Laserfiche WebLink
BV = (7 48/4) X (CD2+P (BD2-CD) 2) x (WD-GW) <br /> • BV borehole xolume (gallons) BD borehole diameter (feet) <br /> CD casing diameter (feet) WD «yell depth (feet) <br /> GW depth to groundwater (feet) P porosity of the graN el pack, 25% <br /> Table of Common Boring and Casing Diameters <br /> Boring Casing Volume 3 VolumesX (WD-GNV) <br /> diameter diameter gallons/foot gallons /foot <br /> inches inches <br /> 4 1 0 042 0 126 <br /> 6 1 0 082 0 246 <br /> 6 2 0 173 0 519 <br /> 8 2 0 277 0 831 <br /> 8 - 4 0671 2013 <br /> 10 ? 057') 1 716 <br /> IG 4 0 844 2 532 <br /> EXAMPLE An 8 inch boring «ith 2 inch casing4equires removal of 0 831 gallons of <br /> -,,,ater per foot of«eater column <br /> The water collected dunng purging is either safely stored on- site in » gallon DOT 17H <br /> drums for later disposition, transported to an approved on-site/off--site treatment facility <br /> or to a sewer discharge system <br /> COLLECTION OF WATER SAMPLE FOR ANALYSIS ' <br /> The groundwater in the well is allowed to recover to at least 80% of its '.olume prior to <br /> purging, if practical, before the ground% ater sample is collected <br /> Percent Recovery = (1 - Residual_drawdol;n) Y 100 <br /> Maximum drawdo«n <br /> A fresh bailer is used to collect enough %%aier for the requirements of the laboratory for <br /> the analyses needed or required The water samples are decanted from the bailer into the <br /> appropriate number and size containers These containers are famished pre-cleaned to <br /> exact EPA protocols, with and without preservatives added, by the analytical laboratory <br /> or a chemical supply company The bottles are filled, with no headspace, and then <br /> capped with plastic caps with teflon liners <br /> ti <br /> The vials or bottles containing the groundwater samples are labeled with site name, <br /> station, date, time, sampler, and analyses to be performed, and documented on a chain of <br /> i <br /> 7 <br />