IRWD water meets all of the exacting standards set by the state and federal governments. Learn more in the 2025 Water Quality Report.
2025 WATER QUALITY REPORT
IRVINE RANCH WATER DISTRICT 2025 Water Quality Report
Every year, Irvine Ranch Water District provides an annual Water Quality Report, sharing information on the safety and quality of its drinking water. We safeguard our water supply year-round to ensure that your drinking water is clean, tasty and high-quality.
Your water quality report at a glance Drink up! In 2024, IRWD drinking water met or exceeded all state and federal standards. Highlights of the quality of your water include: • Your drinking water is safe. • IRWD service lines are lead-free. • IRWD has one of the best-equipped water quality labs in Southern California. • Data reflects more than 250,000 testing results reported annually. • IRWD holds itself to the highest standard and tests its water for many more chemicals than required by the state and federal governments, including metals, pesticides and volatile organic compounds. The U.S. Environmental Protection Agency (EPA), the State Water Resources Control Board and Division of Drinking Water (DDW) establish and enforce drinking water quality standards to ensure public health. IRWD and its regional water suppliers (Orange County Water District and Metropolitan Water District of Southern California) frequently go beyond what is required by these federal and state regulatory agencies — monitoring your water from source to tap for regulated and unregulated elements.
The Irvine Ranch Water District 2025 Water Quality Report covers water quality test results and reporting from 2024. As in years past, we are proud to report that your water passed every test and met or exceeded every quality standard.
Questions about your water? Contact Customer Service at 949-453-5300 or CustomerService@IRWD.com. A copy of this report is available at IRWD.com/quality , where you’ll also find information on IRWD’s drinking water quality monitoring. Go to IRWD.com for information on the District’s water reliability, customer services and additional resources.
IRWD Water Quality Report 2025 | Page 2
Providing safe, clean water — day in and day out
IRVINE RANCH WATER DISTRICT WATER SOURCES Where does your water come from? IRWD water comes from local groundwater, recycled water, local surface water (rainwater capture), and from imported water from Northern California and the Colorado River. Recycled water is not used for drinking but is an important water source that reduces demand for drinking water.
RAINWATER CAPTURE
Shasta Lake
Irvine Lake
ORANGE COUNTY
Lake Oroville
SACRAMENTO- SAN JOAQUIN RIVER DELTA
Rattlesnake Reservoir
SACRAMENTO
Groundwater Well Field
Mono Lake
Syphon Reservoir
SAN FRANCISCO
FOOTHILL RANCH
Groundwater Well Field
LOS ANGELES AQUEDUCT
Michelson Water Recycling Plant
LAKE FOREST
STATE WATER PROJECT (imported water)
IRVINE
Baker Water Treatment Plant
Los Alisos Water Recycling Plant
GROUNDWATER BANKING
Sand Canyon Reservoir
COLORADO RIVER AQUEDUCT (imported water)
NEWPORT BEACH
San Joaquin Reservoir
LOS ANGELES
Local Groundwater Drinking Water Treatment Plants Recycled Water Treatment Plants Recycled Water Reservoirs
Lake Mathews
LOCAL GROUNDWATER
IRWD SERVICE AREA MAP
PACIFIC OCEAN
ORANGE COUNTY IRWD SERVICE AREA
SAN DIEGO
Diversity of supply IRWD has carefully diversified its water supply and is not dependent upon only one source of water. Your drinking water is a blend of local groundwater, groundwater from the Orange County Groundwater Basin managed by the Orange County Water District
In managing these various water sources, IRWD will sometimes switch water sources or blend them based on availability, treatment needs, time of the year, assisting other partner agencies and local geography.
Recycled water is another important water source. While not used for drinking, it significantly reduces demand for drinking water. IRWD has been recycling highly treated wastewater since 1967, and it’s now used to irrigate landscaping, flush toilets in large commercial buildings
(OCWD), and to a lesser degree surface water imported by Metropolitan Water District of Southern California (MWD), which comes from the State Water
Project and the Colorado River Aqueduct. IRWD also has a local watershed that feeds rainwater to Irvine Lake, which IRWD uses as a surface water source. Local water sources keep the costs lower for our customers and significantly increases the overall reliability and resiliency of your water supply.
and even used in some industrial equipment like cooling towers. Using recycled water for these purposes is important because every gallon of recycled water saves a gallon of high-quality drinking water for you, our customers .
IRWD's Baker Water Treatment Plant in Lake Forest produces enough water to serve 63,300 homes and provides an additional source of reliable, high-quality drinking water.
IRWD Water Quality Report 2025 | Page 3
Water hardness and other aesthetics Water hardness refers to naturally occurring mineral content, mostly calcium and magnesium, which are essential for health and found in all water sources. The white deposits sometimes left by hard water on fixtures or cookware can be removed with a simple vinegar solution, and hard water does not pose a threat to human health. Because your water sources vary and are a blend of various sources of water including local groundwater, local surface water, and imported water, you may notice a difference in the taste or hardness (mineral content) of the water at different times of year. None of these factors affects the safety of your water. Having multiple sources of water is beneficial for IRWD customers.
Commitment to scientific innovation IRWD is proud to have a state-of-the-art and state- certified water quality laboratory — one of the best-equipped water labs in Southern California — right in Irvine on-site at IRWD’s Operations Center. Our Water Quality staff continuously monitors the water supply, reporting more than a quarter of a million results each year. • IRWD’s lab is accredited to 13 different fields of testing that include over 300 analytes. This allows IRWD’s Water Quality team to turn around test results faster and more efficiently. • On-site lab instrumentation can identify and measure substances in the low parts per trillion (ppt) range. This is akin to identifying one drop in 20 Olympic-sized swimming pools. • Laboratory staff reported an estimated 270,000 test results annually. Key objectives of IRWD’s laboratory are to produce high-quality, reliable data for regulatory monitoring and reporting, process control and research projects — meaning that every day, some of the brightest, most analytical minds are hard at work in our lab ensuring your drinking water is safe.
Tap water vs. bottled water Did you know the federal government does not require bottled water to be safer than tap water? Tap water is regulated by the U.S. Environmental Protection Agency (EPA) under the Safe Drinking Water Act, while bottled water is regulated by the Food and Drug Administration (FDA). The EPA requires tap water to be tested more frequently than bottled water using state-certified laboratories. Public water systems are required to provide annual reports, and the EPA enforces regulations through frequent testing and inspections. The FDA does not require the same rigorous certified testing for the water it regulates. What does all this mean? The next time you need to quench your thirst, know that you can do so confidently and safely with IRWD tap water!
IRWD's Water Quality Laboratory is one of the best-equipped water laboratories in Southern California. The lab recently earned additional accreditation from the Environmental Laboratory Accreditation Program to test for PFAS, making IRWD one of the handful of laboratories in California to do so.
IRWD Water Quality Report 2025 | Page 4
Understanding drinking water and water quality testing
The sources of drinking water (both tap and bottled water) include rivers, lakes, streams, ponds, reservoirs, springs and wells. As water travels over the surface of the land or through the ground, it dissolves naturally occurring minerals — and, in some cases, radioactive material — and can pick up substances resulting from the presence of animals or from human activity.
In order to ensure that tap water is safe to drink, the EPA and the State Water Resources Control Board (State Water Board) prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. FDA regulations and California law also establish limits for contaminants in bottled water that provide the same protection for public health. Drinking water, including bottled water, may reasonably be expected to contain at least small amounts of some contaminants. The presence of contaminants does not necessarily indicate that water poses a health risk. More information about contaminants and potential health effects can be obtained by calling the EPA Safe Drinking Water Hotline at 800-426-4791. Immunocompromised people Some people may be more vulnerable to various contaminants in drinking water than the general population. Immunocompromised persons such as persons with cancer undergoing chemotherapy, persons who have undergone organ transplants, people with HIV/AIDS or other immune system disorders, some elderly and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers.
Contaminants that may be present in source water include: • Microbial contaminants, such as viruses and bacteria, that may come from sewage treatment plants, septic systems, agricultural livestock operations and wildlife. • Inorganic contaminants, such as salts and metals, that can be naturally occurring or result from urban stormwater runoff, industrial or domestic wastewater discharges, oil and gas production, mining or farming. • Pesticides and herbicides that may come from a variety of sources such as agriculture, urban stormwater runoff and residential uses. • Organic chemical contaminants, including synthetic and volatile organic chemicals, which are byproducts of industrial processes and petroleum production, and can also come from gas stations, urban stormwater runoff, agricultural application and septic systems. • Radioactive contaminants that can be naturally occurring or the result of oil and gas production and mining activities.
U.S. EPA/Centers for Disease Control and Prevention (CDC) guidelines on appropriate means to lessen the risk of infection by cryptosporidium and other microbial contaminants are available from the Safe Drinking Water Hotline at 800-426-4791.
IRWD Water Quality Report 2025 | Page 5
Drinking water additives Fluoride IRWD’s drinking water is a blend of local groundwater and surface water, including water imported by MWD. IRWD’s local groundwater contains some naturally occurring fluoride, but we do not supplement with additional fluoride. In 2007, MWD joined a majority of the nation’s public water suppliers in adding fluoride to drinking water to help prevent tooth decay. MWD was in compliance with all provisions of the state’s fluoridation system requirements. For information on MWD’s fluoride program, visit bit.ly/MWDfluoride . For information on the fluoridation of drinking water, contact the DDW or U.S. Centers for Disease Control and Prevention.
Water quality and your health Lead
IRWD has no lead pipes in its water-distribution system. IRWD also has no galvanized service lines requiring replacement. That good news was confirmed in a comprehensive 2024 inventory of the District’s water lines. See the complete results at IRWD.com/nonlead . Lead can cause serious health effects in people of all ages, especially pregnant people, infants (formula- fed and breastfed) and young children. While the District’s service lines are lead-free, lead in drinking water is primarily from materials in home plumbing. IRWD is responsible for providing high-quality drinking water and removing any lead pipes in its distribution system but cannot control materials in home plumbing. Because lead levels may vary over time, lead exposure is possible even when sampling results do not detect lead at one point in time. You can help protect yourself and your family by identifying and removing lead materials within your home plumbing and taking steps to reduce your family’s risk. Using a filter certified by an American National Standards Institute accredited certifier to reduce lead is effective in reducing lead exposures. Follow the instructions provided with the filter to ensure the filter is used properly. Use only cold water for drinking, cooking and making baby formula. Boiling water does not remove lead from water. Before using tap water for drinking, cooking or making baby formula, flush your pipes for several minutes by running your tap, taking a shower or doing laundry or dishes. If you have a lead service line or galvanized requiring replacement service line, you may need to flush your pipes for a longer period. Contact info@IRWD.com if you are concerned about lead in water and have questions. Find information on testing methods and steps to minimize exposure at epa.gov/safewater/lead . Nitrates The drinking water IRWD supplies to its customers is below the maximum allowable levels for nitrates. Nitrate in drinking water at levels above 10 mg/L is a health risk for infants less than 6 months of age. Such nitrate levels in drinking water can interfere with the capacity of infants’ blood to carry oxygen, resulting in a serious illness; symptoms include shortness of breath and blueness of skin. Nitrate levels above 10 mg/L may affect the ability of blood to carry oxygen in other individuals, such as pregnant women and those with certain specific enzyme deficiencies. If you are caring for an infant or are pregnant, ask advice from a health care provider.
Disinfectants Drinking water regulations require some form of chlorine to be used at water treatment plants and to be maintained throughout the entire distribution system to prevent harmful bacteria from making it to the customer’s tap. IRWD uses chloramines to maintain a robust disinfectant for these purposes. Chloramines effectively inactivate harmful bacteria and are safe for consumption by humans (as well as our furry four-legged friends) at certain levels. Chloramines are monitored throughout the system, and we also watch for the presence of bacteria to be sure your drinking water is safe from end to end. People who use kidney dialysis machines may want to take special precautions and consult their physician for the appropriate type of water treatment. Customers who maintain fishponds, tanks or aquariums should also make necessary adjustments in water quality treatment, as these disinfectants are toxic to fish. For more information or questions about chloramines, visit IRWD.com or call 949-453-5300 .
IRWD Water Quality Report 2025 | Page 6
IRWD water quality results for 2024
How to read this Water Quality Report This report lists results from drinking water quality assessments in 2024. The following charts show drinking water quality results for all of last year. Data includes the range of detection, the typical sources of contaminants for a variety of regulated elements and how they compare to water quality standards. To provide our customers more insight, the tables include secondary standards that are for aesthetic qualities of the water, such as water hardness, pH, color, corrosivity and more. The legend at right defines the acronyms, explains water quality standards and goals, and outlines how substances are measured. Your water has been tested for many more chemicals than are listed in this report, including metals, pesticides and volatile organic compounds. If you don’t see something on the chart, don’t worry. That does not mean we didn’t test for it. Rather, if we test for a chemical and don’t find it — or if its concentration is too low to be distinguishable — we don’t list it. For example, we tested for mercury. We didn’t find it. So we didn’t list it.
Chart legend What are water quality standards?
Drinking water standards established by U.S. EPA and DDW set limits for substances that may affect consumer health or aesthetic qualities of drinking water. The charts in this report show the following types of water quality standards: • Maximum Contaminant Level (MCL): The highest level of a contaminant that is allowed in drinking water. Primary MCLs are set as close to the PHGs (or MCLGs) as is economically and technologically feasible. • Maximum Residual Disinfectant Level (MRDL): The highest level of a disinfectant allowed in drinking water. There is convincing evidence that addition of a disinfectant is necessary for control of microbial contaminants. • Secondary MCLs are set to protect the odor, taste and appearance of drinking water. • Primary Drinking Water Standard: MCLs for contaminants that affect health along with their monitoring and reporting requirements and water treatment requirements. • Regulatory Action Level (AL): The concentration of a contaminant, which, if exceeded, triggers treatment or other requirements that a water system must follow. What is a water quality goal? In addition to mandatory water quality standards, U.S. EPA and DDW have set voluntary water quality goals for some contaminants. Water quality goals are often set at such low levels that they are not achievable in practice and are not directly measurable. Nevertheless, these goals provide useful guide posts and direction for water management practices. The charts in this report includes three types of water quality goals: • Maximum Contaminant Level Goal (MCLG): The level of a contaminant in drinking water below which there is no known or expected risk to health. MCLGs are set by U.S. EPA. • Maximum Residual Disinfectant Level Goal (MRDLG): The level of a drinking water disinfectant below which there is no known or expected risk to health. MRDLGs do not reflect the benefits of the use of disinfectants to control microbial contaminants. • Public Health Goal (PHG): The level of a contaminant in drinking water below which there is no known or expected risk to health. PHGs are set by the California Environmental Protection Agency. How are contaminants measured? Water is sampled and tested throughout the year. Contaminants are measured in:
• Parts per million (ppm) or milligrams per liter (mg/L) • Parts per billion (ppb) or micrograms per liter (μg/L) • Parts per trillion (ppt) or nanograms per liter (ng/L)
2024 water quality results
MCL (MRDL/MRDLG)
Average amount 24.1*** 10.0***
MCL violation?
Disinfection byproducts Total Trihalomethanes (ppb) Haloacetic Acids (five) (ppb) Chlorine residual (ppm) Aesthetic quality Color (color units)
Range of detections
Typical source of contaminant Byproducts of chlorine disinfection Byproducts of chlorine disinfection Disinfectant added for treatment
80 60
9.1 - 44.2 4.1 - 19.6 ND - 3.9
No No No No No No
(4.0 / 4)
1.9
15*
<3 0.1 <1
ND - 4
Erosion of natural deposits Erosion of natural deposits Erosion of natural deposits
Turbidity (NTU)
5* 3*
ND - 6.9
Odor (threshold odor number)
ND - 4
Other Fluoride (mg/L)
2/0.8**
0.54
0.18 - 0.80
No
Erosion of natural deposits, water treatment
Twelve locations in the distribution system are tested quarterly for total trihalomethanes and haloacetic acids; 60 locations are tested monthly for color and odor, and weekly for chlorine residual and turbidity. MRDL = Maximum Residual Disinfectant Level; MRDLG = Maximum Residual Disinfectant Level Goal *Contaminant is regulated by a secondary standard; **MCL/Optimum Level for our climate; *** Highest running annual average at any individual sample location Lead and copper action levels at residential taps Action Level (AL) Public Health Goal (PHG) 90th percentile value Sites exceeding AL / number of sites AL violation?
Typical source of contaminant
Copper (ppm)
1.3
0.3 0.2
0.1908
0/72 0/72
No No
Corrosion of household plumbing
Lead (ppb) Corrosion of household plumbing The most recent lead and copper at-the-tap samples were collected from 72 residences in 2022. Lead was detected in zero homes and copper was detected in 26 homes, but none of the samples for lead and copper exceeded the respective regulatory Action Level (AL). A regulatory Action Level is the concentration of a contaminant which, if exceeded in more than 10% of samples, triggers treatment or other requirements that a water system must follow. Unregulated chemicals requiring monitoring in the distribution system Chemical Notification level PHG (MCLG) Average local and imported Range of detections Most recent sampling date Germanium, total (ppb) N/A N/A 0.82 ND - 1.1 2020 Manganese, total (ppb) MCL = 50* N/A 1.6 0.8 - 2.2 2020 *Contaminant is regulated by a secondary standard. 15 <5
IRWD Water Quality Report 2025 | Page 7
Local and imported drinking water quality results
Average Average
Average imported MWD
local treated surface water
PHG (MCLG)
Range of detections
MCL violation? Typical source of contaminant
groundwater local treated
Chemical
MCL
Radiologicals – tested in 2024 Alpha Radiation (pCi/L)
15
0 0
1.9 NR 2.2
3.8 4.6 2.2
ND 4.0 1.0
ND - 3.8 ND - 5.0 ND - 3.0
No No No No No No No No No No No No No No No No No No No No No
Erosion of natural deposits
Beta Radiation (pCi/L)
50 20
Decay of natural and man-made deposits
Uranium (pCi/L)
0.43
Erosion of natural deposits
Inorganic chemicals – tested in 2024 Aluminum (ppm)
1
0.6
ND
ND Highest RAA = 0.105 ND - 0.110
Treatment process residue, natural deposits
Arsenic (ppb) Barium (ppm) Bromate (ppb) Chlorine (ppm)
10
0.004
2.00
<2
ND
ND - 3.04 ND - 0.134 1.5 - 3.9 ND - 0.19 ND - 0.83
Erosion of natural deposits Erosion of natural deposits
1
2
<0.100
<0.100
0.124
10
0.1 4.0
NR 2.4 0.1
NR 2.5 ND
Highest RAA = ND ND - 1.6
Byproduct of drinking water ozonation
4.0
2.5 ND NR 0.7 ND ND
Drinking water disinfectant added for treatment Erosion of natural deposits; industrial discharge
Hexavalent Chromium (ppb)
10
0.02
Erosion of natural deposits; IRWD does not add Fluoride to its local treated groundwater and surface water
Fluoride (ppm) naturally-occurring
2
1
0.29
0.35
Control range 0.6 - 1.2 ppm Optimal level 0.7 ppm
Fluoride (ppm) treatment-related
NR 2.3 2.3
NR ND ND ND 112 <3
0.6 - 0.8 ND - 4.3 ND - 4.3
Water additive for dental health
Nitrate (ppm as N)
10 10
10 10
Fertilizers, septic tanks Fertilizers, septic tanks
Nitrate+Nitrite (ppm as N)
Secondary standards* – tested in 2024 Aluminum (ppb)
200* 500*
600 N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
8.4
Highest RAA = ND ND - 110
Treatment process residue, natural deposits Leaching from natural deposits; seawater influence
Chloride (ppm) Color (color units)
41.5
104
17.8 - 124
15*
<3
2
ND - 8 ND - 6
Naturally-occurring organic substances Naturally-occurring organic materials Ions in water; seawater influence Runoff or leaching from natural deposits Runoff or leaching from natural deposits Runoff or leaching from natural deposits Runoff or leaching from natural deposits Runoff or leaching from natural deposits Runoff or leaching from natural deposits Runoff or leaching from natural deposits Runoff or leaching from natural deposits Byproduct of drinking water chlorination Erosion of natural deposits
Odor (TON)
3*
1
2
1
Specific Conductance (µmho/cm)
1,600*
490 62.1 289
1,065
979 224 621
358 - 1126 21.5 - 253 134 - 738
Sulfate (ppm)
500*
237 642
Total Dissolved Solids (ppm)
1,000*
Turbidity (NTU)
5*
<0.10
<0.10
ND
ND - 0.4
Unregulated contaminants – tested in 2024 Alkalinity, total (ppm as CaCO3)
Not regulated Not regulated Not regulated Not regulated Not regulated NL = 1 Not regulated Not regulated Not regulated Not regulated Not regulated Not regulated Not regulated NL = 800
101
124 124 0.14 0.02 72.7 <0.6 12.2 0.41 295 17.3 27.9 NR
114 NR
70 - 233 70 - 144 ND - 0.25 0.02 - 0.29 16.7 - 79.5 <0.6 - 1.1
N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A
Bicarbonate (ppm as HCO3)
96.1 0.16 0.14 35.2 <0.6
Boron (ppm) Bromide (ppm) Calcium (ppm) Carbonate (ppm) Chlorate (ppb)
0.14
NR
68.0
NR
NR
77.0 12.5 0.62 270 15.8 15.0
77.0
Corrosivity (Aggressiveness) Corrosivity (Langlier Index) Hardness, total (ppm as CaCO3) Hardness, total (grains/gal)
12.1 0.33
11.0 - 12.9
Elemental balance in water Elemental balance in water
(-)0.72 - 0.81
128
53.9 - 321 7.5 - 17.3 2.9 - 29.8 ND - 19.1
Runoff or leaching from natural deposits Runoff or leaching from natural deposits Runoff or leaching from natural deposits
7.5
Magnesium (ppm) Molybdenum (ppb)
10.1
7.9 ND 1.5 8.3 1.3
5.4 NR ND 7.9 5.9 105 1.9 2.4
NR 2.5 ND 8.2 4.9 103 2.4 ND
Drinking water treatment chemical for aesthetic quality Byproducts of drinking water chloramination; industrial processes Industrial chemical factory discharges; runoff/leaching from landfills; used in fire-retarding foams and various industrial processes
N-Nitrosodi-n-butylamine (NDBA) (ppt) Perfluorooctanoic acid (PFOA) (ppt)
2.5
NL = 5.1
0.007 (0)
ND - 2.4 7.1 - 8.6
No
pH (pH units)
Not regulated Not regulated Not regulated
N/A N/A N/A N/A N/A
N/A N/A N/A
Acidity, hydrogen ions
Potassium (ppm) Sodium (ppm)
0.65 - 21.2 25.1 - 116 0.37 - 2.5
Runoff or leaching from natural deposits Runoff or leaching from natural deposits Various natural and man-made sources Runoff or leaching from natural deposits
53.7 0.4 4.0
Total Organic Carbon (ppm)
TT
TT
Vanadium (ppb)
NL = 50
ND - 6.3
N/A
Your water has been tested for many more chemicals than are listed above, including metals (such as mercury), pesticides and volatile organic compounds. Chemicals not detected in any water sources are not included in the table. *Contaminant is regulated by a secondary standard to maintain aesthetic qualities (taste, odor, color).
ppb = parts-per-billion; ppm = parts-per-million; ppt = parts-per-trillion; pCi/L = picoCuries per liter; ntu = nephelometric turbidity units; ND = not detected; N/A = not applicable; NR = not required to be tested; < = average is less than the detection limit for reporting purposes; MCL = Maximum Contaminant Level; (MCLG) = federal MCL Goal; PHG = California Public Health Goal; µmho/cm = micromho per centimeter; NL = Notification Level; TT = Treatment Technique; RAA = Highest Running Annual Average
Turbidity – combined filter effluent
Treatment technique
Turbidity measurements
TT violation?
Typical source
Baker Water Treatment Plant 1) Highest single turbidity measurement
0.1 NTU
0.043 100%
No No
Soil run-off Soil run-off
2) Percentage of samples less than or equal to 0.3 NTU Metropolitan Water District Diemer Filtration Plant 1) Highest single turbidity measurement 2) Percentage of samples less than or equal to 0.3 NTU
100%
0.1 NTU
0.06
No No
Soil run-off Soil run-off
100%
100%
Unregulated chemicals requiring monitoring at entry points to the distribution system Chemical Notification level PHG Average local and imported Range of detections Most recent sampling date Bromide (ppm) N/A N/A 0.20 0.025 - 0.72 2020 Germanium, total (ppb) N/A N/A <0.3 ND - 0.8 2020 Manganese, total (ppb) MCL = 50* N/A 0.88 ND - 2.7 2020 Total Organic Carbon (ppm) N/A N/A 1.2 0.06 - 6.5 2020 Lithium, total (ppb) N/A N/A 51.6 ND - 166 2020 Perfluorooctanoic Acid (PFOA) (ppt) 5.1 0.007 0.19 ND - 2.3 2020 *Contaminant is regulated by a secondary standard.
IRWD Water Quality Report 2025 | Page 8
Source water assessments
Water sources are assessed regularly to examine potential pollutant sources in the area. This does not mean contaminants are actively being discharged into these water sources. Rather, these surveys are used to evaluate the vulnerability of water sources to contamination and determine what protective measures are needed.
Date of assessment
Location/assessment
Vulnerabilities assessed
IRWD Baker Water Treatment Plant water assessment Santiago Reservoir (Irvine Lake) Sanitary Survey See MWD Imported Water Assessment below for water received from MWD IRWD groundwater assessment Lake Forest service area of IRWD
Septic systems and wildfires
2019
Dry cleaners and sewer collection systems Gas stations, historic gas stations, metal plating/ finishing/fabrication facilities, military installations, and plastics/synthetics producers Sewer collection systems, automobiles (gas stations), historic gas stations, and underground storage tanks (confirmed leaking tanks)
December 2022
Dyer Road Well Field
July 2023
Wells 21–22 Desalter
May 2009
Irvine Desalter Project
Crop irrigation and fertilizers Sewer collection systems Historical mining operations
March 2006 March 2003 January 2003
Orange Park Acres service area of IRWD Santiago Canyon service area of IRWD MWD Imported Water Assessment Colorado River Watershed Sanitary Survey
Recreation, urban/stormwater runoff, increasing urbanization in the watershed, and wastewater Urban/stormwater runoff, wildlife, agriculture, recreation, and wastewater
2020
Northern California’s State Water Project Watershed Sanitary Survey
2021
You can request copies of the IRWD reports listed by writing to IRWD, Attn: District Secretary, 15600 Sand Canyon Ave., Irvine, CA 92618. To request copies of MWD reports, call MWD at 800-225-5693 .
At-home water testing At-home test kits provide generic, approximate detections of substances in water but do not offer the analytical chemistry testing levels necessary to determine the quality of the water sample. These test kits are not based on standardized methods and do not have any way to verify accuracy. Customers who have their home’s water tested should contact a certified laboratory to ensure accurate results. Find a list at IRWD.com/laboratories . IRWD does not endorse specific laboratories for home testing. The data presented in this report is analyzed and reported by California Environmental Laboratory Accreditation Program certified laboratories that follow extensive quality assurance and quality control programs and are managed by qualified, trained scientists. Water providers take on the responsibility of verifying water quality data, and that process is heavily regulated by state and federal agencies.
The data in this report draws from 270,000 analytics performed using one of the best equipped, state- certified water laboratories in Southern California. Call IRWD at 949-453-5300 for any questions.
IRWD Water Quality Report 2025 | Page 9
Stay in the know
NOTE OF IMPORTANCE This report contains important information about your drinking water. Contact Irvine Ranch Water District at 15600 Sand Canyon Ave., Irvine, CA 92618, or 949-453-5500 for assistance in other languages. Chinese (Simplified) 这份报告含有关于您的饮用水的重要讯息。请用以下地址和电 话联系 Irvine Ranch Water District 以获得中文的帮助: 15600 Sand Canyon Ave., Irvine, CA 92618, 949-453-5500. Chinese (Traditional) 這份報告含有關於您的飲用水的重要訊息。請用以下地址和電 話聯繫 Irvine Ranch Water District 以獲得中文的幫助: 15600 Sand Canyon Ave., Irvine, CA 92618, 949-453-5500. Korean 이 보고서는 당신의 식수에 관한 중요한 정보를 포함하고 있습니다. 한국어로 된 도움을 원하시면 Irvine Ranch Water District, 15600 Sand Canyon Ave., Irvine, CA 92618, 949-453-5500 로 문의 하시기 바랍니다. Spanish Este informe contiene información muy importante sobre su agua para beber. Favor de comunicarse Irvine Ranch Water District a 15600 Sand Canyon Ave., Irvine, CA 92618, o 949-453-5500 para asistirlo en español. Arabic برشلا هايم لوح ةمهم تامولعم ىلع ريرقتلا اذه يوتحي عم لصاوتلا ىجرُي ،تامولعملا نم ديزمل .كيدل Irvine Ranch Water District مقرلا ىلع 15600 Sand Canyon Ave., Irvine, CA 92618. وه فتاهلا مقر 949-453-5500. Farsi .تسامش یندیماشآ بآ دروم رد یمهم تاعالطا یواح شرازگ نیا رب افتل یندیماشآ بآ نامزاس هب تاعالطا بسک یا Irvine Ranch Water District سردآ رد هک 15600 Sand Canyon Ave., Irvine, CA 92618 نفلت هرامش .دیریگب سامت 949-453-5500 .تسا Hindi इस रि पोर्ट में आपके पीने के जल से सम्बंधि त महत्वपूर्ण जानकारी है l हिं दी में सहायता के लि ए, Irvine Ranch Water District को 15600 Sand Canyon Ave., Irvine, CA 92618 अथवा 949-453-5500 पर संपर्क करें. Japanese この報告書には上水道に関する重要な情報が記されております。 ご質問等ございましたら、 Irvine Ranch Water District, 15600 Sand Canyon Ave., Irvine, CA 92816 949-453-5500 まで日本語でご連絡下 さい。
IRWD social Follow IRWD news and updates online. IrvineRanchWaterDistrict
@IRWDnews
@IRWDnews
youtube.com/IrvineRanchWD
IRWD website Visit IRWD.com for the latest news and information. Board meetings The IRWD Board of Directors meets the second and fourth Monday of each month at 5 p.m. at IRWD headquarters, 15600 Sand Canyon Ave., Irvine, CA 92618. Members of the public are welcome to attend.
IRWD Water Quality Report 2025 | Page 10
Page 1 Page 2 Page 3 Page 4 Page 5 Page 6 Page 7 Page 8 Page 9 Page 10Made with FlippingBook Annual report maker