Laserfiche WebLink
46 <br /> GROUNDWATER TECHNOLOGY, INC. <br /> STANDARD OPERATING PROCEDURE <br /> CONCERNING GROUNDWATER MONITORING <br /> SOP 8 <br /> Groundwater monitoring of wells at the site shall be conducted using an ORS Environmental Equipment <br /> (ORS)INTERFACE PROBE' and SURFACE SAMPLER'".The INTERFACE PROBE" is a hand-held, battery- <br /> operated device for measuring depth to petroleum product and depth to water as measured from an <br /> established datum (i.e., top of the well casing which has ben surveyed). Separate-phase hydrocarbon <br /> (product) thickness is then calculated by subtracting the depth to product from the depth to water. In <br /> addition, water elevations are adjusted for the presence of fuel with the following calculation: <br /> (Product Thickness) (0.8) + (Water Elevation) = Corrected Water Elevation <br /> Note: The factor of 0.8 accounts for the density difference between water and petroleum <br /> hydrocarbons. <br /> The INTERFACE PROBE � consists of a dual-sensing probe which utilizes an optical liquid sensor and <br /> electrical conductivity to distinguish between water and petroleum products. A coated steel measuring tape <br /> transmits the sensor's signals to the reel assembly where an audible alarm sounds a continuous tone when <br /> the sensor is immersed in petroleum product and an oscillating tone when immersed in water. The <br /> INTERFACE PROBE" is accurate to 1/1 6th inch. <br /> A SURFACE SAMPLER'" shall be used for visual inspection of the groundwater to note sheens (difficult to <br /> detect with the INTERFACE PROBE'"), odors, microbial action, etc. <br /> The SURFACE SAMPLER` used consists of a 12-inch-long case acrylic tube with a Deirin ball which closes <br /> onto a conical surface creating a seal as the sampler is pulled up. The sampler is calibrated in inches and <br /> centimeters for visual inspection of product thickness. <br /> To reduce the potential for cross contamination between wells,the monitorings shall take place in order from <br /> the least to the most contaminated wells. Wells containing separate-phase hydrocarbons (free product) <br /> should be monitored last. Between each monitoring the equipment shall be washed with laboratory-grade <br /> detergent and double rinsed with distilled water. <br /> 1 ��iiGROUNDWATER <br /> A� TECHNOLOGY,INC. <br />