EPA SDWIS Β· Riverside County, California Β· 451 providers profiled
Riverside County, CA Water Quality Report
Riverside County is served by 451 major public water systems on file with the EPA.
Data current as of July 2026
πStraight from EPA
π§ͺReal Lab Results
π Updated Quarterly
π Local Expertise
Results for Riverside County, CA
451 water providers on file for this county, sorted by population served.
Quick answer: Riverside County has 451 water providers profiled, sorted by population served.
Lead Summary
Magnesium
Potassium
Sodium
Calcium
Hardness, Total (ASCACO3)
Alkalinity, Total
Alkalinity, Bicarbonate
TDS
Sulfate
Chloride
Fluoride
Nitrate
Turbidity
Radium-228
Combined Uranium
Gross Alpha Particle Activity
pH
Odor
Iron
Zinc
Conductivity (at 25Β°C)
Manganese
Nitrate-Nitrite
Vanadium, Total
Chromium, Hex
Aggressive Index
Langelier Index (pH(s))
Langelier Index (Source Temp.)
Arsenic
Copper Summary
Perfluorohexanesulfonicacid (PFHxS)
Perfluoroctanesulfonicacid (PFOS)
Perfluoroctanoicacid (PFOA)
Perfluorohexanoicacid (PFHXA)
Perfluorobutanoicacid (PFBA)
Perfluoropentanoicacid (PFPEA)
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromoform
Bromodichloromethane
Dibromochloromethane
Dibromoaceticacid
Dichloroaceticacid
Lead
Copper, Free
Selenium
Barium
Alkalinity, Carbonate
Trichloroaceticacid
Perfluorobutanesulfonicacid (PFBS)
Chromium
Boron, Total
Color
Monobromoaceticacid
Foamingagents (SURFACTANTS)
Adsorbableorganicfluorine
Aluminum
1, 2, 3-Trichloropropane
1, 2-Dichloropropane
Gross Beta Particle Activity
Radium-226
TotalradiumforntncperΒ§64442(B) (3)
Temperature (CENTIGRADE)
Silica
PFHXS
Lithium
Perchlorate
Bromide
Hexachlorocyclopentadiene
Perfluoroheptanoicacid (PFHPA)
Perfluoropentanesulfonicacid (PFPES)
PFBA
Combined Radium (-226 & -228)
Carbon, Total
Perfluorononanoicacid (PFNA)
Perfluorodecanoicacid (PFDA)
pH, Field
Hydroxideascalciumcarbonate
Turbidity, Field
PFHXA
PFPEA
PFBS
Nickel
PFOA
PFOS
PFHPA
Molybdenum, Total
Violations on file
Fluoride
Older/archived health-based violation
Found at 17 of 451 providers
Often added deliberately for dental health; can also occur naturally.
Coliform (TCR)
Older/archived health-based violation
Found at 6 of 451 providers
Nitrate
Older/archived health-based violation
Found at 21 of 451 providers
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Lead And Copper Rule Revisions
Currently open health violation
Found at 24 of 451 providers
Combined Uranium
Older/archived health-based violation
Found at 1 of 451 providers
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Arsenic
Older/archived health-based violation
Found at 2 of 451 providers
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Revised Total Coliform Rule
Currently open health violation
Found at 4 of 451 providers
Selenium
Older/archived health-based violation
Found at 2 of 451 providers
TTHM
Older/archived health-based violation
Found at 1 of 451 providers
A group of disinfection byproducts formed when chlorine reacts with organic matter. Long-term exposure above the legal limit has been linked to increased cancer risk in some studies.
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.018 mg/L (ppm)
Found at 147 providers
Combined Uranium
Detected: 43 PCI/L
Found at 19 providers
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Iron
Detected: 9500 UG/L (ppb)
Found at 23 providers
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Zinc
Detected: 350 UG/L (ppb)
Found at 10 providers
Manganese
Detected: 560 UG/L (ppb)
Found at 20 providers
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Vanadium, Total
Detected: 81 UG/L (ppb)
Found at 11 providers
Chromium, Hex
Detected: 21 UG/L (ppb)
Found at 35 providers
Arsenic
Detected: 51 UG/L (ppb)
Found at 29 providers
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Copper Summary
Detected: 3 mg/L (ppm)
Found at 9 providers
Lead
Detected: 71 UG/L (ppb)
Found at 14 providers
A metal that can leach from old pipes, solder, and fixtures. Current medical guidance holds there is no truly safe level of lead exposure, especially for children and pregnant women.
Copper, Free
Detected: 2200 UG/L (ppb)
Found at 20 providers
Selenium
Detected: 12 UG/L (ppb)
Found at 4 providers
Barium
Detected: 540 UG/L (ppb)
Found at 18 providers
Chromium
Detected: 17 UG/L (ppb)
Found at 12 providers
Occurs in two forms β trivalent (an essential nutrient in trace amounts) and hexavalent (linked to increased cancer risk).
Aluminum
Detected: 170 UG/L (ppb)
Found at 4 providers
Nickel
Detected: 11 UG/L (ppb)
Found at 2 providers
Molybdenum, Total
Detected: 14 UG/L (ppb)
8/26/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 38 UG/L (ppb)
Found at 27 providers
TTHM
Detected: 80 UG/L (ppb)
Found at 43 providers
A group of disinfection byproducts formed when chlorine reacts with organic matter. Long-term exposure above the legal limit has been linked to increased cancer risk in some studies.
Chloroform
Detected: 39 UG/L (ppb)
Found at 33 providers
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 47.6 UG/L (ppb)
Found at 36 providers
Bromodichloromethane
Detected: 29 UG/L (ppb)
Found at 34 providers
Dibromochloromethane
Detected: 26 UG/L (ppb)
Found at 37 providers
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 470 MG/L (ppm)
Found at 36 providers
Chloride
Detected: 680 MG/L (ppm)
Found at 36 providers
Fluoride
Detected: 8.5 MG/L (ppm)
Found at 48 providers
Often added deliberately for dental health; can also occur naturally.
Nitrate
Detected: 19 MG/L (ppm)
Found at 100 providers
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Nitrate-Nitrite
Detected: 3.9 MG/L (ppm)
Found at 8 providers
Boron, Total
Detected: 476 UG/L (ppb)
Found at 8 providers
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 53 MG/L (ppm)
Found at 35 providers
Potassium
Detected: 10 MG/L (ppm)
Found at 33 providers
Sodium
Detected: 300 MG/L (ppm)
Found at 38 providers
Calcium
Detected: 160 MG/L (ppm)
Found at 41 providers
Hydroxideascalciumcarbonate
Detected: 5 MG/L (ppm)
8/25/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 590 MG/L (ppm)
Found at 38 providers
Gross Alpha Particle Activity
Detected: 34 PCI/L
Found at 26 providers
pH
Detected: 9.2 PH
Found at 41 providers
A measure of how acidic or basic the water is (7 is neutral). Affects taste and plumbing, not a direct health measure.
Langelier Index (pH(s))
Detected: 0.79 LANG
Found at 5 providers
pH, Field
Detected: 7.95 PH
Found at 3 providers
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
PFHXS
Detected: 0.0138 Β΅g/L (ppb)
Found at 9 providers
Lithium
Detected: 152 Β΅g/L (ppb)
Found at 18 providers
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
PFBA
Detected: 0.0179 Β΅g/L (ppb)
Found at 7 providers
PFHXA
Detected: 0.011 Β΅g/L (ppb)
Found at 9 providers
PFPEA
Detected: 0.025 Β΅g/L (ppb)
Found at 10 providers
PFBS
Detected: 0.0122 Β΅g/L (ppb)
Found at 4 providers
PFOA
Detected: 0.0137 Β΅g/L (ppb)
Found at 5 providers
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFOS
Detected: 0.0314 Β΅g/L (ppb)
Found at 6 providers
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFHPA
Detected: 0.0033 Β΅g/L (ppb)
3/23/2023
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
1, 2, 3-Trichloropropane
Detected: 0.011 UG/L (ppb)
9/8/2025
1, 2-Dichloropropane
Detected: 0.74 UG/L (ppb)
9/8/2025
Bromide
Detected: 0.031 MG/L (ppm)
1/14/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 330 MG/L (ppm)
Found at 39 providers
Alkalinity, Carbonate
Detected: 12 MG/L (ppm)
Found at 4 providers
Other
Additional substances tested that don't fit neatly into the categories above
Alkalinity, Total
Detected: 270 MG/L (ppm)
Found at 40 providers
TDS
Detected: 2600 MG/L (ppm)
Found at 57 providers
Turbidity
Detected: 31 NTU
Found at 32 providers
A measure of water cloudiness from suspended particles.
Radium-228
Detected: 0.851 PCI/L
Found at 11 providers
Odor
Detected: 2 TON
Found at 18 providers
Conductivity (at 25Β°C)
Detected: 2100 UMHO/CM
Found at 35 providers
Aggressive Index
Detected: 12.4 AGGR
Found at 9 providers
Langelier Index (Source Temp.)
Detected: 0.8 LANG
Found at 8 providers
Perfluorohexanesulfonicacid (PFHxS)
Detected: 14 NG/L (ppt)
Found at 9 providers
Perfluoroctanesulfonicacid (PFOS)
Detected: 35 NG/L (ppt)
Found at 10 providers
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluoroctanoicacid (PFOA)
Detected: 19 NG/L (ppt)
Found at 9 providers
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Perfluorohexanoicacid (PFHXA)
Detected: 24 NG/L (ppt)
Found at 10 providers
Perfluorobutanoicacid (PFBA)
Detected: 17 NG/L (ppt)
Found at 10 providers
Perfluoropentanoicacid (PFPEA)
Detected: 38 NG/L (ppt)
Found at 10 providers
Dibromoaceticacid
Detected: 12 UG/L (ppb)
Found at 23 providers
Dichloroaceticacid
Detected: 16 UG/L (ppb)
Found at 23 providers
Trichloroaceticacid
Detected: 22 UG/L (ppb)
Found at 14 providers
Perfluorobutanesulfonicacid (PFBS)
Detected: 26 NG/L (ppt)
Found at 10 providers
Color
Detected: 30 UNITS
Found at 8 providers
Monobromoaceticacid
Detected: 1.5 UG/L (ppb)
Found at 3 providers
Foamingagents (SURFACTANTS)
Detected: 0.14 MG/L (ppm)
Found at 5 providers
Adsorbableorganicfluorine
Detected: 3900 NG/L (ppt)
Found at 3 providers
Gross Beta Particle Activity
Detected: 16.3 PCI/L
Found at 2 providers
Radium-226
Detected: 0.93 PCI/L
Found at 2 providers
TotalradiumforntncperΒ§64442(B) (3)
Detected: 1.64 PCI/L
7/10/2025
Temperature (CENTIGRADE)
Detected: 72.5 C
Found at 6 providers
Silica
Detected: 43 MG/L (ppm)
Found at 11 providers
Perchlorate
Detected: 7.1 UG/L (ppb)
Found at 11 providers
Can occur naturally or from industrial/military sources; may interfere with thyroid function at elevated levels.
Hexachlorocyclopentadiene
Detected: 0.09 UG/L (ppb)
5/20/2025
Perfluoroheptanoicacid (PFHPA)
Detected: 11 NG/L (ppt)
Found at 6 providers
Perfluoropentanesulfonicacid (PFPES)
Detected: 2.9 NG/L (ppt)
Found at 2 providers
Combined Radium (-226 & -228)
Detected: 1.03 PCI/L
Found at 3 providers
A naturally occurring radioactive element found in some groundwater.
Carbon, Total
Detected: 1.41 MG/L (ppm)
Found at 5 providers
Perfluorononanoicacid (PFNA)
Detected: 2.4 NG/L (ppt)
Found at 3 providers
Perfluorodecanoicacid (PFDA)
Detected: 2.8 NG/L (ppt)
Found at 2 providers
Turbidity, Field
Detected: 0.27 NTU
9/29/2025
Filtration considerations: General system types, not a specific product recommendation.