CORRESPONDENCE_1959 - 1989 - Laserfiche WebLink

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0 ell Mile If surface waters are threatened by constituents in a constituent in the liquid waste exceeds this level,the waste,increases in the distance of travel from the site waste is classified as a'designated waste'and Class II of waste discharge to surface water,in the volatility,re- containment is required if discharge is to occur to a activity,degradability or octanol/water partition waste management unit at this site. Wastes having coefficient of the waste constituent,and in the amount concentrations below the Designated Level are as- of initial dilution that the waste or leachate would sumed not to pose a significant water quality threat at receive upon entering surface waters will cause the the site and may be discharged with less than this level attenuation factor to be larger. Increases in the steep- of containment. ness of the terrain,in the polarity of the constituent,in the amount of interconnection of ground and surface Soluble Designated Levels for Solid Wastes waters,in the concentrations of solvents or other chemicals that can act as carriers for the constituent, As moisture from within a waste or from rainfall and in the total constituent loading will lower the percolates toward the base of a landfill,soluble waste attenuation factor. constituents are accumulated and leachate is formed. Constituents in leachate at the base of a landfill pose a Undoubtedly the most important characteristic that similar water quality threat to constituents in an must be evaluated in the derivation of environmental impounded liquid waste. The processes of environ- attenuation factors is the relative uncertainty of the mental fate which act to attenuate constituent concen- data and assumptions used to quantify environmental trations are the same in either case. Therefore,Desig- fate processes. The more uncertainty involved in the nated Levels may be calculated for leachate constitu- estimation of environmental attenuation factors,the ents in the same manner as for liquid waste constitu- more the assumptions being used in their derivation ents,as shown in Figure 6. In this example,the drink- should lean in the direction of underestimating the ing water standard for arsenic(0.05 mg/1)has been amount of attenuation expected to occur. In this way,a chosen as the water quality goal to protect ground greater assurance of water quality protection is pro- water at this site for domestic use,and the environ- vided. The degree of uncertainty in the estimation of mental attenuation factor has been estimated to be environmental attenuation should also be reflected in equal to "n". The Designated Level for arsenic in the amount of vadose zone and ground water monitor- ing that is required for a waste management unit. Greater uncertainty necessitates a greater monitoring SOLUBLE DESIGNATED LEVEL FOR effort to assure that the attenuation factor setting A CONSTITUENT OF A SOLID WASTE process was sufficiently protective of water quality. DOMESTIC WATER UNLINED LANDFILL OR WASTE PILE Site-and constituent-specific information regarding WELL key environmental fate characteristics under reason- s^ ^ n.... 0.�xn _n mg soka As!kg waoa able worst-case conditions may be used to estimate liter a® :ctt attenuation factors for specific waste constituents at the bio�m°A`�fromr»wEr v vv iv site. The DHS publication The California Site Mitigation Decision Tree Manual,the EPA document Water Related ::. r,..•.;.. :,,. m0 > :<: Environmental Fate of the 129 Priority Pollutants,the (o.as in) ti :•:: .`. Handbook of Environmental Data on Organic Chemicals by :;r;k: '` Karel Verschueren,and the EPA publication DRASTIC. A Standardized System em f or Evaluating Ground Water y er Pollution Potential Using Hydrogeologic Settings contain n.-FOLD..._...... information and procedures that can be used to assess ATTENUATION << the fake ofh c emical s in the environment ent and estimate environmental attenuation factors for specific waste constituents and site conditions. Designated Levels for L Lquuid Wastes _ TIM Once the water quality goal is selected and an environ- • • ' ' • ' ' ' ' • • ' ' • • • • mental attenuation factor is estimated,their values are • • 0.05 Mg /wer o1 GROUND W. standard) <3 WATER multiplied together to obtain a Designated Level . . . . . . . . . . . .. . . . . . . . . FLOW applicable to the specific liquid waste constituent and site of proposed discharge. If the concentration of a Figur:.6 Page 5 Designated Level Methodology Summary