ARCHIVED REPORTS XR0008636 - Laserfiche WebLink

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Class I and II landfills accept material with higher contaminant concentrations, even hazardous waste, often treating it at their facility prior to landfilling. However, disposal costs are generally on the order of $60 to $100 per ton or more, and there may be substantial hauling, profiling, and analytical fees Another off-site treatment/disposal option is thermal incineration at an asphalt or building materials plant. These facilities will not accept hazardous waste, however, many are appropriate for soil containing petroleum hydrocarbons Costs average $60 to $70 per ton, not including loading, hauling, profiling, and analytical fees ' Often it is more cost effective to treat highly contaminated soil on site and haul to a cheaper facility, rather than pay $60 per ton or more dispose of highly contaminated material 1 2 2 Landfarming and Ex-Situ Bioremediation Landfarmcng consists of excavating the soil and spreading to a 1 to 1 5 foot layer in a treatment cell The purpose of the cell is to create an environment to allow for organic constituents to be degraded by indigenous and/or cultured bacteria. Creating ' the environment is achieved by enhancing, maintaining, and monitoring oxygen, pH, moisture, and nutrient levels The cell includes a liner system to contain and prevent migration of constituents Indigenous organic-degrading bacteria may be relied upon, or the soil may be inoculated with cultured aerobic bacteria Oxygen, nutrient and moisture levels are maintained in the cell by physically turning, watering, and fertilizing the soil, at least weekly If the soil cannot be spread to a relatively thin layer, it may be stockpiled and nutrient and oxygen requirements maintained by placing slotted PVC piping horizontally through the soil at various depths The PVC would be manifolded in two bask sections One section would be connected to the intake and one section connected to the discharge of a blower Monitoring the cell would be done at regular intervals, with nutrient, pH, microbe, and moisture levels adjusted accordingly, utilizing the same PVC manifold system that provides air to the cell To implement such a project, either ' the site must have sufficient room to build the cell{s} on the surface or a cell can be built in the existing excavation Depending on site-specific conditions, atypical ex-situ bioremediation project may take from 30 to 90 days or more Once treated the soils sometimes may be used to backfill the excavation 1