f. Equipment needs.
Equipment for surface
Operation of the land treatment unit in a
impoundments includes that needed for
manner that protects human health and the
Removal of liquid from the impoundment.
(2) Additional information on conducting a
treatment demonstration, selecting appropriate field
Dewatering sediments prior to their final
tests, and designing test procedures for the
demonstration is presented in EPA SW-874.
Solidification and stabilization of residual
(3) Special requirements for ignitable or
reactive wastes and for incompatible wastes are
(1) At the time of closure, impounded liquid can
contained in 40 CFR 264.281 and 264.282. Ignitable
be removed by a number of methods described in
and reactive wastes must be immediately incorporated
paragraph 5-3c; typical equipment used for this purpose
into the soil so that they are no longer considered
is a centrifugal pump or a hydraulic pipeline dredge.
ignitable or reactive. They must also be protected from
Waste residuals can be removed by means of a vacuum
any material or condition that could cause ignition or
truck to pump slurried sediment from the impoundment,
reaction. Incompatible wastes, such as those listed in
a rotary cutter to remove hardened sediments that do not
appendix V of 40 CFR 264, may not be placed in the
flow freely, or a dragline or front-end loader to excavate
same treatment zone unless precautions are taken to
hard, solidified sediments. To dewater sediments, filter
avoid fires, explosion and violent reactions, the
presses may be used to produce a nonflowable solid.
generation of heat and pressure, the production of toxic
(2) Any equipment used for liquid sediment
mists, fumes and gas, or the creation of other conditions
removal or dewatering must be decontaminated before
that might threaten human health or the environment.
being taken out of the disposal operation area.
Federal regulations (40 CFR 264.276) also outline
special requirements for application of cadmium and
other hazardous wastes to lands used for growth of food-
5-4. Land Treatment
a. Suitable Wastes. Land treatment is potentially a
b. The land treatment option is limited by (1) the
cost-effective method of disposing of industrial wastes
availability of sufficient quantities of usable land, (2) the
such as bulk organic sludges that have a high water
assimilative capacity of the plant-soil system, (3)
content. A variety of industrial wastes, effluents, sludges
regulatory restrictions concerning food-chain crops, and
and solid wastes are suitable for treatment and disposal
(4) environmental conditions.
by the land treatment method, including those containing
(1) The availability of sufficient quantities of
or derived from hazardous constituents listed in appendix
usable land is dependent upon a number of additional
VIII of 40 CFR 261. However, for wastes that contain
limiting factors, including the application rate and
very high concentrations of toxic organics, a disposal
regulatory requirements specifying the depth of the
method other than land treatment is required.
(1) Hazardous waste land treatment facilities
(a) The application rate is dependent not
must include plans for conducting a treatment
only on the waste constituent, but also on the
demonstration and reporting the complete demonstration
assimilative capacity of the soil (see EPA SW-874).
The objective of the demonstration is to
While it is theoretically possible to specify land
establish the operating practices that will completely
application rates and required land areas for most
wastes, in practice, the complete degradation,
constituents. Regardless of the demonstration method
transformation or immobilization of some constituents
selected, the following criteria must be met:
would require application over such large tracts of land
Accurate simulation of the characteristics
that land treatment would not be cost-effective.
and operating conditions of the proposed
Economic factors might therefore preclude land
treatment unit, including
treatment of some wastes.
(b) With respect to the treatment zone,
-climate in the area
EPA regulations require that the zone which wastes are
introduced be no deeper than 5 feet and that there be a
-soil characteristics and depth of the
3-foot separation between the bottom of the treatment
zone and the seasonal high water table.
-operating practices to be used
requirements could limit land treatment in certain areas.
Complete degradation, transformation, or
(2) The second factor limiting the land
immobilization in the treatment zone of the
treatment option is the assimilative capacity of the plant-
hazardous constituents in the waste
soil system to handle a particular hazardous waste; this
is a complex limiting factor due to the large number of
variables within the system. Among these are the
physical, chemical, and biological properties of the