An Open-File Report SW-36c. of


                      Final Report
    This open-file report (SW-36c.of) was written for
      the Federal solid waste management program by
The Western Company, Research Division, Richardson, Texas
              under Contract No. CPE 70-132


     A brief summary  is made of past and current studies on the pipeline

transportation of solid waste. A plan is made  for a proposed program to augment

existing knowledge on this means of transport. The testing facility necessary

to perform this plan is described and equipment layout sketches and material

lists are provided. An economic analysis of a  truck transfer system is presented

and requirements for the economic analysis of  a pipeline transport system are


     This report was submitted in fulfillment  of contract CPE-70-132 between

the U.S. Department of Health, Education and Welfare,  Bureau of Solid Waste

Management and The Western Company.

                                 TABLE OF CONTENTS


SECTION I  CONCLUSIONS                                                     1

     Recommendations                                                       2

SECTION II  INTRODUCTION                                                   3

     Background                                                            4
          Slurry Transport                                                 4
          Capsule Transport                                                5
          Size Reduction                                                   6
          Solid Waste Composition                                          7
          Limitations                                                      8
          Polymer Use                                                      9
     Purpose                                                              10
     Scope                                                                10
     Program Description and Approach                                     10


     Technical Approach                                                   14
          Test Plan Logic                                                 14
     Test Program Requirements                                            16
          Sizing                                                          17
          Injection                                                       17
          Dewatering                                                      18
          Transport Testing                                               18
     Facilities Requirements                                              20
     Economic Considerations                                              24

SECTION IV  REFERENCES                                                    28

APPENDIX A  POLYMER ADDITIVES                                             31

APPENDIX B  TEST PROGRAM                                                  32

APPENDIX C  TEST FACILITY DRAWINGS                                        41

APPENDIX D  TRUCK TRANSFER ECONOMIC ANALYSIS                              47

                                      SECTION 1


     The literature search revealed some prior work has  been accomplished

verifying that solid waste can be transported in  a slurry form thr.mgh  pipelines

just as many other materials have been over the past 30  years. There  are

accessory operations which are required by a slurry transport system  which

have not been perfected for a solid waste system.  The grinding of  solid waste,

while possible, is not as efficient or predictable as desired. The  state-of-the-art

of introducing the wastes into the pipeline has not been perfected. Dewatering

units have been used for many materials but never for solid waste slurries.

Although solid waste research programs are now in progress using some methods

of slurry dewatering, the results are as yet unpublished. Finally, while all

of the unit operations associated with slurry transport  have been used  on other

products, they have yet to be all put together in a single solid waste  slurry

transport system. The program plan outlined in this study will put  it all


     Capsule transport to date has been done only on a laboratory scale.

Evaluation of the laboratory scale capsule transport shows some potential

benefits over slurry transport.

     To be economically feasible, any pipe transport system must compete

with the current method of transport to the disposal site. Pipelines  represent

an alternative transport mechanism which can be most readily integrated into a

transfer station operation. Typical cost of a transfer station with large

compacter truck haul to the disposal site is $.09 per ton mile of trash handled

on a round trip mileage basis.


     To increase the available information on solid waste handling,  it  is

recommended that the program plan outlined in this  study be undertaken  at  the

earliest opportunity. It is further recommended that  the unit operations

necessary for the slurry transport be used in their present state of development,

rather than attempt to optimize their operation during this study.  If the  results

of this program show economic or other tangible benefits, work should be

undertaken to optimize the various unit operations  used in  the pipe transport

of solid waste and a complete transport system demonstrated on the municipal


                                     SECTION 2


      The solid waste problem has been characterized as a health problem which
needs an engineering solution.  It has been estimated that 75 percent of the

cost of disposing of solid waste is in the collection and transportation to a

disposal site. Some $ 3 billion are spent annually in the United States to

collect and dispose of solid refuse. The collection and disposal practices in
common usage are but little improved over those of a quarter century ago.

      The trend toward concentration of people plus the increase in poundage of

refuse per person is compounding the problem. The cost and the air pollution

problems which are currently inherent with incineration has resulted in most

cities turning to the only acceptable alternative techniquesanitary landfill.

However, in many areas there are no satisfactory landfill sites within a

reasonable distance. The long haul distances plus the hazards and restrictions

imposed upon refuse trucks moving through suburban cities creates a major

problem, particularly for large metropolitan areas.

      An engineering solution for one facet of the solid waste collection and

disposal would be the use of a pipeline to transport solid wastes the long

distances from collection area to disposal site. Traditionally,

pipelining has many advantages over truck transport, such as reduced

transportation costs, less recurring capital costs, less labor costs, etc.


     Presently, there are no programs ongoing which study the complete pressure

system of pipe transport of solid wastes in other than a theoretical manner.

The Foster-Miller Associates household grinder contract (CPE-70-115) is,  in

essence, experimentally studying a complete pipe transport system in connection

with nonpressure flow in sewer pipelines. There are projects completed or in

progress which are examining unit operations required by a pipe transport

system. For example, size reduction of solid waste has been done at Madison,

Wisconsin, for direct landfill. Size reduction has been done at Gainesville,

Florida, for composting solid waste and also at New York City and other towns

to aid in incineration of the waste.

     Zandi, at the University of Pennsylvania, has studied the hydrodynamics  of

various concentrations of solid waste slurries and has pumped solid waste

slurries through three size of pilot pipelines.  Stanford Research Institute  is

doing an examination of hydraulic pipe transport of solid waste in slurry,

capsules, and slugs.^ To date all of their work has been entirely theoretical

with pilot pipelines to be constructed later. No other programs which dealt with

the actual hydraulic transport of solid waste was found.

Slurry Transport

     Slurry transport of solid material through pipes is a handling process

used many years by various industries. The flow of slurries in pipes, however,

cannot be qualified by density and viscosity as can pure fluids. Because of the

interaction between fluid and solid and the properties of the solid and fluid,

each system must be treated individually. The solids-carrying pipelines now in

use have been designed and modified by the use of empirical formulas and

large-scale tests losing the specific solid being transported. For example,

Condolios, through such testing, limits the particle size to no more than

one-half the transport pipe diameter.

      A recent program has been completed in which development of eapirical

data was made on the slurry transport of ground solid wastes. Zandi and Hayden

have demonstrated that solid wastes, sufficiently ground and pulped can be

transported through a pipe.  Formulas were developed which will allow

calculation of pressure losses from a knowledge of pipe diameter, mean velocity,

and solids concentration. It was further demonstrated that a solid waste slurry

behaves, from a pressure loss standpoint, identically with a slurry formed

from only the paper portion of the solid waste.

      Hayden observed pressure losses of approximately 500 psi per mile when

transporting a 10 percent solid waste slurry at 3.7 feet per second through a

6-inch pipe.

Capsule Transport

      Hydraulic capsule transport of solids can be used when the solid cannot

stand contamination from the carrier fluid or when the separation of the solid

from the carrier is difficult or expensive. Experimental work to date on capsule

transport has been on a laboratory scale only.

      Ellis investigated both single spherical and single cylindrical capsule

transport in a 1 1/4-inch diameter pipe.^ He found that the velocity of the

capsule varied from 1.05 to 1.5 times the average water velocity which ranged

from 0.20 to 12.15 feet per second. The velocity ratio increases with increasing

length/diameter ratio of the capsules. Trebling the L/d ratio increased the

velocity ratio about 3 percent. The presence of the capsule appeared to delay

the onset of turbulence in the annulus between the capsule and the wall to a

much higher value of Reynolds number than would hold in unobstructed fluid flow.

This indicates a reduction in normal head losses as a result of the capsule

being transported.

      Evaluation of the small scale tests indicated favorable possibilities in

the use of hydraulic capsule transports assuming scale up to commercial

quantities is possible. Among the benefits indicated are:

                    lower power requirements

                    minimum expense in separating the capsule

                    from the carrier fluid.

      Information on the technical feasibility or cost of forming the capsules

from solid waste was not found in the literature.

Size Reduction

      The size reduction of solid waste presents an unusual problem. The

unlimited variety in the composition of solid waste with regard to density, size,

shape, and composition of the components increases the difficulty in selecting

and sizing the necessary equipment.

      Size reduction is a grinding and crushing operation. Crushing denotes

size reduction by the application of compression stresses which in turn cause

tensile and shear stresses to break the particle. Grinding is size reduction due

to abrasive or attrition forces.

      The common hammermill combines both these forces in its operation. Sanders

reports satisfactory size reduction and homogenizing of solid waste when passed

through a hammermill.  He indicates a grate size (1.5-inch) but does not state

the resulting particle size or range of particle sizes.

     Wixson reports the reduction of urban solid wastes is generally feasible

by use of the hammermill.  Here again the grate size is given (3/4-inch) but no

resultant particle size range.

     Zandi and Hayden report that the haimnermill is capable of premizing solid

wastes but requires considerable maintenance.  They further stated that, while

sufficient size reduction for pipe transport is possible, a more efficient

system must be developed for an actual industrial application. However, in their

solid waste transport study, a two-stage reduction, a combination of a Wascon

pulper and a Dorr-Oliver Gorator, was used.

     The city of Madison, Wisconsin, started a solid waste reduction study using

a horizontal mill (a Gondard) but ended the study using a vertical mill made by

Tollemache.10 This study related to direct landfill and did not report the

particle size range resulting from the reduction.

Solid Waste Composition

     The physical and chemical characteristics of the waste material, as

determined by its composition, has a significant impact on the handling of solid

wastes. The as-collected household and commercial refuse is composed of varying

amounts of each general group of the various waste categories. Table 1 indicates

the primary components of each refuse group.

     The actual percentage of any caregory from a specific location on any given

day is dependent on the geographic location, season of the year, day of the

week, the economic status of the collection area, and many other variables.

     Niessen and Chansky in their study have defined the nature of solid waste

and projected the quantity and composition through the year 2000.H They predict

an increase in the total solid waste load by a factor of 2.7 by the year 2000

with the ratio of paper and plastics increasing and food wastes and yard wastes

decreasing. Table 2 lists the solid waste composition range in a number of U.S.


      From the wide range in composition of the various categories,  the

difficulty in obtaining a uniform solid waste from an as-collected municipal

source can be easily understood. Therefore, a synthetic or manufactured solid

waste will be required, for uniform or equivalent products during pipe transport

tests. The manufactured solid waste composition could be expected to conform

to the average shown in Table 2.


      To date, no previous work has been found which demonstrates equipment or

methods to introduce presized solid waste particles into a slurry transport line

on a regular and continuous basis. Nothing is reported yet on the largest solid

waste particle size which can be made into a pumpable slurry. Zandi and Hayden

reduced the solid waste to a pulp, evidently uniformly approaching the size of

the paper fibers. No method has been demonstrated which will introduce the

presized solid waste into a pipeline running full.

      Wixson's study pumped the solid waste slurry from a main reservoir and

returned the slurry to the same reservoir for further cycling. Zandi and Hayden

also recirculated the slurry from a mixing tank.

      The slurry transport pipe system has also been neglected at the discharge

end. The dewatering method or degree of dewatering has not been demonstrated,

nor has the disposition of the carrier fluid been specified. The handling of the

dewatered slurry should be possible in conventional equipment. Metcalf and

Eddy, under subcontract to the Environmental Protection Agency Contract with

Foster-Miller Associates have performed bench-scale studies of the vacuum

filtration of solid waste slurries. Indications are that this method is quite

successful. Screw press dewatering of pulped refuse is also being practiced

in New Haven, Connecticut, as a part of EPA Contract PH-86-67-167 "Solid

Waste Research in the Application of On Site Refuse Storage, Colle -tion and

Reduction Systems for High-Rise Residential Structures... The results of these

efforts have not yet been published.

Polymer Use

     Current oil field technology uses polymers as additives to water to

improve the solid carrying capacity and as a friction reducer. The oil field use

requires the suspending of sand, glass beads, aluminum shot, ground walnut

shells, and other materials in very high concentration. This suspended material

must be moved in large volume through small pipe requiring high pump horsepower.

The polymers used, in addition to their suspension qualities, reduce the

boundary layer turbulence thereby lowering the friction loss in moving through

the pipe. It is believed that similar polymers may act as a suspension aid and

a friction reducer in the slurry transport of solid waste. The polymers for this

application can be found in the general class of polyelectrolytes used in water

and sewage treatment and paper manufacturing as coagulants or coagulant aids.

Appendix A lists manufacturers and products which have been used or considered as

friction reducing materials and suspension aids.

     The following criteria should be used in determining the best polymer

additive for use in the waste slurry transport.

               friction reduction capability

               Solubility in water

               high molecular weight

               shear stability in flow systems

               storage life

               toxicity to biological systems

               resistance to biological attack

               chemical stability under repeated use

               availability from commercial sources

               cos t.


     The purpose of this program is to advance the knowledge and technology

toward better methods of solid waste management. The total program will result

in the generation and collection of data to show to what extent pipelining of

solid waste is a practical and economic process. The program will also result in

design data necessary to construct a demonstration project in the slurry

pipelining of solid waste.


     The scope of this phase of the program is limited to the investigation and

evaluation of the state-of-the-art of slurry transport of solid waste and the

development of a test plan to acquire the data necessary to design and demonstrate

a complete operational pipeline slurry transport system for solid waste. The

system under investigation is to involve the transport of solid waste from the

collection area to the point of disposal.

                             Program Description and Approach

     To meet the purpose and scope of the program, the work was divided into four

areas. The first area of investigation was the review of all work completed and

ongoing studies. This was done to take advantage of the available information, to

learn of needed areas of investigation, and to prevent duplication of effort.

The second work area was a detailed plan on the number, kind, and variation of tests

which would be conducted. The test plan took into account the variables which

would exist in each test, for example, amount of polymer, solids concentration,

flow velocity, size of solids, data to be taken, etc. The third area of work

consisted of the designing of a pilot system which could provide a maximum of

needed data with a minimum of equipment cost for the several types of tests to be

performed. Economy and ease of operation were considered second only to the

capability of providing acceptable data. The last work area was an economic

analysis of a typical refuse truck transfer transportation system for comparison

later to the transportation costs developed for a typical pipeline transportation


                                  TABLE 1

                           REFUSE DESCRIPTION



Leather, Rubber



Food Wastes

Mis cellaneous

Yard Wastes
Bottles (primarily)

Cans, wires, and foil

Various types, some with fillers

Polyvinyl Chloride, Polyethylene,
Styrene, etc., as found in packaging,
housewares, furniture, toys, and
nonwoven synthetics

Shoes, tires, toys, etc.

Cellulosic, protein, woven synthetics

Wooden packaging, furniture, logs,


Inorganic ash, stones, dust

Grass, brush, shrub trimmings

                                 TABLE 2

                    SOLID WASTES IN 21 U.S. CITIES*
      Category                       Percent Composition by Ne , Weight
                                     Low          High         Average
Glass and Ceramics
Paper Products
Plastics, Rubber, and
Food Waste
Rock Dirt, Ash, etc.
Garden Waste
 Unpublished data, Division of Technical Operation, Bureau of Solid Waste
 Management. Values were determined from data taken at 21 cities in
 continental United States between 1966 and 1969.

                                 SECTION 3


                             Technical Approach

Test Plan Logic

     Before any flow tests can be made, certain basic data must be collected,

and operating procedures established. Results, in terms of particle size

ranges must be obtained from the various screen plate openings on the size

reduction units. Injection techniques must be developed which will result in a

uniform slurry in the pipe and a consistent injection of capsules. The test

facility must then be calibrated by transporting a solid waste slurry,

measuring the results, and comparing the results to previous work by others.

     Figure 1, from Zandi and Hayden, shows the pressure losses observed as a

result of solid waste concentration and velocity changes. It appears from the

graph that pressure losses of all solid waste slurries of seven percent

concentration and above are independent of the velocity. However, examination

of the curve for the six percent slurry shows its pressure losses to be

velocity dependent for the low velocities of two to five feet per second. At

velocities above six feet per second, the pressure losses are approximately

parallel to the pressure loss line for water. The referenced paper did not

report any velocities greater than shown on the graph because the upper limit

of pump capacity had been reached. If it can be assumed that the slurries

higher than six percent concentration will behave similarly to the six

percent slurry it will only be necessary to increase the velocity of each

concentration until the curve breaks upward.

                                      V  V
                                       o   o

                                                        m     */*
                                                       o   J+
uj -010



'. /
* V/ATER y *
v 10 y
: : /
 6 /
o 2
1 I 1 ! ! 1 1 I 1 I 1 1 1 1 1 I 1 f I 1
1.0 10 30
                                     VELOCITY  (ft./sec.)

     Figure 1.  Concentration Effect, 6 inch Pipe  from Zandi,  I and J.  Hayden.

(Reference 6).

     Capability and capacity tests must be run on the dewatering device, not

for the purpose of optimizing the dewatering, but to define quantitatively what

dewatering results are being accomplished. The accumulation of such basic data

will provide insights into the transport tests and permit the most efficient

performance of those tests.

     The capsules for this test will be made of polyethylene bags, 5 inches in

diameter, filled with ground solid waste, compacted to the fill density listed

in the test program, and heat sealed. The capsule length/diameter ratio should

not exceed 3/1 due to the dimensions of the available rotary valve used for


     The transport tests, both slurry and capsule, will result in the

establishment of transport rates, power requirements and losses. Once the

optimum transport  conditions have been established, fluid reuse tests will be

made, which should show savings possible through reuse of the carrier fluid.

Again, in establishing optimum conditions, the slurry solids concentration will

be increased to find the highest concentration which can be transported.

Optimum conditions in this instance means the highest transport rate with the

least power requirement and losses.

                          Test Program
     The test program is outlined in Appendix B. The methods and sequence of

performing the tests are discussed. A detailed test plan gives specifics on the

test variables to be examined.


     The first information needed prior to the injection tests is a particle

size range resulting from the use of various size screen plates or grate bars

in the grinders. It is not intended to optimize the grinding or grinders.

Here again, knowledge is needed to define the operating conditions during the

transport tests.

     Three tests will be performed with each grate size; 1-inch, 2-inch, and

3-inch openings. The output will be classified on Tyler Standard screens, 2 to 1

opening ratio, 14 mesh to 3-inch opening, (7 screens).  The results will be

reported by percentage passing through each screen. A solid waste particle size

classifier is being developed in-house by the EPA in Cincinnati. It is a

potential candidate for performing this aspect of the testing.


     Two general methods to inject solids into a pipeline are: pump installations

using sludge or solids handling pumps, and pump installation using clear water

pumps. To determine the best injection technique, both  methods will be used. The

criteria for the best injection system will be that system which can produce a

uniform slurry concentration using the least amount of  work added to the system.

The measurements required will be: work required to inject solids (kilowatthours,

foot-pounds, horsepower, etc.), the resulting slurry concentration, and the rate

of slurry generation in gallons per minute, pounds per  minute, etc.

     The solids handling pump will take suction from the bottom of a reservoir

into which a measured rate of water and ground solid waste is being inserted.

Three tests each using different particle distributions and nine solids insertion

rates will be performed.

     The clear water pump will take suction from a reservoir with the solids

introduced into the pump discharge through an eductor.  In each type solid

introduction, three tests each will be made using three different maximum

particle sizes and six solids insertion rates.

     It will be necessary to determine the head losses obtained transporting

slurry in the test facility being constructed for this program. These head

losses when compared with previous work done by others, will provide a baseline

for calculating improvements or efficiencies resulting from this new work. The

head loss determination will be accomplished while holding the solid

concentration constant at 4, 6, and 8 percent,  using one injection technique,

the best grinder grate size, and flow velocities from 2 to 12 feet per second.

Measurements during the test will include screen analysis of solid waste, input

of water and solid waste, flow rate of slurry,  and resulting pressure and

pressure losses.
     The capacity of the dewatering equipment will be measured by varying the

slurry feed to the unit and measuring the slurry concentration, quantity of

water removed, and water content of the dewatered slurry. If there is a vacuum

capability on the dewatering unit, it will be varied and appropriate

measurements made.

Transport Testing

     The following parameters need to be considered when performing the slurry

transport tests: velocity, particle size, slurry concentration, polymer used,

and polymer concentration. The test range of each of these variables should be:

          Velocity - 1.0 to 14 feet per second

          Maximum particle size - dependent on information in baseline tests

          Slurry concentration - 2 to 10 percent

          Polymer - Polyacrylamide or acrylate/acrylamide copolymer

          Polymer concentration - 10 to 100 ppm

     The flow velocity will be measured. The particle sizes will ba determined

by screen analysis. The slurry concentration will be determined by measuring

water and solid waste input and confirmed by analysis. The polymer concentration

will be calculated from application rates. The pressure losses will be


     The test items to be considered during capsule transport without polymer

are: capsule weight and shape, fluid velocity and capsule insertion rate. Tests

to be run are:

          1.   Three capsule configurations

          2.   Fluid velocities

          3.   Three capsule fill densities

          4.   Three capsule spacings

     Measurements will be made of head loss and capsule velocity. Transport

rates will be calculated and capsule damage will be noted.

     The following test items are to be considered during the gravity slurry

transport tests. These tests are to be conducted with the pipe running half


               Velocity 1 to 4 ft/sec

               Solids concentration 1 to 9 percent

     Measurements will be made of the fluid velocity, transport rates, and

slope required to obtain the required velocity. Visual observations will be

made of saltation tendencies of the slurry.

     The gravity slurry transport with polymer will consider the same

items, and make the same measurements with the following additions?

               Two polymers will be used

               Three polymer concentrations will be used

     Carrier fluid reuse tests will be conducted for:

          1.   Slurry - the fluid will be recovered and recycled a minimum

of 10 times. Polymer degradation will be measured on a viscometer and

bacterial accumulation will be determined by a plate count after each


          2.   Capsule - the fluid will be recovered and recycled a minimum

of 10 times. Measurement of polymer degradation and bacterial accumulation

will be determined as in the slurry fluid reuse tests.

     In determining the most efficient flow velocity, particle size, polymer,

and polymer concentration, tests will be run with increasing slurry solids

concentration measuring the flow rate and head loss. Figure 2 is a flow

chart of the test plan.

                          Facilities Requirements

     The test facility drawings and equipment list are presented in Appendix C.

Schematic layout drawings are presented of the three major tests. An Isometric

of the general equipment layout is included.

     The pilot transport facility was designed for maximum flexibility in test

setups. The grinder, storage tanks, pump, test pipe section and dewatering

device will all be permanently located with test changes made by changing

elevator location, removing a spool from the pipeline for rotary valve or

eductor insertion, etc.

     The grinder, a hammermill, will be equipped with a suitable hopper and

three grates with 1- to 3-inch openings. The elevators can be screw, bucket

or pneumatic of the capacity noted on the equipment list. The stora ,e tanks

should be mild steel, painted or galvanized corrugated iron construction. The

ground waste storage bin must not necessarily be shaped exactly as shown on

the isometric general layout drawing (figure C-4).  The ground refuse by its

nature is very reluctant to flow and is highly susceptible to bridging in a

holding tank. In general, constrictions in movement must be avoided with this

material. The slurry mix tank will require motor driven agitation to achieve

complete mixing. The legs should support the tanks  high enough to allow working

under the cone, if necessary, to change piping or other hookups. The pump will

be capable of handling solids up to three inches in diameter and variable in

pumping rate by changing the motor speed. A gasoline driven trash handling

centrifugal pump will probably be best suited for this temporary application.

The magnetic flow meter is used because of no internal obstructions. The test

pipe section requires six inch cast iron or epoxy lined steel pipe. When the

solids are being inserted in the pressure side of the pump via the eductor, the

solids from the ground storage tank will be discharged directly from the metering

feeder into the eductor hopper. When capsules are being inserted in the

pressure side of the pump, a slat conveyor will move the capsules to the rotary

valve. The Geneva drives of the conveyor and rotary valve will be synchronized

so that the conveyor will drop a capsule during the valve rest cycle. The

pressure measurements will be made by pressure transducers located at the

pressure tap locations noted on the schematic drawings. The pressure will be

transmitted through an oil filled chamber from the flush mounted diaphragm to

the transducer. The pressure differential will be  determined electronically and

displayed on a direct readout recorder.

     The dewatering unit will have the capacity indicated on the  equipment

list and will be a revolving or vibrating screen with or  without  vacuum

assistance, a dewatering screw and press or some other suitable type  of water

removal process. There will be a capability of returning  the removed  water to

the slurry tank for subsequent carrier reuse tests.


                           Economic Considerations

     Any evaluation effort dealing with an operational problem, such as solid

waste management, lacks meaning and relevance without the parallel development

of a standard of comparison. In addition, past and current programs have not,

for the most part, evaluated pipeline systems that are truly representative

models of anticipated operating conditions. The technical evaluation cannot be

divorced from economic evaluation of the system, including a comparison with

other available alternatives.

     The proposed program will result in data identifying the operating

characteristics of a pipeline system model that will be representative of

anticipated full-scale operating conditions and practice. This basic data can

be used to provide a realistic evaluation of a pipeline system compared to

other transport alternatives, and as a standard of comparison for the evaluation

of potential improvements to pipeline operations such as polymer and capsules.

As a result, the data will permit a realistic appraisal of both investment

cost and recurring operating cost for both the basic pipeline concept and the

specific potential improvements to be investigated.

     The program proposed is primarily addressed to the utilization of

pipelines as an alternative in the solid waste transfer station operation. Due

to the large geographic variation in operating conditions and results it is

felt to be most productive to analyze carefully a specific application.

From the standpoint of comparability and ease of potential early implementation,

the transfer operation is well suited to the pipeline application. Within that

operation, the long haul truck transport mechanism is the current practice and 

the appropriate standard of comparison for a pipeline.

     Figure 3 portrays a comparison of the two alternative systems in terms

of their functional components. To be valid, the economic evaluation must

compare equivalent systems and these components identify the basis of such a

couparison. It is assumed that the equivalent systems identified in the figure

have no influence on the operating characteristics of units outside either

system. With this assumption, for example, collection schedules and resulting

input to the systems are fixed. Investment (and resulting operating costs)

for this fixed handling capability is the variable of comparison between these

systems .

     Appendix D outlines the operating characteristics and economics of an

operational and typical truck transfer system. It is intended that a pipeline

system operation, based on the results of the proposed testing, will be

compared to the key performance measures developed in the Appendix.

     Specifically, the Appendix indicates that the pipeline must process

a given quantity at less than $2.83 per ton or about $.09 per ton mile for a

33 mile round trip to justify as an alternative to truck transport. These

operating costs are also shown to be within the ranges established through

previous analysis. ^ ^' ^ ^ It is also useful to more directly identify

these costs with functional components such as station operations and transport

operations. In this way, a clearer picture of the less competitive aspects and

sensitivities of each system can be given.

     The equivalent systems identified in Figure 3 relate only to the direct

costs associated with each system. Overhead costs are not considered. It is

assumed that these are fixed relative to any transport alternative and need not

be included. Some differences other than direct cost must also be taken into

account, however. Most important of these are the differences in the impact

of each system on the environment. Noise, odor, litter, traffic congestion,

and .other nuisance costs associated with truck transport which are reduced

or eliminated with a pipeline must be taken into account. Many of these are

effectively intangibles. However, methods for approximating their value have

been attempted and should be utilized.1"

     While the operating measures of cost per ton and cost per ton mile

are useful and common tools in the economic comparison of alternatives, they

fail to take into account a fundamental difference in the nature of the


     Pipeline transport represents a high initial investment relative to

truck transport in anticipation of lower operating costs. The truck system

represents smaller incremental, but more frequent investment requirements.

Operating measures such as cost per ton do not take funds flow or the timing

of cash outlays into account. To recognize these differences, the system must

be ultimately compared on the basis of the discounted or present value of the

cash flows they require. The discount rate employed in this analysis should

represent the cost of capital to the cognizant operating unit. It is anticipated

that a rate of about 8-10 percent would be appropriate. However, the analysis

should be conducted over a range large enough to reflect changing financial

conditions and identify the limits of economic justification of each system.

                                 CP "rj
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                                  SECTION 4


                              Literature Cited

1.   Black, R.J., and L. Weaver.  Action on the solid wastes  problem.  Journal

          of Sanitary Engineering Division, Proc.  ASCE:  91-95,  Dec.  1967.

2.   Ludwig, H.F., and R.M. Black. Report on the solid wastes problem.

          Journal of Sanitary Engineering Division,  Proc.  ASCE:  355-370,

          Apr. 1967.

3.   Zandi, I., and J. Hayden. Collection of municipal solid wastes  in

          pipelines. Preprint No. 640.  ASCE National Meeting of Transportation,

          San Diego, Calif., Feb. 19-23, 1968.

4.   Personal Communication. R.A. Boettcher, Stanford Research  Institute,  to

          R.M. Clarke, The Western Company, Oct. 13, 1970.

5.   Condolios, E., and E.E. Chapus. Operating solids pipelines.

          Chemical Engineering;  145, July 22, 1963.

6.   Zandi, I., and J. Hayden. The flow properties of solid waste slurries.

          Paper Jl. Hydrotransport 1, Cranfield, Bedford,  England, Sept.  1-4,


7.   Ellis, H.S., P.J. Redberger, and L.H. Bolt. Transporting solids by

          pipeline capsules and slugs. Industrial and Engineering Chemistry,

          55(9): 29-34, 1963.

8.   Sanders, T.G. Grinder evaluation and development. Progress Report No.

          WP-02-69-26, Open File, Bureau of Solid Waste Management, 1970.

9.   Wixon, E.G., J. Huang, and W.L. Sago. Improved concepts for the

          processing and tube transport of urban solid wastes. Conference

          on solid waste collection systems trends for the 1970s, University

          of Houston, Houston, Texas, Mar. 23, 1970.

10.  Reinhart, J.J., and G. Rohlich. Solid waste reduction/salvage plant.

          Interim Report, Grant No. D01-UI-00004, U.S. Department of Health,

          Education & Welfare, Dec. 31, 1967.

11.  Niessen, W.R., and S.H. Chansky. In Proceedings of 1970 National

          Incinerator Conference, Cincinnati,  Ohio, May 17-20, 1970.

12.  Comprehensive studies of solid waste management, Research Grant

          EC-00260, University of California,  1970.

13.  California integrated solid waste management project systems study in

          the Fresno area. Report No. 3413, Agreement No. 15100, 2v.,

          Aerojet-General Corp. with Engineering Science, Inc. for California

          Dept. of Public Health, Mar. 1968.

14.  Marks, D.H., and J.C.  Liebman. Mathematical analysis of solid waste

          collection. Final Report (SW-5rg)  on BSWM Grant EC-00309, 1970.

15.  Jones and Henry Engineers Limited.  Proposals for a refuse disposal

          system. Report (SW-7d)  on BSWM Grant No.  D01-UI-00068,  Oakland

          County, Michigan, 1970.

16.  California waste management study.  Report No.  3056, Von Karman Center,

          Aerojet-General,  Aug. 1965.

                               APPENDIX A

                            POLYMER ADDITIVES

Percol 139
Percol 155
Percol 351

RC 301
RC 322

Polyfloc 1100
WCL 727
WCL 755
WT 3000

Separan AP 30
Separan AP 273

FR 4
NGL 3958

Polyox WSR 301
Polyox Coagulant
Polyox FRA
Probable Composition



Copolymer Aerylate/

Copolymer (Acrylamide)


Cellulose Copolymer
Copolymer (Acrylate/

P o ly ac ry lami de

Polyethylene Oxide
Polyethylene Oxide
Polyethylene Oxide

Allied Colloids
Allied Colloids
Allied Colloids

American Cyanamid
American Cyanamid

Betz Chemical Co.
Calgon Chemical Co.
Calgon Chemical Co.
Calgon Chemical Co.
Calgon Chamical Co.
Calgon Chemical Co.

Dow Chemical Co.
Dow Chemical Co.

Hercules Corporation
Hercules Corporation
Stein, Hall and Co.

Union Carbide
Union Carbide
Union Carbide

                                 APPENDIX B

                                TEST PROGRAM


     The solid waste sizing tests will be performed using the standardized

manufactured solid waste as previously defined.  It is imperative that all

refuse be tested for initial moisture content before mixing with the test

fluid. This moisture may account for up to 30 percent by weight of the

refuse. Final slurry concentration determinations will involve drying and

weighing of the residue and these must take into account the initial

moisture. Each hammermill grate size will result in a distribution of solid

waste particle sizes. The material from each grate size will then be used to

perform the injection tests for the particular particle size and the flow tests

requiring that distribution of particle sizes. The capability and capacity tests

of the dewatering equipment will be performed on the exit material from the

flow tests. The dewatered solid waste will be disposed of in a sanitary

landfill adjacent to the test facility. The carrier fluid will be lagooned

nearby for natural oxidation prior to ultimate disposal.

     The sizing tests, injection tests, flow tests, and dewatering tests will

then be performed in sequence using each of the remaining grate sizes.

     After the base information tests have been performed, an analysis will

determine the best grate size and the best injection technique for

slurry. These will be used for all of the slurry transport tests with polymer.

     Gravity transport of the slurry will be performed with the pipe running

half full with the velocity varied by changing the slope of the test line.

The slurry will be blended continuously in the mixing tank and gravity

flowed into the line.

     All slurry transport tests will be performed on a once-through basis with

none of the solid waste or carrier fluid being reused. The solid waste will be

disposed of in a nearby sanitary fill and the carrier fluid lagooned for

future disposal.

     The capsule transport tests will be performed on a once-through basis for

the carrier fluid with the capsules being reused if there is no contamination

of the capsules from broken containers in transport. The capsules will be

segregated according to size and fill density and stored between tests.

     The capsule transport tests without polymer should reveal the difference

caused by either the fill density or the capsule configuration. An analysis

will allow the selection of a capsule size and a fill density to be used

on the tests with polymer.

     The capsule transport tests, with polymers, will also be performed with

the carrier fluid discharged to waste. The capsules will be reused if undamaged

or not contaminated from prior transport tests.

     The carrier fluid reuse tests will be performed by collecting and

returning the carrier fluid to the mixing tank. It will then be mixed with new

manufactured solid waste and measurements of flows, velocities and losses made

as before.

                                 TEST PLAN

                              Base Information

Grinder Tests - 9 Tests

     1 in. grate size, 3 tests of 20 min. each
     2 in. grate size, 3 tests of 20 min. each
     3 in. grate size, 3 tests of 20 min. each

Classify outputs on each test - use these outputs in performing injection tests,

Injection Tests - 15 Tests

     Through Pump

     1 in. grate output

          3 percent solids concentration rate
          5 percent solids concentration rate
          10 percent solids concentration rate

     2 in. grate output

          2 percent solids concentration rate
          6 percent solids concentration rate
          8 percent solids concentration rate

     3 in. grate output

          1 percent solids concentration rate
          4 percent solids concentration rate
          9 percent solids concentration rate

     Eductor Method
     1 in. grate output

          3 percent solids concentration rate
          6 percent solids concentration rate

     2 in. grate output

          1 percent solids concentration rate
          4 percent solids concentration rate

     3 in. grate output

          2 percent solids concentration rate
          5 percent solids concentration rate

Flow Tests - 27 Tests

     4 Percent Solids
          1 in. grate plate

               flow velocity 4 ft/sec
               flow velocity 8 ft/sec
               flow velocity 12 ft/sec

          2 in. grate plate

               flow velocity 2 ft/sec
               flow velocity 6 ft/sec
               flow velocity 10 ft/sec

          3 in. grate plate

               flow velocity 3 ft/sec
               flow velocity 5 ft/sec
               flow velocity 9 ft/sec

     6 Percent Solids
          Same matrix as 4 percent

     8 Percent Solids

          Same matrix as 4 percent

                                Transport Tests

Water Slurry with Polymers - 54 Tests

     First polymer (Use the same test matrix for the second polymer)

     10 ppm polymer concentration

          slurry concentration 2 percent

               velocity 6 ft/sec
               velocity 10 ft/sec
               velocity 14 ft/sec

          slurry concentration 5 percent

               velocity 5 ft/sec
               velocity 9 ft/sec
               velocity 13 ft/sec


     slurry concentration 8 percent

          velocity 2 ft/sec
          velocity 5 ft/sec
          velocity 8 ft/sec

50 ppm polymer concentration

     slurry concentration 3 percent

          velocity 4 ft/sec
          velocity 7 ft/sec
          belocity 10 ft/sec

     slurry concentration 6 percent

          velocity 3 ft/sec
          velocity 6 ft/sec
          velocity 9 ft/sec

     slurry concentration 9 percent

          velocity 1 ft/sec
          velocity 3 ft/sec
          velocity 5 ft/sec

100 ppm polymer concentration

     slurry concentration 4 percent

          fluid velocity 4 ft/sec
          fluid velocity 8 ft/sec
          fluid velocity 12 ft/sec

     slurry concentration 7 percent

          fluid velocity 2 ft/sec
          fluid velocity 4 ft/sec
          fluid velocity 6 ft/sec

     slurry concentration 10 percent

          fluid velocity 1 ft/sec
          fluid velocity 3 ft/sec
          fluid velocity 5 ft/sec

Capsule in Water Without Polymer - 81 Tests

     Capsule size L/D = 1
     Fill density looae fill (10 lb/ft3)

          Capsule spacing - close spaced

               capsule velocity 1 ft/sec
               capsule velocity 2 ft/sec
               capsule velocity 3 ft/sec

          Capsule spacing - 1/2 capsule length between capsule

               capsule velocity 1 ft/sec
               capsule velocity 2 ft/sec
               capsule velocity 3 ft/sec

          Capsule spacing - 50 percent occupied by capsule

               capsule velocity 1 ft/sec
               capsule velocity 2 ft/sec
               capsule velocity 3 ft/sec

     Fill density - 50 percent compacted (15 lb/ft3)
     Same test matrix as loose fill

     Fill density - 100 percent compacted (20 lb/ft3)
     Same test matrix as loose fill

     Capsule size L/D = 2/1
     Same test matrix as L/D = 1

     Capsule size L/D = 3/1
     same test matrix as L/D = 1

Capsule in Water With Polymer - 54 Tests

     First Polymer (Second polymer use same test matrix)

     10 ppm polymer concentration

          capsule spacing - close

               capsule velocity 1 ft/sec
               capsule velocity 2 ft/sec
               capsule velocity 3 ft/sec
          capsule spacing - 50 percent occupied by capsule

               capsule velocity 1 ft/sec
               capsule velocity 2 ft/sec
               capsule velocity 4 ft/sec

     50 ppm polymer concentration

          capsule spacing - close

               capsule velocity 1 ft/sec
               capsule velocity 2 ft/sec
               capsule velocity 3 ft/sec

          capsule spacing - 1/2 capsule length between capsule

               capsule velocity 1 ft/sec
               capsule velocity 2 ft/sec
               capsule velocity 4 ft/sec

     100 ppm polymer concentration

          capsule spacing - 1/2 capsule length between capsule

               capsule velocity 1 ft/sec
               capsule velocity 2 ft/sec
               capsule velocity 4 ft/sec

          capsule spacing - 50 percent occupied

               capsule velocity 1 ft/sec
               capsule velocity 1 ft/sec
               capsule velocity 4 ft/sec

     Second Polymer - same matrix

Water Slurry Gravity Transport - 12 Tests

     Flow velocity 1 ft/sec

          solids concentration 2 percent

          solids concentration 6 percent
          solids concentration 8 percent

     Flow velocity 2 ft/sec

          solids concentration 1 percent
          solids concentration 5 percent
          solids concentration 9 percent

     Flow velocity 3 ft/sec

          solids concentration 2 percent
          solids concentration 4 percent
          solids concentration 8 percent

     Flow velocity 4 ft/sec

          solids concentration 1 percent
          solids concentration 3 percent
          solids concentration 7 percent

Water Slurry with Polymer Gravity Transport - 24 Tests

     First Polymer (Use the same test matrix for the second polymer)

     10 ppm polymer concentration

     Flow velocity 1 ft/sec

          solids concentration 2 percent
          solids concentration 4 percent

     Flow velocity 3 ft/sec

          solids concentration 2 percent
          solids concentration 4 percent

     50 ppm polymer concentration

     Flow velocity 2 ft/sec

          solids concentration 1 percent
          solids concentration 5 percent

     Flow velocity 4 ft/sec

          solids concentration 1 percent
          solids concentration 3 percent

     100 ppm polymer concentration

     Flow velocity 2 ft/sec

          solids concentration 5 percent
          solids concentration 9 percent

     Flow velocity 4 ft/sec

          solids concentration 3 percent
          solids concentration 7 percent

Carrier Fluid Reuse

     Slurry w/o polymer
     10 cycles of fluid
     Slurry with polymer
     10 cycles of fluid
1 cone, solid
1 flow velocity
1 particle size

1 cone, solid
1 flow velocity, 1 polymer cone.
1 particle size
     Capsules w/o polymer
     10 cycles of fluid

     Capsules with polymer
     10 cycles of fluid

Slurry Solids Concentration Limit

     Start at solids concentration of 12 percent and increase concentration by
     2 percent steps until slurry cannot be pumped.

                                  APPENDIX C

                            TEST FACILITY DRAWINGS


Figure C-l       Schematic Layout of Slurry Pumping Tests                42

Figure C-2       Schematic Layout of Dry Solids Injection Tests           43

Figure C-3       Schematic Layout of Capsule Insertion Tests             44

Figure C-4       Equipment Layout of Slurry Pumping Test                 45

Table C-I        Equipment List                                          46

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Item No.
Capacity, Size, Etc.
    1       Hammermill

    2       Grinder Feed Hopper

    3       Elevator, Grinder to Storage

    4       Tank, Ground Waste Storage

    5       Rotary Valve

    6       Elevator Ground Storage

    7       Slurry Storage Tank

    8       Slurry Agitator

    9       Pump, 6-in.

   10       Flow Meter

   11       Pressure Transducer
            (2 ea)

   12       Test Flow Pipe

   13       Visual Pipe Sections (2)

   14       Solids Separator

   15       Dry Solids Eductor

   16       Slat Conveyor (Capsule)

   17       Rotary Valve

   18       Polymer Injection Pump

   19       Polymer Mixing and Storage

   20       Water Supply Meter
                         4 tons/hr of solid waste

                         4 cubic yards

                         150 Ibs/min of 10 lbs/ft3

                         2000 cubic feet

                         750 Ibs/min of 10 lbs/ft3

                         705 Ibs/min of 10 lbs/ft3

                         15,000 gallons

                         7.5 Hp Lightning

                         100-2000 gpm vs 150-ft head

                         6-inch magnetic 100-2000 gpm

                         0-50. psi

                         6-in. C.I or steel epoxylined

                         6-in. cast acrylic

                         750 Ibs solid/min

                         6-in. hopper equipped

                         18-in. wide-Geneva Drive

                         14-in. x 20-in. blow-through w/6-
                         in. pipe and Geneva Drive

                         Duplex piston 250 gph

                         300 gallons

                         2 1/2-in. rate indicating

                                      APPENDIX C


     In 1967, The City of Dallas began definitive planning for the Fair

Oats Solid Waste Transfer Station. The station was designed to service the

northeast quadrant of the City where no disposal sites were available. The

site has frontage along the Southern Pacific Railroad. Both rail and pipeline

movement to ultimate disposal sites were envisioned as potential alternatives

to truck transport from this central depository. Operations began in October

1969 utilizing tractor-trailer transport via a peripheral freeway to a

sanitary landfill operation on the northwest side of Dallas.

     The station was completed and placed in operation at a cost of $400,000

including $50,000 for 19.4 acres of land. Receipts consist of garbage and

trash exclusively from three-man crew city collection trucks delivering to the

station's three hoppers. Overall design will permit expansion of the facility to

six hoppers as future thruput requires.

     Transfer operations are carried on five days per week by one foreman, four

drivers, one hopper operator, one spotter, one scaleman, and two night

watchmen. Four one-man transfer trucks are currently utilized, each having a 60

cubic yard self-packing trailer. A solid waste density of about 500 pounds per

cubic yard is achieved using these trailers, and each transfer load has

averaged approximately 4.5 collection truck loads. The round trip distance to

the disposal site is slightly under 33 miles.

     Table D-l summarizes, quantitatively, the results of the first full year

of operation and identifies certain key comparative operational measures. The

total cost of operation shown is total direct cost and does not include any

allocated overhead or burden. Table D-2 details basic operational data on a

monthly basis.

     It is the general feeling of Dallas officials that this data represents a

relatively accurate long term picture of the operation. Some efficiencies and

a reduction in cost are expected with increased operating experience and

growing volume, but those are expected to be partially offset by some inflation

in basic costs, primarily labor.

     The cost of $2.83 per ton and $0.09 per ton mile compares favorably with

most previous data available from published studies in other geographic areas

of the United States. This data, which also typically combines station and haul

operations, is highly dependent on local operating conditions, which can vary

dramatically. However, some overall consistency is apparent. Costs developed in

central California range from under $1.00 through $2.60 per ton and from $0.05

to $0.10 per ton mile, while in Maryland they were found to range from $1.50 to

just under $3.00 per ton and from $0.08 to $0.13 per ton mile. Comparable

systems in the suburban Detroit area are found to fall within the same ranges.

Obviously, alternatives to truck transport, which tend not to be as variable

with local operating conditions, must be justified economically on an

installation by installation basis as the available data suggests.

     The Fair Oaks truck transfer operation in Dallas was originally justified

on the basis of savings in total rolling stock investment and associated labor

costs. No substantive data is yet available on how well the system measures up

to that objective, but, on the basis of the first year's operation, it is

generally felt that a decrease in total truck investment will be achieved. As

Table D-2 indicates, the transfer ratio has been steadily improved and a ratio of

about 5.0 has probably been achieved on a permanent basis. This ratio alone

has an important impact on rolling stock investment.

                                  TABLE D-l

                         NOVEMBER 1969 - OCTOBER 1970
Total transfer truck cost

Direct driver cost

Transfer hauling cost

Direct transfer station operating cost

Total direct cost of operations

Tons transferred

Average tons per working day

Loads received

Loads transferred

Transfer ratio (loads received/loads transferred)

Miles driven in transfer

Manhours employed

Hours of equipment downtime

Average transfer mileage, round trip
Cost per ton

Cost per ton per mile
Truck cost per mi
                  $ 43,600














Station    Hauling    Total

$.92       $1.91      $2.83

 .03 '        .06        .09

             .55        .55
      driver wage of $2.98 per hour.
"Does not include driver cost.



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