Laserfiche WebLink
1 <br /> I <br /> GROUNDWATER TECHNOLOGY <br />' STANDARD OPERATING PROCEDURE <br /> CONCERNING GROUNDWATER MONITORING <br /> GOP a - <br />' Groundwater monitoring of wells at the site shall be <br /> conducted using an ORS Interface Probe and Surface <br /> Sampler. The Interface Probe 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 /> (Product Thickness) ( .8) + (water Elevation) <br /> i Corrected Water Elevation <br />' Note : The factor of 0. 6 accounts for the density <br /> difference between water and petroleum <br />' hydrocarbons. <br /> The Interface Probe consists of a dual sensing probe <br /> . utilizing an optical liquid sensor and electrical con- <br /> lie <br /> on- <br /> iductivity to distinguish 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 /> Ito 1/16-inch. <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 of a 12-inch long cast <br /> I 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 /> Ifor visual inspection of product thickness. <br /> To reduce the potential for 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 oath monitoring <br /> the equipment shall be washed with laboratory grade <br />' detergent and double rinsed with distilled water. <br /> �1 <br /> ITER <br /> G Rt)t h(1M 1kc <br />