WORK PLANS - Laserfiche WebLink

Home Browse Search

Horizon Field Methods and Procedures plastic bag, the headspace will be screened with the PID for volatile petroleum hydrocarbon vapors. The highest observed reading will be recorded on the boring logs. Samples of the stockpiled soil will be collected for disposal characterization. Four stockpile samples will be collected per approximately 50 cubic yards by selecting random locations accessible around the soil pile, removing approximately six inches of overburden soil, and driving a clean brass sleeve into the soil pile. The samples collected will be prepared for transport and submittal to a State -certified laboratory for the required analyses. 4.0 GROUNDWATER DEPTH EVALUATION Depth to groundwater is measured with an electronic water level indicator to the nearest 0.01 -foot from the top of casing (TOC). The tip of the probe will be inspected to evaluate whether a liquid -phase hydrocarbon (LPH) is present. 5.0 MONITORING WELL DEVELOPMENT/PURGING AND SAMPLING Following installation, the wells will be surged with a surge block to remove fines from the sand pack. After surging, groundwater will be purged from each well using a bailer or centrifugal pump to remove sediment and enhance representative sample quality. Groundwater sampling events conducted after the initial well development will be preceded by purging a minimum of three well casing volumes. Purge water will be monitored for the parameters temperature, pH, and conductivity until stabilized. Wells will be allowed to recharge to 80% before sampling. If wells dewater, they will be allowed to recharge for a minimum of one hour prior to sampling. Groundwater samples will be collected with a clean disposable bailer. Groundwater is transferred to laboratory -prepared vials with a minimum of contact with air. Sample vials will be labeled to identify the job number, sample date, time of sample collection, and a sample number unique to that sample, and packed in an iced cooler for transport. Samples will be transported with a chain -of -custody form. 6.0 WELL LOCATION AND TOP -OF -CASING SURVEY The TOC of new wells will be surveyed for location and elevation position. The survey point on the well TOC will be marked for future identification. Location coordinates will be surveyed relative to a surveyed benchmark and will meet GeoTracker requirements (latitude and longitude to seven decimal places). Elevation will be measured to the nearest 0.01 -foot relative to a surveyed benchmark. A-2 HORIZON ENVIRONMENTAL INC.