# El Cajon, CA — Drinking Water Quality (2024)

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

- Page: https://www.thewatermap.com/water/ca/el-cajon/2024
- JSON API: https://www.thewatermap.com/api/water/ca/el-cajon/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: 45
- Contaminants with a federal limit: 29
- Contaminants at or above the federal limit: 3
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Chloramine | Disinfectants | 1.9 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Bromate | Disinfection byproducts | 1.6 ug/L (Average) | Purchased Water | 10 ug/L (MCL) | Within the limit |
| Chlorate | Disinfection byproducts | 186 ug/L (Average) | Purchased Water | 800 ug/L (NL) | Within the limit |
| HAA5 | Disinfection byproducts | 13.4 ug/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| NDMA | Disinfection byproducts | Not detected ng/L (Average) | Helix Plant | 10 ng/L (NL) | Within the limit |
| TTHM | Disinfection byproducts | 19.9 ug/L (Average) | Helix Plant | 80 ug/L (MCL) | Within the limit |
| Bromide | Inorganic chemicals | Not detected mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Chloride | Inorganic chemicals | 88 mg/L (Average) | Purchased Water | 500 mg/L (MCL) | Within the limit |
| Fluoride | Inorganic chemicals | 0.7 mg/L (Average) | Helix Plant | 2 mg/L (MCL) | Within the limit |
| Nitrate | Inorganic chemicals | Not detected mg/L (Average) | Helix Plant | 10 mg/L (MCL) | None detected |
| Sulfate | Inorganic chemicals | 140 mg/L (Average) | Helix Plant | 500 mg/L (MCL) | Within the limit |
| Aluminum | Metals | 140 (Average) | Helix Plant | 200 (MCL) | Within the limit |
| Arsenic | Metals | 2.3 ug/L (Average) | Helix Plant | 10 ug/L (MCL) | Within the limit |
| Barium | Metals | Not detected mg/L (Average) | Purchased Water | 1 mg/L (MCL) | Within the limit |
| Boron | Metals | 0.39 mg/L (Average) | Purchased Water | 1 mg/L (NL) | Within the limit |
| Calcium | Metals | 51 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Chromium, Hexavalent | Metals | Not detected ug/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Copper | Metals | 0.054 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 | 15 ug/L (Action level) | Within the limit |
| Lithium | Metals | 28 ug/L (Average) | Purchased Water | 10 ug/L (NL) | At or above the limit |
| Magnesium | Metals | 21 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Potassium | Metals | 6 mg/L (Average) | Purchased Water | No federal limit | Detected — no federal limit |
| Silica | Metals | 9.7 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Sodium | Metals | 76 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Strontium | Metals | 0.86 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Vanadium | Metals | Not detected ug/L (Average) | Purchased Water | 50 ug/L (NL) | Within the limit |
| Escherichia coli (E. coli) | Microbial | 0 % (Minimum) | Helix Plant | 0 % (MCL) | None detected |
| Total Coliform | Microbial | 0.6 % (Maximum) | Helix Plant | 5 % (MCL) | Within the limit |
| Hexafluoropropylene oxide dimer acid | PFAS ("forever chemicals") | Not detected ng/L (Minimum) | Helix Plant | No federal limit | None detected |
| Perfluorobutanesulfonic acid | PFAS ("forever chemicals") | Not detected ng/L (Average) | Helix Plant | 500 ng/L (NL) | None detected |
| Perfluorohexanesulfonic acid | PFAS ("forever chemicals") | Not detected ng/L (Maximum) | Purchased Water | 3 ng/L (NL) | None detected |
| Perfluorononanoic acid | PFAS ("forever chemicals") | Not detected ng/L (Average) | Purchased Water | No federal limit | None detected |
| PFOA | PFAS ("forever chemicals") | Not detected ng/L (Minimum) | Purchased Water | 5.1 ng/L (NL) | None detected |
| PFOS | PFAS ("forever chemicals") | Not detected ng/L (Minimum) | Helix Plant | 6.5 ng/L (NL) | None detected |
| Alkalinity | Physical & aggregate | 118 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Hardness | Physical & aggregate | 214 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| pH | Physical & aggregate | 8.3 (Average) | Purchased Water | No federal limit | Detected — no federal limit |
| Specific Conductance | Physical & aggregate | 800 (Average) | Helix Plant | 1 (MCL) | At or above the limit |
| TOC | Physical & aggregate | 2.6 mg/L (Average) | Helix Plant | No federal limit | Detected — no federal limit |
| Total Dissolved Solids | Physical & aggregate | 483 mg/L (Average) | Helix Plant | 1 mg/L (MCL) | At or above the limit |
| Turbidity | Physical & aggregate | 0.09 NTU (Average) | Helix Plant | 5 NTU (MCL) | Within the limit |
| Combined Radium | Radionuclides | 0.16 pCi/L (Average) | Purchased Water | 5 pCi/L (MCL) | Within the limit |
| Gross Alpha | Radionuclides | Not detected pCi/L (Average) | Helix Plant | 15 pCi/L (MCL) | Within the limit |
| Gross Beta Particle Activity | Radionuclides | 2.7 pCi/L (Average) | Purchased Water | 50 pCi/L (MCL) | Within the limit |
| Uranium | Radionuclides | 1.4 pCi/L (Average) | Purchased Water | 20 pCi/L (MCL) | Within the limit |

## What these contaminants are

- **Chloramine** — A longer-lasting disinfectant made by combining chlorine with ammonia. Holds disinfection further into the pipe network, but is regulated under the same residual-disinfectant cap as chlorine.
- **Bromate** — A disinfection byproduct formed when bromide-containing water is treated with ozone. Classified as a probable human carcinogen; the EPA sets a strict maximum contaminant level.
- **Chlorate** — A byproduct that can form during disinfection, especially when hypochlorite solutions degrade. Has no enforceable federal limit but is on the EPA contaminant candidate list; high levels can affect the thyroid.
- **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.
- **Bromide** — A naturally occurring salt found in source water. Not directly regulated, but a precursor that increases formation of brominated disinfection byproducts.
- **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.
- **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.
- **Chromium, Hexavalent** — Hexavalent chromium ('chromium-6') — the more toxic form of chromium. A known carcinogen by inhalation; regulated nationally only within the total-chromium limit, with stricter limits in some states.
- **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.
- **Lithium** — A naturally occurring element found in some groundwater. No enforceable federal limit; on the EPA contaminant candidate list for further study.
- **Magnesium** — A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.
- **Potassium** — A naturally occurring mineral from rock and soil. Not federally regulated for health.
- **Silica** — A naturally occurring compound from sand and rock. Not federally regulated for health; relevant mainly for industrial water use.
- **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.
- **Total Coliform** — A group of bacteria used as an indicator of overall water-system sanitation. Coliforms themselves are usually harmless, but their presence signals that disease-causing organisms could enter the system.
- **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.
- **Perfluorobutanesulfonic acid** — Perfluorobutanesulfonic acid, a shorter-chain PFAS 'forever chemical.' Has no standalone limit but is part of the EPA PFAS Hazard Index that limits PFAS in combination.
- **Perfluorohexanesulfonic acid** — Perfluorohexanesulfonic acid, a PFAS 'forever chemical.' Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- **Perfluorononanoic acid** — Perfluorononanoic acid, a PFAS 'forever chemical.' Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- **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.
- **PFOS** — Perfluorooctanesulfonic acid, a PFAS 'forever chemical' once used in firefighting foam and coatings. Linked to cancer, thyroid disease, 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.
- **Hardness** — A measure of dissolved calcium and magnesium minerals. Not federally regulated for health; affects scaling, soap use, and taste.
- **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.
- **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.
- **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 2026-05-25 from thewatermap.com._