TM 5-814-7
d. Design elements. Design requirements, as well
area or prevent contaminated water from leaving the unit
as requirements for construction, operation and
by directing it to a retention basin; and (2) run-off
maintenance, of a land treatment facility are specified in
retention and sedimentation control basins (figure 5-4).
the facility permit to ensure compliance with regulations.
In addition, tanks, surface impoundments, or waste piles
The design goal must be to maximize the degradation,
may be needed for waste storage during inclement
transformation
or
immobilization
of
hazardous
weather. For example, land treatment facilities in cold
constituents in the specified treatment zone, in
regions may require storage facilities, particularly if the
accordance with all design and operating conditions used
application season is limited to spring, summer, and fall.
in the treatment demonstration; and minimize both runoff
A water balance may be performed to aid in design of
of hazardous constituents from the treatment area and
such facilities.
Subsurface drainage systems and
inflow of water into the treatment area.
leachate control and treatment systems may also be
(1) Fulfillment of these specific design
required at some hazardous waste land treatment
requirements, as well as meeting the principal design
facilities.
e. Closure. Closure of a land treatment unit may
goal of nondegradation of the land, requires a number of
be accomplished by either establishing a permanent
steps, including analysis of the waste stream and site soil
vegetative cover capable of maintaining growth without
characteristics, evaluation of waste-soil interactions and
extensive maintenance, removing and landfilling the
site assimilative capacity, determination of application
zone of incorporation, or capping the land treatment area
rate, selection of an application method, and layout of the
to control wind and water erosion. General closure
facility and control structures.
practices called for include minimizing run-off from the
(2) 40 CFR 264.278 of RCRA requires an
treatment zone, continuing ground-water monitoring, and
unsaturated zone monitoring program for all land
continuing restrictions on food-chain crops. In addition,
treatment units to determine whether hazardous
the unsaturated zone should be monitored as part of the
constituents have migrated below the treatment zone.
closure procedures; however soil-pore liquid monitoring
Soil and soil pore liquid must be monitored on a
may be suspended 90 days after the last application of
background plot and immediately below the treatment
waste at the unit. Each of these practices is described in
zone. If any migration is detected, the owner/operator of
chapter 12 of EPA SW-874.
the land treatment unit must notify the EPA Regional
f. Equipment needs. Equipment required for a
Administration (RA) of this finding within seven days.
Within 90 days the owner/operator should recommend
land treatment operation ranges from the simple to the
modifications to the facility permit that will maximize
sophisticated, depending on the application technique
treatment of hazardous constituents within the treatment
employed. However, all are conventional and readily
zone.
available. Any equipment used for operations must be
(3) There are several possible configurations
decontaminated before taking from the treatment unit
for a land treatment facility, including single cell, rotating
(1) For surface irrigation by furrow or flood
cell and progressive cell configurations. In the single cell
techniques, piping and a pump are needed to transmit
configuration a waste is applied uniformly over the
the waste to the point of discharge. Alternatively, a truck
required acreage without subdividing the land treatment
or trailer-mounted tank may be used to apply wastes by
area. In the progressive cell configuration (figure 5-3),
gravity flow or through a sprayer or manifold. Equipment
the land treatment unit is subdivided into cells or areas
needs for sprinkler systems will vary, depending on
which are treated sequentially, cultivated and
system type, but will generally require properly sized
revegetated.
piping, pump, nozzles.
(4) Adequate buffer zones should be provided
(2) A vacuum truck with flotation tires and rear
between the land treatment unit and property boundaries
sprayer or manifold may be used for surface spreading
to minimize odor problems, permit easy access to water
of sludge. If the sludge is too thick to be pumped, a
retention facilities, and allow implementation of
conventional truck with moisture-proof bed may be used
contingency measures to control unusual runoff.
to dump the waste, which is then spread with a road
(5) To protect ground-water, surface waters
grader or bulldozer. The blades of both road graders
and off-site property, water management facilities must
and bulldozers should be equipped with depth control
be designed and coordinated with application method
skids and edge wings to aid in uniform application. Once
and facility configuration. The amount of water which
the waste has been spread on the land, there are several
contacts treatment areas (run on) must be minimized,
types of equipment that can be used to incorporate the
and run off from treated areas must be collected and
waste into the soil-moldboard plow, disk, and/or rotary
treated prior to discharge, unless it is free of
tiller. Similar equipment can also be used for low-
contamination from hazardous wastes. Two types of
moisture solids. A spreader can also be used to apply
structures are needed: (1) diversion structures, which
solids which tend to be sticky or chunky.
either intercept clean run on and divert it around the
treatment
5-10
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