# Fairfield, CA — Drinking Water Quality (2024)

> Contaminant levels for the Fairfield, CA public water system from its 2024 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/fairfield/2024
- JSON API: https://www.thewatermap.com/api/water/ca/fairfield/2024
- 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: 2024
- Contaminants measured: 22
- Contaminants with a federal limit: 17
- Contaminants at or above the federal limit: 0
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Chlorine | Disinfectants | 0.61 mg/L (Running annual avg) | System-wide | 4 mg/L (MRDL) | Within the limit |
| HAA5 | Disinfection byproducts | 18 ug/L (Running annual avg) | System-wide | 60 ug/L (MCL) | Within the limit |
| TTHM | Disinfection byproducts | 58 ug/L (Running annual avg) | System-wide | 80 ug/L (MCL) | Within the limit |
| Chloride | Inorganic chemicals | 10 mg/L (Average) | Drinking Water | 500 mg/L (MCL) | Within the limit |
| Fluoride | Inorganic chemicals | 0.71 mg/L (Average) | Drinking Water | 2 mg/L (MCL) | Within the limit |
| Sulfate | Inorganic chemicals | 45 mg/L (Average) | Drinking Water | 500 mg/L (MCL) | Within the limit |
| Aluminum | Metals | 72 ug/L (Average) | Drinking Water | 200 ug/L (MCL) | Within the limit |
| Copper | Metals | 0.17 mg/L (90th percentile) | At the tap | 1.3 mg/L (Action level) | Within the limit |
| Iron | Metals | 21 ug/L (Average) | Drinking Water | 300 ug/L (MCL) | Within the limit |
| Lead | Metals | Not detected ug/L (90th percentile) | At the tap | 15 ug/L (Action level) | None detected |
| Lithium | Metals | Not detected (Average) | System-wide | No federal limit | None detected |
| Manganese | Metals | 24 ug/L (Average) | Drinking Water | 50 ug/L (MCL) | Within the limit |
| Sodium | Metals | 23 mg/L (Average) | Drinking Water | No federal limit | Detected — no federal limit |
| Escherichia coli (E. coli) | Microbial | 0 (Reported level) | Distribution System | 0 (MCL) | None detected |
| PFAS | PFAS ("forever chemicals") | Not detected (Average) | System-wide | No federal limit | None detected |
| Hardness | Physical & aggregate | 157 mg/L (Average) | Drinking Water | No federal limit | Detected — no federal limit |
| Odor | Physical & aggregate | 1.4 (Average) | Drinking Water | 3 (MCL) | Within the limit |
| Specific Conductance | Physical & aggregate | 385 (Average) | Drinking Water | 1600 (MCL) | Within the limit |
| TOC | Physical & aggregate | 1–3.1 % (Running annual avg) | System-wide | No federal limit | Detected — no federal limit |
| Total Dissolved Solids | Physical & aggregate | 226 mg/L (Average) | Drinking Water | 1000 mg/L (MCL) | Within the limit |
| Turbidity | Physical & aggregate | 0.11 (Average) | Drinking Water | 5 (MCL) | Within the limit |
| Combined Radium | Radionuclides | Not detected pCi/L (Average) | Source Water North Bay Aqueduct | 5 pCi/L (MCL) | Within the limit |

## What these contaminants are

- **Chlorine** — A disinfectant added to drinking water to kill bacteria and viruses. Effective and necessary, but high residual levels can cause taste and odor issues; the EPA caps the residual disinfectant level.
- **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.
- **TTHM** — Total trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. Long-term exposure above the federal limit is linked to liver, kidney, and central-nervous-system effects and 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.
- **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.
- **Aluminum** — A common element sometimes used as a treatment coagulant. Regulated only as a secondary (cosmetic) standard; high levels can discolor water.
- **Copper** — A metal that enters water from corroding household plumbing. Short-term exposure causes stomach distress; long-term exposure can damage the liver and kidneys.
- **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.
- **Sodium** — A naturally occurring salt component. Not federally regulated for health; relevant for people on sodium-restricted diets.
- **Escherichia coli (E. coli)** — Escherichia coli — bacteria found in the gut of humans and animals. Its presence in drinking water indicates fecal contamination and a real risk of waterborne illness.
- **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.
- **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.
- **TOC** — Total organic carbon — a measure of organic material dissolved in the water. Not harmful itself, but it is the raw material that forms disinfection byproducts; removal is a treatment requirement.
- **Total Dissolved Solids** — Total dissolved solids — the combined content of all dissolved minerals and salts. Regulated only as a secondary (cosmetic) standard; high levels affect taste and hardness.
- **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.
- **Combined Radium** — Combined radium-226 and radium-228 — naturally occurring radioactive elements. Long-term exposure above the federal limit increases the risk of bone cancer.

## 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 2026-05-25 from thewatermap.com._