SANITARY
LANDFILL
one part earth
to four parts
refuse
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SANITARY LANDFILL
one part earth to four parts refuse
This narrative (SW-6) has been prepared
by Lester A. Haug and Ralph J. Black
to describe the film made by
the Los Angeles County Sanitation Districts
for the Federal solid waste management program
under contract No. PH-OS-DQ-66.
U.S. ENVIRONMENTAL PROTECTION AGENCY
1972
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Many viewers of the film by this title have
asked for a copy of the film narrative,
since there is so much content to be
remembered. The narrative has been
prepared with line diagrams and minor
revisions to improve its value in the
written format.
A limited number of prints of the film are
available on loan from the National
Medical Audiovisual Center (Annex),
Section K, Atlanta, Ga. 30324. Prints of the
film are available for purchase from
Capital Film Laboratories, Inc., 470 E
Street SW., Washington, D.C. 20024, at
a cost of $97.04 FOB Washington.
An environmental protection publication
in the Solid Waste Management Series
(SW-6).
This publication is also in the Public
Health Service numbered series as Public
Health Service Publication No. 2003.
Its entry in two government publication
series is the result of a publishing interface
reflecting the transfer of the Federal solid
waste management program from the
U.S. Public Health Service to the
U.S. Environmental Protection Agency,
•frll.S. GOVERNMENT PRINTING OFFICE: 1972 O 3B1-36O
For sale by the Superintendent of Documents,
U.S. Government Printing Office,
Washington, D.C. 20402 • Price 30 cents
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SANITARY LANDFILL
one part earth to
four parts refuse
SOLID WASTE DISPOSAL is primarily
an urban problem, increasing in
magnitude as the population grows in size
and affluence. Virtually everything used
by man will, in time, be discarded.
A large part of it finds its way into storage
receptacles, which receive worn-out
clothes, broken household appliances,
forgotten toys, yesterday's newspapers
.... The collection truck then carries these
discarded materials to the sanitary landfill
for burial. Eventually, even our homes
and stores are discarded!
Almost everything man uses, he eventually
discards. In the past, when land was plentiful, solid
waste disposal posed fewer problems. But
urbanization is reducing the land available for
disposal; at the same time, a population growing in
both size and affluence is generating increasing
quantities of solid wastes. The result: communities
across the country, large and small alike, are hard
pressed to dispose of their solid wastes economically,
and without blighting the environment or
endangering public health.
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Industrial,
commercial,
and
agricultural
Construction
and
demolition
The Los Angeles area's production of solid wastes—
7Vz pounds per person per day—is about equally
divided among the three major classifications of solid
wastes. The production of tionhousehold wastes can
vary widely from community to community.
Industry produces mountains of mer-
chandise, all to be used and eventually
disposed of once it has served its purpose.
No two communities have exactly the
same per capita solid waste generation.
Recent studies indicated that the Los
Angeles area was producing about 7Vfe Ib
solid wastes per person per day. House-
hold refuse accounted for about 2l/2 Ib of
this. An additional 21/2 Ib was contributed
by industrial-commercial-agricultural
activities, and a like amount, mostly inert
material, came from construction and
demolition work. In small or rural
communities, the quantity of industrial,
agricultural, construction, and demolition
wastes may vary greatly according to the
type of activities in the community.
Some communities use incinerators as a
means of partial disposal and volume
reduction. Some have tried, or are trying,
composting. These methods, however, do
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not reduce inert wastes and must be
accompanied by landfilling for disposal of
their own plant residue. Land disposal of
solid waste is practiced by every urban
community for part, if not all, of its waste.
Site Selection
Successful landfill operations don't "just
happen." They result from the application
of sound engineering and economic prin-
ciples governing the disposal of refuse on
land without nuisance or hazard to public
health. Planning begins with the selection
of a site. Land in the heart of a city is
usually too costly to be used for disposal
so that selection of more remote sites
generally must be made.
The expense of hauling refuse from the
collection area to the landfill is an impor-
tant cost factor in determining the relative
merit of one prospective site over another.
Travel time on surface streets, open roads,
or freeways, and turnpikes is affected
The first step in planning a sanitary landfill is to
select a suitable site, The site will generally be in a
remote area,' to keep land acquisition cost low.
But a landfill can still be a good neighbor, if it is
properly engineered and operated. Expensive houses
weie intentionally built overlooking the Mission
Canyon landfill west of downtown Los Angeles
(aLove), in anticipation of the park and golf course
that will be built when the fill is completed.
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by road grades, traffic, and weather
conditions. Time—travel studies are made
by actually driving the loaded refuse
vehicle from the collection area to
each proposed site.
With urban land so valuable for other
uses, shallow refuse fills spreading over
large areas are not economical. Some sites
in the Los Angeles area that are being
filled to depths in excess of 400 ft justify
use of relatively high-cost land.
The availability of utilities is included in
any site value determination. Water for
fire protection and dust control is partic-
ularly important. The cost of bringing in
electrical power and telephone service
must be considered. Restrooms should be
provided for employees and customers.
Public acceptance of the access road is
another important consideration in
choosing a site. In Glendale, California, the
residents did not want large refuse trucks
traveling their streets to the landfill each
day. It was necessary to construct a road
to bypass the residential area and to-
provide access from a major commercial
boulevard. In this case, the landfill is very
large, so that the cost of the access road
can be amortized over many tons of refuse.
As has been demonstrated in the Los
Angeles area, refuse landfills can be
operated near homes, provided a very
careful housekeeping job is accomplished.
At the request of owners of surrounding
homes, Rockbluff Canyon was sanitary
landfilled to create suitable land for
horse stables, riding and other
recreational purposes.
Homes at Mission Canyon were inten-
tionally built overlooking a large sanitary
landfill because the owners knew that a
park and golf course would be constructed
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on the completed fill. This is evidence that
the public will accept a landfill in their
backyard, if the operation is attractive
and free of nuisances.
Landfilling Method
Sanitary landfills can be located on
various types of terrain—for example, in
a valley, canyon, and pits, on level or
sloping ground.
A sanitary landfill requires about one part
earth for daily cover to four parts refuse.
Additional soil is needed for final cover.
When all of the earth cover is to be
acquired from within the site, the amount
of earth available determines the amount
of refuse that can be placed within the site.
Moreover, it is necessary to know not
only the amount of refuse being produced,
but also the density that will be achieved
in the fill. Refuse carefully compacted
in place with crawler tractors weighs
approximately 1,250 Ib per cu yd.
The maximum side slope cut possible in a
valley or canyon is determined and the
total volume of available earth calculated.
After deducting the earth for final cover,
the remaining earth volume multiplied by
4 gives the approximate volume of refuse
that can be placed within the site without
importing additional cover material.
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FINAL ELEVATION
A
CUT
B
FILL
FILL
CUT
FINAL COVER
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CUT
GROUND WATER
In a typical sanitary landfill, the maximum cut is
made on the side slope. As the solid wastes are
deposited, they are covered with the earth taken from
the cut. This is continued until the site is filled.
The entire area is then covered with a clean layer of
earth. The final elevation depends on the planned
use for the site.
For example, when a site is cut to a depth
of 25 ft, 3 ft of this is reserved for final
cover, leaving 22 ft of material to be used
in the fill. With the use of the ratio of
one part earth to four parts refuse, the
surface of the completed fill is 88 ft above
the original ground surface.
After the volume and the resulting eleva-
tion of the fill have been estimated, it may
be decided that the final elevation is not
compatible with the planned ultimate use
and some compromise will have to be
made. Property may be acquired to
provide sufficient cover material. Soil from
the lowest elevations is used early in the
fill, with soil at the higher elevations
reserved for later use.
When a site is short on cover material, soil
taken from the initial cut is stockpiled
away from the refuse disposal area to
provide cover during the last phase
of the operation.
As the refuse is placed, the initial exca-
vation is enlarged by the amount of earth
used for daily cover material.
This is continued until the site i^ filled.
The steep-wall canyon sile ":,as -j.reat
refuse capacity, but these i-jn^r,- steep
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canyon walls often indicate hard soil that
may be very expensive to use for cover
material, If the rock is loose enough to be
ripped by tractors, the site can be worked.
When it becomes difficult for the scraper
to load material, assistance from a tractor
may be necessary.
Fine soil can also be troublesome because
of dust. The soil at Palos Verdes,
California, is diatomaceous earth and care
must be exercised to keep dust from
becoming a nuisance.
An underlying groundwater table may
limit the depth of cut. Organic and soluble
wastes are not deposited at locations
where groundwater pollution will result.
Rainfall is diverted from the site to prevent
percolaied water from becoming a con-
taminant. The advice and consent of those
governmental agencies charged with the
responsibility of protecting groundwater
supplies must be solicited.
The pit site has its special problems. When
the site includes only the pit and it has
been excavated near or below ground-
water, cover material must be imported.
If excavated below groundwater level, the
Rainfall must be diverted from a sanitary landfill
site to prevent wajer from percolating through the
refuse and contaminating the groundwater.
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"•'.•'•'•'•'•"•I GROUND WATER l7':V
INERT SOLIDS
O
•"-:':• • •V// // / /////z/..-;.:-'.- • •- -
/////// /VV / //.••.•.'• • •;
A pit site poses special problems if it has been
excavated below ground-water level. It must first be
filled with inert solids to a safe level above the
groundwater before refuse can be deposited.
pit must be filled with inert solids to a
safe elevation above the groundwater
before refuse can be placed in it.
Scales are used to weigh refuse vehicles
in and out of the disposal site. Accurate
weights are the basis for charges levied
for disposal and also provide a method of
production control and density determi-
nation. The traffic pattern must allow room
for slow-moving or halted vehicles to be
off public thoroughfares.
Many of the roads inside the disposal site
may be temporary in nature, but they must
be well maintained. Nonetheless, some
paving is necessary for operating during
wet weather. Roads must be kept clear of
snow and ice so the heavily laden trucks
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•
All entering vehicles at the sanitary landfill—the
municipal collection truck or the householder's vehicle
with trash and yard debris—must be weighed as
they enter and leave. Disposal charges are based on
weights. Weight information is also important in
determining in-place densities.
Many roads inside the disposal site have short
lives, since they will be abandoned as the areas are
filled in. The roads must nevertheless be properly
maintained. Snow and ice must be cleared away.
To prevent heavily loaded trucks from slowing
traffic- -or even stalling—-on roads in the site, steep
grades must be avoided.
• ^f- •
'•
' •
•
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will have traction. Grades in excess of
7 percent are difficult for loaded trucks.
Roads on refuse fill are satisfactory, but,
where possible, permanent roads of com-
pacted earth should be constructed to
reduce maintenance cost. Bricks or broken
concrete are often used in roadbeds or
other places where a firm subgrade is
desired. Sometimes these roads can be
used both during the fill operation and
later as an access road to the. recreational
area or for whatever other ultimate use is
planned for the completed fill,
Once at the disposal area, the large trucks
need ample room to maneuver. Graders
are used to dress up and level the truck
unloading area. Leveling ensures stability
for the trucks with high centers of gravity.
Trucks utilize many unloading techniques.
Some use a yoke and cable placed in the
trucks before it is loaded. The refuse is
pulled from the truck by a tractor hooked
to the pull-off cable. Many trucks,
however, must be unloaded by hand.
Separating self-unloading vehicles from
the slower hand unloaders increases
efficiency and safety and eases traffic
congestion at a busy working face. Small
areas of exposed refuse minimize wind-
blown papers, and the more confined
quarters also discourage wandering
seagulls from loitering.
Keeping the unloading area confined
reduces the travel distance of the crawler
tractors, thereby increasing efficiency.
Generally, loads are discharged at the
bottom of a slope and the refuse is pushed
and spread in layers with an inclination,
approximately 4-it horizontal to I-it
vertical, prior to compaction. At the sites
operated by the Los Angeles County
Sanitation Districts, no special compacting
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The crawler tractor equipped with a bulldozer
blade is the mainstay of sanitary landfill equipment.
Los Angeles uses them for compacting, having
found that special compacting equipment does not
appreciably increase the in-place density
of solid wastes.
equipment is used; the weight of the tractor
is sufficient to compact the refuse.
Other types of equipment are available
for pushing, spreading, and compacting
solid wastes. However, in-place density of
refuse, especially in deep fills, is not
appreciably increased by the use of
wheeled equipment in lieu of
crawler equipment.
Water is necessary for dust control,
standby fire protection, and, on windy
days, to help prevent papers from blowing.
Water may not be warranted as an aid
to compaction because volume reduction
generally does not justify the cost and
the additional water also increases the
production rate of methane gas, a
hazardous byproduct of decomposition.
Many different types of material are
disposed of in a typical sanitary landfill.
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Waste paper represents a larger portion
of today's refuse than in years past.
Large numbers of rubber tires are
discarded, collected and dumped at the
fill, sometimes to roll down the slopes
to some obscure corner of the site, adding
to housekeeping chores. Items such as
telephone poles can be landfilled, but they
require special attention. In some areas,
building demolition wastes amount to as
much as a third of the total tons handled.
Loads of clean dirt are used to advantage
for cover.
Daily covering of refuse is a major part
of the operation of a sanitary landfill.
At the Mission Canyon site, to take one
example, the gate closes to incoming
refuse trucks at 5:00 p.m. Scrapers have
been working stockpiling earth and
covering refuse. Starting to unload at the
top of the ramp, they come down the
refuse slope, spreading the cover
evenly over the exposed refuse. Cover
material is conserved by compacting
the refuse to a tight, uniform surface
ahead of the covering operation. Within
an hour after closing time, the cover
is complete and there is a thick layer
of clean soil over the refuse.
There is no refuse in sight at the
end of the day.
Day's end at a sanitary landfill finds no refuse in
sight, A thick topping of clean soil makes a landfill
nuisance-free. It means no rats, no odors, no fires,
no papers scattering in the wind. It means waste
disposal that protects the environment.
I
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Cover is important, because more than
any other single factor it makes a sanitary
landfill nuisance free. It keeps rodents
out and odors in. It prevents fires and
keeps papers from scattering in the wind.
Each day's refuse is sealed in an earthen
cell.
An important consideration in operation
is control of access to the site. A fence
is both a physical and psychological
barrier that helps to isolate the operation.
Planting large shrubs or trees is beneficial
for screening the site.
Equipment Needs
Although many types and sizes of
equipment find application in sanitary
landfills, the most commonly used piece of
equipment is the crawler tractor
equipment with a bulldozer blade. The
crawler tractor can also be used to haul
cover material by coupling it to a towed
scraper. At large sites, however, it is
more economical to haul cover material
in self-propelled, rubber-tired scrapers.
The basic equipment for sanitary landfill operations
handling 200 tons or more of refuse daily consists
of the crawler tractor, scraper, water wagon, and
part-time use of a motor grader. In operations
handling less than 200 tons daily, smaller crawler
equipment can be used, including all-purpose
units with combination bulldozer-clamshell buckets,
which push and compact refuse and also
carry dirt for cover.
EQUIPMENT REQUIREMENTS
UNIT
CRAWLER
TRACTOR
EARTH
SCRAPER
WATER
WAGON
MOTOR
GRADER
TONS PER DAY
200
1
1
1
1
500
2
1
1
1
1000
3
1
1
1
4000
10
3
2
1
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If the daily business rate is less than
200 tons per day, smaller crawler
equipment can be used, including
all-purpose units with combination
bulldozer-clamshell buckets, which push
and compact refuse as well as carry
dirt for cover, A front loader cannot do
the work of a larger crawler tractor, but,
in a small operation, it can be used to
maintain cleanliness between visits of a
large crawler.
The basic equipment for operations larger
than 200 tons of refuse per day is the
crawler tractor, scraper, water wagon, and
part-time use of the motor grader.
As the daily business rate increases,
the equipment requirements will climb
approximately as shown in the table. The
numbers for the larger operations include
standby units. The crawler tractor is a
machine weighing close to 50,000 Ib and is
equipped with an engine of 200 or more
horsepower. The scraper is a self-propelled
unit of 14-yd capacity. A twin-engine unit
will, in many cases, eliminate the
necessity of having an additional tractor to
push-load the scrapers. The water wagon
is built to haul and power spray between
1,500 and 4,000 gal of water per load,
depending on the length of unpaved road
and type of soil. (All-wheel drive is
particularly desirable.) Larger operations
use scrapers with capacities in excess
of 20 cu yd and off-highway type
water wagons with tank capacities of
6,000 gal. or more.
Personnel Needs
Landfill operating personnel requirements
also vary with the daily rate of disposal.
The listing in the table shown below, from
the records of the Los Angeles County
Sanitation Districts, applies to a sanitary
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PERSONNEL REQUIREMENTS
CLASSIFICATION
EQUIPMENT
OPERATORS
LABORERS
WEIGH
MASTERS
FOREMEN
TONS PER DAY
200
1
0
1
0
500
2
0
1
0
1000
4
1
1
1
4000
12
3
2
1
The personnel required by a landfill depends not
only on its size but also its operating procedures.
The Los Angeles requirements (above) apply to a
landfill open to the public with charges based on
the net weight of the refuse load. On a part-time
basis, a landfill might also need managerial,
supervisory, engineering, planning, administrative,
clerical, and legal personnel.
landfill open to the public with disposal
charges levied on the net weight of the
refuse load.
Additional staff requirements on a
part-time basis include managerial,
supervsory, engineering, planning,
administrative, clerical, and legal
personnel.
Weather Problems
Storm drains and debris settling basins
are required to prevent storm water
erosion and release of debris-laden water
to off-site drainage works. Runoff from the
upper surface is controlled by proper
surface grading and construction of
improved drain channels. Corrugated
metal pipe is excellent for interim drainage
systems because of its flexibility during
the early stages of settlement and its
potential for salvage and reuse as the
fill level is raised in successive lifts. Refuse
fills do settle, and, wherever possible,
permanent storm drains are located in
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solid ground. An easily maintained slope
is provided by limiting the finished rise
to 1 ft for every 2 ft of horizontal run.
Interrupting the slope every 40 ft of
elevation with a 12- to 15*fi-wide bench
permits diversion of surface water to
a lined channel. A ground cover of
vegetation is established on all finished
slopes for slope stabilization. Forming open
channels by the gunite process is an
effective method for some of the smaller
drains.
Special operating procedures must be
adopted in inclement weather. Asphaltic
pavement scraps are sometimes spread
in the wet season to form a mat on which
the refuse trucks drive to empty their
loads, and the landfill is kept open. An
operational technique that can be
employed in the winter season consists
of using leaves, gathered from the city
streets, to cover portions of the disposal
site to prevent ground freezing in the
winter months. Snow presents no real
problem within the landfill areas because
it is relatively simple for the tractors to
clear the onsite roads and the dumping
area. Snow is, nevertheless, a factor to
As an area is filled, vegetation is established
to stabilize slopes and prevent erosion.
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•
Collection trucks must continue to move during bad
weather- as they did in Duluth, Minn., during a snow
storm. Snow on the site itself is no great problem,
since the tractors can clear the site roads and
dumping area. But snow can be a problem to landfill
operation if nearby roads are not kept clear.
consider in choosing a site, for if it is not
near streets or highways that are normally
kept clear* it may be necessary for the
operators of the refuse site to clear roads
leading to the site.
Ultimate Site Use
As an additional benefit, a completed
sanitary landfill provides land for other
purposes. In planning for the ultimate
use of a site, one question always arises,
"How much will the fill settle?" The curve
shown represents a typical settling
rate in the sites operated by the Sanitation
Districts of Los Angeles County. An
80-ft fill settled less than 2 ft in 4 years,
and the rate of settlement is decreasing.
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Although a refuse fill will never be as
stable as a compacted earth fill, there are
many uses for a completed sanitary
landfill At Palos Verdes, a til] is being
developed as a botanical garden. The
topography was created by filling to the
specifications for planned park usage.
The low area will become an artificial
stream bed and small lake. Advance
planning allowed the lake to be located
on original ground. Alternatively, the
surface of a refuse fill has provided a
parking area for a new shopping center.
Refuse contains much organic material
that is subject to bacterial decomposition.
The "decomposition process entails the
production of heat and the generation of
carbon dioxide and methane gases and
is accompanied by a reduction in volume.
Addition of water accelerates the process,
If water is allowed to enter the fill in
sufficient quantities, it can cause high
concentrations of methane that may travel
horizontally through surrounding porous
soils. One occurrence of this nature was
remedied by constructing a rock-filled
A typical 80-ft fill in Los Angeles settles only
about 2 h in 4 years, and the settlement rate at lhat
time is decreasing. A refuse fill, although it will
never be as stable as a compacted earth fill,
can still be used for many purposes.
0
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trench through the porous soil area
to serve as a vent. Also, a reduction
in the watering program for the surface
vegetation on the completed fill minimized
the rate of gas production. Much research
is being directed to the solution of this
and many other problems in solid waste
disposal.
There are many variables affecting cost,
operation, public acceptance, and
ultimate use of a sanitary landfill. These
variables mean that each community
must carefully plan its own program. The
plan should not only provide for proper
location and operation of the refuse
disposal site, but must also consider the
most beneficial use of the completed site.
In this way, solid waste disposal by
sanitary landfilling doubly benefits
the community.
Most of the available sanitary landfill
films serve to promote sanitary landfill as
a general concept, and sometimes the
merits of a specific piece of equipment.
The film Sanitary Landfill: One Part Earth
to Four Parts Refuse, made by the Los
Angeles County Sanitation Districts under
contract with the U.S. Government,
presents specific design and operation
information. While much of the film
concerns deep filling and sanitary landfills
of 200-ton-per-day capacity or greater,
the design and operation information can,
with judgment, be applied to smaller
facilities.
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