CITy INCORPORATEO OR ORANGE
APRIL 6, 1888
CITY OF ORANGE
2025 PUBLIC HEALTH GOALS REPORT
JUNE 2025
861 S. Village Oaks Drive, Suite 100 • Covina CA 91724
Phone: (626) 967-6202 • Fax: (626) 331-7065 • Website: www.stetsonengineers.com Northern California Southern California • Arizona • Oregon
STETSON
ENGINEERS INC.
2025 Public Health Goals (PHGs) Report
City of Orange
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 PHGs Report was due on July 1, 1998, and subsequent reports are due every three years thereafter.
The 2025 PHGs 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 2022, 2023, and 2024 or, if certain analyses were not performed during those years, the most recent data is used. The 2025 PHGs Report has been designed to be as informative as possible, without unnecessary duplication of information contained in the Consumer Confidence Report (also known as Water Quality Report), which was available 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 2025 PHGs 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.
2.0 California Drinking Water Regulatory Process
California Health and Safety Code Section 116365 requires the State to develop a PHG tor 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.
City of Orange 1 2025 PHGs Report
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 (DW) 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. State 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 activity and gross beta particle activity) 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 2025 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.
The City of Orange (City) water system has approximately 36,597 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:
• Bromate - formed when naturally-occurring bromide reacts with ozone during the disinfection process in treated surface water purchased from the Metropolitan Water District of Southern California (MWDSC) and treated water purchased from East Orange County Water District (EOCWD).
• Gross alpha particle activity (gross alpha) - naturally-occurring in local groundwater, treated surface water purchased from MWDSC, and treated water purchased from EOCWD.
• Gross beta particle activity (gross beta) - naturally-occurring in treated surface water purchased from MWDSC and treated water purchased from EOCWD; not required to be tested in groundwater.
• Hexavalent Chromium - naturally-occurring in local groundwater. • Perchlorate - industrial contamination in local groundwater. • Perfluorooctanesulfonic acid (PFOS) - industrial contamination in local groundwater.
• Perfluorooctanoic acid (PFOA) - industrial contamination in local groundwater. • Radium, Combined, is the sum of Radium-226 and Radium-228 - naturally- occurring in local groundwater, treated water purchased from EOCWD, and treated surface water purchased from Serrano Water District (SWD).
City of Orange 2 2025 PHGs Report
• Uranium - naturally-occurring in local groundwater, treated surface water purchased from MWDSC, treated water purchased from EOCWD, and treated surface water purchased from the SWD.
The accompanying table shows the applicable PHG or MCG and MCL for each contaminant identified above. The table includes the maximum, minimum, and average concentrations of each contaminant in drinking water supplied by the City in calendar years 2022 through 2024.
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 table. Only numerical risks associated with cancer- causing chemicals have been quantified by OEHHA.
Bromate - OEHA has determined the health risk associated with the PHG is 1 excess case of cancer in a million people and the risk associated with the MCL is 1 excess case 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. USEPA has determined the risk associated with the MCL is 1 excess case of cancer in 1,000 people exposed over a 70-year lifetime for the most potent alpha emitter.
Gross Beta - OEHHA has not established a PHG. USEPA has established an MCLG of
0. USEPA has determined the risk associated with the MCL is 2 excess cases of cancer in 1,000 people exposed over a 70-year lifetime for the most potent beta emitter.
Hexavalent Chromium - OEHHA has determined the health risk associated with the PHG is 1 excess case of cancer in a million people and the risk associated with the MCL is 5 excess cases of cancer in 10,000 people exposed over a 70-year lifetime.
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.
PFOA - OEHHA has determined the health risk associated with the PHG is 1 excess case of cancer in a million people. There is no California MCL for PFOA; therefore, the risk information associated with the MCL is not available/applicable.
PFOS - OEHHA has determined the health risk associated with the PHG is 1 excess case of cancer in a million people. There is no California MCL for PFOS; therefore, the risk information associated with the MCL is not available/applicable.
City of Orange 3 2025 PHGs Report
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 70-year 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 70- year lifetime exposure.
Uranium - OEHHA has determined the health risk associated with the PHG is 1 excess case of cancer in a million people and the risk 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 table.
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 table.
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.
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 the treated surface water purchased from MWDSC and treated water purchased from EOCWD. The City is in compliance with the MCL for bromate. The estimated cost to reduce bromate levels in MWDSC water and EOCWD water to below the PHG of 0.1 microgram per liter (ug/l) using reverse osmosis was calculated. Because the DDW detection limit for purposes of reporting (DLR) for bromate is 1 ug/l, treating bromate to below the PHG level means treating bromate to below the DLR of 1 ug/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 $1,330,000 to $11,400,000 per year, or between $36 and $312 per service connection per year.
City of Orange 2025 PHGs Report
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 (three wells), treated surface water purchased from MWDSC, and treated water purchased from EOCWD. Gross beta was detected above the MCLG in the treated surface water purchased from MWDSC and treated water purchased from EOCWD. Combined radium was detected above the MCLG in the local groundwater (one well), treated water purchased from EOCWD, and treated surface water purchased from SWD. Uranium was detected above the PHG in the local groundwater (five wells), the surface water purchased from MWDSC, treated water purchased from EOCWD, and treated surface water purchased from SWD. The cost of providing treatment using reverse osmosis to reduce gross alpha levels to the MCLG of 0 pico Curie per liter (pCi/l) (and consequently gross beta to below the MCLG of 0 pCi/l, combined radium to below the MCLG of 0 pCill, and uranium to below the PHG of 0.43 pCill) was calculated. Because the DLR for gross alpha is 3 pCill, treating gross alpha to 0 pCi/l means treating it to below the DLR of 3 pCi/l (and treating gross beta, radium-226, radium-228, and uranium to below their respective DLRs of 4 pCi/l, 1 pCill, 1 pCill, and 1 pCill). Achieving the water quality goal for gross alpha could range from $6,230,000 to $53,400,000 per year, or between $170 and $1,460 per service connection per year.
Hexavalent Chromium - The BATs for removal of hexavalent chromium in water for large water systems are: ion exchange, reduction/coagulation/filtration, and reverse osmosis. Hexavalent chromium was detected above the PHG in the local groundwater (seven wells). The City is in compliance with the MCL for hexavalent chromium. The estimated cost to reduce hexavalent chromium levels in the groundwater to below the PHG of 0.02 ug/l using reduction/coagulation/filtration was calculated. Because the DLR for hexavalent chromium is 0.1 ug/l, treating hexavalent chromium to below the PHG level means treating hexavalent chromium to below the DLR of 0.1 ug/l. There are numerous factors that may influence the actual cost of reducing hexavalent chromium levels to the PHG. Achieving the water quality goal for hexavalent chromium could be approximately $12,600,000 to $78,800,000 per year, or between $344 and $2,150 per service connection per year.
Perchlorate - The BATs for removal of perchlorate in water for large water systems are ion exchange and biological fluidized bed reactor. Perchlorate was detected above the PHG in the local groundwater (three wells). The City is in compliance with the MCL for perchlorate. The estimated cost to reduce perchlorate levels in the groundwater to below the PHG of 1 ug/l using ion exchange was calculated. Because the DR for perchlorate is 1 ug/l, treating perchlorate to below the PHG level means treating perchlorate to below the DLR of 1 ug/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 be approximately $1,850,000 to $4,060,000 per year, or between $51 and $111 per service connection per year.
City of Orange 5 2025 PHGs Report
PFOS and PFOA - The BATs for removal of PFOS and PFOA in water for large water systems are: granular activated carbon, ion exchange, and reverse osmosis. PFOS and PFOA were detected above their respective PHGs in the local groundwater (seven wells).
The City is in compliance with the State requirements for PFOS and PFOA. Currently, the City has an ion exchange treatment system for PFOS and PFOA for groundwater extracted from four of the City's water supply wells; treated water from these water supply wells does not have detectable levels of PFOS and PFOA. The estimated cost to reduce PFOS and PFOA levels in the groundwater extracted from the non-treated water supply wells (three wells) to below their respective PHGs of 1 nanogram per liter (ng/l) and 0.007 ng/l using ion exchange was calculated. Because the DDW Consumer Confidence Report Detection Level (CCRDL) for PFOS and PFOA is 4 ng/l, treating PFOS and PFOA to below their respective PHG levels means treating PFOS and PFOA to below the CCRDL of 4 ng/l. There are numerous factors that may influence the actual cost of reducing PFOS and PFOA levels to their respective PHGs. Achieving the water quality goal for PFOS and PFOA for the non-treated water supply wells could be approximately $2,510,000 to $34,400,000 per year, or between $69 and $939 per service connection per year.
All Contaminants - In addition, a cost estimate to treat all water produced 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 table may be removed to non-detectable levels by ion exchange and reverse osmosis.
As shown on the accompanying table, achieving the water quality goals for all contaminants using ion exchange and reverse osmosis could range from $9,800,000 to $72,100,000 per year, or between $268 and $1,970 per service connection per year.
For additional information, please contact the City of Orange Water Division at (714) 288-2475, or write to 189 S. Water Street, Orange, California 92866.
City of Orange 6 2025 PHGs Report
2025 PUBLIC HEALTH GOALS REPORT
CITY OF ORANGE
UNITS PHG MCL DLR CONCENTRATION CATEGORY CANCER RISK CANCER BEST AGGREGATE COST PER PARAMETER oF OR OR AVERAGE RANGE OF AT PHG RISK AVAILABLE COST SERVICE CONNECTION MEASUREMENT (MCLG)* (CCRDL) RISK OR MOLG AT MCL TECHNOLOGIES PER YEAR PER YEAR
INORGANIC CHEMICALS
Bromate 4g/l 0.1 1 ND ND - 6.3 1x10° 1x10* C/F, GAC, RO $1,330.000 - $11.400,000 (a) 536 - $312 (a) Hexavalent Chromium 0.02 10 0.13 ND - 1.3 1x10° 5x10* IE, R/C/F, RO $12,600,000 - $78,800,000 (b; $344 - $2,150 (b) Perchlorate Ng/l 1 ND ND - 2.5 E NA NA IE, BFBR $1,850,000 - $4,060,000 (c) $51 - $111 (c)
ORGANIC CHEMICALS
Perfluorooctanesulfonic Acid (PFOS) ng/l 00o7 (4) ND ND - 17 1x10% (d) GAC, IE, RO $2,510,000 - $34,400,000 (e; 569 - (e) Perfluorooctanoic Acid (PFOA) ng/l (4) ND ND - 14 1x10€ (d) GAC, IE, RO
RADIOLOGICAL
Gross Alpha Particle Activity pCi/l (0) 15 3 ND ND - 10 1x103 RO $6,230,000 - $53,400,000 (f) S170 - $1,460 (f) Gross Beta Particle Activity pCi/l (0) 50 4 ND ND -9 2x103 IE, RO Radium, Combined (g) pci/l (0) 5 ND ND - 2.2 1x10° 3x10% IE, LS, RO Uranium pCill 0.43 20 2.3 ND - 9.1 1x10° 5x105 IE, RO, LS.C/F ALL CONTAMINANTS - - - - IE and RO $9.800.000 - $72.100.000 (h $268 - $1,970 (h) • MCLGs are shown in parentheses. MCLGs are provided only when no applicable PHG exists. •* Federal MCL
TREATMENT TECHNOLOGIES
RISK CATEGORIES BFBR = Biological fluidized Bed Reactor C (Carcinogen) = A substance that is capable of producing cancer. C/F = Coagulation/Filtration E (Endocrine Toxicity and Developmental Toxicity) = A substance that can affect the thyroid or cause neurodevelopmental deficits. GAC = Granular Activated Carbor = lon Exchar
NOTES = Lime Softeni
CCRDL = Consumer Confidence Report Detection Level R/C/F = Reduction/Coagulation/Filtratio DLR = Detection Limit for Purposes of Reporting RO = Reverse Osmosis MCL = Maximum Contaminant Level
MCLG = Maximum Contaminant Level Goal
g/l = micrograms per liter or parts per billion
NA = Not Applicable
ND = Not Detected
ng/| = nanograms per liter or parts per trillion
pCi/l = picoCuries per liter
PHG = Public Health Goal
(a) Estimated cost to remove bromate using RO.
(b) Estimated cost to remove hexavalent chromium using R/C/F. (c) Estimated cost to remove perchlorate using IE.
(d) Not applicable. Cancer risk cannot be calculated.
(e) Estimated cost to remove PFOS and PFOA using IE.
(f) Estimated cost to remove gross alpha particle activity using RO, which also removes combined radium, gross beta particle activity, and uranium. (g) As the sum of radium-226 and radium-228. DRs for radium-226 and radium-228 is 1 pCi/L and 1 pCi/L, respectively. (h) Assuming treating the entire production by IE and RO, which can remove all contaminants listed in the above table to below the detectable levels. 1124602160-001 Oranse PHd 20290anse shaltle 2005 ce