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microgram per liter (pg/1) using ion exchange was calculated. Because the DDW <br />detection limit for purposes of reporting (DLR) for arsenic is 2 pg/l, treating arsenic to <br />below the PHG level means treating arsenic to below the DLR of 2 pg/l. There are <br />numerous factors that may influence the actual cost of reducing arsenic levels to the <br />PHG. Achieving the water quality goal for arsenic could be approximately $2,120,000 <br />per year, or $47 per household per year. <br />Bromate — The BATs for removal of bromate in water for large water systems are: <br />coagulation/filtration optimization, granular activated carbon, and reverse osmosis. <br />Bromate was detected above the PHG in surface water supplied by MWDSC. The City <br />is in compliance with the MCL for bromate. The estimated cost to reduce bromate <br />levels in MWDSC surface water to below the PHG of 0.1 pg/I using reverse osmosis <br />was calculated. Because the DDW DLR for bromate is 1 pg/I, treating bromate to below <br />the PHG level means treating bromate to below the DLR of 1 pg/I. There are numerous <br />factors that may influence the actual cost of reducing bromate levels to the PHG. <br />Achieving the water quality goal for bromate could range from approximately <br />$2,280,000 to $19,500,000 per year, or between $50 and $431 per household per year. <br />Gross Alpha, Gross Beta, Combined Radium, and Uranium — The only BAT for the <br />removal of gross alpha in water for large water systems is reverse osmosis, which can <br />also remove gross beta, combined radium, and uranium, if detected. Gross alpha was <br />detected above the MCLG in the local groundwater (Wells 18, 20, 21, 24, 27, 28, 30, 31, <br />33, 34, 35, 36, 37, 39, and 41) and in the surface water supplied by MWDSC. Gross <br />beta was detected above the MCLG in the surface water supplied by MWDSC. <br />Combined radium was detected above the MCLG in the surface water supplied by <br />MWDSC. Uranium was detected above the PHG in the local groundwater (Wells 18, <br />20, 21, 24, 27, 28, 30, 31, 33, 34, 35, 36, 39, and 41) and in the surface water supplied <br />by MWDSC. The cost of providing treatment using reverse osmosis to reduce gross <br />alpha levels in local groundwater and in MWDSC surface water to the MCLG of 0 <br />picoCurie per liter (pCi/1) (and consequently gross beta in MWDSC surface water below <br />the MCLG; combined radium in MWDSC surface water below the MCLG; and uranium <br />City fity ouncil 23 — 9 port <br />