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Dr. Andrew Altevogt December 15, 2017 Page 4 of 6 same classification (under Article 3 of this subchapter) as the Unit(s) from which leachate was extracted; (2) the discharge to a different Unit is approved by the RWQCB; (3) the discharge of leachate to a different Unit shall not exceed the moisture holding capacity of the receiving unit, and shall comply with section 20200(d). A review of SWRCB Resolution No, 93-62 indicates that it does not prohibit the discharge of leachate or condensate to a different MSW unit from which it came. Federal regulation 40 CFR 258.28 also does not prohibit the discharge of leachate or condensate to a lateral expansion of an MSW landfill. 40 CFR 258.28, similar to CCR 20340(g) allows the discharge of leachate and condensate to a lateral expansion if that unit has a composite liner and a leachate collection system. Federal Subtitle D design regulations give additional guidance for the discharge of leachate into a MSW unit. The leachate collection system should be designed to maintain less than a 30 -centimeters (cm) depth of leachate over the liner. Based on the above State and Federal regulations for MSW landfills, it appears that the RWQCB can allow condensate from LF -1 to be discharged into LF -2. The County can comply with the referenced regulatory criteria for allowing LF -1 condensate to be discharged into LF -2: • LF -1 contains Class III MSW that is similar to the Class III MSW waste that is currently being placed in LF -2. The waste material that was placed into LF -1 came from the same municipalities that currently provide waste material to LF -2. Furthermore, the County has conducted laboratory analysis of the LF -1 condensate and the condensate profile is as expected similar to LF -2 leachate composition. The analytical lab results are attached. The discharge of condensate from LF -1 into LF -2 will not exceed the moisture holding capacity of the waste in LF -2. The extraction of LFG from both LF -1 and LF -2 commenced in 2006. Since 2006, the LFG from both units have been conveyed in a single pipeline to either a flare or an engine for destruction. The condensate from both units is removed prior to destruction, and is handled as a single source for input into LF -2. At no time during the operation of this single condensate source to LF -2 has there been any evidence that the moisture holding capacity of the waste in LF -2 has been exceeded. • The discharge of condensate from LF -1 to LF -2 will not cause leachate to rise above 30 - cm in the leachate collection system of LF -2. Since 2006, when the discharge of combined condensate into LF -2 commenced, all leachate monitoring records from LF -2 have shown that leachate has not risen above 30 -cm. It is not possible to separate the condensate generated from LF -1 gas from the condensate of LF -2 gas. Liquid condensate is produced whenever landfill gas cools as it travels through piping. In the system installed at the FSL in the Site Improvement Project of 2006, and as approved by Water Board, wells from both LF -1 and LF2 are connected by a common LFG header pipe. Moisture continually condenses from this comingled gas as it travels along the common header pipe to the gas -to -energy plant. As such condensate cannot be exclusively assigned to one unit or the other. Condensate production is roughly proportional to LFG production, and is expected to decline exponentially beginning two years after the last deposit of refuse, which at LF -1 occurred in 2003.