Chemical & Biological  Remediation

Waste Water Treatment Biosolids & Composting

Animal Waste & Effluent
Remediation

Soil Enhancement & Crop Amendments

GENERAL:

Composting of mixed municipal solid waste is becoming a common process. This generally occurs at a medium-to-large scale facility, operated by private sector firms or community public works departments. Generally, mixed Municipal Solid Wastes (MSW) is received at the site. Recyclables such as glass and aluminum, and non-compostables are removed early in the process. The remaining organic material is composted, generally using aerated windrows. In-vessel composting, where the material is left to decompose while enclosed in a temperature and moisture controlled chamber, is another possibility. Final screening steps remove any remaining plastic film and similar contents. The finished compost can be sold, given away, or used by the company or municipality in local landscaping projects.

Any garbage, refuse, sludge from a wastewater treatment plant, water supply treatment plant, or air pollution control facility, and other discarded material, including solid, liquid, semisolid, or contained gaseous material, resulting from industrial, commercial, mining, and agricultural operations and from community activities.:

Treatment

Treatment is any process that changes the physical, chemical, or biological character of a waste to make it less of an environmental threat. Treatment can neutralize the waste; recover energy or material resources from a waste; render the waste less hazardous; or make the waste safer to transport, store, or dispose.

Hazardous waste generally must be treated before it can be disposed. The treatment standards for each specific hazardous waste (by hazardous waste code) are outlined in 40 CFR §268.40. Detailed descriptions of the appropriate treatment technologies are outlined in 40 CFR §268.42, Table 1, "Technology Codes and Description of Technology-Based Standards".

One common method of treatment is hazardous waste combustion or incineration. Combustion or incineration is used to destroy hazardous organic constituents and reduce the volume of waste. Depending upon the type of waste and its constituents, residual ash may in some cases be landfilled or may require further treatment. A brief description of several other treatment technologies is available at EPA's Waste Treatment Technologies page. Additional information on treatment technologies is also available from OSWER's Technology Innovation Office.

Storage/Storage Units

Storage is the holding of waste for a temporary period of time prior to the waste being treated, disposed, or stored elsewhere. Hazardous waste is commonly stored prior to treatment or disposal, and must be stored in containers, tanks, containment buildings, drip pads, waste piles, or surface impoundments that comply with the RCRA regulations (see list below). The regulatory requirements for these types of storage units are found in 40 CFR Part 264 for permitted facilities and 40 CFR Part 265 for interim status facilities.

• Containers – A hazardous waste container is any portable device in which a hazardous waste is stored, transported, treated, disposed, or otherwise handled. The most common hazardous waste container is the 55-gallon drum. Other examples of containers are tanker trucks, railroad cars, buckets, bags, and even test tubes.

• Tanks – Tanks are stationary devices constructed of non-earthen materials used to store or treat hazardous waste. Tanks can be open-topped or completely enclosed and are constructed of a wide variety of materials including steel, plastic, fiberglass, and concrete.

• Drip Pads – A drip pad is a wood drying structure used by the pressure-treated wood industry to collect excess wood preservative drippage. Drip pads are constructed of non-earthen materials with a curbed, free-draining base that is designed to convey wood preservative drippage to a collection system for proper management.

• Containment Buildings – Containment buildings are completely enclosed, self-supporting structures (i.e., they have four walls, a roof, and a floor) used to store or treat non-containerized hazardous waste.

• Waste Piles – A waste pile is an open, uncontained pile used for treating or storing waste. Hazardous waste waste piles must be placed on top of a double liner system to ensure leachate from the waste does not contaminate surface or ground water supplies.

• Surface Impoundments – A surface impoundment is a natural topographical depression, man-made excavation, or diked area such as a holding pond, storage pit, or settling lagoon. Surface impoundments are formed primarily of earthen materials and are lined with synthetic plastic liners to prevent liquids from escaping.

Disposal

Disposal is the placement of waste into or on the land. Disposal facilities are usually designed to permanently contain the waste and prevent the release of harmful pollutants to the environment. The most common hazardous waste disposal practice is placement in a land disposal unit such as a landfill, surface impoundment, waste pile, land treatment unit, or injection well.

Underground injection wells are the most commonly used disposal method for liquid hazardous waste. Because of their potential impact upon drinking water resources, injection wells are also regulated under the Safe Drinking Water Act (SDWA) and by the Underground Injection Control (UIC) Program.

The RCRA regulations governing injection wells are found at 40 CFR Part 265 Subpart R and 40 CFR Part 264 Subpart X. The SDWA and UIC regulations governing underground injection of liquid hazardous waste can be found in 40 CFR Part 144 through Part 148.