ARCHIVED REPORTS_2019 - Laserfiche WebLink

Home Browse Search

Mr. Brendan Kenny July 03, 2019 • during the tests, to confirm the transducer data, after water levels stabilize, and then once before completing the step-drawdown test. During step-drawdown testing, the flow rate will be periodically measured using an inline flow meter and if required adjusted to maintain constant steps. For each pumping step, the flow rate will be maintained for at least 30 minutes,or until drawdown has stabilized(less than 10%change in total drawdown over 15 minutes).At least four pumping rate steps will be assessed, with the actual number of steps based on field conditions. After completion of the step-drawdown test, water-level data will be downloaded from the data loggers for analysis. The analysis will include preliminary estimates of well efficiency and the hydraulic properties of the groundwater in the adjacent water bearing zone. The analysis will be used to identify the optimal pumping rate for the extraction well and for the permanent pump specification. Conveyance Piping and Treatment System Upgrades The GWTS water conveyance lines and carbon treatment system will be upgraded based on the results of the hydraulic testing,well specific potential extraction rates, and groundwater capture estimations for the POC. Depending on the specific well extraction rates the groundwater conveyance system will be re-designed to maximize delivery to the treatment system and the extraction rates from the respective wells and zones along the POC. It is anticipated that this will require replacement of the existing PVC conveyance piping • with appropriately sized HDPE conveyance piping and the installation of conveyance lines to specific wells,well pairs or zones of the POC. The actual design will be based on the hydraulic testing results. Additionally, the carbon treatment capacity will be adjusted based on the total extraction rate required to enable capture of VOC impacted groundwater at the POC. From preliminary estimations it is anticipated that the current capacity will be increased to obtain capture. Improvements to the electrical service, valves and gauges will also be completed as part of the overall system upgrade project. Investigation Derived Waste Soil cuttings, development water, and other investigation derived waste(IDW)generated during the boring advancement and well completion activities will be stored on-Site in properly labeled California Department of Transportation (DOT)approved containers. Soil cuttings will be disposed of in the Forward Landfill. Development water will be allowed to settle, before being transferred to the leachate collection pond,with the remaining solids disposed of as per solid waste. Groundwater generated as part of the hydraulic testing activities will be routed directly into the current groundwater extraction and treatment infrastructure. REPORTING Following completion of the well installation and hydraulic testing, Arcadis will evaluate the data and prepare a summary of the results. A Monitoring Well Installation Report shall be submitted, and the boring logs shall be uploaded to Geotracker following completion of the wells. The hydraulic testing step test data collected from the new extraction well and re-developed existing • extraction well will be assessed to evaluate the optimal extraction well pumping rates, to recommend arcadis com Page: Forward LF GWTS Upgrade WP07032019.docx 6/7