GRASS VALLEY is served by 3 water providers on file with the EPA.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
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Results for GRASS VALLEY, CA
3 water providers on file serving this city.
Quick answer: GRASS VALLEY's water has no violations on file and no single reading stands out against its peers (3 other providers in this area). It serves roughly 4,947 people, and the full breakdown below reflects everything EPA and California have on record for it.
Lead Summary
Lead
Totalhaloaceticacids (HAA5)
TTHM
Chloroform
Bromodichloromethane
Dichloroaceticacid
Trichloroaceticacid
Copper, Free
Carbon, Total
Iron
Color
Alkalinity, Total
Alkalinity, Bicarbonate
Nitrate
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0.000884 mg/L (ppm)
Found at 2 providers
Lead
Detected: 1.4 UG/L (ppb)
Found at 2 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: 1220 UG/L (ppb)
Found at 2 providers
Iron
Detected: 290 UG/L (ppb)
5/14/2025
Mostly an aesthetic issue (metallic taste, staining) rather than a health concern at typical levels.
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 11.3 UG/L (ppb)
9/16/2025
TTHM
Detected: 11.6 UG/L (ppb)
9/16/2025
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.
Chloroform
Detected: 10.6 UG/L (ppb)
9/16/2025
One of the individual trihalomethane disinfection byproducts, formed when chlorine reacts with organic matter.
Bromodichloromethane
Detected: 1 UG/L (ppb)
9/16/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Nitrate
Detected: 1.9 MG/L (ppm)
3/27/2025
Commonly from agricultural fertilizer runoff or septic systems. Above the legal limit, it's an immediate concern especially for infants.
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 14.4 MG/L (ppm)
10/13/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dichloroaceticacid
Detected: 5.5 UG/L (ppb)
9/16/2025
Trichloroaceticacid
Detected: 5.8 UG/L (ppb)
9/16/2025
Carbon, Total
Detected: 0.65 MG/L (ppm)
9/8/2025
Color
Detected: 6 UNITS
9/15/2025
Alkalinity, Total
Detected: 14.4 MG/L (ppm)
10/13/2025
Filtration considerations: General system types, not a specific product recommendation.