The Irvine Ranch Water District 2024 Water Quality Report includes water quality test results and reporting from 2023. As in years past, we are proud to report that your water passed every test and met or exceeded every quality standard. Learn more at IRWD.com/waterquality.
2024 WATER QUALITY REPORT
IRWD 2024 Water Quality Report
Since 1990, California public water utilities have provided an annual water quality report to their customers. This year’s report covers calendar year 2023 drinking water quality testing and reporting. Irvine Ranch Water District (IRWD)
supplies imported treated surface water; and IRWD, which operates a local surface water treatment plant and several groundwater treatment plants, all test for unregulated chemicals in our water supply. Monitoring for unregulated chemicals helps U.S. EPA and DDW
vigilantly safeguards its water supply and, as in years past, the water delivered to your home meets the quality standards required by federal and state regulatory agencies. The U.S. Environmental Protection Agency (U.S. EPA) and the
determine where certain chemicals occur and whether new standards need to be established for those chemicals. Through drinking water quality compliance testing programs carried out
State Water Resources Control Board, Division of Drinking Water (DDW) are the agencies responsible for establishing and enforcing drinking water quality standards. IRWD and other regional water suppliers frequently go beyond what is required by testing for unregulated chemicals that may have health risks but do not have drinking water standards. For example, the Orange County Water District (OCWD), which manages the groundwater basin; the Metro- politan Water District of Southern California (MWD), which
by OCWD (groundwater), MWD (treated surface water) and IRWD (treatment plants and the distribution system), your drinking water is constantly monitored from source to tap for regulated and unregulated constituents. The state allows drinking water agencies to monitor for some contaminants less than once per year because the concentrations of these contaminants do not change frequently. Some data, though representative, is more than one year old.
This report contains important information about your drinking water. Translate it, or speak with someone who understands it.
Questions about your water? Contact us for answers. If you have questions about this report, please contact Customer Service, which will route your call appropriately. To reach IRWD Customer Service and for other information, please call 949-453-5300, or email CustomerService @ IRWD.com. Community participation The IRWD Board of Directors meets the second and fourth Monday of each month beginning at 5 p.m. at IRWD, 15600 Sand Canyon Avenue, Irvine, California 92618. A copy of this report is also available on our website: IRWD.com. For more informa- tion about the health effects of the listed contaminants in the following tables, call the U.S. EPA Safe Drinking Water Hotline at 800-426-4791.
Ce rapport contient des informations importantes sur votre eau potable. Traduisez-le ou parlez en avec quelqu’un qui le comprend bien.
Arabic
Chinese
French
Der Bericht enthält wichtige informationen über die Wasser- qualität in Ihrer Umgebung. Der Bericht sollte entweder offiziell uebersetzt werden, oder sprechen Sie mit Freunden oder Bekannten, die gute Englischkenntnisse besitzen.
Questo rapporto contiene informazioni inportanti che riguardano la vostra aqua potabile. Traducetelo, o parlate con una persona qualificata in grado di spiegarvelo.
German
Italian
Japanese
Este informe contiene información muy importante sobre su agua potable. Para mas información ó traducción, favor de contactar a Customer Service Representative. Telefono: 949-453-5300.
Korean
Spanish
Vietnamese
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The quality of your water is our primary concern
Sources of supply IRWD is committed to providing a clean and reliable water supply for its customers. Our drinking water is a blend of groundwater from the Orange County Groundwater Basin and surface water imported by MWD. MWD’s imported water sources come from the State Water Project and the Colorado River Aqueduct. Local groundwater is pumped from a natural underground reservoir that stretches from the Prado Dam and fans across the northwestern portions of Orange County, stretching as far south as the El Toro “Y.” Additional water comes from the Harding Canyon Dam watershed and the Santiago Creek Dam watershed. Local groundwater comprises approximately 65% of the total IRWD drinking water supply. Basic information about drinking water contaminants Drinking water sources (both tap and bottled water) may include rivers, lakes, streams, ponds, reservoirs, springs and wells. As water travels over the surface of land or through the layers of the ground, it dissolves naturally occurring minerals and, in some cases, radioactive material, and can
Lake Mathews Reservoir in Riverside County
• Organic chemical contaminants , including synthetic and volatile organic chemicals, which are byproducts of industrial processes and petroleum production, and can also come from gasoline stations, urban stormwater runoff, agricultural application and septic systems. To ensure that tap water is safe to drink, the U.S. EPA and DDW prescribe regulations that limit the amount of certain contaminants in water provided by public water systems. U.S. Food and Drug Administration 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 reason- ably 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 U.S. EPA Safe Drinking Water Hotline at 800-426-4791. Immuno-compromised people Some people may be more vulnerable to contaminants in drinking water than the general population. Immuno- compromised people, such as those with cancer who are undergoing chemotherapy, people who have had organ transplants, people with HIV/AIDS or other immune system disorders, some elderly people and infants can be particularly at risk from infections. These people should seek advice about drinking water from their health care providers.
pick up substances resulting from the presence of animal and human activity. Contaminants that may be present in source water include:
• Microbial contaminants , such as viruses and bacteria, which may come from sewage treatment plants, septic systems, agricultural livestock operations and wildlife. • Pesticides and herbicides , which may come from a variety of sources such as agriculture, urban stormwater runoff and residential uses. • Radioactive contaminants, which can be naturally occurring or be the result of oil and gas production or mining activities. • Inorganic contaminants , such as salts and metals, which can be naturally occurring or result from urban stormwater runoff, industrial or domestic sewage discharges, oil and gas production, mining and farming.
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Information the U.S. EPA would like you to know
Drinking water fluoridation Fluoride has been added to U.S. drinking water supplies since 1945. In December 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. IRWD’s local groundwater contains naturally occurring fluoride, but is not supplemented with added fluoride. Fluoride levels in drinking water are limited under California state regulations at a maximum dosage of 2 parts per million. There are many places to go for additional information about the fluoridation of drinking water: U.S. Centers for Disease Control and Prevention
Chloramines Water imported from MWD and locally produced ground- water contains chloramines, a combination of chlorine and ammonia, as a drinking water disinfectant. Chloramines effectively kill bacteria and other microorganisms that may cause disease. Chloramines have no odor when used properly. 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 fish ponds, tanks or aquariums should also make necessary adjustments in water quality treatment, as these disinfectants are toxic to fish. For further information or if you have any questions about chloramines please visit IRWD.com or call 949-453-5300. Total Coliform Rule This Water Quality Report reflects changes in drinking water regulatory requirements instituted during 2016. All water systems are required to comply with the state Total Coliform Rule. Effective April 1, 2016, all water systems are also required to comply with the federal Revised Total Coliform Rule. The state Revised Total Coliform Rule became effective July 1, 2021. The federal and state rules protect public health by ensuring the integrity of the drinking water distribution system by monitoring for the presence of microbials (i.e., total coliform and E. coli bacteria). U.S. EPA anticipates greater public health protection as the new rule requires water systems that are vulnerable to microbial contamination to identify and resolve potential issues. Water systems that exceed a specified frequency of total coliform occurrences are required to conduct an assessment to determine if any sanitary defects exist. If found, these must be corrected by the water system. IRWD tested the distribution system water quality for E. coli bacteria in 2023 and did not detect it. Arsenic advisory While your drinking water meets the federal and state standard for arsenic, it does contain low levels of arsenic. The arsenic standard balances the current understanding of arsenic’s possible health effects against the costs of removing arsenic from drinking water. The U.S. EPA continues to research the health effects of low levels of arsenic, which is a mineral known to cause cancer in humans at high concentrations and is linked to other health effects such as skin damage and circulatory problems.
800-232-4636 • cdc.gov/fluoridation State Water Resources Control Board, Division of Drinking Water
waterboards.ca.gov/drinking_water/ certlic/drinkingwater/Fluoridation.html American Water Works Association: awwa.org For more information about MWD’s fluoridation program, please contact Edgar G. Dymally at 213-217-5709 or at edymally @ mwdh2o.com. Cryptosporidium Cryptosporidium is a microscopic organism that, when ingested, can cause diarrhea, fever, and other gastrointestinal symptoms. The organism comes from animal and/or human waste and may be in surface water. MWD and IRWD tested the source waters and treated surface waters for Cryptosporidium in 2023 and did not detect it. If detected in any drinking water samples, Cryptosporidium is eliminated by an effective treatment combination including sedimentation, filtration and disinfection. The U.S. EPA and the federal Centers for Disease Control guidelines on appropriate means to lessen the risk of infection by Cryptosporidium and other microbial contami- nants are available from the U.S. EPA Safe Drinking Water Hotline at 800-426-4791.
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Water quality issues that could affect your health
About lead in tap water IRWD meets all standards for lead in the U.S. EPA Lead and Copper Rule. If present, elevated levels of lead can cause serious health problems,
steps you can take to minimize exposure is available from the Safe Drinking Water Hotline or at epa.gov/safewater/lead. If you are concerned about lead in your water, you may wish to have your water tested. Nitrate advisory Nitrate in drinking water at levels above 10 mg/L is a health
especially for pregnant women and young children. Lead in drinking water is primarily from materials and components associated with service lines and home plumbing. IRWD is responsible for providing high-quality drinking water, but cannot control the variety of materials used in plumbing components. When your water has been sitting for several
risk for infants of less than 6 months old. Such nitrate levels in drinking water can interfere with the capacity of the infant’s blood to carry oxygen, resulting in a serious illness; symptoms include shortness of breath and blueness of the skin. Nitrate levels above 10 mg/L may also affect the ability of the
hours, you can minimize the potential for lead exposure by flushing your tap for 30 seconds to 2 minutes before using water for drinking or cooking. IRWD encourages you to collect the flushed water and reuse it for another beneficial purpose, such as watering potted plants. Information on lead in drinking water, testing methods, and
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, you should ask advice from your health care provider.
Want additional information? Explore water online.
The r e’ s a w e a lth of i n fo rma tio n o n the i n te rn et ab o u t d r i n ki n g wa te r q ua lity, wa te r r eli ab ility an d wa te r i ssu e s i n ge n e ra l. A good pl a ce to b egi n yo ur r e s e ar ch i s IRWD.co m /q ua lity . I n a dditio n to exte ns i v e i n fo rma tio n ab o u t yo ur loc a l wa te r an d the su ppo r t an d s e rv ice s w e offe r , yo u ’ll fi n d li n k s to man y othe r r egio na l, s t a te w ide an d na tio na l wa te r r e s o ur ce s . Yo u c an a l s o v ie w “Jo urn ey of a Wa te r S am ple: Ho w W e S a feg uar d Yo ur Wa te r ,” a s ho r t v ideo depicti n g the s tep s IR W D s t a ff t a ke to e nsur e the high q ua lity of o ur d r i n ki n g wa te r .
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Irvine Ranch Water District Local and Imported Drinking Water Quality Results for 2023 PHG Average Average Average MRDLG Local Treated Local Treated Imported MWD Range of MCL Typical Source
Chemical
MCL MRDL
(MCLG)
Groundwater
Surface Water
Treated Water
Detections
Violation?
of Contaminant
Radiologicals – Tested in 2023 Alpha Radiation (pCi/L)
15 50 20
0 0
3.6 NR 2.1
5.4 5.1 1.7
<3 <3 1.0
ND – 5.4 ND – 6.0 ND – 3.2
No No No
Erosion of Natural Deposits
Beta Radiation (pCi/L)
Decay of natural and man-made deposits
Uranium (pCi/L)
0.43
Erosion of Natural Deposits
Inorganic Chemicals – Tested in 2023 Aluminum (ppm)
1
0.6
ND
ND <2
Highest RAA = 0.105
ND – 0.070 ND – 8.38 ND – 0.115 ND – 6.3 1.5 – 3.2 ND – 0.72
No No No No No No No
Treatment Process Residue, Natural Deposits
Arsenic (ppb) Barium (ppm) Bromate (ppb) Chlorine (ppm)
10
0.004
2.16
ND ND ND NR NR 0.7
Erosion of Natural Deposits Erosion of Natural Deposits
1
2
ND NR NR
<0.100
10
0.1 4.0
NR 2.5
Byproduct of drinking water ozonation
4.0
Drinking water disinfectant added for treatment
Fluoride (ppm) naturally-occurring Fluoride (ppm) treatment-related
2
1
0.26
0.32
Erosion of Natural Deposits Water Additive for Dental Health
Control Range 0.6 – 1.2 ppm
NR
NR
0.5-0.8
Optimal Level 0.7 ppm
Nitrate (ppm as N)
10 10
10 10
1.6 1.6
ND ND
0.7 0.7
ND – 4.3 ND – 4.3
No No
Fertilizers, Septic Tanks Fertilizers, Septic Tanks
Nitrate+Nitrite (ppm as N)
Secondary Standards* – Tested in 2023 Aluminum (ppb)
200* 500*
600
ND
ND
Highest RAA = 105
ND – 70
No No No No No No No No n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a n/a No n/a n/a n/a n/a n/a
Treatment Process Residue, Natural Deposits Leaching from Natural Deposits; Seawater Influence
Chloride (ppm) Color (color units)
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
34.4
89.2
66.0
19.0 – 111
15*
<3
<3
2 2
ND – 5 ND – 4
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
Odor (TON)
3*
1
1
Specific Conductance (µmho/cm)
1,600*
429 56.4 247
1,001
642 122 394
229 – 1085 27.0 – 240 128 – 672 ND – 0.55 47.4 – 154 47.4 – 153 ND – 0.24 0.04 – 0.18 16.6 – 81.4 <0.6 – 1.3
Sulfate (ppm)
500*
217 612
Total Dissolved Solids (ppm)
1,000*
Turbidity (NTU)
5*
<0.10
<0.10
ND
Erosion of Natural Deposits
Unregulated Contaminants – Tested in 2023 Alkalinity, Total (ppm as CaCO 3 )
Not Regulated Not Regulated
92.8 70.6 0.15
138 137 0.14
84 NR
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
Bicarbonate (ppm as HCO 3 )
Boron (ppm)
NL = 1
0.13
Bromide (ppm) Calcium (ppm) Carbonate (ppm) Chlorate (ppb)
Not Regulated Not Regulated Not Regulated
<0.10
NR
NR
28.2 <0.6
74.7 <0.6
38.0
NR
NL = 800
NR
NR
19.0 12.4 0.54 160
19.0
Corrosivity (Aggressiveness) Corrosivity (Langlier Index) Hardness, Total (ppm as CaCO 3 ) Hardness, Total (grains/gal) Hexavalent Chromium (ppb)
Not Regulated Not Regulated Not Regulated Not Regulated Not Regulated Not Regulated Not Regulated Not Regulated Not Regulated Not Regulated
11.8 0.20 93.3
12.4 0.59 297 17.4
10.8 – 12.9 (-)0.72 – 1.1 57.2 – 321 3.3 – 18.8 ND – 0.14 3.1 – 29.9 ND – 15.2 7.1 – 8.8 ND – 4.3 20.7 – 112
Elemental Balance in Water Elemental Balance in Water
Runoff or Leaching from Natural Deposits Runoff or Leaching from Natural Deposits Erosion of Natural Deposits; Industrial Discharge Runoff or Leaching from Natural Deposits Drinking Water Treatment Chemical for Aesthetic Quality
5.5 0.1 8.0 7.1 8.2 1.2
9.4 ND
0.02 **
ND
Magnesium (ppm) Molybdenum (ppb)
n/a n/a n/a n/a n/a n/a n/a
27.9
15.0
4.8 8.0 4.2
NR 8.5 3.4
pH (pH units)
Acidity, Hydrogen Ions
Potassium (ppm)
Runoff or Leaching from Natural Deposits Runoff or Leaching from Natural Deposits Various Natural and Man-Made sources Runoff or Leaching from Natural Deposits
Sodium (ppm)
48
92
69
Total Organic Carbon (ppm)
TT
0.4 3.9
1.8 ND
2.4 3.1
ND – 3.0 ND – 6.4
TT
Vanadium (ppb)
NL = 50
n/a
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
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). **There is currently no MCL for hexavalent chromium. The previous MCL of 10 ppb was withdrawn on September 11, 2017.
Turbidity – combined filter effluent
Treatment Technique
Turbidity Measurements
TT Violation?
Typical Source
Baker Water Treatment Plant
1) Highest single turbidity measurement
0.1 NTU
0.03
No No
Soil Run-Off Soil Run-Off
2) Percentage of samples less than or equal to 0.3 NTU
100%
100%
Metropolitan Water District Diemer Filtration Plant 1) Highest single turbidity measurement
0.3 NTU
0.08
No No
Soil Run-Off Soil Run-Off
2) Percentage of samples less than or equal to 0.3 NTU
100%
100%
Turbidity is a measure of the cloudiness of the water, an indication of particulate matter, some of which might include harmful microorganisms. Low turbidity in treated surface water is a good indicator of effective filtration. Filtration is called a “treatment technique” (TT). A treatment technique is a required process intended to reduce the level of contaminants in drinking water that are difficult and sometimes impossible to measure directly.
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
n/a n/a n/a n/a n/a
0.20 <0.3 0.88
0.025 – 0.72
2020 2020 2020 2020 2023
Germanium, Total (ppb) Manganese, Total (ppb) Total Organic Carbon (ppm)
ND – 0.8 ND – 2.7 0.06 – 6.5 ND – 64.2
MCL = 50*
n/a n/a
1.2
Lithium, Total (ppb)
45.8
*Contaminant is regulated by a secondary standard
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2023 Irvine Ranch Water District Distribution System Water Quality
MCL
Average Amount
Range of Detections 11.4 – 57.7 6.2 – 42.8
MCL
Typical Source of Contaminant
Disinfection Byproducts
(MRDL/MRDLG)
Violation?
Total Trihalomethanes (ppb) Haloacetic Acids (five) (ppb) Chlorine Residual (ppm)
80 60
30.2*** 19.0***
No No No
Byproducts of Chlorine Disinfection Byproducts of Chlorine Disinfection Disinfectant Added for Treatment
(4.0 / 4)
1.7
ND – 4.8
Aesthetic Quality Color (color units)
15*
<3
ND – 7 ND – 15 ND – 3
No No No
Erosion of Natural Deposits Erosion of Natural Deposits Erosion of Natural Deposits
Turbidity (NTU)
5* 3*
0.12
Odor (threshold odor number)
<1
Other Fluoride (mg/L)
2 / 0.8**
0.51
0.23 – 0.82
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
90 th
Action Level
Public Health
Sites Exceeding AL /
AL
Typical Source of Contaminant
(AL)
Goal (PHG)
Percentile Value
Number of Sites
Violation
Copper (ppm)
1.3
0.3 0.2
0.1908
0 / 72 0 / 72
No No
Corrosion of Household Plumbing Corrosion of Household Plumbing
Lead (ppb)
15
<5
The most recent lead and copper at-the-tap samples were collected from 72 residences in 2022. Lead was detected in 0 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) Manganese, Total (ppb)
n/a
n/a n/a n/a n/a n/a n/a
0.82
ND – 1.1 0.8 – 2.2 1.5 – 13 0.6 – 3.8 0.4 – 2.5 0.9 – 7.0 1.7 – 25 ND – 1.2 ND – 3.8 ND – 10
2020 2020 2019 2019 2019 2019 2019 2019 2019 2019
MCL = 50*
1.6 3.9 1.3 1.0 2.5 4.9 0.3 0.2 1.3
Bromochloroacetic Acid (ppb) Bromodichloroacetic Acid (ppb) Chlorodibromoacetic Acid (ppb) Dibromoacetic Acid (ppb) Dichloroacetic Acid (ppb) Monobromoacetic Acid (ppb) Monochloroacetic Acid (ppb)
n/a n/a n/a n/a n/a n/a n/a n/a
(0)
n/a
(70) (20)
Trichloroacetic Acid (ppb)
*Contaminant is regulated by a secondary standard
Chart legend What are water quality standards?
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 guideposts and direction for water management practices. The chart 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:
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 chart in this report shows 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.
• Parts per million (ppm) or milligrams per liter (mg/L) • Parts per billion (ppb) or micrograms per liter ( µ g/L) • Parts per trillion (ppt) or nanograms per liter (ng/L)
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Source water assessments (IRWD) Baker Water Treatment Plant water assessment
Imported (MWD) water assessment Every five years, MWD is required by DDW to examine possible sources of drinking water contami- nation in its State Water Project and Colorado River source waters. The most recent surveys for MWD’s source waters are the Colorado River Watershed Sanitary Survey – 2020 update, and the State Water Project Watershed Sanitary Survey – 2021 update. Both source waters are exposed to stormwater runoff,
groundwater is considered most vulnerable to contamination from gas stations, historic gas stations, metal plating/finishing/fabrication facilities, military installations and plastics/synthetics producers. An assessment of the groundwater sources in the Wells 21-22 Desalter Project was completed in May 2009. This groundwater is considered most vulnerable to contamination from sewer collection systems,
The Baker Water Treatment Plant receives untreated surface water from MWD (see MWD water assess- ment above) and untreated surface water from Santiago Reservoir, also known as Irvine Lake. The surface water assessment of Santiago Reservoir is provided by Serrano Water District, which also uses
source water from Santiago Reservoir. The most recent sanitary survey for Santiago Reservoir was updated in 2019. Water supplies from Santiago Reservoir are most vulnerable to septic systems and wildfires. The Source Water Assessment for Santiago Reservoir was completed in
automobiles (gas stations), historic gas stations and underground storage tanks (confirmed leaking tanks). An assessment of the groundwater sources in the Irvine Desalter Project was completed in March 2006. This groundwater is considered most vulnerable to contami- nation from crop irrigation and fertilizers.
recreational activities, wastewater discharges, wildlife, fires, and other watershed-related factors that could affect water quality. Water from the Colorado River is considered to be most vulnerable to
April 2001. The assessment was conducted for the Serrano Water
An assessment of the groundwater source in the Orange Park Acres service area of IRWD was completed in March 2003. This groundwater is considered most vulnerable to contamination from sewer collection systems. An assessment of the groundwater in the Santiago Canyon service area of IRWD was completed in January 2003. There have been no contaminants detected in the water supply, however the source is still considered vulnerable to contamination from historical mining operations. Copies of the complete assessments may be viewed at the IRWD Water Quality Department, 3512 Michelson Drive, Irvine. You may request a summary of the assessments by writing to District Secretary, Irvine Ranch Water District, 15600 Sand Canyon Avenue, Irvine, California 92618.
District by Boyle Engineering Corporation with assistance from the Serrano Water District staff. A copy of the complete assessment may be viewed at the IRWD Water Quality Department, 3512 Michelson Drive, Irvine. You may request a summary of the assessment by writing to District Secretary, Irvine Ranch Water District, 15600 Sand Canyon Avenue, Irvine, California 92618. Groundwater assessment An assessment of the groundwater sources in the Lake Forest service area of IRWD was completed in December 2002. This groundwater is considered most vulnerable to contamination from dry cleaners and sewer collection systems. An assessment of the groundwater sources in the Dyer Road Well Field was completed in July 2003. This
contamination from recreation, urban/stormwater runoff, increasing urbanization in the watershed, and wastewater. Water supplies from Northern California’s State Water Project are most vulnerable to contamination from urban/stormwater runoff, wildlife, agriculture, recreation, and wastewater. U.S. EPA also requires MWD to complete one Source Water Assessment that uses information collected in the watershed sanitary surveys. MWD completed its SWA in December 2002. The SWA is used to evaluate the vulnerability of water sources to contamination and helps determine whether more protective measures are needed. A copy of the most recent summary of either Water- shed Sanitary Survey or the SWA can be obtained by calling MWD at 800-CALL-MWD (800-225-5693).
Start outdoors Your yard can be the biggest source of water waste —— and offers the greatest opportunity to be more water- efficient. For lots of ideas, visit IRWD.com/savewater . Or (if you are viewing a digital copy of this report) click the links below. Whether it’s dry or rainy, it’s always good policy to use water wisely.
• Design: • Check out our helpful tips for landscape design • Plant a sustainable garden • Hydrozone • Planting tips: • Events and classes • Healthy soil • Benefits of mulch
• Landscape: • Beautify your yard with water-wise plants • Read The Dirt , IRWD’s quarterly gardening newsletter • Watch The Shed Show • Irrigation: • Types of systems • Money-saving rebates • Watering guide
Get water-saving tips customized for your home Take the guesswork out of saving water with the IRWD WaterInsight Program. Register for free at IRWD.waterinsight.com and receive water savings recommendations specific to your household.
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