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CORRECTIVE ACTIONS AFTER SOURCE INYESTIGATIQN: Upon correcting the identified physical deficiencies,disinfect the water in the well casing using NSF 61 approved chlorine and AWVVA procedures, Apply chlorine at 60 ppm concentrations into the well. Circulate the chlorinated water within the well, up through the pump column,into the pressure tank and back Clown into the weal by turning on time well and opening a valvelhose bib at ttte pressure tank. Connect a hose to a hose bib at the pressure tank that terminates with a small diameter wand able to spray a circular spray pattern to wet the sides of the weft casing and pump column above the water table, when the wand is inserted into the 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, tum off the well, close the valvefhose bib at the pressure tank, disconnect the hose, and seal the wellhead at access port to be water tight, A3iow 12-24 hours for the 50 ppm chlorinated water 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 water to waste and resample the well for Hort detect ehlorina residuals. Contact your lakoratofy to cdlegt a wellhead sampi to test for chlorine residuals and TO bacteria, using_enumeration test methods, Once SOURCE is absent proceed with disinfecting DISTRIBUTION SYSTEM as noted below. Contact the END if you need guidance with this procedure, If Well Confinisets to Fails. Investigate the well casing using a camera and record the findings to determine the condition of the casing, movement of groundwater in and out of the well column, presence of o]I from a turbine pump, tree roots, other contributing deficiancles that may cause the well to test positive for TC_ Submit a copy of the well down-hole investigation recording to the EHD and contact the EHD for guidance at(209)468-3420. INVESTIGATION of a TCR INCL. If the SOURCE is absent and the DISTRIBUTION SYSTEM is positive for TC:: Have your laboratory collect additional "Other" TC Bacteriologicaf samples to determine If the pressure tank, storage tank, andlor treatment system is a TC source. Collect a sample down stream of these components to determine if the bacteriologlcal problem begins at these components. If the initial"tither"result is absent for TC, then go to DISTRIBUTION SYSTEM & investigate the distribution lines clown stream of these components, ff the°'Other" result is posiffv�, then sample downstream of each component to further ID where the 5y tem begins to fail for TC. Perform an inspection as detailed below in the Treatrr►ent Storage, and Pressure Tank sections. 4g, , g.�r -r._ •,c ,ice,-'V >. _ 5 � .,�.. Inspect each point where disinfectant Is added and report, any leaks? YIN is ttie disinfectant feed tank full with chlorin & what is the ppm concentration? A' Are there contaminants in the chlorine feed tank?YIN 1 A _ What is the disinfectant residua] down stream of injection point? What is the disinfectant residual at the end points of the system or repeat sites? A drop in chlorine indcates the Repeat 1f Repeat 21 Repeat 3l' ,End pt 11 End locatlon of the problern, Find where pt.21 the initial decrease begins, clown stream of the injection point, is the disinfectant teed tank and equipment skwad Ina pmh5cted manner ti.e.Is tank Stored ouI of the House equipment in an enclosure to sun,p(otsaW From rain,lid ks sealed on tank&lid sealed at tins,no openings to lank,irrigation I exclude vermin and elements. water is not sprinklin over the eVOrtent,birdsfvermin are not nesting ovetiead)? YIN Is the tank's water fill line protected by a back flow device or proper air gap? YINInstall a proper back flow device on fresh water flit line. What is the MPN concentration of bacteria in each vessel'? i What is the media in each vessel? j Is a vessel not in use, is it valved ofd YIN Inspect each treatment vessel for leaks at joints,valves,connecbans at top and bottom of the vessels man-ways not closed. Note if a leak was found and where at each vessel. Was the med is recently exchanged in a vessel or repair made to a vessel? YIN This vgxk may have caused TCR MGL.