UFC 3-280-02A Hazardous Waste Land Disposal/Land Treatment ...

d. Design elements. Design requirements, as wellas requirements for construction, operation andmaintenance, of a land treatment facility are specified inthe facility permit to ensure compliance with regulations.The design goal must be to maximize the degradation,transformation or immobilization of hazardousconstituents in the specified treatment zone, inaccordance with all design and operating conditions usedin the treatment demonstration; and minimize both runoffof hazardous constituents from the treatment area andinflow of water into the treatment area.(1) Fulfillment of these specific designrequirements, as well as meeting the principal designgoal of nondegradation of the land, requires a number ofsteps, including analysis of the waste stream and site soilcharacteristics, evaluation of waste-soil interactions andsite assimilative capacity, determination of applicationrate, selection of an application method, and layout of thefacility and control structures.(2) 40 CFR 264.278 of RCRA requires anunsaturated zone monitoring program for all landtreatment units to determine whether hazardousconstituents have migrated below the treatment zone.Soil and soil pore liquid must be monitored on abackground plot and immediately below the treatmentzone. If any migration is detected, the owner/operator ofthe land treatment unit must notify the EPA RegionalAdministration (RA) of this finding within seven days.Within 90 days the owner/operator should recommendmodifications to the facility permit that will maximizetreatment of hazardous constituents within the treatmentzone.(3) There are several possible configurationsfor a land treatment facility, including single cell, rotatingcell and progressive cell configurations. In the single cellconfiguration a waste is applied uniformly over therequired acreage without subdividing the land treatmentarea. In the progressive cell configuration (figure 5-3),the land treatment unit is subdivided into cells or areaswhich are treated sequentially, cultivated andrevegetated.(4) Adequate buffer zones should be providedbetween the land treatment unit and property boundariesto minimize odor problems, permit easy access to waterretention facilities, and allow implementation ofcontingency measures to control unusual runoff.(5) To protect ground-water, surface watersand off-site property, water management facilities mustbe designed and coordinated with application methodand facility configuration. The amount of water whichcontacts treatment areas (run on) must be minimized,and run off from treated areas must be collected andtreated prior to discharge, unless it is free ofcontamination from hazardous wastes. Two types ofstructures are needed: (1) diversion structures, whicheither intercept clean run on and divert it around thetreatment5-10TM 5-814-7area or prevent contaminated water from leaving the unitby directing it to a retention basin; and (2) run-offretention and sedimentation control basins (figure 5-4).In addition, tanks, surface impoundments, or waste pilesmay be needed for waste storage during inclementweather. For example, land treatment facilities in coldregions may require storage facilities, particularly if theapplication season is limited to spring, summer, and fall.A water balance may be performed to aid in design ofsuch facilities. Subsurface drainage systems andleachate control and treatment systems may also berequired at some hazardous waste land treatmentfacilities.e. Closure. Closure of a land treatment unit maybe accomplished by either establishing a permanentvegetative cover capable of maintaining growth withoutextensive maintenance, removing and landfilling thezone of incorporation, or capping the land treatment areato control wind and water erosion. General closurepractices called for include minimizing run-off from thetreatment zone, continuing ground-water monitoring, andcontinuing restrictions on food-chain crops. In addition,the unsaturated zone should be monitored as part of theclosure procedures; however soil-pore liquid monitoringmay be suspended 90 days after the last application ofwaste at the unit. Each of these practices is described inchapter 12 of EPA SW-874.f. Equipment needs. Equipment required for aland treatment operation ranges from the simple to thesophisticated, depending on the application techniqueemployed. However, all are conventional and readilyavailable. Any equipment used for operations must bedecontaminated before taking from the treatment unit(1) For surface irrigation by furrow or floodtechniques, piping and a pump are needed to transmitthe waste to the point of discharge. Alternatively, a truckor trailer-mounted tank may be used to apply wastes bygravity flow or through a sprayer or manifold. Equipmentneeds for sprinkler systems will vary, depending onsystem type, but will generally require properly sizedpiping, pump, nozzles.(2) A vacuum truck with flotation tires and rearsprayer or manifold may be used for surface spreadingof sludge. If the sludge is too thick to be pumped, aconventional truck with moisture-proof bed may be usedto dump the waste, which is then spread with a roadgrader or bulldozer. The blades of both road gradersand bulldozers should be equipped with depth controlskids and edge wings to aid in uniform application. Oncethe waste has been spread on the land, there are severaltypes of equipment that can be used to incorporate thewaste into the soil-moldboard plow, disk, and/or rotarytiller. Similar equipment can also be used for lowmoisturesolids. A spreader can also be used to applysolids which tend to be sticky or chunky.CANCELLED