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Water Quality Monitoring Report Forward Landfill fe (CDM, 1997) and an estimated effective porosity of 35 percent. An estimated groundwater flow velocity was calculated using Darcy's Law: V = Ki = (255 ft )* 0.003 ;,, 2.19 ft/day ne day 0.35 where: V=Groundwater flow velocity. K=Hydraulic conductivity of the water-bearing unit(255 ft/day). i=Average hydraulic gradient:i;:t�0.003 during the first quarter 2017. ne=Effective porosity(ne=0.35);an estimated value. The maximum groundwater flow rate is calculated to be 2.19 feet per day(798 feet/year). 2.1.4 Detection Monitoring Program Field and laboratory results for the Forward Unit groundwater monitoring wells for the first quarter 2017 monitoring period are summarized in Table 2-2. 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 2017 monitoring period, non-statistical indications of a release was identified at well MW-2A as a result of trace concentration of 1,1-dichloroethene (1,1-DCA) and a quantifiable concentration of cis-1,2-dichloroethene (cis-1,2-DCE); MW-13 as a result of a quantifiable concentration of diisopropyl ether (DIPS); MW-14 as a result of a quantifiable concentration of dichlorodifluoromethane (DCDFM); MW-16 as a result of a quantifiable concentration of DIPS; and at well MW-17 as a result of quantifiable concentrations of chloroform and carbon tetrachloride. Constituents exceeding a CNSDAM were place in "tracking mode" and are being evaluated quarterly for temporal trends (discussed below). Historically, low-level concentrations of VOCs have been detected in the samples collected from the Forward Unit. On behalf of Forward Inc., GLA prepared a letter report dated February 14, 2001 (RWQCB Case No. 2209), to assess the source and potential impacts of low-level VOCs in groundwater adjacent to the Forward Landfill. The letter report concluded that the sporadic detection of low-level VOCs in groundwater (and lysimeter samples) at the Forward Unit are most likely due to landfill gas from unlined unit WMU-B. Forward has continued to minimize gas related impacts to groundwater by preventing ponding of water through regular site maintenance. Project No.5017.1030 I Water Quality Monitoring Report 6 April 2017