COMPLIANCE INFO_1973-2003 - Laserfiche WebLink

Home Browse Search

iL L►IS�SAL -4- 23 May 19 waste extraction test (WET) is designed to establish the amounts of mobile 11 ;.vxic constituents that would exist in a waste which is placed in a Class II-2 (new Class III) landfill , and not the concentrations of these constituents in the landfill leachate . WET results are expressed in mg/l of extract , a ten-fold dilution of concentrations of soluble constituents in the waste itself. The Statement of- Reasons for the CAM regulations states that the initial landfill leachate could contain these constituents in equal , or even greater, concentrations than exist in the waste. One can, therefore, assume that the initial leachate could contain at least ten times the concentrations of constituents seen in the WET extract. The attenuation of all components for which 1Ox the WET results exceed applicable water quality objectives should be studied by the discharger. A reasonable and justifiable attenuation factor should be derived for each constituent at each site where the waste discharge is proposed. 2) Applicable water quality objectives for ground water must protect potential as well as existing beneficial uses. Saline waters may become potable in 'he future due to changing technologic and/or economic factors. Degradation of these waters by new constituents to levels above background concentrations could prevent that potential use. For this reason, ground water should be sampled at each site for constituents rent in__th�_ ste, such that back- ground water quality objectives may _be._determined_. - 3) To establish actual attenuation factors for waste constituents at each site, detailed lithologic analysis should be required. On-site soil characteristics that are relevant to their attenuative capacity (e.g. , clay content, perme- ability, organic matter content, cation exchange capacity, phosphorus content) should be determined by detailed sampling in all layers between the waste and ground water. Only in this way can the comparison with other soils, having established literature attenuation values, be validated. Actual soil column testing with leachate would also be useful . 4) Waste constituents adsorbed to soil could be remobilized by changing leachate conditions (e.g. , pH) as refuse in the landfill degrades and stabilizes. Data should be presented which would indicate the interaction of waste consti- tuents, leachate, and soils over the entire life and post-closure period of the landfills in question. 5) Actual testing of the solubility of waste constituents in ground water samples would be needed to show that solution chemistry would limit concentrations in ground water to below applicable water quality objectives . Variances under Section 2520(a)(1) must be reviewed in this rigorous a fashion in order to be sure that water quality will be protected. Once significant quan- tities of waste are discharged to landfills, water quality problems are difficult, if not impossible, to rectify. JSM:cab Attachment . 1