ARCHIVED REPORTS_2012_1 - Laserfiche WebLink

Home Browse Search

MW-1 (Up-gradient) No general water quality parameter concentration limits were exceeded during the first semester 2012 sampling event. No VOCs were detected in MW-1 during the first semester 2012 sampling event The trend analysis by Sanitas software indicates an increasing trend for Bicarbonate Alkalinity during the first semester quarter 2012. However MW-1 is the upgradient well. The increasing trend in Bicarbonate Alkalinity could be from changes in background water quality conditions. In addition, Bicarbonate Alkalinity does not have a drinking water standard. MW-2 MW-2 was previously impacted by a landfill gas as previously described in the Compliance History Summary; however, we are pleased to report that: • No general water quality parameter concentration limits were exceeded during the first semester 2012 sampling event. • No VOCs were detected in MW-2 during the first semester 2012 sampling event. The presence of VOCs will continue to be checked for at this well during the next semiannual event. Historically, the impact to groundwater at MW-2 has been believed to be due to landfill gas, as indicated by the presence of the following VOCs: • CFC-12 (last reported fourth quarter 2007) • 1,2-Dichloropropane (last reported in 2006) • PCE These three VOCS were not detected in MW-2 during this sampling event and two of these VOCs were not detected in MW-2 in the fourteen previous quarters. The lack of these compounds indicates removal of these VOCs from the groundwater at MW-2. Therefore, it is believed that the i landfill gas extraction has been successful in reducing or removing the VOC impact near this well. The trend analysis by Sanitas software indicates an increasing trend for the following parameters during the first semester 2012: • Total Dissolved Solids (TDS) • Turbidity However, none of these parameters have exceeded their concentration limits, and the concentration of these components today are very similar to those of years past. In addition, the Chloride concentration in this well (18 mg/L) is far below the secondary maximum contaminant level (MCL) of 250 mg/l, and indicates good water quality. TDS and EC have also not exceeded their secondary MCL standards, which address aesthetics rather than human health issues. Harney Lane Sanitary Landfill 6 Department of Public Works/Solid Waste 1"Semester 2012 Groundwater Monitoring Report County of San Joaquin—July 31,2012