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CORRECTIlfE ACTIONS AFTER SOURCE INVESTIGATION: Upon correcting the identified physical deficiencies, disinfect the water in the well casing using NSF 63 approved chlorine and AVVWA procedures. Apply chlorine-at 50 ppm concentrations into the well. Circulate the chlorinated water within the well, up through the pump column, into the pressure tank and back down into the well by turning on the well and opening a valve/hose bib at the pressure tank. Connect a hose to a hose bib at the pressure dank that terminates with a small diameter wand able to spray a circular spray pattern to wet the sides of the well casing and pump column above the water table, when the wand is inserted into he wellhead seal access port. Circulate the chlorinated water down the sides of the well casing for 30 minutes, as noted above. Test the chlorine residual through this process to ensure 50 ppm chlorine residual. Dose well as needed to maintain 50 ppm chlorine residual. After 30 minutes, turn off the well, close the vaive/hese bib at the pressure tank, disconnect the hose, and seal the wellhead at access port to be water tight. Allow 12-24 hours for the 50 ppm chlorinated ,Nater to reside in the well. A successful disinfection requires a residual of at least 10 ppm to be present after the 18-24 hours. If the chlorine residual is found to be non-detectable, then the disinfection process may not have been successful. Repeat the disinfection process. If residual is at least 10 ppm, flush the well Nater to waste and resampie the well for non-detect chlorine residuals. Contact your laboratory to collect a wellhead sample to test for chlorine residuals and TC bacteria, usino enumeration test methods. Once SOURCE is absent proceed with disinfecting DISTRIBUTION SYSTEM as noted below. Contact the EHD if you need guidance•,vith this procedure. If Well Continues to Fails: Investigate the well casing using a camera and record the findings to determine the condition of the casing, movement or groundwater in and out of the well column, presence of oil from a turbine pump, tree roots, other contributing deficiencies that may cause the vied to test positive fcr TC. Submit a copy of the well down-hole investigation recording to the EHD and contact the EHD for guidance at(209)4.68-3420. INVESTIGATION of a TCR I)ACL if the SOURCE is absent and the DISTRIBUTION SYSTEM is positive for TC: Have your laboratory collect additional"Other" TC 3acterioiogical samples to determine if the pressure tank, storage tank, and/or treatment system is a TC source. Collect a sample down stream of these components to determine if the bacteriological problem begins at these components. If the initial "Other" result is absent for TC, then go to DISTRIBUTION SYSTEM & investigate the distribution lines down stream of these components. If the"Other" result is positive, then sample down stream of each component to further ID where the system begins to fail for TC. Perform an inspection as detailed below in the Treatment,Storage, and I'tessure Tank sections. TREATMENT USING CHLORINE FEED SYSTEM?Y COMMENTS If M.then go to next section Plant ID Plant ID Plant ID Inspect each point where disinfectant is added and report, any leaks? Y N Is the disinfectant feed tank full with chlorine &what is the ppm concentration? Are there contaminants in the chlorine feed tank?Y/N What is the disinfectant residual down stream of injection point? What is the disinfectant residual at the end points of the system or repeat sites? A drop in chlorine indicates the location of the problem. Find where Repeat I/_,Repeat 21 , Repeat 3/ ,End pt 1/ End the initial decrease begins,down pt.2/ stream of the injection point. Is the dist .. tont feed lank and equipment stored in a protected manner(i.e.Is tank stored out of the House equipment in an enclosure to sun,protected from rain,lid is sealed on tank&lid sealed at tubes,no openings to tank, irrigation exclude vermin and elements. vater is not sprinkling over the equipment,birds/vermin are not nesting overhead)? Y/N Is the tank's Nater fill line protected by a back flow device or proper air gap? YIN fresh water Install a proper back flow device on fill line. TREATMENT USING MEDIA? Y& If N,then go to next section. Vessel ID vessel ID vessel ID COMMENTS Is a Treatment Vessel positive for Bacteria? ff N,then go to next section What is the MPN concentration of bacteria in each vessel? ,Alhat is the media in each vessel? Is a vessel not in use, is it valved off? YIN inspect each treatment vessel for leaks at joints,valves,connections at top and bottom of the vessels man-ways not closed Note if a leak was found and where at each vessel. '1Vas the media recently exchanged in a vessel or repair made to a vessel? Y/N This work may have caused TCR�1CL.