Your Local Water Profile: Tustin
This profile explains what the applicable water provider reported for Tustin, what those results may mean throughout a home, and where property-specific testing or inspection may still be needed.
First, confirm your water provider.
Water service can vary by address. Confirm the provider shown on your water bill before applying provider-specific results.
What the official water report says
Your water at a glance
City of Tustin
The report lists hardness as 377 ppm; this is very hard on the USGS scale.
Reported range: 133 - 609 ppm
USGS hardness scale: 0–60 soft; 61–120 moderately hard; 121–180 hard; >180 very hard, in mg/L as CaCO3.
Golden State Water Company
The report lists hardness as 236 mg/L; this is very hard on the USGS scale.
USGS hardness scale: 0–60 soft; 61–120 moderately hard; 121–180 hard; >180 very hard, in mg/L as CaCO3.
Irvine Ranch Water District
The report lists hardness as 295 ppm as CaCO3; this is not classified because the reported unit could not be normalized on the USGS scale.
USGS hardness scale: 0–60 soft; 61–120 moderately hard; 121–180 hard; >180 very hard, in mg/L as CaCO3.
East Orange County Water District
The report lists hardness as 333 ppm; this is very hard on the USGS scale.
Reported range: 191 - 344 ppm
USGS hardness scale: 0–60 soft; 61–120 moderately hard; 121–180 hard; >180 very hard, in mg/L as CaCO3.
City of Tustin Water Services Division — compliance, as reported
The report states: “The water delivered to your home meets the quality standards required by federal and state regulatory agencies.”
Violations or advisories, as reported: The report states that there were no MCL violations for any of the tested contaminants. It notes that while all service lines within the distribution system are lead-free, 120 customer-side service lines have been identified as galvanized requiring replacement.
Cowan Heights Water System — compliance, as reported
The report states: “YOUR WATER MEETS ALL CURRENT FEDERAL AND STATE REQUIREMENTS [p. 8, How to Read This Table]”
Irvine Ranch Water District — compliance, as reported
The report states: “In 2024, IRWD drinking water met or exceeded all state and federal standards. [p. 2]”
East Orange County Water District — compliance, as reported
The report states: “The water delivered to your home meets the quality standards required by federal and state regulatory agencies.”
Violations or advisories, as reported: None stated. The report indicates no violations for any of the tested contaminants.
The Three C's — 1 of 3
Chemistry
What does this water tend to do in a home?
City of Tustin Water Services Division
Alkalinity, total as CaCO3
The utility reported: 201 ppm
Reported range: 93 - 270
Reported constituent · report p. [7] · official report
Calcium
The utility reported: 104 ppm
Reported range: 39 - 160
Reported constituent · report p. [7] · official report
Hardness, total as CaCO3
The utility reported: 377 ppm
Reported range: 133 - 609
Reported constituent · report p. [7] · official report
Hardness, total
The utility reported: 22 grains/gallon
Reported range: 7.8 - 36
Reported constituent · report p. [7] · official report
Magnesium
The utility reported: 28 ppm
Reported range: 7.3 - 51
Reported constituent · report p. [7] · official report
pH
The utility reported: 7.8 pH units
Reported range: 7.5 - 8.3
Reported constituent · report p. [7] · official report
Potassium
The utility reported: 2.3 ppm
Reported range: 1.8 - 4.8
Reported constituent · report p. [7] · official report
Sodium
The utility reported: 74.8 ppm
Reported range: 53.1 - 111
Reported constituent · report p. [7] · official report
Total Organic Carbon
The utility reported: 0.08 ppm
Reported range: ND - 2.6
Reported constituent · report p. [7] · official report
Chloride
The utility reported: 115 ppm
Reported range: 34 - 199
Reported constituent · report p. [6] · official report
Specific Conductance
The utility reported: 1,023 µmho/cm
Reported range: 550 - 1,560
Reported constituent · report p. [6] · official report
Sulfate
The utility reported: 148 ppm
Reported range: 79 - 220
Reported constituent · report p. [6] · official report
Total Dissolved Solids
The utility reported: 541 ppm
Reported range: 120 - 916
Reported constituent · report p. [6] · official report
Lead
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND\u201311
Reported constituent · report p. [5] · official report
Copper
The utility reported: 0.17 ppm
Reported range: ND\u20130.48
Reported constituent · report p. [5] · official report
Cowan Heights Water System
Hardness [as CaCO3]
The utility reported: 13.8 grains/gal
Other Parameters · report p. 8 · official report
Total Dissolved Solids
The utility reported: 498 mg/L
Secondary Standards - Aesthetic · report p. 8 · official report
Chloride
The utility reported: 84 mg/L
Secondary Standards - Aesthetic · report p. 8 · official report
Sulfate
The utility reported: 140 mg/L
Secondary Standards - Aesthetic · report p. 8 · official report
Chlorine [as Cl2]
The utility reported: 1.7 mg/L
Disinfection Byproducts and Disinfectant Residuals · report p. 9 · official report
Irvine Ranch Water District
Hardness, total
The utility reported: 295 ppm as CaCO3
Unregulated contaminants · report p. 8 · official report
Hardness, total
The utility reported: 17.3 grains/gal
Unregulated contaminants · report p. 8 · official report
Alkalinity, total
The utility reported: 124 ppm as CaCO3
Unregulated contaminants · report p. 8 · official report
Total Dissolved Solids
The utility reported: 642 ppm
Secondary standards · report p. 8 · official report
Lead
The utility reported: <5 ppb
Lead and copper action levels at residential taps · report p. 7 · official report
Copper
The utility reported: 0.1908 ppm
Lead and copper action levels at residential taps · report p. 7 · official report
Chlorine residual
The utility reported: 1.9 ppm
Disinfection byproducts · report p. 7 · official report
Corrosivity (Aggressiveness)
The utility reported: 12.5
Unregulated contaminants · report p. 8 · official report
Corrosivity (Langlier Index)
The utility reported: 0.62
Unregulated contaminants · report p. 8 · official report
East Orange County Water District
Alkalinity, total as CaCO3
The utility reported: 187 ppm
Reported range: 93 - 191
Reported constituent · report p. [7] · official report
Calcium
The utility reported: 91 ppm
Reported range: 44 - 97
Reported constituent · report p. [7] · official report
Hardness, total as CaCO3
The utility reported: 333 ppm
Reported range: 191 - 344
Reported constituent · report p. [7] · official report
Magnesium
The utility reported: 23 ppm
Reported range: 19 - 25
Reported constituent · report p. [7] · official report
pH
The utility reported: 7.8 pH units
Reported range: 7.7 - 8.3
Reported constituent · report p. [7] · official report
Potassium
The utility reported: 2.2 ppm
Reported range: 2.2 - 4.8
Reported constituent · report p. [7] · official report
Sodium
The utility reported: 63 ppm
Reported range: 60 - 97
Reported constituent · report p. [7] · official report
Total Organic Carbon
The utility reported: 0.23 ppm
Reported range: ND - 2.6
Reported constituent · report p. [7] · official report
Chloride
The utility reported: 101 ppm
Reported range: 84 -102
Reported constituent · report p. [7] · official report
Specific Conductance
The utility reported: 885 µmho/cm
Reported range: 759 - 987
Reported constituent · report p. [7] · official report
Sulfate
The utility reported: 123 ppm
Reported range: 117 -218
Reported constituent · report p. [7] · official report
Total Dissolved Solids
The utility reported: 571 ppm
Reported range: 465 - 625
Reported constituent · report p. [7] · official report
Lead
The utility reported: 5.71 ppb
Reported range: ND - 8.72
Reported constituent · report p. [8] · official report
Copper
The utility reported: 0.383 ppm
Reported range: ND - 0.468
Reported constituent · report p. [8] · official report
The Three C's — 2 of 3
Contaminants
What was reported, and what do the applicable standards mean?
Legal limit — maximum contaminant level (MCL)
The highest level legally allowed in public drinking water under the applicable rule. Do not use MCL as a generic label for goals, action levels, notification levels, or independent guidelines. It is different from a non-enforceable health goal.
California health goal — public health goal (PHG)
A non-enforceable health-protective target developed for standard-setting context. It is not the California legal limit.
Federal health goal — maximum contaminant level goal (MCLG)
A non-enforceable EPA public-health target used in setting standards. It is not the legal limit.
Legal disinfectant-residual limit — maximum residual disinfectant level (MRDL)
The highest level of a drinking-water disinfectant allowed under the applicable rule. It is not an MCL for a contaminant.
City of Tustin Water Services Division — regulated contaminants reported as detected (16)
Chlorine Residual
The utility reported: 1.3 ppm
Reported range: 0.83 - 1.8
Benchmark: 4 · Health goal (goal): 4 — not an enforceable limit
Violation per report: No
Typical source, per the report: Disinfectant Added for Treatment
Reported constituent · report p. [5] · official report
Haloacetic Acids
The utility reported: 6 ppb
Reported range: ND - 9.8
Benchmark: 60
Violation per report: No
Typical source, per the report: Byproducts of Chlorine Disinfection
Reported constituent · report p. [5] · official report
Total Trihalomethanes
The utility reported: 24 ppb
Reported range: ND - 34
Benchmark: 80
Violation per report: No
Typical source, per the report: Byproducts of Chlorine Disinfection
Reported constituent · report p. [5] · official report
Gross Alpha Particle Activity
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 5
Benchmark: 15 · Health goal (goal): (0) — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of Natural Deposits
Reported constituent · report p. [6] · official report
Gross Beta Particle Activity
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 6
Benchmark: 50 · Health goal (goal): (0) — not an enforceable limit
Violation per report: No
Typical source, per the report: Decay of Natural and Man-made Deposits
Reported constituent · report p. [6] · official report
Uranium
The utility reported: 2.7 pCi/L
Reported range: ND - 3.7
Benchmark: 20 · Health goal (goal): 0.43 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of Natural Deposits
Reported constituent · report p. [6] · official report
Aluminum
The utility reported: 0.058 ppm
Reported range: ND - 0.082
Benchmark: 1 · Health goal (goal): 0.6 — not an enforceable limit
Violation per report: No
Typical source, per the report: Treatment Process Residue, Natural Deposits
Reported constituent · report p. [6] · official report
Barium
The utility reported: 0.13 ppm
Reported range: ND - 0.13
Benchmark: 1 · Health goal (goal): 2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Refinery Discharge, Erosion of Natural Deposits
Reported constituent · report p. [6] · official report
Bromate
The utility reported: 2.4 ppb
Reported range: ND - 8.4
Benchmark: 10 · Health goal (goal): 0.1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Byproduct of Drinking Water Ozonation
Reported constituent · report p. [6] · official report
Fluoride
The utility reported: 0.18 ppm
Reported range: 0.11 - 0.22
Benchmark: 2 · Health goal (goal): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of Natural Deposits
Reported constituent · report p. [6] · official report
Fluoride (treatment-related)
The utility reported: 0.7 ppm
Reported range: 0.6 - 0.8
Benchmark: 2 · Health goal (goal): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Water Additive for Dental Health
Reported constituent · report p. [6] · official report
Hexavalent Chromium
The utility reported: 0.32 ppb
Reported range: ND - 0.64
Benchmark: 10 · Health goal (goal): 0.02 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of Natural Deposits; Industrial Discharge
Reported constituent · report p. [6] · official report
Nitrate (as N)
The utility reported: 3 ppm
Reported range: ND - 4.9
Benchmark: 10 · Health goal (goal): 10 — not an enforceable limit
Violation per report: No
Typical source, per the report: Fertilizers, Septic Tanks
Reported constituent · report p. [6] · official report
Nitrate+Nitrite (as N)
The utility reported: 3 ppm
Reported range: ND - 4.9
Benchmark: 10 · Health goal (goal): 10 — not an enforceable limit
Violation per report: No
Typical source, per the report: Fertilizers, Septic Tanks
Reported constituent · report p. [6] · official report
Perchlorate
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND - 1.3
Benchmark: 6 · Health goal (goal): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Industrial Discharge
Reported constituent · report p. [6] · official report
Selenium
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND - 5.7
Benchmark: 50 · Health goal (goal): 30 — not an enforceable limit
Violation per report: No
Typical source, per the report: Treatment Process Residue, Natural Deposits
Reported constituent · report p. [6] · official report
City of Tustin Water Services Division — unregulated monitoring and secondary (aesthetic) records (20)
Unregulated means monitored without an applicable enforceable legal limit (MCL) — it does not mean unimportant or illegal. Secondary records address aesthetic, cosmetic, or technical effects such as taste, odor, staining, or scale, and are not automatically primary health standards.
Color
The utility reported: Not detected at the report's stated reporting limit color units
Reported range: ND - 5
Reported constituent · report p. [5] · official report
Odor
The utility reported: Not detected at the report's stated reporting limit threshold odor number
Reported range: ND - 1
Reported constituent · report p. [5] · official report
Turbidity
The utility reported: Not detected at the report's stated reporting limit ntu
Reported range: ND - 0.29
Reported constituent · report p. [5] · official report
Aluminum
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND - 82
Reported constituent · report p. [6] · official report
Iron
The utility reported: 9.43 ppb
Reported range: ND - 334
Reported constituent · report p. [6] · official report
Turbidity
The utility reported: 0.21 ntu
Reported range: ND - 2
Reported constituent · report p. [6] · official report
Boron
The utility reported: 0.1 ppm
Reported range: ND - 0.19
Reported constituent · report p. [7] · official report
Lithium
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND - 38
Reported constituent · report p. [7] · official report
Perfluoro Butane Sulfonic Acid
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 3.4
Reported constituent · report p. [7] · official report
Perfluorobutanoic Acid
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 11
Reported constituent · report p. [7] · official report
Perfluoro Hexane Sulfonic Acid
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 4.4
Reported constituent · report p. [7] · official report
Perfluoro Hexane Sulfonic Acid (1)
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 3.5
Reported constituent · report p. [7] · official report
Perfluorohexanoic Acid
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 4.9
Reported constituent · report p. [7] · official report
Perfluorohexanoic Acid (1)
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 3
Reported constituent · report p. [7] · official report
Perfluoro Octane Sulfonic Acid
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 5.7
Reported constituent · report p. [7] · official report
Perfluoro Octane Sulfonic Acid (1)
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 4.2
Reported constituent · report p. [7] · official report
Perfluorooctanoic Acid
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 5.2
Reported constituent · report p. [7] · official report
Perfluorooctanoic Acid (1)
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 4
Reported constituent · report p. [7] · official report
Perfluoropentanoic Acid
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 14
Reported constituent · report p. [7] · official report
Perfluoropentanoic Acid (1)
The utility reported: Not detected at the report's stated reporting limit ppt
Reported range: ND - 3.7
Reported constituent · report p. [7] · official report
Cowan Heights Water System — regulated contaminants reported as detected (16)
Turbidity (Highest single measurement of the treated surface water)
The utility reported: 0.05 NTU
TT: 1.0
Violation per report: No
Typical source, per the report: Soil runoff
Primary Standards - Health Based · report p. 8 · official report
Turbidity (Lowest percent of all monthly readings less than 0.3 NTU)
The utility reported: 100% %
TT: 95
Violation per report: No
Typical source, per the report: Soil runoff
Primary Standards - Health Based · report p. 8 · official report
Aluminum
The utility reported: Not detected at the report's stated reporting limit mg/L
Reported range: ND - 0.08
Legal limit (MCL): 1 · Health goal (PHG (MCLG)): 0.6 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; residue from some surface water treatment processes
Primary Standards - Health Based · report p. 8 · official report
Barium
The utility reported: Not detected at the report's stated reporting limit mg/L
Reported range: ND - 0.13
Legal limit (MCL): 1 · Health goal (PHG (MCLG)): 2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Discharges of oil drilling wastes and from metal refineries; erosion of natural deposits
Primary Standards - Health Based · report p. 8 · official report
Chromium, Hexavalent
The utility reported: Not detected at the report's stated reporting limit µg/L
Reported range: ND - 0.2
Legal limit (MCL): 10 · Health goal (PHG (MCLG)): 0.02 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; transformation of naturally occurring trivalent chromium to hexavalent chromium by natural processes and human activities, such as discharges from electroplating factories, leather tanneries, wood preservation, chemical synthesis, refractory production, and textile manufacturing facilities.
Primary Standards - Health Based · report p. 8 · official report
Fluoride
The utility reported: 0.4 mg/L
Reported range: 0.2 - 0.8
Legal limit (MCL): 2.0 · Health goal (PHG (MCLG)): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; water additive that promotes strong teeth; discharge from fertilizer and aluminum factories
Primary Standards - Health Based · report p. 8 · official report
Nitrate [as N]
The utility reported: 1.0 mg/L
Reported range: ND - 2.2
Legal limit (MCL): 10 · Health goal (PHG (MCLG)): 10 — not an enforceable limit
Violation per report: No
Typical source, per the report: Runoff and leaching from fertilizer use; leaching from septic tanks and sewage; erosion of natural deposits
Primary Standards - Health Based · report p. 8 · official report
Gross Alpha Activity
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 5
Legal limit (MCL): 15(a) · Health goal (PHG (MCLG)): (0) — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Primary Standards - Health Based · report p. 8 · official report
Gross Beta Activity
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 6
Legal limit (MCL): 50(b) · Health goal (PHG (MCLG)): (0) — not an enforceable limit
Violation per report: No
Typical source, per the report: Decay of natural and manmade deposits
Primary Standards - Health Based · report p. 8 · official report
Uranium
The utility reported: 1.3 pCi/L
Reported range: ND - 3
Legal limit (MCL): 20 · Health goal (PHG (MCLG)): 0.43 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Primary Standards - Health Based · report p. 8 · official report
Bromate
The utility reported: 2.4 µg/L
Reported range: ND - 8.4
MCL (MRDL): 10 · Health goal (PHG (MRDLG)): 0.1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
Disinfection Byproducts and Disinfectant Residuals · report p. 9 · official report
Chlorine [as Cl2]
The utility reported: 1.7 mg/L
Reported range: 0.1 - 3.1
MCL (MRDL): (4.0) · Health goal (PHG (MRDLG)): (4) — not an enforceable limit
Violation per report: No
Typical source, per the report: Drinking water disinfectant added for treatment
Disinfection Byproducts and Disinfectant Residuals · report p. 9 · official report
HAA5 [Sum of 5 Haloacetic Acids]
The utility reported: 7.0 µg/L
Reported range: ND - 7.7
MCL (MRDL): 60
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
Disinfection Byproducts and Disinfectant Residuals · report p. 9 · official report
TTHMs [Total Trihalomethanes]
The utility reported: 29 µg/L
Reported range: 2.8 - 27
MCL (MRDL): 80
Violation per report: No
Typical source, per the report: Byproduct of drinking water disinfection
Disinfection Byproducts and Disinfectant Residuals · report p. 9 · official report
Copper
The utility reported: 0.12 mg/L
Reported range: None of the 21 samples collected exceeded the action level.
Action Level: 1.3 · Health goal (PHG (MCLG)): 0.3 — not an enforceable limit
Violation per report: No
Typical source, per the report: Internal corrosion of household plumbing systems; erosion of natural deposits; leaching from wood preservatives
Inorganic Constituents · report p. 9 · official report
Lead
The utility reported: 8.7 µg/L
Reported range: 1 of the 21 samples collected exceeded the action level.
Action Level: 15 · Health goal (PHG (MCLG)): 0.2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Internal corrosion of household water plumbing systems; discharges from industrial manufacturers; erosion of natural deposits.
Inorganic Constituents · report p. 9 · official report
Cowan Heights Water System — unregulated monitoring and secondary (aesthetic) records (7)
Unregulated means monitored without an applicable enforceable legal limit (MCL) — it does not mean unimportant or illegal. Secondary records address aesthetic, cosmetic, or technical effects such as taste, odor, staining, or scale, and are not automatically primary health standards.
Aluminum
The utility reported: Not detected at the report's stated reporting limit µg/L
Reported range: ND - 82
Typical source, per the report: Erosion of natural deposits; residue from some surface water treatment processes
Secondary Standards - Aesthetic · report p. 8 · official report
Color
The utility reported: Not detected at the report's stated reporting limit units
Reported range: ND - 1
Typical source, per the report: Naturally-occurring organic materials
Secondary Standards - Aesthetic · report p. 8 · official report
Specific Conductance
The utility reported: 799 µS/cm
Reported range: 717 - 987
Typical source, per the report: Substances that form ions when in water; seawater influence
Secondary Standards - Aesthetic · report p. 8 · official report
Potassium
The utility reported: 3.2 mg/L
Reported range: 2.1 - 4.8
Other Parameters · report p. 8 · official report
Perfluorobutanoic acid (PFBA)
The utility reported: 2.9 ng/L
Reported range: ND - 6.9
Typical source, per the report: Discharge from manufacturing and industrial chemical facilities, use of certain consumer products, occupational exposures, and certain firefighting activities.
Unregulated Drinking Water Constituents · report p. 8 · official report
Perfluoropentanoic acid (PFPeA)
The utility reported: 2.1 ng/L
Reported range: ND - 7.5
Typical source, per the report: Discharge from manufacturing and industrial chemical facilities, use of certain consumer products, occupational exposures, and certain firefighting activities.
Unregulated Drinking Water Constituents · report p. 8 · official report
Lithium
The utility reported: 26 ug/L
Reported range: 9.4 - 59
Typical source, per the report: Naturally-occurring; used in electrochemical cells, batteries, and organic syntheses and pharmaceuticals
Unregulated Drinking Water Constituents · report p. 8 · official report
Irvine Ranch Water District — regulated contaminants reported as detected (22)
Total Trihalomethanes
The utility reported: 24.1 ppb
Reported range: 9.1 - 44.2
Legal limit (MCL): 80
Violation per report: No
Typical source, per the report: Byproducts of chlorine disinfection
Disinfection byproducts · report p. 7 · official report
Haloacetic Acids (five)
The utility reported: 10.0 ppb
Reported range: 4.1 - 19.6
Legal limit (MCL): 60
Violation per report: No
Typical source, per the report: Byproducts of chlorine disinfection
Disinfection byproducts · report p. 7 · official report
Chlorine residual
The utility reported: 1.9 ppm
Reported range: ND - 3.9
MRDL: 4.0 · Health goal (MRDLG): 4 — not an enforceable limit
Violation per report: No
Typical source, per the report: Disinfectant added for treatment
Disinfection byproducts · report p. 7 · official report
Color
The utility reported: <3 color units
Reported range: ND - 4
Legal limit (MCL): 15
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Aesthetic quality · report p. 7 · official report
Turbidity
The utility reported: 0.1 NTU
Reported range: ND - 6.9
Legal limit (MCL): 5
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Aesthetic quality · report p. 7 · official report
Odor
The utility reported: <1 threshold odor number
Reported range: ND - 4
Legal limit (MCL): 3
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Aesthetic quality · report p. 7 · official report
Fluoride
The utility reported: 0.54 mg/L
Reported range: 0.18 - 0.80
Legal limit (MCL): 2 · Health goal (MCLG): 0.8 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits, water treatment
Other · report p. 7 · official report
Copper
The utility reported: 0.1908 ppm
AL: 1.3 · Health goal (PHG): 0.3 — not an enforceable limit
Violation per report: No
Typical source, per the report: Corrosion of household plumbing
Lead and copper action levels at residential taps · report p. 7 · official report
Lead
The utility reported: <5 ppb
AL: 15 · Health goal (PHG): 0.2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Corrosion of household plumbing
Lead and copper action levels at residential taps · report p. 7 · official report
Alpha Radiation
The utility reported: 1.9 pCi/L
Reported range: ND - 3.8
Legal limit (MCL): 15 · Health goal (PHG): 0 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Radiologicals · report p. 8 · official report
Beta Radiation
The utility reported: 4.6 pCi/L
Reported range: ND - 5.0
Legal limit (MCL): 50 · Health goal (PHG): 0 — not an enforceable limit
Violation per report: No
Typical source, per the report: Decay of natural and man-made deposits
Radiologicals · report p. 8 · official report
Uranium
The utility reported: 2.2 pCi/L
Reported range: ND - 3.0
Legal limit (MCL): 20 · Health goal (PHG): 0.43 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Radiologicals · report p. 8 · official report
Aluminum
The utility reported: 0.105 ppm
Reported range: ND - 0.110
Legal limit (MCL): 1 · Health goal (PHG): 0.6 — not an enforceable limit
Violation per report: No
Typical source, per the report: Treatment process residue, natural deposits
Inorganic chemicals · report p. 8 · official report
Arsenic
The utility reported: 2.00 ppb
Reported range: ND - 3.04
Legal limit (MCL): 10 · Health goal (PHG): 0.004 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Inorganic chemicals · report p. 8 · official report
Barium
The utility reported: 0.124 ppm
Reported range: ND - 0.134
Legal limit (MCL): 1 · Health goal (PHG): 2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Inorganic chemicals · report p. 8 · official report
Bromate
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND - 1.6
Legal limit (MCL): 10 · Health goal (PHG): 0.1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Byproduct of drinking water ozonation
Inorganic chemicals · report p. 8 · official report
Chlorine
The utility reported: 2.5 ppm
Reported range: 1.5 - 3.9
Legal limit (MCL): 4.0 · Health goal (PHG): 4.0 — not an enforceable limit
Violation per report: No
Typical source, per the report: Drinking water disinfectant added for treatment
Inorganic chemicals · report p. 8 · official report
Hexavalent Chromium
The utility reported: 0.1 ppb
Reported range: ND - 0.19
Legal limit (MCL): 10 · Health goal (PHG): 0.02 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; industrial discharge
Inorganic chemicals · report p. 8 · official report
Fluoride naturally-occurring
The utility reported: 0.35 ppm
Reported range: ND - 0.83
Legal limit (MCL): 2 · Health goal (PHG): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits; IRWD does not add Fluoride to its local treated groundwater and surface water
Inorganic chemicals · report p. 8 · official report
Fluoride treatment-related
The utility reported: 0.7 ppm
Reported range: 0.6 - 0.8
Control range: 0.6 - 1.2 · Health goal (Optimal level): 0.7 — not an enforceable limit
Violation per report: No
Typical source, per the report: Water additive for dental health
Inorganic chemicals · report p. 8 · official report
Nitrate
The utility reported: 2.3 ppm as N
Reported range: ND - 4.3
Legal limit (MCL): 10 · Health goal (PHG): 10 — not an enforceable limit
Violation per report: No
Typical source, per the report: Fertilizers, septic tanks
Inorganic chemicals · report p. 8 · official report
Nitrate+Nitrite
The utility reported: 2.3 ppm as N
Reported range: ND - 4.3
Legal limit (MCL): 10 · Health goal (PHG): 10 — not an enforceable limit
Violation per report: No
Typical source, per the report: Fertilizers, septic tanks
Inorganic chemicals · report p. 8 · official report
Irvine Ranch Water District — unregulated monitoring and secondary (aesthetic) records (30)
Unregulated means monitored without an applicable enforceable legal limit (MCL) — it does not mean unimportant or illegal. Secondary records address aesthetic, cosmetic, or technical effects such as taste, odor, staining, or scale, and are not automatically primary health standards.
Germanium, total
The utility reported: 0.82 ppb
Reported range: ND - 1.1
Unregulated chemicals requiring monitoring in the distribution system · report p. 7 · official report
Manganese, total
The utility reported: 1.6 ppb
Reported range: 0.8 - 2.2
Unregulated chemicals requiring monitoring in the distribution system · report p. 7 · official report
Aluminum
The utility reported: 8.4 ppb
Reported range: ND - 110
Typical source, per the report: Treatment process residue, natural deposits
Secondary standards · report p. 8 · official report
Chloride
The utility reported: 112 ppm
Reported range: 17.8 - 124
Typical source, per the report: Leaching from natural deposits; seawater influence
Secondary standards · report p. 8 · official report
Color
The utility reported: <3 color units
Reported range: ND - 8
Typical source, per the report: Naturally-occurring organic substances
Secondary standards · report p. 8 · official report
Odor
The utility reported: 2 TON
Reported range: ND - 6
Typical source, per the report: Naturally-occurring organic materials
Secondary standards · report p. 8 · official report
Specific Conductance
The utility reported: 1065 µmho/cm
Reported range: 358 - 1126
Typical source, per the report: Ions in water; seawater influence
Secondary standards · report p. 8 · official report
Sulfate
The utility reported: 237 ppm
Reported range: 21.5 - 253
Typical source, per the report: Runoff or leaching from natural deposits
Secondary standards · report p. 8 · official report
Total Dissolved Solids
The utility reported: 642 ppm
Reported range: 134 - 738
Typical source, per the report: Runoff or leaching from natural deposits
Secondary standards · report p. 8 · official report
Turbidity
The utility reported: <0.10 NTU
Reported range: ND - 0.4
Typical source, per the report: Erosion of natural deposits
Secondary standards · report p. 8 · official report
Alkalinity, total
The utility reported: 124 ppm as CaCO3
Reported range: 70 - 233
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Bicarbonate
The utility reported: 124 ppm as HCO3
Reported range: 70 - 144
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Boron
The utility reported: 0.16 ppm
Reported range: ND - 0.25
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Bromide
The utility reported: 0.14 ppm
Reported range: 0.02 - 0.29
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Calcium
The utility reported: 72.7 ppm
Reported range: 16.7 - 79.5
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Carbonate
The utility reported: <0.6 ppm
Reported range: <0.6 - 1.1
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Chlorate
The utility reported: 77.0 ppb
Reported range: 77.0
Typical source, per the report: Byproduct of drinking water chlorination
Unregulated contaminants · report p. 8 · official report
Corrosivity (Aggressiveness)
The utility reported: 12.5
Reported range: 11.0 - 12.9
Typical source, per the report: Elemental balance in water
Unregulated contaminants · report p. 8 · official report
Corrosivity (Langlier Index)
The utility reported: 0.62
Reported range: (-)0.72 - 0.81
Typical source, per the report: Elemental balance in water
Unregulated contaminants · report p. 8 · official report
Hardness, total
The utility reported: 295 ppm as CaCO3
Reported range: 53.9 - 321
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Hardness, total
The utility reported: 17.3 grains/gal
Reported range: 7.5 - 17.3
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Magnesium
The utility reported: 27.9 ppm
Reported range: 2.9 - 29.8
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Molybdenum
The utility reported: 7.9 ppb
Reported range: ND - 19.1
Typical source, per the report: Drinking water treatment chemical for aesthetic quality
Unregulated contaminants · report p. 8 · official report
N-Nitrosodi-n-butylamine (NDBA)
The utility reported: 2.5 ppt
Reported range: 2.5
Typical source, per the report: Byproducts of drinking water chloramination; industrial processes
Unregulated contaminants · report p. 8 · official report
Perfluorooctanoic acid (PFOA)
The utility reported: 1.5 ppt
Reported range: ND - 2.4
Typical source, per the report: used in fire-retarding foams and various industrial processes
Unregulated contaminants · report p. 8 · official report
pH
The utility reported: 8.3 pH units
Reported range: 7.1 - 8.6
Typical source, per the report: Acidity, hydrogen ions
Unregulated contaminants · report p. 8 · official report
Potassium
The utility reported: 5.9 ppm
Reported range: 0.65 - 21.2
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Sodium
The utility reported: 105 ppm
Reported range: 25.1 - 116
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
Total Organic Carbon
The utility reported: 1.9 ppm
Reported range: 0.37 - 2.5
Typical source, per the report: Various natural and man-made sources
Unregulated contaminants · report p. 8 · official report
Vanadium
The utility reported: 4.0 ppb
Reported range: ND - 6.3
Typical source, per the report: Runoff or leaching from natural deposits
Unregulated contaminants · report p. 8 · official report
East Orange County Water District — regulated contaminants reported as detected (14)
Gross Alpha Particle Activity
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 5
Benchmark: 15 · Health goal (goal): (0) — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of Natural Deposits
Reported constituent · report p. [7] · official report
Gross Beta Particle Activity
The utility reported: NR pCi/L
Reported range: ND - 6
Benchmark: 50 · Health goal (goal): (0) — not an enforceable limit
Violation per report: No
Typical source, per the report: Decay of Natural and Man-made Deposits
Reported constituent · report p. [7] · official report
Uranium
The utility reported: 2.7 pCi/L
Reported range: ND - 3.7
Benchmark: 20 · Health goal (goal): 0.43 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of Natural Deposits
Reported constituent · report p. [7] · official report
Aluminum
The utility reported: Not detected at the report's stated reporting limit ppm
Reported range: ND - 0.082
Benchmark: 1 · Health goal (goal): 0.6 — not an enforceable limit
Violation per report: No
Typical source, per the report: Treatment Process Residue, Natural Deposits
Reported constituent · report p. [7] · official report
Barium
The utility reported: Not detected at the report's stated reporting limit ppm
Reported range: ND - 0.13
Benchmark: 1 · Health goal (goal): 2 — not an enforceable limit
Violation per report: No
Typical source, per the report: Refinery Discharge, Erosion of Natural Deposits
Reported constituent · report p. [7] · official report
Bromate
The utility reported: NR ppb
Reported range: ND - 8.4
Benchmark: 10 · Health goal (goal): 0.1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Byproduct of Drinking Water Ozonation
Reported constituent · report p. [7] · official report
Fluoride (naturally-occuring)
The utility reported: 0.15 ppm
Reported range: 0.13 - 0.16
Benchmark: 2 · Health goal (goal): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Erosion of natural deposits
Reported constituent · report p. [7] · official report
Fluoride (treatment-related)
The utility reported: NR ppm
Reported range: 0.6 - 0.8
Benchmark: 2 · Health goal (goal): 1 — not an enforceable limit
Violation per report: No
Typical source, per the report: Water additive for dental health
Reported constituent · report p. [7] · official report
Hexavalent Chromium
The utility reported: 0.31 ppb
Reported range: ND - 0.31
Benchmark: 10 · Health goal (goal): 0.02 — not an enforceable limit
Violation per report: No
Typical source, per the report: Industrial Discharge, Erosion of Natural Deposits
Reported constituent · report p. [7] · official report
Nitrate (as Nitrogen)
The utility reported: 2.9 ppm
Reported range: ND - 3.2
Benchmark: 10 · Health goal (goal): 10 — not an enforceable limit
Violation per report: No
Typical source, per the report: Fertilizers, Septic Tanks
Reported constituent · report p. [7] · official report
Turbidity - combined filter effluent
The utility reported: 0.05 NTU
Reported range: 100%
Benchmark: TT
Violation per report: No
Typical source, per the report: Soil Runoff
Reported constituent · report p. [8] · official report
Total Trihalomethanes
The utility reported: 8 ppb
Reported range: ND - 18
Benchmark: 80
Violation per report: No
Typical source, per the report: Byproducts of Chlorine Disinfection
Reported constituent · report p. [8] · official report
Haloacetic Acids
The utility reported: 4 ppb
Reported range: ND - 9.7
Benchmark: 60
Violation per report: No
Typical source, per the report: Byproducts of Chlorine Disinfection
Reported constituent · report p. [8] · official report
Chlorine Residual
The utility reported: 2.04 ppm
Reported range: 1.5 - 2.3
Benchmark: (4/4)
Violation per report: No
Typical source, per the report: Disinfectant Added for Treatment
Reported constituent · report p. [8] · official report
East Orange County Water District — unregulated monitoring and secondary (aesthetic) records (9)
Unregulated means monitored without an applicable enforceable legal limit (MCL) — it does not mean unimportant or illegal. Secondary records address aesthetic, cosmetic, or technical effects such as taste, odor, staining, or scale, and are not automatically primary health standards.
Aluminum
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND - 82
Reported constituent · report p. [7] · official report
Color
The utility reported: Not detected at the report's stated reporting limit color units
Reported range: ND - 1
Reported constituent · report p. [7] · official report
Turbidity
The utility reported: 0.28 NTU
Reported range: ND - 0.55
Reported constituent · report p. [7] · official report
Boron
The utility reported: 0.12 ppm
Reported range: 0.12 - 0.13
Reported constituent · report p. [7] · official report
Lithium
The utility reported: NR ppb
Reported range: 28 - 42
Reported constituent · report p. [7] · official report
Perfluorobutanoic Acid
The utility reported: 10 ppt
Reported range: ND - 11
Reported constituent · report p. [7] · official report
Perfluoropentanoic Acid
The utility reported: 9.2 ppt
Reported range: ND - 14
Reported constituent · report p. [7] · official report
Odor
The utility reported: Not detected at the report's stated reporting limit threshold odor number
Reported range: ND - 1
Reported constituent · report p. [8] · official report
Turbidity (distribution)
The utility reported: Not detected at the report's stated reporting limit ntu
Reported range: ND - 0.2
Reported constituent · report p. [8] · official report
The Three C's — 3 of 3
Corrosion
What conditions could influence pipes, fixtures, and a water heater?
City of Tustin Water Services Division
Alkalinity, total as CaCO3
The utility reported: 201 ppm
Reported range: 93 - 270
Reported constituent · report p. [7] · official report
pH
The utility reported: 7.8 pH units
Reported range: 7.5 - 8.3
Reported constituent · report p. [7] · official report
Chloride
The utility reported: 115 ppm
Reported range: 34 - 199
Reported constituent · report p. [6] · official report
Sulfate
The utility reported: 148 ppm
Reported range: 79 - 220
Reported constituent · report p. [6] · official report
Lead
The utility reported: Not detected at the report's stated reporting limit ppb
Reported range: ND\u201311
Reported constituent · report p. [5] · official report
Copper
The utility reported: 0.17 ppm
Reported range: ND\u20130.48
Reported constituent · report p. [5] · official report
Gross Alpha Particle Activity
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 5
Typical source, per the report: Erosion of Natural Deposits
Reported constituent · report p. [6] · official report
Cowan Heights Water System
Chloride
The utility reported: 84 mg/L
Secondary Standards - Aesthetic · report p. 8 · official report
Sulfate
The utility reported: 140 mg/L
Secondary Standards - Aesthetic · report p. 8 · official report
Gross Alpha Activity
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 5
Typical source, per the report: Erosion of natural deposits
Primary Standards - Health Based · report p. 8 · official report
Irvine Ranch Water District
Alkalinity, total
The utility reported: 124 ppm as CaCO3
Unregulated contaminants · report p. 8 · official report
Lead
The utility reported: <5 ppb
Lead and copper action levels at residential taps · report p. 7 · official report
Copper
The utility reported: 0.1908 ppm
Lead and copper action levels at residential taps · report p. 7 · official report
Alpha Radiation
The utility reported: 1.9 pCi/L
Reported range: ND - 3.8
Typical source, per the report: Erosion of natural deposits
Radiologicals · report p. 8 · official report
East Orange County Water District
Alkalinity, total as CaCO3
The utility reported: 187 ppm
Reported range: 93 - 191
Reported constituent · report p. [7] · official report
pH
The utility reported: 7.8 pH units
Reported range: 7.7 - 8.3
Reported constituent · report p. [7] · official report
Chloride
The utility reported: 101 ppm
Reported range: 84 -102
Reported constituent · report p. [7] · official report
Sulfate
The utility reported: 123 ppm
Reported range: 117 -218
Reported constituent · report p. [7] · official report
Lead
The utility reported: 5.71 ppb
Reported range: ND - 8.72
Reported constituent · report p. [8] · official report
Copper
The utility reported: 0.383 ppm
Reported range: ND - 0.468
Reported constituent · report p. [8] · official report
Gross Alpha Particle Activity
The utility reported: Not detected at the report's stated reporting limit pCi/L
Reported range: ND - 5
Typical source, per the report: Erosion of Natural Deposits
Reported constituent · report p. [7] · official report
Whole-Home Relevance
What this may mean throughout your home
Local conditions can be relevant to equipment and fixtures — actual effects depend on your property.
Water heater (tank and tankless)
- What the local report can tell us
- The report's hardness and mineral values above are the system-level inputs most relevant to scale and sediment where water is heated.
- What a homeowner may notice
- Hardness minerals can contribute to scale on heating surfaces, sediment in tanks, and more frequent flushing or descaling needs.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Dishwasher and washing machine
- What the local report can tell us
- Reported hardness and secondary (aesthetic) records are the relevant system-level context for spotting and residue.
- What a homeowner may notice
- Hard water can change soap behavior and may contribute to spotting on dishes and residue in laundry.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Pipes, fixtures, faucets, and supply lines
- What the local report can tell us
- The corrosion-related inputs above (such as pH) describe the water entering the property — not the condition of any specific plumbing.
- What a homeowner may notice
- Mineral deposits can appear on aerators and fixtures; corrosion outcomes depend on materials, age, and water conditions together.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Drinking and cooking water
- What the local report can tell us
- The contaminant records above show what the utility reported for the system and period, with each benchmark type labeled.
- What a homeowner may notice
- Taste, odor, or aesthetic preferences can be noticeable even when health-based standards are met.
- What the report cannot tell us
- Property-specific outcomes — actual effects depend on temperature, use, equipment design, installation, maintenance, and property plumbing.
- Responsible next step
- Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Decision Pathways
Treatment pathways to evaluate
Treatment is a decision pathway, not a product conclusion — no equipment can be responsibly chosen from city-level data alone.
The evaluation sequence we follow, in order:
- 1Define the concern
- 2Verify utility-level and home-specific evidence
- 3Choose point of treatment
- 4Verify the exact certified reduction claim for the exact model
- 5Review tradeoffs and maintenance
Water filtration
- Objective it can address
- Specific substances or aesthetic conditions (taste, odor, chlorine character).
- Point of treatment
- Point of entry or point of use, depending on the objective.
- Limitations to verify
- A filter works only for the conditions and reduction claims its exact design and certification support — filtration does not soften water.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
Water softening
- Objective it can address
- Hardness minerals (calcium and magnesium) and the scale they can contribute to.
- Point of treatment
- Typically point of entry, confirmed by evaluation.
- Limitations to verify
- Softening primarily exchanges hardness minerals — it is not a universal contaminant-removal device.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
Reverse osmosis
- Objective it can address
- Specified dissolved substances at a dedicated outlet, commonly drinking and cooking water.
- Point of treatment
- Typically point of use.
- Limitations to verify
- Produces a reject-water stream and needs pressure and maintenance; verify the exact NSF/ANSI 58 reduction claims for the exact model. It is not automatically the best system for every home.
Certification note: a standard number alone doesn't prove a product reduces every contaminant — the exact model's certified claim must match your objective.
When testing is the right next step
Use a certified laboratory when the concern is tap-specific, property-specific, or not resolved by the utility report.
When inspection is the right next step
Inspect the actual water heater and plumbing when symptoms involve hot-water odor, scale, sediment, corrosion, flow, noise, or repeated service demand.
Evidence You Can Check
Official reports, sources, and methodology
Official report — City of Tustin Water Services Division
2025 City of Tustin Drinking Water Quality · data year 2025 · Older retained data; verify the latest publication before republishing
View the 2025 City of Tustin Water Services Division Consumer Confidence ReportSource water, per the report: The City’s water supply is a blend of local groundwater wells and imported water connections originating from Northern California and the Colorado River by MWDSC via the Municipal Water District of Orange County (MWDOC). Groundwater comes from a natural underground aquifer that is replenished with water from the Santa Ana River, local rainfall, Groundwater Replenishment System recycled water, and imported water. The City’s water supply also includes local treated groundwater from East Orange County Water District (EOCWD).
Official report — Cowan Heights Water System
Consumer Confidence Report on Water Quality for 2025 · data year 2025 · Current 2025 monitoring cycle
View the 2025 Cowan Heights Water System Consumer Confidence ReportSource water, per the report: Water delivered to customers in the Cowan Heights System is a blend of treated groundwater pumped from the Orange County Groundwater Basin and imported water from the Colorado River Aqueduct and the State Water Project (imported and distributed by the Metropolitan Water District of Southern California).
Official report — Irvine Ranch Water District
2025 Water Quality Report · data year 2024 · 2024 data retained; monitor for the next official update
View the 2024 Irvine Ranch Water District Consumer Confidence ReportSource water, per the report: IRWD water comes from local groundwater, recycled water, local surface water (rainwater capture), and from imported water from Northern California and the Colorado River. Your drinking water is a blend of local groundwater, groundwater from the Orange County Groundwater Basin managed by the Orange County Water District (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.
Official report — East Orange County Water District
2025 EAST ORANGE COUNTY WATER DISTRICT DRINKING WATER QUALITY · data year 2025 · Older retained data; verify the latest publication before republishing
View the 2025 East Orange County Water District Consumer Confidence Report (PDF)Source water, per the report: In 2025, East Orange County Water District supplied its customers with 87% groundwater and 13% imported surface water. The groundwater is managed by the Orange County Water District (OCWD) and comes from a natural underground aquifer. The imported water is from Northern California and the Colorado River, provided by the Municipal Water District of Orange County (MWDOC) via the Metropolitan Water District of Southern California (MWDSC).
Nearby community water profiles
Property-Specific Next Step
Request a Water Quality Evaluation
Request a water-heater and water-quality evaluation tailored to the property, equipment, and homeowner objective.
A property-specific evaluation confirms your goals, provider, tap conditions, plumbing, equipment, installation, and maintenance before any treatment recommendation — this profile alone is never used to prescribe equipment.
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