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Home My WebLink AboutSS2 - Water Quality Report on Public Health Goals - Copper LevelsStudy Session Item No. 2 UTILITIES DEPARTMENT Electrical • Oil & Gas • Water • Wastewater TO: Mayor and City Council FROM: Eldon Davidson, Utilities Director DATE: March 12, 2002 RE: Water Quality Report on Public Health Goals - Copper Levels Purpose The purpose of this report is to explain, in plain language, information about the presence of any contaminants in the drinking water supply, detected at levels above the Public Health Goals (PHG's) published by the State Office of Environmental Health Hazard Assessment (OEHHA), and in effect on January 1, 2001. Background The USEPA and the California Department of Health Services (CDHS) establish very conservative water quality standards for domestic drinking water systems. These standards are based on various risk - assessment factors, and are expressed in terms of an allowable Maximum Contaminant Level (MCL) for every regulated contaminant. The MCL is the regulatory definition of what is "safe." The MCL's are strictly enforced. Water agencies are required to take specific actions to notify consumers, and to mitigate the problem if an MCL is exceeded. The City of Newport Beach water system consistently meets all federal and state drinking water MCL standards. California, also, establishes Public Health Goals (PHG's) for drinking water systems. The federal equivalent to PHG's are called Maximum Contaminant Level Goals (MCLG's). PHG's and MCLG's are not enforceable standards. Water agencies are not required to take any actions regarding them. These goals are not based on a comprehensive risk assessment analysis. Instead, they are set to only represent a contaminant level that would result in either zero health risk or "no significant" (one in a million) health risk for a lifetime of exposure. Determinations of health Water Quality Report on Public Health Goals - Copper Levels Page 2 risks at these low levels are frequently and theoretically based on risk assessments with many assumptions. Many PHG's are set at zero. California legislation requires water agencies to prepare a special report every three years, if their water exceeds any PHG or MCLG. The report must identify all contaminants in excess of a PHG, the public health risks involved, and a general estimate of the costs that would be involved in removing the contaminants in order to meet the goals. The purpose of this report is to address contaminant levels and to fumish information about the cost to basically eliminate even small traces of contaminates from the water supply. A listing of regulated contaminates and their MCL's PHG's, and MCLG's are attached (see Attachment 1). All of the water quality data collected in 1998, 1999 and 2000 for purposes of determining compliance with drinking water MCL standards was considered for the purposes of this report. This data was summarized in the 2001 Annual Water Quality & Consumer Confidence Report and mailed to all customers every year. As indicated previously, the City of Newport Beach water system complies with all federal and state MCL standards. The City of Newport Beach water supply from wells and imported sources, with only one exception during the last three years (copper level), met all of the PHG and MCLG standards. Substances Detected That Exceed a PHG or a MCLG: In 2000 only 29 of the substances listed on Attachment No. 1 were detected in the City's water supply. All were at levels far below the enforceable drinking water standards (MCL's). Of those 29, only copper was found at a level above the PHG or MCLG. Copper Levels There is no MCL in the primary drinking water standards for copper. Instead, the 90"' percentile value of all samples from household taps in the distribution system cannot exceed an Action Level 1.3 mg /1 for copper. The PHG for copper is 0.17 mg 11. Based on 30 household tap sampled in 2000 our 90th percentile value for copper was 0.23 mg /I. Source water samples taken for copper in 2000 from MWD supply and City wells, were below the PHG. Potential source of contamination is internal corrosion of household plumbing and erosion of natural deposits. The category of health risk for copper is. gastrointestinal irritation. Numerical health risk data on copper have not yet been provided by OEHHA, the State agency responsible for providing that information. Our water system is in full compliance with the Federal and State Lead and Copper Rule. Based on our extensive sampling, it was determined according to State regulatory requirements that we meet the Action Levels (AL's) for Lead and Copper. AL's are health - based advisory levels established by CDHS for chemicals in drinking water where no MCL's have been set. AL's are set at a level which will pose no significant health risk. Water Quality Report on Public Health Goals - Copper Levels Page 3 In general, optimizing corrosion control through chemical treatment is considered to be the best available technology to deal with corrosion issues and with any lead or copper findings. CDHS considers an agency to have optimized corrosion control whenever their gOTh percentile copper level (0.23 mg /L for Newport Beach) is below the action level of 1.3 mg /L. We continue to monitor our water quality parameters that relate to corrosivity, such as the pH, hardness, alkalinity, total dissolved solids, and will take action if necessary to maintain our system in an "optimized corrosion control" condition. Since we are meeting the "optimized corrosion control" requirements, it is not prudent to initiate additional corrosion control treatment as it involves the addition of other chemicals and there could be additional water quality issues raised. Therefore, no estimate of cost has been included. Conclusion The City of Newport Beach Utilities Department meets all State of California, Department of Health Services and USEPA drinking water standards set to protect public health. To further reduce the levels of the copper identified in this report that is already significantly below the health —based action levels established to provide safe drinking water, would require unwarranted costly treatment processes. The effectiveness of the treatment processes to provide any significant reduction in copper levels at these already low values is uncertain. The health protection benefits of these further hypothetical reductions are not all clear and may not be quantifiable. Therefore, no additional measures are recommended. ATTACHMENT NO. 1 CALIFORNIA MCLs AND PHGs AND FEDERAL MCLGs PARAMETERS( mg/L STATE 0.05 PHG CONSTITUENTS Units MCL DLR or ARSENIC mg/L 0.05 0.002 (MCLG) INORGANICS ALUMINUM mg/L 1 0.05 none ANTIMONY mg/L 0.006 0.006 0.020 ARSENIC mg/L 0.05 0.002 none ASBESTOS fibers/L 7 million 0.2 million 7 million BARIUM m L 1 0.1 2 BERYLLIUM mg/L 0.004 0.001 (0.004) CADMIUM m 0.005 0.001 0.00007 CHROMIUM mg /L 0.05 0.01 0.0025 COPPER (at-the-tap,, 90th Percentile) mg/L I AL--1.3 0.05 0.17 CYANIDE mg/L 0.2 0.1 0.15 FLUORIDE mg /L 1.4 -2.4 0.1 1 LEAD at theta - 90th percentile m L AL =0.015 0.005 0.002 MERCURY mg/L 0.002 0.001 0.0012 NICKEL mg/L 0.1 0.01 none NITRATE as NI mg/L 10 0.4 10 NITRATE Fes NO3 m 45 2 45 NITRITE as NI m 1 0.4 1 SELENIUM mg /L 0.05 1 0.005 0.05 THALLIUM mg/L 0.002 1 0.001 1 060001 ORGANICS ACRYLAMIDE TT TT 0 ALACHLOR mg/L 0.002 0.001 0.004 ATRAZINE mg/L 0.003 0.001 0.00015 BENTAZON mg/L 0.018 0.002 0.2 BENZENE m 0.001 0.0005 0 BENZO a PYRENE mg/L 0.0002 0.0001 0.000004 CARBOFURAN mg/L 0.018 0.005 0.0017 CARBON TETRACHLORIDE mg/L 0.0005 0.0005 0.0001 CHLORDANE mg/L 0.0001 0.0001 0.00003 CHLOROETHENE rVINYL CHLORIDEJ mgtL 1 0.0005 0.0005 0.00005 CIS -I2- DICHLOROETHYLENE mg/L 0.006 0.0005 0.07 2,4-D mg /L 0.07 0.01 0.07 DALAPON mg/L 0.2 0.01 0.79 DIBROMOCHLOROPROPANE DBCP m 0.0002 0.00001 0.0000017 12- DICHLOROSENZENE IORTHOJ m 0.6 0.0005 0.6 1 4- DICHLOROBENZENE PARR mg/L 0.005 0.0005 0.006 11- DICHLOROETHANE 11 -DCA mgfL 0.005 0.0005 none 1 2- DICHLOROETHANE 12 -DCA m 0.0005 0.0005 0.0004 11- DICHLOROETHENE 11 -DCE mg /L 0.006 0.0005 0.01 DICHLOROMETHANE mg/L 0.005 0.0005 0.004 12- DICHLOROPROPANE m 0.005 0.0005 0.0005 13- DICHLOROPROPENE mg/L 0.0005 0.0005 0.0002 D( (2- ETHYLHEXYL ) ADIPATE mg/L 0.4 0.005 0.4 DI 2- ETHYLHEXYL PHTHALATE mg/L 0.004 0.003 0.012 DINOSES mg1L 0.007 0.002 0.014 DIOXIN (2,3,7,8 - TCDD mg/L 3x10 5x10' 0) DIQUAT mg/L 0.02 0.004 0.015 ENDOTHALL mg /L 0.1 0.045 0.58 ENDRIN mg/L 0.002 0.0001 0.0018 EPICHLOROHYDRIN TT (0 ETHYLBENZENE mg/L 0.7 0.0005 0.3 ETHYLENE DIBROMIDE rEDBJ mg/L 0.00005 0.00002 0 GLYPHOSATE mg/L 0.7 7F 0.025 1.0 ATTACHMENT NO. 1 CALIFORNIA MCLs AND PHGS AND FEDERAL MCI-Gs PARAMETERS/ mg/L STATE 0.00001 PHG CONSTITUENTS Units MCL DLR or HEXACHLOROBENZENE mg/L 0.001 0.0005 (MCLG) HEPTACHLOR mg/L 0.00001 0.00001 0.000008 HEPTACHLOR EPDXIDE mg/L 0.00001 0.00001 0.000008 HEXACHLOROBENZENE mg/L 0.001 0.0005 (0) HEXACHLOROCYCLOPENTADIENE mg/L 0.05 0.001 0.05 LINDANE mg/L 0.0002 0.0002 0.000032 METHOXYCHLOR mg/L 0.04 0.01 0.03 METHYL TERTIARY BUTYL ETHER MTBE mg/I 0.013 0.003 0.013 MOLINATE mg/L 1 0.02 0.002 1 none MONOCHLOROBENZENE mg/L 0.07 0.0005 0.1 OXAMYL mg/L 0.2 0.02 0.05 PENTACHLOROPHENOL mg/L 0.001 0.0002 0.0004 PICLORAM mg/L 0.5 0.001 0.5 POLYCHLORINATED BIPHENYLS [PCBsj mg/L 0.0005 0.0005 0) SILVER 2 4 5 -TP mg/L 0.05 0.001 (0.05) SIMAZINE mg1L 0.004 0.001 (0.004) STYRENE mg/L 0.1 0.0005 0.1) 1 1 2 2- TETRACHLOROETHANE 0.005 0.0005 0) TETRACHLOROETHYLENE PCE mg /L 0.005 0.0005 (0 THIOBENCARB mg /L 1 0.07 0.001 0.07 TOLUENE mg/L 0.15 0.0005 0.15 TOXAPHENE mg/L 0.003 0.001 (0) TRANS -I,2- DICHLOROETHYLENE mg/L 0.01 0.0005 (0.1 1 2 4- TRICHLOROBENZENE mg/L 0.07 0.0005 0.005 1 1 1 -TRI CH LOROETHAN E f 1 1 1 -TCAI mg/L 0.2 0.0005 (0.2) 112- TRICHLOROETHANE 112 -TCA mg/L 0.005 0.0005 (0.003 TRICHLOROETHYLENE rTCEJ mg/L 0.005 0.0005 0.0008 TRICHLOROFLUOROMETHANE FREON 11 mg/L 0.15 0.005 0.70 TRICHLOROTRIFUOROETHANE FREON 113 mg/L 1.2 0.01 4.0 TRIHALOMETHANES TOTAL Ms mglL 0.1 0.0005 none XYLENES rSUM OF ISOMERS mg/L 1 1.750 0.0005 1.800 MICROBIOLOGICAL COLIFORM % POSITIVE SAMPLES % 5 zero GIARDIA LAMBLIA TT (zero) LEGIONELLA TT (zero) VIRUSES TT (zero) RADIOLOGICAL ALPHA ACTIVITY GROSS pCill- 1 15 1 none' BETA ACTIVITY GROSS pCUL 1 50 L 4 none RADIUM 228 & 228 TOTAL pCUL 5 1 none' STRONTIUM 90 p CUL 8 2 none TRITIUM pCUL 1 20000 1 1000 I none URANIUM pCill- 1 20 1 2 0) MCL = Maximum Contaminant Level PHG = Public Health Goal MCLG = Maximum Contaminant Level Goal DLR = Detection Limit for Reporting purposes; set by DHS 'MCLGs of zero adopted in 2000 but not effective until 2003