902R76002
WASTE MANAGEMENT
TECHNOLOGY
and
RESOURCE & ENERGY
RECOVERY
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PROCEEDINGS
OF THE FOURTH NATIONAL CONGRESS
WASTE MANAGEMENT
TECHNOLOGY
and
RESOURCE & ENERGY
RECOVERY
Cosponsored by the National Solid Wastes Management Association
and the U.S. Environmental Protection Agency
Atlanta, November 12-14, 1975
U, S- fiTvi;.. ;",.
£D;SON, N. L
U.S. ENVIRONMENTAL PROTECTION AGENCY
1976
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An environmental protection publication (SW-8 p) in the solid waste management series.
For sale by the Superintendent of Documents, U.S. Government Printing Office
Washington, D.C. 20402
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Foreword
The U.S. Environmental Protection Agency and the National Solid Wastes Management
Association cosponsored the Fourth National Congress on Waste Management Technology
and Resource and Energy Recovery in Atlanta, Georgia, on November 12-14, 1975. The
Congress gave particular attention to three major areas of solid waste management: hazardous
wastes, land disposal, and resource recovery. A Special Technical Symposium, which focused
on problems of leachate from land disposal sites, was also conducted as part of the Congress.
The meeting included participants from State and local, as well as Federal, government,
waste management and resource recovery firms, universities, research and development com-
panies, and the financial community. The papers given represent a range of viewpoints and
provide a valuable store of current information and opinion on vital areas of interest in our
field.
SHELDON MEYERS
Deputy Assistant Administrator
for Solid Waste Management
in
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Acknowledgments
The National Solid Wastes Management Association is pleased to express its apprecia-
tion to the participants of the Fourth National Congress. The candid and often controver-
sial discussions on the state of technology development and application provided attendees
an opportunity to learn of the important issues being addressed in the fields of hazardous
wastes management, resource recovery, and land disposal.
JAMES R. GRECO
Technical Director
National Solid Wastes Management Association
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Contents
OPENING GENERAL SESSION REMARKS
page
ROLE OF THE STATE IN SOLID WASTE MANAGEMENT
Moses N. McCall III 2
STATUS OF RESOURCE RECOVERY
James R. Greco 5
HAZARDOUS WASTES
REGIONAL APPROACH TO CHEMICAL WASTE MANAGEMENT:
HOW DO YOU DERIVE YOUR DATA BASE?
Gay nor W. Dawson and Michael W. Stradley
REGULATORY ASPECTS OF SITING HAZARDOUS WASTE
TREATMENT AND DISPOSAL FACILITIES
John P. Lehman .......................... 22
THE CHEMICAL VIEWPOINT OF HAZARDOUS WASTES MANAGEMENT
William E. Brown, Ph.D ........................ 37
A CASE HISTORY: IMPLEMENTING A CHEMICAL WASTE LANDFILL
Edward Slover ........................... 46
CALIFORNIA'S HAZARDOUS WASTE MANAGEMENT PROGRAM
Dr. Harvey Collins ......................... 67
STATE HAZARDOUS WASTE PROGRAM
Thomas Tiesler .......................... 76
LAND DISPOSAL
ESTABLISHING URBAN LANDFILLS FROM START TO FINISH
Michael Pope 82
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THE ROLE OF PROCESSED REFUSE IN LANDFILLIIMG: YESTERDAY'S
EXPERIENCE, TODAY'S STATUS, TOMORROWS FORECASTBALING
Truett DeGeare, Jr 113
THE ROLE OF PROCESSED REFUSE IN LANDFILLING: YESTERDAY'S
EXPERIENCE, TODAY'S STATUS, TOMORROW'S FORECASTSHREDDING
R. K. Ham 128
HANDLING DIFFERENT WASTE TYPES: BASIC OPERATIONAL
CONSIDERATIONS
Cecil Iglehart, Jr., P.E 137
FUNDAMENTALS OF SELECTING LANDFILL EQUIPMENT
Chris Klinck 143
EQUIPMENT MAINTENANCE FOR LANDFILL MACHINES
Richard Molenhouse 154
STRATEGIES FOR MONITORING GROUND WATER AT LAND
DISPOSAL SITES
David W. Miller 164
METHANE GAS IN LANDFILLS: LIABILITY OR ASSET?
John Pacey 168
GAS RECOVERY: NATIONAL POTENTIAL
Robert H. Collins, III 191
RESOURCE RECOVERY
ENERGY FROM WASTE RESEARCH AND DEVELOPMENT PLANS
Donald K. Walter.
204
RESOURCE RECOVERY-PLANNING A STRATEGY FOR
IMPLEMENTATION
Samuel Hale, Jr 222
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FEASIBILITY CONSIDERATIONS FOR ESTABLISHING A RESOURCE
AND ENERGY RECOVERY PROGRAM
David J. Darniano 230
FINANCING RESOURCE RECOVERY SYSTEMS
Dorsey H. Lynch 238
DESIGN FACTORS FOR TRANSFER STATIONS/RESOURCE
RECOVERY SYSTEMS
Bruce Hendrickson 243
CONSIDERATIONS FOR COMPONENT EQUIPMENT DESIGN
SPECIFICATIONS
Irving Handler, P.E 253
TECHNOLOGY UPDATE: ONOISIDAGA COUNTY ENERGY RECOVERY
PROJECT
Ned R. Mann 267
TECHNICAL SYMPOSIUM SELECTED PAPERS
IDENTIFYING AND CORRECTING GROUNDWATER
CONTAMINATION AT A LAND DISPOSAL SITE
James S. Atwell, P.E 278
LIVING WITH LEACHATE
Joseph Bern, P.E 302
A STUDY OF QUANTITY AND QUALITY OF GAS AND
LEACHATE GENERATION FROM WHOLE AND SHREDDED,
BALED AND NON-BALED MUNICIPAL SOLID WASTE
Daniel J. McCabe 321
AEROBIC TREATMENT OF LEACHATES FROM SANITARY LANDFILLS
Dale A. Carlson and Ole Jakob Johansen 359
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Opening General
Session Remarks
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ROLE OF THE STATE IN SOLID WASTE MANAGEMENT
Moses N.McCall III
Director, Solid Waste Management Services, Georgia Department of Natural Resources
President, Association of State and Territorial Solid Waste Management Officials
The evolution of State involvement in solid waste management can be
appropriately summarized by plagarizing a currently popular cigarette commercial--
"You've come a long way baby". Ten years ago only two States had administrative
programs for solid waste management. Now, all States have programs, and many
state programs are substantial in size, budget, and technical expertise.
What then is the proper role of State government in coping with our increasing
solid waste problem? I submit that at the State level this is "where its at"
program wise. State governments have the obligation of assuring that local
governments provide for efficient, environmentally sound solid waste services
for their inhabitants, either by the public or the private sector. Regulation,
therefore, is a prime concern of the State. We at the State level cannot be
content with only a regulatory role however. We must provide various forms of
aid to assist and encourage expanded and improved services. The State role
therefore is threefold: (1) Regulation, (2) Assistance, and (3) Leadership.
Regulation--Each State is relatively unique in size, physical land
characteristics, geology, economic development and population distribution.
This individuality has been recognized in the regulatory practices of the States--
State solid waste laws and administrative procedures have been geared to meet
individual needs. Federal regulation has been nonexistant; therefore, States
have not been forced to all follow the beat of the same drum as has been the case
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in such EPA regulatory programs as air and water pollution. The regulatory
process has been evolutionary--initially concentrating on elimination of open
burning dumps and installation of sanitary landfills. Programs have progressed
and now many states are taking on more sophisticated regulatory roles--requiring
groundwater monitoring, leachate collection and treatment, and improved hazardous
waste handling. This will be the trend for the future the regulatory role of
the states will continue to become more sophisticated as technology improves.
More states will require monitoring wells and leachate treatment, and more
states will embark on hazardous waste programs. As proper solutions are derived,
I foresee more uniformity in the regulatory programs of the states.
Assistance--The hand that regulates must also assist. State solid waste
agencies must provide aid (administrative, managerial, financial and technical)
to local governments and to private industry. Many local governments serve small
populations, have part-time administrations and have limited professional assistance
to develop and operate effective solid waste systems. Further, local governmental
officials are faced with a myriad of regulations from the State and Federal
governments--water supply, water pollution, fair labor standards, ad infinitim.
It is therefore the obligation of the State to assist--to provide training and to
give technical assistance whenever requested. The same is true regarding the
private sector. State programs have becone more sophisticated and have technical
staffs which have developed considerable expertise in solid waste management. A
proper role is for the State to share this expertise in an effort to get a job
done well.
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Leadership--Although not normally involved in the direct provision of
solid waste service, the states have an obligation to assure that adequate solid
waste services are provided for their inhabitants--either through public or
private means. This then commits the State to a strong leadership role. We
must remain committed to promoting positive programs through the legislative
process. We cannot remain static--antiquated laws which impede progress or
hinder effective solid waste management must be changed. We must take the lead
in promoting resource recovery and proper management of hazardous waste. And,
the States must maintain an open line of communications--among themselves, with
EPA, and with private industry. Individually and through the Association of
State and Territorial Solid Waste Management Officials, the States will continue
to make known our needs and our viewpoints to EPA and to Congress.
If this is the role of the state, how then does this mesh with the role of
the Federal agency, specifically EPA. I contend that the state is the best level
of government to carry out an effective solid waste program of the type I have
described--not EPA. The Federal solid waste program should concentrate on
resource and energy conservation, research and development, demonstration projects,
establishing markets for recycled materials, and education and training programs.
In addition, the Federal program should provide worthwhile data regarding hazardous
wastes and should encourage (monetarily and otherwise) implementation of hazardous
waste programs by the States. Implementation, however, should remain a state
function. And last, but certainly not least, any planning must be coordinated
through the state solid waste agency. Utilizing this approach, the States will
continue to further the leadership role we have assumed.
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STATUS OF RESOURCE RECOVERY
James R.Greco
Technical Director, National Solid Wastes Management Association
Resource recovery resource recovery from wastes resource recovery from
solid waste resource recovery from municipal solid wastes. It is im-
portant to recognize the distinctions. Of all the significant developments af-
fecting the environmental management of our nation's discards, perhaps the mu-
nicipal solid waste resource recovery movement is the most promising and surely
provides the most exciting speculations. For theoretically, if there were to
be an ultimate solution to the problems of managing our wastes, would it not be most
appropriate to recover the latent resources existent in the waste stream, whether
those resources be in the form of energy or materials or both! Lest there be any
confusion through the rest of this Congress, I shall use the term "resource
recovery" as the general descripter for the means of recovering either energy
or materials from municipal solid wastes.
The past 12 months have brought resource recovery to the forefront of
waste technology. The announcements, the plans, the rumors,the realities
have literally exploded into the mainstream of solid waste disucssion and press
coverage. A full two-page article entitled "The Dollars Mount Up For Resource
Recovery," appeared in the August issue of Business Week. The subhead read, "The
Technology May Be An Answer to Communities Waste Disposal Practices." Un-
questionably, the general public's fancy is being captured and the elected
officials' views are turning in favor of changing this liability solid waste
into an asset. Whereas some have been swept away by the movement, others can't
feel it is happening fast enough or soon enough. So, we have the optimists and
pessimists, the promoters and the critics, and those largely uncommitted
patiently waiting for national policies to be established and the telling data
for resource recovery programs going on-the-line the operational and econom-
ic data.
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Last year at the Third National Congress in San Francisco, we learned that
the decision to undertake the New Orleans prototype materials recovery demonstra-
tion facility had finally been settled construction would commence in early
1975. Union Electric had recently announced plans to build an 8000 ton per day
Solid Waste Utilization System which would prepare solid waste for use' as a
supplementary fuel for electric power generation. And Chicago's plans were
described for constructing a similar refuse-derived-fuel program. As of the fall
of 1974, Milwaukee's supplemental fuel from wastes program was not yet. firm,
Baltimore's pyrolysis plant was yet to commence shakedown operation, Ames and
Saugus were still under construction, and although Bridgeport had selected a con-
tractor, the design, construction, and operating contracts were yet to be finalized
Within a year's time, however, Bridgeport executed its contracts for design,
construction, and operation, ground has been broken in New Orleans, Milwaukee,
and Chicago. Baltimore, Ames, and Saugus have begun to process wastes, and recover-.
plants are yielding operational data in South Charleston, Nashville, St. Louis,
Houston, East Bridgewater, Franklin, and Ft. Wayne. As a result, the technology
is being developed. Nonetheless, municiapl officials may likely be hesitant,
the resource recovery industry waiting, and the public wanting to accelerate
the movement. So the question seems to be, "How fast will resource recovery become
a part of the system for managing our waste?" The answer unfortunately, is yet
ahead of us in the near future when key issues can be thoroughly and objectively
addressed, such as:
proven technology throughout the system for every facet of
waste reception, processing, and derived end-products,
be they energy or materials; and,
economic viability, namely, the tasks of financing the
projects and determining the bottom-line reality amongst
a myriad of other considerations.
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There is no clear, simple, and curable analysis or evaluation. Simply
speaking, technology is being developed. It does seem clear, however, that
the emphasis is on energy recovery where the "return-on-development" may be most
appropriate and realizable. This should not discount, however, the potential
viability of shred and ferrous recovery operations where ferrous markets and
landfill operating requirements may warrant this technological approach. Three
sessions on resource recovery will be presented at this Congress:
(1) Energy Recovery from Solid Wastes
(2) Procurement of a Resource Recovery System
(3) Technology Implementation Status Report
The first will focus on policy issues and strategies for using refuse as an
energy-producer complemented by a roundtable discussion on the perspectives of
utility companies. Session II will delve more deeply into the strategies and
implementation approaches whereby the roles of the public and private sectors,
and planning contractual, and financial considerations will be aired. Session III
will identify the status of development and operating experience of system tech-
nologies and component equipment design. A notable array of speakers and panelists
have been gathered to directly address these topics. Finally, we will summarize
our discussions and candidly characterize the resource recovery movement and where
it fits in the environmental management of our wastes.
There is a dire need for a clear and candid characterization of the role of
resource recovery. To that end this Congress is directed.
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Hazardous Wastes
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REGIONAL APPROACH TO CHEMICAL WASTE MANAGEMENT:
HOW DO YOU DERIVE YOUR DATA BASE?
Gaynor W. Dawson, Senior Research Engineer, and Michael W. Stradley, Research Engineer
Battelle Pacific Northwest Laboratories
The need to address the problem of Hazardous Waste Management
was recognized in the Resource Recovery Act of 1970. Sub-
sequent efforts led to a series of research studies1"3 which
attempted to identify and quantify hazardous wastes within
the United States. All were conducted on a national scale
and have been valuable in providing order of magnitude esti-
mates of the national hazardous wastes problem and as aids in
formulating national policies on hazardous waste management.
Further studies on specific industry groups are now unde;rway.
Nevertheless, the scale or level of resolution of these
studies is such that their applicability to local, state, and
even regional planning for hazardous waste management IE;
limited. Detailed information relating to waste types and
quantities, disposal practices, and spacial distribution of
sources is not evident in these studies. The collection and
evaluation of such detailed information is an essential pre-
cursor to meaningful and effective action by federal, regional
and state environmental protectiOT agencies.
The study discussed herein represents an attempt to generate
the type of detailed information described above. The area
selected for study covered the States of Oregon, Washington,
Idaho and Alaska. The specific goals of the study included
the following:
* Identification and location of hazardous waste being gen-
erated in the States of Alaska, Idaho, Oregon, and Washington;
Estimation of the types and quantities of these wastes;
Determination of the waste management and disoposal prac-
tices associated with these wastes;
Identification of existing and potential hazardous waste
disposal sites;
* Projection of future waste generation patterns;
'Battelle Memorial Institute. "Program for the Management of
Hazardous Wastes," Environmental Protection Aoency, Contract
No. 68-01-0762, July 1973.
20ttinger, R. S., at al. "Recommended Methods of P.eduction
Neutralization, Recovery, and Disposal of Hazardous Wastes,"
TRW Systems for Environmental Protection Agency, February 1973.
3Booz-Allen Applied Research, Inc. "A Study of Hazardous Waste
Materials, Hazardous Effects, and Disposal Methods," Environ-
mental Protection Agency, June 30, 1972.
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Evaluation of current hazardous waste management prac-
tices; and
Development of cooperative concepts which could enhance
hazardous waste management within the region.
The study was carried out by Battelle-Northwest Laboratories
with the assistance of federal, state and municipal pffices
and the cooperation of literally hundreds of industries within
the four state regions. The study is now complete. It is,
therefore, appropriate to step back and evaluate the approach
taken, and the desirability of conducting similar efforts in
other regions of the country. Such an analysis is provided in
the following paper.
THE APPROACH METHODOLOGY
Hazardous wastes may be generated in a variety of ways. The
approach used in the subject study to identify sources of
hazardous waste began with a categorization of the general
types of activities which had the potential to produce hazard-
ous wastes. These potential sources were initially grouped
under three major headings:
Industrial Operations - which produce a hazardous residual
as part of their process or handle hazardous materials, a
portion of which is wastes.
State and Federal Activities - which handle hazardous
materials. Also included under this heading are utilities
and public utility districts.
* Agricultural Operations - which handle large quantities of
pesticides.
The hazardous waste management industry formed a fourth group
of potential sources. At the present time, these are a number
of private companies in the u. S. which dispose of and/or pro-
cess hazardous wastes. These companies are a potential source
of hazardous wastes which could arise from reprocessing resid-
uals and improper disposal. The assumption that assignment
of hazardous wastes to these companies constitutes proper
management of the wastes cannot be made automatically. Hence,
inclusion of these companies as a source is dictated not only
by the need to document their important role in the management
of hfl^ardous wastes, but also to insure that new wastes com-
posited from a variety of primary sources are not being generated.
This breakdown of potential sources not only facilitated the
management and direction of the study, but more importantly,
due to the rather unique characteristics of the wastes and the
organizations producing the wastes, allowed the use of the most
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appropriate techniques of ascertaining waste' quantities and
management practices for each category. For example, deter-
mination of waste quantities from centralized state and federal
agencies was most easily determined by directly approaching
the agencies, while the disperse nature of the agricultural
pesticide usage required an indirect and less precise approach.
Specific approaches taken to delineate waste quantities and
management practices are discussed below by source category.
Industrial Operations
The survey of industrial sources used a combination of direct
and indirect procedures to ascertain hazardous waste types
and management practices. The first step in this procedure
was the compilation of a list of industries in the region
with the potential to generate hazardous wastes. Industries
were selected on the basis of their Standard Industrial
Classification (SIC).1* A SIC list1 corresponding to industries
which had the potential to generate hazardous wastes was cross
referenced with the Manufacturing Directories5"8 of the States
of Alaska, Idaho, Oregon, and Washington. This cross refer-
encing resulted in a list of industrial operations within the
four states which were considered to have the potential to
generate hazardous wastes. For the most part, thislist
proved to be quite comprehensive although some additional
sources (primarily new operations) were identified during the
course of the study as a result of contacts with various
federal, state, and local regulatory authorities, industrial
representatives, and waste processors.
Given the list of candidate industrial sources, the effort
was directed to the identification of hazardous waste quantities
and management practices in the industrial sector. This con-
stituted the bulk of the study effort. Each of the industries
identified as a potential generator of hazardous wastes was
considered individually, using inputs from the following data
sources:
State Manufacturing Directories - aside from identifying
individual firms in a category, these directories typically
give brief descriptions of the size of the operation, by
employment level, basic products, and ir. some instances,
the type of process.
""0. S. Office of Management and Budget. "Standard Industrial
Classification Manual," U. S. GPA, Washington, D. C., 1972.
5Alaska Department of Economic Development. "Directory of
Alaska Commercial Establishments," Juneau, July 1974.
6Idaho Department of Commerce and Development. "Manufacturing
Directory of Idaho," Boise, 1973.
'Oregon Department of Economic Development. "Directory of
Oregon Manufacturers," Salem, 1974.
Ev;=shington Department of Commerce and Economic Development.
"Directory of Washington Manufacturers," Olympia, 1974.
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State Surveys - the states of Idaho, Oregon, and Washington
had previously conducted industrial solid and hazardous waste
studies9"11 of varying scope and depth in their respective
states. The data included hazardous wastes quantities and
present disposal practices. The state of Alaska had not
conducted a survey of industrial hazardous waste generation;
however, they were able to comment on the list of industries
provided to them by the study team on the basis of their
working experience.
NPDES Permits - the list of potential industrial hazardous
waste generators was crossed with the NPDES filed maintained
at the EPA Regional Office in Seattle. Although the infor-
mation contained in these files is oriented toward water
quality and effluent characteristics, these files proved
quite helpful in identifying specific manufacturing and
waste treatment procedures used by individual companies.
Information contained in field "trip reports" often included
discussions of airborne and solid waste management. Data
on plant effluent characteristics was also a useful indicator
of the existance of a hazardous solid waste as well as the
potential for increased sludge volumes with stricter water
pollution controls in 1977 and 1983.
National Industrial Surveys - data was extracted from com-
pleted and on-going industrial hazardous waste studies
sponsored by the EPA Office of Solid Waste Management Pro-
grams. These studies proved helpful in two ways: 1) pro-
viding general background information on hazardous wastes
produced by selected industries, and 2) providing specific
information on some of the Pacific Northwest hazardous
waste generating industries which had been surveyed directly.
Collection of the latter data required direct contact with
the individual contractors who conducted the various
studies since the final reports submitted to the EPA did
not characterize hazardous wastes from individual industrial
operations.
Municipalities - some of the larger municipalities in the
Pacific Northwest maintain industrial effluent monitoring
programs. Data collected from these municipalities proved
helpful in identifying hazardous effluent constituents and
in determining which industrial operations within the muni-
cipal jurisdiction were practicing effluent pretreatment.
'Idaho Department of Environmental and Community Services.
"Idaho Solid Waste Management Industrial Survey Report,"
Boise, June 1973.
1"Oregon Department of Environmental Quality. "Hazardous
Waste Management Planning 1972-73," Salem, March 1974.
1'Washington Department of Ecology. "A Report on Industrial
and Hazardous Wastes," Olympia, December 1974.
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Waste Processors - records maintained by some of the waste
processing companies within the region were used to identify
and quantify the wastes from a number of industrial sources.
The Literature - various reports and publications were
located and used to provide background material and operating
characteristics for specific industries.
The data collected from the aforementioned sources allowed the
candidate industries to be divided into four basic groups:
1. Know Hazard Waste Generators
2. Suspected Hazardous Waste Generators
3. Industries for which Little was Known
4. Industries Known not to Generate Hazardous Wastes
At this point it was necessary to shift from an indirect to a
direct survey mode in order to realize the level of resolution
desired. This was accomplished through direct contact with
the industries in order to fill in gaps in the data collected
from other sources, verify waste quantities and disposal prac-
tices, and survey industries for which no information (other
than SIC and products) was available. All firms in Group 1
were contacted No firms in Group 4 were contacted. Spot
contacts with individual firms in Groups 2 and 3 were made.
If these indicated hazardous waste generation potential for
a SIC Category, all firms in that industrial category were
contacted. Industries to be contacted were approached by phone
or letter and asked to provide information relating to:
Type of Operation
Number of Employees
Products and Production Capacity
Hazardous Wastes Generated
Hazardous Waste Disposal Practices
Effluent Characteristics Including Treatment Practices
After the initial telephone or letter contact, a "profile" on
the company was prepared. This profile contained a summar/ of
pertinent information derived from the aforementioned sources
and the telephone survey. Copies of these profiles were sent
to each industry for inspection and comment as to accuracy and
completeness. Cooperation by the industries contacted during
the initial contact period was excellent. The most common down-
fall was a failure to respond to the profile. A very few firms
refused to answer the initial inquiry.
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Agricultural Operations
Virtually all Agricultural Operations utilize pesticides for
vegetation and insect control. These pesticides are handled
not only by licensed applicators, but also by individual
farmers. A direct survey of individual pesticide disposal
practices was beyond the initial scope of the study; however,
during the early stages of the program, meetings with state
Solid Waste Management representatives from Idaho, Oregon and
Washington revealed an unanimous consensus that spent pesticide
containers represented a significant question mark in the area
of hazardous waste management and that some quantification of
the magnitude of this problem was needed. Therefore, an
approach was derived to make maximum utilization of existing
resources.
The procedure used to estimate regional agricultural pesticide
usage and the number of containers resulting from this usage
was a statistical one based on data generated during the 1969
Census of Agriculture12 and the 1971 Farm Production Expenditure
Survey13 conducted by the U. S. Department of Agriculture.
The Expenditure Survey was based on personal interviews with
8,600 farmers in 394 counties throughout the contiguous states
and Hawaii. The region was r3presented by 28 counties. These
are illustrated in Figure 1.
The numbers in the shaded areas correspond to the identification
numbers of the Primary Sampling Unit (PSU). The numbers in the
non-shaded areas indicate which PSU or PSU's were used to
estimate pesticide use densities in non-surveyed counties. The
PSU usually consists of one county, but in areas containing
few farms, two or more counties are grouped into one PSU.
Selections of farmers for interview was based on a two-stage
multiple frame sample designed to represent all United States
farms. The first stage of sampling consisted of selecting
counties or groups of counties to form the PSU's. The second
stage of sampling was selecting farms within each PSU for
interview. The interview provided detailed information on
costs of certain groups of pesticides and quantities of
specific pesticide materials used to treat growing crops,
stored crops, seeds, livestock, and storage or livestock
buildings.
For purposes of this study, the data for the Pacific Northwest
were printed out, "clean up," and interpreted manually. They
consisted of 1798 observations. In order to disaggregate these
data to the county unit, it was necessary to define the per acre
12Bureau of Census, U. S. Department of Commerce. "1969 Census
of Agriculture," Washington, Part 46, Oregon, Part 47, and
Idaho, Part 39, Vol. I, Area Reports, Washington, D. C., 1972.
1 3S .atist:cal Reporting Service, U. S. Department of Agriculture.
" -971 Farm Prociaction Expenditure Survey," Interviewers Manual,
Washington, D. C., 1971.
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application for major crop categories. This was done in terms
of ounces of active ingredient by reported units. The reported
units consist of ounce, pound, pint, quart, or gallon. The
total quantity of pesticide used in each crop category, by
specific reported unit, was divided by the total number of
reported acreas in each crop category. The value of each of
the unit quantities sums to the average per acre value.
When the application of pesticides was reported for specific
crops in the Farm Production Expenditure Survey, but no acreage
was reported for these crops in the Census of Agriculture, they
were collected together in a category defined as "Other Crops."
Pesticides were found to be reported on land which was not
being farmed. These uses included roadsides, fence rows, and
around buildings. It also included streams, ponds, lakes, and
irrigation and drainage ditches. Quantities of pesticides
used for these purposes, as well as on pastures and summer-
fallow, were aggregated with quantities used on crops and
presented in a "County Average" category.
Total pesticide usage was computed by multiplying the appli-
cation rates by the most recently reported crop acreage allot-
ments by county. Estimates of the number of spent containers
generated in each county were made from these tonnage figures.
The reported units (e.g., pounds, ounces, gallons, etc.) for
each crop' in each county were extended to determine what
percent of total tonnage was reported in each unit for a given
county. These data were then categorized. Pesticides reported
in ounce and pound units were assumed to have been shipped in
50 pound bags. Hence, bag quantity estimates were derived by
multiplying county tonnage data by 40. Pesticides reported in
pint and quart units were assumed to have been delivered in
quart bottles. Hence, bottle estimates were derived by
multiplying county tonnage data by 1000 (the latter is based
on an average density of 8 pounds per gallon). Pesticides
reported in gallons were assumed to have been delivered in
5 gallon pails. (This results in an over estimation because
of the use of 30 gallon drums and 55 gallon drums by some
large users and applicators.) Hence, drum estimates were
derived by multiplying county data by 49.8. (The latter
also assumes an average density of 8 pounds per gallon.)
State and Federal Agencies
Hazardous wastes resulting from the activities of various
state and federal agencies were identified through direct
contact wit-h the individual agencies. The list of state
agencies was compiled from previous state solid and hazardous
waste surveys9~ and individual communications from the
Oregon Departm nt of Environmental Quality, Washington Depart-
ment of Ecology, Idaho Department of Health and Welfare, and
Alaska Department of Environmental Conservation. Federal
agencies were identified through the Federal Regional Task
Force on Hazard Wastes. Also included under this heading was
17
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a direct survey of 157 utilities and public utility districts
for the specific purpose of ascertaining waste management
practices for polychlorinated biphenyl's (PCB's) found in
transformer and capacitor oils.
Waste Processing and Disposal Companies
Commercial waste processing and disposal companies were identi-
fied through state and federal regulatory agencies. Other
firms such as tank cleaning and spetic tank companies which
may pick up wastes, but do not process them or operate dis-
posal sites, were not identified systematically. Rather, the
main source of identification for these types of operation
were the industries who were using or had used their services.
Because no systematic approach was used to identify these
operations and because the industries contacted were not
always able to identify these companies by name, coverage of
these operators was not complete.
AN EVALUATION
The program approach described here was the first survey of
its kind and as such should be viewed as a pilot program.
Therefore, it is appropriate to evaluate the desirability of
such a program and the effectiveness of the approaches taken.
A regional study of this nature is valuable only if it can be
taken to a fine level of resolution. Broader, more general
data are already available from previous studies conducted on
a national level. When high resolution is achieved, the final
product can be expected to give a clear picture of the total
hazardous waste management cycle both technically and spatially.
In the final analysis, the degree of resolution desired for this
type of study necessitates the use of direct contact with waste
generators, transporters, and processors. The latter cannot
be accomplished effectively with form letters, but requires
personal interaction with allowance for active feedback. There-
fore, in planning such a. study, strong consideration must be
given to logistical aspect. There is no quick and dirty way
to achieve the requisite high level of resolution and detail.
Rather such detail is achieved through the methodical evalu-
ation of each potential source which will ultimately dictate
personal contact with known or highly suspect hazardous waste
generators. The cost of such an effort is directly and for
the most part linearly proportional to the number of such
sources. This implies major costs for highly industrialized
areas and suggests that an objective evaluation be made prior
to initiating any work to determine if the additional benefits
to be gained from high resolution justify the costs.
It was originally thought that indirect estimates using waste
generation factors (e.g., units of hazardous waste/unit of
production) would provide an adequate method for determining
hazardous waste. Sach an approach is obviously less expensive
18
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than direct contact and does not rely directly on industry as
a data source. Indeed, for some industries in which the process
or processes are stoichometrically governed, a good estimate
of "first generation" wastes can be made. However, this pro-
cedure does not allow individual consideration of inplant modi-
fications, recycling procedures, and housekeeping practices,
nor does it enable the user to predict which disposal options
are being practiced by any given company.
The excellent response by industry to the survey is felt to be
partially attributable to the fact that in almost all contacts
some information on the hazardous wastes (either potential or
actual) for each facility was already in the hands of the
survey team as a result of the data collection effort which
preceeded the direct contacts. Fewer than one percent of the
industries contacted flately refused to discuss their hazard-
ous wastes. This phenomenon could also be a local one attri-
butable to the relative high visibility of industry in the
Pacific Northwest and the fact that public opinion, especially
in Oregon and Washington, is strongly in favor or environmental
protection. It may be that industries in the region, especially
the larger ones, are highly cognizant of this concern and
having acknowledged their responsibilities toward environmental
protection are more willing to discuss these matters. This
open atmosphere may not prevail in other areas of the country.
A comment regarding SIC codes is also in order. The use of
SIC codes to identify potential sources can be very misleading
and must be handled with discretion. Initial identification
using this approach will typically generate many candidates
that do not actually produce hazardous wastes. In this regard,
estimates will be conservative. If individual firms are
identified through cross reference with state directories,
outside input will be required since directories are not com-
plete. State agencies and municipalities can be of assistance
here. The latter source is particularly good for effluent data.
The approach described here for quantification of agricultural
sector wastes is considered a very cost-effective methodology.
The results appear to be very reasonable for individual
counties and should be valuable for future planning. Since
the existing data base covers all of the continental U. S.,
there is no reason to believe that the same level of resolution
cannot be obtained in an effort covering all the counties in
the nation. Since much of the data is computerized, a
national scale study would most likely be airenable to data
processing techniques. A study in the State of California
recently generated data on the distribution of container
sizes employed by agricultural interests. Use of this dis-
tribution is probably more desirable than the blanket
assumption of 50 pound bags and 5 gallon pails employed here.
19
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If the latter is undertaken, it would be possible to include
a sub-routine to identify chemical families and pesticide
groups from the Frear Codes included in the present data
base. This would give an even better picture of the manage-
ment needs for pesticide residues and containers from the
agricultural sector. This refinement is hard to justify cost-
wise on an individual regional study.
While the agricultural survey approach produced estimates of
pesticide usage, it provided no data on waste management
practices. There is a real need to supplement it with a survey
of farmers and applicators to generate a better picture of
what is presently being done with the literally millions of
spent pesticide containers generated annually.
The diverse nature of activities conducted by state and
federal agencies dictates the use of direct contacts to assay
this source of hazardous wastes. This is not as complicated
for agencies as it is for private industry since potential
sources are more easily identified, and official lines of
communication are already in place. The existence of regional
task forces and state hazardous waste offices further simpli-
fies data collection.
Considering the approach outlined here, and the potential
difficulties noted, the decision to pursue similar efforts
in other regions can be made in an objective manner. The
most important points to be taken into account are:
1. What are the expected benefits of detailed information?
Potential benefits can consist of a large body of data
from which to design an optimal management system which
will eliminate environmental insult, or the recognition
that the present problem does not warrant large scale
expenditures.
2. Do these benefits exceed the cost of direct contact
with all potential sources? It is estimated that 1 - J.. 5
man months are required to survey each 100 potential
sources. This requirement can be reduced if staff
have experience from previous studies in this area.
The first question can be answered only if some very definite
plans exist for future management of hazardous wastes in the
region.
Surveys of this nature can be conducted on either a state or
regional level. Studies conducted on a state level (especially
in the industrial sector) are probably best accomplished by
state agencies who are more familiar with local problem areas.*
*Cooperation from state agencies involved in hazardous waste
management played an important part in the reported study.
20
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In this case, consullation either with federal agencies or
independent consultants in the evaluation of waste management
practices may be required if such expertise does not exist
at the state level. The exploration of cooperative concepts
for hazardous waste management on a regional level may well
require federal coordination.
In all cases, the conduct of an agricultural sector survey
for pesticide containers appears both feasible and warranted.
Great economies are available if this is done on a national
scale rather than by individual regions.
21
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REGULATORY ASPECTS OF SITING HAZARDOUS WASTE TREATMENT
AND DISPOSAL FACILITIES
John P. Lehman
Director, Hazardous Waste Management Division, Office of Solid Waste Management Programs
U.S. Environmental Protection Agency
At the outset, let me state that a meaningful
discussion of the regulatory aspects of siting a hazard-
ous waste treatment and disposal facility presupposes
that such facility siting is, in fact, regulated by some
governmental entity under authority of hazardous waste
management legislation. Although some States do have such
legislation and authority, the majority do not. And
although comprehensive Federal hazardous waste management
legislation has been proposed, at present there is no
Federal requirement for facility siting, with the exception
of radioactive waste. Consequently, the following dis-
cussion is based primarily on premise, not fact.
Another aspect to bear in mind is that all waste
treatment and disposal facilities should be regulated
not just those dedicated to hazardous waste. Otherwise,
there can be no assurance that hazardous waste will reach
appropriate treatment and disposal facilities. If open
dumping and environmentally unacceptable treatment facili-
ties are allowed, hazardous waste will go to these dumps
for simple economic reasons.
22
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In other words, regulation of hazardous waste
i»
facility siting must be viewed in the context of an
overall waste management program, with the necessary
legislative authority in place.
Many people assume that a regulatory agency should
concern itself only with the technical aspects of hazard-
ous waste facility siting, such as whether or not the site
is environmentally suitable for hazardous waste disposal.
Based on our experience with some of the State programs
to date, and projecting our thoughts to the time when there
are stronger mandates to manage hazardous waste properly,
I can assure you it's not that simple. Socio-political,
economic and jurisdictional issues also are part of the
regulatory process.
Socio-Political Aspects
When it comes to solid waste management facilities
siting, the almost universal public reaction is, "Don't
put that dump near my property!" Regardless of the technical
merits of each case, landfill siting decisions are among
the most sensitive decisions a politician must face.
When the additional dimension of "hazardous" wastp is
added to the equation, the public reaction to facility
siting proposals is usually even more strident and negative.
For example, one firm I know of has tried 26 times to get
local government approval for a new, apparently well-designed
23
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hazardous waste treatment and disposal facility i
States and was turned down cold 26 times in a row.
Clearly, adverse citizen reaction to hazardous waste
treatment and disposal facilities is a very serious
problem whicji will become more prevalent as more States
adopt new hazardous waste management legislation and regu-
lations. The laws cannot be implemented if there are
insufficient facilities to handle the waste load.
Balanced against this pressure for new facilities is
the public's right to participate in regulatory decisions.
Clearly, there must be open hearings concerning hazardous
waste facility siting decisions. Citizens have a right
to know what's going on and to comment on the proposals.
Government officials sometimes make unpopular
affirmative decisions which they believe are for the public
good in the long run. More often, officials bow to local
reaction and make negative decisions, which again can be
interpreted as being for the public good. The merits; of
each case must be known before we pass judgment. It is
clear, however, that a negative decision is the easiest
course.
We have given a great deal of thought to the citizen
acceptance issue, since it is a prerequisite to a viable
hazardous waste management program. Some principles have
24
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emerged. First, it is obvious that the public needs to
t*
know the facts, rather than heresay. It should know the
dimensions of the problem and how the particular hazard-
ous waste facility proposal fits into the solution. The
public needs to be assured that safety precautions will
be taken. It needs to know what the alternatives are and
the economic and environmental costs vs. benefit tradeoffs
of each. In short, a public education program is a
necessity. If the public knows the facts, and considers
them objectively, hopefully a wise decision will evolve.
It is when emotions get the upper hand, or when data
biased one way or the other is the only basis, that poor
decisions are made and citizen reaction intensifies.
Another way to alleviate public concerns about
hazardous waste treatment and disposal facilities is to
locate them on Government-owned land. This has been the
approach used at a number of locations with nuclear and
other hazardous wastes (i.e., Los Angeles County, San Diego
County, Gulf Coast Waste Disposal Authority, and several
nuclear sites). This approach will also be taken at the
Minnesota demonstration which is being partially sponsored
by EPA. Somehow the fact that a Government entity is
actively involved in the proposed facility, and presumably
would have long-term control over the site, goes far in
gaining public approval. I do not want to imply that a
25
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Government entity should also own and operate the facilities
on the land made available. Although this is one option,
I believe the private sector would be amenable to building
and operating hazardous waste facilities on Government-
leased land, particularly if there were no other land
parcels available.
In addition, although we are not aware of specific
instances regarding hazardous waste sites, State governments
can obtain land by eminent domain proceedings if suitable
land is not otherwise available. Use of the eminent domain
process can, on the other hand, stir up much local opposi-
tion, and, therefore, should be used as a last resort.
Another socio-political aspect associated with
hazardous waste facility siting is the waste non-importa-
tion controversy. Many industrial concentrations are
located in metropolitan areas which overlap State boundaries.
New York, Philadelphia, St. Louis and Chicago are examples.
Also, many existing hazardous waste facilities have customers
located in several States. If such facilities are to be
financially self-sustaining, they must be able to draw
waste from as many waste generators as possible in a logical
geographical area. While it is understandable that local
citizens would prefer to restrict access to facilities to
local industry, hazardous waste facility siting decisions
should be based on economic and technical factors
irrespective of political boundaries.
26
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Economic Aspects
Obviously, there is interplay between some economic
and socio-political aspects of facility siting, as we just
mentioned. From a regulatory perspective, there are other
economic issues to be resolved. These issues arise as a
result of the "start-up" problem of regulatory controls
vis-a-vis disposal facility availability. If a Governmental
agency has regulatory powers, but no facilities exist with-
in its jurisdiction, it is very difficult to actively
enforce the regulations. This leads to the decision
whether to provide some fiscal incentives to industry to
build and operate such facilities in order to provide
acceptable "pathways" for the wastes. Such incentives
include grants, loans, loan guarantees and preferential
taxation. Another alternative is to set up a quasi-
governmental financing authority.- supported by public
bonding, to provide the funds for facilities.
An important economic aspect of regulating private
hazardous waste facilities is the fiscal responsibility
of the owner. There have been several cases in vrhich a
private entrepreneur has opened a hazardous waste treatment
and disposal facility, accepted (and collected fees for) a
large quantity of waste, and then abandoned the facility,
usually leaving a mess for Government authorities to clean
up at public expense. Some safeguards against this slip-
shod practice should be built into the facility permitting
27
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process. Examples include requirements for a complete
*
financial statement and posting of a performance bond by
the permit applicant.
Institutional and Jurisdictional Aspects
As before, there are linkages between institutional
and Jurisdictional aspects, and economic and socio-
political aspects of hazardous waste facility siting.
The basic institutional and Jurisdictional question
is whether or not hazardous waste facilities should be
provided by the public sector or by the private sector,
or by a mix of both.
It is certainly within the power of State, regional
or local governments to set up a public authority to pro-
vide the necessary facilities. The Gulf Coast Waste Dis-
posal Authority serving the Houston area is an example of
this concept. A variant could be a public utility
corporation with a franchise or monoply in a given area,
and with rate structures regulated by an oversight
commission.
One advantage of the public authority or utility
concepts is that public facilities could be required to
accept all types and quantities of hazardous waste. By
contrast, a private facility may elect to accept only
high volume, concentrated wastes to maximize profitability,
and to reject low volume wastes which may be the most
28
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difficult to process. In opposition/ one can argue that
J»
open competition among private operators will result in a
lower cost, more efficient service than a public facility
can provide. But, if private facilities are not available,
some form of public service facility may be the solution.-
The same regulatory criteria must apply to any facility,
public or private, however.
Another jurisdictional aspect is the issue of whether
Federal, State, regional or local government should have
regulatory authority over hazardous waste facilities.
This is a different issue than which level of government
should implement construction and operation of such
facilities, if a public facility option is chosen. The
distinction is important, since, in our view, regulatory
and implementation authorities should be separated whenever
possible. AT. analogy at the Federal level is the recent
reorganization of the atomic energy program to provide a
regulatory body (the Nuclear Regulatory CoiPitission)
separate and distinct from an implementation body (ERDA).
While there are pro and con arguments for each
governmental level to have facility regulatory authority,
our view is that State government should exercise this
authority. This conclusion derives from the unique
potential of hazardous wastes to cause public health and
environmental damages, the fact most haza.rd.ous wastes
29
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originate from private industry, and the potential need
*;
for inter-State compacts regarding facility access, as
discussed previously. We feel that State governments can
judge hazardous waste facility siting decisions better
than the Federal Government cam due to a better under-
standing of unique conditions within the State. Also, as
mentioned before, States can exercise eminent domain
powers if necessary. Most States which are currently
operating hazardous waste regulatory programs have retained
hazardous x-raste facility siting authority at the State
government level.
Technical Aspects
Assuming all the socio-political, economic and
jurisdictional aspects are resolved satisfactorily, the
crux of regulatory facility siting decisions comes down
to a thorough and objective evaluation of numerous technical
criteria. Is a proposed site technically adequate for
treatment and disposal of hazardous waste? Should a permit
be issued or withheld? These are the hard questions.
Future protection of public health and the environment rides
or. the answers,
We have studied over a dozen different schemes con-
cerning facility site selection criteria from both the U.S.
and Europe. Several guiding principles emerge from such
analyses, as well as an understanding of pitfalls to be
30
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avoided. It is my intention here to discuss the general
principles of technical criteria selection, rather than
details of the criteria themselves, thus avoiding one of
the major pitfalls we discovered, namely that many criteria
are valid only for a very limited geographical area, and
are better left to State-level decision makers.
In a 1972 article in the Journal of the American
Water Works Association*, Stokinger discussed "seven
commandments" for setting environmental policy. Four of
these are germane to the exercise of developing site
selection guidelines. Briefly, proposed guidelines should
be:
0 based on scientific fact, not politics
0 well documented and defensible
0 realistic and not unnecessarily severe
0 based on an accurate interpretation of trends
Based on our recent studies, we would suggest
additional principles. Wherever possible, site selection
procedures should endeavor to:
0 Treat each site parameter independently in order
to fully consider the impact it may have on the
site's suitability for hazardous waste disposal.
This avoids one pitfall of a weighted-average
*Stokinger, H.E. How to achieve a realistic evaluation
(in seven commandments). Journal of the American Water Works
Association, 64(4): 262-265 (April 1972).
31
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approach, namely that additive totals will mask
a basic defect of a proposed site.
0 Minimize the amount of judgment or arbitrary
decision used. Decisions should be based on the
best technological data available.
0 Evaluate site parameters that are measurable and
definable by known test procedures.
0 Provide variance procedures or options to eilleviate
or modify unacceptable site parameters.
0 Make use of existing sources of environmental data.
0 Be applicable to a broad range of environmental
conditions.
0 Be flexible to change with a minimum of retooling.
With these general principles in mind, the next step
is to design a decision procedure which addresses the key
parameters in the selection process. The most significant
parameters are those which determine (1) the behavior and
movement of soil moisture, and (2) the social and political
acceptance of the facility. Examples of such site
parameters are:
" Ilydrogeology, including seismic activity
0 Topography, including slope and floodplain aspects
0 Climatic factors, such as rainfall, winds,
prevalence of tornadoes, hurricanes, etc.
0 Ecological factors, such as presence of endangered
32
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species and migratory wildlife
0 Cultural factors, such as
land use and zoning
transportation access
- historical significance, and
aesthetics, including visual and noise level
aspects
One promising decision making format is the decision
tree, that is, a flow chart of yes-no decision points.
The decision tree contains a. complete set of decision
parameters arranged in a logical sequence, A well designed
decision tree would provide a means of modifying an
unsatisfactory site parameter to meet a given criterion,
and also provide variance and appeal procedures. One
virtue of the decision tree system is that each parameter
is decided upon independently.
Before leaving the technical aspects, I would like to
mention two very important technical parameters which
should be part of a hazardous waste facility operating
permit decision, even though they are not necessarily
part of the facility siting decision.
First, there should be some criteria for the technical
adequacy of the facility staff at both the management and
operating levels. The people who operate hazardous waste
33
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facilities have got to know what they are doing. Secondly,
.it
we feel it is very important to require a routine monitoring
and surveillance program for hazardous waste facilities.
The degree and frequency of monitoring will vary with
individual circumstances, but it is imperative in our view
to have a baseline survey before facility operations
commence, and regular monitoring surveys thereafter to
detect trouble before it becomes serious.
Summary
In summary, the regulation of hazardous waste
facility siting encompasses social, political and economic
aspects as well as technical aspects. Each aspect is
linked to all the others, often in complex ways. Further-
more, regulation of hazardous waste facility siting must
be viewed in the context of an overall waste management
program.
Citizen acceptance of hazardous waste facilities is
the most significant socio-political aspect. We believe
an active, factual, unbiased public education program is
the key to success in this area. Locating hazardous waste
facilities on Government-owned land is another way to
alleviate public concerns. This should be done only as
the last resort, however.
34
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If hazardous waste facilities are to be financially
self-sustaining, they must be able to draw waste from
all waste generators in a logical geographical area,
irrespective of political boundaries. Consequently, we
feel that waste importation bans are counter-productive.
Some safeguards against abandonment of hazardous waste
facilities should be built into the facility permit process.
For example, fiscal responsibility of owners should be
firmly established, and posting of a performance bond by
the permit, applicant could be required.
If private facilities are not available, providing
some type of fiscal incentive or setting up some form of
public service facility may be the solution. Regulatory
criteria must apply equally to any facility, whether
public or private. Our view is that State governments
should exercise such regulatory authority.
Technical site selection criteria should be addressed
independently, rather than with some weighted-average
scheme, since additive totals may mask a basic defect of
a proposed site. Facility evaluations should be based or.
site parameters that are measurable by standard test
procedures, wherever possible, to minimize the amount of
arbitrary decision used. A decision tree with a logical
sequence of yes-no decision points is one promising
decision making format.
35
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Lastly, we believe minimum training requirements for
facility operators, and a routine monitoring and surveil-
lance program, are essential parts of the regulatory
criteria for hazardous waste treatment and disposal
facilities..
Clearly, a lot of meat must be added to the bones of
the site regulatory criteria approach I have outlined.
Detailed numbers and amounts must be specified for each
criterion, and these quantities will likely vary in
different parts of the Nation. However, once these values
are set, they should remain constant until substantial new
evidence dictates a change. Industry'cannot cope with
moving targets by regulatory agencies.
I hope this discussion has provided some food for
thought to you all and will stimulate a dialogue. The
regulation of hazardous waste facility siting is a
relatively new area of concern, and the basic concepts
and criteria are still evolving. I am sure State regula-
tory agencies, and the EPA, are open to new ideas. Now
is the time to discuss these criteria; please share your
thoughts with us.
Thank you very much.
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THE CHEMICAL VIEWPOINT OF HAZARDOUS WASTES MANAGEMENT
William E. Brown, Ph D.
President, Bio-Ecology Systems, Inc., Grand Prairie, Texas
INTRODUCTION
To successfully manage any business, it is a primary requirement
to know enough about it to not only handle the routine matters and be
prepared for emergencies, but to also avoid creating major additional
difficulties through decisions based on insufficient or misleading infor-
mation. We have all heard the story about the group of blind men describing
an elephant variously as like a tree, a wall, a brush and a snake, etc.
How many decisions have we made based on a one-sided view of the problem?
Today I will discuss some of my ideas regarding the chemical
viewpoint of hazardous wastes management. The chemical viewpoint is dif-
ferent from other viewpoints. Each viewpoint has substance. If we put
these all together we can more intelligently handle the problems at hand -
be they elephants or hazardous wastes.
A review of the papers presented at the Third National Congress -
Waste Management Technology and Resource Recovery in November, 1974,
indicates that operational technology and basic treatment techniques have
been very adequately described in Dr. Eugene Nesselson's paper "Treatment
Techniques for Chemical and Hazardous Wastes"1 and specific problem areas
and opportunities by Mr. Louis E. Wagner's paper, "Application of Chemical
and Hazardous Wastes Management Technology".2 The purpose of this paper
is threefold:
to present to you the viewpoint of the chemist
regarding hazardous wastes management
to compare it to the Sanitary and Civil Engineering
viewpoints of the same problems
to develop a unified aspect of hazardous wastes
management in which the different viewpoints can
be synthesized into a basis for better management
of hazardous waste problems.
THE CHEMICAL VIEWPOINT OF HAZARDOUS WASTES MANAGEMENT, BENEFICIAL CHANGE
A. Terminology
I will discuss language and communication first. All
substances are chemicals, most substances are combinations of many
37
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chemicals. Water, salt and sugar are relatively simple pure chemicals.
Wood, wool, bread and hamburger more complex chemicals. We often think
of chemicals as things that emit green fumes and will "eat your arm off!"
That is correct for a few hazardous substances, but totally untrue for most.
About 90% of industrial wastes can be handled in an
environmentally acceptable manner by good waste management practices.
The other 10$ may require special handling. These are the hazardous wastes,
those which "pose a substantial danger, immediately or over time, to humans,
plant or animal life and which, therefore, must oe handled or disposed of
with special precautions."3
B. Reversibility
All hazardous wastes have been created by man from natural
materials. Life evolved and has prospered in equilibrium with all of the
natural materials. We have heard the alarm that life will perish because
of our accumulated hazardous wastes. Net so, man can return all of these
to their natural non-hazardous state or its equivalent. It is not necessarily
difficult or excessively costly to convert hazardous wastes to a non-hazardous
form (with the exception cf radio-active wastes).
In many cases the hazardous portion of a waste can be separated
and/or concentrated with recovery or normal disposal procedures applied to
the non-hazardous portion. The hazardous end product must then be processed
to render it acceptable to the environment.
C. Individuality of Characteristics
Referring back to the introduction of this paper. I said that
it is necessary to have adequate information to do an effective job. This
is especially true of hazardous waste management; it is essential to know
or find out what is in the waste before any attempt is made to process it.
From the chemical viewpoint, it is infinitely simpler and less costly to
have the originator provide details on the composition cf the waste than
to attempt to analyze it.
Each hazardous waste material has individual chemical char-
acteristics and it usually can be handled by standard chemical processes
without complications. In contrast, if wastes are blindly mixed together,
the complexity of the resultant mess can require extremes in treatment and
astronomical costs. The potential cost is not of the order of twenty-five
percent but more likely two times to five times and even as high as ten
times or a hundred times the cost of treating the unmixed wastes. Thus,
it is essential to segregate waste streams and T.o maintain separation until
processing has been completed.
Dilution is not the solution to pollution, although it has
long been a favorite method for reducing the concentration of hazardous
wastes. It is almost always more costly to process large volumes of dilute
3S
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hazardous wastes. Dr. Nesselson^ listed four basic groups of treatment
operations with more than fifteen individual processes for hazardous wastes.
Mr. Wagner2 documented the operational necessity for multiple path processing
and the cost impact of it. It is unlikely that a single process could be
developed that would be capable of economical treatment of a broad range of
hazardous wastes. From the chemical viewpoint, it will be necessary to
process hazardous wastes according to their individual characteristics to
assure completely detoxified residual products that can be returned to the
environment safely.
Certainly as progress is made in processing technology for
hazardous wastes, there will be lower cost and improved methods for hazardous
wastes management.
G. Summary
The chemical viewpoint of hazardous wastes management can be
summarized as follows:
1. Segregate the hazardous wastes from all other wastes.
2. Keep the various kinds of hazardous wastes separated from
each other.
3. Process these hazardous materials to produce environmentally
acceptable end products when there is no opportunity for
recycling.
In short, BENEFICIAL CHANGE by processing can convert hazardous
wastes to environmentally acdeptable materials. The near term cost is higher,
but the long term cost is much lower in dollars and environmental damage
than the alternates.
THE SANITARY-CIVIL ENGINEERING VIEWPOINT - CONTROL
Substantial advances in waste management technology have been
developed and are being employed in some of the more recently established
solid waste disposal operations. Research in advanced wastewater treatment
has made similar studies toward improved technology. The basic engineering
principles employed in waste management operations have been established
for many years and when properly applied have met environmental requirements.
There is a difference between these engineering viewpoints and the chemical (
viewpoints.
A. Singularity of Method
The technology which has been developed for waste handling
has as a common characteristic the combination of wastes into one stream
which is then processed in a large capacity facility. Solid wastes are
gathered from all sources and transferred to a landfill where efficiencies
of scale provide economically attractive disposal operations. Similarly,
41
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liquid wastes are gathered and conducted to a central wastewater treat-
ment facility which handles the combined wastes of the entire community or
even an entire region. Inherent in the central processing concept are
efficiency of large scale operation, lower cost and high volume capability.
On the other side there cannot be flexibility of operations to suit
individual waste characteristics. All wastes must proceed through the
established process.
B. Technology Status
The operational and the design principles employed in waste
management have been developed and refined over many years to the point
that additional improvements are mainly in the areas of increased cost
effectiveness through better machinery and equipment, modern management
techniques, long term planning, optimum site locations and the like.
This is in strong contrast to the hazardous waste management area which
is in its infancy and is still struggling to carve out its niche as a
service industry.
C. Methodology
Conventional concepts in solid waste management have included
the following:
1. A large, relatively constant volume of wastes
2. A constant composition of waste
3. Containment of the waste in a specific location
4. Control of waste to prevent adverse environmental effects
The waste management methods which have been developed to
meet the requirements of these concepts are, in general, environmentally
adequate for non-hazardous wastes when well engineered and implemented.
These methods were not intended to handle hazardous wastes and indeed
they will not do so.
THE NEEDS OF HAZARDOUS WASTES MANAGEMENT
From the foregoing it should be evident that while we may view
the "elephant" differently, both the chemical and engineering disciplines
recognize it as a formidable entity "jhat must be handled with the best
means at our disposal.
A. Capabilities Required
There can be no question that the capabilities of the
sanitary, civil and possibly other engineering professions as well as
those of the chemical biological and other sciences are needed for the
42
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development of effective, economical methods for managing hazaardous
wastes.
B. Apparent Standoff in Viewpoints
Despite the differences that are apparent in the methodology
now employed in waste management and that which is needed for adequate
management of hazardous wastes, the problem can be resolved by joint action
to separate the hazardous materials at the source with consequent benefits
for the environment and the segments of the waste management industry
concerned.
C. Communication - Vocabulary
Effective coordination of the efforts of all disciplines
applied to waste management will necessitate definition and standardization
of terminology. The technical vocabulary of one group can easily be mis-
understood by the other. Progress in this area is becoming evident in the
definitions which have been appearing in industry publications, technical
journals and government agency publications. It should not be an insur-
mountable task to unify the various vocabularies into a series of working
definitions. This can be illustrated by the following examples of potential
differences in the meaning of terminology:
1. "Waste processing", does it mean producing a chemical
change in the waste material, or does it imply trans-
portation or compaction or a physical change, or all
of these?
2. "Waste treatment", is the meaning of this term the same
as "processing", is it limited to wastewater, to fluids,
or does it imply the application of a chemical or physical
process to the waste?
3. "Waste disposal", does this term simply mean to discard,
does it mean storage, is there any implication of causing
a beneficial change in the waste?
4. "Containment", does this mean that the wastes have been
placed in one location, or that they cannot migrate from
the location, that they are confined in some sort of
container?
D. Overlap in Waste Management Areas
A realistic view of the management of both non-hazardous and
hazardous wastes shows that while there may appear to be overlapping of
operations, it is not necessarily a conflict situation. Once it is recognized
that there are two paths to be followed in managing the two classes of wastes,
the operational aspects are clarified. Both disciplines involved in the
43
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management of wastes have the same objective of establishing and promoting
the growth of a viable and effective waste management industry. Here again,
terminology differences may be at the root of the problem. The apparent
conflicts are likely to be resolved by generation of clear, unequivocal
definitions of the terminology employed in the waste management areas.
It is important to note that in the proper management of hazardous wastes
many of the best practices currently in use in the waste management
industry are required. Land disposal of the detoxified residues of some
hazardous waste treatment processes is one example of this.
E. The Prospects and Necessity for Synthesis
It is still astounding to me to realize that I watched men
walking on the moon, in full color, from the comfort of my home. The
combined efforts of every variety of discipline in engineering, science,
management and even politics, to attain a common goal that seemed
impossible just a few years ago demonstrates that the synthesis of
disciplines in the waste management area is entirely possible.
In the waste management area the diversity between the
requirements for environmentally acceptable processing of hazardous
and non-hazardous wastes make a common effort essential. While parallel
and independent work by both segments of the industry could produce some
beneficial results, the greatly multiplied power of a combined industry
striving for a single goal offers overwhelming advantages to all concerned,
the industry, the public and the environmentalists.
SIBMARY
The purpose of this paper is to present several aspects of the
different viewpoints regarding hazardous waste management and to elaborate
on their impact on the methods employed to process and dispose of wastes.
The chemical viewpoint is that the relatively small volume cf hazardous
wastes must be kept segregated from the bulk of non-hazardous wastes.
Further, the hazardous wastes must be subjected to processing appropriate
for their chemical composition to render them acceptable to the environment.
The residues from processed hazardous wastes may require special handling
to prevent regeneration of toxic characteristics. The cost of proper
management of hazardous wastes will be higher than that of non-hazardous
wastes, but the potential cost of inadequate disposal of these wastes is
infinitely higher, not only in dollars but in environmental damage.
I do not view the differences in waste management viewpoints
as a barrier to effective coordination within the waste managemeit industry
in developing environmentally sound and economically viable means for
handling hazardous wastes. I hope that the viewpoints presented will
increase the understanding of the hazardous wastes problem and help to
generate productive interactions with and between the many professional
individuals and organizations who are coming together to create the new
hazardous wastes management industry.
44
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REFERENCES
1. Nesselson, E., "Treatment Techniques For Chemical and Hazardous
Wastes", Third National Congress, Waste Management Technology
and Resource Recovery, National Solid Waste Management
Association, p. 23, Nov. 1974.
2. Wagner, L. E., "Application of Chemical and Hazardous Wastes
Management Technology", ibid., P. 137.
3. "Hazardous Wastes and Their Management", Office of Public Affairs
(A-107), U. S. Environmental Protective Agency, Washington, D. C.
20460, May 1975.
4. Steward, F. A., "EPA Discharge Regulations, Explanatory Remarks and
Comments", Metal Finishing, p. 47, Sept. 1974.
45
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A CASE HISTORY: IMPLEMENTING A CHEMICAL WASTE LANDFILL
Edward Slover
Senior Process Engineer, Environmental Systems, Union Carbide Company
Introduction
Union Carbide's Institute, West Virginia, plant employs about
2000 people in the manufacture of some 300 chemicals. Wastes from
these operations vary from waste paper to chemical sludges, and the
problems connected with their disposal represent a real challenge.
Chemical landfill has been on the list of disposal alternatives
at Institute since 1965 when the Plant received the first chemical
landfill permit issued in the State of West Virginia. Because of
water pollution control considerations in the construction and oper-
ation of a chemical landfill, West Virginia elected to issue its
first permit of this kind through the Department of Natural Resources
Division of Water Resources with consultation from the State Health
Department and the State Air Pollution Control Commission (1).
Institute's chemical landfill passed through two design and oper-
ation periods before being finalized in 1969 into the phased-construc-
tion, dynamic, "wet-process" system that it is today.
The following discussion is a brief summary of the development
of the present chemical landfill at the Institute Plant with emphasis
on historical influences, waste classification and control, regula-
ting agency relationships, and the evolution of current design and
operating practices. Adequate references to other books and mono-
graphs covering this installation are provided for those who desire
detail beyond the scope of this general overview.
46
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OHEMICAI. LMTEFILL IMPLEMENTATIOK - Continued
Decisions Leading to Chemical Landfill Project
Prom the beginning of the Institute Plant during World War II,
miscellaneous wastes that could not be used as fuel for the Plant
steam boilers were handled in a variety of ways that included open-
pit burning, crude landfill, ponding, and occasional sales where
valuable constituents could be recovered by interested buyers.
Open burning was recognized as both a public nuisance and a
personnel hazard. Black clouds of smoke over the burning Pits
drew unfavorable attention, and unexpected reactions between wastes
destroyed this way created an ever-present risk to employees invol-
ved in disposal work.
As the Plant added more chemical processes and expanded exist-
ing facilities more wastes were generated that could not be used as
boiler fuel or fed to the biological wastewater treatment unit. A
few examples of this are: partially polymerized plastic monomers,
spent filter media, chemically-contaminated ground cover (slag, lime-
stone), viscous materials, and solids generally.
General practices during the early disposal history of the
Institute Plant tended to involve large tracts of prime land that
were lost to more profitable enterprise because of adjacent dispo-
sal activities or because of permanent alteration of the land itself.
Hewer production processes brought with them more complicated
wastes that required more care in the final handling and destruction
steps. Reactivity with water, autolgnition on extended contact with air,
the production of undesirable leachates, odor emission, and reaction
with other wastes were a few of the problems.
47
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CHEMICAL LANDFILL IMPLEMENTATION - Continued
Decisions Leading to Chemical Landfill Project - Continued
By 1962 the search for alternatives was well underway, but
progress was severely limited by the lack of available disposal
technology. Existing municipal incinerators were considered at
the time, but the systems in the surrounding communities lacked
adequate water and air pollution control equipment and their oper-
ating temperatures varied widely, A uniform temperature of some
1800°F. was considered necessary to completely oxidize the organics
in these wastes. Waste feed was another area of concern because
municipal units were designed to receive fuels with uniform physical
characteristics. They were hardly able to accommodate mixtures with
glue-like and/or rock like consistency in the same batch, and many
wastes had these properties.
Often the drum, pan or fiber pak used to transport the waste
had to be destroyed because the contents could not be removed. Some
industries tried to overcome this problem by dumping
the containers into sanitary landfills. Institute found this to be
unsatisfactory because of fire and leachate discharge problems. San-
itary fills using the "pit-and-cover" approach were particularly fire-
prone. Each "cell" became a sealed concentrator with a rich organic
core that heated rapidly as anaerobic oxidation progressed. The re-
quired earth seal on the top kept the generated gases in place so
that all the essentials for underground fires were assembled in a
single, tight package with spontaneous combustion as the end result.
During the Plant's search for a disposal technique likely to
conquer many of the problems listed here, several companies announced
48
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CHEMICAL LANDFILL IMPiaMBNTATIOH - Continued
Decisions Leading to Chemical Landfill Project - Continued
success in the miscellaneous disposal field with, rotary kilns rigged
to take whole containers of waste materials and completely oxidize
the contents leaving only the compacted metal remnant from the con-
tainer. Air pollution was controlled through a system of scrubbers
whose liquors were given biological treatment. Overall the kiln appeared
to offer a good solution.
Land disposal where close attention was paid to waste segregation,
leachate control, and proper drainage continued to offer attractive
possibilities, so a study was made covering kiln disposal and Im-
poundment landfill.
Impoundment landfill was selected for two reasons: superior
ability to receive wastes in a variety of physical states, and lower
capital cost (a third advantage - energy conservation - in the form
of lower fuel consumption has become apparent as the current energy
crisis mounts).
Evolution of Design and Operating Practices
Experience with crude landfills and ponds that were used prior to
decision to construct a chemical landfill pointed out some essential
requirements that would have to be met by a disposal facility designed
to handle miscellaneous wastes in a safe and environmentally acceptable
manner. These needs were:
(1) Large Available Volume - Any landfill used for chemical
waste from the Institute Plant should justify the initial
investment in land and special facilities through a long
operating life;
49
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CHEMICAI LANDFILL IMPLEMENTATION - Continued
Evolution of Design and Operating Practices - Continued
(2) Proximity to Plant - Manning, transportation, supervision,
security, and operation can all be done more safely and
efficiently if the landfill is located close to the par-
ent plant (as it turned out later, this was the valuable
feature that permitted a direct tie-in to the Plant's
wastewater treatment unit and gave fun control over
all drainage (2), (3));
(3) Protection Against Uncontrolled Leaching and Excessive Rain
Contamination of surface and subsurface waters was a major
concern of the Institute Plant because of its pioneer posi-
tion in the field of wastewater treatment. A particular
problem in West Virginia is the heavy annual rainfall that
can easily saturate and flood landfill installations;
(4) Protection of Personnel - Protection of disposal workmen
against hazards to health, exposure to flammable chemicals,
and involvement in reactive incident was a primary reason
for seeking alternate disposal methods to the crude fills
and ponds used earlier;
(5) Avoidance of Fires and Odors - Personnel safety and pro-
tection against property loss through fire damage had been
major problems in the early days of miscellaneous waste
diaposal and the need to protect against atmospheric pol-
lution was being recognized as this chemical landfill con-
cept was being developed.
50
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CHEMIOAIi LANDFILL IMPUSMEHTATION - Continued
Evolution of Design and Operating Practices - Continued
At the outset of chemical landfill design there was little
data available in the literature. Most information was concerned
with sanitary landfills designed to accommodate municipal solid
wastes.
Early design, then, had to rely largely on previous experience
with these miscellaneous wastes and take what it could from principles
of sanitary landfill practice that seemed to apply.
Site location on Plant property just across a perimeter highway
was based on the observations of a disposal foreman who noticed that
non-volatile chemicals ponded there had not penetrated the clay floor
of the deep "hollow" making up most ? this land parcel. Test cuts
with a bulldozer confirmed the presence of a thick clay layer at all
points where landfill might be carried out, so a seal against leachate
penetration of groundwater under the site could be constructed by com-
pacting material already in place.
Figure 1 shows the plan view and Figure 2 the elevation of the
"impoundment" concept that evolved in this first stage of chemical
landfill development. Imported, loamy earth was to be placed between dikes
674, 673-A, and 675-B after the original "hollow" floor and the dikes
had been compacted as much as possible with sheep*s-foot rollers and
bulldozer treads. Beginning at dike 674 waste was to be placed in a
trench parallel to this dike, blended with loam and loosely covered.
The process was to be repeated in successive trenches, each north of
the one preceding. Effort was to be made to keep each class of waste
in a. single row lying along a north-south axis.
51
-------
52
-------
BY?..?..S.lpve_r
CHKO. 0V DATE
'JECT.U.CC_Go_ff__Hgngw.Land_fin SHEET HQ....&?.. OF.
Basic "CELL" Design - Elevation View JOB NO
^^<
^
^
0)
o
C\J
0)
^
I
J
f
53
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CHEMICAL LANDFILL IMP1EMEHTATION - Continued
Evolution of Design and Operating Practices - Continued
Sanitary landfill literature studied during this early design
phase had warned of gas generation problems from biological oxida-
tion so a technique of blending the waste intimately with earth using
a clam-shell crane was employed. Heavy compacting of the final earth
cover would be avoided to allow the gas to escape uniformly over the
entire working face of the fill.
Normal drain water flow down the "hollow" was carried through
the waste impoundment by a 28" and a 36" reinforced concrete pipe
sealed with concrete at the joints and resting on the clay floor.
Rain and water delivered to the impoundment basin in wastes remained
there until evaporation removed it. A program of grassing and sloping
was to be followed to minimize penetration of the impoundment surface.
Surface water drains were provided to carry off peripheral and impound-
ment surface waters.
Water pollution was deemed the greatest control problem in this
design. Therefore, application was made to the West Virginia Depart-
ment of Natural Resources - Division of Water Resources for a license
to operate the chemical landfill. This was the first time a request
to license such a landfill had been received by the State so a stan-
dard wastewater treatment permit form was modified to fit the situation.
The new permit was further cricumscribed by an agency statement of pol-
icy covering drainage ownership by the applicant. Agreements were
reached between the Division of Water Resources, the State Health
Department, and the State Air Pollution Control Commission that Water
Resources would be the prime licensing agency for industrial waste
fills while sanitary landfills would remain the province of the Health
Department. Information on chemical landfill progress and difficulties
54
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CHEMICAL LANDFILL IMPLEMENTATION - Continued
Evolution of Design and Operating Practices - Continued
was to be shared among all three agencies. This agreement has con-
tinued in its original form aince the license was issued in 1965.
Shortly after test operation began in early 1965, Institute
found that the impoundment approach was seriously hampered by water
accumulation in the blended fill. Efforts to replace the crane with
bulldozer to speed earth/waste mixing resulted in the latter's being
swamped in a "mud lake", making it difficult to keep up with the
daily work load.
Some sort of relief was necessary so the Plant turned to a soil
consulting firm for guidance. Continued problems with impounded
water coupled with leakage in the 28-inch and 36-inch pipes carry-
ing drainage through the fill prompted Carbide and the soil consul-
tant to shift their basic plan for this type operation from impound-
ment to a "wet" system that allowed water entering the earth/waste
blending area to pass out through "leaky" retainer dikes into a leach-
ate collector pond bounded by an impervious dike. Collected leachate
was to be trucked to the Plant's wastewater treatment unit for stabil-
ization. Figure 3 shows a schematic elevation diagram of this process
(4).
The "wet" system in its first phase (one leaky dike) was com-
pleted in 1969 and placed in operation. It has been successful in
providing a dry work face that permits the use of end loaders and
bulldozers to replace the original crane, and the "dynamic" water
removal system prevents the formation of "mud lakes" that were en-
countered in the "static" water-holding system of the impoundment
fill used in the beginning.
55
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CONTAMINATED
WATER BASIN
lirJL
i HL
ji
0 . ^^ il
1-1 H
H <£
t i
C3
3
CO
CO
WEH
OPx
56
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CHEMICAL LANDFILl IMPLEMENTATION - Continued
Evolution of Design and Operating Practices - Continued
Earth blending with the waste has continued with an average
of one volume of earth being added to each volume of waste. While
the blending machinery has been changed to a faster and more flexible
end-loader based system, Carbide has found it desirable to fabricate
a special drum crusher to open and reduce those drums that must be
worked into the fill. Performance of the crusher is still not cer-
tain because construction of the machine has not been completed.
A second leaky dike was scheduled for completion in 1972, but
the project was changed to a series of fill lifts to reduce capital
expenditures at a low in the Company's business cycle.
A thorough study of the underlying geology in the fill area
was made by the soil consultant befor the first leaky dike was con-
structed. A second study is now underway by a second firm as the
engineering for the third (and largest) dike gets underway. This
is expected to be the last of these dikes to be built during the
life of the fill (estimated at 20-years from 1969).
Gas production, a problem in many sanitary landfills, has not been a
concern at this chemical landfill. There is no doubt that gas is present
because bore holes drilled 30-feet into the work face have tapped gas pockets
that explode during test ignition. The gas does not migrate laterally through
the bottom and side seal because it is released evenly to the atmosphere through
the loose, uncompacted cover earth on the work face. Much like the spongy soil
on the top of certain marshes, the loose earth cover serves to aerobically de-
odorize the gaseous products of anaerobic decomposition deep in the fill.
Odor has been a problem, however, with the oil layer that emerges on the
leachate collection basin. It is necessary to skim the layer regularly and burn
it in the steam generating boilers within the Plant. When this is not done, a
57
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CHEMICAL LANDFILL IMPLEMENTATION - Continued
Evolution of Design and Operating Piactices - Continued
strong odor reminiscent of oil well casinghead gas rises from the leachate basin
and permeates the fill area. Rough analysis of this oil layer shows that it con-
tains linear paraffins known to enter the fill with one of the process wastes.
Many of the wastes handled in this landfill are of a "hazardous" nature
because of their health hazard, flammability potential, chemical reactivity,
or environmental impact. Special procedures are written when a disposal order
for one of these materials is received by the landfill supervisor. No work on
the order is done until approval of the procedures has been obtained from the
Plant Safety/Hygiene Department, the Maintenance Department which will do the
work, the Waste Generating Unit, and the Plant Environmental Protection Depart-
(which operates the landfill). Work may involve processing at the waste source,
sale of the waste to an outside buyer, incineration of the waste at the steam plant,
bio-oxidation of the waste in the wastewater treatment unit, anaerobic decompositior
of the waste in the chemical landfill, or some combination of these and other chem-
ical methods. A more complete discussion of the Order for Waste Removal that in-
itiates action on a particular waste is given in the next section of this paper.
Costs for the operation were based initially on an annual waste load of
12,000 cubic yards per year. Capital and comparative costs for other disposal
methods are shown in the tables given in Figure k. Current aerial surveys and
volume determinations indicate that the real annual load is 6,000 cubic yards,
making costs shown somewhat higher (costs do not double because the charges are
for loads taken from Orders for Waste Removal that specify the containers and
sizes that must be handled - the cost for a partially full drum is essentially
that for a full, one as far as most handling is concerned.).
58
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UHIOH CARBIDE CHEMICAL LANDFILL -INSTITUTE, WEST VIRGINIA
Total Estimated 20-Year Cost *
Study and Design $ 77,^97
Capital Costs Through Phase I 198,000
Land Cost 100,000
Estimated Phase II and Phase III Costs 52,000
Operating Costs for 20-Years 3,300,000
Total cost for stabilizing 2^0,000 cubic yards $ 3,727,^95
of refractory chemical wastes
* = 1971 Estimate
Note: An incinerator system to take a comparable
waste load showed a capital cost of ... $ 3,000,000
COMPARATIVE DISPOSAL COSTS **
1971 Dollars
Disposal Method Cost/Cubic Yard (a)
Chemical Landfill $ 9.27
Incineration (Municipal) 1.64
Sanitary Landfill (Municipal)
** = Assumes hazardous wastes could be placed in municipal incinerators and
municipal sanitary landfills - a condition contrary to fact!
(a) = Based on p density of 501* pounds per cubic yard.
Figure 4. 11-1-75
59
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CHEMICAL LANDFILL IMPLEMENTATION - Continued
Waste Classification and Control
Waste control at the source is the key to chemical landfill operating suc-
cess. Institute's facility bases its entire chemical landfill control on a special-
ly-designed Chder for Waste Removal.
This instrument was used by miscellaneous disposal personnel several years
before the landfill was conceived, so it was ready to serve the new facility the
day it went into service. The form had undergone considerable change before the
fill became operable, and as experience was gained changes were made to reflect
landfill needs.
The form shown in Figure 5 is requirec from every miscellaneous v.aste
generator before his waste will be considered for disposal. The generator
fills out the document to the best of his ability and sends it to the miscel-
laneous disposal supervisor who reviews it, requests procedures - if necessary -
requests pre-processing and advises the generator on the steps he must take.
Once agreement is reached, the supervisor stamps the portion of the form that is
to travel with the waste (as its identification to all who come in contact) with
a special stamp and returns it to the generator who may now a*^ for transportation.
The form travels with the waste to the disposal point where it serves as a pass to
enter the landfill. Disposal is performed £,s directed by the order and the order
is entered in the disposal supervisor's file where it serves as a record for fill
loed estimation, monthly billing of waste generators (volume basis), a disposal
procedure record, and a hazard warning when that waste is encountered again.
A special hazard rating system must be entered on the form for eech known
chemical component in the areas of Health (H), Flammability (F), and Stability or
Reactivity (S). A number from one to four is entered under each heading to indicate
the relative hazard. Generally, a four is naximum hazard and a one is minimum.
( Reference (5) provides more detail on this system.) Handlers of the waste are,
then, required to protect themselves according to the indicated hazard code.
60
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OBDER FOB WASTE REMOVAL
INSTRUCTIONS
USE BALL POINT PEN. Read all instructions before completing form Each container must ha\e contents
identified, with paint stick, on side of container along with -hazard rating Containers must be placed near
roadway loi truck pickup This is a 3 part form. Remove 3 sheets or put in backing board This form is to be
filled out in its entirety by person requesting disposal, and returned to Waste Disposal Co-ordmator for approval,
Sheet No 1 & 3 It is the responsibility of the person filling out this order, to list all personal precautions for
handling this material required to be taken by any personnel working in the unit. Failure to insert this informa-
tion, resulting in injury or illness to personnel handling this material, will compel an investigation by the Industrial
Hygiene Department. Fill in all components contained in mixtures. Mail completed form to Waste Disposal
Co-ordmator.
MATERIAL Fill i« name of material completely Do not write chemical terms The men «ho handle this
matenal are not chemicaHy orientated If you have a mixture or compound, write in all components that make
this mixture, unless it is aXrade named item
ORDERED BY Name of person filling out form and who is requesting the removal This, should be one and
the same person. No filling out forms for someone else
LOCATION Where material is to be picked up
DATE Date form is filled out
FORM: 612-1747-H OR DE R FOR WASTE R EMOVAL
Shop Ordftr No
GOFF LANDFILL
I ) Store to crush
{ ) Loose fill
I ) Leachale Pond
I ) Clean for scrap
I ncfff*^ f»' Ova"t'ty
WASTE TREATMENT
' ) Sump
I I Sludge Pond
( > Dowlherm Tank
1 1OM Stg Tank
( I STEAM PLANT Power House
Dump Tank No -
Tank Trailer No
Jn
UNIT HAZARD OPERATING INSTRUCTIONS
ARF AS ecu i nws
DESCRIPTION
1 iLiq Thin
I )Liq Thick
1 I Solid
1 ) Polymer Present
IDENTIfY CONTAINERS
MARK HAZARD RATING
SET BY ROADWAY
Yds
. ». Gal
NO OF CONTAINERS
I Drum 55 Gal
I Drum 30 Gal
I Can 5 Gal
1 Fiber Pak 60
1 Fiber Pak 30
J Dump Pan
COMPONENTS Name
%
FOR OFFICE USE ONLY
Disposal No
Total Yds Ch
jrged _
( ) Dump Hopper
1 ) Dump Truck
No __ nf
M.D.C. FILE
H
F
S
HAZARD RATING
PRECAUTIONS Chemical gloves-coverall goggles-coveralls required Do not allow skin Disposal Crew By
contdct with materialDo not breach in any vapors Follow unit hazard instructions listed must sign DdH*
FORM: 612 1747-H ORDER FOR WASTE REMOVAL
J IDENTIFY
MARK Ht
SET BY R
CONTAINERS
IAZARD RATING
FOR OFFICE USE ONLY
drciftrtxi By
Shnpr,rrt.,Mn ,~.=,-.,, n,,,n,,,y v.,.
GOFF LANDFILL
' t Store to crush
I > Loose fill
1 1 Leachale Pond
I ) Clean for scrap
i I STEAM PLANT
Dump Tank No -
Tank Trailer N"
WASTE TREATMENT
( ? Sump
1 1 Sludge Pond
( ) Dowtherm Tank
1 1 Oil Stg Tank
Power House
Mo
UNIT HAZARD OPERATING INSTRUCTIONS
ARE AS F01 1 nWS
PRECAUTIONS Chemica
contact with mater-dl Do
DESCRIPTION
1 ) tiq Thin
( t Liq Thick
[ I Solid
1 ) Polymer Present
. *. Gal
NO OF CONTAINERS
) Drum 55 Gal
1 Drum 30 Gal
1 Can 5 Gal
) Fiber Pak 50
1 Fiber Pak 30
) Dump Pan
COMPONENTS Name
gloves-coverall goggles-coveralls required Do not allow skin
not breath in any vapors Follow unit hazard instructions listed
%_
Total Yds Charged
( ) Dump Hopper
t ) Dump Truck
No _. .of -
WITH MATERIAL
H
F
S 1
HAZARD RATING
"<<*>
Disposal Crew By -
must sign Dale - -
10-j -.-7-
61
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CHEMICAL LAHDFILL IMFLEMEHTATIOH - Continued
Waste Classification and Control - Continued
A special point here should be made of the review procedure used by the
miscellaneous disposal supervisor to select the final disposal process that will
be used. Disposal techniques at the Institute Plant are given a rating according
to desirability from an economic and environmental standpoint. Each Order for
Waste Removal is checked against this list and the highest priority method
selected and assigned. Figure 6 shows this list.
Future Goals and Objectives
Leachates and gases from sanitary landfills in several parts of the U. S.
are being used commercially. While the Institute Chemical Landfill has beam
going through a three-stage construction program there has been little oppor-
tunity to tap these same resources./rs the final construction phase is completed,
however, attention will be turned to evaluating chemical fill production potential.
Facultative bacteria are currently under stbdy as leachate treatment agents for
the fill. As this work progresses, commerical opportunities will be searched cu;-.
Conclusions From Experience
Chemical landfill is a viable method for handling hazardous and refractory
chemical wastes at the Institute Plant. Underdesign of the leachate collection
system has been a problem d'*±t^ extremely wet years, and this will be corrected
during the third phase .1- -:< ior. : h a larger collection system.
Odor has been anothe. tc' -ous problem that will be dealt with during the
final construction. A ski' . will be installed and recycle of the leachate
back over facultative-bacteria charged portions of the fill work face will be
used to remove odorous components.
A high quality landfill operator familiar with chemicals and chemical process
operations is essential to the successful control of the facility. This man has bee
hard to obtain in the past, so several new approaches to manning are under consider-
ation.
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MISCELLANEOUS WASTE DISPOSAL ALTERNATIVES
(Listed In Descending Order of Preference)
Institute Plant - Union Carbide Corporation
METHOD
1. Reprocess the Haste
2. Sell the Waste-
3. Burn the Wast*
4. Bio-oxidation
S. Chemical Landfill
ADVANTAGES
Best financial return
No environmental impact
Sane as Ite» 1 above
Heat recovered as
steam
Protects the river
Lou environmental
impact; Handles con-
centrated, bulky
wastes
DISADVANTAGES
Investment cost;
Technical difficulty
SaM as Item 1 above;
Toxicity, chipping t
market problems
Air, water, * land
pollution) transport-
ationk
Cost i
tained organic chem.
Investment: $45 ,/lb.
contained, continuously-
fed organic chemical.
Strict Control to avoid
environ, pollut i on &
Cost: 6. It «/lb.
Strict Control to avoid
environ! pollutions
Requires land
a - UCC eqpt. often too large
b - Requires tanks, trucks, 6 miles of pipelines
c - Air, water, land
Note: Costs shown on l&fk ba»is.
NSWMA
11-1-75
63
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CHEMICAL LAHDFILL IMELEMEHTATIOH - Continued
Conclusions From Experience - Continued
When the license for the landfill was issued in 19^5> Carbide agreed to
follow the guidelines shown in Figure 7. Looking back on these checlcpoints
from 10 years of operation, Carbide finds them to be just as applicable today
as they were then.
- End -
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UNION CARBIDE INSTITUTE PLANT
GOFF MOUNTAIN LANDFILL CONTROL
To maintain our License No. 3141 with the West Virginia State Department
of Natural Resources. Water Resources Division we have agreed to the following:
1. NO BURIAL OF "SANITARY" WASTE - Garbage from food and direct human
activity must be handled in special landfills licensed by the State
Health Department. Ordinary "garbage" attracts rats and flies. We
have agreed that there will be none of these vectors at Goff Chemical
Landfill.
2. NO POLLUTION OF SURFACE OR UNDERGROUND WATER - Special drains, collec-
tion basins, clay seals, and chemical inerting procedures are followed.
to guarantee that no chemical leaches into any water supply.
3. NO POLLUTION OF THE ATMOSPHERE OVER THE FILL - Fire control and odor
elimination are required by the State Air Pollution Control Commission.
No breathing hazards or attraction of pests is permitted.
U. NO WASTE OF THE LAND - A definite development program for the landfill
is being followed to guarantee that the filled area will be usable
when project life is complete in 20 years.
5. NO EMISSION OF TOXIC MATERIALS - No toxic substances may escape from
the fill area by any route. Chemical reaction and encapsulation
are used to guarantee that this does not happen.
6. MULTIPLE LAND REUSE IS REQUIRED - Every effort is made to degrade the
chemical waste scientifically so that its volume is reduced. Chemical
and biological techniques are used. This enables burial of more than
one waste in the same place.
MAIN OBJECTIVE: PRODUCTION OF AN INERT. USABLE SOIL OUT OF SOLID CHEMICAL WASTE!
Figure 7.
NSWMA 10-13-75
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REFERENCES
1. "Water Pollution Control Permit Ho. 3l')l"; State of West Virginia - Department
of Water Resources, July 26, 1965.
S. ibid. Policy Statement
3. C. L. Mantell, et al, "Solid Wastes: Origin, Collection, Processing, and Dispos
Wiley Interscience Publication, John Wiley and Sons, New York, p-999-
h. ibid.
5. J. J. Duggan, "See Hazards at a Glance", Chemical Engineering, pp. 162-166,
February 23, 1959.
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CALIFORNIA'S HAZARDOUS WASTE MANAGEMENT PROGRAM
Dr Harvey Collins
Supervising Engineer, Vector Control Section, California Department of Health
I. BACKGROUND
California's hazardous waste management program has nearly
completed its developmental phase and recently entered its opera-
tional phase. Evidence indicates the operational phase will not
be premature.
Last spring 31 people were hospitalized for treatment of
poisoning after a truck carrying 24,000 pounds of a carbamate
insecticide in methanol overturned and caught fire at a southern
California freeway interchange. Police and firemen at the scene
did not discover the nature of the truck's cargo until after many
of them had inhaled toxic fumes or had accidently been sprayed with
water directed onto the pesticide.
Recently the driver of a 30-barrel tank truck accidentally
sprayed a private residence in the San Francisco Bay area with a
mixture of acids, heavy-metal salts and organic solvents while
enroute to a disposal site. The incompatible wastes had been
combined in the tank truck at a transfer station-, and on-the way
to the disposal site pressure in the tank began to increase. When
the driver discovered that the pressure had risen dangerously high,
he decided to make a run for the disposal site. As he drove through
a residential area near the disposal site, the truck's pressure valve
released.
In September 1975, at a small, private hazardous waste disposal
site in southern California, the driver of a tank truck was emptying
a 4000-gallon load of hydrochloric acid into an open disposal well.
As the acid entered the well, dense brown fumes of toxic nitrogen
dioxide began emanating from the well opening. Reportedly, nitric
acid had been placed in the well previously, and the two acids were
reacting to produce-the toxic gas. When the driver finished un-
loading, emission of gas decreased, but several hours later nitrogen
dioxide began billowing from the well, and a brown cloud of the gas
spread into manufacturing plants across the street from the site.
An inspector from the local air pollution control district was
called to the scene. Because the disposal site is unsupervised, the
site operator had to be telephoned. He responded by sending a laborer,
who could not speak English, to shovel dirt over the well opening. The
person, who was not equipped with safety gear, worked directly in the
path of the toxic gas.
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Without a vigorous statewide program of hazardous waste man-
agement, incidents like these could become increasingly common.
The California Legislature concluded in 1972 that the mismanagement
of hazardous wastes could result in a serious threat to public
health and the environment. Consequently, the Hazardous Waste
Management Act was passed by the Legislature during the 1972
Legislative Session and was signed into law in December 1972.
That Act, which became effective July 1, 1973, now Section 25100
et seq., Health and Safety Code, required the State Department of
Health to adopt and enforce minimum standards for managing said
wastes to protect against hazards to the public health, domestic
livestock and wildlife.
II. SHIFTING FROM A DEVELOPMENTAL TO AN OPERATIONAL PROGRAM
In accordance with the Hazardous Waste Act, the Department-has
developed and adopted regulations governing hazardous wastes. '
Emphasis is now being placed on the operational phase of the program,
five aspects of which will be discussed below:
1. policy regarding land disposal;
2. monitoring hazardous waste producers, haulers,
processors, and disposal site operators;
3. enforcing the minimum standards for the collection,
processing, and disposal of hazardous wastes;
4. surveying production of hazardous wastes statewide;
5. participating in the state's plan for managing
spills of hazardous materials.
1. Department Policy Regarding Land Disposal
Several disposal techniques are used to handle hazardous wastes
at approved facilities (Class I or Class II-l Disposal Sites) in
California. Such wastes are: (1) ponded to utilize solar evaporation
for concentrating the wastes; (2) mixed with soil; (3) mixed with
refuse on the open face of a landfill or injected through shallow
wells into buried refuse; (4) buried in soil;'or (5) injected into
deep wells.
No doubt, the need to continue to use these land, disposal tech-
niques will remain for the forseeable future. However, the Department's
policy in regard to the disposal of highly hazardous, but reusable,
materials is to work with the waste producers to find markets for such
materials. This prevents the depletion of natural resources, but, more
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importantly, eliminates the hazards to the public and the envir-
onment that exist when such materials are disposed of onto the
land. Pursuant to this policy and the Hazardous Waste Management
Act, the Department shall decline to issue permits for land disposal
of extremely hazardous materials for which alternatives to disposal
do exist.
2. Monitoring Hazardous Wastes
The Department's monitoring program centers on the hauler's
manifest (trip ticket). The waste producer must submit a copy of
the manifest directly to the Department on a monthly basis. The
waste processor or disposal site operator accepting the waste must
also send a copy of each completed manifest to the Department monthly.
The waste producer, hauler, and processor or disposal site operator
must certify under penalty of perjury that the information they have
provided on the manifest is accurate. The Department can compare
the two copies of the manifest received, one from the waste producer
and one from the waste processor or disposal site operator, to ensure
that each load of hazardous wastes produced is processed or discarded
at a plant or site authorized to accept such wastes.
Since July 1974, the Department has received about 72,000 mani-
fests and $291,087 in fees. This large amount of paperwork requires
computer processing. Using flow charts and other information from
EPA's Hazardous Hastes Information System, Preliminary Design (draft
report), the Department prepared the first segment of a computer
program for processing these manifests and auditing the fees collected.
This program segment records on tape information coded from the copies
of the manifests received from hazardous waste processors and disposal
site operators. Each month the program segment yields a summary of:
the total amounts of each type of waste carried by each hauler; the
total amounts of each type of waste received at each processing plant
or disposal site, and the method used to process or dispose of the
waste; and the total fees collected'from each waste processor and
disposal site operator for payment to the Department. The computer
program segment has been run successfully using test data and the
University of California's computer in Berkeley.
3. Enforcing the Minimum Standards
The Department's enforcement program recently received some
preliminary testing in the field. The two primary goals of the
preliminary field test'were: (1) to sample and analyze hazardous
wastes entering Class I and Class II-l disposal sites; and (2) to
verify the accuracy of information on the manifests identifying
the wastes and the hazards associated with them.
-------
The enforcement activity utilized sampling teams. The team
approach has several advantages over an individual working alone
1n the field because the team can: provide more than one witness
to a violation; provide help in an emergency; and sample waste
loads more rapidly without delaying drivers at the busier disposal
sites. For the preliminary field test, two teams composed of
personnel from the Department and from EPA, and graduate engineering
students from the University of Southern California were used. Each
team consisted of three individuals; (1) a supervisor in charge who
obtained a copy of each waste hauler's manifest and recorded pertinent
data from it; (2) a technician who sampled the waste; and (3) an
assistant. Each member of each team received protective gear to be
worn while sampling hazardous wastes: a hard hat with clear plastic
visor; a respirator; a rubber raincoat and overalls; and rubber boots.
The two sampling teams collected nearly 400 samples of hazardous
waste from trucks arriving at the three Class I and selected Class II-l
disposal sites in the Los Angeles area during a two-week period. Chem-
ists at the Department's Berkeley and Los Angeles laboratories and at
U.S.C.'s laboratories are now analyzing these samples. Results from
the tests performed so far indicate that the information provided by
the waste producer on the manifest often fails to reveal the true com-
position or the hazardous properties of the waste.
4. Survey of Hazardous Waste Production
The Department is currently sponsoring a pilot survey of hazardous
waste production in one southern California county. Its purpose is to
test a survey questionnaire and techniques that will be used in a
statewide survey to be conducted later. The questionnaire is designed
to obtain the following information from waste producers in the area
being surveyed: names and locations of waste producers; present and
projected rates of waste production; probable composition and concen-
tration of the wastes produced; and present methods used for disposal.
If available, other information about the wastes will be sought, such
as: chemical composition; physical, chemical and biological properties;
and the nature of hazards commonly associated with the wastes.
When conducted statewide, the survey will reveal the amounts of
wastes being discarded on property belonging to private industries
and the amounts of wastes being reclaimed or recycled by industries
throughout California. The manifest system, discussed above, provides
neither of these categories of data. Furthermore, the requested pro-
jections of future waste generation supplied by industries will help
the Department to plan the future course of hazardous waste management
in the state.
5. Hazardous Materials Spill Plan
Incidents like the mismanaged pesticide fire described above have
amply demonstrated the need for a comprehensive, coordinated plan for
managing spills of hazardous materials in California. The State's
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Office of Emergency Services (OES) has already developed comprehensive
programs for managing spills of oil and of radioactive materials. How-
ever, the management of spills of other hazardous materials has been
left almost entirely to the discretion of local officials who were
first on the scene. Many of these officials have had little or no
training and have no equipment or money for managing such spills.
The OES has now developed a prototype hazardous materials spill
plan to be adopted by all counties in the state. Under the plan,
local agencies are responsible for notifying state agencies by call-
Ing the State toll-free emergency number and for initiating immediate
action to correct the spill. State agencies, including the Department
of Health, will provide technical and financial assistance to local
agencies, particularly for preventing contamination of the environ-
ment. The Department of Health has taken the position, and OES
agrees, that any hazardous material usually becomes a waste when
spilled and is, therefore, subject to the Department's hazardous
waste regulations.
Although the prototype plan represents an important first step
1n managing spills of hazardous materials, the final plan must incor-
porate a chain-of-command to avoid jurisdictional squabbles among
local agencies responding in an emergency.
III. RECENT ACTIVITIES IN CALIFORNIA
AFFECTING HAZARDOUS WASTE MANAGEMENT
As reported at the June 20, 1975 National Solid Wastes Management
Association International Equipment and Technology Exposition in Los
Angeles, the Department has encountered several problems, including
illegal disposal of wastes, in administering the State's Hazardous
Waste Management Program. At that time, it was also reported that:
(1) the limited number of Class I sites in California, as well as the
fees charged for the disposal of hazardous wastes, had probably encour-
aged illegal disposal; (2) the State Solid Waste Management Board (SSWMB)
had appointed an Industrial Liquid Wastes Committee (ILK'C) made up of
members of the Board, as well as representatives of the Department of
Health and the State Water Resources Control Board (SWRCB), to obtain
information regarding the illegal disposal of non-sewerable liquid
wastes; and (3) Assemblyman Z'berg (recently deceased) had introduced
Assembly Concurrent Resolution (ACR) No. 79 regarding Class I sites.
ACR 79, which has now been passed, recogniz'ing that "the shortage
of Class I sites creates serious environmental problems and presents
severe hardships on local governmental agencies and industries which
generate these wastes", directs the SSWMB, in conjunction with the
State Department of Health, the State Department of Food and Agriculture
and the State Water Resources Control Board, to "evaluate the role of
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the state 1n establishing new Class I sites. Such evaluation shall
Include (1) whether the state should assist in the location and
evaluation of potential sites, (2) if these sites should be purchased
and owned by the state, and (3) the manner by which the state should
control or regulate the operation of waste disposal procedures".
The ILVIC held eight days of public hearings during June and Julv
throughout California from San Diego to Eureka. Testimony concerning
the problems was received from liquid waste producers, haulers and
disposal site operators as well as from representatives of private
groups, including environmentalists, and of governmental agencies.
Testimonies received at those hearings indicate that:
1. Additional Class I sites are needed in California.
2. Long haul distances are expensive and also result in
wasted energy and concomitant illegal disposal.
3. Industries are not locating in the Antelope Valley area
of Los Angeles County because of the lack of nearby
suitable disposal sites.
4. It may be necessary, due to the physical difficulties asso-
ciated with finding sites which meet the Class I require-
ments and due to local social and political difficulties
associated with the establishment of Class I sites, for
the State to acquire sites and then lease them to local
governments or private operators for use.
5. It may be necessary to develop a statewide requirement
for adequate buffer areas surrounding Class I sites so
as to minimize the impact of the disposal operations on
adjacent properties.
6. The Department's monitoring and enforcement program is
good, but the regulations are not adequately enforced.
7. Legitimate, licensed waste haulers are competing unfav-
orably with persons who have little to lose by engaging in
illegal disposal activities. Consequently, it may be
advisable to develop a statewide licensing system for
all haulers, including haulers of solid wastes and septic
tank wastes, in order to facilitate enforcement of proper
disposal procedures.
8. Sites that are open 24 hours per day, 7 days per week,
help minimize illegal disposal.
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9. The technology of recovering usable products from most
Industrial wastes is still in the developmental stage
and, therefore, very little is being done to reclaim
the wastes. A noted exception is petroleum solvents;
about 80% of all such solvents produced in the San
Francisco Bay Area are reportedly reclaimed.
Based on the testimonies summarized above, the ILWC recommended
that the SSWMB undertake the following:
1. Develop a statewide master plan for Class I disposal sites.
Such a plan should determine regional needs, locate sites,
and include methods of implementing the establishment of
sites as proposed in ACR 79 introduced by Assemblyman
Z'berg. Such a plan should utilize data being gathered
through the county solid waste management plans to identify
current remaining site capacity and projected quantities
of industrial liquid wastes. The plan should outline
methods for early action to implement State purchase of
suitable sites well in advance of need. The "warehousing"
of sites is considered essential as they are a scarce
resource which enables continued industrial production
in concert with environmental protection. In formulating
the plan, the Board shall select a committee on which local
government and concerned industries are represented.
2. Pursue, in cooperation with the State Department of Health
and the State Water Resources Control Board, stronger
monitoring programs and enforcement procedures. These
should include:
a. Implementation of the Department of Health's authority
to delegate hazardous waste enforcement to local en-
forcement agencies only where disposal sites are
privately operated. The local enforcement agencies
should be those which are established by the county
solid waste management plans as required by the
Board's guidelines.
b. Pooling of the separate inspection activities of the
Air Resources Board, Water Resources Control Board,
Solid Waste Management Board and the Department of
Health to maximize the effectiveness of state sur-
veillance responsibilities.
c. Legislation to expand the existing state licensing
requirement for liquid waste haulers to include
solid waste haulers, septic tank haulers and all
disposal site operators.
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3. Sponsor, in cooperation with the State Department of
Health and the State Water Recources Control Board,
legislation to modify the current hazardous waste fee
structure to include not only hazardous waste but all
non-sewerable liquid wastes.
4. Other considerations:
a. All wastes considered detrimental to water quality
or considered hazardous to public health shall be
consolidated into a single list, and the list shall
be reviewed to determine its applicability in relation
to the physical characteristics of each new and exist-
ing Class 1 site.
b. Where Class 1 sites are required, sufficient buffer
areas should be established either by outright
purchase, purchase of development rights, or other
means to minimize adverse impacts on adjacent commun-
ities.
c. A more concentrated effort should be developed to
educate the public on the vital need for adequate
disposal sites for industrial liquid wastes to
prevent public health and environmental problems
and to permit the industrial sector of the State's
economy to operate as efficiently as possible.
The report of the ILWC was approved by the SSWMB and has sub-
sequently been transmitted to various State agencies.
IV. CONCLUSIONS
California's hazardous waste management program has nearly com-
pleted its developmental phase and recently entered its operational
phase. Five important aspects of the program's operational phase are
currently progressing well: (1) seeking alternatives to land disposal
of extremely hazardous wastes; (2) monitoring production, processing
and disposal of hazardous wastes; (3) enforcing minimum standards
for safe management of such wastes; (4) surveying statewide production
of these wastes; and (5) participating in a coordinated plan for man-
aging spills of these wastes. However, the program still has many
challenges, particularly in the area of resource recovery. The biggest
challenge, however, is in developing a truly equitable hazardous waste
management system throughout the State. Implementation of the mandates
of ACR No. 79 and of the recommendations of the Industrial Liquid Waste
Committee will certainly be a "giant step forward" in achieving that
goal.
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References Cited
1. Collins, H.F., and Storm, D.L., "California's Legislative
and Regulatory Policy for Hazardous Waste Management",
Paper presented at the Third National Congress on Waste
Management and Resource Recovery, San Francisco, CA,
November 1974.
2. Collins, H.F., "Experiences of a State Hazardous Waste Program",
Paper presented at the National Solid Wastes Management
Association International Waste Equipment and Technology
Exposition, June 1975, Los Angeles, CA.
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STATE HAZARDOUS WASTE PROGRAM
Thomas Tiesler
Director, Solid Waste Management Programs, Tennessee Department of Public Health
It is certainly a pleasure to be a part of the Fourth National Congress on
Waste Management Technology and Resource and Energy Recovery. I
would like to admit, however, that there are other areas related to solid
waste management in Tennessee that I am a bit more proud to talk about
than the hazardous waste program. Like many other states, our hazardous
waste program is still in its infancy; and we are still learning and attempting
to do what is possible to control the problem. The State of Tennessee
is like many other states in that we have a basic solid waste disposal law
which deals somewhat with the hazardous waste disposal problem. The
"Tennessee Solid Waste Disposal Act" was passed in 1969 and became fully
implemented July 1, 1972. Fortunately, at the time of the passage of the
law and the writing of the regulations, we had enough insight to include
within the "Solid Waste Disposal Act" acme regulations which cover the processing
and disposal of hazardous waste materials. We included two basic sections
that dealt with hazardous waste disposal. One section is concerned with
the registration of hazardous waste processing and disposal facilities.
This would include land disposal sites for hazardous waste and any type
of hazardous waste processing facilities, including incinerators. The other
regulation deals with "special waste" which is aimed basically at controlling
these types of materials from going into normal sanitary landfills.
In order to gain a better understanding of the situation in Tennessee,
it would probably be best to talk about the character of the state. Tennessee
presently has a population of approximately four million people with about
six thousand industries of various types. Some of these industries produce
large amounts of hazardous waste while other industries have smaller amounts
of hazardous waste in their processing and disposal operations such as
solvents, sludges, and other chemicals. I consider these types of industries
very typical of many other states. One unique problem in Tennessee is that
we do have some large pesticide manufacturers which have a large amount
of pesticide residues remaining from processing. These problems have
been improperly dealt with over the past years and have left scars within
the State of Tennessee which we are currently having to monitor and deal
with continuously. Another somewhat unique problem in Tennessee is
the fact that we have very few privately operated disposal facilities. The
majority of the sanitary landfills operated in Tennessee are operated by
either city or county governments and we have only about twenty percent
of the sanitary landfills operated by private industry. This is probably
more typical of the states in the southeast than the northeastern, or mid-
western states.
We are very much aware of the hazardous waste problem in Tennessee and
feel like in one sense that due to the strict control and monitoring of sanitary
landfills, we have made it a separate disposal problem. We have limited
or tried to exclude certain types of materials from being disposed of in normal
7b
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municipal disposal sites and for this reason we have separated the municipal
solid waste disposal problem from the hazardous waste problem. In the
past, all types of municipal and industrial wastes went to the city dump.
It was believed at that time that the city dump was a disposal or burial
ground for any type of material that could not be handled cheaply in any
other manner. We even had some industries who carried their liquid waste
discharges to the dump. This material should have been treated in a treatment
facility and discharged into a sewer. Instead of going to the expense of
treating the material properly, they would simply pick it up in tank trucks,
haul it to the dump, and pour the liquid into trenches. In one specific instance,
we had an industry which disposed of eight thousand gallons a day of raw
metal plating waste in this manner for about eight years. It was not long
before the material had saturated an entire ridge and began to seep into
a nearby spring. As you can imagine, this problem is going to continue
for many years until all of the material has finally leached out of the soil.
These types of situations are not unusual and I would say it is probably
typical of many of the disposal problems that exist in Tennessee and many
other states. Until a strong hazardous waste law is enacted, we will have
to deal with these problems as best we can. We have been fortunate in most
situations that we can handle them through legal action either through the
"Tennessee Solid Waste Disposal Act" or through joint legal actions with
the Division of Water Quality Control.
In attempting to handle the hazardous waste problem, we have approached
it in a number of ways. First with a limited staff, we have attempted to enforce
those sections of the "Tennessee Solid Waste Disposal Act" which relate
to hazardous waste disposal. Second, we have tried to eliminate as much
as possible the hazardous materials from entering the sanitary landfill.
When hazardous materials are unacceptable for sanitary landfilling, additional
problems arise as to what alternatives for disposal are left to industry.
In an effort to solve some of these problem we have put together a list of
companies across the country which are in the process of handling toxic
and hazardous materials. We encourage the industries to contact these
people and make arrangements to have their waste disposed. As you can
imagine some industries cooperate and some do not. We do not feel that
this arrangement will in all cases correct the problem - it depends on the
industry.
A couple of years ago, we conducted an industrial waste survey in an
attempt to determine the magnicude of the industrial and hazardous waste
problem in Tennessee. We do not feel like from the standpoint of determining
the real problem of hazardous waste disposal that this survey was very beneficial.
Probably the most important result to come out of the survey was the personal
contact with various industries and actual training for our staff. We soon
realized that only those industries who did not have a problem or had a
solution to their problem would respond to the survey. Those industries
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that had a real problem were not interested in participating in the survey.
We also found out that many industries which were surveyed in personal
interviews did not reveal all of their problems - this stands to reason.
We therefore have somewhat of a negative attitude about hazardous waste
surveys.
We feel that proper training is a vital part of any regulatory program;
therefore, we conduct two solid waste training courses per year for municipal
and industrial sanitary landfill operators. These are two day meetings where
the operators come to a training center in Murfreesboro, Tennessee and
we go through various elements of sanitary landfill operation. During this
training session, we also devote a couple of sessions to hazardous waste
management in an attempt to alert the operators to the problem of handling
certain types of hazardous waste materials. We feel that this has been effective
from the standpoint of keeping these materials out of municipal sanitary
landfills.
In addition to training, we hold an annual Solid Waste Conference each
year in January where we devote time to various topics in solid waste management.
This year we are concentrating a large portion of the program on industrial
and hazardous waste management.
We have a basic philosophy about liquid and hazardous waste disposal.
We attempt in Tennessee to keep as much water or liquids out of sanitary
landfills as possible to cut down on possible leachate production and ultimate
groundwater pollution problems. For this reason, we have a blanket
policy that no liquids will be disposed of in sanitary landfills. We do however
under the "special waste" provision allow certain sludges to go into sanitary
landfills if they have been dewatered to the point of having no free water.
We also have some hesitation about the use of liners and other artifical
barriers for prevention of groundwater contamination. It is usually decided
that these types of devices are used in marginal landfill sites where the
soil is not sufficient for use without a liner. It is our feeling that there is
still some question about the I ife of certain liners and other problems relating
to placement where they might be punctured during operation; we therefore
do not allow their usage in marginal sites. We will not approve the us.e of
a marginal sanitary landfill site even with artifical barriers.
We have in the past and are presently attempting to get a strong hazardous
waste control law passed. We feel that this is the only way to really get
a handle on the hazardous waste disposal problem and find a solution to
solving the problem. Most private companies are not going to come into
the State of Tennessee and spend a lot of money investing in a facility to
handle certain types of waste if there is not a strong control agency which
will force the various industries to use these facilities. Most industrial
waste generators are opposed to a strong hazardous waste control law because
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they do not want to spend the extra money for proper treatment. However
we are not going to have a solution to the problem until someone will provide
the treatment facilities. The State of Tennessee, like other states, is having
economic problems and the administration is not interested in passing
any new legislation which will cause an increase in spending. The type
of legislation which could possibly be passed is that which is funded by
the people who are being regulated by the use of a permit fee.
Another problem facing Tennessee and other states, besides not having
adequate legislation, is not having sufficient manpower. Until we have enough
manpower to follow-up and routinely monitor all industries in the state,
we are not going to have a viable program. Any regulatory program
has to be consistent in their control. It is not fair to be more stringent in
one area of the state or with one type of industry and with a limited staff
of only two people working in hazardous waste this becomes extremely difficult.
I feel like the only true solution to the hazardous waste program is the passage
of a hazardous waste control law which is stringent and wi II provide enough
monies to adequately fund the staff which are to control the problem. I think
when this law is passed, private industry will establish themselves in
Tennessee and be willing to invest money and construct facilities to solve
the problem. Until that is done, we will continue to put out fires.
JTT/RS/cm 3/10
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Land Disposal
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ESTABLISHING URBAN LANDFILLS FROM START TO FINISH
Michael Pope
Chief Executive Officer, Pope, Evans, and Robbins
A. INTRODUCTION
To an average citizen the term "sanitary landfill" conjures
up thoughts of a smelly, rat infested, open dump, usually
burning.
And we really can't blame the public. In many instances the
term "sanitary landfill" has been misused.
I think those of us involved in the business of solid waste
management have a responsibility to educate the community.
A sanitary landfill is a planned and engineered method for the
disposal of solid waste, and does not involve burning or open
dumping.
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The best definition of a sanitary landfill was set forth by
the American Society of Civil Engineers. It reads:
"Sanitary Landfill is a method of disposing of refuse on land
without creating nuisances or hazards to public health or
safety, by utilizing the principals of engineering to confine the
refuse to the smallest practical area, to reduce it to the
smallest practical volume, and to cover it with a layer of
earth at the conclusion of each day's operation, or at such
more frequent intervals as may be necessary. "
Why a Sanitary Landfill Instead of Some Other Method0
It has been proven time and agaii. that, where land is avail-
able, sanitary landfilling is the most economical and efficient
method of solid waste disposal.
Economics of Sanitary Landfills
Landfill costs can be generally divided into initial investment
and operating costs.
The extent of the initial investment will depend on the size and
degree of sophistication of the landfill. The major items will be:
land, planning and design, and site development and equipment;
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with the larger share of this cost going for land and
equipment. However, regardless of the cost, the initial
investment in a sanitary landfill will usually be lower than
that for any other method of solid waste disposal.
The total operating cost of a sanitary landfill varies between
$1.00 and $5. 00 per ton depending on the size, method and
efficiency of the operation. The cost breakdown is about 40
to 50 percent for wages, 30 to 40 percent for equipment
maintena ce and supplies and 20 percent for general overhead
and miscellaneous.
We must remember to consider the total life cycle cost of the
operation when comparing different methods of solid waste
disposal. On this basis, the operating costs of a sanitary
landfill is usually lower than that of any other method.
A major advantage of sanitary landfills is that the land
value of the site can be increased by reclamation to a park,
playground, golf course or other recreational facility.
B. PER Landfill Projects:
Pope, Evans and Robbins Incorporated has been involved in
a number of solid waste management projects.
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The projects that I would like to present to you
are three sanitary landfills for the Town of Brookhaven
on Long Island. New York and one of my favorite
"specialty" sanitary landfills, the proposed RECAP
Island in Lower New York Bay.
a) The Sanitary Landfills on Long Island
In 1970 the New York State Environmental Facilities
Corporation commissioned us to prepare a comprehensive
Solid Waste Management Program for the Town of
Brookhaven in Suffolk County, New York, for the
twenty year period between 1970 and 1990. At the
time of the study, the Town of Brookhaven population
was estimated to be 235,000. By the year 1990 the
town population will have more than doubled to about
590,000.
In 1970, the amount of refuse generated by the town was
4,000 tons per week. By 1990, it is estimated to be 14,000
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tons per week.
During the preparation of the long range Plan we
considered various methods of solid waste disposal
including: sanitary landfill, conventional incinera-
tion, high temperature incineration, pyrolysis, corn-
posting, hauling to out of town sites, as well as
shredding, compacting and baling.
We found that incineration or pyrolysis required
large initial investments in equipment that might
soon become obsolete or depended on processes
still in the experimental stage.
Composting and salvage turned out to be very costly
and lacked the type of assured market required to
make the operation competitive.
The results of our study indicated that sanitary landfill
was the most economical method of solid waste disposal.
Shredding and/or baling, while prolonging landfill life,
was an additional cost not justified in view of the
available land and comparatively low land costs.
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The sanitary landfill method had the additional advantage
of yielding much needed recreational facilities for the
ever growing population of the Town of Brookhaven. In this
way we were able to turn a necessary evil into an asset that
would enhance the quality of life in the community.
The decision to use sanitary landfills for the disposal of
solid waste was followed by the selection of a number of
available sites for evaluation. We analyzed the relative
advantage and total cost of solid waste disposal at each of
the chosen sites and combination of sites. The evaluation
criteria included: the cost of land, site preparation, trans-
portation of refuse, landfill equipment, facilities and opera-
tion, as well as site location, site capacity, area zoning
regulations, land acquisition problems, landfill impact on
site environment, site topography, geology and hydrology,
and the potential contribution of the completed recreational
facility to the surrounding community and to the Town of
Brookhaven as a whole.
Three sites were finally selected. The three landfills
would be operated in sequence and they would be capable
of receiving the Town's solid waste for the full 20 year
period.
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The three sites would ultimately become parks, each
with its own theme and physical characteristics. The first,
known as Holtsville, would be a strolling and athletic park;
the second, named Brookhaven Park, would emphasize
summer and winter recreation featuring a skiing mountain,
the third park, known as Middle Island East, would be made
up of hills and lakes similar to New York City's Central
Park.
To give you more specific details we will look at
each one individually.
b) Holtsville Park
The Holtsville sanitary landfill was the first sitp
to be developed.
This site consisted of 74 acres which were at the time
being utilized for solid waste disposal. We cannot say
that it was a typical dump, since some covering was
being done, but the operation did not follow the rules
and guidelines that have come to be accepted as essential
in the running of an economical and efficient sanitary
landfill.
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Since the existing site obviated the need for many of
preliminary steps, our first action was to prepare opera-
tional plans and specifications that would guide the daily
operations as well as the construction and installation of
facilities and utilities required to make the operation more
efficient. The specifications included those for the purchase
of the equipment necessary to do the job, such as weigh
scale, payloaders, and scrapers.
In addition, end use plans and spec_ucations were prepared
for the facilities to be constructed at the completion of a
sanitary landfill. These included swimming pools, base-
ball fields, tennis and handoall courts, kiosks, bath house
and concessions building as well as a senior citizen recrea-
tion area.
Please note the differentiation made between operational
and end use plans and specifications. The operational
documents tell the landfill operators when, where and how
to place the refuse, utilities, and facilities necessary to
run the landfill. On the other hand, the end use plans
and specifications are the architectural, structural,
mechanical and electrical documents normally required
for any new facility.
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Sanitary landfill activities at the Holtsville site were
completed over two years ago and many of the planned
recreational facilities have been built. For the last two
years the residents of Suffolk County have enjoyed the u
of the Holtsville Park swimming pools, which include
an Olympic size as well as diving and a wading pool. The
senior citizens recreation area has also been completed
These are a few pictures of the official opening of the pa
of the construction of a paddle tennis court and of the co
pleted pools. Artist's rendering present the planned fin
configuration of the Holtsville park.
c) Brookhaven Park
For approximately a year before landfilling activities
ceased at the Holtsville landfill, site preparation work \
been going on to get the second site, at Brookhaven,
ready to receive garbage after the last ton was dumped
at Holtsville.
The Brookhaven site, located about 8 miles from the
Holtsville site, is a parcel containing about 225 acres o
wooded virgin land set in a rural area of Suffolk County.
Because the land was the property of a number of privat
owners, land acquisition proceedings had started a coup
of years before the site was to be used. However, whei
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the site was finally opened to landfilling activities, not
all the land had been acquired. As we all know, land
acquisition is one of the critical items in site selection.
In this particular case the fact that not all the required
land was owned by the Corporation resulted in the costly
and time consuming job of resurveying the land and re-
designing the operational plans,, so that all site preparation
such as fencing, access roads and utilities - as well as the
landfilling operations could take place on land that had
already been acquired.
The theme of this completed landfill was to be a summer
and winter recreation park, having as its main attraction
a large skiing mountain. Together with a special ski-
mountain design consultant, we developed a layout for a
skiing mountain that would suit the site and accommodate
a number of slopes suitable for beginners and experts.
The mountain turned out to be 250 ft. high and 85 acres at
the base. In addition to the mountain, the finished park is
to have many summer recreational facilities including
swimming pools and athletic fields and courts.
No two engineering projects are alike, and sanitary landfills
are no different. What made this particular landfill
unusual \\as the great height to which the garbage was going
to be placed. To our knowledge this was and still is
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the highest sanitary landfill ever planned. Since w«
must cover the refuse with at least 6 inches of soil daily
and provide a final cover no less than 2 ft. thick, we needed
much cover material. Roughly 4 million cubic yards. I
don't care what you multiply that by, its going to be a lot of
money.
Fortunately, the landfill was to be seated on top of that good
and plentiful Long Island sand. We decided to mine the
material required for daily cover right from under the land-
fill. To obtain the amount of soil ^e need, part of the excava-
tion is as much as 35 feet below the ground surface.
Another interesting aspect of this sanitarj' landfill is the
way in which we decided to handle the leachate. Since
the groundwater is the sole water supply for Brookhaven
and surrounding Long Island communities, prevention of con-
tamination by leachate was a critical design concern. The
usual solution to this problem involves doing one of the
following:
1. Select a site where the groundwater is far
enough below the landfill base to permit natural biological
and physical processes to purify leachate percolation.
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2. Select a site that has a natural impermeable
clay layer, between the landfill and the groundwater
table.
3. Place a bentonite layer at the bottom of the land-
fill.
Since our site did not have a natural protective barrier,
and to put in a layer of clay on 85 acres would have been
too costly, we decided, after successful testing, to use
a 20 mil PVC membrane at the bottom of the landfill.
The membrane is economical, effective and easy to handle
and install. After installation, the membrane is covered
with a protective layer of sand and is ready to accept
refuse. The leachate that is trapped by the membrane
is collected by a system of perforated subdrain pipes,
pumped to a treatment station, treated and discharged to
local streams.
Because the base area of the landfill is so large, the
operational plans are very detailed. They show how
the area has been subdivided into small portions ranging
from 5 to 10 acres. They also show the sequence in
which these small areas are surveyed, cleared of vege-
tation, excavated, graded to the appropriate contours
and covered with the PVC membrane to make it ready
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to receive the garbage. Just to give you a feeling
for the size of this landfill, it will take 2 large scrapers,
working continuously. 5 years to excavate all the required
cover material.
The Brookhaven landfill has been operating for the last
two years and we anticipate that it will take about ten
more years for it to be completed. By that time,
approximately ten million tons of garbage will have been
disposed of at this sanitary landfill
Upon completion of landfilling operations, work will start
on the construction and installation of skiing and summer
recreation facilities. At the end, Brookhaven Park will
stand as a model of what can be done with a well planned
and properly engineered sanitary landfill.
d) Middle Island East Park
Sometime before the end of operations at Brookhaven Park,
site preparation work will start at the Middle Island East
sanitary landfill. This landfill will serve as the solid waste
disposal site for the Town of Brookhaven for the remainder
of the 20 year period.
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Unlike the other parks, the theme of this completed
facility will be a naturalistic environment. Where the
other two parks emphasize athletics and recreational
activities this one will contain rolling hills and lakes.
In addition to good planning, good design and an appropriate
site we were very much concerned about sound financing and
public approval of the project.
The three landfills in Brookhaven, New York, have been financed
by the New York State Environmental Facility Corporation
(EFC). In addition to our role as technical and economic
advisor, we also acted as mediators between EFC and the
Town of Brookhaven during contract negotiations. The
contract calls for the Town to reimburse EFC on a per ton
basis. The actual dump fee reflects EFC's financing costs
plus an amount set aside for the development of the end
use projects by the Town.
During the planning stage, as well as during the design
stage, we prepared a series of presentations to the State
Department of Environmental Conservation (DEC), to the
Town Supervisor and the Town Council, to a special advisory
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committee appointed from among leading citizens by
the Town Council and to numerous citizens' and civic
groups. Some of these presentations were through formal
meetings and public briefings and hearings, while others
were only courtesy meetings to familiarize various groups
with the scope, purpose and objectives of the project.
We do believe that involvement of local and state authorities
and of interested citizens in the early phases of the project
is one of the main factors contributing to the success of any
urban sanitary landfill project.
e) RECAP Island
One of the most challenging projects we have been associated
with is finding a solution to the refuse disposal crisis develop
tn New York City. Currently, New York City produces
26, 000 tons "of waste per day, and incinerates approximately
25 percent of it. The remaining 75 percent along with the
incinerator ash go to landfills. The landfill capacity will
be exhausted in 1985. There is practically no land area
available within the City for new sanitary landfills.
New York City has under consideration a series of tentative
plans to increase its disposal capacity. Some of the propose
programs rely on out of state rail haul, others include the
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construction of resource recovery pilot plants.
Exportation of garbage to out-of-state locations is
expensive, makes New York City dependent on the
legal and political whims of others and will cost two
or three times the present costs. The pilot plant
approach will add a minimum of five years to a
decision making process.
Our firm undertook a comprehensive review of available
and developing alternative concepts, based on their
respective technical characteristics, environmental
impacts, financial implications and implementability.
Existing or possible alternative locations on land,
immediately offshore and in the ocean were considered
for a variety of conventional disposal practices,
such as sanitary landfill, incineration and ocean
disposal, and resource recovery technologies.
One of the main conclusions of this evaluation process
was that, while any modern solid waste disposal program
should be resource recovery oriented, it is mandatory
that the system contain a sanitary landfill.
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With land for a sanitary landfill practically impossible to
obtain within New York City limits or in the neighboring
areas, our study concluded that a readily accessible arti-
ficial island providing considerable fill volume and accommo
dating a resource recovery oriented solid waste processing
facility was the best s;olution for solving the City's current
and future disposal needs.
RECAP is the name of the proposed artificial island to be
located in lower New York Bay. Recap Island will provide
a modular, centralized disposal and recovery system capabl
of handling from 11,000 to 44,000 tons of refuse per day.
Four modules are considered. The first stage of RECAP
will be an island of approximately~250 acres of which about
30 acres is allocated to an operations area with sufficient
space to accommodate equipment for processing from
11,000 to 22,000 tons of refuse per day. Up to three
additional stages, each of approximately 250 acres, can be
provided to extend the island life span. A second operating
area, identical to the first, will allow for the expansion
of refuse processing capacity to 44, 000 tons per day.
Various processing alternatives have been considered,
ranging from minimal to maximum justifiable resource
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recovery. In the first extreme case,refuse will be shredded,
ferrous metals magnetically separated, and the residual,
equivalent to 95. 5 percent of the input refuse will be baled
and placed. In the second case, the light
organic fraction of the input refuse will be recovered
for use as supplementary fuel; ferrous metals, and possibly
glass and aluminum will also be recovered. Additional
processing could be added for further recovery of other
non-ferrous metals, if justified. Other alternatives, involving
various degrees of resource recovery in between these
extremes, have also been analyzed. In all cases, the residue
will be placed on the Island site. Refuse processing equip-
ment will be installed on the operations area.
Phase I life span will vary from 10 to 42 years at a refuse
input rate of 11,000 tpd depending upon the extent of
resource recovery. The Phase IV life span could vary
from 15 to 251 years depending upon the refuse input rate
and the extent of resource recovery.
Currently, approximately 35 percent of the refuse of
New York City is transported by barge to a landfill located
in Staten Island. Using these existing refuse transfer
facilities and barge fleets, refuse could be transported to
RECAP.
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Each module will be circular in shape. Phase I will
consist of a fill area, operations and barge basin. An
enclosure wall of precast reinforced concrete sections
will define these areas.
The enclosure wall will be constructed of precastj rein-
forced concrete sections. The box-like "units, will be
constructed on shore and towed to the site, where they will
be positioned and sunk on a prepared foundation of sand
and crushed stone. After placement, the caissons will be
filled with dredged sand and/or construction debris and
rocks. Joints between concrete caissons will be specially
constructed to prevent leakage. To protect the enclosure
wall from wave and wind action, two or three layers of
armor rock will be placed against the caissons.
To prevent contamination of the surrounding sea water
and to contain solid waste leachate within the island enclosure,
an impervious liner will be installed on the seabed. The
basic liner material will be poly vinyl chloride (PVC).
Approximately 30 acres adjacent to the barge basin will
be used for the construction of processing, support and
maintenance facilities.
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The costs of the Phase I Island for processing 11,000 tons
per day of refuse is as follows:
Minimal Resource Recovery $10.81 per ton
Maximum Resource Recovery 2. 85 per ton
Costs include all construction, marine transportation and
an allowance for revenues.
The environmental studies, conducted in connection with
the Recap Island project involved oceanographic, hydrological,
and ecological surveys to determine the data necessary
to design a facility that will haye minimum potential
detrimental impacts. These studies concluded that:
1. the Island's physical influence on the movement
of the water in the Bay is negligible.
2. the placement of an impervious, protective liner
at the bottom of the Island would prevent contamination
of the groundwater and bay waters.
3. dredging required for the construction of RECAP
will have only short term effects. Those organisms in the
area that might be affected will begin to repopulate almost
immediately, when dredging is completed.
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4. long-term effects of RECAP Island on the ecology
of Raritan Bay, now a highly polluted estuary, will probably
be beneficial. The placement of the Island will allow coloni-
zation of encrusting organisms, producing an artificial
reef community. The localization of fish around the reef
would increase the recreational value of the area.
RECAP Island will allow the early closing of poorly operatec
landfills and will accelerate the return to public use of
thousands of acres now occupied by disposal facilities.
With the sale and use of recovered resources still
uncertain due to economic and socio-political concerns,
RECAP offers the option of being capable of operating
as a landlill until such time as the use of refuse fuel or
other recycled products becomes accepted practice.
When a market for energy recovered from waste can be
developed in the New York City area, at 22,000 tons per
day, RECAP will provide the energy equivalent of approximj
10 million barrels of low sulfur fuel oil per year. Used
as a supplement in public utility boilers, the Island's
waste fuel can satisfy approximately 5% of New York City's
electricity requirements.
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No community wants a disposal facility in its backyard.
By being located offshore, RECAP will eliminate the pro-
blems of siting a refuse handling facility in urban neigh-
borhoods. One facility will serve the entire Metropolitan
Region.
We have completed an extensive feasibility study and pre-
sented RECAP Island to various City, and State authorities
as well as to numerous citizens' groups.
We believe that the RECAP Island concept can be used
by other water front communities with high population
concentration, if land areas for landfills cannot be
easily acquired.
C. CONCLUSIONS AND RECOMMENDATIONS
In conclusion to summarize the requirements for a successful
landfill, I like to think of 6 ingredients that must come to ether:
They are.-
1. Good Planning
2. Sound Financing
3. Appropriate Site
4. Public Approval
5. Good design and adequate site preparation
6. Clean and Efficient Operation
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1. Good planning means establishing very early, a
comprehensive Solid Waste Management Program. An important
phase of this program will be the investigation and outline
of all pertinent parameters, such as:
Population
Quantity of Waste
Type of Waste
Distances Involved
Collection Patterns
Traffic Patterns
Impact of Landfill on Environment
Public Attitude
Regulatory Agencies
Ultimate Use of Facility
Potential Landfill Sites
The planning stages should produce a comprehensive report as
well as plans and specifications for the implementation of the
program.
2. Sound Financing requires a comprehensive study of the
economic base that will fund the project. All interagency agree-
ments should be reached as early as possible and long range fisca
plans should be prepared and approved by the appropriate authorit
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3. A crucial element to the success or failure of the pro-
gram is the sanitary landfill site. Site selection goes hand in
hand with good planning as far as eliminating future operational pro-
blems and reducing operational costs. Since the factors to be considered
will require technical know-how ana experience we
strongly advise that a well qualified consulting engineer
be responsible for the selection of the site. Looking
once again at some of the factors that must be considered:
Zoning. This is probably the major stumbling
block in the selection of an appropriate site. Before full
scale investigation is undertaken regarding the suitability
of a potential site, all zoning ordinances must be reviewed.
An early review of ordinances saves time, money, and
energy. At that time we can make a determination as to
whether the site is clear or whether it is necessary to rezone
or change the ordinances to eliminate any legal restrictions
that could hamper the use of a particular parcel as the site.
In some cases the review will show that the area in question
can be zoned for sanitary waste disposal thereby circumventing
many of the potential problems.
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The location of the site. Is it easily accessible
to the handling trucks and the general public? What is
the hauling distance? What type of roads will receive
the main traffic? What will be the impact of the vehicles
transporting the refuse on the existing traffic patterns?
How close is the site to populated areas?
Do the prevailing winds transport odors from the landCill
to the populated are as ?
Land Acquisition: In the ideal case the land will
already be owned oy the community or agency and then of
course, there is no problem. However, in many cases,
the land will be privately owned, and must be acquired.
Land acquisition is a long process. The ususal approach
is to deal with the individual owners directly. If this
approach does not work, it is then necessary for the
community or agency to condemn the land. At this
point, however, we are dealing through the courts and
it is well known how lengthy court proceedings can be.
The only thing to do is to start land acquisition pro-
ceedings as early as possible.
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Land Requirement: The amount of land needed
for sanitary landfill is a function of the quantity of solid
waste that we must dispose of, the depth of the fill which
is dictated by the ultimate use of the landfill, the efficiency
of the compacting operation and the desired life of the
landfill.
In addition to the actual landfill requirements we need land
for storage, stockpiling, facilities, access roads and most
important for a buffer zone between the landfill and the rest
of the community. There are no hard and fast rules for the
extent of the buffer zone. But, usually, depending on location
and its ultimate use, it will be from 200 to 1, 000 feet wide.
Site Topography and Geology studies are necessary
since the methods of preventing surface and ground water
pollution will depend on the geology and topography of the site.
The Environmental Impact of the Sanitary Landfill
on the Particular Site must be investigated especially as it
affects neighboring residences through noise and traffic and
the existing wild life and vegetation.
The Availability and Cost of Cover Material may
be a significant factor in certain cases and must not be
overlooked.
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4. Another most important element in the success
of a new landfill project is public approval.
Very few people will willingly accept a "sanitary
landfill" in their neighborhood or community. They
must be convinced that the operation will be clean,
efficient, odorless, and they will not suffer any
inconveniences.
This can be accomplished with a well prepared and
well executed public information program. If the opposition
is unusually strong consider hiring a professional public
relations firm and even conducting a small model sanitary
landfill project to show the community the type of clean
and efficient operation that you plan to conduct. Also,
models and architectural renderings of the ultimate use
of the completed facility are usually a great help in obtain-
ing public support.
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5. The design should include detailed
drawings and specifications for the operation in-
cluding the sequence of clearing, excavating and
landfilling portions of the site until the desired
landfill shape is achieved. Plans should also show
construction and installation details for access
roads, utilities, weigh scales, storm drainage, fences,
personnel and equipment facilities.
Similar drawings and specifications are prepared by
the engineer to show all the topographic, architec-
tural and structural features of the completed land-
fill.
An Environmental Baseline Survey is also necessary since
it serves as a guide and datum against which to measure the
impact of the landfill on the environment.
Before starting landfilling operations, it will be necessary
to:
a) obtain all necessary local and state permits
and approvals.
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b) fence the site, construct access roads and
install a weigh scale, utilities and all other personnel
and equipment facilities,
c) at this time you must also: purchase or lease
the required equipment.
6. The one facet of the Solid Waste Management Program
that will be under constant observation by the public is
the actual operation of the landfill. No matter hov.' good
the planning, how sound the financing, how well the
early stages of the program were received by the public
and how adequate the landfill is, an operation that is
not clean and quiet, but disrupts the normal life of the
community, will create opposition and hostility.
In addition to appropriate equipment and adequate day
by day operating procedures, a major and permanent
concern should be protection of public health and environ-
ment.
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A System.of..Vector Control must be established to control
insects and rodents. Strict adherence to daily landfill
cover procedures are essential.
Prevention of Air and Water Pollution: Air pollution is
avoided by prohibiting burning and by provisions to
extinguish accidental fires. Odors can be eliminated by
spraying with non-toxic chemical agents. Surface water
pollution is eliminated by the proper design of the landfill
and its surface drainage features. Groundwater pollution
is avoided by selecting a site possessing a natural leachate
barrier, like clay, or by the use of an impervious membrane
under the landfill.
Gas Control: Landfills generate methane, nitrogen, carbon
dioxide, hydrogen and hydrogen sulfide. Provisions
must be made within the landfill to allow the gases to be
vented to the atmosphere, unless special gas capture programs
are part of the design.
«
We are strong believers in the potential of resource recovery
from solid waste. But we also know that until resource
recovery is accepted and implemented on a large scale,
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there will always be a primary need for well
planned, well designed, well financed, well
operated and environmentally sound urban
sanitary landfills.
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The Role of Processed Refuse in Landfilling: Yesterday's Experience, Today's Status,
Tomorrow's Forecast-BALING
Truett DeGeare, Jr.
Acting Chief, Technology Applications Branch, OSWMP
U.S. Environmental Protection Agency
The Environmental Protection Agency's Office of Solid Waste Management
Programs (OSWMP) has recently been involved in two efforts to assess the
use of baling in the processing of solid wastes.
The earlier project was a demonstration funded jointly by the OSWMP
and the City of San Diego, California. The project involved the construc-
tion and evaluation of a pilot facility by the City of San Diego. This
project has been completed and a final report submitted. However, we
have not yet reviewed the report for possible publication. Thus, this
system will be discussed in only a limited manner.
The second project was a contracted evaluation of a full-scale
facility which was constructed and operated in St. Paul, Minnesota,
without Federal funds. Federal funding was involved only in the evalua-
tion, which was conducted by Ralph Stone and Company under contract to
our office. This project has been completed and an acceptable final
report submitted. The report has been reviewed and submitted for publication.
Evaluations
San Diego Plant
This pilot plant system consisted of the following unit operations:
1. Unloading and storage
2. Conveying to shredder
3. Shredding
4. Transport and feed to baler
5. Baling
6. Bale tying
7. Conveying, weighing and truck loading
8. Transport to disposal site
9. Balefilling
Solid Waste was unloaded and stored on a flat area adjacent to a
pan conveyor. A rubber-tired front-end loader was used to load the
conveyor which transported the waste to the hammermiII located below
grade to reduce noise and dust. Transport away from the shredder was
accomplished on a slider bed conveyor. A doffer roler was used to
increase the density of the shredded waste from about 2 pounds per cubic
foot to about 9 pounds per cubic foot. A bucket elevator was used to
transport the waste to the baler.
113
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Baling was accomplished by a 25 ton per hour continuous horizontal
extrusion type baler. Successive charges of waste were dropped into the
baling chamber and compressed against the end of a previously formed
bale. Shredded waste was successively charged and compressed in a
series of sandwiches until a bale of desired length was formed. Bale
size was 30 inches by 40 inches by a variable length averaging 76 inches.
Average bale density was about 1,700 pounds per cubic yard. Bales were
wire-tied to assure integrity. Tying was done by a system of bale
separator blocks designed with slots through which the wires were manually
inserted and secured around the bales.
Completed bales were transported to a scale and onto trucks by
roller conveyors. Dump trucks outfitted with roller conveyors transported
the bales one-half mile to the balefill where they were unloaded by
gravity.
San Diego Balefill
The balefill was located in a narrow canyon in San Diego's Balboa
Park. Various devices were tried for use ir bale placement before it
was decided to use a rubber-tired front-end loader. The loader's bucket
was equipped with a hydraulic logging hook for bale handling. Bales
were placed three high in an orderly building-block fashion and covered
daily on the top surface with 6 inches of soil.
Provision was made for collection of leachate; however, after 2
years of operation no leachate had been detected. This is probably due
in large part to the relatively low rainfall experienced in San Diego.
Although quantitative data is not available, neither odors nor
vectors were considered to be problems at the balefill. It was noted
that the typical garbage smell experienced at the unloading area was
reduced to a slight musty odor at the balefill.
San Diego Costs
In April 1971, the cost of facility construction, including engi-
neering services, was about $164,000. The cost of plant equipment (baler,
shredder/motor, all conveying equipment, scale, air compressor, tools,
hoist etc.) was about $183,000. An hourly depreciation rate for equipment
and facility and services, based on expected life for each piece of
equipment, was applied for the actual hours used to process a total of
7,523.4 tons over the cost evaluation period (March 1, through August 31,
1973). The total depreciation amounted to $1.22 per ton of solid waste
processed. Operating costs (labor, materials and supplies, equipment
rental, utilities, equipment maintenance) amounted to $5.93/ton of
refuse processed. The total processing system cost, less cost of land,
was therefore $7.15 per ton.
114
-------
The transportation cost to the balefiTI (labor and equipment rental
was $1.42/per ton of solid waste. Disposal cost (labor and equipment
rental) amounted to $.35 per ton, excluding land cost. Site preparation
came to an additional $.12 per ton for a total disposal cost of $.47 per
ton of solid waste disposal.
The total pilot plant cost including processing, transport to the
disposal site and disposal was $9.04 per ton of solid waste processed
and disposed.
St. Paul Plant
The full-scale facility at St. Paul was owned and operated by the
American Hoist and Derrick Company. It is represented by the schematic
of Fig. 1 and consisted of the following unit operations:
1. Unloading and storage
2. Conveying, weighing, and baler charging
3. Baling
4. Truck loading
5. Transport to disposal site
6. Balefilling
As at the San Diego plant, a rubber-tired front-end loader was used
to load the conveyor with waste from incoming collection vehicles. The
conveyor passed a picking stand where corrugated cardboard was segregated
manually for recycle. The conveyor then discharged the waste onto a
platform scale. On accumulation of about 3,000 pounds of waste, the
scale contents were charged into the baler charging box for baling.
Bales were formed by a 32 ton per hour high pressure single charge baler
with three hydraulic baling rams, an exit platform, and two hydraulic
bale pusher rams. The baling chamber size was about 36 inches by 36
inches by variable length averaging 48 inches. Completed bales were
ejected, then positioned and loaded onto a waiting flat-bed truck by the
pusher rams. The trucks hauled the bales to the balefill where they
were unloaded by a forklift.
In cooperation with the American Hoist and Derrick Company, our
contractor studied several aspects of this facility, one of which was
bale characteristics. Table 1 summarizes measurements made on several
bales at various times after bale formation. Bale volumes were observed
to increase an average of 7.4 percent, 28.4 percent, and 24.6 percent at
one hour, one day, and one week, respectively, after production. This
expansion is shown graphically in Fig. 2 and indicates that bales stacked
in a fill would tend to close in on each other and fill gaps between the
bales.
115
-------
Average production time for the baler was found to be fairly constant
at about 1.7 minutes per bale. This is the time period from closure of
the charging box lid to complete ejection of the bale. Table 2 summarizes
plant production observed during a typical five-day monitoring period.
Bales were produced at an average rate of 17 per hour, or 24 tons per
day.
Although bales are amenable to rail haul, the bales at St. Paul
were transported to the baledfill on 40-foot flat-bed trailers towed by
enclosed cab tractors. The trailers were loaded by the hydraulic
pusher rams. Haul distance was about 24 miles round trip; and, in
order to comply with State load limits, 14 to 16 bales comprised the
normal load. On arrival at the balefill, the trailers were unloaded by
forklift. On the average, unloading required about 12 minutes.
St. Paul Balefill
Bales were stacked by the forklift three high in tiers and side-by-
side to form horizontal rows. The study indicated that about 2.2 percent
of the bales received broke during handling. An average 6 inches of
cover soil was placed once or twice weekly on the top surface of each
lift.
In order to provide controlled conditions for balefill evaluation,
a special test cell was constructed. The test cell was 90 feet by 110
feet by 15 feet deep and contained about 1,500 bales. The test cell was
monitored for settlement, gas, leachate, and temperature. Filling of
the test cell was completed in October 1973, and monitoring was conducted
over the following year. Hence, the results should be considered as
representative of only the very early stages of the biographical and
chemical systems active within the balefill.
Leachate was collected for analysis from the sump which drained the
impervious cell liner. Figure 3 shows trends for leachate and precipitation.
Leachate flow was less than one liter per day except during the months
of June, July, and August 1974. During this period about 19,000 liters
of leachate was generated. This amounted to about 8 percent of total
precipitation for the period. Results of some of the leachate analyses
are shown in Table 3 indicating relatively low values for BOD and chlorides
and an almost neutral pH.
Average tmperatures rose about 45°C to a peak of about 65°C over
the first 20 days. Over the next 60 days temperatures decreased to
about 30°C where, with some deviation, they remained over the rest of
the test period.
Gas composition was monitored at several points in the test cell.
Trends over time were slight, indicating a decrease in 02 and increases
in COp and CH^. CH concentrations generally remained below 15 percent
by volume. "
116
-------
Settlement monitoring conducted over the one-year period indicated
expansion over the first ten days after placement, followed by a basically
stable condition.
Emergence of flies from the balefill was also studied. Data
obtained from the fly traps employed is shown in Table 4 along with data
from another study conducted in Oceanside, California. The beneficial
effect of cover soil was especially evident in the final study conducted
in June 1974.
St. Paul Costs
Table 5 summarizes cost information obtained over about 20 months
of operation at St. Paul. Costs are presented for the system as a
whole, as well as for each of the three basic cost centers: baling
plant, transportation network, and balefill.
The information I have presented is somewhat abreviated and cursory.
It is based primarily on the report "Evaluation of St. Paul Solid Waste
Baling and Balefill Project" by Ralph Stone and Company. For more
details on the system studied and the results of the studies, I suggest
that you consult that report. It should be available in January from
the National Technical Information Service, U.S. Department of Commerce,
Springfield, Virginia.
We anticipate that the use of balers will increase in the future
where it is found that the processing costs are offset by savings in
transport, either by rail or road, and disposal site space. In light of
this and in order to provide more information on the behavior of balefills,
our Solid and Hazardous Haste Research Division is conducting further
research in this area. Systems Technology Corporation, under contract
to that Division, has constructed and is evaluating the five test cells
listed in Table 6. This three-year effort will allow evaluation of the
quantity, as well as quality, of gas and leachate produced by the closed
cells. Dan McCabe of Systems Technology Corporation will describe the
study and results to date in a paper on Friday.
We are fortunate in the location of this meeting, as one of the two
known operating bale facilities in the nation is in the Atlanta area.
This facility is owned and operated by neighboring Cobb County. This
baler, manufactured by American Hoist and Derrick, is similar in nature
to the St. Paul baler I discussed earlier. Flat-bed trailers are used
for transport, and the balefill is operated as described for St. Paul.
In this case, the balefill is located about 20 miles from the baler. If
you are considering adding baling to your system, I encourage you to
observe operating facilities such as this one and discuss actual costs
and operating features with the responsible officials.
117
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TABLE 2
OVERALL BALING PLANT PRODUCTION DURING 5-DAY PLANT MONITORING
1
Date 1
9/73 1
Total Wt.
Per Days:
Kg (tons)
Avg. V/t.
Per Bal«:
Kg (Ib)
No. Bales '
Per Day j-
Hours/Day/Shift
First
Second
Bales/
Hour
20
21
24
25
26
Average
263,591
(290)
362,661
(400)
350,123
(386)
383,059
(422)
275,386
(303)
326,964
(360)
1,305 202
(2,878)
1,277 284
(2,816)
1 ,273 275
(2,807)
1,277 300
(2,816)
1,263 218
(2,785)
1,278 256
(2,818)
8 3.5 17.5
8 7.5 18
8 8 17
8 8.5 18
8 7.5 14
8 7 17
121
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Cumulative P.-ecipHarion (1,000 lifers)
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The Role of Processed Refuse m Landfilling. Yesterday's Experience, Today's Status,
Tomorrow's Forecast-SHREDDING
R K.Ham
Professor, Qvtl & Environmental Engineering, The University of Wisconsin
Madison, Wisconsin
INTRODUCTION
This presentation will begin with a history of shredding, trying to trace major factors
leading up to the present situation. The second section provides a summary of reasons
previously cited for shredding, and as presently applied. Third will be a discussion01
present shredded refuse landfill practices, criteria for proper operation of such landf:
and a critique of present landfills. Finally, there will be predictions as to the
future of solid waste shredding for landfill disposal.
This presentation will emphasize the landfilling aspects of solid waste shredding.
This was suggested by the title of the paper as determined by conference leaders.
Please note, however,that certain aspects of the equipment and its role in the overall
field of solid waste management and resource recovery do affect the landfilling
aspects, and this will be discussed briefly.
HISTORY OF SOLID WASTE SHREDDING
Originally, the shredding of solid waste was conceived primarily as a preparation of
refuse for landfill disposal. There was some associated concern for resource recovery
and there are installations to be found in Europe which, over the years, have had
a degree of resource recovery in addition to the shredding and landfilling aspects,
The original experience in shredding for landfill disposal was in Europe where the
concept dates back some 25 years in England and in France. The concept was largely
unknown in the U.S. until about ten years ago when various reports and publications
appeared in this country. These reports indicated that shredding so changed the
characteristics of refuse that it could be landfilled without daily cover. In the
late 1960's and early 1970's a rapid expansion in the number of shredders took place
in Europe. By 1970 shredding was an established practice in most European countries
and was considered a viable alternative to other then common methods of refuse
management.
In the U.S., early shredding installations were installed largely for reducing bulky
or industrial wastes to improve their handling characteristics. It was never a common
practice,and many of these units are no longer operating. Quite often these shredders
prepared material for incineration in order to allow a wider range of wastes to be
burned in the normal residence time available. In 1966 reports of European experience
and claims led to the second demonstration project ever funded in solid waste by the
then U.S. Public Health Service. The Madison, Wisconsin, project was a major effort,
portions of which are still under way, designed to demonstrate the feasibility of
shredding American refuse and to determine if shredded refuse could be placed in a
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landfill without daily cover. Because of the state of landfill knowledge at that
time, this project was called upon to develop data and testing techniques which
advanced knowledge about both shredded refuse landfills as well as sanitary landfills.
For a variety of reasons the results were too often unavailable or misrepresented
for several years, and conflicting rumors and reports of the utility of shredders for
landfill operations were commonplace.
Additional installations started appearing in the U.S. in the early 1970's. These
installations were established generally to gain experience in shredding, for public
relations purposes, to avoid daily cover, and for other basically adventurous reasons.
Little data was generated at these installations and simple matters such as continuous
weighing programs were seldom addressed.
In drawing from European and early U.S. experience, supplemented by the Madison testing
program, there are some statements which can be made regarding the shredding and
placement of shredded refuse in landfills. (1) Shredding can be accomplished and,
depending upon the choice of equipment, good reliability can be achieved in grinding
residential, commercial, and most industrial wastes. Materials excluded are major
pieces of metal or wood, flammable or explosive materials, and shock loadings of other
specific wastes as hose, wire, etc. (2) The shredding installation presents new
problems not ordinarily faced by many solid waste management agencies. These problems
relate to the necessary orientation of the management of such a facility to production,
with the various long term implications of this orientation. Host municipalities
have not been in a position of operating anything similar to a factory where production
is the objective. For this reason some unusual managerial problems have been
observed at shredding installations.
(3) Many solid waste professionals have determined that a shredded solid waste
landfill can be operated without daily cover without causing rodent, insect, odor,
fire, blowing debris, aesthetic or other problems, the lack of which are commonly
considered indicators of quality landfilling operations. Most observers will find
such a landfill more acceptable on a day to day basis than they will the normal
sanitary landfill. (4) Landfill sites will be easier to obtain using shredded
refuse,for the public has been shown to be more likely to accept it. In some cases
this acceptance may have no other basis than the refuse being"treated"and, thus, no
longer recognizable as such, and what is not recognized is not recognized as a problem.
(5) Because the refuse is shredded but, more importantly, because of the lack of
daily cover, dispersion of landfill gas is more readily obtained and leachate quality
is altered. Leachate quality will be worse than the normal sanitary landfill for a
period of time, but it will rapidly improve to levels better than those of the normal
sanitary landfill. (6) Because of the lack of cover, mud tracking and operational
problems caused by wet or frozen weather conditions need not be a problem. A further
result of the use of less cover is the relatively low level of activity on the site,
which improves the acceptability of the site to the public. (7) The density of the
refuse will be increased, where the dry refuse density will increase some ten to
twenty percent through shredding. The overall density increase, including provision
for cover in the case of a sanitary landfill, will be in the neighborhood of 30%.
This represents the air space savings which can be achieved through the use of
shredded refuse without daily cover compared to the normal sanitary landfill.
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(8) The above advantages are not necessarily needed, useful, or even applicable
in all situations. Thus, local input is necessary for each site in order to
determine if these advantages are, in fact, worthy of the cost. Even if the
advantages are substantial, these must be weighed carefully against the costs, which
are also substantial. Depending largely on the fraction of plant capacity actually
achieved, shredding operation and depreciation costs generally range from a low
of approximately $3.00 per ton to a high of approximately $7.00 per ton. This cost
must be weighed against the decreased landfilling costs, landfill quality, and
any savings in hauling costs made possible by the acceptance of a closer site or
the use of the shredding facility as a transfer situation.
WHY SHRED?
It is appropriate at this point to draw from history and present day experience to
discuss the question: why shred refuse? As was mentioned previously, initial interes
in shredding installations emphasized landfill aspects. Reasons cited were
extending site life, improved public relations and site acceptability, doing somethin
progressive or new, avoiding daily cover, and generally improving landfill quality.
Experience spanning two decades has resulted in three of these reasons being emphasiz
in England: improved density, the "treatment" of refuse to gain public acceptance,
and better all round landfill quality.
In the last few years in the U.S. several new factors have emerged, while other facto
have become less important. The increased concern of the public exerts pressure, now
to "do something". People are less willing to settle for poor systems, even at
increased cost. Another impetus for shredding relates to the regulatory agencies
clamping down on bad practices and bad sites, forcing reevaluation of present methods
This reevaluation typically incorporates shredding as one available alternative, and
once one realizes the inevitable increased costs associated with trying to do a
better job, shredding can appear to be viable. Other factors which have enhanced
greatly the acceptance of shredding as an option include the facts that other
people are doing it and that shredding is usually a first step in advanced processing
schemes. The interest in resource recovery, spurred by concerns for materials and
energy conservation, coupled with the lack of widely acceptable resource recovery
systems, makes it desirable to keep one's options open in developing a final system,
yet, at the same time, maintaining a progressive attitude by improving present methoc
Shredding followed by magnetic separation of iron is available; hence, this is often
reason enougt to initiate a shredding operation with the idea that additional separat
or resource recovery modules will be incorporated as they become feasible.
Thus, it appears that the major reasons for shredding seem to be less concerned with
the landfill than they were in the past,and more concerned with keeping future option
open and resource recovery. There seems to be less concern with saving money
per se, and more concern with the quality of the reduction-disposal systom. Unfortur
it appears that in some places shredding is still used as an excuse to run an open
dump. This is of great concern, for bad operations breed adverse acceptance by the
public and regulatory agencies and future problems in imoroving waste management-resc
recovery systems.
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THE STATUS OF SHREDDING FOR LANDFILL DISPOSAL
I must approach this section with some sense of insecurity, for at one time I had
the good fortune to have personal knowledge of most of the shredding installations
in this country and had toured and discussed extensively the application of shredding
in European countries. The tremendous increase in the number of shredders has made
it Impossible for any one person to be on top of the rapidly moving field and makes
it difficult to try to describe any state of the art on shredding technology and
subsequent landfilllng practices. What I will do is supplement my experience with
two surveys of shredder installations and one survey of state regulatory agencies.
The first survey is the recent Waste Age (July, 1975) listing of shredder installations.
Following this will be some comments from a survey by Mr.Richard DeZeeuw of Green
Bay, Wisconsin, who checked by personal contact most of the shredder installations.
The original objective of this study was to attempt to relate costs of shredding to
basic variables such as tonnage shredded, rated capacity, shredder manufacture, etc.
In so doing, Mr. DeZeeuw obtained some very up to date information on the status of
various operations around the country. The final source of data for this paper is
a survey made by the author of state regulatory agencies. The purpose of this survey
was to learn of regulatory opinions regarding landfills containing shredded solid
waste and, in particular, to learn of any unusual positive or negative aspects of such
landfills.
The Waste A^e survey of 1975 indicated 126 shredding installations operating or under
construction in the U.S. Of these, 46 were listed as being primarily for bulky or
industrial refuse reduction, 59 for municipal refuse only, and 21 units were cited
as working with both types of refuse. Of the 126 shredding installations, 66 were
listed as preparing refuse for landfill with some possible interest in resource
recovery, while 60 were listed as preparation for some further processing. Usually
this processing was resource recovery of some sort, hut in some cases it would be
nothing more than bulky refuse reduction prior to incineration. Undoubtedly, all
installations involve some landfill aspects for final disposal of residuals, but
in many cases little or no information is available regarding the landfill. Note that
some of these installations will recvcle only iron for the forseeahle future and
cannot truly be classified as resource recovery installations.
One of the results of the Green Bay and state agency surveys is knowledge that the
comprehensive listing in Waste Age does not indicate the present status of the various
installations. In many cases in the Green Hay survey, no local person could be
found with any knowledge whatsoever about the installation. Tt is likely that many
of these units were for industrial,research, or other private purposes, and are not
of immediate concern to this conference. Some are located outside the U.S. and were
not contacted. Of 63 installations for which knowledgeable people were found, 9 were
closed or had never been constructed, 33 were operating and had been operating for
at least several months and had some degree of operating experience, and 21 were
too new to have any experience or data. Many of the latter were still under
construction as of July or August, 1975, indicating the rapid recent expansion in
the number of shredders.
In the author's survey of state solid waste agencies, 37 states responded. According
to the Waste Age survey, these states had 57 municipal refuse shredders and 37
industrial or special waste shredders for a total of 9i installations. The state
regulatory agencies listed 38 municipal refuse shredders and 11 industrial or special
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waste shredders for a total of 49 installations. It is obvious that the states
may not be aware of in-house industrial shredders, but the discrepancy for the
municipal refuse shredders is not so easily explained. These same states cited 32
known operating shredders, and 25 Vnown shredded waste landfills. Thus, according
to both the Green 'ay an
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left unattended. Every site the author has observed with both shredded and
unprocessed refuse being filled together has had problems. These, problems include
rodents, flies, fires, blowing debris, odors, and others. The only exception to this
was a site in the United Kingdom where decomposed shredded refuse ten to fifteen
years old is excavated and placed over industrial and bulky unprocessed refuse in a
carefully run operation. We have a test site in Madison, i-hich has been monitored
closely, in which two feet of shredded refuse was placed over two feet of compacted
unprocessed refuse in a 30 x 60 ft. area. No unprocessed refuse was visible,
yet rodent problems were documented, with extensive burrow development on the site.
4. In order to change the characteristics of refuse to the extent that the
material can be landfilled without dailv cover, there are some particle size require-
ments which must be met. The absolute particle size requirement is for no food
waste to be visible upon careful inspection of the shredded solid waste. The only
exception would be an occasional beaten piece of orange peel or some such item.
If food waste particles are observable by humans, thev will be even more observable
to rodents and insects, and they will undoubtedlv cau^e infestation problems and
probably odors. Experience suggests that if material is ground so that at least
90% of the material passes a 3 inch screen, this will be adequate. Note that
different shredders tend to produce different particle size distributions. Some
shredders may change food waste particle characteristics considerably, while others
may not, even though both shredded products pass the three inch particle size
criteria. It is apparent that additional information is needed regarding particle
size requirements for landfill disposal for the various shredder configurations.
Critique and Experience of U.S. Shredded Landfills
Personal experience and contacts, together with information from state regulatory
officials, provides a degree of experience which can be drawn upon in attempting to
determine the success and problems '-'ith shredded refuse landfills. It is observed that
states often lack the field personnel to evaluate properly such landfills. Thus,
much of the information one obtains does not come from first hand experience, but
rather by word of mouth and hearsay evidence. There appears to be a real need for
a well documented survey where a few experts visit many of the shredded solid waste
landfills to assess problems properly, operating experience, etc.
A shredding facility is not without problems and this has to affect the landfill as
well. Frequently the emphasis in running a shredding-landfill facility is placed on
the plant, which is the most interesting and crisis prone part of the system in
some respects, to the neglect of nroper operation of the landfill. Explosions
continue to be a hazard at shredding plants, but these explosions appear to be not
of great concern if the plant is designed for their inevitable occurrence. The
Wilmington, Delaware,plant, for example, has had nine explosions in the last one and
one-half vears. One item that was fortunately caught before it entered the plant
was a live landmine. The conveying and feeding of refuse is still difficult; even
though it is less of a problem now than it used to be. Other problems relate to
the fact that appropriate manpower is often not available for proptr operation and
naintenance, with provision for contingencies, of the plant and landfill. There
may he no provision for long-term maintenance on a routine basis. Finally, it is
noted that the equipment still is not off-the-shelf. There is a shakedown period
*rhich wjll he required, including some experimentation on the part of the plant
operators to determine the best way of operating their particular plant.
Information and opinion regarding certain features o£ the shredded waste landfills
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is contradictory. From the replies of the 37 state agencies that responded to the
questionnaire, it is interesting that of the reasons cited for shredding in
the installations in their states,14 were to avoid daily cover, 11 to provide resoi
recovery, and 7 to increase refuse density. in 18 cases no daily
cover was applied to shredded solid waste landfills, but in 7 landfills daily
cover was provided. In 10 landfills unprocessed refuse was placed on the fill
along with shredded. In 8 landfills no unprocessed refuse was disposed on site. 1
critique of the sites by state agencies indicated a lack of common experience or
common guidelines for critiquing. Several agencies reported that the sites were
causing no problems at all and that they were very bappv with them. Other agencies
described problems which they thought were serious. Problems cited included
leachate, blowing paper, insect problems, rdor, and mechanical problems. On the
other hand, positive aspects cited were increased density, easier operation, lack
of odor, lack of flies, and the ability to operate in a situation where cover was
unavailable.
It was interesting to observe the lack of uniformity of experience or knowledge
with respect to shredded solid vaste landfills. This indicates a lack of acceptanc
of information available, a lack of knowledge of information available, or incorrec
information being available. For example, there is at least one city that has tolc
the state regulatory agency that no_ leachate will be produced as long as they shrec
the solid waste before landfilling. On the other hand, another state specifically
required daily cover of shredded solid waste in order to avoid leachate problems.
It is obvious that at least one of these two statements is wrong and, according to
studies performed by the author, it appears that both are incorrect (1). At least
one state apparently requires daily cover unless a shredded refuse landfill has
leachate collection; however, data in reference (1) indicated that the lack of covs
improves overall leachate quality.
Other areas of disagreement or misinformation are the questions of odor and fly
problems. Some state agencies and other professionals say they have specific
knowledge of odor and fly problems on shredded refuse landfills; whereas others sa^
they have specific knowledge of no odor problems or fly problems on such landfills.
Apparently, there is lack of criteria for judging,a lack of first hand knowledge, c
the sites are, in fact, very different. One rather unfortunate comment that came i
several times in the response from state agencies was that there are several
situations where shredded refuse is placed in what is otherwise an open dump, think
that the problems of the open dump would, thereby, be solved. Of course, this is
incorrect, and it is unfortunate that these kinds of operations are allowed to
continue.
From personal experience and contacts, it does appear that odor is more of a proble
than was commonlv thought. The odor is musty and soil-like at a minimum, which is
not as strong nor as disagreeable as the odor of unprocessed refuse. However, to
some people it is still disagreeable. Claims of shredded refuse having no odor
are absolutely false. It appears that odor problems are sometimes related to the
moisture content of the refuse and, if any water is allowed to be in continuous
contact with shredded solid waste,maintaining saturation conditions over a period t
tune, odor problems are likely.
This section has attempted to look at both the number and purpose of shredder
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installations in order to evaluate the status of shredding in this country.
Guidelines based on U.S. and European experience concerning the right way to run a
shredded refuse landfill were presented, along with a qualitative critique of landfills
from experience gained by the author personally and from contacts with state
regulatory agencies. In concluding this section, the significant discrepancies
observed in trying to develop information about the number of shredding installations
and the success of shredded refuse landfills should be emphasized. I had assumed,
perhaps naively, that the field was becoming more mature and that a realistic
appraisal of shredding was being accomplished, both from a prospective shredder
operator's viewpoint as well as that of a regulatory agency. It is obvious that
there are still some major problems in this area, and that additional documentation
needs to be provided. There is confusion regarding who is operating what facilities
and for what purpose, guidelines for operating a shredded refuse landfill, and the
degree of success of these landfills.
THE FUTURE OF SHREDDING
Drawing from information already presented in this paper, one can make some
predictions regarding the future of iolid waste shredding. First of all, editorially,
t'"u' aut'ior certainlv hopes that the futurp vill brinp, about a norf nature evaluation
and use of shredding technology. There '.-'ill be, hopefully, a day when those people
who need a shredder will realize they need it, and those people who do not need a
shredder will realize they do not need it. Perhaps this is too much to ask, but at
least it appears that we could he closer to that day than we are now. Also, we
should have criteria for running a shredded refuse landfill operation established
and accepted to a wider degree than we have today. These points are significant,
in my opinion, for they will impact on the number and purposes of shredding
installations, and whether shredding is considered an independent, useful solid waste
management tool or an Interesting side venture.
The field of shredding has changed rapidly in the last five years. Remembering that
it was conceptually visualized only 25 years ago, that virtually no literature on
the subject was available until about ten years ago, and that the first U.S.
experience receiving any documentation was available not more than five years
ago, it is amazing that the field has come along as far as it has.
It is obvious that there will continue to be an increasing number of shredding
installations. These installations will continue the trend toward larger systems
having multiple shredders which are able to handle a wider range of solid wastes.
The trend to the shredding of bulkv and industrial wastes, along with municipal solid
wastes, will undoubtedly continue. It appears that shredding will be done primarily
to facilitate resource recovery as opposed to strictly sanitary landfill purposes,
but the landfill is an inevitable part of any forseeable shredding installation
and, so, must be of professional concern.
There appear to be several areas for which further study or documentation is needed.
There is confusion as to the importance and effect of particle size on the successful
landfilling of shredded solid waste. It is likely that in future years the emphasis
on resource recovery as part of the reason for shredding will, in turn, dictate
the particle size distribution required. Even at that point, however, one must be
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sure that the particle size distribution of the material to be lane1 . jed is
adequate for running a good nuisance free landfill. Another problerr :. lau-d to the
effect of incorporating resource recovery in shredding installations is the effect
on refuse quality of removing various components of the waste prior to landfilling.
Changes in waste composition may invalidate experimental results and experience
regarding shredded refuse landfills.
There is continuing concern about leachate production from shredded solid waste
landfills. Considerable data is available on the quantity and quality of leachate
produced, but this data has not included some of the very practical considerations
found in any actual landfill. For example, it seems of less importance to determin
the leachate quality from one layer of refuse than it does to determine the leachat
quality from multiple layers of refuse, as one would have in an operating landfill.
The first study, of which the author is aware, to examine the effect of placing fresh
refuse over aged refuse in a landfill has just been Initiated at Madison, Wisconsin
This is just one of several areas needing study before the leachate question can be
resolved.
Finally, there is considerable confusion as to the importance of daily cover and it
relation to site acceptance. There is need for a comprehensive survey of existing
sites to document problem areas and make recommendations regarding appropriate desl
and operational procedures for shredded refuse landfills. Until this kind of
documentation exists, we will continue to have hearsay evidence and conflicting
opinions on the worth and reliability of these landfills. Ultimately, this confusi
will reflect back to the acceptability of the shredding concept whether it be
primarily for landfill or resource recovery purposes.
REFERENCE
(1) Ham, R.K. and R. Karnauskas, "Leachate Production from Milled and Unprocessed
Refuse", 1SWA Bulletin, No. 14/15, p.3, Dec. (1974).
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HANDLING DIFFERENT WASTE TYPES: BASIC OPERATIONAL CONSIDERATIONS
Cecil Iglehart, Jr., P.E.
Civil Engineer, SCA Services, Inc., Kentucky
Different types of solid waste are handled by different methods
depending upon the size of the landfill and characteristics of the waste to
be disposed of.
Size of landfill, in my discussion, means volume of waste to be disposed
of daily. High volume landfills will have no problems handling many types of
bulky wastes because of more equipment and personnel on site, the larger
working face, and the large volume of residential waste to mix with and cover
the bulky or special waste. A small operation handling only a few hundred
yards of solid waste per day will have a hard time handling even one tandem
dump load cf logs. Tliexefoie, sifce of landfill plays a very major role in
determining how to handle the different waste types.
Landfill foreman and operators must become familiar with every load of
solid waste entering the landfill. Solid waste coining to the landfill is
either residential, commercial, industrial, residential trash, construction
or deraolation waste. Residential waste usually comes to the site in rear loaders,
is well broken up, and easy to spread and compact. Commercial waste usually
comes to the landfill in large front-end loaders and is also well broken up.
Industrial waste usually comes to the landfill in large open top or closed
roll-off containers holding from 20 to 50 cubic yards. Industrial waste can
be anything and is the hardest to handle and sometlines requires special techniques.
Residential trar>h usually comes in on dump trucks or flat bed trucks and
consists of tree liipbs, whito goods, old furniture, old torn up shed:>, tires,
and other bulky Items. Construct ion waf-ti? is wood, plaster board, large plastic
sheets, tree roots and logs, old tai roofs, broken up concrete and asphalt.
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Demolation material is large tandem dumps or sixty five yard open top trailers
filled with broken up buildings usually loaded with a two or three yard bucket
on a crane or track loader. Material is mostly broken up wood, brick, and
concrete with some metal pipes and steel beams.
Landfill personnel can become familiar with every contractor hauling to
the site. The operators can observe industrial waste being unloaded from roll-
off s and can ask the driver where certain loads come from. Since certain
industrial waste are the hardest to handle, the landfill operator can soon
recognize the problem loads and can direct the driver to the proper unloading
area. By becoming familiar with the haulers using the site, and knowing where
his load is coining from, the operator is in a better position to spot some
hazardous material or unknown substance which should not be in the solid waste.
In large metropolitan areas where there are large volumes of industrial
vaste, there are larger landfill operations where the site has two or more piec
of landfilling equipment and large volumes of residential and commercial solid
waste. Landfills of this size usually operate by unloading trucks at the base
of the sloping working face where earthmoving equipment then push, spread, and
compact the solid waste upslope. In a majority of cases, wastes which cannot
be spread easily are pushed up against the toe of the slope, but not pushed
upslope. The landfill operator usually directs the driver of a load such as tt
to the side of the working face which may be 150 fio 250 feet wide. When this
is pushed into place the next several loads of residential waste can be directe
to dump in the same general area. The residential waste loads are then pushed
in around and over the industrial waste load, and compacted to form a new
working slope. It may take several residential loads to completely establish
a new working face over the hard to handle industrial waste load. An example
of this vould be a twenty yard open top full o£ old coble and cable reels
from a telephone company. If this"cable were spread out and pushed upslope
it would become entangled in the dozer tracts or compactor wheels nod would can1
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serious equipment problems. By keeping the load pushed together and moving it
as little., as possible it can be covered with other trash which can be worked
in and around it where eventually a machine will be compacting by running over
the load.
I have several slides which I will show later, showing different types of
industrial waste and how they are handled. On large sites however, a general
statement can be made: almost all industrial waste can be handled on the main
working face of the landfill by spreading upslope or by pushing against the
toe of slope and filling over the special waste with residential and
commercial refuse.
Residential trash which comes in by dump truck and contains a lot of brush
and white goods are best handled by breaking the load loose, spreading it out
and running over it before it is pushed upslope. All loads being pushed upslope
should be spread and run over by the dozer or compactor before the machine starts
back down the slope. This process breaks the load up, mashes it into the previous
load and makes it possible to push the next load over it.
Work with the haulers using the landfill and let them know of some of the
operational problems they generate. It can sometimes be helpful to have certain
loads come to the landfill before noon or even before the first loads of
residential trash start coming in. Large loads of rubber tires are a good
example of this. These loads can be spread along the entire base of the working
face and ten feet of solid waste placed over then before the day is over. It
would be ideal to have these tires cut up, shredded, or split before they enter
the landfill, but only one state regulates tire disposal E.t this time.
Pick-up trucks and other hand unloaders themselves are considered a
special waste problem simply because of the space they take up and the time
to unload. If the sane, guys come in regular they ran usually be talked into
coming in before or qf tc-r peak traffic times and sometimes they will stay away on
very muddy dnys. Large landfill may have a separate working face for hand
unloaded trucks. 139
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Some construction and demolation waste can be used to build all weather
access roads on site. Talk to the contractor, let him dump broken up asphalt,
brick., dirt and concrete free if he keeps it seperated from other wastes which
must be covered daily.
Sludges are usually best handled by pushing upslope and letting the sludge
waste spread and mix with the other wastes which are mostly paper. This
spreading allows for maximum absorption of the liquid in the sludge and causes
the least operational problems.
Special waste problems can start with the land clearing of the site for a
sanitary landfill. If the site is heavily wooded, you've got problems. Many
urban areas will allow no open burning even for land clearing. In some cases t
property can be logged and the timber sold. In a majority of cases, however,
the timber is pushed down with dozers and windrolled. It can be pushed in the
bottom of trenches later, stockpiled between rolls or spread over the bottom of
a lift.
Every T^ndf-OI site will receive some druu.s. They may be empty, they may
contain some solid which has set up and can't be removed or they may contain sot
non-hazardous liquids. If your dumping ia a trench, push them to the bottom
and cover with refuse. If you're pushing upslope, try to keep them at the toe
of the slope and cover. There is a market for a clean drum in good condition
if you've got time and people to handle them. Some drums can even te used for
traffic control. Like everything else, drums are handled by whatever method
works best based on volume of site. The wide wheel of an LF280 Michigan
compactor on an 826 B Caterpillar can easily mash a drum flat with no problems.
Small trench type landfills can usually handle special wastes easl then
small area-filled type landfills. They just push the waste over the slope and
continue pushing other vaste over the slope until the special waste is covered.
The slope is then reworked and compacted.
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Some small landfills in urban areas where larger landfills are available
should not even attempt to handle large industrial waste loads which present
special waste handling problems which could mess up the working face for a whole
day or may present a danger to the equipment.
The manager of a landfill operation which is having problems with a special
type industrial waste because of the size or contents of the material or because
of its volume relative to the size of the landfill can visit the plant manager
and discuss the situation. It could be the material could be handled differently
at the plant to put it in a more acceptable form. This statement may sound
ridiculous to a manager of a Los Angeles County landfill or from a site in Chicago,
but for a mojority of cases it is a very direct approach to a very difficult problem.
The savings in operating costs at the landfill because of less handling or
equipment breakdown can also make that customer easy to live with instead of
dreading to see that load come in.
Another example of a special waste is a rubber dust from a tire recapper
or a carbon dust from a paint or ir.k maker. These materials are like powder
and blow up and cover the equipment spreading them. This material can be drawn
into the radiator by the fan blades or it can be drawn into the engine air intake.
The idea here is to move this type waste as little as possible and to get other
waste over the carbon or rubber as soon as possible. Sometimes the industrial
plant can change this material into a slurry which is much easier to handle.
Pushing logs and large limbs is another special problem because of the
possibility of running one of the limbs through the radiator of the landfill
machine or tearing up a hydraulic hose.
Sometimes a landfill operator will be called upon to handle a special
problem. An example could be a grocery store fire, where the entire contents
of the store must be buried under the eyes of a federal or state inspector. In
this case it uill usually be easier to dig a special trench Cor all the grocery
waste where it can be dumped, compacted and buried.
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There is also special types of hot loads which must be handled,, I am
familiar with a diatomaceous earth type material used as a filter for cleaning
vegetable oil. This material must be spread in thin layers and allowed to
cool down. If it is not spread heat will build up and the material will start
to smoke. If this material is dumped on other material it could start a fire.
This material must be spread and allowed to cool in a separate location from
the working face. Once the material has cooled it can be mixed with dirt and
covered. Loads of incinerator ash should also be dumped in a separate location
and allowed to cool.
Some of the factors which lead to good sanitary landfill operations are
also needed to properly handle special type wastes.
A site can be engineered to prevent pallution, but proper operating
procedures are also important and necessary to insure proper pollution control.
Spreading refuse in thin layers, compacting, and covering with six inches of
soil at the end of each day is good operating procedure which also help control
pollution.
To me, one of the most important factors effecting the good operation of
a sanitary landfill is the access road. This road is important relative to
handling special type waste because if your access road is not adequate to
handle the heavy loads coming to the site, you won't have any special waste to
worry about.
The all weather access road must extend as close as possible to the working
face of the landfill. A wet weather dumping area near the entrance to the landfil
is an important part of any operation and i=; a good way to keep up the other
roads which have a way of deteriorating very rapidly when they are used in bad
weather without being properly crowned and '-caled, especially when they are over
filled or completed areas of the site. Maintaining access roads is a daily job
just like providing daily cover and if oporntinp po t>onnel arc made to realize
this they will soon considci it part of their daily job.
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FUNDAMENTALS OF SELECTING LANDFILL EQUIPMENT
Chris Klmck
Product Manager, Rexnord, Inc
It's a pleasure to address such a wide cross section of the
Solid Waste Industry and to share the speakers' plattorm wi'.h
such knowledgeable and experienced leaders as Cecil Iglehart,
Mike Lawler, Dick Mollenhouse, Dick Eldredge, Fred Pohland
Ron Schwegler, Bob Sterns, Mike Heker and Lonnie Hickman.
I am told that in colonial days, land disposal of solid waste
was accomplished by turning pigs loose on the accumulated
garbage. It was a simple way to handle the solid waste dis-
posal problem. As the years passed, our society has become
more complex and the resultant problem of how to dispose of
the waste that this complex society produces has also become
more complex. As the title of the conference suggests, this
has become quite a puzzle. It is, therefore, necessary for us
to fit the various bits and pieces of the gigantic puzzle of
solid waste management together correctly so that it will
provide a picture that makes sense. One of the reasons the
pieces of the puzzle don't always go together properly can be
blamed on Murphy's Law. For those of you who are not familiar
with Murphy's Law, it is the general hypothesis on why things
go wrong. Simply stated, it says - "if anything can go wrong,
it will" - or said another way, it states - "That of two possible
events, only the undesired one will occur". Murphy's Law explains
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why a board cut to the exact length will always be too short or
why your air conditioner only breaks down during the middle of
the July heat spel] or why the $300.00 color picture tube in
your TV set will protect its 10c fuse by blowing first.
I'm afraid that Murphy's Law creeps Into all of our lives from
time to time. I guess it also explains why some landfills do
not turn out as well as we hoped they would. I'm glad that I
was assigned to talk about selecting landfill equipment this
morning, because it is my opinion that of all the phases of
sanitary landfill planning, noniis more critical than machine
selection. Although the landfill operation may be carefully
planned with all operating techniques outlined, a refuse dis-
posal system can't be a success if the wrong size or type of
equipment is used. There aren't any hard and fast rules govern-
ing machine selection. The particulars of your operation --
whether it is an area method or a trench method, site charac-
teristics, volume of refuse, type of refuse, land geography,
type of soil - sand or clay,-weather conditions - do heavy rains
make traction tough or in cold weather operation, must frozen
material be dug or used for cover material, how far must cover
dirt be transported, and the end use of the landfill are all
factors that must be considered in selecting landfill equipment.
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Of all the different types of machines used in a landfill, the
crawler tractor has been used in more operations than any other
type of machine. The reason for this is that the crawler
tractor has outstanding dozing ability. It can be used for
pioneering and to strip top soil as well as for excavation and
to move cover dirt up to 250' to 300". It can also be used for
spreading and placing refuse as well as spreading and placing
cover dirt.
Crawler loaders are often used in smaller trench type landfill
operations because while they can be used in pretty much the
same manner as crawler tractors, their bucket is about the same
width as the machine so they can work up closer to the side of
the trench, than can crawler dozers. They can also be used to
load dirt into trucks if dirt is being hauled out of the land-
fill for other uses. Also in small communities where the
landfill is open only 2 or 3 days a week, they can do double
duty and be used to do other road maintenance work that may be
required by the community.
The tendency is to use a crawler tractor or crawler loader in a
small landfill where only one machine can be afforded because
of its versatility. However, this is the situation where Murphy's
Law will probably come into play in landfills. If you're trying
to operate a landfill with just one piece of equipment and without
a back-up machine, Murphy's Law of landfill machine behavior will
cause that machine to break down when the landfill is the busiest.
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This usually occurs just before the EPA inspector drops in for
a routine evaluation of your landfill. Frankly, I don't believe
it is practical to run a true landfill with only one machine.
Many times the size of the landfill and the accompanying econo-
mics don't justify more than one machine. This is one of the
best cases for a regional approach to sanitary landfills, where
a number of small communities band together so there is suffi-
cient volume and funds to have the right equipment to do a
proper job of sanitary landfilling.
As the volume of material coming into the landfill starts to
increase, definite efficiencies can be achieved by using
specialized equipment. One cost savings that can be realized
is to increase the density of the refuse placed in the landfill.
Longer land use, less trench area required if this landfill
method is used, less cover dirt required and increased value of
the completed landfill are some of the cost savings that can be
achieved through better compaction. Proper machine operational
methods, such as thin lifting of the refuse, will increase density.
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Another way to increase refuse density is by the use of steel
wheel compactors to spread and compact the refuse that is
brought into the landfill. The reason that a 50,000# steel
wheeled compactor is capable of achieving more density in a
landfill than a 50,000# crawler tractor is that the compactor
concentrates its weight on the steel wheels, which results in
more compactive effort being exerted on the refuse, while the
crawler tractor spreads its weight over a large track area
which results in less compactive effort being exerted on the
refuse.
Steel
wheel compactors are also used to spread and compact cover dirt
in many landfills.
Another specialized machine that can produce definite cost sav-
ings for digging trenches, preparing sites, stripping top soil
and for moving cover dirt is the tractor-scraper. Without
question, wheel scrapers are the most prevalent earthmoving
system in the construction industry today. Their ability to
handle a wide variety of material, combined with a relatively
low loading cost, are the key factors in their economic per-
formance and accounts for their wide acceptance. There are
numerous variations and sizes of scrapers. You should select
the one that best fits your needs.
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The crawler drawn scraper, which is the original scraper config-
uration, can move dirt efficiently for distances of 300' - 600'.
It is an all-weather machine which can be an advantage in some
areas of the country especially, in northern climates. The
tractor can also be disconnected from the scraper to serve as a
back-up machine for spreading and placing refuse.
The effort to perfect the economies of dirt hauling has produced
many money-saving and innovative modifications to the crawler
drawn scraper. Once the haul distance starts to approach the
600' and up area, rubber tire scrapers become the most economical
way to move dirt. Rubber tired scrapers can be placed into two
classes - conventional and elevating. The biggest difference
between the two is that the elevating scraper has the ability to
self-load many types of soil. Because of this, the elevating
scraper can move dirt at a lower cost than its conventional
counterpart. It is important to remember, however, that push
loading of elevating scrapers should be avoided. The
conventional scraper on the other hand has the ability to load
material, such as wet clay containing rocks with the help of a
pusher tractor. All wheel drive - twin engine, self-propelled
scrapers also have better traction and can handle steeper grades
twin-enqine scraper
than single engine conventional scrapers. The A can also self-
load certain soil types.
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In some operations, wheel type loaders are used to haul cover
dirt in the neighborhood of 600'. This works out best in small
landfill operations where the wheel loader can be used to load
trucks with gravel or can serve double duty on road maintenance
work, snow removal or other loading jobs.
In landfills using the trench method, drag lines can be used
effectively where conditions do not lend themselves to scraper
excavation. Drag lines are particularly useful when working in
highly plastic, wet clays. The drag line has the ability to dig
in wet conditions and can cast the dirt to either side of the
trench where it can then be used later for cover dirt. When
the conditions are right, this can be the most economical way
to provide the necessary trench.
As I said earlier, there are no hard and fast rules. If you
have doubts concerning the best dirt moving equipment for your
particular needs and site characteristics, I suggest that you
consult an experienced equipment distributor.
No matter what equipment will provide the best and most econom-
ical landfill for you, it must be kept in mind that landfills
are severe duty equipment applications, that must operate in
all types of weather, 52 weeks a year. The equipment must be
optioned with this in mind.
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For instance, consideration should be given to:
1) An enclosed cab with sound suppression and equipped with
tinted glass and windshield wipers so the operator can
work in bad weather.
2) A Roll Over Protection Structure is also a good idea.
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3) A Heater and Defroster, along with an air conditioner or
cab pressurizer, are popular options in many climates.
However, I should point out that air conditioners require
special maintenance considerations.
4) Special protection is required for landfill use -
a. Underneath the machine must be protected with heavy
steel plate to prevent damage.
b. Special radiator guards are also necessary.
c. Fenders to deflect flying objects or pipe are also a
good idea.
d. Perforated engine enclosures help keep debris out of
the engine compartment.
e. An Anti-Vandalism Kit is a good idea if the machine is
left parked on the landfill overnight.
I would like to emphasize at this point that the special protec-
tion required for landfill use should also permit easy access
into the machine for service and cleaning.
5) Signal horns mounted on the machine are used by many operators
to direct truck drivers.
6) Since many landfills work in dusk or dark conditions,
especially during the winter months, lights, front and rear,
are also a good idea.
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7) Fire suppression equipment mounted on the machine is also
good insurance. A clean machine will also help to prevent
heavy damage from fire.
Murphy's Law also applies to those of you in the public sector
of the waste management business who must decide on the type
of equipment you need and then must write a specification that
gets you what you need and also encourages competitive bidding.
The low buck buy is not always the best buck buy. Evaluate and
analyze the equipment bid, not just in terms of the dollars
involved in the equipment itself, but also in terms of the
overall cost of operation. It may very well turn out that the
rubber tired scraper that costs more may have better traction
and gradability, and therefore, will increase your dirt moving
production and thus reduce your cost of operation by much more
than its price differential. It is very important to not only
evaluate the initial cost of the equipment, but also to analyze
the effect that the equipment will have on the overall cost: of
the landfill operation.
Another important consideration in selecting landfill equipment
is choosing the proper size equipment. Even though a certain
size equipment may be adequate for today's needs, the tendency
is for landfill volume to increase. Since landfills are the
cornerstone of the solid waste disposal industry and most
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experts do not see any change in this for the next decade,
you should size your landfill equipment to not only meet
today's needs, but also to meet your future needs. Select
large, heavy-duty equipment for your landfill it will be
much cheaper in the long run.
Gentlemen, I guess Murphy's Law is a fact of life just as
gravity is a fact of life. However, just as we don't go
looking for harm from gravity by standing under a falling
boulder, I recommend that we shouldn't ask for trouble from
Murphy's Law by selecting the wrong landfill equipment.
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EQUIPMENT MAINTENANCE FOR LANDFILL MACHINES
Richard Molenhouse
General Manager, C I.D./Waste Management, Inc.
To begin this discussion of sanitary landfill equipment maintenance,
I'd like to express confidence in the future of the sanitary landfill as
a prime factor in the waste processing and disposal systems of the future.
I feel just as strongly that systematic operational controls are an absolute
requisite if sanitary landfill is going to be fully responsive to future
solid waste management needs. Let me explain what we face in the age of
environmental concern all of us, whether we're managers of large or
small sanitary landfills, and whether we represent governmental waste
management agencies or private industry.
Equipment needs have substantially increased during the past decade
as state, regional and local regulatory agencies have begun to mandate the
open dump out of existence. Increased demand for environmental control
and improved housekeeping practices -- long overdue-- have become the rule
rather than the exception.
At the same time, equipment costs have risen -- both as a result of
the larger and more specialized equipment required and as a result of
inflationary pressures that have seen equipment costs soar by 50 percent
and more in the past two years. Real estate, labor and engineering costs
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are also increasing as the availability of close-in disposal sites diminishes,
as the standard of living escalates, and as broadening environmental regu-
lations are applied.
It is generally accepted that operating an environmentally sound san-
itary landfill wil cost at least two to three times what it formerly cost
to operate the uncovered, open dumps which unfortunately, still serve many
urban areas of this nation.
If we are to upgrade our disposal practices to meet ever increasing
and badly needed environmental legislation -- if we are to "clean up our
act" in solid waste disposal -- some operational cost increases will be
unavoidable. But, the successful sanitary landfill operator must discover
and eliminate the wasteful practices of a simpler era past.
We cannot avoid spiraling land costs. We must compete financially
for qualified equipment operators. Therefore, I belive that the one area
in sanitary landfill management that promises true opportunity for cost
control is to be found in effective selection, maintenance, and utilization
of sanitary landfill equipment.
I am responsible for the management of three sanitary landfills, re-
ceiving and disposing of several thousand tons of refuse each day, and
utilizing approximately 25 pieces of earthmoving equipment and support
vehicles. I would like to challenge you -- fellow solid waste management
and sanitary landfill professionals -- to answer a few basic questions.
What does it cost per hour to own, operate and maintain a 24-yard
scraper? What does it cost per hour to operate a 30-ton tracked dozer?
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What does it cost per hour to operate a steel-wheeled sanitary landfill com-
pactor? What is the most common parts failure on any of these machines, and
how large an inventory of replacement parts and supplies should your shop
supervisor carry in order to avoid the delays necessitated by reliance on
outside suppliers in the event of equipment failure?
For example, let me give you a brief maintenance history of one of our
firms more than 300 pieces of sanitary landfill and earthmoving equipment.
It is a 30-ton dozer, manufactured in 1972. It has logged 6,058 hours, of
sanitary landfill operation. The track assembly was rebuilt at 3,378 hours,
and the engine has operated 6,058 hours without a major overhaul. In 1974
we spent a total of $5,004.75 on preventive maintenance, $4,472.31 for fuel
and lubricants, and $7,291.76 on major repairs. To date, this machine has
cost $16.16 per hour to operate.
This history record -- that's what it really is tells me that the
machine was last lubricated on November 3, 1975, and that we will probably
have to perform a major on the engine in about another 4,000 to 6,000
operating hours. We record all maintenance performed on every machine
we operate. By consolidating these individual operating histories, we
have, in fact, been able to establish true hourly operating costs for each
type and manufacture of equipment in our fleet.
Armed with this type of information, we have been able to develop
effective parts inventories, to design a more effective maintenance program,
and to discover and eliminate individual machine abuses which were formerly
accepted as a normal cost of doing business.
This program is now used to train managers and shop supervision at each
of Waste Management's 53 sanitary landfills across the nation. Even equipment
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manufacturers and dealers are turning to our shops for methods of improving
their parts supply and customer service procedures.
To organize an equipment maintenance program of this scope our mainten-
ance record system is the foundation of our entire maintenance program, and
the results we have achieved since instituting this program 3 years ago
are, we think, quite dramatic. We have realized nearly a 30-percent increase
in engine life, and a substantial reduction in drive chain and undercarriage
repairs. We have even reduced the total number of machines necessary to
serve our disposal sites.
The first step in this detailed record systems is the Employee's
Daily Work Sheet, which must be completed each day by every employee at
any of the three sites. One side of the form is completed by the equipment
operator, and identifies the unit operated, the job assignment performed
the hours worked, and the operator's comment on the condition of the unit
at day's end.
The other side of the form is completed by the night service man
at our high volume CID site in Illinois, and by the operator who is responsi-
ble for daily equipment maintenance at our two smaller outlying sites.
In either case, the individual performing equipment maintenance records
fuel consumptions, engine oil consumption, hydraulic oil added, trans-
mission oil added, radiator coolant added, and whether the machine was greased
or not. He is also asked to report any conditions that should be brought
to the supervisor's attention.
A second key report in successfully tracking and controlling unit
maintenance costs and needs is our Monthly Fuel Consumption Report which
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enables operational personnel to record the amount of fuel consumed each day.
One side of the Report records daily fuel meter readings at each disposal
site, gallons used each day, daily fuel pruchases and fuel inventories in
the storage tanks. In Illinois these records are required to qualify for
non-highway use fuel tax rebates. This report also gives dailv fuel con-
sumption for each machine by unit number. This provides a centralized
check point for comparison of unit and fleet fuel use as each month pro-
gresses, and provides management with a visual check of day-to-day equipment
utilization and fuel consumption patterns.
A third element in our maintenance reporting system is the Daily
Maintenance Report, a copy of which is maintained on each piece of equipment.
This sheet is numbered 1 through 31, and provides for daily entry of fuel,
lubricant, hydraulic fluid, radiator coolant usage, and remarks on daily
maintenance performed. This report allows our shop supervisor to construct
a month-to-date recap of the general condition of each piece of equipment
at the end of the month.
Next is the Equipment Repair Report maintained on each piece of equip-
ment, where a detailed history of parts and repairs is kept. This informa-
tion is transferred to the Work Order as future repairs become necessary, and
provides both mechanics and supervisors with a cross check on replacement
parts failures or improper repair work. It also provides information on
hard to get parts, or parts not listed in the maunufacturer's parts book.
Finally, these reports aid in selection and maintenance of parts inventories.
We also maintain a Daily Charge Out Sheet on the parts room counter.
All materials removed from inventory are recorded on this form, showing the
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parts number, quantity used, and a brief description of each item. Entries
from this form are transferred to a repair order, and are also posted to the
Calrdex Inventory System.
This index system -- the Vicotr Visual Cardex System is fundamentally a
written visual record of repair parts in stock, and the flow of inventoried
items through the shop. Cardex listings reveal the part number and des-
cription or model of machine on which the part is used, the sub-assembly in
which the part in installed, and the exact location of the part within the
parts room itself. Entries are made to show the date each part was received,
the order number on which it was purchased, the quantity received, and the
balance on-hand.
Working with these various forms, the shop supervisor completes a
Daily Report of Expenses, which is turned in to my office at the conclusion
of the day. This enables me to immediately review what was purchased during
the previous day. The report provides an explanation of use for any items
purchased, including the vendor, the price, and the specific machine or
function for which the item was purchased.
I also receive a Daily Report Sheet which records exactly what each
machine and each employee did during the previous work period. This report
provides accurate costing on a project-by-project basis, and is completed by
the supervisor from individual employee's daily work reports. It shows which
operator was assigned to a particular machine, and the number of hours the
machine was employed in a particular function, such as compacting, earthmoving,
trenching, or road maintenance. It also tells me how many hours employees
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spent in these functions, or in various equipment and site maintenance
functions, or on assignment to one of our outlying disposal sites.
finally, we consolidate entries from these various forms on a Summary
of Cost History maintained for each piece of equipment. This form allows
us to construct accurate hourly operating costs on each and every machine.
computations are based on the actual work hours, rather than on the hours
meter of the machine itself. These reports record the accumulation of hours
from one month to the next, allowing us to effectively spread periodic
major repairs over the operating life of the machine, rather than showing
an uneven swing in operating costs during a month of major repairs.
In this way, we accurately track each operator's wages, without dis-
counting for time consumed in equipment warmups, engine tests, etc. The
form incorporates all costs -- including parts, operating labor, maintenance
labor, oils, fuels, lubricants, and taxes -- providing a total monthly cost
which reflects both operating and maintenance costs. It is then a simple
matter to compute capital costs, and to arrive at an accurate monthly and
lifetime hourly cost on each and every piece of equipment. It is even
possible to trace those job functions and maintenance procedures which create
major positive or negative swings in equipment operating costs.
In conclusion, I should point out that maintenance of all this paperwork
is not as time consuming as its sounds in explanation. Still, the reporting
system itself would not be worth the effort if the cross-reporting system
was not thoroughly studied for the insight it provides in improving establish
maintenance practices. These studies have enabled us to expand our service
to other Waste Management operating divisions with no addition to either staff
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or facilities. We have also been able to accurately weigh comparative costs
of sending mechanics into the field versus bringing a piece of equipment into
the shop for repairs.
Using these reports as a basis of comparison, we charted both equipment
utilization and maintenance costs for both of our smaller outlying landfills,
to develop new and improved field maintenance procedures. We purchased a
boom truck that is used as a portable hoist for field repairs, as well as a
vehicle on which engines, transmissions, undercarriages, compactor wheel assemblies,
and other heavy equipment parts could be transported to and from the field.
The unit is used as a portable crane, saving multiple investment in permanent
hoists at smaller, infrequently used shops. It has also provided considerable
savings in time formerly spent rigging field hoists.
We discovered that in some cases, it is cost effective to remove a major
component such as an engine, transmission or track assembly and bring it
to the central maintenence facility for repair. In others, the disabled machine
is brought to the shop, and a spare machine is provided for the field operation.
We have, consequently, placed a 50-ton, low-boy into service increasing
our ability to effectively service machinery for an expanding number of sites.
But, none of this outside service was possible before institution of our sys-
tematized maintenance reporting system. We were, quite simply, failing to imploy
either manpower or equipment in a truly cost-effective manner. We were working
harder and accomplishing less. Consequently, we had neither the space nor the staff
to accommodate outside work which has since become an integral part of our main-
tenance function.
More importantly, we have been able to establish a vastly improved parts
inventory reducing our per-unit investment in infrequently used replacement
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ment parts, and eliminating much of the equipment downtime resulting from
parts shortages. For example, standardization and on-site fabrication of
hydraulic lines and couplings has eliminated costly delays in repairing
hydraulic leaks and failures. In many cases, a mechanic can repair hydraulic
leaks on the actual face of the working landfill. Similar saving?, in time and
investment are being experienced in filters and other items necessary to an
effective preventive maintenance program because we can accurately calendarize
our PM needs.
Also as a result of these studies, we have been able to more effectively
employ both manpower and physical facilities by standardizing daily PM pro-
cedures and work assignments. Major repairs are normally completed during the
day when our maintenance facility is staffed by the supervisor, three mechnanics,
and one apprentice mechanic. This crew, as I said, handles major engine, under-
carriage and drive chain repairs, plus normal day shift equipment failures, and
any outside work we assume for the other Waste Management sanitary landfills.
The night shift is staffed by a mechanic, one apprentice, and a greaser
and is responsible for normal preventive maintenance activities. Machines
returning from the day shift are parked in a staging area, where the apprentice
cleans all tracks and undercarriages. This completed, he moves each machine to
the fueling area where he checks engine oil levels and reviews the Employee's
Daily Work Sheet for possible operating irregularities. Finally, each machine
is moved to a cleansing area where radiators and engine compartments .are cleaned
with high-pressure hoses to control overheating which might result from the build
ups of dust and debris so common to sanitary landfill operation.
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The mechanic, meanwhile, is responsible for scheduled lubrication and
ireventive maintenance, and for on-site repairs of any equipment failures
>ccurring within his shift. In many cases, repairs are assigned as a result
)f comments entered on the Employee's Daily Activity Report at the conclusion
if the previous shift.
As equipment operators and maintenance personnel have become familiar with
:he reporting system, the entire maintenance program has become more and more
responsive to our needs. Every employee knows his responsibility, and the PM
jrogram, in particular, requires relatively little day-to-day supervision.
:ven at smaller sites, where preventive maintenance is performed by the equip-
ment operator, we have been able to affect a substantial improvement in our
PM program. Supervisors and employees alike know their responsibilities, and they
know that failure to complete assigned and scheduled maintenance on any machine
can be easily traced on the maintenance and operating history of a given machine.
In addition, operators and maintenance personnel alike appreciate working with
quality equipment.
Visitors, in fact, are often amazed at the pride our people show in a par-
ticular machine. It's not at all uncommon to see an employee point to a parti-
cular machine and proclaim with pride that it has logged so many thousand hours
without a major repair. This pride in doing a job correctly is ceratainly not
unique to our people, and it is not exclusively the result of our maintenance record
system. But, it's there. You can feel it when you first step into the shop and,
believe me, this enthusiastic attitude can impact positively on improved maintenance
and to control cost.
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STRATEGIES FOR MONITORING GROUND WATER AT LAND DISPOSAL SITES
David W. Miller
Partner, Geraghty & Miller, Consulting Ground-Water Geologists and HydrologisK
SUMMARY
Why the monitoring program is being initiated should be the first basic question con-
sidered before strategies are developed for collecting information on geology, hydrology,
and water quality at a particular landfill site. There are four principal reasons for mon-
itoring:
1) You wish to set up a monitoring program for a brand new site in which
modern sanitary landfilling techniques will be used. In this case you are
not expecting significant ground-water contamination to take place, and
the monitoring system will be one in which you are only trying to establish
whether your design against pollution has been successful. Such a program
might call for four to six monitoring wells with a total installation cost of
$5,000 to $20,000, depending on the geology of the site, depth to the
water table, etc.
2) You wish to develop proof for potential or existing litigation. The
principal work to be carried out in this type of program might be limited
simply to establishing that pollution of a water supply source (ground
water) has taken place. In some instances the installation of a few tem-
porary wells in or near the landfill site for water sampling purposes may
be all that is required to prove that ground-water quality has been de-
graded. One monitoring well could be installed in the suspected plume
of contaminated ground water and a second monitoring well in an area
that is considered underlain by natural, unaffected ground water. In
fact, litigation has been initiated at several landfill sites in the north-
east on the basis of field inspection and the sampling and analysis of
water from seeps issuing from the base of the landfill. An example of
this type of situation is one in which a small number of shallow monitor-
ing wells were installed in addition to an inventory and sampling program
of water from nearby domestic wells. Enough information was developed
to bring about, under threat of litigation, corrective action by the land-
fill owner. Costs for the effort normally required in such an instance range
from $5, 000 to $10, 000.
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3) You wish to develop enough information to assess the impact on ground-
water quality from an existing landfill in order to determine whether it can
be expanded or, conversely, it should be shutdown and a ground-water pol-
lution abatement program initiated. In this case, a scientific evaluation is
carried out somewhat similar to that described under Item 4, except that ad-
ditional work may be required. This would include soil borings to determine
whether slopes have stabilized, detailed gas analysis to establish whether a
gas venting program is needed, and collection of geologic and hydrologic
data in areas adjacent to the existing landfill operation. The cost of such
a monitoring program can be as much as $20,000 fora small landfill site to
$150,000 for a landfill serving a population of several hundred thousand.
4) You wish to carry out a very scientific analysis of ground-water pollution
including the volume of contaminated water, rate of ground-water movement,
overall effects of variations in geology, profiles of ground-water quality, de-
tails of attenuation, etc. An example of such a study is the research that has
been carried out by the U.S. Geological Survey in Long Island, New York,
over the past four years at two landfills, one in Babylon and the other in Islip.
The purpose of this investigation was to generate data that could be applied
to landfills in similar geologic environments throughout the country. The
project involved the installation of a number of monitoring wells and the col-
lection of numerous water samples for detailed chemical analysis. In addition,
evaluations were made of aquifer characteristics and how they might affect the
movement of the contaminated fluid. Plumes of contaminated ground water
were traced for as much as 4,000 feet from one landfill site. The estimated
cost of the study was $125,000 per landfill.
In all of these situations there are a number of tools available to the investigator for use
in determining the effects of landfilling on the geohydrologic environment. The wide variety
of such tools and how they are applied can best be illustrated by describing two actual case
histories of landfill investigations in the northeast. Both instances fall under the conditions
listed for Item 3. Determination was needed to establish whether the landfills should be
shut down because of ground-water pollution. Also, if shut down, then a pollution abate-
ment program was required.
At one or another of these two sites the following techniques were used with some de-
gree of success in establishing and evaluating ground-water conditions. The technique and
a brief description of its purpose are listed.
A. Field Inspection: Identify the presence of leachate in springs and seeps; determine
configuration of the landfill, surface drainage patterns and potential vegetative stress,
and surface geologic features.
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B. Analysis of Seeps: Map locations of small springs or seeps of leachate; take samples
for water-quality determinations.
C. Specific Conductance and Temperature Profiles: Gather data on conductance and
temperature of shallow ground water by using specialized remote sensing probe equipment.
D. Electrical Earth Resistivity: Conduct resistivity surveys to define the areal extent of
the body of contaminated ground water.
E. Seismic Surveys: Determine the thickness of unconsolidated materials overlying bed-
rock.
F. Surface Water Quality Measurements: Establish if leachate discharge has affected
the quality of surface water bodies in the general area; obtain water samples for anal-
ysis of standing surface-water bodies associated with the landfill.
G. Landfill Gas Measurement: Determine the pattern of methane gas accumulation.
H. Aerial Photography: Employ multi-spectral photographic techniques to define the
extent of stressed vegetative species; use standard aerial photographic techniques to
construct contour and location maps of the site.
I. Hydrologic Parameters: Determine water balance by means of infiltration rests; ob-
serve run-off patterns on the landfill surface.
J. Construct Monitoring Wells: Drill single-point wells within and nearby to the land-
fill in order to collect water samples for physical and chemical analyses; drill cluster
wells (screened at different depths) in order to establish water level and water-quality
relationships beneath and adjacent to the landfill.
K. Geophysical Well Logging: Run resistivity and spontaneous potential profiles in
open boreholes to help locate zones of highly mineralized ground water.
L. Zone of Aeration: Install suction or trench lysimeters; examine and analyze soil
samples.
The first case investigated involved a large municipal landfill in southern New York State.
The site was located in a marshland on a penninsula extending two miles into the Hudson River.
Operations have been carried out for 15 years, and the refuse covers an area of approximately
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70 acres. When the study began, the landfill was approximately 60 feet thick. Many of the
tools described above were used to establish the generation, movement, and discharge of
leachate from the landfill and into surrounding land areas and the Hudson River. For example,
specific conductance and temperature profiles were taken in the marsh surrounding the landfill
by means of specialized remote sensing probe equipment.
The data obtained permitted an accurate mapping of the areal extent of the contaminated
ground-water body. It was shown that temperature of ground water affected by leachate, as
much as 400 feet away from the base of the landfill, had been raised in excess of 5°F. Later
exploration with monitoring wells penetrating the landfill itself revealed that ground-water
temperatures at the base of the landfill were in excess of 120°F. Normal ground-water tem-
perature in the area is 52°F.
Construction of cluster wells, which tapped formation zones at different depths, allowed
for the development of a hydraulic profile through the landfill and surrounding areas. It was
revealed that the landfill had become a significant recharge area for the penninsula. Water
levels had been artificially raised as much as 14 feet beneath the landfill. Approximately
80,000 gallons per day of leachate was being discharged into the Hudson River from the land-
fill. The hydraulic profile also permitted computation of the average rate of ground-water
movement, which was slightly less than 1 foot per day.
The second landfill investigated is located in southern Connecticut adjacent to Long
Island Sound, again in a marshy area. Filling operations cover an area of about 50 acres,
and the refuse is about 40 feet thick. Measurements of dissolved oxygen in the stream
draining the marsh area showed that leachate was being discharged and affecting that sur-
face-water body.
Another tool used successfully at the Connecticut site was electrical earth resistivity.
Based on marked differences in ground-water quality underlying various portions of the
site, a map could be prepared which defined several ground-water quality zones: one
underlain by ground water of high quality unaffected by leachate; a second underlain by
ground water which had been degraded by the presence of leachafe; and a third that was
underlain by brackish ground water related to intrusion of sea water from Long Island
Sound. Later installation of monitoring wells verified the results of the geophysical sur-
vey.
Another technique used successfully at the Connecticut site was mulri-spectral aerial
photography. Stressed vegetation indicated on the photographs showed portions of the
landfill site where high water table conditions created by the refuse pipe had affected trees,
shrubs, and marsh grass. Water level data collected in monitoring wells showed that the
water table had been artificially raised three feet or more beneath much of the marsh area.
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METHANE GAS IN LANDFILLS: LIABILITY OR ASSET'
John Pacey
President, Emcon Associates
INTRODUCTION
Sanitary landfilling, a modification of the historically ancient
open dump, is currently the prevalent method utilized for solid waste
disposal in this country. Sanitary landftlling practice evolved in
response to increasing concern for environmental protection. In the
majority of areas it has proven an effective solution to these concerns.
Sanitary landfills do, however, provide an environment conducive to the
production of methane gas, as contrasted to the old methods where
burning destroyed the decomposable wastes and non-covering fostered an
aerobic environment, toxic to methane-producing micro-organisms. The
assets and liabilities associated with production of methane in landfills
are the subject of this paper.
Nearly every landfill produces methane gas, varying only in total
quantity and the time frame in which It is produced. Methane is highly
combustible In certain concentrations in air, a characteristic that:
gives methane a dual personality. On the positive side, methane can be
a definite asset, representing, in certain cases, an economically recover-
able energy resource. On the negative side are hazards and liabilities
associated with uncontrolled release of the gas from the fill confines,
with an accompanying possibility of fire, or when accumulated in confined
areas, explosion.
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This paper first examines the production potential for landfill-
generated methane gas, and then describes the energy and use potential,
as well as the liabilities associated with gas production. It is the
intent of this paper to lay a basis for better understanding landfill-
generated methane gas potential, whether it be an asset or liability.
PRODUCTION
Background
Methane gas is a by-product of degradation of susceptible organic
(carbon-containing) materials by methoanogenic bacteria under certain
limited conditions. From extensive experience with sewage digestion
systems, we know that these methane-forming bacteria operate most effec-
tively under conditions of complete anaerobiosis (absence of oxygen),
moisture saturation (preferably continuously mixed), and within a pH
range of 6.5 to 8. While these optimum conditions are approximated in
the typical anaerobic sewage digester, they are certainly far from
satisfied in a landfill. In estimating probable methane production,
whether from a sewage digestion system or landfill, one generally commences
with 100 percent theoretical conversion, which is then adjusted downwards
for less than ideal conditions. We believe that landfill system efficien-
cles may result in conversion of between 25 and 75 percent of the theoreti-
cal maximum amount. Ongoing research being conducted at the Georgia
Institute of Technology and Sonoma County, California field scale test
cells Indicate that landfill degradative efficiency may be enhanced by
operations such as pH control and/or leachate recirculation.
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Potential Total
The maximum methane production from composite refuse by methane
fermentation has been estimated stoichiometrical 1y to be approximately
*» cubic feet per pound refuse. Estimations utilizing an empirical
chemical formula for composite refuse agree with those in which indi-
vidual biodegradable constituents of composite waste are assessed separately
and then summed. Anal ternate estimation of methane production incorporates
the gross characteristics of the organic fraction of the waste expressed
in terms of volatile solids content and effective biodegradabi1ity.
Each degradable organic constituent of composite waste is evaluated and
weighted according to its fraction present in refuse. This approach
yields a methane production capability of approximately 1 cubic foot
methane per pound of refuse. In actuality, the production ultimately
obtained probably lies in the range of 1 to 3 cubic feet per pound.
Kinetics of Production
Methane production from a given refuse fill will take many years to
complete, the active gas production life being dependent on site specific
conditions. Life may range from a few years in cases where controlled
leachate recirculation and pH control are practiced to hundreds of years
in certain environments. The rate of gas production is dynamic, respon-
ding to numerous conditions, but being principally dependent upon the
levels of oxygen present, refuse moisture content, and environmental pH.
Typically, landfill refuse degradation might be generalized as an
Initial rapid breakdown of the easily decomposable fraction due to both
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aerobic and anaerobic processes, followed by a slower anaerobic decomposi-
tion of the remaining decomposables. For purposes of simplification In
model aluatlon, two assumptions are proposed. First, the biodegradable
organlcs In the refuse can be subdivided Into rapidly decomposable (food
and garden wastes), moderately decomposable (paper, textiles, wood), and
refractory (plastics, rubber) portions. Second, at the extremes, condi-
tions In landfills will promote either a maximum rate of decomposition
or a minimal rate, and these rates can be expressed as a set of half-
lives. The half-lives (time required for half of the organlcs to decom-
pose) chosen for the rapidly decomposables were one-half year under
maximum conditions, and 1J years under minimal conditions. Those chosen
for the moderately decomposables were 5 years for maximal and 25 years
for minimal conditions.
Using the above assumptions, zero, first, and second order mathema-
tical kinetic models were tested under both maximal and minimal conditions.
The results of the zero and second order models were not found relatable
to experiences in either the production of gas in landfill or in anaerobic
sewage digester operation. The first order model appeared reasonable,
however, and was chosen as an approximation of the kinetics of methane
production In a landfill. The results of applying this model to a
landfill of 1 million tons, and utilizing the probable production range
of from 1 to 3 cubic feet of methane per pound of refuse derived previously,
are presented in Figure 1 for the mean of maximal and minimal conditions.
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800 H
600-i
u
400 H
2oo -
Figure. I
FIRST ORDER KINETIC ESTIMATION
OF M£THAME PRODUCED BY
MILLION TON
10
-l60O
O
\-8oo
*
5^
^ "
£^
U) Vj
\-4oo
TIME FROM REFUSE PLACCME.UT
£ years)
172
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ASSET
Gene ra1
Methane gas is continuously produced within a landfill and, as it
has an Inherent heating value, can be considered a potential energy or
fuel source, and hence a potential asset. The recoverabi1ity and use of
the gas are now generally recognized, although the evaluation of the
economic viability of recovery is yet in its infancy.
The determination as to whether or not to recover landfill-produced
methane is obviously an economic one, although in some cases credence
might be given to resource utilization even though a certain level of
subsidization is necessary. A thorough study of the viability of gas
recovery for a given landfill involves an estimation of the gas production,
both total and time variant; determination of the percent of the gas
produced which could be realistically (economically) recovered; and an
evaluation of the processing and marketability of the gas. Expressed
another way, can sufficient gas be recovered to return enough revenues
to be economically compatible with the cost of producing, processing,
and transmitting the gas?
Gas Recoverabi1ity
Of particular concern in evaluating a landfill for recovery is the
determination of what portion of the gas predicted to be produced can
realistically be recovered. Methane production in a given fill starts
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shortly after refuse placement. The gas produced prior to commencement
of gas recovery operations Is therefore lost. This time lag from place-
ment to commencement of recovery must be considered In evaluation of a
fill as a resource. Other loss potentials Include areas not affected by
the recovery well field, loss of gas through cover and sides, and the
likely lack of economy In continuing recovery operations after the
production tails off In later years.
For practical purposes,.a landfill can be modeled as a shallow
(compared to other dimensions) layer of more or less densely compacted
wastes of a homogeneous nature. As a further simplifying assumption,
any point in the fill that would be a likely candidate for location of
an extraction well can be considered to have only the upper surface of
the fill as an interface with atmospheric gases. The principal method
utilized for gas recovery is by pumping from recovery wells in a manner
analogous to extracting from groundwater reservoirs. The yield or
deliverabi1 Ity of a particular section of a landfill when tapped by a
well and pumped at a given rate is determined by several factors, among
which are rate of gas production, refuse permeability, and cover integrity.
A theoretical approach to estimation of production has already been
presented.
Methane production by microbiologic activity is strictly anaerobic.
The microorganisms are poisoned by contact with oxygen, the source of
which, for purposes of this discussion, is the atmosphere. To simplify
the discussion, assume that the only path of access of oxygen to the
fill during the gas extraction phase is through the cover layer.- The
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inflow of oxygen will alter the upper layer environment of the refuse to
an aerobic decomposition system. The thickness of this layer will be
largely determined by the rate of oxygen inflow. The aerobic process
will consume the oxygen by respiratory mechanisms and produce carbon
dioxide. Thus, as atmospheric gases pass through the aerobic zone, the
percentage of oxygen will decrease and carbon dioxide increase. At the
point where the oxygen has been eliminated, the anaerobic, methanogenic
processes may again occur, assuming other conditions are favorable.
Establishment of a given differential pressure gradient on a landfill
zone by well pumping has two important effects. First, it causes gases
produced in a region of the fill to flow to the well, and second, it
may, if a negative gradient is established relative to barometric, cause
the flow of atmospheric gases into the fill through the cover. The goal
of a landfill gas recovery program should be to extract gases at the
approximate rate at which they are produced, without creating a large
inflow of air. This objective might best be accomplished by installation
of a large number of closely spaced wells, each operated at a low flow
rate. Well field design and operation must, of course, satisfy the
criteria of cost effectiveness, a consideration that, with various site
specific parameters, will tend to limit the extent of well fields and
Increase the rate of flow per well. If few wells are utilized to extract
gas from a given landfill section, a relatively high differential pressure
must be established at each well to assure scavenging of the gases in
the interval between adjacent wells. This procedure increases the
likelihood that negative differential pressures will be developed across
the cover, resulting in air inflow and loss of system efficiency.
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Previous sections of this paper discussed theoretical and probable
gas production (both total and time dependent) and factors which govern
the amount of gas recoverable. The following table illustrates the theo-
retical, probable, and recoverable gas production for 1 million tons of
mixed refuse. Comparable figures for larger, or smaller, landfills can
be roughly prorated based on tonnage of waste contained in the landfill.
Approach
Theoretical
Probable
Recoverable
Refuse
Tonnage
1,000,000
1 ,000,000
1,000,000
Methane Gas
(billion cubic ft.)
9
2-6
1-5
Heat Content*
(trillion BTU)
8
2-6
1-5
*Methane @ 1000 BTU/cubic foot STP.
Field testing is required to define the approximate productivity
of a given fill. A program formulated for landfill evaluation designed
to empirically integrate the production and actual recoverabi1 Ity with
suitable control points is presented in Table 1. This program should
yield a gas recovery system design and operation oriented toward recovery
of a high percentage of the gas produced from a landfill without degrading
the quality of the gas.
Once the methane gas yield is known or has been predicted, consider-
ation can then be given to the most effective means of utilizing it.
Table II presents various ways In which landfill gas might be utilized.
These methods are presently under evaluation in an EPA-supported study
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TABLE I
LANDFILL EVALUATION PROGRAM FOR METHANE RECOVERY
PHASE I - BACKGROUND SEARCH
Fill volume and density
Fill configuration
Cover material and integrity
Geologic and hydrologic setting
General refuse characteristics
Utility system and market
PHASE II - LANDFILL INVESTIGATION AND ANALYSIS
A. Refuse Characterization
1. Recover representative samples by boring
2. Conduct laboratory analysis of samples
Moisture content profile
Volatile solids profile
Biodegradabll1ty profile
B. Gas Production and Recoverabi1ity
1. Install test wells and probe network
2. Observe landfill response to various extraction rates
Well head gas composition
Landfill pressure field
Gas movement through cover
C. Data Analysis
Reduce and correlate data
Predict deliverability of the fill
Estimate kinetics of production
Design well field configuration
Specify operation of withdrawal system
PHASE III - PROCESSING AND MARKETING
Evaluate alternative gas use systems as to
compatibility with fill deliverability and
market characteristics
Select a gas use system
Design necessary facilities
Install and operate plant
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TABLE I I
METHODS OF UTILIZING LANDFILL GAS
1. Injection of low BTU gas directly from landfill Into
an existing natural gas transmission line.
2. Delivery of low BTU gas to adjacent interruptible gas
consumers.
3. On-site treatment of landfill gas to produce pipeline
quality synthetic natural gas (ft^lOO percent methane).
. On-site generation of electric power through use of
raw landfill gas as fuel.
5. On-site conversion of landfill methane to methanol.
6. Conversion of methane to liquified natural gas.
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being conducted jointly by the City of Mountain View, California and
Pacific Gas and Electric Company. The first two process options are
those with the lowest capital cost, wherein gas from the landfill Is
sold as Is (approximately 50 percent methane, 50 percent carbon dioxide,
500 BTU per cubic foot). The third option requires construction of a
processing facility to develop almost pure pipeline-quality methane by
stripping of the carbon dioxide, water, hydrogen sulfide, and other
undesirable components from a typical, landf111 gas stream. Processes in
use or possibly suitable for gas purification are molecular sieving, as
used by the NRG Company, or possibly an amine (MEA) system. These
processes will yield a gas consisting of almost 100 percent methane with
a heat content of nearly 1000 BTU per cubic foot (STP). The fourth
option, on-slte power generation, Is presently being demonstrated by the
Los Angeles Department of Water Power and Department of Public Works at
the Sheldon Arleta Landfill. This project utilizes landfill gas as fuel
for a 300 horsepower, specially modified Internal combustion engine
which drives a 200 kilowatt generator. The energy produced is distributed
on the existing subtransmlsslon system. Options five and six are rela-
tively costly, and may be suited only to landfills with very high gas
del I verabi II ty.
LIABILITY
Introduction
Whereas gas recovery represents a feasible option at a relatively
small percentage of landfills, the potential for gas hazard is orobably
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present to varying degrees at the majority. The liability aspects of
landfill-produced methane are generally recognized throughout the industry,
although understandably considerably less well publicized than gas
recovery. Gas liability can range from a nuisance level, as when vegeta-
tive growth Is affected, to having fatal consequences. This section of
the paper will concentrate on defining the various general situations
under which migration might result in hazard to public safety, and on
various approaches that have proven effective in their mitigation.
Background
Concern for methane stems from its combustibility when present in
concentrations between 5 and 15 percent by volume in air. While fire
alone is concern enough, combustion initiated within a confined space
can result in an explosion. Also, methane is not necessarily contained
in the refuse fill in which it Is generated, being able, as a gas, to
migrate subterraneously, often to great distances through permeable
media such as porous soils, trench backfill, and utility or drainage
corridors. If migrating methane accumulates in a poorly-ventilated area
(i.e., building subfloor, basement, closet, utility vault, storm drain)
and achieves combustible concentrations, a hazard to public safety
and/or property exists. Since methane is usually present In concentrations
above the combustion range in landfills, it always must pass through the
combustion range when diluted with air. Fortunately, under the majority
of circumstances, a combustion energizer such as an open flame is not
present during passage through the critical range and combustion does
not occur. The numerous instances on record of fires and explosions
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resulting from landfill-originating methane, however serve to warn that
all too often gas migration proves hazardous.
In 1968, seepage of gas from a landfill caused an explosion in a
National Guard armory in Winston-Salem, North Carolina that took the
lives of three men and seriously injured two others. Two workmen were
killed when methane seeping into a deep storm sewer trench ignited. In
1975, buildings at two separate fills in Michigan suffered structural
damage due to methane explosions. In Vancouver, Canada this year, a
newly-poured foundation slab was structurally destroyed by an explosion
in the underslab air space initiated by a cigarette. The list of similar
incidents is certainly much larger and continues to increase annually.
Law suits are beginning to evolve around methane hazard and its effect
on adjacent property value, public safety and health, and on vegetation.
Responsive to the increasing concern for methane and its effects were
special hazard studies conducted this year in San Diego, City of Carson,
Newport Beach, Duarte, and Los Angeles, all in California; Franklin,
Madison, and Glenview in Wisconsin; Battle Creek, Michigan; and Winnipeg,
Canada.
Migration
The movement of gas to the limits of a refuse fill and into the
surrounding soils occurs by two basic processes: convection, or movement
In response to pressure gradients; and diffusion, or movement from areas
of high gas concent ratior to regions of lower concentration. Gas flow
is greater in materials with large pore spaces and high permeability
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(I.e., sands, gravels) and lower In materials of lower permeability
(I.e., clays). Gas migration from landfills Is therefore dependent in
part on the geological environment of the site. In general, a landfill
constructed In a sand-gravel environment experiences greater vertical
and lateral movement of gases than one in a clay environment (Figure 2).
Being lighter than air, methane tends to rise and will exit preferen-
tially through the landfill cover if It is of sufficient permeability.
A cover of clay with small diameter pores is relatively impermeable, and
tends to restrict gas loss. Also, any type of soil may be made less
permeable by saturation with rain or irrigation water, or by paving or
frost. Gas flow through the cover will then be impeded or restricted,
and lateral migration will be encouraged. Also, rain water may infiltrate
the refuse and increase the moisture content, which in turn Increases
the rate of decomposition, and thus the gas production. This condition,
occurring in combination with the decreased permeability of surface
soils, can result in significant seasonal variation in the extent of gas
migration. Also, methane gas is essentially insoluble in water, and
where a groundwater table exists beneath a disposal site, it provides an
absolute limit to the depth of gas migration.
The gas produced within a landfill must escape; the geologic-
hydrologic environment and construction of a particular site combining
to determine the direction the gas will flow, either through the cover,
laterally, or in both directions. In certain conceivable Instances, a
structure located direcHv atop a fill may be in less danger than one
located some distance beyond the edge of fill. This situation, and the
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Figure 2
DIFFERING LAMOF/Lt.
G£LA7/V£ TOGAS MIGRATION
-Impervious cover
2' mot'sf clay
-Impervious topsail
(frosf, irrigation, e/c.)
REFUS£
. .
-Permeati!? so/7
EXAMPLE "A"
EX7GMStVE LATERAL MIGQATIOU
iPorous cover
Impervious liner 'Impervious soil
3
VERTICAL MfGRATfOfiJ
183
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converse, are depicted in Figure ?.. Example A shows a fill enclosed In
an environment of permeable material (sand or gravel). The cover of the
landfill is constructed of impermeable material and the surface of the
adjacent ground has been made impermeable as a result of water infiltra-
tion, paving, snow, or frost. At a significant distance from the fill
Is a building with a subfloor or basement. Under these conditions, the
methane produced within the fill, being confined by the landfill cover
and the impermeable surface of the surrounding soils, migrates laterally,
possibly entering the building. This situation of permeable lateral
soils with seasonal surface sealing due to freezing has frequently been
encountered in the Great Lakes Region. If the landfill cover is exception-
ally impermeable and the building on top of the fill of appropriate
design, then it may be completely safe.
Case B, wherein the landfill is constructed in an impermeable
environment, illustrates a situation in which a building might be located
almost at the edge of fill and yet be totally free ot hazard. A building
or facility immediately above the refuse, however, must be concerned
with potential gas hazard as, with lateral migration precluded, the
cover becomes the principal means of gas egress.
Hazard Mitigation
Recognizing that nearly every landfill represents a potentially
hazardous condition, remedial and/or preventive action must be considered
when public safety is threatened or decline in property value, property
damage or litigation is likely. In the future this might be accomplished
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by controlling the production itself, but at present, this does not
appear to be generally applicable or economical. Practical solutions
center on either preventing migration by introduction of impervious
barriers to flow, or by encouraging the gas to take an alternate flow
path by venting. Additionally, but of long-term significance only, is
the possibility of changing operational methods and design details to
shorten the fill gas production life, or to improve recovery efficiency.
The following discussion describes general mitigatory solutions.
Area I Protection: Impermeable membranes consisting of natural clay;
plastic, rubber, or similar film sheet; asphalt; and other materials can
be utilized to control gas flow. Soil barriers are generally most
effective when maintained at a high moisture content. Soils utilized
for cover sealing may develop cracks as a result of large differential
settlement occurring across the surface of the fill. For this reason,
the thinner flexible membranes made of heavy gauge plastic such as PVC
or reinforced rubber are often preferred for migration control. Barriers
typically are best implaced during landfill construction, as subsequent
installations are often costly, less extensive than required, and occa-
sionally impossible to accomplish. During construction, barriers can be
placed to cover the base and lateral surfaces of the fill space. Instal-
lation after fill completion might be limited to trenching in the area
requiring protection and insertion of a membrane into the trench, followed
by backfilling.
Venting systems may be either passive (relying on naturally occurring
pressure or diffusion gradients) or induced exhaust (oumps are utilized
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to create a pressure gradient) with selection being dependent on site
conditions. The passive systems rely on imposition of material of high
permeability, such as gravel, in the path of the gas flow, the intent
being to present a path for gas flow more conducive to flow than the
surrounding medium, and thereby redirecting flow to a point of controlled
release. Passive systems are most effective in controlling convective
gas flow, less so in instances of diffusive flow.
Induced flow systems, particularly those employing suitably designed
vertical wells, have proven very effective in migration control. Typically
these systems incorporate a series of vertical wells emplaced in large
diameter bore holes not unlike those utilized in gas recovery for fuel
systems. Systems combining both recovery and migration control should be
considered whenever practical. The wells are spaced at intervals along the
margin of the landfill requiring protection, either located interior
to the limit of fill, or externally in the surrounding native soils,
depending on system requirements. The wells are connected by manifolding
to a central exhaust pump which draws gas from the well field. The gas
flow in the volume of refuse or soil influenced by each well is therefore
toward the well, effectively controlling migration.
Gases collected by exhaust systems are generally disposed of by
direct stacking, incineration, or by passage through various sorption
media. Gases from passive vent systems usually are allowed to direct
discharge; in certain cases, the gases are combusted as in "tiki torches."
In all instances, uncombusted gas must be exhausted at a location where
It is not subject to careless ignition, generally in a protected enclosure,
or above normal reach.
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Structural Protection: Frequently, only a portion of the landfill
surface or adjacent area is considered as warranting hazard corrective
action. These cases usually involve structures, utility lines or other
facilities where it Is less costly to protect the facility than provide
a large-scale control system. Buildings with slab or grade floors
should be designed, as a minimum, with impervious membranes between the
slab and subgrade. A permeable blanket with exhaust pipes between the
membrane and subgrade provides an improved system where intercepted gas
can be vented passively or by exhaust. An additional feature which
further adds to system credibility is a thin layer of permeable material
between the membrane and slab in which automatic methane gas sensors
are positioned. The sensors should be selected to trigger an alarm
should the methane gas concentration exceed a selected value, say, one
percent. Where buildings are designed with an air space between subgrade
and floor, similar protection can be provided by a system of vent and
barrier layers progressing upward of subgrade, permeable material with
exhaust piping, membrane, and a ventilating and monitoring system in the
air space. In all cases, vertical risers through the floor slab and/or
membrane should be sealed to preclude upward gas migration.
Building codes generally incorporate requirements for good ventila-
tion and undoubtedly have precluded many methane related incidents from
happening. However, we cannot relax in thinking that building ventila-
tion is sufficient hazard protection in itself. Many homeowners or
building operators are unaware of the potential problem and unknowingly
block the vent system, thus, in effect, creating a gas hazard. Buildings
Immediately over the landfill must be specially suspect as cracks in the
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soil cover, settlement of the building, and resultant rupture or crack-
ing of slabs may allow gas flow into the building. It is recommended
that future additions to building codes consider the requirement that a
building or grading permit not be issued for development within 1000
feet of a landfill unless the developer provides adequate safeguards
during construction and submits a report and design signed by a quali-
fied engineer addressing the gas condition.
System Effectiveness Monitoring: The success of any of the migration
control systems described above must be continuously appraised through-
out the gas production life of the landfill. In areal protection syscems,
probes may be permanently empiaced at suitable locations in the interval
between the migration control system and the facilities to be protected.
These may either be monitored on a frequent; schedule by gas sampling and
analysis or in-situ gas detectors connected to an alarm system might be
employed. Structural protection systems also must incorporate apparatus
for measurement of gas concentrations above the protective layers.
Again, probes or electronic detection may be utilised.
SUMMARY
Decomposition of refuse in nearly all landfills produces methane
gas which csn be used as fuel and hence is a potential energy
source, or, if allowed to disperse naturally to the environment, it
may be a potential hazard to public safety and health and may
adversely affect property value and vegetative yrcwth.
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The theoretical maximum production potential for methane generation
Is k cubic feet of methane per pound of mixed refuse, whereas the
estimated probable production in a landfill environment is in the
range of 1 to 3 cubic feet per pound of mixed refuse.
The recovery potential of the methane gas produced in a landfill is
dependent upon numerous site specific factors and is probably in
the range of 0.5 to 2.5 cubic feet per pound of mixed refuse.
Most of the landfills of today provide methane in sufficient concen-
tration as to produce a hazard potential. Fire and explosion
incidents are being reported in increasing frequency; however,
present and future technology should be able to provide adequate
safeguards, where necessary.
Methane migrates vertically through the cover soil and laterally,
if conditions permit. Buildings, utilities or other facilities
could be subject to serious hazard potential if the gas is able to
concentrate in its combustion range and then is ignited.
Remedial and preventive measures are available to prevent vertical
and lateral gas migration. Impermeable membranes and vent systems
are suitable for the control of methane gas.
Special design details should be considered for buildings, utilities
and other facilities on or near landfills.
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A monitoring system should be provided at locations where a gas
hazard concern exists.
In the future, permits for development within 1000 feet of a landfill
should require a gas report and special design details addressing
the gas condition by a qualified engineer.
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GAS RECOVERY. NATIONAL POTENTIAL
Robert H Collins, III
President, NRG Nu Fuel Company
If I were to stand here and say that there was presently an energy shortage
in this country, it would be about the same as telling General Custer at
the Battle of Little Big Horn that there were Indians in the area. At the
present time, everyone in the country is well aware of the fact that our
affluent approach to consumption, combined with governmental control of
prices, has caused us to over-consume our energy resources to the point
where we are now scrambling for survival. Both new and alternate sources
of energy are being sought out as never before.
In the general field of energy recovery from solid waste, there are literally
dozens of front-end systems which take refuse as it is being collected and
convert it to a variety of different forms for use as fuel. The cost of
the commercial versions of these plants and processes may run anywhere from
$20-$50 Million Dollars per project, and while a few of them are operational,
most are still plagued with major operational problems, or are in the
developmental stage.
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I do not intend to belittle these projects, but am merely stating a fact of
life. The development of a practical front-end system for recovery of energy
from waste is a difficult and costly process. These efforts should nonetheless
be pursued to the utmost, since they represent a tremendous potential in
helping to satisfy the energy needs of the country.
But let us look at where most of the refuse has already gone and will continue
to go for many years to come - into landfills.
A survey taken in January 1975, showed that there are over 18,000 known land
disposal sites in the United States. While almost half of these sites have
been closed since 1967 as a result of new solid waste disposal legislation,
there are still almost 5,600 authorized disposal sites in operation, 3,800 of
which fall into the category of sanitary landfills.'Obviously, not all of
these sites would be feasible for commercial recovery of methane. Many of
them serve areas too sparsely populated to accummulate a large enough volume
of refuse. Others handle only demolition-type wastes, such as concrete,
asphalt and building materials, which generate little or no gas whatsoever.
The configuration of a landfill or lack of depth might also make it impractical
to extract methane. Extreme dryness may result in no gas being produced,
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while at the other end of the scale, excess moisture may result in standing
liquids within the landfill, making it difficult or impossible to extract the
gas. If only 5% of the sanitary landfills within the country were suitable
for methane recovery, however, this could mean from 175 to 200 sites with the
potential for providing methane for today's energy markets. This potential
would, of course, still be subject to confirmation by extensive testing, but
it does give you an order-of-magnitude picture.
Now let's talk about the gas supply picture. Until 1970 everyone had gas to
burn. But then something odd happened. In 1970, the annual demand exceeded
domestic production by one trillion cubic feet. This year, demand will exceed
production by five trillion cubic feet, and in 1980, it will be 10 trillion
cubic feet.
Landfill gas is but a small portion of the national gas supply picture.
However, any new source of fuel is needed and desirable. We see a potential
recovery on the order of 10 million cubic feet per day of pipeline standard
gas (virtually pure methane) from the largest landfills, ranging down to as
little as 200,000 cu. ft. or less for others. We also see problems in collecting
and converting that gas for actual use: problems with landfill size, configuration,
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moisture content, gas composition, to mention but a few. If we consider
primarily those landfills in large metropolitan areas where garbage can be
piled fast and deep, with ideal characteristics, we might project 120 billion
cubic feet per year of recoverable gas, only 1.2% of the estimated shortfall
in 1980 - not much in a game where shortages are measured in multi-trillions -
but every little bit helps.
In evaluating and testing sites across the country, we have found that there
is no easy way to qualify or categorize landfills for potential methane
recovery without detailed investigation of operational history and on-site
inspection. Even then, accumulated information is subject to question because
many landfills have poor or nonexistent operational history data. It is more
or less a "Garbage in - garbage out" situation, if you'll pardon the pun.
In order to properly ascertain the potential methane recoverability of any
particular site, an extensive and complex testing program, with proper
interpretation and evaluation of accumulated data, must be accomplished. No
one has ever written a book on the subject, so this information can be developed
only through extensive experience in the field.
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We have found a tendency on the part of landfill owners and operators to over-
estimate the potential of their landfill sites for commercial methane recovery.
This is due in large part to the wide degree of publicity which resource
recovery, in particular landfill gas production, has received. Since this
business opportunity is still in its infancy, only through extensive operational
history will we really be able to prove out the viability of commercial methane
recovery.
While all fairly large landfills with a reasonable percentage of volatile
organics can be considered potential methane recovery prospects, the economics
of extraction and purification, the price which can be obtained for the gas,
the proximity to existing gas distribution lines, and the end users of the gas
dictate what landfills can be considered as realistic sources of recoverable
methane. The size of the landfill and the characteristics that would qualify
for commercial recovery will change, of course, as technologies improve change
and as the cost of all forms of energy escalates.
If maximum energy is to be recovered from sanitary landfills as a whole,
operational specifications and guidelines must be set up and adhered to.
At some landfills, accelerated decomposition may be accomplished through
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various techniques, such as the addition of water. This may be in contrast to
some state environmental regulations, but we believe the two can be tied
together under the supervision of experienced "landfill gas experts".
Our experience has shown that the gas MUST BE cleaned up to some degree,
regardless of its eventual use. This may range from dehydration and removal
of toxics all the way to full purification to pipeline standard. I stress
that the gas must be cleansed to some degree. Although small in percentage of
the total gas composition, toxics are present in all landfill gas streams, and
present a real hazard to life if not properly handled.
We see three primary categories of use for methane recovered from landfills.
First, is utilization of low BTU gas as a source of fuel for steam generation
or direct gas turbine power generation. In this case energy utilization is
low as compared with utilizing the gas as a source of energy directly. Such
applications could be subject to state utility commission jurisdiction. Where
such usage is considered low priority, it could be curtailed so that the gas
could be purified to pipeline standards for higher priority residential
distribution.
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The second category is direct sale of partially cleaned up low BTU gas to
industrial customers. This application could have the same regulatory problems
as stated previously. Also, many high cost redundancy features may have to be
built in to satisfy industrial customers. In most cases new pipeline systems
will have to be installed and maintained, and many such industrial user's do
not need gas 24 hours, 7 days a week. This makes for extensive operational
problems.
Our comparative analysis of the potential uses of methane indicates that the
most logical and economically sound alternative is the third alternative,
conversion of the refuse gas to pipeline standard fuel for injection into the
nearby utility company pipeline. Regulatory problems are eliminated, since
the utility company will bring their distribution system to the processing
facility and the cleansed gas will serve the entire distribution area. This
also provides greater flexibility in distribution of the gas.
In considering the alternatives for gas cleanup, we have evaluated the positive
and negative features of ten different gas cleanup systems. They are: Selexol,
Fluor Solvent, MEA, DEA, TEA, Purisol, Rectisol, Benfield, Sulfinol and Pressure
Swing Adsorption. Several factors resulted in the selection of the PSA process
as the best for landfill gas cleanup.
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First, all of the processes considered, except PSA were found to be cost
effective only at volumes greater than 10 million cubic feet per day, which is
larger than the anticipated volumes of gas from most landfills. Some of the
systems do not reach optimum cost efficiency until flow rates of 50 million
cubic feet per day are reached.
Secondly, PSA is the only dry adsorbent process. All of the other processes
use an aqueous solution which results in a saturated product gas. Consequently,
another step of dehydration may be required to reach pipeline standard. In
over half of the systems considered, this solvent is highly corrosive, requiring
extensive use of stainless steel in the construction of the facility, thereby
increasing capital costs.
Third, all of the other processes considered are more mechanically intensive
than the PSA system. For example, in some of the systems, the height of the
towers required for solvent purification is in excess of fifty feet as opposed
to only thirty feet for the PSA system. These other systems also have much
higher operating pressures, some as high as 500 psi, since they are normally
used in chemical plants or gas field operations and have inlet pressures as
high as 1500 psi. When applied to a landfill where the inlet pressure is
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vacuum, much larger compressors would be required to bring the gas up to
system pressure. The noise levels associated with the larger compressors,
plus the extreme height of the towers would make these systems much less
environmentally acceptable than the relatively quiet, low profile, PSA system.
Fourth, the PSA system has a higher energy efficiency. Most of the other
processes contain extensive recirculation systems requiring additional pumps
and resulting in a greater loss of energy within the system itself.
The considerations which I have just listed were sufficient by themselves to
result in our selection of the PSA process as the best for landfill gas
purification. In addition, after extensive laboratory and actual plant testing,
we found molecular sieve manufactured from high grade natural zeolite ore to
be the best adsorbent for removal of the main contaminant of the gas, which is
co2.
Anyone who performs a detailed analysis such as we have of the various gas
cleanup systems available, will probably find that in terms of operating
efficiency, net energy savings, system flexibility and overall cost effec-
tiveness, the PSA molecular sieve process is the most efficient for cleanup of
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the volumes of gas to be found in the vast majority of landfills throughout
the country.
The final factor which must be considered in selecting a cleanup system is the
fact that none of the systems mentioned can be used by itself. The composi-
tion of raw landfill gas is such that major modifications to these systems
must be made in order to remove all contaminants not acceptable in pipeline
quality gas. Our own modification of the PSA molecular sieve process., for
example, has been so extensive as to result in a pending patent on the overall
system.
Where does the country stand in the development of this relatively small, but
very important energy market? At the present time, there are three active
landfill methane recovery projects underway, only one of which is commercially
operational.
In Mountain View, California, a joint effort is underway between the City of
Mountain View, Pacific Gas and Electric Company, and Easley and Brassy, with
partial funding from the EPA. This project is still in its infancy with
questionable test results. The program is to be expanded with federal funding
for a total collection system with PG&E funding a gas cleanup system.
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The second project is a pilot plant operated by the City of Los Angeles
Department of Sanitation and the Los Angeles Department of Water and Power at
the Sheldon-Arleta landfill for gas turbine power generation. Full scale
testing of the Los Angeles fill will determine commercial potential. The
Department of Water and Power would purchase refuse gas as fuel for a nearby
power plant, or a separate power generator would be constructed adjacent to
the landfill site for direct conversion to electricity.
Our own project at Palos Verdes, California, is operated by Reserve Synthetic
Fuels, Inc., for the joint venture between NRG and Reserve Oil and Gas. The
Los Angeles County Sanitation Districts and the City of Rolling Hills Estates
are also participants. Approximately two million cubic feet of refuse gas is
being converted to one million cubic feet of pipeline standard gas, for sale
to Southern California Gas Company.
As with any first-of-its-kind facility, operation of the plant to date has not
been without its problems. Since the Palos Verdes Landfill accepts liquid
industrial wastes, some gaseous compounds are extracted which can cause serious
problems if not completely removed. Some modifications of our original plant
were necessary to eliminate these problems.
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While it is not anticipated that other landfills which do not accept liquids
would create the same problems, it is not inconceivable that other refuse of
unknown composition, decomposing over longer periods, could combine to produce
other hazardous compounds. Future plant design of any type must therefore
incorporate these anti-hazards features.
And so you see, even with three years of experience in direct testing of
landfills throughout the country and many years of related technological
experience, we are still learning. We are at the present time actively involved
with several other projects that are already under initial construction.
Scores of other landfills have been tested or are in the process of being
tested.
As detailed above, the recovery and purification of refuse gas will not solve
the energy problems of the nation. We must be careful not to over-emphasize
the potential impact of landfill gas on the national energy scene. However,
since sanitary landfilling is and will continue to be used for refuse disposal,
and the by-product is both a new and alternate source of fuel, we feel that it
is important that this relatively small, but important energy market will
continue to be actively developed.
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Resource Recovery
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ENERGY FROM WASTE RESEARCH AND DEVELOPMENT PLANS
Donald K. Walter
Chief, Urban Waste Branch, Division of Inter-Program Applications
U S. Energy Research and Development Administration
Ladies and Gentlemen, first let me place the Energy Research
and Development Administration in Perspective. On October 11,
1975, Congress recognizing a need to make the nation self-sufficient
in energy passed the Energy Reorganization Act of 1974. That act
split the Atomic Energy Commission into a research arm and a
regulatory arm and then added to the research arm certain elements
of the Department of the Interior, National Science Foundation
and EPA to form ERDA.
Now let's briefly consider the background of the waste disposal
question.
During our early years we were blessed with extensive empty land
areas. In certain portions of the country we still are. We had
plenty of room for the little waste we had. It could be thrown
in a nearby gully or, in urban areas, dumped on nearby vacant land
or dumped in rivers or oceans. Until World War II this generally
worked. During that war the formation of large training
installations led the Army to search for a disposal means and to the
development of the sanitary landfill. At the same time we undertook
one of our first recycling efforts with scrap metal, tin foil, tin
cans, steel and paper drives. After that war, the United States
underwent an economic boom. Technology proceeded rapidly and
convenience items mushroomed. The returnable bottle became the
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lisposal can, the local butcher's cut meat became prepackaged
neat, the meal prepared from scratch and cooked individually at
lome became the frozen TV dinner and on and on. As a result, the
amount of material discarded also mushroomed. As for disposal, the
sanitary landfill became popular. Recycling became too expensive
or too much trouble and stopped. We had extensive natural resources
available within our borders. Among these were sources of cheap
energy. In addition, our government encouraged development,
sometimes through fiscal incentives, that tended towards development
of the new rather than reuse of the old. The final point, the
competitive system led to separation of the function of trash
disposal from the function of energy production and particularly
from the function of electric generation.
The expanding disposal problem and the increasing concern for
the environment led Congress to action. In the mid-60's the
Clean Air Act was amended to include a section entitled the
Solid Waste Disposal Act whose purpose states that trash quantities
and disposal problems are rising and that failure to salvage and
reuse materials results in unnecessary waste.
This act was further amended in 1970 with the purpose expanded
to promote solid waste management and methods of collection,
separation, recovery, recycling and environmentally safe disposal.
The thrust of this act remains to reduce the volume so that trash
is easier to handle, but it also displays an awaking concern for
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energy available from trash. In fact, this act is the basis for
several Federal demonstration grants.
The oil embargoes of 1973 perhaps more than any other single
event gave credence and stature to what some had been saying for
some time. Oil is limited in quantity and alternate sources of
power are necessary. The AEC had within its authority the task
to develop nuclear power which had been amended to include
nonnuclear energy resources. However, other sources were ava-'lable
to be developed. To encourage tnat development, Congress passed
the Federal Nonnuclear Energy Research and Development Act of 1974
which charged ERDA with and I quote, "(A) to advance energy
conservation technologies including but not limited to (i)
productive use of waste including garbage, sewage, agricultural
waste and industrial waste heat; (ii) reuse and recycling of
materials and consumer products . . . ."
Other paragraphs charge us to produce low sulphur fuels, substitutes
for gas and oil, determine economics and accelerate demonstrations
all of which are things we may also accomplish in waste systems
and utilization. That sums up where the United States is today.
In fewer words,what happened in other countries most notably
western Europe and Japan? These countries were and are land
poor where we are land rich. History tells us that the conflicts
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of Europe were primarily related to nations desiring to expand
their territory because they were confined and desired to control
natural resources. They generally shared our early frugality and
did not have a great deal of waste for disposal. They also
developed into compact towns and cities often with central district
steam heating systems surrounded by apartments heated with
individual coal or wood fired space heaters. Thus, much of their
waste was ash that had a fairly high energy content remaining.
Also, one entity was responsible, for energy production (either
steam or electricity) and waste disposal.
Finally, the quantity of fossil fuel available within their
borders and under their direct control was limited. A series
of Franco-German wars centered on the coal rich saar. The end
result seems obvious. With little land to bury waste of a fairly
high energy content why not burn it for heat value. Thus, they
developed incinerators to produce steam instead of our traditional
incinerator which was designed to reduce volume.
What is the way out of our dilemma? We use one-third of the
worlds energy to sustain the world's highest standard of living and
to produce an inordinate share of the world's food and manufactured
goods. We are heavily dependent on oil and our internal supplies
are dwindling while our external supplies are not under our control
and the price is soaring. As an overall strategy, ERDA will
develop a series of alternatives including solar, nuclear, enhanced
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oil and gas recovery and environmentally sound coal uses.
The area of your- and my- interest is in ERDA's objective to
develop, demonstrate and foster implementation of technologies
to recover energy and materials resources from urban (including
sewage sludge), industrial, agricultural (including animal manures)
and forestry wastes. The specific short range objective is to
achieve sufficient implementation of technologies to supply the
equivalent energy of 1 million barrels of oil per day from
wastes 1985. To put that in a different light, 1 million barrels
of oil per day while only amounting to 2 percent of our estimated
1985 energy consumption of 95 quads at the best ERDA scenario that
million barrels still represents 4 billion dollars per year at a
cost of $11 per barrel. By the way, in case you're not familiar
with the term, a quad is a quadrillion or lo""* BTU.
How do we plan to get there? We propose to accomplish our
research by both software and hardware programs. The greater
part of waste is produced in small amounts over large areas, but
some are sufficiently concentrated to be economically collected
and processed now. Secondly, wastes are highly regional in
character ranging from the wood wastes of Maine, the urban wastes
of the East Coast megapolis, the agricultural wastes of the
Midwest, the animal wastes of the Southwest and back to the
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wood wastes of the Northwest. Obviously, this list is not all
inclusive. This conference is held in the center of a very large
poultry industry with very large problems in disposing of chicken
manure (and you don't know how hard it is to say that and not what
I'm accustomed to saying). This program will characterize wastes
and their source and quantity. It will concentrate on the
demonstration and acceleration of implementation of existing tech-
nology and will foster research and development in innovative
technologies, particularly those that will convert wastes that are
now discarded in relatively small amounts.
The research will cover the spectrum of combustion, pyrolysis,
bioconversion, and chemical processes as well as combinations of
these processes. Whether the waste is domestic grass cuttings,
paper, garbage, agricultural manure, field waste, forestry slash
or the organic waste streams of industry, its composition permits
conversion by similar means. The task of sorting out and recycling
those items which represent net energy and virgin materials economies
will not be neglected. For instance,a pound of aluminum can be
separated and reprocessed at an estimated 5 percent energy cost
compared to the production of a pound of virgin aluminum. The
task remains to determine the means to optimize the energy production
fr'om waste materials and to select the most valuable product for the
particular application.
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While the principal thrust of the program is energy production,
there will be a threefold umbrella over the program; removing the
social, industrial and political barriers to using wastes; preserving
the environment; and as an incidental but important benefit,
reduction of the waste disposal burden.
That is a broad brush strategy of how we intend to save the
equivalent of 1 million barrels of oil per day. Let's consider
specifics.
As I mentioned, our task is broad-based. Many papers and figures
have been presented on how much trash is produced, where and when
and how much is collectable. Those figures vary widely. For
instance, I can quote to you 210, 125 or 55 million tons of forest
and wood industry waste depending on the source of data. The
difference is obviously significant. We must know the very base
of our action. We hope while updating and accuratizing both the
total and the collectable quantities, to stimulate thought and
research in improved collection methods. As an example, many
agricultural harvesters strip-off the food portion and leave the
waste behind to be plowed in or burned. It is better to have the
harvester also collect that waste to be converted to energy with the
waste of that process to be fertilizer? What is the overall effect
on fertilizer products and what is the economics?
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In this same area of studies we will be considering the
feasibility of projects. One of the major elements missing in
most of our proposals is an energy balance to determine the overall
energy efficiency of the process and if the process produces a
net energy increase. That idea of energy balance is a tough nut
to crack. The variables are numerous and many of the so-called
knowns argumentative.
Before leaving studies, .work must be done in the area of
identifying and breaking down the political, social and insti-
tutional barriers to waste utilization. EPA addressed the political
problems on the Federal level in their Second Annual Report to
Congress. For instance, they concluded that rail freight rates
discriminated against scrap steel. That work must be updated,
expanded and implemented. Beyond this, the local political
problem must be addressed. Before joining ERDA I worked for a
small city. It was the only self-functioning municipality in the
surrounding country primarily, in my opinion, because of state
laws. The two entities, although they occasionally tried, had
extreme barriers to cooperation and joint ventures. In the social
and industrial field, convincing the market that the material is
useful and developing techniques for its use is crucial. For
example, the steel industry is reluctant to purchase other than
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home or prompt scrap because of stated potential contamination
problems. Tin and aluminum are two products that frequently
appear in conjunction with steel that are particularly demaging.
It is analogous to your reaction if your home town officials
announced that they were going to feed your sewage plant effluent
directly to your water plant. The answer, "no way," but if they
expand capacity by building an intake in the local river, you're
not concerned even though the effluents of sewage plants empty
into that river upstream. The dilution and out of sight, out of
mind effect takes place. Although our major thrust is not
environmental, that area belongs to EPA and elsewhere in EROA,
we do plan to keep an overlook on this vital area to insure a process
we are developing does not create irreversible results elsewhere.
Of course simple success in our program will benefit the environment
by reducing waste problems. I only needed a quick description of
a West Texas feedlot processing 200,030 cattle each producing
7 pounds of manure a day each to be assured of that.
Now let's discuss the processes we will be looking at. They
generally are not really new and at least in the short term we
do not plan much basic research. We will be doing a great deal
of work in applied research, that is, trying to adapt existing
technology and knowledge to the very heterogenous mass of wastes
and attempting to optimize the processes that now exist.
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As I prepared this, it occurred to me that up to this point I
had not stated why the Federal government is or should be in the
energy business. After all, think about the waste to energy field.
Without Federal help waterwall incineration is being slowly
imported from Europe; companies, notably Union Carbide, Monsanto,
Occidental and Combustion Power Company and a host of others,have
developed and tested pilot size waste pyrolysis systems, source
separation of recyclables was started, etc. The answer lies in
the heavy capital, long lead time and high risk associated with
the scaleup to full size operation and the need to develop
innovative systems to utilize small quantities of waste and to
utilize regional wastes to produce regional product needs.
These demand Federal assistance to accelerate demonstration and
implementation of technologies ancl to stimulate and encourage
work on the mroe innovative ideas.
The first process I'd like to mention is combustion to produce
energy. As I have stated, this technology is well developed and
has been slowly implemented. There does appear to be valuable
work to be done on corrosion and control and gaining a more complete
knowledge of the process of incineration. There is also a need for
feasibility studies to prove out the economics and markets for a
proposed system prior to detailed design and funding work. We
conceive that assistance in conducting these studies will be
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the catalyst necessary to convince areas, to implement these systems.
Incidentally, there is available off the shelf a number of small
incinerators (up to 1 ton per hour) which can be married with waste
heat boilers for small applications, such as a single building.
Since these are here and available, we will not provide much
hardware support but will be interested in assisting in implementation
by feasibility or economic studies.
A question, if incineration has been demonstrated from small
incinerator/waste heat boiler through 1200 ton or larger units why
not, as I said in the introduction,get on with it and stop "messing"
with other processes. The basic answer lies in several areas. One
is the regional, widely diversified type, and scale of waste available;
another, the amount of waste that can be assembled and the last is
the use of the end product. Very wet wastes, such as sewage sludges
and some chicken manures cannot be incinerated at a net energy
increase because of the mass of water to be heated. Electricity is
an energy form can be used anywhere but cogeneration, that is
generation from a large number of small sources, needs research.
Steam cannot be used everywhere as has been proven at Chicago
Northwest and Harrisburg. Other processes are necessary. New
combustion processes need investigation. Among these are high
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temperature and fluidized bed processes. The latter utilizes a
heated bed of granular material, such as sand, and a fluid
introduced from below, such as hot air. At a sufficient volume
of air, the bed becomes a floating mass like quicksand. When
substances are placed on the bed, the reaction occurs rapidly and
because of the fluid nature, hot spots are eliminated. The off gases
can be used for a variety of purposes depending on their composition.
If excess air is used, they are like any other incinerator gas and
can be used to produce steam. If there is a deficiency of air, the
process approaches pyrolysis and depending on temperature and
oxygen available, the waste products can be varied. This leads to
the next process, pyrolysis. Simply stated,pyrolysis is destructive
distillation or heating in an oxygen deficient atmosphere. Depending
on the temperature, pressure and oxygen levels,a series of products
are available ranging from heavy to light oils, and various gas
compositions from low to medium BTU value. Char that is essentially
carbon and molten slag may be produced along always with ash and
possibly other waste products.
The heavy and light oils may be substituted for fossil oils.
The gas may be burned for energy as in Monsanto's landguard system
or used as a synthesis gas to produce a variety of chemicals.
Processes have been researched at least on paper to economically
produce methanol, anhydrous ammonia and ethylene.
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These processes are in varying levels of implementation from
demonstration to bench stage. Each is different in its front end
process, its feed, its fuel and its off products. One process will
use manure that is only 15 to 25 percent moisture and the method
would not work well on a local layer chicken ranch where moisture
content may exceed 8 percent.
What to do with that chicken manure? One process to be considered
is again a familiar one, anaerobic digestion. This has been
utilized for many years to reduce the bulk of and stabilize sewage
sludge. For years the methane has been used to power the plants
where produced. For various reasons the practice has fallen into
disfavor and incineration and other sludge treatment systems have
been slowly adopted. These because of energy consumption and polluti
implications are no longer desirable solutions, although they do star
as monuments to the era of reducing volume to solve waste problems.
Anaerobic digestion research needs exist to optimize the process,
shorten the digestion time and increase methane production. One of
these at the bench level promises to produce twice as much as in half
the time. This process has potential for serving rather small
applications. Since the 1950's, farmers in India have supplied
their cooking and heating needs from anaerobic digesters fueled
wfth cattle manure.
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In this same bioconversion field is an enzymatic process to convert
cellulose to glucose which can then be fermented to ethanol or other
products. Think, your old newspapers could be converted to your
favorite beverage. The process itself was discovered in New Guinea
during World War II. Cotton cloth kept disappearing and no one
knew why. Research demonstrated that an organism was producing
an enyzme that converted the cellulose of the cotton to glucose which
the organization then fed upon. We expect to support the Natick
Laboratories of the U. S. Army on prepilot plant activity for this
process.
Perhaps least developed of the processes is hydrogenation. Again,
this is borrowed technology from the chemical industry, but needs
a great deal of examination as a process when applied to the
heterogenous mass of wastes. These processes have operated at bench
scale under high pressure and temperature regimens.
Supporting these processes as well as standing alone, will be work
on resource recovery and feedstock preparation systems. As I stated
earlier, a pound of recycled aluminum represents a 95 percent savings
in energy as well as $200 to $300 per ton on the economic side.
In addition to other potential projects in this area, we expect to
support the NCRR Test and Evaluation Facility. This facility is a
pilot plant developed to test separate components in a complete
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plant chain to determine the efficiency of recovery. Further
projects will develop economic end uses for the products of the
separation system.
We are formulating a program while awaiting appropriation of funds.
That program will stimulate research and unsolicited ideas, conduct
feasibility studies and encourage and assist pilot plant construction.
Depending on the funds and authorities available, i.e., loan guarantees
we may be funding or assisting in demonstrations. We are particularly
interested in the latter authority since throughout our programs we
are most interested in working with sources that are willing to put
effort into their proposal. That effort can be indirect, that is
prior laboratory work, remission of overhead costs, etc. That is
not to say that we will not totally finance good ideas where the
proposer has no capability to support.
In addition to the proposed projects I have mentioned previously,
we will be conducting a 50 to 100 ton/day experiment converting
urban waste and sewage sludge to methane for the next several years.
This program was inherited from NSF. A letter contract is in being
and the final contract being negotiated based upon a request for
proposals. The selected contractor is Waste Management, Inc., who
is to supply the site and some front end processing. The plant will
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be located at Pompano Beach, Florida, and will operate as follows.
Mixed municipal refuse will be shredded to minus 3 inches with a
nominal size of 1-1/4 inches. The ferrous fraction is then removed
by magnetic separation and the waste stream split. The pilot process
stream split. The pilot process stream will pass through a trommel
screen (1/4 to 1/2 inch hole size) to remove fines (principally
glass, sand, etc.). The stream will then be air classified to light
and heavy fractions. The light fraction consisting mainly of orgam'cs
with some plastic will be conveyed to a surge bin to buffer the
5 day per week front end system against the 7 day per week digester
system. From the light fraction will be transferred to a mixing
tank where water, sewage sludge and filtrate recycle as well as
ammonia, lime and phosphorous will be mixed. The mixed material
will be transferred to two anaerobic digesters. The off gas and
wastes from the digesters will be collected and analyzed. Several
parameters are to be varied to maximize gas production. They include
the digestion temperature, retention time, percent solids applied,
amount of recycle liquid, mixing energy applied, waste/sludge
mixture and nutrient level.
The most significant responses to be measured are methane
production per unit of solids fed, gas composition, reduction of
solids remaining for ultimate disposal, dewatering characteristics
of waste slurry, process stability, energy requirements for
operation and chemical costs for nutrient and pH control.
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The waste stream will undergo a series of operations. Some will
be recycled without processing. Various filter systems will be
tried to separate the solids and liquid. As much liquid as
possible will be recycled. The remaining liquid may be disposed
of by treatment in a packaged treatment plant or most likely sprayec
on the nearby landfill. That landfill is monitored for leachate;
and, therefore, groundwater quality can be checked while the
spraying is being done. The filter cake will have a BTU content
of 5 to 7000 BTU per pound. If,at 35-40 percent moisture, it will
sustain combustion. Any excess may be buried on the landfill, but
some will be utilized at a nearby Incinerator to test its
burnability. Other uses for the waste solids will also be sought.
Principally, in the wastes systems and utilization program we
will be conducting studies on waste, its composition, its
collectabi1ity, economic feasibility and on the systems to convert
it directly or indirectly to useful energy, particularly in
smal1er scales.
To close, let me tell a true story I heard recently. An
American Company in an attempt to solve a small portion of the
waste problem economically, is completing installation of
shredders and feed mechanisms to use wood in a boiler that
is not coal fired. When they applied for their air pollution
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control permit they were told that to burn trash they would need
electrostatic precipitators since the trash state-of-the-art said
they could attain 3000 pounds of particulate per day from the same
boiler; however, using coal, 6000 pounds is acceptable. Despite
the investment already made, the company in effect said okay I'll
burn coal and put out 6000 pounds of particulate and bury my wood
in a landfill rather than go to further expense. This type barrier
to solving the waste to energy problem must be stopped. Government
must train its bureaucracy to look at total problems and not to
limit itself to narrow interpretations.
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RESOURCE RECOVERY-PLANNING A STRATEGY FOR IMPLEMENTATION
Samuel Hale, Jr.
Vice President, Market Development, SCA Services, Incorporated
As the leadoff speaker this morning, I would like to discuss.
the resource recovery implementation process, from the point of
view of the resource recovery systems industry (that is, those
companies in the business of designing, constructing and operating
resource recovery facilities). This also will be, to some
extent, an overview, with more specifics in the papers to follow.
At the outset, let me present two caveats to my remarks. First,
there are other "industry" points of view besides that of the
so-called "systems" companies the view of the consulting
engineers, for example. Second, although I am confident that
the general sense of my remarks is supported by most of the
system companies, there obviously is not unanimity of opinion
on every point. With these caveats, then, let me proceed.
The Problem
The first question to be answered is why the resource recovery
systems industry would even bother to articulate a point of
viev; on how a State, region, or city should go about selecting
and installing a resource recovery system. There are, in fact,
many reasons:
1. From our perspective, progress in implementing resource
recovery systems has been slow and extremely frustrating.
I can count on one hand the number of full-scale resource
recovery plants that have commenced operation over the; last
two years and on two fingers the number that are expected
to do so next year . (Also, interestingly, of those that
have started up, two were entirely private industry vemtures
and two tohers are having very serious problems. None was
based on a competitive system procurement. These seven
systems compare with estimates around EPA two years aqo of
50 to 100 systems up and running by 1980-1985.
2. We see major problems with the system selection and procurement
process generally employed to date, in at least two respects.
First, most municipal Requests for Proposals, to which various
of the companies have responded (at a cost of well over
$100,000 per company in most cases), have gone absolutely
nowhere. My list, which I'll say at the outset is subjective
and not necessarily complete, shows tvcprojects -- Milwaukee
and Monroe County, N.Y. -- which appear to be going ahead
after one round of competitive proposals and a third project
New Orleans which is proceeding after two rounds of
competitive proposals (together with grants or other financial
incentives provided by the EPA and NCRR). Against this, three
municipalities have cancelled their RFP's after bids were
received, and no new RFP's have been issued. Seven projects
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are "under development" or (more generally) in limbo after
receiving one set of competitive bids, and four other
projects are in limbo after having had two or three
different sets of competitive bids (that is, having issued
two or more separate RFP's at various times).
Some of the projects I have included still may go forward
(although each has slipped well past its original schedule),
but certainly the record to date is one predominantly of
false starts and little in the way of concrete results.
Certainly, a batting average of 3 for 23 -- the number of
"go" projects versus the total number of RFP's issued
is not impressive.
A second distrubing aspect of the process is that there have
been some obviously poor system choices. For example, two
municipalities selected companies with an idea but with no
assets, no experience (in this or any other field), no
engineering staff, and so forth. Not surprisingly, both
the companies and the projects subsequently folded.
3. In an infant industry, any system failure anywhere in the
country could jeopardize the future of the industry.
Resource recovery has had two systems which recently have
had very bad (and very visible) problems -- problems which,
if repeated elsewhere, could cause the entire resource
recovery effort to be aborted. Thus, we feel that we all
must do everything possible to insure that the likelihood
of selecting a "white elephant" is minimized. A proper
selection process should provide such insurance.
4. Finally, large-scale municipal resource recovery involves
very large system capital costs, the need to make a long-
term commitment to a particular system and set of products,
the need to allocate risks in areas where there is very
little experience, and so forth. As a result, the system
procurement and contracting process, under the best of
circumstances, is much more difficult and time-consuming
than we initially thought. For example, the Connecticut
Resourch Recovery Authority selected and publicly announced
the teams (on one of which SCA was a member) for the first
two plants in its statewide system in May 1974, yet at
this point it still is not certain that either project will
go forward. A major reason for the delay and present
uncertainty has been the difficulty in agreeing on allocation
of risks among the many parties involved -- the State, the
participating municipalities, the system contractor, the
fuel/energy user, and the bondholders.
In view of this "litany of woes", it is no wonder that the major
concern expressed at three recent formal meetings of industry
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members has been that the system selection and procurement process
must be improved. I might add that some members of the industry
wonder whether even this will be enough.
System Selection as a Phased Process
So much for the problem. What do we do about it? To the extent
that improvements in the system selection process constitute a
solution (and I recognize that this is only a partial solution),
I would like to describe how we generally feel that process
should look.
We see system selection as a phased process, with different
objectives and outputs at each stage. The first step in this
process is not to issue a Request for Proposals, tempting as it
may be to do so, to short-cut the process. Rather, we see the
following sequence of phases (and I present these to convey our
general sense of what is required rather than to lay down a
rigid set of rules:
1. A study phase, during which the State, region or
municipality assesses its disposal situation, its
energy and materials markets, the general system alternativ
available to it, financial-legal-political constraints,
its possible system objectives, and so forth.
2. A system selection and specification phase, during which
decisions must be made as to what the community's
objectives are, where the wastes will come from, what
markets are most favorable, what system type or types
seem best suited to the area's particular conditions and
objectives, what legal entity and what financing methods
will be used, and so forth.
3. The system procurement and contracting phase, during which
a Request for Proposlas is issued (if this is the
procurement method chosed), proposals are received, and
contracts are negotiated.
4. The implementation phase, from design through construction
to actual operations and marketing of the recovered outputs
The sense of these phases is obvious, so I will not try to
elaborately detail each phase (this detail is available, with
some differences in the conceptual framework, from the EPA).
However, I do want to make some points, from a purely subjective
point of view, about each phase preceeding actual implementation.
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I. Study Phase
The study phase should begin by answering the question, "Is
resource recovery really a good idea for us at this time?" The
answer clearly will not be "yes" everywhere. For example,
SCA has a 300 ton per day prototype waste-to-dry-fuel plant
in Fort Wayne, Indiana which works very well but which, given
Fort Wayne's combination of low-cost landfills and plentiful
local coal, is not economic there. This plant, on the other-
hand, would be quite economic in Boston or many other locations
with different disposal-cost and energy market combinations.
I do not mean to suggest that the answer to the question "is
resource recovery for us" should be a function of economics
alone. It should include an assessment of what disposal alter-
natives will be available a few years hence, the environmental
impacts of those alternatives, the benefits of the potentially
recoverable materials and/or energy for the area's development,
and so forth. It also should include an assessment of what the
public wants. It certainly is entirely legitimate for a com-
munity to take the public policy position that it wants resource
recovery even where less expensive, environmentally acceptable
disposal alternatives will continue to be available (some
communities already have taken this position. Rather, my point
is this: be explicit and be honest in assessing your particular
situation.
While a number of other issues also should be addressed in the
study phase, I believe a few are particularly critical:
- What are the specific markets in the area, especially for
the organic fraction (as a fuel, as energy, as compost, or
in other forms)? Because this will be a major determinant
of what system types are best for a given area, it is not
enough merely to identify potential users. At some, potential
users' actual willingness to commit to a long-term contract,
and on what terms, must be pinned down.
- Where will the waste come from (since most systems require
large waste volumes to be economic? Also, where waste from
more than one community will be involved, what be the
mechanism for bringing those communities together? (The
difficulty in securing regional compacts should not be
underestimated: it took Newton and Waltham, Massachusetts
three years to get together even with pressing incinerator
closure deadlines and an EPA grant, on a simple transfer
station).
What are the legal constraints (such as competitive bidding
laws or laws limiting the duration of contracts), financial
constraints, and political-institutional constraints which will
influence both what system is selected and how that system
is procured?
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What should be the community's resource recovery objectives?
One must make tradeoffs among the various possible objectives
to minimize risk, to maximaze resource recovery, to minimize
environmental discharges, to maintain maximum flexibility
to adopt emerging new technology, and so forth.
Finally, let me make a few points about the study phase process.
First, there obviously is no single "best" resource recovery
system. Rather, what is best for a given area can be judged
only by answering questions such as those above. Second, use
experts -- financial experts, legal experts, political experts,
and above all a good consulting engineering firm with extensive
resource recovery experience. A relatively small expenditure
at this stage (generally 1% or less of the ultimate systen
cost) will save millions of dollars later. Third (which is
easier to say than to achieve), use this phase to build your
political consensus and support, through broadly-bases task
forces, keeping the decision-makers informed and involved, or
whatever works best in you situation. Finally, from the systems
companies' perspective, please do not use KFP's at this stage
to get information or advice. Companies will spend money need-
lessly, many will be "turned off" and will not come back for
the "real" RFP later, and you won't get much useful information.
A reputable consulting engineer is skilled in obtaining the
information you will need, without RFP's, so use him.
II. System Selection and Specification Phase
The second phase system selectioi and specification is
that in which the municipality must make decisions, based on
input from the study phase. It involves a number of things:
Selection of the general type of recovery system or systems
adjudged best for the area.
Decisions on such issues as the system users' organizational
form (authority, district, separate contracts, etc.) where
more than one community will use the system, how the system
will be procured (traditional A & E approach, turnkey design-
construction-operation contract) and how it will be financed
(general obligation bonds vs. State or city revenue bonds
vs. industrial revenue bonds vs. other alternatives), whether
the system will be publicly or privately operated (and, if
public operated, who will market the outputs), and so forth.
Again, let me make a few subjective points about this phase.
First, one issue to be faced in a "total system" or even turnkey
procurement is how narrowly to specify the system (and hence
the end-use of particular the organic fraction) on which you will
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seek bids. Everyone has a different answer to this question -
I personally favor providing some flexibility to bid alternative
end-uses, to take advantage of the private sector's strength in
securing, e.g., favorable fuel or energy contracts. So far,
based on an admittedly small sample, the more narrowly defined
system procurements (e.g., New Orleans and Monroe County, N.Y.)
generally have progressed better than more "open" procurements
such as Connecticut (although Milwaukee's RFP was quite broadly
defined). This may be due to other factors, or it may be that
it is harder to consummate an agreement where the range of
possibilities is broader.
The second point I would like to make is this: given the very large capital
outlay, the long-term commitment, the complex and still-Corking technology,
and the range of economic and market uncertainties inherent in resource recovery
(which, let us remember, still is in its infancy), one should commit the time,
effort, and attention to the problems thoroughly at this stage, to avoid
surprises, long delays, or even failure later on. I strongly recommend, for
example, that you identify all the riskstechnological risks, market risks,
economic risks, force majeure-type risks, and so forthat this stage and
think through those that you are willing to take, those that you are not, and
the costs of not taking a particular risk (since if you don1t take a certain
risk inherent in a given system, some other party must--and that party, public
or private, will exact a price for taking that risk). Also, I recommend that,
as you make your decisions, you get written opinions from legal counsel, bond
counsel, and other experts approving (and more particularly, passing on the
legality of) what you intend to do. A depressing number of RFP's have been
declared illegal after the fact because of failure to take this simple step.
III. System Procurement
The final stage before actual implementation consists of: system procurement
and actual contacting. With respect to this phase, my first recommendation is
to use, under your direction, consulting agencies and other experts. 1 must
add three other recommendations:
1. Regardless of the procurement method chosen, contractor experience
and other qualifications (size, general reputation, willingness to
assume risks, etc.) should be a major selection criterion. Because
this field is in its infancy,and no system has been replicated in
great numbers, you will of necessity, be taking the chance that the
contractor actually can perform. Thus, a normal competitive
procurement where the lowest bid is accepted pretty much automatically
is inappropriate in resource recovery at this time, because one must
use 3udgement to decide both what system is best and whether in fact a
given contractor can make his system work as well as he has said in his
proposal that it will work. Thus, either through a separate qualifying
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round prior to issuance of the RFP or through other means, give your-
self room legally to excercise that judgement.
2. Wherever possible, standardize the RFP, in terms of format and of
assumptions as to system scale and redundancy, the interest rate and
auortization period to be used, future levels of secondary materials
prices, residue disposal costs, and so forth. Let me give but one
example of why standardization is important: our Ft. Way'na plant and
CEA's East Bridgewater, Massachusetts resource recovery plant are almost
exactly the same size in terms of the number of lines, primary (one
line a piece) ,- and physical origins of the equipment
, yet while we call ours a 300 ton
per day plant, E. Bridgewater has been referred to as a 1200 ton per
day plant. Clearly, these two figures by themselves would be highly
misleading. My point is this: it is hard enough to conduct an
accurate comparative evaluation where everything is standardized; it
is a lot more difficult where such standardization of facts and
assumptions is not imposed.
3. Because of the interaction of risk-assumption, the financing
mechanism chosen, and pricing, spell out, in the RFP, the risks proposed
to be allocated to the contractor. Wherever possible, an actual draft
contract should be included as an attachment to the RFP. I would
add that, even under the "total system" procurement method, (1) no
contractor will take 100% of the risk (especially in those areas over
which he has no control , such as the risk of changes in waste
composition or of changes in environmental standards or of loss of
his major energy user caused by, say a strike or plant shut down)
and (2) no contractor will take any risk without expectation of what
he feels is a reasonable reward (i.e., contractors don't take risks
for free) . As a result, the risk allocation process under the "total
systems" approach can be difficult. I would point out, however, that
the traditional ASE-and-public-operation approach, in which the issue
of risk allocation usually is not raised and hence does not constitute
a source of delay, the municipality generally takes all of the risks
I have talked about as well as the risk of absolute systeir failure or
deterioration of system economics down the road. From their base,
virtually anything is an improvement in terms of risk allocation.
Let me make one final point about this phase: besides using experts, learn
from others' experience. I would recommend that you get and use others'
RFP's (both those that have resulted in actual contracts and tho&e that have
not), publicly available systems evaluation, and examples of actual signed
contracts and bond prospectuses. Unfortunately, there currently is no single
clearing house for this information, although EPA is a logical focus for such
an activity and hopefully will provide such a service at some point.
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Conclusion
I have presented a fairly gloomy view of the present and a hodgepodge of ideas
about how to improve in the future. Let me pull these together with the
following list of recommendations:
1. Undertake a phased program, with study and decision phases preceding
actual system procurement.
2. Budget for and make use of legal, financial, engineering, and other
experts.
3. Take advantage of the small but growing body of experience in system
evaluation, procurement, risk allocation, contracting and financing.
4. Be prepared for a lengthy, frustrating processone that will lead
nowhere without thorough analysis, political support and, above all,
an aggressive public catalyst pushing to make it happen.
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FEASIBILITY CONSIDERATIONS FOR ESTABLISHING A RESOURCE AND
ENERGY RECOVERY PROGRAM
David J. Damiano
Commissioner, Department of Streets, City of Philadelphia
The fundamental problem faced by an urban area is to identify
viable energy recovery opportunities. There is no substitute for
professional engineering investigations and planning. However, I
have yet to meet the municipal manager who is not deluged by myriads
of proposals from self-appointed experts, salesmen, politicians,
contractors, charlatans, whose problems are solved by signing on
the dotted line. The cardinal rule to follow is that the advice
is worth the price paid for it; Nothing;
Philadelphia's approach to energy recovery dates to 1961 when
the sixth municipal incinerator plant was under final engineering
design. One option was an incinerator boiler unit to produce steam
and sell to an adjacent Philadelphia Electric power plant 1/4 mile
away. The cost study including operation and capital amortization
was 71C/1.000 Ibs. of steam as compared to fossil fuel of 55C/1,000 Ibs
which resulted in abandoning the concept at that time.
More recently the Penna. Dept. of Environmental Resources par-
tially funded a $60,000. Resource Recovery or Energy Recovery Study.
Recognizing that the recent energy crisis has made solid waste com-
petitive as a substitute fuel, a renewed interest has developed to
identify markets for steam or energy.
The first phase of our Resource Recovery Study was evaluation
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of six refuse-to-energy options which was a result of prior investi-
gations and were prepared to be implemented. These opportunities were
rank ordered in technical-economic feasibility, interest of the ener-
gy and/or steam consumer, time phasing with our refuse disposal needs,
ability to integrate with the logistics of our system.
The second phase is a survey to identify new markets for energy
or steam as well as R.D.F. preparation as a fossil fuel substitutes.
However, although studies of markets are continuing capitalizing on
present opportunities is a prudent course for cities to follow. One
such opportunity is an existing center-city steam loop, owned and
operated by Philadelphia Electric Company, serving five square mile
area of downtown Philadelphia. Customers include department stores,
office buildings, hotels, apartment houses, 13 major hospitals, two
universities, two newspaper plants, and most of the federal, state,
and city properties in this area. In addition to space heating,
this steam is used for numerous process requirements and for air-
conditioning. The load varies from 2,500,000 Ib/hr. in the winter to
roughly 500,000 Ib/hr. in the summer, thus providing a year-round
market. All of the steam is generated in oil fired boilers, and
300,000 to 500,000 Ib/hr. of new oil fired capacity is anticipated
to be required by 1978 or 1979. Philadelphia's energy conservation
project proposes to substitute a refuse fired boiler plant for the
Philadelphia Electric planned new oil fired facility. The refuse
fired energy conservation plant proposed consists of a modern, aesthetic-
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ally designed building completely enclosing the required refuse
receipt and storage facilities, four, 400 tons per day furnaces
and their ancillaries. The energy plant is geared to steam demamd
requirements of the Philadelphia Electric steam loop, details of
which are being developed with Philadelphia Electric. This partner-
ship is a unique situation involving a major urban area and its
utility company.
The alternatives available for reliable production of re::use
derived steam have been narrowed to the most feasible, based on cur-
rent and emerging technology, which can be easily implemented without
waiting for technological developments. This concept involves fur-
naces of waterwall construction for direct combustion of received
refuse on a mechanical grate system providing useful low pressure
steam. Each furnace unit will have comprehensive air pollution con-
trol systems consisting of a conditioning tower, electrostatic pre-
cipitators, induced draft fan, and stack. Provision will l)e made for
recovering ferrous material from the residue and its sale to scrap
industry.
Some of the developments in Phase I that surface as criteria may
be of interest to other cities.
1. In addition to the market opportunity, one of the essential
ingredients in developing a successful refuse-to-energy program, is
to have an interested, willing, and cooperative customer. Both the
President and staff of Philadelphia Electric Company have extended
themselves to the fullest in analysis, data, planning and programming
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the project. Their singular effort and commitment to the refuse-
to-energy project is the most iraportant factor contributing to its
success.
2. Refuse collection and disposal being the second highest
municipal expenditure, the City cannot afford to subsidize alternate
systems or processes. Initial studies of our system and anticiapted
income from steam sales indicate the project is self-sustaining and/
or a savings will result attributable to the reduction of our present
disposal costs.
3. The impact of this facility on refuse collection requires
no major changes in scheduling, routing, and transfer location making
it very favorable from a sanitation operations point of view. There-
fore, we will not face any additional collection costs to take advan-
tage of this opportunity.
4., Time phasing is a three to five year term to provide on line
steam to the customer and is the normal time period for engineering
study, design, and construction for public works facilities to ob-
tain the optimum bid and construction costs. No unnecessary costs
will be found for time phasing the on lire steam demand.
5. Competent technical consulting engineering services with
particular expertise in refuse-to-energy systems is essential. In
addition to technical-economic feasibility of each refuse-to-energy
project, the consultants sensitivity to systems, reliability, per-
formance, legal, contractural, financial, requirements are some
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factors which constitute part of the overall project.
6. One of the most important factors in a refuse-to-
energy project is siting. In urban areas, land is scarce. In
this case, an abandoned railroad yard is conveniently located with-
in a 1/4 mile of the steam loop of the center-city business dis-
trict of the Philadelphia Ecletric Company. There is sufficient
land area to site the plant with suitable access and egress for
refuse collection trucks and trailers from an expressway. Little
or no change will take place with the traffic pattern in adjacent
neighborhoods, an important factor to community acceptance.
7. The benefits of the Philadelphia Electric Company's refuse-
to-energy project are:
Conservation Energy conservation; refuse being substituted
for oil, conserving an estimated 630,000 barrels per year, roughly
equivalent to 30,000 domestic oil heated homes per year. This is
enough oil saved to provide heating requirements for 100,000 people
or 5% of the City's population.
Economics -- A potential reduction in refuse disposal costs of
10% from $10/ton conventional method to $9/ton.
Environmental Reduction in air pollution in critical center
city location of Philadelphia's basin and in land requirements for
refuse disposal.
Employment Underprivileged low income residents facing 14%
unemployment crisis, will have an additional 100 jobs of higher skill
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and training opportunities available to them.
Uniqueness -- Demonstrate a government-utility partnership
acting with one another in the consumers' interest.
Urban Crisis Independent of social and educational programs,
the urban crisis that is faced is a fiscal dilemma. The second
highest municipal expenditure is refuse handling and disposal. Future
costs are escalating at an unprecedented rate. This project will
affect 30% of the total refuse disposal budget of the City.
Timeliness Energy crisis has demanded exploration of new oppor-
tunities for energy conservation. This is reflected in the Federal
Energy Program and the Energy Research and Development Agency Program
and policies. The Philadelphia Program offers an immediately imple-
mentable energy conservation measure which does not require a decade or
more of research to become useful to the customers of our urban area.
The preliminary investigations of the aforementioned seven points
is more than ample incentive for the City of Philadelphia to pursue
a refuse-to-energy project. The subsequent steps are the traditional
final engineering design, bid, construction, and operation of the
facility. However, several unique considerations in the implementation
phase should be elaborated on for the guidance and information of other
cities.
1. Contract for steam sales. Terms and conditions for contract
with the customer Philadelphia Electric Company will be fully developed
and executed before any major capital commitments are made. Contract
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must address a term of 25 years, rate structure with percentage credits
of fossil fuels, capital facilities credit, base load demand, peak
load demand, summer/winter load with appropriate guarantees and penal-
ties for consumer protection shall be developed.
2. With capital requirements in excess of $50 million, this is
beyond the normal financing capability of the City. New institution-
al arrangements, via utility, authority or alternate form of a public
agency must be investigated to carry out project. Concurrently an
I.R.S, ruling will be pursued to take advantage of an unique private/or
authority arrangement to benefit the investment tax credit and accel-
erated depreciation for the eligible components of the facility and the
low cost financing through bonds for a public agency. It is possible
to realize an interest rate in five to eight per cent range for financ-
ing capital cost of this facility.
3." A unique approach saving time, construction cost, an unneces-
sary duplication of efforts from the conventional specification bid
and construction routine will be employed. It is commonly known that
the incinerator-boiler furnaces and appurtances constitute some 45%
of the total construction cost and the building enclosure is normally
tailored to fit the equipment manufactured. The unique approach to be
employed will be prior to final engineering building design, the pre-
purchase of incinerator-boiler equipment on performance specifications
will be made directly from the manufacturer.
With known equipment and manufacturer and supplier, the consul-
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tants will then be directed to proceed with final building design
of the supports and enclosure around details furnished by manufacturer.
The successful bids by the building contractor will stipulate
installation of the equipment pre-purchased by the City to be furnished
and installed concurrent with the building and mechanical trades cont-
tracts.
This will result in an overall savings in time and costs to the
City and a more efficient installation.
4. In conclusion, to demonstrate the confidence level and cooper-
ation in a unique government-private utility arrangement, an agree-
ment was reached to carry out the next phase of this project. The
$400,000 in design and engineering funds to move the project to the
ext stages of completion will be shared equally between the City of
Philadelphia and Philadelphia Electric Company. This reinforces the
point made in the beginning of our discussion where the most important
ingredient is a successful refuse-to-energy project is an interested,
willing and cooperative joint venture by the government and the cus-
tomer.
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FINANCING RESOURCE RECOVERY SYSTEMS
Dorsey H. Lynch
Assistant Vice President, The First Boston Corporation
The U.S. Environmental Protection Agency, acting by
and through its Office of Solid Waste Management Programs,
delivered on September 3, 1975, its Third Report to Congress
on Resource Recovery and Waste Reduction. This report con-
tained what I believed at first to be a startling conclusion -
"financing of resource recovery systems does not appear to be
a problem. Any existing constraints can be overcome by experience
and information, and a strong Federal program to develop informatioi
and provide technical assistance." While EPA's report was
liberally sprinkled with self-justification and examired financing
of resources recovery systems from a long-term, marco-economic
viewpoint, I had to agree that the conclusion reached, although
almost totally unsupport by present experience, was never-
theless very perceptive and, in my own opinion, quite accurate.
While I am sure that many of you, based upon your own personal
experiences, disagree with this statement, 1 would like to defer
further discussion of it until later in my speech. Instead, I
would like to launch into the general topic of financing resource
recovery systems.
Traditionally solid waste collection and disposal have
been a highly decentralized combination of local goveriment
services and private small business with relatively low and
dispersed capital requirements. Thus, capital for solid waste
operations has been provided either by local commercial bank
business lending (for private firms) or from general revenues
or by general obligation bond financing (for municipalities).
While these traditional sources of capital continue to
be important, there is reason to believe that new sources of long-
term capital wi11 have to be tapped to meet the growing nood
for capital resulting from rapidly changing solid waste technology.
While the ultimate nature of this new technology may bo in some
doubt as new labor and fuel saving devices and resource recovery
techniques arc being tested, the financing implications are un-
mistakeably clear:
(1) solid waste collection and disposal will require
much more capital in the future than it has
traditionally;
(2) the capital will tend to be concentrated in
fewer and larger facilities;
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(3) capital will .1 .ve to be amortized over a longer
term than allowed by traditional bank lending;
and
(4) the revenue potential of resource recovery will
introduce a new element of entrepeneurial risk
and reward not previously contemplated by
traditional lenders. Because of these trends,
we believe financing solid waste operations is
a whole new ballgame for bankers as well as for
municipalities and industry.
With this overview, I would like to discuss the outlook
for financing both traditional solid waste operations and new
large scale resource recovery facilities.
As we all know, private waste collection firms have
been hard hit during the past year by a combination of inflation,
depressed industrial collections and high interest rates on bank
loans. In addition, those firms with significant revenues from
paper sales have been further hurt by the collapse of the secondary
paper market. To make matters worse, the structure of most
collection and disposal contracts has made it difficult or
impossible to pass these added costs on to the municipalities
and industrial clients. None of this looks good to bankers and
investors. Therefore, I suspect the current bearish attitude
toward the industry will persist for some time until a more
favorable profit picture emerges. This will make it extremely
difficult for most solid waste firms to obtain the two kinds of
financing they desperately needincreased equity and long-term
fixed rate debt. So the banks will have to continue to carry
the industry on relatively short-term business loans.
And now for the good news. Interest rates on bank loans
will be much lower than they have been for the past year, so the
overall debt service burden of waste collection firms should
decline. I do not share the view that short-term interest rates
will rise significantly in response to hugh federal borrowing in
the next few months, and I expect, therefore, that current bank
lending rates will be available for some time. Furthermore, as
banks attempt to maintain profitability in the face of declining
business loan demand, it should be possible for waste collection
firms to negotiate somewhat longer term bank loans than have
been available during the past year.
In the long run, though, private waste collection firms
will have to find additional long-term capital to meet the
growing cost and possibly longer depreciable life of new technology
and equipment. This may require placement of new debt instruments
with long-term investors such as insurance companies and pension
funds. Such a restructuring of debt would also help to insulate
solid waste firms from some of the worst cyclical effects of
short-term bank borrowing.
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With regard to large-scale resource recovery financing,
the picture is more complicated and confusing. Basically
resource recovery plants can be viewed either as municipal servi
facilities (much like water and sewer facilities) or as
entrepeneurial ventures which consume raw materials, manufacture
products for sale and hopefully make a profit (much like a paper
manufacturer or a chemical plant). Financing a municipal servici
function is, of course, quite a different matter from financing
an entrepeneurial enterprise. The basic financing mechanism is
tax-exempt municipal bonds (either general obligation bonds or
revenue bonds) and the primary security behind the bonds is the<
promise of a responsible public body to pay debt service on the
bonds either from taxes or user charges. Financing an
entrepeneurial enterprise, on the other hand, requires an assess-
ment of business risk and reliance on the creditworthiness and
experience of the entrepeneur. The basic financing mechanisms
are corporate bonds, taxable bonds, equity and tax-exempt
industrial revenue bonds.
Much of the current confusion regarding resource recover
financing results from inability to decide whether such facilitie
should be financed as a municipal service function or as a privat
corporate entrepeneurial activity. Both the public and private
sectors would like to lay off financing risks on the other party
while maintaining control and retaining profit for themselves
an unlikely solution, in my view, since control and profit are
usually associated with risk assumption in our economy.
The major types of resource recovery financing being
utilized at the present time are:
1. General Obligation Bonds (tax-exempt) - backed
by the full faith and credit of the issuing
municipality - used by Ames, Iowa and to be
used by Monroe County, N.Y. and Dade County,
Florida.
2. Revenue bonds with additional security pledge
(tax-exempt) - backed by revenues from project
and pledge of debt service back-up from the
general funds of a municipality - to be used by
Connecticut Resources Recovery Authority.
3. Revenue bonds secured by pledge of controllable
revenues (tax-exempt) - backed by promise of
municipality to charge rates sufficient to cover
debt service - used by Nashville Thermal Transfer
Corporation.
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4. Industrial revenue bonds (tax-exempt) - promise
of corporation to make lease or sale payments
sufficient to cover debt service on the bonds -
Saugas, Massachusetts and to be used by Southern
Essex, Massachusetts.
5. Corporate bonds or equity (taxable) - full faith
and credit of the private corporation - used by
Milwaukee.
On the basis of my experience, I believe that there will
be increasing reliance upon the public financing (examples 1-3)
rather than private corporate credit (examples 4 and 5). Uncer-
tainties about long-term operating costs, composition of the waste
stream and value and marketability of recovered energy and materials
make private long term investment in resource recovery plants
relatively unattractive to most firms without the active and forcible
participation of the public sector. While a few private firms,
such as American Can, may be willing to finance one or two projects
in order to establish themselves in the business, I believe that
private financing will be the exception rather than the rule.
Public financing of resource recovery will probably
evolve toward some form of revenue bond financing along the lines
of example 3. This is basically the same kind of financing used
predominately for water and sewer systems where the key element
is a pledge of controllable revenues sufficient to cover operating
costs and debt service. As applied to resource recovery systems
this means that the key element in financing will be the ability
of a public body to collect gross disposal fees large enough to
cover gross costs, if necessary. Revenues from the sale of
energy and recovered materials will reduce actual disposal fees,
of course, but the bond investor will not rely on such revenues
as primary security for financing.
Given the hard-nosed requirements for resource recovery
financing described above, the question is whether municipalities
will be willing to commit themselves to the relatively high gross
disposal fees typically required by resource recovery even though
there is reasonable expectation that revenues from the sale of
recoverables will reduce net disposal foes to levels competitive
with sanitary landfill. For example, gross disposal fees presently
appear to range from §12-525 per ton whi]e expected revenues from
sale of recoverables appear to range from about $4-$13 per ton,
with a range of expected net disposal fees of about $8-$12 per ton.
These are very rough numbers but they demonstrate the type of
economic risk decision confronting many communities which are
committed in principle to full scale resource recovery. A
further problem is that communities financing resource recovery
systems must commit themslves to recovery technology which could
well become outdated, economically uncompetitivc or even environ-
mentally unacceptable long before the capital costs have been
amortized.
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Tho successful imp I - .acntation of a resource recovery
system by state, regional aiid local governments or by private
companies is a tremendous challenge because resource recovery
systems are complex and expensive and carry large potential risks,
both technical and economic. Therefore, such implementations
require detailed planning and analysis and, in almost all cases,
the use of new procurement and acquisition techniques. To date,
several proposed implementations have encountered serious problems
which have led to long delays, costly price increases and
partial or complete failure.
The reason why I initially disagreed with the EPA's con-
clusion that financing will not be a probem is that several
proposed implementations have fallen apart during the contractural
and financing process after apparent successful acquisitions -
that is, selection by a municipality of a company to supply the
resource recovery system. At a very minimum., contractura]
negotiations and financing arrangements have been a torturous
process.
These failures have improperly created the impression
that contract and financing process is a more difficult and
formidable process than the acquisition or procurement process
itself. These impressions are misleading because the contracting
and financing process are an integral part of the overall
acquisition. If the misunderstandings, disagreements or un-
resolved issues exist at the outset of the contractual or financing
process, they will become evident during contractual negotiations
and will require further negotiations before a definitive contract
and financing can be accomplished.
While it is difficult to determine the precise reason
why any particular project failed, some clearly have been caused
by inadequate planning and research and impractical system
concepts. More than any other reason, however, most failures
are directly attributable to a lack of understanding of the
acquisition process and the financial, technical, institutional,
organizational and financing implicacions of a particular
acquisition approach.
In summary, financing for well-conceived resource
recovery systems is no problem. However, most projects never
develop a workable basis for contractual and financing arrange-
ments and are doomed to failure from the outset. No matter how
simple the eventual financing of a resource recovery system, it
is the job of financial advisors and bankers to help communities
understand the acquisition process so that a sound basis can be
developed for the eventual financing of the resource recovery
system. I find this a challanging and rewarding task ard look
forward to many successful implementations in the future.
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DESIGN FACTORS FOR TRANSFER STATIONS/RESOURCE RECOVERY SYSTEMS
Bruce Hendrickson
Vice President, Engineering Services, Browning-Ferris Industries, Inc.
It would not be feasible in the following discussion to try to cover
. of the detailed technical and engineering factors that must be consid-
;d in the design of transfer stations and resource recovery plants. I
.1 discuss some of the most important factors that determine the success-
operation of these systems both from the standpoint of markets and
:ual plant operation.
Transfer stations and resource recovery plants have many things in
nmon. Prom the standpoint of the collection vehicle they serve the same
iction; that is, they are a point of disposal and therefore should be
aluated by private collection companies and municipalities collecting
ste based upon their ability to serve their disposal needs. These needs
n be summarized by the following factors:
(1) Convenience of location
(2) lifficient traffic handling
(3) Reasonable waiting time
Whether you represent public or private interests, you must also
cognize a fourth factor in that you must make sure that the potential
ansportation savings offered by the transfer station justifies the higher
st of disposal normally charged at the transfer point. In the area of
onomic evaluation we arc finding that many transfer stations have a use-
il life of only five to eight years because of changing waste collection
actices. This type of situation can be overcome by obtaining long-term
intracts, but it is sometimes impossible to obtain long-term contracts from
micipalities because of local limitations on contractural commitments by
lose governing bodies. In cases where long-term commitments cannot be
:ached, we feel that a more rapid rate of depreciation would have to be
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developed to account for the probable short-terra life of the facility.
This, of course, increases the operating costs of the facility and raises
the rate which must be charged.
New transfer stations should be designed so that they can be con-
verted to resource recovery plants if at all possible. It is unlikely
that waste can be economically processed through a transfer station for
delivery to a resource recovery plant at some other location since double
handling is involved. While there will be exceptions to this rule, we
feel that the basic economics of waste handling argue against it.
Providing for expansion of transfer stations to resource recovery
facilities basically involves providing sufficient expansion area and
adequate transportation capabilities. The need for additional space and
transportation capabilities will become more evident as we discuss some
of the factors involved in designing resource recovery facilities.
The need for resource recovery has become a vital concern in most
industrialized countries, particularly during the last several years when
we began to realize that our supply of raw materials was not inexhaustable
nor would we forever have land available fcr disposal of wastes. One shoult
not automatically assume, however, that because of our need for conserva-
tion of materials and because conventional disposal becomes more difficult
each year, that resource recovery, which helped solve both of these prob-
lems, will automatically be successful. Whether you represent a private
firm or a governmental gioup, you must still consider basic economics.
No recovery system, whether designed to recover paper, metals, glass, or
energy, will be successful if there arc no reasonable markets for the re-
covered materials once the plant is in operation. By reasonable markets,
I mean markets that will support the cost of extracting the recovered
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material from the waste stream.
There are numerous examples of resource recovery systems developed
during the past ten years that have failed, not because of technical prob-
lems or faulty design, but because they recovered a material or prepared
a product that could not be sold at a competitive price, or in some cases,
at any price. Since most of these recovery plants were single purpose
facilities, they are too costly to serve as conventional transfer stations;
and their owners have suffered accordingly.
You should, therefore, consider marketing of recovered materials as
an essential prerequisite of good system design. After a thorough market
study has been completed and realistic recovery goals have been established,
actual engineering design can be initiated. You may find that a phased or
staggered implementation plan would be best because limited markets exist
for recovered materials at the present time in many areas.
Major resource recovery systems have little chance of success in com-
petitive disposal markets unless they include use of the major part of the
solid waste stream made up of low grade paper, plastics, wood, yard wastes,
food wastes, and other organic materials. Collectively these components
represent approximately 75'i by weight of solid waste. Most recovery sys-
tems being offered today obtain energy m some form from these components
of waste though fiber iccovery, chemical production and composting systems
are under development. Most of these processes reduce the volume to be
disposed of by from 70 to 90». This ieduction represents a real improve-
ment over the more generally used sanitary landfill system, provided the
revenue cost relationship provides an adequate return on equitv for the
owner of the system, or in the case of the municipality, adequate debt
retirement. hith both the iccovery and the sale of energy (or other bulk
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product) and the resulting significant reduction of residue, most recovery
systems will not stand the test of a truly competitive market. There are
exceptions to tnis rule vvhere governmental subsidies alter the basic eco-
nomics of the situation so that normally non-competitive systems are put
into operation. Sociological and environmental factors can be ecually im-
portant as economic factors however, complete reliance on them will jeop-
ardize true progress in recovery and reuse of waste materials. Progress
in resource recovery is and will continue ,vith or without direct subsidies.
IVe feel that tax incentives, research grants, and some types of limited
loan guarantees which promote development of markets for recovered mater-
ials offer a hotter way to support this now industry.
As previously stated, most existing technologies and mos^ developing
technologies produce energy products such as solid fuel, steam, electricity
or gas that were too expensive to be competitive until the oiL crisis of
1974. The rising cost of energy has thus been the most important factor
in the development of major recovery systens. IVith oil at $3.00 per bar-
rel there was little liklihood that an industrial plant or a utility would
consider using a prepared waste fuel at any price. Kith oil at approxi-
mately $12.00 per barrel and with the supply not always dependable at that
price, we have a whole ncu market place £01 prepared solid fuel, gas, oil
or possibly steam produced from solid waste.
An important advantage of the energy market is that it LS so large
that the entire solid waste stream from a najor metropolitan area will
often provide only a small percentage of the energy requirements for the
area. For example, a medium-sized chemical plant might require enough
process heat to use all of the combustible waste from a city as large as
Chicago. Uith this situation, it is unlikely that conventional fuel pro-
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;ers will feel that their markets ar'_ threatened. Large volume recovery
ints with their higher efficiencies are therefore possible.
While considering the subject of processing volume, it might be help-
to make note of some design considerations that are directly related
volume. Properly designed waste processing equipment and systems cannot
tfays be scaled up or down to match the volume of waste. Additional equip-
it and processing lines can be added to increase capacity but equipment
rmot be decreased below a size which provides proper flow of the waste
livercd to the plant. The unit capital and operating cost arc thus higher
r small volume plants. We believe that tins fact makes it much more dif-
cult for small communities to have efficient recovery plants.
When most people speak about our waste problems, they are thinking in
rms of the type of waste that goes in their household garbage can. Uhen
u design a resource recovery plant it is important to know that there are
veral types of waste which must normally be processed in order to have
fficient tonnage for efficient operation. Municipal, commercial, and
dustrial waste with their differing characteristics must all be received
d handled efficiently in order to obtain the maximum economic benefits from
'Cycling. Each of these waste streams has its own particular characteristics
id creates its own difficulties i\hcn processed through .1 recovery plant.
ifortuantely, the scaracity of operating experience with these different
'pes of wastes makes it difficult to anticipate all of the design prob-
:ms and you should, therefore, plan on a few adiustmcnts in the system
) obtain best efficiency.
It is important in the early planning stages of a resource recover}'
reject to obtain a thorough working knowledge of the t\pe of markets avail-
ale for each potential recovered material. An example tnat might help
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you understand the influence of market.; would be the effect that various
ferrous can markets have on the processing equipment required for ferrous
metal recovery from municipal waste. If the recovered ferrous cans are
to be sold to the detinning industry or to the copper refining industry,
you must choose shredding and magnetic clean up equipment that does not
completely crush the can body because fully exposed metal surfaces are
required for both markets. On the other hand, the basic steel industry
normally requires a dense ferrous product which may require fine shredding
and/or compaction. A close working relationship with your market partners
is essential because they can give you valuable technical guidance that
will make marketing of your recovered materials easier and more profitable.
We have found that availability of low cost freight is a fundamental
requirement in marketing several of the materials you normally expect to
recover in a resource recover}' plant. In many cases the actual cost of
freight hill be equivalent to the cost paid for the recovered material
FOB the recoxery plant, so thorough consideration must be given the type
of freight system that will be used.
Because of the bulk nature of recovered materials, rail freight will
often prove to be more economical than shipping by truck. An adequate rai."
siding may, therefore, be an essential requirement of your recovery plant
sjte. In most cases, you should locate the recovery facility with access
to both rail anJ truck lines.
We have already discussed the fact that a customer for some type of
refuse-derived fuel will be essential for nost resource recovery projects,
therefore, the potential fuel customer becomes the most critical link in
the entire project. In some areas of the country, a dry fuel product,
consisting primal il> of the combustible components found in solid waste,
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y find a market with existing coal-fired steam plants or perhaps with a
earn user who may install new boiler equipment specially-designed to burn
dry waste fuel product. The primary design consideration in any of the
y fuel systems, except the water wall incinerator, is the particle size
quired for the fuel product. With these systems, we generally feel that
u should start with the largest particle size consistent with efficient
mbustion since any unnecessary particle size reduction reduces the net
ergy available and will, therefore, raise either the fuel cost and/or
e disposal cost.
Particle size is determined by the shredding equipment. Since shredder
eration and maintenance cost will be your largest non-capital expense you
ould provide ample engineering time to properly evaluate the various shred-
rs available. It will be extremely valuable to you to visit as many of
e existing shredder installations as possible in order to get first hand
erating knowledge of the various types of equipment. You can learn by
her peoples' mistakes, and there have been a number of mistakes made.
Shredders should be selected on the basis of a number of factors.
me of these are listed below to help in your selection:
(1) Durability
(2) Cutting surface maintenance cost
(3) Power requirements per ton processed
(4) Throughput capacity (tons per hour) for various types of waste
(5) Feed opening (ability to handle large objects)
(6) Original cost
(7) Explosion resistence
The raw waste storage facility required for any resource recovery plant
st be given careful consideration if steady economical operation is to be
hieved. The storage system or area should be designed so that the first
ste received is the first waste fed to the processing plant. Ke feel
at the two best techniques to achieve this first-in first-out requirement
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are: (1) storage pit with bucket cranes and, (2) covered floor storage wit
front end loader feed onto conveyors. Both of these systems are versatile
in that the waste can be fed as required and adequate back-up equipment is
easy to provide. Positive air control should also be provided for these
storage facilities to eliminate unnecessary odors from the surrounding are;
While not a source of large direct operating expense, the feed system
used to transfer the unprocessed waste from the storage area to the shred-
ders is an important element of a well designed system because plant capac
cannot be achieved without a consistent waste flow through the plant. The
rated capacity of a shredder is based on a steady flow of material. Sixty
tons per hour also means one ton per minute. Normally, you cannot average
highs and lows on a feed conveyor to give you the rated capacity. You mus
make sure your feed system gives you adequate agitation and surge leveling
capacity to provide a steady input flow in order to maintain a higher
throughput at your plant. A skilled operator in the feed conveyor area of
the plant will greatly improve your ability to maintain high throughputs.
We feel that additional test data must be developed by the boiler
manufacturers and their customers to determine the most efficient particle
size for a refuse-derived fuel. The general opinion of the boiler manu-
facturers at the present time is to keep the particle size very small in
order to achieve complete combustion, but there have been few technical
or economic evaluations to determine the effects of burning larger partial
sizes with slightly less complete combustion. Because secondary shredding
is so expensive, we anticipate that a slightly higher carbon loss through
the boiler would be less expensive than requiring a smaller particle size.
Comprehensive testing of this characteristic of refuse-derived fuel has
not been completed to our knowledge. 25o
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Some waste fuel systems involve more complex processing but produce
gher quality fuel products than simply shredding waste with air separa-
_on to remove the non-combustible fraction. The waste fuel products pro-
iced by these systems, which include both oil and gas, have broader
irketability than the simpler solid fuels. In some areas, markets for
icse fuels may represent the only ones available and will, therefore,
;termine the type of system required for successful operation. The higher
-ices normally paid for these premium fuels may cover the more expensive
occssing cost involved. A number of test programs are underway to prove
le large scale economics of these relatively new systems and, hopefully
ley will pave the way for broader application of them.
In any discussion of particle size, it is very important to develop
proper definition for the method of particle size determination. In our
m tests we have found that a high percentage of particles (percentage by
:ight) will go through a much smaller screen opening than is apparent by
joking at a sample of the shredded material. Most of the large particle
.zes are made up of paper and film plastic which should have a fast burn-
ig time regardless of particle size.
The degree of redundancy in processing equipment is a factor of tre-
:ndous importance to the economics of any resource recovery plant. If the
ant becomes the only disposal site available to an area, it must normally
ive back-up systems to insure that it can operate enough hours per day
per week to process all waste received. Many recovery plants achieve
cost savings in this area by providing less expensive conventional trans-
:r equipment as back-up for their processing equipment. The cost for
ansferring unprocessed waste to the residue disposal site for short periods
iring unscheduled maintenance will often be more than offset by the capital
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cost savings realized by having less redundancy in the process equipment.
Considering economics only, this method will usually be chosen. A firm
energy or fuel commitment however, may require adequate back-up equipment
to guarantee a minimum delivery rate. As an example, a steam contract wi
probably require uninterrupted delivery of steam so back-up equipment wil
be a necessity and plant costs will be higher. In some cases, the use of
conventional oil or gas-fired equipment as back-up will be the most eco-
nomical solution to this guaranteed supply requirement.
During the period when actual disposal and supply contracts are writ
it is very important for everyone to understand the processing equipment
operating cost relationships so that equipment requirements can be optimi
to give the best overall economics for the customers and the recovery pla
From the private sector standpoint, providing adequate return on investme
for most of these new systems will require careful planning. Too often t
separate parties involved in these contractural relationships each set th
own standards without realizing the others' problems and costs and the op
timum cost situation is never obtained.
In summary, technology and engineering skills presently exist to re-
cover most of the valuable materials from our waste stream, but the marke
to reuse these recovered materials must be thoroughly developed before re
source recovery will be a truly practical solution to some of our long ra
raw material and disposal problems. The shortage of basic raw materials
the rising cost of conventional disposal are both contributing to the dev
opment of these market conditions and will help make resource recovery ec
nomically competitive and, therefore, a grouth area of our industry.
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CONSIDERATIONS FOR COMPONENT EQUIPMENT DESIGN SPECIFICATIONS
Irving Handler, P.E.
Principal Mechanical Engineer, Waste Management, Inc.
The selection and arrangement of equipment to process solid waste entails
immense effort, and must be approached in a logical manner to achieve the desired
results.
FLOW SHEET
The essential first step is to establish a Flow Sheet. A thorough Flow Sheet
will include the following elements:
1. Identification of basic families of equipment to be used.
2. Consideration of alternate lines for the refuse to follow when
the basic line experiences problems.
3. Quantitative analysis of the amount of material entering each
point of the total process, and the split of material leaving the
process, generally presented in tons per hour. Some of these
values are known from data derived from tests in processing
plants or in pilot plants; some are theoretical.
4. The rate of material processing any piece of equipment is to handle,
specified in terms of surges, or the maximum rate of material
throughput.
5. Qualification of refuse before and after each sf :>ge of the total
process. For example, before the primary shredding process, the
refuse is described at New Orleans as "municipal solid waste as
discharged from a packer truck," including "occasional refri-
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- gerators." This discription clarifies what the first equipment
has to handle. After the primary shredding process, the material is
called (-5"). This means that a horizontal shredder requires grates
of a certain spacing and an electric motor of a specific horsepower;
a vertical shredder will require a specific motor horsepower and hammer
pattern.
The total process bulk density is another value required of a thorough flow
sheet at each step. This must be known to determine the volume of material to be
handled by each piece of equipment. For example, if the bulk density of packer
truck waste is given at 280 Ib/yd , and the maximum tonnage per hour (or surge)
is 75 tons, then the volume of refuse handled by the primary conveyors is:
75 ton x 2000]^ x l_hr_xj_yd3 x 27 ft3 = 24| ft3
"hT" ton 60 min 280 Ib yd3 Min.
This value, coupled with conveyor speed calculations, is necessary to arrive at
a cross section for the conveyor.
For many portions of the process, a minimum bulk density is a required value.
Again an example - if a primary shredder discharges 75 tons per hour of refuse with an
average bulk density of 6lb. the volume per minute to be conveyed by a discharge
-fj-3
conveyor would be:
75 ton x 2000 jb._ x 1 hr. x 1 ft.3 = 417^
fir ton 60 min 6 Ib min
3
However, if the minimum bulk density for this process is 4 Ib/ft , then the volume
3
per minute becomes 6 x 417 ftj = 6 26 ft
4 min min
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This means a (626-417)100 ~50% increase in the volume of material to be handled,
417
directly affecting the conveyor width, skirt height, and conveying speed.
PHYSICAL ARRANGEMENTS
The physical arrangement of the equipment requires basic decisions relating
to reliability of flow, access to equipment, and costs, including that of the building
structure. The receiving and shredding buildings and the primary infeed conveyors,
involving considerations of significant proportions, will be discussed in detail.
At Recovery 1, two separate lines of equal capacity conveyors and primary
shredders were layed out to give complete stand-by or reliability to the process.
Should one line of equipment be down, the process can continue on the other line.
Ours is to be a tipping floor operation, therefore, the two (2) lines require two
(2) pit conveyors.
The next decision point is the direction of flow desired for the primary
onshredded refuse, which, in turn, affects the component equipment design. We
felt that handling the waste in a straight line from receiving conveyors through the
shredders presented fewer problems, and, thus, greater reliability. Once oriented,
long items of construction demolition, bulky items and brush cannot change direction
or interfere with conveyor skirts,which results in bridging or jams. If, for instance,
the refuse is fed at right angles and dropped onto another conveyor, reliability of
feed has to depend upon a speed differential between the conveyors and some good
design in transfer chutes.
The receipt of large volumes of material per day usually in short but con-
centrated bursts requires a large size tipping floor and receiving building. We
looked at the primary conveyor design to assist in minimizing building construction costs.
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The movement of refuse from a pit conveyor into the opening of a shredder
infeed hood requires a significant elevation change. For a large (75 TPH) unidirectional
horizontal shredder, the height of the conveyor head shaft centerline is approximately
17 feet above the shredder base. At Recovery 1, the horizontal shredder is mounted
on a massive pedestal, adding 12 feet more to height. Consequently, the conveyor
leading to the shredder is 29 feet above the floor. Maximizing the incline of a
conveyor minimizes the horizontal component of the conveyor and thus, permits a
shorter building, with consequent cost savings.
Although most conveyor manufacturers recommended a 30 maximum incline
for metal pan refuse conveyors,in-field observation revealed such a conveyor
operating effectively at more than the recommended angle. Consequently, we
specified a 35° incline, to which all the bidding companies finally agreed. Analysis
indicates how much building structure is saved this way. By triangulation, the
horizontal conveyor component is the vertical leg divided by the tangent of the
angle.
29ft. =29 =50 ft.
Tan 30° .577
29 ft. = 29 = -41 ft.
Tan 35° .70 9ft. saved
(9ft.) 100 = 18% savings
50ft.
This says that 9 ft. x (building width) = area saved. Also, triangulation shows the
actual conveyor length shortens 8 feet, affording additional savings in equipment
purchase price.
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SHREDDER CONSIDERATIONS
Design decisions concerning the primary infeed conveyors were primarily
based on other shredder considerations.
Vibrations coursing the shredder structure must be dampened before encounter-
ing conveyor structures to avoid damage to the conveyor structure and anchor bolts.
A flexible member for insertion between the conveyor and shredder hood should be
included in one of the two (2) equipment specifications. Conveyor head end supports
also should be provided independent of the shredder hood, or any portion of the
shredder structure. Adding any portion of this weight to the shredder not only
transmits vibrations, but also adds to the static loading to be considered for the
shredder foundation.
The introduction of an even material flow is an extremely important require-
ment. Wide material load fluctuations have a resulting similar fluctuation in
shredder motor loading. This, in turn, can force the power to be cut off, stopping
the shredder. Such motos cannot be stopped and started at will.
Shredders for given capacity ranges have infeed hoods with fairly defined
width dimensions, and since infeed conveyors slightly penetrate the hood, conveyor
widths cannot exceed this opening. To do so introduces a restriction to refuse flow
and can result in bridging or jams.
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CONVEYOR ARRANGEMENTS
What logical conveyor arrangement provide even or mefered flow? We
selected a separate pit conveyor feeding onto an inclined conveyor, in turn
emptying into the shredder. With two (2) separate drives, the inclined conveyor
can be run at a speed much aster than the pit conveyor. This speed differential
reduces the burden depth on the incline, reducing "roll back" problems, and
spreads the material so it can enter the shredder throat without major inter-
ference. This provides less fluctuation of work required for the shredder motor.
If bridging occurs in the pit, the separate pit conveyor can be reversed to aid
in breaking the jam. A single pit and incline conveyor cannot do this.
Another design provides a single conveyor with a pit and inclined
section feeding onto an oscillating or vibrating conveyor, which, in turn,
feeds into the shredder. Vibratory motion will level the refuse and introduce
a more constant flow of refuse. Given the shredder silhouette previously
mentioned, the vibrating conveyor must be supported high above the floor, requiring
significant supporting structure design. Yet another consideration was the reliability
of feed of a heavily loaded flat and 35 inclined single drive conveyor. The linear
velocity of the conveyor is constant from pit to incline. Heavy burdens will stay
in the same relation on the incline as in the pit and the tendency is to experience
"roll back". Refuse falls back down the conveyor causing a build up or "balling"
of material at the transition point, in turn resulting in erratic feed and occasional
bridging.
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Splitting these conveyors forced design decisions at the transfer points
between them. "Carryback", or the refuse clinging to the conveyor return strand,
creates a "housekeeping" or neatness problem. The basic solution is to have the
pit conveyor head shaft located forward of the inclined conveyor foot shaft. Thus,
the returning material, most of which drops within 3 ft. of backward travel, can be
intercepted and carried upward on the inclined conveyor.
Two variations of design exist here;
1. The foot shaft and a portion of the inclined conveyor is actually
horizontal, parallel to and beneath the pit conveyor. Essentially,
the inclined conveyor is still a compound conveyor with flat and
inclined section.
2. The inclined conveyor is in one plane only, with the foot shaft
below and back of the pit conveyor head shaft.
A compound conveyor may have some better housekeeping results, and it
permits a shallower pit. A compound conveyor, however, is more expensive,
requires additional horsepower to pull the conveyor strand around the transition
point, calls for more maintenance, and may be costly to install. Since the function
of either design was equal, total cost factors, including operation and maintenance,
over a contract period of 12 years determined the selection of a straight incline.
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For housekeeping purposes, be sure to consider keeping the return conveyor
strand enclosed by means of a continuous fixed surface of metal, called a dribble
pan. As refuse carried back on the return strand drops, it can be contained in the
pan. Cleats, or projections, on the conveyor can sweep this pan's debris to the
foot shaft area. Here, a removable cover would permit removal of accumulated
waste periodically. The alternative is to let the debris fail on the floor or pit
and sweep daily. Certain metal pan conveyor designs don't require cleats for
feeding, and it would be necessary to hose the dribble pans to thoroughly clean
them.
PIT CONVEYORS
A basic requisite in determining the final size of the pit conveyors is to
have sufficient volume provided so that a wheel (or front) loader can alternate
its duties. The loader must push tipping floor refuse into loading patterns, sort some
refuse such as tires, and also load the pit conveyor.
Data needs to be developed, with distributors of wheel loaders, to determine
the estimated time for loading given tons per hour, using the plant layout chosen.
Similar data are needed for tipping floor work and for conveyor loading. At
Recovery I, our objective was at least 5 minutes storage on the conveyor before
the loader had to replenish the waste pile. Final dimensions provided a conveyor
4 feet deep from top of pans to floors, 7 feet wide, and 60 feet long (between
shaft conveyors). As previously mentioned, storage is correlated not only with
conveyor volume but also with conveyor speed.
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Assume 10 FPM for conveyor
1. Cross section of refuse to be stored at
75 TPH:
241 Ft.3 =24.1ft.2
2. Storage on conveyor in:
(a) Tons - (24.1 ft.2) (60 ft.) (I yd.3 (280 Ib. (1
27ft.3) ydT3""" ) 2'OOOlt). =7.5 ton
ton
(b) Minutes -
(60Min.) (1 hr. ) (7.5 ton) = 6 min.
hr. 75 ton
HOPPER DESIGN
The hopper must be considered part of the available cross section to be totally
clear on storage capacity. Hopper design also should include a steel wall of practical
height opposite the load side to avoid housekeeping problems. Hopper wall thickness
and bracing is also important, because impacts will produce dents and misshape the
wall unless it is stoutly braced. Abrasion will wear away thin walls quickly. At
Recovery 1, our pit walls are 4 feet above the tipping floor above the foot shaft
and on the side opposite the loading and are of 3/8" steel plate.
METAL PAN CONVEYORS
Three basic designs of metal pan conveyors are presently offered for refuse
service. They are:
1. Double beaded
2. "Z" Bar
3. Piano Hinge
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Each offers certain advanfages not found in the other two (2) designs. Selection
of the pan design requires special care because they can affect the operating
efficiency and definitely affect maintenance.
Piano hinges have no gaps between pans as they articulate around head and
tail sprockets, and damage to the pans by refuse entering the joints should not occur.
Cleanliness on the top of the return strand also is enhanced since fine size refuse
has no gaps in the top strand to fall through.
"Z" bars offer ready-made pockets for transporting material, particularly
up inclines. They also offer a clever increase in the moment of inertia without
adding a lot of metal.
Double beaded pans offer a fairly stiff section modulus, and a simplified
arrangement for disassembly.
Several other design features should be analyzed for successful conveyor
application. A retaining wall is required on either side of the pan to keep material
from easily falling off the conveyor, creating major housekeeping problems.
These walls, or end plates, can vary in height, thickness, and method of
attachment to the pan. Some conveyors offered use the walls of the links, or
side bars, as retaining walls. However, because of construction, there is
necessarily a continuous, though small, gap between pans and links.
The moment of inertia for each style pan offered on the pit conveyors must
be checked because impact loading is continuous. This is a measure of the stiffness
of the structure and indicates how well the pan resists being under load. Fixed
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mpacf rails used to provide intermediate support points along the width of
the conveyor to prevent any pan deflections from reaching major proportions and
permanently damaging the pan vary between manufacturers in quantity,
material, and structure. The pit conveyor purchaser should insist on some restrain-
ing member for lateral or side motion on the pit conveyor metal pans. For example,
at Recovery I, the refuse is loaded completely from the conveyor side, creating
a force which pushes the pans at right angles to their normal travel. Without
a restraining member, the conveyor support rolls would have been forced off their
tracks resulting in downtime.
Conveyor manufacturers provide allowable chain tension for their specific
conveyors. These values should be compared, because the higher the value the
more load the conveyor can pull.
MAINTENANCE CONSIDERATIONS
The length of contract, or number of years of desired life, should be the
starting point in maintenance considerations. If a line of conveyors is to operate
for four years, asking for features which extend the wear life of "perishable"
items on the conveyors significantly beyond 4 years will needlessly raise the
purchase price. However, if the contract or operating life is 12 years, then
extended wear life and the resultant increased cost has logic. For example,
conveyor support rolls can be purchased with chilled rims or completely hardened.
Chilled rims are hardened skins of about 1/8 inch thickness . They can wear
through into the soft metal of the roller in much less time than the completely
hardened roll. The chilled rims could be acceptable for four years, but definitely not 12 years
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because you can expect to replace the chilled rim rollers in that time. The
comparisons between drive sprockets for the conveyor chain are in the same
category. These are offered flame cut or chilled rim. The flame cut style
offers no hardness at all and thus becomes the first to need replacement.
Maintenance requirements should be given extra thought in restricted
areas of movement, such as pits and inside shredder pedestals. Such problems
as removal of pins from piano hinge conveyors and their replacement, versus
bolt on features of other conveyor styles, become decision points of importance.
Be sure to have access for head and foot shaft removal for any conveyor style
in these situations, either by allowing lateral clearances in the concrete walls
or by provision for lifting vertically from the conveyor frames.
For other maintenance features, consider grease fittings on support tolls,
ease of access to remove support rolls, and how well conveyor links retain their
fit after two or three re-assemblies.
OTHER SPECIFICATION ITEMS
It is evident that significant analysis can be devoted to conveyor design
specifications. Other major items for consideration are:
1. OSHA regulations
2. Need for ladders and walkways
3. Type of conveyor drive desired
4. Provisions for conveyor drive stands
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5. Conveyor supports minimized for floor access and for neatness
6. Skirt dimensions
7. Shipping procedures and assembly requirements
8. Controls required
9. Transfer chutes
10. Standardization of drive components
RECOMMENDATIONS
The experience gained in analyzing and arranging lines of equipment for
Recovery I suggests a number of ways in which the procedures might be made more
effective.
1 . Allow ample time for vendor discussions. Equipment suppliers
have developed specialized knowledge that should be exchanged
during discussion periods. In presenting equipment proposals,
suppliers can clarify and enlarge upon the information being
offered, to the benefit of both buyer and seller. Adequate time
also should be provided for proposal development by supplier.
2. Scheduled field trips to resource recovery plants or shredding
and landfill facilities for observation of actual operating situations.
Knowledge gained in this way will enable you to analyze equipment
requirements with more insight.
3. With additional experience gained in the relatively new field of refuse
shredding and resource recovery, as well as advanced landfill
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operations, standardize equipment arrangements and equipment
specifications. Rather than rely on performance specifications,
switch to detailed equipment requirements. This will give all
suppliers common ground for bidding.
4. Take advantage of opportunities to gain "state of the art" infor-
mation, such as this meeting. More data will be forthcoming
and it should be assembled and assessed to aid in the decision-
making process. An important aspect of this is greater knowledge
of the requirements of prospective purchasers of recovered
materials, which, in turn, bears on equipment decisions.
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TECHNOLOGY UPDATE: ONONDAGA COUNTY ENERGY RECOVERY PROJECT
Ned R.Mann
Marketing Manager, Energy Systems Division, Carrier Corporation
This morning I want to spend a few minutes talking about the
resource recovery activities underway at Carrier Corporation. In particular,
I will discuss the project that we are designing for Onondaga County of
New York State.
First, let me spend a few minutes on social studies to refresh
your memory on New York State geography and political matters that one
encounters in attempting to implement any resource recovery project.
Onondaga County is located almost in the geographic center of
New York State, about halfway between Buffalo and Albany. It has a
population of about a half million people, half of whom live in the City
of Syracuse. The other half live in a number of towns and villages that
make up the entire metropolitan area. Within the area, there is a mixture
of light, medium and heavy industrial activity. Because of the location
in New York State, Onondaga County has become quite a distribution center
for Upstate New York and there are many warehouses, sales offices, and
other service activities. In most respects, one can think of Onondaga
County as a very typical American metropolitan area.
There are many levels of government active in the county,
including the County government, City government, plus the independent
towns and villages around the city. Almost every one of these governmental
units has some involvement in solid waste management, either in the
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collection or the disposal end. The trend, however, is for the County
government to assume a greater responsibility, especially for waste
disposal. Already, we have an Onondaga County Solid Waste Disposal
Authority actively in the disposal business. The Solid Waste Authority
operates three shredder units and three landfills, plus the transport
system used to convey the shredded refuse. The major customers of the
Authority are the City of Syracuse and now three of the surrounding towns.
The rationale for installing the shredder was based on the
Madison, Wisconsin experience with landfilling of shredded refuse without
daily cover. Many of the landfills used in Onondaga County do not have
cover material available at the site, and purchase and acquisition of cover
is a major expense. Although there was some thought given to resource
recovery when the shredders were committed for, there were no plans or
facilities provided other than magnetic separation of ferrous material at
one of the units.
Subsequently, the New York State Department of Environmental
Conservation has decreed that landfill of shredded refuse without cover
would not be permitted and, therefore, the County is not realizing the
hoped-for benefit of the shredder operation.
When resource recovery became a matter of general interest,
we had an idea that Carrier might have something to offer in the field.
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Carrier already has a major stake in the solid waste management business
through its Dempster Dumpster Systems Division, a leading manufacturer of
solid waste handling equipment. Also we were aware that many existing
waste disposal projects in Europe" use energy produced from solid waste
to provide steam for district heating systems and we have considerable
expertise in such systems. With the help of an outside consultant, we
evaluated the idea of energy resource recovery from solid waste with
district steam systems at the specific end user. The results of this
evaluation were encouraging.
We learned that it is possible to produce low pressure and low
temperature steam from the direct combustion of refuse, but that if one
were to produce high pressure superheated steam such as is used in modern-
day power plants, there were apt to be severe corrosion problems. District
steam systems, on the other hand, use low pressure, low temperature steam.
A typical district steam system might deliver steam at less than 200 psi
and 500°F.
Also, we learned that the energy requirement of the solid waste
typically available in an area is about in line with the energy requirement
for many district steam systems. A typical district heating boiler produces
in the range of 100,000 to 200,000 pounds of steam per hour, which is the
output of larger refuse combustion units.
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But most importantly, we learned that district steam customers
are able to pay a much higher price for steam than industrial or utility
customers because the cost of providing heat themselves is higher yet.
It is not unusual today for district steam systems to charge $5 or $6 per
1000 pounds of steam and we know of some whose rates exceed $9 per 1000
pounds. With this kind of revenue, it is possible for energy sales to
provide 75% or more of the revenue for a district heating-resource recovery-
refuse disposal system.
There are two major district heating systems in the cLty of
Syracuse. One, owned and operated by Syracuse University, provides heating
and cooling for many campus buildings and dormitories. Also, it supplies
steam to six hospitals, two large senior citizens housing developments,
and several hundred units of low-income housing, plus two units of the
State University of New York. Currently, this steam system is fueled by
natural gas, and the supply is threatened with curtailment.
The second district heating and cooling system is owned by the
County itself. It provides service for six county-owned buildings in the
downtown area. It, too, is fueled by natural gas, but on several occasions,
this plant has been forced to switch to oil during months of peak demand.
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The two systems are not interconnected, but they are less than
2000 feet apart and the cost of installing a connecting steam pipe will
be a small portion of the total project.
These two district heating systems are ideal as the major
customers for an energy resource recovery project.
It is no coincidence that the headquarters of Carrier Corporation
is located in Syracuse. Therefore, the local political situation is well
known and we did not face the problem of establishing credibility that an
outsider might.
The first phase of the project, completed about a year ago, was
a feasibility study designed to show that the pieces would fit together,
the amount of solid waste would match the steam demand, and the economics
of the project were favorable. The outcome of the feasibility study was
a report affirming the idea and suggesting that the County proceed with the
project. Therefore, the first phase of the design study was authorized by
the Legislature and has just been completed. We expect that the project
will proceed to completion in the next three years.
The Onondaga Resource Recovery Project, as it is now called,
will involve the purchase by the County of the existing district steam
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system from the University. On the site of the present steam plant will
be built a refuse burning boiler with a capacity of 1000 tons of refuse
per day, capable of producing 250,000 pounds of steam per hour. This
steam will be distributed to the existing customers of the University's
steam station and the system will be extended to include the County
buildings now served by the smaller district steam plant. We expect
that about 80% of the energy needed for this system will come from solid
waste, the other 20% being provided by peaking facilities using fossil
fuel. In all, the project will release about 2 billion cubic feet of
natural gas badly needed by residential and industrial customers in the
County.
Economically, the objectives for this project are to produce
and distribute steam at a price competitive with the present price which
is about $4.50 per 1000 pounds of steam while accepting refuse at a
tipping charge, the objective for which is $4.00 per ton. These prices
would be subject to some escalation, of course, but the escalation should
be less than that brought about by the increasing price of oil alone.
Technologically, the objective of the project is to minimize
the risk inherent in all resource recovery projects. A local municipal
government is not in a position to take large risks in this type of
project since there is very little to gain for doing so, but much to lose.
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Resource recovery projects are risky ventures. The performance may not
meet standards, for example, atmospheric emissions or burnout of the
solid waste. The sale of the recovered resource may not yield the expected
revenue. Or the operating cost of the plant may higher than predicted.
We are minimizing the risks in Onondaga County by insisting on
the use of technology proven in the plants of a comparable size which
have operated over a period of years. The heart of an energy resource
recovery plant is the combustion system, that is the equipment between the
charging chute and the stack. This includes not only the grates and the
boilers, but also the electrostatic precipitators, the fans, the controls
and probably the ash handling system. This part of the project will be
supplied to the county on an installed basis under a single contract.
A draft specification for the "chute-to-stack" system has been
prepared and responses obtained. A key part of this specification calls
for the supplier to show that a system comparable to one that he proposes
has been operated successfully with municipal solid waste as the fuel.
Responses to the draft specification indicate that there will be between
three and six qualified suppliers.
In one item of the specification, we are being somewhat venturesome.
We are asking for systems that can burn solid waste either as-received or
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coarsely shredded, as produced by the existing shredders. The units must
also be able to burn mixtures of processed and unprocessed material.
This ability will enable the Onondaga Resource Recovery Project to practice
front-end material recovery of steel or aluminum or even glass if that is
economically justified. At the same time, the energy recovery process
will not be jeopardized by a "weak link" in that it will not be necessary
for the refuse to be processed in order to extract its energy values.
From the vendors' reactions to the specification for burning
processed or unprocessed refuse, we have positive evidence that this
requirement can be met.
Even though the Onondaga County Project is based on established
proven technology, there have been challenging engineering tasks. The
site chosen for the project is on 2j acres of land in an urban area.
This is a much smaller plot than is normally committed for projects of
1000 tons per day capacity.
Transport of refuse to the site has required considerable effort
to develop routes and schedules to minimize impact on the urban roadways.
Transportation will be entirely by truck from transfer stations to the
steam plant site. The location has been chosen to make maximum use of the
interstate highway system and keep vehicles off local streets.
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We are often asked whether the Onondaga Resource Recovery
Project will be a steam plant or a refuse disposal plant, by which the
questioner really means: "Are you going to guarantee to dispose of
refuse or deliver steam?" The answer is: "Both." This project will
include standby systems to insure that solid waste can be accepted and
disposed of while steam can be produced and distributed under almost
any circumstance.
In summary, the Onondaga Resource Recovery Project looks like
one of the best opportunities to bring into existence a real resource
recovery project. The economic, political, and technical factors are all
favorable so that in 1978 "cash for trash" should be a reality in Syracuse.
CAJ/bjg
10/23/75
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Technical Symposium
Selected Papers
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IDENTIFYING AND CORRECTING GROUNDWATER CONTAMINATION
AT A LAND DISPOSAL SITE
James S. Atwell, P.E.
Director, Solid Waste Management Services, Edward C. Jordan Co., Inc.
INTRODUCTION
Groundwater contamination can be a serious long-term result of the
improper disposal of solid waste on land. For the last two years EPA
has been actively studying the environmental effect of leachate result-
ing from solid waste disposal. Yet many municipal officials remain una-
ware of this problem, which may already be affecting the ground and
surface water quality in their communities. For most towns and cities,
preventive or corrective action is spurred only by a gross pollution
problem observed in a nearby well, lake or stream.
Such was the starting point in this case study for Saco, Maine, a
city of approximately 14,000. The study was prompted when a property
owner adjacent to a city dump reported a deterioration in the quality of
a small spring feeding a pond on his land. The city had operated the
land disposal site, partly as a burning dump and later as a landfill,
for a period of about 15 years. When the water quality problem was
first noticed, the city was in the final stages of the development of a
sanitary landfill at a new site. The original disposal area was aban-
doned approximately six months after the problem was discovered. A site
plan of the abandoned city disposal site and adjacent area is shown in
Figure 1.
A dump was operated at this site for approximately 15 years.
During the initial years of the dump operation, burning was commonplace.
The frequency of burning decreased gradually, however, as a reS'jlt of
citizen complaints and problems associated with fire control. As the
disposal operation moved towards the easterly corner of the site, a high
groundwater table was encountered and refuse was often placed in direct
contact with exposed groundwater. Without an operating plan, cover was
provided only on an intermittent basis using highly permeable soils.
The principal purpose of the cover material was to control blowing
papers and allow vehicle access; it did riot prevent surface water per-
colation. This disposal area was not a sanitary landfill.
The problem was aggravated in 1973, when a primary wastewater
treatment facility serving a large Saco tannery was placed in operation.
This facility produced 4 to 5 tons per day of sludge (dry basis} which
was transported to the site for disposal. The solids content in the
sludge was generally no more than 5 to 1C percent. The sludge was
handled separately from other solid wastes. The sludge was placed
directly on the ground or in shallow trenches, occasionally in contact
with groundwater; cover was provided only intermittently.
278
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FIGURE 1
CITY OF SACO
REFUSE DISPOSAL AREA
SITE PLAN
SCALE
.IN FEET
EDWARD C. JORDAN CO JNC
Jj
279
-------
The neighboring property owner's water quality complaint in April
1974 prompted an initial series of surface water testing and analysis by
the city's engineer and by the Maine Department of Environmental Protec-
tion (DEP). This study found that leachate was contaminating surface
and groundwater in the vicinity. In order to determine the most envi-
ronmentally and economically acceptable means for correcting this prob-
lem, the city undertook a program designed to trace the path of the
contamination migrating from the disposal area, characterize the nature
of the contaminants, and come up with alternative solutions to the
problem. The Edward C. Jordan Company of Portland, Maine, was; selected
to provide consulting engineering services to the city, as well as
testing and laboratory services in conjunction with the Maine DEP.
The city's program was undertaken in two phases:
1. Hydrogeological investigation
2. Evaluation of alternate corrective measures
The objective of the hydrogeological investigation was to identify sub-
surface soils conditions, groundwater levels and to install groundwater
monitoring wells. These wells permitted the measurement of groundwater
levels and the sampling of groundwater. During Phase 2 alternative
corrective measures were identified and evaluated based on the existing
site conditions.
SCOPE OF STUDY
Hydrogeological Investigation and Groundwater Monitoring Progr;im
A subsurface investigation and groundwater monitoring program was
designed and initiated. Thirteen soil borings were taken, and monitor-
ing wells installed in eleven of these bore holes. In addition, a study
was made of the groundwater and surface water hydrology of the area.
A marine clay is found beneath the abandoned disposal area at a
depth of approximately 25 ft. This clay is overlain by a fine permeable
sand. The grouudwater varies seasonally between five and fifteen ft.
Refuse depth averages ten ft. In several areas refuse was found to be
in the groundwater. Where this occurred, the submergence did not
exceed five ft.
The major groundwater recharge area in the vicinity of the disposal
site is the Heath, a large, partially forested land area about 7,500 ft
north of the site. From the Heath, groundwater moves outward ii a
radial pattern as indicated by several small surface and underground
streams, one of which is Sandy Brook. As shown in Figure 1, Sandy Brook
runs along the west side of the abandoned dump. A small well defined
drainage ditch is located on the east side.
Groundwater and surface water level measurements were taken to
develop the groundwater contours shown in Figure 2. Typical of most
280
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281
-------
land disposal areas, a. groundwater mound has developed beneath the fill
area. This mound causes a hydrostatic pressure in all directions,
however, the primary groundwater movement is in a southerly direction.
This movement is confirmed by the groundwater analysis which showed the
greatest groundwater contamination to be in this direction. The primary
area of leachate contamination lies south of the disposal area between
Sandy Brook and the small stream.
Surface water samples taken over an 18-month period were supple-
mented by sampling at the new monitoring wells, as well as at several
private wells in the vicinity. Samples were analyzed1 to identify the
extent of groundwater contamination and the direction of its movement.
The location of the borings and sampling wells is shown in Figure 3.
Samples taken within the dump and adjacent to it show contamina-
tion, as shown in Table 1. There is some upstream dispersion because of
the mounding effect; however, the highest levels of contamination occur
south of the site. The dump and immediate vicinity are believed to be
the major groundwater recharge source for the area contaminated by the
leachate.
Chromium, believed to be from the tannery sludge, occurred at a
peak concentration of approximately 2.0 mg/1 in samples taken within or
directly south of the area. The high iron and manganese concentrations
do not indicate that inordinate amounts of these elements were disposed
of at the dump site. What they may indicate is that the soil is being
affected by the leachate plume. The plume produces low pH levels and
reducing conditions in the natural soils, resulting in the release of
iron and manganese from the soil which is then detected in the samples
to indicate the plume's presence.
ALTERNATIVE CORRECTIVE MEASURES
Two basic philosophies are available for the control of leachate at
an existing site: (1) collection and treatment, and (2) prevention of
refuse-water contact. The effective use of a collection and treatment
system is very dependent upon the character of the site. Normally, this
alternative is very difficult and expensive to implement once a problem
has developed. Prevention of refuse-water contact requires that both
surface and groundwaters be controlled. This is a major goal in the
design of all sanitary landfills. When no refuse-water contact occurs,
leachate will not be a problem.
Collection and Treatment
Leachate collection can best be accomplished by installing an
"^Results of water analyses performed by the Jordan Company and the Maine
Department of Environmental Protection are appended.
282
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FIGURE 3
CITY OF SACO
REFUSE DISPOSAL AREA
MONITORING POINTS
EDWARD C. JORDAN CO ,INC.
Ji
283
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TABLE 1
WATER QUALITY FINDINGS
Uncontaminated
Groundwater ^.0.1
Contaminated
Surface Water 50-75
Groundwater Beneath
Disposal Area 300-1500
Groundwater South
of Disposal Area 200-1900
Manganese
.(mg/1)
<0.025
1-25
20-300
6-100
Conductance
(utnhos)
60-80
1400+
1200-7900
100-5000
284
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underdrain system and associated works surrounding the site, in conjunc-
tion with the proper closing and capping of the area. In Saco this
system involves installation of underdrains in the area defined by wells
B-101, 102, 103 and 104 as shown in Figure 4. During and immediately
following installation, a substantial amount of contaminated water would
be collected and would require treatment prior to discharge to Sandy
Brook. The leachate collected initially would have been in contact with
the refuse for varying periods of time. In addition to the iron, mangan-
ese and chrome, the leachate would contain a wide range of complex
organic compounds resulting from the decomposition of materials placed
in the landfill. Temporary treatment would be required during this
period, however, treatment would not need to continue after the system
reaches a steady state and no contaminated water was being collected.
Treatment of this temporary flow of leachate which might last for
several months could not be economically accomplished in any system re-
quiring a large initial capital expenditure. As an economical alterna-
tive, a treatment system consisting of two holding ponds in series sepa-
rated by a dike of graded filter sand was initially considered.
However, systems of this type are still being tested and evaluated
and there were considerable problems associated with achieving suffi-
cient treatment prior to discharge to Sandy Brook. Since a proven
system including chemical and/or biological treatment was not economi-
cally feasible and since no suitable receiving water was located nearby,
collection and treatment was not given further consideration as an
overall solution to the leachate problem.
Prevention of Refuse-Water Contact
Leachate formation may be controlled by preventing water from
coming in contact with refuse. Water may reach the refuse by percola-
ting through the surface or by lateral movement of groundwater. Both of
these sources of water must be controlled to eliminate the formation of
leachate. The percolation of surface water into the buried refuse can
be controlled by properly grading the surface of the landfill and cover-
ing with an impervious layer. The lateral movement of groundwater
through the refuse and the movement of leachate away from the landfill
may be controlled by constructing a vertical barrier to prevent this
movement. These objectives can be met by any of several alternative
methods.
The prevention of surface water percolation involves the placement
of an impervious cover. The placement of the cover involves several
steps: (1) site grading, (2) placement of necessary soil to cover the
refuse and to protect the barrier, (3) placement of impervious barrier,
and (4) placement of topsoil, fertilizer, and seed. The area to be
covered at the Saco dump covers about 9 acres (42,500 sq yd). Several
alternative impervious liner systems were studied. Since each of these
systems is capable of effectively restricting percolation of water into
the refuse, the cost is the major factor in selection. Cost data is
285
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presented following a brief description of alternative systems.
Synthetic Liners. Synthetic materials such as Hypalon and EPDM
(Ethylene Propylene Diene Monomer) have been used to contain water in
lagoons and holding ponds. These materials could also be effective in
providing a water tight seal for this application. The installation of
the liner must be handled with care to assure that no breaks occur.
Soil-Bentonite Mixture. The use of bentonite clay as an additive
to native soils can be used to form an impervious barrier. Bentonite is
an imported form of naturally occurring clay which has enormous swelling
properties when placed in contact with water. When it swells, it fills
voids in the soil and reduces permeability. This system has also been
used extensively in the construction of ponds and lagoons. After site
preparation, the bentonite is spread using conventional farm machinery
at an application rate of 1.5 to 2.0 Ibs/sq ft. The material is mixed
to a predetermined depth (2 to 6 inches), then rolled and covered.
Soil-Cement Mixture. A soil-cement liner is similar to the soil-
bentonite system described previously; however, cement is used as the
admixture rather than clay (bentonite). Liquid asphalt is sprayed over
the surface (0.25 gal/sq yd) to aid the curing process.
Natural Clay. Natural marine clays or other impervious soils can
be used to form a. watertight liner. The location of a source of this
material within an acceptable haul distance determines the feasibility
of this method.
Since much of the coastal areas of southern Maine are underlain by
an impervious marine clay, this material offers an inexpensive, readily
available source of a suitable liner material.
In Saco this alternate would involve grading of the site, placement
of 6 inches of soil, placement of a 1-ft layer of clay, and finally
placement of a 6-inch soil layer suitable for supporting a grass crop.
Minimum surface grade would be 2 percent to encourage efficient runoff.
Once the impervious liner has been covered with topsoil, fertilizer and
seed would be placed according to the schedule in Table 2.
In conjunction with each of the surface sealing systems, provisions
must be made to improve surface runoff from the vicinity of the aban-
doned disposal area. The drainage system would consist of well-defined
impervious drainage channels leading to the major natural drainage areas
in the vicinity. Improved surface runoff will reduce percolation and
reduce recharge of the groundwater beneath the disposal area.
In addition to controlling percolation, a complete encapsulation
system must include a vertical barrier to prevent lateral groundwater
movement. The vertical barrier would extend from the ground surface to
the impervious clay layer which lies beneath the disposal area at a
depth of approximately 25 feet. Vertical barrier alternatives are
286
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TABLE 2
SEEDING SCHEDULE
Seed
Tall Fescue (ky. 31)
Red Fescue
Red Top
Landino Clover
Annual Ryegrass
TOTAL
50 ///acre
20 ///acre
6 ///acre
4 ///acre
10 ///acre
90 ///acre
Fertilization
Lime
Fertilizer (15-15-15)
2 tons/acre
1000 ///acre
287
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described below.
Slurry Trench. The slurry trench method involves the construction
of an impervious bentonite clay wall around the abandoned disposal area.
As the soil is removed during trench excavation, the space created is
filled with a bentonite slurry. The slurry pressure forces the benton-
ite into the pores of the soil, thus restricting groundwater flow and
stabilizing the trench wall. After the excavation has proceeded for a
short distance (about 100 ft), the trench is backfilled with a soil-
bentonite mix to form an impervious wall 18 to 24 inches thick. No site
dewatering is required. Additives to the bentonite prevent Its break-
down in the presence of leachate.
Grouting. Grouting is a process which involves the injection of a
material such as bentonite clay, cement, or various chemical grout
compounds into the pores of the soil to form an impervious seal. The
grout wall is installed by pumping the mixture into the soil through a
pipe. As the grout fills the voids, pressure increases and the tube is
manually removed. Since close spacing is required to form a tight
barrier, the quantity of material and the long installation time make
this an expensive alternative.
Imper-Wall. The Imper-Wall system is a proprietary grouting tech-
nique which increases the efficiency of grout injection. In this process,
a special 24- to 48-inch steel I-beam with a grout pipe attached is
driven by a vibrating hammer through the soil to the underlying clay
layer. As the beam is driven into and extracted from the soil, a grout
of bentonite is pumped through the pipe into the soil. As the beam is
removed, the void space is filled with the grout forming an impervious
barrier. Subsequent sections are formed by overlapping to form a con-
tinuous wall. The Imper-Wall method is faster than conventional grout-
ing and requires less material, thereby reducing cost.
Steel Sheeting. Leachate movement may also be controlled by plac-
ing steel sheet piling around the abandoned disposal area. The piles
would be driven into the clay layer beneath the refuse and interlocked
to form a watertight barrier. The cost of protecting the piles against
corrosion and subsequent failure makes this alternate extremely expen-
sive.
Concrete Wall. A concrete wall could be used to form a barrier to
prevent water movement. However, the high groundwater and unstable soil
conditions complicate the excavation process. In order to permit trenches
to be excavated and forms placed, dewatering of the site would be neces-
sary. Since the dewatering process would require the pumping of contam-
inated water, this method does not offer a feasible alternative.
Based on our evaluation of the alternatives presented above, the
following conclusions were reached:
1. The use of a locally available clay for the surface cover
288
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offers the city of Saco the most cost-effective means of pre-
venting percolation of surface runoff into the refuse.
2. The use of the Imper-Wall technique with a bentonite barrier
offers the most cost-effective means of constructing a verti-
cal barrier to restrict lateral groundwater movement and to
encapsulate the buried refuse.
ECONOMIC ANALYSIS
Since the cost of the corrective system is a major factor in selec-
tion, preliminary cost estimates were developed for the various alterna-
tives.
Table 3 summarizes the capital costs associated with closing the
abandoned dump area and placing an impervious liner. These costs in-
clude site preparation and grading; cover material; the impervious
liner, including installation; fertilizer and seed; additional wells to
monitor the effectiveness of the system; and contingencies and engineer-
ing. The majority of these items do not vary from system to system.
The principal factor which contributes to the cost range of $0.40/sq ft
to $0.60/sq ft is the impervious liner and associated cover material.
This portion of the cost varies from $179,000 for a synthetic membrane
to $100,000 for a natural clay system. Table 4 compares the total cost
of the various landfill cover systems, while Table 5 compares total
encapsulation (vertical barrier) costs.
Cost estimates for the vertical barriers were developed from a
review of recent contractors' bids for similar projects, and were com-
puted primarily on the basis of cost per square foot of wall. These
costs, as summarized in Table 5, include material and installation.
CONCLUSIONS AND RECOMMENDATIONS
Based on available geotechnical information, the abandoned refuse
disposal area and the adjacent land to the northwest of Foss Road are
the major recharge areas for the groundwater found in the area of con-
tamination between Sandy Brook and the small stream.
Water levels in the dump area are slightly higher than the adjacent
areas, creating a gradient for flow in all directions. The gradient to
the north, however, is very gradual and only a minimum dispersion of
contaminants occurs. The movement of leachate from the dump appears to
be generally confined to the area between Sandy Brook and the stream
located to the east of the abandoned dump.
The use of a leachate collection and treatment system to control
the groundwater contamination was discarded for the following reasons:
1. The high degree of uncertainty in being able to provide suf-
289
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TABLE 3
LANDFILL COVER
CAPITAL COST ESTIMATE
Synthetic Liner
Site Preparation - Grading $ 11,000
Cover Material (Include Placement) 49,000
Synthetic Liner 130,000
Seed and Fertilizer 10,000
Off-site Drainage 5,000
Monitoring Wells 1,000
Contingencies and Engineering 25,000
$231,000
($0.60/sq ft)
Soil Bentonite
Site Preparation - Grading $ 11,000
Cover Material (Include Placement) 60,000
Bentonite - Material 60,000
Bentonite - Placement 30,000
Seed and Fertilizer 10,000
Off-site Drainage 5,000
Monitoring Wells 1,000
Contingencies and Engineering 25,000
$202,000
($0.53/sq ft)
Soil Cement
Site Preparation - Grading $ 11,000
Cover Material (Include Placement) 60,000
Soil Cement Liner (Include Preparation and Placement) 60,,000
Seed and Fertilizer 10,000
Off-site Drainage 5,000
Monitoring Wells 1,000
Contingencies and Engineering 25,000
$172,000
($0.45/sq ft)
Native Clay
Site Preparation - Grading $ 11,000
Cover Material (Include Placement) 30,000
Clay Liner (Include Placement) 70,000
Seed and Fertilizer 10,000
Off-site Drainage 5,000
Monitoring Wells 1,000
Contingencies and Engineering 25,000
$152,000
($0.40/sq ft)
290
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TABLE 4
LANDFILL COVER
COST COMPARISON
Native Clay
Soil Cement
Bentonite
Synthetic Liner
$152,000 ($0.40/sq ft)
$172,000 ($0.45/sq ft)
$202,000 ($0.53/sq ft)
$231,000 ($0.60/sq ft)
TABLE 5
ENCAPSULATION SYSTEMS
COST COMPARISON
Material
Installation
Slurry Trench ($6/sq ft)
Imper-Wall ($4/sq ft)
Grouting ($15/sq ft)
Concrete Wall ($6.75/sq ft)
$80,000 $290,000
$40,000 $200,000
Total
$370,000
$240,000
$900,000
$400,000
291
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ficlent treatment to permit discharge to Sandy Brook or to the
land.
2. High cost.
To prevent refuse-water contact, a two-phase control program was
recommended. Phase I includes the following steps:
1. Cover the area delineated in Figure 4 with an impervious liner
of local clay.
2. Improve the efficiency of surface runoff in the vicinity of
the disposal area by constructing drainage ditches to convey
runoff to natural drainage courses.
3. Institute an expanded monitoring program to measure ground-
water levels and groundwater quality.
Phase I includes grading, covering and seeding of the area outlined
on Figure 4. In conjunction with this, the flow of surface water in the
vicinity of the abandoned dump must be improved to encourage runoff to
the nearby drainage areas. The use of locally available clay soil
offers the most economical method of covering the dump and preventing
percolation of surface water into the refuse. The estimated cost of the
cover and associated work is $152,000. The covering of the abandoned
dump is a normal part of the closing of a land disposal area and is a
step which must be undertaken as an integral part of any leachate con-
trol system. Therefore, any further steps which may be necessary to
control the leachate may be undertaken at a later date without affecting
the integrity of the surface cover.
The covering and improved surface flow will prevent the percolation
of surface water through the buried refuse and will lower the ground-
water in the vicinity of the disposal area. Although the change in
groundwater level cannot be precisely predicted, there is a good chance
that the change will be sufficient to lower the water below the refuse.
If successful, this will minimize refuse-water contact and will prevent
further generation of leachate.
The effectiveness of these measures will be determined by continued
monitoring of the groundwater through the use of the existing wells as
well as several additional wells to be installed as part of this program.
If the Phase I steps fail to lower the groundwater table suffi-
ciently to prevent the generation of Leachate, additional measures will
be necessary. The actual steps to be taken will be dependent on the
efficiency of the initial steps. The Phase II alternatives would in-
clude an underdrain system or the Imper-Wall vertical barrier.
The installation of an upstream underdrain system is the preferred
alternate because it has a lower initial cost and fewer potential long-
term risks. The underdrain system would be installed on the north side
292
-------
293
-------
of the disposal area to further lower the groundwater level. The objec-
tive would be to collect uncontaminated water. However, as a safety
measure, water collected by this system would be pumped to the area
south of the landfill but would not be treated. Based on preliminary
conceptual data, the cost of this system is estimated at $75,000.
If the groundwater cannot be lowered sufficiently by the underdrain
system, it may be necessary to completely encapsulate the refuse. If
this is necessary, the use of the Imper-Wall technique is recommended,
at an estimated cost of $240,000. The use of complete encapsulation
would pose substantial long-term problems related to gas production,
venting and leakage; such hazards would require detailed evaluation
prior to implementation.
It is felt that Phase I recommendationsa more impervious surface
cover and better management of surface runoffhave a good probability
of lowering the groundwater table sufficiently to minimize refuse-water
contact at the site and to economically reduce future leachate production.
Recommendations for dealing with the leachate-groundwater contam-
ination problem at the abandoned Saco dump basically consist of the same
steps involved in the proper closing of any land disposal areasanitary
landfill or otherwise.
It must be recognized that the steps described herein will control
the generation of additional leachate and prevent an increase in the
contamination of groundwater. These steps will not immediately improve
water quality in the plume area. Water quality improvement in the plume
area will occur gradually as uncontaminated water migrates through the
area and the contaminants are leached from the soil by natural ground-
water movement. The complete improvement of water quality to its; initial
state may take many years.
294
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APPENDIX: WATER QUALITY ANALYSES
SACO Dl/MP WATER SAMPLES
DATE: May 5, 1975
LOCATION
Cr
Fe Mn Zn NH3-N NOj-N pH
COND.
Bucci Well
Tripp Well
Angers Well
Vachon Well
Blunt Well
Cousens Well
Tyrell Well
Austin Well
Cousens Spring
Cousens Fond Influent
B-101
B-102
B-103
B-104
B-105
B-106
B-109
B-110
B-lll
B-113
Sandy Brook Near B-112
5
<1
< 2
<2
<1
<,!
<1
<2
2200
470
750
150
650
290
410
530
63
40
55.0
3
150.0
4.0
9.0
14.0
9,5
1,0
2,0
0.5
1.0
1.0
2.0
2.5
6,5
6,5
6.1
5.9
6.5
6.5
150
40
2500
40
60
60
KEY
Cr - Total Chromium mg/1
Fe - Total Iron mg/1
Mn - Manganese mg/1
Zn - Zinc rag /I
NH3-N - Ammonia As Nitrogen mg/1
N03-N - Nitrate As Nitrogen mg/1
pH - In pH Units
Cond - Specific Lcm'ucLance
Analysis by DEP
imhos
295
-------
SACO DUHP WATER SAMPLES
LOCATION
Cr
Fe
Mn
Zn
N03-N pH
COND.
Buccl Well
Tripp Well
Angers Well
Vachon Well
Blunt Well
Cousens Well
Tyrell Well
Austin Well
Cousens Spring
Cousens Pond Influent
B-101
B-102
B-103
B-104
B-105
B-106
B-109
B-110
B-lll
B-113
Sandy Brook Near B-112
,12
.09
<.06
<,06
<-06
< .06
< .06
.12
.06
.24
lit,
180
750
300
300
44
340
78
54
190
15
54
32
28
50
1.4
230
1.7
1.8
11
0,2
0,3
.08
.18
.22
.19
.08
.43
0.3
1.7
250
3200
2000
900
2500
50
4800
40
110
65
KEY
Cr - Total Chromium mg/1
Fe - Total Iron mg/1
Mn - Manganese mg/1
Zn - Zinc mg /I
NH3~N - Ammonia As Nitrogen mg/1
N03~N - Nitrate As Nitrogen mg/1
pH - In pH Units
Cond - Spcnftc Condu. tance £2l
cm"
ihos
Analysis by DEP
296
-------
SACO DUMP WATER SAMPLES
DATE: August 8.19'/
LOCATION
Cr
Fe
Zn NH3-N NOj-N pH
COND.
Bucci Well
Tripp Well
Angers Well
Vachon Well
Blunt Well
Cousens Well
Tyrell Well
Austin Well
Cousens Spring
Cousens Pond Influent
B-101
B-102
B-103
B-104
B-105
B-106
B-109
B-110
B-lll
B-113
Sandy Brook Near B-112
<.01
<.01
<.0l
<.01
.05
.075
C.01
0.1
2.25
.017
.05
.025
<.025
.05
C025
.15
.35
48
38
300
35
.15
<,01
<.01
<.01
<.01
<.01
.05
36
14
41
0.7
.10
3,6
.02
7
.08
0.6
.01
.05
.22
.08
.22
.005
<.01
<.01
<.01
<.01
<.01
<.01
1U2
.01
9.78
<.01
<. 01
13.2
2.12
9.4
2.8
0.96
0.4
1.28
.04
.32
.04
5.0
6,2
6.1
6.4
5.8
6.1
5.3
6.4
6.35
6.3
5.5
5.9
350
112
160
68
58
72
1200
530
5600
54
130
KEY
Cr - Total Chromium mg/1
Fe - Total Iron mg/1
Mn - Manganese mg/1
Zn - Zinc mg /I
NH^-N - Ammonia As Nitrogen mg/1
N03-N - Nitrate As Nitrogen mg/1
pH - In pH U'lt t-5
Cond - Si>cnfir Co.idn, t.incei^°i
Analysis by E.G. Jordan
297
-------
SACO DUMP WATER SAMPLES
DATEAugust 13,
LOCATION
Cr
Fe
Mn
Zn NH3-N N03-N pH
COND.
Bucci Well
Trlpp Well
Angers Well
Vachon Well
Blunt Well
Cousens Well
Tyrell Well
Austin Well
Cousens Spring
Cousens Fond Influent
B-101
B-102
B-103
B-104
B-105
B-106
B-109
B-110
B-lll
B-113
Sandy Brook Near B-112
1.2
0.35
0.14
< .02
.05
<.05
0. 15
<0.05
0.3
170
340
820
340
37
320
40
3.0
130
67
170
47
31
1.2
150
0.97
0.15
3.5
0,75
2.2
0,87
0.08
0.56
0.09
0.64
0.10
1.62
6.5
900
3400
7000
1400
120
5000
60
90
110
KEf
Cr - Total Chromium mg/1
Fe - Total Iron mg/1
Mn - Manganese mg/1
Zn - Zinc mg /I
NHj-N - Ammonia As Nitrogen mg/1
N03~N - Nitrate As Nitrogen mg/1
pH - In pH I'nits
Cond - Specific Conductance ^HtS£
Analysis by DEP
298
-------
3ACO DUMP "WATER SAMPLES
DATE.AUg. 20, 1975
LOCATION
Cr
Fe Mn Zn NH3-N NOj-N pH
COND.
Buccl Well
Trlpp Well
Angers Well
Vachon Well
Blunt Well
Cousens Well
Tyrell Well
Austin Well
Cousens Spring
Cousens Pond Influent
B-101
B-102
B-103
B-104
B-105
B-106
B-109
B-110
B-lll
B-113
Sandy Brook Near B-112
<.025
.025
<; .025
< .025
0.1
^.025
0.8
1.2
1.6
2.1
1.3
<..025
0.2
0.4
< .025
0.3
< .025
0.1
C.025
<.025
.025
75
<025
275
1200
1475
1575
1175
4.5
1900
350
0.1
130
1.4
.025
<.025
<.025
.05
25
<.025
55
350
37.5
75
60
0.6
120
7.35
0.1
3.5
< .025
3.4
3.3
0.9
<.01
0.7
2.7
4.9
4.75
6.15
30
7.3
3.5
1.25
3.3
<.01
1.62
< .01
0.1
0.15
.06
< .015
6.5
0.135
2.98
212.
151.
0.7
34.3
.054
19.7
0.8
0.36
0.3
0.3
9.6
2.4
0.1
.02
<0.1
0.84
0.3
0.1
0.3
0.5
0.1
0.1
0.2
1.2
0.4
0.4
0.6
6.1
6.4
6.0
5.5
6.3
6.8
6.4
6.5
6.1
6.4
6.5
6.5
6.5
5.6
6.0
6.5
7.0
360
76
60
80
1400
110
890
4400
7900
1200
3200
48
5700
37
150
110
300
KEY
Cr - Total Chromium mg/1
Fe - Total Iron mg/1
Mn - Manganese mg/1
Zn - Zinc mg II
NHj-N - Ammonia As Nitrogen mg/1
N03-N - Nitrate As Nitrogen mg/1
pH - In ;>1 I'm is
Cond -
ifi' '.inductance
nmhos
Analysis by E.G. Jordan
299
-------
SACO DUMP WATER SAMPLES
DATEiAug 28r 19
LOCATION
Cr
Fe Mn Zn NH3-N NO-j-N pH
COND.
Bucci Well
Tripp Well
Angers Well
Vachon Well
Blunt Well
Cousens Well
Tyrell Well
Austin Well
Cousens Spring
Cousens Pond Influent
B-101
8-102
B-103
6-104
B-105
B-106
B-109
B-110
B-lll
B-113
Sandy Brook Near B-112
C025
<;.025
<.025
<.025
.025
<.025
0.1
<0.025
0.1
0.1
0.15
.05
0.1
0.1
0.1
0.3
0.25
.125
<,.025
<,025
<,025
<.025
.35
<025
<025
50
<025
50
168.5
650
167.5
31
22.5
231.25
420
6.A5
44
1.4
<.025
< .025
< .025
.025
<.025
.025
0.8
< .025
55
25
29
25
20
0.9
147.6
6.3
0.17
2.27
<.025
.904
.016
.64
.01
.08
.01
.056
<-002
1.04
.105
0.82
.105
.005
0.45
.24
1.98
6.9
.43
<.002
< .01
.01
< .01
< .01
0.1
.04
7.68
.01
2.44
224.4
131
4.34
29.16
0.21
25.44
< .06
0.35
0.17
0.48
r^ 9
2.72
1.04
.76
.24
.36
0.6
2.2
0.1
0.6
0.8
1.3
0.1
1.3
1.7
5.6
5.6
1.0
1.16
6.1
6.2
6.35
6.0
6.4
6.9
6.0
6.3
6.0
6.5
5.95
6.6
6. '
6.8
6.:;
6.5
6.15
6.5
6.5
335
80
58
77
44
780
1480
115
900
4450
7200
1200
3000
62
5500
93
155
110
300
KEY
Cr - Total Chromium mg/1
Fe - Total Iron mg/1
Mn - Manganese mg/1
Zn - Zinc mg /I
NH-j-N - Ammonia As Nitrogen mg/1
N03-N - Nitrate As Nitrogen mg/1
pH - In pH Units
Cond - Specific tor.du, Uince*
Analysis by E.G. Jordan
ihos
300
-------
SACO DUMP WATER SAMPLES
DATE: 9/20/75
LOCATION
Cr
Fe
Mn
Zn NH3-N N03-N pH
COND.
Buccl Well
Tripp Well
Angers Well
Vachon Well
Blunt Well
Cousens Well
Tyrell Well
Austin Well
Cousens Spring
Cousens Pond Influent
B-101
B-102
B-103
B-104
B-105
B-106
B-109
B-110
B-lll
B-113
Sandy Brook Near B-112
.05
<.05
<.05
.05
<.05
.05
.10
.20
.05
.25
.05
<.05
120
0,4
67
630
760
400
170
110
540
150
36
1.5
42
< O.V
47
470
29
34
31
3.1
150
4.2
1.3
.20
<.02
<.02
.05
.51
.11
.03
.39
.66
.07
1.2
.24
<.02
6.5
6.5
6.1
6.5
6.7
6.8
6.5
-»
6.2
6.9
1250
100
800
4200
7000
1100
2500
80
9000
50
160
280
KEY
Cr - Total Chromium mg/1
Fe - Total Iron mg/1
Mn - Manganese mg/1
Zn - Zinc mg/1
NHj-N - Ammonia As Nitrogen mg/1
N03-N - Nitrate As Nitrogen mg/1
pH - In pH Units
Cond - Specific Conductance j"»ho_s
Analysis by DEP
301
-------
LIVING WITH LEACHATE
Joseph Bern, P E
Vice-President, Research & Development, U.S Utilities Services Corporation
Monroeville, Pennsylvania
Introduction
A well known axiom regarding landfills is "when
yearly precipitation exceeds evaporation generation of
leachate is a foregone conclusion". In the Commonwealth
of Pennsylvania, where the above holds true, all land-
fills are considered leachate generators. Therefore,
compliance with regulations dictates the need for treat-
ment of leachate where natural renovation is not avail-
able.
Chambers Landfill located in the Pittsburgh
region is one disposal site that includes an operating
leachate treatment facility. The system has been in
operation for almost two years. Leaching data has been
accumulated for conditions before and after the construc-
tion and operation of the plant. It appears to be
achieving its objective (i.e. compliance with the water
effluent standards), however this may be due to a chain
302
-------
of fortuitous circumstances. Comparison with leaching
data from another disposal site, approximately 25 miles
distant, would indicate that utilization of all possible
attenuation techniques is necessary to meet water quality
requirements, if tertiary treatment is to be avoided.
Leachate treatment plants must be designed on the
basis of influent characteristics. There is a difference
between raw leachate (as it seeps out of the toe of the
fill area) and that which enters the plant.
At this point in time almost all of the leachate
treatment plants in planning, design, construction, or
operation in Pennsylvania use chemical treatment (lime
addition), sludge sedimentation, biological treatment, and
post chlorination to some extent. The installations
range from massive lagoons (2% million gallons at Chambers)
to small oxidation ponds (150,000 gallons at Southern
Alleghenies). Automatic pH control may be used in the
chemical treatment section with automatic feeding of the
lime. Batch treatment with hand feeding of lime (on a
guess basis) is also practiced in many locations.
Normally, untrained labor and minimal time are
alloted for the operation and maintenance of the treatment
facility. Great difficulty in starting up the system and
in bringing the process into equilibrium with the required
effluent quality may be attributed to the use of untrained
303
-------
personnel. Daily high tonnage operations and large
capacity sites are necessary to sustain this added cost
of operation.
Leachate Characteristics
In order to obtain a clear understanding of the
wastewater or leachate under consideration, we will look
at it in a number of ways. Raw leachate as it comes
directly from the degrading refuse, treatment plant in-
put, and treated leachate effluent are examined. Con-
ditions at two landfills (Chambers and Lower Burrell) are
illustrated as a case study for this presentation.
A. Raw Leachate
Soluble fractions of the deposited wastes will
eventually dissolve in the water moving through the fill.
Samples were collected at the toe of the disposal area
(seeps) and are outlined in Table I. Four water quality
parameters, pH, 8005, Total Iron and Ammonia-Nitrogen,
are the descriptors of the leachate character.
The values are well within the ranges of leachate
quality reported in the EPA publications. Acceptance of
some high 3005 (organic) wastes at the Lower Burrell
landfill (the refuse comes from a less urbanized area
with practically no commercial rubbish) may account for
304
-------
the higher values. The high iron content at Chambers may
be due to acid mine drainage discharges for this is a
former strip mine-ravine type fill.
B. Treatment Facility Influent
Allegheny County Sanitary Authority laboratory
personnel carried out an extensive sampling and analytical
program (over a two month period) on the leachate from
Chambers Landfill. The main objective of the endeavor was
to determine the feasibility of handling untreated leac-
hate in the sewerage system. The water samples were ob-
tained at the discharge of a large clay pipe which runs
through the center of the existing fill and acts as a
leachate main. This pipe was ultimately connected to
the wet well unit of the treatment system. Results were
compiled for: Fourteen water quality parameters (not
including heavy metal ions) such as pH, alkalinity, dis-
solved oxygen, BOD5, COD, chlorine demand, greases,
chlorides, phenols, cyanides, etc.; two bacteriological
parameters including fecal and strep coliform; and eight
heavy metals including lead, manganese, total chromium,
iron, selenium, cadmium, zinc, and copper. Figure 1 shows
frequency distributions of some selected parameters (ap-
proximately eighteen values for each variable).
Analyses of samples collected on the same day (raw
305
-------
leachate seeps - See Table I and plant influent) indicate
a considerable difference in leachate quality parameters.
See Table II for the modified leachate.
In the case of Chambers, we believe there are two
factors operating to attenuate the leachate. They are
dilution due to infiltration of surface water and abandoned
mine discharges, and some natural renovation. Chambers
landfill is an existing dump which was upgraded to a sani-
tary landfill. Until 1970 there was no attempt to isolate
the refuse from mine discharges. In fact, a former lake
bed acts as the main leachate sump in the collection
system. In addition, the leachate moves laterally almost
500 feet to reach the collectors and possibly providing
some attenuation.
Conditions at the Lower Burrell operation are quite
different. The site was first used as a household waste
landfill in 1970. Refuse was deposited in high ground
water table areas and several springs were covered at the
lower end of the fill. This fill area is located less
than 200 feet from the property line. Inlet to the treat-
ment facility is located 25 feet from the toe of a (75 foot
deep) leaching refuse cell allowing small opportunity for
natural renovation despite the fine quality of the soils
in the area. Dilution is not a great factor as evidenced
by the leachate volumes - 8-10,000 gpd when compared to
306
-------
the 25-40,000 gpd at Chambers.
Leachate quality also varies seasonally and over
the years. Table III shows this variation at both sites.
The low BODs values at Lower Burrell (in 1971) may be due
to this being a young fill and full leaching had not
started. High iron at Chambers is due to mine discharges.
C. Treated Leachate
The treated leachate (plant effluent) completes the
cycle of living with this waste water. Acceptable dis-
charges are based on stream criteria and discharge stan-
dards which are established by regulation and not on the
capabilities of treatment unit processes or plant per-
formance. Table IV reflects the results of treating the
leachate at both landfill facilities. It also shows the
required water quality of the discharges.
Chambers' treatment facility appears to be meeting
the effluent standards for the tabulated parameters.
This only applies to the summer months. The critical
operating period may be between November and July, We
cannot account for the low 8005 readings in the last two
months at the inlet to the plant. It may be due to the
excessive and above normal precipitation experienced this
year during that time period. The Lower Burrell facility
cannot hope to comply with the BODs requirement with the
307
-------
strong leachate coming into the system.
Treatment Facilities
A tabulation of the various configurations util-
ized in Pennsylvania for treating leachate is shown in
Table V. Most facilities depend on chemical treatment
(lime addition) to render the heavy metals (mainly iron
and manganese) insoluble. In the case of the two plants
with stream discharge, (Southern Alleghenies and Penn Twp.)
which do not provide neutralization, the preliminary
leachate analyses were low in iron and manganese and had
neutral pH readings. Chemical treatment will most likely
be added after operation begins since compliance with
effluent standards is required. Some municipal sewage
plants have agreed to accept partially or totally untreated
leachate. There are some questions which must be answered
before this can become a viable solution to leachate
treatment. Almost all of the facilities depend on hydra-
ted lime for the neutralizing agent mainly due to availa-
bility and price. Concomitant with this process is the
large volumes of sludge that are generated.
Sludge produced by the chemical treatment section
of the plant is essentially insoluble metallic hydroxides,
untreated lime, and calcium hydroxide. The settling ponds
308
-------
will concentrate the sludge to 5 - 10 percent solids. In
order to reduce the sludge volumes to be handled and allow
for easier removal, clarifiers are used in some of the
installations listed. Plant operation can continue
during the sludge removal phase. Disposal of this resi-
due is in the landfill. Some enforcement agencies require
deposition of this material in a highly alkaline environ-
ment such as a clay lined disposal area with a bed of
alkaline fly ash, slag, or crushed limestone.
The biological section of the treatment plant is
the weakest link in the system. Most landfill operators
do not have personnel with the necessary training to
start-up and maintain the unit. Some expert technical
help will be needed to evaluate the efficiency and oper-
ation of the biological treatment unit. Will seeding of
the diffused aeration unit be required? Are additional
nutrients needed to insure proper and continued operation
with maximum BOD5 removal?
Post chlorination is used at Chambers for two
reasons. During the design period very little infor-
mation was available on the leachate characteristics and
there were no leachate treatment plants in existance.
The need for disinfection was not clear and conservative
engineering practices required its inclusion. Addition
of chlorine does provide an opportunity albeit an
309
-------
expensive one to further reduce the 8005 by overdosing.
Figures 2 and 3 show the flow diagrams of the two
leachate treatment facilities described in the above
case history. Table VI lists the design specifications
of both plants. While BOD5 removal rates of 85 percent
are possible theoretically by biological treatment, it
would require a very efficient plant with model operations.
To attain a removal rate of 98.5 percent is questionable.
The leachate data presented above would lead to the con-
clusion that a weak influent is very desirable if ef-
fluent standards are to be met.
Treatment Costs
After two years of actual operation, we have ac-
cumulated some cost data for the treating of landf:.ll
leachate at Chambers Landfill. U. S. Utilities Services
Corporation is in the process of building two leachate
treatment facilities at its other landfills, (Arden and
Southern Alleghenies). One system includes lime addition
and mechanical aeration in an oxidation pond with a
polishing pond following to collect the sludge. The other
proposed operation includes chemical treatment (lime ad-
dition) , sludge settling (in a clarifier) and discnarge
to the adjacent sewage treatment plant. Table VII
310
-------
lists the comparative costs of each system based on a
ten year life (of the landfill) at Chambers and fifteen
years at the other sites. Cost of capital is based on
a six percent add-on interest and escrow funds are re-
quired by state regulation to provide funds to operate the
facility for a ten year period after closure of the land-
fill.
Cost of leachate treatment ranges from 2.6 mils/
gallon to 3.5 mils which is an actual cost at the Chambers
installation. However, when the costs are based on
refuse tonnages, they range from 14 cents/ton to 91 cents/
ton. The above costs are equivalent to 5 percent of the
disposal price at Chambers, 6 percent at Arden, and 37
percent at the Southern Alleghenies landfill operation.
High quantities of solid wastes must be processed at the
landfill site to bear the cost of leachate treatment.
Conclusions
Leachate treatment is technically and economically
feasible when: (1) the chemical characteristics of the
leachate are established; (2) any opportunities for at-
tenuation is utilized; (3) resources (personnel and money)
are allocated for maintenance; and (4) the landfill
311
-------
operation is at a sufficiently high level to sustain the
cost.
Unit processes now being used to treat the Leachate
are marginal and must be upgraded in order to meet the ef-
fluent requirements. The other alternative is to set
realistic effluent standards for this waste water.
312
-------
Raw Leachate
PennDER (BuWQM) Standards
Chambers 4/30/74
Lower Burrell 7/29/74
pH
6-9
5.9
5.2
BOD5
10/20
3025
6300
Fe, Total
5
410
100
NH3-N
-
61.5
73.5
Specific
Conductance
-
3200
4300
All readings in mg/1 except pH and Specific Conductance (mircomhos)
TABLE I: Raw Leachate Quality at two Pennsylvania Landfills.
Modified Leachate
PennDER (BuWQM) Standards
Chambers 4/30/74
Lower Burrell 7/29/74
PH
6-9
5.8
5.7
BOD5
10/20
123
2080
Fe, Total
5
93.8
170
NH3-N
-
9.61
28.5
Specific
Conductance
-
1700
3200
All readings in mg/1 except pH and Specific Conductance (mircomhos)
TABLE II: Leachate Quality (Plant Influent) at two Pennsylvania Landfills.
313
-------
15
10
in
tP
C
-H r-
13 5
t8
!D
A
m
o
S o
_
-
_
- c> ^r ci ^J1
. >
» ^S* LO LO ^O
* I \ \ \
- m o m o
~> *? m m ^D
n n
M^
m
^D
1
in
U3
^. 8
r-- ra
Cr fi
1 C b
-H
0 T3
10 /I
r- 0) 4
n:
n '2
1 n c o
o
-
_
o
« o
rH
_
1
o
in rH
in
:nn
0
m
fH
1
rH
O
H
O
CN
1
rH O rH
m u~t in
rH m ro
n i ^
o
'H >
o O
CO
n n
pH
BODC
tp
c
H
t)
-------
PennDER(BuWQM) Standards
Chambers 6/12/72
8/9/72
9/26/74
6/12/75
8/12/75
Lower Burrell
9/5/71
10/13/71
5/8/74
7/29/74
pH
6-9
6.5
7.4
5.8
6.8
6.5
5.9
5,2
6.4
5.7
BOD5
10/20
121
198
123
36
23
48
56.4
4300
2080
Fe, Total
5
45.2
38.0
93.8
.01
120
35
57.5
230
170
Mn
5
_
9.5
-
6.9
6.7
17.5
19.5
66
~
TABLE III: Leachate Quality (Plant Influent) Over Time
at Two Pennsylvania Landfills
PennDER(BuWQM) Standards
Chambers 4/24/75
6/12/75
8/12/75
9/23/75
Lower Burrell
5/29/74
6/6/74
6/18/74
6/21/74
7/5/74
7/29/74
pH
6-9
8.0
8.4
8.2
7.5
7.7
7.3
7.6
7.5
6.8
7.3
BOD 5
10/20
80
37
3
21
770
1420
860
947
866
645
Fe, Total
5
.47
.03
.65
1.6
9.2
6.0
35.0
-
5.0
7.75
SS
25
20
44
35
27
256
164
-
-
-
-
TABLE IV: Leachate Quality (Plant Effluent) at
Two Pennsylvania Landfills
315
-------
i 0)
4J GO
G M
o) rt
3 J3
H O
>w -H
W Q
Additional
Treatment
a a
M >
1 1
rH dJ
to pi
rH
n) 4-J
a a
H d)
CD a
!t CO
H J-i
PQ H
__,
oo >
T3 O
rH dJ
CO Crf
Chemical
Treatment
Installation
a a a e a a a
QJ Q> d) QJ dJ QJ d)
to co to co co co co
0 O 0 0 0 O 0
H H H H H H H
O O O
rH rH rH
CJ O CJ
4-1 4-1 4-J
cn cn J-< 4-1 4J
4J 4-1 nJ 4-) 4-1
dJ QJ rH QJ QJ
CO tO O CO CO
*
D QJ QJ QJ QJ
a e a as
H -H -H -H -H
Chambers
Lower Burrell
Rostraver
Penn Twp.
So. Alleghenies
Inmans
Lower Paxton
QJ »
>* >> to
U O >-i
Oi Crf CO
Filtration
5
,C
QJ
S-J ^
dJ OJ
H -rH
H -H
V4 l-l
CT) Cfl
rH rH
O O
-K
d) d)
H -H
rJ hJ
Derry Twp.
Kelly Run
Hidden Valley
H
* J
* * a s
d) d) dJ it QJ
CJ CJ 4-> U dJ
>> >, CO CO tO
0 0
-i rH rH rH
-H O cfl O rH rH
"4H rH CO (1) 0)
TJ !>* O l-J )-4
C IH Td ^ Td Mr*
tO dJ O 3 QJ 33
l-i O 3 -H CO
'O QJOOC> QJ l-ii-J
QJ C4JQJQJ 00 CUCU
G J-lCrHAi 00 33
H nj o I-H nj 3 o o
I
o
G
rt
316
-------
u
3
00
317
-------
Neutralizatioi
(Lime Additio:
0
Settling
«»
Biological
Treatment
[Mech. Aeratic
i)
Polishing
(Additional
Settling)
FIGURE 3: Flow Diagram for Leachate Treatment Facility at Lower Burrell
Landfill
318
-------
CHAMBERS
Average Influent Flow - 94,000 gpd
Max. Influent Flow - 150,000 gpd
Reduction - BOD5 85%
COD 707,
Susp. Solids 98%
WASTE LOAD CHARACTERISTICS:
Waste Flow, gpd
PH
Susp. Solids
Total Fe
Mn
BOD 5
Raw Treated
94,000 94,000
6.8 7.5
158 20
56.4 10
5.65 5
120 10
EFFLUENT REQUIREMENTS:
PH
Max. BOD5 10
6-9
LOWER BURRELL
12,000 gpd
15,000 gpd
98.5%
94%
Raw Treated
12,000 12
5.6
150
40
130
700
Same as Chambers
mg/1 ave. of 5 consecutive samples or
,000
7.4
9
0.3
0.05
10
20 mg/1 max. on any reading
Disinfection 200/100 ml Fecal Coliform (a geometrical
average value no greater than 1000/100 ml
in more than 10% of samples tested)
Lime Dosage
Chlorine
400#/day
7.5#/day C12
TABLE VI: Design Specifications for Two Pennsylvania
Landfill Leachate Treatment Plant Facilities
319
-------
1.
2.
3.
4.
5.
Level of
Operation, tons/day
Useful Life of Site, years
Leachate
Leachate
Fixed
Annual
Total
Variable
Total
TOTAL
Treatment Plant Volumes gpd
Treatment Facility:
Costs: Construction, $
Costs: Construction
Capital (6% Add-on)
Escrow Account
Annual Fixed Costs:
Costs:
Chemicals
Electricity
Sludge Removal ****
Variable Costs (Annual)
COSTS (ANNUAL) : $
Unit Cost $/gallon
Chambers*
900
10
35K
180,000
15,000**
10,800
10,000
35,000
3,066
4,840
2,000
9,906
44,106
0.0035
Unit Cost $/ton of refuse
processed
0.19
Arden***
400
25
12K
80,000
5,333
4,800
2,000
12.133
1,500
1,200
-
2,700
$14,833
0.0035
0.15
So. Alleghenies*
40
25
10K
45,000
3,000
2,700
1,600
7,300
1,000
800
-
1.800
$ 9,100
0.0026
0.91
* Actual Costs at Chambers Landfill
** Already in operation for two years with ten years remaining
*** 15 year plant life
**** Sludge removal every three years
TABLE VII: Leachate Treatment Facility Costs.
320
-------
A STUDY OF QUANTITY AND QUALITY OF GAS AND LEACHATE GENERATION FROM
WHOLE AMD SHREDDED, BALED AND NON-BALED MUNICIPAL SOLID WASTE
Daniel J. McCabe
Environmental Engineer, Systems Technology Corporation
Thus study is investigating the quantitative and qualitative
production of gases and leachates produced in simulated landfill
cells. Five tost cells are involved in this study, and they are
designed to sinulate municipal refuse deposited in landfills
under the following conditions:
3el] Cell Composition
#1 Baled Shredded .Solid rtaste
#2 Baled ",/hole Solid laste
*3 3aled ,Vhole Solid Waste (Saturated;
A Shrpdded Solid Wasto
15 '.-(hole Solid Waste
7nece test cells permit the conparison of .^as and leaohate
production fron processed and unprocessed solid waste in both the
loose anJ bale] forms ana also provides dr.ta on the effect of
.-at.iraticn w:t'-ir. a iar.i3:'!!l. rhei-e"'o"C, the specific objective
of this project is to determine the pas production, rate quantita-
tively ana qua] itr. tively in municipal solid waste in a simulated
l^ndfil1 environment. A second objective is to raoritor simultaneously
the quality and quart!tv of leachate produced during this research.
Fn,s paper discusses the construction of the test cells, the
loadi"" of the test cells, an-1 all analytical data collected for
the first ter nor.ths of the study.
321
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LYSI>STSR CONSTRUCTION
A facility consisting of five identical test cells and an
instrumentation cell was designed and constructed to fulfill the
research objectives. The facility layout (figure 1) illustrates
the arrangement of the cells. This arrangement provides for good
cell accessibility without creating instrumentation difficulties
or causing temperature influence problems between cells. The
design of the test cells was determined by both the size of the
baled refuse as well as the requirements for compacting refuse in
the test cell. Instrumentation access was provided by casting
sleeves into the cell walls and then installing bulkhead fittinzs.
Test cells were constructed of reinforced concrete and have irside
dimensions of 2.1 meters x J.k meters x 3.7 meters (? ft. x 11 ft. x
12 ft.;. The instrumentation cell is centrally located on one side
of the test cells. This contains the terminals and collection
ports for the seas, leachate, temperature, and moisture measuring
' qulpner.t.
The contents of the charged or completed cell, as illustrated
in Figure 2, consists of the following a 15.2 cm. (6 in.) base
of non-reactive silica gravel; 3 layers of baled refuse, or 2,7
meters (9 ft.) of compacted refusej 3Q.5 of. (12 in.) of clay
soil compacted to a density of 1V*2 ksc/m* (9C Ibs./ft,^); 30.5 cm.
(12 in.) of pea gravel; and 15.2 cm. (6 in.) of freeboard. This
simulation typifies a sanitary landfill environment in that it does
contain compacted refuse with soil cover and a water source (water
injection rake buried in the pea travel;, but differs due to its
322
-------
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.1MU-&1PEH
COMPACTED
Cl-JW
2.T M C3'
COK/\PO.CTEO
^6j
A
^**&xs*e***»(totig4s^^ o
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FIGURE 2
TEST CELL CONTENTS
324
-------
smaller size and sealed environment. The pea gravel was used to
aid in moisture distribution while silica gravel provided a porous,
non-reactive base to support the compacted refuse.
The on site instrumentation for this facility consists of temper-
ature, moisture, and pas volume measuring equipment.
Temperature monitoring equipment consists of a total of 125
copper oor.stantan thermocouples with each cell having 2k probes
distributed throughout the refuse. Temperature probes are located
at the top, middle, and bottom portions of each test cell.
The moisture monitoring instrumentation consists of both gypsum
soil blocks and porous cup tensiometers. Each cell contains 9
gypsum blocr1 moisture probes. These probes are located in the top,
middle, and bottom portions of the cells so moisture routing through
the ref"usp .r.th watr-~' applications can be noted.
The ijas monitoring system consists of 10 collection probes for
each cell which are connected to a common manifolding arrangement
inside the instrumentation cell. The gas collection piping within
each of the test cells consists of 3 gas probes in the top, middle,
and bottom portions of each test cell. One collection port is in
the cell freeboa^-fl so that the oxygen content of the gas over the
clay layer can be measured.
EXFi%R::-'E.';TAL DATA
Refuse Composition Data
The solid waste loaded into all of the test cells was sorted in
order to ascertain the composition of the waste. This categorization
325
-------
of the municipal waste was necessary In order to draw meaningful
conclusions about the waste composition and decomposition products.
The waste material was separated Into eleven categories as follows)
1) Pood Waste
2) Garden Waste
3) Paper
4) Plastics, Leather, Rubber
5) Textiles
6) Wood
?) Metals
8) Glass
9) Ash, Rocks, Dirt
10) Diapers
11) Fines (less than 2.5^ cm. (1 In.) ).
Figure 3 gives the refuse composition comparison averages for the
Oakwood and Atlanta refuses. (The baled refuse was secured from
Atlanta, Georgia due to compaction densities required by contract.)
Table 1 gives the quantities of silica gravel, refuse, clay, pea gravel,
and densities for each of the five teet cells at the Franklin test facility.
Temperature Data
Figures k and 5 indicate typical average temperature data for the
top, middle, and bottom sections of the test cells during the reporting
period. Figure fr indicates representative temperature data for the
baled teat cells. The temperature shows a peak during the initial
326
-------
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loading period and a gradual decrease in temperature thereafter.
The cool ambient temperatures recorded during January and February
had the effect of reducing the peak temperature in the top and
middle sections of the test cells. 'The initial high temperature
is the result of aerobic decomposition of the solid waste. The
subsequent reduction in temperature is an indication of the charge to
anaerobic conditions. Due to logistics the initial increase in the
temperature in the bales occurred before placement in the test cells,
As can be seen from these figures the temperature decrease from the
initial aerobic peak took JO days to drop in the top portion of the
cell and approximately twice that long to drop in the bottom portion
of the cell. The temperatures during the colder months showed a
temperature gradient which indicated a loss of heat to the atmosphere.
The top and middle portions of the cell were cooler than the bottom
section of the cell by a minimum of 2°C. This trend reversed itself
when warmer temperatures occurred due to seasonal changes. A warming-
trend is evident for the months of April, May, and June. It is antici-
pated that future temperature variations will be due to seasonal varia-
tions.
Figure 5 presents typical temperature data recorded for the
shredded and whole refuse cells . This refuse was placed directly
in the test cells on the same day as it was collected, so that iritial
peak temperatures due to aerobic decomposition were observable. This
initial peak temperature was more noticeable in the middle and bottom
portions of the cell due to the loss of heat to the atmosphere and
cell cover material. These cells nlso show the same warming trend
330
-------
during the months of April, Kay, June, and July.
Moisture Data
Eleven moisture probes (gypsum block and porous cup types) are
being used to measure the mositura content of the refuse within the
test cells. Figures 6 through 10 present the measured moisture
contents of the Franklin test cells. The moisture probes in cells 1,
2, 3« and 5 "ere placed in a wet condition, and thus the initial
readings on the probes placed in this cell are higher than that
actually in the refuse. A period of time (as long as 60 days) was
required for the equalization of the probe with the refuse. Thus,
the initial readings on these cells are high. The opposite was the
case for cell k. The moisture probes were placed in an extremely dry
condition upon placement in the cells. Thus, the initial moisture
probe readings on this cell were lower than that encountered in the
refuse itself. It appears as if a 60 day period was also required for
the equilibration of these moisture probes as well. The moisture probe
data for all the test cells was very useful in noting the moisture routing
through the cells (the increases in moisture contents in various
portions of the cell with the water additions), and predicting when
leachate was to be obtained from the test cells. It is now apparent
that plug flow is approximated in the test cells. Hater was added by
means of a distribution rake at the clay-pea gravel interface covering
the refuse. Generally, the moisture probes in the top portions of the
cell reached saturation first, followed by the middle and bottom
probes respectively.
In one of the baled cells (Cell 2), it was evident from the
331
-------
332
-------
333
-------
* s
334
-------
335
-------
1/1
0
-J
<
h-
a
336
-------
moisture probe data that short circuiting had occurred in the cell.
Short circuiting was also observed in the shredded waste cell,
but to a lesser extent.
The quantity of moisture retained within each of the test cells,
as determined by the quantities of water added and the quantities
of leachate withdrawn, are given in Figures 11, 12, 13i and 1U
for cells 1, 2, **, and 5. As expected, shredded baled cells retain
more moisture than the whole refuse baled cells, but the contrary was
true for the shredded and whole unbaled refuse. The possibility exists
that this unexpected variation was due to the apparent short circuiting
within cell 4 (shredded refuse). The gypsum block moisture probes have
generally proven to be unreliable in their operation. A total of 1? of
these probes out of ^5 have failed thus far.
Gas Data
The gas composition data is given in Figures 15 through 19.
These figures present graphically the percentages of the components
in the gas stream. Several trends in the gas composition data can
be identified. The first noticeable trend is the increase in nitrogen
content due to the selective absorption of oxygen in these test cells.
This trend indicates that the selective absorption of oxygen has
occurred in the initial phases. The oxygen content is reduced due
to aerobic bacterial respiration. This in turn increases the percentage
component of the nitrogen gas.
The second trend which is noticeable in all the cells is the
increase in C02 or "C02 bloom." This "CO,, bloom" exceeds 60$ on all
of the cells! and on cells 3, ^, and 5, exceeds 90?S by volume. The
carbon dioxide bloom is accompanied by a. decrease in the nitrogen content
337
-------
338
-------
stara.L.i-i m i v\
339
-------
Figure 13
340
-------
figure 14
okve SIMC.C LOXQ
341
-------
Bj
tr __L_-r
342
-------
343
-------
344
-------
___j ^__ ___ i I i_ _. . ' h.- -
345
-------
346
-------
and the elimination of oxygen within the test cells. This is not as
noticeable in cells 1 and 2 due to air contamination in several of the
gas samples. Another occurrence which is evident from the gas data
is the appearance of methane at a late point in the C02 bloom curve.
This has occurred in all of the cells except cell 5- Cell 5 is
currently experiencing a drop in the W bloom curve, and methane
production is expected in the near future. It is evident from the
gas production data thus far that the gas production pattern has
entered the phase 3 stage , or methogenic unsteady phase, for cells
1, 2, 3, and b. Cell 5 is still within phase 2 (anaerobic non-methogenic
phase). One important exception to the pattern for sanitary landfill
gas production proposed by Farquhar is the absence of significant
concentrations of hydrogen gas during the COg bloom period. Only
trace quantities (less than . 01>-') of hydrogen gas were encountered
on the franklin test cells. The tine required to complete the aerobic
and anaerobic non-methogenic phases was approximately 165 days froa
the time they were loaded for cells 1 through 4, Cell 5 should enter
the third phase shortly,
Gas production for all of the cells at Franklin has been insignificant
in terms of volume to date. Gas volumes have been measured following
water additions. However, it is believed that this does not represent
actual gas volumes produced, but rather displacement of volumes within
the cells. With the occurrence of methane in the gas samples secured
at the Franklin site, it was suspected that gas production should have
been taking place. A close investigation of the test cells revealed that
1. "Gas Production during Refuse Composition," by G.J. Farquhar, and
F.A. Rovers from Mater. Air, and Soil Pollution, 2, (1973),
347
-------
the wet test gas meters were incapable of measuring the gas volume
produced due to the low production rate. The gas system was modified
to allow the collection of gas over a longer period of time with
subsequent accurate volume measurements at a proper flow rate
through the wet test gas meters. Current gas production rates
measured using this system average less than 1 liter per day per
cell. With the present low gas production rate in an early methogenic
phase, it is postulated that little gas was generated in the initial
phases of the study.
Leachate Data
Leachates have been collected monthly since January, 1975-
All of the leachate data thus collected thus far is contained in
Tables 2 through 6.
The volume of leachate collected is related to the amount of
water additions made to the cell and the quantity of water absorbed
by the refuse. The highest quantities of leachate obtained ha.ve
been from the baled test cells, 1, 2, and 3. It is also evidesnt from
Figures 11 through 14- that the lowest quantities of moisture retained
within the test cells are also for the baled cells. Cell 1 has a
higher quantity of moisture retained p«r unit of refuse because the
shredded nature of the refuse within the bales contains more :3ites
for moisture absorption.
The pH of the leachate shows an initial downward trend in all
cases. This is due to the formation of organic acids which is the
initial step in the anaerobic decomposition of refuse. The initial
348
-------
drop of pH has leveled out, and in some cases started to rise. This
is due to the breakdown of organic acids into their components.
The oxygen reduction potential values are all negative with
respect to the hydrogen electrode. Most of the ORF values are in
the range of -200 to -400 millivolts. Cell k, the shredded refuse cell,
shows initial ORP values of -400 and -500. This is possibly due to the
high initial strength of the leachate collected from this cell.
The TOG and COD values for all test cells show increases with
time and leachate collections. Initial values from the "squeezings"
from the refuse during compaction were extremely low. These have
increased to TOG values of 10,000 and COD values approaching Jk-,000
milligrams per liter. There is no correlation between TOO and GOD for
the baled shredded refuse cell; however, the baled and baled saturated
refuse cells have a high degree of correlation; and the shredded and
whole refuse cells have a moderate degree of correlation for these
parameters. In general, cells exhibiting high TCG values exhibit high
COD values and vice versa. Cell b (shredded refuse cell) exhibits the
highest COD and TOC concentrations. Cells 3 (baled whole saturated)
and 1 (baled shredded) also indicate high initial TOC and COD values.
Cell 2 (baled whole refuse) exhibits the lowest concentrations of both
these parameters. It is apparent that both shredding and moisture
additions have the effect of increasing the initial leachate strengths
whereas baling has the general effect of decreasing the leachate strength.
349
-------
Leachate color at the time of collection is generally yellow,
yellowish green, or dark green. Black or iron oxide colored leachate is
leachate which has been aerated due to the oxidation of iron and manganese
compound!; within the leachate, giving rise to their colors. The color of the
initial squeezings from the refuse was a very pale yellow to clear
liquid. This is not typical of normal leachates.
The odors of the leachates have been generally very pungent.
However, during the initial leachate collections, putrid odors or faint
organic solvent odors could be detected. The initial squeezing from
the refuse had no detectable odor.
The conductivity, chloride, hardness, and alkalinity show continuous
increases with time. Cell #H (shredded refise) leachate contains the
highest concentration of the above parameters and Cell #2 (baled whole
refuse; the xowesb.
The total solids is relatable to a high extent to dissolved solids
concentration, n.oving a correlation coefficient of .998 with this
parameter. This ij also relatable with the hardness, conductivity,
chloride, and alKalinity values obtained for all the cells.
The total Kjeldahi nitrogen values vary from a low of 9 mg/1 to a
high of 480 mg/1 and their concentration values show a steadily increasing
trend. Total Kjeldahl nitrogen, indicates the same general trends;
exhibited by the other cells with respect to the physical form of the
refuse. Ce'j-'' A .'shredded refuse) has once again the highest con-
centration vajueG, followed by cell 1 (shredded whole refuse). Cell 2,
(baled whole refuse) generally exhibits the lowest concentration.
350
-------
The initial concentrations of lead, copper, and cadmium appear to
be higher than the normal concentrations obtained in the leachates.
These parameters show decreases from the initial concentrations found
in the squeezings. Their present concentrations do not show any
significant trends. The concentrations of iron, zinc, and nickel show
increases in strength with time of leachate collections. Values for
chromium generally have been in the low range in the order of .2 to
.4 mg/1 except for one value for cell 1 obtained in July. It is
suspected that this value is a result of analytical error.
The bacteriological results for total coliform and fecal strep-
tococcus show a high degree of variation. No significant trends can
be interpreted from this data at this time. All Salno'ella determinations
(total of 10J have been negative. However, the following organisms
have been identified in the leachate: pseudomonas, alcaligenes,
enterobacter, proteus, citrobacter freundii, and Arizona. Other
organisms which have been isolated include klebsiella and shigella.
SUMMARY
The first year of this project included the installation and
loading of the test cells, and the first eight months of data collection
on the project. It appears from the data at this point that the shredded
refuse cells (cell 1, shredded baled refuse, and cell 4, shredded refuse)
produced the strongest initial leachates. It is also obvious that the
quantity of moisture and shredding contribute to the strength of the
initial leachates.
351
-------
The highest volumes of leaohate have been from the baled cells.
Consequently, the lowest quantities of moisture retained within the
test cells are also for the baled cells. Cell 5 (whole refuse) retains
a larger amount of moisture than the shredded waste cell. This is
unexpected due to the physical nature of the material. The moisture
probe data indicates that short circuiting has occurred within the
shredded waste cell. Cell 1 (baled shredded refuse) has a higher
quantity of moisture retained per unit weight of refuse because the
shredded nature of the refuse within the bales allows more sites for
moisture absorption.
Data colleoted on temperature indicates that the baled cells in
general have higher initial temperature peaks due to aerobic decomposition
than the nonbaled test cells. This is relatively independent of the
temperature upon loading because similar temperatures were encountered
on the loading of baled and nonbaled test cells.
The gas composition data indicates that the shredded and baled
wastes entered the methogenic phases at approximately the same time,
whereas the whole refuse cell is somewhat slower in its decomposition
as indicated by the gas data. This cell is approximately one month
behind the others with respect to gas composition data. This is possibly
due to the lack of physical treatment of the refuse.
352
-------
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353
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TABLE 2 -
LEACHATE CHARACTERISTICS' CELL #1
BALED SHREDDED REFUSE
PARAMETER
Volume
Density
Odor
Color
pH
ORP
COD
TOC
Cl
Conductivity
Hardness*
TKN
TP**
Alk
Total Solids
Total Diss. S.
Fe
Cu
Cd
Zn
Ni
Cr
Pb
Fecal Strep
Total C.
UNITS
1
g/cc
S.U.
M.V.
mg/1
mg/1
mg/1
umhos
mg/1
mg/1
mg/1
mg/1
%
%
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
it/ml
#/ml
1/13/75 5/12/75
1.0 696.4
1.008
N.D. Strong
Pungent
Clear Dark
Green
5.7 5.4
-254
455 14,674
74 5,800
3,185
4,100 11,800
232 5,600
204
20
4,580
1.45
1.43
150
0.01
0.01
15.1
0.12
0.01
0.05
93,000
93
6/9/75
318.0
1.006
Pungent
Dark yellow
green
5,3
-244
18,730
7,300
2,870
9,400
8,200
235
26
7,600
1.67
198
0.08
0.05
1)2.1
0.1*2
0.08
0.02
119,000
<3
7/14/75
197.5
1.005
Strong
Pungent
Yellow
5.26
-225
20,560
5,750
3,500
8,500
5,000
...
1.49
...
260
0,11
0. 05
60. 0
0.9
O.U
0.02
7,500
<.3
8/18/75
1.18
1.004
Putrid
yellow/gri
5.38
-223
14,125
7,000
3,340
9,000
5,100
1.098
_-
295
0.05
0.05
5
1.2
2.5
0.03
90
<.03
Salmonella
* As CaC03
**As Phosphorous
364
-------
TABLE 3
LEACHATE CHARACTERISTICS CELL #2
BALED WHOLE REFUSE
'ARAMETER
'olume
tensity
>dor
lolor
>H
)RP
:OD
'OC
:i
UNITS
1
g/oc
S.U.
M.V.
mg/1
mg/1
mg/1
lonductivity umhos
[ardness*
'KM
T,,
dk
'otal Solids
'otal Diss. S.
'e
lu
Id
in
li
!r
'b
'ecal Strep
'otal C.
lalmonella
*As CaC03
**As Phosphorous
mg/1
mg/1
mg/1
mg/1
*
*
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
+ . -
1/13/75
lt.0
N.D.
Clear
6.1*
783
360
1,800
1,016
lit
1.0
0.5
.1*2
.25
0.5
0.1*
~
2/17/75
15.1
1.0
3/10/75
181
1.002
l*/ll*/7
356
1.005
Faint or- slight pungent
ganic solv. pungent
Lt. yellow Lt.yellov Lt.
green
6.2 5.85 5.5
-281*
3,29!*
880
2,800
3,1*00
2,580
9.5
0.1
2,820
.1*1
.39
560
.001
0.5
0.08
0.33
0.5
0.5
1*3
3
(-)
-21*
6,1*70
1,800
2,700
It, 600
2,760
22.1*
2,581*
.53
.51
75
0.01
0.02
12.5
0.25
0.2
0.05
2.1*
2,1*00
(-)
-91.
7,780
3,550
3,060
5,300
2,800
78.1*
2,700
.81
125
0.03
0.02
25
0.60
0.5
0.02
210
3
1*58
1.003
6/9/75
325.5
1.005
slightly pungent
pungent
Lt. yellow Yellow
5-1* 5.6
-381t
9,053
3,700
2,715
6,200
1*,800
155
1*
2,800
0.78
0.772
200
0.05
0.01
29
0.65
0.35
0.05
11,000
3
-32U
11,178
1*,000
2,555
6,500
5,500
168
2
1,800
0.83
301*
0. 05
0.05
1.6
0. 1*1
0.09
0. 02
<300
21*0
7/Ht/75
133.2
1.001*
pungent
Clear
5.67
-288
12,015
3,650
3,025
5,900
2,900
.701
395
0.05
0. 05
7.2
0.75
0.2
0.02
1*6
<.3
S/18/75
38.3 1
l.OOl*
pungent
Pale yellow
5-97
-308
10,000
5,300
3,185
6,000
3,162
.792
1*12
0. 05
0.05
0.1
0.6
0.2
0.02
9
<.03
355
-------
TABLE \i
LEACHATE CHARACTEHISTICS CELL (C3
BALED REFUSE SATURATED
PARAMETER
Volume
Density
Odor
Color
pH
ORP
COD
TOC
Cl
Conductivity
Hardness*
TKK
TP*«
Alk
Total Solids
Total Diss. S.
Fe
Cu
Cd
Zn
Ni
Cr
Pb
Fecal Strep
Total C.
Saljaonella
» As CaCOj
**As Phosphorous
UNITS
1
g/cc
S.U.
M.V.
mg/1
mg/1
mg/1
umhos
mg/1
mg/1
mg/1
mg/1
?
%
mg/1
mg/1
rag/1
mg/1
mg/1
mg/1
mg/1
+ f _
1/13/75 2/17/75
1.0 83.8
1.0
N.D. Musty
Red-yellov Light
green
6.1* 5.9
-251*
957 5,322
1*10 1,550
3,000
3,000 It ,100
1,320 2,780
112
1.9
3,120
.53
.51
50 180
1.0 .002
0.5 0.5
0.20 0.96
.25 0.25
0.5 0.5
O.U 0.5
2,1*00
It3
(-)
3/10/75
8.7
1.002
Strong
Pungent
Light
yellov
5.9
-5»*
7,353
1.80C
2,900
U, TOO
3,060
58.?
2,930
.59
.57
100
0.02
0.0?.
0.8
O.U8
0.13
0.05
0.04
93
(-)
lt/lU/75
210
l.OQl*
Very Strong
pungent
Light
green
5.8
-lit It
8.92U
3,300
2,985
5,100
2,560
89.6
2,9'tO
.8
125
0.01
0.02
32.5
0.59
0.27
0.05
93
3
5/12/75
7.6
1.002
Strong
pungent
Lt . gray
green
5.85
-291*
10,377
3,700
3,100
6,300
3,ltOO
116
<2
3,01*0
0.69
0.676
175
0.02
0.02
1*2.5
0.95
0.19
0.01
15
.It
6/9/75
7.6
1.005
Strong
pungent
Lt.gr ay
green
5.8
-30li
13,1*29
l*,200
3,025
7,000
5,300
213
?
It, 580
0.95
520
0.10
0.09
0.08
1.0
0.05
0.06
1,100
<3
__
7/ll*/75
7.6
1.003
Strong
pungent
Light
Yellov
5.7
-356
22,31*0
5,800
7,lt57
9,000
3,900
1.1»2
675
0.07
0.07
1.2
1.1
0.3
O.Olt
93
<.3
8/li
8.
l.C
Sti
pur
PaJ
Ye]
5-'
-32
25,;
8,(
>*,<
10, (
>*,<
-
-
-
L.:
-
61
0.
0.
1.
1.
0.
0.
i:
<,
356
-------
PARAMETER
TABLE 5
LEACHATE CHARACTERISTICS CELL #4
SHREDDED REFUSE
UNITS 1/13/75 4/14/75 .5/12/75 6/9/75
Volume
Density
Odor
Color
pH
ORP
COD
TOC
Cl
Conductivity
Hardness*
TKN
TP**
Alk
Total Solids
Total Diss. S.
Fe
Cu
Cd
Zn
Ni
Cr
Pb
Fecal Strep
Total C.
1
g/cc
S.U.
M.V.
mg/1
mg/1
rag/1
pmhos
mg/1
mg/1
mg/1
mg/1
%
%
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
mg/1
#/ml
*/ml
1.0
N.D.
Clear
5.7
164
60
1,500
588
0.5
1.0
0.5
0.22
.25
0.5
0.4
87.9
1.013
Pungent
Dark
green
5.2
-404
17,723
7,600
3,480
8,000
6,800
145.6
5,920
2.27
225
0.05
0.09
117.5
1.2
1.1
0.05
15,000
93
159
1.01
Strong
Pungent
Dark
yellow
5.3
-504
21,896
8,100
2,870
12,000
6,800
317
52
4,120
2.1
2.093
300
0.01
0.05
103
1.21
0.42
0.02
46,000
93
117.3
0.103
Pungent
Dark
green
5.7
-334
19,604
7,600
3,025
12,000
9,200
325
6
7,000
1.98
--
26U
0.05
0. 05
TU
1.2
0.09
0.02
460,000
2,400
64.3
1.005
Strong
Pungent
Light
yellow
5.61
-239
21,630
7,200
3,670
10,100
6,900
2.05
U15
0.05
0. 05
95
1.5
0.5
0.02
210,000
<3
64.8
1.009
Strong
Pungent
Dark
yellow
5.28
-209
27,202
9,000
3,770
12,000
7,242
1.332
U88
0.12
0. 06
80
1.8
0. 5
0.02
400
<.03
Salmonella
* As CaC03
**As Phosphorous
357
-------
PARAMETER
Volume
Density
Odor
Color
pH
ORP
COD
TOC
Cl
Conductivity
Hardness*
TKN
TP**
Alk
Total Solids
Total Diss. S.
Fe
Cu
Cd
Zn
Ni
Cr
Pb
Fecal Strep
Total C.
LEACHATE
UNITS
1
g/cc
~
S.U.
M.V.
mg/1
mg/1
mg/1
Vi mhos
mg/1
mg/1
mg/1
mg/1
%
%
mg/1
rag/1
mg/1
mg/1
mg/1
mg/1
mg/1
#/ml
#/ml
CHARACTERISTICS CELL #5
WHOLE REFUSE
1/13/75
1.0
~
N.D.
6/9/75
6.0
1.006
pungent
light Dark Gray
yellow green
5.8 5.8
197
56
3,600
480
~
0.3
1.0
0.5
0.14
.25
0.5
0.4
-284
11,439
5,300
2,715
8,700
7,000
213
8
4,800
1.25
U7.5
0.05
0.05
It. 2
0.1*1
0.29
0.02
460,000
<3
7/14/75
,21.1
1.0004
urine odor
light
yellow
5.88
-258
14,760
4,250
3,700
8,500
4, 000
1.23
80. 0
0.05
0.05
10. 0
0.7
0.02
0.02
1.1 X 106
<.3
8/18/75
17.5
1.005
pungent
yellow
5.98
-266
15,125
5,500
3,440
8,000
4,080
1.085
7U.6
0.05
0.05
2.5
0.5
0.02
0.02
400
<.03
Salmonella
* AS CaC03
**As Phosphorous
358
-------
AEROBIC TREATMENT OF LEACHATES FROM SANITARY LANDFILLS
Dale A. Carlson
Professor, University of Washington, and
Ole Jakob Johansen
Norwegian Institute for Water Research
INTRODUCTION
The various organic and inorganic substar.ces in a sanitary landfill can
be leached by water moving through tha refuse. Tb.it> is especially true in
huffid climates as a resalt of infiltrating rain or xrovelling ground vater. The
leachate produces in these landfills can seriously degrade the quality of both
surface and gxouncwater and hence can be c. potential hazard for hunan health.
These water pollution prob]ems have increased because of the increased disposal
of solid vasts to landfills and the selection of improper hydrogeological
landfill sites. Therefore more and more landfills must be built with provision:,
for collection and treatment of the leachate, thereby making the selection of
the fill site and operation of the fill more flexible.
Aerobic and anaerobic stabilization of landfill leachate have been studied
by Boyle and Har, (1972). They also evaluated chemical treatment of leachates
using such parameters as COD, iron, chlorides and total solids. Aerobic and
anaerobic treatabxlity studies also have been reported by Force and Cook (1972),
Foree and Reid (1973) and Chian and DeWalle (1971*). Other biological treatability
studies of leachates are described by Knoch and Stegmann (1971) and Knoch (2972)
(1973). The composition of leachates has beer, studied by Qasim and Burchinal
(1970), Fungaroli and Steiner (1971) and Chian and DeWalle (1971*). KLotter and
Hantge (196S) and Keuss (1971) have studied the leachate productions from
sanitary landfills.
The objective of this study was to evaluate leachate treatability and
369
-------
provide design criteria for biological treatment of leachate from sanitary
landfills. Two leaohate sources from the Seattle area and six frcir the Oslo
area, were investigated. Of these, four sources were treated aerob.v:ally and
t«ro anaerobically. In this paper only the results from the aerobic treatment
studies will be discussed.
LEACHATS CHARACTERISTICS
The most important parameters affecting the composition and quality of
leachate are, annual reinfall, runoff, infiltration, age of fill, mean and
annua] tfir.peralure, waste- composition, type of disposal, initial moisture conto
and depth of the landfill. However, rainfall, runoff and infiltration are the
most important, Therefore, depending on the amount of water allowed to enter
the landfill, the composition of leachate and its production may vary consider-
ably.
Typical suirmer constituent concentrations for the leachatas investigated
in this study ere shown in tables 1 and 2. For the data shown, no
precipitation had occurcd in the weeK in August preceding sampling for the six
Norwegian stations. Dry veather had prevailed for several weeks prior to trJtiag
the American samples.
Considerable variation in constituent concentrations occur between the
sites. Note in the tables that concentrations of organics, nitrogens, iron and
zinc are high while the concentrations of other heavy metals are low.
To identify the organics in the leacha-ce samples analyses of carbohydrates
and organic acius were run. The concentrations of proteins were calculated from
the concentrations of organic nitrogen. The results are giver, in table 2.
Table 2 show3 that for the leachate sources with high concentrations of
360
-------
Table 1. j>g_Wgs.ther Analysis of Leaehates From _ Norway
and the Pacific Northwest.
Parameter ^_^
C01. me 0/1
BOD tc+^i mg 0/1
TOr . mg C/l
Total 3 0£ »/i
tll^-Il nt, 11/1
KOj-Ii mg H/l
Oiganic if mg fl/1
Total P mij P/l
Suspended KO'-GE cg/1
Volatile » j.5
C.10
C.l'1
0.01
'0.1
-
as the dn'ferancc be*.vise:, total R and KH,-S.
361
-------
o
.e
-p
I
03
SI
a
5
0)
I
CM
01
All
g g
CM -O SO rH CO
c\J-a\£i^-'\c
o o o o o o
"? -S d -"S o "H
.J -< (J i-f O
S'J u s> h a)
fl) 3 S
U O " 3
'3 +J Si X
> C
O R-
362
-------
organics, the organic acids naks up the largest fraction of the organics.
Acetic-, propionic - and "butyric acids are the most important. These contri-
buting up to 7J percent of the total organics. The characteristic bad odor
from leachate is due to the high concentration of butyric t-cids.
3IODEGRADATION
For the leachate sources from Noiway, respiration tc-sts were used to provide
a preliminary orientation of their biodegradability and toxicity effects. For
these tests, leachate at different dosages were added to samples of domesti"
sewage. The velimes added to each test flask were so that the additions of the
leacnates should contribute a prefixed amount of total organic carbon. The samples
were then run in oanometric BOD apparatus.
The domestic sewage which was sampled after sedimentation, had the following
concentrations:
COD = 120 mg/1
TOC = 30 mg/1
Tot-II = 16.8 mg N/l
Tot-P = !».5 wg P/l
To compare the respiration results of the different leacnate sources, figure
1 to figure 1+ are given. The curves are all drawn by means of the manome"cric HOD
values and vith the domestic wastewater as reference. This is done by reducing
the respiration values (BOD) of the samples added leachate by a factor: TOC
domestic sewage/TOC for the actual sample added leachate.
Figures 1 to U show how respiration rates are suppressed or stimulated by
increasing amounts of leacnates. For example, with leachates from landfills at
363
-------
IOC CONTRIBUTION FROM LEACIHATES 15%
O Grdnnio
D Bronosdnlen
: Reference Domestic wostewater
INCUBATION T!ME DAYS
Figure 1 Relative respiration vs, incubation time, TCC contribution
from ieacha'oes 15$-
IOC CONTRIBUTION FROM LEACHATES 30%
O Grormo
O Branosdalen
V Toronrod
A Isi I
Reference Domestic wostewoter
2 uo-
P 120-
E 100
to
K I 6^
UJ
I
O
§
60-
iO-
20-
0
5 10 15 20
INCUBATION TIME DAYS
25
Figure 2 Relative respiration vs. incubation time, TOO contribution
from leachates 303*.
364
-------
TOC CONTRIBUTION FROM LEACHATES 45%
O Grdnmo
O Pronosdolen
0 Yggcscth
2
O
t-
oc
E
LL)
K
UJ
t
_J
i
o
Figure 3
3
<£
Ct
0.
i
ID
1
2^
o
140-
120-
100 -
" 80-
^ 60-
40-
20-
«
Vv lafojirua
a IslI
~ Reference Domestic wastewater
-O^rt ..
a XA'I^5tv"X^x^-1=Jit) ^J *~~
^>C^aaGtH^ 0
9^^^^^-^^^^^
^o^o0i:! \^^ "o^-a^^^8 D
""^KitKr^0^ ^~*
^£t A-^**^
^W-A-A-A-£NWt_i,rA/'
1 1 1 1 1
0 5 10 15 20 25
INCUBATION TIME DAYS
Figure k Relative respiration vs. incubation time, TOC contribution
froE leachates 65%.
365
-------
Yggeseth and Taranr^d contributing ^5 percent of -che TOG, the respiration rates
were stimulated. On the other hand, the SOD curves are significantly suppressed
when receiving leaohates fron the Gr^lnmo and Isi I landfills. The curves show
decreasing degradabilities of the leachate iu the following order: Yggeseth,
Taranr^d, Branasdalen, Isi I and GrjzJnmo. These results were confirmed 'ay later
experiments with biological treatment.
BIOLOGICAL TREATMENT OF LEACHATE
The biological treaiability of the different leachate sources war, studied
by the treatment methods given in table 3 following.
Table
Treatment Studies
Wash.
US
Oslo
Horway
Leachate
source
Kent Highland
GrpSnmo
Branasdalen
Yggeseth
Type of
treatment
Activated
sludge
Activated
sludge
Aerated
lagoons
Biodisc
Trickling
filter
Activated
sludge
Biodisc
Activated
sludge
No of
plants
5 Batch units
3 Continuous units
6
2
1
1
6
1
3
For the activated sludge experiments, conducted at the leachate source from
Kent Highland, five 10 liter batch activated sludge units were used. The treatn-
366
-------
bility of this leachate source was also studied in three continuous units with
aeration volumes of two liters.
The activated sludge units treating the leachate from SrjzJnmo, brauasdalen
and Yggeseth consisted of six continuous activated sludge units, each with
aeration volumes of 39 liters.
The aerated lagoons consisted of 200 liter plastic tanks filled to a
level corresponding to ito liters of leachate.
The tjiodisc consisted of a half cylindrical trough of plexiglass, discs
of wood fixed to a steel axis and a slow-rotating motor. The 16 discs had a
2
total wetted area of 3.3 m .
The trickling filter of the Floccor type had the dimensions 0.6'6.1-1.8 i.
vhich gave a filter volume of 650 liters. The filter was equipped with a recireu
latior. pump.
RESULTS
Biological processes are only expected to give high removals of organics.
The results discussed in this paper thus will mainly be directed -co the
reductions of organics and oxidation of nitrogen compounds. Due to the toxicity
effects of leachate and the time aspect for BOD analyses, COD was selected as
the main parameter for organic matter. Samples for TOG were also taken, but not
as frequently as the sampling for the COD analyses.
AEROBIC BIOLOGICAL TREATMENT
The program cf experimentation vas designed to determine the performance
of different aerobic treatment processes under the following conditions:
367
-------
1. Operation at different organic loadings
2. Treatment of different leaohate sources with high and low
concentrations of organics
3. Influence of pre-treatrient on the organic removal efficiencies
Treatment by the activated sludge process gave the "best results, Therefore,
the main attention will be given TO the discussion of the result? fron these
studies.
The experimental conditions for the activated sludge studies art: given
in table 1*. With the exception of test run No 4, the activated sludge studies
were performed in continuous ur.its.
Table 1*. Experimental Conditions, Activated Sludge
Test run
No
1+
5.
I
11
III
IV
VIII
XI
IX
leachate
source
Kent-
Hiehland
Gr^mao
Branas-
dalen
Yggeseth
Influent
CCL-ELX
EL
RL
RL
CCL
CCL
RL
PL
RL
COD
influent
mg/1
3k 38-3658
3760
530
1*20
398
h-k
1260
T31
91*25
Days of
operation
28
20
1*9
35
95
5T
67
73
1.0
No of
plants
5
3
6
6
3
3
6
5
3
Hansre 01"
organic
loading
kg_COD
kg MLVSS clay
O.S6-0.95
0.28-0.70
0.03-0.31
0.07-1.05
0.05-0.15
0.17-0.1*3
o.ii*-o.i*s
0.17
0.08-0.28
x CCL «s Chemically precipitated leachate
RL = Raw leachate
Pretreatment of the raw leachate tefore biological treatment wc.s assumed
to have beneficial affects, mainly duo to removal of heavy metals. Therefore,
for two of the leachate sources chemically precipitation was performed before
368
-------
feeding tha leachate to the activated sludge units. In test run Ko !*, aluminium
sulphate, Al (SO, ) « 18 H^O, in dosages 200 ng/1, was used as coagulant. Due
to the low pit, about 6.0, the 'removals of the heavy metals were less than
50 percent.
In test run No III and IV the lenchate was treated in an existing plant
for chemical precipitation. In this plant treating leachate from Gr^nir.o sanitary
landfill, the iron content in the leachate, roughly 50 mg/1, is used as coagulant.
When the pH is increased to about 8.0 with sodium hydroxide, efficient coagulation
and precipitation occur. The removal of iron was normally higher than 95 percent.
The other heavy metals normally occur in concentrations lower than C.I mg/1, so
the removals of these were not as high as for iron.
A disadvantage with the pretreatment of the leaehate is the removal of
phosphorus. This increases the BOD:P ratio so that phosphorus could limit ths-
degradation processes. The raw leachates, shown in table I, all have low concen-
trations of phosphorus. Thus the BOD:P ratio is considerably hicher than 100:1
vhich is assumed to be the ratio where phosphorus are limiting to growth. This
problem will be discussed later.
ORGANIC REMOVALS
Leachate Source Kent Highland
The experimental results of Lreating leachate from Kent Highland ure shown
in figure 5. The filled and open signs are results obtained by treating precipi-
tated ar.d raw leachate respectively. The results from test run Ho k shov that
the plants treating rav and chemically precipitated le&chate at tre oame- loading,
gave the same COD removal efficiencies. At organic loading less than 0.1* ks
COD/kg MLVS3 day, tha COD concentrations of the raw respectively chemirally
-------
LEACHATE SOURCE:KENT HIGHLAND
^ 100-
b
Lu 80~
o 60-
o
<-> 40-
LU
O
o:
LU
CL
20-
QJ
1 Test run no 4
Test run no 5
0 0.2 (U
ORGANIC LOADING
O.G 0.8
kg COD
1.0
kg MLVSS day
Figure 5, COD removal vs. organic loading, Kent Highland.
LEACHATE SOURCE : GRONMO
_J
>
0 40-
2
LU
or
820-
o
i
z
LU
0 0-
~ o - Test run
V Test run
van,.i__^7 *~~ ^est run
G"v&< ^V, 7 Jest run
e ^S7
7 ^^^
"~"~~
I'll
f*. 0 0.2 0.4 0.6 0.8
LU
a- kq COD
noriAMir i n A ri i M r; =*
I
11
III
IY
V
J
1.0
kg MLVSS doy
Figure 6 COD removal vs. organic loading, Gr^nmo.
370
-------
LEACHATE SOURCE:BRANASDALEN
PERCENT COD REMOVAL
100-
60-
40-
20-
\
\
0 0.2 0.4 0.6
rvPr.AMir ir\AniMr. ... " -Vlr.-
Figure 7 COD removal vs. organic loading, Bran&sdaler.,
LEACHATE SOURCE:YGGESETH
> 100-
o
" 80-
UJ
60-
Q
O
0 40H
UJ 20-
o
ce (
ID l
a.
0.2 0.4
LOADING
0.6
COD
kg MLVSS day
Figure 8. COD removal vs. organic loading, Yggeseth.
371
-------
precipitated leaehate were effectively reduced from 3658 and 3^*58 mg/I to
values of about 100-150 itg/1. This corresponds to COD removals of about
96 percent. Some BOD measurements were also performed. At low loading the
effluent BOD values were about 10-20 rng/1, corresponding to 99 percent BOD
removals.
At higher loadings than about Q.k kg COD/kg MLVSS the orgunic removal
efficiencies began to fall spyerly. When overloading occurred, analyses of the
effluent showed very high concentrations of organic acids. These acids
reflected little or no degradation of the influent organic acid during treatment,
Leachate source Gr0nrpo
Activated sludge treatment of leachate from the Gr^nrco sanitary landfill
was investigated in four test runs. In two of these, treatment of chemically
precipitated leachate was studied. Thes results, given in figure 6, show very
lov COD removal efficiencies. Organic loadings as low as 0.03 kg COD/kg MLVSS
day did not give higher efficiencies than about 35 percent. Many of the samples
analyzed for TOC also gave the same removal efficiencies. The somewhat different
results from tha different test rons were related to the influent COD. The
results showed that the organics expressed as COD could be removed to a threshold
value of about £50-300 mg/1. Therefore, the test series with low strength
leachate gave lorfer organic removal efficiencies.
The 303 removal efficiencies at low organic loadings were normally higher
than 90$. Thus a very high fraction of the organics in the treaced effluent
was inert to biological degradation.
In test run Mo III, where chemically coagulated leachate was treated, one
of the activated sludge plants was given daily phoshorus additions to provide
BOD:P ratios of about 50:1. The other plants, without phosphorus additions,
operated with BOE:P ratios in the range of (1000-2000):!. The plant witn
372
-------
phosphorus additions which operated at an organic loading of 0.1 kg COD/kg
MLVSS day, gave no higher treatment performance than the other plants. Non of
the results obtained in this test run or in test run No k (Kent Highland)
indicated that phospliorus was a limiting nutrient.
Dae to the very low COD removals, the curve in figure 6 does not have a
sharp decrease to denote the critical organic loading. The results, however,
indicate that no higher organic loading than 0-3 kg COD/kg MLVSS day should be
applied in treatment of this leacbate. The few effluent BOD analyses perforinad
confirmed this.
Leachate source Bra.nasda.len and Yggeaeth
1'he results of treating raw leachate from Branasdalen and Yggeseth sanitary
landfills are shown in figure 7 and figure 8.
Treatment of the leachate source from Yggeseth showed very high COD removaJ
at low organic loadings. Thus at organic loadings lower than about 0.2 kg
COD/kg MLVS§ day the COD values were reduced from 9^25 mg/1 to values of about
150-200 Eife/l- Ihis corresponds to the COD removal efficiences of about So percent.
Corresponding samples analyzed for TOG gave nearly indentical removal efficiencies.
The results indicated a relatively sharp decrease in the organic removal
efficiencies at organic loadings higher than about 0.3 kg COD/kg MLVSS day.
For the leachate source from the Branlsdalen sanitary landfill the results
showed relatively high COD removals for oragnic loadings lower than about 0.3 kg
COD/kg MLVSS day. Ilia COD values were then reduced from an average influent
value of 1260 to values of about 200-250 mg/1. This corresponds to COD removal
efficiencies of about 82 percent. Good agreement was obtained between organic
removal efficiencies based on COD and TOC.
373
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NITF.OGEK COMPOUNDS
All the investigated leachate sources had high contents of nitrogen
compounds. These are mainly present in the for:a of ammonia. Under aerobic
conditions a gradual oxidation of airaioaia to nitrites and nitrates occurs.
For a ccnplete oxidation of 100 rag NH,--N/1 the stoiohometric calculations
show an oxygen ds.iand of h^J jsg 0/1. According to this, the oxidation of
the wmnor.ia compounds in the lot; strength leachates in table 1 may correspond
to a biologjcsj oxygon demand higher than the chemical oxygen denp.r.d. This is
possible because oxidation of ammonia compounds does not take place in the
method used for determination of COD. To reduce the oxygen demand in treated
water, it is therefore important to apply sufficient low organic loading ',o
secure a hi^h degree of nitrification.
In figure 9 the degree of nitrification for treating leachate from 3rjz(n:iio
is plotted as a function of the organic loading. The experiment gave no diffe-
rence in the degree of nitrification for treatment of raw nor chemically treated
leachate. If the leachate had contained higher concentrations of heavy metals, a
difference in the shape of the nitrification curve would have been expected.
Among the organisms normally present in activated sludge, the nitrification
bacteria is one of the species most sensitive to heavy metal toy.ici~:y. "'h^refore,
at higher concentrations of heavy metals, the nitrification processes are
suppressed.
At higher organic loadings thac about 0.3-0.1+ kg COD/kg MLVSS day, the
degree of nitrification falls sharply. The maximum obtainable degree of nitrifi-
cation seems to be about 75 percent. Thus, about 25 percent of the nitrogen
compounds are not biologically degradable.
374
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LEACHATE SOURCE : GRONMO
-o Nitrification T r II
-Nitrification T r !Y
» Effluent T r II
» Effluent T r IV Total
Influent T r II-l02mgN/l nitrogen
Influent T r !V.l28rng N/l
r-140
§100-
H-
< 80-
o
t 60-
5 40-
5 20-
1U
K °-
» » * ,
{?--*»- o- o-«
y
\
V
^^^
O
~T T I 1 1
-100
-80
-60
-40
-20
-0
iu D 02 04 06 06 10
r\or-_ ..mr* i n* niiir- 9
w
6
y
ai
O
O
a:
z
<
5
kg MLVSS day
Figure 9. Nitrification end removal Of nitrogen vs. organic loading, Grpmao.
Figure 9 also shows the concentration of total nitrogen in the influent and
effluent. For "both test runs no significant reduction of total nitrogen took
place.
For treatment of the leachate source from Brauasdalen, the nitrification
processes, drawn in figure 10, show the same form and degree of nitrification
as the leachate source from Grjzfnmo. At low organic loadings the removal of total
nitrogen was atout 30 percent.
In the treatment of leachate from Yggeseth the degradation of the nitrogen
compounds appeared quite differently than for the leachate sources from
Bran&sdalen and Gr^imo. Figure 11 shows very high removal efficiencies i'or
375
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LEACHATE SOURCE:BRANASDALEN
Nitrification
Influent j Total
Effluentj nitrogen
z
o 100-
0 80-
UL
o; 60-
tz
Z 40-
H-
5 20-
o
fv r*
UJ °.
Influent
^S*
v - ^\"
>
1
\
\
\
\
-250 Z
-200 E
Z
-.50 UJ
0
-100 K
50 *
0 <
n i r\ L n K *-'
ORGANIC LOADING
kg COD
kg MLVSS day
Figure 10. Nitrification and removal of nitrogen vs. organic loading,
Branasdalen.
LEACHATE SOURCF:YGGESETH
Nitrification
Influent j Tc,,ol
Effluent ( nitrogen
if 100-
o 80-
60-
. 0 02
ORGANIC
0.6
kg COS
250 z
o>
200 E
-.50
-.00
-50
0
kg MLVSS day
Figure 11. Sitrificfttion aad renoval of nitrogen vs. organic loading,
Yggeseth.
376
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total nitrogen. Thus at organic loadings lower than about 0.2, the removal
of total nitrogen was higher than 80 percent. The degree of nitrification,
however, appeared to be lower than for treating leachate from Gr^rimo and
Br&nasdalen. This was caused by the very low concentrations of nitrogen in the
treated effluent and because the remaining nitrogen compounds showed high
degree of resistance to nitrification.
The treatment of leachate from Branasdalen and Yggeoeth were treated in
parallel units. So avoid vigorous recirculation of sludge from the settling
chambers, the recirculation pumps were timer operated with an interval of 1
hour between each retirculation and with a pumping time of three minutes.
Therefore, very little replacement and oxygen supply took place in the settling
chambers. For the leachate from Yggeseth this provided efficient denitrification.
The difference in the nitrogen removal efficiency between the two leachate
sources may be attributed to the differnece in the biodegradability of the two
leachate sources. Thus, the carbon source in the treated effluent from the
leachate source Yggeseth is obviously more readily available for the denitrifi-
eation processes.
ACTIVATED SLUDGE CHARACTERISTICS A5D SLUDGE PRODUCTION
In all the treatment studies the settleability of the activated sludge was
good at all organic loadings. For instance, the sludge volume index was very
seldom higher than 100. Among the factors contributing to the good settleability
are probably the high concentrations of iron in the leachates. The general
improvement of the se^tleability caused by iron has been studied by Pfeffer (1967)
and Carter et al. (1973).
Heufeld et al. (1973) also discussed the improved settleability caused
377
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by iron. Bat they also indicated that e. deflocaulation may occur, and that
this increases in severity with increasing metal concentrations. This agrees
very well with the results found in this study. The activated sludge settled
very fast, but the supernatant contained relatively high concentrations of
suspended solids. This was especially a problem in treating leachate from the
Grjzinmo sanitery landfill. For this leachate source the deflocculat ion was so
severe that the loss of cells in the effluent was about the sain= as the growth.
Thus, no sludge wss withdrawn as excess sludge in spite of more than 80 days
of operation. Another factor contributing to lack of sludge production was the
.low fraction of the organics in the leachate available for nicrobial grovth.
Hence the actual food to organic ratio given for the leachate source from Gr^naio
is much lower than the given organic loadings.
In treating the leachate sources from Kent Highland, Brniiiisdalcn and
Yggeseuh, the deflocculation of the activated sludge vas not sc severe as for
treatment, of leachate from Gr^nmo. Especially the treatment of the- leachate
sources from Kent Highland and Yggeseth gave effluents with low concentrations
of suspended solids. In these two leachate sources the concentrations of iron
was low compared to the concentrations of organics.
The sludge production as a function of organic loadings for the examined
leachate sources is given i figure 1?.
TS1ATMENT OF LEACHATE BY AERATED LAGOONS, BIODISC AND TRICKLING FILTER
Treatment of leachate by the above mentioned treatment processes did not
give as promising results as did treatment by the activated sludge prpcess.
Therefore, the results obtained by those different treatment processes will be
only briefly described.
378
-------
o
1
UJ
u "
O 01
Q *
_j
to
Leachate source
o Kent Highland
v Yggeseth
Branasdalen
0.8-
0.6-
£
O
0 nA
0 Ufc-
O)
02-
0-
C
S-p'^'o
S^
S'
:/'°
/
01 02 03 06 05 05
kgCOO
kg MLVSS day
'\
07
Figure 12. Sludge production vs. organic loading.
Raw 3.eaohate from Grftamo sanitary landfill was treated in aerated lagoons
with detention tines of 10 and 35 days. The influent COE was on the a"eraire
reduced from ^29 ng/1 to values of 311 and 28? mg/1 for the 10 and 35 day
detention times respectively. This corresponded to COD removals of ?1,^ and
32.7 percent. Tho average degrees of nitrification at the 10 and 35 day dent,ion
times were 39-7 and 77.5 percent respectively. Compared to treatment ty the
activated sludge process the aerated lagoon at a 35 day detention time gave a
slightly lower organic removal efficiency than the activated sludge process
operating at organic loadings lower than about 0.3 kg COD/kg ML7SS day. The
aerated lagoons, however, gave an effluent with considerably lower concentration:
of suspended solids than the activated sludge process.
Chemically precipitated leachate froa Grfzinmo sanitary landfill was treated
in a plastic media trickling filter. The organic loading applied vas about
379
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0.9 kg COD/m day which is a value frequently used in treating domest-.c waste-
water. During the 90 days of operation no attached growth on the filter media
was observed. The analyses of the treated effluent also showed that no organic
removal efficiency had occurred.
The sam? precipitated leachate as used in the trickling filter study was
also treated by e. rotating biodisc. To initiate attached raicroba] growth, the
biodisc was first used to treat municipal sevage. After three weeks of operation
che.nieally coagulated leachate from Gr^nmo was used as ths feed al ar, organic
p
leading of 6.2 g COD/m day. In spite of this low loading the average- COD
removal efficiency in a 110 day period was not higher than 15-9 percent. The
average nitrification in th« same period was 21.U percent. The activated sludge
process treating the identical leachnte gave av an organic loading o:.' O.P-0.3 kg
COD/kg MLVSS day, a COD removal efficiency of ibout 35 percent and a nitrifi-
cation of aboat 75 percent.
The rotating biodisc was also used for treatment of leachate from
o
Branasdalen. The organic loading was then as low as 1.8 g COD/m day. 1'ne
average COD removal ootained was U7.1 percent and with no degree of nitrifi-
cation. A parallel study with the activated sludge process opera/ting at the
sane temperature and organic loading O.l6 kg COD/kg MLVSS day, gave an average
removal of 60 percent and a degree of nitrification of 7't percent.
CONCLUSIONS
1. The composition of the eight leachate soirees investigated exhibited
a significant range of values.
2. In the high strength leachates organic a^ids contributed up to PO percent
of the total organics.
3. High concentrations of nitrogen compounds, mainly as ammonia, prevailed
in all the leachate sources.
380
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U. Of the heavy metals iron was found in high concentrations in all the
leachate sources. Hextto iron, zinc had the highest concentrations.
For Cr, Hi, Cu, Cd and Fp the concentrations were very low.
5. Bespiratdon tests for the different leachate sources showed a significant
difference in the treatability and biodegradability.
6. The results of the respiration tests to study the treatatility and
biodegradabiiity of the different leachates coincided very welj with the
results froci the treatment studies obtained by the activated sladge process.
7. Of the aerobic biological treatment systems examined, the activated blud^o
process gave the most promising results.
8. The results of the treatment studies showed big differences in the organic
removal efficiencies of the different, leachate sources. The rair.oval
efficiencies increased significantly with increasing conccntr-allo'is of
organics in the influent.
9. No difference in the treatment efficiencies was founc in treating chraically
precipitated or raw leacahte.
10. In spite of very low phosphorus concentrations in the raw leachate phosphorus
was not found to limit biodegration.
11. At sufficient low organic loadings the degree of nitrification was about
75 percent.
12. For the leachate sources highest in organics, denitrification in the
settling chamber caused a nitrogen removal higher than 90 percent. The
organic loading was then below 0.2 kg CODAg MLVSS day. For the other
leachate sources investigated the nitrogen reiaoval was low.
13- Treatment of the leachates low in organics resulted in def]occupation of
the activated sludge. This was probably caused by high iron cortents 'n
the leachates.
lU. Good settleability of the activated sludge was observed in all the treatment
studies.
15- Treatment by rotating biodisc and trickling filter both gave low organic
removals and lov degree of nitrification.
16. Treatment by aerated lagoons at sufficient detention times gavt slightly
lower organic removals than corresponding activated sludge treatment.
381
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REFERENCES
Boyle, W. C. and Ham, H. K., "Treatment of Leach&te from Sanitary Landfills1',
Presented at 27th Annual Purdue Industrial Waste Conference, Lafayette,
Indiana, May 3, 197^.
Heufeld, R. D. and Hermann, E, R., "Effects of Iron on Activated Sludge Treatment"
ASCL, No 12, 966-968, ( Dec. 1973).
Chian, F. S. K. and DeWalle, F. B., "Characterization and Treatment of
Leachetes generated from Landfill?", Presorted at the 76th Ifetioiial Meeting
AIChE, Tulsa, Oklahoma, March 10-13, 197i»-
Faroe, E. 0. and Reid, V. M, "Anaerobic Biological Stabilization cf Sanitary
Landfill. Lea'_-h?te", Technical Report, University of Kentucky, TP. 65-'?3-C?-17,
January, 1973.
Force, 3. C-. and Cook, E. K., "Aerobic Biologicr.1 Stabilization of Sanitary
Landfill Leasha-te", Technical Heport, University of Kentucky, TR 53-7;;'-CE21,
Septer'ber. 1972.
Pun^arcli, A. A., "Pollution of Subsurface Water by Sanitary Landfill", Fir.a]
Kepoil VSPH3 Grant No 5-R03-VI00516, PP- 132, 1970.
Klotter, H. E. and Hantge, E., "Abfallbeseitigu'ig und Crundwas^erscbulti",
Mull ur.d Abfal.1 3: 1-8, 1968.
Kuoch, J., "Reinigung von ^5ullsickerwasser mit beluffeten Teicher:", Hull und
Abfall k: 123-133, 1972.
Knock, J. and Slegmann, R., "Versuche zur Reirdgung von Mullsickerwasser",
Mull und Abfc.ll 3: 3.60-66, 1971-
Qasim. S. R. and Burchinal, J. C., "Leaching fron Simulated Landfills",
JVffCF, '
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