Laserfiche WebLink
..F <br /> PUBLIC nEALTH SERVICES <br /> SAN JOAQUIN COUNTY <br /> ENVIRONMENTAL HEALTH DMSION <br /> Karen Fursr, M.D., M.P.H., Health Officer <br /> 304 East Weber Avenue, Third Floor• Stockton, CA 95202' 'FOR <br /> 209/468-3420 FILE Cu <br /> KRAZAN & ASSOCIATES INC <br /> BRUCE MEYERS OCT 9 SM <br /> 215 WEST DAKOTA AVE <br /> CLOVIS CA 93612 <br /> RE: Monitoring Well Installations SITE CODE: 507797 <br /> 212 Industrial Blvd. <br /> Stockton, CA., 95206 <br /> On September 25, 1998 San Joaquin County Public Health Services, <br /> Environmental Health Division (PHS-EHD) inspected the monitoring well <br /> installations and grouting procedures at the above noted site and brings to your <br /> attention the concerns noted by the inspector. <br /> Only in emergency situations should soil borings not be grouted by the end of <br /> the day. When this situation is deemed necessary as determined by the PHS- <br /> EHD staff inspecting the wells, the exact method of ensuring that any surface <br /> contaminants cannot enter the boring(s) will be established with the drilling <br /> contractor. The practice of leaving soil borings open overnight for grouting at a <br /> later time should not be a "planned" procedure. Monitoring well installation field <br /> procedures are to include grouting the borings or wells before leaving the site for <br /> the evening. <br /> There appears to have been a misunderstanding concerning removing the <br /> hollow stem augers from the bore hole prior to grouting the monitoring wells. <br /> PHS-EHD does not allow "sluff' soil to be between the bentonite sanitary seal <br /> and the grout. By removing the hollow stem augers before installing the grout, <br /> there is always the possibility that soil could "sluff' off and settle on top of the <br /> bentonite. If this occurs, PHS-EHD will require the "sluff' to be removed prior to <br /> placing the grout in the hole. Re-drilling the hole to the top of the bentonite could <br /> be required. Gravity installation of grout is limited to 30 feet maximum in soil <br /> borings (10 feet of groundwater maximum). Gravity installation of grout, in the <br /> annular space between the well casing and the wall of the drilled hole for <br /> monitoring, vapor extraction, and air sparge wells, without a tremie pipe is <br /> prohibited unless the interval to be sealed is dry, less than 10 feet deep, and <br /> there is no "sluffing" of the bore hole wall. <br /> In order to avoid re-drilling the borehole and possibly damaging the casing and <br /> the integrity of the well, PHS-EHD strongly suggests that the hollow stem augers <br /> remain in place after the bentonite seal is placed and be used as a tremie device <br /> for the pumping of the grout. <br /> A Division of San Joaquin County Health Care Services <br />