ARCHIVED REPORTS FIRST QUARTER GROUNDWATER MONITORING REPORT FEBRUARY 2014

Home Browse Search

First Quarter 2014(Semi-Annual)Groundwater Monitoring Report Pilkington North America,Inc. Lathrop,California ' Page 2 of 6 Summary of Diesel Skimming Operations(October 1,2013 through March 31, 2014) ' Thirteen diesel recovery and skimmer operations and maintenance (O/M) events were conducted at the Site during the current six-month reporting period. Free product was observed in recovery wells RW-2, RW-3, and RW-4, and approximately 1.19 gallons of product were recovered during the monitoring and skimming period (Figures 3A-3F, Attachment A). Product recovery from the Site's recovery wells has ' produced a cumulative total of approximately 241.64 gallons of recovered diesel (Figure 4, Attachment A). ' FIRST QUARTER 2014 GROUNDWATER MONITORING EVENT Field Observations ' On February 24, 2014, a Condor representative measured the depth to groundwater at the three monitoring and six recovery wells. On February 25, 2014, a Condor representative recorded field observations at the three monitoring wells and collected groundwater samples from the three monitoring ' wells and two facility sumps. Field observations included the physical appearance of samples (color, clarity,and presence of petroleum product sheen or phase in samples) and collection of water quality field parameters. Field parameters included dissolved oxygen (DO), oxidation reduction potential (ORP), pH, electrical conductivity (EC), total dissolved solids (TDS), and temperature (see Attachment D for field ' forms). Groundwater field inspection samples collected from the monitoring wells were noted as clear without ' odor or sheen. The monitoring wells were purged until at least three well-casing volumes of water were removed and sampled with single-use disposable bailers. All wells were purged until the EC, pH, and temperature stabilized. ' Groundwater elevation measurements indicate that the average groundwater elevation in the three Site monitoring wells on February 24, 2014, was 2.31 feet, a decrease of 0.98 feet since previously measured ' on August 12, 2013. An estimated groundwater gradient of 0.002 ft/ft to the east-northeast was calculated using water level data from monitoring wells MW-1, MW-2, and MW-3 (Figure 2). The groundwater levels measured on February 24, 2014, are included in Table 1, below. Groundwater measurements are ' provided in the field forms (Attachment D). Table 1.Groundwater Elevation Data (February 24 2014 ' Monitoring Well Screened Interval(b s) TOC Elevation Depth to Water Groundwater Elevation MW-1 7— 17 15.12 12.58 2.54 MW-2 6— 16 15.24 13.22 2.02 MW-3 6— 16 14.81 12.45 2.36 ' 'Top of Casing(TOC)Elevation:Elevations surveyed on 05/09/05 relative to NAD83 and NGVD29 datuin. bgs:below ground surface All measurements are in feet. ' Laboratory Analytical Results The groundwater samples collected from the three monitoring wells and two facility sumps were analyzed ' for TPH-D, TPH-K, and TPH-MO by EPA Method 8015M. Laboratory analytical results indicate that TPH-MO was detected in the groundwater samples collected from MW-2 and the SW-sump at concentrations of 0.518 and 1.32 milligrams per liter(mg/L), respectively. The samples were analyzed by ' Excelchem Environmental Labs of Rocklin, California. Laboratory analytical results from the February 2014 sampling event are summarized in Table 2, on the following page, and are also provided in Attachment E.Historic groundwater monitoring data is provided in Table A,Attachment C. ' 4 IL 41 CONDOR