# Cotati, City of — Cotati, Ca, CA — Drinking Water Quality (2023)

> Contaminant levels for the Cotati, City of — Cotati, Ca, CA public water system from its 2023 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/cotati-cotati-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/cotati-cotati-ca/2023
- Source: the utility's annual Consumer Confidence Report (CCR)
- Verification: transcribed by a model, cross-checked by a second model, approved before publishing
- Reporting year: 2023
- Contaminants measured: 37
- Contaminants with a federal limit: 23
- Contaminants at or above the federal limit: 1
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| HAA5 | Disinfection byproducts | 11.99–12.46 ug/L (Range) | Sonoma Water | No federal limit | Within the limit |
| Chloride | Inorganic chemicals | 39–68 mg/L (Range) | City Of Cotati | No federal limit | Detected — no federal limit |
| Fluoride | Inorganic chemicals | 0–0.25 mg/L (Range) | City Of Cotati | 1 mg/L (Public health goal) | Within the limit |
| Nitrate | Inorganic chemicals | Not detected mg/L (Reported level) | City Of Cotati | 10 mg/L (Public health goal) | None detected |
| Sulfate | Inorganic chemicals | 9–34 mg/L (Range) | City Of Cotati | No federal limit | Detected — no federal limit |
| Arsenic | Metals | 0–3.1 ug/L (Range) | City Of Cotati | 0.004 ug/L (Public health goal) | Within the limit |
| Barium | Metals | 0.12–0.2 mg/L (Range) | City Of Cotati | 2 mg/L (Public health goal) | Within the limit |
| Calcium | Metals | 23–46 mg/L (Range) | City Of Cotati | No federal limit | Detected — no federal limit |
| Iron | Metals | 0–620 ug/L (Range) | Sonoma Water | No federal limit | Detected — no federal limit |
| Lead | Metals | 23 ug/L (Range) | Sonoma Water | 0.2 ug/L (Public health goal) | At or above the limit |
| Lithium | Metals | 14–32 ug/L (Range) | City Of Cotati | 9 ug/L (Public health goal) | Detected — no federal limit |
| Manganese | Metals | 0–110 ug/L (Range) | Sonoma Water | No federal limit | Detected — no federal limit |
| Selenium | Metals | 0–6.4 ug/L (Range) | City Of Cotati | 30 ug/L (Public health goal) | Within the limit |
| Sodium | Metals | 8.8–46 mg/L (Range) | Sonoma Water | No federal limit | Detected — no federal limit |
| Chromium | Other | 0–1 ug/L (Range) | City Of Cotati | 0.02 ug/L (Public health goal) | Within the limit |
| Hexafluoropropylene oxide dimer acid | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | Sonoma Water | 0.005 ug/L (Public health goal) | None detected |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | Sonoma Water | 0.005 ug/L (Public health goal) | None detected |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | City Of Cotati | 0.006 ug/L (Public health goal) | None detected |
| Perfluorodecanoic acid (PFDA) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | City Of Cotati | 0.003 ug/L (Public health goal) | None detected |
| Perfluorododecanoic acid (PFDoA) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | City Of Cotati | 0.003 ug/L (Public health goal) | None detected |
| Perfluoroheptanesulfonic acid (PFHpS) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | Sonoma Water | 0.003 ug/L (Public health goal) | None detected |
| Perfluoropentanesulfonic acid (PFPeS) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | City Of Cotati | 0.004 ug/L (Public health goal) | None detected |
| Perfluorotetradecanoic acid (PFTeDA) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | Sonoma Water | 0.008 ug/L (Public health goal) | None detected |
| Perfluorotridecanoic acid (PFTrDA) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | Sonoma Water | 0.007 ug/L (Public health goal) | None detected |
| Perfluoroundecanoic acid (PFUnA) | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | Sonoma Water | 0.002 ug/L (Public health goal) | None detected |
| PFAS | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | Sonoma Water | 0.003 ug/L (Public health goal) | None detected |
| PFBA | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | Sonoma Water | 0.005 ug/L (Public health goal) | None detected |
| PFOA | PFAS ("forever chemicals") | Not detected ug/L (Reported level) | City Of Cotati | 0.004 ug/L (Public health goal) | None detected |
| Alkalinity | Physical & aggregate | 120–140 mg/L (Range) | City Of Cotati | No federal limit | Detected — no federal limit |
| Bicarbonate | Physical & aggregate | 150–200 mg/L (Range) | City Of Cotati | No federal limit | Detected — no federal limit |
| Color | Physical & aggregate | 0–12 (Range) | Sonoma Water | No federal limit | Detected — no federal limit |
| Hardness | Physical & aggregate | 98–220 mg/L (Range) | City Of Cotati | No federal limit | Detected — no federal limit |
| Odor | Physical & aggregate | 0–7.1 (Range) | Sonoma Water | No federal limit | Detected — no federal limit |
| pH | Physical & aggregate | 7.15–8.38 (Range) | Sonoma Water | No federal limit | Detected — no federal limit |
| Specific Conductance | Physical & aggregate | 330–490 (Range) | City Of Cotati | No federal limit | Detected — no federal limit |
| Turbidity | Physical & aggregate | 0–7.2 (Range) | Sonoma Water | 5 (MCL) | Detected — no federal limit |
| Gross Alpha | Radionuclides | 0.73–1.8 pCi/L (Range) | City Of Cotati | 0 pCi/L (Public health goal) | Within the limit |

## What these contaminants are

- **HAA5** — Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. Long-term exposure above the federal limit is associated with an increased cancer risk.
- **Chloride** — A naturally occurring salt compound. Regulated only as a secondary (cosmetic) standard; high levels cause a salty taste and can corrode pipes.
- **Fluoride** — A mineral often added to drinking water to help prevent tooth decay. Beneficial at low levels, but long-term exposure above the federal limit can cause bone disease and tooth mottling.
- **Nitrate** — A compound from fertilizer runoff, septic systems, and erosion of natural deposits. Levels above the federal limit can cause 'blue baby syndrome,' a serious oxygen-transport condition in infants.
- **Sulfate** — A naturally occurring mineral from rock and soil. No health-based federal limit; high levels can have a laxative effect and a bitter taste.
- **Arsenic** — A naturally occurring element that also enters water from industry and agriculture. A known human carcinogen; long-term exposure is linked to skin, bladder, and lung cancer.
- **Barium** — A metal from erosion of natural deposits and industrial discharge. Long-term exposure above the federal limit can raise blood pressure.
- **Calcium** — A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.
- **Iron** — A naturally occurring metal common in groundwater. Regulated only as a secondary (cosmetic) standard; causes rusty color, staining, and metallic taste.
- **Lead** — A toxic metal that leaches into water from old service lines, solder, and plumbing fixtures. There is no safe level of lead; it harms brain development in children and raises blood pressure in adults. The EPA sets an action level, not a health goal above zero.
- **Lithium** — A naturally occurring element found in some groundwater. No enforceable federal limit; on the EPA contaminant candidate list for further study.
- **Manganese** — A naturally occurring metal from soil and rock. No enforceable federal limit; high levels stain fixtures and laundry and can affect taste, with a health advisory for infants.
- **Selenium** — A trace element from natural deposits and industrial discharge. Essential in tiny amounts, but long-term exposure above the federal limit can cause hair and fingernail loss and circulatory problems.
- **Sodium** — A naturally occurring salt component. Not federally regulated for health; relevant for people on sodium-restricted diets.
- **Hexafluoropropylene oxide dimer acid** — HFPO-DA ('GenX chemicals'), a newer-generation PFAS replacement compound. Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- **N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)** — N-ethyl perfluorooctanesulfonamidoacetic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)** — N-methyl perfluorooctanesulfonamidoacetic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **Perfluorodecanoic acid (PFDA)** — Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluorododecanoic acid (PFDoA)** — Perfluorododecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluoroheptanesulfonic acid (PFHpS)** — Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluoropentanesulfonic acid (PFPeS)** — Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluorotetradecanoic acid (PFTeDA)** — Perfluorotetradecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluorotridecanoic acid (PFTrDA)** — Perfluorotridecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluoroundecanoic acid (PFUnA)** — Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **PFBA** — Perfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment and the human body.
- **PFOA** — Perfluorooctanoic acid, a PFAS 'forever chemical' once used in nonstick and stain-resistant products. Linked to cancer, liver damage, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
- **Alkalinity** — A measure of the water's capacity to neutralize acids. Not federally regulated for health; relevant to corrosion control and treatment.
- **Color** — A measure of visible tint in the water. Regulated only as a secondary (cosmetic) standard.
- **Hardness** — A measure of dissolved calcium and magnesium minerals. Not federally regulated for health; affects scaling, soap use, and taste.
- **Odor** — A measure of detectable smell in the water. Regulated only as a secondary (cosmetic) standard.
- **pH** — A measure of how acidic or basic the water is. Regulated only as a secondary standard; very low or high pH can corrode pipes or affect taste.
- **Specific Conductance** — A measure of how well water conducts electricity, which tracks dissolved mineral content. Not federally regulated for health; used as a proxy for total dissolved solids.
- **Turbidity** — A measure of cloudiness from suspended particles in the water. High turbidity can shelter microbes from disinfection; the EPA enforces it through a treatment-technique standard.
- **Gross Alpha** — Gross alpha particle activity — a combined measure of alpha-emitting radioactive substances. Long-term exposure above the federal limit increases cancer risk.

## How to read this

- A water-quality report covers an entire service area, not a single address.
- 'Federal limit' is the EPA standard (MCL, action level, treatment technique, etc.) that the measured level is compared against.
- 'At or above the federal limit' means the utility's own reported figure met or exceeded that standard.

_Figures are the utility's own published numbers. Generated 2026-06-04 from thewatermap.com._