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The EPA promulgated the Centralized Waste Treatment (CWT) Effluent Guidelines and Standards (40 CFR Part 437Exit EPA’s website) in 2000 and amended the rule in 2003. The regulations cover discharges from facilities that treat or recover metal-bearing, oily, and organic wastes, wastewater, or used material received from off-site. The CWT Effluent Guidelines and Standards are incorporated into NPDES permits for direct dischargers, and permits or other control mechanisms for indirect dischargers (see Pretreatment Program). On this page: * What is Centralized Waste Treatment? * Facilities Covered * Compliance Assistance * Study of CWT and Oil & Gas Wastewater – 2018 * Rulemaking History * Additional Information
Related Information * Stormwater Fact Sheet (Sector K - Hazardous waste facilities)
The CWT industry handles wastewater treatment residuals and industrial process by-products that come from other industries. CWT facilities receive a wide variety of hazardous and non-hazardous industrial wastes for treatment. Many of the wastes contain very high pollutant concentrations and are unusually difficult to treat. CWT facilities typically fall within NAICS codes 562211 (hazardous waste treatment and disposal), 562219 (other nonhazardous waste treatment and disposal) and 562920 (materials recovery facilities).
The CWT Effluent Guidelines apply to facilities in four subcategories: * Metals Treatment and Recovery (Subpart AExit EPA’s website) * Oils Treatment and Recovery (Subpart BExit EPA’s website) * Organics Treatment and Recovery (Subpart CExit EPA’s website) * Multiple Wastestreams (Subpart DExit EPA’s website)
Examples of discharges covered by the regulation: * Discharges from stand-alone waste treatment and recovery facilities receiving materials from off site. These facilities may treat hazardous or non-hazardous waste, hazardous or non-hazardous wastewater, and/or used material from off site, for disposal, recycling or recovery. * Certain discharges from waste treatment systems at facilities primarily engaged in other industrial operations. Thus, industrial facilities which process their own, on-site generated, process wastewater with hazardous or non-hazardous wastes, wastewaters, and/or used material received from off site, in certain circumstances, may be subject to this category with respect to a portion of their discharge.
Covered wastestreams include materials received from off-site, solubilization water, used oil/emulsion breaking wastewater, tanker truck/drum/roll-off box washes, equipment washes, air pollution control waters, laboratory-derived wastewater, wastewater from on-site industrial waste combustors, landfills, and contaminated stormwater. The CWT category does not apply to: * operations at facilities which are subject to other effluent guidelines categories and which receive wastes from off-site for treatment or recovery that are subject to the same effluent guidelines as the on-site generated wastes * operations at facilities which receive off-site wastes whose nature and treatment are compatible with the treatment of on-site non-CWT wastes * operations engaged exclusively in landfilling and/or the treatment of landfill wastewaters, whether generated on- or off-site (See also the Landfills Effluent Guidelines, 40 CFR Part 445Exit EPA’s website)
Facilities that treat wastewater that results from cleaning tanker trucks, rail tank cars, or barges may be subject to the CWT effluent guidelines if not subject to the Transportation Equipment Cleaning Effluent Guidelines (40 CFR Part 442Exit EPA’s website). See the applicability and definitions sections in 40 CFR Part 437Exit EPA’s website for complete descriptions of coverage and exclusions.
The EPA conducted a study of CWT facilities accepting oil and gas extraction wastewater from 2014 to 2017. The EPA has prepared a compilation of data collected to date, including information on CWT facilities that accept such wastewater, available treatment technologies (and their associated costs), discharge characteristics, financial characteristics of CWT facilities and the environmental impacts of discharges from CWT facilities. * (4.3 MB, May 2018, 821-R-18-004)
In 2018, the EPA announced as part of its effluent guidelines planning process that it is beginning a holistic study of oil and gas extraction wastewater management under the Clean Water Act. As part of that study, the EPA evaluated the role of CWT facilities in managing oil and gas extraction wastewater from onshore wells. * Study of Oil and Gas Extraction Wastewater Management
For additional information regarding the CWT Effluent Guidelines, please contact Anthony Tripp (tripp.anthony@epa.gov) or 202-566-1419.
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