Laserfiche WebLink
15 ,•iK� <br /> • The level of the top of the product will be measured with an interface probe When <br /> product is suspected but not measurable with the Interface probe, a visual evaluation <br /> can be made using clear bailers A bailer will be lowered Into the water/product surface <br /> so that the top of the baiter Is NOT submerged, the bailer is then removed from the well <br /> and the thickness of the product visually measured and documented on the Well <br /> Gauging Form <br /> • When the Interface probe contacts liquid, the visual/audible alarm on the reef will be <br /> activated An oscillating alarm indicates water, a continuous alarm Indicates <br /> hydrocarbon* To determine the exact thickness of a hydrocarbon layer, the probe <br /> should be slowly lowered to the air/hydrocarbon Interface until the alarm is activated <br /> With the probe at the exact point where the alarm comes on, read the numbers on the <br /> tape to determine the distance from the top of casing elevation mark Next, lower the <br /> probe through the hydrocarbon layer and well Into the water An oscillating alarm will be <br /> obtained The probe should then be raised slowly to the hydrocarbontwater interface <br /> until the point where the alarm changes from oscillating to continuous The thickness of <br /> the hydrocarbon layer is determined by subtracting the first reading from the second <br /> reading Record the calculated value on the Well Gauging Form and Groundwater <br /> Sampling Form <br /> " The process described here Is equipment specific Follow the procedures applicable for your monitonng equipment <br /> Groundwater Sampling <br /> Groundwater samples will be collected from selected groundwater monitoring wells to provide data which <br />. will be statistically representative of local groundwater conditions at the site Groundwater samples will <br /> be collected as follows <br /> All measuring and sampling equipment will be decontaminated prior to sample collection <br /> from each well and documented on the Groundwater Sampling Form <br /> • Prior to sampling activity, the water level in the well will be measured and the minimum <br /> purge volume of each well will be calculated using the purge volume calculation portion <br /> of the Groundwater Sampling Form A minimum of three casing volumes will be purged <br /> prior to sample collection The actual total volume purged will be recorded on <br /> Groundwater Sampling Form <br /> • Prior to sampling, a submersible pump, centrifugal pump, peristaltic pump, or a Teflon or <br /> stainless steel bailer will be used to purge a minimum of three casing volumes from each <br /> well Purge volumes will be estimated using a flow meter or a stopwatch and a bucket to <br /> estimate flow rate, from which a time to purge the required volume will be calculated <br /> The pump will be lowered to a depth of two to three feet from bottom of the well When <br /> bailers are used for purging, the bailer should be gently lowered Into the water and <br /> allowed to fill, then removed Purged water may be placed into 5-gallon buckets to <br /> determine the volume of groundwater removed Care should be taken to not agitate the <br /> water which could release volatile organics <br /> • Whenever possible, groundwater parameters pH, temperature (in degrees Celsius [C]), <br /> specific conductance (in micromhos per centimeters squared [umhos]), and turbidity (in <br />. Page 2 of 5 <br /> P 1GWMPIFORMSITEX-SOP DOC <br />