SIMI VALLEY is served by 2 water providers on file with the EPA.
Data current as of July 2026
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Results for SIMI VALLEY, CA
2 water providers on file serving this city.
Quick answer: SIMI VALLEY's water has no violation currently counted toward its compliance status. EPA's record shows a Selenium violation dating to 10/28/1979 (47 years ago) — because it's more than five years past its deadline, EPA's policy no longer treats it as part of this system's current standing, though it remains on the public record.
Lead Summary
Aggressive Index
Langelier Index (pH(s))
Magnesium
Hardness, Total (ASCACO3)
Calcium
Alkalinity, Total
TDS
Sulfate
pH
Conductivity (at 25°C)
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromoform
Lithium
Nitrate
Chromium, Hex
Tetrachloroethylene
Perchlorate
Selenium
Bromodichloromethane
Dibromochloromethane
Dibromoaceticacid
Monobromoaceticacid
Dichloroaceticacid
Violations on file
Selenium
Older/archived health-based violation
Found at 1 of 2 providers
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
Found at 2 providers
Chromium, Hex
Detected: 4 UG/L (ppb)
1/21/2025
Selenium
Detected: 62 UG/L (ppb)
10/7/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 7.9 UG/L (ppb)
Found at 2 providers
TTHM
Detected: 14 UG/L (ppb)
Found at 2 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: 1.4 UG/L (ppb)
Found at 2 providers
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromoform
Detected: 5.8 UG/L (ppb)
Found at 2 providers
Bromodichloromethane
Detected: 2.4 UG/L (ppb)
8/8/2025
Dibromochloromethane
Detected: 5.1 UG/L (ppb)
8/8/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 910 MG/L (ppm)
Found at 2 providers
Nitrate
Detected: 15 MG/L (ppm)
10/7/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 11.7 MG/L (ppm)
9/24/2025
Calcium
Detected: 54.2 MG/L (ppm)
9/24/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Langelier Index (pH(s))
Detected: -0.588 LANG
9/17/2025
Hardness, Total (ASCACO3)
Detected: 184 MG/L (ppm)
9/24/2025
pH
Detected: 6.4 PH
9/17/2025
A measure of how acidic or basic the water is (7 is neutral). Affects taste and plumbing, not a direct health measure.
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 20.7 µg/L (ppb)
12/17/2024
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
VOCs (Volatile Organic Compounds)
Industrial solvents and fuel-related chemicals that evaporate easily
Tetrachloroethylene
Detected: 1 UG/L (ppb)
10/7/2025
Other
Additional substances tested that don't fit neatly into the categories above
Aggressive Index
Detected: 10.7 AGGR
9/17/2025
Alkalinity, Total
Detected: 150 MG/L (ppm)
9/17/2025
TDS
Detected: 690 MG/L (ppm)
Found at 2 providers
Conductivity (at 25°C)
Detected: 2400 UMHO/CM
Found at 2 providers
Perchlorate
Detected: 4.2 UG/L (ppb)
10/7/2025
Can occur naturally or from industrial/military sources; may interfere with thyroid function at elevated levels.
Dibromoaceticacid
Detected: 2.9 UG/L (ppb)
8/8/2025
Monobromoaceticacid
Detected: 1 UG/L (ppb)
2/11/2025
Dichloroaceticacid
Detected: 1.5 UG/L (ppb)
8/8/2025
Filtration considerations: General system types, not a specific product recommendation.