CORRESPONDENCE_1959 - 1989 - Laserfiche WebLink

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0 fore,the Designated Level Methodology can be used to acidic conditions often encountered in sanitary select cleanup levels which will protect the quality of landfills. If the site being investigated presents neutral nearby ground and surface waters. As always,back- or basic conditions,cleionized water or another more ground concentrations of contaminants must be suitable extraction solution may be substituted for the factored into the cleanup level-setting process. Back- standard WET buffer solution(assuming the contami- ground water quality data in conjunction with water nated soils themselves cannot generate acid). quality standards and criteria are used to select water quality goals which protect the beneficial uses of CONCLUSION AND STATUS UUMMMMENIMM ground and surface waters which could be adversely impacted by contaminants. Attenuation factors are When combined with the waste classification and estimated based upon site hydrogeologic data and cleanup level setting processes of DHS and the State information on the contaminants themselves. Soluble Water Board's Subchapter 15 regulations,the Desig- Designated Levels are then calculated by multiplying nated Level Methodology can provide a complimen- the water quality goals by the attenuation factors and tary set of procedures to ensure the protection of both dividing by the ton-fold dilution of the WET. The the public health and the quality of usable waters of results are expressed as milligrams of soluble constitu- California. Comments received during public review ent per liter of extract. of an earlier draft of the Designated Level Methodol- ogy report were used to produce the October 1986 Soil samples are subjected to the WET procedure and version. Staff of the Central Valley Regional Water results are compared with these site-and constituent- Quality Control Board submitted this version of the specific Soluble Designated Levels. Cleanup and/or report to the State Water Resources Control Board and mitigation would be required for soils having ex- is currently working with staff of that agency to tractable concentrations which exceed Soluble Desig- develop statewide policy in this area. In June 1989,an nated Levels. For site cleanup situations the WET updated version of the Methodology was produced to procedure is often modified to account for conditions keep the document current with changes in water that exist at the site. The WET uses an acidic buffered quality criteria and waste testing methods. extraction solution which is designed to account for the tum 19W Page 7 Designated Level Methodology Summary