Laserfiche WebLink
TUSD <br /> Delta Island School - 2 - 31 January 2017 <br /> Stockton, San Joaquin County <br /> material in the excavation. If TPH-d concentrations are detected, the stockpile may be off <br /> hauled and disposed of or subsequently, separated into quadrants and resampled to identify the <br /> soil that cannot be reused. <br /> Due to shallow groundwater at 7 to 9 ft bgs, there is potential to have to remove, store and <br /> dispose of generated groundwater during the soil excavation and backfilling processes. If <br /> groundwater dewatering is required appropriate dewatering equipment will be mobilized and <br /> staged at the site, including pumps, hoses and a holding tank. Samples of the stored water will <br /> be collected and analyzed by a State-certified laboratory, prior to arranging appropriate disposal <br /> at an approved facility. Proper manifesting documentation will accompany the waste if <br /> warranted. <br /> Removed hydrocarbon impacted soil will be placed onto and covered with plastic sheeting <br /> pending sample analysis by a state-certified laboratory for waste profiling and eventual transport <br /> and disposal at a state-approved disposal facility. <br /> Confirmation samples will be collected from the sidewalls of the excavation to determine if <br /> excavation activities are complete. Once the excavation is completed the excavated area will <br /> be backfilled with reuse soil and soil generated from grading of the property. <br /> Comments <br /> The Subsurface Investigation Report (Report) dated 25 July 2016 prepared by GHD Services <br /> Inc. for the former Delta Island School property noted that a hydropunch groundwater sample <br /> collected in June 2016 from the center of the former transformer pad area contained 0.858 <br /> milligrams per Liter (mg/L) TPH-d. Groundwater samples collected outside the former <br /> transformer pad did not contain concentrations of TPH-d above their respective detection limits. <br /> As this concentration exceeds the taste and odor threshold of 100 micrograms per Liter and <br /> constitutes a nuisance, the beneficial use of water has been impacted at the site. Therefore, <br /> before a No Further Action can be considered, the TPH-d in the groundwater must be <br /> addressed. <br /> The Central Valley Water Board staff concurs with work proposed in the Remedial Action Plan <br /> as an interim remedial action. Please provide a plan on how the TPH-d in groundwater will be <br /> addressed by 28 February 2017. Please provide 48 hours notice to Central Valley Water Board <br /> staff prior to commencement of excavation activities. <br /> If you have any questions regarding the above please contact me at <br /> bshelton65�waterboards.ca.gov or 916-464-1588. <br /> Sincerely, <br /> Brad Shelton, P.G. <br /> cc: Mr. Nuel Henderson <br />