Serving roughly 5,538 people in Colusa County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
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Results for CITY OF WILLIAMS
1 water provider directly on file, serving roughly 5,538 people in Colusa County, California.
Quick answer: CITY OF WILLIAMS has no violations on file and no single reading stands out against its peers (67 other providers in this area). It serves roughly 5,538 people, and the full breakdown below reflects everything EPA and California have on record for it.
Lead Summary
Lithium
Totalhaloaceticacids (HAA5)
TTHM
Bromoform
Dibromoaceticacid
Sodium
Alkalinity, Total
Alkalinity, Bicarbonate
pH
Manganese
Utility CITY OF WILLIAMSPopulation served 5,538Owner Local government
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2023
Manganese
Detected: 22 UG/L (ppb)
10/15/2025
Mainly a taste/staining concern at typical levels; long-term neurological research at high chronic exposure is ongoing.
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
Totalhaloaceticacids (HAA5)
Detected: 1.1 UG/L (ppb)
8/19/2025
TTHM
Detected: 2.43 UG/L (ppb)
8/19/2025
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: 2.43 UG/L (ppb)
8/19/2025
Minerals
Everyday minerals that mainly affect taste and water hardness
Sodium
Detected: 120 MG/L (ppm)
10/21/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
pH
Detected: 7.93 PH
10/21/2025
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: 28.4 µg/L (ppb)
8/7/2024
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
Calculated Parameters
Values worked out mathematically from other test results, not measured directly
Alkalinity, Bicarbonate
Detected: 260 MG/L (ppm)
10/21/2025
Other
Additional substances tested that don't fit neatly into the categories above
Dibromoaceticacid
Detected: 1.1 UG/L (ppb)
8/19/2025
Alkalinity, Total
Detected: 260 MG/L (ppm)
10/21/2025
Filtration considerations: See the table below for how whole-house carbon, under-sink reverse osmosis, and under-sink carbon systems compare against what's actually on file here. These are general system types, not a specific product recommendation.