# City of San Clemente — San Clemente, Ca, CA — Drinking Water Quality (2021)

> Contaminant levels for the City of San Clemente — San Clemente, Ca, CA public water system from its 2021 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/san-clemente-san-clemente-ca/2021
- JSON API: https://www.thewatermap.com/api/water/ca/san-clemente-san-clemente-ca/2021
- 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: 2021
- Contaminants measured: 31
- Contaminants with a federal limit: 10
- 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 | 68.5 ug/L (Average) | Average Amount | 4000 ug/L (MCL) | Within the limit |
| Chlorite | Disinfection byproducts | Not detected mg/L (Average) | Average Amount | 1 mg/L (MCL) | Within the limit |
| HAA5 | Disinfection byproducts | 17 ug/L (Average) | Average Amount | No federal limit | Within the limit |
| TTHM | Disinfection byproducts | 54 ug/L (Average) | Average Amount | No federal limit | Within the limit |
| Chloride | Inorganic chemicals | 101 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Fluoride | Inorganic chemicals | 0.77 mg/L (Average) | Average Amount | 4 mg/L (MCL) | Within the limit |
| Sulfate | Inorganic chemicals | 221 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Aluminum | Metals | 140 ug/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Arsenic | Metals | Not detected ug/L (Average) | Average Amount | No federal limit | Within the limit |
| Barium | Metals | 0.107 mg/L (Average) | Average Amount | 2 mg/L (MCL) | Within the limit |
| Boron | Metals | 0.137 mg/L (Average) | Average Amount | 1 mg/L (NL) | Detected — no federal limit |
| Calcium | Metals | 71.6 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Copper | Metals | 0.064 mg/L (90th percentile) | At the tap | 1.3 mg/L (Action level) | Within the limit |
| Lead | Metals | Not detected ug/L (90th percentile) | At the tap | No federal limit | None detected |
| Magnesium | Metals | 27.6 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Manganese | Metals | 0.88 ug/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Potassium | Metals | 5.14 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Sodium | Metals | 98.8 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Chlorine Total | Other | 1.56 mg/L (Average) | Average Amount | 4 mg/L (MCL) | Within the limit |
| Alkalinity | Physical & aggregate | 126 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Color | Physical & aggregate | 1 (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Hardness | Physical & aggregate | 292 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Odor | Physical & aggregate | 3 (Average) | Average Amount | No federal limit | Detected — no federal limit |
| pH | Physical & aggregate | 8.2 (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Specific Conductance | Physical & aggregate | 991 (Average) | Average Amount | No federal limit | Detected — no federal limit |
| TOC | Physical & aggregate | 2.5 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Total Dissolved Solids | Physical & aggregate | 628 mg/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Turbidity | Physical & aggregate | Not detected NTU (Average) | Average Amount | 1 NTU (MCL) | Within the limit |
| Gross Alpha | Radionuclides | 2 pCi/L (Average) | Average Amount | 15 pCi/L (MCL) | Within the limit |
| Gross Beta Particle Activity | Radionuclides | 6.2 pCi/L (Average) | Average Amount | No federal limit | Detected — no federal limit |
| Uranium | Radionuclides | 2 pCi/L (Average) | Average Amount | 20 pCi/L (MCL) | Detected — no federal 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.
- **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.
- **Boron** — A naturally occurring element from rock and soil. No enforceable federal limit; the EPA has issued a health advisory level.
- **Calcium** — A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.
- **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.
- **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.
- **Magnesium** — A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.
- **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.
- **Potassium** — A naturally occurring mineral from rock and soil. Not federally regulated for health.
- **Sodium** — A naturally occurring salt component. Not federally regulated for health; relevant for people on sodium-restricted diets.
- **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.
- **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.
- **Gross Alpha** — Gross alpha particle activity — a combined measure of alpha-emitting radioactive substances. Long-term exposure above the federal limit increases cancer risk.
- **Gross Beta Particle Activity** — Gross beta particle activity — a combined measure of beta-emitting radioactive substances. Long-term exposure above the federal screening level increases cancer risk.
- **Uranium** — A naturally occurring radioactive metal from erosion of natural deposits. Long-term exposure above the federal limit can damage the kidneys and increase 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._