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Water Quality Monitoring Report Forward Landfill per day per square foot (0.04 cm/sec) and an estimated effective porosity of 35 percent (CH2M Hill, 2000). An estimated groundwater flow velocity was calculated using Darcy's Law: Ki cm 0.002 sec — ft V = — _ [( 0.04 ) * ] * 2835 = 0.65 ft l da_y ne sec 0.35 cm — day where: V = Groundwater flow velocity. K = Hydraulic conductivity of the water -bearing unit (0.04 cm/sec). i = Hydraulic gradient: i = 0.002 at the site during the first quarter 2016. ne= Effective porosity (ne = 0.35); an estimated value. The maximum groundwater flow rate is calculated to be 0.65 feet per day (237 feet/year). 2.1.4 Detection Monitoring Program Field and laboratory results for the Forward Unit groundwater monitoring wells for the first quarter 2016 monitoring period are summarized in Table 2-2. 0 Non -Statistical Data Analysis The California Non -Statistical Data Analysis Method (CNSDAM) was performed for VOCs detected less than 10 percent of the time in background samples. Under the CNSDAM, a measurably significant indication of release occurs in a given sample when: two or more VOCs exceed their respective Method Detection Limits (MDLs); or one or more VOCs equals or exceeds its respective practical quantitation limit (PQL). During the first quarter 2016 monitoring period, non -statistical indications of a release were identified at wells MW -13 and MW -16 as a result of a quantifiable concentrations of diisopropyl ether (DIPE); at well MW -14 for trace -level concentrations of dichlorodifluoromethane (DCDFM), tetrachloroethene (PCE), and trichlorofluoromethane (TDFM); and at well MW -17 for trace -level concentrations of carbon tetrachloride, chloroform, and TCFM. In a letter dated August 13, 2015, similar concentrations of VOCs in wells MW -16 and MW -17 were reported to the RWQCB for the second quarter 2015 and confirmed in retest samples collected on July 29, 2015. It should be noted that these confirmed VOCs are well below state and/or federal maximum contaminant levels (MCLS), and were place in "tracking mode" and are being evaluated quarterly for temporal trends. For wells MW -13 and MW -14, the RWQCB was notified of these exceedances in a letter dated April 18, 2016 and retesting is scheduled for April 2016. The results of the verification sampling will be reported under separate cover. M:\ 2016.0007\FA 1Q16.docx 6 Historically, low-level concentrations of VOCs have been detected in the sampled iscollected from the Forward Unit. On behalf of Forward Inc., GLA performed an M:\ 2016.0007\FA 1Q16.docx 6