EPA/530/SW-165
September 1975
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An environmental protection publication in the solid waste management
series (SW-165). Mention of commercial products does not constitute
endorsement by the U.S. Government. Editing and technical content of
this report were accomplished by the Hazardous Waste Management Division
of the Office of Solid Waste Management Programs.
Single copies of this publication are available from Solid Waste
Information, U.S. Environmental Protection Agency, Cincinnati,
Ohio 45268.
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LANDFILL DISPOSAL OF HAZARDOUS WASTES:
A REVIEW OF LITERATURE AND KNOWN APPROACHES
This report (SW-165) was written by
TIMOTHY FIELDS, JR., and ALFRED W. LINDSEY
U.S. ENVIRONMENTAL PROTECTION AGENCY
JUNE 1975
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Table of Contents
Section Page No.
1. Introduction 1
2. Background 2
3. The Conventional Sanitary Landfill 4
4. The Chemical Waste Landfill 5
a. Existing Industrial Waste Landfills
b. Site Selection/Evaluation n
c. Site Design, and Preparation 13
Liners 13
pH Adjustment 17
Cover Materials 17
(ill-
(iv) Observation/Monitoring Wells 19
d. Waste Preparation 19
(i) Chemical Fixation 19
(ii) Volume Reduction 20
(111
(iv
(v
(vi
Waste Segregation 20
Detoxification 20
Degradation 20
Encapsulation 21
5. Alternatives to Chemical Waste Landfill
Disposal 22
6. Research, Development, and Demonstration 23
References 27
Appendix
Landfill Disposal of Specific Materials 30
111
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Figures
Page
1. Costs for Adequate Treatment are Significantly
Greater than Ocean or Land Dumping 3
Tables
Page
I. California Class I Site Criteria 7
II. Private Hazardous Waste Management Companies 8
III. U. S. Companies with Chemical Waste Landfills 9
IV. Liner Costs 16
IV
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1. Introduction
The landfill has been developed over a number of years as
a means of disposing of various types of waste materials. However,
due to the increasing quantities of hazardous waste sludges (most
of which are generated by air and water pollution control processes),
land disposal is becoming more widely used as a hazardous waste
disposal technique, and as a receptor of larger waste volumes. In
1973, an effort was made by the TRW Systems Group, under EPA contract,
to review the available information and summarize the state-of-the-
art of hazardous waste land disposal.1 This work was included in
an broad effort to identify and analyze all treatment and disposal
practices potentially applicable to hazardous wastes.
Since issuance of this pioneer study, sufficient additional
information has surfaced to justify a new compendium. In this
report, OSWMP has extracted the most useful information from the
"TRW report" and added pertinent information from office files.
The information and data contained are for information and
guidance purposes only. The report does not present regulations
or guidelines for treatment or disposal. It is meant simply to
be a digest of the most useful technical and economic information
on the subject, known to the Office of Solid Waste Management
Programs (OSWMP), EPA. Much of the information has been received
from contractors and other outside sources and has been accepted
largely on face value. OSWMP is therefore not in a position
to confirm data presented, or to make definitive judgement on
the adequacy of the operations and methods discussed.
This report has been prepared for those not intimately
familiar with hazardous waste materials or disposal methods.
It can serve as a starting point in addressing any situation
or question involving hazardous waste land disposal. The
report presents an overview of conventional sanitary landfill ing,
the chemical waste landfill, and alternatives to chemical
waste landfill disposal. A discussion of research, development,
and demonstration programs in the area of hazardous waste land
disposal is presented. Finally, Appendix A presents a listing
of hazardous waste materials and applicable pretreatment and
land disposal methods. OSWMP anticipates revising this report
periodically as additional information becomes available.
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2. Background
Hazardous wastes have been defined as any "wastes or
combinations of wastes which pose a substantial present or
potential hazard to human health or living organisms because
they are lethal, non-degradable, persistent in nature, can
be biologically magnified, or otherwise cause, or tend to
cause, detrimental cumulative effects."2 The five general
categories of hazardous wastes are: (!) toxic chemical, (2)
radioactive, (3) flammable, (4) explosive, and (5) biological.
There is overlap, of course. For example, flammable and
explosive wastes may be toxic as well; however, in this case,
the primary waste characteristics of concern are flammability
and explosiveness, rather than toxicity. The same logic
applies to many radioactive and some biological wastes as well.
Most of the non-radioactive hazardous waste generated in this
country (about 10 million tons annually) fall into the toxic
chemical category. Most toxic wastes can be subcategorized
as: (a) inorganic toxic metals, salts, acids or bases, and (b)
synthetic organics.2
Some of the primary findings of EPA's Report to Congress
on Hazardous Waste Disposal, which was mandated by Section 212
of the Solid Waste Disposal Act as amended, are that current
hazardous waste management practices are generally unacceptable,
and that public health and welfare are unnecessarily threatened
by the uncontrolled discharge of such waste materials into the
environment, especially upon the land.2 It was also concluded
that usage of the land for hazardous waste disposal is increasing
due to the implementation of air and water pollution controls,
and the limitation of disposal methods such as ocean dumping.
The Clean Air Act (as amended), the Federal Water Pollution
Control Act (as amended), and the Marine Protection, Research,
and Sanctuaries Act (as amended), are curtailing the discharge of
hazardous pollutants into the Nation's air and water. 3il*<5 The
basic objective of the latter is to prohibit the dumping of some
materials, and strictly regulate the dumping of all materials
(except dredge material controlled by Army Corps of Engineers).30
Increasing volumes of sludges, slurries, and concentrated liquids
will therefore find their way to land disposal sites.
Few economic incentives exist to encourage waste generators to
utilize environmentally acceptable disposal methods (Figure 1).
Current methods frequently result in contamination of groundwaters
from leachates; surface waters from run-off and leachate; and air
from evaporation, sublimation, or dust dispersal. For example, toxic
heavy metals create a chronic hazard when deposited in the land environ-
ment. As a result of arsenic buried more than 30 years ago, several
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NOTE
: 1000 gallons - approximately 4.2 tons
~ 400 (106.00)
j; 300 (79.40)
O
•o
£ 200 (52.80)
8
o.
i
= 100 (26.40)
w
8
50 (13.20)
UJ
0 15 C
t 5 (1.32)f-
A = ENVIRONMENTALLY ADEQUATE TREATMENT AND DISPOSAL
B = LAND DISPOSAL
C = OCEAN DISPOSAL
NOTE DIFFERENCE IN
COST IS ROUGHLY A
^FACTOR OF TEN
t-
\
I
25
(94.6)
I
120
(454)
I
200
(758)
1,000
(3.78E.)
WASTE VOLUME [ 1,000 gal/day (1.0CW liters/day)]
Figure 1. Costs for adequate treatment are significantly greater
than ocean or land dumping. Source: Report to Congress. 2, p?13.
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people in Perham, Minnesota, had to be hospitalized due to
arsenic poisoning of drinking water from a groundwater supply
source contaminated by leachate from the buried deposit.2
With the exception of radioactive and pesticide wastes,
land-based hazardous waste treatment, storage, and disposal
activities are essentially unregulated at the Federal level.
The Atomic Energy Act of 1954, as amended (P.L. 703) and the
Federal Insecticide, Fungicide, and Rodenticide Act, as
amended (P.L. 92-516) do provide mechanisms for control of
disposal of radioactive, and pesticide-containing wastes.6'7
Hazardous waste legislation has been enacted in a few States,
of which Oregon, California, New York, and Minnesota are
examples. These programs are new and staffing levels are
fairly low. The disposal of the majority of hazardous wastes
generated in the U.S. is not regulated by the State of Federal
Government. Of those few States with some type of hazardous
waste management controls, less than half have acceptable
treatment/disposal facilities within their boundaries. Due
to the generally spotty nature of Federal, State, and
local solid waste and land protection legislation, regulation
and enforcement, there has been little pressure applied to
generators of hazardous residues to force disposal by
environmentally acceptable methods.
3. The Conventional Sanitary Landfill
Open dumping involves the deposition of wastes on the
land with little or no regard for environmental and/or public
health protection.8 The preferable alternative for many wastes,
such as municipal solid wastes, is the conventional sanitary
landfill which may be defined as "a land disposal site employing
an engineered method of disposing of solid wastes on land in
a manner that minimizes environmental hazards by spreading the
solid wastes in thin layers, compacting the solid wastes to
the smallest practical volume, and applying cover material at
the end of each operating day."9 The potential for leachate
generation exists even in a well-designed and operated sanitary
landfill.10 However, good site selection and design and careful
attention to operating procedures minimizes this potential, and,
in many instances prevents its occurrence. Other potential
problems include escape of hazardous vapors and gases and
possible explosive reactions within the fill. Thus, additional
precautions over and above those taken during sanitary land-
filling of municipal solid wastes are required for land disposal
of many hazardous wastes. The conventional landfill might be used,
however, in those instances where the wastes contain a hazardous
substance but in a form which is not particularly hazardous, i;e.,
insoluble salts, or in a concentration so low as to be innocuous.
Certain other wastes should probably never be land disposed because
of extreme hazards posed by escape of even small quantities.
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Because of the lack of effective controls, many hazardous
wastes are currently being disposed of in dumps and conventional
sanitary landfills. As an example, for several years a large
municipal land disposal site in Delaware accepted both domestic
and industrial wastes.2 In 1968, this disposal site had to be
closed because chemical and biological contaminants had leached
into the groundwater. By 1974, two major groundwater supply
fields which had provided water for about 40,000 households in
the area were contaminated. The cleanup costs are expected to
be over $10 million. Although this situation has not directly
been linked to the hazardous nature of any of the industrial
wastes constituents, this example serves to point up the potential
problem caused by disposing of any wastes in an unacceptable land
disposal site.
4. The Chemical Waste Landfill
Methods have been developed to modify the conventional sanitary
landfill to make it acceptable for receipt of hazardous materials.
Taken together, these modifications result in a "chemical waste
landfill." In general terms, such operations provide complete
long-term protection for the quality of surface and subsurface
waters from hazardous waste deposited therein, and against hazards
to public health and the environment. Such sites should be located
or engineered to avoid direct hydraulic continuity with surface and
subsurface waters. Generated leachates should be contained and
subsurface flow into the disposal area eliminated. Monitoring
wells should be established and a sampling and analysis program
conducted. The location of the disposal site should be recorded
in the appropriate local office of legal jurisdiction.11 A
special operating permit will most likely be required under the
terms of future regulations. Of course, these requirements are
also desirable in standard sanitary landfills. The primary
difference involves the degree of concern and care which must
be exercised where hazardous materials are involved. If there
is potential for hazardous wastes to percolate or leach to
groundwater, then the use of barriers and collection will be
necessary. Due to potentially hazardous reactions, wastes must
be segregated and records kept of disposal areas. Neutralization,
chemical fixation, encapsulation, and other pretreatment techniques
are often necessary. Because of the high concentrations of
hazardous wastes, attenuation capacity may be reached relatively
quickly. Leachate treatment may be more complex due to the wide
variety of waste types and constituents. Due to volatility or
for other reasons, hazardous materials may require immediate cover.
Due to these reasons, land disposal of hazardous wastes normally
requires a greater degree of care and sophistication in design and
operation at a given site than would normally be necessary with
municipal refuse.
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a. Existing Industrial Waste Landfills
There have been some efforts made by the public and
private sectors to dispose of hazardous wastes in an environmentally
acceptable manner. Private companies operate six Class I (designated
for hazardous wastes) landfill sites in the State of California.
Five other California Class I sites are operated by local jurisdictions.12
According to recent California hazardous waste management criteria
and standards, Class I disposal sites are ''those at which complete
protection is provided for all time for the quality of ground arid
surface waters from all wastes deposited therein and against hazard
to public health and wildlife resources.13 "There are nine criteria
developed by California which must be met by Class I facilities
(Table I).
Most other industrial waste landfill sites identified by OSWMP
are those operated by the small private hazardous waste management
industry. There are at least eight such sites, some of which appear
to be operating environmentally sound facilities (Table II).11* As
an example, Chem-Trol Pollution Services, Inc., Model Ctty, New York operates
an industrial waste landfill which receives residues from its
physical-chemical hazardous waste treatment plant. This plant
receives a large variety of industrial wastes for treatment.15
The Chem-Trol landfill consists of a series of clay-lined pits
or cells tnto which solid-sludges, chemically stabilized or
.solidified liquids, and slurries are deposited. A sump at the
bottom of each cell recycles leachate to the treatment plant. A
three-dimensional inventory is kept of wastes buried in each cell
to facilitate reclamation at a future date, should economics
permit. The company estimates this landfill can be utilized for the
next 150 to 200 years.
A few large U.S. chemical companies also have landfill facilities
which are reportedly capable of handling hazardous waste materials
(Table III). The Union Carbide Corporation, for example, has
operated a State licensed "chemical" landfill a-t their Institute,
West Virginia, plant since 1965.16 The initial system experienced
drainage problems, and resulted in a re-engineered landfill which
was completed in 1969. Wastes coming to the landfill are generated
by the broad-range plant production mix of some 200 or more chemicals
(mostly organic). According to the company, all leachate from the
landfill is collected and treated either in the plant's five million-
gallon per day activated-slydg^qwastewater treatment system, or burned
as a source of heat for steam generations Biological sludge from the
treatment of wastewater is dried in special beds, cycled back into
the chemical landfill, and mixed with soil and incoming chemical waste
sludge. Dried chemical sludges are introduced into the landfill on a
one-to-one basis by "blending" with soil. Blending the wastes with
earth reportedly reduces the gas and fire hazards sometimes associated
with conventional landfill cell construction techniques. It also
tends to hasten bio-oxidation of the chemical wastes. The landfill
handles approximately 10 tons (20 cubic yards) per day of chemical
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TABLE I
CALIFORNIA CLASS I SITE CRITERIA
(a) Geological conditions are naturally capable of preventing
hydraulic continuity between liquids and gases emanating from the
waste in the site and usable surface or groundwaters.
(b) Geological conditions are naturally capable of preventing
lateral hydraulic continuity between liquids and gases emanating
from wastes in the site and usable surface or ground waters, or the
disposal area has been modified to achieve such capability.
(c) Underlying geological formations which contain rock
fractures or fissures of questionable permeability must be per-
manently sealed to provide a competent barrier to the movement of
liquids or gases from the disposal site to usable water.
(d) Inundation of disposal areas shall not occur until the
site is closed in accordance with requirements of the regional
board.
(e) Disposal areas shall not be subject to washout.
(f) Leachate and subsurface flow into the disposal area shall
be contained within the site unless other disposition is made in
accordance with requirements of the regional board.
(g) Sites shall not be located over zones of active faulting
or where other forms of geological change would impair the
competence of natural features or artificial barriers which prevent
continuity with usable waters.
(h) Sites made suitable for use by man-made physical barriers
shall not be located where improper operation or maintenance of
such structures could permit the waste, leachate, or gases to contact
usable ground or surface water.
(i) Sites which comply with a,b,c,e,f,g, and h but would be
subject to inundation by a tide or a flood of greater than 100-year
frequency may be considered by the regional board as a limited Class
I disposal site.
Source: California State Water Resources Control Board, Disposal
site design and operation information, Sacramento,
March 1975. p. 19-21
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Table II
Private Hazardous Waste Management
Companies
(non-inclusive)
1. Rollins Environmental Services, Inc.
3208 Concord Pike
Wilmington, Delaware 19899
2. Chem-Trol Pollution Services, Inc.
P.O. Box 200
Model City, N.Y. 14107
3. Hyon Waste Treatment Services
Chicago, Illinois 60617
4. Conservation Chemical Company
Kansas City, Missouri
5. Nelson Chemical Company
12345 Schaefer Highway
Detroit, Michigan 48227
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Table III
U.S. Companies With Chemical Waste Landfills
(non-inclusive)
Union Carbide Corporation
Institute, West Virginia
Dow Chemical Company
Midland, Michigan
American Cyanamid
Willow Island, West Virginia
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waste sludges, and 28 tons (33 cubic yards) per day of wastewater
treatment plant sludges. The chemical wastes make up only three
to six percent by volume (two to four percent by weight) of the
total plant wastes, but are by far the most difficult and costly
to manage. According to the company, the cost of "chemical" landfill
disposal is $36.80 per ton ($9.27 per cubic yard), while the costs for
disposing of municipal-type plant wastes (garbage, rubbish, metals,
etc.) in a conventional sanitary landfill are $2.50 per ton ($0.63 per
cubic yard).
The Union Carbide landfill has a two foot thick rolled-clay
liner to keep leachate from entering adjacent groundwaters. A
20-year life (based on a 4,000-tons, or 12,000 cubic yards, per
year waste disposal rate) has been projected for the landfill.
An internal drainage system permits all-weather operation, and
serves to collect the leachate for treatment. The basic operating
procedures for hazardous waste disposal consists of strict segregation
of in-plant wastes; deactivation before landfilling, where practical;
continuous blending of wastes and soil, and daily earth cover. Union
Carbide indicates that not all chemical wastes are degraded in the
landfill. Some liquid flows out of the landfill as an "oil" layer
into a contaminated water basin, where it is skimmed for residue fuel.
Other waste leaves as dissolved chemicals in the leachate and goes to
wastewater treatment.
The estimated costs for the expected 20-year life of the fill can
be summarized as follows:
1973 $
(a) Study and Design $ 77,495
(b) Land Costs 100,000
(c) Capital Costs 250,000
(d) Operating Costs 2.884,505
(20-year)
Total $3,312,000
10
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Some foreign companies also operate industrial waste
landfill facilities. The Bayer Chemical Company's main
plant in Leverkusen, West Germany, for example, has a large
(150-acre) specially designed landfill.17 About 1,000 cubic
meters (35,310 cubic feet) per day (about 5,000,000 metric
tons, or 550,000 tons, per year) of solid waste are deposited
in the landfill, which has a one meter thick clay bottom.
Landfill ing is done in 10-meter (33 feet) layers, which will
lead ultimately to construction of a plateau 60 meters (197
feet) high. Estimated life is 70 years. Approximately 35
monitoring wells are located around the landfill. Wastes
accepted at the landfill include organic sludge from biological
wastewater treatment, slag from the plant's high temperature
(1,200°C or 2,190°F) incinerator, insoluble salts from titanium
dioxide production, and heavy metal hydroxide sludges precip-
itated from inorganic production wastewaters.
b. Site Selection/Evaluation
Chemical waste landfills should be sited to take advantage
of geologic factors responsible for optimum attenuation of
the wastes and any decomposition products, and designed
to overcome the disadvantages posed by less favorable sites. 18
The factors to be considered in the selection of a site include:
waste characteristics, topography, geology (rock type, geologic
structure, weathering characteristics), hydrology (permeability,
depth to water table, direction and rate of groundwater flow),
climate, and composition of soils (which affect pH and sorptive
capacity). Design factors to be considered include: waste pre-
paration, construction of impermeable liners, leachate collec-
tion systems, and monitoring equipment. The objectives of an
engineering design are to overcome the natural drawbacks of
the site and to control and monitor the release of hazardous
wastes into the environment.
In selecting and evaluating a chemical waste landfill
site, some of the general criteria to be considered are as
follows:10
(a) Chemical waste landfills ideally should be located
in areas of low population density, low alternative
land use value, and low groundwater contamination
potential.
(b) All sites should be located away from flood plains,
natural depressions, and excessive slopes.
(c) All sites should be fenced, or otherwise guarded
to prevent public access.
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(d) Wherever possible, sites should be located in
areas of high clay content due to the low
permeability and beneficial adsorptive
properties of such soils.
(e) All sites should be within a relatively short
distance of existing rail and highway transportation.
(f) Major waste generation should be nearby.
Wastes transported to the site should not require
transfer during shipment.
(g) All sites should be located an adequate distance
from existing wells that serve as water supplies for
human or animal consumption.
(h) Wherever possible, sites should have low rainfall
and high evaporation rates.
(i) Records should be kept of the locations of various
hazardous waste types within the landfill to permit
future recovery if economics permit. This will help
facilitate the analysis of causes if undesirable
reactions or other problems develop within the site.
(j) Detailed site studies and waste characterization
studies are necessary to estimate the
long-term stability and Teachability of the waste
sludges in the specific site selected.
(k) The site should be located or designed to prevent
any significant, predictable leaching or run-off
from accidental spills occurring during waste
delivery.
(1) The base of the landfill site should be a suffi-
cient distance above the high water table to prevent
leachate movement to aquifers. Waste Teachability
and soil attenuation and transmissivity character-
istics are important in determining what is an
acceptable distance. Evapotranspiration and pre-
cipitation characteristics are also important. The
use of liners, encapsulation, detoxification, and/or
solidification/fixation can be used in high water or
poor soil areas to decrease groundwater deterioration
potential.
(m) All sites should be located or designed so that no
hydraulic surface or subsurface connection exists
with standing or flowing surface water. The use
of liners and/or encapsulation can prevent hydraulic
connection.
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(n) In arid regions where the cumulative pre-
cipitation is less than the evapotranspiration,
water will not likely accumulate in the landfill
or migrate through the soil. Under such con-
ditions, leachate containment precautions (liners,
etc.) will not be necessary unless the water table
is high or large quantities of liquid wastes are
disposed.
(o) Unless leachate generation or escape is prevented
in some manner, such as by encapsulation, location
in arid regions or naturally impermeable basins, or
by immediate cover with an impermeable membrane to
prevent infiltration, it will be necessary to line
the basin with an impermeable membrane, collect the
leachate in headers, and recycle it through the fill
or pump it to an appropriate treatment facility.
(p) All liners, cover materials, and encapsulating
materials must be tested or have known chemical resist-
ance to the materials it will contain or might other-
wise come in contact with. Ideally, such materials
should have an effective life greater than the toxic
life of the wastes they contain.
(q) Studies will be necessary to determine general site
monitoring requirements. Hydro-geological monitoring
will be required to detect routine and accidental
releases of liquid effluents. A system of observation
wells should be installed in aquifers around the site
and concentrated in potential water and waste movement
paths downgradient from the site. A monthly sampling
frequently has been suggested by one source.10
Downstream monitoring stations and a bimonthly sampling
frequency were suggested for surface streams in the
site vicinity.
c. Site Design and Preparation
Although the criteria used by the State of California, Union
Carbide and Bayer vary, all have incorporated site design and
preparation requirements considerably more stringent than those
normally required for a standard sanitary landfill.
Liners. The use of liners is becoming more widespread, and is
being incorporated even in some conventional sanitary landfills.
When impervious basins are desired at a landfill site and the
existing soil is not suitable, artificial liners are a potential
solution to the problem. All prospective liners should be
pretested for strength and compatibility with the expected wastes.
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Due to relatively few applications and recent emergence of
various liner materials, the long-term effects of different
hazardous wastes in a landfill upon the liner's life cannot
be determined in a definitive manner.
In addition, the use of liners for environmental pro-
tection may require collection and treatment of leachate if
rainfall is significant.
Common types of liner materials include clay, rubber,
asphalt, concrete and plastics such as Hypalon (a chlorinated
polyethylene plastic) and PVC (polyvinyl chloride). The leachate
collection process usually requires plastic pipes, risers, and
pumps. Leachate treatment methods are not well defined but
may require neutralization, biological treatment, evaporation
or precipitation.
DuPont, the manufacturer, claims that 30 mil Hypalon
sheeting is essentially impermeable to water.19 The material
is also said to resist tearing and puncturing, but may be
readily patched if an accident occurs. Also, it is claimed that
the liner resists aging, weather, ozone (a chief enemy of
rubber), and a wide range of hydrocarbons and chemicals. It is
reportedly not adversely affected by soil chemicals and micro-
organisms. The cost of rubber and Hypalon liners varies
between $0.25 and $0.50 per square foot, while certain other
plastic liners cost $0.15-$0.25 per square foot.20 The plastic
pipes and risers for leachate collection range between $3 and
$7 per linear foot.20
At a recent NSWMA Congress in Chicago, the use of liners
in landfills was discussed. One speaker discussed a sanitary
landfill on Long Island which uses a 20-mil thick Hypalon
liner with sand cover. The liner costs were $20,000 per-acre
installed and the leachate collection system adds an additional
$6,000 to $7,000 per-acre.20
To protect groundwater, a Pennsylvania firm has lined
a 52-acre sanitary landfill with 1/2 inch thicfc asphalt covered
with a one foot thick layer of sandy loam.20 It is being
developed in five-acre sections. The low point of the land-
fill is two feet above the groundwater level. The base is
excavated, graded, and rolled. The asphalt is applied in several
coats. Sandy loam is applied on top of the asphalt to protect
the liner and allow a flow path for leachate. The depth of
each 5-acre fill is 22 feet. Leachate is collected from a
manhole at the low point of the fill. Laboratory tests have
indicated that the asphalt liners resist normal leachate.
Solvents cannot be accepted, however, since tests have indi-
cated that dissolution of the asphalt will result. Lab tests
14
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indicate that the life of an asphalt liner is at least 50
years. Asphalt liner costs, including installation, vary
between $6,000 and $12,000 per-arce. The higher cost
applies when the sand cover must be trucked long distances.
The asphalt used is a special flexible type, and not the
normal paving grade. It is applied at the rate of 2
gallons per square yard. An estimated 65 gallons per
minute of leachate is expected upon completion of this
facility. A leachate treatment plant will be constructed,
though process details are not currently available.
Another approach is to collect the landfill leachate
and circulate it back through the wastes.18 This reportedly
recycles the successful flora and nutrients which may improve
and speed waste degradation. Further research is needed
regarding the interactions between appropriate types and
concentrations of micro-organisms and different hazardous wastes.
The Hypalon liner was introduced commercially in 1951.
Primary uses of Hypalon include the lining of pits, ponds,
lagoons, and landfills.19 At least two of the larger regional
hazardous waste processing firms have begun using this material
in their operations. Rollins Environmental Services, Inc.(RES),
experienced holding basin failures using rubber liners and clay
liners (8 to 12 inches thick), and have switched with apparent
success to a concrete base with a Hypalon liner.20 Rollins
estimates that construction of a 500,000 gallon holding basin,
square in cross-section and 9 feet deep in the center, costs
approximately $19,000, including 4 to 8 inches of concrete. The
Hypalon liner adds an additional 20-25 cents per square foot
(or approximately $4,500) to the cost. Company officials
indicated that initial difficulties were experienced with the
adhesive used to bond the liner to the concrete.
The EPA-sponsored Kansas City Model Sanitary Landfill
demonstration project is operated on a 46-acre site. The cost
of installing an 18-inch clay liner was $54,500, or approxi-
mately $1,185 per-acre.21 A summary of available cost data
for the liner types discussed above is presented in Table IV.
The Lindenmaier-Precision Company of West Germany is
promoting the use of polyurethane foam to seal landfills.22
A top layer of the same foam material is used to cover the
compressed waste, and a final earth cover is applied over the
foam. Complete containment of the waste reportedly results.
There is no infiltration of water into the landfill, and no
contamination of air and water resources.
15
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Table IV
Liner Costs
Liner Type Cost/Acre (1973)
Clay (18 inch) $1,185
Asphalt $6,000 - $12,000
Rubber $11,000 - $22,000
Hypalon $11,000 - $22,000
Polyvinyl Chloride (PVC) $ 4,840 - $ 9,680
16
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Recent controlled research evaluated the stability of
concrete, asphalt, rubber, and plastic in contact with
selected acids and organic solvents (benzene, ethyl alcohol,
acetone, chloroform). 8 The relative durability was found
to be in the following decreasing order: (a) concrete, (b)
plastic, (c) rubber, and (d) asphalt. Asphalt was the least
suitable, according to the tests, reacting with all of the
reagents tested and completely dissolving in benzene and
chloroform.
pH Adjustment. The above study also investigated the effect
of pH on soil attenuation capabilities.18 A low pH, apart
from inhibiting the growth of beneficial micro-organisms,
reportedly increases the solubility of metals and affects the
ion exchange and absorption properties of the colloidal
fraction of soils. Clays are more effective absorbers of
metals at higher pH's while most organics are more effectively
absorbed under more acid conditions.
As a general principle, maintaining the soil pH at 7.0
to 8.0 is encouraged to reduce leaching potential of heavy
metals and promote biological activity. The effectiveness
and longevity of most liners is also improved.
Cover Materials. A sufficient supply of suitable cover
material is a necessary item. Ideally, the cover material
will minimize or eliminate infiltration of water, and pre-
vent sublimation or evaporation of harmful pollutants into
the air.
A recent EPA study indicated that a good cover for a
chemical waste landfill in arid regions of the U. S. might
consist of a one-foot layer of sand topped by a four-foot
layer of silty loam or clay.10 However, in other regions of
the country, more stringent requirements may be necessary.
If infiltration of water to the fill can be minimized
sufficiently, very little leachate will form, and collection
and treatment might not be necessary. It is apparent that
landfilling wastes on a one-shot basis, as opposed to semi-
continuously, has advantages since the site can immediately
be sealed to infiltration, eliminating the need for leachate
collection.
17
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The importance of adequate cover materials is demonstrated by
the following case history.23 In early 1973, excess levels of
hexachlorobenzene (HCB) were detected in slaughtered cattle from the
Ascension Parish area of Louisiana. A quarantine was imposed on food
animals in an area of over 100 square miles surrounding this area.
Studies conducted by State and EPA Region VI personnel confirmed that
the problem was associated with chlorinated hydrocarbon manufacture in
the vicinity. The HCB transfer mechanism from manufacturing operations
to cattle is believed to be sublimation from two dump sites receiving
wastes from the manufacturing facilities. No cover was provided at
the sites. To rectify the situation, land disposal of the HCB wastes
has been halted and one of the dumps has been sealed with a sheet
of 10-mil polyethylene covered with two feet of silty sand material
dredged from river banks. The polyethylene sheet is separated from
the wastes by a 1-2 foot layer of soil material. Air monitoring by
State Department of Health officials indicates a marked decline in
HCB concentrations over the dump site.
When a top liner is used at a landfill to provide a waterproof
covering, care must be exercised to avoid potential gas problems.
Gas venting mechanisms must be provided, since even minimal accumulations
can cause ballooning and rupture. A recent journal article mentioned
one instance where the application of a clay soil cover forced migrating
methane gas into an adjacent farm, ruining crop production.24
The primary factors affecting the rate at which gas is
produced in a landfill are:21
Moisture - The greater the moisture, the greater
the rate of decomposition.
Temperature - Increased temperatures tend to
increase bacterial productivity and resulting gas
production.
Amount of Organic Matter - Greater amounts of
organic material increase the amount of substrate
material from which the micro-organisms can produce
gas.
pH - A pH of 6.5-7.5 is optimum for methane gas
production.
The possibility of recovering gases from sanitary
landfill operations is beginning to be examined. The Solid
and Hazardous Waste Research Laboratory, EPA, is planning a
18
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case study of the methane recovery method in effect at the Palos
Verdes sanitary landfill operated by the Los Angeles County Sanitation
Districts. The objectives of the study will be to determine:
(1) whether such methods of methane recovery are feasible and, (2) how
the economics and techniques of such methods might be exploited.
Additional work is being sponsored by OSWMP and Pacific Gas and Electric
(PG & E) at the Mountainview, California municipal landfill. This work
will investigate gas withdrawal rates in relation to stability of gas
quality over time. PG & E will build a facility to dehydrate the gas
but plans for ultimate use have not been finalized.
Observation/Monitoring Wells. Prior to the deposition of hazardous
wastes, observation and monitoring wells should be installed around
the periphery of the site. Locations should be determined by the
appropriate regulatory authorities based on the site topography and
hydrogeological conditions. A recent OSWMP documented case history2
illustrates the importance of monitoring wells. A company in the
north central United States had utilized the same dump site for
laboratory waste disposal since 1953. More than half of the waste
dumped was arsenic. Although the monitoring wells around the site
were superficial in nature, arsenic concentrations greater than 175
ppm were detected. The U.S. Public Health Service drinking water
standard for arsenic is 0.05 ppm.2 The dump site is located above a
limestone bedrock aquifer which supplies about 70 percent of a
nearby city's residents with drinking and crop irrigation water.
Indications are that this water is in danger of being contaminated by
arsenic seepage through the bedrock. Without monitoring wells, this
waste transport would not have been detected, and serious illness
could have resulted.
d. Waste Preparation
Many of the hazardous wastes disposed of in chemical waste
landfills should be prepared or treated in some manner prior to
deposition to lessen potential environmental and health effects.
Methods of hazardous waste preparation for chemical landfill
disposal include chemical stabilization (fixation), volume
reduction, waste segregation, detoxification/degradation, and
encapsulation.
Chemical Fixation. Chemical fixation of industrial waste materials
has been developed by several companies, including: the Chemfix
Division of Environmental Sciences, Inc., I. U. Conversion Systems,
Inc., Dravo, Inc., and Chicago Fly Ash Company. Although the
environmental adequacy of these processes has not been evaluated
by OSWMP, the resulting solidified waste sludges are less likely to
cause environmental damage than if the wastes were deposited on land
as is. Long-term leaching and defixation potentials are not under-
stood at this time. In all fixation systems, proprietary chemicals
are mixed with the waste sludges, and the resulting mixture is pumped
onto the land, where solidification occurs between a few days and a
few weeks (depending upon the process). Some of these processes
result In the formation of a matrix in which wastes are entrapped;
19
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others claim that pollutants such as heavy metals are chemically
bound in insoluble complexes. Processes such as these have been
applied to many varied waste streams, including heavy metal sludges,
oil refinery wastes, and lime/limestone wet scrubber sludges.
Reduced leaching should result, but the permanence of the resulting
structure and the absolute environmental adequacy of these techniques
have not as yet been fully demonstrated. Typical costs quoted by one
firm are in the range of 2-10<|: per gallon 25; however, certain waste
types involve much higher treatment costs.
Volume Reduction. Incineration is the most widely used hazardous
waste volume reduction technique. Approximately 60 percent by weight
of the hazardous waste generated in this country are organics and
can normally be destroyed and/or detoxified by incineration. The
potential for use of incineration as a hazardous waste management
technique is apparent. Many wastes can be completely destroyed;
others leave small amounts of solid residues which may or may not
be hazardous. In any case, they must be disposed of, usually on the
land. Several of the larger regional hazardous waste processing firms
use incineration in combination with land disposal. Emission control
devices are usually required for hazardous waste incineration since
combustion by-products may also be hazardous. More details regarding
incineration can be found in the EPA report entitled, "Incineration in
Hazardous Waste Management."31
Waste Segregation. Segregation by type and chemical characteristics
of wastes is usually practiced to prevent undesirable reactions
within the fill. A number of dangerous problems can develop from
mixing. For example, acid wastes combined with cyanide-containing
wastes produce extremely toxic hydrogen cyanide gas. Segregation
prior to disposal may allow the acquisition of sufficient quantities
of particular waste types to realize economies of scale in design
of treatment facilities for detoxification or recovery. Also, it
may be possible to use acidic wastes to neutralize high pH wastes,
or perhaps to use waste sulfides to precipitate toxic heavy metals.
Detoxification. Detoxification prior to landfill disposal can often
be accomplished by thermal, chemical, or biological processes. Included
in^this category are such techniques as ion exchange, neutralization,
oxidation-reduction, pyrolysis, incineration, activated sludge, aerated
lagoons, waste stabilization ponds, and trickling filters.2
Degradation. Some chemical degradation methods being developed and/or
utilized primarily for pesticides include hydrolysis, dechlorination,
photolysis, and oxidation.26 No single chemical procedure for degrading
the entire spectrum of hazardous materials is effective. Hyrdolysis is
the best method for destroying organophosphorous and carbamate pesticides.
Chemical dechlorination can be used to degrade polychlorinated pesticides.
Photolysis may be applied to partially degrade 2,4-D and 2,4,5-T. The
use of strong oxidants offers still another approach to destroying
ssrae^pesticides and herbicides. However, the water insolubility of many
of the compounds, particularly the chlorinated pesticides, makes the
20
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use of strong oxidants in aqueous solution impractical. The above
methods are usually more expensive than alternative pesticide
disposal methods (e.g., incineration, biodegradation, etc.), and
for the most part have not been demonstrated on a full-scale basis.
Economically, biological degradation of pesticides by
soil incorporation may be a useful disposal method. Soil
degradation requires that the soil micro-organisms not be
inhibited, and be capable of metabolizing the waste com-
ponents.27 Also, the site must have minimum potential for
pollution of groundwaters or via dust dispersal.
Encapsulation. Those wastes which are not amenable to
detoxification may be encapsulated in some permanent material
prior to disposal. Available materials include concrete,
molten asphalt, and plastics (polyurethane, polyethylene).
Leachable heavy metal wastes are examples of wastes which may
require encapsulation prior to land disposal28 In some cases,
the resulting encapsulated wastes will require casting in drums
prior to deposition in the landfill. The purpose of encapsulation
is to limit the Teachability of the potentially toxic materials
contained therein by physically keeping water from contacting the
hazardous materials or their containers.
A recent OSWMP study28 provides some cost data regarding
encapsulation of heavy metal sludges (20 percent solids by
weight). For asphalt or polyethlene scrap encapsulation, it
is assumed that still bottoms or other tar residues might be
used at an average cost of one cent per pound. Off-standard
polymers are available at the same price. It is further
assumed that wastes are cast into used steel 55-gallon drums
costing about $2 each. The study estimates the fixed capital
expenditures for asphalt encapsulation of 115 cubic feet per
day of chrome waste sludge at $21,000. The corresponding
operating costs are $0.65/cubic foot of sludge encapsulated,
and an additional $0.12/ft3 of sludge landfilled.
In another process, dilute metal sulfide or hydroxide can
be used as added water in mixing concrete, thus incorporating
the wastes into the poured concrete. A portable cement mixer
can be used to mix the cement and the water containing the
insolubilized metal. The cement mixture is then cast into
fiber drums, or used steel drums. It is estimated that cement
encapsulation and burial on-site of volatile sludges cost about
$.ID/gallon of sludge. According to this report, cement is
preferred over molten asphalt or plastics for metal sulfides or
hydroxides since volatile heavy metal sludges may have high
vapor pressures at the temperature of the molten asphalt or
21
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plastic polymers.
The Lindenmaier-Precision Company of West Germany has
developed a unique encapsulation technique in which the
waste sludge is placed in 55-gallon drums. An inch
thick layer of polyurethane foam material is then sprayed
completely over the drum's exterior, so that air and water can
no longer reach this surface.22 If the inside of the drum
is not resistant to the sludge deposited therein, an inside
liner of plastic or some other suitable material might be
necessary. The polyurethane foam prevents rusting of the
steel, thus eliminating deterioration of the capsule and
ultimate release of the contents. Long-term testing of this
approach is continuing under actual landfill conditions.
Encapsulating a 55-gallon drum in polyurethane foam costs
about $4 in Germany.
5. Alternatives to Chemical Waste Landfill Disposal
When considering any waste for disposal, the potential
for resource recovery or reuse of hazardous constituents
within the particular waste should be examined first. Where
recovery or reuse is not technically possible or economically
practical, and where land disposal does not appear environ-
mentally acceptable, then other alternatives might be considered.
Alternative techniques which have been practiced in the past
include incineration, deep well injection, detonation, ocean
disposal, and engineered storage. Several of these options
have been, or will be, greatly curtailed as a result of recent
environmental protection regulations.
The advantages of incineration as a means of detoxifying
wastes and reducing volumes for land disposal were discussed
in Section 4. However, a large proportion of the hazardous
wastes can be destroyed in the sense that no solid residue
remains for land disposal. Through use of the correct com-
binations of excess air, temperature, and dwell time, these
organics are completely converted to gaseous products. Thus
incineration is sometimes considered to be a "disposal"
technique. Incineration can also create air and water pollu-
tion problems which require emission control facilities. Also,
inorganic and heavy metal containing wastes generate residues
which may also be hazardous and, in any event, will require
disposal.
Deep well injection of liquid and semi-liquid hazardous
wastes can pollute groundwaters unless great care is taken
in site selection, construction, and operation of these wells.
The EPA subsurface waste management policy opposes deep well
injection unless all other surface disposal alternatives have
been found to be less satisfactory.30 Proof of environmental
adequacy is a responsibility of the disposer. The difficulty
in defining adequacy of well disposal lies in the fact that
22
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Considerable quantities may be deposited and a number of years may
elapse before problems (possibly very serious) develop.
The recent ocean dumping legislation mentioned in Section 2
was enacted to control the use of the ocean as a waste disposal
sink. At present, persons wishing to discharge to the ocean must
obtain permits from EPA (or the Army Corps of Engineers in the
case of dredge spoils). It is EPA's intention that ocean dumping
be strictly regulated where discharge might adversely affect human
health, welfare, or amenities, or the marine environment, ecological
systems, or economic potentialities.31
Detonation of hazardous wastes (explosives, munitions, etc.)
results in air pollution problems and should not be carried out
unless a severe explosion hazard is presented and no other means
of deactivation can be found. Underground detonation of hazardous
wastes is not generally practiced due to the absence of sufficient
oxygen for combustion purposes.
In those few instances where a hazardous waste cannot be
treated or disposed of adequately, the best alternative is
engineered storage until adequate methods are developed.
However, only a very small percentage of the total quantity
of hazardous wastes generated in this country should require
permanent storage. An engineered storage facility must provide
for safe storage of hazardous wastes for long periods of time,
and retrievability of the wastes at any time during this storage.
Solidification of wastes prior to storage may be desirable to
eliminate leakage. The storage facility should be routinely
monitored and deteriorating drums or other containers replaced
as required. Ultimately, the goal is to reclaim these wastes
or transform them so they are acceptable in a permanent disposal
facility.
6. Research, Development, and Demonstration
It is obvious that there are many things not known, or known
imperfectly, and thus, there are many technical questions which
need to be answered if hazardous wastes are to be properly controlled
in a secured landfill. More work is required to fully answer such
questions as:
(a) Which hazardous materials can be satisfactorily
landfilled?
(b) How must a hazardous waste material be prepared
before deposition in a landfill?
(c) How must the landfill site be prepared before
deposition of the hazardous waste material?
23
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(d) What monitoring requirements are necessary for
effective landfill site operation?
(e) How might a landfill site be prepared for re-use
at a future date?
(f) What are the requirements for long-term surveillance
of such sites?
EPA, in cooperation with other governmental agencies and the
private sector, is endeavoring to find answers.
The primary EPA program responsibility for land disposal of
hazardous wastes resides in the Office of Solid Waste Management
Programs (OSWMP). OSWMP has initiated a contract assessment of
available physical, chemical, and biological treatment technology
for potential application to detoxifying or recycling of hazardous
wastes. Another significant contract is evaluating incineration as
a means of destroying hazardous wastes. A series of test burns will
be conducted in full-scale commercially available incinerators
utilizing real world wastes. Other work is planned in the area of
damage monitoring in existing dump sites which have a history of
receiving hazardous wastes.
A rather major effort being conducted by OSWMP involves the
development of a full-scale model hazardous waste land disposal
demonstration project. Appropriate waste and site preparation
procedures necessary to dispose of selected hazardous wastes will
be included. Site selection, management, and operating procedures
and problems will also be highlighted.
The Solid and Hazardous Waste Research Division of the Municipal
Environmental Research Laboratory (Office of Research and Development),
in support of OSWMP is conducting some much needed research in the
following areas:
(a) Deep Well/Salt Mine Disposal Studies - A review is being
made of the existing information on disposal and/or storage
of hazardous wastes in deep wells, salt mines and hard rock
mines. An assessment of the environmental adequacy of these
techniques for different wastes is also being made.32 These
reports will draw together the known current information and
present best current opinions by experts on design criteria
and potential problems associated with subsurface disposal.
Research, development and demonstration needs will be
highlighted.
(b) Hexachlgrobenzene (HCB) Research - Due primarily to the
national concern which grew out of the aforementioned
Louisiana HCB problem, SHWRD has initiated a research program
addressing the Teachability of HCB when landfilled,
the effect of acids (generated by mixed municipal refuse)
24
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on HCB solubility, the sublimation of exposed HCB wastes
at various conditions of temperature, humidity and moisture,
the effect of various soil types and cover depths on HCB
sublimation, and the effect of covering HCB-bearing wastes
with plastic sheeting to prevent sublimation.
(c) Soil Transport Studies - There remains much to learn
about the movement of hazardous wastes in the land environment.
Laboratory-scale (soil column) investigations of transport
mechanisms of specific hazardous wastes have been undertaken
by SHWRD. This work is designed to prove that potentially
dangerous leachates (or air emissions) can and do result from
conventional sanitary landfilling of individual hazardous
wastes. The resulting reports will include characteristics
of the wastes and soils used, other pertinent experimental
conditions, the data obtained including transmissions rates
and attenuation coefficients, and analysis of the potential
environmental impact in the real world. The latter will
include an analysis of the potential transportation rate through
various soils under given rainfall conditions.
A second study area will document on-site research
into the transport mechanisms associated with actual instances
of environmental degradation, or health hazard associated
with hazardous waste disposal. The final report shall contain
a summary and analysis of this in-depth investigation, and
establish the connection and the pathway between the source
and the effect.
(d) Chemical Stabilization/Fixation - As stated earlier,
several companies have developed and are providing chemical
fixation services. An evaluation of this technique is necessary
to substantiate environmental claims made for the processes.
SHWRD is conducting research to evaluate different approaches
to the stabilization of hazardous wastes prior to ultimate
disposal. One project will examine the fixation and solidifi-
cation of waste sludges via the various commercial techniques
now available. This approach is felt to be attractive for
waste materials containing significant quantities of water,
since the wastes can be agglomerated and solidified without
the need for separating the bulk of the water from the solids.
Other research involves the utilization of organic cements
and coatings to obtain stabilized agglomerates having a waste
solids content of greater than 90 percent. This latter technique
is applied to heavy metal wastes which are essentially dry,
and for which more effective stabilization may be achieved
at a much higher waste loading.
25
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In addition to the above EPA programs related to land
disposal of hazardous wastes, other Federal agencies have
pertinent programs. The Energy Research and Development
Agency (ERDA) has authority over and conducts programs in
all aspects of radioactive waste management, while the
Department of Defense (DOD) is conducting a waste manage-
ment program primarily devoted to items such as chemical
and biological warfare agents, explosive/ordnance materials,
and pesticides.
26
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REFERENCES
1. TRW Systems Group. Recommended methods of reduction,
neutralization, recovery, or disposal of hazardous
waste, v.l. Summary Report. U. S. Environmental
Protection Agency. 204 p. (Distributed by National
Technical Information Service, Springfield, Va. as
PB 224580.)
2. Office of Solid Waste Management Programs. Report
to Congress; disposal of hazardous wastes. Environmental
Protection Publication SW-115. Washington, U. S.
Government Printing Office, 1974. 110 p.
3. U. S. Congress. Clean Air Amendments of 1970. Public
Law 91-604, H.R. 17255, 91st Congress, Dec. 31, 1970
Washington, U. S. Government Printing Office. 32 p.
[U. S. Code, Title 42, sec. 1857 et seq.]
4. U. S. Congress. Federal Water Pollution Control Act
as ammended. Public Law 92-500, 92nd Congress,
S. 2770. Washington, D.C., October 18, 1972. 89 p.
[U. S. Code, Title 33, sec. 1251 et sec.]
5. U. S. Congress. Marine Protection, Research, and
Sanctuaries Act, as amended. Title I—Ocean dumping.
Sec. 101. Public Law 92-532, 92nd Congress, H.R. 9727.
Washington, D.C., October 23, 1972. 12 p.
[U. S. Code, Title 33, sec. 1401 et seq.J
6. U. S. Congress. Atomic Energy Act of 1954. Public Law
703, 83rd Congress, H.R. 9757. Washington, D.C.,
August 30, 1954. 41 p.
7. U. S. Congress. Federal Insecticide, Fungicide, and
Rodenticide Act as amended (1972). Sec. 19. Disposal
and transportation. Public Law 92-516, 92nd Congress,
H.R. 10729. Washington, D.C., October 21, 1972. p. 23-24.
8. Brunner, D.R., J. Hubbard, D.J. Keller and J.F. Newton.
Closing open dumps. Environmental Protection Publication
SW-61ts. Washington, U. S. (GPO), 1972. p. 19.
9. Thermal processing and land disposal of solid waste.
Guidelines - Federal Register 39(158):28334, August 14, 1974,
27
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10. Program for the management of hazardous wastes for
Environmental Protection Agency, Office of Solid Waste
Management Programs; final report. Richland, Wash.,
Battelle Memorial Institute, July 1973. 385 p.
11. Pesticides and containers; acceptance, disposal, and
storage; proposed rulemaking and issuance of procedures.
Federal Register, 38 (99): 13622-13626, May 23, 1973.
12. Hazardous waste disposal survey—1971. Sacramento,
California State Department of Public Health, Jan. 1972.
69 p.
13. Hazardous Waste Control Act, Assembly Bill 598; draft
criteria and standards. Sacramento, California State
Department of Public Health, Feb. 11, 1974.
14. Hayes, A., Hazardous waste disposal operations.
Washington, U. S. Environmental Protection Agency,
May 15, 1974.
15. Fields, T., and A.W. Lindsey, Hazardous Waste Technology
assessment summary—hazardous waste treatment/disposal
at Chem-Trol Pollution Services, Inc. Washington, U. S.
Environmental Protection Agency, Apr. 3, 1974.
16. SI over, Edwin E. solid waste disposal in a multi-product
chemicals plant, Institute Plant - Union Carbide Corp.,
Institute, West Virginia. Presented at Symposium on
the Textile Industry and the Environment - 1973,
Washington, May 22-24, 1973. 22 p.
17. Personal communication. J.P.Lehman, Office of Solid
Waste Management Programs, to F. Green, Office of
International Affairs, Oct. 10, 1973.
18. Saint, P.K., C.P. Straub and H.O. Pfannkuch. Effect of
landfill disposal of chemical wastes on groundwater
quality. Presented at Hydrogeology Section of Annual
Meeting, Geological Society of America, Minneapolis,
Nov. 14, 1972.
19. Pond pit reseryior liners of DuPont Hypalon (synthentic
rubber). Wilmington, Del., E.I. DuPont de Nemours and
Co., Inc., Elastomer Chemicals Department.
20. Personal communications. J.P.Lehman, Office of Solid
Waste Management Programs, to the record.
'Sept. 12, 1973, and Jan. 23, 1974.
28
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21. Rhyne, C.W. Landfill gas. Washington, U. S.
Environmental Protection Agency, Apr. 4, 1974. 20 p.
22. Personal communication. W. Lindenmaier, Lindenmaier -
Precision Company, West Germany, to J.P. Lehman,
Office of Solid Waste Management Programs, Oct. 25, 1973.
23. Hayes, A. J. OSWMP files on Lousisiana hexachlorobenzene
episode. Unpublished data.
24. Eldredge, R.W., Minimizing Leachate at Landfills.
American Public Works Association Reporter,
vol. (no.): 22-23, Jan. 1974.
25. Fields, T., and A.W. Lindsey, Hazardous Waste Technology
assessment summary—chemical fixation of industrial wastes
at Chemfix, Division of Environmental Sciences, Office of
Solid Waste Management Programs, U. S. Environmental
Protection Agency, Washington, D.C., Apr. 3, 1974.
26. Dennis, W.H. Methods of chemical degradation of pesti-
cides and herbicides - a review. Edgewood Arsenal, U. S.
Army Medical Environmental Engineering Research Unit,
Oct. 1972. 30 p.
27. Goulding, R.L. Waste pesticide management. Washington,
U. S. Environmental Protection Agency, Aug. 1973. 81 p.
28. Funkhouser, J.F., Alternatives to the management of hazardous
wastes at national disposal sites. Washington, U.S.
Environmental Protection Agency, May 1973. 85 p.
29. Scurlock, A.C., A.W. Lindsey, T. Fields, Jr., D.R. Huber.
Incineration in Hazardous Waste Management. Washington,
U.S. Environmental Protection Agency, Feb. 1975. 104 p.
30. U.S. Environmental Protection Agency - Administrators'
decision statement No. 5 on EPA policy on subsurface
emplacement of fluids by well injection.
31. Ocean dumping, final regulations and criteria. Federal
Register 38(198):28618. October 15, 1971.
32. Personal Communications. C.C. Wiles, Solid and Hazardous
Waste Research Laboratory, to A.W. Lindsey, and T. Fields,
Office of Solid Waste Management Programs. Procurement
requests for deep well and salt mine disposal work,
Feb. 6 and 27, 1974.
29
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APPENDIX
Landfill Disposal of Specific Materials
The attached Table 1 presents hazardous waste stream constituents
for which landfill disposal is considered an acceptable waste disposal
alternative. A brief summary of each applicable landfill disposal
process is found in Table 2, including design and operating parameters
where known. These processes are coded alphabetically in Table 1.
Other equally acceptable or preferable treatment/disposal techniques
are mentioned. By examining the disposal methods in Table 2, it is
obvious that a great deal of additional detailed information on
suitable operating parameters is needed. Some of the programs planned
to help fill these knowledge gaps were presented in Section 6.
The material in these tables conies primarily from the TRW Systems,
Inc. report entitled, Recommended Methods of Reduction, Neutralization,
Recovery or Disposal of Hazardous Waste, which was performed as an
adjunct study relative to the requirements of Section 212 of the Solid
Waste Disposal Act of 1965, as amended. Additional material from OSWMP
files was added where appropriate. Reference to these tables will
provide the user with an indication of whether a material in question
is landfill able and in many cases, some of the operating parameters
and procedures required. These tables should be used in making
preliminary investigations to indicate the overall practicality of the
landfill approach to specific hazardous waste problems. In many cases,
more detailed information can be obtained by referring to the TRW
report or to the Hazardous Waste Management Division of OSWMP.
Although OSWMP is of the opinion that land disposal is acceptable
for the named wastes, this table should not be construed as unqualified
OSWMP endorsement, since detailed studies have not been performed with
OSWMP monitoring to confirm the information. Specific criteria should
be viewed as examples of criteria known to have been used with reported
success and not hard and fast rules for universal land disposal of all
materials containing the subject substance. In the end, any decision
regarding the environmental adequacy and safety aspects of land disposal
of a given waste material must depend on an overall analysis of the
individual situation.
30
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Because of the threat to public health and the potential
for environmental damage, land disposal of hazardous waste
materials must not be entered into lightly. Reference is made
to the list of considerations in Section 4 which should be
addressed in analyzing any hazardous waste landfill proposal.
It is OSWMP's plan to update these tables on a periodic
basis as more information is gathered. In this regard, users
of this information can be of assistance by notifying OSWMP of
new information regarding landfill test results for various
substances or waste materials.
31
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Table 1-1
LAND DISPOSAL OF SPECIFIC MATERIALS
Hazardous Material Recommended Disposal Method
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
28.
29.
30.
31.
32.
33.
34.
35.
36.
37.
38.
39.
Aluminum Fluoride
Aluminum Oxide
Ammonium Bifluoride
Ammonium Fluoride
Ammonium Perchlorate
Ammonium Persulfate
Antimony Pentaf luoride
Antimony Pentasulfide
Antimony Sulfate
Antimony Trifluoride
Antimony Trisulfide
Barium Fluoride
Barium Nitrate
Barium Sulfide
Benzene Sulfonic Acid
Beryllium Carbonate
Beryllium Chloride
Beryllium Oxide
Beryllium (powder)
Beryllium Selenate
Boron Trifuluoride
Cacodylic Acid
Cadmium Fluoride
Calcium Arsenate
Calcium Arsenite
Calcium Fluoride
Calcium Hypochlorite
Calcium Phosphate
Chromic Acid (Liquids,
Chromium Trioxide)
Chromic Fluoride
Chromic Sulfate
Cobalt Chloride
Copper Acetoarsenite
Copper Acetylide
Copper Arsenate
Copper Nitrate
Copper Sulfate
Diphenylamine
(Phenylaniline)
Hypochlorite (Sodium)
A
B
C
C
D
D
E
A
A
E
A
F
G
G
H
I
I
I
I
I
J
K
F
L
L
B
D
B
M
N
N
G
L
X
L
O
0
P
D
32
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Hazardous Material Recommended Disposal Method
40.
41.
42.
43.
44.
45.
46.
47.
48.
49.
50.
51.
52.
53.
54.
55.
56.
57.
58.
59.
60.
61.
62.
63.
64.
65.
66.
67.
68.
69.
70.
71.
72.
73.
74.
75.
76.
77.
78.
79.
Lead
Lead Arsenate
Lead Arsenite
Lead Oxide
Magnesium Arsenite
Magnesium Chlorate
Magnesium Oxide
Manganese
Manganese Arsenate
Manganese Chloride
Manganese Sulfate
Metallic Mixture of
Powdered Magnesium
and Aluminum
Nickel Antimonide
Nickel Arsenide
Nickel Selenide
Nitrochlorobenzene (dilute)
Potassium Arsenite
Potassium Bifluoride
Potassium Binoxalate
Potassium Fluoride
Potassium Oxalate
Potassium Permanganate
Selenium (powdered)
Silica
Sodium Arsenate
Sodium Arsenite
Sodium Bifluoride
Sodium Cacodylate
Sodium Carbonate Peroxide
Sodium Fluoride
Sodium Oxide
Sulfur
Tantalum
Thallium (dilute)
Thallium Sulfate (dilute)
Vanadium Pentoxide
Zinc Arsenate
Zinc Arsenite
Zinc Chlorate
Zinc Oxide
Q
L
L
R
L
D
B
B
L
S
S
B
T
T
T
A
L
C
U
C
U
V
A
B
L
L
C
K
D
C
W
B
B
A
A
B
L
L
D
B
33
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Table 2
Disposal Methods
A. Disposal in a chemical waste landfill.
B. Disposal in a sanitary landfill. Mixing of industrial
process wastes and municipal wastes at such sites is
not encouraged however.
C. Reaction of aqueous waste with an excess of lime,
followed by lagooning, and either recovery or land
disposal of the separated calcium fluoride.
D. Dissolve the material in water and add a large volume
of concentrated reducing agent solution, and then acidify
with H2 SO^. When reduction is complete, soda ash is added
to make the solution alkaline. Ammonia will be liberated
and will require recovery. The alkaline liquid is decanted
•from any sludge formed, neutralized, diluted, and discharged.
The sludge is landfilled.
E. The compound is dissolved in dilute HC1 and saturated with
H2S. The precipitate (antimony sulfide) is filtered, washed,
and dried. The filtrate is air stripped of dissolved H2S and
passed into an incineration device equipped with a lime
scrubber. The stripped filtrate is reacted with excess lime,
the precipitate (CaF - CaCl mixture) is disposed of by land
burial.
F. Precipitation with soda ash or slaked lime. The resulting
sludge should be sent to a chemical waste landfill.
G. Chemical reaction with water, caustic soda, and slaked lime,
resulting in precipitation of the metal sludge, which may
be landfilled.
H. Biological or chemical degradation of dilute streams using
conventional waste water techniques; treatment with lime
to precipitate out calcium benzene sulfonate which can be
disposed in a chemical waste landfill.
I. Wastes should be converted into chemically inert oxides using
incineration and particulate collection techniques. These
oxides may be landfilled.
J. Chemical reaction with water to form boric acid, and fluorboric
acid. The fluorboric acid is reacted with limestone forming
boric acid and calcium fluoride. The boric acid may be discharged
into a sanitary sewer system while the calcium fluoride may be
recovered or landfilled.
34
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K. Long-term storage in concrete vaults or weatherproof
bins; small amounts may be disposed in a chemical waste
landfill.
L. Long-term storage in large, weatherproof, and sift-proof
storage bins or silos; small amounts may be disposed in
a chemical waste landfill.
M. Chemical reduction of concentrated materials to
chromium-Ill and precipitation by pH adjustment.
Precipitates are normally disposed in a chemical waste
landfill.
N. Alkaline precipitation of the heavy metal gel followed
by effluent neutralization and discharge into a sanitary
sewer system. The heavy metal may be disposed in a
chemical waste landfill.
0. Copper wastes can be concentrated through the use of
ion exchange, reverse osmosis, or evaporators to the point
where copper can be electrolytically removed and sent to
a reclaiming firm. If recovery is not feasible, the
copper can be precipitated through the use of caustics
and the sludges deposited in a chemical waste landfill.
P. Wastes may be incinerated, or disposed in a chemical
waste landfill.
Q. Recycle using blast furnaces designed for primary lead
processing to convert waste into lead ingots. Small
quantities may be disposed in a chemical waste landfill.
R. Chemical conversion to the sulfide or carbonate
followed by collection of the precipitate and lead
recovery via smelting operations. Landfill ing of the
oxide is also an acceptable procedure.
S. Chemical conversion to the oxide followed by landfilling,
or conversion to the sulfate for use in fertilizer.
T. Encapsulation followed by disposal in a chemical waste
landfill.
U. Ignite to convert it to a carbonate. The carbonates
(non-toxic) may be sent to a landfill.
V. Chemical reduction in a basic media, resulting in
manganese dioxide formation. The material
may be collected and placed in a landfill.
35
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W. Chemical neutralization followed by solids separation
with deposit of solids into a chemical waste landfill.
X. Detonation (on an interim basis until a fully satis-
factory technique is developed); the copper salts
liberated may be disposed of in a chemical waste landfill
36
i U. b GOVf R!N MENT PRINTING OFHC L 1975 632-192/1036
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