Laserfiche WebLink
MM MRIM1 <br /> I <br /> r <br /> I • <br /> I GROUNDWATER TECHNOLOGY <br /> STANDARD OPERATING PROCEDURE <br /> CONCERNING GROUNDWATER MONITORING <br /> SOP 8 <br /> Groundwater monitoring of wells at the site shall be <br /> I conducted using an ORE; Interface Probe and Surface <br /> 1 Sampler. The Interface Probc is a hand held, battery <br /> operated device for measuring depth to petroleum product <br /> and depth to water as measured from an established datum <br /> (i.e., top of the well casing which has been surveyed). <br /> Product thickness is then calculated by subtracting the <br /> depth to product from the depth to water. in addition, <br /> water elevations are adjusted for the presence of fuel <br /> with the following calculation: <br /> t (Product Thickness) (.B)+(Water Elevation) <br /> [ � o Corrected Water Elevation <br /> Notes The factor of 0.8 accounts for the density <br /> difference between water and petroleum <br /> hydrocarbons. <br /> The Interface Probe consists of a dual sensing probe . <br /> IIi utilizing an optical liquid sensor and electrical con- <br /> ductivity to distingish between water and petroleum <br /> products. . A coated steel measuring tape transmits the <br /> sensor's signals to the reel assembly, where an audible <br /> alarm sounds a continuous tone when the sensor is <br /> immersed.in petroleum product and an oscillating tone <br /> when immersed in water. The Interface Probe is accurate <br /> II to 1/16-in,:h. <br /> A Surface sampler shall be used for visual inspection of <br /> the groundwater to note sheens (difficult to detect with <br /> the Interface Probe), odors, microbial action, etc. <br /> The Surface Sampler used consists ofa 12-inch long cast <br /> acrylic tube with a Delrin ball which closes onto a <br /> conical surface creating a seal as the sampler is pulled <br /> up,. The sampler is calibrated in inches and centimeters <br /> s' <br /> for visual inspection of product thickness. <br /> To reduce the potential fox cross contamination between <br /> wells the monitorings shall take place in order from the <br /> least to most contaminated wells. Wells containing free <br /> product should be monitored last. Between each monitoring <br /> the equipment shall be washed with laboratory grade <br /> ' detergent and double rinsed with distilled water. <br /> GROUNDwArER <br /> TECHNOLOGY,INC. <br /> CONSULTING GROUNDWATER GEOLOGISTS <br /> maw <br />