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HomeMy WebLinkAboutItem 23 - Report on Water Quality Relative to Public Health Goals Public Works Agency www.santa-ana.org/pw Item # 23 City of Santa Ana 20 Civic Center Plaza, Santa Ana, CA 92701 Staff Report October 18, 2022 TOPIC: Report on Water Quality Relative to Public Health Goals AGENDA TITLE Public Hearing – Report on Water Quality Relative to Public Health Goals RECOMMENDED ACTION Receive and file the Report on Water Quality Relative to Public Health Goals. DISCUSSION The California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment establishes Public Health Goals (PHGs) for drinking water contaminants. The PHGs are guidelines, not requirements, for any public water system. PHGs are frequently much lower than the maximum contaminant levels (MCLs) established by the United States Environmental Protection Agency (USEPA). Under provisions of the California Health and Safety Code, the City is required to prepare a special report every three years identifying water quality measurements that have exceeded PHGs (Exhibit 1). For the years of 2019, 2020, and 2021, the report depicts that Santa Ana’s drinking water continues to meet all State of California, Department of Health Services, and USEPA drinking water standards set to protect public health. The City’s drinking water consists of naturally-occurring arsenic, radium, uranium, gross alpha particle activity, and gross beta particle activity, as well as bromate and perchlorate. The report provides estimated costs for using the best available technologies for treatment of these contaminants and intended actions by the City to reduce the concentration of the contaminants. No further treatment programs are planned at this time due to the extraordinary capital and maintenance costs that would be required to construct and operate these treatment systems. The report indicates that using the best available treatment options, ion exchange and reverse osmosis, may remove all the contaminants detected above the PHGs but would cost between $10,200,000 and $80,000,000 per year. State law specifies that a public hearing for the purpose of accepting and responding to public comments on the report be held. This public hearing meets the legal requirement. Water Quality – Public Health Goals October 18, 2022 Page 2 3 0 0 6 ENVIRONMENTAL IMPACT There is no environmental impact associated with the action. FISCAL IMPACT There is no fiscal impact associated with this action. EXHIBIT(S) 1. City of Santa Ana Report on Water Quality Relative to Public Health Goals Submitted By: Nabil Saba, P.E., Executive Director – Public Works Agency Approved By: Kristine Ridge, City Manager EXHIBIT 1 CITY OF SANTA ANA 2022 PUBLIC HEALTH GOALS REPORT JUNE 2022 2022 Public Health Goals (PHGs) Report City of Santa Ana 1.0 Introduction Under the Calderon-Sher Safe Drinking Water Act of 1996 public water systems in California serving greater than 10,000 service connections must prepare a report containing information on 1) detection of any contaminant in drinking water at a level exceeding a Public Health Goal (PHG), 2) estimate of costs to remove detected contaminants to below the PHG using Best Available Technology (BAT), and 3) health risks for each contaminant exceeding a PHG. This report must be made available to the public every three years. The initial report was due on July 1, 1998, and subsequent reports are due every three years thereafter. This report has been prepared to address the requirements set forth in Section 116470 of the California Health and Safety Code. It is based on water quality analyses during calendar years 2019, 2020, and 2021 or, if certain analyses were not performed during those years, the most recent data available. The report has been designed to be as informative as possible, without unnecessary duplication of information contained in the Consumer Confidence Reports, which are mailed to customers by July 1 of each year. There are no regulations explaining requirements for the preparation of PHGs reports. A workgroup of the Association of California Water Agencies (ACWA) Water Quality Committee has prepared suggested guidelines for water utilities to use in preparing PHGs reports. The ACWA guidelines were used in the preparation of this 2022 report. These guidelines include tables of cost estimates for BAT. The State of California (State) provides ACWA with numerical health risks and category of health risk information for contaminants with PHGs. This health risk information is appended to the ACWA guidelines. City of Santa Ana 1 2022 PHGs Report 2.0 California Drinking Water Regulatory Process California Health and Safety Code Section 116365 requires the State to develop a PHG for every contaminant with a primary drinking water standard or for any contaminant the State is proposing to regulate with a primary drinking water standard. A PHG is the level of a contaminant in drinking water that poses no significant health risk if consumed for a lifetime. The process of establishing a PHG is a risk assessment based strictly on human health considerations. PHGs are recommended targets and are not required to be met by any public water system. The State office designated to develop PHGs is the California Environmental Protection Agency’s Office of Environmental Health Hazard Assessment (OEHHA). The PHG is then forwarded to the State Water Resources Control Board, Division of Drinking Water (DDW) for use in revising or developing a Maximum Contaminant Level (MCL) in drinking water. The MCL is the highest level of a contaminant that is allowed in drinking water. California MCLs cannot be less stringent than federal MCLs and must be as close as is technically and economically feasible to the PHGs. DDW is required to take treatment technologies and cost of compliance into account when setting an MCL. Each MCL is reviewed at least once every five years. Two radiological contaminants (gross alpha particle and gross beta particle) have MCLs but do not yet have designated PHGs. For these contaminants, the Maximum Contaminant Level Goal (MCLG), the federal U.S. Environmental Protection Agency (USEPA) equivalent of PHGs, is used in the 2022 PHGs Report. 3.0 Identification of Contaminants Section 116470(b)(1) of the Health and Safety Code requires public water systems serving more than 10,000 service connections to identify each contaminant detected in drinking water that exceeded the applicable PHG. Section 116470(f) requires the MCLG to be used for comparison if there is no applicable PHG. City of Santa Ana 2 2022 PHGs Report The City of Santa Ana (City) water system has approximately 45,256 service connections. The following constituents were detected at one or more locations within the drinking water system at levels that exceeded the applicable PHGs or MCLGs:  Arsenic – naturally-occurring in local groundwater.  Bromate – formed when naturally-occurring bromide reacts with ozone during the disinfection process in surface water purchased from Metropolitan Water District of Southern California (MWDSC).  Perchlorate – industrial contamination in local groundwater.  Gross alpha particle activity (gross alpha) – naturally-occurring in local groundwater and surface water purchased from MWDSC.  Gross beta particle activity (gross beta) – naturally-occurring in surface water purchased from MWDSC.  Radium, Combined (sum of Radium-226 and Radium-228) – naturally-occurring in surface water purchased from MWDSC.  Uranium – naturally-occurring in local groundwater and in surface water purchased from MWDSC. The accompanying chart shows the applicable PHG or MCLG and MCL for each contaminant identified above. The chart includes the maximum, minimum, and average concentrations of each contaminant in drinking water supplied by the City in calendar years 2019 through 2021. 4.0 Numerical Public Health Risks Section 116470(b)(2) of the Health and Safety Code requires disclosure of the numerical public health risk, determined by OEHHA, associated with the MCLs, PHGs and MCLGs.Available numerical health risks developed by OEHHA for the contaminants identified above are shown on the accompany chart. Only numerical risks associated with cancer-causing chemicals have been quantified by OEHHA. City of Santa Ana 3 2022 PHGs Report Arsenic – OEHHA has determined the health risk associated with the PHG is 1 excess case of cancer in a million people. USEPA has determined the risk associated with the MCL is 2.5 excess cases of cancer in 1,000 people exposed over a 70-year lifetime. Bromate – OEHHA has determined the theoretical health risk associated with the PHG is 1 excess case of cancer in a million people. USEPA has determined the risk associated with the MCL is 1 excess cases of cancer in 10,000 people exposed over a 70-year lifetime. Gross Alpha – OEHHA has not established a PHG. USEPA has established an MCLG of 0 and the risk associated with the MCL is 1 excess case of cancer in 1,000 people over a lifetime exposure. Gross Beta – OEHHA has not established a PHG. USEPA has established an MCLG of 0 and the risk associated with the MCL is 2 excess cases of cancer in 1,000 people over a lifetime exposure. Perchlorate – OEHHA has not established a numerical health risk for perchlorate because PHGs for non-carcinogenic chemicals in drinking water are set at a concentration at which no known or anticipated adverse health risks will occur, with an adequate margin of safety. Radium, Combined – OEHHA has determined that the health risk associated with the PHG is 1 excess case of cancer in one million people over a lifetime exposure and the risk associated with the MCL is 1 excess case of cancer in 10,000 people for radium- 226 and 3 excess cases of cancer in 10,000 people for radium-228 over a lifetime exposure. Uranium – OEHHA has determined the theoretical health risk associated with the PHG is 1 excess case of cancer in a million people. USEPA has determined the risk City of Santa Ana 4 2022 PHGs Report associated with the MCL is 5 excess cases of cancer in 100,000 people exposed over a 70-year lifetime. 5.0 Identification of Risk Categories Section 116470(b)(3) of the Health and Safety Code requires identification of the category of risk to public health associated with exposure to the contaminant in drinking water, including a brief, plainly worded description of those terms. The risk categories and definitions for the contaminants identified above are shown on the accompanying chart. 6.0 Description of Best Available Technology Section 116470(b)(4) of the Health and Safety Code requires a description of the BAT, if any is available on a commercial basis, to remove or reduce the concentrations of the contaminants identified above. The BATs are shown on the accompanying chart. 7.0 Costs of Using Best Available Technologies and Intended Actions Section 116470(b)(5) of the Health and Safety Code requires an estimate of the aggregate cost and cost per customer of utilizing the BATs identified to reduce the concentration of a contaminant to a level at or below the PHG or MCLG. In addition, Section 116470(b)(6) requires a brief description of any actions the water purveyor intends to take to reduce the concentration of the contaminant and the basis for that decision. Arsenic – The BATs for removal of arsenic in water for large water systems are: activated alumina, coagulation/filtration, electrodialysis, ion exchange, lime softening, oxidation/filtration, and reverse osmosis. Arsenic was detected above the PHG in the local groundwater (Well 37). The City is in compliance with the MCL for arsenic. The estimated cost to reduce arsenic levels in local groundwater to below the PHG of 0.004 City of Santa Ana 5 2022 PHGs Report microgram per liter (µg/l) using ion exchange was calculated. Because the DDW detection limit for purposes of reporting (DLR) for arsenic is 2 µg/l, treating arsenic to below the PHG level means treating arsenic to below the DLR of 2 µg/l. There are numerous factors that may influence the actual cost of reducing arsenic levels to the PHG. Achieving the water quality goal for arsenic could be approximately $2,120,000 per year, or $47 per household per year. Bromate – The BATs for removal of bromate in water for large water systems are: coagulation/filtration optimization, granular activated carbon, and reverse osmosis. Bromate was detected above the PHG in surface water supplied by MWDSC. The City is in compliance with the MCL for bromate. The estimated cost to reduce bromate levels in MWDSC surface water to below the PHG of 0.1 µg/l using reverse osmosis was calculated. Because the DDW DLR for bromate is 1 µg/l, treating bromate to below the PHG level means treating bromate to below the DLR of 1 µg/l. There are numerous factors that may influence the actual cost of reducing bromate levels to the PHG. Achieving the water quality goal for bromate could range from approximately $2,280,000 to $19,500,000 per year, or between $50 and $431 per household per year. Gross Alpha, Gross Beta, Combined Radium, and Uranium – The only BAT for the removal of gross alpha in water for large water systems is reverse osmosis, which can also remove gross beta, combined radium, and uranium, if detected. Gross alpha was detected above the MCLG in the local groundwater (Wells 18, 20, 21, 24, 27, 28, 30, 31, 33, 34, 35, 36, 37, 39, and 41) and in the surface water supplied by MWDSC. Gross beta was detected above the MCLG in the surface water supplied by MWDSC. Combined radium was detected above the MCLG in the surface water supplied by MWDSC. Uranium was detected above the PHG in the local groundwater (Wells 18, 20, 21, 24, 27, 28, 30, 31, 33, 34, 35, 36, 39, and 41) and in the surface water supplied by MWDSC. The cost of providing treatment using reverse osmosis to reduce gross alpha levels in local groundwater and in MWDSC surface water to the MCLG of 0 picoCurie per liter (pCi/l) (and consequently gross beta in MWDSC surface water below the MCLG; combined radium in MWDSC surface water below the MCLG; and uranium City of Santa Ana 6 2022 PHGs Report in local groundwater and in MWDSC surface water below the PHG) was calculated. Because the DLR for gross alpha is 3 pCi/l, treating gross alpha to 0 pCi/l means treating it to below the DLR of 3 pCi/l. Achieving the water quality goal for gross alpha could range from $9,180,000 to $78,500,000 per year, or between $203 and $1,735 per household per year. Perchlorate – The BATs for removal of perchlorate in water are: ion exchange and biological fluidized bed reactor. Perchlorate was detected above the PHG in the local groundwater (Wells 18, 21, 24, and 36). The City is in compliance with the MCL for perchlorate. The estimated cost to reduce perchlorate levels in local groundwater to below the PHG of 1 µg/l using ion exchange was calculated. Because the DLR for perchlorate is 2 µg/l, treating perchlorate to below the PHG level means treating perchlorate to below the DLR of 2 µg/l. There are numerous factors that may influence the actual cost of reducing perchlorate levels to the PHG. Achieving the water quality goal for perchlorate could range from $1,040,000 to $2,270,000 per year, or between $23 and $50 per household per year. All Contaminants – In addition, a cost estimate to treat all water produced or purchased by the City using ion exchange and reverse osmosis to remove all the contaminants detected above the PHGs or MCLGs was calculated.All the contaminants listed in the accompanying chart may be removed to non-detectable levels by ion exchange and reverse osmosis. As shown on the accompanying chart, achieving the water quality goals for all contaminants using ion exchange and reverse osmosis could range from $10,200,000 to $80,800,000 per year, or between $226 and $1,785 per household per year. For additional information, please contact Mr. Robert Hernandez, Water Services Quality Supervisor, at (714) 647-3341, or write to the City of Santa Ana, 220 South Daisy Avenue, Santa Ana, California 92703. J:\2605\2605-003 - Santa Ana 2022 PHG\Santa Ana_2022 PHG_text_Final.docx City of Santa Ana 7 2022 PHGs Report 2022 PUBLIC HEALTH GOALS REPORT CITY OF SANTA ANA UNITS OF MEASUREMENT PHG OR (MCLG)* CONCENTRATION GROUNDWATER SURFACE WATER CATEGORY CANCER RISK CANCER BEST AVAILABLE TECHNOLOGIES AGGREGATE COST PER YEAR COST PER HOUSEHOLD PER YEAR PARAMETER MCL DLR OF AT PHG RISK VALUE RANGE VALUE RANGE RISK OR MCLG AT MCL INORGANIC CHEMICALS Arsenic μg/l μg/l μg/l 0.004 0.1 1 10 10 6 2 1 2 ND NR ND ND - 2.2 NR ND 1.3 ND ND ND - 7 ND C C E 1 x 10-6 1 x 10-6 NA 2.5 x 10-3 1 x 10-4 NA AA,C/F,E,IE,LS,O/F,RO C/F, GAC, RO $2,120,000 (a)$47 (a) Bromate $2,280,000 - $19,500,000 (b) $1,040,000 - $2,270,000 (c) $50 - $431 (b) $23 - $50 (c)Perchlorate ND - 5 IE, BFBR RADIOLOGICAL Gross Alpha Particle Activity Gross Beta Particle Activity Radium, Combined (e) Uranium pCi/l pCi/l pCi/l pCi/l (0) (0) 15 50 5 3 4 ND NR ND 2.8 ND - 14 NR ND ND ND 1.3 ND - 3 ND - 7 ND - 1 ND - 3 C C C C 0 1 x 10-3 2 x 10-3 3 x 10-4 5 x 10-5 RO IE, RO IE, LS, RO RO $9,180,000 - $78,500,000 (d)$203 - $1,735 (d) 0 -- -- -- -- -- -- (0)1 (e) 1 ND 1 x 10-6 1 x 10-60.43 20 ND - 8.2 ALL CONTAMINANTS ----------------------IE and RO $10,200,000 - $80,800,000 (f)$226 - $1,785 (f) * MCLGs are shown in parentheses. MCLGs are provided only when no applicable PHG exists. RISK CATEGORIES TREATMENT TECHNOLOGIES AA = Activated Aluminum BFBR = Biological Fluidized Bed Reactor C/F = Coagulation/Filtration E = Electrodialysis C (Carcinogen) = A substance that is capable of producing cancer. E (Endocrine Toxicity; Developmental Toxicity) = Affects tyroid; causes neurodevelopmental deficits NOTES PHG = Public Health Goal GAC = Granular Activated Carbon IE = Ion Exchange LS = Lime Softening O/F = Oxidation/Filtration RO = Reverse Osmosis MCL = Maximum Contaminant Level MCLG = Maximum Contaminant Level Goal NA = Not Appplicable or Available ND = Not Detected NR = Not Required ug/l = micrograms per liter or parts per billion pCi/l = picoCuries per liter DLR = Detection Limit for Purposes of Reporting (a) Estimated cost to remove arsenic using IE. (b) Estimated cost to remove bromate using RO. (c) Estimated cost to remove perchlorate using IE. (d) Estimated cost to remove gross alpha particle activity using RO, which also removes combined radium, gross beta particle activity, and uranium. (e) As the sum of radium-226 and radium-228. DLRs for radium-226 and radium-228 is 1 pCi/L and 1 pCi/L, respectively. (f) Assuming treating the entire production by IE and RO, which can remove all contaminants listed in the above chart to below the detecchart levels. J:\2605\2605-003 - Santa Ana 2022 PHG\Santa Ana_phgtable_2022.xlsx