbage rates was  that there would
     be an increase in litter  and illegal dumping.  In  response
     to this concern, the City instituted a  comprehensive series
     of neighborhood cleanup programs.  The City has a Conserva-
     tion Corps which is  staffed by  at-risk,  older teenagers who
     need to develop job skills.    The Conservation Corps runs
                             725

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     the neighborhood cleanup programs.   All  neighborhoods in
     the City are scheduled  for cleanup.  On the appointed day,
     customers can  leave items on the  curb where  they will be
     picked up and dumped  free  in the transfer stations.   By
     having  free  neighborhood  cleanup  days,  customers  are
     encouraged to save materials for that day  and not to litter
     or dump.

C.   Economics

     1.   Rates/Fees

          The linchpin of Seattle's  entire recycling and waste
          reduction  program is  a volume-base  rate structure.
          The underlying belief of such a  rate  structure is that
          customers will  change  behavior  more  rapidly and more
          substantially if  they  save money from  the changes.
          Seattle  instituted volume-based rates  in 1980.   At
          that time  the basic garbage  pickup  rate  was low and
          the difference  between one, two  or  three can  was
          minor.   In  1986  and 1987, Seattle  customer had two
          rate increases  which brought rates up more than 82%.
          At that point,  the differential  between  can  sizes
          became greater and behavior began to  shift dramatical-
          ly.  Now customers have a  choice of  a small mini-can
          (20 gallons)  for $10.70 per month; 1-can  (30 gallons)
          for $13.75  a month; 2-cans  (60  gallons)  at $22.75 a
          month;  3-cans (90 gallons) at  $31.75 a  month.   This
          steeply   inverted   rate   structure  combined   with
          diversion options  for  citizens  has led to 86% of the
          City being  oh  one  can  or  less of  garbage pickup.
          Seattle is now experimenting with the idea of charging
          "garbage by the pound."  The concept  is that customers
          would have cans that are bar-coded with their name and
          billing address; the bar-coding could be read  by a
          laser scanner on a garbage  truck and the can would be
          weighed and then dumped. Billing would be done by the
          weight  of  the garbage  in  the can.    The  idea behind
          this concept is to encourage those  customers who can
          further reduce their waste to do so because they would
          be charged only for the amount of garbage in the can.

          Other aspects of the volume-based rate system are that
          people are encouraged to select curb/alley collection.
          Therefore, even though they are offered  a service of
          backyard collection,  they are  charged a  40% premium
          for that backyard  service.   Customers who are handi-
          capped or elderly and unable to  get a container to the
          curb are allowed   backyard  collection   at  curbside
                             726

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     rates.  Low income and  elderly  customers are given  a
     rate break. Another aspect of the volume-based  system
     is  that waste  reduction  and  diversion  methods —
     recycling and yard waste — are provided free or at  a
     low  cost.     In  Seattle recycling  is  free and  yard
     waste pickup  is  charged at the rate of $2 per  month
     for nearly unlimited curbside pickup.

     At  the  transfer station the  concept of encouraging
     customers to separate recyclable waste  is carried out
     in the fee structure.   The  fee for dumping  clean yard
     waste is reduced from the normal dumping fee, recycl-
     ing is free,  and charitable groups  receive a special
     low-cost  dumping  rate.    Finally,  the  household
     hazardous waste  dropoff is a  subsidized  rate.   The
     City is considering moving  to  free dumping  of hazard-
     ous waste to encourage further separation of hazardous
     wastes from the waste stream.

     Another program in Seattle using  economic  incentives
     to  encourage  behavior  change  is a battery deposit
     program. Whenever a person purchases a  new  automotive
     battery, a  special fee is charged for disposal of that
     battery.  If the customer brings back an old battery,
     the  fee  is eliminated.   For  the commercial sector,
     economic incentives  include  a  lower  rate  for the
     collection of recyclables than for garbage.  However,
     the rate differential is not great enough at this time
     to encourage the  kind of behavior change desired. The
     City is working  with the Utilities and Transportation
     Commission (UTC) to provide  a more steeply inverted
     rate structure for commercial collection.

2.   Incentive Grant Programs

     The City has  initiated  a number of  grant programs to
     gather ideas  or to encourage creativity.   The belief
     is that creativity  and involvement in problem solving
     are fostered  by encouraging agencies and individuals
     through grant programs.  The City's school recycling
     program  is based  on a competitive  grant process.
     Elementary schools  compete for   grants of $5000 to
     design waste  reduction/recycling programs for  their
     individual  schools.    They  are  given  a  series of
     bonuses  for  achieving  certain  levels  of  recycling.
     Once they achieve a level of 7 pounds per student and
                        727

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     faculty, they are eligible  for special funds for field
     trips.  They also receive bonuses for PTSA involvement
     in  order to  encourage parents  and teachers  to be
     involved in the recycling programs.

     Another experimental program started by the City is
     called the Environmental Allowance Program (EAP) . The
     EAP program was designed to be a research and develop-
     ment  program to  get  private  sector involvement in
    .solving problems.  One  idea  that developed  from this
     program is to develop a latex paint recycling program.
     Recyclable  latex paint is  separated at  the  household
     hazardous waste shed from non-recyclable paint and
     after processing  and mixing  is turned into  an  indus-
     trial grade reusable paint.  The EAP has experimented
     with  co-composting  of  sludge  and  solid waste,  with
     methods of  cleaning glass used  for recycling,  with
     public information on issues such as use  of cloth vs
     disposable  diapers,  and   currently  is  involved in
     setting up  a  commercial audit program.   Some  of the
     programs  originally  designed  by  the EAP have  then
     become   integrated   into   regular    solid    waste
     programming.

     The same  concept was used  to encourage City depart-
     ments  to begin new recycling and  waste  reduction
     behaviors.  Departments  competed for grant funding for
     projects  to initiate recycling  and waste  reduction
     programs.   The  Parks Department as a result of  this
     program is starting to  compost garden materials; the
     Seattle Center (similar  to  a large central urban park)
     is experimenting with  methods of collecting recycl-
     ables  on outside grounds.   Departments  have  also
     bought  compactors and  capital intensive  pieces of
     equipment necessary for recycling cardboard or other
     materials.

3.   Mitigation

     One of the unique problems that Seattle had in design-
     ing its  programs was  to retain  existing levels of
     private recycling that had been going on  in the  City
     before the curbside programs began.  Retaining those
     high levels of private recycling is highly cost  effec-
     tive for the  City because  people entered into  those
     recycling behaviors at  no  cost to  the  City.   In an
     effort to keep private recyclers in business, the City
     tried to work on  effective ways to maintain existing
     recycling through mitigation programs. One initiative
                         728

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          is to  publicize small recyclers1  activities  and to
          provide them with  grants to do  market  research.   A
          second type of mitigation is to find new  program areas
          that can  be saved  for smaller  recyclers.   The City
          designed an apartment recycling program  geared to be
          provided by existing recyclers.  However,  the diver-
          sion credit price that was  offered  in the program was
          too low and the private recyclers chose not to partic-
          ipate.  Mitigation has not been entirely  successful in
          Seattle and a number of  private recyclers have gone
          out of business.  However, Seattle is still working on
          ways to maintain and support  existing  recyclers in
          business.

CONCLUSIONS

The use of incentives has been an  important element underlying
Seattle's waste reduction/recycling programs.  Clearly, giving
people economic incentives to change  their behavior is the most
effective way of getting  change.  The fact that Seattle charges
a rate for garbage  has turned out  to be an unusual benefit in
the  design  of its  solid waste  programs.   Although  the most
influential  method  of  changing behavior has  been  providing
economic incentives, giving customers choice and making programs
convenient have also been important additives  to a volume-based
structure.   Peer pressure  and environmental  ethic  are  the
"frosting  on the cake"  that encourage  people  to  make good
environmental decisions,  but by themselves will not affect the
vast majority of  the public.   Finally,  the fact  that programs
are  voluntary  and people  are given  the  choice to  select the
services they want to meet their own  solid waste disposal needs
(and, thereby, to customize their  bill) seems to  have contrib-
uted  to  customer   satisfaction   with  programs.    By  using
incentives Seattle has been able to  rely  on voluntary programs
and  is  well on  its way to  achieving its 60%  goal  for waste
reduction and recycling of its waste stream.
                              729

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       VARIABLE RATES IN SOLID WASTE: APPROACHES FOR
PROVIDING INCENTIVES FOR RECYCLING AND WASTE REDUCTION AND
             A MORE EFFICIENT SOLID WASTE SYSTEM
                      Lisa A. Skumatz, Ph.D.
                  Synergic Resources Corporation
                        Presented at the
      First U.S. Conference on Municipal Solid Waste Management

                        June 13-16, 1990
                               731

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             VARIABLE RATES IN SOLID WASTE: APPROACHES FOR
     PROVIDING INCENTIVES FOR RECYCLING AND WASTE REDUCTION AND
                  A MORE EFFICIENT SOLID WASTE SYSTEM
                            Lisa A. Skumatz, Ph.D.
                         Synergic Resources Corporation1
   THE WASTE DISPOSAL CRISIS

   Landfill space is becoming a major nationwide crisis.  Almost 40% of
   respondents to a recent survey conducted by the American Public Works
   Association indicated that their landfill space would run out within 5 years.2 In
   addition, this survey indicated that 74% were currently doing nothing to reduce
   solid waste volume.  There is a nationwide disposal crisis,  and  it is affecting
   jurisdictions that are large and small, urban and rural, all across the nation.

   Locally, the crisis can manifest itself in  rapidly increasing disposal tipping fees,
   in the  need  to haul waste  hundreds of miles for disposal, in mandatory
   recycling programs, in struggles to comply with changing landfill standards, in
   public  opposition to the siting of needed new disposal facilities, or in barges
   filled with waste with no place to dock.

   What can jurisdictions do to solve this crisis?  Traditional options include:

    o    building a new landfill,
    o    building an incinerator in hopes of extending the life of  existing landfills.

    o    more recently, jurisdictions have  begun imposing mandatory recycling
         programs.

  Many jurisdictions are facing very significant economic investments in either
  closing landfills, building new ones, or building incinerators.  And the out-of-
1  This work  was partially  funded by grants from  the  Environmental Protection
  Agency.  The work was conducted by the  author  while employed at the Seattle
  Solid Waste Utility.

2  Solid Waste Collection  &  Disposal: 1987. by American Public Works Association
  (APWA), 1987.
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pocket costs of these huge investments don't include the significant problems of
siting, changing regulations, public pressure, and long lead times.

IS THERE ANOTHER SOLUTION?

The problem would be reduced if residents could be induced to reduce waste,
increase recycling, and do a number of other "good things".  However, there are
many citizens who simply will not react to the crisis unless there is an
economic, or "pocketbook", reason to do so.

In most parts of the country, garbage is removed once or twice a week with
the revenues coming from one of two places:

  o   from  a portion of the property tax,  or
  o   from  fixed bills for unlimited pickup (bills that  do not vary with respect
      to the amount of garbage taken away.)

Neither of these methods gives residents any incentive to reduce their waste.
In fact,  with the property tax method, residents never even see a bill, and
generally have no idea how much it costs  to remove their garbage every week.
Areas with these  methods of payment have often had  to resort to mandatory
recycling programs in order  to try to reduce their amount of garbage.

      Residents in several jurisdictions around the  country have come to
      recognize that you can achieve remarkable successes in recycling
      and waste reduction without any mandatory features through one
      simple measure: volume-based garbage rates.
WHAT ARE VOLUME-BASED RATES?

In volume-based rates, the level of payment varies with a measure of the
volume of waste disposed.  Customers who use more service pay a higher rate,
and those who use less pay less.  There are several possible volume-based rate
designs which provide the same principles ~ customers putting out more waste
pay higher fees. Seattle uses a subscribed variable can system.  Several  other
jurisdictions use a pre-paid bag system.   Briefly, a variable can system involves
having customers select subscription levels based on the number of cans  of
garbage they need to dispose of each week.  The jurisdiction usually offers
subscription levels in standard 30-gallon increments (one can, two cans,  etc.).
Seattle and  Olympia, Washington also offer smaller service levels that hold 19
and 10 gallons respectively as a reward for small  waste generators.  Higher
service levels are charged higher rates.
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  Jurisdictions that employ a bag system charge a fee for each "official" bag that
  includes the cost of disposal.3 Under a bag or tag system customers purchase
  special garbage bags (or tags) from the jurisdiction or from outlets at a price
  that includes the cost of disposal.  The more bags of waste they put out, the
  more they must pay.

  The key under both these systems is that the amount that customers pay
  increases significantly as they use higher levels of service. Customers are not
  limited in what they may dispose, but they are required to pay for what they
  use.
  VOLUME-BASED RATES ARE AN EFFECTIVE RECYCLING It
                                  Average Cans Subscribed
                                              1981-1989
Volume-based rates have
proven to be an
extremely effective
recycling incentive.
Since Seattle's
introduction of variable
can rates in 1981,
Seattle's customers,
eager to reduce their bi-
monthly garbage bills,
have reduced the
average number of cans
subscribed from 3.5
down to just over 1
can.  And the recycling
percentage (in terms of
actual tons of waste
diverted, not just
participation rates) was over 24% before the introduction of any City-sponsored
recycling programs.

Volume-based rates have also contributed to the quick success of Seattle's city-
operated recycling programs, which provide customers a convenient opportunity
to reduce subscription levels by recycling materials they might otherwise have
                                                                       1986
                                   WMU Utility
                          Figure 1
3 The charge usually includes at least the cost of disposal.  Some jurisdictions also
  include a share of the system's fixed costs.
                                    734

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thrown away.  The City has achieved an amazing 75% sign-up rate in its
curb/alley recycling program.  More important than sign-up statistics, however,
is the amount of waste diverted by the program.  The program currently
collects about 3,500
tons per month, or an
average of 63 pounds
per participating
household.  Over 60%
of Seattle's customers
subscribe to the City's
new yardwaste
collection and
composting program.
This year alone, the
curbside program is
expected to divert about
27,000 tons of
residential waste to a
composting facility.
SEATTLE SOLID WASTE TONNAGE, 1987-1989
           Monthly Residential Tonnage
 TONS {Thousands)
JAN  FE8  MAR APR  MAY  JUN  JUL  AUQ  SEP  OCT  NOV  DEC
                     MONTH
         • 1987 Tons
                    •1988 Tons
                                1989 Tons
                         Figure 2
In addition, based on an
analysis of numerous factors, the Utility has determined that the introduction of
variable can rates has helped slow the growth of disposed tonnage. There have
been two factors assisting this result.  First, the level of Seattle's rates increased
to a point at which customers took notice.  In addition, the rate structure
provides clear rewards for reducing waste.  The steep rate structure adopted at
the beginning of 1989 has been particularly effective in achieving this goal.
Customers can achieve real savings on their garbage bills by participating in
this  program,  and Seattle's customers understand and take advantage of this.

Incentive-based rate design goes hand-in-hand with recycling and waste-
reduction programs, and is a critical part of integrated solid waste management.
In Seattle, the combination of rate incentives and additional recycling and
diversion  programs has  allowed Seattle to decrease the  amount  of waste it
brings  to  the landfill by 24% compared with 1988 levels (see Figure 2).
Similar and  dramatic  reductions in landfilled tonnage have also  been noted at
jurisdictions that have instituted bag systems.  Perkasie, Pennsylvania for
instance, noted a 35-45% decline in tonnage brought to its transfer stations
after the introduction of their bag system and recycling program.
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 WHAT OTHER BENEFITS DO VOLUME-BASED RATES OFFER?
         Volume based rates can benefit a community in a number of
         ways:

          o Customers receive an incentive to reduce disposal.
          o The rates are fair.
          o Incentives support recycling programs.
          o Mandatory recycling can be delayed or avoided altogether.
          o Fees  make  customers  aware  of  the  environmental
            consequences of their actions.
This system gives customers a very clear reward for reducing the amount of
waste that they dispose of:  they pay a distinctly lower bill.  An additional
benefit of the system is that it does not favor any particular method of reducing
waste.  Other benefits  of volume-based rates include:
      Volume based rates are fair -- customers who dispose of similar amounts
      of waste pay similar amounts of money.  Those who dispose of less, pay
      less.  Customers get control over the bill they pay.  In addition, the rates
      reward all methods of reducing waste including waste reduction and
      recycling.

      Implementation of any City-sponsored recycling programs will be much
      more successful with these rate incentives in place.  The combination of
      variable rates and convenient recycling programs makes for a much more
      integrated garbage system, and gives customers good alternatives and
      choices.

      Customers get a chance to show what they can do through  voluntary
      rate-induced waste reduction.  Your programs need not be mandatory
      and therefore your enforcement burden can be reduced, and you may
      still invoke mandatory programs later if you don't achieve the goals you
      need.

      This method gives customers  a better idea of the actual cost of disposing
      of waste and provides  a better relationship between customer behavior
                                  736

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      and rates.  Masking the cost of garbage service all these years has made
      the cost associated with new landfills and incinerators particularly hard
      to justify to customers in some areas.  It is difficult to condemn
      customers for making unwanted choices in their waste disposal behavior
      if they are not given the information (generally costs of disposal) to
      make intelligent choices.  Customer education is key to getting customers
      to work with  the system.

  o   Pricing  garbage services  in this manner puts solid  waste on an equal
      footing  with the way water and electricity services are priced.
      Customers pay based on the amount of service they use, and have
      economic reasons to conserve.

  o   Using volume-based rates to reduce waste is quicker to implement than
      building new  capital facilities to handle additional waste. The rates
      provide an environmentally sound alternative and  can be implemented in
      a variety of situations.  In addition, they integrate well with programs
      and can help  lead to lower long-run system costs.
WHAT DO WE GAIN?
         From a city management perspective, volume based garbage
         rates can gain the City:

           o Time to site new disposal facilities.
           o More options in terms of recycling vs. disposal investment
           o Support of low volume dumpers and recycling groups
Volume-based (specifically, variable-can) rates, and the additional awareness of
the solid waste issue that they have brought, have allowed Seattle to seriously
propose a set of non-mandatory programs that will bring it to an aggressive
60% recycling goal by the year 1996.  Rate design is an integral part of this
program.  Seattle considers its volume-based rates its most effective recycling
program.  It can be yours too!

In addition, implementing volume-based rates is  quicker than building new
capital facilities.  Even if capital facilities are also needed, volume-based rates
may help buy extra time,  and accustom customers to the idea of paying on the
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 basis of service provided.  Implementing variable can rates (and recycling
 programs) can help win support for additional disposal facilities because
 customers may recognize that the jurisdiction has made a good faith effort to
 avoid siting additional disposal capacity and is taking an integrated planning
 approach to the issue.

 Volume-based rates can be implemented to reward voluntary reduction of waste
 by customers.  The jurisdiction can still hold out mandatory measures as a
 threat if customers do not achieve the needed goals voluntarily. However,
 allowing customer choice and emphasizing voluntary programs  often produce
 less ill-will than proceeding without giving customers a chance  to "show what
 they can do".

 Volume-based rates can produce a closer relationship between the costs and
 revenues for a solid waste jurisdiction.  Rather than a rate system that
 generates revenues that do not vary with  the amount of waste  disposed,
 charging volume-based rates will tend to generate higher revenues for
 customers  that cost more to serve.

 Finally, volume-based rates are fair, provide excellent recycling  incentives, are
 environmentally sound, and can help slow or even reverse growth in tonnage
 disposed.
WHO CAN IT WORK FOR?

Because the economic concepts underlying volume-based rates are universal, a
volume-based rate structure can help a wide variety of jurisdictions, including
those:

  o   with collection performed by contract, franchise, municipal, or private
      arrangements,
  o   that cover large, medium, or small numbers of customers, and
  o   in any part  of the country.

Whether variable can rates make sense depends on an assessment of specific
circumstances, including those related to cost, timing, and political factors.
           ICTS WHETHER IT WILL WORK IN OUR

Although costs are obviously a key factor, there are a number of other
situations that help make adoption of a volume-based rate system simpler and
                                   738

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more politically appealing:

  o   Hauling contracts, franchises, rates, or billing systems are up for a
      change.
  o   The jurisdiction faces any of a wide array of landfill or disposal
      problems, including a shortage of landfill space, high tipping fees,
      changing landfill regulations, or public opposition or other difficulty
      siting new landfill or disposal options.
  o   Jurisdictions in which the community wants to create recycling incentives
      to increase participation in  an established or planned recycling program
      or satisfy local recycling advocates.
  o   The existing system is perceived as unfair and encourages abuse.
  o   The jurisdiction is running out of tax  authority and can use the
      establishment of separate rates to free up tax revenues.
  o   Medium to larger jurisdictions may have some advantages in being  able
      to spread implementation and fixed costs over more customers.

It may also be helpful if the solid  waste jurisdiction is legally established as an
entity that must cover its costs via fees,  e.g. a utility or enterprise fund.

Although the factors mentioned above can make adoption of volume based
rates simpler,  none are essential.  A volume  based  rate system may be
appropriate anywhere.
WILL IT PAY/CAN WE AFFORD IT?

The question is whether you can afford not to do it!

Continuing to landfill is becoming more and more expensive, especially if the
true costs of landfilling are considered (that means including costs of closing,
difficulties of replacement of the  landfill, etc.).  Extending the life of existing
landfills pushes the closure (and  siting) costs out to later years, and means real
dollar savings now that can be invested in recycling programs, etc. with actual
benefits to the solid waste jurisdiction and its customers.

The final judgment of whether the new system will pay depends on a
comparison of the costs vs. the savings of the new system.
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          The  types  of  costs  that  will   be  incurred  with  the
          implementation of volume based rates may include:

           o Contractual changes
           o Public information, outreach, and PR
           o Billing system changes
           o Cost of designing the rate system
           o Staffing increases, especially in customer service and field
             inspection crews.
 The operation of a solid waste system funded with volume based rates is almost
 certain to be more expensive than a flat fee or tax-funded system.  Thorough
 planning involves examining potential cost increases and compare them with
 potential savings.
         Savings resulting from the change may include:

           o Savings on current disposal costs
           o Savings from extension of the life of existing disposal sites
           o Savings in crews  and overtime at transfer,  hauling, and
             disposal facilities
           o Improved utilization (and improved economies of scale)
             of recycling programs.
The "benefits" described above are often referred to as "avoided cost".  Avoided
cost refers to money that does not have to be paid as a result of some activity.
Considering avoided cost allows a complete comparison of alternative
investments, and allows planners to design their least-cost system.

Using avoided cost analysis in 1988, Seattle found that the status quo system
(landfilling at a local site) was more expensive than investing in very aggressive
                                   740

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and expensive recycling programs, and long-hauling the remaining waste to an
alternate site.
     Local factors affecting cost-effectiveness may include:

       o     Costs and lifetimes of specific landfill or disposal alternatives
       o     Access to and strength of regional recycling markets
       o     How rural vs. urban the collection area is - distance between
             stops, distance to landfill, distance to recycling markets
       o     The portion of collection cost that varies with volume of waste
             collected.
ISNT IT A LOT OF TROUBLE TO IMPLEMENT?

A volume-based system is more  complicated than some alternative rate systems.
However, the steps involved in implementation are manageable.  They include:

  o   Determining whether state law empowers your agency to bill for solid
      waste on the basis of volume.
  o   Establishing an ordinance that makes solid waste service, or at least
      charges,  mandatory
  o   Establishing an ordinance that bans (and penalizes) illegal dumping and
      burning  of waste
  o   Establishing the solid waste entity as an enterprise fund (not essential,
      but can  be helpful)
  o   Assuring that there are convenient  recycling alternatives (public or
      private)
  o   Creating a sensible system of rates on the basis of system costs and
      desired changes in disposal behavior.
  o   Extensive public education/information efforts
  o   Preparation for some changes within the solid waste agency,  including
      increased staff in some areas (particularly billing and customer service),
      changed  responsibilities for some employees, and a possible refocusing of
      the services that the utility offers.

Of course, establishing local political support is a key ingredient in the process.

Some obstacles to successful implementation are peculiar to individual volume
based systems.  For example, variable can rates  can require a complex billing
                                   741

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system, and pre-paid bags or tags may require a retail distribution system.
WHAT LEGAL POWERS DO I NEED TO WORRY ABOUT?

New recycling and landfill legislation has helped make a volume-based rate
system an appealing option in many states.  Existing law can affect the level of
difficulty associated with a move to a volume-based rate system.

The legal powers necessary for a solid waste agency to charge for refuse
collection on the basis of volume generally either already exist or can be
created through a local ordinance, if the local political climate permits.  Some
states may limit local agencies' power.  Unfortunately, therefore, legal questions
must be answered on a state-by-state basis.

Several legal situations can affect the ease with which a volume-based billing
system can be  implemented.   Ideally,  a  jurisdiction considering such a change
would have the following powers:
         Legal Powers Needed:

          o Power to bill or set/approve rates
          o Flexibility to perform non-traditional services
          o Power to prevent illegal dumping.
 o    Power to bill (municipal or contract system) or to set (or approve) rates
      for refuse franchisee.  This power must include some means of enforcing
      payment of bills.  The power to make refuse service mandatory can also
      be helpful.

 o    Flexibility to perform services other than traditional collection and
      disposal of refuse.  Laws that strictly limit ways in which refuse system
      funds must  be spent can complicate recycling efforts.  Limited recycling
      options can affect the desirability of a volume-based rate system.

 o    Power to prevent illegal dumping.  Although the solid waste agency will
      probably not enforce illegal dumping laws itself, there must be a strong
      penalty for  disposing of waste outside the system.
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The powers listed above are generally available to jurisdictions that currently
provide refuse service.  Flow control may also be needed for a smoother
system.
WONT IT CAUSE A LOT OF PROBLEMS?

Changing from fixed fees for unlimited pickup, or from a system where fees are
collected via taxes may not be a simple, problem-free process.  However, most
of the potential problems are manageable, especially if you expect them.
         Communities considering implementing volume based rates
         should  be prepared  to address  several of  the following
         problems:

           o Confusion with the new system
           o Resistance from customers  who  are  not used to  paying
             bills or who are unwilling to change  behavior
           o Illegal dumping or burning of waste
           o Enforcement of the system
           o Complaints  by the poor
           o Contractual or legal  limitations on the flexibility of the
             solid waste  agency
           o Change in the responsibilities of your agency and staff
           oNeed for increased  staff (some  temporary increases for
             analytical tasks,   and longer term increases needed in
             customer service,  etc.)
 CAN THESE PROBLEMS BE HANDLED?

 The answer is that the problems can be significantly reduced -- if you anticipate
 them and prepare for them.

 Customer Confusion and Resistance: Working with the press and preparing
 mailers can help  customers understand the reasons for the change, can help
 with resistance to behavioral changes, and can help explain the new system.
 Initial stories about local problems related to solid waste, and about solutions
 that have worked in other jurisdictions,  can help increase understanding of
 solid waste issues.  Repeated mailers, television spots and bus cards can be
                                    743

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 helpful in reinforcing the new behavior.

 Illegal Dumping and Burning: Some increase in illegal dumping and burning
 can sometimes be associated  with variable can rates.  Making sure that there
 are convenient opportunities  for customers to recycle waste and imposing
 regulations that provide penalties for illegal dumping are helpful. Requiring a
 minimum level of service and minimum fee for all households can help reduce
 the problem.  In addition, getting a public attitude change that  says illegal
 dumping isn't socially acceptable (like the recent changes in the social
 perception of drunk driving)  can go a very long way in mitigating problems of
 illegal dumping and burning.

 While many areas have had trouble with illegal dumping in response to sharp
 increases in refuse rates,  Seattle does not appear to have experienced a
 significant problem with illegal dumping or burning of waste. Other large cities
 have had problems.  However, it is difficult to get a very accurate or
 quantitative handle on the problem.  Seattle does not have a comprehensive
 program to pick up illegally-dumped waste.  Rather, some  incomplete
 information is provided by street cleaning crews, and are subject to
 complicating effects from seasonal  labor availability and other problems.  Also
 complicating the problem is the fact that waste can easily  be dumped across
jurisdictional lines, and burning can be difficult to detect or trace to  its source.
There are several factors that may contribute to Seattle's relatively small
problem in this area:  1) there are few vacant lots in the City,  2) the
Northwest has a strong environmental ethic, 3)  the areas has many private
recyclers,  city programs, and other legitimate ways to reduce the amount of
waste that needs to be disposed, and 4) volume-based rates are not new  to the
area, so customers have had time to modify their behavior.

Enforcement:  Enforcement may or may not be needed.  For many years,
Seattle's Solid Waste Utility relied on an honor system for enforcement of
service levels. Although it is clear that some customers put out more waste
than they were paying for, on-site inspections indicated that the levels of abuse
were not high, and were in fact, offsetting.

Seattle's new collection system is much simpler to enforce.  The contractors
provided 'official' semi-automated toters sized to the subscription level paid for.
This system greatly simplified  enforcement, because any waste that is not in the
official toter is not paid for and is generally not collected,  unless it has a pre-
paid sticker on it.  A decision  on enforcement in a particular jurisdiction  may
be able to be deferred until after the system is in  place for a while.  However,
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  provisions for enforcement should be included in any contracts, etc.
  Low Income Assistance:  Because an economic incentive to reduce waste
  disposal below a minimum level can lead to illegal dumping, volume-based
  rates require the introduction of mandatory charges.  These separate and
  discrete charges can be a burden to low income customers.  However,
  establishing special rates for low income citizens, or building "lifeline"
  components into the rates will mitigate the impact of mandatory rates on
  customers with fixed or low incomes.  Some jurisdictions offer carry-out service
  for curbside rates.

  Staffing Considerations:  In-house problems can be reduced if management
  prepares staff for changes in emphasis of the job, for instance realignment of
  staff toward recycling efforts and away from traditional collection and disposal.
  Management also need to prepare staff for growth in some areas in particular,
  some of which will involve  permanent increases and some more  temporary.
  Management may be able to cope with some of the burden in areas with
  temporary workload through the use of temporary labor, or with loans of
  municipal employees or staff from other sister agencies, or with  consultants.

  Although these steps take planning, they can set the stage for a  very effective
  solid waste system.
  AREN'T THERE OTHER RATE OPTIONS OUT THERE THAT ARE JUST AS
  GOOD?

  No.  Volume-based4 rates are equitable and provide better incentives than rate
  designs that do not vary the charge with some measure of the amount of
  service provided.  They provide  customers with choices, integrate well with new
  recycling and yardwaste programs,  encourage participation in recycling
  programs without making them  mandatory, and can lead to an extension of the
  life of existing landfill space.

  As a comparison, many jurisdictions are considering offering recycling credits,
  which reduce garbage bills for people who participate in recycling.  While
  credits may be better than nothing, they are not the best alternative because
  the amount of the  credit is fixed, and does not give customers an incentive to
4 Another experimental alternative, a weight-based rate system, is discussed later in
  this paper.

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 recycle more.  In addition, credits for participating in "official" recycling
 programs do not encourage careful buying in the first place (many jurisdictions'
 first priority for waste reduction), backyard composting, re-use, or recycling
 through private firms.


 WHAT ADDITIONAL CONSIDERATIONS ARE INVOLVED IN RATE DESIGN?
                     System Design Decisions

      o Choice of Bag/Tag vs.         o Charges for Recycling or
       Variable Can System                   Diversion Programs
      o Subscription vs. Usage         o Rates for Multi-family
      o Steepness of Rates              Buildings
      o Payments for "Extras"          o Rates for Compacted Waste
      o Curbside vs. Backyard         o Alternatives for Low
       Differentials                     Income Households
Choice of Variable Can vs. Bag/Sticker Systems:  The selection of the type of
volume-based rate system will depend on the evaluation of the tradeoffs of
several factors in the context of the jurisdiction's situation,  including:

  o   Equity
  o   Simplicity, implementation considerations, and cost, and
  o   Revenue Stability.

There are pros and cons for each of these systems, and jurisdictions need to
weigh their particular needs.

A 'variable can'-based system may be a good option for areas using semi-
automated toters, areas  with problems  of animals or rapid spoilage, or places
already using a can system where customers may already own their own cans.
Variable can rates also show customers the full cost of disposal in  one bill.
Can systems may provide more stable revenues than bag systems, and may be
easier to forecast.  Especially important is the  fact that variable can rates also
allow a  great deal of flexibility in the pricing increments between can
subscription levels.  The jurisdiction can implement  rates that provide very
aggressive recycling/waste reduction incentives with this system.
                                  746

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  However, a variable can system has fairly high implementation costs,
  particularly because of the complexity of the billing system needs. A fairly
  complex computer system is needed that will keep track of each customer's
  selected subscription level, and will calculate bills accordingly.  In addition,
  customer service costs may be higher, and some confusion on the part of
  customers is fairly likely because subscription levels will need to be selected.

  Bags or pre-paid stickers  generally charge for smaller increments of waste than
  a variable can system, letting customers pay more precisely for the amount of
  service they use.  This provides a better link between customer behavior and
  the bill they pay, and allows a better waste reduction/recycling incentive. In
  addition, the purchase of the bags may provide a more  immediate price signal
  to customers.  The billing system is much simpler, and customer questions and
  confusion can be lower than with a variable  can system.  Enforcement may  also
  be simpler.   Although bags are generally easier for collection staff to dump,
  allowing the bags or stickered waste to  be placed inside cans may help alleviate
  animal problems where that is a difficulty.
           Selection Between Variable Can and Bag/Tag System

       Variable Can System                 Bag/Tag System

       o Full cost on bill                    o More usage-based
       o Relatively stable revenues          o Immediate price signal
       o Flexibility in pricing                      o Limited flexibility in
         incremental 'can* levels               pricing incremental bags
       o Relatively high billing,             o Fairly easy to implement
         customer service, and enforce-        and enforce
         ment implementation costs
  A bag or tag system will require the jurisdiction to set up a distribution system
  for pre-paid garbage indicators, but allows the jurisdiction to avoid the cost of
  a billing system.5 The jurisdiction must also establish and communicate (and
  presumably enforce) clear limits on the size of items that may have stickers
5 Seattle employs a combined approach - a "can" based system, with special stickers
  for occasional "extras".  These stickers, or 'Trash Tags" may be purchased from the
  Utility or at retail outlets like 7-Eleven and grocery stores.
                                    747

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   attached. However, a bag system limits the agency to equal price differentials
   no matter how many bags are put out by a household. This restricts the
   jurisdiction from charging increasingly higher rates for additional waste.6

   If the jurisdiction attempts to charge for all the costs of disposal through the
   price of the bag, it runs the risk of not recovering the system's fixed costs.  It
   may be more prudent to charge for the fixed cost of the collection/disposal
   system through a separate charge to customers, and  keep the cost of the bags
   closer to the Variable' cost of the system (generally disposal).  In this latter
   case, the "fixed" portion of the system costs would be recovered through a
   "customer charge"  on a regular periodic bill, or through a tax mechanism7.
   Then bags or stickers could be purchased for an additional fee  that would
   reflect the "variable cost" of the system, and would show customers a savings if
   they dispose of less waste (use fewer bags or stickers). Charging separately for
   the fixed portion of the collection/disposal system assures that  the fixed costs
   of the system will  be recovered, and the system will remain solvent.
   Attempting to charge for all costs on  the price of bags can lead to revenue
   instability and potential financial insolvency.

   Choice of Subscription vs. Usage-based system:  The best incentives are
   provided by systems that charge customers based closely on the actual amount
   of waste disposed.  In this way, the customer's  behavior is more directly
   associated with the amount paid.  However, such a system requires either
   recording the number of items at  each pick-up, or requires the  use of pre-paid
   bag or stickers.

   Pre-paid bag or sticker systems are  a  good option, especially in that they may
   offer charges based on smaller increments of waste and make it easier for
   customers to vary  the amount  of waste they put out.  However, the system
   must allow for the recovery of fixed costs in some manner, perhaps through an
   additional "customer charge".

   Subscription systems may provide an  incentive to completely fill up the cans  or
   bags paid for,  and may decrease the recycling incentive. However, subscription
   systems can also work to remind customers to reduce to that subscription level
6 This can be mitigated to some degree if the household is issued a fixed number
  of bags per year at  a  certain rate, but then additional bags are available at a
  higher rate.

7 The jurisdiction could  charge this customer charge through its existing revenue
  mechanism.

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  on weeks when waste might be higher.  Subscription systems are often easier
  to implement than systems that require the recording of items for each pick-up,
  and provide revenue stability.  Providing the option for pre-paid stickers or bags
  in conjunction with subscription systems can improve the flexibility of the
  system for customers  with occasional higher garbage levels, and may reduce the
  risk of illegal dumping.

  Steepness of the Rate Structure:  The steeper the extra charge for additional
  waste, the greater the incentive to recycle.  Jurisdictions may wish to steer
  clear of excessively steep rates for two reasons, however:

        1.    An increased incentive  to dump illegally.
        2.    Volatility of revenues.

  Fixed costs of the system are incurred no matter what level of waste is
  disposed.  Because the revenues for  higher levels of waste are generally less
  certain (and indeed, through recycling, etc. you are trying to reduce these
  higher levels of waste),  many of these fixed costs must be recovered through
  the customer charge or  integrated into the "first-can" rate to assure  the agency's
  financial solvency.  The more of these costs that are put on  the first service
  level, the less  steep will be the rates.
              Selecting the steepness of the rates requires balancing:

                  Increased recycling/waste reduction incentives
                                       vs.
                     Increased incentives for illegal dumping
                             and revenue uncertainty
  In addition, pure cost-of-service pricing would not necessarily justify steeply
  increasing rates.  This can be a difficult trade-off.  This situation can arise for
  several reasons.  One of the largest costs of providing solid waste service is
  getting the trucks and labor to the house, a cost that will not vary much with
  how much waste is put out for collection.  In addition,  many landfills are not
  priced at a level that reflects the full cost of providing service.8  This will tend
8 Many jurisdictions do not charge appropriately for all the costs associated with
  adding tonnage to a landfill.  Costs that are often undervalued or omitted include
                                      749

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   to reduce the steepness of the rate structure because a large component of the
   variable cost (the landfill fee) is underpriced compared to the long-term fully-
   inclusive price of disposal.

   Seattle instituted rates that are higher than cost-of-service for higher
   subscription levels, and this approach was favored by the Utility, policy-makers,
   and citizen groups.  The amount of excess funds that were projected to be
   collected from customers subscribing to higher can levels were used to reduce
   the rates for lower can levels.  This approach allowed Seattle to enhance its
   waste reduction and recycling incentive in two ways:  first, by implementing an
   enhanced 'penalty* for large amounts of waste; and second, by increasing the
   'reward' for disposing of small waste volumes.9

   Payments for "extras": "Extras" are cans or bags of waste that customers dispose
   of in excess of their subscription levels.  Under  a  subscription or variable can
   approach, a system of payment  for extras must  be established to allow honest
   customers to dispose of occasional extra garbage without illegal dumping.

   Care  must be  taken to assure than the price of  one "extra" is greater than one-
   fourth the cost of an additional permanent monthly service level (with weekly
   service, or four pickups in the month).  This becomes more complicated if the
   dollar differentials between service levels are not constant across service levels,
   and if the differentials vary for curbside  vs. backyard service.

   Differentials for Curbside vs. Backyard Service:  Generally, backyard or carry-
   out service is more expensive to provide than curbside or alley service.
   Allowing customers to select — and pay for — the service arrangement of their
   choice can save your system money and provide more service options to
   customers.  The savings may help pay for the switch to volume-based rates.

  Jurisdictions currently show a wide range of differentials for these service
  differences.  Some charge only cost-of-service differentials (perhaps 10%).
  Others charge as  much as four times as much for backyard service. Seattle
  charges 40% more for backyard service,  and found that over 95%  of customers
  selected curb/alley service.  Allowing customers to choose the service type  gives
  ultimate landfill closure costs and the cost of siting a replacement landfill.

9 However, care must be taken in implementing this 'enhancement'. Recall that the
  revenues for higher subscription levels are less certain, while subscriptions at lower
  can levels are very certain.  As the subsidy increases,  the  agency increases the
  chances it will  not recover the fixed revenues needed to run the system.
                                     75O

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them control over the size of their bills and continues the principle of providing
a direct relationship between customer behavior and the size of bill.

Charges for Recycling or Diversion Programs:  One controversial area is
whether jurisdictions should charge separately for recycling or diversion
programs.  If these services are provided, but not separately charged, the costs
will be included in the basic  garbage rates.  Not charging may enhance
incentives to sign up for these programs.

However, there are strong arguments that this may not be an equitable system.
Customers who do not use the program are charged.  Although the jurisdiction
may seek to penalize customers who  do not use the City's programs and do not
recycle or work to reduce their garbage, it is less clear that they would want to
extend those penalties to customers who reduce their garbage through  private
recyclers or who reduce waste through careful purchasing or re-use.  If the
charge for recycling programs is included in the basic customer charge, then the
likelihood of recovering the program  costs is high, but these inequities  are
exacerbated.  If the charges are put on higher subscription levels, the- penalties
are directed more accurately  at customers  who dispose of a great deal of waste,
but the program costs are less likely to be recovered,  affecting financial
stability.
Indeed, as the solid
waste jurisdiction is
more successful in
diverting waste from the
landfill disposal stream
to recycling and
diversion programs, it
reduces the revenue
base (number of cans or
bags) over which to
spread recycling costs,
so the extra cost per
unit must increase. The
result could be a system
in which, as people
recycle more, they pay
higher and higher  garbage
        RELATIONSHIP BETWEEN DISPOSAL
         PRIORITIES AND RATE INCENTIVES
   Increasing
    Priority
         Waste Reduction. Careful
     ^ '   Buying, and Composting
         Private Recycling

         City-sponsored Recycling
         and Waste Diversion Program
         Garbage to Landfill or
         Incinerators
NO CHARGE
HIGHEST RATE
                                          Increasing
                                           Rate*
       Well-designed Rates can Induce Customer Behavior
            That Reflects Waste Disposal Priorities
fees.
 To avoid finding itself in this situation, the jurisdiction should consider charging
 a separate (but relatively lower)  fee for City-sponsored recycling, yardwaste
 collection/composting, and diversion programs.  The fee may not recover all the
                                    751

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  costs of the programs, but should provide an incentive for taking care of the
  waste through careful purchasing (so that the waste is never produced in the
  first place), private recycling programs, or other ways to remove the waste
  from the city's waste and recycling system.10 As the job of the solid waste
  jurisdiction changes from one of solely disposing of waste to an integrated
  system of waste disposal as  well as waste diversion and recycling, it may be
  appropriate to charge customers some portions of the cost of these additional
  services, since a fee-for-service approach provides greater long-term financial
  stability and gives customers greater control over their bills. However, that
  doesn't  mean it is inappropriate to provide some level of subsidy to these
  programs from garbage revenues.  This approach reinforces the waste disposal
  priorities that  have been adopted in  most jurisdictions.

  Seattle provides a curbside recycling program for no additional charge,11 but
  charges a $2.00 monthly subscription fee for the City's weekly curbside
  yardwaste collection and composting program.  This charge is  considerably
  below the $9.00  charged for an additional subscription level.

  Rates for Multi-family Buildings:  Rate options  for multi-family buildings can be
  complex for any utility, but may be  especially so for solid waste service.  The
  problems include:

    o   The tenant, or garbage-producer, is often not the bill-payer, so the rate
        incentives  are diluted and indirect.
    o   Garbage is usually disposed of in a joint area, so tenants may not  feel
        responsible if they over-dispose of waste because of the  problem of
        determining which tenant is responsible.
    o   Rate equity can be difficult to maintain if two different  systems (cans or
        bags; vs. dumpsters)  are available.
    o   Maintaining equity between multi-family and single-family rates as well
        as between large and small multi-family buildings can be complex.
    o   The fact that some costs may be properly allocated on a building basis
        (e.g. the stopping of  a garbage  truck), some on a household basis  (e.g.
        landfill  closure), and  some on a volume-basis (e.g.  disposal) makes
        designing rates for multi-family applications much more  complex than for
        single-family buildings.
  This approach may also mitigate  the  amount of harm  to  any existing private
  recycling enterprises, and the potential for political fallout.

11 The cost of the recycling programs  and planning are covered through the garbage
  fees.
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   o    Offering a high degree of choice in subscription levels may complicate
        both billing and enforcement.

  It would be possible to bill multi-family buildings on a fixed-fee basis (either
  per-building, or perhaps more fairly, per-household).  However,  that approach
  would eliminate any possibility of providing signals to either the property
  owner or the tenants that reducing waste is a benefit.

  Although it may seem difficult,  there are at least two possible volume-based
  approaches that may be practical in multi-family buildings:

    1)   A bag or tag system, with a per-household customer charge,12 or
    2)   A variable can subscription approach.

  Either system could be set up so  that the owner is generally charged based on
  the volume generated per complex.  However, the former system has the
  possibility of passing some of the direct incentives to the tenants. A per-
  household charge could be assessed through a bill or through the property
  taxes.  Then all the waste that  is in official pre-paid bags or that is tagged with
  pre-paid stickers would be picked up. Presumably tenants could be made
  responsible for paying for the bags.  This system would tend to  get some of the
  waste reduction incentives inherent in the rates  to the waste producers.

  However, realistically, some buildings may need enforcement efforts to try to
  reduce the amount of waste that is disposed in unofficial bags or waste that is
  not tagged.  This may be a problem, and the relevant ordinances may need to
  make the landlord ultimately responsible for paying for this waste.

  A variable can system is  another alternative. Seattle's system of multi-family
  variable can rates  is complex and imperfect.  The City's billing system maintains
  records of the number of apartment units in each multi-family building and
  requires the building owner to  select a subscription level.13  The multi-family
  rates are charged with a structure that is identical to the  single  family rates for
12 The customer charge would probably be billed to the building owner.

13 The system gives owners two options.  They may either sign up for a number of
  cans that is equal to or larger than the number of units in  the building (a five-
  plex may sign up for five, six, seven,  etc. cans). Alternatively, the entire building
  may sign  up for the  mini-can  service (that same five-plex would pay for and
  receive five mini-cans of service per week).
                                     753

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  each apartment unit.14,15  The system is veiy complex and inflexible.  However,
  the biggest weakness of this system is the fact that if one tenant is a strong
  recycler, he/she cannot generally reap the benefits of that behavior - the
  system is unable to get the recycling incentive directly to the tenant.

  Some non-rate options may need to be employed.  Passing an "opportunity to
  recycle" ordinance requiring each complex to provide a convenient recycling
  opportunity may assist in increasing recycling by these customers.

 • Rates for Compacted Cans or Dumpsters:  There may be a case for charging
  differential rates depending on whether waste is compacted or not. If landfill
  charges are weight-based, this may be especially appropriate.16  However, in
  many cases, compacted waste may not  incur extra disposal charges, and
  therefore may be priced the same as uncompacted waste.

  In cases where a differential is appropriate, practical considerations may make
  it impossible17 to charge additional amounts for compacted waste in cans, but
  may allow additional charges for compacted dumpsters. This is the case  in
  Seattle. The Utility pays per-ton fees for landfill disposal and the  Utility
  charges an additional fee for compacted dumpsters, which brings dumpster rates
  closer to cost of service.  Seattle deals  with compacted cans through a weight
  limit, which allows the City to deny pick-up to gross weight-limit violators.

  Alternatives for Low Income Households:  When mandatory fees are required,
  social concerns may make special rates for classes of low income customers
  appropriate.  The jurisdiction may want to consider:

    o   alternate eligibility criteria  ~ all  low income, low income with children,
        low income elderly or handicapped, medical eligibilities, etc.
14 Prior to  1989, Seattle charged multi-family rates  lower than those charged to
  single-family households  to account for savings related to fewer stops  and the
  'clustering' of cans. However, the most recent analysis showed these savings were
  very low and the lower rate was eliminated.

15 Therefore, a five-plex building subscribed to six cans would pay for five full one-
  can subscriptions  (including five customer charges) plus one additional can rate.

16 However, for the most part, transfer and hauling costs may vary more on the basis
  of volume more than weight.

17 Weight-based rate systems, discussed later in this paper, may eventually eliminate
  this problem.
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   o    the effect of alternate rates on billing system cost and efficiency
   o    how to determine eligibility.
   o    whether the rates should be lower throughout all volume-levels or
        whether discounts should be truncated after a "basic" level of service.
   o    whether aid should take the form of lower rates, special services (such as
        free backyard collection), or emergency funds.
   o    which classes should pay for the  rate subsidy, and which rate subsidy
        design is most equitable to all customers.
  BUT VOLUME BASED RATES ARENT PERFECT. ARE THEY?

  No. Metered systems, or systems that allow customers to pay for the exact
  amount18 of waste they dispose, would be better.  Systems based on smaller
  increments of waste are better, and could provide recycling incentives that are
  more volume-sensitive.  In addition, the more immediate  the payment, the more
  reinforcement provided.  A more immediate payment for solid waste service
  provides a stronger message to customers.

  However, trade-offs with ease of implementation and understandability must be
  made.  Workable compromises include  Seattle's system of subscribed cans
  augmented  (for flexibility)  with  pre-paid  stickers, or the pre-paid bag systems
  used in other jurisdictions.
  ARE THERE BETTER METHODS AROUND THE CORNER?

  One of the major objectives of variable rates is to establish a link between a
  customer's solid waste disposal choices and the bill that the customer pays.
  This is the key to providing an incentive to reduce the amount of waste
  disposed through waste reduction and recycling.  Variable rates systems, unlike
  tax methods or systems with fixed bills for unlimited service,  provide these
  incentives.

  The volume-based methods of variable garbage rates discussed above are in
  place now in a number of communities.  However, volume-based rates have
  some weaknesses.
    /
    o    Existing variable can rate systems charge on the basis of subscription,
        not usage.  Under a variable can system, if a customer uses less than the
18 and even type of waste
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      subscribed level of service in a particular week, that customer sees no
      savings reflected on the bill.  The variable can system is not geared to
      the actual amount of service  used by the customer.

      Customers are charged on too large an increment of service.  With either
      variable can or bag/tag systems, one of the problems is that the
      increments on which customers are charged are generally quite large —
      either a "can" or a "bag" of waste.   In order for customers to save money
      on their bill, they must reduce or recycle a full can or bag of waste. If
      customers have waste that even partially fills a service  level, they have
      every incentive to fill it up because they will  be pay for that entire
      service level.

      Both types of systems can be inconvenient. On the customer's part, they
      must decide on a "normal" subscription level,  and make calls for changes.
      They must purchase and have on hand an adequate supplies of bags or
      tags. The solid waste jurisdiction may need large inventories of cans of
      different sizes, and have a network for providing bags or tags as needed.
Some modifications to the current volume-based methods could be considered.
Variable can systems could be modified with a variety of smaller can sizes -
half cans, quarter cans, etc. A variety of bag sizes could be introduced.
However, this would not solve the inconvenience problems  that exist, and
would not necessarily provide the flexibility needed to maximize the waste
reduction and recycling incentives.

However, with grant funding from the Environmental Protection Agency,
experimental work is currently being done to test the feasibility of an
innovative new idea in garbage rates -- a field-test called "Garbage by the
Pound".
WHAT IS "GARBAGE BY THE POUND"?

The concept behind the Garbage by the Pound experiment is to test whether it
would be feasible to introduce a system that would charge customers by the
amount of solid waste service they use based on the pounds of waste disposed.
The project is designed to test the mechanical, operational, and customer-
related feasibility of a solid waste collection system that would weigh customer
cans and charge  on the  basis of the weight of waste removed.  This system
would be flexible for the customer and the collection system, and would
decrease the size of the increments by which  customers are charged for solid
                                  756

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waste service.  Special cans or bags would not be needed. Requests for service
level changes would no longer need to be coordinated. This approach is closer
to "metered garbage service", bringing the delivery and charges for solid waste
services into closer alignment with  that provided for other utilities like
electricity, gas, and water.  Charging  by the pounds of waste actually disposed
each week would dramatically improve the link between behavior and bill, and
thereby improve the customer's waste reduction and recycling incentives.  And
although it is true that landfills do  not fill up because they are too heavy,  and
many jurisdictions pay for disposal  based on a volume measure (cubic yards), a
weight-based approach shows particular promise because:  1) quick measures of
small volume measure increments would be difficult to implement and may
require judgment on the part of the field staff, and 2) technologies to
accurately measure small increments of weight are convenient to use, well-
accepted, and proven in the marketplace (scales).

The objective of the project is to do a field test of a system of this type to
begin to determine whether such a  system might be feasible.  This project  has
several major tasks.

  o    Identify  and install weighing/scanning equipment.  The preferred system
       would simplify or minimize changes to  current collection procedures.
       More complex collection procedures would lead to  higher long-term  labor
       costs for collection and adversely affect the cost-benefit analysis.   The
       initial system that was  considered was a truck-mounted automatic
       scanning device to read bar-codes on the individual garbage cans, with
       the weight for each can automatically recorded, to be downloaded into a
       billing computer.  This automatic  approach would minimize the
       collection system changes, requiring generally one step to register the
       weight.

  o    Field test the system on customer routes.  This includes modifying the
       installed system as operational  or mechanical difficulties are found.  A
       three-month field test was envisioned.

  o    Customer studies.  Customers on the selected routes will receive  bi-
       weekly statements that summarize for them the amount of waste they
       disposed. This phase of the  project includes an evaluation  of customer
       behavior pre- and post-to see if the dummy bills caused them to  reduce
       waste, evaluating a survey to determine effectiveness of the approach
       based on socio-demographic  and behavioral factors, and to  elicit  feedback
       on the system.

  o    Estimate costs and benefits of  the system.  This part of the project
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      includes an evaluation of the system costs, accuracy, time/convenience,
      learning skill, reliability and durability, results regarding collection and
      system changes, effectiveness, payback, and tradeoffs.

  o   Dissemination of results. The results of this EPA-sponsored project will
      be fully available.  If the approach is successful, it is hoped that private
      industry (truck and scale companies)  will work to further develop and
      enhance the technology on a larger-scale basis.

HOW FAR ALONG IS THE PROJECT?

At this point, the project has selected one technology and is doing preliminary
field testing.
Scale:  The scale technology being evaluated is a small industrial crane scale.
A crane scale is  primarily a hook and load cell suspended at the back of the
truck.  The barrels are hung on the hook manually by their handles.  The
system is  based  on available technology,  can be installed so that it minimizes
the external attachments that could be damaged by ground or alley clearance
problems, weighs consistently on grades and inclines, and fits easily into the
current collection system.  During later stages of the project, we are examining
the feasibility of retrofitting the cart dumper to weigh the barrels during semi-
automated dumping.  This  technology would be  less labor intensive and may be
more applicable to systems in other jurisdictions.

Scanner:  It has proved infeasible to have a truck-mounted automatic scanning
system because no rugged technology is currently available.  Instead, the
project is using  a bar code system that uses a 'rugged-ized' hand-held module
(that is mounted in a bracket on the truck)  and requires the use of a manually-
activated  "gun" to read the bar code. This two-step process (hanging the can
plus activating the "gun") is still simple, but may not be efficient from a labor
point of view.  The project will be evaluating whether the "gun" bar code
reader can be mounted in a holster and the programming modified so that the
system can automatically read the bar codes on the cans.  Although radio
frequency may provide a quicker data collection  method, installation and
purchase cost have been  prohibitive for the field test. This technology may
show promise for full scale implementation.

Logger: Data storage during collection is in the portable data collection unit.
Data from both the bar code scanner and the scale are stored here, and
uploaded and downloaded to a PC for updating the customer file and preparing
the biweekly customer reports.

The field test is  expected to continue throughout the summer,  with a report


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due in early fall. Information on the project will be available at its conclusion.
Preliminary information certainly demonstrates the equity benefits of the project
in that there was considerable variation in the amount of waste currently being
disposed in similar-sized containers -- one test run showed variations between
10 and 63 pounds of waste in identical 32-gallon cans!

Although this is an experimental project, it  is hoped that in the long run, a
system can be developed that is practical and flexible for use in the variety of
solid waste collection services.  Such an approach has the capability to be more
equitable than current approaches and to provide significantly unproved waste
reduction and recycling incentives.
SUMMARY

Many solid waste jurisdictions are facing tough challenges.  Landfill space is
becoming a problem, and jurisdictions need ways to reduce the amount of
waste going to increasingly expensive disposal facilities. Expensive recycling
programs are being under-utilized.  Variable rates give  an economic incentive
for customers to reduce the waste they dispose of, and provide incentives for
recycling and waste  reduction.

Variable rate systems are fair and effective, and provide a number of other
advantages, including:

  o   they can be implemented in a variety of situations
  o   the rates can  be implemented relatively quickly
•  o   variable rates can lead to system savings, and
  o   they integrate well with other programs, increase participation in
      recycling programs, and reinforce waste-reducing behavior.

There is no doubt that, from a variety of perspectives,  many jurisdictions could
benefit  from replacing their current fixed-rate systems with volume-based rates.
Variable rate systems work, and make a great deal of sense from a system
perspective.  A variable can rate structure has proven to be one  of Seattle's
most effective recycling programs, and bag systems have proven  to be very
effective in a variety of smaller communities. The rates are a vital part of the
Seattle's integrated solid waste system,  and have allowed that Utility to set an
aggressive, but achievable. 60% recycling goal.  Seattle's customers have
responded well to a rate structure that  gives them alternatives and control, and
they have responded with high levels of private recycling,  very high
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participation levels in City-sponsored programs, significant reductions in service
levels, and significant decreases in the waste brought to landfills.  Customers
have become an integral part of the solid waste system.
For further information, contact:

Lisa A. Skumatz, Ph.D.
Synergic Resources Corporation
1511  Third Avenue, Suite 1018
Seattle, Washington 98101
(206) 624-8508
To order a copy of the Variable Rate Manual,
contact:

Winnie Hooker
EPA Region 10, HW072
1200 Sixth Avenue, 7th floor
Seattle, Washington  98101
(206) 442-6640
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              ZONING FOR RECYCLING

                   Patricia H. Moore
               Moore Recycling Associates
                    Presented at the
First U.S. Conference on Municipal Solid Waste Management

                    June 13-16,1990
                           761

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                     ZONING FOR RECYCLING

INTRODUCTION

Solid waste disposal is becoming an increasing problem throughout North
America. As a result of rising costs for waste disposal, there has been an increase
in the number of waste reduction and recycling facilities. Increasingly, these
facilities are running into barriers to their development in the form of local
zoning ordinances which often do not address  recycling facilities or, when they
do address them, it is in very narrow terms.

HISTORY OF ZONING

The U.S. Supreme Court approved the concept of zoning in 1926 with Euclid v.
Ambler Realty Co. (272 U.S. 365), and has since upheld zoning unless it was
arbitrary or denied the owners all reasonable use  of their property.  According to
Alexandra Dawson, in Landuse and The Law. "Every state now has a zoning act
or a zoning enabling act authorizing cities, towns or counties to adopt zoning
codes".  Zoning was originally used as a tool to protect the "highest and best use,11
normally single family homes, from less desirable uses (multi-family dwellings
or industry), which might lower property values. Thus, from its inception
zoning was not used to create a comprehensive land-use pattern which could
make the best use of natural, economic and social resources, but to protect the
aesthetics and property values of neighborhoods.
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Concern about the denial of all reasonable use of property, known as "the taking
issue" has led to the institutionalization of a variety of options for property
owners who want to pursue a use for which their property is not zoned.  The
most common option is the variance which allows a local board to vary the
zoning when it would create a hardship to the owner, thus denying the owner
use of his or her property.  The variance has come under considerable criticism
because of its misuse. It is  often used when better solutions, such as reclassifying
the use, may prove to be a lengthy process or cause political difficulties.

RECYCLING CENTERS AND ZONING

Recycling is quickly becoming an integral part of solid waste management. As ?.
rapidly expanding industry its relationship to land-use is still unclear. Public
officials, planners and politicians are becoming aware that there is an increasing
need for recycling facilities  and that there are many sizes and types of recycling-
operations.  Yet most local governments still do not have provisions in their
zoning  ordinances for the proper siting of the various types of recycling facilities.
In many cases all recycling  centers are classified as salvage yards which are
traditionally zoned as light industry.  While this may be appropriate for large
processing centers, which have little contact with the general public, it is  highly
undesirable for a buy-back  center which is set-up to provide the public a
convenient location to bring such recyclable materials as aluminum cans, glass
bottles, newspaper and plastic bottles. In addition, as waste processing becomes
more sophisticated, there is growing concern over  the definition of a recycling
center versus a solid waste facility.
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CAN PAK RECYCLING INC

Can Pak Recycing, Inc. is an example of a business which encountered a zoning
problem. Can Pak Recycling, Inc. tried to set up a buy-back center in an old two
bay gas station/convenience store, in Del City, OK.  Del City is a middle-class
bedroom community near Oklahoma City with a population of around 30,000.
The local zoning ordinance, voted into effect in March, 1987 after a three year
study, considers all permanent recycling operations as salvage yards classified as
light industry.

Can Pak, Inc. operates buy back centers nationwide, though it primarily operates
in the west, midwest and southeast. It is a subsidiary of IMS Recycling Servicss
of San Diego CA.  Oklahoma City area manager Jim Jenkins, oversees two
successful buy-back centers currently operating in nearby Norman and Nicoma,
OK, as well as a central processing facility in Oklahoma City. He hopes to open
several more satellite  facilities (buy-back centers) which will be serviced by the
Oklahoma City processing facility.

The proposed site, in Del City was located in a Cl zone (commercial zone), in a
residential neighborhood on a corner lot of a major east/west thoroughfare, East
Reno Street, a section  line road1.  Mr. Jenkins expected about 25 to 30 cars per day
would bring material  to the center, with the busiest days being Mondays and
1 The term "section line" refers to the division of the area into 640 acre parcels when the territory
  was first homesteaded.  The borders of these sections have naturally become major travel routes.
                                  764

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Saturdays.  Can Pak's goal was for the facility to bring in 4000 Ibs./week of
aluminum cans.  According to Mr. Jenkins, there was plenty of parking to
accommodate the expected flow of traffic.

A successful buy-back center needs to be convenient and attractive.  Consumers
generally don't want to go out of their way or to traditional areas (industrial
zones), to recycle their bottles, cans and paper. Participation is much higher if the
public can recycle materials as easily as they buy goods at their local convenience
store. It is  important for the facility to be neat, clean and attractive to the general
public.  Mr. Jenkins explained  that as well as being concerned about the esthetics
of their facilities, Can Pak uses low noise aluminum can densifiers to avoid
disturbing  the neighbors.

Mr. Pat Salvator, Regional Director of Can Pak Recycling Inc., explained that the
facility was given both the electrical permit and building permit but when they
tried to get an occupancy permit they were denied due to the zoning discrepancy.

Mr. Jenkins questioned the City Planner about why two buy-back operations, run
by Reynolds Aluminum, consisting of tractor trailers parked in privately owned
parking lots in a commercial zone, had no trouble getting permits.  The City
Planner knew nothing about the Reynolds trailers, which were operating wi:h
the permission of the parking lot owners but without any City permits. The City
Planner felt this brought up some  "question of the legality" of the Reynolds
operations and an "investigation" was launched. According to the Chief
Inspector of Code Enforcement for Del City, the decision was to grant 90-aay
                                  765

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outdoor use permits, as they would for a parking lot tent sale, though the matter
has not been settled.

Mr. Jenkins, after he "tried everything else", determined that Can Pak's only
option was to try to have the lot rezoned as light industrial.  Because of the
wording of the zoning ordinance there were no grounds for a variance and no
"permit by right" exists in the ordinance, so reclassifying the use or rezoning
became the only possible solutions if Can Pak wanted to keep the buy-back center
at the proposed location. Reclassifying is a much lengthier procedure than
rezoning. As a result, Can Pak filed to have the lot rezoned to light industrial.

To rezone, all abutting property owners have to be notified and  a public hearing
must take place.  Although there were no objections from the public at the
meeting, Can Pak had to withdraw their request for rezoning because the light
industrial zone requires a minimum one acre lot size. The lot in question  was
.29 acres. Frustrated, Mr. Jenkins noted "we are trying to get the public and public
officials to understand that we're not a junkyard", though he admits it will be a
"long drawn-out process" because "nobody has figured out what procedures to
use to get away from the junkyard  image."

Ironically, everyone involved, including Del City officials and Can Pak
employees, understands the value of having the recycling facility in Del City.  It
is simply that the zoning code has not allowed for a buy-back recycling center ir.
the use classifications.
                                  768

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CALIFORNIA'S SOLUTION (AND THE SOLUTION'S PROBLEMS)

In recognition of the zoning barriers for commercial recycling centers and in
response to the enactment of the 1986 California Beverage Container Recycling
and Litter Reduction Act (AB 2020), the State of California has developed a
model local zoning ordinance for beverage container recycling.

AB 2020 states that there must be a certified recycling facility in every
convenience zone defined  as: within 1 /2 mile of a supermarket with $2 million
or more in annual sales. According to Tania Lipshutz of the California
Department of Conservation, Division of Recycling, this resulted  in the
establishment and permitting of approximately 2,000 new recycling centers
within one year, as well as processing facilities to support them.

The Act permits local governments to adopt rules and regulations governing ;>.e
operation of mobile recycling units or reverse vending machines.  AB-2C20
prohibits any agency from denying permits for the operation of mobile recycling
units or reverse vending machines which have the permission of the property
owner and are located on property zoned for commercial or industrial use
within a convenience zone, unless the agency specifically finds  that the
individual facility would be detrimental to the public health, safety and well
being. AB-2020 does not address the permitting of other larger recycling facilities
or facilities outside of the  convenience  zones though the model zoning
ordinance does.
                                 767

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Ms. Lipshutz notes in her paper Zoning and Planning for Recvcline, presented to
the 1988 National Recycling Congress; "the Division [of Recycling] found that
elements of existing zoning ordinances  hampered the permitting of even these
small recycling centers, zoning ordinance amendments were often necessary,
since the ordinances often included:

       • Treatment of any type of recycling center as a junkyard, and therefore,
        restricting them to heavy industrial zones;

       • Prohibition of outdoor activities or outdoor storage in commercial or
        manufacturing zones;

       • Limited procedural options, requiring extensive and expensive use
        permits and architectural review for large permanent recycling cenrers
        and small donation centers alike; and,

       • Prohibition of any activity not specifically allowed in the zoning
        ordinance."

The model ordinance divides recycling  centers into five categories: 1) Reverse
Vending Machines, 2) Small Collection Facilities, 3) Large Collection Facilities, 4)
Small Processing Facilities and 5) Large Processing Facilities. The ordinance
defines the recycling terms used, determines the permits needed (see figure 1),
and sets criteria and standards for each of the categories of recycling facilities.
                                  768

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                                      Figure 1
Type of Facility
Reverse Vending
Machine(s)
Small Collection
Large Collection
Zones Permitted
All Commercial
All Industrial
All Commercial
All Industrial
C-l
Other Commercial
Industrial
Permit Required
Administrative (or by right)
Administrative
Minor Use
Site Development
Site Development
Alternative
Permit
Minor Use
Minor Use
Minor Use
Minor Use
Light Processing


Heavy Processing
Heavy Commercial
All Industrial

Light Industrial
Heavy Industrial
Conditional Use
Minor Use

Conditional Use
Site Development
Conditional Use


Conditional Use
  	Source: California Beverage Container Recycling - Local Government Guide	

                                       f1

   In reviewing the ordinance there are two potential problems that could arise if it

   is adopted.  The first is the definition of a processing facility versus a collection

   facility. The distinction made in the model ordinance is the use of power driven

   equipment.  The ordinance fails to recognize that the use of volume reduction

   equipment is necessary for most collection facilities  to ship material cost

   effectively.  This is especially true for materials that have a high volume to

   weight ratio such as plastic bottles and aluminum cans, which are costly to ship

   without some densification.



   One possible solution would be to include performance specifications in the

   zoning law  to protect neighbors from unwanted noise and  (as mentioned in the

   model ordinance) unsightly operations.
                                      769

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The second potential problem is the definition of recyclable material: "Recyclable
material is reusable material including but not limited to metals, glass, plastic
and paper, which are intended for reuse  [emphasis mine], remanufacture, or
reconstitution for the purpose of using the altered form. Recyclable material
does not include refuse or hazardous materials."  This definition may be a
problem because, as landfill tipping fees rise, the recovery of materials is
becoming more sophisticated and the distinction between recyclables and refuse
is becoming less obvious. Without a  clear definition of what constitutes
"recyclable" material there is  the potential for the permitting of recycling centers
which in reality are waste transfer stations or facilities which are stockpiling
materials "intended for reuse" but for which there is no market.3

One solution could be to specify designated  materials as being "recyclable" but
this may have the unwanted effect of discouraging the development of new
recycling technologies.

NEW JERSEVS SOLUTION (AND THE SOLUTION'S PROBLEMS)

The New Jersey Department of Environmental Protection (NJDEP) is curreniiy
struggling with the problem of defining a recycling center. Under New Jersey's
law, solid waste facilities are exempt from local zoning laws and recycling centers
are considered solid waste facilities.  However, recycling centers do not  have to
go through  the rigorous Environmental Impact Statement (EIS) process and are
not regulated by the State.  The only requirement is that recycling facilities musi
3 Many state and local statutes cover this problem by specifying a time limit for storage.
                                  770

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be in the County Solid Waste Plan. This has led to a few facilities taking
advantage of the system and calling themselves recycling centers when they are
actually waste transfer stations as well as recycling centers.

As per N.J.S.A. 13:lE-99.34 " no recycling center shall receive, store, process or
transfer any waste material other than source separated nonputrescible or source
separated commingled nonputrescible metal, glass, paper, or plastic containers,
and corrugated and other cardboard without the prior approval of the
Department."  With the increasing profits to be made handling solid waste ir is a
difficult law to enforce.

The problem became headline news in New Jersey when on August 7,1989, a fire
at Hub Recycling & Scrap Co. buckled a portion of Interstate 78 in Newark.  Hub,
which had declared bankruptcy in 1987, built up 30-foot piles of debris, most c: it
on neighboring property, using the recycling center as a front for an illegal
landfill.

Prior to the Hub fire, Senators Contillo, Costa, and Ambrosio introduced an act
amending the New Jersey Statewide Mandatory Source Separation  and Recycling
Act to "facilitate the growth and development of commercial recycling activities
in this State." The bill, which has been  accelerated through the legislative
process since the Hub fire, attempts to set definitions to distinguish between
regulated solid waste facilities which also engage in recycling activities (termed
by the bill as "recycling facilities") and unregulated facilities which are strictly
commercial recycling operations (termed by the bill as "recycling  centers"). In
                                   771

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addition, the bill requires the, newly defined recycling centers to be licensed by
the DEP. The revenues from the fees collected are to be used by the DEP to
support enforcement, including the periodic inspection of licensed recycling
centers to ensure that they are not accepting solid waste.

The definitions for recycling operations are very clear:

       "Recycling center" means any facility, including a scrap processing
       facility, and designed and operated solely for receiving, storing,
       processing and transferring source separated, nonputrescible or
       source separated commingled nonputrescible  metal, glass,  paper,
       wood, rubber, plastic and plastic containers, and corrugated and
       other cardboard, or other recyclable materials approved by the
       department, and licensed under the provisions of section 5 of P.L.
       1988, c. (now before the Legislature as this bill);

       "Recycling facility" means any transfer station or other solid waste
       facility at which putrestible or nonputrescible solid waste is accepted
       for disposal or transfer and at which recyclable materials are
       separated or processed from solid  waste onsite for the purposes of
       recycling:

Originally, the bill was not well received because it placed an additional burden
on the operators of legitimate recycling centers but, due to the Hub fire, it becarr.
dear that such legislation was needed.
                                   772

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SUMMARY

As the volume of waste and cost of solid waste management increases the
viability of more extensive recycling and waste reduction activities will also
increase and decisions to determine the best land-use options will become more
complicated.

It is important for all public officials, like those in California and New Jersey, to
recognize that these issues exist.  We must begin to address them by using the
available tools.  One of these tools, zoning, will be extremely useful for attracting
the kind of private sector initiatives necessary to help solve our growing solid
waste problem. With zoning which encourages recycling operations of all types,
a city, town or region can expect to see an increase in commercial recycling
activities which will mean an increase in jobs, a boost for the local economy £r.d
a reduction in the amount of solid waste needing disposal
                                   773

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COMBUSTION

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                 CHALLENGE OF COMPLIANCE
                WITH EPA'S NEW MUNICIPAL
     WASTE COMBUSTION REGULATION - MDDTJLAR FACILITY
                 PASCAGOTJLA,  MISSISSIPPI
                    Lloyd J. Corapton
                        President
                Comptcn Engineering, P.A.
                 Pascagoula, Mississippi
                    Presented at the

First U.S. Conference on Municipal Solid Waste Management

                    June 13-16, 1990
                            775

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I.  ABSTRACT
      The Pascagoula Energy  Recovery T^acility  is   a typical  european
style ness-bum excess air facility.   It houses  two (2)  solid  waste  75
ton/day modular units capable  of  producing   an  average  of 151 million
pounds of steam  per  year.    The  steam  generated  is  sold to Morton
International, a nearby chemical plant.  Although the facility  is owned
by the City of Pascagoula,   it  is  considered a regional plant.  The
plant is located in the adjoining City of Moss Point and  receives solid
waste from Pascagoula and  Moss  Point  as  well  as  over  50% of Jackson
County.

      The  plant,  the  first  and    only   facility  of   its   kind   in
Mississippi, has been in  operation   since  1985,  has since incinerated
over 180,000 tons of solid waste and   generated over 800  million pounds
of  steam.    Attachments  to  this    paper   are   furnished containing
additional information on this system.

      This paper is  presented  to  discuss   the   impact   of the USEPA
Proposed Environmental Guidelines,  particularly  their effects  on small
scale modular facilities.
 II.   INTRODUCTION
      The  topics  discussed   in  this  paper  are  in  response  to the
proposed rules of Emission Guidelines  for  municipal waste combustors
including:  controlling   emissions    from   existing  municipal  waste
combustions  (MWC)  and  recent  USEPA  notices  relative to pending ash
disposal legislation.     The   overall  goal  of  these guidelines is to
reduce air emission pollutants by 90%.

      We have attempted  to discuss each of the proposed regulations and
compare them with existing performance  based on current test data.  Vfe
have also  estimated the  cost  of  the  improvements required to meet the
new standards.

      In generally, the  following topics are discussed:

                              MWC Emissions
                          Materials Separation
                           MWC Ash Disposal
 III.   MWC EMISSIONS


       Based on the proposed guidelines,  the  emission requirements are
 divided into several categories:

                               Page 1

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                     Best Demonstrated Technology
                             MWC Organics
                              NWT Metals
                            M3W Acid Gases
                          Coirbustion Control
                 Certification and Operation Training

1.  Rest Demonstrated Technology

      According to the guidelines for  small scale facilities, the best
demonstrated  technology  requires  (1)  good  combustion  and   (2)  an
electrostatic precipitator.  We believe  the Pascagoula plant basically
fits these guidelines, therefore,  capital  or operation cost increases
are not expected.

2.  MV
-------
tons/day.

5.  Combustion Control

      The CO emissions at the  facility  have  been  tested at less than
100 ppmv.  The exact CO content of the flue gas has not been accurately
determined.  However, since the unit operates en excess air with a flue
gas O2 content of 15%, the proposed CO limit should be easy to achieve.

      The proposed flue gas temperature   limit of 450 degrees F or less
is consistent with present operations at  the facility.  The temperature
is measured upstream of the PM control device.

      We object to the proposed  continuous  monitoring locations.  The
guidelines require testing for the  flue gas CO level at the inlet to
the electrostatic  precipitator.    We  feel  the  location  should  be
dovnstream  of  the  device  since   upstream  measurements  result  in
increased  maintenance.    Additionally,   a   continuous  load  weight
measuring device at  the  MWC  was  installed  as  part of the original
design.  We found  this  equipment  inpossible  to  maintain as well as
inaccurate in measurement.

      We believe daily monitoring of the  waste via mass balances (total
in minus bypass and  oversized bulky  waste)  will  provide sufficient
records.

      Regarding  continuous    temperature   monitoring,  the  facility
maintains  adequate  temperature  records since  this  information  is
imperative for proper operation of a steam plant.

      We estimate the cost for installing the  added monitoring system
(including the opacity meter)  at $  100,000.  The annual operating cost
is approximately $ 5,000/year.

6.  Certification and Operator Training

      We support the  requirement  for  certification  by  the American
Society of Mechanical Engineers  (ASME)  for the Chief Facility Operator
and Shift Supervisor.  The  facility  presently  is under contract to a
private operating firm which monitors  their owi certification program.
Standardization to  the  ASME  regulations  would  assure the City that
operators  possess  adequate    "knowledge  of   conbustion  and  power
generation.   It is possible that  operation certification will cost  the
City  an initial  cost  of  $   10,000  and an  annual   labor  cost of $
30,000/year.
 TV.   MATERIAL SEPARATION
       The proposed 25% reduction  will  have  an  adverse effect en  the
 facility.  This  will  result  in  a  tonnage  reduction from 36,000 to

                               Page 3

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27,000 tans/year.  For the purpose of  evaluation, we have assumed that
50% of the glass, metals and plastics  are  recycled, 10% of the garden
wastes are composted and 25% of  the  paper waste  is recycled.  The BIU
loss plus the reduction of disposal  fees result in a 25% revenue loss.
This would  increase  the  tipping  fee  from  $   17.40/ton  to  over  $
26.00/ton  (over  $  240,000  annual   increase).   Since  two  private
landfills will charge approximately  $   18.00  per ton  for hauling and
disposal, the increased cost  will  more than likely make the facility
non-competitive.

      We have reviewed two material  separation methods  (1) curbside or
source separation and (2) separation at  the plant.  There are potential
financial benefits for the facility for  separation at the plant en site
separation will maintain  waste  volume  at  current levels and provide
income from material sales.  These benefits, however, do not offset the
added cost of plant modification and operation and maintenance.  In our
opinion, therefore, curbside separation  is the  only viable option.

      Unless consistent markets can provide sufficient income to offset
costs, it is doubtful that communities   around Pascagoula will continue
to support the facility.  These communities will more than likely elect
to utilize the less expensive option of  landfilling.

      We support the material  separation  and  recycling options, they
are  viable   in  larger    populated   areas   with   limited  disposal
alternatives.    In  Mississippi,  however,  the   markets  for recycled
materials are scarce,  and  the  County  may  not  produce a sufficient
volume to entice long-term agreements.

      We believe that incineration is  a  form of  solid  waste reduction
and  at least  the reduction programs be site specific in  areas where  (1)
the  costs are not prohibited,   (2)  the  waste volume is significant to
entice markets, and  (3) the reduction  requirements are  applied only to
landfills or  incineration which are not  producing  an energy by-product.
An energy recovery system is  a   form  of  recycling by  reducing fossil
fuel requirements and  conserving energy  for   future generations.  We
feel the requirements  should  at least be  delayed  until sufficient
markets  for recycled materials have been established to  offset the cost
of material separation and handling.
 V.  MWZ ASH DISPOSAL
       Presently,  the  Pascagoula  facility  deposits  the  ash from the
 facility in a monofill.   The site was constructed in 1988, specifically
 for ash, by a private contractor.    The  facility includes grcundwater
 monitoring wells  and leachate  collection.   The monofill is located in
 an area having over  40  feet  of  clay  liner  and  so  far  has been
 successfully operating.     Tests  have  been  performed to quantify the
 dioxin/furan content. The results indicate the dioxin and furan levels
 are 0.107 ppb, well below  the  maximum  allowable concentration of 1.0

                               Page 4

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      Additionally, the ash is  tested   for  heavy metals  (EP toxicity)
both at the plant and  at  the  ash  disposal   site.  Based on over  100
samples,  no  metals  above   the    maximum concentration   have  been
encountered.  The tests performed  are   based   on  composite ash samples
from the following locations in the  facility:

           Bottom Ash                     93.5%
           Undergrate                      5.28%
           Post Combustion Units           0.03%
           ESP Fly Ash                     1.06%

      Future legislation may impose  additional  requirements on ash from
the facility.  We feel that only the fly ash should be regulated. -The
remaining should  be  approved  for  use  as road fill,  cinder block
manufacturing, etc.  We recommend test   programs be widely initiated to
demonstrate the uses  of  ash.    Based   en  cur   experience  at the  ash
landfill, we have found that ash is  an excellent road base material  and
may have a high market potential  in South  Mississippi due to the lack
of conventional fill materials.

      Although  regulations  have  not   been completely   developed, we
understand that the EP toxicity  test  will  be  modified with  additional
testing  required.    If  annual  .tests   are required  to measure  the
dioxin/furan contents, we estimate an added  cost of $ 30,000/year.
VI.  SUMMARY AND COSJCLUSICN
      Overall,  small  scale   facilities   such  as   the   Pascagoula  Plant
 should have no  major  problems   meeting   the  majority of  the proposed
 emission  -regulations.       The     additional   testing and  monitoring
 requirements, however,  will add  substantially   to  the operation and
 maintenance costs  at  the  facility.   If a material separation program  is
 mandated, the cost increase  will be even more  significant.

      Summarizing,  the added costs  at the facility are:

                        Estimated Cost Increase
                      Based on Proposed Regulations

      Item                   Capital           Annual       $/Ton (1)

 Demonstrated Technology        -0-              -0-
 Organic Emissions              -0-           ?   30,000
 Metal Emissions               -0-              10,000
 Acid Control                   -0-              -0-
 Combustion Control        $ 100,000           5,000
 Certification                 10,000           30,000
 Material  Separation           -0-             240,000

                               Page 5

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Subtotal                   $ 110,000        $ 315,000        11.66

Annual Cost of Capital (2)                     16,000         0.59

Total Annual Increase                       $ 331,000        12.26

Existing Fee                                                 17.43

Adjusted                                    $ 29.69/Ton      29.69

% Increase                                    70%

(1)  Based en 27,000 tons/day from existing 36,000 tons/day.

(2)  8% interest - 10 year payout.

      In  comparison,  landfill   costs   also   have  had   changes   in
regulations resulting in  increased  disposal  costs.  To control  these
added costs, regionalized landfills  have  been developed charging from
$ 12 -  $  15/tcn.    As  recycling  or  material  separation  becomes
mandatory, landfill costs will also increase.

      Material separation and recycling most be cost effective based on
the sale of recyclables.  This  requires  market development (presently
in  progress) and regionalized  recycling  centers.   Until  such time as
consistent  markets  for  recycled  materials  are  developed, it  is my
opinion that material  separation  will  increase  disposal cost at  all
facilities and compound the communities economic problems.

      The challenges that that each public official mist  meet are:

       1.  Finding the most cost effective nethod of meeting the
          environmental regulations of solid waste disposal.

and   2.  Determining the most acceptable method to the public.

      Most  decisions  regarding  solid   waste  are  based  solely   on
economics and public opinion.    If  the  public is willing to increase
their  taxes and/or user fees,  the  waste  streams will be  dramatically
reduced.  If not,  this  problem  will  continue  and  all  waste  in  our
region will be landfilled.

      To assist the communities in  these  decisions, the USEPA and  the
State Taivircnment Quality  Departments  mast  work  with site specific
requirements based  on  each  community's  environmental problems.   In
areas  like  Mississippi,  the  most  abundant  resource   is  land.   In
counties directly north of the  Coast,  land  is available  for $  300.00
per acre.  Since these  regions  are  sparsely  populated,  landfills in
most cases can be easily sited.   A  dramatic increase in environmental
regulations may force future disposal in Mississippi to  be  landfills at
the expense of resource recovery.

                               Page 6

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      Additionally, air pollution limits  should be considered based on
location and existing conditions, not blanket requirements for all.  A
2000 ton per day facility in downtown  New York City should be required
to meet more stringent regulations than a 250 ton per day plant in Moss
Point, Mississippi (population 19,000).

   Finally, we must combat environmentalists  vho express their opinion
without the basis  of  fact.    The  general  public responds to issues
emotionally and tend to sway political  decisions.  As a point in fact,
our  facility  was  recently  attacked  by  a  major  Washington  based
Environmental  Coalition  as  generating  a  "cloud  of  death"  due to
dioxin/furans.  Since  we  had  already  conducted tests to demonstrate
compliance, we contacted the  individuals  to determine their source of
information.  Their source was data  en  ten "similar" facilities, with
less than one half of these showing  problems.  The Pascagoula Facility
was included without basis of fact.

      Divircnmental protection is  an  issue facing all the population.
We feel it would  be  in  everyones  best  interest  for  our community
leaders, environmental leaders,  local  and state government officials,
and technical experts to work  together  to  help solve the problems we
face.  Through their  combined  cooperation,  they  can  find solutions
based on fact and community concern.
                               Page 7

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             CHARACTERIZATION OF MUNICIPAL WASTE
               COMBUSTION ASHES AND LEACHATES

                RESULTS OF TWO FIELD STUDIES
                       HAIA K.  ROFFMAN
                   AWD TECHNOLOGIES, INC.
                          ABSTRACT
Incineration of MSW has become an important alternative to the
land disposal of MSW.  Incineration is an effective means of
reducing the volume of MSW and can provide an important source
of energy.   Ash from the combustion  of  household waste has
been excluded from regulations under Subtitle C of RCRA, which
regulated  disposal of hazardous  wastes.   However,  in  some
instances   testing  the  residues   from  municipal   waste
incinerators by the Extraction  Procedure (EP)  Toxicity test
is being  required to determine  if  these  residues  would be
classified  as  hazardous  waste and, therefore,  subjected to
disposal  regulations  under  Subtitle C.    Ashes  from  MWC
facilities,  on  occasion,   have   exhibited hazardous  waste
characteristics as  determined by  the  EP  Toxicity  test.   The
debate regarding  the representativeness  and  the validity of
this  test  and the relation  of these   results  to  actual
leachates from ash disposal facilities has not been settled.

For  this  reason,  EPA and  CORRE have  cosponsored a  study
designed to  enhance the  data  base on  the characteristics of
MWC ashes,  laboratory  extracts  of MWC ashes,  and leachates
from MWC ash disposal facilities.  Ash samples were collected
from 5 MWC facilities and leachate samples were collected from
the companion  ash disposal sites.   These ash  and leachate
samples  were  analyzed  for the  Appendix IX  semivolatile
compounds, polychlorinated dibenzo-p-dioxins/polychlorinated
dibenzofurans (PCDDs/PCDFs), metals  for which Federal primary
and secondary  drinking water standards  exist, and several
miscellaneous conventional  compounds.  The ash samples were
also subjected to  six laboratory extraction procedures and the
extracts were then analyzed  for the  same compounds as the ash
samples.  All sampling, laboratory preparation, and laboratory
analysis followed stringent  quality assurance/quality control
(QA/QC) procedures.
                            777

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A major environmental  concern regarding the effects of ash-
monofill  leachates  is   the  long-term  changes  in    the
composition of such leachates.  To address this concern, EPA
has  committed to  study  such  effects  at the  Woodburn Ash-
Monofill located in Marion County, Oregon.  To date, the EPA
selected monofill was visited three times during the past two
years.  Ash,  leachate, and  soil  samples were collected and
subjected to  the same testing and QA/QC procedures  as the
CORRE/EPA study samples.

The major findings of these two studies  are described in this
paper.
                        INTRODUCTION
This paper provides  a  summary  of the findings provided in a
recent report which  has  been prepared for the United States
Environmental Protection Agency (EPA) and the  Coalition on
Resource Recovery and the Environment (CORRE).  EPA and CORRE
have cosponsored this  study  to enhance the data base on the
characteristics  of  MWC  ashes,  laboratory  extracts  of  MWC
ashes, and leachates from MWC ash disposal facilities.

The Coalition on Resource Recovery and the  Environment  (CORRE)
was established to  provide credible information about resource
recovery and associated environmental issues to the public and
to public officials.   In providing information,  CORRE takes
no  position  as to  the  appropriateness  of   one  technology
compared to  others.   CORRE recognizes that successful waste
management is an integrated utilization of many technologies
which  taken  as a  whole, are  best selected  by  an  informed
public and informed public officials.

Incineration  of municipal solid waste (MSW) has become an
important waste disposal alternative because it provides an
effective means of reducing  the volume of MSW as well as an
important source of  energy recovery.   Currently,  10 percent
of the United States MSW  is incinerated.   Based on the number
of municipal waste combustion  (MWC) facilities being planned
across the country,  this percentage is expected to increase
to 16-25 percent by the year 2000.

As incineration of MSW has increased in recent years, so has
concern over  its management.   To resolve  the many legal and
technical issues   surrounding  ash,  Congress  is  considering
several legislative initiatives that would classify municipal
waste combustion (MWC)  ash as a special waste under Subtitle D
of  the Resource Conservation  and  Recovery  Act  (RCRA)  and
require the Environmental Protection Agency  (EPA) to develop
                          778

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special management standards for the full life cycle of ash.
In anticipation of Congressional action, EPA and the Coalition
on Resource Recovery and the Environment  (CORRE) cosponsored
this  study  to  characterize  ash  and  to  gain  a  better
understanding of how it behaves in the environment.

To provide long term ash,  leachate, and soil characterization
data, EPA committed  to a  long-term (several years)  study at
an EPA selected ash-monofill.   EPA  selected the Woodburn Ash-
Monofill  located  in Marion County,  Oregon.    To  date,  this
disposal facility was  sampled three times.
             DESCRIPTION OF THE CORRE/EPA STUDY


Combined bottom and fly ash samples were collected from five
mass-burn MWC facilities and leachate samples were collected
from the companion ash disposal sites.

The  facilities  sampled were selected  by CORRE  to  meet the
following criteria:

   o    The facilities were to be state-of-the-art facilities
        equipped  with   a   variety  of   pollution   control
        equipment.

   o    The facilities were to be located in different regions
        of the United states;

   o    The  companion ash disposal  facilities  were  to  be
        equipped with leachate collection  systems  or some
        means of collecting leachate  samples.

The identities of the  facilities are being held in confidence.

The ash and  leachate  samples collected were analyzed for the
Appendix    IX   semivolatile   compounds,   polychlorinated
dibenzo-p-dioxins/polychlorinated dibenzofurans (PCDDs/PCDFs),
metals for which Federal primary and  secondary drinking water
standards  exist,  and  several  miscellaneous   conventional
compounds.   In addition,  the ash  samples were analyzed for
major components in the form of oxides.

The  ash  samples  were  also  subjected  to   six laboratory
extraction procedures and the extracts were then  analyzed for
the same compounds as  the original ash samples. The following
six extraction procedures  were used during this  study:
                          779

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   o     Acid Number 1 (EP-TOX)
   o     Acid Number 2 (TCLP Fluid No.  1)
   o     Acid Number 3 (TCLP Fluid No.  2)
   o     Deionized Water  (Method  SW-924),  also known  as the
        Monofill Waste Extraction Procedure  (MWEP)
   o     CO2  saturated deionized water
   o     Simulated acid rain (SAR)

These extraction procedures have been used  separately by a
variety of  researchers on MWC ashes but never have all six
procedures been used on the same MWC ashes.  This was intended
to compare the analytical results of the extracts from all six
procedures with  each other  and with leachate collected from
the ash disposal sites used by the MWC facilities.

All sampling, laboratory preparation, and laboratory analysis
followed  stringent  EPA quality  assurance/quality  control
(QA/QC)  procedures.   The detection  limits  of the analytical
methods  used  were  well  below   present  levels  of  human,
environmental, or regulatory concerns.

The EPA publication  "Interim  Procedures  for  Estimating Risk
Associated   with  Exposures  to  Mixtures   of   Chlorinated
Dibenzo-p-Dioxins and Dibenzofurans  (CDDs and CDFs)" was used
to evaluate  the  dioxin data.  These procedures  use Toxicity
Equivalency  Factors  (TEFs)  to express  the  concentrations of
the different isomers and homologs as an equivalent amount of
2,3,7,8-Tetrachloro  Dibenzo-p-Dioxin  (2,3,7,8-TCDD).    The
Toxicity  Equivalents,  as calculated by using the  TEFs,  are
then totaled and compared to the Centers for Disease Control
(CDC)  recommended  upper  level  of  2,3,7,8-TCDD  Toxicity
Equivalency of 1 part per billion in residential soil.

The major features of the  five MWC  facilities and ash sites
sampled are  provided in Table 1, and  Table  2  respectively.
Pertinent information on the operating conditions of the MWC
facilities,  as  well  as information about the air pollution
control equipment used is also provided in Table 1.
                            780

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           CORRE/EPA STUDY RESULTS AND CONCLUSIONS
Major  findings of  and conclusions  drawn  from  the results
obtained  from  the  sampled  ash,  natural  leachates,   and
laboratory  extracts  are summarized in the paragraphs which
follow.
                    Ash Analysis Results
Of the five ash samples (one from each facility) analyzed for
the Appendix IX semi volatile compounds, four samples contained
bis(2-ethylhexyl)phthalate,   three    contained    di-n-butyl
phthalate, and one contained di-n-octyl phthalate.  Two PAHs,
phenanthrene and  fluoranthene,  were  detected in only one of
the  five ash  samples.   These  semi-volatile compounds were
detected in the parts per billion  (ppb) range.

The results for the ash samples analyzed for PCDDs/PCDFs are
presented in Table 3.  This table also includes the  calculated
Toxicity Equivalents (TE)  for each homolog  of PCDD/PCDF.  The
data  indicate  that PCDDs/PCDFs were  found at  extremely low
levels in each of the ash samples.  The Total TE for each ash
sample was well below  the Centers for Disease Control (CDC)
recommended Toxicity Equivalency limit of  1 part per billion
2,3,7,8-TCDD in residential soil.

All  25  of  the ash samples  (five  daily composites from each
facility) were  analyzed for the metals listed on the primary
and  secondary  drinking water standards as well  as  for the
oxides of five major ash  components.   Although,  the results
from  these analyses  indicate  that the ash is heterogeneous,
this heterogenicity appears to have been reduced by the care
taken when  compositing the  ash samples during  this study.
Data  from this  study showed less variability than  comparable
data  in the literature.

Metals  showing  the  widest  range of  concentrations  among
samples  collected at  each facility  included barium  (ZB) ;
cadmium  (ZB);  chromium (ZD,  ZE) ; copper  (ZA,  ZB,  ZC) ; lead
(ZD) ; manganese (ZA,  ZC) ; mercury (ZE); zinc (ZB,  ZD,  ZE) ; and
silicon dioxide  (ZA).

Metals showing the widest  variation of concentrations between
the  facilities  included barium  (results for Facility ZC are
lower  than  the results  for  the other  facilities) ;  iron
(results  for  each facility  vary  from  all of   the  other
facilities) ; lead (results for Facility ZD are higher than the
results  for the other  facilities);  mercury  (results  for
                         781

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Facilities ZC and ZD are lower than the results for the other
facilities);  sodium (results  for  Facilities ZD and  ZE are
lower than the results  for the other  facilities);  calcium
oxide (the results  for  Facilities  ZA and ZB are higher than
the results  for the other  facilities);  and silicon dioxide
(the results for Facility ZC are higher than the results for
the other facilities).

Some additional findings of the ash sampling and analyses are
as follows:

   o     The ashes are alkaline  with the pH ranging from 10.36
        to 11.85.

   o     The ashes are rich  in chlorides and sulfates.   The
        total soluble solids in the ashes  varied from 6,440 to
        65,800 ppm.

   o     The ashes contained unburnt total  organic carbon (TOC)
        ranging from 4,060  ppm (0.4 percent) to  53,200 ppm
        (5.32 percent).
                  Leachate  Analysis  Results
Only four Appendix IX semivolatile compounds were found in the
leachates.   Benzoic acid was found  in  two leachate samples
collected   at   one  site.    Phenol,   3-methylphenol,   and
4-methylphenol were found in the leachate samples from another
site.  All of these compounds were detected at very low levels
(2-73 ppb).

PCDDs/PCDFs of the higher chlorinated homologs were found in
the  leachate  from one  site  only.    This indicates  that
PCDDs/PCDFs  do  not readily leach out  of the ash.   The low
levels  found  in  the  leachates of  the  one  site  probably
originated from the solids found within the leachate samples
because these samples were not filtered  nor centrifuged prior
to analysis.

The metal content in the leachate samples did not exceed the
EP Toxicity Maximum Allowable Limits established  for the eight
metals in  Section 261.24 of 40  CFR 261.   Indeed,  the  data
indicate that although the leachates are not used as a source
of potable water, they are close to being acceptable as such
as far as the metals are concerned.
                             782

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The major constituents in the leachate samples was salt.  The
main  salt constituents  in  these leachates  were chloride,
sulfate, and sodium.  Additional observations on the leachate
analyses were:

   o    Sulfate values ranged from 14.4  mg/L to 5,080 mg/L,
        while  Total  Dissolved  Solids  (TDS)  ranged  from
        924 mg/L to 41,000 mg/L.

   o    The field pH values ranged from 5.2 to 7.4.

   o    Ammonia (4.18-77.4 mg/L)  and nitrate  (0.01-0.45 mg/L)
        were  present in almost all leachate samples.

   o    Total  Organic Carbon  values  ranged  from 10.6  to
        420 ppm.
                Ash Extracts Analysis Results
The  data obtained  during the  metals  analyses  of  the ash
extracts indicate, in general, that the extracts from the EP
Toxicity, the  TCLP  1,  and the TCLP  2 extraction procedures
have  higher  metals  content  than  the extracts  from  the
deionized water (SW-924),  the saturated CO2 solution, and the
Simulated Acid Rain  (SAR)  extraction procedures.

The EP Toxicity Maximum Allowable Limits for lead and cadmium
were frequently exceeded by the extracts from the EP Toxicity,
TCLP 1, and TCLP 2 extraction procedures. One of the extracts
from the EP Toxicity extraction  procedure  also exceeded the
EP Toxicity Maximum Allowable Limit for mercury.

None of the extracts from the deionized water (SW-924), the
saturated CO2  solution, and  the Simulated Acid  Rain   (SAR)
extraction  procedures  exceeded  the  EP  Toxicity  Maximum
Allowable Limits.  In addition, all of the extracts from these
three extraction procedures also met the Primary arid Secondary
Drinking Water Standards for metals.

Table  4  compares  the range of concentrations  of  the metals
analyses of the ash  extracts with the  range of concentrations
for leachate as reported  in the  literature and the range of
concentrations for the  leachates  as determined  in this study.
For the  facilities  sampled during this study, the  data in
Table  4 indicate that  the extracts from the  deionized water
(SW-924), the saturated CO2 solution, and the SAR extraction
procedures simulated the concentrations for lead and cadmium
                          783

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in the field leachates better than the extracts from the other
three extraction procedures.

Additional observations are:

   o    Of the five composite samples of the deionized water
        (SW-924)   extracts  analyzed  for  the  Appendix  IX
        semivolatile compounds  (one  from each facility), only
        one  sample  contained  low  levels  of  benzoic  acid
        (0.130 ppm).

   o    None of the extracts contained PCDDs/PCDFs.   These
        data confirm the findings of the actual  field leachate
        samples that PCDDs/PCDFs are not leached from the ash.
             DESCRIPTION OF THE LONG TERM STUDY
The Woodburn Ash-Monofill, located in Marion County, Oregon,
was selected by  EPA  as  suitable  to provide the needed long-
term  characterization  data of leachates generated  from the
monofill,  of  the  ashes aging in the monofill  and  of  the
surrounding soils potentially affected by airborne dust from
the ash-monof ill.

As  part of  the  EPA commitment  to study  these long  term
effects, EPA  sponsored the  first year study  (1988)  during
which two sampling trips were conducted and the results were
summarized in the report entitled:  Municipal Waste Combustion
Ash  and Leachate Characterization.  Monofill-Baseline Year.
which was published in August of 1989.  EPA  also sponsored the
second year study, which took place in 1989  and which resulted
in  a  report entitled:   Municipal Waste Combustion  Ash and
Leachate. Monofill - Second  Year  Study and was published in
January of 1990.

The soil, ash,  and leachate samples collected during the past
two  years  were  subjected to  the same chemical  analytical
testing as outlined previously for the CORRE/EPA study.  All
sampling and analytical procedures were subjected to the same
EPA required QA/QC protocols as the CORRE/EPA study.
           LONG-TERM STUDY  RESULTS AND CONCLUSIONS
Major  findings of  and  conclusion  drawn  from the  results
obtained from the samples collected during the past two years
(three trips)  from  the  Woodburn  Ash-Monofill are summarized
in the paragraphs which follow.
                          784

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                    Ash Analysis Results


As expected, the ash samples contained metals and low levels
of phenolic and phthalate compounds.

The  ash  samples  also  contained  low  levels  of  dioxins.
However,  the  2,3,7,8-TCDD  toxicity  equivalency   of  these
samples, calculated following EPA prescribed procedures, did
not reach  the center for Disease  Control (CDC) recommended
limit for residential soils of 1 ppb.
                  Leachate Analysis Results
The major constituent in the leachate samples, collected from
this  site,  is salt.   This agrees with  data  available from
other sites.  The total dissolved solids (TDS) levels ranged
from  approximately  one-third  to somewhat  higher  than  the
levels  found  in sea water.   The main  salt  constituents in
these leachates were chloride, sulfate, and sodium.

The  leachate  samples  contained  elevated concentrations of
total organic carbon (TOC) and ammonia-nitrogen.  The presence
of  these  constituents indicates that  uncombusted  organic
matter remains in the ash and anaerobic biodegradation may be
occurring.

As  expected,  the  leachate  samples  also contained  metals.
However, all metal concentrations in all leachate samples were
below the EP-toxicity maximum allowable limits.

The leachate samples were essentially free of dioxins and the
leachates contained essentially no semivolatile compounds on
the Appendix IX list.
                    Soil Analysis  Results
To  date,  the  soils in  the vicinity  of  the Woodburn  Ash-
Monofill have not been affected by the  airblown ash dust from
the  monofill.    The soil samples were essentially  free  of
dioxins and semivolatile compounds on the Appendix IX list.

The  soil  samples did  not  contain  metal  levels  beyond  the
levels  found in  the  site  background sample.    Those  soil
samples collected from locations close to roads,  which  are
                          785

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subject  to vehicular  emission effects,  contained somewhat
higher lead  levels  than the site background  sample and the
rest of the soil samples.

The soil samples collected from locations  close to roads also
contained somewhat higher  levels of  dioxins.   The levels of
2,3,7,8-TCDD toxicity  equivalency  in all soil  samples were
below one part per billion, which is the level recommended by
the CDC for residential soils.
              FUTURE LONG TERM  STUDY OBJECTIVES
Studies to be  conducted  in years to come at this  site will
provide data on time trends  for  the  ash,  the  leachates,  and
the  soils.   Some  data  gaps may be  closed,  and answers  to
important questions regarding the heterogenicity of the ashes,
the  varying  levels  of  TDS  in  the  leachates,   and  the
verification of the existence of anaerobic conditions in ash
monofills may be obtained.
                            786

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   ENVIRONMENTAL AUDITING OF RESOURCE RECOVERY FACILITY

                      DINESH C. Patel
Department of Environmental Protection,  State of  New Jersey
                     Presented at the

 First U.S. Conference on Municipal Solid Waste Management

                    June  13-16, 1990
                          787

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    Modern   society  today   is   the   product  of   constantly  advancing
technology.   Technological  progress is responsible for  our overall living
standard  and  also for  pollution  and  waste.   Ihe  production  of  waste
material  is an  inherent part  of  natural processes,  but nature,  in its
wisdom,  reuses whatever  it produces,  from fallen  leaves to  manures and
carcases, all  things  which  live,  and all the substances  which their body
exceret, are subject  to  decay,  a process which transforms organic waste in
to  nourishment for new life.   Mankind has  disrupted  this  natural  cycle
through  the sheer volume of its waste production and introduction of new
substances which do not breakdown and may poison the environment.

    Concerns for  the  environment  are  not limited to deterimental  effects
of  pollution,  but also  include recovery and utilization  of  resources now
reconized as finite.   It was  determined  that'energy contents of  all the
municipal waste  generated  in  U.S.  is equivalent  to 50  million  tons  of
coal.   Number  of  resource  recovery  facilities  continues  to  increases
rapidly  in  response  to growing  shortage  of landfill  space.  Resource
recovery facility  (Waste to Energy)  reduces the amount of material  to be
disposed of by 75  to 80% and  hense increases the landfill  lifespan; and
steam  generated  by  recovering  heat  of  combution  can  be  utilized  to
generate electricity.

    The resource recovery facility must not only meet  the solid waste
                                  788

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needs   of  local   community,  but   must  also   comply   with  applicable
environmental regulations, be acceptable  to public and be compatible with
the  environment.   Failure  to  recognize these  four  aspects  of  facility
development can result into a  filed project.   Facility  owner or operator
has a  responsibility to inspect such facility  at regular interval to make
sure  that the  facility continue  to  meet all  air,  water and  solid  waste
regulations.   In order  to perform an  effective  compliance  inspection of
resource  recovery  facility  the  inspector  must  be famililar  with  all
aspects  of facility  operation  and  the  regulations which  applys to  it.
This  protocol  is designed  to provide sufficient information to  carry out
compliance inspection of Resource Recovery Facility.
What is Resource Recovery Facility?

    The primary objective  of the resource recovery  facility  is to capture
the energy  released by combustion of solid  waste and to reduce the volume
of  solid  waste  to  be landfilled.  The figure  shows schematic of resource
recovery  facility:
    Trucks  enter in  the  receiving area  and unload directly in  to refuse
pit.   The refuse pit is sized  to hold  4  to 7  days  worth of trash.  Crane
operator  working from the overhead cabin control the grapple to move waste
from  refuse pit  to the feeding hopper.  From  the feeding hopper waste is
pushed by  a  ram  feeder  in to  combustion  chamber.    Here,  temperature
greater   than   2000  F  turn  garbage  in  to  ash.   Primary   and  secondary
combustion air  from the pit  is blown in,  below  and above the  grates
                                   789

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respectively to  fuel the  combution process in a furnance  and to maintain
negative pressure  over the  pit to  prevent  dust escape  and  to reduce the
odor.   Excess  combustion  of all  volatiles while  still in  the combution
chamber.   Heat  of  combustion  will  be  recovered  in  a  boiler  thereby
producing  superheated steam,  which will  be  used  to  drive  a  turbine to
generate electricity.   The  flue gases  from  the  boiler will  preheat the
boiler  feed  water  and  then  passes  through the  spray/wetscrubber  and
baghouse to control  acid  gases and to separate fly ash and then discharged
to atmosphere  through  a  stack.   Ash remaining in a  combustion chamber and
boiler will be removed by a ram discharger  and  then conveyed to a storage
area.  After determining characteristics of ash it will be dumped in a
appropriate landfill.
              AUDITING:
    All  facility  should establish  self  auditing procedure to  assure that
compliance  with  all  applicable  envirormental laws  and  regulations  is
maintained.   Advanced   preparation  should  remove  nearly  all   of  the
potential  surprises, and  assure  that  your facility  is  not  exposed  to
serious  legal risk  because of non-compliance with environmental  rules and
regulations.

    An environmental auditing of  an  operating resource  recovery  facility
should be a thorough examination of a facility's operating records and
                                   790

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environmental  practices,   gather  informations  about  its  compliance  with
federal  state  and  local  regulations and  to identify non-compliance  with
environmental  regulations  for  follow-up  corrective action.    Following
comprehensive checklist may vary  for each facility depending upon specific
permit conditions for respective facility.
                                  791

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                  HflttRGNMBHAL COMPLIANCE INSPECTION PEPORT
A.  General Information:
Name of the fadlilty:



Facility I.D. number :



Facility Address     :



Facility Manager &   :



  Phone Number



Date of Inspection   :



Inspected By         :
                                      792

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B.  Incoming and outgoing wastes:

                Conditions
                                                                      Y    N
  1. Are only permitted waste being accepted at this facility?
     (Permitted waste ID # 10, 13, 23, 25)                           	

  2. Are all wastes being accepted according to the approved
     delivery schedule                                               	  	

  3. Are all traffice control signs and/or measures implemented
     to provide, orderly vehicle movement?                            	  	

  4. Are only registered vehicles being permitted to off load
     their wastes at this facility             •                      	  .	

  5. Are all incoming vehicles equipped with functional exhaust
     silencer system?                                                	  	

  6. Is all waste being delivered to this facility at a rate that
     will not exceed the facility's capacity to store and/or process
     the wastes?  (Processing Rate 12 Tone/hr, Storage 800 Tone)     	  	

  7. Is there a continuous visual monitoring of all incoming wastes
     for unauthorized waste material?	  	
                                     793

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                                                                     Y    N
 8.  Are all unauthorized wastes pulled out from the waste stream,



    and segragate and stored in a secured manner?







 9.  Are spot checks being performed by facility personnel in



    accordance with the approved operation and maintenance



    manual?







10.  Have all noise control conditions been implemented?







    a. All ash haulage vehicles and ferrous metal transfer



       trailer, parking, connecting and disconnecting are to be



       conducted within the ash storage building.







    b. All ash and ferrous metal revocery being performed within



       the ash loading building with doors closed during loading



       operation.







    c. All vehicles should equipped with functional exhaust



       silencer system.







11. Is the operation of the facility in accordance with following



    conditions?
                                   794

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                                                                         N
    a. Odor associated with solid waste should not be dectected



       off site.







    b. The tipping floor entrance and exit doors should remain



       closed at all times other than normal operation hours.







    c. Air drawn off from the refuse bunker and tipping area



       should be used in combustion process.







12. Are non-processible waste materials, process residues  and



    recovered ferrous metals handled and stored according  to the



    following:







    a. Non-processible waste, process residues and recovered



       ferrous metals are to be stored within the confines of



       an enclosed facility at all times.







    b. All ash residue and recovered ferrous metals from the ash



       are to be stored within the ash load-out building and ash



       storage building.
                                   795

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                                                                           N
 13. Are all trailer/roll offs containers being loaded solely
     within the ash loadout building in a controlled manner  to
     prevent dusting, leakage, and spillage?

 14. Are all trailer/roll offs containers for ash labeled properly
     for tracking outside of the ash load-out building?

C.  Operational and Maintenance Requirements:

  1. Is the operation of the facility meeting the approved
     processing rates? (12 tons/hr or 108 million BTO/hr)

  2. Are all systems and related equipments kept in proper
     operating order at all times?

  3. Are all Emission conditions of Air pollution control
     permit being maintained?

     a.  So2 (Sulfur Dioxide)
     The 3 hour average concentration of So2 in the stack gas
     from a unit must be less than 20% of the average concentration
                                    796

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                                                                      N
of So2 at the inlet to the acid gas control equipment for
that unit.  However the concentration of So2 can never
exceed 100 ppmv on a dry basis corrected to 7% oxygen.

b.  HCL (Hydrogen Chloride)
For any one hour period the average conce. of HCL in the
stack gas of each unit shall not exceed 50 ppmv on a dry
basis corrected to 7% oxygen or 10% of the HCL concentration
at the inlet to the acid gas control equipment.

c.  CO (Carbon Monoxide)
For any one hour period the average concen. of CO in the
stack gas of each unit shall not exceed 400 ppmv on a dry
basis corrected to 7% oxygen.  However, the 4 day moving
average concen. of CO in the stack gas should not exceed
100 ppmv on a dry basis corrected to 7% oxygen.

d.  No2 (Nitrogen Dioxide)
For any 3 hour period the average concen. of No2 in the
stack gas of each unit shall not exceed 350 ppmv on a dry
basis corrected to 7% oxygen.
                                797

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                                                                         N
  e.  Oxygen:
  The conoen. of oxygen in the flue gas at  the boiler exit
  of each unit must be no less than 6% by volume measured
  on a dry basis.

  f.  Non Methane Hydrocarbon's as Methane
  For any 3  hour period the average concen.  of non-methane
  hydrocarbon in the stack gas shall not exceed 43 ppmv on a
  dry basis corrected  to 7% oxygen.

   g.  Opacity:
   The  opacity of  the  emission from each unit must not exceed
   20%.   Note: an exception to the 20% limit' is if opacity
   did  not exceed  20%  for more then 3 minutes, during a period
   of 30 consecutive minutes.  However, it never exceeded 40%.

4. Boiler operating parameters are in accordance with
   following Air Pollution control permit  conditions?
                                   798

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                                                                   Y    N
   a.  Within one  hour after  the  waste has been introduced
   in  the  boiler the temp,  one second  downstream of  the secondary
   air injection area may not be  less  than 1500 degree Farenheit.

   b.  No  waste being introduced  into  a boiler  unless the temp.
   0.3 seconds downstream of  the  secondary air  injection area is
   greater than 1500 degrees.

   c.  The temp, one second downstream of  the secondary air
   injection area  may not be  less than 1600 degree at least 90%
   of  the  time waste is  being incinerated.

   d.  Permanent temp, sensors located in  the combustion chamber
   and at  the inlet of the  boiler convection section will be
   correlated to read the required temp. 0.3 and 1 second
   downstream, of  the secondary air injection area.

   e.  Auxiliary burners must be  able  to operate automatically
   if  the  temp, one second  downstream  of the secondary air
   injection area  drops  below 1550 degree  while waste is being
   incinerated.

5. All emission control  equipments are in  line  while waste
   is  being incinerated?                                          	
                                   799

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                                                                         N
   a.  At no time baghouse be bypassed while waste is being
   incinerated unless the temp,  of the flue gas entering the
   baghouse exceeds 475 degrees  or falls below 130 degrees in
   which case the waste charging to the affected unit will cease.

   b.  If the temp, of 1500 degree is not maintained one
   second downstream of the secondary air injection area,
   waste should not be charged to the affected unit.

   c.  If 6% oxygen by volume can not be maintained at the boiler
   exit, waste should not be charged to the affected unit.

   d.  During periods the scrubber is down because of a
   malfunction, and if for any 3 hour period the average concen.
   of So2 in the stack gas for the unit exceeds 250 ppmv on a dry
   basis corrected to 7% oxygen, cessation of waste to the affected
   unit is required.

6. Are provisions being implemented according to the approved
   NJPDES - DWW/DSW section of the permit?
   a.  Whenever any activities result in a discharge of toxic
   pollutants, into the surface  or ground waters, the incidents
   are to be reported when occure or believed to occur.
                                    800

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                                                                    Y    N
   b.  All effluent limitations and monitoring requirements
   should be implemented.

   c.  All general requirements of DGW and DSW should be
   implemented.  (Physical inspection on weekly basis)

7. Are provisions being implemented according to the  water
   allocation diversion?

8. Are following conditions of the approved 0 & M manual being
   implemented?

   a.  Inspections of all  major aspects of the facility in
   which adverse environmental or health consequences are
   possible, should be performed on daily basis.

   b.  Preventive maintenance are to be performed according to
   potential equipment deterioration or malfunction.

   c.  In the case of any  emergency all the facility  personnel
   should follow the contigency plan contained in the 0 & M manual.
                                    801

-------
                                                                     Y    N
 9. Are routine housekeeping and maintenance procedures being
    implemented within the facility to prevent accumulation of
    dust and debris?

    a.  Tipping floor is to be cleaned at least once a day.

    b.  All facility floors/ traps, sumps or catchment basins
    maintained free of obstruction to facilitate effluent drainage.

    c.  Facility grounds are to be maintained in a manner free of
    litter and debris.

    d.  All incoming wastes, facility processed wastes and
    effluents stored in a bunker, basin, pitss, sumps or other
    containment vessels are to be kept at a level that prevent
    spillage or overflow.

10. is all facility exterior facing maintained in a manner
    keeping with the original design?

11. Is a qualified applicator of pesticides directing an
    effective vermint control program?
                                     802

-------
                                                                          N
12. is all fly ash that has been processed through the fly



    ash conditioning units being properly wetted so it remains



    in the wetted state throughout the rest of the residue



    processing and or transportation of the ash?







13. Is all water discharge to the river at a temp, not more



    than 20 degree greater when it was withrawn from the river?



    (If facility's process water is supplied by a river)







14. Are the approved sampling and analysis requirements being



    implemented?







    a.  All samples are to bollected from the approved location.







    b.  All daily samples are to be composited into a monthly



    sample and to be analyzed using EPA Toxidty Test.







15. Are all operational records being recorded on a daily and



    monthly basis and have the required monthly summaries and/or



    tallies been submitted to the proper agencies
                                     803

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D.  Safety and Boergency Procedure:
  1. Are all security equipment and systems in proper operating



     conditions?







  2. If there is a turbine/generator trip condition was waste



     processing operations reduced accordingly to reflect the



     reduction in the boiler thermal load?







  3. Are fire detection and protection systems kept operable at



     all times?







  4. Are all occupational safety and health (OSHA) standards



     being implemented in the operation of the facility?







  5. Are only facility personnel and authorized visitors allowed



     on site?
                                                                      Y    N
                                      804

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E.  Files and Records:

  1. Are following documents and records are maintained all the
     times at the facility?

     a.  Operating Permits and supporting documents
     b.  Process Flowsheets
     c.  Emergency Action Plan and Notification procedure
     d.  Operating Log
     e.  Maintenance Records
     f.  Periodic reports filed with regulatory agencies
     g.  Permit exceedences reports
     h. Storage and disposal records
     i.  Emissions inventories
     j.  Sampling records and description of analytical method
     Y  = In Compliance
     N  - Not in Compliance
                                     805

-------
F.  Inspection Consents:
     Inspector's Signature                        Facility Representative's
                                                   Signature
                                     8O6

-------
THE FINANCIAL IMPACT OF THE EMISSIONS GUIDELINES

     ON AKRON, OHIO'S RECYCLE ENERGY SYSTEM
                       Ray Kapper
                     Service Director
                   City of Akron, Ohio

                          and

                    Robert L. Johnson
                     Project Manager
                     wTe Corporation
                     Presented at the

  First U.S. Conference on Municipal Solid Waste Management

                     June 13-16, 1990
                         807

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                         INDEX








SECTION                                            PAGE






Local Capital Comparison                                   1




Total Cost                                                 2




Incinerator Ash                                            3




Recycling                                                 4




Particulate & Acid Gas                                     5




Organics                                                  6




Cost Impact                                               7




Tipping Fee Distribution @ $72 Per Ton                      8




Curb Service Fee Dollars Per Month                          9
                          808

-------
                           LOCAL CAPITAL
                             COMPARISON
            TRANSPORT. (BH)
           DEBT 8ER. (6.67%)
         PUB. FACTE8 (4.87%)
                OTHER (1.88%)
                                           PUBLIC UTLmES (39.3S)
                                           EPA QUDELME8 (40%)
    The  Recycle  Energy  System  is
located in downtown  Akron,  Ohio.  The
facility serves the residents of the  City
of Akron as well as several surrounding
communities.  The R.E.S. is owned by the
City of Akron and is currently, and has
been for  the  last  three years,  operated
under contract by wTe  Corporation of
Ohio.

    The facility, completed in 1979 at a
cost  of  65 Million Dollars,  currently
receives and combusts 1,000 tons per day
of residential and  commercial solid
waste.   It  has taken  10  years for  the
facility to achieve its design capacities.
After struggling  with low  production
rates caused  primarily  by  the  fuel
delivery system, the City was forced to
invest 2.5 Million  Dollars to replace the
pneumatic conveyor system with a more
conventional  belt conveyor system.
Safety problems also developed  and
numerous fires and  explosions caused
damage  which  required additional
capital  investment and expensive
repairs.  In addition,  operating revenues
did not cover  operating costs requiring
heavy City subsidies and  the diversion
of  limited  funds  from  other much
needed municipal improvements.

    Only within the last three years  has
the facility begun to operate safely and
continuously  providing steam,  hot and
chilled water, as well as tipping services,
on  a  continuous basis  to its customers.
Just as the facility has  begun to provide
the services for which  it was originally
designed,  the City finds  itself  facing
another new challenge as has been posed
by  the  recent  Source  Emissions
Guidelines and the pending Draft Ash
Management Guidance (U.S. EPA  March
1988).

    For the  purpose of this paper,  we
have  included a brief discussion on
incinerator ash management.  The U.S.
EPA Draft Ash Management Guidance,
if enacted, will also have  a significant
cost impact  on  municipal  solid waste
combustors.   We believe it is important
for  communities to  consider  the
aggregate  effect  of recent  EPA
activities.
                                      809

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                             TOTAL COST
                                  ),914,139
             Rtoyolng (28.1%)
                     (10.7%)
                                               Air (20.9%)
    The City of Akron, along with many
other  mid-western cities,  struggles with
a declining industry base  and increasing
costs.   Akron  locally   funds
approximately 90 Million Dollars in
capital improvement projects per year.

    With  the  new  Source Emissions
Guidelines,  initial  estimates  are  that
Akron will be required  to fund a 40
Million  Dollar capital investment.  Our
initial  estimate  for incinerator ash
disposal  is 20 Million  Dollars  which
suggests  that  Akron will face a total
capital investment of .60 Million Dollars.
This would represent approximately 40%
of  a  total 150 Million   Dollar  capital
program.  This new potential  financial
burden is selective in that it only affects
those  communities  who  have been
progressive and forward thinking and
have  already  funded municipal  waste
combustion facilities to address growing
solid waste problems.
    Most citizens
environment.   We
importance  of
 support  a clean
all  understand  the
preserving  the
environment  in  which we live  for
ourselves and  future generations.  The
challenge  is  how  to  accomplish these
goals in a logical  and equitable manner
and provide the best use of funds for
long-term solutions.

    To  the  layman,   the  Emissions
Guidelines  only requires new equipment
which is intended to better clean smoke
from the combustion of municipal  solid
waste,  but   this is only one part of the
Guidelines.    There is also a  section
which  deals with recycling.   It is the
combination  of  these elements  that
makes the Guidelines costly; not  only in
terms of  capital  expense,  but  also in
annual  operating  expenses.   When Ash
Management is included, the total cost is
devastating.

    For  the  Akron  Recycle  Energy
System, of  the 60  Million Dollar  total
capital investment estimated  for the new
Emissions Guidelines and Draft Ash
Management Guidance, the largest single
cost would be new  ash  management
requirements,  followed  by  the
                                      810

-------
                           INCINERATOR ASH
                               $20,884,148
              Rtoyoflng (29.1%)
                      (10.7H)
                                                Air (2S.»%)
                                                 (34.3*)
requirement to remove recyclables.

    It  is  unclear  to  what  extent  the
recycling requirement will affect clean
air, but without discussion as to whether
or not  recycling actually impacts clean
air,  even the remaining components
carry  a  heavy financial burden  for
existing facilities in consideration of the
relatively  small  number  of such
facilities  and  their  significant
importance to solid waste  management.

    Before we discuss the impact of the
EPA's new Source Emissions  Guidelines^
we must pause  to consider current
thinking regarding incinerator ash.

    One  of the  most hotly  contested
issues  of recent years  has been  the
method of disposal of incinerator ash.
The two extreme view points  are:

I)  incinerator ash  is  a hazardous waste
    and  should  be  disposed  of  in
    hazardous waste landfills, and
2)  incinerator ash is not a waste at all,
    but can  be reused as road bases and
    other types of soil stabilizers.

    The question  is whether or not ash
will  leach heavy  metals under landfill
conditions.   Under  current regulations,
the test which is  used to determine the
teachability  of  heavy metals  from
incinerator ash  is the extraction
procedure toxicity test.  Several studies
suggest that  this particular test  unfairly
represents  the actual teachability of
heavy metals from  incinerator  ash.  A
recent  study,  prepared jointly by the
EPA  and   CORRE  (Coalition  On
Resource  Recovery  And   The
Environment), suggests that in actual
landfill  conditions,    leachate  from
incinerator  ash is very close to primary
drinking water  standards.   If  these
findings are  true,  rules requiring special
treatment and handling are unnecessary.
Despite  the  fact that a growing amount
of data indicates  that  incinerator ash
should  be considered a useful  material,
the EPA continues to suggest that ash be
landfilled  in a monofill  constructed to
                                     811

-------
                                iECYCLING
                                £17,727,854
                    (29.1H)
               Organic* (10.714)
                                                Air (25.9%)
                                             Ash (S4.SS)
current  landfill  standards.  At present,
very few such landfills exist.

    It will be difficult for communities
which  had  the  foresight  to  build
incinerators  to  comply with the  more
stringent  Source Emissions Guidelines,
but at the same time to  require  these
incinerators to either locate or construct
a specialized landfill for the disposal of
ash in light of current knowledge seems
excessive.

    For  a  City the  size  of  Akron,
estimates  indicate  that  the  capital
investment required for the construction
of a incinerator  ash landfill  alone will
represent  34.4%,  or  approximately 21
Million  Dollars  of the total 60 Million
Dollar investment.

    Ash   Management  and  recycling
together  represent over 60% of the total
capital cost.  The requirement to recycle
25% of  the input to the Akron facility
represents approximately 18  Million
Dollars  of the  60 Million Dollar total
capital investment.
    Recycling is  a very  popular  issue
and it appears that the requirement of
recycling is being written  into all  new
legislation.   In Ohio, Akron, along with
most  other communities,  is  already
struggling  with  the development of
effective City-wide recycling programs.
Ohio  has been required to do this as a
result of State House Bill 592 which was
signed into  law in June of 1988.   The
State  of Ohio has elected to include
recycling  as  one  component of  a
comprehensive solid  waste management
plan.

    The new  Emissions  Guidelines
assumes that the removal of recyclables
will  remove pollutants  from  the  air.
Although in some  cases this may be true,
there is little  comprehensive and
conclusive data to support this approach.
Recycling is a solid  waste management
issue  and  communities all across  the
United  States  will eventually  recycle a
significant percentage of their solid
waste stream.   Front-end processing at
municipal waste combustors is only  one
option and  communities should be free
                                      812

-------
                     P ARTICULATE Be ACID GAS
                               $15,773,737
              RMycBng (Z9.1S)
               Orgiriea (tt.T*)
                                                 Mr (2BAH)
                                             Art (SX.3%)
to elect or develop  those options which
work  best and  provide the  best  cost
benefit.

    In  Akron,  the  Recycle Energy
System is a waste-to-energy facility, thus
those  recyclables which  are  combusted
and provide an energy contribution are
being recycled.   During the  next  few
years,  as  markets develop for recycled
materials, combustion may  be the  most
economical alternative.

    Another  major  component  of
emissions regulations requiring extensive
capital investment is paniculate  and
acid gas control.  Paniculate emissions
are being  regulated  to approximately
one half of the allowance that existed at
the time of construction of  the Akron
Recycle  Energy System.   Acid  gases,
such  as hydrochloric  acid  and sulfur
dioxide, were not  considered and  thus
not regulated at  that time. The result is
that Akron will be required  to replace
all existing air  emissions control
equipment.   It  is  estimated that  this
requirement will cost approximately 15.8
Million  Dollars  and  will  require the
installation of lime injection equipment
and  new  fabric filters to  replace the
existing precipitators.   This represents
26% of the total investment.

    Because Akron has its own landfill,
the  City will  also  experience  a
significant side  effect of the proposed
Best  Available Control Technology.  The
current  strategy  to  control  acid  gases
proposes the  injection of  lime into the
gas  stream,  thus transferring  an air
pollution  problem into  a  solid  waste
problem.  For every 22 pounds of sulfur
dioxide  that  is removed  from the  flue
gas stream, the facility will  generate an
additional 2,000 pounds of  solid waste
which must  be landfilled.  Aside  from
the economic impact  of the installation
of new equipment, a  community such as
Akron will also suffer serious landfill
life depletion whether speaking in terms
of existing  landfills  or new landfills
specifically  designed  to  accept
incinerator ash.

    Organic  toxin control represents
                                      813

-------
                                OEGAN1CS
                                $6,528,400
              RMydng (2B.TK)
             Orgariet (10.7%)
                                               Air (28.eS)
                                             Art (844%)
another  element  of  the  capita!
investment at approximately 6.5 Million
Dollars.   The  new Guidelines propose
that  dioxins  and  furans  can be
controlled  in  the combustion  process.
The assumption is that improved mixing
of the RDF with combustion air will
create  higher  combustion temperatures
and destroy dioxins and furans  within
the furnace. These are newly discovered
elements  in  the exhaust gas stream, and
existing facilities,  in many cases,  were
not designed or  constructed  with this
type of control in mind.  For the City of
Akron, this involves the  entire  fuel feed
system as well as the overfire air system.
Major  changes,  including  the
replacement of fans and  fuel feeders,
will be required in order to comply.

   The level which is  being  proposed
for a large facility is 250 nanograms per
standard  cubic  meter.   In  consideration
of  the  fact  that these  are  newly
discovered elements, control technologies
have not  been fully proven, and the EPA
has not fully developed a  cost benefit
for such a stringent level of control, this
requirement,  at this time,  may  not
represent  the  best  use  for  scarce
resources.   To  retrofit  a  10-year  old
facility  such as the  Akron Recycle
Energy System to a level of technology
commonly known as "Best Available
Control Technology"  will require
significant investment  in new controls,
fuel  delivery equipment, fabric  filters,
lime handling equipment and   front-end
separation equipment.

    After the initial capital investment,
the financial burden does not end. The
estimated annual operating cost  for all
of the new equipment, as well as a new
landfill,  is approximately  8 Million
Dollars a year.  This  will represent an
increase of approximately  60% over
current operating costs.

    Akron,  not  unlike  other
communities across the  United   States
that  have invested in incinerators and
waste-to-energy facilities,  has found it
necessary to subsidize the facility since
its start-up  in  1979.   This substantial
increase in operating cost could lead to

-------
                              COST IMPACT
      UTLITE8 & FUEL (T7.1S)

          AOMM A MAN. (3.42%)
                                          OPERATIONS (424%)
                                                  AIR (37.2%)
additional local subsidies throughout the
remaining life of the facility.

    The current solid waste management
crisis has only come to light as a  result
of the dwindling  number  of  landfills.
Aside from  the  accelerated  rate  of
landfill closures,   more stringent  rules
for siting and permitting  has  rendered
this  process time consuming  and
expensive resulting in few  new landfills
being opened.   The  new Emissions
Guidelines  place  a  heavy burden  on
those  few communities  which  have
already constructed incinerators and
could  result  in a  similar  scenario  for
municipal solid waste combustors.  With
landfills  and  incinerators  being
legislated  out of  existence, the entire
effort towards integrated  solid  waste
management could  be defeated  at great
expense to the economic welfare of  the
nation.

    Just how significant is a 8 Million
Dollar increase in the operating cost of a
facility  such as  the  Akron  Recycle
Energy  System.    The current annual
operating  budget  for  the  facility is
approximately 14 Million Dollars.  If the
estimated 8 Million Dollars  required to
comply  with  the  new  Emissions
Guidelines and  possible new Ash
Management  Guidance is  included,  the
new  operating  budget will  be
approximately  22  Million Dollars  per
year.   When compared  with the other
major components of  the cost of
operation, the additional cost represents
approximately  37%  of  the  total cost,
second only to the  total  cost  of all labor
and material consumed at the facility on
an annual basis.

    With  a  14  Million Dollar  annual
operating cost, the  facility is required to
set its tipping fee at $42  per ton in order
to approach break  even.    This  is
substantially  above tipping fees charged
by surrounding landfills, and thus it is
difficult to acquire the amounts of
waste necessary to meet steam demand.

    The  Akron plant  operates as a
utility providing steam "on demand" to
critical businesses and hospitals  in the
                                      815

-------
                      TIPPING FEE  DISTRIBUTION
                            @  $72.00 PER TON
       UTIUTJE8 4 FUEL (T7.1SJ
           ADMM I, MAN. (8.42%)
                                           OPERATIONS (4&3K)
                                             CLEAN AIR (37.2H)
downtown  Akron area and is forced to
burn expensive natural gas when MSW is
not available which defeats the purpose
of  the facility and unnecessarily
consumes precious, non-renewal natural
resources.   Of  the $42/ton tipping fee,
67% of the fee dollar goes to labor and
materials required  to  operate the
facility.

    On an annual basis, the Akron
Recycle  Energy  System  requires
approximately 250,000 tons of municipal
solid waste in  order to meet its  steam
requirement.    The City  of Akron
provides only  50% of this requirement.
Once   the  operating  cost  has  been
increased by 8 Million Dollars, a tipping
fee  of  $72  per ton will be required  in
order to break even.

    At $72 per ton,  waste haulers who
are  not required to use the facility will
have a strong  incentive  to  take  their
waste  to  local landfills, thus  more
quickly using  up  an  already  rapidly
dwindling waste  management  resource
and leaving Akron  with  a shortage  of
 the  required fuel  to  meet its  steam
 demand.

    The new requirements represent
 approximately 37% of  the  $72 tipping
 fee  provided  that  the  Guidelines are
 enacted as proposed.

    Finally,  we  must consider  the
 impact  upon the citizens of the City of
 Akron.    The  Akron  Recycle Energy
 System  processes 1,000 tons per day of
 municipal solid  waste.  Approximately
 500  tons is  collected  from  the City of
 Akron's residents. If we distribute a $72
 per ton  disposal cost to those households
 in Akron which  are required to use the
 facility, it will increase  their  curb
 service fee by approximately 70%.

    This represents an increase of $5 per
 household per month, or $60  per  year.
 This agrees  with the EPA's projections
 of an average increase of  $58 per  year
 per household.  This is  a local increase
 which will affect communities currently
 incinerating  their solid waste much more
than others not currently incinerating.
                                      816

-------
                           CURB SERVICE  FEE
                          DOLLARS PER MONTH
                DOLLARS
                                          «TO A CLEAN AM
    The  purpose of  the  Emissions
 Guidelines is to reduce airborne
 pollutants which is to the benefit of all
 of the citizens of the United States, but
 it appears that during the initial years
 the heaviest burden of cost  will  fall
 upon those  communities which already
 operate municipal waste combustors.

    Ohio's House Bill 592 required the
 establishment  of  solid  waste
 management districts and charged those
 districts  with  the responsibility  of
 establishing  a  ten-year  waste
 management plan.  The key component
 missing from the Emissions Guidelines is
an  analysis  of  its  impact  upon
comprehensive solid waste management.
                                  817

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                FLEXIBLE AND ENFORCEABLE

                    RESOURCE RECOVERY

      PERFORMANCE  GUARANTEES FOR MASS BURN PROJECTS
                Trudy Richter Gasteazoro
         Richardson, Richter & Associates, Inc.
                Public Projects Advisors

                     John W. Matton
              ABB  Resource Recovery Systems
              Combustion Engineering, Inc.
                    Presented at the

First U.S. Conference  on Municipal  Solid Waste Management

                    June 13-16, 1990
                         819

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                                   ABSTRACT







     Resource  Recovery  Service  Agreements  typically contain  performance



guarantees  that  require  the  vendor/operator  to  process  a  guaranteed



quantity of waste over  a  given  period of time and to  produce  a guaranteed



quantity of energy  from that waste,  based  on a specified  energy  content.



The community/owner,  on the other  hand,  typically guarantees  to  deliver,



within set time frames, a minimum quantity of municipal  solid  waste.   The



vendor's  processing  and  energy   guarantees   are  conditioned  upon   the



community meeting its delivery commitment.



     In order  to  establish  both  parties' guarantees, certain  assumptions



normally have  to  be made about the weekly,  monthly and yearly amounts  of



waste available to be delivered and its average composition, and therefore,



energy value.  The  accuracy  of  these  agreed upon assumptions has  a direct



effect on  the  validity and  enforceability  of these  long-term  guarantees.



However,  communities   frequently  do  not   have  accurate   databases   for



establishing these assumption.  In addition, the resource recovery industry



recognizes that  waste  composition, energy  value and waste quantity  will



change over time.  To protect both  the vendor  and the community during the



typical twenty-year  term  of a Service   Agreement,  flexible yet  accurate



guarantees are essential.



     This paper  describes a guarantee structure  that gives the community



flexibility when establishing its waste delivery schedule and waste
                                    820

-------
composition by permitting  greater variations  in  waste  stream quantity and
energy  value  without  relieving  the vendor  of  its  waste  processing and
energy production guarantees.

Introduction

     A  major  problem  facing most  drafters of  Resource  Recovery  Service
Agreements is how to structure a set of performance guarantees that provide
the community/owner with the maximum benefits of high unit availability and
performance while  protecting the vendor/operator from wide  variations  in
waste stream  quantity  or energy value.  Typically, the  weekly quantity  of
waste in a  community will  vary by 20% over the course of  the year  and the
energy value  can range  from 3800 Btu/lb to 6000  Btu/lb.   Communities are,
therefore,  faced with  the  difficult  decision  of whether  to design  for
average conditions or peak conditions.
     While resulting in  some bypassing of waste,  a design  based on  average
daily waste  flow and  energy value  results in  the facility  operating  at
maximum  efficiency  during  the most  frequent  operating  conditions.   A
facility design based on peak  conditions  results  in frequent operations  at
partial  load  and  inefficient energy generation.   If the community  decides
to design for peak  conditions,  it then faces the  problem  of insuring that
the facility  operates  as  efficiently as  possible during  periods of  low
waste flow or low energy value.  If annual performance guarantees are used,
what typically results is either very conservative performance guarantees
                                   821

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which  do   not   adequately  protect  the   community  against  inefficient



operation,  or  guarantees  which  are  very  difficult  for  the  community to



enforce.



     Most  Resource  Recovery  Service  Agreements  attempt  to  avoid  this



problem  by  assuming  that over  an  extended  period  of time,  such  as an



operating year,  conditions will average  out.   In addition,  the  contracts



generally provide for retesting the facility if the community or the vendor



suspects that these  "average conditions" assumptions are no  longer valid.



In  reality,  any failure  by  the vendor to meet  its annual  guarantees  of



waste throughput and energy, which  could possibly  result  in damages to the



community, may well be  unenforceable  not  only  because the community cannot



establish what  the energy value  of  the  waste was,  but  also  because  the



community may  not have consistently met  its weekly or monthly  delivery



guarantees.



     Guarantee  interpretation  and  enforcement problems  are  particularly



difficult when a community sizes a  project to  its  existing  or future waste



processing  needs  in addition  to allowing  for the  seasonal  variation  of



waste  quantities.   For such communities,  there  is  little possibility  of



averaging out waste  flow  and energy  value  or  making up for  lost  capacity



during peak waste flow periods.



     This paper proposes a solution for communities  to  assure flexible yet



enforceable performance guarantees.  To  accomplish  this,  both  processing



and energy guarantees are developed and monitored  separately  in such a way



that the community  is  assured  of efficient operations  even during  periods



of considerable deviation from the facility design condition.
                                  822

-------
Processing Guarantee

     As stated  earlier,  many Resource Recovery  facilities  are  designed to
process the  daily tonnage at  some  specified heating  value.   However,  the
amount of  waste generated in  a community,  as  well  as  its  heating value,
will vary from day to day and from month to month.  In addition, allowances
have to be made for  scheduled  and  unscheduled plant  maintenance during  the
year.  There  is also a  problem in determining  the  exact amount  of  waste
that is being processed.  It is a simple  process to  accurately measure  the
amount  of waste  received  by   a  facility,  but  it  is  very  difficult  to
instantaneously measure on a continuous basis how much material  is actually
being  loaded into  the  boilers.   In  most  communities  the waste  profile
cannot be exactly matched by the facility's processing profile,  which leads
to  either  bypassing  of waste or  under-utilization  of the facility.  In  a
situation where the  facility will be  under-utilized  during  portions of  the
year, a monthly processing guarantee  protects  the community  better than an
annual guarantee.
     It is suggested that the  following processing guarantee structure be
used.   First,  a  monthly processing  target  is  established  based on  the
facility's daily  throughput  rating and  the number of days in  the month.
For example,  the target for a 1000 ton per day (TPD)  plant for the month of
June, would  be  30,000 tons.   Secondly,  using this target, allowances  are
made  for  scheduled  and  unscheduled  maintenance  during the  month.   For
example, for a two boiler plant with an 85% availability guarantee, there
                                   823

-------
would be 2628 boiler-hours  (8760  hr/yr  x  0.15 x 2) allowed for maintenance



during  the year.   It  is  suggested  that  30%  to 50%  (depending  on  the



operator's normal  maintenance procedures)  of these hours  be  allocated to



scheduled maintenance to  be agreed  upon by  the vendor and the community at



the  beginning  of  each  operating year  to  coincide  with the  expected  low



waste flow  periods.   Once  set,  the vendor must  use  scheduled maintenance



hours in a  given  month  or lose them.   The  remaining  maintenance  hours are



then  available  to  the  operator  for  use  as   he  deems  necessary  for



unscheduled maintenance  during the year.   For a  1000  TPD plant  with  two



boilers this would result in a maintenance  allowance of 20.83 tons for each



hour of boiler downtime.








       1000 TPD    _^_   24 hrs.    =    20.83 TPH/boiler
           "^™"^^^~P    •


          2








     For  our  example,   assume that  there  were  five   days  of  scheduled



maintenance for one boiler  during the month and  there were  three  days used



for  one  bailer  for  unscheduled  maintenance.   The  monthly  processing



guarantee for June would then become:








       30,000 - (5 x 24 x 20.83) -  (3 x 24  x 20.83) =26,000 tons








     Once  the  vendor  uses  his allotment  for  scheduled  and  unscheduled



maintenance during the  year,  any outages  beyond  this  do not result  in  a



reduction in his monthly processing guarantee.
                                   824

-------
     To determine  if  the vendor has  met his guarantee,  it  is recommended
that the  plant's truck  scales be  used  to  determine  the amount  of  waste
delivered to the plant  during the month and how much nonprocessible waste
such as white  goods,  or unacceptable  waste, etc., is  bypassed  around the
boilers.  The quantity of waste in  the pit  or on the  tipping floor is then
estimated at  the  beginning  and the  end of each  month  to  determine  any
change in pit  inventory.   Assuming  a  six day pit  storage capacity and a +
10% measurement accuracy on the quantity of waste  in the pit, the amount of
waste actually processed during the month can be determined to within + 2%.
     Monthly penalties or bonuses can then be assessed based on whether the
vendor  has  met or  exceeded  the monthly  processing guarantee.   Using  the
June examples  above,  if the  vendor  exceeded its  processing  commitment  of
26,000 tons, it may be  entitled  to  a fee for processing  excess  waste.   In
contrast, by failing  to  process  26,000 tons, the  vendor may  be  liable for
costs of landfilling waste it  should  have processed as  well  as lost energy
revenues or  other  damages.   However,  it is  recommended,  that there  be  a
yearly reconciliation of these penalties and bonuses based  on  the yearly
throughput guarantee, i.e.,  at year end if  the vendor has met  his yearly
throughput guarantee,  then the monthly  penalties  are  rescinded.  If  the
vendor  has  not  met  its  yearly  throughput  guarantee,  then any  monthly
bonuses would be refunded.
     Developing a  processing  guarantee similar  to the one  outlined  above
solves  only  half  of  the  community's  concern,  that  of  processing  a
guaranteed amount of waste and decreasing the community's dependence on
                                    825

-------
limited  landfill  space.   Just  as  critical to  the community  is efficient



facility operations, which assures energy revenues at a guaranteed level to



offset the facility's costs.







ENERGY GUARANTEE







     Most  Resource   Recovery  operating  contracts  require  the  vendor  to



guarantee the net energy production capability of the  facility.   Usually,



both a  short-term (acceptance  test) guarantee and an annual  guarantee are



required.   Actual   energy  production   is  dependent  upon  many  variables



including  waste heating  value,  boiler  load,  and  operating  efficiency.



Energy guarantees are normally made based  on  a  reference  waste composition



and heating value; a factor which neither the vendor nor  the  community can



control.  During acceptance testing,  the facility can  be operated  at full



load and careful calculations can be made of the quantity  and  heating value



of waste  processed.   Therefore, an accurate  comparison of guaranteed and



actual energy production can be made.



     An annual  energy  guarantee  based on a reference waste composition is



difficult  to  enforce because  there is  no realistic  method   of  measuring



heating  value  over   long  periods of  time.   In  addition,  the boilers  and



turbine  will   not  always  operate  at   full  load  and  therefore,   design



efficiency.   These   variations  make  any  annual  energy  guarantee  very



difficult to monitor and enforce.
                                    826

-------
     The primary concern  of the community  should be that  the  facility is
operated efficiently at all  times,  under all conditions  of waste flow and
energy value.  Efficient operation  provides comfort to  communities relying
heavily on energy revenues  when  setting  service fees and guaranteeing debt
service payments.  If efficient operation can be demonstrated on an ongoing
basis, then  the  community  is assured that  the maximum  amount  of energy is
being extracted  from the waste,  and the maximum energy revenue  is  being
generated by the facility.
     The  best  way to  determine if  the  vendor  is operating the  facility
efficiently  is to continuously measure key  operating parameters.  To verify
energy  guarantees,  these operating  parameters  must  be equated  to  energy
production.  Before  outlining  the  proposed  guarantee  structure, a  brief
electrical energy production primer is helpful.
     When waste  is burned in  the boilers, heat  is absorbed  by boiler  water
which is  then  converted into steam.   For a specific facility  design,  the
amount of steam  produced is primarily dependent on the heating value of the
waste, the waste feed  rate,  and boiler cleanliness.   The steam is piped to
a turbine-generator  where its energy is  used to generate electricity.  The
amount  of  electricity  produced  by the   turbine-generator  is  primarily
dependent on the steam flow and  ambient air conditions;
     The best measure  of  whether a boiler  is  operating efficiently  is the
temperature  of  the  flue  gas leaving the  boiler.  If  this temperature is
higher than  the  design point, energy is  being wasted.  If this  temperature
is  lower than the design point,  the boiler  is being operated more
                                    827

-------
efficiently than  predicted.  The  guarantee structure  presented uses  the



boiler economizer exit gas temperature to determine  if  the  boiler is being



operated efficiently.  The net electricity  generated  per  pound  of steam is



used  to  determine  if  the  turbine-generator   and  auxiliaries  are  being



operated efficiently.



     The proposed  performance guarantee  structure  uses  three  performance



curves and the monitoring of  five  operational  parameters.   The  first curve



shows boiler economizer exit gas temperatures as a function  of boiler steam



flow.  The second  curve  shows the  impact  of differential  boiler exit  gas



temperature on  boiler efficiency.  The  third  curve  shows  net  electrical



generation as a function of  steam flow and ambient  air temperature.   To



protect the community, these  curves  should  be  made  a part  of the vendor's



bid  proposal  and compared  to other  vendor's  curves to  insure that  they



fairly represent the facility's guaranteed operating performance.   The five



parameters which are  continuously measured  are boiler  steam flow,  boiler



economizer  exit   gas  temperature,  turbine   steam   flow,  ambient   air



temperature, and  net electrical  generation.   If the facility  uses a  wet



cooling tower, humidity must also be measured and incorporated into  the net



electrical generation curve.



     In order  to determine  if the  facility  is  producing  the  guaranteed



electrical  output,  the  following  calculation  is  made  hourly  by  the



facility's computer.







Step 1 -  For each of the boilers, use Curve 1  to determine  the  theoretical



          boiler exit gas temperature.
                                   828

-------
Step 2 - -Calculate the boiler exit gas temperature differential by
          subtracting  theoretical   boiler exit  gas  temperature  from  the
          actual measured boiler exit gas temperature.

Step 3 -  Using Curve 2, determine the boiler efficiency adjustment factor
          for each boiler.

Step 4 -  Calculate an adjusted boiler steam flow by multiplying the actual
          boiler steam flows by the associated boiler efficiency adjustment
          factors.   Sum  the adjusted  boiler steam  flows  to  calculate  an
          adjusted turbine steam flow.

Step 5 -  Using Curve 3, determine a guaranteed net electrical production
          using the  adjusted turbine steam  flow and the  measured  ambient
          air temperature.

Step 6 -  Calculate an electrical production deviation by subtracting the
         •actual  measured  electrical  production  from  the  adjusted  net
          electrical production (Step 5).
     If the  vendor  has  produced more energy than guaranteed, the deviation
will  be  positive.   If  less  energy  than  guaranteed   is  produced,  the
deviation will be negative.   For every  hour  in the month that energy is
                                  829

-------
produced,  the  deviations  can  be  summed  to  calculate  a  monthly  net
electrical production deviation,  which represents, in  kilowatt-hours,  the
excess or shortfall in energy generation.
     The  following  example illustrates  how  this  procedure  would work  in
practice.  As  stated  earlier,  the  five operating  parameters  that  are
measured  continuously  are boiler  steam  flow,  boiler  economizer exit  gas
temperature,   turbine  steam   flow,   ambient  air  temperature,  and   net
electrical production.
     For  our example,  assume  that there  are  two boilers and the measured
parameters are as follows:

Boiler 1:
         steam flow
         exit gas temp.
95,000 Ibs/hr
452°F
Boiler 2:
         steam flow
         exit gas temp.
75,000 Ibs/hr
434°F
Turbine steam flow
Ambient air temp.
Net electrical production
170,000 Ibs/hr
70°F
14,200 KW
                                   830

-------
Step 1:







From  Curve  1,  the  theoretical  boiler  economizer  exit gas  temperatures



are:







                    Boiler 1       :         442°F



                    Boiler 2       :         414°F







Step 2:







The boiler exit gas temperature differentials are then:







                    Boiler 1       :    +    10°F



                    Boiler 2       :    +    20°F







Step  3:







Using  Curve 2  the  boiler efficiency adjustment factors are:







                    Boiler  1        :         1.005



                    Boiler  2        :         1.011
                                   831

-------
                                       CURVE 1
          4€0
                              EXTT RUE GAS TEWPERWURE -
in
3
ft
M4


i




UJ
          350
                         55        65       75        85       95


                               BOILER STEAM FLOW (X 1000 LBS/HR)-W«
105
                                                                                        01
                                                                                        CO
                                                                                        oa

-------
                                                  CURVE 2
                                    7EUP. DIFFERENTIAL ADJUSTMENT FACTOR

^ ^ M
}
I i '
i
* t
»
\
• \
i
• •
i
i-
-j--
!
I
t
                                "\	1
            1J03
            1J02
5
*^
I  i
              CO
              CO
              00
                 -tOO   -«0   -60   -MO   -;
80     100
                                        To(actual)  - To(Curve 1)  (Degrees)

-------
                                          CURVE 3
                                                  GUARANTEE: -
w  g
3  S
   Lkl
             14.
                                    ADJUSTED TURBINE ST&U FTJDW - Wig
                                            ( X 1000 LBS/XR)
                                                                                       100-7
                                                                                             00
                                                                                     225

-------
Step 4:







The  adjusted  boiler steam  flows and  the adjusted  turbine  steam flow  is



then:







          Boiler 1       :    95,000 x 1.005 = 95,475 Ibs/hr



          Boiler 2       :    75,000 x 1.011 = 75,825 Ibs/hr



          Turbine        :                     171,300 Ibs/hr







Step 5:







Using  Curve  3 with  an  ambient air  temperature  of 70°F the  guarantee  net



electrical production at the  adjusted  turbine  steam flow of 171,300  Ibs/hr



is:







        Net electrical production:           14,700 KW







Step 6:







The electrical production deviation  for  the  hour  is then:



Net electrical production deviation  =  14,200 -  14,700 =  - 500 KW
                                    835

-------
The vendor then would be penalized 500 KWH In its energy guarantee for this
hour.

This  process  is   repeated  automatically  every  hour  by  the  facility's
computer  and  the   differentials  between  the  guaranteed  net  electrical
production and the measured electrical output are summed to compute monthly
and/or yearly bonuses or damages.
Summary

     The  above  set  of performance  guarantees  can  be used  to provide  a
guarantee  structure  that meets  the primary  needs  of  the  community of  a
contracted quantity of waste being processed efficiently.   These guarantees
are  clear  and  easy  to administer  and  enforce.   Although  no  set  of
guarantees  can  be  completely  rigorous  and  cover  all  eventualities,  the
approach presented allows for a wide range of plant operations, waste flow,
and  energy value while  maintaining an  acceptable  level  of  validity  and
enforceability.
                                   836

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IMPLEMENTATION OF GUIDELINES FOR AIR EMISSIONS
  FROM EXISTING MUNICIPAL WASTE COMBUSTORS
                 David F. Painter
                   U.S. EPA

                 Presented at the
       First U.S. Conference on Municipal Solid
               Waste Management

                 June 13-16,1990
                     837

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                Implementation  of  Guidelines  for  Air  Emissions
                   from Existing Municipal Waste Combustors
Summary
     This presentation provides an overview of proposed guidelines for air
emission limits for existing municipal  waste combustors as they were proposed
in the Federal Register (54 FR 52209).   The overview is followed by a summary
of public comments on the proposal.  The remainder of the presentation covers
the practical aspects of implementing the guidelines.  Topics covered include
timetables and assignment of responsibilities during the implementation
process.  Also legislative proposals under consideration at the time of the
presentation will be reviewed in the context of how they might impact the
current implementation procedures.
                                       838

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   MINIMIZATION OF TRACE METAL LEACHINGS IN SEAWATER
          FROM STABILIZED MSW INCINERATION ASH
                     Chih-Shin Shieh
                          and
                     Yung-Liung Wei

  Department of Chemical and Environmental Engineering
             Florida Institute of Technology
                    Presented at the

First U.S. Conference on Municipal Solid Waste Management

                    June  13-16, 1990
                         839

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      MINIMIZATION OF TRACE METAL  LEACHINGS  IN  SEAWATER
             FROM STABILIZED MSW INCINERATION ASH
                       Chih-Shin Shieh
                             and
                        Yung-Liung Wei

     Department of Chemical and Environmental Engineering
                Florida Institute of Technology
                   Melbourne, Florida 32901
                           ABSTRACT

     Municipal solid waste (MSW) incineration ash has been

stabilized into a non-friable solid block form which can be

used as construction material in marine environment.  Studies

were conducted on full-size (5 cm x 15 cm) blocks and also on

ground samples of stabilized ash blocks to demonstrate that

trace metals are retained inside the stabilized MSW ash block

and that leaching of trace metals from MSW ash is minimized by

the stabilization process.  Results show that release of Cu

and Cd from the stabilized ash block is insignificant,

occurring only in the initial three days after the submersion

in seawater.  Lead was found to not be released from the

stabilized ash block in seawater.  Leaching of Cu, Cd, and Pb

from loose MSW ash was significantly reduced by stabilization

process.  Retention of Cu, Cd, and Pb inside the stabilized

MSW ash blocks is due to the combination of physical

enclosement and chemical binding.
                              84O

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                          INTRODUCTION
     Incineration of municipal solid waste  (MSW) is currently
the main alternative to landfill disposal of the bulk solid
waste.  Incineration of the wastes may generate toxic
substances both in gaseous and solid forms  [1-2].  MSW
incineration ash is the solid residue that  remains when the
wastes is burned in an incinerator.  The ash is enriched in
trace metals and contaminants of environmental concern [3-6].
The physical and chemical properties of incineration ash vary
with source of MSW being burned and operational procedures
used at individual incinerator facilities [7-8].  Incineration
results in a reduction in volume of MSW by  about 90 percent
and a reduction in weight by 75 percent.  Production of MSW
incineration ash will continue to increase  because more MSW
incinerator will be built to solve the problem of managing the
increasing quantities of MSW due to rapid growth.  It is
estimated that 19 million tons of ash will  be generated in the
U.S. by the year 2000 [9].  Methodologies for ash management
have to be developed, including ash utilization.  The
methodologies mu'st be environmentally acceptable to reduce the
burden on an already shrinking land space for landfills.
     Reuse of the ashes should be considered.  Ash recycling,
if demonstrated environmentally acceptable, represents an
alternative to ash disposal with potential  economic and social
benefits.  For its safe and beneficial use, ash must be
physically and chemically characterized and the treated ash
                              841

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products must not create damage to the environment and pose no



problem to human health.



     Stabilization of the friable ash materials into non-



friable solid forms is one of the potential methods for ash



reuse.  For over a decade, studies have been conducted to



demonstrate that the stabilized ash products can be used as



artificial reef materials in the ocean [10].  Wastes applied



using the methodology include coal ash, flue-gas



desulfurization (FGD) sludge [11], oil ash [12], dewatered



sewage sludge [13], and metal processing waste [14].  To



demonstrate the suitability of using the stabilized ash



materials for reef application at sea, studies conducted have



included comprehensive engineering, chemical, and biological



investigations.  Generally, laboratory evaluations are first



conducted, followed by a field demonstration and monitoring



before the methodology is adopted for managing ashes.



     In this paper, the laboratory evaluation of metal



leaching from both loose and stabilized MSW ash is presented.



The goal of the study was to demonstrate the effectiveness of



stabilization in reducing metal leachings from MSW ash in



seawater.  The results are useful for the assessment of the



fate of trace metal in MSW ash after the stabilized ash block



becomes debris at sea.
                              842

-------
                          METHODOLOGY
Ash Stabilization
     The methodology of ash stabilization has been described
elsewhere [10].  In brief, the process begins with the mixing
of the ashes with water and chemical additives, such as lime
and cement.  The mixture is then fabricated into block forms
using conventional concrete block technology.  The blocks are
then cured at a constant temperature for a period of time so
that a solid product is produced.  From a series of mix
designs, an optimum mix is selected based on the development
of compressive strength and its chemical characteristics.
Factors in determining the effectiveness of stabilization are
ash-additives ratio, particle size distribution of the ashes,
water content of the mix, and curing condition.  The
production of an optimum mix is the result of a unique
combination of these factors.
     MSW incineration ash used in this study are fly ash,
scrubber ash, and bottom ash.  Three types of stabilized ash
blocks were produced, i.e., 100% bottom ash (block B), 70%
bottom ash + 30% scrubber ash (block BS) , and 60% bottom ash +
40% fly ash  (block BF).  Desirable amounts of cement and water
were added to each type of mix.  Lime was only used in the
formation of block BF.
Elemental analysis
     Analysis of elemental composition in MSW ash samples was
conducted by analyzing hydrofluoric/boric acid digests of the
                              843

-------
ashes using the method reported by Silbennan and Fisher [15].



Approximately, 500 g of the starting materials were dried and



ground to fine powder using a porcelain mortar and pestle, and



then oven dried again at 105"C.  About 0.5 g samples of the



dried materials were placed into 125-ml Nalgene plastic



bottles followed by the addition of 10 ml of distilled-



deionized water and 10 ml of concentrated hydrofluoric acid.



The samples were shaken mechanically for 24 hr and then 80 ml



of saturated boric acid solution were added.  The samples were



again agitated for 24 hours, followed by ultrasonication for



one hour.  The digests were filtered through a 0.45 /im



MilliporeR filter paper and then analyzed for  major and trace



elements using atomic absorption spectrophotometer (AAS)



equipped with Zeeman background correction.



Seawater Tank Leaching Study



     Metal leachings from the stabilized ash blocks into



surrounding seawater was examined following the method used by



Duedall et al. [16].  A solid cylinder of stabilized ash



sample was suspended with monofilament line inside



polyethylene tanks containing 2 liters of filtered seawater.



Each tank was placed on a magnetic stirrer to generate a



constant motion to the seawater.  A 0.45.jra membrane filter



was placed over an opening in the cover of the tank to ensure



aeration.  The tank water was replaced with fresh seawater



after the initial 3-day period, and then was replaced at two-



week intervals for the remainder of the leaching period.  The
                              844

-------
water samples were taken at the  interval  of 1,  2,  3,  6,  9  and
12 days in the initial 12-day period,  then  weekly  sampled  for
6 weeks and biweekly sampled for 8 weeks.   Collected  water
samples were filtered through a  0.45 urn MilliporeR filter,
acidified to pH 2 using UltrexR nitric acid, and stored for
later analysis by AAS.
Ash—Seawater Leaching Study
     To evaluate the effectiveness of  stabilization on
reducing element release from MSW ash  exposed to seawater, a
series of leaching experiments were conducted on the  loose ash
and ground stabilized ash blocks.  The powdered stabilized ash
samples were dried at 105°C and  then were passed through a
series of sieves to form different size fractions  ranging  from
< 250 /zm to > 1000 /im.  Samples  of each size fraction were
placed in plastic (LPE) bottles  containing  seawater to form
1:1000 (wt/vol) mixtures; the mixture  was placed on the shaker
to allow the reaction to occur at an interval of 0.5, 2, 8,
24, and 48 hrs, respectively.  At the  end of the leaching
period, the aqueous phase was collected by  filtering  the
mixture through a 0.45 /am MilliporeR filter.  The filtered
solution was then analyzed for selected elements.
     Three replicate samples of  the study materials were
analyzed.  Matrix modifiers, i.e., NH4NO3  and (NH4)2HPO4, were
used for the analysis of Cu, Cd, and Pb in  seawater samples.
National Institute of Standard and Technology (NIST)  Standard
Reference Material (SRM) 1633a fly ash and  NIST SRM
                               845

-------
Multielement Mix Solutions  (3171 and 3172) were analyzed  in



order to determine the completeness of digestion of the ashes,



the accuracy of the analytical methods, and to provide quality



assurance of the analysis.







                    RESULTS AND DISCUSSION



     Results of elemental analysis on the ash samples prior to



stabilization are shown in Table 1.  These data are considered



average value of the ash used in the study.  In general, the



range for elemental variation in MSW incineration ash is very



large due to the nature of the waste stream and operational



conditions in the incinerator.  The batch of ash samples



collected is assumed to be well-mixed as a result of sample



collection and of transportation.   Data shown in Table 1



indicate that Ca, Si, and Al are enriched in all ash samples,



including fly, scrubber, and bottom ash.   These ashes may thus



have pozzolanic characteristics which is a preferred property



for stabilization.



     Cadmium, Pb, and Zn were found to be enriched in fly ash



indicating fly ash is the ash of concern environmentally.



Enrichment of Cd in fly ash is expected because Cd is



vaporized by incineration and is recondensed on the fly ash



particles during the cooling of the off-gases [17].  The



distribution of Zn is different from that predicted [17]  and



may be due to the operation condition at the incinerator.
                              846

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Table 1.  Elemental concentrations  in MSW incineration  ash
          (N = 6) .
Element
Al (%)
Si (%)
Ca (%)
Mg (%)
Fe (%)
Zn (%)
Pb (Mg g"1)
Cu (Mg g )
Ni (Mg g"])
cd (Mg g' )
Cr fixer cr )
Fly Ash
4.6
15
6.8
1.1
1.1
4.2
5500
810
120
380
155
Scrubber Ash
6.5
19
8.6
1.8
3.4
0.4
1200
1100
250
30
403
Bottom Ash
2.8
22
7.'7
0.9
6.8
0.4
1700
2100
160
24
201

     Table 2 shows the results of tank leaching studies on

stabilized MSW ash blocks.  The detected concentrations in

test solution were less than 5 /ig IT1  for Cu and less than 1

L"1 for Cd.  Lead was not detected in  the solution.  The

results indicate that leaching of Cu, Cd, and Pb from

stabilized MSW ash blocks in seawater is insignificant.  The

initial leaching for Cu and Cd occurs at the surface of the

block which is in direct contact with seawater.  Previous

studies on stabilized energy waste blocks [18] also showed

that interaction of the stabilized blocks with seawater after

the emplacement at. sea occurred mainly at the surface of the

block.
                              847

-------
Table 2. Leaching of Cu, Cd, and Pb (/ig L"1)
stabilized MSW ash blocks in seawater.
Stabilized
Time
fdav)
1
2
3
6
9
12
19

CU
3.58
4.08
2.81
n.d.
n.d.2
n.d.
n.d.
B1
Cd
0.24
0.16
n.d.
n.d.
n.d.
n.d.
n.d.

Pb
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.

Cu
2.35
1.56
n.d.
n.d.
n.d.
n.d.
n.d.
from

MSW Ash Block
BF1
Cd
0.15
0.42
n.d.
n.d.
n.d.
n.d.
n.d.

Pb
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.

Cu
1.21
3.23
1.91
n.d.
n.d.
n.d.
n.d.
BS1
Cd
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.

Pb
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
n.d.
    Block B represents 100% bottom ash; BF represents 60%
    bottom ash and 40% fly ash; BS represents 70% bottom ash
    and 40% scrubber ash.
    n.d. represents not detectable.
    Detection limit for Cd is 0.1 fig L"1; for Cu is 1 ng L"1;
    for Pb is 1 ng L"1.
     As mentioned above, application of the stabilized ash

block in marine environment requires a demonstration that the

materials are environmentally acceptable.  Data shown in Table

2 indicate that trace metals, such as Cu, Cd, and Pb, are

retained inside the block which has a good physical integrity.

     One question may be raised dealing with the fate of these

metals if the block is cracked or turned into debris after

placement into the ocean.  Investigation of this concern can

be achieved by examining the release of metals from ground ash
                              848

-------
blocks.  Table 3 shows the percent leaching of Cu, Cd, and Pb

from both the powdered stabilized MSW ash blocks and loose

ash.  Without stabilization, Cd was nearly depleted from fly

ash after placement into seawater, while only about 10% of Cd

was released from loose bottom ash after it was in contact

with seawater for 48 hours.  Stabilization of the ash by

mixing 60% of bottom ash with 40% of fly ash results in a very

significant reduction in Cd leaching.
    Table  3.   Percent  leaching <%) of Cu, Cd, and Pb  from
        loose MSW  ash and powdered stabilized ash block.
Time
(hr)
0.5
2
8
24
48
Flv Ash
Cd
97
98
83
94
91
Cu
2.9
1.8
2.1
1.6
1.6
Pb
0.39
0.32
0.30
0.25
0.23
Bottom Ash
Cd
2
5
11
13
14
Cu
0.34
0.54
1.06
1..42
1.64
Pb
0.49
0>29
0.34
0.63
0.30
Cd
1.0
1.6
-
2.6
2.7
Block BF
Cu
0.13
n.s.
n.s.
n.s.
n.s.
Pb
n.s.
n.s.
n.s.
n.s.
n.s.
1.  Block BF represents the mix containing 60% bottom ash and
    40% fly ash.
2.  n.s. represents not significant; the value is less than
    0.01%.
     For Pb and Cu, only small percentage was released from

the ashes  into seawater.  This is still of concern because

high concentration of Pb and Cu are found in most of MSW

ashes.  Stabilization process also significantly minimizes the

leaching of Pb and Cu in seawater.
                               849

-------
     Research conducted is for a worst case, i.e., assuming

the stabilized MSW ash blocks become cracked leading to debris

soon after the emplacement at sea.  However cracking is

improbable based on previous engineering investigations which

have shown that stabilized ash blocks made from coal fly ash

and FGD sludge residue have maintained their physical

integrity in the ocean at least 10 years [19].

   To  understand the  mechanism  of  the  stabilization process on

retaining trace metals in the stabilized blocks, studies were

conducted on ground block samples of varying sizes fraction.

The results are shown in Table 4; leaching of Cd increased as

the particle size decreased indicating that physical

enclosement may be the major mechanism for retaining Cd within

the block matrix.   Leaching of Cu showed little influence from

particle size indicating that retention of Cu is mainly by

chemical bindings.
Table 4.  Leaching of Cu and Cd from ground stabilized ash
block (BS) in seawater.
Particle Size
(um)
< 250
250-500
500-1000
> 1000
Cu
(ua L"1)
6.80±0.14
3.80±1.10
7.87±0.25
9.5012.70
Cd
(ua L~1)
0.47±0.07
0.26±0.12
0.1210.05
0.1410.02
                              850

-------
                          CONCLUSIONS

     Stabilization has significantly minimized leaching of Cu,

Cd, and Pb from MSW incineration ash.  Copper, Cd, and Pb are

retained inside the stabilized MSW ash block.  Retention of Cd

is mainly due to physical enclosement while Cu is retained by

chemical bindings.  The study indicates that the stabilized

MSW ash block is chemical stable in seawater.  Application of

this material in marine environment should be further

considered and investigated.



                        ACKNOWLEDGMENTS

     We thank Dr. Iver W. Duedall for reviewing the paper and

valuable suggestions.  We also thank H. Emma Yoo for preparing

digest samples for elemental analysis.  This work was funded

by HDR Engineering, Inc.



                          REFERENCES
1.   Neal, H. A. and J. R. Schubel.  Solid Waste Management
     and the Environment - The Mounting Garbage and Trash
     Crisis. Prentice-Hall, Inc., New Jersey, 239 pp., 1987.

2.   Frame, G. B.  "Air Pollution Control Systems for
     Municipal Solid Waste Incinerators", Journal of Air
     Pollution Control Association. 38, 1081-1087, 1988.

3.   Greenberg, R.R., W.' H. Zoller, and G. E. Gordon.
     "Composition and Size Distribution of Particles Released
     in Refuse Incineration", Environmental Science and
     Technology. 12, 566-573, 1978.

4.   Law, S. L. and G. E. Gordon.  "Sources of Metals in
     Municipal Incinerator Emissions", Environmental Science
     and Technology. 13, 432-438.
                              851

-------
5.   Eraser, J. L. and K. R. Lum.  "Availability of Elements
     of Environmental Importance in Incinerated Sludge Ash",
     Environmental Science and Technology. 17, 52—54, 1983.

6.   Denison, R. A.  "Municipal Solid Waste Incineration in
     Context: Assessing Risks and Assigning Roles", In:
     Governmental Refuse Collection and Disposal Association
     26th Annual International Solid Waste Exposition. 22-25
     August 1988, Baltimore, Maryland, 16 pp. 1988.

7.   Sawell, S. E. and T. W. Constable.  "The National
     Incinerator Testing and Evaluation Program:
     Characterization of Residues from a Mass Burning
     Incinerator.  In: 10th Canadian Waste Management
     Conference. Winnipeg, Manitoba, October 1988

8.   Stewart S. L.  "MSW Incinerator Ash Management", In:
     Municipal Solid Waste Technology Conference. San Diego,
     California, January 30 - February 1, 1989

9.   National Research Council.  "Monitoring Particulate
     Wastes in the Oceans, The Panel on Particulate Waste in
     the Oceans", Marine Board, NRC-NAS: Washington, D.C.,  pp.
     176 -i- appendix. 1988.

10.  Shieh, C. S., I. W. Duedall, E. H. Kalajian, and F.  J.
     Roethel.  "Energy Waste Stabilization Technology for Use
     in Artificial Reef Construction", In: Emerging
     Technologies in Hazardous Waste Management. ACS symposium
     series 422, Chapter 19, American Chemical Society,
     Washington, D.C., 328-344, 1990.

11.  Woodhead, P. M. J., J. H. Parker, and I. W. Duedall.
     "The Use of By-Products from Coal Combustion for
     Artificial Reef Construction",  In: Artificial Reefs.
     Marine and Freshwater Applications. F. M. D'ltri (Ed.),
     Lewis Publishers, Inc., Chelsea, Michigan,  pp. 265-292,
     1985.

12.  Shieh, C. S., I. W. Duedall, E. H. Kalajian, and J.  R.
     Wilcox.  "Stabilization of Oil  Ash for Artificial Reefs:
     An Alternative to the Disposal  of Oil Ash Waste", The
     Environmental Professional.  11, 64-70, 1988.

13.  Shieh, C. S. and F. J. Roethel.  "Physical  and Chemical
     Behavior of Stabilized Sewage Sludge Blocks in Seawater",
     Environmental Science and Technology. 23, 121-125,  1989.

14.  Lechich, A. F. and F. J. Roethel.  "Marine  Disposal  of
     Stabilized Metal Processing Waste", Journal Water
     Pollution Control Federation.  60, 93-99, 1988.
                             852

-------
15.  Silberman, D. and G. L. Fisher.  "Room Temperature
     Dissolution of Coal Fly Ash for Trace Metal Analysis by
     Atomic Absorption", Analytical Chemistry. 106, 299-307,
     1979.

16.  Duedall, I. W.,  J. S. Buyer, M. G. Heaton, S. A. Oakley,
     A. Okubo, R. Dayal, M. Tatro, F. Roethel, R. J. Wilke,
     and J. P. Hershey,  "Diffusion of Calcium and Sulphate
     Ions in Stabilized Coal Wastes", In: Wastes in the Ocean.
     Vol. 1, Industrial and Sewage Wastes in the Ocean, I. W.
     Duedall, B. H. Ketchum, P. K. Park, and D. R. Kester
     (Eds.), Wiley-Interscience, New York, pp. 375-395. 1983.

17.  Brenner, P. H. and H. Monch.  "The Flux of Metals Through
     Municipal Solid Waste Incinerators", Waste Management &
     Research. 4, 105-119, 1986.

18.  Stabilized Oil Ash Reef Program, Final Report, to be
     submitted to Florida Powder and Light, Juno Beach,
     Florida, (in preparation).

19.  Hans van der Sloot, personal communication; Coal Waste
     Artificial Reef Program - a visit after ten years.
                              853

-------
              PROPOSED AIR POLLUTION EMISSION RULES
            FOR MUNICIPAL WASTE COMBUSTION FACILITIES

           Walter H. Stevenson and Michael G. Johnston
                   Emission Standards Division
              U. S. Environmental Protection Agency
          Research Triangle Park, North Carolina  27711

INTRODUCTION

    The EPA proposed regulations for municipal waste combustors
(MWC's) on December 20, 1989.  The regulations include (1)
performance standards under Section lll(b) of the Clean Air Act
(CAA) for new, modified, or reconstructed MWC's and (2) emission
guidelines for the States to use to develop control requirements
for existing MWC's under Section lll(d).

    This paper will summarize the proposed air emission
standards and guidelines, as well as the bases for the prescribed
emission limits.  The schedule for the remainder of the
regulations development will also be discussed.

REGULATORY APPROACH

    The EPA has chosen to regulate MWC's under Section 111 of
the CAA
(52 FR 25339).  The Administrator determined that MWC's would be
regulated under Section 111 because the range of health and
welfare effects and the range and uncertainties of estimated
cancer risks did not warrant listing of MWC emissions as a
hazardous air pollutant under Section 112.  Section 112 also
could not be used to address particular constituents of MWC
emissions including lead and hydrogen chloride (HC1).  Finally,
the development of emission guidelines under Section lll(d) would
permit a more thorough evaluation of existing MWC's at the State
level than would be possible with a general rulemaking at the
Federal level under Section 112.

    The implementation of Section 111 involves several steps
commencing with the selection and characterization of the source
category to be regulated.  The source category is characterized
in terms of types, numbers, and sizes of facilities and an
emissions evaluation.  The applicability of the standards is
established by defining affected facilities.  Under Section 111,
the Agency must then identify the best demonstrated technology
(BDT), which is defined as the best system of continuous emission
reduction that has been adequately demonstrated taking into
account costs and other environmental and energy impacts.
Regulations development under Section 111 also requires the
selection of the pollutants to be regulated from the particular
                              855

-------
source categry.  Finally, the EPA must  select  the  format  for  the
standard and establish the numerical emission  limits  for  the
pollutants which will be regulated.

    The proposed MWC standards address  air emissions  from new
and existing sources.  Air emission limits for new sources are
proposed under Section lll(b) for the criteria pollutant  nitrogen
oxides (NOX), and a designated pollutant.   A designated pollutant
is a pollutant which is not listed as a hazardous  air pollutant
under Section 112 of the CAA or is not  a criteria  pollutant under
Sections 108-110.

    The designated pollutant selected for  regulation  under this
standard is the collection of compounds emitted by MWC's  referred
to as "MWC emissions."  "MWC emissions" are categorized into
three general subclasses of pollutants:  MWC organics, in
particular dioxins and furans; MWC metals, the condensible metals
associated with particulate matter (PM) emissions from MWC's; and
MWC acid gases, specifically sulfur dioxide 
-------
that over 90 percent of new capacity will be attributed to large
facilities, and the dramatic increase in costs associated with
emissions control for new, small facilities.

    The proposed NSPS for large, new MWC facilities would
require an emission limit of 5 to 30 ng/dscm for total tetra-
through octa-chlorinated dibenzo-p-dioxins and dibenzofurans for
the control of MWC organics.  MWC metals would be controlled by
an emission limit on PM of 0.015 gr/dscf.  This level of PM
control would result in greater than 97 percent control of all
MWC metals with the exception of mercury.  The level of PM
emissions would be monitored continuously by the use of an
opacity monitor at the stack and a 10 percent opacity limit,
based on a 6-minute average, would apply.  MWC acid gases would
be reduced through emission limits for both HC1 and S02-
Emission limits of 95 percent reduction or 25 ppmv for HC1, and
85 percent reduction or 30 ppmv for SO2 are proposed.  Compliance
with the HC1 emission limit would be demonstrated using proposed
EPA Method 26 (54 £E 52190).  The SO2 emissions would be
continuously monitored.

    The emission limits for large facilities are based on the
application of good combustion practices (GCP) and a spray
dryer/fabric filter (SD/FF).  In addition to "MWC emissions"
control, large, new combustors would also be limited to 120 to
200 ppm of NOX based on the application of selective non-
catalytic reduction technology.  Continuous monitoring of NOy
would also be required.

    For small, new MWC facilities, the proposed maximum emission
level of dioxin/furan emissions is 75 ng/dscm.  The PM emission
limit is identical to that for large facilities.  The level of
acid gas reductions required is 80 percent or 25 ppm for HCl and
50 percent or 30 ppm for SO2-  These proposed emission limits are
based on the application of GCP and duct sorbent injection (DSI)
followed by an electrostatic precipitator (ESP) or FF.

    Annual emissions testing would be required for all new
MWC's.  However, if a small, new MWC is in compliance with the
standards for three consecutive annual tests, the facility may
skip the next two annual tests.  If the next test demonstrates
compliance, the facility may again skip the next two years.
Therefore, at a minimum, a small MWC must conduct emissions
testing at least once every three years.

EMISSION GUIDELINES fEGI FOR EXISTING SOURCES

    The emission guidelines for "MWC emissions" from existing
MWC sources are proposed pursuant to .Section lll(d).  Emission
guidelines and compliance times are described in the proposal and
are to be used by States in developing State regulations for the
control of existing MWC facilities.  The intent of the proposed
                              857

-------
guideline is to compel State regulation of MWC's through the
application of the best demonstrated technology.

    The proposed emission guidelines for existing  facilities  are
outlined in Table 2.  The guidelines are subdivided into three
subcategories of facilities based on plant capacity:  small
facilities, up to 250 tpd; large facilities, between 250 and
2200 tpd; and regional facilities with capacities greater than
2200 tpd.

    The proposed guidelines for existing, small facilities would
require the application of good combustion control for the
control of MWC organic emissions and an ESP upgrade for
particulate control for the reduction of MWC metals.  Total
tetra- through octa-chlorinated dibenzo-p-dioxin and dibenzo-
furan emissions would be limited to 500 ng/dscm.  Particulate
emissions would be limited to 0.03 gr/dscf.

    The emission guidelines for existing, large MWC facilities
would require additional control of organic emissions as well as
the control of acid gas emissions.  The proposed guidelines would
require the application of GCP and dry sorbent injection into the
furnace or the duct for the control of MWC acid gases followed by
an ESP or FF.  Dioxin and furan emissions would be limited to
125 ng/dscm while PM would be limited to 0.03 gr/dscf.   MWC acid
gases would be controlled through a 50 percent reduction of both
HC1 and SC>2 or an emission limit of 25 ppmv and 30 ppmv,
respectively.

    The proposed guidelines for regional MWC facilities are
based on the application of GCP and a SD/FF.  The emission limits
are identical to those discussed above for large,  new MWC
facilities except that NOX control would not be required for
existing MWC's.

    The proposed emission guidelines in most cases would be
expected to result in compliance with State standards within
3 years of adoption.  However, longer compliance times may be
required for those facilities requiring extensive retrofit and
schedule adjustment would be considered.

    Annual testing would be required for all existing MWC
facilities.  However, if a facility shows compliance with the
emission guidelines for three consecutive annual tests, they will
be permitted to skip the next two annual tests.  If they again
demonstrate compliance in the third year following their last
test, they may skip another two years.   In any circumstance,  each
existing facility will be tested a minimum of once every 3 years.
                              858

-------
MATERIALS SEPARATTQN

    The proposed MWC standards would require that all municipal
solid waste (MSW) to undergo preprocessing prior to combustion.
This preprocessing is defined as the removal of 25 percent or
more by weight from the MSW of the following components:  paper
and paperboard; ferrous metals; nonferrous metals; glass;
plastics; household batteries; and yard wastes.However, no more
than 10 percent of the total 25 percent can be attributed to the
yard waste component.  This materials separation requirement
would apply to all MWC facilities, existing and new.  The
proposed standards would also preclude the combustion of lead
acid vehicle batteries and require the removal of household
batteries.

    The materials separation requirement may be met by an on-
site mechanical or manual separation program or an off-site
community separation program, or a combination thereof.  If an
off-site or community program is implemented to comply with the
requirements, a plan describing the separation program and the
compliance demonstration methods would be submitted to the EPA or
the State agency for approval.  Compliance with the proposed
materials separation requirements would be demonstrated based on
the calendar year average of measurements of the total weight of
MSW received, the weight of MSW combusted, and the weight of
materials separated.

    Demonstration of compliance with the materials separation
requirement would not be required until the end of the second
full calendar year after initiation of the materials separation
program.  A report of the percent materials separation achieved
would be submitted after the first full calendar year of
operation to determine the progress toward meeting the
requirement.  However, this report would not be used to determine
compliance.  The second and subsequent annual report would be
used to determine compliance.

    A new MWC facility must have a separation program in place
at the initial start-up of the facility.  However, for new
facilities which commence construction between proposal and
promulgation, a materials separation program would not have to be
implemented until December 31, 1992, or at initial start-up,
whichever is later.  Demonstration of compliance with the
materials separation requirement would not be required until
December 1994, or at the end of the second full calendar year
after start-up.

    The proposed emission guidelines for existing MWC facilities
would require the implementation of a materials separation
program by December 31, 1992.  Recordkeeping and reporting
requirements would be identical to those for new facilities.
Therefore, the first annual report would be due December 31,
                                   859

-------
1993.  However, this interim report would not be used for
compliance purposes.  The initial demonstration of compliance
would occur the following year with the submittal of the
December 31, 1994 report.

    Removal of lead-acid vehicle batteries would result in  a
reduction of lead emissions from MWC's.  Household battery
separation is proposed to effect reductions in mercury emissions
from MWC's.  Add-on control systems have proven to be ineffective
in achieving consistently high removals of mercury from MWC flue
gas.  Since much of the mercury in MSW is in the form of
batteries, EPA is proposing separation of batteries from the
waste stream as a means of reducing MWC mercury emissions.  The
EPA continues to study this issue.

    Finally, the proposed materials separation reguirements
include a provision whereby the EPA would grant a facility a
permit to combust separated, combustible materials if no markets
exist for the material.  A recycling market would be considered
to be unavailable if, after separating the material and searching
for a market for 120 days, the MWC operator could demonstrate to
EPA that either no recycler will take the material or that-the
cost of recycling is egual to or exceeds the cost of landfilling.
However, the materials separation reguirement would remain in
place even where a combustion permit has been granted.   This will
assure stability in the materials separation program.  The
combustion permit would be effective for one year,  but is
renewable on an annual basis.

COMBUSTIOK CONTROL REQUIREMENT

    The proposed MWC standards would establish combustor
operating practices for both existing and new sources.   Good
combustion practices (GCP) involve the proper design,
construction, operation, and maintenance of an MWC.   The
implementation of GCP would result in a reduction of MWC organic
emissions by promoting their destruction.   These practices would
include limits on carbon monoxide (CO), combustor load,  and the
flue gas temperature at the control device outlet as outlined in
Table 3.

    Techniques employed to minimize CO are similar to those
required for the effective destruction of organics.   Therefore, a
CO emission limit is proposed for the various combustor types.
For modular starved air and modular excess air types of MWC's,
the CO emission limit would be 50 ppmv (at 7 percent O2 on a
block 4-hour average basis).  For mass burn waterwall,  mass burn
refractory, and fluidized-bed types of MWC's,  the CO emission
limit would be 100 ppmv (at 7 percent O2 on a block 4-hour
average basis).  For mass burn rotary waterwall,
refuse-dervied fuel (RDF), and coal/RDF co-fired MWC's,  the CO
                              860

-------
emission limit would be 150 ppmv (at 7 percent O, on a block 4-
hour average basis).

    Combustor load also affects MWC organic emissions.  At
combustor loads exceeding maximum capacity, the potential for PM
carryover increases and residence times decrease leading to an
increase in organic emissions.  Municipal waste combustors would
not be allowed to operate above 100 percent of their maximum
capacity as demonstrated during compliance testing (1-hour
average basis).  Municipal waste combustors that do not generate
steam would be exempt from maximum load level requirements
because these types of MWC's cannot feasibly measure load level.

    The proposed standards would require all MWC's to maintain a
flue gas temperature of 230*C (450*F)  or less (4-hour block
average) at the PM control device inlet.  The purpose of this
requirement is to prevent post-combustion formation of dioxins
and furans.

    Operator training is considered by EPA to be an integral
part of the implementation of GCP.   The proposed GCP would
therefore require American Society of  Mechanical Engineers (ASME)
certification of the chief facility operator and shift
supervisors.  In addition, a training  manual must be developed
for the remaining MWC personnel who occupy positions associated
with the combustion process.  The training manual should focus on
the various components of the combustion process and how they
impact performance and emissions.  The manual should also specify
remedial measures that are effective during process upsets and
startups and shutdowns.

SCHEDULE

    The remaining schedule calls -for promulgation of the new
source performance standards and emission guidelines in December
1990.  The States will then be required to develop and submit a
plan implementing the guidelines.  Approximately 9 months is
expected to be necessary for State plan submittals.   The EPA must
prescribe a plan for a particular State if that State fails to
meet the deadline or submits an unsatisfactory plan.   The EPA
will approve State emission standards  which meet the emission
guidelines through the application of  the best systems of
continuous emission reduction which are reasonable available.
For health-related pollutants, as is the case for "MWC
emissions". State emission standards must ordinarily be at least
as stringent as the emission guidelines.  However, where
justified due to the unreasonableness  of application,  relief may
be granted on a case-by-case basis.
                              861

-------
                      TABLE 1.  MHC EMISSION LIMITS FOR
                                NEW FACILITIES3

Plant Capacity, tpd
MWC Metals, gr/dscf (as PM)
MHC Organ ics, ng/Nm3 (as CDD/CDF)
MWC Acid Gases
HC1, % Reduction0
S02, % Reduction01
NOX, ppmv
NEW
<250
0.015
75
(250)D

80
50
none
FACILITIES
>250
0.015
5-30

95
85
120-200
a Corrected to 7% 02
b Value indicated for RDF  facilities
c Indicated percent reduction  or less  than  25  ppmv.
" Indicated percent reduction  or less  than  30  ppmv.
                                     862

-------
                    TABLE  2.  MWC  EMISSION  GUIDELINES  FOR
                               EXISTING FACILITIES9
Plant Capacity, tpd
MWC Metals, gr/dscf (as PM)
MWC Organics, ng/Nm3 (as CDD/CDF)
MWC Acid Gases
   HC1, % Red.c
   S02, % Red.d
   NOX, ppmv
                                             EXISTING FACILITIES
<250
 0.030
  500 ,
(1000)*
>250 to 2200    >2200
                                                     0.030
                                                      125
                                                     (250)t
                 0.015
                 5-30
none
none
none
50
50
none
95
85
none
a Corrected to 7% 02.
b Value indicated for  RDF facilities.
c Indicated percent reduction or less  than 25ppmv.
  Indicated percent reduction or less  than 30 ppmv.
                                     863

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                     TABLE 3.   GOOD COMBUSTION PRACTICES
                                    LIMITS
POLLUTANT OR PARAMETER
               LIMIT
MAXIMUM LOAD LEVEL

MAXIMUM TEMPERATURE AT PM
CONTROL DEVICE INLET
100% OF DEMONSTRATED CAPACITY

230'C (450*F)
CO Emissions:

Modular MWCs
Mass burn waterwall
Mass burn refractory
Fluidized bed combustor
Mass burn rotary water wall
RDF spreader stoker
Coal/RDF co-fired
50 ppmv
100 ppmv
100 ppmv
100 ppmv
150 ppmv
150 ppmv
150 ppmv
OPERATOR CERTIFICATION AND
TRAINING
ALL OPERATORS CERTIFIED BY ASME;
TRAINING MANUAL AND TRAINING FOR
OTHER PERSONNEL
                                    864

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       SALES OF ELECTRIC POWER USING MUNICIPAL SOLID WASTE

                       Freddi L. Greenberg*
                         Attorney at Law
                        Presented at the

    First U.S. Conference on Municipal Solid Waste Management

                       June  13 - 16, 1990
*Freddi L. Greenberg is an attorney who  practices in the area of
energy and  public utility law.   She has represented  clients in
connection  with  regulatory   and  contract  matters  concerning
electric  generating  projects  in  15  states.    Ms.   Greenberg
maintains offices in Evanston and Chicago,  Illinois.
                             865

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       SALES OF ELECTRIC POWER USING MUNICIPAL SOLID WASTE
                      FREDDI L. GREENBERG
                        ATTORNEY AT LAW
Introduction

     My topic today is "Sales of Electric Power Using Municipal

Solid  Waste."   I  have  divided the  topic  into four  parts.

First,  I  will  discuss   the  current  state  of  non-utility

generation in the United States.  Then I will turn to state and

federal  regulatory issues  which you  should  be  aware  of  in

connection  with electric generating  projects.   Third,  I'll

mention some of the more important contract issues you will see

in your negotiations with utilities.   I'll  close with a  couple

of  practical  suggestions   to   keep   in mind  when  you  are

developing  a  project.    I will  use the term  municipal  solid

waste, or  "MSW",  to refer to both landfill gas and municipal

solid waste.

Overview of Power Sales Opportunities

     Let's begin by  looking  at where we are  today compared to

where we were five or ten years ago.  One of the most important

changes in  the electric  utility  industry during the  last ten

years  has  been the  development  of  an active  and  growing

independent power  industry.   A primary  reason for this  change

is that Congress passed the  Public  Utility  Regulatory Policies

Act or ("PURPA") in 1978.   PURPA requires utilities to purchase

electricity  from non-utility   generating  facilities   using
                           866

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certain technologies.   These include facilities  fueled by MSW
and are known as "qualifying facilities" or "QF's".
     During   the  early  and  middle   1980's  most  utilities
purchased  power  from  qualifying  facilities and  other  non-
utility generators  with  great  reluctance.   This  was  because
utilities  preferred  to build  their own  generating plants  so
those plants  would  be  included  in rate base.   Utilities also
questioned the reliability of non-utility generation.
     Today  many  utilities  are  actively  seeking  bids  for
generating capacity — from qualifying facilities and from non-
utility generators which  do not  qualify under  PURPA and which
cannot force utilities to buy their power.   This is because,  in
recent years, many utilities have had  difficulty including the
cost  of  their own generating  plants in rate base.  They may
have had cost overruns or they may have found that they did not
need  all  of their new  capacity  once it was built.  In these
cases, utility  shareholders, rather than  ratepayers, have had
to bear all  or  part  of the  cost  of  a new  plant.   As a  result,
utilities  are more  reluctant than before  to  bear, the  risks  of
building new capacity.
     At the  same time,  non-utility generation has  been around
for a while and  has  been  proven  to be  reliable.   Utilities who
have  dealt  with  these  generators  have  acknowledged  their
reliability  in  situations  such  as  last  year's  San Francisco
earthquake.   For these reasons,  I  think  you  will find that
utilities  which  need new generating capacity are increasingly
                              867

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willing  to  buy  your power.    In  addition,  many  economists



suggest  that  electric utilities  in  the United States  have



underforecast load growth during the '90's, so opportunities to



sell capacity to utilities may increase during the next several



years.



     There is  another side  to  this story which you should also



be   aware  of.    Regulatory   and  economic   barriers  which



discouraged non-utility generation which did not qualify under



PURPA  have been  reduced.   As a  result, there  is  interest in



this area  by  large developers,  including non-regulated utility



subsidiaries.   Generally  the projects are increasing  in size,



with capacities as high as several hundred megawatts.



     As  I  mentioned,  utilities  are  turning  to  competitive



bidding when they need new capacity.  What this means to you is



that  there  will  be  more  competition  when  you  try  to  sell



capacity to a utility and that your larger competitors may have



a price  advantage due to  the economies  of scale.   In  spite of



this   competition,  I  am   optimistic   about   the  future  of



generating projects fueled by MSW for three reasons.



     First, a  project like yours may be ideal  where a utility



is of the old school and has not wanted to deal with qualifying



facilities,  despite   the   legal  obligation  to  do  so.    Your



projects  typically will be  small enough  so they will  not be



viewed as  threats to  the  utility's rate  base.   The utility may



be happy  to  sign  a contract with you, so  it can point to your



contract  when larger  developers  complain that the  utility is
                              868

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discouraging the development of QF's.
     Second,  the national  concern  about  the  environment and
waste disposal has led some states to pass laws which encourage
non-utility generation fueled by  landfill  gas and MSW.   Two of
those  states  are  Illinois and  Michigan.    In Illinois  the
standard rate available to a qualifying facility is less than 2
cents/kwh.   Where  the  qualifying facility  is  fueled  by MSW,
Illinois law requires that the utility purchase power at a rate
equal to  the rate paid to  that utility by the  city  or county
where  the  facility  is  located.    (Such  facilities must  be
qualifying  facilities under PURPA and  must be certified by the
Illinois Commerce Commission.)   This can be  as  high  as 6 or 7
cents a  kilowatt hour.   The utility receives a tax credit for
the difference between the  two  rates.   The generating facility
must  repay  the difference  between the two rates to  the state
after  it  has been  in  operation for  ten  or twenty  yea'rs,
depending  upon the  type of  project.    The  end result  is  an
interest-free  loan  which enhances the project's cash  flow in
the early years.
     Michigan has taken  a slightly different approach.   Under
the Michigan law, utilities must pay the highest legal rate for
energy and  capacity purchased from MSW  facilities  even if the
utility goes out for bids and is able to purchase capacity from
other sources at  a  lower  rate.   In both states, purchases from
MSW facilities are not counted in  determining whether a utility
has exceeded its permitted capacity reserve margins.
                               869

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     The  third  reason   I   am  optimistic  about  MSW  fueled



generation is that utilities do not want to be overly dependent



on generation  which burns  a single type  of fuel.   They seek



fuel diversity  in  order to limit the  impact  of  outages due to



interruptions  in fuel  supply.   Landfill  gas and  MSW enhance



utility fuel diversity.   For example,  if  a  utility is heavily



dependent  on natural  gas,  your projects  will  be attractive



because,  unlike natural  gas,  your fuel  supply  will not  be



affected by  outages  or curtailments of transporting pipelines.



This  advantage  is  significant  because,   if  you  bid to  sell



capacity  to  a  utility,   most  of  your   competitors  will  be



projects fueled by natural gas.



     In  evaluating  a seller's   fuel  supply  when  it  buys



generating capacity,  a utility  also  will want  to see  a  firm



fuel contract  for  the term  of the power sale contract.   Here



again,  your  projects  have  the  edge  over natural  gas  in  the



current gas  market.   This is because,  at  the present time,  it



is almost  impossible to sign a contract for  a firm,  long term



supply  of  natural  gas at a reasonable  price.  In  contrast,  it



is generally possible to  line up  a  supply  of  MSW on  a  firm



basis.  Your ability to present a  strong  fuel supply contract



will help sell your project to a utility.



Federal Regulatory Issues



     Now that I have given you  a look  at where we  are today, I



want to turn to some of the state and federal regulatory issues



you will face  in connection  with your  generating facility.   As
                             870

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I  mentioned earlier,  PURPA requires  that  utilities  purchase
electricity generated by  qualifying  facilities which burn MSW.
Under PURPA,  a qualifying  facility  is entitled to  received a
rate  equal to the  purchasing utility's  avoided  cost.    The
avoided cost is the cost to the utility if it had generated the
same  amount of  power  itself  instead  of buying  it  from  the
qualifying  facility.     If  the   utility  needs  additional
generating  capacity, the  avoided  cost  must include a component
to  compensate  the  qualifying  facility for  the fact  that  the
power purchase has allowed  the  utility  to  avoid or  to  defer
building  new  capacity.    The actual method of  calculating
avoided  cost  is determined  at the  state level and will vary
from one utility to another.
     Besides  a guaranteed  market for  their power, there  are
three other important  benefits  available to  facilities  which
qualify  under  PURPA.   First,  qualifying  facilities and  their
parent companies  are exempt from regulation by the Securities
and  Exchange  Commission  under  the  Public  Utility  Holding
Companies  Act.   Second,  utilities  are  required to  provide
backup  power  to  qualifying  facilities   at  cost-based,  non-
discriminatory rates.   Backup power is the  catch-all  term for
any power  the qualifying facility is  unable to supply for its
own use.   With  an MSW project,  you  are  most likely  to need
utility  service for  startup  after  an outage.    Third,  PURPA
exempts most qualifying facilities from regulation as utilities
at  the  state  and  federal levels.   Facilities larger  than 30
                              871

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megawatts  are  subject to  regulation  by  the  Federal  Energy
Regulatory  Commission  (FERC)  and  must  make  certain filings
before commencing operation.
     The  benefits   of  PURPA  are  available  to  MSW  fueled
facilities which meet the following three criteria:
     1.   First, the generating facility must have a generating
          capacity no  greater than 80 megawatts.   This should
          include most MSW fueled facilities.
     2.   Second, a  utility may  not own  more than a 50 percent
          equity interest in the facility; and
     3.   Third, the facility must be fueled primarily by MSW.
     This means  that use of natural gas  or other fossil fuels
cannot  exceed  25 percent  of  the  total  energy  input  in  a
calendar year.  More importantly, fossil fuels can be used only
for  certain  purposes specified  in PURPA or otherwise permitted
by the  FERC, the federal agency which administers PURPA.   You
cannot  simply  oversize  your  facility  in relation  to  your
projected supply of  fuel and burn fossil fuel 25 percent of the
time, unless your usage falls within the permitted uses.
Once you know that your facility meets these criteria, the next
step  is  to  qualify  the  facility with the  FERC.  This  can be
done  in  one  of two ways.  First, the owner or operator of the
facility  can  self-certify  by  filing  a  Notice  of  Qualifying
Status with  the FERC.   The second  alternative is to ask the
FERC  to  issue an order certifying  that  the facility qualifies
under PURPA.   From a legal  standpoint,  both approaches achieve
                              872

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the  sane  result,  although  there may  be practical  reasons to


seek an FERC order instead of self-certifying.


     Besides  defining qualifying  facilities,  the  FERC  rules


address various other aspects of PURPA.  For example, the rules


define those times when,  for operational reasons,  a utility is


not  required to purchase power from a  qualifying  facility.  I


will not  discuss those rules here  other than to  say that you


should become familiar with them.


     Non-utility  generating  facilities  which  do  not  qualify


under PURPA  are commonly known as  independent  power producers


or  "IPPs".    If  your  facility is  an IPP,  you  will  have

                                 /
opportunities  to  respond  to  bids   for   capacity  by  some


utilities,  although   utilities  are not required  to buy  your


power.    You  will have  to  seek  certain  authorizations  and


waivers from the FERC, and the Public Utility Holding Companies


Act  may  affect the ownership structure of your project.   The


regulatory climate is becoming  increasingly favorable to IPPs,


so  inability  to  qualify under PURPA  should not necessarily


deter you from developing a project.


State Regulatory Issues


     Now  I'm  going  to  turn to  the  state  regulatory  scene.


Because  the  FERC regulations  are  implemented at  the  state


level,  you will  have to look  to  your state public  utility


commission after  you  qualify your  facility with  the  FERC, if


you  plan  to  sell power to  an investor-owned  utility.    For


municipal  utilities,   the situation varies by  state.  - Often
                              873

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there is no  state regulation,  so you will have  to look to the
FERC if you want to enforce your rights under PURPA.
     As you  have  seen,  the basic issues of who qualifies under
PURPA  and  the  benefits  available  under  PURPA  are  federal
questions.   State public  utility  commissions  administer PURPA
insofar as rates paid to qualifying facilities, rates utilities
may  charge  for backup  power,  utility interconnection charges,
and  most other aspects  of the relationship between the utility
and  the qualifying  facility.   All  of these items must meet the
standards set  out in  the federal rules,  but you will find that
each state has its own  interpretation of those rules.  For that
reason, it is essential that you become familiar with the PURPA
rules  of  your state  commission  before you  approach a utility
about buying your power.
     As you  know,  a utility is required to pay a rate for your
power  which is  equal  to its  avoided cost.   That  rate will
either be  set  or approved by the state commission.  Typically,
the  rate will  include an energy payment for each kilowatt hour
of   electricity   delivered.     The  energy  payment  generally
reflects  the utility's costs for  fuel  and for  operating and
maintenance  expenses.   The capacity component also may be paid
on a kilowatt hour basis.  More  commonly, however, the capacity
component is a monthly  payment per kilowatt  of capacity.
     During  the  last  several years, utility avoided costs have
decreased in most areas of the country.  One major exception is
the  northeast, where  utilities need generating capacity.  Where
                             874

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we  saw  avoided costs  as high  as  eight or  ten cents/kilowatt
hour six or eight years ago, many people consider four cents an
attractive rate today.   Where utilities do  not need capacity,
avoided costs  may be 2 cents  or less,  which can make  it very
difficult  to support  a  project, unless  the state  has passed
legislation similar to the Illinois law I mentioned earlier.
     You will  find that many utilities have  a  tariff in place
which includes a  standard  rate to  be paid  for purchases of
energy  (and sometimes  capacity)  from  qualifying  facilities.
However, you should keep in mind  that  you are  not  limited to
the  tariff rate.    Instead  of  the tariff,  you  may  negotiate a
rate with  the utility  for  the  purchase  of  your power.   This
rate must  reflect the utility's avoided cost over  the  life of
your  contract, as  it exists  when  the  power  is  sold,  or as
projected  when the  contract is signed.  There are  many ways to
design such  a  rate.  For this reason, you may  want to use the
services of  a rate  consultant to be sure that any non-tariff
rate you  propose is designed  in a way which is acceptable to
the state  commission.
     Besides   setting  the  power   purchase   rate,   the  state
commission sets the rate which you pay to buy backup power from
the  utility.   This  rate can  be significant  because  it  can
include  a  demand  component  which  you  must pay  every month
whether or not you use backup  power that month.    The demand
component  may  be based  on  your maximum usage  of  power during
the  year.    Here  as with  avoided cost,   you may  be  able  to
                              875

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propose  a negotiated  rate,  subject to  approval of  the state
commission.
     There are  also several indirect  ways in which  the state
commission  will  affect  your   project.     The  commission's
determinations of utility need for generating capacity, type of
new capacity, and  timing of  capacity additions all impact your
ability to sell power to utilities regulated by the Commission.
In addition, the state public  utility commission may prescribe
standard  contracts for  power  purchases by  utilities.   State
commissions also may adopt generic rules which will affect your
project.
     In  each of these situations you  can  intervene  before the
commission,  individually or as  part  of a group with similar
interests.   Whether or  not  you  decide to invest the  time and
money  to fully participate  in  a commission  proceeding,  your
very presence as an  intervenor will  remind the commission, and
its  staff,  that there  are  interests to  consider other  than
utility interests.
     Your state commission also  can  be helpful if you reach an
impasse in negotiating with the utility,  either before or after
a contract is signed.   In most states  you  can reguest that the
commission resolve your dispute  with  the utility.   Sometimes
commission staff will mediate a dispute  and you can  reach  a
reasonable settlement without filing a formal complaint.
     As  I mentioned,  many utilities  are  turning to competitive
bidding  if they need  capacity.   This is  because they generally
                             876

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have  offers to  buy  more capacity  than  they need.    At the


present time, there  is a trend toward greater consideration of


non-price  factors in selecting  a winning  bid.   Here,  fuel


diversity  and  environmental concerns  may favor  MSW  projects.


Some  bidding schemes  may include a  set-aside  which provides


that  a  certain  block  of  capacity   must be purchased  from


generating facilities burning fuels such as MSW.


     Bidding  schemes  are  generally  approved  by  the  state


commission.  A  bidding scheme may be  proposed by a utility or


may grow out of a generic rulemaking.   As a participant in this


process,  you will have yet another  opportunity to  develop a

                                s
climate in your state which is favorable to MSW projects.


Contract Issues


     Now  I  am  going  to turn from  the  regulatory arena to your


power  sale  contract  with the utility.   I  want to mention some


of  the major contract terms which you  should be  aware of in


your negotiations.


     I  have already  discussed avoided  cost   and  backup power


rates  so  I  won't  mention them  again here.   Some other contract


provisions which  will have a strong  impact on the economics of


your project include  these five:


     1.   "Regulatory  out" clauses,


     2.   Dispatchability reguirements,


     3.   Cost of  interconnection facilities,


     4.   Cost of  upgrades on the utility's system, and


     5.   Performance  standards.
                              877

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     First, a  "regulatory out" clause  is  a contract provision



which allows  the utility to  reduce its payments to  you or to



seek a refund of past payments if it cannot pass those payments



on  to  its customers.   Utilities often want the right  to use



this  "regulatory out"  at any time during the  contract term.



The risk  of having  this provision in a contract can be reduced



if you request that your state commission approve the utility's



passthrough  of  its  payments  to  you  for the  life  of  the



contract, before the  contract term  begins.   Whether or not you



achieve  this  goal, you may  want the  right  to terminate the



contract  rather  than  receive  a lower rate for  the remainder of



the contract term.



     Second, a utility may require the ability to dispatch your



plant.  That means  the  utility can  tell you to shut your plant



down  in  certain situations.   Sometimes the utility  will want



the  ability  to  automatically  back  off  your  generation  by



computer.   In  negotiating this  provision, you  will want  to



specify  those  times  when  you will  be reguired to  shut down,



including a maximum number  of hours each year.   You should not



be  required to  back  off  your generation   where  the  utility



would not back off its own plant of equivalent  size and type.



Even if  you are asked to back off  your generation,  you should



continue  to  receive capacity payments.   You will  probably end



up losing the energy payments in such cases.



     The  third  and fourth contract  terms  are  at issue because



PURPA  requires  that  you  pay  for  additional  equipment  and






                            878

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facilities  required  by  the  utility to  enable the  utility to

receive your  power.   This includes  interconnection facilities

which are  required so that  you may begin  delivering  power to

the  utility.    You  may  also  be  asked to bear  the  cost of

upgrades required  by the utility at the interconnection or on

its transmission system during the term of your contract.

     In both  cases,  it is  important that your contract specify

your  maximum  financial  obligation  for each  of  these  items.

Otherwise you will have signed a blank check for the utility to

cash.  With regard to upgrades,  you  may also want the right to

terminate  the  contract  rather  than   incur substantial  cost
                                /
toward the  end of the contract term.   You  should also require

that the  utility provide a  detailed explanation of its actual

costs for interconnection facilities and subsequent upgrades.

     Fifth  and last,  if  you  are selling capacity to a utility,

the  utility will  specify a  level at which you must generate.

For  example,  you may be required to generate  at 75 percent of

nameplate  capacity  on   an   annual  basis.    This  is  called a

capacity factor.   If you do  not meet this level of performance,

your  capacity  payments  will  be  reduced.    In  setting  the

capacity  factor,  you must  be  realistic as  to how well  your

plant can perform.   You  should also be sure that your plant is

not  expected  to perform  any  better than an equivalent utility-

owned plant.

Conclusion

     In the remaining few  minutes,  I want to offer a couple of
                              879

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practical suggestions  which may be  of help to you.   First, I



want to stress the opportunities for input into actions by your



state  legislature and  your state  public  utility commission.



They  have  to  be  educated about   the  value  of MSW  fueled



generation.    Many  experts  believe  that  one  half  of  the



generating  capacity needed  in  this country  by the  year 2000



will be supplied  by non-utility operators.   This  will create a



window  of opportunity  for  you, particularly if  your industry



joins together to market MSW fueled generating projects.



     Second,  it is  important  that  you  keep up  on regulatory



developments  in this area.  These  developments may  suggest a



new  approach  which you had  not considered in  connection with



your  project.    For example,  the  FERC has  recently  issued



several   orders  which  permit  qualifying  facilities  to  own



electric  transmission  and  interconnection  facilities.   There



are two situations  where  you may want  to own these facilities.



The  first is where  a  utility  quotes  a  prohibitive charge for



interconnection facilities.  You may be able to construct some



of those  facilities  at  a  lower  cost.  In the second situation,



you may find  that a neighboring utility will  pay  more for your



power  than your  local  utility.   Your  local  utility  may not



agree  to  wheel or  transmit  your power  to  the  second utility.



In  that  situation,  you  should consider building  a line  to



deliver your own power to the second utility.



     If  utility  rates  won't  support  your project,  consider



selling your  power  directly  to  a large consumer.   You may risk
                             680

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becoming subject  to regulation at  the state level,  but there



may be ways to minimize that risk.  In this situation, consider



involving the purchaser in your facility's ownership or seeking



an order exempting your project from state regulation.  The key



is to  be aware of all your options  as the environment changes



and to think creatively.



     That concludes  my prepared  remarks.   Thank you  for your



attention.   I will  be happy to  answer any questions  you may



have.
                              881

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        THE UNITED  STATES  ENVIRONMENTAL  PROTECTION  AGENCY
                MUNICIPAL WASTE COMBUSTION RESIDUE
         SOLIDIFICATION/STABILIZATION  EVALUATION  PROGRAM

                         Carlton C.  Wiles
               Risk  Reduction Engineering  Laboratory
          United  States  Environmental  Protection  Agency
                     Cincinnati, Ohio  45268

                         David  S. Kosson
           Rutgers, The  State University  of New Jersey
                      Piscataway,  New Jersey

                           Teresa Holmes
               United States Army Corps of Engineers
                   Waterways Experiment Station
                      Vicksburg, Mississippi
                         Presented at the

First United States Conference  on Municipal  Solid Waste  Management

                         June 13-16,  1990
                               883

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               THE  UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
                      MUNICIPAL WASTE COMBUSTION RESIDUE
                     SOLIDIFICATION/STABILIZATION PROGRAM
ABSTRACT
    Vendors of solidification/stabilization (S/S) and other technologies are
cooperating with the U.S. Environmental Protection Agency's (U.S. EPA's)
Office of Research and Development (ORD), Risk Reduction Engineering
Laboratory to demonstrate and evaluate the performance of the technologies to
treat residues from the combustion of municipal solid waste (MSW).
Solidification/stabilization is being emphasized in the current program.  This
technology may enhance the environmental  performance of the residues when
disposed in the land, when used as road bed aggregate, as building blocks, and
in the marine environment as reefs or shore erosion control barriers.

    The program includes four S/S process types: cement, silicate, cement kiln
dust and a phosphate based process.  Residue types being evaluated are fly
ash, bottom ash and combined residues. An array of chemical leaching tests and
physical tests are being conducted to characterize the untreated and treated
residues.

    The S/S evaluation program is the first part of ORD's Municipal  Solid
Waste Innovative Technology Evaluation (MITE)  program.

INTRODUCTION

    During the past two years there has been a significant concern expressed
about the management of the residues from the  combustion of municipal  solid
waste.   Much of this concern has centered on  the fact that when the residues
are subjected to the Extraction Procedure for  Toxicity (EP tox)  and  the
Toxicity Characteristics Leaching Procedure (TCLP) they will fail  for lead and
cadmium a significant portion of the time.  This occurs more often for the fly
ash, less for the combined fly ash and bottom  ash, and least often for the
bottom ash alone.   Because of this, a controversy exists as to whether or not
the residues should be considered and regulated as a hazardous waste or
exempted because they originated from burning  municipal solid  waste.   Several
states are requiring that these residues be disposed into landfills  with
designs and operating procedures as, or more,  stringent than those for
hazardous waste.  Municipal Waste Combustion (MWC) ash characteristics are
extremely variable as is the leachate-from these ashes.  Ranges  of metal
concentrations observed in bottom and fly ashes from many sources are
presented in Table p1'.  Detailed descriptions of the chemical  and  physical
characteristics of MWC residues are available^'-*'^'-' L
    Because of the growing concern about the residues and anticipating the
need for appropriate treatment techniques, the Office of Research and
Development designed and implemented a program to evaluate the use of
solidification/stabilization technologies for treating the residues.  The
                                      884

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program was formally announced on September 19, 1989.  Originally known as the
U.S.  EPA MWC Ash Solidification/Stabilization Evaluation Program, it is now
the Municipal Innovative Technology Evaluation program (MITE).  This paper
presents the design and status of the current program.

THE MITE PROGRAM

    The MITE program is an Office of Research and Development (ORD) program
designed to conduct demonstrations of technologies for managing municipal
solid waste.  The objective is to encourage development and use of innovative
technology for municipal solid waste management.   The program is patterned
after the Superfund Innovative Technology Evaluation program (SITE).  It is,
therefore, a cooperative program in which the technology developer and/or
vendor pays the cost of conducting the demonstration.  U.S. EPA pays the cost
of testing and evaluation, including analytical cost.  U.S. EPA will report
the results of the evaluations in an unbiased manner, thus providing a means
for assisting municipalities and others to better evaluate and select
technologies more appropriate for their given situation.

    The current program is demonstrating and evaluating alternatives for the
treatment of residues from the combustion of municipal waste. While it is
uncertain if treatment will be required prior to  disposal, it is most likely
that treatment will be necessary for any utilization option.  Solidification/-
Stabilization (S/S) technology was selected for initial evaluations !;3sed upon
experience and knowledge of the technology for treating hazardous waste and
experimental studies on solidifying municipal waste combustion (MWC)
residues^6'.  Solidification/Stabilization (S/S), in general terms, is a
technology where one uses additives or processes  to transform a waste into a
more manageable form or less toxic form by physically and/or chemically
immobilizing the waste constituents.  Most commonly used additives include
combinations of hydraulic cements, lime, pozzalons, gypsum, silicates and
similar materials.  Other types of binders, such  as epoxies, polyesters,
asphalts, etc. have also been used, but not routinely.  More detailed
descriptions of S/S technology are available* '.   The program objective is to
provide a credrble data base on the effectiveness of S/S technology for
treating the residues.

    Preliminary design of this program was completed by the U.S. EPA.  Because
U.S. EPA believed it important to have results completely unbiased and as
scientifically credible as possible, a panel of international experts was
assembled to provide oversight to the program.  This Technical  Advisory Panel
(TAP) consists of experts from academva, industry, state and federal
governments, and environmental groups.

PROGRAM ORGANIZATION AND DESIGN

    Organization - The program involves the participation of several different
organizations with separate roles.  The Risk Reduction Engineering Laboratory
(RREL) is managing and directing the program.  The TAP is providing valuable
peer review, oversight and technical design. This service is donated.   Staff
                                    885

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at the U.S. Army Corps of Engineers Waterways Experiment Station  (WES) are
coordinating and observing the demonstrations at WES facilities located in
Vicksburgh, Mississippi.  WES is also responsible  for performing  the physical
testing and some of the extraction/leaching tests.  A Versar laboratory
experienced in MWC residue analysis is performing  the majority of the
analytical work.  Specialized analyses, testing and modeling is being
performed by the University of Illinois and the Netherlands Energy Research
Center.  Rutgers University in conjunction with the Mew Jersey Institute of
Technology is assisting in the coordination of the various activities and
participants.  Vendors are participating by providing valuable time and money.

    Tests and Analyses - The program was conceived by U.S. EPA and the basic
design was based on the testing and evaluations performed on hazardous and
other waste treated by solidification/stabilization technologies  in various
research and evaluation programs of U.S. EPA.  At the request of  U.S. EPA, the
TAP reviewed and modified this preliminary design.  The tests and analytical
protocols included in the program are provided in Tables 2, 3, 4, 5, 6 and 7.
The purpose for conducting the test and analysis listed is also included.
Methods listed in the Tables are either approved U.S. EPA or ASTM methods.

    Ash Types Tested - Residue selected for testing was limited to that
collected from a modern state-of-art waste to energy facility (i.e., high  burn
out, lime scrubber with fabric filter, etc.).  There were several reasons  for
limiting the number of residues included in the program.  The prime objective
is to  evaluate solidification/stabilization for treating the residues, rather
than determine how characteristics of different residues may affect the
performance of the technology. In addition the apparent variability of MWC
residues  is becoming less of an issue, especially with the newer combustion
facilities.  Proper sampling and analysis, changes in air pollution controls
and similar factors will play more important roles in the variability of
residues.  The program currently includes four different S/S process types
plus one control.  Because of the extensive list of tests being performed, the
analytical cost for the program is the major U.S. EPA expense.  For each
additional source of residue added these costs must be duplicated.  This would
have reduced the number of processes which could be evaluated to  an
unacceptable number.  The program is also developing and evaluating testing
protocols that can be used to evaluate selected S/S processes on  different
residues if required in the future.

   These considerations quickly led to the conclusion that the program would
test the residue from only one facility.  The residue types are the fly ash
(including the scrubber residue), the'bottom ash and the combined ash.  The
MWC facility samples has the following process sequence:  (i).primary
combustor with vibratory grates, (ii) secondary combustion chamber, (iii)
boiler and economizer (iv) dry scrubber with lime, and (v) particulate
recovery using baghouses (fabric filters).  Bottom ash sampled was quenched
after exiting from the combustion grates.  Fly ash sampled was mixed residuals
from the  scrubber and baghouses.  The fly ash was screened to pass a 0.5 inch
square mesh.  The bottom ash and combined ash were screened to pass a 2 inch
square mesh at the MWC facility.  Materials not passing through the 2 inch
                                     886

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mesh were rejected.  After shipment to the WES, each ash type was  dried  to
less than 10% moisture, crushed and screened to pass a 0.5  inch mesh
(nominally 3/8 inch after clogging), and homogenized.

    Processes Selected  - Process types selected in the program are cement
based, silicate based, cement kiln dust and phosphate based.  A non-vendor
cement process is being performed by experienced staff of WES and  U.S. EPA  in
Vicksburg, MS.

    Process selection was competitive based upon evaluation of proposals
submitted by parties interested in participating.  A formal Request For
Participation was issued by U.S. EPA which provided information required
to respond.  Under direction of U.S. EPA, the TAP developed evaluation
criteria which was used to make final selections.

    Twenty-one responses were received and evaluated.  The  responses were
.divided into 11 S/S processes, 6 vitrification processes and 4 other
miscellaneous processes.  Rased upon the evaluation criteria, the  S/S process
proposals were judged to be superior.  In order not to select similar S/S
process types {e.g., two cement based) with the limited resources  available,
the decision was made to select the best proposal out of the different types
available.  The vitrification process proposals were generally incomplete and
failed to address some major issues.  This, in conjunction with the potential
high quantities of residues required for most of these processes,  resulted  in
the decision not to select one for evaluation.  Alternatives for evaluating
vitrification processes are being pursued.  Proposals in the other
miscellaneous category were not acceptable and were rejected.

    During the request for participation, evaluation and selection process,
provisions were made for maintaining confidentiality of information so marked
by the responders.

    Following is a brief description of each of the processes selected.

    Cement Based Process - This process involves the addition of polymeric
adsorbents to a slurry of MWC ash prior to the addition of Portland cement.
The final product is soil-like rather than monolithic.

    Silicate based process - This is a patented process using soluble
silicates as an additive with cement.  The additives are used to promote
several types of reactions with the polyvalent metal present to produce
insoluble metal compounds, gel  structures, and promote hydrolysis, hydration
and neutralization reactions.  The process immobilizes heavy metals through
reactions involving complex silicates.  The final product is clay-like
material.
                                   *
    CKD process - This is a patented process involving mixing the MWC ashes
with quality controlled waste pozzolans and water.   Good quality control  on
the reagents is required because they are secondary materials derived from
processing other materials.  Therefore, the pozzolanic characteristics
                                      887

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critical to the process are subject to change.  The finished product  is
similar to moist soil, but hardens to a concrete-like mass within several
days.

    Phosphate process - A water soluble phosphate  is used  in this patented
process to convert lead and cadmium to insoluble forms.  The process  is
designed such that fly ash is mixed with lime, then this material can be mixed
with the bottom ash and the mixture treated with a source  of water soluble
phosphate.  The process does not alter the physical state  of the ash.

DEMONSTRATIONS

    Process - The procedures for conducting the demonstrations were
established so  that the process vendors could  review data  from
characterizations of the various ash  prior to  the  demonstration.  Samples of
the ashes  were  also furnished to the  vendors  so that they  have the opportunity
to pretest their process prior to  the demonstration.  This permitted  them to
make modifications  if desired.  Vendors were  responsible for providing any
specialized equipment or ingredients  required.  Each agreed to permit
observation by  U.S. EPA selected observers if it was necessary to conduct the
demonstration at the vendor's facilities.  Otherwise the demonstrations were
to  be  conducted at  a U.S.  EPA selected  facility and observed by U.S.  EPA
designated staff.

     During the  process demonstration, each vendor  was  requested to carry out
 three  replicate batches for  each ash  type.  A total of  between 50 and 100
 gallons of each ash type  is  being  treated  for each process.  Numerous molds
 and  samples are prepared  from these batches.   All  molds and sample containers
 are provided  by WES and U.S.  EPA.   Each  vendor provides enough process
 additives for analysis and archiving.   Most equipment and  laboratory
 facilities required for the  demonstrations are provided by WES.

     Scale - The processes  are being demonstrated at bench  scale.  Reasons for
 this include  the technologies  being tested,  resources  required  for  full  scale
 demonstrations  and  the desire  to  include  as many different processes  as
 possible within available  resources.   The  program  plan  was to conduct a  full
 scale  field demonstration  of a  selected  process  if deemed  necessary.   Because
 of the nature of S/S  technologies, U.S.  EPA  and  the TAP believed  that bench
 scale  demonstrations  were  adequate to prove  if the technology is  an effective
 treatment for MWC  residues.   Sufficient experience is  available  for conducting
 the engineering and design required  for scaling  to a  specific situation.
 Furthermore,  the bench scale permitted  much  more  detailed  testing  to  be
 completed and thus  more exploration of  the basic mechanisms  involved  in  the
 process.  This in  turn will  assist in the determination of expected  long-term
 behavior.  A  drawback  with this  scale however, is  the  difficulty  in  sampling
 and variability associated with bottom  ashes.

     Schedule  - At  this writing  three  of the  process demonstrations  have  been
 completed.  Barring unexpected  difficulty all will be completed  by  mid-May.
 Because of curing  times  (i.e.,  28 days)  and  other  test  requirements  the
                                      888

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 physical testing, chemical testing and analytical  procedures  will  not  be
 completed until mid-October.  The final report  is  expected  by the  end  of
 December 1990.

    Future MITE Demonstrations -  It  is planned  that future  MITE demonstration
 candidates will be solicited by notice in the Commerce  Business Daily, through
 appropriate MSW trade organizations,  interested developers  and similar means.
 At this time, emphasis  for these  demonstrations is expected to be  on  processes
.for recovering marketable products from the  MSW stream.   Resources of 1000K
 have currently been allocated in  FY'91 for MITE.

 RESULTS AND CONCLUSIONS

    Results from  the various physical and chemical tests are  not available at
 this writing.  Statements and conclusions concerning process  performance are
 therefore not  possible.  The final report will  provide  the  results from all
 the testing and will provide a sound  basis for  determining  the effectiveness
 of S/S  techniques to treat MWC residues.  The results will  also provide
 information on the most  useful testing protocols  for evaluating, selecting and
 designing the  S/S process for treating MWC ash.
                                       889

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               TABLE  1.   Ranges  of Total  and teachable Metals
                          in  United States MSW Combustor Ash
                          as  Determined by Researchers^'
Com- Bottom Ash
pound
mg/kg
Pb
Cd
As
Cr
Ba
Ni
CU
31 -
0.81
0.8
13 -
47 -
MD(1
40 -
36,600
- 100
- 50
1,500
2000
.5) - 12,910
10,700
Bottom Ash
Leachate
mg/1
0.02 - 34
0.018 - 3.94
MD(O.OOl) - 0.122
ND(0.007) - 0.46
0.27 - 6.3
0.241 - 2.03
0.039 - 1.19
Fly Ash
mg/kg
2.0 - 25,000
5 - 2,210
4.8 - 750
21 - 1,900
88-9000
Nn(1.5) - 3,600
187 - 2,300
Fly Ash
Leachate
mg/1
0.019
0.025
ND(0.
0.006
0.67
0.09
0.033
- 53.35
- 100
001 - 0.858)
- 0.135
- 22.8
- 2.90
- 10.6
NO = Not Detectable; ()  = Detection Limit
                   TABLE 2.   Chemical  Analysis  Performed  on
                             Treated and Untreated  Ash
Assay
Method
Purpose
Total Extractable Metals
Dioxins/Furans
pH, Anions, Total
Available Dissolved
Solids, and Ammonia

Loss on Ignition
Chemical  Oxygen
Demand

Total  Organic Carbon
3050, 6010


8280
9045, 300.0,
160.1, 350.2
209D
508A
See Metals Analysis List
(Table 6)

Community Concern
(Untreated Only)

Salts and Ionic Species
Residual Organic Matter
(typ. 2-5S)  and Water of
Hydration

Reduced Inorganic and
Organic Matter

Residual Organic Matter
                                     890

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                    TABLE 3.  Physical Tests Conducted on
                              Treated and Untreated Ash
Physical  Test
Purpose
Moisture Content

Loss on Ignition


Modified Proctor Density

Bulk Density

Particle Size Distribution

Cone Penetrometer

Pozzolanic Activity*

Porosity/Surface Area


Permeability



Unconfined Compressive
Strength  (UCS)

UCS after Immersion

Freeze/Thaw**

Wet/Dry**
Useful general data

Residual/Organic Matter and
Hydrated Water

Compressibility

Volume and Similar Physical Changes

Potential Use as Aggregate

Curing Rate and Hardness

Untreated S/S Potential

Potential for Liquid-Solid Contact
and Diffusion Effects

Resistance to FUO Transmission;
Assist in determining contaminant
Release Mechanisms

Load Bearing Capacity


Hydration Effects and Swelling

Physical  Weathering Effects

Physical  Weathering Effects
* Untreated Ash Only
** Treated Ash Only
                                    891

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                     TABLE 4.  Leaching Tests  for Treated
                               and Untreated Ash
Leach Test
          Purpose
TCLP (1 extract)

Distilled Water Leach Test
(4 extracts)

Acid Neutralization
Capacity (10 extracts)

Monolith Leach Test
(7 extracts)

Static pH 0 pH = 4.0
with HNO, Li quid:Sol id
Ratio  is 100:1 .
          Regulatory Leach Test

          Extended Extraction in a Well-Mixed
          System without Acid

          Buffering Capacity of Solid and pH
          Dependence of Metals Release

          Estimate Potential Release Rates
          Through Diffusion

          Total Species Available for Release
          Under "Worst Case" Scenario
                   TABLE 5.  Chemical Analysis Performed on
                             Leach Test Extracts
Assay
Method
Purpose
Metals


Chemical Oxygen
Demand  (COD)

Total Suspended Solids

Total Dissolved Solids

PH
3020


508A


160.2*

160.1

150.1
See Metals Analysis List
(Table 6)

Surrogate for Leachable
Organic Species

Physical  Erosion of Solid

Leachable Total Salts
* Monolith leach test only (ANSI 16.1)
                                    892

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TABLE 6.  List of Metals
          Subjected  to  Analysis
Metal



Aluminum
Antimony
Arsenic
Barium
Beryll ium
Boron
Cadmium
Calcium
Chromium
Cobalt
Copper
Iron
Lead
Lithium
Potassium
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Selenium
Sodium
Sil icon
Silver
Strontium
Thorium
Tin
Ti tanium
Vanadium
Zi nc
Untreated
Ash (

ICP or AA
X
—
X
X
X
X
X
	
X
	
X
	
X
X
	
—
—
X
	
X
X
	
	
X
	
	
X
	
	
X
and Treated
Solid)
Neutron
Activation
X
X
X
X
—
___
- —
X
X
X
	
X
	
	
X
X
X
	
X
	
X
X
X
X
X
X
	
X
X
X
Extracts


ICP or AA
X
X
X
X
X
X
X
X
X
X
X
X
—
X
X
X
X
	
X
X
	
X
X
X
X
	
X
X
X
X
           893

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TABLE 7.  Additional Metals Analysis
          Using Neutron Activation
  Untreated  and  Treated  Ash  (Solid)

                        Neutron
  Metal             Activat"ion~0nly

  Cesium                   X
  Dysprosium               X
  Ga 11 i urn                  X
  Hafnium                  X
  Indium                   X
  Rubidium                 X
  Scandium                 X
  Uranium                  X
                 894

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References

1.  Wiles, C. C. "Characterization and teachability of Raw and Solidified
    U.S.A. Municipal  Solid Waste Combustion Residues" ISWA 86 Proceedings of
    the 5th International Solid Waste Conference, Copenhagen, Denmark.
    September 1988.

2.  U.S. EPA (Environmental Protection Agency) Characterization of MWC Ashes
    and Leachates from MSW Landfills, Monofills and Co-Disposal Sites.
    EPA 530-SW-87-028A, Office of Solid Waste.  October 1987.

3.  U.S. EPA (Environmental Protection Agency) Addendum to Characterization of
    HWC Ashes and Leachates from MSW Landfills, Monofills and Co-Disposal
    Sites, Office of Solid Waste, June 1988.

4.  J. L. Ontiveros, T. L. Clapp and D. S. Kosson.  "Physical Properties and
    Chemical Species Distributions Within Municipal Waste Combustor Ashes."
    In Environmental Progress, Vol. 8, No. 3, pp 200-206, August 1989.

5.  H. A. van der Sloot, et. al.  "Leaching Characteristics of Incinerator
    Residues and Potential for Modification of Leaching."  In Proceedings of
    the International Conference on Municipal Waste Combustion, Vol.  1,
    p 2B-1, April 1989.                     /  •

6.  D. R. Jackson, "Evaluation of Solidified Residue from Municipal  Solid
    Waste Combustors."  U.S. Environmental Protection Agency, EPA/600/S2-
    89/018, February 1990.

7.  Wiles, Carlton C., "A Review of Solidification/Stabilization Technology."
    Journal of Hazardous Materials, 14:5-21, 1987.
                                      895

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"UTILIZATION APPLICATIONS OF RESOURCE RECOVERY RESIDUE"




       8Y =  Dr.  Richard W.  Goodwin,  P. E.




    ENVIRONMENTAL ENGINEERING  CONSULTANT




14  RAMAPO LANE;  UPPER SADDLE  RIVER,  NEW JERSEY 074!




       PHONE:  201-034-D8SS; FAX: 201-034-5S82




                      Presented at the




First U.S. Conference on Municipal Solid Waste Management




        Washington, D.C.; June 13-16, 1090
                             897

-------
       "UTILIZATION APPLICATIONS OF RESOURCE RECOVERY RESIDUE"

                   BY:  Dr.  Richard W. Goodwin, P.E.

                 ENVIRONMENTAL ENGINEERING CONSULTANT

         14 RAMAPO LANE; UPPER SADDLE RIVER, NEW JERSEY 07458

                PKONE:  201-934-9866; FAX: 201-934-5682

                           Presented at the
      First U.S. Conference on Municipal Solid Waste Management
                  Washington, D.C.; June 13-16, 1990

INTRODUCTION

In 1989 MSW ash will amount to between 2.8-5.5 million tons and its
annual generation rate is expected to increase two to five depending
on how many facilities arc built (1). The manner in which these resi-
dues arc regulated impact the Waste-to-Encrgy Industry. Such regula-
tion, however, varies by state and with proposed federal legislation.
Attempting to regulate and legislate MSW ashes without a technical
appreciation may be one reason for such diversity. This paper provides

and cost-effective ash disposal and utilization.

o In-Plant Ash Fundamentals

The ash generated from Mass Burn MSW systems is composed primarily of
Bottom Ash [EAJ (75-85 weight*} and FA (15-25 weight*}. The ash gene-
rated from Refuse Derived Fuel [RDF] reflects a higher FA (40 weight*}
to BA (60 weight*} distribution; due to RDF's suspension firing.

A typical Flue Gas Cleaning [FGC] system consists of reacting the
incinerator flue gas with lime (usually in an absorption vessel) fol-
lowed by particulatc removal (bag house or electro-static prccipitatcr}
While these systems arc designed to remove Acid Gases and particulatc,
they increase the waste generation rate due to the product of reaction
products and unrcactcd lime. The AGC waste is composed of Fly Ash [FA]
and Dry Flue Gas Cleaning (i.e. Scrubber Residue [SR]) Reaction
Products. Equipped with a FGC system, the combination of BA, FA, and
SR amounts to 1/4 to 1/3 of the weight of the MSW feedstock.

Depending upon the design of the Ash Handling system the FA/SR waste
may be combined with the BA. Since the BA is quenched, the resultant
blend will contain water. This mixture of ash and FGC wastes arc con-
veyed to a disposal site. This Combined Ash [CA] may be thixctropic
mud-like and contains considerable lime. Its solids content should be
maintained to ensure optimal transportability characteristics i.e. (a)
prevention of fugitive dusting; (b) elimination of spillage; (c) pre-
vention of prc-maturc set-up reaction. Typically, the transportation
solids content could range from SO-DC1  to satisfy these criteria.

In view of the industry-wide trend toward installation of dry lime Air
Pollution Control [APC] to remove such acid gases as S02, KC1 etc. and
in light of the USEPA's proposed air emissions requirements of MSW
                                898

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incinerators (2), this paper's discussion of MSW ash emphasizes the
presence of unrcaetcd lime reagent. Engineering properties arc discus-
sed to provide a basis for utilizing the ash. Due to the controversy
and previous misconceptions surrounding MSW ash, however, its environ-
mental characteristics should be considered.

c Environmental Considerations of MSW Ash

Recent field studies of MSW ash landfills strongly supports the rela-
tively benign characteristics of this ash.

MUS {3} states that "the leachatcs ... arc close to being acceptable
for drinking water use, as far as the metals arc concerned". Soth the
public and regulatory community have focused on the results of labora-
tory tests (e.g. EP Tox, TCLP) to predict MSW ashes' leaching. These
tests, however, do not reflect field leachatcs results; "leachate from
the disposal sites tested out below the level that those two tests
deem hazardous" (4).

Although EP Tox results have shown excessive levels of- Pb and Cd, the
presence of unrcactcd lime (from the APC system) could account for
significant reductions of such constituents (5). The author has con-
tended that such ash should be deemed.pozzolanic and recognized by
regulatory authorities (5). Recently some state regulatory agencies
have recognized this behavior and incorporated it within their
classification of MSW ash landfills. The California Dcpt. of Health
Services concluded that MSW "... ash possesses intrinsic physical and
chemical properties rendering it insignificant as a hazard to human
health and safety, livestock, and wildlife". The "intrinsic property"
is the formation of a "lime/pozzclan mixture" so that when "compacted
(the) ash forms a hard, non-credible surface" (7).

o Low Empirical Solubilities of MSW Ash

Rather than regarding the presence of lime inducing pozzolanic beha-
vior as a benefit (to reduce the ashes' potential leachate}, some
regulators have postulated that the lime could dclctericusly affect
underlying clay liners (5). The following summarises the leachate and
raw pH data:

             Lime-based APC                  ESP Only
          ASH            LEACHATE       ASH            LEACHATE

pH        11.68 - 11.85  5.7 - 7.4      11.58 - 11.32    S.9
          10.Ql - 11.67    6.5

The significant pH drop from raw ash levels to leachate values arc
explained by considering the inherent pozzolanic behavior of lime-
based MSW ash. As CaC enters into the pozzcianic reaction it is no
longer available as a soluble component and is not detected in the
leachate. The alkaline pH of the non-lime based ash and its similar
reduction of leachate also may be explained by considering the pozzc-
ianic chemistry. CaO reacts with A1203, Fc203, and Si02 to form pozzo-
lanic end-products (8). MSW Ash inherently reflects an alkaline pH;
Water Leach testing of Hcnncpin Energy Resource Company's Bottom Ash
pH = 9.2 - 9.3 .(9). The reduction of soluble alkalinity (water leach
                              899

-------
pH)  in ashes  from Resource Recovery  Facilities  with and without lime-
based APC  could  be  due  to consumption of  pczzolanic rcactants.

TABLE 1: POZZOLANIC RSACTANTS  -  LSACHATS  PH

                         W/  Lime APC	W/0 Lime  APC

% A1203  [A]              7.39  -  10.30        5.93 - 13.00
% Fc203  [F]              3.90  -  18.15        5.73 - 10.64
% Si02   [S]              19.00  -  43.80       32.00 - 62.90
% CaO    [C]              15.10  -  25.70        9.70 - 12.00

% A  + S -!-  F              32.76  -  65.85       50.83 - 77.65
[A -!- S + F]/  C           1.27  -  3.63         4.24 - 8.01

pH - Ash                 10.91  -  11.85       10.35 - 11.82
pH _ Wat.  Lcach-Int.     11.78-12.48        9.97-10.70
pH - Wat.  Leach-Fin.     11.12-12.48       10.28-10.60
pK - Field Leach        6.50-7.40         8.90 - N.A.

NOTE: N.A. =  Not Available

Table 1  depicts  that both types  of ashes  lie  within the  pozzoianic
requirements  (ASTM  618)  and  that the ratio  of pczzclanic rcactants
lies within the  range of analogous clean  coal technology rcsiducs(10) .

The  lower  field  leach pH's (6.5  - 7.4) compared to raw pK  (10.28  -
12.48) and initial  water leach pK (9.97 - 12.48)  suggest a reaction.
This reaction, however,  may  not  be a neutralization mechanism since
the  final  water  leach pH of  10.28 -  12.48 predicts soluble alkalinity.
Realizing  the final water leach  pK is much  higher than the field  leach
pK,  infers the reduction of  soluble  alkalinity  due to  a  dissipativc
reaction.  This reaction could  represent the CaO combining with  the
other pozzoianic constituents. Lacking gco-tcchnical engineering  data
from the NUS  study  prevents  a  more definitive explanation. Nonetheless,
all  the  data  indicates  that  the  actual field  pH's of MSW do not reflect
their initial basic alkalinitics and that only  slight  solubilization
of alkaline constituents occur in nature.

ASK  UTILIZATION  AS  NATURAL LINER

The  Waste-to-Encrgy facility's primary concern  regarding MSW ash
involves yielding a transportable material. This  ash,  however, upon
exiting the mechanical  conveying system, awaiting transport to a  land-
fill, may  be  subject to regulatory testing  and  should  be subject  to
proper Disposal  Site Management.  This  paper offers data  demonstrating
the  concrete-like behavior of  MSW ash  and incorporates such results
into Ash Management Principles to ensure set-up.  Regulatory agencies
should review this  technical information and  allow the application of
basic Civil Engineering and Concrete  Chemistry  to be reflected within
Sample Preparation  Procedures  and Testing.

Achieving  the Inherent Concrete-like Behavior

Table 2 compares the author's  derived mincralogical  content of MSW
ashes (Mass Burn and RDF) to Portland Cement. The  comparative similar-
                              9OO

-------
 itics suggest  that  solubilization  of MSW  Combined Ash  [CA]  (i.e.  BA,
 FA, and SR)  should  react  in  a  concrctc-likc  manner.  The  author's  prior
 work has discussed  this potential  behavior of  MSW ash  (due  to  its
 favorable mineral composition)  and of  the relatively high lime content
 of MSW ash  (due to  higher stoichiojnetrics and  no recycle) (9).  RDF
 ash, also,  reflects a  higher lime  content than Mass  Burn Residues.
 This theoretical basis provides a  framework  for considering Heavy Metal
 Reduction and  enhancement of gcotechnical properties.  Achieving such
 behavior depends upon  solubilizing the free, available lime and
 attaining optimal compaction.

         TABLE 2: CHEMICAL COMPARISON  TO  PORTLAND CEMENT

 Composition  of Portland Cement	MSW  Ash

 Component	Cement	Clinker	Mass Burn    RDF
Si02
A1203
Fc203
CaO
13-24
4-3
1.5-4.5
62-57
21.7-23.3
5.0-5.3
0.2-2.6
57.7-70.8
24
6
3
37
37
4
C
w
43
Laboratory work has revealed an  inverse  trend  relationship between  (a)
Percent Solids/Water of Solubilisation and  (b  Mean and Particle Size
Distribution. To achieve  a Gcotechnical  Property  (i.e. strength, per-
meability), reflecting set-up conditions, more water of solubilization
was required for a recipe with finer Particle  Size Distribution. A
possible explanation for  this relationship  is  that the smaller sized
particles exhibit a greater surface area; thus requiring mere water of
solubilization within the voids  to promote  the pczzolanic or set-up
behavior.

Effect of Water of Solubilization on Set-up Time

Not only docs the introduction of additional water of solubilizaticn
facilitate attaining concrete-like behavior but optimizing the % Water
of Solubilization reduces the set-up time.  When highly reactive Com-
bined Ash (i.e. Bottom and Fly Ash with  Scrubber Residue) was tested
at two different Percent  Solids  the following  permeabilities and cur-
ing times were determined.

S Solids  Permeability {after 120 Krs)   Permeability (after 23 days)

75        2.5 X 10 EXP-7  cm/sec          1.31 X 10 EXP-S cm/sec
30        2.3 X 10 EXP-5  cm/sec          1.02 X 10 EXP-S cm/sec

Achieving the significantly lower permeabilities  (i.e. two orders of
magnitude reduction) at the early cure time (120 Hours), when more
water was present in the  sample, suggests that adding water of solubi-
lization accelerates the  reaction. An aqueous  phase is more quickly
established for the chemical constituents to react. Since 28 day per-
meabilities were essentially the same for both Percent Solids samples,
the reactions were completed for these ashes of equivalent composition.
fWhcn more water is available for solubilization of reactive constitu-
ents, reaction time is reduced and a harder, less permeable material
produced.


                                9O1

-------
 Field Demonstration of In-Situ Permeability

Such encouraging laboratory results justified a field dcmcnst ration. A
field program, designed to demonstrate the viability of low-cost in-
situ. chemical treatment achieving liner-like permeabilities, was ini-
tiated at an older Mass Burn facility. Ash from this facility, not
equipped with a FGC system, represented an opportunity to demonstrate
the cost-effective methodology of in-situ addition of Portland Cement
and of lime [CaO] to non-chemical ly reactive MSW ash. Field Curing
occurred during worst-case winter conditions. A detailed description
of this study has been reported by Forrester and Goodwin (11).

Test Patches were formed from non-reactive Combined Ash [CA] . Portland
Cement [PC], 6-10 % by weight, and Lime [CaC] , 6-75K by weight, were
added in-situ to separate patches. Optimum waters of sclubilization
were attained to promote chemical reaction.

The permeabilities derived from the Field Demonstration Test Patches
are compared to the results of a Laboratory Study. The Laboratory
Study reflects PC dosages ranging from 6-9% and CaO dosages from 3-6%
{by weight) . Ashes used in the Laboratory Program were composite sam-
pled from a newer Mass Burn facility, equipped with a FGC system con-
tributing unrcactcd CaO to the Combined Ash [CA]. Permeability results
of the field and laboratory programs arc reported in Table 3. The
variation of in-situ and laboratory permeabilities reflect typical
field and lab testing differences (12).
                     vsr^'M^4"r%M.T -?lr^»\ Or<*»^<^i^T«v*^'»
                     AAW AW »• W ___ A JUg^W / *^W C*W W .A W*A«J
Bottom Ash [BA] should not contain free available CaO, since it is
collected upstream of the FGC system. Combined Ash [CA] studied
in the laboratory represents the combination of BA with the separately
collected FA and SR. Since the CA studied in the field did not reflect
liaac contribution from a FGC system, the laboratory BA should repre-
sent a similar composition. Table 3 reports that older non-reactive CA
+ 0% exhibited a laboratory permeability of 1.0 X BXP-5 era/sec; prac-
tically equivalent to raw laboratory studied BA permeability of 1.8 X
EXP-5 cm/sec. Thus, the CaO Test Patch CA permeability results can be
compared to Lab Program results for CA with and without CaO addition.
These latter ashes were obtained from a newer facility reflecting
significant inherent CaO due to high stoichicmctry of the FGC system.

The Test Patch Program (Table 3) reports permeability results from
6.4 X EXP-6 cm/sec to 2.3 X EXP-S cm/sec.  The one to three orders
of magnitude permeability reduction in the presence of free CaO sug-
gests concrete-like behavior. The raw, but reactive, CA permeability
of 5.5 X EXP-6 cm/sec could reflect the presence of excess lime con-
tributed from the operating FGC system. Upon the addition of lime to
reactive CA,  permeabilities ranging from 4.2 X EXP-5 cm/sec to 8.1 X
EXP-7 cjn/scc were achieved. These permeabilities agree with field
measurements . Both sets of results demonstrate at least an order of
magnitude reduction of permeability; suggesting the presence of a
lime-based concrete-like reaction.
                                902

-------
Effect of Adding Portland Cement

Adding Portland Cement [PC] tc non-reactive Test Patch CA reduced the
permeability by two to four orders of magnitude. The field in-situ and
cored permeabilities ranged from 7.5 X EXP-7 cm/sec to 2.8 X EXP-9
cm/sec. The permeabilities, obtained from the laboratory study of BA
with similar PC dosages, ranged from 1.5 X EXP-7 cm/sec to 1.7 X EXP
10-8 cm/sec. Thus, the addition of 6-10ft Portland Cement added to non-
reactive MSW ash attained permeabilities varying from slightly greater
to at least an order of magnitude less than the liner requirement of 1
X EXP-7 cm/sec.

TABLE 3; PERMEABILITY COMPARISON FIELD AND LABORATORY PROGRAM

                    Field Program Permeability Results

Dosage	In-Situ and Cores

CA + Oft             1.9 X EXP-5 cm/sec
CA 6 - lOftPC        7.5 X EXP-7 to 2.8 X EXP-9 cm/sec
CA 6 - 7 ftCaO       6.4 X EXP-6 to 2.3 X SXP-8 cm/sec

                 Laboratory Program Permeability Results

Ash	Additive (ft)	Permeability
BA
BA
CA
CA
0
-------
Standards [DWS], but indicate one to two orders of magnitude lower Cd
and Pb than reported by the EP Toxicity tests  (15). Such discrepancy
between field and lab data questions the EP Tcxicity test to realisti-
cally predict the concrete-like behavior of MSW ash. Furthermore,
comparing the leachatc/runcff pH of 6.7 to CA's inherent pH of 12-13
suggests a 'set-up' reaction. The resultant monolith precludes surface
soiubilizaticn of chemical specie. Based upon  the operating results
presented, the MSW ash from Resource Recovery  systems, equipped with
Flue Gas Cleaning, when properly managed in an engineering fashion,
will achieve liner-like low permeable characteristics and leachatc/
runoff approximating primary DWS.

           TABLE 4: LSACHATE RUNOFF COLLECTION RESULTS

PARAMETER	CONCENTRATION (mq/1)   PRIMARY DWS (ng/I)

Cadmium [Cd]             0.022               0.010
Lead [Pb]                0.007               0.050
                                             0.005 [Proposed]
pH                        5.7                6-9

ROAD CONSTRUCTION APPLICATIONS

In the past, MSW residues have been utilized for road construction
(15). Incinerator ash has been tested at a few road construction
c* 4-^
Phila, PA  (1075)    50        Acceptable
Co, PA  (1975)       50        Acceptable

Karrisburg
PA  (1976)          100        Excellent (Fused Residue)

Conclusions derived from this work can be summarized as:  (a) Loss On
Ignition [LOI] < 10% - eliminate organics;  (b) achieve ASTM specifica-
tions;  (c) limit application to 50£ ash and 50% residue; and (d) mini-
mize fine particle component i.e. eliminate Fly Ash [FA].

BA has been used in Europe and Japan for road construction. These
studies addressed not only the technical suitability issues as a road
construction material, but they discussed such environmental factors
as leachatc, fugitivity, runoff, etc..

Analogous Chemical Comparison

Table 5 compares the Chemical Composition of MSW ash to Oil Shale Ash
and to Portland Cement (Cement and Clinker) . Between 4-8% gypsum was
added to Oil Shale Ash to coniprcssivc strength reaching 23 MPa  (4100
psi) (17). By analogous comparison, Table 5 suggests that approximate-
ly 15% lime should also be added to the MSW ash; assuming a dry lime
scrubber. Based on this oil shale analogy, the resultant material
would satisfy the specified (ASTM C-593) minimum comprcssivc strength
                               904

-------
(600 psi) (4100 kPa) for a pczzclaii. Although lime addition also may
be required to achieve parity with Portland Cement, based upon the
chemical comparison a high potential exists for utilization of MSW ash
as a ccmcntiticus by-product. Adding 10% Portland Cement to ash,
without Acid Gas Cleaning Reaction Products and from an operating Mass
Burn facility, yielded ccasprcssivc strengths exceeding 1000 psi  (18).

       TABLE 5: CHEMICAL COMPAPsISON TO ANALOGOUS MATERIALS

COMPONENT-5SWT     OIL SHALE ASK      RESIDUE/APC WASTE
Mass Burn RDF
Si02
A1203
Fc2C3
CaO
20
S
4
50
24
6
3
•31
W A
37
4
c
43
Composition
Component
Si02
A1203
FC203
CaO
of Portland
Cement
18-24
4-8
1.5-4.5
62-67
Cement
Clinker
O 1 *7_OO
tm J. . A «• U .
W . »rf ~" »^ •
0.2-2.
67.7-70.


8
3
6
8

Mass
24
6
3
37
MSW Ash
Burn RDF
37
4
e
43
Particle Size Restrictions

In addition to chemical composition, potential end-uses require speci-
fic particle size distribution. Table 6A depicts the size distribution
of Bottom Ash and Fly Ash; representative of a 240 TPD (218 Metric
ton/day) Mass Burn facility. A comparison of these distributions shew
potential uses of Bottom Ash as Coarse Highway Aggregate (ASTM D 448}
and of Fly Ash as Fine Cement Aggregate (ASTM C33). In both cases,
additional segregation would be required to achieve conformity to size
distribution requirements. Incorporating such segregation could yield
approximately 75% of the Bottom Ash as suitable for Coarse Highway
Aggregate and 25% of the Fly Ash as suitable for Fine Cement Aggregate.
Separating (i.e. screening) coarser (>3/8" to 3/4") material from
Bottom Ash improves the Combined Ash characteristics and enhances
recycle potential of the coarser residues. CBR's of non-reactive ash
achieved approximately 40%;i.e. suggesting that six (6) inches could
be used in a pavement sub-base (10).

As indicated by Table 6B, the FA size distribution favors consideration
as Soil Aggregate, for paving application (ASTM 1241). The combined
Mass Burn Ash also conforms to Soil Aggregate, for paving application
(ASTM 1241).  Such uses may not require additional size segregation.
                              905

-------
    TASLE SA: POTENTIAL USES OF KSM ASH - ADDITIONAL SEGREGATION

OQTTQJII £cu £c COARSE AGGREGATE - HIGHWAY CONSTRUCTION    FLY ASH AS FINE AGGREGATE - CEMENT
                          nGSS uuPPi

Sieve Sirs      ASTM (0 44S)    Sottoa Ash
                  iSPCSHw iTnSP
2 Inch (50 an}   100

1.5 In.(37.5 as)  35-100
   --k tic ~-^
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mn i t.-k ten -~\ inn
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en n ?o i- 'n c ~-\ 
-------
c Types of Sanitary Landfill Cover

Bottom Ash [BA] is proposed to be used as cover material for a MSW
Landfill. Three (3) cover applications arc considered:  (1) Daily
Cover; (2) Side Cell Intermediate Cover; and  (3) Interim Final Cover.

Daily cover is usually applied at the end of working day at six inch
thicknesses.  Intermediate cover is applied in six inch  lifts to a
thickness of one foot when the working area will be inactive for one
to three months. Interim cover pertains to the material which becomes
a component of the final cover of the landfill. Interim cover is applied
in six inch lifts to a two feet thickness. Table 7A describes the
three types of Sanitary Landfill Cover:

TABLE 7A: TYPES OF SANITARY LANDFILL COVER
Cover Type
Thickness
Exposure
Application Rate
                                        Comment
Daily S inch
Intermediate 1 foot
Daily/Weekly
30-00 Days between
Compacted Daily
6" cover lifts
Interim
2 feet
                              MSW  lifts
               Within one week of
                          C»-% *W*V^ "^ <"^ ^*  ^^*^f*l*«
                          Sy ili^ V4\j- ^  v, *u\ V* \ 1
                         Cover Lift


                         6" cover lifts


                         Cover Lift
                         wi ^AA^jTi v^no WQC«C
c Technical Requirements Cover Material

Traditional cover material range from using sand as Daily  Cover,  sandy
clay as Intermediate Cover, and clay/silt as  Interim  Cover.  The
engineering requirements for each type of cover material may be
categorized according  to its permeability and/or particle  size
distribution. Table 7  B summarizes such  criteria:

TABLE 7B: ENGINEERING  CRITERIA SANITARY  LANDFILL COVER

Cover Type     Permeability	Size
Daily
10 E-3 cm/sec
 Cover Type
Pcrmcab i1i ty
                    100& < 3  inches
                    Max 25% < No. 100 Sieve
                    Max 1035 < No. 200 Sieve  (NJ)
                    Max  5% < No. 200 Sieve  (NY)

                    •j 3.ZC
 Intermediate


 Interim
10 E-4 to 10 E-5
cm/sec

Same as Intermediate
                               9O7

-------
o Substitution of Resource Recovery Bottom Ash

Previous work in New England using Coal Ash as Sanitary Landfill Covers
offers the prospect for using Resource Recovery Bottom Ash in the same
applications (20). Based upon prior work Bottom Ash conforms to the
Particle Size Requirements (21). Although the typical Bottom Ash exhi-
bits a Permeability of about 10 E-5 cm/sec, such values were obtained
at 95% modified proctor compaction. By applying a Standard Proctor
compactivc effort of 85% the resultant permeability should be increased
approaching the Daily Cover requirement. The Bottom Ash generated from
a 2000 TPD Mass Burn Resource Recovery facility will satisfy the daily,
intermediate and interim cover requirements of a Sanitary Landfill
servicing approximately 100,000 people. In the Mid-Atlantic region,
final capping, composed of Bcntcnitc Clay, costs $160/CY (f.o.b.) or
approximately $300/CY  (delivered)  (22),
o Daily and Interim Sanitary Landfill Cover

Sweden has applied slag or bottom ash as an interim cover for several
years. Daily and interim cover is applied to prevent dusting, control
vermin, and provide for some passage of moisture to the buried MSW. As
a general guideline, New Jersey suggests a Particle Size Distribution
of  <  3 inches  to a maximum of 10% passing a No. 200 sieve. New York
limits the percentage of fines to 5% passing a No. 200 sieve. NJ and
New Hampshire  recommend a maximum permeability of  10-3 cm/sec for
daily cover. NH allows a lower permeability of 10-5 cm/sec for interim
cover. MSW Bottom Ash conforms to such requirements.

c  Effect Upon  Lcachatc and Biological Activity Rates

McEnroe  and Schrocdcr  (23) have shown that the Leakage or Lcachatc
Rate  through the Drain Layer is directly related to its degree and
depth of saturation. Since BA exhibits permeability of approximately
10 E-4 to  10 E-5 cm/sec and typical daily and intermediate cover
material's permeability ranges as low as 10 E-3 cm/sec, the  amount and
depth of saturation will be reduced. Hence the underlying head and
Lcachatc or Leakage Rate  [QLJ is reduced. Therefore,  the rate of  flow
from  underlying cells and eventually to the final  liner is reduced.
Using less permeable BA as Daily and Intermediate  Cover hydraulically
reduces  the leachatc/leakage flow rate.

Moisture content of MSW is directly related to biological activity  in
terms of Gas Production and Consolidation/Settlement  Rates  (24).  Since
the saturation and  transfer rate of  leachatc would be reduced,  due  to
the presence of less permeable BA, both gas and settlement rates  should
be  reduced - reaching an  equilibrium or steady-state  condition.  By
controlling these rates both safety and cracking  issues arc  mitigated.

c  Effect Upon  Lcachatc Quality

Gray  (25)  demonstrated the  improvement of MSW  leachatc quality  upon
passage  through a  layer of  coal/wood ash. Both organic and  heavy metal
contaminants were observed. One-third  reductions  of  BOD and  COD were
observed;  while Cd  and Pb were  reduced by  31-100%. A compositional  and
physical analogy has been developed between  coalfired ash and MSW ash
 (26). BA's surface  area  is  approximately  2  sq.  cm./gm (27)  and  typifies


                                9O8

-------
Granular Activated Carbon [GAG]. GAG media removes organics via adsorp-
tion. BA's alkaline pK  [> 9] should mitigate the growth of deleterious
microorganisms. The mechanisms of adsorption and biological inhibition
could account for the expected reductions of crganics and heavy metal
contaminants.

MSW ASK AS RAW MATERIAL SUBSTITUTE - PORTLAND CEMENT MANUFACTURE

MSW ash reflects a mineralogy similar to Portland Cement Clinker. ASTM
C618 Cement Product Specification requires that the total of Si02 -*-
Fc203 + A12O3 contain a minimum range of 50 - 70% by weight. ASTM,
however, docs not provide a specification for Raw Material Portland
Cement Manufacture. Table S compares the mineralogy of MSW residues  to
Cement Clinker and to conventional and advanced S02 conversion and/or
coal combustion.

TABLE S; RAW MATERIAL SUBSTITUTE - PORTLAND CEMENT

                             Percent by Weight

                      A1203  CaO  Fc203  Si02  LOI  sg.m/gn


COAL-FIRED FLY ASK    25      1     12 .   54    5    0.55

DRY FGD FLY ASH        9     25      4    21    4    6.85

LFI FLY ASK           17     38     12    16   11    4.25

AFBC FLY ASH          15     23     19    15   13    23.9

MSW ASK                5     37      3    24  <10    0.38

CEMENT CLINKER         6     62      4    22    5    N.A.
                                              (max)

NOTE: Dry Flue Gas Dcsulfurization (FGD) Fly Ash = Calcium Based Spray
Dryer Adsorption Applied to Coal-fired Plants
      LFI = Limestone Furnace Injection; Limestone (CaC03) injected
into coal-fired burners e.g. Limestone Injection Multi-Burner [LIMB]
      AFBC = Atmospheric Fluidizcd Bed Combustion

Only 7% of the conventional coal combustion ash is used for Portland
Cement manufacture. Such a low utilization may be attributed to a
relatively low CaO content in conventionally fired ash compared to
residues from advanced S02 conversion and/or coal combustion systems.
Dry FGD, LFI,  and AFBC reflects Clean Coal Technology in terms of
advanced S02 conversion and/or combustion. Portland Cement represents
their high potential utilization option (10). Given the favorable
mineralogy and compatible surface area of MSW residues relative to
typical raw materials and analogous ashes, up to approximately 71%
substitution could be expected. Based on a typical 2000 TPD Mass Burn
Resource Recovery facility generating 500 TPD of residue and assuming
a 71% substitution, one cement plant could accommodate all of the ash
from five such plants.
                              909

-------
o Chlorides

Typically a maximum Chloride concentration of 4% by weight can be
tolerated in Portland Cement Manufacture. In some instances, MSW resi-
dues may exceed such limitations. Based upon the author's experience
the chloride levels can be reduced through preprocessing.

o Unburnt Carbon - Excess Organics

In addition to Chlorides affecting the ccmcntitious reaction, excess
organics (i.e. unburnt Carbon) reflects another impurity of concern.
ASTM C518 requires a maximum of 6& LOI. Typically a newly designed
Mass Burn facility will yield residues of LOI < 1.0 %. Warren County
exhibited LOI's between 2.6 - 3.85 during their start-up and shake-
down phases (1988/1989). After retrofitting an improved combustion
efficiency design Wcstchcstcr County consistently demonstrated LOI's
of < 0.5%.

o Potential Air Emissions

Cement Kilns typically exhibit a nominal firing temperature of 2600
dcg F - having a flame temperature of 3400 - 3500 dcg F. At such tem-
peratures,  the emission contribution from MSW ash substitution should
be < 10 ppm.

c Concrete Admixtures using MSW Ash-derived Portland Cement

Based upon the coal combustion analogy, the following represents
potential Concrete Admixture menus incorporating MSW Ash as a Raw
Material substitute in Portland Cement Manufacture.

                    Preliminary Concrete Blends - Replacement

                         Cement              Cement-Fine Aggregate

COMPONENT	WEIGHT PERCENT	WEIGHT PERCENT

Incinerator Ash - based
Portland Cement               14                  14

Fine Aggregate                34                  32

Coarse Aggregate              46                  43

Water                          6                  11

IMPURITIES

Since the conceptual considerations appear encouraging, research and
development efforts arc justified. Such efforts should include the
possible adverse effect of soluble impurities. Table 9 reports consti-
tuent/impurities based on ASTM Product Specification. To ensure end-
user acceptance and product conformity, further testing of MSW residue:
according to ASTM procedures arc recommended.
                                910

-------
               TABLE 9; POTENTIAL IMPURITIES - MSW ASH

                    	MSW ASH	

Constituent	w/ Lime APC    w/o Lintc APC   Limit	ASTM Spec

A + F + S (£)       32.76 - 66.35  50.83 - 77.65  50-70   C 613

Sulfur as S03        0.06-0.51    0.14-0.36
(Total - £}
                                                 3.0 - 5.0  C 595
Sulfur as S03
(Soluble - 35)          ND - 0.05    0.02-0,04

Sodium as Na20       1.59-2.97    1.59-2.57
(Total - «)
                                                  1.5       C 613
Sodium as Na2O
(Soluble - %)        0.02 - 0.06    0.01 - 0.05

Water Soluble
Fraction  {%)       0.64 - 6.53     1.12 - 3.55   10.0      C 593

NOTE: ND = Non-Detectable
C 518 = Standard Specification for Fly Ash and Raw or Calcined Natural
Pozzolans for Use as Mineral Admixtures in Portland Cement

C 595 = Standard Specification for Blended Hydraulic Cements

C 593 = Standard Specification for Fly Ash and Other Pczzcians for Use
with Lime

In addition a practical chloride limitation of 4% by weight should be
considered; based upon extrapolation from the NUS Study a soluble
chloride concentration of 0.0034 - 0.034 & has been derived. Therefore,
these derivative soluble impurities in MSW ash appear to satisfy ASTM
allowable concentrations.

BY PRODUCT UTILIZATION CONCEPT - ECONOMICS

Establishing a scenario for By-Product Utilization would reduce dispo-
sal costs and offer the potential for revenue from the sales of the
Waste Material. Demonstrating the concrete-like characteristics of MSW
Ash and its suitability as a self-liner, suggest applying this paper's
engineering principles to utilization concepts. A close approximation
to Portland Cement has been shown by Tables 2, 8 and 9. Obtaining By-
Product Properties may be accomplished by seeding the MSW with Stan-
dard Additives. Table 10 tabulates the Chemical Additive Unit Costs
used in developing a Stabilization Treatment Cost Matrix. This matrix
was based upon a typical Mass Burn facility:

     o 1500 Ton/Day Capacity
     o  500 Ton/Day Total Ash
     o  BA = 85% by weight = 425 Ton/Day
     o  CA = 15% by weight =  75 Ton/Day
     o  300 Operating Days per Year


                               911

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This matrix indicates  that  adding commercially available additives
to MSW ash would only  increase  Operating Cost by $ 1.60/tcn of MSW Ash
to $4.20/ton of MSW Ash.

  TABLE 10: STABILIZATION COST  ANALYSIS OF COMMERCIAL ADDITIVES

UNIT ADDITIVE COSTS

Chemical Additive	$/Ton	Comment

Portland Cement [PC]          75              	
CaO (Pebble Lime)             60              	
Lime Kiln Dust [LKD]          12              50% reactive
Cement Kiln Dust [CKD]        12              50% reactive
Coal-Fired Fly Ash [CFFA]       3              	
Gypsum [CaS04.2H20]           45              Purity = 87-90%

By applying the principles  of optimizing (a)  Particle Size Distribution,
(b) % Water of Sclubilization,  (c)  Chemical Additive Dosage, and (d)
Degree of Compaction or Dcnsification,  a conceptual Utilization System
is preliminarily engineered. Table  11 presents a conservative budgetary
estimate for a Utilization  Plant  augmented to a resource recovery
facility. The Unit Process  Cost of  $32  per ton of ash (about $1I/ton
of MSW) is 1/3 to 1/2  the cost  of ash monofill disposal in NJ. Rather
than expend resources  to discard  MSW Ash,  the Waste-tc-Encrgy field
(private and public sector)  is  urged to implement By-Product concepts.

TABLE 11; COST COMPARISON:  BY-PRODUCT UTILIZATION VS.  DISPOSAL
     Capital Equipment  Investment             =    $ 5 . 5 MM
       «n«. •*- •;•»-«+••«'•***  rr>UT?.  1 nv /»»».  «a  in  v^^f      —    <• n r» MM /v»«
       W^ C .Ai 4**A v ^ «^AA  ^ X^AXA; •  Awu/jf*k  v~^w  A^«^J      —    v '•'•*•' i'i*'A/ A ^
                                  tno-l         —    c on /T^*-,
                                  ^ w« j         —    V w/ A «^«A
     Operation £ Maintenance                  =    35 %
C      *-»»•» ^ -4 »^ f<
      V^AA <>. ^4*
                                     oo
New Jersey Resource Recovery Ash Mcncfill

       UNIT DISPOSAL COST    =  $   75   to  110  Per Ash Ton

By implementing the above Utilization  Concept,  savings of $12 to $16
per ton of MSW could be realized.  Just donating the processed
ash could save millions of dollars per year.

     SUMMARY

Ashes from both Mass Burn and RDF  MSW  incinerator systems reflect
chemical composition suggesting inherent pozzolanic behavior. These
ashes were generated from Resource Recovery facilities equipped with
Flue Gas Cleaning Systems. The high stoichicmctrics of such systems
produce considerable excess lime which promotes pozzolanic or ccncrci
like behavior. The principles of proper Site Management,  including
adding the optimum water of solubilization and  attaining  optimal ccm-
                              912

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paction, have yielded permeability coefficients  between  10  X  EXP-7
ens/sec to 10 X EXP-9 cm/sec, after 14-23 days  curing.  Empirical  Confir-
mation of achieving Lev,* Permeabilities and High  Lcachatc Quality have
been Demonstrated. Collected Undcrdrain Lcachatc,  from an active Ash/
Scrubber Residue Moncfill approximated Drinking  Water  Quality for
Inorganic and Organic specie and the resultant pH  of 5.7 reflect low
solubility and in-situ permeability  { *^ lUf 4*4_A^1*^i'*4>*«^ «•** **r j **v*  ^4v%*^l  ^^•*\v%vs-«v%^>v
Vt£«£SX W^^^ilAtdt W !•» .A. Jf V ^ ^* *. W / ^-» A • A A. A t.AAW *'* -i *-* tt \m ^ IAAA W.LW .kW^^WAAf ± .LAA^ni.^  W «**£>£/ ^ **^ f
composed of Bcntonitc Clay, costs $150/CY  (f.o.b.) or  approximately
$300/CY delivered. The deficiency of Portland  Cement Raw Materials
(shale,  clay, limestone) in Wastc-tc-Encrgy intensive  regions (New
England, Mid-Atlantic and south eastern seaboard)  provides  a  receptive
and economically-driven scenario for MSW substitution.

Chemical Comparisons suggest adding approximately  15%  lime  (for  Port-
land Cement) and 4-S& gypsum (for an ASTM pczzclan). Based  on Particle
Size Distribution of MSW Ash, segregation could  yield  approximately
758J of the Bottom Ash (suitable for Coarse Highway Aggregate)  and 25%
of the Fly Ash (suitable for Fine Cement Aggregate). Segregation,
however, would not be required for cither MSW  Fly  and  Combined Ash  for
direct use as Soil Aggregate, for paving application.

This paper postulates that using Bottom Ash [BA] as interim/final
cover material would better control the passage  of water and  encourage
attaining a bio-kinetic stabilization within the landfill before plac-
ing final impermeable capping. As discussed the  intermediate  layers of
BA and MSW would transmit a reduced hydraulic  rate to  the bottom liner
and would reduce respective saturation and moisture contents.  The BA
generated from a 2000 TPD Mass Burn Resource Recovery  facility will
satisfy the daily, intermediate and  interim cover  requirements of a'
Sanitary Landfill servicing approximately 100,000  people.

Given the favorable mineralogy and compatible  surface  area  of MSW
residues relative to typical raw materials and analogous ashes,  up  to


                              913

-------
 approximately  71%  substitution  for  traditional  Portland  Cement  Raw
 Material  could be  expected.  Based on a typical  2000 TPD  Mass Burn
 Resource  Recovery  facility generating 500  TPD of  residue and assuming
 a  71% substitution,  one  cement  plant could accommodate all  of the ash
 from five such plants. Based upon derivative soluble impurities,  MSW
 ash appears  to satisfy ASTM  allowable concentrations.

                      AUTHOR'S  RESTRICTION

 THIS DOCUMENT  IS NOT TO  BE QUOTED,  CITED,  REFERRED TO, PUBLISHED  OR
 COPIED WITHOUT THE EXPRESS WRITTEN  CONSENT OF THE AUTHOR.

     REFERENCES

 1. Office of Technology  Assessment  [OTA];  Facing  America's  Trash:  What
 Next for  Municipal Solid Waste? Dec.  19S9.
 2. CORRE  Newsletter; Volume  Three,  No.  12;  Dec  19S9
 3. NUS Corp.;  Characterization  of Municipal Waste Combustion Ash.  Ash
 Extracts, and  Lcachatcs; USEPA  Contract No. 68-01-7310;  Feb.  1990}
 4. Resource  Recovery Focus;  "Study  Shows Real Combustion Ash Less
 Toxic Than Lab Test  Results"; Vol.2,  No. 1; Winter 1990.
 5. "Managing Ash From Municipal Waste Incinerators"; Center for Risk
 Management Resources for the Future;  Nov.  1983.
 S.Goodwin, R.W.; "Residues from Wastc-to-Encrgy Systems"; comments
 submitted to USEPA pursuant  to  proposed amendment Subtitle  C of RCRA
 [40 CFR Parts  251, 271 and 302];  7/31/86.
 7. California  Dcpt.  Health Services;  "Classification of  Stanislaus
 Waste Energy Company Facility Ash";  2/8/90.
 8. Goodwin,  R.W.;  Schuctzcnducbcl,  W.G.; "Residues from  Mass Burn
 Systems:  Testing,  Disposal and  Utilization Issues";  Proceedings
 of the NYS Legislative Commission's Solid  Waste Management  and
 Materials Policy Conference; NYC  Hilton Hotel;  Feb.  11-14,  1987.
 9. W. Schuctzcnducbcl; Personal Communication;  Blcunt Energy Resource
 Corp.; 4/24/90.
 10. Goodwin, R.W.; "Engineering Evaluation: Residues From Clean Coal
 Technology"; POWER;  August,  1990.
 11.  Forrester, K. E. and Goodwin,  R.W.; "Engineering Management  of
 MSW Ashes: Field Empirical Observations of  Concrete-like Characteris-
 tics"; Proceedings USEPA International Conference  of Municipal
 Waste Combustion:  Hollywood, FL.; April 11-14,  1989.
 12. Zimmie,  T.F. and Riggs, C.O.  (editors); ASTM  Publ. No.  745; Perme-
 ability and  Groundwatcr Transport;  pages 55-58.
 13. Goodwin, R.W.; "MSW Ash: Liability or Asset";  presented  at  the
 McGraw Hill's  Wastc-to-Encrgy '88:  The Integrated Market Conference;
 {Oct.  3-4, 1988; L'enfant Plaza Hotel; Washington,  D.C.)
 14. Forrester,   K.E.; "State-cf-thc-Art in Thermal  Recycling  Facil-
 ity Ash Residue Handling, Reuse, Landfill Design  and Management";
 presented MSW  Technology Confer.; San Diego, CA;  1/30 -  2/1,  1989.
 15. Goodwin, R.W.;  "Utilizing MSW Ashes as Monofill Liner";   Proceedings
 1989 National  Solid Wastes Forum on  Integrated Waste Management;
Association of  State and Territorial Solid Waste Management  Officials;
 Grcsvenor Hotel; Lake Bucna Vista, FL; July 17-19,  1989.
 16. Resource Recovery Report; Proceedings MSW Ash Utilization Confer-
 ence:  Oct. 13-14,   1988;  Pcnn Tower Hotel; Phila, Pa.
 17. A.  Bcntur and T.  Grinbcrg;   "Modification of the Cementing Properties
 of Oil Shale Ash";  Ceramic Bulletin; Vol. 63,  No.2, 1984; Pgs.  290-300.


                                914

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     REFERENCES

18. Goodwin, R.W.; "Pczzolanie Behavior of MSW Residues"; presented at
Northwest Center for Professional Education Conference - "New Develop-
ments Incinerator Ash Disposal"; {NYC Hilton; Apr. 26, 19SS)
19. Poran, C.J. and Ahtchi-Ali, F. ; "Properties of Solid Waste
Incinerator Ash"; Journal of Gcotcchnical Engineering; ASCE; Vol. 115,
No. 8; Aug. 1D80; Pgs. 1118 - 1133.
20. Click, H.B.; "Coal Ash Use as an Economical Cover at Sanitary
Landfills"; Proceedings of the 7th International Ash Utilization Sym-
posium;  May, 1985
21. Goodwin, R.W. ; "Ash from Refuse Incineration Systems: Testing,
Disposal and Utilization Issues"; presented at MASS-APCA 33rd Technical
Conference and Exhibition: Air Pollutants from Incineration and
Resource Recovery; Nov. 3-6, 1987; Atlantic City, NJ.
22. D. Gallagher, Burdc Associates; Personal Communications; 10/5/89.
23. McEnroe, B.M. and Schrocdcr, P.R.; "Lcachatc Collection in Landfills
Steady Case"; J. Snvir. Engr. Div.; ASCE; 1988, 114 (5); 1052-1062.
24. DcWaiic, F.E.; ct. al.; "Gas Production from Solid Waste Landfills";
J. Envir. Engr. Div.; ASCE; 1978, 104 (EE3); 415-432.
25. Gray, M.N.; Rock, C.A.; and Pcpin, R.G.; "Predicting Landfill
Leachatc with Biomass Boiler Ash"; J. Envir. Sngr. Div.; ASCE; 1988,
114 (2); 465-470.
25. Goodwin, R.W.; "Coal and Incinerator Ash in Pczzclanie Reaction
Applications"; presented at MSW Ash Utilization Conference
by Resource Recovery Report; Oct. 13-14, 1988; Tower Hotel
 27. Forrester, K.; Whcclabratcr Tech.; Personal Communication; 10/5/89.
sponsored
Phila, Pa.
                               915

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                   VITRIFICATION OF
        MUNICIPAL SOLID WASTE COMBUSTOR ASH

          Ray S. Richards? and Gary F. Bennetts

     aAssociated Technical  Consultants,  Toledo, Ohio.
      t>Professor; University of Toledo; Toledo, Ohio.
                   Presented at the

First U.S. Conference on Municipal Solid Waste Management

                  June 13- 16, 1990
                         917

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 Vitrification  of Municipal  Solid Waste  Combustor Ash
                  Ray S. Richards and Gary F. Bennett
Introduction

   Nationally there  is a concern for pollution that may be caused by the
land  disposal of solid and hazardous waste.  Consequently, using the
authority given to them by RCRA, the USEPA is severely limiting land
disposal of hazardous waste. If land  disposal is  to be permitted, then
the disposer will probably be required to detoxify or to immobilize his
waste to the greatest extent possible.  This  requirement may well
apply to municipal waste combustor ash (MWC ash)  For ash resulting
from the combustion of municipal  solid waste  ,  vitrification represents
immobilization of the toxic metals to  the  maximum extent possible  .

Why   Vitrification

    The vitrification  process produces  a  glass-like, non-leachable
material  by melting  municipal  waste combustor (MWC) ash.  This
process is  not encapsulation! The ash feed materials are no longer in
their original form.  Their physical  and  chemical  form have  been
changed.  This process  is similar to dissolving sugar in coffee;  the
sugar crystals  are gone  and the flavor is  changed.  The glass exiting the
melter is usually a  homogeneous material but some compositions  can
partially crystalize  on  cooling.  Both glasses and crystalline materials
can be very inert and unleachable.
   There are at least two benefits in  this process.
         1.  Reduction in volume
        2.  Delisting
               -Very large  reduction  in surface area
                  (leaching surface).
                -Production of chemically inert glass

   MWC fiy ash densities have  been measured^')  at 0.37 to 0.73
gms/cm3 and bottom ashes  were measured at 0.82 to 1.04 gms/cm3
Typical commercial  glass densities  are  2.6 gms/cnv
                            918

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Thus, there is a significant reduction in volume  to be gained by
vitrification.
   The surface area of the fly ash that may be exposed to leaching is
large.  Moreover the  toxic materials are  deposited on the surface of  the
particles.  The vitrification  process combines all of these surfaces  into
a coarse non-leachable aggregate of minimum volume and surface area.
   Occasionally  MWC  ashes exceed EP Tox and TCLP limits by modest
amounts (2). The dissolution of  the toxic, materials  on the surface of
the ash into the glass and the multiple orders of magnitude  reduction in
surface area almost guarantee that any glass produced as a  result of
vitrification will pass the required hazardous waste toxicity tests.
While the non-leachability of vitrified  ash has not  been  certified by
innumerable tests, glass technologists have little doubt  that non-
leachability can easily be achieved as it  has been in the nuclear
industry.
   Vitrification  of high level  nuclear waste hss  been under  study for
over 20  years.  The leaching  standards are much more strict than those
faced by MWC ash and acceptable levels  of leach resistance  have been
attained  for nuclear  waste.
   There are concerns for the durability of other disposal methods.
Structural grade concrete bridges and roads may not last 20 years due
to  freeze-thaw winter cycles.  "Waste material" aggregate  with
uncontrolled chemistry would be even more suspect.  In  contrast, our
Toledo Museum  of Art has glass objects  recovered  from burial  sites
thousands  of years old which are in excellent condition.
   Vitrification is the answer to municipal waste  combustor ash
disposal.

Demonstrated    Capability

   Several  companies are actively  pursuing vitrification  as  a method of
MWC ash treatment.   The following is a partial list  of these companies.

   Argonne National  Laboratories
         Argonne,  IL

   Penberthy  Electromelt International.  Inc.
         Seattle,  WA
                                919

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   Westinghouse Electric Corp., Environmental System Dept.
        Madison, PA

   U.S. Environmental
        Ml. Laurel, NJ

   Vortec Corp.
        Collegeville, PA

   Geosafe Corp.
        Kirkland, WA

   Inorganic  Recycling
        Worthington, OH

   Associated Technical Consultants in  affiliation with  Glasstech, Inc.
        Toledo, OH

Gas  Versus  Electric  Melting.

   Commercial gas  fired gl?ss melting furnaces,  which might be
considered for MWC ash vitrification, utilize  more than A million BTUs
of natural gas energy and generate over  A tons of exhaust gasses for
each ton of glass produced.  These figures are for very large, efficient
furnaces.  The furnaces have large heat recovery  systems and bag
houses for dust collection and require a great deal  of  capital
investment.
   Smaller gas fired melters, called unit melters, are also available
without energy recovery systems.  There  is a significant increase in
fuel consumption for these furnaces over the larger units.
   For more  modest capacity melters, such as those appropriate for
MWC ash,  electric melting is a better choice  than gas fired  melters.
Electric melters are smaller and cost less than a gas fired  furnace of
the same  capacity.   While electric melters are efficient, they use an
energy source that normally costs over  three times as much as natural
gas on a per  ton melted basis.  However, in MWC co-generation
facilities,   the electric  costs can  be more attractive.
                              92O

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Special  Applicability  of Vitrification  to  MWC  Ash

   MWC facilities  with co-generation of electricity capability  present
a unique opportunity to utilize electric melting for vitrification
because their electric  costs can be very reasonable. Some of the new
electric melter designs lend themselves to very rapid on-off operation.
This operational advantage will allow  utilization  of off-peak power.
   It also is fortunate  that most of the major  oxide constituents of the
ash stream are good glass formers.  Table  1  shows the weight percent
of the  major components in the fly ash.  One equipment supplier
recommends modest additions  of cullet (scrap glass)  to the  ash  feed
streams to adjust the  melt chemistry for reasons described  later.

Fly Ash  versus  Bottom Ash
   Fly ash and bottom  ash have different compositions and  toxicities.
Many  papers^-6)  have been written  on the chemical and physical
distribution of toxic metals in  MWC ash.  It is generally agreed that the
fly ash contains a larger portion of most of the toxic  elements than
does bottom ash.
   A  typical  waste-to-energy  incinerator of  600 tons/day capacity will
produce approximately  150 tons per day  of total ash.  Of this total,
about 20%, or 30 tons per day, will be fly ash .
   The high surface area of the fly ash,  the distribution of the toxic
elements  on the surface of the fly  ash, and the  lower weight of fly ash
per ton of waste as compared  to bottom  ash  make it the waste stream
of most toxic concern  and the most  likely candidate for vitrification.
Table 2 shows  the toxic metals present in the ash.

Typical  Electric  Vitrifying Units

   Electric glass melters  which are  used for bottle, window, and
specialty  glass around  the world are available in  a  wide range of sizes.
In electric glass melting,  molybdenum electrodes are  inserted into the
molten glass and current is passed through the  glass to heat  it.  There
are two different melter designs: cold top and  hot top.
   The cold top design  is a refractory box which  is open on top,  full of
molten glass, with a layer of  raw  materials  floating on top of the melt.
                               921

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This layer insulates the furnace top  and  is replaced as batch melts
away.  There  is a drain hole located  elsewhere in  the furnace which
removes the melted glass.
   The second design is a fully enclosed  furnace and uses some gas
firing or electric  heating elements above the  melt in addition to  the
electrodes in the melt.   This is called a hot top design.
   Arc furnaces, typical  of those used in steel melting,  also have been
used for  ash  vitrification^) .  Since steel  making  involves slag  or glass
on top of the  molten steel,  it is reasonable to consider these units for
ash vitrification.  Herb Hollander, Wyomissing, PA, is Chairman of an
ASME program which is evaluating the arc melting furnace for ash
vitrification.  Arc furnsces operate with very high temperature zones
and can melt any residual metallic components in  the ash.  The  plan is
to process both fly and .bottom ash with removal  of the molten metallic
fraction  from the  bottom of the furnace.

 Stir-ttelter™

    Associated Technics! Consultants  (ATC) and Glasstech, Inc.  are
developing a highly stirred, electric melter (Stir-Mel ter™).  This newly
designed electric melter  will be used  to  melt  MWC ash  late this
summer.  The work is being carried out by ATC with support from the
State of Ohio  under an  Edison Seed Fund Grant to the University of
Toledo.  Glasstech, Inc. will  manufacture and market the new Stir-
Nelter™furnaces.   These furnaces are smaller than other electric
furnaces with the same capacity  and  are more easily sealed against
vapor loss than other furnace  designs.
   This new furnace is a small eletric melting unit with a high speed
stirrer to circulate the melt rapidly.   This provides rapid melting rates
and uniform operating temperatures.  The small size minimizes energy
consumption. They operate within a very narrow and tightly controlled
temperature  range and thus allow significant  control over chemical
reactions in the melting process. The Stir-Melters™ respond to
temperature and load changes  quickly and can  be idled  or returned to
full production in  minutes.  In  this regard, they are the most flexible of
the electric melters described.
                              922

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Operating  Cost  Considerations

   The operating cost of an electric  melter is highly dependent on the
actual cost of the 450 to 550 Kwh required to melt  each ton of ash.
More energy may be required if high levels of additional materials are
added to the ash stream.  Off peak power  at co-generating facilities
should be very reasonable.
   A second cost factor is the need for other materials to be added to
the ash  feed stream. There can be several  reasons for doing this.  One
is to lower  the melting point  of the ash stream  to make melting easier.
   Another is to balance the chemistry to get a  good durable product
(high leach resistance).   While  optimum glass chemistry  has not been
determined  and will vary from  location to  location,  it seems reasonable
that the cost  of additions to the feed stream will be modest.
   The  cost of vitrification was described  in general terms  above.
Exact costs depend  upon size, electricity costs, and several chemical
factors which have  not yet been resolved.  Based on an in-house, off-
peak electricity cost of 2 cents/Kwh, it is  our estimate that
vitrification direct costs will be between  $50 and $60/ton of glass
output.   One must remember  that  fly ash contains significant levels of
carbon  and volatiles and that some additional materials may have to be
added to the ash stream. Our estimate is that 1  ton of fly ash will
produce 1.0 to  1.2 tons of glass.
   Lastly, when  more sophisticated end products are being
manufactured from  the glass stream, there will  be  additions to
maintain  a  consistent chemical  composition of the  glass  despite
seasonal variations  in the  ash stream .  This will be discussed later.

Capital   Costs

   Approximations of capital  costs for  electric  melters are not reliable
because of the large variations  from site to site.  The type of melter
selected  will  affect the plant space requirements,  the ventilation and
exhaust gas processing needs.  Mass burn incinerators will have
different types and quantities of ash than  incinerators burning refuse
derived  fuel.    The  incinerator  combustion  system will heavily affect
the percent of fly ash to total ash as well  as the residual carbon
content.
                               923

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   As a starting  point, a furnace for vitrifying ash in the size range of
50 tons per day might cost from $ 1,750,000 to $2,500,000. If only fly
ash were being vitrified the capacity  required  for a mid-size
incinerator would be substantially  less, although  the cost per  ton  of
capacity would be somewhat greater.  Beyond this, the requirements of
the individual  site would need to be appraised.

Vitrification   Concerns

   The research  currently underway at Associated Technical
Consultants addresses several  of the  chemistry problems inherent in
the vitrification of MWC ash. Although glass is known  as the universal
solvent,  readily incorporating lead, zinc, chromium, and selenium,
several toxic  species  can partially  vaporize in addition to  dissolving in
the melt.  Consequently, air pollution  control of the furnace effluent
will have to be considered.   This is a  problem that  is routinely
addressed in commercial glass  melting.
    Fly ash can contain significant  amounts of carbon.   This can lead to
the reduction of  some metal oxides to their metallic state  and the
glass melting temperature is high enough to cause  boiling of some of
these metals.  For some tightly closed furnace  designs, this is not a
difficult problem and the vapors can be condensed in  fairly simple
systems.  The concentrated  condensate then can be recycled as a  metal
source.

   One groupie)  reports the following data that  illustrate  the volatility
of two heavy metals:

                Fly Ash            Vitrified Glass
   Cadmium  1000-2000 ppm          10  ppm
   Lead          5000   "           100  "

In this case, the  cadmium probably  left the furnace in the exhaust gas
stream.   The lead can either be lost to the  exhaust stream or  found as
metallic lead in the bottom of  the furnace.  The chlorides and  sulfates
in the  ash also may combine with some metal species which then
volatilize.
                               924

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   From the  perspective of a glass technologist, the extreme
variability of the  ash stream chemistry makes melting control  difficult
and yields a  low quality glass output.  For example, the concentration of
silica (SiOz)  varies between 0  to 57% as shown in Table 1.  At the low
end of silica concentration, sand will  have  to be added  to the melt.
   Other species such as chromium are locked  in the glass structure
and are also  in a non-toxic valence state.

By-Products

   There  have been proposals too numerous to  detail on potential uses
for MWC ash as it comes from the combustor.  Construction  aggregate
uses predominate  and ash  is utilized for aggregate in many countries.
Bottom  ash which has been sized and  washed may be suitable for this
application.  This aggregate is a relatively low value product.  The
result is small cash return instead  of an expense.  Several other similar
uses have been proposed.  There have  been fewer uses suggested for fly
ash.

   We at  ATC-Glssstech feel  that there are other products which can be
made from the vitrified ash stream that would  have a higher value  than
aggregate.  However,  these future higher value  products, and indeed
some of the  ones  presently being discussed, will require that the glass
properties and thus its composition be under better control.   This
control  feature is not incorporated  in current MWC  installations.  To
accomplish better ash  chemistry control, stock piling and blending  or
chemical  sampling  followed by  corrective  additions will be  needed.
Long  range developments will probably trend in this direction.

Summary:

   Given  the  public  concern for the potential  impact of toxic chemicals
in the leachate on ground  water, there  is resistance to  siting of land
fills. We feel that vitrifying of fly ash to produce a virtually non-
leaching product will enhance landfill acceptance  or alternative uses.
In addition,  discontinuing the present practice  of mixing the potentially
hazardous fly ash with the bottom  ash  also should enhance the
acceptance of bottom ash for land fill or other uses.
                                925

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   We  feel that the Stir-Melter™ can effectively and economically
vitrify fly ash.  Currently we are on a research and development
program to scale up a lab melter to a commercial melting unit.
Additional work will be conducted on producing higher value products
from the vitrified  ash.
   As  we look  to the  future, it is our belief that production of useful
products from  this vitrified ash can produce an economic benefit,
secure a  concomitant reduction in disposal costs and lead to a
reduction of land disposal.

REFERENCES

 1  J. L. Ontiveros, T. L. Clapp, and D. S. Kosson, "Physical  Properties
   and Chemical Species Distribution within Municipal  Waste
   Combustor Ashes," Environmental Progress, Vol 8, No.  3, 1989, 200
   -206.

2  T. J. Clapp, J. F. Mageell, R. C. Ahlert, and D. S. Kosson, "Municipal
   Solid Waste Composition and  the  Behavior of Metals in Incinerator
   Ashes," Environmental Progress V7, No. 1, 1988,  22-30.

3  Cundari, "Laboratory Evaluation of Expected Leachate Quality from a
   Resource Recovery Ashfill," Ash Disposal Workshop  Proceedings.

A  EPA, "Characterization of MWC Ashes  and Leachates from MSW
   Landfills,  Monofills, and /Co-Disposal Sites," EPA 530-SW-87-028A,
   Oct 1987.

5  Hjelmer, "Swedish  Study", ref. unknown,  data from Victor Pearson,
   Argonne National Laboratories.

6  L. Penberthy, Personal  communication, "Philadelphia Incinerator
   Data"

7  T. Furukawa, E. Inagaki,  S.  Shimura, "Application of Electric  Arc
   Heating for Melting Treatment of Sewage and Municipal  Incinerator
   Residue,"  XI Congreso Internacional de Electrotermia,  Malaga,
   Espana, 1988.
                               926

-------
8  Russel Cepko, Westinghouse Elec. Corp; Environmental Systems Div.
   Persona! Communication.
                              927

-------
TABLE 1   ASH COMPOSITION


Si02
CaO
A 1203
{§ F6203
CD
Na20
Ti02
MgO
K20
P205
_ ^*
ZnO
nun
WESTCHESTER (2
TOTAL ASH
RANGE
40.3-46.8
11.3-15.4
10.5-16.3
8.0-19,2

3.1-4.2
1.5-2.1
2.4-4.2
1.4-3.4
1.0-1.4



5) E.P.A.(4)
FLY ASH
RANGE
0.3-57
2-38
0.9-33.2
0.1-12

1.3-6,7
T-7.0
0.33-3,5
1.3-8.0
0.7-2.1
OTR 1 Q
,OO I :T
0 09-9. Q
SWEDISH (5)
RANGE
31.6-63.6
9.4-15.5
11.5-20.6
2.0-5.7

2.9-5.7
0.5-2.1
2.0-4.6
2.6-7.2
1.2-2.5



PHILADELPI-

32.8
13.1
21.9
2.0

9.3
2.2
2.2
10.9
	
2 2
/L. >£-
1.1

-------
                    TABLE
RANGES OF CONCENTRATIONS OF INORGANIC CONSTITUENTS
     IN FLY ASH, COMBINED ASH. AND BOTTOM ASH
   FROM MUNICIPAL WASTE INCINERATORS IN ng'g (ppm)
Parameter
Arsenic
Barium
Cadmium
Chromium
Lead
[Mercury
Selenium
Silver
Aluminum
Antimony
Beryllium
Bismuth
Boron
Bromine
Calcium
Cesium
Cobalt
Copper
Iron
Lithium
Magnesium
Manganese
Molybdenum
Fly Ash
15-750
88-9,000
< 5-2,2 10
21-1.900
200-26.600
0.9-35
0.48-15.6 -
ND-700
5,300-176.000
139-760
ND-<4
36-<100
35-5.654
21-250
13,960-270,000
2.100-12,000
2.3-1.670
187-2,380
900-87.000
7.9-34
2.150-21.000
171-8,500
9.2-700
Nickel | 9.9-1,966
Combined Bottom
and Fly Ash
2.9-50
79-2.700
0.18-100
12-1.500
31-36.600
005-17.5
0.10-50
0.05-93.4
5.000-60,000
<120-<260
ND.1-2.4

24-174

4.100-85,000

1.7-91
40-5,900
690-133.500
6.9-37
700-16.000
14-3.130
2.4-290
13-12.910
Bottom Ash
1.3-24.6
47-2.000
1.1-46
13-520
110-5.000
ND-1.9
ND-2.5
ND-38
5.400-53.400

ND-<0.44
ND
£5

5,900-69.500

3-62
80-10,700
1,000-133.500
7-19
880-10.100
50-3.100
29
9-226
                    929

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TABLE 2
RANGES OF CONCENTRATIONS OF INORGANIC CONSTITUENTS
IN FLY ASH, COMBINED ASH, AND BOTTOM ASH
FROM MUNICIPAL WASTE INCINERATORS IN pg'g (ppm)

PAGE TWO
Parameter
Phosphorus
sotas$ium
Silicon
Sodium
Strontium
Tin
Titanium
Vanadium
Yttrium
Zinc
Gold
Chloride
Country
Fly Ash
2,900-9,300
11,000-65,800
1.783-266,000
9.780-49.500
98-1,100
300-12.500
< 50-42,000
22-166
2-380
2.800-152.000
0.16-100
1.160-11,200
USA. Canada
Combined Bottom
and Fly Ash
290-5,000
290-12,000

1,100-33,300
12-640
13-380
1.000-28.000
13-150
0.55-8.3
92-46.000


USA
Bottom Ash
3,400-17.800
920-13,133
1.333-188.300
1,800-33.300
81-240
40-800
3,067-11.400
53

200-12.400


USA, Canada
 ND - Not detected at the detection limit
 Blank - Not reported, not analyzed for
 Source: Literature (Volume IV) and Versar Study (Volume V)
                             930

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CONVERSION OF MSW INCINERATION ASH INTO CONSTRUCTION AGGREGATE
           MEETING FEDERAL DRINKING WATER STANDARDS
                   Frederick H.  Gustin,  P.E.
                     Hugh P. Shannonhouse
                   Municipal Services Corporation
                       Presented at the

   First U.S.  Conference on Municipal  Solid Waste Management

                      June  13 - 16, 1990
                          917-A

-------
Conversion of MSW Incineration Ash Into Construction Aggregate
           Meeting Federal Drinking Water Standards

by F.H. Gustin 1 and
   H.P. Shannonhouse 2
Introduction



     Opponents to municipal  solid waste incineration cite  two

major  concerns  with incineration.  The first is the question

of ash quality and the presence  of contaminants.   The  second

is  flue  gas emissions.   This  paper  describes  the program

developed  by Municipal Services  Corporation  (MSC)  to address

the  first problem.    The  air quality  control system industry

has  addressed the second.



     A recent estimate by the Leading Edge Report,  as reported

in  the  June,  1990  issue of  Solid Waste  &  Power Magazine,

indicates  that the  number  of  waste-to-energy plants  in  the

U.S.  is expected  to double  by  the year 2000, to about  350

plants.   Total incineration  capacity will reach approximately

250,000 tons of solid waste per day.
      Frederick  H.  Gustin,  P.E.  is a  Senior Project  Engineer
      with  Municipal Services  Corporation,  777 Franklin  Road,
      Marietta,  Georgia  30067

      Hugh  P. Shannonhouse  is  President of Municipal  Services
      Corporation,  a USPCI,  Inc.  subsidiary.  USPCI, Inc.  is  a
      wholly-owned  subsidiary of  the Union Pacific Corporation,
      Bethlehem,  PA.

-------
     The number  of  plants  in operation will increase by  about


6.7 percent  annually,  while the  annual throughput  capability


will increase by 12 percent.






     Along with an  increase in  incineration  capacity,  there


will be a  corresponding  increase  in ash production.  If  a  75%


reduction  in  weight is assumed when  municipal solid waste  is


incinerated,  the 250,000  tons of  solid  waste per day will


result  in  62,500 tons  of ash  per  day, or  almost  23  million


tons of ash per year.






     On the  other hand,  the number of permitted  landfills  in


the U.S. is expected to decrease.   According to the EPA,  there
                                                        «

are  presently  approximately  6000  solid  waste  landfills   in


operation  in  the  U.S.    More than  half  of  these  existing


landfills  will  reach  their  capacities within  the next  six


years.  Stricter federal and state  standards,  Superfund,  and a


reluctance on  the  part of  the  general  public to allow  new


landfills  to  be built in  the  vicinity of populated areas  all


play roles in the decline  of the  number of landfills that will



be in operation in  the near future.






     In  addition,  a  general  trend  has  developed  for  the


recycling  and  reuse  of  heretofore  unusable  industrial  by-


products.   Such materials as paper mill sludge, foundry  sand,







                             Page  2

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municipal  sewage sludge,  and power plant  coal  fly  ash  and

bottom  ash  have  all  found  beneficial  and  environmentally

benign uses over the past several decades.



     It   is  for   these  reasons   that  Municipal   Services

Corporation has decided  to pursue the opportunity  of  recycling

MSW incinerator ash.



The MSC Program



     The  Municipal  Services  Corporation  (MSC)  program  consists

of contracting  for  removal  of 100% of the MSW incinerator  ash

production  from  a  waste-to-energy  plant.     The  ash   is
                                                        •
transported to  another facility  owned  and  operated  by  MSC

where  metals  are  removed  and  the  ash  is   converted  into  a

construction-grade  aggregate material  which  can  be  used  for

road  construction  or  a variety  of  other  uses.    A  small

percentage of the  ash  is unprocessible and  requires  by-pass

disposal.



     The  ash is  first  processed to  remove  metals  and  unburnt

paper  and to produce a  more consistent particle size.   It is

then  "chemically  fixed" using  K-20 3,  which  is a  patented

3    Patented -  U.S.  Patent  Office.    The   K-20  Lead-in-Soil
     Contaminant  Control  System   is   a  product  of   Lopat
     Enterprises, Inc.,  Wannamassa,  N.J.




                             Page 3

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product using  a potassium silicate  formula that causes  heavy
metals  to  form metal  silicates,  thus  permanently  reducing
their  solubility and therefore mobility  in the environment.
The chemically-fixed ash  is  then mixed with other  proprietary
ingredients  and pelletized into  smooth  round pebbles  ranging
in  size  from  approximately  1/8 to  3/4  inch  in  diameter.
Following  a curing period  to  provide  for  optimum  strength
gain,  the  aggregate can be  used  in  road  construction  or
elsewhere  as permitted  by the state environmental  protection
agency.

     Ferrous   metals   and  mixed   non-ferrous  metals   are
relatively clean and can be  sold to  scrap  metal dealers,  steel
mills, and foundries.

     MSC  has   been awarded   contracts  by  two  counties   in
Minnesota:  Hennepin  County,   which  encompasses  the  City  of
Minneapolis,   and   Dakota  County,  just   to   the  south   of
Minneapolis.   MSC  will provide  MSW  incinerator ash  recycling
services,  including disposal of  unprocessible residues,  for up
to  90,000  tons per  year  of  ash  from  the  Hennepin  County
incinerator  and another 60,000  tons per  year  of ash  from  the
Dakota County  incinerator.
                            Page  4

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Environmental Testing of MSC Synthetic Aggregate







     In  order  for MSC  to  market the  synthetic aggregate  for



use in highway  construction and elsewhere, it must  first  pass



stringent  testing  for both  environmental  safety and  physical



performance characteristics.







     During  the   course   of  product  development,  MSC   has



subjected  the  synthetic aggregate  to the  following tests  to



ensure environmental safety:







*    Extraction  Procedure   Toxicitv Method  1310.   or  EP-Tox,



     which was  the  standard EPA  test by  which a  waste  was



     judged  hazardous  or   non-hazardous.    EPA has  recently



     dropped this test in favor of the TCLP test.







*    Toxicitv Characteristic Leaching Procedure Method 1311.



     or  TCLP,   which  is   similar  to  EP-Tox,  but  for which



     results are more  readily  replicated  from laboratory  to



     laboratory.







*    Multiple Extraction Procedure. Method  1320. or  MEP, which



     is  an indication of  the  stability  of a  material in  the



     environment  over  many  years.   The test  is  commonly



     referred to as the "Thousand Year Leach Test."
                            Page 5

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*    To a limited  extent,  MSC has tested for 2,3,7,8-TCDD  and



     2,3,7,8-TCDF,  Method 8270.  To date, these compounds have



     not been detected in the aggregate.







     Tables  1-3 show the  results  of  environmental  testing



performed  by   National   Analytical  Laboratories  of   Tulsa,



Oklahoma, on samples submitted by MSC.







     Table  1 consists  of  a  compilation  of results  of TCLP



analyses of  nine samples of  raw  combined MSW incinerator  ash



that  MSC  is  presently  working  with  in  its   Research   and



Development  Facility  near Atlanta,  Georgia.   As  expected,  the
                                                      — •


variability  of the ash is quite high.







     Table  2 depicts  the results  of  TCLP analyses on  samples



of  synthetic aggregate obtained  from six consecutive  batches



made at  the MSC R&D  Facility.   Each batch varies slightly in



terms  of mix design  or  treatment.   Results were consistently



in  the range of  federal drinking water standards.







     Also  tested for  leachability of heavy  metals  using  the



TCLP  were  fines  that passed  through  a No.  100  mesh when



samples  of aggregate were  screened.   These results  are shown
                             Page  6

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in Table 3.  As  was  the case with the aggregate,  results  were



consistently in the range of federal drinking water standards.







Physical Testing of MSC Synthetic Aggregate







     In  addition to  meeting strict  environmental  standards,



the  MSC  synthetic  aggregate  has  been  developed  with   the



objective  of  meeting  the  physical  standards  necessary  to



withstand  heavy  traffic and  harsh climatological  conditions.



As MSC has been  working towards the use of its aggregate  in  a



demonstration    project   in   the    State   of    Minnesota,



specifications   in  use   by  the   Minnesota  Department   of



Transportation  (MnDOT)   have  been  used  as the  standard  for



physical performance of the material.







     The MnDOT battery of tests consists of the following:







*    Los Angeles Abrasion Test  fAASHTO T96) -  a measure  of the



     aggregate's  hardness  and  durability  in  relation to  its



     resistance  to abrasion.







*    Soundness by  Use of Magnesium  Sulfate (AASHTO T104)   -  a



     determinant of  the  aggregate's  resistance  to  chemical



     attack, primarily  road  salt.   To a certain  extent, it is



     also  a measure  of  resistance to freezing  and thawing.









                             Page 7

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*    Freeze-Thaw  fMnDOT  procedure)   -  an   indicator of  the



     aggregate's durability when exposed to a series of rapid



     freezing  and  thawing  cycles.     The  MnDOT   procedure



     consists of  16 rapid cycles  of  freezing  and thawing of



     the  aggregate  in  a  0.5%  solution  of  methyl alcohol in



     water.







*    Absorptivity   -   another   indicator   of   freeze-thaw



     durability,  it is necessary  in  order to  determine the



     amount of  excess  asphalt  required in a bituminous paving



     mix   to   compensate   for  quantities   absorbed  by  the



     aggregate.







*    Specific Gravity  - A measure of  particle  density,  it is



     used  for calculating bituminous paving mix proportions.







*    Sieve Analysis  (AASHTO  T27)  -  different  paving  mixes



     require  varying  particle  size  distributions.    The MSC



     synthetic  aggregate  is deficient  in  fine material  (the



     MnDOT BA-1 bituminous aggregate  specification requires 2-



     8%  minus  No.  200  mesh  fines) ,   but this  is  easily



     compensated  for  at  the  asphalt  batch plant using  fine



     material from  other sources, if needed.
                            Page 8

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     Typical  results  showing ranges  of values obtained  using



the above test procedures are depicted  in Table 4.







Minnesota Demonstration Project







     The Minnesota Pollution Control  Agency  (MPCA)  has  drafted



a  permit  to authorize  MSC  and Hennepin  County  to  jointly



conduct  an  MSW  ash utilization  demonstration project.    The



permit  is   currently  on  30-day  public  notice   and  it   is



anticipated  that it will be issued in July of this year.







     The  demonstration project  will  consist of  the  use  of



approximately 80  to 100 tons of MSC  synthetic aggregate as  a



partial  replacement  for  natural  aggregate  in   a  2"  thick



overlay  of bituminous  pavement.   The synthetic aggregate will



be  incorporated  into the asphalt at  a fixed rate, which will



be  determined based on physical  and environmental  laboratory



testing.







     The test strip will  consist of  paving  approximately  1000



feet  of   roadway  containing  the   synthetic  aggregate   and



approximately 1000  feet of standard roadway  using  only  natural



aggregate.   The natural  aggregate  roadway will be used as  a



control  for comparing  data  obtained  from  the  physical,
                             Page  9

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chemical  and  environmental  testing  program  that  has  been



developed in conjunction with the demonstration.







     The synthetic aggregate  was  produced at the MSC Research



and Development Facility located near Atlanta, Georgia.   It  is



presently in  the  curing period before  samples are shipped  to



Minneapolis  for testing  by  Braun  Environmental  Laboratories



and  Braun  Engineering  Testing,   subsidiaries  of The  Braun



Companies.   Braun is  an independent testing  agency  that has



been certified by the State of Minnesota.







     The  synthetic aggregate  was produced  from combined MSW



ash from the  Hennepin  Energy  Resources  Company facility (HERC)



in Minneapolis.   Prior to  transporting the ash to Georgia  in



trucks, representative samples of the  ash  in each truck were



obtained  for  testing purposes.   Four  samples of the  ash will



be analyzed using  the  TCLP  for an extensive list of parameters



contained in  Table 5.







     In addition to TCLP  analysis of the raw combined ash, the



TCLP  will  be  performed on  four   samples  of  the  synthetic



aggregate,  the  asphalt  cement,  the  natural  aggregate, and



samples of the  synthetic  aggregate that have been crushed into



powder.
                            Page 10

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     The ash  will also be  subjected to  analyses for  dioxins



and furans using  EPA Method 8290.   This  list of compounds  is



contained in Tables 7 and 8.







     Prior to construction  of  the roadway,  a  mineralogical



evaluation  of the  synthetic  aggregate  and  of  the  crushed



synthetic aggregate will be performed.







     Physical testing  of  the synthetic and natural  aggregates



will   be   performed  using  the   list   of  MnDOT   procedures



previously discussed in  this  paper, in  addition to physical



testing  of the  asphalt  cement  and the  bituminous pavement



mixtures.







     Braun  will   conduct  trial  mix  design  testing  using



different  proportions  of synthetic  and  natural aggregates  to



determine an  optimum mix  design.   The optimum mix design will



then be subjected to  a series of  physical bituminous tests,



the  most  important  of  which will be the Cold Water Abrasion



Test.







     The  Cold Water Abrasion Test  is  used  to determine the



durability of compacted bituminous  mixtures  and  as  an aid  in



identifying  mixtures  that  may  have a  tendency to strip  or



unravel.   The test  consists of  subjecting 6 cylinders of the









                            Page 11

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mixture to 1000 revolutions in the Deval Testing Machine using



cold water  as a liquid medium.   The amount of material  lost



from the  cylinders  through abrasion  is then  calculated  and



reported as abrasion loss percentage.






     For purposes of this demonstration, acidic water  (pH <5),



alkaline water (pH  >9),  and brine  solution will  be  used  as



media in addition  to conventional tap  water.   The liquid  and



particulates  obtained  from  this series  of  tests will then  be



analyzed for  the short list of the eight RCRA heavy metals  as



shown in Table 6.






     Additionally,  the following  tests will  be  run  on  four



samples  of  the   bituminous  mix  containing  the  synthetic



aggregate  and four  samples of the  bituminous  mix  containing



the natural aggregate.  These include:






*    TCLP for the parameters listed in Table 5.






*    Multiple Extraction  Procedure  using   the  TCLP  for  the



     parameters listed in Table 5.
   -/





*    ASTM  Water Leach Test  (ASTM  1312)   for  the  parameters



     listed in Table 5.
                            Page 12

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     All  laboratory  tests will  be performed  and the  results


will be submitted to the MPCA for  review  and approval  prior to



proceeding with construction in late August, 1990.






     During  construction,  samples  of the  asphalt cement  and


the  bituminous mixture will  be obtained  from the  bituminous


plant and tested.   Results will be compared to those  obtained


previously in the laboratory for verification.






     Within  30  days  of  placement,  core  samples   will   be


obtained  from both  the synthetic aggregate  roadway  and  the


control   strip  and  tested for  mineralogical   composition   as


previously described.   ASTM Water Leach and TCLP  testing will
                                                        •

be performed on the cores  for the parameters in Table 5.






     The  test strip  will  be monitored  for a  period  of five


years after  construction.  Each year,  four  core samples of  the


test strip  and the control will  be obtained and  subjected  to


the  TCLP  and ASTM Water Leach  Tests.   In addition, an annual


analysis  of  the mineralogical composition will be  performed to


detect  any  changes  in  the  aggregate  or  in  the  pavement


structure due  to changes in the aggregate.






     Two  high volume air  samplers will  be  placed  near  the


roadway to detect  if  any of  the materials contained in the  ash
                            Page 13

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become airborne due  to  roadway wear.   Soil samples will  also



be obtained annually.   Air and soil  samples will be  analyzed



for the list of parameters  in Table 5.   Background samples  of



both air and soil will be obtained prior to construction.







     A  plan is  presently  being  developed  to  evaluate the



quality  of  run-off and   airborne  emissions  entering  the



environment  from  normal  wear  and  tear   on  the  synthetic



aggregate roadway.  The evaluation will use  the data collected



from the physical  and environmental testing conducted in  this



project  in  a  program of  mathematical  analyses  and  computer



modeling.







     An  additional 15 to  20  tons of the  synthetic aggregate



will be trucked to  Minneapolis  and stockpiled  outdoors on  a



lined  area.   Samples of  any  air emissions  and surface  water



runoff  from the  stockpile will be  collected and analyzed for



the list of parameters in Table 5.







     After the  synthetic aggregate roadway  has  been  in  place



for  two years,  results of testing will  be reviewed by the



MPCA.   The MPCA  will then make  the determination  as to the



feasibility of proceeding  with  a  full-scale  ash processing



plant  that will  have  the  capability  of  processing  up  to



150,000 tons of MSW  ash per year.









                            Page 14

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     A  permit application  for construction  and operation  of
the  ash processing  plant,  to be  known as  the Metropolitan
Resource Utilization  Center (MRUC),  has been submitted to  the
MPCA.


     Based on information  and  data generated  during  the course
of  this  project,  a  report  will  be  prepared  that can   be
utilized  in  the  preparation  of a Health  Risk Assessment  for
the  general  use of the MSC  synthetic  aggregate in the   state
of Minnesota.  This  report will be used during  the preparation
of an Environmental  Impact Statement (EIS) for  the purposes  of
evaluating   any   potential   fugitive    dust   emissions  from
                                                        •
synthetic aggregate  roadways and  the effects of  any emissions
on the  environment and human health.


     MSC  has volunteered to prepare the EIS  on the  full-scale
synthetic aggregate  production plant that has been proposed  as
well  as potential utilization applications  of the  synthetic
aggregate  product,   in  order  to  confirm  the  environmental
safety  of the process.   The Minnesota  Pollution Control Agency
is the  responsible governmental unit for scoping and managing
the  EIS.
                            Page 15

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     Results  obtained  during  the   course  of  this  year's



demonstration project will be used not only in the preparation



of  the  EIS,   but  in  the  development   of  standards   and



regulations for the  use  of MSW ash in  the state of Minnesota



as well.







     It is  expected  that the Minnesota demonstration  project



and  the   EIS  will  result  in   what  could   be  the  most



comprehensive evaluation of MSW ash utilization to this date.



It  is  through  this  plan that Municipal  Services Corporation



intends to  lead the  way  in safely recycling the residues from



the combustion  of municipal solid waste.  This will extend  the



lifetimes  of  landfill disposal sites by  many  years,   thereby



helping to  solve  a pressing problem for incinerator operators



and  municipal  governments  throughout  the United  States,  as



well  as  safely  returning  a valuable natural   resource  to



commerce and industry.
                            Page 16

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                              Table 1
           Results Of Toxicity Characteristic Leaching
               Procedure (TCLP) Performed On Nine
             Samples Of Combined MSW Incinerator Ash
                National Analytical Laboratories
                      (All Units In mg/1)
Parameter
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
Low
Value
<0.1
<0.01
<0. 01
<0.01
<0.1
<0. 0005
<0.1
<0.01
High
Value
<0.1
0.52
1.24
0. 36
19.1
0.0028
<0.1
0.02
Average
Value
<0. 1
0.31
0.60
0.09
5. 12
0. 0006
<0. 1
<0.1
Det.
Limit
0. 1
0.01
0.01
0. 01
0. 1
0.0005
"0.1
0.01
Note:
When results indicated parameter levels
below detection limits, one-half of the
detection limit was used for calculation
of the Average Value.
                         Page 17

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            Table 2

       Results of TCLP Analyses
 Performed on MSC Synthetic Aggregate

   National Analytical Laboratories
        (All Units in mg/1)
         Batch Number

Parameter
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver


Parameter
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
P-66

__
1. 28
—
—
0.004
--
—
— —

P-69

0.006
0.68
—
__
0.007
--
— —
— —
P-67

0.004
0.92
—
—
0.007
--
--
— —
Batch Number
P-70

0.005
0.57
—
0.01
0.007
--
—
— —
P-68

0. 003
0.78
--
—
0.004
--
--
— —

P-71

0.005
0.79
—
0.01
0.005
--
—
~ ~
Det.
Limit
0.002
0.01
0.01
0.01
0.002
0.0005
0.005
0.01

Det.
Limit
0.002
0. 01
0.01
0.01
0.002
0.0005
0.005
0.01

DWS
0.05
1. 00
0.01
0.05
0.05
0.002
0.01
0.05
•

DWS
0. 05
1.00
0.01
0. 05
0.05
0. 002
0. 01
0.05
Note:  -- = Below Detection Limit
                  Page  18

-------
               Table 3

Results of TCLP Analyses Performed On
    Minus No.  100 Sieve Dust From
       MSC Synthetic Aggregate

  National Analytical Laboratories
         (All Units in mg/1)
         Batch Number
Parameter
Arsenic
Barium
Cadmium
Chromium
Lead
Mercury
Selenium
Silver
P-53A
DUST
0.008
0.65
—
0.06
0.008
— —
— —
P-54B
DUST

0.70
—
0. 06
0. 01
Mi W
— —
P-58A
DUST
0.003
0.64
—
0.02
0.021
«. ..
•"• —
P-58B
DUST
..
0. 41
--
0.06
0.007
— —
. ...
Det.
Limit
0.002
0.01
0.01
0.01
0.002
0. 0005
0.005
0. 01
DWS
0. 05
1.00
0. 01
0. 05
0. 05
0. 002
0.01
0. 05
Note:  — = Below Detection Limit
                  Page 19

-------
                            Table 4

               Typical Results Of Physical Testing
                   Of MSC Synthetic Aggregate
                       Range Of Values        MnDOT     ,
Test                   For MSC Aggregate      Requirement

L.A. Abrasion          25-35% Loss            <40% Loss at
                                              500 Revolutions
Soundness By MgSO4      5-10% Loss            <15% Loss at
                                              5 Cycles
Freeze-Thaw             3-18% Loss            <12% Loss at
                                              16 Cycles
Absorptivity            12-16%                Not Specified

Bulk Specific Gravity   1.8-1.9               Not Specified

Sieve Analysis         May be varied through  Varies by
                       production techniques  Application
Note:  Physical testing performed at Law Engineering, Atlanta,
       GA, and the MSC Research and Development Facility.
                           Page 20

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                     Table 5
         List Of Parameters For Analysis
         Minnesota Demonstration Project
Aluminum
Antimony
Arsenic
Barium
Beryllium
Boron
Cadmium
Calcium
Chloride
Cobalt
Copper
Chromium
Iron
Lead
Lithium
Magnesium
Manganese
Mercury
Molybdenum
Nickel
Nitrate + Nitrite
Phosphorous
Potassium
Selenium
Silicon
Silver
Sodium
Strontium
Sulfur (Sulfate-S)
Thallium
Tin
Titanium
Zinc
                     Table 6
         Short List Of Parameters For Analysis
            Minnesota Demonstration Project
                     Arsenic
                     Barium
                     Cadmium
                     Chromium
                     Lead
                     Mercury
                     Selenium
                     Silver
                           Page 21

-------
                          Table 7
           List Of Dioxin Compounds For Analysis
              Minnesota Demonstration Project
Polychlorinated Dibenzodioxins

Total Monochlorodibenzodioxin
Total Dichlorodibenzodioxin
Total Trichlorodibenzodioxin
2,3.7,8-Tetrachlorodibenzodioxin
Total Tetrachlorodibenzodioxin
1,2,3,7,8-Pentachlorodibenzodioxin
Total Pentachlorodibenzodioxin
1,2,3,4,7,8-Hexachlorodibenzodioxin
1,2,3,6,7,8-Hexachlorodibenzodioxin
1.2,3,7,8,9-Hexachlorodibenzodioxin
Total Hexachlorodibenzodioxin
1,2,3.4,6,7,8-Heptachlorodibenzodioxin
Total Heptachlorodibenzodioxin
Octachlorodibenzodioxin
                           Page 22

-------
                         Table 8
           List Of Furan Compounds  For  Analysis
             Minnesota Demonstration  Project
Polychlorinated Dibenzofurans

Total Monochlorodibenzofuran
Total Dichlorodibenzofuran
Total Trichlorodibenzofuran
2,3,7,8-Tetrachlorodibenzofuran
Total Tetrachlorodibenzofuran
1.2,3,7,8-Pentachlorodibenzofuran
2,3,4.7,8-Pentachlorodibenzofuran
Total Pentachlorodibenzofuran
1, 2. 3, 4. 7, 8-Hexachlorodibenzofuran
1,2,3,6,7.8-Hexachlorodibenzofuran
2,3.4,6,7,8-Hexachlorodibenzofuran
1,2,3,7,8,9-Hexachlorodibenzofuran
Total Hexachlorodibenzofuran
1, 2, 3, 4, 6, 7, 8-Heptachlorodibenzofuran
1, 2, 3, 4, 7, 8. 9-Heptachlorodibenzofuran
Total Heptachlorodibenzofuran
Octachlorodibenzofuran
Total Mono-Octachlorodibenzofuran
                            Page 23

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LAND DISPOSAL

-------
COMMUNICATION, COMMUNITY PARTICIPATION AND WASTE MANAGEMENT
 An  Examination of Public  Opinion,  Citizen Participation,
 Education  and Communication  Strategy  in  the Siting  Process
        Cynthia-Lou Coleman and  Clifford W.  Scherer
                Department of Communication
                     Cornell University
                     Presented at the

 First U.S. Conference on Municipal Solid Waste Management

                     June 13-16, 1990
                           931

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Communication, Community Participation and Waste .Management*
     It just isn't enough for managers in the field of waste
siting  to  be  good  scientists,  engineers  or  technicians.
Today's administrators better know how to effectively manage
staff, practice community relations, interpret public opinion,
arbitrate  disputes,  converse with news  reporters,  and plan
effective  communication strategies.
     The classic model of siting communication,  top-down and
one-way, is outmoded.  Yet  some  agencies  continue to promote
such  dated strategies only  to find  costly delays  or even
abandonment of the project. Why  do such methods  no longer
work?
     A  review  of waste  siting  case studies  and  journal
articles reveals  that  unsuccessful  siting campaigns have in
common several, important factors — factors which are
*(Development of  this paper was made possible  by a special
grant from the Cornell University College of Agriculture and
Life Sciences.)
                            932

-------
critical  to the success  or failure  of a  siting strategy:



public opinion, citizen participation, continuing education,



and communication strategy. And while no one can guarantee a



successful  outcome, those  who  have written about successful



outcomes agree that when these four factors are fused into a



workable  plan,  citizens  are more willing  to  discuss siting



options.



     This paper examines the literature and case studies on



siting of solid waste, hazardous  and low-level radioactive



waste facilities.  While we  recognize that each type of siting



has its own unique problems in  terms of public perception and



operation  management,  the  issues  of participation,  public



opinion, education and strategies provide a common foundation



to all of the situations we have studied.







Public Opinion and the Perception of Risk



     The attitudes which  Americans  have  about the environment



serves as the backdrop to our examination of public opinion.



That Americans  care deeply about  the  environment  is well-
                             933

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documented in opinion polls. Cambridge Reports, for example,



notes  that pro-environmental  sentiment is  pervasive among



American people, who were  "somewhat abstract and aesthetic"



in their concerns about  the environment 15 to 20 years ago.



Today,  however,  attitudes  "grow  out  of  deeply felt  and



personal worries about human health and safety." Furthermore,



environmental  threats are highly  correlated with  whether



people see problems as a  threat to  personal health and safety



 (Cambridge Reports, 1988).



     Not only  have  environmental concerns  taken a prominent



position on the public agenda  — the power to influence and



shape   opinion  in  the  environmental  arena   has   grown



concurrently. The nuclear power industry is one example cited



frequently in the literature. American perceptions concerning



the health and safety  surrounding  nuclear  power have become



increasingly  salient, particularly after  such  newsmaking



events as Three Mile Island and Chernobyl.  Californians, for



example, have rallied effectively in halting the reopening of



nuclear power facilities (Sussman,  1988).



     Such attitudes extend  beyond the realm of nuclear energy:



planners of  radioactive, hazardous, toxic, and  solid waste
                             934

-------
facilities also  report considerable opposition  to land use
siting.
     The general public feeling of environmentalism, coupled
with  self-interest,  are important  variables in  the public
opinion-land  use  siting  equation.  When  self-interest  is
present, wrote Hadley Cantril in 1944, opinion is not easily
changed. And it is this self-interest which  has a demonstrable
effect on attitudes (Newsom and Scott, 1985).
     The  issue of self-interest  becomes  critical  when the
benefits of  locating  a waste  repository are weighed against
the costs.  Payne and Williams  (1985)  report  that "Citizens
feel  they are paying high costs  (in perceived  risks)  for
benefits  they do not receive  in  the same  proportion."  In
discussing benefit versus  cost  to the community, case study
writers agree that host communities bear a greater burden of
cost than accrued benefits. Moreover, host communities and lay
publics perceive "costs" as including unacceptable health and
safety risks.
                             935

-------
Risk Perception



     Studies  of  risk  perception by  Slovic, Fischhoff  and



Lichtenstein illustrate that the public's perception of risk



differs from scientific,  quantifiable  risks.  For example, the



lay public overestimates  exotic or catastrophic risks (deaths



due to  nuclear power)  while underestimating everyday  risks



(deaths  due to  automobile accidents.)  The  issue  of  self-



interest  also  affects  perception of  risks... some  types of



risks  associated with greater  reward or benefits  are more



readily acceptable to publics.



     Scientists and experts have difficulty dealing with what



they consider the lay public's  inaccurate assessment of risk,



which is reflected in the case studies  of siting failures. For



example,  members of the New York siting commission,  after



meeting with area residents over a low-level radioactive waste



site,  were troubled by  the vehement public response.  One



commissioner called  the  reaction "hysterical" while another



said opposition would diminish "once people hear the message



that there's no hazard to the environment." Opposition did not



diminish, and  local  citizens to date  have been  effective in
                             936

-------
stymieing the siting process (Coleman, 1989).
     Experts, like the New York commissioners, relied on the
traditional  model  of scientific persuasion,  which involves
trying to convince  publics that their attitudes about risk are
unfounded. Communication and risk  scholars generally concur
that  this technique doesn't  work.  Instead  of  persuading
publics  of  the low  (actual) health risks  of sitings,  some
pragmatists  have recommended offering compensation packages
to host  communities. Zeiss, who studied  21 facility siting
attempts, reports  that,  due to  the imbalance of  cost over
benefit,  compensation alone is not enough to cinch a siting
agreement.   Zeiss   proposes   a   package  which   includes
compensation and reduction of perceived community "costs" or
losses.
     Another central aspect of risk perception is the issue
of voluntary and  involuntary control.  Slovic, Fischhoff and
Lichtenstein,  1987,  note that  acceptability of risk depends
on  such  factors  as catastrophic potential,  uncertainty,
familiarity  and voluntariness.  The  literature supports the
notion that, when  communities believe they have no voice in
the siting process,  projects are doomed to fail. "Community
                              937

-------
control," write Matheny and Williams (1985),  is a key element
in achieving acceptance.
     The issue of community control  is more than attitudinal,
however. According  to  researchers,  community participation,
which leads to the perception of control, serves as a linchpin
in the siting process.

Citizen Participation
     Common  to much of the siting  literature  is  the notion
that community publics play a vital role in land use siting.
But, judging from case studies, public input is either ignored
or  invited too late in the siting process.
     Planners need to examine siting "in a radically new way,"
suggests  Edeburn,  1988.  She calls on government agencies to
redirect  their communication focus away from ratification to
input.   "The  public's   role   should  be  defined  clearly,
preferably by citizens  and officials together." Involvement
in  the planning  process,  Edeburn  adds,  "leads  to  greater
understanding of, and appropriate reactions to, environmental,
health  and  economic risks." other experts agree.  In writing
about knowledge versus NIMBY (Not in My Backyard) , Matheny and
                             938

-------
Williams make a strong case for involving the Florida public
at the  decision-making level,  noting that  "it's  largely a
matter  of community participation  in management"  and that
residents  and  facility  operators   need to share  in  the
decisions about the disposal of wastes. Involving the public
at this level,  the authors note, may  not  reduce risks, but
will shift the  perception of  risk "from an involuntary to a
voluntary consciousness."
     Blackburn  and Reed,  1985,  take  the  example  one step
further, suggesting that increased involvement by citizens in
the  siting  process leads  to  acceptance of  the  project.  In
their study of a low-level radioactive waste facility siting
in Texas, the authors report that planners established avenues
for community comment early in the siting process. The purpose
of these  meetings  was  not to  reach  consensus but to promote
11 free-flowing question and answer sessions," allowing planners
to hear concerns first-hand. Formation of citizen committees,
funding of  surveys, and  sponsorship of visits  to disposal
sites paved the way for community involvement.
     Abrams  and   Primack,  1980,  suggest  that  timing  is
important in citizen  input.  When comments  are  invited too
                             939

-------
early, "plans are vague,"  and if participation is requested



too late, the public perceives the project as a fait accompli.



Moreover, agencies are unfamiliar with how to involve citizens



throughout  the  process. "Often  agencies don't know  how to



maintain citizen input."



     One solution borrowed from marketers,  is segmentation of



publics.  Abrams and  Primack offer  a  blueprint  of  typical



publics, including local elected officials, business owners,



opinion leaders, scientists, special interest groups, etc. By



segmenting  publics  into  special  groups,   planners  greatly



increase  their  ability to  understand audience needs  while



identifying specific channels to each special publics.



     Albrecht and Thompson, 1988, have examined the issue of



special publics more closely. In their paper on attitudes in



repository  sitings, they note  that citizens find  meaning in



a community frame of reference. If researchers develop methods



to  examine  deep social  values which people attach  to their



communities, planners can build a more complete composite of



community concerns.  It's not enough to interpret attitudes and



public  opinion; planners   need  to  understand against  the



community influences  and  norms which  influence beliefs and
                             940

-------
behaviors.
     Three central themes appear in the literature concerning
involvement  of  publics  in  the  siting  process:  reaching
consensus,  willingness  to  negotiate,  and  segmentation of
publics.
     Planners  should resist  trying to  reach  consensus on
issues, according to Payne and Williams. In their article on
conflict and public communication,  the authors make a case for
incorporating  citizen  input  to  reduce long-term strife. And
while it may seem antithetical to waste managers, conflict has
a positive consequence, the authors report. "Managers should
not become discouraged... conflict is normal."
     Another benefit to opening  dialogue between planners and
citizens,  according to Vincenti  (1985),  is  that planners
thereby send signals to the public that they value  the  input -
-  assuming   planners   take  comments  to  heart.  "Citizen
involvement must be more than just names on a register" and
public groups must be willing to spend time examining issues,
not just time  sounding  off, warns  Vincenti.
     One  way  to   gain the  most from  citizen   input is
segmentation  of  publics.  Although this  is best accomplished
                             941

-------
on a case-by-case basis,  publics are typically divided into



these  types  of groups:  concerned local  citizens;  involved



citizens  (teachers,  business owners,  other professionals);



environmentalist  groups;   opinion   leaders  (official  and



unofficial);    news    media;     elected    officials    and



representatives;  appointed  officials;   city,   county  and



regional planners; myriad government  agencies involved in the



planning  process;  scientists,  university  professors  and



experts; etc.



     A critical public  is  the  group  of  local  officials,



whether appointed  or elected.  Blackburn and Reed  note that



involvement of these key people in projects can greatly help



the siting process.  New York planners bore the wrath of local



officials when  the  news media learned  about  low-level site



selection prior to local citizens and  local officials. Because



they were snubbed  in the siting process, local decision-makers



vowed  to fight the state agencies.



     Payne, 1984,  notes that involvement of community groups



is  more  manageable   than   hammering   out  solutions  with



individuals. Groups  can bring concerns and priorities into



focus  better  than   individuals.  By   segmenting   publics,
                             942

-------
discovering their  concerns and  suggestions,  and  getting a
range of opinions, planners can get a better handle on salient
issues.
     Involving the  public,  however, does  not  guarantee the
success of an unwanted landfill siting facility. Jubak, 1982,
points out that  "Public  participation  can make a difference
in people's  attitudes. It can raise the level of  trust by
providing good  information and  a  chance to get answers to
genuine  worries. Trust  is  absolutely  vital   to  siting  a
facility." Yet, having an informed public does not necessarily
translate to successful siting. Matheny and Williams caution
that raising awareness may also "encourage the NIMBY syndrome"
and that  "too much  public  involvement  leads  to rejection of
proposed  sites." The  authors  suggest  complementing  public
involvement with a  public  education program  in an  effort to
gain acceptance  of community sitings. We believe that public
education must happen prior to any specific siting activity.

Public Education
     Matheny  and Williams propose  that the combination of
citizen involvement and education "is necessary  for legitimate
                             943

-------
decision-making."   Participation   isn't   enough   without



enlightened decisions, they add. In California, for example,



a grassroots educational campaign paved the way toward public



acceptance  of  a low-level radioactive facility.  Pasternak,



1985,  notes that the state's well-planned  campaign,  which



focused heavily on targeted groups,  "had a positive impact on



local government officials, leaders of the business community,



journalists,  and  other  citizens  in  potentially  affected



regions of the  state." Public and private organizations joined



together to establish specific,  concrete objectives in siting



a  facility and educating California  publics  on radioactive



uses and disposal. The organization  hosted a speakers bureau,



conferences  and field inspection trips to  acguaint publics



with  disposal  information.  The  League of Women  Voters and



other groups sponsored public forums in several locations, and



lobby



     In  other  education  programs,  Texas officials  changed



their opinions following site visits to waste facilities; in



Pennsylvania, strategists worked directly with the news media



in developing a series of news programs on radioactive waste,



while communicating with concerned individuals via direct mail
                              944

-------
and by sponsoring programs for officials and leaders in 42 of



the state's 67  counties;  and a state-wide education program



in Florida  included promotion  of  "Amnesty Days,"  an event



which allowed citizens, small businesses,  schools and local



governments to  have  small  quantities  of hazardous  wastes



collected free of charge, bringing the siting issue into focus



for targeted publics and the news media.



     Waste  siting  authors   concur   that  special  events,



educational programs,  and  targeted news  stories must directly



tie in  with forums which allow for  public discussions.  And



researchers also agree that communication must be truly two-



way and symmetric,  to  allow  for give-and-take on both sides



of the waste siting issue. If these  essential components —



public education, citizen  participation,  and an understanding



of public opinion and risk — are not  well-grounded  in the



siting management,  communication strategies will fall short



of meeting the requisite goals.
                             945

-------
Communication Strategy



     As we suggested earlier, planners who report successful



sitings  borrow  from  the  marketing,  public relations  and



strategy   areas   in   designing   effective   communication



strategies.



     Unfortunately,  and  too   often,   strategies  rely  on



techniques, rather than broad-based research and public input,



in developing effective strategies.



     Working with news media, for example, is problematic for



many managers and planners. While the news media may provide



an effective  and powerful source of  informing  publics,  the



public  media  cannot  be  controlled  by waste planners.  The



controversial  nature of  siting  does,  however,  guarantee



placement of such  issues  on  the news media  agenda,  and it's



likely that the siting opposition will  be adroit at obtaining



media coverage. Unfortunately,  planners often lack the skills



to carry their messages  to  the news  media,  and resist  or



refuse opportunities to present their  case  to reporters.  In



the example of  New York's Cortland County,  siting opponents



effectively set  the media agenda  through a  series  of well-
                             946

-------
timed  and  targeted protests  and  recurring demonstrations.



Siting  officials  were  less  available  and less willing to



discuss issues publicly with members of the press.  Officials



were on the defensive, and their public posture in the press



reinforced this.



     Waste facility managers can be  more effective in their



relations with  the news media, but  are reminded  that good



press  relations are no  substitute  for dealing with targeted



publics  face-to-face.   In  an  article  about   the  "new



environmental ism," Lukaszewski, 1989, points out that "Success



means  keeping your own interests on  the agenda."  Reporters



generally want to explain both sides of controversy to their



audiences,  but managers must take the  initiative in addressing



concerns via the public press. "Start  early, speak often, and



don't  let*the other side get away with framing the issue for



the  media,"  Lukaszewski  counsels.   Vincenti  notes  that



"Government cannot rely on news media to educate the plblic



on issues that may be controversial."



     The issue,  therefore, becomes one of information versus



education.  While the news media may inform publics concerning



events, waste managers need to take over the reins for public
                             947

-------
education  —  and  •this is  best done  prior  to controversy



erupting on television or in the newspaper.



     Communication   strategists    and   public   relations



practitioners can  provide  numerous,  proven  techniques for



channeling messages  and information to  audiences...  public



service announcements,  feature articles, special newsletters,



brochures, television talk shows, slide presentations — but



the   literature  supports   the  view  that   interpersonal



communication — face-to-face interaction with host community



publics — is the sine qua non of successful siting.







Recommendations



     Local government officials are faced with  a difficult and



unique situation. On one side is the  need to  make efficient



decisions in the best long-term interest of the community. In



the  past  that  meant making  the site selection, holding  a



public hearing  to discuss the decision with a few concerned



members  of the community,   and then  proceeding with  site



development. Today, however,  the public  is  less trustful of



government  and   science  and  technology.  Today the  public



questions  decisions more,  and  demands  to  be involve  in
                             948

-------
decision-making. And  while a full discussion  of the issues



with members of the public and  involvement of the public in



decision-making may appear to be inefficient, it  is often not



only the best,  but the only way communities can make effective



decisions on some issues.



     Three recommendation emerge from this study.



     1. Utilize community  expertise.  Treat the public as an



equal  partner  in decision-making. Encouraging  and actively



using citizens advisory and study groups bring the public into



the decision-making process. It  also helps focus attention on



the real issues and real risks involved in the siting of waste



management facilities.  Focus  should be  on citizens who have



special expertise: the  local  cooperative extension agent or



educator  may  help  develop  an  educational  plan  for  the



community; a communication specialist  at the local college or



university may help design an  overall communication strategy;



local  business owners may  help  develop  a speakers bureau of



volunteers to  talk with organizations about various aspects



of the program, etc.



     2. Develop a team  oriented approach. No one individual



or  group can  manage  all  the aspects  of a community  risk
                             949

-------
situation. Recognize and  believe  that others can contribute



valuable ideas to the discussion.



     3. Keep the process open to the public.  Even the hint of



secret  decisions  can  destroy credibility  and  create  an



adversarial feeling  in the community. Every effort must be



made to make members of the community feel that "this is our



problem, we must make the decision."



     4. Be proactive in your communication efforts. Take your



concerns to the public as soon as  you can. Don't wait for the



final  study or more information.  Be honest  —  if  you don't



know,  say so and explain why.
                             950

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                          Bibliography
Abrams, N. E. and J. R. Primack. "Helping the Public Decide: The
    Case of Radioactive Waste Management." Environment; April
    1980.
Albrecht, S. L. and J. G. Thompson. "The Place of Attitudes and
    Perceptions in Social Impact Assessment." Society and Natural
    Resources; 1988.


Blackburn, T. W. and J. B. Reed. "Local Government Participation
    in the Siting of a Low-Level Radioative Waste Disposal
    Facility: The Texas  Experience."  Roy  G.  Post,  editor. Waste
    Isolation in the  US,  Technical Programs and Public
    Participation. 1985.


Brem, S. and A.L. Rydant. "Not in My Backyard: Siting a Regional
    Solid Waste Landfill." Studies in New England Geography,
    Number 4; October 1988.


Coleman, C-L. "What Policy Makers Can Learn from Public
    Relations Practitioners." Public Relations Quarterly; Winter
    1989-90.


Davis, C. "Perceptions of Hazarous Waste Policy Issues Among
    Public and Private Sector Administrators." Western Political
    Quarterly; 1985.


Edeburn, M. "Getting the Nod for Waste Disposal." American
    City & County; November 1988.


Fitzpatrick, T. B., editor. "How Environmental Concerns Affect
    Consumer Behavior," Canbridge Reports, 1988.


Forester, J. "Mediated Negotiation: Neither Panacea nor Hand
    Maiden"  (A Review of L. Susskind et al., "Resolving
    Environmental Regulatory Disputes"; December 1984.
                               951

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Forester, J. "Planning in the Face of Conflict: Negotiation and
    Mediation Strategies in Local Land Use Regulation." APA
    Journal; Summer 1987.

Furuseth, O. J.; M. S. Johnson. "Neighbourhood Attitudes Towards
    a Sanitary Landfill: a North Carolina Study."
    Applied Geography; 1988.


Heiman, M. K. "Not in Anybody's Backyard: The Grassroots
    Challenge to Hazardous Waste Facility Location." 85th Annual
    Meeting of the Association of American Geographers; 1989.


Jubak, J. "The Struggle Over Siting." Environmental Action;
    February 1982.


Lukaszewski, J. E. "Is Your Company Ready for the New Activism?"
    New Jersey Bell Journal; Winter 1989-90.


Marks, N. S. "Citizen Enforcement of Environmental Laws."
    Environment; June 1987.


Matheny, A. R. and B. A. Williams. "Knowledge vs. NIMBY:
    Assessing Florida's Strategy for Siting Hazardous Waste
    Disposal Facilities." Policy Studies Journal; September 1985.


Newsom,  D.  and A. Scott, "This  is  PR," Wadsworth Publishing
     Company, Belmont, California, third edition, 1985.

Pasternak, A. D. "California's Response to the Low-Level
    Radioactive Waste Policy Act of 1980: Policy and Progress."
    Roy G. Post, editor. Waste Isolation in  the  US,  Technical
    Programs and Public Participation. 1985.


Payne, B.A.  and R.G. Williams. "Conflict, Public Communication, and
    Radioactive Waste Management." Roy  G. Post,  editor.  Waste
    Isolation in the US, Technical Programs  and  Public
    Participation. 1985.


Payne, B. A. "Estimating and Coping with Public Response to
    Radioactive Waste Repository Siting." Waste Management '84;
    1984.
                                 952

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Pojasek, R. B.; M. Lefkoff. "Stepping Beyond Public
    Communications." Roy G. Post, editor. Waste Management 85.


Slovic, P., B. Fischhoff and S. Liechtenstein. "Behavioral Decision
    Theory Perspectives on Protective Behavior." Taking Care:
    Understanding and Encouraging Self-Protective Behavior; 1987.


Sussman, B. "What Americans Really  Think,"  Pantheon Books,  New
    York, 1988.


Vincenti, J. R. "A Perm State Continuing Education Program on
    Low-Level Radioactive Waste Disposal and Management: Lessons
    Learned." Roy G. Post,  editor.  Waste Isolation in the US,
    Technical Programs and Public Participation. 1985.


Willard, D. E. and M. M. Swenson. "Why Not in Your Backyard:
    Scientific Data and Non-rational Decisions About Risk."
    Conference on Hazardous Waste Facility Siting; June 1982.
                                  953

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   "CONSIDERATIONS IN THE DESIGN OF LINERS
    FOR MUNICIPAL SOLID WASTE LANDFILLS"

               Charles D. Miller, P.E.
             Rogers, Golden & Halpern
                  Presented at the

First U.S. Conference on Municipal Solid Waste Management

                  June 14-16, 1990
                             955

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                           INTRODUCTION
    Landfill containment systems consist of liners in combination with a
system for withdrawal and treatment of landfill leachates.  Residues from
the treatment of leachate are returned to the landfill.  In the idealized
landfill, liners are impermeable and treatment of leachate  insures that no
contaminants are  released to the environment. In practice, impermeable
liners do not exist. Consequently, the landfill developer is  faced with a
variety of landfill  design alternatives that offer a trade-off between cost
and containment efficiency.

    Conventional landfill liners consist of layers of clay or  synthetic
membrane intended to impede the release of leachate. Composite liners
include a clay layer overlain by a synthetic membrane (See Figure 1).
Different liner types vary greatly in their capacity to contain leachate and
in their cost of construction.  In choosing a containment system suited to
his specific needs and conditions, the landfill developer should evaluate
the degree of containment required to prevent significant contamination of
soil or groundwater.
                            CONTAINMENT
    Impermeable liners do not exist. Normal migration of leachate through a
liner as anticipated by the designer is termed "permeance" to distinguish it
from "leakage", which is the product of imperfections or damage sustained by
the liner.

    Most conventional liners are designed with leachate collection systems
that will limit the depth of leachate over top of the liner to about one
foot. Under these conditions, a carefully constructed liner consisting of a
two-foot layer of remolded clay with an in-place permeability of
                                       956
    052/040690

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             FIGURE 1
         LINER TYPES
           Single        Single
Clay         Synthetic  f     Composite^
<••••••••**•••••  •**
.••••*»•••••*••  ••*



^//S/f//,
                            RGH
                 957

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1 x 20"^ CM/SEC will sustain a permeance of about 16,000 gallons of
leachate per year per acre (GPY/AC). Flaws in the clay liner resulting from
poor compaction, desiccation or fissuring may result in leakage flow which
is much higher.

    By contrast, a liner consisting of a 40 mil (.0035 foot) layer of
synthetic membrane should permit no more than 100 GPY/AC of permeance when
the maximum depth of leachate on top of the liner is one foot (See Figure
                                                                17
2). This permeance rate is based on a hydraulic permeability of 1 x 10"1Z
CM/SEC for a typical synthetic liner material. Liner permeabilities are
difficult to measure and may be significantly lower in many cases. The
superior containment properties of synthetic membrane liners are partially
offset by the vulnerability of these materials to damage during
construction. For membrane liners constructed over a subbase consisting of
soil with a permeability of 1 x 10"5 CM/SEC, only eight penny-sized holes
per acre are required to reduce the containment efficiency to that of a
two-foot layer of clay (K.W. Brown et al.  Quantification of Leak Rates
through Holes in Landfill Liners. 1987. EPA/600/S2-87/062). Moreover, only
 16 holes the size of a pinhead may be just as damaging.  The task of
constructing synthetic liners to eliminate such tiny imperfections  is
daunting. In practice, some damage to liners during construction must be
anticipated.
                         LEAK MINIMIZATION
    Leakage flow is the result of imperfections in a liner. As previously
discussed, leakage can occur in liners constructed of either clay or
synthetic membrane materials. The rate of leakage flow is directly
proportional to:

    1)   depth of leachate over the liner
    2)   size of the imperfection
    3)   permeability of the underlying subbase (membrane liners only)
                                       958
    052/040690

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               FIGURE 2
     LINER PERMEANCE
                  r
2'
Clay
              41
              Clay
                             40 mil PVC (.0035')
  16.000 GPY
       AC
            8.000 GPY
                AC
100 GPY
   AC
     Note: EPA "De minimus" rate = 300 GPY/AC     RGH
    * Not Leakage
                     959
                                           Rogvn, OoUtenftHalpvrn

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    Of course, the first line of defense against leakage is the careful
construction and inspection of the liner system. Quality assurance programs
for liner construction should be rigorous and well documented. Detailed
construction specifications and extensive testing of in-place liners are
essential to eliminate problems associated with bad materials, poor
workmanship, or accidental damage to liners.

    Effective methods of reducing leakage include reduction in the depth of
the leachate on top of the liner. This can be accomplished by either
utilizing a more permeable drainage medium, or by reducing the spacing of
leachate withdrawal conduits. New products that incorporate geotextiles and
plastic grids offer relatively inexpensive methods of improving the
effectiveness of leachate collection systems.

    An alternative method of reducing leachate leakage is to construct a
double liner. The double liner incorporates two liners of identical design,
with one immediately overlying the other. Double synthetic membrane or
double clay liners are commonly found in current landfill designs. Since
leakage through the upper or primary liner will be a small fraction of total
leachate generated, the depth of leachate over the lower or secondary liner
will always be much less than that over the primary Liner.  The potential of
leakage from the combined system is thus proportionately decreased. The
effectiveness of double liners is further enhanced by the probability that a
flaw in the secondary liner will not directly underlie a flaw producing a
leak in the primary Liner. In practice, a ten-fold improvement in overall
containment efficiency of double Liners compared to single Liners can be
anticipated.

    The influence of puncture diameter in synthetic membrane liners is much
less important than the permeability of the subbase in determining the
importance of leakage flow. Decreasing the diameter of a puncture by an
order of magnitude will only cut leakage flow in half. By comparison, an
order of magnitude reduction in subbase permeability, without any reduction
in puncture size, will reduce leakage flow by an order of magnitude also
(K.W. Brown et al. Quantification of Leak Rates through Holes in Landfill
Liners. 1987. EPA/600/S2-87/062.  This suggests a method of compensating

    052/040690

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for the vulnerability of synthetic membrane liners to leakage related to
small perforations which may escape detection. By utilizing a low
permeability subbase in combination with a synthetic membrane liner, a liner
with containment efficiency and reliability that is superior to both clay or
synthetic liners can be achieved. This is the composite liner.

    Figures 3 and 4 illustrate the effectiveness of different strategies for
the reduction of leachate leakage.  The optimal strategy for a landfill
developer will depend upon the local costs of construction.  However, the
adoption of composite liner designs will in most cases produce the greatest
improvement in containment efficiency per dollar spent.  Composite liners
are most attractive in localities where clay is relatively inexpensive.
                        HYBRID LINER DESIGNS
    Hybrid liners, first cousins of double liners, have gained acceptance in
 various designs. Like double liners, hybrid liners are composed of two
 liners with one system directly overlying the other. However, in hybrid
 designs the two liners are constructed of different materials and have
 inherently different containment efficiencies.

    There are two philosophies of hybrid liner designs. The first approach
 is to place the liner with the greatest containment efficiency on top.
 Examples are synthetic-over-clay liner and composite-over-synthetic liner.
 In these designs, it is typical to describe the upper drainage layer that
 overlies the upper liner as the leachate collection  system, and the lower
- drainage layer that occupies the space between the upper and lower liners as
 the "witness" or "leak detection"  system. The implication is that the
 "witness" layer is intended to verify that the containment system is
 working. Since all liners have a  normal permeance flow, this approach
 introduces the possibility that the detection of normal leachate flow  in the
 "witness" section will be misinterpreted by regulatory or third party
 observers as a liner failure.  Since the lower liner is acknowledged to have
                                          961
    052/040690

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                 FIGURE 3
      EQUIVALENT LEAKAGE
   MINIMIZATION STRATEGIES

   (Reduction of Leakage Flow by 90%)
Synthetic Liner:
                   _ 4 .    4 _ ,
                   Containment Enhancement

Synthetic
              Double          Single *
              Synthetic         Composite
* Sublayer permeability lower than native soil by one order of magnitude
                   962

                                        Bogan, GeJdnt ft HoJp*

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                FIGURE 4
      EQUIVALENT LEAKAGE
   MINIMIZATION STRATEGIES

   (Reduction of Leakage Flow by 90%)
Clay Liner:            Containment Enhancement
              ,10t
                 i  I
                          t
                        Double
                        Clay
* Reduction in leakage flow typically exceeds 90%
Single *
Composite
                   963
                                      Begw*. «old»n It Ho»p«n

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a lower containment efficiency, it also difficult for the landfill operator
to argue that leachate observed in the "witness" system does not constitute
a threat to the environment.

    The alternative approach in hybrid liner design is to place the liner
with the greatest containment efficiency on the bottom. The most common
example of this type is the synthetic-over-composite liner design. In
effect, this a double synthetic liner constructed over a clay subgrade
layer. In this configuration, like the double liner design, it is natural
to regard the lower liner as an integral part of the leachate containment
system. The lower drainage layer, which lies between the upper and lower
liners, is properly described as a "secondary leachate collection" system.
Leachate observed in the "secondary leachate collection" system does not
reflect a failure of the containment system and is anticipated in the
provision of an amplified secondary liner.
                     ELIMINATING WEAK POINTS
    The leachate containment strategy for a landfill extends beyond the
 selection of a liner type. The overall design must be examined to minimize
 weak, failure-prone elements. Among the most important considerations is
 the design of the leachate collection system. Most conventional designs
 require that piping associated with the leachate collections system
 penetrate the liner at three points (See Figure 5). The advantages of these
 designs is that the leachate flows by gravity to the treatment works.
 However, penetrations are difficult to seal reliably and are prone to damage
 associated with settlement of the landfill and its foundation. Potential
 problems associated with penetrations can be minimized by reducing the
 number of penetrations, providing for local monitoring of penetrations,
 adding secondary containment at penetrations, and by making penetrations
 more accessible to repair in the event of a leak. The single penetration
 design,  illustrated in Figure 5, satisfies these requirements.
 Alternatively, all penetrations can be eliminated by the introduction of
 on-liner sump pumps.
    052/040690                              964

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    The vulnerability of synthetic membrane liners to damage during
construction has been well documented.  The most common cause of liner
perforation, other than negligent construction practices by the installer,
is the puncture or abrasion of liners by coarse rock fragments in granular
liner subbase or cover material. Recent research by the EPA (D.L. Lane, et
al. Loading Point Failure Analysis of Geosynthetic Liner Materials. 1988,
CER1-88-20. Proceedings of USEPA 14th Annual Research Symposium,
Cincinnati, Ohio.) has shown that all liner materials are vulnerable to this
sort of damage. However, by providing a geotextile sheathing for the liner,
puncture and abrasion  resistance can be significantly improved.
Furthermore, the use of geotextiles is much  more effective in improving
puncture resistance than is increasing liner thickness. The landfill
developer should consider the potential improvement in containment
efficiency that can be obtained at the cost of incorporating geotextiles in
the liner design.

    Construction-related and post-construction damage to liners can also be
minimized by eliminating hard or brittle materials from the leachate
containment and collection system. Among these are brittle plastic pipes
and steel or concrete manholes and sumps.  The entire containment and
collection system should be engineered to deform without failure due to
yield, puncture, or misalignment. To the extent possible, plastics used in
the construction of the liner  should be compatible so that penetrations,
extensions, and connections can be sealed with confidence.
                          QUALITY CONTROL

    The reliability of any containment system depends upon the quality of
the construction All landfill construction projects should incorporate a
detailed construction specification coupled with rigorous inspection and
documentation.  Synthetic liners are the easiest of the liner types to
inspect, but also the most prone to damage during construction. Landfill
    052/040690

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developers should insist upon the testing of 100 percent of all liner
seams. In addition, destructive testing of randomly selected coupons of the
seams should be conducted.  Where double or hybrid liners are installed and
the base of the landfill is gently sloping, pond testing of the liner prior
to acceptance should also be considered.

    Clay liners are more difficult to inspect, since small inhomogeneities
in a clay layer may escape a gridded sample coring and testing program.
Furthermore, flaws associated with dehydration or variation in moisture
content may be difficult to identify. Consequently, a very rigid
construction specification, including frequent measurement of clay
composition, moisture content, and compacted density is the best protection
against poor liner performance.
                         LANDFILL FAILURES
    The only accepted evidence for liner failure is the measurable release
of contaminants into the environment. This usually is associated with the
detection of degradation of groundwater or surface water resources by a
network of monitoring wells and stream sampling points.  The observation of
leachate in "witness" or "secondary leachate collection" systems does not
indicate a failure of the landfill's containment system. A certain amount
of permeance and leakage flow into these systems should be anticipated as a
normal feature of any liner design.  However, unexpectedly large leachate
leaks in the upper liner should be regarded as indicating potentially
significant flaws or damage to the system as a whole and should be
investigated by expanding and intensifying monitoring functions. It is one
of the responsibilities of the landfill designer to establish realistic
estimates of line permeance and leakage against which containment permeance
can be judged.
                                       966
    052/M0690

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             FIGURE 5
 PENETRATION DESIGNS
No Penetration
Design with Pumping
Three Penetration
Design (gravity)
                        e-
Single Penetration
Design (gravity)
                                 ROH
                  967
                                      Degws. Gold*n * Holpwn

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     CONTROLLED LANDFILLS  - A SYSTEMATIC APPROACH TO
                  SOLID WASTE DISPOSAL
                           by
                  Frederick G. Pohland
             Department of Civil  Engineering
                University of Pittsburgh
                  Pittsburgh, PA 15261


                    Presented at the

First U.S. Conference  on Municipal  Solid Waste Management

                    June  13-16, 1990
                            969

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Introduction
      Landfills  are and  will likely  continue to  be the  most frequently
employed method for disposal of solid wastes.   Unfortunately, landfills have
not been  managed well in the past, and  that lack of good management has
resulted  in   problems   with  leachate  and   gas   migration  and  adverse
environmental impacts.  As a consequence,  the  continued use  of landfills has
become  a major  societal  issue which  has often  stifled  or  delayed the
development of new solid waste disposal systems.   Yet  these same concerns
have led to a variety of  technological developments, ranging from landfills
designed  and  operated  for total containment and  isolation  to controlled
disposal.   Therefore,  the  choice  of  technology  applied  today  is  often
dependent on not only designer preference, but a desire to accommodate public
perception,  economic constraints,  and  regulatory  inertia.   In  the  final
analysis, the  relative priority and effectiveness of integration of each of
these  elements determines which landfill  management option is selected and
successfully implemented.
       This  presentation  provides  a review and summary of the  nature  of
landfills as  potential  generator sources of  leachate and  gas,  and couples
this with a discussion of the  relative merits of  available techniques for
containment, control and treatment.  It begins with a brief perspective of
the nature and characteristics of landfill leachate  and gas, and the factors
affecting their magnitude and intensity.  This  is followed by a discussion of
the principles of  controlled landfill  stabilization as  provided by in situ
leachate  management  with leachate  containment,  collection and  recycle.
Finally, options for ultimate disposal or utilization of leachate and gas are
addressed,  including discharge to municipal  wastewater  treatment systems,
land application,  and energy  recovery.
General Perspective
       The development of rational, economically sound and publicly acceptable
approaches to landfill disposal of solid wastes involves the  recognition that
a given landfill potentially will affect and be affected by prevailing site-
                                     97O

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specific hydrologic and geologic conditions that must be understood in order
to  minimize  human health  and  environmental  risks.    The  environmental
consequences of leachate and gas formation and potential migration, and their
dependence on the availability of moisture from external sources as well as
from  associated   waste  decomposition,  are  of   particular  importance.
Therefore,  leachate and gas  generation  must be  controlled  to  transform
landfill behavior from a realm of uncertainty to one of predictability.
      Such predictability is enhanced by understanding the causes for changes
in the magnitude and intensity of leachate and gas production as the landfill
matures  and progresses  through  a  sequence of microbially-mediated  phases
toward  stabilization.    Operational  control  over  the  release  of  waste
constituents is possible either through the preselection or conditioning of
the source waste,  or by management of the rates of generation and transfer of
waste constituents to the principal  transport  media (leachate and gas).  The
latter approach appears to be  a  more logical choice in  the case of municipal
landfills, whereas the former, perhaps coupled with features of the latter,
would seem more attractive for codisposal  landfills receiving inputs of both
municipal and  industrial wastes or where source separation or recycle are
practiced.
      Based upon an understanding of the processes determining leachate and
gas  characteristics,  management of generation and transfer  rates can  be
implemented by controlling the moisture  regime within the landfill.  Without
moisture, a principal transport medium will not exist and the conversions and
interactions determining leachate and  gas  production and quality, as well as
the overall progress of waste stabilization,  will be suppressed.  Such "dry"
landfills, whether induced by climatic conditions  or impervious containment
systems  (liners  and caps), may reduce  the rate,  amount  and  intensity  of
leachate and  gas  generation,  but may also extend  the  intrinsic reactivity
and, therefore,  the environmental  impact uncertainty  into  perpetuity.   In
contrast, the  availability  of sufficient  moisture, either  accompanying the
waste  or  permitted  to  accumulate  under  controlled  conditions  during
                                     971

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operations, may be used  to  advantage  to:  accelerate the inherent processes
producing and converting leachable constituents; extract waste constituents
and reaction  products from the waste mass;  dilute out  inhibitory and/or
refractory; distribute microbial seed, nutrients or buffer capacity necessary
for  viable  microbial  activity;   and,  transport   residuals  for  ultimate
treatment  or disposal.    Because  of the  attendant  acceleration of  the
microbially-mediated conversion of the waste constituents and the contracted
time for stabilization of the readily available organic  substrates, rates and
amounts  of  gas production  are  concomitantly increased, thereby encouraging
energy recovery and utilization.  Such "wet" landfills create opportunities
for innovative design and operation as a controlled biochemical systems which
enhances predictability and minimizes long-term liabilities after closure.
      Implicit  in  this latter management  concept are  requirements  for
containment and ultimate removal, disposal or utilization of  the leachate and
gas residuals.  Current technology provides a sufficiency of techniques for
containment with natural  or fabricated  liners and for  leachate  and  gas
management  with  collection, distribution and treatment systems.   Ultimate
disposal requires  an inspection  of  the  sensitivity  of  the  eventual
environmental  receptor, whether  it  be  the  land,  water  or air.    With
prevailing  regulatory constraints  and implementation  of  state-of-the-art
technology, all  of  these  potential receptors  may require  some  degree  of
residual pretreatment  before   ultimate  disposal  of  leachate  or  gas  is
acceptable. Such pretreatment  can be best provided by either on-site or off-
site  engineered  systems  that have  the  flexibility   to   accommodate  the
predicted and actual  changes in leachate and gas characteristics.
Characterization of Landfill Stabilization
      As indicated previously,  most landfills  progress through  a series of
rather  predictable  stages  or  phases of  stabilization,  the  longevity  and
significance of which are determined by local conditions and the operational
strategies  being applied either externally or internally.  Fortunately, these
phases can  be detected and  monitored by leachate and gas analyses which are
                                    972

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physically, chemically and biologically interrelated.
      To  direct the choice  of analyses to  be employed  to  characterize a
particular  phase of  stabilization,  it  is  necessary  to recognize  that a
landfill  exists  throughout  most  of  its   active   life as  an  anaerobic
microbially-mediated process.  This process is analogous  in principle to an
anaerobic batch digester, with limited inputs or outputs except for the solid
waste originally deposited and the moisture which may have gained access by
infiltration, and the eventual leachate and gas production and their possible
migration.    In a  sense, therefore,  landfills  become  large,  long-term,
anaerobic  leach-bed  reactors consisting  of  compartments  or cells  that
progress  through the various  stabilization  phases  at  different  rates and
somewhat independently, unless influenced by operational control or connected
by an absence of confining barriers.  If connected,  the principal transport
media   (leachate  and  gas)   tend  to  merge  and  dampen oscillations  in
characteristics, yielding a combined and temporally-averaged leachate  and gas
quality for the contiguous cells.
      Phases of Landfill Stabilization.  Using the anaerobic process analogy,
and recognizing that the functional retention times for landfills extend over
periods of years  rather than days,  it is  possible to  describe landfill
stabilization on the basis of certain performance-related and  time-dependent
descriptors.    Accordingly,   most  landfills   experience  a  lag or   initial
adjustment phase which persists until  sufficient moisture has  accumulated to
encourage the development of a viable  and abundant microbial community.  The
evidence  of  this  adjustment phase  is first  apparent  with the   initial
production  of gas  (mainly carbon dioxide), possibly accompanied by elevated
temperatures due to incipient aerobic conditions.  The existence and relative
persistence of  elevated temperature serves  to catalyze the initial microbial
activity, but ordinary is short-lived, depending on the insulating conditions
prevailing within the landfill system and the opportunity for  dissipation of
heat.   This  lag phase  becomes  more  evident  when  leachate  is  formed and
released  after  "indicated field  capacity"  is reached.  Thereafter,   further
                                     973

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incremental saturation of the waste mass  with moisture and the concomitant
distribution of nutrients will promote the development of an active anaerobic
and interdependent microbial consortia  of acid-forming and me thane-forming
bacteria in each  compartment of the landfill.  The evidence  of this consortia
will be  manifested in the  changes in  magnitude and  intensity  of various
indicator parameters used for leachate and gas characterization.  As readily
available  supporting  substrates  are  exhausted,   these   changes  become
diminished and the associated indicator parameters will reflect an approach
to stabilized conditions.  Accordingly,  five sequential stabilization phases
can be described in this manner and include:  Initial Adjustment (Phase I);
Transition  (Phase  II); Acid Formation (Phase III);  Methane  Fermentation
(Phase IV); and,  Final Maturation (Phase V).
      Since this  sequential development is a natural landfill phenomenon, all
of these phases are encountered at one time or  another in landfills receiving
municipal  solid  waste, provided  that  the  associated microbially-mediated
conversion processes have a sufficiency of moisture and nutrients and are not
inhibited.   As  indicated previously, because the manifestations  of these
phases often overlap within  a landfill  setting,  it has become customary to
characterize them  in a combined fashion.   This has   tended to  obscure and
limit a mechanistic understanding of landfill  behavior and the corresponding
potential  for  the  operational  control necessary  for process  optimization.
Moreover, no landfill has a  single "age",  but rather a family of different
ages associated with the various landfill  cells as they evolve toward final
maturation.
      The  rate  of  evolution   through  the   phases  of  stabilization,  as
determined by  leachate  and gas analyses,  will vary  depending not  only on
waste characteristics, but on the physical, chemical and microbial conditions
established within  each  cell with  time.    For example,  low pH  conditions
established during  acid formation (Phase III) may delay or preclude the onset
of active  methane   fermentation  (Phase  IV),  inhibition  or retardation of
microbial activity may be induced by the  presence of toxic substances, and
                                    974

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high physical  compaction or the use  of  impermeable intermediate and final
covers may restrict the movement and accessibility of moisture and essential
nutrients.  Collectively, these constraints could decrease or neutralize the
 in  situ  mechanisms  of  attenuation  and  assimilation responsible  for
stabilization  of  the  waste constituents,  prolong  the  time  required for
ultimate  stabilization to occur, and extend the  period and uncertainty of
environmental  liability  after site closure.
      Indicator  Parameters.  A variety of indicator parameters may be used
to detect and describe the presence, intensity and longevity of the phases of
landfill stabilization.  Many of these apply for the analysis of leachate and
whether physical,  chemical or biological, each has a particular utility and
significance  in terms of monitoring  and control.   For instance,  of those
parameters included in Table 1, pH and ORP are physical parameters indicative
of acid-base and oxidation-reduction conditions, respectively, and important
in evaluating  the  acid formation and methane  fermentation phases (Phases III
and IV);  COD and BOD5  are chemical and biological parameters, respectively,
but are both indicative  of relative leachate strength and biodegradability;
and,  nitrogen and phosphorus  are  chemical parameters  important  in  the
determination  of nutrient sufficiency and condition (aerobic/anaerobic) of a
particular phase.  Similar importance  can be assigned to the other parameters
such  as  alkalinity (buffer  capacity), heavy metals  (potential inhibition),
conductivity  (ionic strength/activity effects), chlorides  (tracer/migration
potential),   sulfates   and  sulfides  (oxidation  condition/precipitation
potential), and coliforms and viruses (potential health implications).
      Ranges  in intensity and concentration of  these   indicator parameters
will  vary throughout  each phase of stabilization,  again dependent  on the
principal  function of  the  phase  as  defined,  the  physical  influence  of
dilution  or washout, and the continuing flux of moisture.   Relative moisture
availability  during leaching will tend  to  affect concentrations,  and will
influence  the  total  mass  potentially  leached.    It  will  also  influence
reaction  opportunity and intensity and thereby  lead to either accelerated or
                                   975

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diminished microbially-mediated transformations.   Unfortunately, dilution



effects  are  often  poorly measured  or recorded,  leading to  variances in



interpretation   when  analyses   are  based   upon   concentration  alone.



Nevertheless,  it is possible  to provide  general  ranges of  intensity and



concentration  of the various indicator parameters  throughout the landfill



phases when leachate (and gas)  is available for analysis.  Although reported



in more detail elsewhere  (Pohland and Harper, 1985), the general pattern is



presented in Figure 1 which serves to demonstrate the linkage between a few



important indicator parameters and the phases of landfill stabilization.



      As illustrated in Figure 1, the initial  lag or adjustment phase (Phase



I)  is eventually  followed by:   a  transition  from  aerobic  to  anoxic or



anaerobic  conditions with  increasing production  of  leachate  (Phase  II) ,



active acid  (TVA)  formation  with high leachate  strength (COD),  low pH, and



mobilization of ionic species (Phase III); methane fermentation with high gas



production and quality,  reduced leachate  strength  (COD  and TVA),  increased



pH,  low  ORP and  enhanced  complexation and reduction of ionic species (Phase



IV); and, final maturation (Phase V) when nutrients  may become limiting, more



difficult  to  degrade  substrates  are utilized,  gas  production  decreases



dramatically,  and poststabilization conditions are established. .



Accelerated Landfill Stabilization



      The progress of landfill  stabilization and  concomitant attenuation and



assimilation of  waste constituents can be accelerated by the elimination of



the constraints indicated previously and by optimizing operational features.



One technique to accomplish this goal is to  nurture the microbially-mediated



conversion  process by  leachate  containment,  collections  and recycle  as



originally  conceived  and   demonstrated   by  Pohland  (1975,   1980),   and



subsequently extended to  include codisposal with both inorganic and organic



priority pollutants  (Pohland et  al..  1985;  Pohland and  Gould,  1986;  Graven



and Pohland, 1987).  Indeed, recent surveys (Pohland and Harper, 1985;  EPA,



1988) have  indicated rather widespread application of  the  technique,  with



over 200 landfills  sites  in the Unites States now practicing  some  form of
                                     976

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leachate recirculation.



      The  inherent  advantages of  accelerated  landfill  stabilization by



leachate  and gas  management  over  conventional  landfill practice  can be



demonstrated by  selected results of  laboratory  simulations.   Accordingly,



laboratory-scale landfill  cells,  consisting of  identical 208-L containers



were filled with shredded (10-15 cm) municipal  solid waste (MSW).  The cells



were operated with and without  leachate recycle as indicated schematically in



Figure 2.   After  loading  each cell with a total of 54.6 kg (dry) shredded



MSW with an indicated density of 482 kg/m3, distilled and deionized water was



added  to attain  indicated field capacity,  and measurements  on resultant



leachate and gas production were commenced.



      In terms of mass concentrations of leachate COD and TVA accumulated or



released (Figure 3) and associated gas production and quality (Figures 4 and



5), it is apparent that  accelerated stabilization and conversion of readily



available substrates to intermediate volatile acids  and  gas occurred rapidly



in the recycle cell,  but slowly and only to a  limited extent in the single



pass cell.  In fact, considerably more of the available substrate measured by



leachate COD and TVA was converted to gas by in situ  processes in the recycle



cell  (Figure  5),  whereas the  major  portion of these leachate constituents



were  routinely discharged  as   washout  from the  single pass  cell  without



equivalent gas production.  Such a release of high-strength leachate without



further  treatment  would be unacceptable in practice, thereby incurring the



additional  costs   and  operational  uncertainties  of  separate  treatment.



Moreover, the  opportunities  for potential gas  recovery as an energy source



without  separate treatment are lost.



      In addition  to a lack of conversion of the  organic constituents in the



leachate from the single pass cell,  greater amounts of inorganic species were



released routinely with time.   This is demonstrated by the data in Table 2



where the low pH condition,  consequenced by the abundance of organic acids



and lower buffer capacity (alkalinity) of the single  pass leachate, confirmed



the progressive  washout of constituents and the absence of viable methane
                                    977

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fermentation (Phase IV).  The  time  for stabilization was thereby prolonged
beyond that required with leachate recycle, and is analogous to circumstances
at  conventional landfills  where extended  periods  of  time  (decades)  are
required for such  stabilization to be completed.   Moreover,  with leachate
recycle, many of the heavy metals were  removed in  situ, leached constituents
were contained within the  system (unless  converted to gas), and the quantity
of leachate accumulated and managed was reduced  to that required for recycle
and  to  accommodate associated  mass loading  considerations.   Accordingly,
leachate recycle should be operationally discontinued and the leachate pool
removed  for ultimate  disposal  at  controlled  landfills when  accelerated
stabilization of the readily available  organic substrates has been completed
at the end of Phase IV.  Such physical  removal of  the leachate also deprives
the  landfill of the principal  transport  medium  as well  as the moisture and
nutrients  necessary  for  continued conversion  of  more  resistant  waste
substrates.   As  a  consequence,  active  biological activity  dramatically
declines, and the landfill becomes essentially dormant.
      The  data  in  Table  2  also  may be  used  to reflect  the  relative
acceptability of the respective  leachates for ultimate discharge either to an
existing sewerage/waste treatment or land disposal system.   It  is apparent
that  the  single pass leachate would require  additional  organic  removal by
pretreatment before ultimate discharge, whereas the recycled leachate could
be discharged without such  pretreatment  other than by dilution  or possible
ammonia removal.    In this  latter case,  physical removal of the  residual
leachate from the landfill and discharge either to a publicly owned treatment
works  (POTW)  or  management  by  land  spreading  (irrigation)   would  be
appropriate technology  after Phase IV of in situ stabilization had  been
completed.  As  indicated in Table 3, similar leachate management practices
already are being applied at full-scale landfill sites.
      When compared to conventional landfill practices,  a number of options
are available  for  leachate  and gas management  either  as produced at  the
landfill during  operations  and maintenance  or prior to  ultimate  disposal.
                                    978

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Before  final  discharge  onto  land or  into a  POTW, landfill  leachate may
require polishing by biological and/or physical-chemical methods after either
on-site or in  situ treatment.  It is also widely recognized that the quantity
and quality of  landfill  gas essentially determines when it may be captured
and  treated  for  possible beneficial  use.   The  more  leachate  treatment
accomplished within the landfill before final discharge, the less polishing
treatment  required.   Moreover,  if such  in  situ  treatment  is accelerated
through  leachate  recycle, the opportunities  for energy  recovery  from the
associated  gas  production are  greatly enhanced,  whether the gas  is  used
directly or pretreated to pipe line quality.
Future Prospects  and Conclusions
      Leachate recirculation is being more routinely considered as a landfill
management  option, and  its  advantages in terms of comparative  costs and
enhanced predictability will likely promote more frequent implementation in
future.  The arguments against such implementation are  largely  due to a lack
of understanding  of the  technology required for  successful application, and
of  the  environmental setting  within  which the  method is applicable.   In
locations  where  the infiltration  of  moisture and  leachate  production are
inevitable, leachate collection and controlled recycle becomes particularly
attractive.   As more operating data and experience becomes available,  these
issues will be clearer and better resolved, and controlled stabilization with
leachate management will  also be more readily accepted as a technically and
environmentally sound solid waste management option.  Therefore, development
of  future  controlled stabilization landfills  will more effectively harness
the potent  in situ attenuating and assimilating  capacities of  landfills and
will  link  these directly  to energy recovery.  Elements of design, operation
and maintenance necessary to accommodate such controlled stabilization will
include:
                                     979

-------
      o     engineered  containment  with  fabricated  liner,   cover,   and
            confining barrier  systems (natural  or synthetic  or both)  to
            facilitate leachate and gas management;
      o     appurtenances for  leachate and gas collection, management  and
            ultimate    disposition,    including    drains,    filters,
            collection/distribution systems,  wells, vents,  pumps and energy
            recovery systems;  and,
      o     integrated solid   waste  disposal and operating schedules  to
            permit sequential  cell construction and operation,  controlled
            segregation,  leachate and gas management, closure, and final use
            implementation.
In the final analysis, such an  integrated approach  to control and regulation
of landfill stabilization will not only provide  greater  assurances  against
adverse environmental impacts, but will enhance  opportunities  for  resource
recovery and allay public concerns  about  landfills and  their essential  role
in municipal solid waste management.

REFERENCES
POHLAND,  F.G.  (1975) "Accelerated  Solid  Waste Stabilization and  Leachate
Treatment by Leachate Recycle Through Sanitary Landfills".  Progress in Water
Technology, Vol. 7, 3/4,  pp.  753-765.

POHLAND,  F.G.   (1980)  "Leachate Recycle  as  Landfill  Management  Option".
Journal Environmental Engineering  Division, ASCE,  Vol. 106, EEC, pp. 1057-
1069.

POHLAND, F.G.  (1988)  "Accelerated  Anaerobic  Conversion  of Solid Waste  in
Controlled  Landfills".   Proceedings  IAWPRC  Asian Workshop  on Anaerobic
Treatment, pp.  (16) 1-10.
                                    980

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POHLAND,  F.G.  and  HARPER,  S.R.  (1985)  "Critical  Review  and Summary  of
Leachate  and Gas  Production  from  Landfills".    PB.  86-240 181/AS,  NILS,
Springfield, VA 22161, 182 pp.

U.S. ENVIRONMENTAL PROTECTION AGENCY (EPA).  (1988) "Report to Congress Solid
Waste Disposal in the United States", Vol. II,  EPA/530-SW-88-011B, Chapter 4.
                                     981

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            TABLE 1.  Landfill Leachate and Gas Indicator Parameters
     Parameter Identity
         Utility
Physical
      pH*
      ORP*
      Conductivity
      Temperature*
Chemical
      COD*, TOC
      TKN*. NH3-N*.  P04-P*
      TVA*. SCVS, N03-N
      TS*. Chloride*
      Total Alkalinity*
      Alkali/Alkaline Earth Metals*
      Heavy Metals*
      Gas  (02, CH4,  C02, H2, N2)*
Biological
      BOD5*
      Total/Fecal Coliforms
      Fecal Streptococci
      Viruses
      Pure/Enrichment Cultures
acid-base indicator
oxidation-reduction indicator
ionic strength/activity indicator
reaction indicator
biodegradability indicators
nutrient indicators
stabilization phase indicators
dilution/environmental tracer
buffer capacity indicator
toxicity/environmental fate indicators
toxicity/stabilization phase indicators
stabilization phase indicators
biodegradability indicator
potential health hazard indicator
potential health hazard indicator
potential health hazard indicator
stabilization phase indicator
*Parameters frequently used for evaluation.
                                      982

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Table 2.    Comparative  Characteristics  of Leachates  from the  Single  Pass and
            Recycle Cells after Completion of Accelerated Stabilization
Parameter
Single Pass Cell
           Recycle Cell
Chemical Oxygen Demand (COD) , mg/L
Total Volatile Acid (TVA) ,
mg/L as CHjCOOH
PH
ORP, mV Ec
Total Alkalinity, mg/L as CaC03
Conductivity, (imhos
Cadmium, mg/L
Calcium, mg/L
Chromium , mg/L
Copper , mg/L
Iron, mg/L
Lead , mg/L
Magne s ium , mg/L
Manganese , mg/L
Nickel, mg/L
Potassium, mg/L
Sodium , mg/L
Zinc , mg/L
o- Phosphate, mg/L P
Ammonia, mg/L N
Sulf ide , mg/L
6222

4670
5.3
-198
1829
1475
0.05
13
0.1
0.1
298
0.3
5.9
4.0
0.04
1.6
5.6
0.3
0.1
1-6
0.06
2006

133
7.1
-232
3222
4084
0.05
316
0.1
0.1
1.2
0.3
25.2
0.1
'0.1
266
913
1.8
0.1
105
0.3
Table 3.    Landfill Leachate Management Practices and Operating Status in the United
            States
                                              Number of Landfills
Leachate Management Practice
 Closed
Active
          Relative
Planned     Costs
Recirculate by Spraying
Recirculate by Injection
Recirculate by Other Means
Land Spreading
Truck to POTW
Discharge to Sewer to POTW
Other or Unknown Off -Site Treatment
On- Site Biological Treatment
On- Site Chemical/Physical Treatment
40
10
11
15
48
53
5
41
34
158
36
34
84
76
118
21
102
61
185
16
22
60
245
135
23
108
60
L
L
L
L/M
M/H
M
-
H
H
Source of Landfill Data:  EPA, 1988 (Some facilities use more than one practice.)

Relative Costs:  L (Low), M (Moderate), H (High); includes capital and operating/
                 maintenance costs.
                                         983

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                              PHASE IV

                           METHANE FERMENTATION
Figure 1.   Changes in Selected Indicator Parameters during
            the Phases of Landfill  Stabilization
                            984

-------
                                                IMI
                                                            IJ)
                                                                           Jtfif
                                                                     III  TtUfCIUTUtC
                                                                     Itl  US eOLLCCniM MMCT
                                                                     IS)  LtVtLIH* MTTLt
                                                                     141  US RCLCUC «H.Vt
                                                                     Itl  wan MOTION POUT
                                                                     (•I  Lt«M»TC OMIN PIPC/
                                                                         UUPLIM POUT     '
                                                                     IT I  LticMATc ncscnvoiK
                                                                         COUALI2ATION 0A9 UNC
                                                                     (II  US COU.CCTIOH UN(
                                                                     isi  UACMATC Ktxmmim
                                                                     (KM  LCMHITf KCCTCLC PUMP
                                                                     mi  V«/O»P HcuimiH* pmw
                                                                     lid  LfMMATC  MCTCLC LIMC
                                                 TO us tuicn
Figure 2.   Operational  Features  and Configuration  of
               Simulated  Landfill Cells
                                       985

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                                                                 5000
                                                              COO. SINGLE
                                                                 PRSS CELL
                                                          TVH.  SINGLE
                                                              PflSS CELL
                                                  TVR.
COD. RECYCLE
      CELL

RECYCLE
  CELL
  0    50   100  150  200  250  300  350   400  450
                     TIME,  DRYS

     Figure 3.  Mass  Accumulations and  Releases of Leachate COD
                and TVA during Single Pass and Recycle Operations
                                                         SINGLE PRSS
                                                           CELL
240  260  280  300  320  340  360  380  400  420  440
                       TIME.  DF1YS
     Figure A.  Comparative Accumulated  Gas Production during
                Single Pass and Recycle  Operations
                                 986

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                                                              0
                                                              RECYCLE
                                                               CELL
                                                          SINGLE PRSS
                                                           CELL
240  260  280  300  320  340  360  380  400  420  44Q
                        TIME.  UflYS
  240  260  230  300  320  340  360  380  400  420  440
                         TIME.  DflYS

       Figure  5.   Changes in Gas Production and Quality  during
                   Single Pass and Recycle Operations
                                    987

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              DESIGN AND CONSTRUCTION
                         OF
         SOLID WASTE CONTAINMENT SYSTEMS
                          by

                Steven D.  Menoff, P.E.
             Vice President: - Engineering
           Chambers Development  Company, Inc.
                   Presented at the

First U.S.  Conference on Municipal Solid Waste Management

                   June 13-16,  1990
                           989

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INTRODUCTION

     The past decade has witnessed an ever increasing emphasis on
the  implementation  of  technical   advances   in  the  design  and
construction of solid waste  disposal  facilities.   Driven both by
public  outcry  and  regulatory requirements,  this direction  has
been to minimize the potential environmental impacts of disposal
sites by  enhancing the  integrity  of their  containment systems.
Concurrently, the  reduction  in  available landfill  airspace  and
the difficulty  in  siting and permitting  new disposal facilities
has significantly  increased  the  value of  existing and permitted
airspace  as an  asset.   These two trends  have caused landfill
designers  and   developers  to  reassess existing  technology  and
evaluate new materials  and design methodologies in  an effort to
improve  the performance of  these  facilities  while  maximizing
their disposal capacity.

     Traditionally,  natural   or  processed  soils   have been  the
materials  used  to construct  landfill liner, cover  and leachate
collection  systems.   However, increasingly  stringent regulatory
standards  for  both barrier  and  drainage  layer performance have
led  the solid  waste  industry to  utilize synthetic  products  in
coordination  with,  or  in  place  of,  natural  materials.   If
properly  designed  and  installed,  synthetics can  improve  both
containment  and drainage,  resulting in  a  more  environmentally
sound   facility.    Increases  in   available airspace,   without
sacrificing facility performance, can be realized when synthetics
are substituted for all  or a portion of relatively thicker layers
of natural  materials.   Consistency  of material  and relative ease
of installation are additional factors that have  made synthetic
components a staple of current landfill design.

     This  paper  reviews  the regulatory  history  and  assesses
current  practice  in  the  utilization of  natural  and  synthetic
materials  for the  design and construction of containment systems
for solid waste disposal.


REGUIATORY BACKGROUND

     Containment  technology  and  design  methodology  for  solid
waste disposal  facilities  over the past  five years  has followed
in the  wake of Resource  Conservation and  Recovery Act   (RCRA)
requirements  for  hazardous   waste disposal facilities.   Under
Subtitle  C of  RCRA, the United  States Environmental Protection
Agency  (USEPA)  promulgated  initial regulations on  19 May 1980
that  established  criteria   for  disposal   facility  liner  and
leachate collection  systems.   RCRA was reauthorized  and amended
on 8  November  1984 by  the Hazardous and Solid Waste Amendments
Act (HSWA), which implemented even more stringent technical
                               990

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standards, the most significant  of  which was the requirement for
all hazardous waste facilities to have double liner systems.

     In  order to  implement the  facility standards  mandated by
RCRA  and define performance  standards,  USEPA  has  employed  a
sequence  of  Minimum  Technology Guidance  (MTG)  documents.   The
initial  MTG  document,  issued in  July  1982,  required  a single
synthetic   liner   and   "strongly   recommended"   a   composite
synthetic-clay liner.   As a result of the  HSWA requirement for
double liner systems,  USEPA issued an MTG document on 19 December
1984  specifying  a  synthetic  primary  liner  and  a  composite
synthetic-soil  or  soil  secondary  liner  and  introducing  the
requirement for  a  formal  construction  quality assurance plan for
each disposal  unit.   The 1984 MTG  was updated with  24  May 1985
and  April  1987  documents.   This  guidance,  the most  current,
increased the minimum  permeability requirement  of  the primary
leachate collection system  from  1 x 10  cm/sec to 1 x 10  cm/sec
and extended  this  criteria to the  secondary leachate collection
system.   It  also increased the  soil component  of  the  secondary
composite liner  from  two to three  feet of  1  x 10   cm/sec clay.
The 1985  MTG document allowed  for  the use  of  composite primary
liners.   In  October 1985,  USEPA issued the first  draft  of the
construction  quality  assurance requirements  originally outlined
in  the  1984 MTG document.   In  addition,  a July 1989  technical
guidance  document  refined  the  final  cover  system  requirements
defined in the 1982 MTG document.

     While  federal solid  waste regulations,  to be  promulgated
under Subtitle D of  RCRA,  are  still  in internal USEPA review,
many states have enacted  solid waste regulations as  stringent or
more  stringent  than  what  is  required  by  Subtitle  C.   Several
states require double  synthetic liner  systems  and a  number even
require  double  composite  liner  systems.   Even in states where
regulations call for  minimal design requirements,  some facility
owners have  implemented containment systems based on Subtitle  C
MTG  in  order  to improve  the environmental integrity   of their
facilities and protect themselves from long term liability.


CONTAINMENT SYSTEMS

     From both  a  concerned public and  regulatory  perspective,
three  issues  are  raised by  the land  disposal of solid waste.
These are the containment  of  the  waste  and the control  of its
by-products,  leachate  and landfill  gas.   No single  material or
layer can adequately perform these  functions.  It is only through
the  design  of a multiple  component containment system  that an
environmentally  "secure"   facility can  be  developed.   Equal
emphasis must  be placed  on  both  cover  and liner systems in order
to  minimize  the  accumulation  and accelerate the  removal  of
liquids in the landfill.  The components of a complete
containment system are illustrated  in Figure l.
                               991

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                                                          FIGURE  1
                              MUNICIPAL  SOLID  WASTE  CONTAINMENT  SYSTEM
                                                  • LANDFILL
                                                  GAS
                                                  EXTRACTION
                                                  WELL
                                     LEACHATE
                                  REMOVAL AND
                                    TRANSPORT
                                       SYSTEM
CO
CO
N
  FINAL
 COVER
SYSTEM
  LEACHATE
  TREATMENT
     OR
PRETREATMENT
   SYSTEM
                                                  MUNICIPAL
                                                    SOLID
                                                    WASTE
LANDFILL
GAS
RECOVERY
PLANT
AND/OR
FLARE
                         UPGRAOIF.NT
                         GROUNOWATER
                         MONITORING
                         WELL
                                                      LINER  AND LEACHATE
                                                      COLLECTION  SYSTEM
                                                                          V
                                                     DOWNGRADIENT-
                                                     GROUNDWATER
                                                     MONITORING
                                                     WELL
                                               GROUNDWATER
                                                      TABLE

-------
     The technical basis  for  the  multi-layer containment system,
in  its  many  variations  and  alternative  configurations,  is  to
minimize  liquid   detention   time  on  the   barrier  layers  by
expediting  its - removal  through  highly  transmissive  drainage
layers.   The  relative difference in the  transmissive properties
of  the  barrier   and  drainage   layers   is  therefore  a  major
consideration in  the design  of an  effective containment system.
For  this   reason,   composite  barrier   layers   utilizing  both
synthetic and natural  materials  benefit  from the  qualities  of
both - the  lower  permeability and low  lateral flow resistance of
a  synthetic  supported  by   the   self-healing  and  attenuative
properties of a natural soil.

     Synthetic  and  natural   materials  are  used  in four  basic
applications  in the  liner and cover  portions of  a containment
system.   The  two  primary functions are to provide  a barrier and
drainage.   The  two  support   functions are to provide  interface
layers,   such  as filters  or protective cushions, and  to provide
reinforcement.

     The landfill  designer must consider  a number of criteria in
developing  the  most effective containment system  for  a specific
facility.   The  appropriate regulatory requirements are clearly
the  foremost consideration.   However,  there are   others  which
impact  each specific  design.   Where airspace  is at a premium,
synthetics  can  be  utilized  to design an  effective containment
system  while reducing  the need  for thicker soil  layers.   The
availability  of natural materials is also  a consideration.  The
economics   of   containment  system   components  as  compared  to
airspace  may   also   impact  the  configuration  for  a  specific
facility.   For  example, synthetic drainage layers such as geonets
see  more frequent use as increasingly stringent transmissivity
requirements  dictate the  use of highly  processed,  potentially
difficult to obtain,  and often very expensive granular soils.

     Utilizing  the  advantages  of   both   natural  and  synthetic
materials,  a  number of liner and cover systems  can be developed
to  satisfy  the  various regulatory requirements and environmental
concerns which  need to be addressed in  the  design  of  any solid
waste disposal  facility.   Figure 2  illustrates  some of the more
frequently  seen multi-layer liner and cover systems.


DESIGN CONSIDERATIONS

     As  discussed  above,  various  natural  and synthetic materials
are  used to perform the four   functions  -  barrier,  drainage,
interface   and  reinforcement  -  of a  solid waste  containment
system.  The component  layers are used either individually or in
                               993

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                               FIGURE 2
                                     SOD. DRAINAGE LAYER


                                     SOIL UNER (IN-STTU OR COMPACTED)
      SINGLE  SOIL  LINER
                                      SELECT REFUSE OR SOIL PROTECTIVE LAYER
    "•"•'•"."."•"•\\\".".~.\\".\\\".\\\\^ _ ,- CEOTEXT1LE FILTER

    XXXXXXXXXXXXXXXX)0( - CEONET ORA.NACE LAYER
        SINGLE  SOIL LINER
                                     SOL DRAINAGE AND PROTECTIVE LAYER

                                     CEOTEXT1LE CUSHION
                                     CEOUEUBRANE UNER
                                     CEOTEXTtLE CUSHION
                                      COMPACTED SUBCRADE

SINGLE  GEOMEMBRANE  LINER
                                      SOU. DRAINAGE AND/OR PROTECTIVE LAYER
    _..		..... .•.•.•.•.•.V.'.V.'.'.V/.V.	^_ CEOTDCT1LE H1.TER
    XXXXXXXXXXXXXXXX>&^~GEONET
                                      CEOMEMBRANE UNER
                                      CEOTEXT1LE CUSHION
                                      COMPACTED SUBGRADE

SINGLE  GEOMEMBRANE  LINER

                                  994

-------
                              FIGURE  2
                             (CONTINUED)
                                     SOIL DRAINAGE AND PROTECTIVE LAYER
                                     CEOTEXTILE CUSHION
                                     GEOMEMBRANE UNER
  SINGLE  COMPOSITE  LINER
    .•.•.•.V.V.V.V.V.V.V.V.V.'.V.V.V.V.V.'.V.' y	 SOIL DRAINAGE AND/OR PROTECTIVE LAYER
    V.V.V.'.'.V.'.V.V.'.V.V.V.'.V.'.'.'.V.'.'.'.V.'.  y— GEOTEXTILE FILTER
    xxxxxxxxxxxxxxxx>a— GEONCT D(WNACE
                                   ^- CEOMEMBRANE UNER
  SINGLE  COMPOSITE  LINER
                                      SOIL DRAINAGE AND PROTECTIVE LAYER
                                      GEOTEXTILE CUSHION
                                      GEOMEUBRANE UNER
                                      SOIL DRAINAGE LAYER
                                      GEOMEMBRANE UNER
                                      CEOTEXT1LE CUSHION
                                      COMPACTED SUBGRADE
DOUBLE  GEOMEMBRANE  LINER
                                      SOIL DRAINAGE AND PROTECTIVE LAYER
                                      GEOTEXTILE CUSHION
                                      GEOMEMBRANE UNER
    XXXXXXXXXXXXXXXXXX -
    -                       - . - GEOMEMBRANE UNER
                                  ~^ CEOTEXT1LE CUSHION
                                      COMPACTED SUBGRADE
DOUBLE  GEOMEMBRANE LINER
                                  995

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                         FIGURE  2
                        (CONTINUED)
  V.V.V.V/V.V.V.V •.•.•.•.•/.•!•'•!•'"'•'•'•'•'•'•'•'•' y - SOIL DRA1NACE AND/OR PROTECTIVE 1AYER
  y.v///.v/.v.'.y.v.v.'.'.v.v.%'.v.v.'.v.v. _ ^_ GEOTEXTILE FILTER
  xxxxxxxxxxxxxxxxxx —
  XXXXXXXXXXXXXXXXXK - OE:ONET DRAINAGE LAYER
                          —: —V- CEOMEMBRANE UNER
                                GEOTEXT1LE CUSHION
                                COMPACTED SUBGRADE
 DOUBLE GEOMEMBRANE LINER
                               SOIL DRAINAGE AND/OR PROTECTIVE LAYER

                               GEOTEXTILE FILTER
  xxxxxxxxxxxxxxxxxx—
                		„ " 	 GEOMEMBRANE UNER
  Y////7/S////////////////?^	 BENTONtTE MATTING

  XXXXXXXXXXXXXXXXXX	 CEDNET DRAINAGE LAYER
  ~"                             GEOMEMBRANE UNER
                                GEOTEXT1LE CUSHION
                                COMPACTED SUBGRADE

 DOUBLE GEOMEMBRANE LINER
WITH  COMPOSITE  PRIMARY  LINER
  V-V.V.V.V-V-V-VAV-" • • •••••••-•-• - • _s	 SOIL DRAINAGE AND/OR PROTECTIVE LAYER
  v////////.y.v.v.v.V.V.'.V.v.v.v.y.y/.	^ CEOTCXTILE FILTER
  xxxxxxxxxxxxxxxxxx—
  y//////////
  XXXXXXXXXXXXXXXXXX	 CEONET DRAINAGE LAYER
  /////////////  ^~ GEOMEMBRANE UNER
  /////// //////	 S01L

   DOU3LE  COMPOSITE  UNER
                               SOIL DRAINAGE AND/OR PROTECTIVE LAYER
                 __ _ __  GEOTEXT1LE FILTER
  XXXXXXXXXXXXXXXXX
                               SEOMEMBRANE UNER
                               BENTONrTE MATTING
 /////////////    GEOMEMBRANE UNER
 ////////////r—S01L
  DOUBLE  COMPOSITE  UNER


                            996

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                           FIGURE  2
                          ^CONTINUED)
                                  SOIL COVER AND VEGETATIVE LAYER
                                  DAILY AND INTERMEDIATE COVER

                                  WASTE
    i   i   i   i   l   i   i   i   i
     SOIL  FINAL COVER
                                  SOIL COVER AND VEGETATIVE LAYER
                                  CEOUEMBRANE CAP
                            .—; —— GEOTEXTILE CUSHION
                                  DAILY AND INTERMEDIATE LAYER
                                  WASTE
GEOMEMBRANE  FINAL  COVER
                                  SOIL COVER AND VEGETATIVE LAYER
                                  GEOTEXTILE FILTER
      _
   XX)0
-------
combination with each  other to meet the required design  criteria
and performance standards.   These component layers are generally
described as follows:


        Soil Barrier Layer

      •  Synthetic Barrier Layer

      •  Soil Drainage  Layer

      0  Synthetic Drainage  Layer

        Interface Layers

        Synthetic Reinforcement and Stabilization Layer


A description of  the  general characteristics of  the materials
that  comprise  these  components  and  the  design  considerations
associated with each is presented below.



 Soil  Barrier Layer

      Traditionally,  naturally occurring  or processed clay  soils
 have  been used  as  liners  to prevent leachate migration and  as
• final cover  to prevent stormwater infiltration.  Both in-situ  and
 compacted clays have  been  used  for  liners.   Typically,   in-situ
 and  compacted clays  have  been  used  for liners.   Typically,
 in-situ clay liners have-been ten feet thick with coefficients of
permeability of  1 x 10  cm/sec or  less.   Compacted  clay  liners,
because of their consistency and  uniformity,  have  usually been
thinner (three to five feet) and  resulted in permeabilities  an
order of magnitude  less than in-situ clay.   While  many  states
still allow  the  use  of clay liners for municipal waste disposal,
the  trend  has  been  to  utilize  clay  in conjunction   with  a
synthetic to construct a composite  liner  system.

      In-situ clay liners require extensive geotechnical  testing
programs  to  verify their thickness and consistency.  Continuous
and discontinuous pockets of relatively high permeability granular
materials are often  encountered in  natural  clay  deposits.   To
assure  that  these  types of materials are not in  contact with
leachate, the uppermost three feet of an in-situ liner should be
excavated and  compacted.

      Compacted clay  liners  should  be placed  and  compacted at  a
moisture  content  slightly wet of  optimum.  Since clay liners  are
constructed  in nine to twelve-inch  thick  lifts, the surface of
                               998

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each  lift  should  be  scarified   prior  to  placement  of  the
subsequent lift in order to achieve a homogenous liner and prevent
lateral pathways for leachate migration.

     Either  in-situ or  compacted,  soil  liners  occupy valuable
landfill airspace.  When used with  a  synthetic,  the thickness of
clay  required  is  substantially reduced.   Eighteen  inches  of
compacted clay underlying a synthetic liner provides an effective
composite barrier.  The surface of clay liners are only as smooth
and consistent  as  construction  equipment can  make them.   As  a
result, leachate  can  pond in localized  low  spots and infiltrate
into the soil liner.  Used with a synthetic, the self-healing and
attenuative  capacities  of  clay  are  exposed to  a significantly
lower  volume of  leachate and  can function effectively with  a
thinner layer.

     An innovative method of gaining the benefits of a clay liner
without  sacrificing airspace has  been  developed over  the  past
five years.   Bentonite matting consists of dry bentonite between
two geotextile  layers.   While  this matting  is only  a quarter of
an  inch  in  thickness,   it consists  of  at  least  one  pound  of
bentonite  per  square  foot and testing has  demonstrated  its
effectiveness in plugging a leak in an adjacent synthetic liner.
                                                      —9
     The bentonite can achieve permeabilities of 1 xlO  cm/sec or
less when hydrated.  Reduction in  sheer strength and frictional
characteristics  when hydrated  make  the placement  of  bentonite
matting  within  a containment system a  stability  concern  that
should  be evaluated  by the landfill designer.   An alternative
application  would be to  place the  bentonite matting  beneath  a
clay  liner  in  lieu  of a  portion of  the  required clay  liner
thickness.   Stability is  less  of a concern  in this applicaiton.
It  is  imperative  that  construction  be   staged  so  that  the
bentonite  matting be covered  immediately  by the  next adjacent
layer  in order  to prevent  it  from  being  exposed  to  inclement
weather.

     Vegetative  soil layers  in final  cover systems also serve to
reduce  infiltration along with low permeability  barrier layers.
Soils  capable of  establishing  strong vegetative  cover increase
surface  water  runoff and  decrease  infiltration and  resulting
leachate  generation.


Synthetic Barrier Layer

     Compatibility  with waste and  leachate, physical properties
and  seamability  are  the major  considerations when  selecting  a
geomembrane  for  use as  a  barrier layer  in a liner or final cover
system.   Leachate compatibility  will become a secondary concern
in the design of  a  cover.  For a liner system, however, the
                               999

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geomembrane will  be exposed  to leachate  for  many years.   As a
result, it is  critical  that immersion testing such  as the USEPA
9090 protocol be performed  with the  anticipated  leachate as part
of  the   geomembrane  selection   process.    A  wide   range  of
geomembranes   -   polyvinyl   chloride   (PVC),   chlorosulfonated
polyethylene  (CSPE  or  "Hypalon"),   high  density  polyethylene
(HDPE), and numerous  others - have been utilized  in solid waste
containment applications.   At the present time, however,  it is
the consensus  of both the  disposal  industry and  the regulatory
community that HDPE is the best available product for this use.

     Testing has shown that HDPE has the widest range of chemical
compatibility  of geomembranes   on the  market  and   that  it  is
virtually  unaffected  by  municipal  solid  waste  leachate.   A
specific  gravity  of 0.93 or  greater is generally specified for
HDPE  resin to  be used  for  geomembrane  manufacture.   A  carbon
black content of two to three percent is required to protect HDPE
geomembrane   from  degradation  resulting   from   exposure   to
ultraviolet light.

     Physical  properties of  a   geomembrane  may  require special
consideration  during  design  and installation.   It  is important
that the  design  engineer consider the construction and operating
conditions to which the  geomembrane  will  be exposed.   Conditions
the  designer must  address  include  anchoring,   tensile  stresses
developed over   long  slopes,   dynamic   loads  resulting  from
equipment  operation,   functional   interface   with   adjacent
materials, and the effects of settlement and subsidence.

     While HDPE  has the  best  overall leachate compatibility,  its
physical  properties  are difficult  to  design with  and  require
site-specific  evaluation.   It has a high  coefficient  of thermal
expansion which  makes the placement  of  adjacent  layers difficult
under  extreme weather  conditions.   In the  60  mil   or  greater
thicknesses used in landfill applications, HDPE can be inflexible
and difficult to work with in the field.  Stress  cracking is also
a  concern,  although mainly in  liquid impoundments.    HDPE  has a
relatively  hard  manufactured   surface  which   results  in  low
interface friction  angles.    Design  of HDPE  must  be  limited to
within  its  ten  percent   elastic  yield   point,  beyond  which
permanent deformation will occur.

Soil Drainage Layer

     Granular  soils  such as  sand and gravel have been utilized
for leachate collection and detection and for surface water above
and gas  diversion below the  final cover barrier layer  in solid
waste landfills.  Because granular leachate collection layers are
at least  one foot  thick,  they  also provide protection  for the
underlying barrier layer from drainage during waste placement.
                               100O

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     There are a number  of  concerns that must be  addressed when
iesigning a granular leachate collection layer.   Design standards
jver the past five years have seen  the  permeability_requirements
for leachate collection layers increase from 1 x 10~  cm/sec to 1
zn/sec.   The objective has been  to allow no more than  one foot of
Leachate head buildup on the liner.  This  criteria has virtually
eliminated  sand  from  consideration.   Even gravel  and  crushed
stone must  be washed and  free  of fines  in order  to  perform
satisfactorily.   As a result, granular  leachate  collection zones
:an be costly in a number  of ways.  They consume  airspace,  are
aften  difficult  to  locate,  and   in  many   instances  require
expensive processing prior to use.

     Another concern  is  compatibility  with  leachate.   In  many
areas,  the  available  granular  soils are derived from limestone.
Testing  has  shown that limestone-based  materials  react  with
municipal solid  waste leachate  to  form a precipitate  which  can
eventually  clog  the  collection   zone.    An   effective  design
guideline has been to avoid materials having a  calcium carbonate
content  in  excess of  ten to fifteen  percent.   This  limitation
also makes  acceptable granular  soils  difficult to obtain  and,
resultingly, very expensive.

     The  designer  should  evaluate the  interface  of  granular
drainage layers with both clay and synthetic liners.  With clays,
the potential for  fines  to migrate into the drainage  zone needs
to  be  considered.   A soil  or geotextile  filter  layer may  be
required  for the  containment system  to  function as  designed.
With a  geomembrane,  the concern is  to protect the  liner  from
damage during construction  and operations.  It  is  generally good
practice  to use  a nonwoven geotextile as a  cushion  above  the
synthetic liner  to protect it from angularities in the drainage
stone.   At  least eighteen inches  of soil should be placed above
the geomembrane prior to operating equipment above it.  While the
full eighteen  inches does  not  need to satisfy  the permeability
criteria, it is often designed to do so.

     Other design issues that must be addressed are the stability
of  granular  soil  on  side slopes,  clogging  of  the  soil  by
biological  activity  and sediment  deposition and  physical  and
drainage interaction of  the soil  with the  embedded pipe network.
Removing  leachate • from  the  landfill  is  the  first  step  in
maintaining  an  effective containment system.   To  achieve  this,
composite   collection  systems  consisting  of   granular  soils,
geotextile  filters and  geonets may  be an  alternative for  the
design engineer.


Synthetic Drainage Layer

     Both geotextiles and geonets can be used as drainage layers
                              1001

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within   containment   systems.    However,   the   much   higher
transmissivities  of  geonets  have  made  them  the synthetic  of
choice  for  most drainage applications.   Geonets can be  used in
leachate  collection  and  detection  and final  cover systems  in
place of, or in conjunction with, natural soil layers.

     Geonets being  considered for use  as  drainage layers should
be  subjected  to  carefully  controlled  laboratory  testing  to
determine  the  material's  transmissivity  and   its  response  to
overburden loading.   Laboratory  tests  should carefully  model the
anticipated field conditions and include the materials which will
be placed adjacent to  the  drainage layer,  realistic overburden
loads,  and  be  conducted under  a range  of  hydraulic  gradients
(usually  less than  1.0).  The overburden  loads  applied  should be
increased incrementally  to  at least the  maximum overburden load
anticipated  in  the  field.   If  possible,  testing  should  be
performed  with  applied overburden  pressures  which  exceed  the
maximum anticipated  pressures  by  at   least 50%  to  check  that
significant  transmissivity  reduction   will  not take  place  if
overloading  does occur.   Transmissivity  reductions  may  be  the
result  of material compression, strand rollover, or the intrusion
of adjacent materials into the drainage channels.

     Variations  in  drainage layer  transmissivity are,  in part,  a
function  of  the  components   of  the   drainage  system  and  the
immediately  adjacent  materials.  Typical  observed variations for
drainage  systems utilizing  geonets are outlined in Table 1.   The
transmissivity   values   shown    are    for   extruded    geonets
approximately 0.2 inches thick, nonwoven geotextiles and cohesive
soils.

     Transmissivity tests described above are generally performed
at various  load increments, with these loads being applied for a
time duration ranging typically  from less  than  one hour up to 24
hours.   Limited testing has been performed on  samples  subjected
to  static  loads with  longer durations.    Testing performed  on
geonet  samples  that  have been  loaded   for almost  two  years
indicates only slight transmissivty reductions after one day.

     Other factors  which  may  impact  the long term performance of
the  drainage layer  are its  creep characteristics,  response  to
elevated  temperatures,  and  the  potential  for  biological  or
mechanical clogging.  Laboratory studies  and field monitoring to
evaluate  the  long-term  effects of these  factors have only begun
recently.  A conservative design  approach is  recommended until
conclusive results are available.

     Synthetic drainage materials exhibit preferential drainage
directions which should be taken into  account  during design and
construction.   Geonets  exhibit  a  wide  range  of  directional
drainage behavior.  Some geonets have transmissivity anisotropies
                              1002

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                                               TABLE 1
                             GEONET DRAINAGE SYSTEM TRANSMISSIVITIES
o
o
Drainage System
 Configuration
             geomembrane
             geonet
             geomembrane
             soil
             geotextlle
             geonet
             geomembrane
             soil
             geotextlie
             geonet
             ge9text11e
             soil
Typical  Transmlssivity
  010,000psf.  1=1.0
                            1 x 10~3M2/sec
                            5 x 10"4M2/sec
                            1 x 10~4M2/sec
Granular Material
   Equivalency
                           12" 0 k=3xlO"1cm/sec
                          12" 0 k=1.5xlO~1cm/sec
                          12" @ k=3xlO"2cm/sec

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that  are  insignificant  and  require  no  special  construction
considerations.  Others have drainage preferences that are nearly
unidirectional  and   the   use  of  such   products   may  require
significant design consideration and careful construction control
to be effective.  In general, overall transmissivity behavior can
be significantly effected by the orientation of the strands which
compose the geonet.

     Compatibility  with  leachate  is  also  a  consideration  for
synthetic  drainage  layers.    Like  geomembrane  barrier  layers,
geonets will  be subjected to leachate  contact  for many years.
Therefore, geonets should undergo testing to verify compatibility
with  the  anticipated  leachate composition.   As  a  result,  most
geonet products are manufactured from HDPE resin.

Interface Layers

     In  order  for   the   materials   utilized   for  the  primary
functions -  barriers and  drainage -  in a  containment  system to
perform  as  designed,  "interface"  layers are  often  required.
Interface functions include filtration, separation and protection
and  can be performed  by  either natural or synthetic  materials.
As is  the case for barriers and drainage layers,  synthetics have
the  advantage  of accomplishing the same function  while occupying
less space than natural materials.

     Filters  must  be provided to maintain the integrity  of the
leachate  collection  zones.  In designing  either  an  aggregate or
geotextile   filter,   the  criteria   conforms  to   traditional
geotechnical engineering practice.  The filter layer must provide
adequate  vertical  drainage (referred to as  permittivity)  to the
lateral flow zone; prevent piping of the overlying soils; and
provide durability against chemical  and  biological  degradation.
While  the  use  of  non-carbonate  aggregates  or  polyester  or
polypropylene geotextiles  should provide protection from leachate
attack, the effects of biological growth on filter performance is
only now being investigated by researchers.  Industry experience
indicates  that nonwoven  geotextiles  are  generally superior  in
performance to  woven  geotextiles, particularly when fine-grained
soils  are being filtered.

     Cushion  layers  are generally required  to protect synthetic
liners from the relatively large  granular  soils  required to meet
current transmissivity requirements.   When synthetic liners first
came into general use, a thin layer of sand was placed both above
and below the  geomembrane in order to  provide protection.   This
practice  prevented   the   construction  of  effective  composite
liners.  It also hindered  the rapid removal of leachate from the
top of the liner by  allowing a relatively low permeability (fine
sand  compared  to  clean  gravel)  zone  immediately  above  the
geomembrane.  Nonwoven geotextiles,  generally at least twelve to
                               1004

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sixteen  ounces  per   square   yard,   have  proven  effective  in
protecting  HOPE  and  other  geomembranes.   Thickness  and  bulk
density  are   the   material  characteristics   required  for  an
effective  cushion.   A  laboratory testing  program incorporating
the  actual  containment  system  configuration  and  anticipated
overburden  loads should  be  performed  in  order  to evaluate  a
specific design.

Synthetic Reinforcement and Stabilization Layers

     Synthetic  reinforcement  layers, known as geogrids,  can be
used  to support  containment  systems  constructed  over normally
unsuitable  foundation  soils   and existing waste  materials  in
"overfill"  or  "piggyback"  landfills.   The necessity  for  this
aplication  increases  along  with  the difficulty  in siting and
permitting  new disposal  facilities  and the  resulting need to
expand  or  maximize  the  utilization  of  existing  facilities.
Geogrids are placed during the construction of the subgrade  soils
to  provide  tensile  reinforcement  to   counter the  effects  of
anticipated deflection, subsidence and differential settlement.

     Another application  for  geogrids in containment  systems is
to  stabilize  the  placement  of  protective soil  cover on  side
slopes.  The  natural  characteristics  of the  granular  materials
generally  used for  protective  cover often limit the  length of
slope  which  can be  covered  at  a   given  time.   Incorporating
geogrids in the design can allow for the placement of  a greater
amount  of  protective cover  at a  given  time,  facilitating
construction and operations.

     As  with   all   synthetic   components,  geogrids  must  be
compatible  with  leachate  and  resist  chemical  attack.    Most
geogrid  products currently used  in  landfill applications are
manufactured from polyethylene resins.


Stability

     During  both   construction   and  operation  of  a  disposal
facility,  the  frictional  characteristics  of  the  containment
system  components  can  be  of  significant  importance.   Stability
considerations   control  the  integrity   of   below-grade   and
above-grade   slopes   and   govern   the   sequence   of   landfill
operations.   Published data  suggest  that  synthetic   interfaces
have  lower friction angles and are  therefore  more critical than
natural   soil   or    soil/synthetic   interfaces.     Geonets   and
geotextiles  are often situated  adjacent  to  geomembranes  in  a
variety  of  applications.    Because  laboratory  data  indicate
relatively  low  friction  angles   for   these  interfaces,   the
stability  of the entire disposal  facility may  be dependent on an
accurate analysis and design of these components.  Conservative
                               1005

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friction angle values or site-specific test results should always
be used as a basis for design.


Leachate Compatibility

     Discussions  concerning  compatibility  with   leachate  are
generally  directed  at  the  geomembrane  component  of  a  liner
system.   However,  in  order to  function  as  designed,  it  is
critical  that  all  components  of  the  containment  system  be
evaluated for compatibility.  All of the synthetic components can
be immersed  in  the anticipated leachate and tested  for physical
property  retention  at  various  time  intervals  in  a  similar
protocol  to  USEPA  9090 for  geomembranes.   Both  USEPA and  the
American  Society  for Testing and Materials  (ASTM)  are currently
developing specific protocols for immersion  testing  for gepnets,
geotextiles  and  other synthetics.    Soil  barrier and  drainage
layers can be evaluated by using leachate to perform permeability
and transmissivity tests, respectively.  USEPA  9100  outlines the
protocol  for clay liners.


CONSTRUCTION CONSIDERATIONS

     The  translation  of an  engineering  design  to a  constructed
facility  is  always   an  area  requiring  careful  monitoring  and
observation.   However,  it  becomes  extremely critical when  the
facility  is  a  solid  waste containment  system  the integrity  of
which  is  paramount   to  protecting  the  environment  and  public
health.   In  order to achieve the most secure facility possible,
the development and implementation of both stringent construction
specifications and a comprehensive construction  quality assurance
program become imperative.

     In   order  to  develop   and implement  a  quality  assurance
program,  it  is first  necessary to  define what is meant  by the
term "quality assurance" and  how it  is related  to  the activities
encompassed by the term "quality control".   These terms are often
used interchangeably,  resulting in a misinterpretation  and lack
of clarity  in the intent of  each  term.   Quality  control  can  be
defined as the measures taken by a contractor to determine if the
work performed  is in compliance with the  project  specifications
and  contract  requirements.  Quality  assurance   refers  to  the
measures  taken  by  the  facility  owner  using  an  independent
engineer  to  determine  if  the work  performed  by  the  contractor
complies  with project specifications and  contract requirements.
Quality assurance, then, is the assessment of the contractor's
performance by the facility owner's third party representative.
                               1006

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Quality Control

     Since the synthetic and natural  materials to be used in the
landfill  containment system have been  specified by  the design
engineer  based  on  laboratory  testing,   it  is critical  that the
materials used in the construction of the landfill have identical
properties as those tested in the  laboratory.  Particularly for
synthetics where critical  properties  can vary significantly even
if  manufacturing  processes are varied only slightly,  it  is
necessary  that   good  quality   control  be   exercised  during
manufacturing  or  processing.    Samples  should  be  taken  on  a
regular  basis  during  manufacturing  and   tested  to  evaluate
relevant  properties.   The manufacturer  should maintain detailed
quality   control   documentation   and    be    able   to   provide
certification of the quality of each roll of material produced.

     It is advisable to use only thoroughly tested products from
manufacturers  who  have  a record  of  consistently  producing  a
quality  product  and to  carefully  review their  quality control
procedures with them prior to  running the product for a specific
site.   Any  supplier who  hesitates  to  fully  cooperate  with all
quality  control  efforts  or is  unwilling to  produce  historical
quality control records should be disqualified from consideration
for the project.

     For natural materials, the  line  between quality control and
quality assurance testing  becomes more  difficult to distinguish.
It  is  necessary  to sample  and  test  a  clay  liner or granular
drainage  stone at  its  source in  order  to define its properties.
The soil  must be in the  condition  in which it  will be actually
utilized  in  construction,  such  as  a  processed  clay  or washed
stone.   In  this way,  the properties determined  as part  of the
quality control program will  be the basis of  assessment for the
quality assurance program  during construction.


Quality Assurance

     The principal  objective of  a construction quality assurance
program  is to minimize potential problems by  achieving the best
installation possible.  To reach this goal,  the quality assurance
program must provide for the utilization  of uniform standards and
practices;    the   verification   of  compliance   with  material
specifications,   installation   and  testing   procedures,   and
applicable  regulatory  requirements;  and  a  defined  route  to
obtaining  as-built  documentation  and   certification  that  the
project was constructed in accordance with the specifications.

     An effective quality  assurance plan must define how it will
achieve  its  stated objectives.   It  will  need  to provide  an
explanation of the qualifications, roles, responsibilities,
                               1007

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authority  and  interaction of  all  parties  involved.   It  must
identify  and  describe  all  quality  assurance  activities  and
procedures and  allow  for well thought out  in-field  decisions by
identifying actions to  be followed when a problem occurs  and by
providing the basis for  problem resolution.  A  preconstruction
meeting, involving all parties,  is  required at the outset  of the
project to  clearly outline  the site-specific quality  assurance
plan, construction  procedures and  lines  of communication  to be
adhered to during the course of the project.  A basic outline for
a construction quality assurance plan is presented on Table 2.

     In addition to  the quality  exercised by the  manufacturer
during  production,  conformance  testing  should  be  performed on
samples taken from the rolls of synthetics delivered to the site.
Samples should  be taken at a  predetermined interval (typically,
one  per 100,000 ft2)  and the tests performed will depend  on the
type of  synthetic being  used.    These  tests  should  indicate
whether or not  the materials  delivered to the site have the same
properties as the designer intended.  Conformance testing  is the
primary way in  which  the  quality assurance  program  is applied to
manufacturing of the synthetics.  An additional step which should
be  taken either on  a  regular  basis  or for major  jobs   is to
perform  an  inspection  of  the manufacturing  facility.   At  a
minimum,  a  plant inspection  should be an  integral  part  of the
prequalification  of any manufacturer.

     The handling, storage,  and transportation of the synthetics
should  be  carefully  controlled  so that  they  are  not  damaged
between the manufacturing plant and their  delivery  to  the site.
The  importance  of this intermediate handling should be stressed
to  all  parties  involved.   All  rolls of synthetics  delivered to
the  site  should be visually inspected for  possible  damage.  All
damaged rolls should  be rejected.  Synthetics used  for drainage
or  filter  applications,  such as geonets or geotextiles, must be
kept clean   and  free  of  debris . which   might   impact   their
performance in  the containment system.   These materials must be
stored  in a dry,  covered area prior to  installation.   If this is
not  done,  extensive cleaning  may be required  at  a  minimum and
rejection of  the  rolls may be necessary in the worst case.

     Careful  attention must be paid to  installation requirements
including  placement,   orientation,  and  joining  techniques.   In
general,  geotextiles  should be  sewn and geonets overlapped and
tied.  Geonet ties should not contain any metal  and  should be of
a contrasting color to the geonet  to allow for  easy inspection.
Typically, geonets  are overlapped  a  minimum of four  inches and
ties spaced  on  the  order  of  five feet  along  slopes,  two  feet
across  slopes,  and six  inches in  anchor  trenches.   It is  also
important that  the installation procedures  (placing,  cutting, and
joining) performed  for each synthetic not  be allow  to adversely
impact the performance of  adjacent  synthetics.
                              1O08

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                             TABLE 2
             CONSTRUCTION QUALITY ASSURANCE PROGRAM
0    OUALZFZCATIONS AND RESPONSIBILITIES OF PARTIES

t    CHAIN-OF-COMMAND, MEETINGS AND REPORTING STRUCTURE

•    SOIL COMPONENTS OF CONTAINMENT SYSTEM
     "  PRE-CONSTRUCTION TESTING OF SOIL SOURCES
     "  TEST FILL CONSTRUCTION AND TESTING
     '  CONSTRUCTION TESTING FOR MATERIAL EVALUATION
     "  CONSTRUCTION TESTING FOR PERFORMANCE PROPERTIES

•    GEOSYNTHETIC COMPONENTS OF CONTAINMENT SYSTEM
     *  MANUFACTURING
     *  FABRICATION
     •  HANDLING, STORAGE AND TRANSPORTATION
     *  INSTALLATION
     *  CONSTRUCTION WITH OTHER MATERIALS

•    DOCUMENTATION AND CERTIFICATION
                               1009

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     All geomembrane seams  must  be visually observed  during the
installation  process.    In  addition,  seams  must  be  evaluated
through non-destructive and destructive testing.  Extrusion seams
can be  non-destructively assessed for continuity using  a vacuum
box or  a spark tester.   Fusion  and extrusion  seams between the
geomembranes can be  split to create  a channel in the  center of
the seam.   In this  instance, the seam can be non-destructively
evaluated  for  continuity with air pressure testing through the
seam channel.  The parameters for non-destructive testing must be
defined  in the quality  assurance plan.   Destructive  evaluation
includes  shear and  peel testing  for  both fusion and extrusion
seams.   The quality assurance plan must  outline a program for
destructive testing, including the frequency  of sampling, sample
size,  in-field and  laboratory testing,  criteria for  acceptance
and rejection, and corrective measures when necessary.

     Quality  assurance procedures should be developed to ensure
that  the installation of adjacent materials  does not  result in
any damage to the synthetics.   It is always  necessary  to place
soil  cover  prior  to  allowing   any equipment  traffic  on areas
covered with synthetics.  The thickness of soil  cover may range
from  one to three  feet,  depending on the type of equipment to be
used.   In general,  at least  eighteen inches  of  protective soil
should  be placed prior to initiating disposal activities within a
synthetically-lined  landfill.

      Quality assurance  measures  for  soil  liner components are
based on the need  to perform tests representative of actual  field
conditions while not  damaging the actual  compacted  liner.   One
approach is to do  all destructive  (sample removal for laboratory
testing) and  in-situ  (field permeability)  testing  on  a  "test
fill" constructed  with the  identical equipment  and methods as the
actual  liner.  In this  way,  the  compacted liner will only need
to be tested to verify that it is in the same  condition  (density,
moisture content)  as  the  test  fill  to confirm  its performance
properties.  In-situ permeability testing on  a 1 x 10  cm/sec or
less  clay liner  can  take several  months to perform.  The  use of a
test  fill can prevent construction delays and  prolonged  exposure
and resulting damage to the  liner.  Scarification  and  bonding
between  lifts and maintaining  correct  moisture are  other  clay
liner  construction  concerns  to  be  addressed  by  the  quality
assurance program.

      As a  result  of  having implemented  a comprehensive  quality
assurance plan,  it will be possible for the independent  engineer
to certify the installation and   for the facility owner to accept
the final  product.   The third  party engineer should prepare a
final  certification report at   the  conclusion of  the  project.
This  report  should  include,  at  a minimum,   an outline  of the
project, the  quality  assurance   methods used,  the  test  results,
and the as-built documentation and drawings.   This report will
                                101O

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serve as  a  basis for the formal  acceptance  of the final product
by  the  facility  owner and,  where  required,  by  the regulatory
agency.•


SUMMARY

     The  design  and  construction  of  solid  waste  containment
systems incorporating  natural  and synthetic  components have been
discussed in this  paper.  Since the utilization of synthetics in
conjunction with  or in lieu of natural  soils  is relatively new,
it  is  important  that  designs  be* based as  much as  possible on
carefully  modeled  laboratory  testing  and  verified  by  field
observation  and   testing.    Significant  design  considerations
included  stability  and  interlayer frictional  characteristics,
transmissivity,  filter  characteristics and  compatibility  with
waste and leachate.  However,  design  is only one of the issues
that must be addressed when dealing with synthetics.   By far the
most  important   part   of  a   successful  installation   is  the
implementation  of  a  comprehensive  quality  control  and  quality
assurance  program  during manufacturing  and  construction.   The
importance  of  this  aspect  for a solid waste  disposal  facility
cannot be overstated.

     It  is  anticipated that  in the future  synthetics  will find
increased use in a  variety of functions at solid waste landfills.
This increased use will be  driven by technical criteria directed
at  designing and  constructing more secure containment facilities
and minimizing  environmental impacts as well  as  by  economic and
site life considerations.  In some  cases, synthetic materials can
offer significant advantages over  the use of  natural materials.
The proven  performance  and  widespread   acceptance  of  these
products dictate that  they be routinely considered in conjunction
with  natural  components  during  the conceptual design phase of
solid waste containment systems for all new disposal  facilities.
                               1011

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REFERENCES

 1.  Bell, J.R., "Design and Construction Using Geosynthetics,"
     ASCE Continuing Education, 1989.

 2.  Giroud, J.P., Geotextile and Geomembrane Definitions.
     Properties and Design. IFAI, St. Paul, Minnesota, 1984.

 3.  Koerner, R.M., Designing with Geosynthetics. 2nd Edition,
     Prentice-Hall, Englewood Cliffs, New Jersey, 1990.

 4.  Koerner, R.M., "Solid Waste Containment Systems Using
     Geosynthetics," Chicago Geotechnical Lecture Series, 1990.

 5.  Koerner, R.M. and Bove, J.A., "Lateral Drainage Designs
     Using Geotextiles and Geocomposites," Geotextile Testing and
     the Design Engineer, ASTM STP 952, 1987.

 6.  Lundell, C.M. and Menoff, S.D., "The Use of Geosynthetics as
     Drainage Media at Solid Waste Landfills," NSWMA Waste Tech
     Proceedings. Boston, Massachusetts, 1988.

 7.  Lundell, C.M. and Menoff, S.D., "The Design and Construction
     of Landfill Containment Systems with Geosynthetic
     Components," Geosynthetics '89 Proceedings. San Diego,
     California, 1989.

 8.  Menoff, S.D., Stenborg, J.W. and Rodgers, M.J., "The Use of
     Geotextiles in Waste Containment Facilities," ACS Hi-Tech
     Textiles Symposium. Miami, Florida, 1989.

 9.  Richardson, G.N. and Koerner, R.M., Geosynthetic Design
     Guidance for Hazardous Waste Cells and Surface Impoundments.
     USEPA-GRI Publication, Philadelphia, Pennsylvania, 1987.

10.  Richardson, G.N., and Koerner, R.M., "Design of Geosynthetic
     Systems for Waste Disposal," ASCE Conference on Geotechnical
     Practice for Waste Disposal. Ann Arbor, Michigan, 1987.

11.  Schubert,  W.R.,  "Bentonite  Matting  in  Composite  Lining
     Systems," ASCE Conference on Geotechnical Practice for Waste
     Disposal. Ann 'Arbor, Michigan, 1987.

12.  Slocumb, R.C., Demeny, D.D. and Christopher, B. R., "Creep
     Characteristics of Drainage Nets," Proceedings of the Ninth
     Annual Madison Waste Conference. Madison, Wisconsin, 1986.

13.  USEPA, Reguirements for Hazardous Waste Landfill Design.
     Construction and Closure. Cincinnati, Ohio, 1989.

14.  Vardy, P., "Impact of Current Regulations on Geotechnical
     Practice," ASCE Conference on Geotechnical Practice for
     Waste Disposal. Ann Arbor, Michigan, 1987.
                                1O12

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        AN ENVIRONMENTAL ASSESSMENT OF RECOVERING
          METHANE FROM MUNICIPAL SOLID WASTE BY

            REFCOM ANAEROBIC  DIGESTION PROCESS
                 Philip  R.  O'Leary,  Ph.D.
   Department  of Engineering Professional Development
                  College  of  Engineering
                           and
                 James C.  Converse,  Ph.D.
          Department  of  Agricultural Engineering
        College of Agricultural and Life Sciences

             University of Wisconsin-Madison
                     Presented at  the

First U.S. Conference on Municipal Solid Waste Management

                     June 13-16,  1990
                           1013

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            AN ENVIRONMENTAL ASSESSMENT OF RECOVERING
              METHANE FROM MUNICIPAL SOLID WASTE BY
                       ANAEROBIC DIGESTION
                            Abstract
     The full scale development of the RefCoM process which
produces biogas or synthetic natural gas  (SNG)  by anaerobic
digestion of municipal solid waste (MSW) is evaluated.  This

technology would be utilized in lieu of incineration or directly

landfilling waste.  An environmental assessment describing the

principal impacts associated with operating the MSW anaerobic
digestion process is presented.  Variations in process

configurations provide for SNG or electricity production and
digester residue incineration, composting, or landfilling.  Four

RefCoM process configurations are compared to the conventional

solid waste disposal alternatives of mass burn incineration and
landfilling.  Value analysis techniques indicate that the RefCoM
process was preferred to mass burn incineration or direct

landfilling of MSW.
                               1014

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     I.  Introduction
     New methods and processes are being sought to cope with the
ever increasing quantities of municipal solid waste  (MSW).
Approaches include source reduction, recycling, waste processing
and separation, energy recovery, and better sanitary landfilling
methods.  One such approach, the RefCoM process, produces
biogas by anaerobic digestion of municipal solid waste.  This
technology would be utilized in lieu of incineration or directly
landfilling a portion of the waste.

     II.  The Anaerobic Digestion Process
     A group of obligately anaerobic bacteria will, in the
absence of O2,  consume various types of organic wastes producing
methane, a major component of natural gas, carbon dioxide, and
water (Stanier, et al., 1965).  The speed, and degree to which
the digestion process is completed will depend on the bacterial
community, nutrient balance, temperature, and the specific
nature of the waste material.  This process occurs naturally in
many places and, in addition, has been extensively used to break
down organic wastes in the sewage treatment process.
                               1015

-------
     Laboratory scale experiments to anaerobically process
municipal solid waste and sewage sludge were described by
Pfeffer  (Pfeffer,  1974; Pfeffer and Khalique, 1976; Pfeffer and
Liebman, 1976).   A single stage anaerobic digestion unit was
tested.  The experimental unit was operated over a temperature
range of 35 to 60 degrees C and 4 to 30 days detention time.
Volatile solids destruction ranged from 16 to 52 percent.  Based
on Pfeffer's work, operation of a 100 ton per day pilot plant
located  in Pompano Beach, Florida, began in 1978 (Mooij and
Pfeffer, 1986) .   Based on the results of the pilot plant test,
Isaacson, et al.,  (1987) estimated the necessary waste
processing fee for various combinations of natural gas,
electricity prices and concluded that the RefCoM process has
"significant commercial potential."

      III.  RefCoM Configurations Evaluated
Alternative RefCoM process configurations were compared to the
conventional solid waste disposal technologies of mass burn"
incineration and landfilling.  The four alternative processes
were:
      1.   RefCoM  synthetic natural gas production with residue
          incineration  (REFCOM SNG/INC), see Figures  1-3;
      2.   RefCoM  biogas  and electric production with  residue
          incineration  (REFCOM ELEC/INC), see Figures 4 and 5;
                               1016

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                                 Figure 1.  RefCoM SNG / Incineration Process Diagram
                                                                                                                 atmosphere
solid
waste
          synthetic natural gas
           production module
            (see Figure 3)
incinerator
feed
solid waste
incinerator
                                               I landfill gas
                                               j   electric
                                                 generator
 digestion
 process
 nutrients
          ncnerator
        , by-pass
                          WWTP
                          chemicals
                              wet trommel water

                              mix tank water

                              boiler makeup water

                              cooling tower makeup water
                                                                  Waste Water Treatment Plant  i

-------
                               Figure 2. RefCoM Waste Preparation Module Process Flow Diagram
      solid
      waste
5

waste
storage
wai
prepar
mod
by-p
te
ation
ule
ass
\


*. shredder to magnetic disc
^ anrtHUCr ^ separator ^ ^'W>


i '
disc screen \-
, , T
•^ 	 ' 	 1 air stoncr p^l 	 1 disc screen
t
air
1 classifier
?

i
?
*~ wet
trommel
i '

ferrous




H magnetic
separator
f
1
P— 	 ' 	 — -•-
gas production waste preparation module underflow
module by-pass
i



i
water

te. aluminum ^ f 	 •
^ "'""" — m*- alumini
separator

Hfa
JJ O ^ i™,ir.n

                      gas production
                       module feed

-------
                          Figure 3. RefCoM Synthetic Natural Gas Production Module Process Diagram
                 digestion process
                 nutrients   	
I
                                                  waste
                                                preparation
                                                 module
mix lank
   feed
                                                                                                                synthetic
                                                                                                                 natural
                                                                                                                  gas
                                                       digester
                                                        flaring
                               kdigester
                                \ gas
                                 leaks
                                                      gas
                                                   seperator
                                                   condensate
                                                                digester
                                                             underground
                                                                   leaks
gas separator
permeate
                                                            boiler

                                                            residue
                                                            incinerator
                                                                                                             water

                                                                                                             steam turbine
                                                                                                             condensate

-------
                                        Figure 4.  RefCoM Electric / Incineration Process Diagram
                                                                                                                      atmosphere
          solid
          waste
                 storage
by-
pass
                   mix
                   tank
                   feed
O
CO
O

waste preparation module
    (sec Figure 2)
                         J_
                          JJ
                          gas production    waste preparation
                          module by-pass    module underflow
                                                 M
         biogas             gas turbine
                        electric generator
          APCchemicals  	M APT!
 biogas production
      module

   (see Figure 2)
          digestion
          process
          nutrients
                                                                                                        landfill gas I
                                                                                                            electric I
                                                                                                          generator
                                 *- wet trummel water

                                 »- mix tank water

                                 *• boiler makeup water

                                 *• cooling tower makeup water                                         ,
                                        6           r                   Waste Water Treatment Plant  i                      !          i

-------
Figure 5.  RefCoM Biogas Module Process Diagram
waste
preparation
module
digestion process
nutrients ... , 	 mix tank
feed
=• ? digester
1 8°^
I leaks
digester Ut ^»— i -x^
i — % ' ' ' ' flaring \ ^_ 	
| | L \ digester
mix 1
biogas gas
turbine
..... ^^ !-_!!--


dcwarererf
residue ._,
i
tank i 1 	 ¥
t ^ /

p\ yv I— ' '
i,,.ni r W 1^
w
/// -
' exchanger ' • rcsidue
0 press

t/igester
underground
leaks
incinerator

waste water


-------
          3.   RefCoM SNG production with residue  composting



          (REFCOM SNG/COM), see Figure 6;



     4.    RefCoM SNG production with residue landfilling




          (REFCOM SNG/LF), see Figure 7.




The conventional mass burn incineration system and the sanitary



landfill are depicted in Figures 8 and 9.



     Each configuration has the same waste preparation module



which shreds and separates waste into degradable and non-



degradable fractions plus aluminum and ferrous metals.  The



degradable fraction is directed to the gas production module




while the non-degradable portion is landfilled.



     The gas production module has a mixing tank where water and



possibly nutrients are added.  The slurry is then pumped into an



air tight tank where the material is continuously stirred,



maintained at a constant temperature, and allowed to decompose




anaerobically.  The product gas, a 55-45 percent mixture of



methane and carbon dioxide, is collected from the digester.  In



the SNG configuration the CO2 is removed and the resulting



methane rich gas is pumped into a natural gas pipeline.  With



the REFCOM ELEC/INC configuration, the gas is not purified and




instead powers a turbine/electric generator unit.
                               1022

-------
                                       Figure 6. RefCoM SNG / Composting Process Diagram
                                                                                                                    atmosphere
O
N
CO
      solid
      waste
            [storage
by-
pass
              mix
              tank
             feed
                                         J.
waste preparation module
    (See Figure 2)
                                          jL_L
       gas production
       module by-pass
            waste preparation
            module underflow
                      APC chemicals
   synthetic natural gas
    production module
     (See Figure 3)
      digestion
      process
      nutrients
                                                    lAPCl I CJoi
                                                 4       "    *
                                 I synthetic natural gas  (SNG)

                                    boilerl
                          incinerator
                          feed
                                waste
                            gas incinerator
                                      digester residue
                            waste water
                                 *- wet trommel water

                                 *• mix tank water

                                 *• boiler makeup water

                                 •> cooling tower makeup wafer
                                                    WWTP
                                                    chemicals
                                                                                             ferrous \
                                                                                                        aluminum
                                                                                          landfill gas
                                                                                            electric
                                                                                          generator
                                                                                                                        compost land
                                                                                                                        spreading
                                                                        Waste Water Treatment Plant i
                                                                                                        run-
                                                                                                        off

-------
                               Figure 7. RefCoM SNG / Landfilling Process Diagram
                                                                                                  atmosphere
solid
waste
  r


-*~{sjorage (-»•
mj
tai

stion
ess
ients
aaxx wa
jt
i*
•d
•• .

ste prcparali<
(See Figu
j
^

re 2) j
| | , ^hl
gas production waste preparation \
module by-pass module underflow j synthetic natural gas (SNG)

synthetic natura
production mo
(See Figure 2
i
i


APC chemicals 	 y •
lAPCl 1 Ch^
Igas
dule
0
1 *i
• i
gas
	 	 	 *• incinerator
incinerator
i digester residde




i ,
v*5*C nFQtCf | ^


*~ wet trummel water "."T ,
cwffucaw
+* mix tank water fiilr"
»• Ao/ter makeup water \^~J~
I,
leachate

1
ferrous
aluminum
landfill gas
electric
generator
^ i
' III 1 " UU^i
^1 > I x>^
sanitary ] •
landfill J
f
>o-




•u
electricity
r
electric
service
-
                        ». cooling tower makeup water
                                                           Waste Water Treatment Plant

-------
                                           Figure 8.  Mass Burn Incineration System Process Diagram
                                                                                                                     atmosphere
O
to
01
                  air pollution
                  control chemicals
                                                                                                             electricity \
                                                                    electric
                                                                  generator j
                                          I solid waste
                                          ' incinerator
                            incinerator
                           feed
incinerator
by-pass
                                                                                              landfill gas
                                                                                            1      electric
                                                                                           sanitary
                                                                                           landfill
                              WWTP
                              chemicals
                    boiler makeup water

                    cooling tower makeup water
                                                               Waste Water Treatment Plant

-------
                                                    Figure 9.  Landfill Process Diagram
o
to
0)
                                                                                                              atmosphere
                                                                                          landfill gas
                                                                                             electric
                                                                                            generator
                                               Waste Water Treatment Plant

-------
     IV.  Comparison Procedure




     A mass flow model estimated the quantity of gases and




liquid wastes which will be released to the environment by each



configuration and alternative waste disposal system under




consideration.  In addition, the amount of land permanently



occupied by the landfill alternative and the landfills




associated with the RefCoM process and the mass burn incinerator



was projected.




     The comparison used a systems approach where each RefCoM



configuration and alternative disposal method has the same



function.  Within the system boundaries, landfills received



RefCoM and incineration residues, and a waste water treatment



plant received landfill leachates.  Emissions and effluents from



the original production and manufacturing of natural gas,



electricity, aluminum and iron were estimated to account for the



environmental discharges avoided when the RefCoM process has



SNG, electric energy, and recovered metals as products.








     Each RefCoM process configuration and the alternative mass



burn and landfill systems were assumed to be designed to



comparable technical and regulatory standards.  The standard



selected represents United States Environmental Protection



Agency "new source performance" and, if not defined, "best



implemented control technology."
                               1027

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     Air emissions from the RefCoM process residue incinerator



and mass burn incinerator were characterized from stack test



data at three new incinerators which have advanced air pollution



control technology.  Landfill gas emissions which are



characterized by California and Wisconsin stack tests.  Liquid



discharges from the landfills were predicted with the U.S. EPA



HELP Model.  Air and water emissions from natural gas, electric,



aluminum and iron production were estimated from U.S. EPA new



source standards and emission factors studies.



     The purpose for predicting the emission, effluent, and land



use quantities for the RefCoM process and mass burn and



landfilling alternatives was to make comparisons and draw



conclusions regarding the best system, environmentally.  A more



stringent  test was provided by comparing the RefCoM process to



mass burn  incineration and landfills which are designed to the



latest standards.  Undoubtedly, the RefCoM process will reduce



reliance on landfills, many of which comply with only minimal



standards.  Assuming stringent environmental standards for



natural gas, electric, aluminum and iron production further



strengthened the test.



     Residue from  the anaerobic digester is dewatered and two



configurations, REFCOM SNG/INC and REFCOM ELEC/INC, incinerate



this residue.  The REFCOM SNG/COM configuration assumes the



residue is composted and spread on land.  The residue is



landfilled with the REFCOM SNG/LF configuration.
                               1O28

-------
     V. . Predicted Results




     The results of this predictive and characterization work




are summarized in Table 1.  Emissions, effluents,and land use




from the systems are separated into three locational categories:



     1.  On-site:  occurring at the RefCoM process



         facility or mass burn incinerator;



     2.  Off-site:  associated with the ash and sanitary



         landfills, waste water treatment plant and the



         vehicles hauling solid waste, ash and sludge;



     3.  Remote:  resulting from electric power generation



         and natural gas, aluminum, and iron production.








     From Table 1, it is not possible to deem one system



inherently better than the rest.  To make this judgement,  a



value analysis was conducted.  Four people with broad



environmental backgrounds provided their subjective assessment



of the relative importance of the emissions, effluents, and land



use along with locational judgements.  The four people were:



     1.  -a former local  government official



     2.   an environmental attorney/educator



     3.   an energy management engineer




     4.   a state official



These subjective importance weighting factors, when applied to



the estimates in Table 1, give the results in Table 2.  The
                              1029

-------
S
       Table  1.  Predicted Performance of Four MSW Anaerobic Digestion Process
                  Configurations/  Mass  Burn  Incinerator,  and Sanitary  Landfill.
SOLID WASTE RECEIVED  (tons/yr)

RECOVERED RESOURCES
   Ferrous  (tons/yr)
   Aluminum (tons/yr)
   SNG Production Rate  (SCF/yr)
   Total  Electric Generation  (MWH/yr)
ON-SITE AIR EMISSIONS
   particulate  (tons/yr)
   S02 (tons/yr)
   NOx (tons/yr)
   PCCD (tons/yr)
   C02 (tons/yr)
OFF-SITE  AIR EMISSIONS
   particulate  (tons/yr)
   S02 (tons/yr)
   NOx (tons/yr)
   vinyl  chloride  (tons/yr)
   C02 (tons/yr)
OFF-SITE  DISCHARGE TO GROUNDWATER
   leachate leakage  (tons/yr)
OFF-SITE  SURFACE WATER EFFLUENTS
   WWTP effluent  (tons/yr)
OFF-SITE  PERMANENT LAND USE
   landfill area  (acres/yr)
REMOTE AIR EMISSIONS
   particulate  (tons/yr)
   S02 (tons/yr)
   NOx (tons/yr)
   C02 (tons/yr)
REFCOM
SNG/INC
104000
5860
311.2
3.6E+08
5552
1.956
21
103
2.1E-07
53270
1.24
10.4
2.68
0.0369
31432
5044
25684
0.902
5.9469
240.4
120.33
44126
REFCOM
ELEC/INC
104000
58.60
311.2
0
50579
2.681
36.28
178
3.6E-07
72883
1.245
10.5
2.7
0.0369
31473
5051
26514
0.922
0.0389
117 .8
1.14
1150
REFCOM
SNG /COM
104000
5860
311.2
3.4E+08
-7411
0.298
4.03
19.7
4.0E-08
8455
1.293
13.6
3.14
0.0369
66585
5004
20513
0.776
8.8094
314.1
155.01
56875
REFCOM
SNG/LF
104000
5860
311.2
3.4E+08
-5714
0.298
4.03
19.7
4.0E-08
8455
2.433
16.5
4.81
0.0686
66406
8435
34499
1.306
8.5516
305
150.48
55211
MASS
BURN
104000
0
0
0
36791
3.477
48.43
237.5
4.8E-07
93978
0.94
11.4
2.45
0.027
21467
2704
37954
1.062
21.5398
262.6
79.49
30087
LANDFILL
104000
0
0
0
6032.284
0
0
0
O.OE+00
0
4.555
24.7
8.25
0.1231
125840
16593
67636
2.564
27.1278
458.9
177.81
66142

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Table  2.   Value  Analysis Ranking of  Four MSW  Anaerobic  Digestion  Process
           Configurations,  Mass Burn  Incinerator and Sanitary Landfill
FORMER LOCAL OFFICIAL
   VALUE
   RANK

ENVIRONMENTAL ATTORNEY/EDUCATOR
   VALUE
   RANK

ENERGY MANAGEMENT ENGINEER
   VALUE
   RANK

STATE  OFFICIAL
   VALUE
   RANK

MEAN VALUE
   RANK
REFCOM
5NG/INC
0.8555
2
0.7431
2
0.7656
3
0.5894
3
0.7384
2
REFCOM
E LEG/ INC
0,7615
4
0,7027
4
0.7837
1
0.6169
2
0.7162
3
REFCOM
SNG/COM
0.9176
1
0.8195
1
0.7698
2
0.6191
1
0.7815
1
REFCOM
SNG/LF
0.8391
3
0.7095
3
0.6581
4
0.5329
4
0.6849
4
.MASS
BURN
0.5694
5
0.5913
5
0.5981
5
0.5190
5
0.5695
5
LANDFILL
0.4555
6
0.2805
6
0.1808
6
0.2952
6
0.3030
6
NOTE:  Possible value ranges  are from 0-1 with 1 being best

-------
RefCoM process ranking is always higher than the mass burn or



sanitary landfill rankings.




     Sensitivity analysis showed that less than optimum RefCoM




process performance does not change the ranking.  Changes in MSW




management such as source separation of newspaper, yard waste




and aluminum and ferrous metals also do not impact the ranking.




Sensitivity testing of the value analysis weighting factors



shows that even when the local air emissions weighting is



doubled, the same ranking of RefCoM relative to mass burn and



landfilling is maintained.








     VI.  Conclusions



     This study concludes:



     1.   There is  less  environmental impact as measured by



          emissions, effluents, and landfill area resulting  from



          the  RefCoM process than:




          a.   mass burn incineration;



          b.   sanitary  landfilling.



     2.   The  above conclusions are sustained even  if source



          • separation, suchas recycling of newspapers, yard



          wastes, aluminum or  ferrous metals, significantly



          changes the nature of the waste stream;



     3.   The  REFCOM SNG/COM configuration compares favorably



          with the  other RefCoM processes but should be given a



          site specific  evaluation to confirm this  result.   In
                               1032

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          particular, the land spreading of composted residue



          which contains quantities of plastics, glass, and




          metal needs site specific evaluation.








                           Acknowledgement




     This study was funded by a grant from Renewable Energy




Systems, Inc., Palos Park, Illinois.  The support and guidance



of Peter Benson, President,, is gratefully appreciated.
                                1033

-------
                           REFERENCES
Isaacson, Ron, John Pfeffer, Peter Mooij, and Jim Geselbracht,
     1987.  "RefCoM - Technical Status, Economics and Market,"
     paper presented at the Conference on Energy from Biomass
     and Wastes XI, Orlando, Florida, March 16-20.

Mooij,  H.P. and J. Pfeffer, 1986.  "RefCoM Equipment Research
     and Development Program 1976-1986, Final Report,"
     DOE/CS/20038-T20.

O'Leary, Philip R., 1989.  "RefCoM Environmental Assessment,
     Final Report," University of Wisconsin-Madison.

Pfeffer, John T., 1974.  "Temperature Effects on Anaerobic
     Fermentation of Domestic Refuse," Biotechnology and
     Bioengineering, Vol. XVI, pp. 771-787.

Pfeffer, John T. and Khalique A. Khan,  1976.  "Microbial
     Production of Methane from Municipal Refuse", Biotechnology
     and Bioengineering, Vol. XVIII, pp. 1179-1191.

Pfeffer, John T. and Jon C. Liebman, 1976.  "Energy from Refuse
     by Bioconversion, Fermentation  and Residue Disposal
     Processes," .Resource Recovery and Conservation, pp. 295-
     313.

Stanier, Roger Y., Michael Doudoroff and Edward A. Adelberg,
     1965.  The Microbial  World, 2d  ed.  Englewood Cliffs:
     Prentice-Hall, Inc.
                              1034

-------
                  LANDFILL REMEDIATION
            GREGORY N. RICHARDSON,  PH.D.,  P.E.
                   WESTINGHOUSE -  EGS
                    PRESENTED AT THE


FIRST U.S. CONFERENCE ON MUNICIPAL SOLID WASTE MANAGEMENT


                        JUNE 13-16
                              1O35

-------
Introduction



     Contemporary  waste  containment cells  rely on  a  layered



system of soil liners, synthetic liners,  and  liquid  collection



layers to  prevent the migration of leachate  generated in  the



waste to the  surrounding subgrade.   Such systems have  been in



common usage  for 10  years in RCRA related waste containment



cells, but  are  just now achieving  similiar usage in municipal



solid  waste  (MSW)  waste containment facilities.    This  paper



discusses  three  landfill failures  and the  remediation  efforts



being performed.  The waste category and type of failure for the



three cases are as  follows:



   1 -  MSW Landfill,  General  Foundation Failure,



   2 -  Industrial Landfill, Sidewall  Failure,  and



   3 -  CERCLA Closure, Cap Stability  Failure.



     The MSW case will illustrate the  need for design review of



daily  landfill  operations.   The  remaining   cases  deal  with



stability problems inherent in the multi-layered lining systems.



Case 1 - MSW  Landfill. Maine



     In mid-August  1989, a 500,000m3 landslide  occurred at  a



commercially  operated landfill in central Maine.  The landfill



material consisted of municipal solid waste (MSW) that rested on



a  thick  deposit  of marine clay-silt  which provided a  natural



barrier to  leachate seepage.



     The movement lasted about 15  seconds.   During  the slide,



huge vertical crevices formed in the landfill.  Trash dropped 6
                              1O36

-------
to 9 meters into scarps  formed  in the underlying clay  as  the



soil slid out  from underneath  the landfill.   The  landslide



occurred  following a 10  day period when  over 125 mm of  rain



fell.  During the slide, 6 large  crevices opened up in the trash



pile.   Some of  the crevices were 15  meters wide and up to  9



meters  deep.   Soil was disturbed by  the  landslide up  to  100



meters  beyond  the  original toe  of  the  landfill.    Due  to



remolding,  some  of the  clay lost 90% of its original undrained



shear strength.   At some locations,  the remolded clay and silt



flowed  over undisturbed soil at a shallow depth.   Analysis of



the  slide indicated that a rotational failure  first occurred



under  the original landfill slope.   The  rotation  left steep



unsupported slopes within the trash pile and the underlying clay



and  silt.   Blocks of trash  and clay then followed the direction



of the  initial movement.



     While  the marine  clay and silt  offers an  ideal  natural



barrier to the  seepage of leachate, the  strength  of the soil



limits  the weight of fill which  may  be placed on top of it.  As



the  landfill  expanded,  monitoring wells were  installed  and



laboratory tests  on soils were run.   Some  of  the monitoring



wells  included field vane shear tests  (ASTM D2573-72) and 76mm



Shelby   tube   sampling.      Laboratory  testing   included



 classification,  strength, and consolidation testing.  Figure 1



 shows  typical laboratory Atterberg and consolidation test data,



 as well as vane shear data, for the marine clays and silts.



     Using the vane shear data and what was thought to be a
                              1037

-------
reasonable value  for  the density  of the  landfill,  a  height



limitation of 17 meters was placed on the existing MSW landfill



in mid-1986.   With fill above that level, it was calculated that



the factor of safety against a slope failure would be below 1.25



for  short  term  conditions  and   that  was   not  acceptable.



Laboratory  testing  subsequent  to  the  landslide  and  back-



calculations  from the slide itself have shown that  the  field



vane test values were in fact considerably lower than the shear



strengths developed in the clay-silt.



     However,   another  factor  that  strongly  influenced  the



stability of the landfill slopes was the density of the landfill



material.  In the early stages  of  the operation,  the owner had



little historical on-site data to indicate the landfill density.



Consequently,  a density that seemed  appropriate,  based  on the



appearance of the fill  was used.   A value of 590 kg/m3  (1000



Ib/cy) was estimated and this  value seemed to be corroborated by



historical  information.   In  retrospect,  it  should  have  been



recognized  that   landfill  technology  was  changing.     More



compactive  effort was  being  applied  in  an effort  to  squeeze



greater  amounts  of trash  into limited landfill  space.    In



addition, more daily cover material (sand and gravel) was being



added to  control  odor,  birds  and blowing trash.   These factors



all  contributed  to  a  much  higher  density  than  originally



anticipated   and  used  in  the   stability analyses  that  were



originally performed.



     By mid-1987, weight and volume data was available to
                              1038

-------
indicate the density of the trash and cover was on the order of
1250  kg/m3  (2125 Ib/cy) .   At  that  time,  the  height of  the
landfill was nearing 12 meters.   The reader will recall that an
earlier 17 meter height limitation was based on an analysis that
used a landfill density of 590 kg/m3.  Without strength increases
in  the clay,  the computed factor  of  safety  against a  slope
failure  would have  been less  than  1  with the  height at  17
meters.    Considering  clay  strength  increase,  the  minimum
calculated factor of the landfill slopes was approximately 1.25
with  the height  at 12 meters and  the  density at  1250 kg/m3.
     As an additional tool to monitor the stability of the slopes
while the fill   height  was gradually  being increased,  slope
inclinometers were installed on three sides of the MSW landfill.
Those were  the  east,  south  and   north  sides.    The  owner
recommended  against placing the inclinometers on the west side.
The company  reasoned   that  since  expansion  to  the west  was
thought to be imminent, inclinometers in that area would quickly
be  in the way of new landfill  construction.   In hind sight, it
was to the  west that   the  inclinometers would have  been  most
useful.  As discussed below, slopes  in that direction ultimately
failed because of the  expansion construction activities.
     From•late 1987 to  early 1988 to early  1989, the height of
the MSW landfill was  gradually increased to  about  18 meters.
Biweekly readings  on   the  inclinometers  indicated a  maximum
lateral movement of  19mm per year.   This rate was judged to be
high, but acceptable.
                               1039

-------
     In early 1989, a re-analysis of the landfill slope stability



was  performed.    The re-analysis used  the  latest  height  and



density information,  and extrapolated  strength data from  the



field van shear data. The re-analysis indicated that the safety



factor for the landfill  slopes was very close to 1.  To increase



the  safety factor, the  owner decided to step back the slope at



the present fill height  and add a berm where possible around the



landfill.  Berms  were built on the east and  south sides of the



landfill  to  add counter weight  to the slopes.  Waste piles to



the   north   and  south   also  provided  buttressing in  those



directions.   Again,  however,  the owner was reluctant to  add a



stabilizing berm  on the west side of the landfill due to  planned



westerly  expansion.



     Construction began  on the  westerly expansion  in the late



Spring  of 1989.  Trees cleared, the topsoil was  stripped from



the  clay  and  silt, and all weathered soil was removed below the



topsoil.    Some  of  the weathered  soil  was  mined for  cover



material  for other landfills.   Since digging into the clay and



silt would also increase the capacity of the landfill, the plans



called  for  the  removal of  2  to  2.5  meters  of soil  in  the



expansion area.  Because the new area was to  be  lined  and the



original  area  was  not, a leachate collection trench  was dug



adjacent  to  the toe  of  the old landfill.



     In hind sight, it was probably obvious that removing strong



soil at the  toe,  which  was supporting the existing  landfill
                              1040

-------
slope, and then cutting a leachate collection trench deeper into



the ground at the toe, were not prudent steps to take.



Following  a  10 day  period when over  125mm of rain  fell,  the



landslide occurred.



     To permit more  accurate  back-calculation of the  clay  and



silt shear strengths under the landfill  just before the slide,



the  owner performed  a dozen  large-scale  density tests  and  6



direct  shear tests  in the trash.   Each density  test involved



digging about 8 m3 of trash out of the fill cross sectioning the



excavation   to  measure   its  volume,  and  then  weighing  the



excavated material.   The results of the density tests indicated



an  average density  of 1534 kg/m3  (2600  Id/cy).  Those values



compare reasonably well with the overall density calculated from



1989  tipping data, truckloads of cover material  hauled to  the



site    and    volume    change   computed   from    different



photogrammetrically produced  topographic maps  (1503  kg/m3) .



     To measure the  shear strength  of  the  trash,  the  owner



constructed  a 1.5m2  square shear box.  The box was  loaded with



large concrete blocks to vary the  normal force in the test.



Figure 2  provided a summary of the  results.







Summary...The predicted stability failure at this MSW landfill



demonstrates the  need  for ongoing  engineering review  of  the



operations  of  such  facilities.    Additionally,  the measured



density of the MSW  greatly exceeded that predicted by general



historical data.   Thus, as even greater  efforts are being
                              1041

-------
expended to  maximize airspace utilization,  the designer must
improve such design assumptions.  Design of a new MSW lined cell
is  proceeding  for  this facility.    Future  stability will  be
ensured by limiting the depth of waste and slope of the working
face.  These limits are being established using slope stability
analyses using the measured waste densities and shear strengths.

Case 2 Industrial Landfill. Ohio
     During the construction  of an  industrial landfill in Ohio,
a  layer of cover  soil being placed  over the  synthetic  liner
collapsed.   This  collapse resulted in much of the  synthetic
liner  being  dragged to the base of the sideslope.   The design
profile  of the sidewall liner  system  is shown on Figure 3.   As
is commonly the case, the sidewall  liner system was the product
of both state regulatory demands  and the  designers  original
intent.   Interestingly, the failure occurred between  the HOPE
liner  and  the  lower slit-film woven geotextile.
     Just  such a  failure  had concerned  the design  engineer.
Early  calculations  indicated that  the  cover  soil  would  be
marginally stable if the slope length  was  less than 79 feet.   To
provide  a  greater margin of  safety, the  designer required that
no more  than 15 feet of cover soil be placed in advance of  the
waste.
     As construction progressed, concern was expressed regarding
the ability  of heavy equipment to  operate on the dredge spoils
to be  placed within the cell.  Fearing the future inability to
                              1O42

-------
advance the  cover soil protecting the liner, a  field decision
was made to place the entire cover layer.  A sliding  failure
occurred as  placement  of the cover soil neared  completion and
prior to placement of waste in the cell.
     Post  failure   laboratory   testing  indicated   that   the
coefficient of friction between the HDPE liner and the slit-film
woven  geotextile was approximately 9-degrees.   This  confirmed
that the weight  of the cover soil was carried by tension in the
upper  geotextile and the  liner,  by the frictional  components
between the layers, and by the compressive strength of the cover
layer  itself.  An analysis was performed to estimate the minimum
cover  soil cohesion required to maintain a  minimum factor-of-
safety against sliding of 1.0.  Figure 4 shows  the  results of
this analysis and the range of cohesion values actually obtained
from samples of  the cover soil.   The cause of the failure became
evident when field surveys indicated that slope lengths exceeded
120-feet.
     Remediation of  the  sideslopes involved  replacement of the
smooth HDPE liner with textured HOPE,  and the  use of nonwoven
geotextiles. Both measures dramatically increased the interface
 friction angles  between  the  geotextiles and the  liner.   This
 successfully reduced the load being carried within the plane of
 the cover soil.  Additionally, note that the  geonet drainage
 layer was  bonded to  the geotextiles bounding  it.    This was
 necessary to prevent placing the geonet in tension.
                               1043

-------
Case 3 - CERCLA Cover. Connecticut



     In  a  CERCLA  closure  common to  the  northeast,   sludges



generated from  the closure of  settling  lagoons at an  electro



plating operation were to be consolidated within  the  footprint



of the original lagoons and secured with an impermeable cover.



While no specific regulatory criteria exists for CERCLA covers,



EPA has generally assumed that RCRA Minimum Technology Guidance



provides a  reasonable minimum cover profile.   This results in



a cover that contains the following layered systems:



   •  Low-Permeability Barrier  Layer,



   •  Drainage Layer,  and  a



   •  Protective Layer.



The  design  profile for this cover and the slope toe  drainage



detail are  shown on Figure 5.



     The low-permeability  barrier was  an effective  composite



formed  by  the  30-mil PVC geomembrane  and  the bentonite  mat.



However, the bentonite mat has an upper  surface  composed  of a



woven polypropylene geotextile.  As in the previous case study,



the  coefficient of friction between a geotextile and  a smooth



geomembrane typically ranges  from 9-12 degrees.  Thus  the cap



profile  constructed  on the  design 3H:1V slopes would  either be



unstable or would rely on  the tensile strength of the filter



fabric and  the  geomembrane.



     Just prior to letting bid  documents,  a geogrid was added to



the  cover profile.  The geogrid was placed immediately above the



filter fabric and  was intended to.carry  the weight of the
                              1044

-------
overlying  cover soil.   While  incorporated  into the  project
specifications,  the engineer did  not modify the drawings  to
indicate the proper placement of the geogrid.  Fortunately,  the
small size of the cap,  < 1/2 acre, allowed the geogrid to be run
continuously across the breadth of the cap.
     While no failure occurred in this cap,  the success was due
to the small size of the cap and not to the technical ability of
the designer.  No stability calculations had been performed and
no    geogrid    installation    guidelines    were    prepared.
Interestingly,  the  EPA review  process  did  not detect  these
omissions.

Summary
     The rate  of failures  within waste containment  systems  is
increasing.   This increase rate can be directly traced to  the
following factors:
        The need for the design engineer to establish operational
        guidelines that ensure the stability of the facility as
        waste is being placed, and
        Sliding  instabilities  generated when two geosynthetic
        materials are used in contact on slopes.
     Both  designers  and regulatory reviewers must  ensure that
stability calculations are prepared for construction profiles,
operational conditions, and closure profiles.   Such stability
calculations should be used to establish operational guidelines
for placement of waste within the waste  containment  system.
                              1045

-------
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       1.9 -
       1.8 •
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55
i.
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      0.5-
0.4-
0.3 -
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        Normal Stress, Kg/sq.cm.



Figure 2 - MSW Direct Shear Test Results
             Figure  3  Failed CERCLA Liner  System -  Case 2
                                       1047

-------
u
a
 /-
o
b)
     1000
dl
     Ceo
                          AD
                                   £,e>
                                           fto
                                                     100      izo
                       Figure 4 Cover Soil Shear  Strength  vs
                                             Stable Slope Length - Case 2
12" TRAP ROCK
                            e't
                                          FILTER FABRIC
                                                                  f_    PVC ITfEMBRANE
                                                                      BENTONITE  MAT

                                                            '—GEOTEXTILE  CUSHION
                                         12    i
                    Figure 5   Initial  CERCLA Cover System - Case  3
                                          1O48

-------
                     CASE STUDY:
       LBACHATB CONTAINMENT IN AM  OLD LANDFILL
SPRINGFIELD ROAD LANDFILL - HENRICO COUNTY, VIRGINIA

              DONALD O.  NUTTALL,  P.B.
               DRAPER ADEN ASSOCIATES
                 4136 INNSLAKE DRIVE
             GLEN ALLEN, VIRGINIA 23060
                    804-270-7675
                  Presented at the

   First U.  8.  Conference on Municipal Solid Waste

                  Jane 13-16, 1990
                          1049

-------
                  SPRINGFIELD ROAD LANDFILL
                 LEACHATE REMEDIATION PROJECT
INTRODUCTION
    New regulations and new facilities have held our

attention and much of the limelight in recent months and

years. Many states, with their eyes set on the future, are

implementing tougher regulations for a new generation of

environmentally sound landfills. But what of the old

facilities/ the ones already in the ground. They have

received little attention though many regulations require
remedial action to control offsite leachate migration or

documented groundwater pollution.


    A great deal has been written and said about liner

systems, leachate management systems and the other features
of a modern landfill. But we hear little about how to deal

with the older sites which are going to be with us for years
to come.


     This paper will explain how a corrective action project
was planned, designed and implemented at an existing landfill

in central Virginia. The landfill is a municipal solid waste

landfill located in Henrico County Virginia, a suburban

community of Richmond, Virginia.
                              1050

-------
     In 1985, efforts began to plan for an expansion of the
landfill. As part of that process, a detailed geotechnical
Investigation was made of the landfill. During that
investigation it was discovered that there may have been
problems with contamination  of a major drainage feature*
called Rooty Branch which flowed between the two main fill
areas of the landfill. These indications caused concern that
there might also be leachate entering Aliens Branch and the
Chickahominy River which form the west and north boundary of
the site. (The general configuration of the site is shown on
Figure 1).

    With these concerns in mind, the first step was to review
in detail the available data on the site ground water and
surface water quality. In addition the depth and direction of
groundwater flow and the surface of the bedrock underlying
the site were mapped. This revealed that the landfill was
situated on a thin soil overburden over a granitic bedrock.
In some places, the depth to bedrock was as shallow as 5
feet.

    Review of the data indicated that the flow of ground
water was along the bedrock surface toward Rooty Branch. The
flow ran under the existing landfill sections known as the
                              1051

-------
         ?00
   o
   CJl
   to
                                                 1-295
DRAPER-ADEN  ASSOCIATES, INC.
          Sf-RlfJGriELO  ROAf  LAN'DFILL


MASTER  PLAN-EXISTING  SITE PLAN
                                                                                                   8304
                                                                                                                     OR* WING

-------
western and eastern fills. There was no  flow toward Aliens

Branch or the Chickahominy River which bordered the site.

Flow in the northeast and northwest direction was blocked by

rock ridges. The slope of the bedrock was  found to be  toward

Rooty Branch, this meant that the leachate flow could  be

confined and possibly intercepted at Rooty Branch.



    Analysis of the ground water and surface water data

confirmed the analysis of the hydrogeologic situation. The

levels of indicator parameters in Rooty  Branch were generally

higher than in the other water courses.  (Figures 3,4 and 5
                              /
illustrate selected readings for Chlorides, Iron and TDS in

Rooty Branch). The initial indications led to the conclusion

that leachate from the landfill was entering Rooty Branch.



    Based on the results of the initial  investigation  the

decision was made to find a way to prevent the contaminants

from leaving the landfill and entering Rooty Branch. The next

step in the process was the determination  of the best  method

of achieving that goal.



    The alternatives considered were (1) rerouting of  Rooty

"Branch, (2) the lining of the creek and  (3) the hydraulic

isolation of the creek in its existing location. Relocation

of the creek was eliminated from consideration first,  due to


                             1053

-------
its high cost, the amount of landfill space which would have
baen lost and the potential for creating pathways for
leachate movement since significant blasting of the bedrock
would have been required.

    The second option, lining of the creek, would have
separated the surface water from the ground water but would
not have done anything to prevent movement into the
groundwater. The alternative of hydraulically isolating the
creek appeared to meet the goal of controlling release of
contaminants into the Rooty Branch drainage course, with few
negative effects.

    Several methods were considered to achieve this
isolation. They included the Installation of concrete or
sheetpiling walls down to bedrock; trench drains around the
landfill and slurry walls. In the end, the alternative
selected was to straighten the meandering course of Rooty
Branch, Install perforated  drains along the toe of the
Existing landfill to intercept any leachate leaving the
landfill and to Install a soil bentonite slurry wall down to
bedrock in the area between the creek and the perforated
drains. In this way any leachate leaving the landfill and
flowing toward the creek would be intercepted and diverted by
the drains to a pump station which would pump the leachate to
a regional  wastewater treatment system. The slurry wall
                              1054

-------
would act as a barrier to isolate the creek from the
landfill. (Figure 2 illustrates the concept in schematic
form).

SYSTEM DKSIGH

    Design of the features of this project presented several
challenges. How could a bentonite slurry be installed  in
ground which  was known to contain contaminants? Where  were
the limits of the landfill so the drains could be placed
properly? How could the slurry wall be protected from  the
traffic  and construction activities associated with landfills
and how  would it fit into the final closure configuration of
the landfill? How could this system best fit  into the  overall
landfill design? Could some elements of this  system be used
in conjunction with other parts of the leachate collection
system for the existing and future landfill disposal areas?

    The  final configuration achieved answers  to many of these
questions. To reduce the effects of the known contaminants  in
the ground where the slurry wall was to be  installed,  the
excavated soil was removed and not used for slurry backfill
mix as is common practice. Clean soil was  imported for use  in
the backfill  mix. A bentonite which is listed as contaminant
resistant was specified. The water source  for the slurry
                              1O55

-------
                               REFUSE FILL
                                              A\\\\\
                                      /v\\\\\\x\\\
                                      BENTONITE
                                      SLURRY WALL

                                      LEACHATE COLLECTORS

HYDRAULIC  ISOLATION  OF ROOTY BRANCH
                                           FIGURE 2

-------
mixture was tested and approved. Use of the water in Rooty
Branch itself was not permitted.

    The configuration of the drain and slurry wall system was
based on information gathered from the operating personnel
who actually built the landfill and from test pits dug to
confirm the limits of fill. The geotechnical mapping of the
landfill gave information to guide decisions on the depth of
the drains and slurry wall.

    The slurry wall was designed to tie into the shallow
bedrock on either side of Rooty Branch at both ends of the
project. This was done to help achieve isolation by tying the
slurry wall into the bedrock ridges which isolated the other
parts of the site. Protection from desiccation, erosion and
traffic was achieved by an 18 inch soil cap over the wall at
the ground surface.

    The trench drains are designed to be incorporated into
the overall landfill leachate collection system. The trench
drains act as the gravity connection between the leachate
collection system on the eastern side of the landfill and the
main pump station. The trench drains also connect the
leachate collection system from the landfill expansion area
                               1057

-------
to the main pump station. All collected leachate is pumped to
a regional wastewater treatment facility.

    The final phase in this project will come when the old
fill areas have been finally capped out and closed. This
measure will have the most dramatic affect on leachate
reduction. The landfill is still in operation and final
capping will not be in  place for several years.

 CONSTRUCTION

    Construction of the improved channel of Rooty Branch, the
trench drains and the slurry wall took place during the fall
of 1987 and the spring of 1988. Though the construction went
smoothly, there were two problems which were of particular
note because they potentially could have affected the project
goals.

    The trench drains were to have been installed down to the
rock surface. The rock surface was found to be more irregular
than was expected. It became necessary to resort to some
minor blasting to achieve the required grades to make the
drains work properly. Rock was excavated as much as possible
with heavy backhoes. Only blasting which was absolutely
necessary was allowed and then only with light charges. This

                              1058

-------
Was done to minimize the chance of fracturing the rock and
creating new pathways for leachate migration.

    The installation of the slurry wall presented one problem
which required field correction. Bench scale tests were
performed to determine the appropriate bentonite content for
the soil/bentonite backfill of the slurry wall when onsite
soils were used for the mixture. Field mixtures revealed a
problem with workability not found on the laboratory scale.
The soil/bentonite mixture would not flow into the trench. In
fact, the mixture acted much like a wet clay and was very
cohesive. Additional lab tests found that the cohesive fines
in the mixture were creating this situation. It was decided
to add additional coarse material in the form of sand to the
mixture to create the proper slump and flow characteristics.

SYSTEM EFFECTIVENESS

    The effectiveness of the system is still being evaluated.
The presence of contaminants in the soil between the slurry
wall and the creek make evaluation by sampling the creek
somewhat difficult. However there are some encouraging trends
being observed. The level of contaminants in Rooty Branch has
been steadily downward. (Figures 3,4 and 5 indicate the
downward trend). Continued flushing of the soils  between the

                              1O59

-------
creek and slurry wall will undoubtedly help in reducing the
contaminant level.

    A reduction in  contaminants began  before the
installation of the slurry wall. It is believed this can be
attributed to several factors. One was the exceptionally dry
year preceding the  construction which limited leachate
generation. A second was the temporary capping of the eastern
fill when daily fill operations moved to an adjacent area.
Finally, the removal of much of the contaminant laden soil
from Rooty Branch as it was being straightened is considered
to have contributed to the decrease.

    One notable example of the effectiveness of the project
has been detected in the landfill groundwater monitoring
program. One of the site monitoring wells is located in the
area which lies between the slurry wall and Rooty Branch. The
well traditionally have contaminant levels similar to the
creek. Since the installation of the project, the well has
been dry, indicating no flow from the landfill to the creek.

CONCLUSIONS

    The design of any project to isolate and control leachate
from an old landfill requires a detailed understanding of the
                               1060

-------
o
p
      ROOTY BRANCH  SURFACE  WATER DATA

              CHLORIDES - FIGURE  3
           (mg/l)
          100
          75
          25
             i   I  I	I	1	1	1	L
                                              On Site
            3/86 6/8610/862/87 6/8710/874/88 9/88 1/89 4/89 8/87


                       Sampling Event

-------
5
8
       ROOTY BRANCH SURFACE  WATER  DATA
                  IRON -  FIGURE 4
           (mg/l)
           12
           10
           o __
                   I   I  t   I   I  I
                                               On Site
             2/BB 6/86 10/86 2/87 6/87 10/87 4/88 9/88 1/89 4/89 B/89

                        Sampling Event

-------
       ROOTY BRANCH SURFACE WATER DATA

                   TDS -  FIGURE 5
        Concentration (mg/l)
          500
          400
          300
O
0)
CO
          200
          100
                                                   On Site
             3/86 6/8610/863/87 6/8710/874/88 9/88 1/89 4/89 8/88


                         Sampling Events

-------
hydrologic and geologic setting of the entire site. Once such



an understanding has been established, a variety of



alternatives should be evaluated, the goals of the



alternatives should be the isolation of the source of



contaminants collection of the  contaminants and reduction of



leachate generation. This project has attempted to meet the



first two goals. Final closure and capping of the site will



address the final goal.
                              1064

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         MANAGING OUR SOLID WASTES:
DEVELOPING AN EFFECTIVE SITING FRAMEWORK
                  Michael J. Regan
              Research Triangle Institute

                 R. Gregory Michaels
       U.S. Environmental Protection Agency, OPPE
                   Presented at the
 First U.S. Conference on Municipal Solid Waste Management
                  June 13-16,1990
                         1O65

-------
                          Managing Our Solid Wastes:
                    Developing an Effective Siting Framework
Introduction
   The conflict over solid waste management continues to escalate in many parts of the
country and is likely to be a pressing public policy issue throughout the 1990's.  Even
with increased source reduction, recycling, and composting, new waste disposal facilities
will be needed to manage our growing waste stream. Finding new sites, however,
promises to be extraordinarily difficult.
   Efforts to site new landfills and waste-to-energy facilities, and even recycling transfer
stations,  have been met with mounting opposition from community groups. Much
attention has been paid to the so-called NIMBY (not in my backyard) syndrome which
portrays local residents as emotional opponents of new facilities while often ignoring the
complexity of the underlying issues. In most cases there is a fundamental disagreement
among different groups and individuals over whether the facility is needed, if it is safe, if
the siting decision is fair, and/or who should make the decision.

Rethinking the Traditional Siting Process
   In the traditional siting process—sometimes called the Decide, Announce, Defend
model—decision-making power is concentrated in the hands of a few, key local
government officials. Communication is often limited to legal requirements for technical
information (such as environmental impact studies) and a mandatory public hearing. The
general public is not confronted until key risk management decisions already have been
made, at which time they are presented with a fait d'accompli. At this point, the level of
public opposition becomes intense and both sides become polarized. Although the
traditional siting process  has been modified, the basic tenets of an exclusionary siting
process persist to this day.
                                        1066

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   Each of the statements below highlight an important dimension of the facility siting
problem and each presents public officials with a different set of challenges.

1) The siting problem is not simply a technical one—it is social, economic, and
political. Public opposition to landfills or incinerators is not always generated by the
same siting issue, nor is opposition limited to any single issue in a given case. For
example, public officials might face conflict over estimates of public health risks, equity
in site choices, property value impacts, and the distribution of benefits and burden among
community residents. All of these concerns influence an individuals sense of risk from a
new facility. The solution to the problem must reflect the nature of the problem—a
technical solution simply will not work.

2)  The public fears and mistrusts technical information and the people who
communicate it. As with many risk management problems, the credibility of technical
information has been a major battleground in siting disputes because of a history of
inappropriate use, scientific uncertainty, and communication barriers. For example, a
hydrogeological study might be legitimately disputed by an independent expert. In other
cases, participants might manipulate the use of information in the communication process
to achieve particular ends. Also, many lay people find technical studies
incomprehensible because of technical jargon.
   The role of technical information remains critical to making good public policy. But,
members of the public are making decisions based on incomplete information or
information that is difficult to process.  Both citizens and officials need good, relevant
information to make better decisions about the key controversial issues.

3) Many citizens have lost confidence in the decision-making process for solid waste
management and now demand greater access and involvement. Citizens object to the
                                        1O67

-------
process by which land use decisions have been made in the past. They are concerned
about past facility mismanagement, the credibility of public officials, and the growing
pressures on the environment from our society. Members of the public have
demonstrated that they will not sit by while important waste management decisions are
being made. An effective siting process must be able to incorporate public concerns into
the siting decision.

A Comprehensive Siting Strategy
    Each siting effort requires a strategy tailored to the specific needs and concerns of the
community. Nevertheless, experience from other successful siting suggests that effective
public involvement should be the centerpiece of a comprehensive siting strategy that also
includes risk communication, mitigation, and evaluation activities.  This siting strategy is
presented in an EPA publication, Sites for Our Solid Waste: A Guidebook for Effective
Public Involvement (1990).

Public Participation
    Public participation can bring trust and credibility back  to the siting process but is not
a guarantee for success.  Citizen advisory committees, public meetings, and workshops,
among others, have proven successful in both resolving conflicts and producing effective
waste management policies. Note, however, that the success of the program does not
depend on the number of meetings held, rather the quality of the implementation.  Public
participation is not just window dressing—token participation often backfires by fueling
fears and mistrust. Instead, effective public participation requires integrating public
concerns and values at every stage of the siting process.
    In particular, officials should take steps to understand the various groups and interests
in the community as well as develop a public participation plan that outlines the activities
that will be conducted, their sequence and timing, and responsibility for carrying out each
                                       1068

-------
activity. A comprehensive public participation program is a sizeable effort that requires
careful planning and a significant commitment of time and staff. But the alternative may
be to go through a prolonged, divisive, and expensive siting process and still find yourself
at square one.

Risk Communication
    The term risk communication has different meanings for different people, often
depending on their individual or institutional goals. Many officials restrict its meaning to
the dissemination of scientific information to the public by official sources.  For example,
the Department of Health might want to translate findings from hydrogeological studies
into a fact sheet for homeowners.
    The National Research Council (1989) recently noted that risk communication is
more than simply designing and communicating risk messages to the public; it is a two-
way process that provides government, industry, and individual decision makers with the
information they need to make risk management decisions. For example, the siting
proposal might win support from nearby residents if they take steps to mitigate negative
impacts.
    Public officials should be aware, however, that communication programs are complex
endeavors with many pitfalls. For example, conflicting perceptions of risk among
individuals make it difficult to develop effective risk messages. The news media have
difficulty reporting scientific risk estimates. And, communicators must decide whether
they will simply inform the public's judgment or attempt to manipulate behavior.  Many
resources exist to help officials understand the complexities of communicating about
potential risks to public health.
    Risk communicators should also establish a set of policies and procedures that ensure
that risk messages are both accurate and credible, such as getting participation in the
study plan, providing technical assistance to the public, and presenting technical
                                       1O69

-------
information in understandable language. These steps will not remove all challenges, but
by taking them you reduce the chances of opponents gaining political support by
questioning the technical adequacy of studies.

Mitigating Negative Impacts
    Some public policy issues in local communities, no matter how sensitive to the
concerns of residents, are bound to have negative consequences for a few people.  It is
necessary, however, to find more immediate and direct means of mitigating these
negative impacts.  Mitigation might take any one of three forms: direct compensation,
more advanced technical safeguards, or more extensive environmental monitoring. For
example, a community in New England restricted the number of trips made by non-local
haulers to a regional landfill. In a Florida community, a property value guarantee has
been made to nearby homeowners.
    It is important to note that people view health and safety in  terms of safe and unsafe.
If they perceive a facility is safe, then it is possible to talk about other issues. If they..
perceive a project poses a genuine risk to health or safety, then  everything else is non-
negotiable.

Evaluating Effectiveness
    Evaluation can improve the management of the complex planning and
implementation activities. Project leaders find themselves making important decisions
throughout the siting process based on their judgment of the effectiveness of specific
siting activities. This type of "intuitive" evaluation is often hindered by preconceived
ideas about what people want, as well as the frantic pace of everyday life at the office.
    By evaluating the effectiveness of your siting strategy, you are trying to learn which
activities are working, which activities need improvement, and which siting issues have
                                      107O

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not been addressed. Evaluation tools can help provide important feedback to decision-
makers in a timely, cost-effective way.

Conclusion
   The trash problem in the United States has no easy answers, and the conflict
surrounding the siting of solid waste facilities will be with us for many years. Just as the
issues and challenges facing public officials and citizens have changed over the last two
decades, we should also expect new issues and new challenges to emerge in the coming .
years.
   The siting strategy presented in this paper is not a recipe for success. It tries to
overcome some of the obvious deficiencies in the traditional siting process while
providing a flexible framework for tailoring the strategy to the particular needs and issues
of different communities.  Experiences from around the country suggest that solutions to
the waste management problem, and the siting impasse in particular, will require a
cooperative effort among public officials, waste management professionals,
environmental advocates, and private citizens.
                                       1071

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Sources

Krimsky, Sheldon and Alonzo Plough, Environmental Hazards: Communicating Risks As
a Social Process, Auburn House Publishing Co., Dover MA, (1988).

National Research Council, Improving Risk Communication, National Academy Press,
Washington, DC, (1989).

O'Hare, Michael; Lawrence Bacow; and Debra Sanderson, Facility Siting and Public
Opposition, Van Nostrand Reinhold Company, New York, (1983).

U.S. Environmental Protection Agency £itesfor Our Solid Waste: A Guidebook for
Effective Public Involvement, Washington, DC, (1990).

U.S. Environmental Protection Agency Decision-Makers Guide to Solid Waste
Management,  Washington, DC, (1989).
                                     1072

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                     MIDWAY LANDFILL

                  Bruce D.  Jones, P.E.
               Seattle Solid Waste Utility
                    Presented at the

First U.S. Conference on Municipal Solid Waste Management

                     June 13-16,  1990
                           1O73

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                        MIDWAY LANDFILL





Background



     The Midway Landfill/ a 60-acre site approximately 15 miles



south of  Seattle,  was used as  a  gravel pit from 1945  to 1966



(see figure 1) .  In 1966 the  City  of  Seattle began  using it as



a landfill for nonputrescible waste (such as demolition debris,



woody wastes,  and yard  clippings).  The landfill  is bounded on



the east  and  west  by  major north-south  highways  (Interstate 5



and  Pacific   Highway   South,   respectively).      Residential



neighborhoods  are  clustered  to  the  east and  south  of  the



landfill; commercial businesses and light industries are on the



west,  and  a   mobile  home  park,   drive-in theater,  and  some



undeveloped  property   are  to  the  north.    The  City  stopped



disposing of waste at the landfill in 1983.







Landfill Gas Migration



     The landfill was  initially  brought to public and regulatory



attention   in  1985   by  the   discovery  of  subsurface   gas



infiltrating nearby structures.  Residents were evacuated from



their  homes   in  several  cases  due  to  concerns   about  the



concentration  of combustible gasses accumulating in  the houses.



This occurred  in late  1985 and early 1986.   The  City of Seattle



and  the  Washington   Department   of  Ecology  installed   gas



extraction wells in the  affected neighborhoods and gas migration



control wells  on the perimeter of the landfill.
                              1074

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Midway Landfill HI — City ot Seattle
            HlGHLINE
           COMMUNITY
            COLLEGE
  PARKSIDE
  ELEMENTARY
   SCHOOL
SUNNYCREST
ELEMENTARY
 SCHOOL
SCALE IN FEET
n_ri
     500    l.OOii
                                        1075
         Figure 1
         Location Map

-------
     In 1986,  the  Environmental Protection  Agency placed  the



Midway Landfill on  the National Priorities  List.   A  Remedial



Investigation/Feasibility Study (RI/FS) was begun and completion



is expected late this year.  The RI was an intensive effort by



the City  of Seattle to  investigate the  landfill's actual  or



potential  impact  on human  health  and  the  environment.    The



investigation  covered  surface  water,  ground water,   soils,



landfill  gas  and  ambient air.    The  RI  found that  the  gas



extraction system stopped the off-site migration of gas, removed



the gas from the structures  and created a permanent system to



prevent future gas  migration.







Good Neighbor Program



     During the period of time  when gas  migration  was occurring



and homes  were  being evacuated,  property  values were  dropping



drastically.   While the  City  was  working to  control  the  gas



migration,  it  established a  Good Neighbor Program  to  maintain



property values.  The program allowed home owners  to sell  their



home at a  Fair Market  Value  established by the average of  two



appraisals.  The homeowner and the City of  Seattle  each  obtained



an appraisal and the two were  averaged to determine the Fair



Market Value (FMV).   The City  could subsidize the  purchase by



another party to insure the seller  received the FMV or  the City



could purchase the  house for that amount and  continue to market



it.  The  program ended after 10 homes  were  sold at FMV  which



took about two years.  During the program, 269 homes were sold



through the program and the City purchased 165 of them.



                              1076

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After selling all but one of the homes, the net cost to the City



for  the  program is  approximately  $5 million  including  all



related management costs, real estate commissions, house repairs



and price subsidies.







Ground and Surface Water



     The  next most  serious  concern  of  the RI was the potential



for  groundwater  contamination  by  leachate  from the  landfill



because  of  the  large  amounts  of  water  known  to  enter  the



landfill  by various  means, including direct infiltration  of



precipitation,  infiltration of runoff from surrounding property,



and  inflow  from stormwater  drains.   During additional leachate



sampling  conducted  as part  of  a treatability study  for the FS,



an  oil  was  found floating  on the aqueous phase  leachate.   The



oil  was found to  be contaminated with polychlorinated biphenols



 (PCB's).  A program was instituted to install 9 additional wells



in the landfill to help determine the extent  of the contaminated



oil.   Once the extent  was  determined to be isolated pockets,



pumping began to  remove the material before completion  of all of



the  surface water management projects and the  cap  resulted in



dewatering  of  the  landfill.   only a  small   amount  of oil was



recovered,  approximately 100 gallons,  and recharge of  the wells



with oil  has been minimal.







      A  surface  water management plan was prepared  that would



minimize  the generation of  leachate from surface water.
                               1077

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The plan included a  pumping station to eliminate a  stormwater



discharge into the landfill, a 10 million  gallon detention pond



to store water from  the  pumping station,  the landfill  surface



and some areas surrounding the landfill, and a pipeline to carry



the stormwater to a  creek  approximately one mile to  the  west.



No evidence was  found during the RI  of off-site transport  of



contaminants in surface water runoff from the landfill.







Ambient Air



     Ambient air quality in the  vicinity of  the  Midway Landfill



was not found  to be measurably different from typical  urban air.



The  air moving across  the  site did  not  appear to  show  any



consistent increase in contaminant concentrations that could be



attributed  to  the   landfill.     Widespread  low  levels   of



contaminants  in ambient  air appear  to be  coming  from off-site



sources, including vehicle  emissions from 1-5 directly  east  of



the landfill boundary.







Final Cover



     Currently, the  cap  for the site is under  construction  (a



cross-section  of  the cap  design is  shown  in Figure  2) .   It



includes a base cover of low permeability material placed during



excavation of the detention pond in  1988.  This  material varies



in depth from 2  to  20  feet and provides   the  general  grade



necessary to carry surface  runoff to the detention pond.  A foot



of clay is being placed on top of the existing subgrade.
                              1078

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             MIDWAY  LANDFILL COVER
 vegetation/soil
       top layer"

geotextile filter-

    50-mil FML-
low-permeability
 FML/soil layer"
        waste
      topsoil mix
• a X •• " »• :
! sand
e . .- c ". .' o '
             «» :
             o e€
                1 foot
                      1 foot
                         geonet
                         drainage layer
                                         1 foot
                         2 to 18 feet
                                      NOT TO SCALE
                        Figure 2
                           1079

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The next layer is a 50 mil  layer  of  high density polyethylene.

Then a synthetic geonet material is placed for a drainage layer

and covered by  a filter fabric.   It is then covered  with one

foot of sand and one foot of topsoil and seeded.



Costs

     The overall cost of all of the  work at  Midway is  over $50

million.  A breakdown of the costs is shown  in Table 1.
                            TABLE 1



PROJECT ELEMENT                         COST ESTIMATE (MILLIONS)

Preliminary Engineering
Environmental Impact Statement                 $   3.1

Remedial Investigation/Feasibility Study       $   5.7

Good Neighbor Program                          $   5.2

Claims/litigation                              $  12.3

Right-Of-Way                                   $   1.3

Surface Water                                  $   9.0

Gas Control                          '          $   6.0

Final Cover                                    $   9.1

Staff Costs                                    $   1.2	

                              TOTAL            $  52.9
                              1080

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CLOSURE OF THE CITY OF BOYNTON BEACH LANDFILL
  USING VERY LOW DENSITY POLYETHYLENE (VLDPE)

                   Robert Mackey
          Post, Buckley, Schuh & Jernigan, Inc.
                   Presented at the

First U.S. Conference on Municipal Solid Waste Management

                  June 13- 16, 1990
                       1081

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            CLOSURE OF THE CITY OF BOYNTON BEACH LANDFILL




              USING VERY LOW DENSITY POLYETHYLENE (VLDPE)








INTRODUCTION:




   During the 1980's, Palm Beach County Solid Waste Authority has gradually taken




over the responsibility from most municipalities within it's jurisdiction for the disposal



of their solid  waste.  Previous to that  period, each municipality within Palm  Beach



County  was responsible for disposal of its own solid waste.



   The  City of Boynton Beach obtained a  40-acre site in 1958 from Palm  Beach



County  for use as a landfill.  This site  was utilized through 1976 as an open landfill



that accepted most types of waste, ranging  from septic sludge to typical household



refuse.  It was a common practice in the past, for municipalities in this area to dispose



of their waste  in abandoned sand borrow or  rock pits.  It was believed that the City



of Boynton  Beach was no different in  this  aspect.  Information contained in files



retained by the  City,  the  Palm  Beach  County Health Department  (PBCHD),  and



the  Florida  Department of Environmental Regulation (FDER) alludes  to this type



of disposal of refuse below the water table in the southern end of the 40-acre site.




  The southern and western boundaries of the 40-acre site are dilineated by canals:



Equalizing Canal 3 (E-3) defines the western boundary and Lateral Canal 20  (L-20)



defines  the  southern boundary (See Section 2.2). These canals are part of the local



Lake Worth Drainage District (LWDD).  The City  of  Boynton Beach Municipal Golf



Course  lies to the west of the site beyond the E-3.  A residential development, called



Le Chalet, has been constructed south of the site, and is serviced by a public water



supply system.  The land east of the site was a fish farm from the early 1960s until



it was sold in early 1985.  This  land was bought by a developer who has cleared and
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and developed it for a residential development called Arbor Glen, which is also on



public water.




  The  area north and northeast of the old  landfill site  has, since the early 1960s,



witnessed an increase in the number of private residences.  The first residence was



the Brandywine  Horse Ranch, located on Palm Way.  Today there are  well over 50



private residences in the area north of the site and west of Haverhill Road Extension.



No  public  water supply system  or wastewater collection system serves this  area.



Therefore, each residence has its own private water supply well and septic tank.



  The creation of Chapter 17-7  of the Florida  Administrative Code (FAC) in October



1974 established  a permitting process for the use of sanitary landfills  in the State



of Florida. To  obtain enough  time  to conform  with the rules and regulations of



Chapter  17-7, the City of Boynton Beach applied in  January  1975 for  a temporary



operating permit for the continued use of its  sanitary landfill. On March  12, 1975,



FDER issued a permit to the City, which was valid until March 7, 1976.



  At the time, the  staff of the City of Boynton Beach  prepared a report  including



all of  the information required by FDER for the operation of a  sanitary landfill.



This  report was submitted to  FDER in December 1975, and  is believed to have been



the first submitted  under the new Chapter  17-7  rules and regulations.  This report



did  not,  however, fulfill  the requirement  for a  hydrogeologic study of the strata



underlying the site,  and the City  requested  an extension of its temporary operating



permit through  July 1977.  The FDER granted two  extentions:   the  first,  carried



the City through from March 1976 to  March  1977; the  second overlapped the first



and was  only for  the six-month period from January through June 1977.  The disposal



of sewage sludge at the site was-discontinued in December 1976.



  The City of Boynton Beach initially took steps to get the necessary hydrogeological



data so  it could still utilize  its sanitary landfill.  But,  on  May 19, 1977, the City
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notified the FDER by letter that the site was no longer going to be used as a sanitary



landfill because the City could not comply with the  regulation that disallowed  the



operation of a sanitary landfill within 1,000 feet of a water supply well.  The City



also  expressed concern to FDER about  the  private  residential wells  located north



of the site, if the sanitary landfill should continue operation.  Thirteen private water



supply wells already lay immediately north of  the landfill,  and this number  was



increasing as more homes were being built in that area.



  The City continued using  the site  as  an 8-acre trash-composting faciltiy on  the



northern half of the site and  obtained permits  for  its operation until July 1, 1983.



The remaining waste material that was not  permitted at the trash composting facility



was sent to the nearby Lantana Sanitary Landfill.



  With the operating  permit for the  trash facility  due to expire in July  1983,  the



PBSHD sent a  letter to the  City  on February  27,  1983 outlining  the reasons  for



performing a hydrogeologic  investigation  at the landfill  site.   These  reasons  were



as follows:



  0     Past practices of disposing of putrescible waste into the water table



  0     Numerous depressional areas on top  of the landfill



  0     Inadequate final cover material for the proper closure of the landfill



  0     An increase in the level of pesticides in the monitoring  wells



  0     Groundwater sample  analyses showing a general deterioration of water quality



        at  the landfill, specifically for  iron, chemical oxygen  demand (COD), total



        dissolved solids (TDS) and chloride



  0     Numerous private homes to the east and north of the landfill, using private



        wells for potable water supply



  The FDER requires  that  all  inoperative  landfills be properly closed to reduce



potential pollution problems.  Moreover,  prior to the development of a closure plan,
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a  hydrogeological  investigation  should  be  conducted,  since  the  results  of  the



investigation predicate the closure design for the landfill.




  In early 1984, the City of Boynton Beach  decided to close  the old landfill at  the



site  rather than reactivate  the  trash facility.  It  then requested proposals from



engineering consultants  to conduct a  hydrogeologic  survey  of the  site and  develop



a  closure  plan,  with the  intention of creating  a  9-hole  golf course  that would



eventually be connected to the City's Municipal Golf Course, west of the site.



HYDROGEOLOGICAL STUDY & CLOSURE PLAN:



   Post, Buckley, Schuh and Jernigan, Inc. (PBS&J) was selected as consulting engineers



by the City to conduct a hydrogeological investigation and to  develop a closure plan



for the old landfill.  Jammal and Associates  was selected to conduct the soil-boring



program and drill the  monitor wells installed in the first phase of the drilling program.



The  Testing Laboratory  of  the Palm  Beaches  was selected to drill the  additional



monitor  wells that were  installed  in the second phase of the drilling program.  This



report was submitted to the City of Boynton  Beach  in  May 1986,  and then revised



and resubmitted in  November, 1986.



   The purpose of  the hydrogeological report was to  gather into a single  reference



all the required  and relevant data that will  assist in the understanding of the local



hydrogeology, to describe the field  work conducted  at  the  site, and to  analyze  the



collected data and interpret the effect of the landfill on the surficial aquifer system



and  the  nearby private water supply wells.  The report presented all the information



required to permit  the design of a  closure plan and, in so  doing, described the existing



hydrologic conditions at  the site, the quality of the  groundwater, and the potential



threat, if any, of further contamination.



   The results of the water quality analyses indicated  that a leachate plume underlying



the  site is made up of two areas of high contamination:  one in the northeast corner
                                      1O85

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and the other in the central area  of  the site.  For  iron and lead, the contaminant



center in the northeast corner was a horse manure pile.  Dead and decaying vegetative



matter in the marsh area and the organic matter from the horse manure pile together



affected the water  quality  in the  upper zone of  the surficial aquifer  system in the



northeast corner and north  of the  site. The high levels of various metals,  such as



iron,  lead, strontium,  etc.,  identified in  the central area of the site were not at



the time considered to be a public  health hazard,  because  of the semiconfining layer



underlying the  area in  which they  were  found.  The volatile organic  compounds



identified in various monitor  wells at the site were also  not considered to  present



a public health  hazard.  The high  chloroform levels  found in  Monitor Well 13 were



believed to be a  localized occurrence resulting from an earlier well chlorination.



  The monitor wells to the north of the landfill indicated that the contaminant plume



had not  expanded beyond the northern boundary  of  the site.  Therefore, the report



recommended that  the City of  Boynton  Beach establish  a quarterly  water quality



sampling  program to monitor any movements in  the  contaminant plume.  The water



quality sampling program would monitor quarterly the  leachate indicator parameters.



   It  was believed  that the rainfall that recharged  the upper  zone of the surficial



aquifer system  in  the area  of  the landfill  leaches  through  the  landfill  mound and



replenishes  the  piezometric  mound.  Although  it moved slowly,  the groundwater



flow  from this  piezometric mound flowed away  from  the landfill site.  Therefore,



it was  recommended that the City of Boynton Beach proceed with landfill closure



to eliminate the infiltration of the rainfall  through  the landfill.  The  closure of the



landfill would also greatly reduce,  if not eliminate, the piezometric head differential



between the upper and lower zones of the surficial aquifer system, which could induce



contaminated water into the lower zone.



   As directed by the City of Boynton Beach, PBS&J proceeded to develop closure





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plans for the 40-acre landfill site.  As part of the closure plans, PBS&J had to meet



three major objectives of the closure design:



  0     Meet FDER Closure Rules



  0     Meet South Florida Water Management District (SFWMD) Regulations



  0     Design the closure for the end use of a 9-hole golf course



  The FDER Closure  Rules require the  landfill closure plan to develop a  landfill



gas  management plan,  a  groundwater monitoring plan, a landfill cap design and a



stormwater management plan. Since the landfill was  nearly 30 years old and tests



for methane presence proved negative,  the landfill gas  management  plan required



only the placement  of  landfill gas monitoring wells  along the perimeter of the site



and  within the  landfill  mound itself. The  Groundwater Monitoring Plan had utilized



the previously submitted hydrogeological report  to  develop  the  monitoring plan for



the site.  The Stormwater  Management  Plan had to be developed and approved by



the SFWMD. The  ability to meet the SFWMD requirements and develop the required



landfill closure design offered PBS&J's greatest challenge.



  Like  most old landfills, the City of Boynton Beach had utilized almost the entire



40-acre site for  its landfill operation.  The  marsh  area  in  the  northeast corner of



the site was the  only  area which  was believed not to contain buried refuse.  The



SFWMD requires  all stormwater runoff from  a site  to  be retained in a ponding area



before discharge into an open water way.  This stormwater management rule required



the  construction of dry retention  basins  on the landfill site.  The FDER  requires



that all buried  waste must  be covered by  a clay or synthetic liner or removed from



the ground in areas which are not covered. The need to meet the SFWMD and FDER



rules and still design the site to be utilized as a golf course required close coordination



of PBS&J's Solid  Waste Division, PBS&J's Land Development Division and the golf



course designer of Von Hagge & Devlin, Inc.





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  The closure plan was eventually  developed which took into account all  the design



requirements.  The plan required a contractor to excavate out buried refuse  from



various  areas of  the landfill in order for a dry retention area to be constructed of



sufficient size to retain the rainfall volume from a 25-year storm effecting a 40-acre



site.  A berm was  designed around the entire site  to direct the stormwater to the




dry retention areas.  An outfall structure was also designed to allow a maximum




discharge of 10 cfs.  All excavated refuse was required to  be placed on  top of the



mound and  covered by either  a 20-mil PVC  or HDPE  synthetic liner system.  The



closure  design took into account the  end-use of a 9-hole golf course to be developed




at a later date by the City of Boynton Beach.



  The Closure Plan was  approved by FDER  in  late  1988 and construction started




in mid-spring of 1989.



LANDFILL CLOSURE CONSTRUCTION:



  The City of Boynton Beach  awarded the closure construction contract to Ranger



Construction of Boynton Beach with  Gundle  Lining Corporation as the  subcontractor



to  install the synthetic  liner.  The contract had an  additional  requirement  that



stipulated that the contractor could not perform  any  work after dark.  Since the



landfill had become a sensitive  issue over the years, it was hoped that this requirement



would help relieve any  new public relation problems.  Before construction started,



Gundle  Lining Corporation  requested that they be  allowed  to  use their new  20-mil



very  low density polyethylene  (VLDPE) instead of contracted 20-mil HDPE.  Gundle



Lining Corporation promoted the VLSPW's greater flexibility and percent elongation



(900% @ break) as better product  for landfill caps.   Gundle also gave  assurances



that the VLDPE would meet contract specifications and  not cause the City of Boynton



Beach any  additional cost. After a review  of the  material, PBS&J and the  City



of Boynton Beach approved the use  of the VLDPE for the landfill closure.




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  Once the contractor started clearing and grubbing the, by now overgrown, 40-acre
site,  several  problems  became apparent.  These  problems  encompassed  not only
assumptions of  the closure  design but also public relations with  the  residents of
Arbor Glenn Estates. It  appears that the residents of Arbor  Glenn Estates, (especially
the owners of properties which abut the landfill)  had  no idea  that  they lived next
door  to an old landfill.  The property owners informed the City that they  had been
told that the neighboring property  (the  landfill site), was to  be  developed into a
golf course, and they had paid a higher price for their land for that privilege.  The
City of Boynton Beach and PBS&J had to quickly arrange a meeting with the residents
of Arbor Glenn to inform them of the history of  the landfill site and to  update them
on  present  construction activities.  Obviously, this public relations problem greatly
sensitized  the already sensitive issue  which the landfill had become over the past
years.
  The clearing  and grubbing of the site had also uncovered some  problems  which
effected the  design  of  the  closure,  to  save the  City of  Boynton  Beach  the cost
of  clearing the landfill prior to the design  phase  of  the project,  PBS&J based the
design on boring logs and an aerial topographical map.  It was felt that this information
was adequate to  determine the depth of cover  material and the extent of landfill
mound.  Once the landfill was cleared, it  was quickly determined  that very little
on-site cover material was  present  and more than the estimated off-site  clean fill
would be required brought  in  to  make up  the difference.   Also, not all the  buried
waste was  in the  mounded  areas.  It appears that pits had been dug  where  waste
was placed up to the natural  ground elevation.
  Changes  in design  required the  contractor  to perform more  excavation  and
backfilling  and also stipulated that part of two dry retention areas needed to be
lined. These  design changes were coordinated with FDER  and  SFWMD  and approval

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given before the installation of the liner began.



  One  area of the 40-acre landfill site  which exemplifies the past procedures for



disposing of  waste, was along the L-20  canal in  the very southern portion  of the



site.  The  Lake Worth  Drainage District  (LWDD) operates and maintains both  the



E-3 and  L-20 canals  which run along side the landfill.  The LWDD maintains these



canals  through the use  of 30-foot wide easements  that run along the canals  on the



landfill property.  Through the clearing of the landfill, it was discovered that waste



was  buried within the  southern  LWDD easement.  The most cost effective  method



of handling this problem  would have been to  cover the area with a synthetic liner.



But, the LWDD requested that all waste buried  within their easement  be removed



and  clean  fill  placed  and  compacted.   The dimension of  this  excavation  was



approximately  1000 feet  long by 20 feet  wide and ranged from  4 to 6 feet deep.



This problem area alone cost  the City of Boynton Beach an estimated quarter million



dollars or an additional twenty-five percent of the original contracted cost.



   The last area which required additional earthwork was along the property line



adjacent to Arbor Glenn  Estates.  Arbor  Glenn was platted  to  allow drainage from



the  back of the properties to the road in front.   However, the actual construction



of Arbor  Glenn allowed  the  backyards of these adjacent properties  to drain  onto



the  landfill site.  To relieve  this problem, the City of Boynton  Beach and  PBS&J



met with  the residents and submitted to  them for  their approval, a design to allow



drainage along  a  former  swale.  Ranger  Construction regraded  the property owners



backyards  to  produce a swale,  seeded  and mulched the  regraded area and replaced



a  small  drainage  culvert to  the  L-20  canal at no additional cost to the client or



residents  of  Arbor  Glenn  Estates.   This  cooperative  effort  between  Ranger



Construction, City of Boynton  Beach and PBS&J helped  many small public relation



problems from developing into time consuming, troublesome headaches.
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LINER INSTALLATION:



  Gundle Lining Corporation had developed their new  20-mil  VLDPE liner  system


in hopes of  competing with  the  20-mil PVC  market.  Unlike 20-mil high  density


polyethylene  (HDPE),  20-mil  VLDPE  exhibits  the flexibility of  PVC  liner without


PVC's UV sensitivity and bio-degradability problems.  This landfill closure was Gundle's


first attempt to install VLDPE  in  the State  of Florida  and on a sandy  sub-base.


Due to construction schedule, Gundle had the  additional misfortune  of having to


install the  liner system during the very hot Florida summer. Liner installation  was


expected to  have some problems since Gundle's  20-mil  VLDPE was still considered


to be product  in the development stage.  However,  the scope  and diversity  of  the


problems encountered required Gundle  Lining Corp., the City of Boynton  Beach,


and  PBS&J to develop alternative  installation and testing procedures to insure a
                                                                  •

quality synthetic cap. Problems  which occurred in the VLDPE placement and their


corresponding solutions are described in the following text:


  VLDPE could not  be welded using Gundle's double-wedge welding system. Because


of the thickness and heat sensitivity  of the VLDPE, any small misalignment  of  the


liner through the double-wedge system caused a burn through the liner or  the  failure


of one or  both of  the  weld tracts  to meet contract specifications.  This problem


was resolved  by changing to a single wedge welding system.


  The VLDPE also  had a  limited time span during the day in which it was possible


to be welded.  This was because the  summer  heat caused the  liner material to be


so flexible  that it  increased the potential for burn  through.  This initially limited


Gundle to  early morning  and evening welding.  Once the single wedge system was


developed and produced the high quality seams required by PBS&J, the City of Boynton


Beach released  the  contractor from  the  daylight work only  requirement.  Gundle


was  then able  to weld the  liner at a faster rate with  fewer burn throughs  during


the cooler evenings.
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  The sand sub-base also created a  temporary problem  with  the welding system.



The  VLDPE liner appeared to develop an oily surface when heated by the sun.  This



oily surface attracted sand and had a tendency to clog the lower rollers of the Gundle



welding system.  In the evening, the  liner collected  moisture underneath which also



attracted sand.  This problem  was easily  relieved by an  extensive cleaning of the



liner  by  Gundle's personnel and by keeping the  liner off the ground with the use of



a skid pad under the seam.




  The most critical aspect of the VLDPE  installation which required a revaluation



of the liner was the quality assurance testing of  the seams. In short, Gundle's VLDPE



could not  meet  the  contract  specifications  for peel  and shear  testing  using  the



standards established for  either  20-mil  HOPE or 20-mil PVC.  It  became  apparent



that  the  VLDPE  really could not be  compared to  those  standards because it was



an entirely different type  of material.  At the time, no current ASTM test procedures



or National Sanitation Foundation (NSF) No.  54 test standards existed  for VLDPE.



Through  the combined efforts of Gundle  Lining Corp., Richard Charron of GeoSyntec



(geosynthetic  testing laboratories)  and PBS&J,  new  test standards were developed



to adequately determine the seam  quality. These standards are listed in the Table



below:



                   Comparision of Testing  Standards 20-mil Liner



                  20-mil  HOPE         20-mil  PVC          20-mil VLDPE



Shear Test        36# (Yield)            36.8# (Break)        30#  (Break)



Peel Test         FTB                  10# or  FTB          20#  or FTB



FTB = Film Tearing Bond



  Once the above described problems were resolved, the liner  installation  ran very



smoothly.  After completion of the liner installation, PBS&J felt the VLDPE system



did  meet the design  and quality assurance requirements  for this landfill closure.



A great deal was  learned about the properties and installation procedures for VLDPE
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by both Gundle Lining Corporation and PBS&J.



SUMMARY:




  The City of Boynton Beach has a closed landfill facility designed for possible end-use



as a  golf  course.  Additional expenditures will be needed  by the City to  upgrade



the final closure to an official golf course after any settlement occurs in the following



years. This project was brought to its successful conslusion through  the fore thought



of the City officials.  Unlike  many communities, who wished the problems of their



old landfill would go  away,  the  City of  Boynton Beach came to realize that a



successful  conclusion could  be found only  by  taking  the  responsibility and working



through all of the problems.




  It could be said that the closure of the  Boynton Beach  Landfill exhibited many



of the same problems  in  which many municipalities  face in  dealing with their  old



landfills.  The  City  of  Boynton Beach took on the responsibility for their  landfill



early  in attempting to meet the Florida Regulations. In so  doing, the City of Boynton



Beach has  become one  of  the  few  communities in the  State of Florida  to close their



landfill without the need  for  FDER to issue a  Consent Order requiring its closure.



In addition, each  aspect of the hydrogeological assessment and landfill closure took



the public welfare into account.   In order  to  keep  public  relation problems to a



minimum, the City of Boynton Beach, at  all times tried to keep the public informed



of the progress and/or problems  associated with the landfill closure. Be assured



that further work  at the Boynton Beach Landfill will still need to be  done.  Continued



groundwater  monitoring, general  maintenance  and repair  to any eroded area's will



be required by the City until  an undetermined time in the future.  But, finally, the



potential risks to human  health associated with  this  old  landfill should be  coming



to an  end.
                                      ******
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PUENTE HILLS ENERGY RECOVERY FROM GAS (PERG) FACILITY
        by John Eppich, John Cosulich, and Hsin-Hsin Hsu Wong
                Los Angeles County Sanitation District

                         presented at the

      First  United States Conference on Municipal Solid Wastes
                       Solution for the 90's
                         Sponsored by the
            United States Environmental Protection Agency

                               at

                         Washington, D.C.

                        June 13 - 16, 1990
                              1O93

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                 Puente Hills Energy Recovery from Gas (PERG) Facility
                        by John Eppich, John Cosullch, and Hstn-Hsin Hsu Wong
                               Los Angeles County Sanitation Districts


Abstract


    The Puente Hills Energy Recovery from Gas Facility (Facility) utilizes landfill gas as a fuel


and is currently generating 50 MW gross of electricity.  The Facility is located at the Puente


Hills  Landfill in Whittier, California.  The landfill is owned and operated by the Los Angeles


County Sanitation Districts.  The Puente Hills Landfill has over 45 million tons in place and


is currently receiving refuse at the rate of 72,000 tons per week.  Because of the size and the


extensive gas collection system in place, approximately 24,000 scfm of landfill gas is collected


and burned at the PERG facility and the flaring station.  The average heating value of the


landfill gas is 420 BTU/scf.


    The Facility, which  has been operating since  November,  1986,  consists of two steam


generators each firing 10,300 scfm of landfill gas.  Each unit produces 210,000 Ibs. of steam per


hour at 1350 psig and 1000°F.   The steam is used to drive  the turbine generator and produce


approximately 50,000 kilowatts of electricity.  Several technologies were investigated prior to


selecting  the rankine cycle, the most  common technology  used for power generation in the


United States.   The  other  technologies  included  reciprocating engines,  gas turbines, and


combined cycle  gas turbines.   The factors involved in  the selection  were air  emissions,


construction costs, ease of operation, and efficiency. A significant factor in the final decision


was the large size of the facility.


   Because of the financial and time  constraints, the contractor for the Facility was required


to bid  a fixed  price  project based on  preliminary design requirements  and performance
                                          1094

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specifications which  were prepared by the Sanitation Districts.  Payment to the contractor




consists of 60  monthly  lease payments  which  commenced  30 days after the project  had




completed construction and successfully  passed  the  performance test requirements.  In this




manner, the Sanitation Districts was able to make payments for the Facility out of the revenues




derived from the sale of electricity to the nearby utility, Southern California Edison.




    The emissions from the Facility had to meet  strict requirements from  the South Coast Air




Quality Management District. The emissions from the plant are well below  those numbers




required  by  the Air  District due to several emission control  strategies  required  of the




equipment as part of the Performance Specifications.




    This Facility has successfully demonstrated that landfill gas can be combusted in boilers,




reduce air emissions, and provide significant economic advantages to the  owner.




Introduction




    The Los Angeles County Sanitation Districts (Districts) own and operate both the Puente




Hills Landfill and the PERG Facility.  The Districts are a special purpose  organization created




by the California State Legislature for the management of solid wastes and for water pollution




control, and are governed by a Board of Directors  consisting of elected representatives of the




cities and unincorporated areas which the Districts  serve. The Districts currently manage over




21,000 tons of solid waste per day at four  major landfills and process a total of over 500 million




gallons per day of wastewater at 11 major wastewater treatment and water reclamation plants.




    The Puente Hills Energy Recovery  from Gas (PERG)  Facility, a 50 megawatt  (gross)




landfill gas to energy facility,  commenced operation  in November, 1986.   PERG is currently




generating its design capacity of 46 MW net. During the first three years of operation, the
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availability of the Facility exceeded 92%.  This is to report the operational information on this




Facility including availability, emissions,  and  landfill  gas characteristics  and collection.   A




schematic of the landfill gas collection system  and PERG is shown in Figure 1.
                                    PERG PROCESS SOCMATC
     Figure I - Schematic of the Puente Hills Landfill Gas Collection System and the Encr& Recovery from Gas Facility




Puente Hills Landfill




    The Puente Hills Landfill, formerly a small private operation, was purchased by the Districts




in 1970.  The landfill is a California Class in site,  permitted to accept non-hazardous solid




wastes.  Currently,  72,000 tons per week is landQlled  at Puente Hills.  Over 45 million  tons




have been placed at the Puente Hills Landfill.




    The Puente Hills Landfill consists of 1,365 acres including both the active fill and buffer




areas.  The active area of the landfill is approximately  550 acres.  The maximum depth of the




landfill is approximately 500  feet
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Landfill Gas Generation




    Landfill gas is produced by naturally occurring biological decomposition of the organic




fraction of refuse. The current gas collection rate is approximately 24,000 standard cubic feet




per minute of landfill gas.




    When refuse is landfilled, much of the organic fraction of the refuse will be converted to




landfill gas over a period of 10 to 40 years.  The rate of conversion depends on many factors




including moisture content, refuse composition, nutrients, buffer capacity, refuse compaction,




and temperature.




    The Districts project the landfill gas generation using a first order exponential decay model




with a half life of approximately 20 years. Several other models for landfill gas generation are




also used in the industry.  The Districts estimate that approximately two cubic feet of methane




is produced for every pound of refuse landfilled at the Puente Hills landfill.




    Anaerobic production of landfill gas is approximately 60-65% methane and 35-40% carbon




dioxide. If oxygen is drawn into the landfill by the gas collection system, aerobic decomposition




of the refuse,  or composting will occur.  Composting produces carbon dioxide and water and




raises the  temperature of the landfill.  However,  it is necessary to draw limited quantities of




air into the landfill  for proper odor control. Accordingly, the landfill gas collection system is




monitored to minimize the amount of composting and  to control odors.




 Landfill Gas Collection System



     An extensive landfill gas collection system has been operated at Puente Hills Landfill since




 1981. The gas collection system operation is optimized for odor control, power production is




 a secondary goal. The gas collection system consists of two  major types of collection systems,
                                          1097

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vertical wells and horizontal trenches and includes over 40 miles of collection and header pipes.



The primary purpose of the gas collection system is to control  landfill gas and thus prevent



odors and sub-surface migration.




    Over 400 wells have been drilled  in the front  face of the landfill for odor control.  The




wells are monitored on a biweekly basis for temperature and methane content  A throttling




valve on each well is used to control the tested parameters.  A slight closure in the throttling




valve results in decreasing the temperature and the oxygen, and increasing the methane content.



A typical well detail is shown in Figure 2.
    The trench system is constructed directly in the refuse on the operating deck of the landfill.




 The trenches are installed in four decks of the landfill with collection pipes approximately 260




 feet apart.  A new trench system is installed  on the top of the landfill approximately 60 feet
                                           1098

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in elevation.  The trench system installed to date consists of over 18 miles of landfill gas piping.



A typical trench detail is shown in Figure 3.
12V CORRUGATED-7
STEEL PIPE /
A 	 rr — » _^, f
>_LL. ; " ^ ^—~
L_j 	 	 	 :

2-0' 2'-o"
LAP
LAP
i i
J 	

10 • O
Y"1- — 	 ~~*~J
IKbNgH 	 i
WIDTH
LANDFILL
GAS
f$£~ 	 n •«
nr^r, J ««
T ir^ i
^—15"* CORRUGATED
                                             STEEL  PIPE
                                Figure 3 - Landfill Gas Trench Detail








    Landfill gas delivered to the PERG Facility is approximately 42% methane, 35% CO2, 3%




Oz, 15%  N* and 5% H20  (all by volume).  The landfill gas is normally at  100% relative




humidity or saturated when it comes out of the landfill.  Accordingly, condensate  traps are




located at all low points in the gas collection system.




    The overall gas collection system at the Puente Hills Landfill is designed in a "loop" around




the perimeter  of the landfill.  This allows the  remainder of the collection system to be




operational when part of the  system is out of service for maintenance.




    The entire  landfill gas collection system is under a vacuum to insure odorous gases do not




escape in case  of leaks in the piping.  Occasionally, expansion joints or other components of




the landfill gas system will fail.  The most common cause of failures is differential settlement.




    The heating value of the  landfill gas is monitored  continuously by a calorimeter. Sharp




decreases in methane content  of the landfill gas generally indicate a breakage in the collection




piping.
                                          1099

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Technology Selection


    Several technologies  to  convert the landfill  gas to electricity were investigated by  the

Districts.  These technologies include reciprocating engines, gas turbines (simple and combined

cycle), and the rankine cycle.  The study concluded that the most common technology used for


electrical  power generation in the  United States, the rankine  cycle was best suited for  the


Puente Hills Landfill  The selection criteria included energy conversion efficiency, air emissions

ease of operation, and construction cost as shown in Table  1.
RECIPROCATING GAS COMBINED
CRITERIA ENGINES TURBINE CYCLE
AIR EMISSIONS 1 3 3
NET POWER 4 35
EASE OF
OPERATION 2 32
B TU CONTENT 2 44
CONSTRUCTION
COST 3 43
TOTAL POINTS 12 17 17
STEAM
TURBINE
5
4

3
5

4
21
                   Table I Selection Criteria Used to Evaluate Alumaave Landfill Gas to Entry
                                  Technologies for a SO MW Project


    The rankine cycle's gas fired boiler with multiple control strategies, offered the ability to


achieve very low air emissions, lower than any other of the technologies.  Reciprocating engines


had the highest emissions.


    The combined cycle offered the highest net  power, but at  increased complexity and cost,
                                          1100

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which outweighed the value of the added power.




    The "BTU Content" criteria included the ability to effectively operate on  a  low BTU




content fuel  which  is  subject  to sudden variations.   The landfill is  constantly settling.




Differential settlement often results in line separations and sudden decreases in BTU content.




    Two gas  turbines are also currently operating at Puente Hills Landfill: a Solar Centaur




(2650  kw) and  a NATCO KG-2  (1250 kw).   These  gas turbines  have been operated




intermittently since  1983 when landGll gas  is  available.  The gas  turbines  have operated




successfully.  The Districts consider gas turbines a viable technology for smaller landfills.




PERG Specifications




    In order to assure a competitive bid and quality construction, the Districts prepared detailed




Performance Specifications for bid to pre-qualified engineering contractors.  The Performance




Specifications included  detailed specifications on major equipment and general construction




specifications.  Also,  included in the Performance Specifications were the  design,  redundancy,




and access requirements  for all  major equipment and  systems.  An equipment summary is




provided in Appendix 1.




    Bids were evaluated by calculating the net present worth of the 60 monthly payments and




the residual value purchase to the bid opening using 1% per  month discount rate. Net power




from the Facility was included  as an evaluated credit  of $2,500 per kilowatt to encourage




energy efficient designs.  However, the Performance Specifications included limitations  on the




cycle complexity for ease of operation and reliability, and several mandatory emission control




methods to achieve the stringent air emission limitations.




    The  Performance Specifications  included  redundancy  requirements on  most rotating
                                           1101

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equipment for reliability. The only mechanical equipment without redundancy are the boilers




and steam turbine.




   The successful bid by Schneider, Inc. included a steam turbine by Fuji Electric. The steam




turbine heat rate is 8,545 BTU/kwhr (9.01 MJ/kwhr). The boiler efficiency is over 83% based




on the higher heating value of the landfill gas. The parasitic load of the plant is approximately




8%  of gross.   The  overall Facility's net  heat  rate based on  the higher heating value is




approximately 11,000 BTU/kwhr (11.6 MJTkwhr).




    Performance  requirements  included ASME  performance test codes for  steam turbines,




boilers, and deaerator.  The turnkey contractor was also required to demonstrate that the boiler




could  achieve  the  stringent limitations  imposed  on the project by the local air  quality




management district. Another requirements was to demonstrate the Facility could be operated




reliably, which consisted of an 85% availability requirement for a 30 day period before the




Districts accepted the Facility.




Project Schedule




    A primary concern was to implement a project as quickly as possible to utilize the  landfill




gas. Project implementation, from conceptual design to commercial operation was accomplished




in less than three years.  Conceptual design  was started in early 1984. Applications  for air




permits were filed in May, 1984 and final permits were received  in April, 1985. The contract




was awarded to the  turnkey contractor in March, 1985.   Commercial operation was achieved




in November, 1986.



    The turnkey method of procurement was selected since it offered considerable time  savings




over other procurement methods. The turnkey contractor was required to design and construct
                                          1102

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the Facility in 16 months.  This tight schedule mandated a substantial overlap of the design and

construction phases of the work.


Air Emissions


    Air emissions are a critical issue in Los Angeles County.  From a regulatory standpoint the

South  Coast Air Quality  Management District (SCAQMD), requires that all landfill gas be

collected and flared.  When the permit was filed, the emissions from the flares  provided the


baseline emissions level

    The Performance  Specifications  included several  requirements to assure the stringent


emission levels could be achieved, including derating the boilers, flue gas recirculation, low" NO,

burners, limiting the  air  preheat, and provisions  for Thermal DeNO,  (a proprietary Exxon

process).  However, tests on Thermal DeNO, demonstrated Thermal DeNO, did not effectively

reduce NO, at the" low inlet NO, levels.  Subsequently, the  ammonia injection piping was


removed.  The air pollution control and NO, reduction methods are shown in Figure 4.
                DERATED BOLER

                    LOW
                  NTENSITY
                    FLAME
CONVECTION
 SECTION
  AIR
PREHEATER
         STACK
                                              ECONOMIZER


                                          THERMAL OiNOx
                  LFG
                                  FLUE GAS RECIRCULATION
                               PERG   NOX    CONTROL
                     Figure 4 - Schematic of the PERG Boiler NO, Reduction Methods

    The boiler burners  are low NO, burners supplied by Coen.  The burners, are the dual air
                                          1103

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zone type (Coen Model Number DAZ 42), with adjustable inner and outer scrolls which may
be controlled  to adjust the flame shape turbulence.  The scrolls direct the gases in opposite
rotating directions.  Increasing the opposing spin increase turbulence and results  in a shorter
more turbulent flame.
    The NOX control  strategies including the low NO, burners, oversized  boilers, and flue gas
recirculation have resulted in very low emissions of less  than 24 ppmv NO, (3% O:, dry) or
approximately 0.03  lbs/10* BTU.  Flue gas recirculation has proven to be an effective method
of reducing NO, emissions by approximately 60%.
    A comparison of the PERG boiler emissions to  the  flare emissions is given  in Figure 5.
This Ggure shows the boilers provide substantially lower NOD HC, and CO emissions.
            TOO
            600
            500
            400
          2 300
            200
             100
                                                               2222
                         NOx               CO
                               I   1 FLARES  £2 BOILERS
HC
              Figure 5 - Emission Comparison between the Flares and Boilers at the Puente Hills Landfill
                                           11O4

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Using Landfill Gas as a Fuel




    The operations problems at PERG have for the most part been the result of failures with




equipment common with a natural gas  fired power plant  The availability to date has been




92% for the first three years of operation.




    Any operational problems which could be attributed to landfill gas may be caused by the




moisture, or by the chlorine  and sulfur compounds in the  landfill  gas, or by the variability in




the landfill gas quality. The landfill gas is essentially saturated when it is  collected from the




landfill.




    Landfill gas is a  relatively clean fuel.  The landfill gas from the Puente Hills landfill




contains 30 to 80 ppmv each of chlorinated and sulfur compounds.  This compares favorably




with coal which may contain between 100 and 1,000 times more sulfur and chlorine.




    The  landfill gas  collection at  the Puente Hills Landfill  includes more than 40  miles of




collection  and header piping.  The piping,  being located  in a  landfill is subject to both




differential settlement and vehicle damage.  Differential settlement  within the landfill is  the




most prevalent cause of failure. Differential settlement causes failures by over stressing flexible




joints in the landfill gas piping.  Periodic  inspection  of the  landfill  piping has limited major




failures caused by differential settlement.




    Normally there is a slight diurnal variation in the landfill gas with the  landfill  gas quality




causing the BTU  content to be lower at night. This may  be the result of thermal expansion




of the PVC collection piping during the day resulting in lower air infiltration into the above




ground piping.  The air infiltration may occur at cracks in the flexible joints.




    The  problem  that arises from the  power plant standpoint is  the variability in the BTU
                                           1105

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content of the landfill gas.  Normally the Puente Hills landfill gas varies from 410 to  440




BTU/scf.  However, in the case of a piping failure, the BTU content may drop to below 200




BTU/scf.  This may result in flame stability problems in the boiler.




    Flame stability in the  boilers is  a potential problem,  especially  using  a high flue  gas




recirculation  rate. The  pilot flame for  startup is  fueled by propane.  Prior  to successfully




completing lightoff on landfill gas, the minimum fire settings had to increase in terms of firing




rate and excess air had to be decreased. This is due to the nature of the  landfill gas fuel.




Since landfill gas has less than half the BTU content of natural gas, the flame burns cooler.




This results in occasional burner safety management trips when the flame scanner (Fireye) fails



to sense the  flame.




    The chlorine and sulfur in the landfill gas make the gas and its condensate corrosive. Since




the landfill gas is saturated and the ambient temperature is below the dewpoint of the landfill




gas, moisture condenses along the pipe  walls.   This condensation, or condensate has a  pH




between 2 and 3. Carbon steel corrodes quickly at this pH. Accordingly, the Districts use 304




stainless steel for both landfill gas and condensate piping.




    Landfill gas is generally low in particulate matter.  However, when new collection piping




is placed in service or in upset conditions a large amount of particulate  matter or moisture can




be  passed through the landfill gas piping. Witch hat strainers are located at the inlet of  the




landfill gas blowers to protect the blowers from particulate matter.  A knockout drum protects




the blowers from slugs of water.




    Occasionally a condensate trap which normally removes the condensate from low points in




the landfill gas collection system fails.  This results  in the partial or complete plugging of  the
                                         1106

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associated piping until the water condensate is removed.  Partial plugging of the landfill gas

pipe in the  collection system is detected at the energy  station by oscillating  landfill gas

pressures.  When all the condensate traps are functioning properly, the landfill gas pressure is

very stable.

Availability

    A summary of factors affecting availability during the first three years of operation is given

in Table 2.  The most trouble  prone pieces of equipment  during  the  first three years of

operation were boilers.  The largest factor was the forced draft fan motors which both failed

during rainstorms.  Enclosures around the  motors have precluded subsequent failures.  The

other factors which significantly affected boiler availability were:  a faulty electronics board in

the burner management system; binding of the forced draft fan dampers; bearing failures at the

air preheater rotor (hot end) and the forced draft fan; and the flue gas recirculation fan related

problems.  A boiler feed pump suction bypass from the fifth heater feedwater line was installed

to reduce the NPSH transient due to a sudden load  decrease.  The original forced draft fan

damper was replaced with an external greased ball bearing inlet vane damper.

Item                         Number of Outages             Total Downtime  (hrs")
Boiler                                67                              768
Steam Turbine                         6                               35
Landfill Gas System                   10                               59
Electrical                             12                              135
Instrumentation                       13                               83
Utilities                               17                              118
Other Mechanical Equipment           5                               23
Annual Maintenance Outage           3                            1,051

       Total                         133                            2,272


                         Table 2 - PERG Outage Summary for 1987, 1988, and 1989
                                           11O7

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    The Fuji steam turbine proved to be a reliable piece of equipment during the first three




years of operation.  However, during the scheduled warranty inspection at the end of the three




year warranty period, the following items were discovered and repaired:




    1. Erosion/corrosion noted at the trailing edge of the 33rd stage of stationary blades.




    2. Severe seal fin damages (both moving and stationary blades).




    3.  Erosion/corrosion noted at the stationary blade seal fin bases at 31st and 32nd stage.




    The scheduled maintenance  outage was  extended for these  unexpected  repairs  by




approximately three weeks.




    The landfill gas collection system caused 10 outages  in the first three years of operation.




Five outages were  the result of sharp  drops in the landfill gas methane content.  There were




two scheduled outages for landfill gas piping modifications.  Two outages were caused  by




landfill gas blower  failures. One outage was  caused by  air preheater fouling which required




water washing due  to an excessive pressure drop. The  deposits were analyzed and determined




to be silica, iron, chlorine, and sulfur in  descending order of concentration.




    There were 12 electrical  failures  in the first three years of operation.  Three  electrical




failures were in the uninterruptible power supply system.  Three main breaker trips resulted




from electrical fault in the circulating  water pump motor.  Three outages were resulted from




trips in the 4160 volts transformer. Three scheduled outages totaling 70 hours were resulted




from correcting the overheating in the Southern California Edison  metering (12KV) cubicle.




    Seven instrumentation trips occurred due primarily to  faulty vibration signals. Subsequently,




the vibration switches were changes to  alarms rather than trip.  Six outages resulted from faulty




instrumentation signals. Water leaks through connecting conduit to one of the outdoor process
                                           11O8

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control unit cabinets resulted in 24 hours of down time.




    Two different utility power sources are required for the operation of PERG.  One




electrical service  provides the electric power for the landfill gas collection blowers and the




water booster station.  The other electrical service provides both the generated and parasitic




power for PERG.  Seventeen outages resulted  from interruptions  in service or disturbances




resulting in  the opening of the main breaker  by protective relays for a total of 118 hours of




downtime.




    Outages due  to other mechanical equipment such as pumps and compressors were limited




to 23 hours due to redundancies and automatic  standby controls.




    Annual maintenances were typically scheduled in  May approximately one month before the




four summer months when  power sold at a higher rate.




Economics




    The project capital costs, including design, construction,  and interest during construction




was approximately $33,000,000 for the entire Facility.  On a  unit cost basis this is equivalent




to $650 per kilowatt of installed capacity. The District structured the project financing to allow




the electrical revenues from the project to pay for the project capital costs.




    Project revenues are derived from the sale of electricity to Southern  California Edison.




The gross revenues were $90,688,900 for the first three years of operation in accordance with




the power purchase agreement with Southern California Edison.  Each of the 60 monthly lease




payments is $726,000, and  the average routine monthly operations and maintenance expenses




were $319,000.   The  cost  for  the  FGR  fan modification and a  major  turbine  and boiler




overhaul was $1,200,000.
                                          1109

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Operating Costs

    The  operating costs for PERG were estimated at  $300,000 per month.   The  average

operating costs for the first  three years of operation was $319,000 per month.  A breakdown

of the operating expenses is provided in Table 3.

                Expenses 	        $/Month
                Payroll
                Materials
                Chemicals
                Water
                Electricity
                Services
                Insurance
                Other

                Total
138,000
 49,000
 13,000
 16,000
 35,000
 20,000
 18,000
 30.000

319,000
                                Table 3 - PERG Operating Expenses
Conclusion
     The PERG Facility  demonstrates  that a large scale  landfill gas to energy facility can

combust landfill gas (a waste product), reduce air emissions, and provide significant economic

benefits.
                                         1110

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                                        Appendix 1
                                    PERG FACT SHEET
Owner and Operator
Turnkey Contractor

Engineer (Detailed Design)

Boilers
    Number
    Manufacturer
    Steam Capacity (each), Ibs/hr (kg/hr)
    Steam Pressure, PSIG (MPa)
    Steam Temperature, °F (°C)
    Configuration
    Erection
    Burners
    Air Preheater  (Ljungstrom type)
    Stack Gas Temperature, °F (°C)
    Efficiency (as bid)

 Steam Turbine/Generator
    Manufacturer
    Capacity
    Blading
    Number of Stages
    Extractions
    Condensing Pressure,  'Hg'(kPa)
    Heat Rate (as bid)
 Condenser
     Manufacturer
     Surface Area, ft2(m2)

 Feedwater Heaters
     Manufacturer
     Stages

 Cooling Tower
     Manufacturer
     Heat Rejection, 10'BTU/hr (MJ/hr)
     Superstructure
     Fill Material
     Fans

 Control System
     Supplier
     Type
     Model
   Los Angeles County
   Sanitation Districts

     Schneider, Inc.

Energy Systems Associates
           2
         Zurn
    264,000 (120,000)
       1350 (9.4)
       1000 (538)
        XT Type
         Field
         Coen
 Combustion Engineering
        260 (127)
          83%
          Fuji
       50,000 kw
        Reaction
           35
           6
         2 (6.8)
     8545 BTU/kwhr
     (9.01 MJykwhr)
         Graham
      38,000 (3532)
      Struther-Wells
            5
      BAC-Pritchard
        272 (286)
        Concrete
          PVC
      150 hp, 2 speed
      Bailey Control
       Distributed
       Network 90
                                              mi

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   STABILIZED FOAM AS LANDFILL DAILY COVER

                       A.J. Gasper
                      3M Company

                    Presented at the

 First U.S. Conference on Municipal Solid Waste Management
                    June 13-16,  1990

Abstract
   This paper is concerned with the use of stabilized foam to provide
 daily cover in sanitary waste landfills. The paper will discuss the
 problems faced by landfill operators in using soil and other materials
 as daily cover  and the inherent advantages and needs associated with
 the use of stabilized foam. In addition the paper will discuss the
 experiences of 3M as a material and equipment supplier of stabilized
 foam synthetic daily cover. The paper will highlight the equipment
 and foam technology used to produce the the foam cover and also the
 experiences of 3M and its customers in getting the product approved
 for use in various localities. The paper will discuss the facilities
 required on the site to use the product efficiently and also some of the
 training and service provided to landfill operators to take advantage
 of this technology.
                            1113

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3M-WMA Presentation                     text (ref. slides)
     I. Introduction
            A. Problem Statement
            The generation of waste in the U.S. is accelerating and the available
            technologies to deal with the problem are limited. In particular,
            landfills have been the traditional approach to disposing of
            municipal waste but they are filling up at an alarming rate and the
            siting of new landfills is very difficult There has been a decrease of
            about 8000 permitted landfills from 1987 to 1990 in the United
            States. One of the factors leading to the limited life of existing
            landfills is the use of soil as daily cover material. When soil is used
            as daily cover there are several associated problems:
                  1 - Soil consumes valuable air space.
                  2 - The availability of soil to a local site may be poor
                     and if that is the case, soil cover may be costly.
                  3 - Application of soil cover is quite labor intensive
                     and can be susceptible to adverse weather
                     conditions.
                  4 - Soil may cause unwanted lateral movement of
                     leachate and gas.

            B. Need:
                  Performance criteria for daily coven
                        1 - Control litter
                        2 - Control odors on the workface
                        3- Control Vectors
                        4 - Provide a fire barrier against hot loads,
                           spontaneous combustion and surface
                          ignition
                        5 - Provide a disincentive to scavenging and
                                    1114

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        other undesired activity on the landfill
            6 - Provide a barrier to excessive water
              infiltration which could create excessive
              leachate.
            7 - Provide a degree of acceptible esthetics for
              the landfill relative to neighbors and
              passersby.
C. Non - Soil Alternative Daily Cover material:
      There have been a variety of materials which have
      been used as alternative daily cover material to soil.
      Generally all have had deficiencies.

      Flyash, incinerator ash and bottom ash have been
      tried in some locals as daily cover material. These all are
      considered unacceptable from the standpoint of heavy metal
      content and dust problems.

      Industrial and municipal waste streams such as
      waste water sludge, paper sludge, tire chips, foundry sand,
      wood chips and shredder fluff have all been used occasionally
      as daily cover material. Contamination of by heavy metals,
      PCBs together with materials which cause bad air emissions
      are generally associated with materials of this type. An
      additional problem with sludges is that they can inhibit the
      maneuverability of landfill equipment.

-------
                 There have been several attempts at using geotextiles as daily
                 cover material. Although they appear to satisfy some of the
                 basic criteria for cover such as litter control and esthetics, the
                 geotextiles in use suffer from several important aspects
                 relative to daily cover requirements. They can be very
                 difficult to install especially in windy conditions and
                 inclement weather. They are porous to rain and therefore can
                 create significant problems with leachate. The geotextiles are
                 flammable and if they are reused they can cause problems
                 with air emissions and exposure of workers to refuse
                 residues.

                 D. Solution:
                 An excellent approach has been to use stabilized foams which
                 are designed as daily cover material. These materials are
                 engineered to meet the basic performance requirements of
                 daily cover in conserving valuable air space while providing
                 increased revenue to the landfill operator.

                 Two such materials sold by the 3M Company will be
                 discussed further.
II. Description of foam materials
     3M produces two types of foam materials for use as synthetic daily cover
     (SDC) on municipal landfills. The materials are: 3M Foamat™ SDC and
     3M SaniFoam™ SDC. Each type of foam can substitute for soil cover in
     daily applications. In both cases, foam is produced by combining water, air,
     an aqueous surfactant solution and a stabilizing resin. This combination of
     materials exits from a spray nozzle to give the desired foam material on
     the landfill surface.  Equipment has been developed to apply the materials
     in an efficient and effective manner through either pull-behind spray bar
                                   1116

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units or hand-held spray devices.

While both foam systems are effective replacements for soil as daily cover,
they are based on different polymeric resin systems and have different
physical appearance. They also require different equipment and handling
procedures. We will describe the systems one at a time.

3M Foamat SDC  ~ There are two components (in addition to water and
air) which make up this system. FC-9400 polyurethane resin and FC-9401,
the surfactant/catalyst solution. This system has been designed for use with
the Foamat foam Cart. The resin is provided in a closed-head 55 gal drum
and material  is pumped  directly from the  container.  The FC-9401 is
provided as a concentrate in closed-head 5 gal. pails and is diluted with
water for use.

The gellation rate of the foam is controlled  by the concentration of foamer
used. The recommended range of foamer solution per hundred gallons of
water may range from 10 to  16 gal. depending on  such  things as
temperature and water hardness.   FC-9400  will react with ambient
moisture on prolonged exposure, but has greater than 1 year shelf-life
when stored in its original container in relatively dry conditions at
temperatures less than 100°F.

The FC-9401 foamer is a concentrated solution of the active ingredients in
water. When the Foamat™ system is used/ the foam is  dispensed from
each  of the six nozzles at a rate of 10 gal/min.  The foam expansion is
typically 20-25. The six nozzles will give a spray width of 12-15 ft and when
the cart is pulled over the workface at 1.0 to 1.5 ft/sec., the foam depth is
about 3-4 inches. This foam depth is adequate to cover moderate to well-
compacted refuse.
                              1117

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Environmental Information:

Extensive environmental testing has been done to review the potential
impact of the foam products on the landfill and surrounding environment
as well as to monitor the effectiveness of the product for its intended use.
Leachate testing has shown that very little material leaches from cured
foam and that which does has no adverse environmental impact. Animal
testing has also shown the material to be non-hazardous. The results of
this testing are available to interested persons. With  regard to product
utility, tests have shown the product to be effective in controlling litter,
odors and vectors.  Other tests have  shown that the  material provides
protection against the infiltration of rainwater into the refuse and that this
synthetic daily cover is non-flammable and does not add to the inherent
fire hazard of the landfill. These are very important considerations when
using a daily cover material. Again, specific information on methods and
results can be made available.

The Foamat™  Cart is  designed  to  be towed with normal landfill
equipment such as a D-6 to D-8 Caterpillar. In daily operation, the unit is
filled and prepped in the morning and foaming is done in the afternoon.
Experience has shown that a properly maintained cart requires about 1-2
hrsVday for filling, cleaning and general maintenance. The equipment has
several built-in features for ease of use. These include a drum hoist to
change barrels of FC-9400, an hydraulic jack to aid in moving and handling
the cart and a bottom-fill system to  mix in FC-9401. Foaming and flushing
are controlled by the driver of the tow vehicle  and in many cases the
operation involves only one person. Experience has shown that it takes
about 20-30 min.  to cover a workface of 15,000 sq.ft. This is normally
quicker than it would take to cover a similar area with soil at the end  of
each workday .The foam cover does  not require removal the next morning
and compacts under the next day's waste, thus saving valuable landfill air
space.

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The major difference between Foamat™ and SaniFoam™ SDC from the
standpoint of the user tends to be esthetics. The Foamat® material forms a
dense transparent  membrane  as the water in the foam evaporates.
Although this membrane continues to function effectively as daily cover,
some landfill operators and inspectors prefer a higher level of opacity of
the foam cover. For those operators the SaniFoam™ SDC is the preferred
product

The  following information describes the 3M SaniFoam™ SDC system
including materials and equipment There are many similarities between
the foam systems particularly hi terms of their use. The major differences
are related to the type of polymeric resin employed to produce the foam
and also some differences in the type of equipment used to apply the foam.
The main components of the SaniFoam™ SDC system are FC-4200 resin
and the FC-4201 foamer solution.

FC-4200 is a solution of a urea-formaldehyde prepolymer.  This material is a
very low viscosity/ water-soluble resin which when combined with FC-4201
forms a highly crosslinked matrix which provides the foam stabilization.
FC-4200 is supplied normally in 55 gal.  closed head drums which   is
pumped from the drum into the resin tank on the application equipment
without dilution. At large user sites, the FC-4200 is supplied and stored in
bulk containers. The resin is pumped directly from the  storage container
into the foam trailer. The FC-4200 has a shelf life of approximately 90 days.

FC-4201 is a foamer solution for FC-4200. This material generates the foam
structure and is acidic and catalyzes the FC-4200 crosslinking process. The
FC-4201 is normally supplied in 55 gal drums and is diluted at the rate of
twenty to one one with water in the foamer tank.

A "drum set" which is one drum of resin  and 2.5 gal of foamer will cover
                               1119

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about 2000 sq.ft. with 1-2 inches of foam. The strength and opacity of the
SaniFoam™ SDC system provides for very effective cover.

Many tests have been done to verify the environmental compatibility of
the SaniFoam system. Levels of free  formaldehyde, are extremely low in
the cured resin solution and the foam. The extraction tests show that there
is almost no detectable level of any of the SaniFoam resin components
present in the leachate. The foamer material which is a special surfactant
is very biodegradable and compatible with the landfill environment. Tests
for system efficacy have shown that the SaniFoam blanket provides
excellent protection as daily cover on the landfill. As the material dries, it
maintains its original appearance and this feature is desired by many of the
landfill operators. Details of the test methods and results on this product to
determine environmental suitability can be made available to interested
parties.

There is a wide choice of equipment  available to users of the  3M
SaniFoam™ SDC system. The equipment ranges from relatively small and
portable handline units to large, pull-behind spray bar trailers for high-
volume landfills. All of the units work on the same principle to produce
stabilized foam. The aqueous FC-4201 foamer solution is pumped or forced
by compressed air through a bead chamber where it is combined with air to
produce foam. The foam is then delivered to the nozzle where it is mixed
with the stabilizing resin before ejection to the surface. The material begins
to cure to produce the stabilized foam immediately and its stabilization is
normally complete within 10 min. The stabilized foam is a fluffy white
material which is flexible and has good  adhesion  to all surfaces on  the
landfill including vertical surfaces. In a typical landfill application when a
pull behind unit is used, touchup is done if necessary by using a hand line
available on all SaniFoam™ SDC equipment.  Many users  find it
advantageous to use the hand line simultaneously with the spray bar.  All
application units have a hot water flush system to clean the nozzles after
                               1120

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use. They also have enclosures for the resin and foamer tanks in order to
allow use of the equipment in cold weather. 3M provides technical service
assistance to users  of  all equipment from startup through normal
application.

III. Regulatory concerns:
       The use of foam for daily cover falls under the jurisdiction of
       regulatory agencies at the state and local level. The specific
       regulations differ from locality to locality. Normally, approval to
       evaluate and/or use foam as synthetic daily cover comes only after
       negotiations with several agencies. Typically, the local agencies have
       required a testing period hi order to evaluate the product for
       efficacy and  environmental impact and equivalency to soil in
       meeting the  performance criteria.

       It is extremely important that regulatory agencies be apprised by the
       suppliers of the daily cover alternate products about the benefits
       and disadvantages of their cover material relative to traditional
       soil. This is true because there are occasions where landfill
       economics and operational practices might compel an operator to
       use an inappropriate material such as a fabric or sludge simply
       because there is a perception that the workface is covered adequately
       with little thought given to the long range engineering
       implications such as impact on leachate quality and quantity and air
       emissions upon removal together with the inherent fire hazards on
       the landfill.

       Reputable providers of cover material should have the same
       concerns that are expressed by regulators.
       Regulators should expect that providers of alternative cover
       materials have the type of documentation that indicates the efficacy
       of the product to meet or exceed the requirements of daily cover for

-------
       landfills while having overall environmental acceptance for
       landfill use.

IV. Landfill Requirements
       The landfill is required to have certain facilities in order to
       effectively use the stabilized foam systems. Normally a landfill will
       already have these facilities in place. Occasionally, a landfill is
       required to invest in additional facilities. The major requirements
       are:
       — Adequate water supply to fill the unit efficiently— about
        10 gpm minimum
       — Inside storage of foam materials and equipment in cold
        weather to prevent freezing.
       — An area suitable for daily preparation and routine
        maintenance of the unit.
As indicated, 3M provides all training ,materials and service to assure high
quality, dependable daily cover for the applicator.

V. Actual landfill experience

       The use of stabilized foam as alternative daily cover has been
       studied and approved on landfills both in this country and in
       Europe. Several slides demonstrating the use of the stabilized foam
       materials will be shown at the time this paper is presented.
       In the majority of cases, evaluation of the installation and
       performance of the stabilized foam cover was done by an
       independent consulting engineering firm. Their reports will be
       highlighted in this section of the presentation.
                                1122

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A STUDY OH LEACHATE TREATMENT BY MEANS OF FENTON METHOD

                 Sue-Huai Gau, Ph.D.
                 Associate Professor
           Department of Civil Engineering
                 Taakang University
                Taipei, Taiwan. R.O.C.
                 Presented at the

First U.S. Conference on Municipal Solid Waste Management

                 June 13-16,  1990
                          1123

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   A STUDY ON  LEACHATE  TREATMENT BY MEANS OF FENTDN METHOD

                          ABSTRACT

     During   the   sanitary landfill period, the  COD  value  of
leachate  can  usually   exceed 10,000 or  20,000  »g/l.   After
aerobic   or  anaerobic  biological  treatment,  however,   the
residual COD is still  up to thousands and the effluent  remains
dark  brown.   In  convention, COD and  color  are  removed  by
chemical coagulation followed by carbon adsorption.  But,  even
if a huge coagulant dosage is used, the COD removal  efficiency
is very low and there will be a lot of sludge to be handled.
     The Fenton method, a chemical oxidation," applies  hydrogen
peroxide as an oxidizing agent whose reaction  is accelerated by
ferrous sulfate.    It has been proved that the Fenton method can
break   some recalcitrant organics effectively.  This method  is
thus employed  to treat the leachate after the activated   sludge
treatment,  in  order to find out the proper  chemical dosage  and
operation conditions.
     The  results  are:  (1)  It achieves  lower  COD   and  clearer
supernatant   than  the coagulation method does.   (2)   The  best
ratio  of H.Ot  to FeSO   is between  0.5  and 0.8.  (3)  To  reach 70X
COD  removal  efficiency  (the  final COD  value  400-500 mg/1),  it
needs  0.3-0.5  g  H.Ot/g COD removed, and  the more  HtOt  dosage is
added,  the  better  COD  can be  removed.   (4)  The  proper  final  pH
is between  3  and 4.
                                1124

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1.  Introduction
     Nowadays  the  landfill  of  a  considerably  large  quantity   of
refuse  entails  problems of  leachate.    Generally,   biological
treatment  is utilized to  lower the  concentration  of  organics  in
refuse  leachate.  But the  ability  of biological  treatment   is
limited, especially when confronted  with  the  low  biodegradable
organics.  After the phase  of  biological  treatment,  it  is  thus
necessary  to proceed to chemical coagulation  in addition to the
operation  of filtration and/or adsorption, so that the  treated
water  quality  may  reach  the  effluent  standards.   However,
chemical   coagulation  is   not good  enough  for   dissolved  COD
removal: it will produce a  great deal of  chemical sludge to  be
handled.tlj  This study  employs the Fenton method to solve the
problems of refuse leachate that has undergone activated sludge
treatment,  such as the low  biodegradable  organics which  caused
high COD and color.
     The   Fenton  method,  a chemical oxidation,   uses  hydrogen
peroxide  as an oxidizing agent whose reaction is  accelereated
by Fe**.   In 1860,  Schonbein found that the oxidation of iodide
ion  by means of hydrogen peroxide is markedly  accelerated  by
iron salts.  And. in 1894,  Fenton discovered that a  mixture  of
a  ferrous   salt  and  hydrogen  peroxide  could  oxidize   many
hydroxylic   organic compounds, and that the  mixture  possessed
potent  oxidizing  properties  not  present  in   the   separate
reagents.1"1  Hereafter the Fenton method has been explored  on
and off.
                             1125

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2. Background
     Hydrogen  peroxide  was   found   by   Thenard   in   1818  and
Manufactured for industry at the end  of  the  nineteenth century.
During  World  War  II, because  it became  the   liquid   fuel   to
promote  equipment, its production was rapidly  increased.    The
•elting  point  of hydrogen peroxide  is  at -0.41"C,   liquid   at
normal temperature, and its boiling-point  at 150.2"C .   At  25 "C ,
it becomes viscous liquid with density of  1.4425 g/ml,  and   can
be mixed up with water.  On the market,  its mixing  rate  is from
3X to 90X,  weak acid,  and the specific conductivity  is 5xlO~T
ohm"tcm"1.  The  reaction  of  hydrogen  peroxide itself  is very
slow.  To accelerate the ability of hydrogen peroxide,  it needs
metal  ions  such as Fe. Cu. V. Cr and Hn,  or  materials  with
rough surface such as zeolite and activated carbon, high pH and
radiation  ( short-wave  ultraviolet  rays ). t33   The  common
oxidizing agents used for chemical  treatment of refuse  leachate
include ozone,  chlorine,   hypoch1 orite,  hydrogen peroxide, and
so on. The  installation of ozone costs  much and  cannot remove
COD in an  efficient  way.   Both chlorine and hypochlorite have
weak oxidation  and  may  bring  forth   halogenated  compounds.
By  contrast,   hydrogen peroxide is cheaper,  safe.   and without
bad consequences.   When  combined  with  Fe2*,  the  oxidation
of  hydrogen  peroxide will be strengthened.   Some  experiments
have  indicated   that  the  Fenton  method  is  effective   on
the  decomposition  of ABS, phenol, etc.143  Besides,  in  Japan
                             1126

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the study  of  various  organic  compounds   applies  the   Fenton
method under the following conditions:
H.O./COD = 1.0.  H.O./FeSO*  =  5.0  dole  rate),  PH  =  4,  and   one
hour's  reacting time.  COD  removal   efficiency  for  alcohols,
acids,  aldehydes, and ketones are  30-40X,  30-50*.  30-50*.   and
10-40*. respectively.  As for  dicarboxylic  acid,  COD removal  is
around  60*, for some unsaturated  compounds up  to  90*.  and   for
the  decomposition of aromatic compounds is from  70% to  90*.£83
Some  documents have proved  that through the Fenton  method   TOC
removal  can be more than 75*  for  low  biodegradable  organics,
such as Urea resin, dibromsa 1 ici 1,  POENPE (n =  15).t63  Further,
Takashi  Korenaga  employs   the  Fenton   method  to   treat   the
photographic   wastewater,  whose COD  removal is decreased  from
62.300 mg/1  to 291 mg/1 and  treatment efficiency  is  as  high  as
99.5*.tT:i
The mechanism  of the Fenton  method  is as follows:1"1
     Fe"*  +  H.Oa -»  (FeOH)"* + -OH   -»  Fea* * -OH  +  OH'      (1)
      •OH + Fe"* ->  (FeOH)"*  -»  Fe3*  + OH"                   (2)
      •OH + H.O, -> H.O  *  -O.H                              (3)
      •O.H  <- ->  -Of' + H*                                    (4)
      •0»-  +  H.Oa -> 0. +  -OH * OH'                           (5)
     Fe3*  *  H.Oa -» Fe"*  +  -O.H  *  H*                         <8)
     Fe3*  *  -0." -» Fe8*  + 0.                                (7)
      (  i )   When H.O. < 1Q-*H  and  the initial concentration  of
Fe"  is  low, the main reaction formulas  are (1) and  (2).
                              1J27

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     (ii )   Vith the increasing proportion  of  H«0«  to Fe1*,  -OH
radical  will  strengthen  its competence  to lay   aside  Fonula
(2).   It results in  -0«H radical,  that  is,  the reaction of (4),
(5) and (7).
     •Q.H -> -Ot- * H*                         (4)
     •0.- * H.Oa -» 0, + -OH + OH'             (5)
     Fe" +  -0.- -» Fe1* + 0.                  (7)
     The  above  reaction  will release  Oxygen  to   increase  the
dissolved oxygen in vastevater.
     (iii)   Vhen the organic lonoiers  exist.
     •OH *  CHt=  CHX -> HO-CH.-CHX   ---  polyiers
or   -OH +  RH -» H.O * R-
     R- * CH.=CHX  -> R-CH.-CHX
     R-CH.-CHX  * CH.=CHX -> R-CH.-CHX-CH,.CHX   ---  polyaers
the polyierization occurs.
     (iv )   Vhen there exist the  organics,  the reaction  is   as
the following:
     H»A *  -OH  -»  HA- + H.O
     HA- *  Fe"  -» HA' + Fe"
     HA* *  OH'  ->  HAOH  (priiary product)
     HAOH *  -OH  -> HOA- *  HiO
     HOA- *  Fe" -»  Fe" * H* * AO (secondary  product)
     (  v )   When oxygen exists, the reaction  of  the organics  is
as follows:
                             1128

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     H,A +  -OH_-» HA- + H,0
     HA- + 0, -» HAD.
     HAD, * Fe"* + H* -> HAO.H  +  Fe3*
     HAD, + H.A  -> HAO»H + HA•
     HAO.H + Fe»* -»  HOA- + Fe3*  + OH'
     HOA- * H.A  ->  HAOH + HA •
     HOA- + H*  + Fea+ -» HAOH + Fe3*
     In  the  reaction  process,  the   free   radicals   of    -OH
consisting  of   unpaired electrons are  full  of  activating   and
oxidizing ability.   The oxidation is even stronger than that of
ozone,   and can  decompose high  aolecualr weight  organics   into
low aolecules.   Thus, as has been confirmed,  after applying  the
Fenton   nethod,  BOD is  increased  and the proportion of  BOD  to
COD raises.£'3   Such a deconposition can reiove the color  and
COD  of  the  low biodegradable   organics.    Besides  the  free
radicals  of  -OH  and  -O.H, Fe'* is  oxidized  into  Fe3*  and
Fe(OH)**,  which results in coagulation and,  plus  the  organic
•onoiers. polymerization.   To sum up, the Fenton method retains
the double effect of oxidation and coagulation.
     Judging  from  the  above functioning   structure,  in  the
reaction process the Fenton method will not  produce troublesome
matters.  Vith  the  adding of reagents, this  method  does not
increase  the total solids and chemical sludge, while  chemical
coagulants Ala(S04.)s  and Ca(OH)« do.   Neither does it encounter
such  problems as the hardness of Ca(OH)a may augment  and  the
                             1129

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chloride of FeCls increases.c*a   According to  these  contrasts,
the  Fenton method can avoid producing  troublesome  Matters   in
effluent.   Though the adding of Fea*   can  increase the   amount
of  iron   ion in the system, during  the   reaction  process   the
ferrous  ion  is gradually  oxidized  into  Fe3*,   coagulated   and
removed  as  precipitate.   Moreover,   the  sedimentary   sludge
containing  a  great  deal  of  iron  ion  may   be recovered   and
utilized again by acidification,c*3   and  the  retaining  hydrogen
peroxide   will   react little by  little  to   increase   dissolved
oxygen  in  wastewater. From  these viewpoints,  the Fenton   Method
 is  economical as  well as efficient.
3.  Methods
      The   saiple  for our experiment is the  leachate   fro«   the
sanitary  landfill site of Futekeng  in Taipei   City,   which   was
opened  on  August  29,  1985.   A  semi-aerobic  method  was  designed
as  the  disposing  means but.  after a  short period,  it  turned  out
 to   be   anaerobic.  The  landfill  area is 37   hectares,  and   its
 capacity   is  estimated to be  8  million  cu metres.  The  site   is
 paved  with  HDPE liners  and has  a   1eachate-co1lecting   system.
 Up  to now, it has practised landfill for  five years.   The waste
 organics   are decomposed by micro-organism  within  the  landfill
 layers.  Of the  leachate, COD  is  lowered from  the highest amount
45,700  mg/1  to  the  present  amount  between 3,000 and 4,000 mg/1:
 BOD decreases from  39,520 to  1,000  or so; the concentration   of
 ammonia  nitrogen is raised  from  550  mg/1  to 2.500mg/l;  pH rises
                             1130

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above 8.0; and a great quantity of methane  gas  is  produced.   It
shows that the acid fermentation stage  is transformed  into   the
•ethane  generation stage.  The way of  treating  leachate  is   an
extended   activated  sludge  process,  followed   by   chemical
coagulation.   Nevertheless, as the landfill period   lengthens,
the color matters of the recalcitrant organics  in  the  leachate
can  not  be effectively removed by activated  sludge  process.
Though  BOD of effluent may decrease to be  below 100 mg/1,   COD
is still as high as 2,000 mg/1 and visibility is bad, between 4
and 7 cm.  When FeCl9 is used as a coagulant, it needs reagents
of 1,200 mg/1 to reach the visibility of 37 cm,  sludge  volume
300 ml/1. COD removal efficiency BOX (l,273mg/l).  If the amount
of FeCls is increased, visibility will  be worse and COD  cannot
be  improved.1101   Contrasting the advantages  of  the  Fenton
method  with  the defects of the usual  coagulatns  in  chemical.
coagulation,  this  study  has carried  out  some   preliminary
experiments  and  proved the distinguished  efficiency  of   the
Fenton  method.1111  Thus, we continued to explore  further  the
wastewater  with  COD  and  color that  cannot  be  removed  by
biological treatment.
     The  above-mentioned preliminary experiments have  studied
the   operating  conditions  of  pH,   the  mixing   time,    the
sedimentation time, and the relationship between visibility and
transmittance. and found out the proper scope of operation.  The
management conditions adopted by this paper are as follows:
     (1) pH control is at 6.0.
                            1131

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     tfhen FeSO*  = 1,000 ig/1 and H.O. = 750 ag/1.  the   treated
water  will  be under perfect control   if  pH  <  7.7 or  pH  >  12.
when the concentration of  FeSO  is   lowered.   in  the beginning
pH control must be under 6. Therefore this  study  decides   the
initial pH control to be 6.0.
     (2) Transaittance testing adopted  wave length is 656  na.
     Use Spectrophotoaeter to detect  the absorbance of   saaples
and treated water from 400 ni to 700  na.  A peak appears around
656 na, so the wave is fixed at 656 na.
     (3) The rapid aixing tiae of the experiaent is 10  a in.
     Coapare COD of the experiaent during the  rapid aixing tiae
froa   10 ain to 60 Bin.  After the reacting tiae lasts   for   10
ainutes.  COD  of  the treating solution  does   not  show  auch
change.  Thus the reaction is fixed at  10 Bin.
     (4) Substitute transaittance for visibility.
     To  analyze visibility needs the treated  saaple aore  than
200 al. while transaittance analysis  takes only  10 al.   To save
the    saaple.   the  relationship  between   transaittance   and
visibility should be first exaained.  Vhen transaittance  is over
SOX.   visibi 1 ity can reach above 15 ca: if over  90%.  acre  than
25 ca.
4. Results and Discussions
     (1) Effects of the concentration of FeS04  :
     According to Figure 1, when the  dosage of HsCU is  fixed at
500 ag/1. that of FeSO  is increased  (H.Oi/FeSO* decreased)  and
COD  reaoval rises.  When HiOs/FeS04  = 0.59,  COD reaoval is  at
                             1132

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its  best.  When H«0B/FeS04 is  lowered to  less than 0.45,  that
is,  the  adding  of FeS04 reashes more  than 1,100   mg/1,  COD
removal  decreases  and remains  in a stable  state.   Then  the
adding  of  FeSQ^.  should be confined  in a   proper  scope.    If
exceeding  the  range,  the treatment  effect  will   be   worse.
Judging from the above reaction  control, when the concentration
of Fe3* is too high the chain reaction will  be restrained,  and
that is similar to the phenomenon of chemical coagulation.
     (2) Effects of the dosage  of H«0a:
     Fix the dosage of FeSO  at  750 mg/1.  According  to   Figure
2,  COD removal  is raised as the dosage of  HaOg  is   increased.
It shows that the oxidation of  organics  is in direct  proportion
to the dosage of HaO«.
     (3)  The dosage of H«0« and FeS04 and their  effects  on COD
          remova 1 :
     According   to Figures 1 and 2,  the   suitable  proportions
are  0.59  and 0.73, by which the dosage of  H»0»  and  FeS04   is
changed.  In figures 3 and 4. when HaO«/FeS04= 0.59, it needs  at
least  0.23 g H«0./g COD  removed; hereupon,  COD removal reaches
only 45X.   If  the  dosage  is   added  UP to  0.367 g H.0«/g  COD
removed.  COD  removal  can  reach  70.5X.   But,  afterwards COD
removal does not speed up with  the adding  of H«0».  This  point
may  be   named   the  most  economical  point  of adding  reagents
When H»0»/FeS04 = 0.73, at the most economical point the   needed
amount of HaO«  is 0.522 g.
                             1133

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     According to the most economical point of adding  reagents,



the  dosage  of  FeSO  has great effect on  COD  removal.   When



HtO./FeS04  = 0.59,  it needs  only  0.367 g H»0»/g COD   removed;



if  H»Ot/FeS04 = 0.73,  it needs 0.522 g.  Therefore,   the   more



dosage  of  FeS04 is added, the less amount of H.Oa   is  needed.



The Fenton  method becomes more economical.



     (4) Effects of oxidation reduction potential:



     Compare  the ORP curve with COD removal.  When  the  rising



of COD removal becomes slov and even, so does the ORP.  as shown



in Figures  5 and 6.  The testing of ORP may be regarded as  the



guide of treatment. As for this point,  it needs further survey.



     (5) The dosage effects of the final pH value:



     As  the  dosage  of  FeSQ^  and  HiOi is increased.  pH  is



decreased.  The more dosage of FeSO^ is added.  the more quickly



pH drops.  In Figures 5 and 6. the test of pH  stops   when  the



dosage  of  H»0i  is up to more than 1.500 mg/1. because  the  high



concentration of dissolved oxygen reveals the violent  reaction.



To protect  the   pH  electrodes  from damage,  the test  of  pH  is



ommitted.



     (6) Effects of dissolved oxygen:



     When  the dosage of HiOi is under 1.000 mg/1, there is not



much change in dissolved oxygen (less than 10 mg/1).   When  the



adding  of  H*0i  is up to 3,000 mg/1. the dissolved oxygen   will



rapidly increase and reach 40 mg/1.  It is discovered  that  when



the dissolved oxygen begins to drop, the most economical  point
                             1134

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of  COD reaoval is obtained.   In other words, when COD  removal
becomes  most  effective,  HaOa  is exhausted  by  organics  and
cannot   be  transformed  into   DO.   But,  when  COD   removal
efficiency rs not high, the remaining HaOa  is transformed   into
DO and becomes a waste.  The DO  value can thus  be used  to judge
the treating efficiency.   Then, the DO  ,   ORP  and  pH  values
are guides for the Fenton method.
      (7) The effects of HaO> on  COD:
      HaOi  is  an oxidizing agent, whose  remaining   dosage,   if
much, will interfere COD and makes the COD  testing value higher
than  the actual.  It   is reported  that HaOa can be   removed   by
KMnO*,t63  but  the  equivalent  point  is  hard to  recognize  and
the   organics  will  be  oxidized  by  the  overdosed   oxidant
simultaneously.   So,   it   is   not   a  reasonable  method.  The
interference caused  by  HaOa  is not yet solved.  However,  it   is
understood that COD  value of the sample  is  less than the  tested
one.
      (8)  Effects  on  transmittance:
      The   Fenton  method  is  good at  color  removal.    When  the
dosage   of H.O.  is  300  mg/1  and that of   FeSO*  is 508   mg/1   or
411   mg/1,   transmittance  is above 90S!.   When   using  Fed, and
alum, though  their  high  concentration  can achieve the  wonderful
effect   of decolorization.  they cannot  remove  COD  effectively.
The  Fenton method,  due  to  its  double effect of  coagulation  and
chemical   oxidation,  can  reach the COD  removal  efficiency  more
                               1135

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than 70X.



     (9)  Effects of the final pH control on the Fenton  method:



     Figure 7  shows  the  initial  pH  fixed  at  6, and   the



relationship  between  the final pH  and the  transmittance of



supernantent obtained when the concentration of HaO* and FeSOn.



is changed.  Froi the Figure, it is discovered that  when   the



final pH   is  below  4.5. transmittance can reach  above  92%.



Figure 8 indicateds the effect of the final pH on COD   removal.



tfhen the final pH is less than 4, COD removal can be more   than



60X:  if   lowered  to  3.33,  COD  removal  can  be  above   70%.



According  to these two figures,  suppose the initial pH  control



is  adjusted  by acid to be 6. and the final  pH, decreased by



the Fenton agent . reaches 3.33. COD removal will be more   than



70X,  and  transiittance above 92X.  The actual  experiment has



proved  the  effect,  shown  in  Figure 9.   In  Figure  9,   the



management conditions are:  initial pH is 6,  the concentration



of FeSO»  is 600 mg/1  and  800 mg/1, respectively, that of  H»0»



is changed, and the reacting  time is 10 minutes,   in order that



the  final  pH  is  less  than  4.  Under these conditions,  the



transiittance of  the  treated  water  can reach above  92X.   As



for the COD removal,  if FeSO* = 600 mg/1. the final pH = 3.42.



and H.O.  = 900 mg/1. it can exceed 71.4X: if  FeSO* = 800 mg/1.



the final   pH = 3.33. and  H.Oi  = 780 mg/1,  it  can be  70.6X.



In  this  experiment.  the  final  pH control can make  sure the



definite COD removal efficiency.  (It should be noticed as well
                             1136

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that the initial pH is fixed at  6.   If  it  is   5,  4,  or   3,  the
effect  of COD reioval  will not be certain; as Table 1  shows.)
It is clear that though the final  pH   is  important, -the   adding
of FeSO* and HiO« is also a pivotal point.
5. Conclusion
     (1)  Vhen  the  Fenton method  is  employed  to   treat   the
leachate   that  contains   low  biodegradable   organics   after
biological  treatment,  the  concentration  of   FeSOo.   plays   an
important role on COD reioval.  Vhen  the  concentration of FeSCU
is  too  low,  even  if  that of HiO»  is  high,   the COD  renoval
effect  is not good.  Besides,  the  cost  of H»0«  is higher than
that of FeSO*.  To  be  econonical,   the  proper dosage of FeSO*
should  be first tested with the siall  amount of HaOa,  and later
add  the  dosage of H«0« according  to  the COD reioval  rate.
     (2)  Vhen  H.O./FeSO*.  = 0.59.  the anount of  H.O,  required
to reiove COD per g is between 0.3  g  and  0.5 g;   if H«0«/FeSOit =
0.73, the required aiount is fro«  0.4  g  to  0.6  g.
     (3)  In  search  of  the «ost  suitable  dosage.  ORP   and
dissolved oxygen can be the references.
     (4)  The   initial pH control  is  very  important.   For   our
study   of the leachate, the  initial pH control  is  froa 6  to   4,
and the final pH is between 3 and  4.
     (5)  The  quantity  of sludge  resulting  froi the   Fenton
•ethod  is  related  to the dosage  of  H»0».   In   general,   the
sludge  is  1/4 of the total voluae.   If  the dosage of H.Ot   is
                              1137

-------
increased,   the sludge decreases.  Nevertheless,  if  the   dosage
of  HtOt   is too high and the retention time  of  sludge   is   too
long,   the   reaction within the sludge will accu»ulate a  lot of
bubbles to  lake the sludge float.
6. Acknowledgments:
The  author is grateful to the National Science  Council  of   the
Republic of China for the grants to this study.  The  author  also
wishes to thank his student Fang-Shu Chang, a  candidate  for MS,
for her executing the experiments of this study.
7. References?
    (1)  S. Ho  . W. C. Boyle and R. K. Ham. "Chemical Treatment
of  Leachates   from  Sanitary  Landfills."  Journal   VPCF   46.7
(1974):1776-1797.
    (2) Baxendale. J. H. "Decomposition  of   Hydrogen  Peroxide
by  Catalysis  in Homogeneous Aqueous Solution.   "  Advances  in
Catalysis and  Related Subjects: Volume  IV.   V.  G. Frankengurg,
E. K.  Rideal,  etc.,  ed. New  York:  Academic  Press, 1952.
    (3)  Vindholz, Hartha, ed. The Merck Index:  An Encyclopedia
of  Chemicals,  Drugs, and Biologicals. New Jersey: Merck, 1983.
P.697.
    (4)  Eisenhauer,  H.  R. " Chemical  Removal  of  ABS   from
Wastewater  Effluents."  Journal  WPCF 37  (1965):1567.   And his
"Oxidation of  Phenolic Wastes."  Journal WPCF  36  (1964).
    (5) # ft, K if . Nongnuch Jaksirinont and Jt l£ i§j & .  "Fenton £C
ii£«L*:IB#eD
-------
18.207 (august 1981):20-29.
    (6) &%-m, tt±3§5fc,  etc.  " X#JR&W«i4bgftS*0Jft
S."  PPM (March 1984): 25-36.
    (7) Takashi  KORENAGA,  Fuaiaki TAKEUCHJ, etc.  " Oxidation
of Photographic Waste Waters by Fenton's Reaction."  7ft It B M if
%  12.4 (1989) :233-238.
    (8)  Khan,  Tagui.  M.  M.   Martell,   and   Arthur  Earl.
HoBogeneous Catalysis by Metal Complexes. New York: Acadcaic P,
1974.
*aft*fl>*Rffi| fc ^ (0«* ."  PPM  (Oct. 1986) :50-63.
    (io) flp^tt,  etc.   Mi-n§ffi^fis^^{ii7k^^«a^w
®mm&&&ya Wtt-g .   Taipei: 1989,  PP. 255-267.
    (11) «£[«.  51^^.   "&FENTON&*aS£fc#»»2
*."  mHSglBS^^lif »^ .   Taipei:  1989,  PP. 269-280.
                             1139

-------
  *D.O
»—'70.C -
o
E
o

o
O t».c -
O
                                                   BO.O
                                                   73.0 -
                                                  u
                                                  >
                                                  o
                                                  E
                                                 Q
                                                 O to.o
                                                 O
            H202/FeS04 (H202=500mg/l)
                                                           H202/FeS04   (FeS04=750mg/l)

Figure 1.  Diverse dosage of FeSQ* VS ODD rooval.   Figure 2.  Diverse dosage of H«0« VS COD reioval.
                                          i-aa.o
                                          COD(ss)
                                           1DO.O
                                                                                                COD(??
                                                     2.5000
               'occ,»         iooto         jooc.s
         H202  (mg/l)  H202/FeS04=0.59
                                                     O.CCOC
                                                                    iooe.0         :ooc.o         jooc.c-
                                                              H202 (mg/l)  H202/FeS04=0.73
 Figure 3.  Under the condition H.O,/FeSQ* = 0.59    Figure 4.  Under the condition H.Oi/FeSO* = 0.73

           the required dosage of HtOt to reaove              the required dosage of H,0. to reaove

           000 per g and ODD re»val efficiency.              COD per g and COD reaoval efficiency.
                                           114O

-------
    80.0 -
                                                   BOO.O
  o:
                                                 ORP  DO.  pH*COD(s)

                                                  1000.0 -10O.C  10.0 r'00.0
     40.0 -
     20.0 -
-4.0  p '0.0

    E
                                                                £-20.0
                                                            L o.o *- o.o
        00            100C.O          zooe.u          jv
              H202  (mg/l) H202/FeS04=0.59


Figure 5.  With the chang of dosage, the relationship between COD and


           TRANS., ORP. DO.. and the final pH value, respectivly.



                         ( H»0»/FeSO» = 0.59  )
     100.0
      so.o -
   t/)
   z
   <
   •X.
                                                  ORP  DO.  pH*COD(%)
                                                    1000.0 -100.0 r-10.0  100.0
                                                                 -«0.0
              			Ifl.O  1-0.0  ^0.0 '-O.O
       a°O'o	,0000     '  ' ' ' :oeb.o	Joob.o
               H202  (mg/l) H202/FeS04=0.73


 Figure 6.  With the chang of dosage, the relationship between COD and



            TRANS., ORP, DO., and the final pH value, respectivly.



                          ( H«0»/FeSO» = 0.73 )
                                       1141

-------
     o
     E
     
-------

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-
-


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-
(A 1

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-
-


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-


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1 5
*i
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J
4.50
                       pH
Figure 9.   Under the control of the final pH,
           pH value VS transmittance.
Table 1.   The control of initial and final pH values
           influences COD removal and transmittance.
H.O.,
6nq/l)
450
600
705
750
825
900
345
510
645
705
780
FeSO.
(mg/1)
600
600
600
600
600
600
800
800
800
800
800
inital
PH
4
4.5
5
5
5.5
6
4
4.5
5
5.5
6
final
PH
3.26
3.33
3.36
3.33
3.35
3.42
3.30
3.33
3.33
3.33
3.33
TRANS.
%
94.1
96.4
97.1
97.0
97.1
97.2
94.0
95.5
96.9
97.1
97.7
COD
removal
63.7
67.8
70.2
70.3
68.7
71.4
55.5
59.7
68.5
68.0
70.6
                   1143

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      URBAN LANDFILL SITING STUDIES:  A CASE  HISTORY

                     Thomas Kusterer
         Montgomery County (Maryland) Government
         Department of Environmental  Protection


                    Presented at the

First U.S. Conference on Municipal  Solid Waste  Management

                   June 13 - 16, 1990
                         1145

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     Otto von  Bismarck,  the  19th  Century  "Iron  Chancellor"  of Germany,  said
there are two  things people  should never have  to see being made:   sausages  and
laws.  A third,  and current, "never"  could also  be added:  deciding a  landfill
site for a metropolitan  area.  As  Bismarck suggested for the first two,  none
of these processes are  "picture  pretty."   And  in the case  of landfill  siting,
there probably isn't a less  attractive  but critically key  issue facing
urbanized areas.

     Montgomery County  (Maryland)  needs a  new  landfill  to  serve its 700,000
plus residents.   The county  completed a 15 month, $525,000 landfill  site study
that led to  selection of one site  by  the County  Council  in April.   The site
will undergo detailed engineering  studies  and  work leading to a sanitary
landfill permit.  The Council  also chose one backup site if  significant
problems arise at the selected site during the permit application  phase  - the
county can quickly switch to developing the backup site.   The earliest
projected opening for the new  landfill  is  autumn 1993.

     We faced a number  of challenges  during the  study -  some conventional,
others not so.  These challenges included:

     o    landfill  siting in a high growth county
     o    land use limitations
     o    public opposition
     o    relative scarcity  of sites

As with any challenge,  there were  opportunties,  including:

     o    involvement by elected officials
     o    mitigation  of land use limitations
     o    public participation
     o    a  balanced approach  to the  study

WASTE MANAGEMENT PROGRAM

     If this conference were held  199 years ago, we'd be sitting in Montgomery
County.  The Maryland legislature  ceded 36 square miles  of the county  for the
                                     1146

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new nation's capital in 1791.  The county's population, as well  as its
geographic area, has changed over time.  While I was writing this paper,  the
nation observed the 125th anniversary of the end of the War between the
States.  Since several skirmishes were fought in Montgomery, I was curious
about the county's population then.  Montgomery had about 20,000 residents in
1865 - in 1965, there were about 420,000 residents.  From 1965 to present, the
county has grown to about 715,000 residents.  A recent report by the Greater
Washington Research Center showed the Washington area to be the second fastest
population growth area in the country.  Montgomery led all local jurisdictions
in the area, adding about 23,000 residents between 1987 and 1988.  From its
current population of 715,000, Montgomery is projected to grow to 820,000
residents in the year 2000.

     All of these people generate appreciable amounts of municipal solid  waste
- about 650,000 tons of it in 1989.  Using normal compaction rates, this
yearly waste,  spread over a  football field, would rise more than 700 feet. As
a comparative  reference, the Washington Monument is 555 feet high.  Estimates
suagest that even at modest  growth  rates, the County will top one million tons
of municipal waste  produced  in the year 2000.

      How to manage  this waste becomes the crux.  Montgomery has an ambitious
integrated  solid waste management plan consisting of

      o    source reduction and recycling,
      o    combustion, and
      o    landfill ing,

 in  that order  of preference.

      The  county's  mandated goal  is  to recycle 27* of its waste stream by 1992;
 we  currently  recycle  about 133,.   Recycling progress is evidenced by the
 county's successful  newspaper  recycling program; pilot programs for commingled
 recyclables and yard  wastes, leading to phased  countywide curbside pickup of
 recyclables starting  this  summer;  construction  of a Materials Processing
 Facility for  recyclables,  expected  to begin  operation  in  spring 1991; and a
 nationally  recognized program  for composting leaves, grass clippings and
 sludge.
                                      1147

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     The county and its agent have selected a vendor to construct an 1800 ton
per day resource recovery facility.  The facility is slated to produce about
40 MH of electricity while reducing the amount of landfill  waste by over 7Q%.
We received our approval  of a Prevention of Significant Deterioration Source
for the facility in April, 1990.

     None of these accomplishments, however, dispels the need for
landfilling.  Landfills are necessary for the disposal  of non-recyclables and
for disposal of recovery facility ash.  In fact, having a landfill  is a key
element to help secure financing for the recovery facility.

     The county currently has one municipal landfill, which began operations
in 1982.  It had a projected life of 15 years, but reached  original  estimated
capacity in 1989.  We got a permit modification to serve disposal  needs until
August 1990; we then got a permit for a long-term expansion, relying on
vertical growth capacity at the site, in February 1990.  The projected 23 year
expansion hinges on successful  recycling and an on-line resource recovery
facility; if these elements don't fall in place, we're facing only six or
seven useful years.

STUDY HISTORY

     When the County Executive and County Council hammered  out the integrated
waste management plan I noted, they indicated that county government must
conduct an urgent site search, land acquisition and site development program
to find and prepare a new landfill site.  The goal of this  program was to open
a new landfill as soon as possible so that the current landfill  could close.
Part of this stemmed from a political commitment elected officials made;  part
of it stemmed from good planning practices seeking a disposal  site in a
non-crisis atmosphere; and part of it stemmed to avoid past history.  The
current study marks the county's third effort in the last 15 years to site a
landfill.  Each effort met typical siting constraints - costs, technical  and
environmental issues, and public concerns - but each effort became more
difficult because the county was rapidly losing sites large enough and
environmentally suitable for a landfill given our rapid urbanization.  Between
                                     1148

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1978, when the study began leading to the existing landfill, and 1985, 13 of
the 22 potential sanitary landfill sites identified in the 1978 study were
developed.

     Similar circumstances occurred during the current study.  One of the
sites considered is pegged for residential  development; another site is
adjacent to a high density development.  Even within county government, there
were competing interests for the candidate sites.  A county agency proposed  a
golf course on one site.  Another agency plans to locate a new detention
center on a study site.

     Sites for the current study were chosen from those identified in previous
county landfill studies.  We chose this approach to save time, money, and to
hone in on those areas that had been identified as environmentally suitable
for a landfill.  This process provided a stock of possible sites,  resulting  in
16 sites for study.  In addition, 26 criteria to rate the sites were
developed.  For practical  purposes, these criteria fel