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CORRECTNE ACTIONS AFTER TREATMENT VESSEL. PRESSURE TANK and STROGAE DANK COMPONENT INVESIMATION: Correct all identified structural deficiencies that allowed the entrance of bacteria. After the corrections have been achieved,disinfect the effected vessel, tank;and water line connections between the effected component and the system, per the AWWA Standards,using NSF 61 approved chlorine. Effective disinfection of a pressure tank and storage tank induces the removal of sediment and#cushing clear of all debris,before applying a 200 ppm chlorine solution to all surfaces of the vesselltank.Once all surfaces have been washed with the solution, fill the vesselitank to overflow level with a solution of 50 ppm and hold for 6-24 hours. After two hours of contact time with the disinfectant, sample the vessel/tank for the chiorine residual. If the residual tests below 50 ppm, Increase the concentration to 50 ppm. A successful disinfection requires a residual of at least 10 ppm to be present after the B-24 hours. If the chlorine residual is found to be non-detectable, then the disinfection process may not have been successful. Repeat the cleaning and disinfection process. The media in an effected vessel shall be disinfected per the manufacturer's specifications to eliminate the presence of bacteria in the media and vessel. The contaminated media may be removed from the vessel and appropriately disposed of or reconditioned per the manufacturer's specifications. The empty effected vessel is then disinfected(i.e. initial contact with a solution of 200 ppm chlorine residual and then filed to overflow levels with 50 ppm for 6-24 hours). The vessel may be ra-bedded with new media, after the vessel tests TC absent with <0.05 ppm chlorine residuals. Resarrtple the disinfected component by directing your laboratory to collect samples and test for no chigrine residuals and absence of TC bacteria, using enumeration test.methods, before connecting the components to the system. #the COMPONENT Conti-M91-to Fails; Contact the END for guidance at(209)4.68-5420. DISTRIBLI110N SYSTEM INVE9TIGATION; Review the REPEAT results above. Of these results, which sample location is positive with the highest MPN count? Have your laboratory collect additional"Other"TC samples up stream and down stream of the site (with the highest MPN)to find where the system begins to test TC positive and the highest MPN count,within the system. These"'Other*results will ID where bacteria are entering into the system. Inspect the system, looking criticali-vtAW �u stream and down stream of the site with the highest MPN and review the histo of the s tem for the possible cause of the TCR MCL as noted below. - µ What is the minimum pressureyou are maintainlnp in the distributions ? Must operate system at pressures y 20 psi at all times. Has the distribution system been worked on within the last week? (gaps, hydrant flushing,main breaks, mainline extensions, etc.) If yas. erovide details. YIN 1`4D Are there any signs of excavations near your distribution system not under the direct control of our maintenance stafli I YIN D On what date was the distribution system last flushed? Is there a written flushing procedure you can provide for our review? YIN N 0 Investigate for backflow devices that have been removed that shouldn't have,that need repair,need to be Installed or installed properly. Ensure all testable backflow devices are functioning by a Certified tester after being repayed or installed. Have the backflow devices been tested this year? If N. then have them tested now by a y certified tester. Have the backflow devices bean inspected for leaks,damage,or presence this month? YIN On what date was the system last surveyed to identify cross connections? Is the ground wet in an area that has not been Irrigated? YIN p Are the water meter readings indicating higher than normal water usage? YIN r4b Could Indicate a wager line break. Has anyone connected to the system with:a high pressure washer, a neighboring water s tem, RV, a water tank, or a hose used to tit a poolftnkl Y/N If Y,note date of the event. D Did they system experience a drop of pressure below 5 psi?(evidence of dirty water,no water,power outage, pump failure,break in a water line,was system water used for an event that used more water then normal)If Y, note state of the event. YIN Was system or portion of the system(building,home,RV)not used for a while,then resumed normal water usage or experience a drop of pressure{as desuibed in box above)?If Y,nota slate YIN 1�D