PATTERSON is served by 2 water providers on file with the EPA.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
🏠Local Expertise
Results for PATTERSON, CA
2 water providers on file serving this city.
Quick answer: PATTERSON's water has no violations on file and no single reading stands out against its peers (2 other providers in this area). It serves roughly 24,977 people, and the full breakdown below reflects everything EPA and California have on record for it.
Lead Summary
Lithium
Totalhaloaceticacids (HAA5)
TTHM
Bromoform
Dibromochloromethane
Dichloroaceticacid
Trichloroaceticacid
Dibromoaceticacid
Bromodichloromethane
Monochloroaceticacid
Aggressive Index
Langelier Index (pH(s))
Magnesium
Potassium
Sodium
Hardness, Total (ASCACO3)
Calcium
Alkalinity, Total
Alkalinity, Bicarbonate
TDS
Chloride
Sulfate
Fluoride
Nitrate-Nitrite
Nitrate
Turbidity
Combined Uranium
Gross Alpha Particle Activity
pH, Field
Boron, Total
Vanadium, Total
Iron
Manganese
Chromium, Hex
Tetrachloroethylene
Chromium
Arsenic
Selenium
Zinc
Conductivity (at 25°C)
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2024
Combined Uranium
Detected: 2.9 PCI/L
3/25/2025
A naturally occurring radioactive metal. Long-term exposure above the legal limit is associated with kidney effects and increased cancer risk.
Vanadium, Total
Detected: 9 UG/L (ppb)
7/15/2025
Iron
Detected: 80 UG/L (ppb)
7/15/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Manganese
Detected: 63.2 UG/L (ppb)
7/15/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Chromium, Hex
Detected: 19.7 UG/L (ppb)
8/27/2025
Chromium
Detected: 33 UG/L (ppb)
7/15/2025
Occurs in two forms — trivalent (an essential nutrient in trace amounts) and hexavalent (linked to increased cancer risk).
Arsenic
Detected: 5 UG/L (ppb)
9/2/2025
Occurs naturally in some groundwater. Long-term exposure above the legal limit (10 ppb) has been linked to increased cancer risk and cardiovascular disease.
Selenium
Detected: 13 UG/L (ppb)
7/15/2025
Zinc
Detected: 10 UG/L (ppb)
7/15/2025
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 10 UG/L (ppb)
10/7/2025
TTHM
Detected: 12 UG/L (ppb)
10/7/2025
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.
Bromoform
Detected: 1 UG/L (ppb)
10/7/2025
Dibromochloromethane
Detected: 1 UG/L (ppb)
10/7/2025
Bromodichloromethane
Detected: 1 UG/L (ppb)
10/7/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Chloride
Detected: 140 MG/L (ppm)
7/15/2025
Sulfate
Detected: 382 MG/L (ppm)
7/15/2025
Fluoride
Detected: 0.4 MG/L (ppm)
7/15/2025
Often added deliberately for dental health; can also occur naturally.
Nitrate-Nitrite
Detected: 7.2 MG/L (ppm)
7/15/2025
Nitrate
Detected: 1.7 MG/L (ppm)
9/2/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Boron, Total
Detected: 600 UG/L (ppb)
7/15/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Magnesium
Detected: 57 MG/L (ppm)
7/15/2025
Potassium
Detected: 2 MG/L (ppm)
7/15/2025
Sodium
Detected: 135 MG/L (ppm)
7/15/2025
Calcium
Detected: 78 MG/L (ppm)
7/15/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Langelier Index (pH(s))
Detected: 0.3 LANG
7/15/2025
Hardness, Total (ASCACO3)
Detected: 429 MG/L (ppm)
7/15/2025
Gross Alpha Particle Activity
Detected: 4.22 PCI/L
3/25/2025
pH, Field
Detected: 7.7 PH
6/25/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 72 µg/L (ppb)
12/11/2024
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: 1.8 UG/L (ppb)
9/2/2025
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 230 MG/L (ppm)
7/15/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 4 UG/L (ppb)
10/7/2025
Trichloroaceticacid
Detected: 2 UG/L (ppb)
10/7/2025
Dibromoaceticacid
Detected: 4 UG/L (ppb)
10/7/2025
Monochloroaceticacid
Detected: 3 UG/L (ppb)
1/14/2025
Aggressive Index
Detected: 12.2 AGGR
7/15/2025
Alkalinity, Total
Detected: 190 MG/L (ppm)
7/15/2025
TDS
Detected: 1250 MG/L (ppm)
10/7/2025
Turbidity
Detected: 0.6 NTU
7/15/2025
A measure of water cloudiness from suspended particles.
Conductivity (at 25°C)
Detected: 1870 UMHO/CM
10/7/2025
Filtration considerations: General system types, not a specific product recommendation.