LOS OSOS COMMUNITY SERVICES DISTRICT Water Quality Report
Serving roughly 7,086 people in San Luis Obispo County, California.
Data current as of July 2026
🔍Straight from EPA
🧪Real Lab Results
📅Updated Quarterly
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Results for LOS OSOS COMMUNITY SERVICES DISTRICT
1 water provider directly on file, serving roughly 7,086 people in San Luis Obispo County, California.
Quick answer: LOS OSOS COMMUNITY SERVICES DISTRICT has no violations on file. One reading is worth knowing about: PFOA was measured at 0.0147µg/L, among the highest of the 252 providers on file in this area. It's the most notable figure in this system's record among its 252 local peers.
Lead Summary
Copper Summary
Lithium
PFOA
PFBS
PFPEA
PFHXA
PFHPA
PFHXS
PFBA
PFOS
TTHM
Bromoform
Dibromochloromethane
Magnesium
Calcium
Sulfate
Chloride
Nitrate
Aggressive Index
Temperature (CENTIGRADE)
Langelier Index (Source Temp.)
Alkalinity, Total
Hardness, Total (ASCACO3)
Utility LOS OSOS COMMUNITY SERVICES DISTRICTPopulation served 7,086Owner Local government
No violations on file
Contaminants found
Metals
Naturally occurring or corrosion-related elements, e.g. lead, arsenic, copper
Lead Summary
Detected: 0 mg/L (ppm)
12/31/2023
Copper Summary
Detected: 1.47 mg/L (ppm)
12/31/2000
Disinfection Byproducts
Formed when chlorine used to disinfect water reacts with organic matter
TTHM
Detected: 3.2 UG/L (ppb)
8/4/2025
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: 1.9 UG/L (ppb)
8/4/2025
Dibromochloromethane
Detected: 1.3 UG/L (ppb)
8/4/2025
Inorganics
Common dissolved minerals and salts, e.g. nitrate, fluoride, chloride
Sulfate
Detected: 13 MG/L (ppm)
5/12/2025
Chloride
Detected: 38 MG/L (ppm)
5/12/2025
Nitrate
Detected: 4.2 MG/L (ppm)
11/3/2025
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: 14.9 MG/L (ppm)
9/8/2025
Calcium
Detected: 49.9 MG/L (ppm)
10/20/2025
Properties
General water characteristics like pH, hardness, and cloudiness (turbidity)
Hardness, Total (ASCACO3)
Detected: 119 MG/L (ppm)
3/10/2025
PFAS & Emerging Contaminants
Human-made "forever chemicals" and other substances not yet fully regulated
Lithium
Detected: 16.1 µg/L (ppb)
7/8/2024
Occurs naturally in some groundwater. Not currently federally regulated in drinking water.
PFOA
Detected: 0.0147 µg/L (ppb)
7/8/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
PFBS
Detected: 0.018 µg/L (ppb)
7/8/2024
PFPEA
Detected: 0.0168 µg/L (ppb)
7/8/2024
PFHXA
Detected: 0.0166 µg/L (ppb)
7/8/2024
PFHPA
Detected: 0.0054 µg/L (ppb)
7/8/2024
PFHXS
Detected: 0.0084 µg/L (ppb)
7/8/2024
PFBA
Detected: 0.006 µg/L (ppb)
7/8/2024
PFOS
Detected: 0.0117 µg/L (ppb)
7/8/2024
One of two PFAS with an enforceable federal limit (4 ppt) since 2024.
Other
Additional substances tested that don't fit neatly into the categories above
Aggressive Index
Detected: 12.5 AGGR
10/13/2025
Temperature (CENTIGRADE)
Detected: 20.7 C
10/13/2025
Langelier Index (Source Temp.)
Detected: -0.87 LANG
7/7/2025
Alkalinity, Total
Detected: 245 MG/L (ppm)
10/20/2025
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.