# San Gabriel Valley Water Co-montebello 1 — El Monte, Ca, CA — Drinking Water Quality (2023)

> Contaminant levels for the San Gabriel Valley Water Co-montebello 1 — El Monte, Ca, CA public water system from its 2023 Consumer Confidence Report, compared to federal limits.

- Page: https://www.thewatermap.com/water/ca/san-gabriel-valley-water-co-montebello-1-el-monte-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/san-gabriel-valley-water-co-montebello-1-el-monte-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: 35
- 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 | 2.09 mg/L (Average) | Purchased Surface Water | No federal limit | Within the limit |
| Bromate | Disinfection byproducts | 2 ug/L (Average) | Purchased Surface Water | 0.1 ug/L (Public health goal) | Within the limit |
| Chlorate | Disinfection byproducts | 80 ug/L (Average) | Purchased Surface Water | 800 ug/L (NL) | Detected — no federal limit |
| HAA5 | Disinfection byproducts | 6 ug/L (Average) | Purchased Surface Water | No federal limit | Within the limit |
| Perchlorate | Disinfection byproducts | Not detected ug/L (Average) | System-wide | 1 ug/L (Public health goal) | None detected |
| TTHM | Disinfection byproducts | 40.3 ug/L (Average) | Purchased Surface Water | No federal limit | Within the limit |
| Bromochloroacetic acid | Inorganic chemicals | Not detected ug/L (Average) | Groundwater | No federal limit | Within the limit |
| Chlorodibromoacetic acid | Inorganic chemicals | Not detected ug/L (Average) | Groundwater | No federal limit | Within the limit |
| Dibromoacetic acid | Inorganic chemicals | 0.43 ug/L (Average) | Groundwater | No federal limit | Within the limit |
| Dichloroacetic acid | Inorganic chemicals | Not detected ug/L (Average) | Groundwater | No federal limit | Within the limit |
| Fluoride | Inorganic chemicals | 0.7 mg/L (Average) | System-wide | 1 mg/L (Public health goal) | Within the limit |
| Nitrate | Inorganic chemicals | Not detected mg/L (Average) | System-wide | 10 mg/L (Public health goal) | None detected |
| Aluminum | Metals | 93 ug/L (Average) | System-wide | 600 ug/L (Public health goal) | Detected — no federal limit |
| Arsenic | Metals | Not detected ug/L (Range) | System-wide | 0.004 ug/L (Public health goal) | None detected |
| Barium | Metals | 124 ug/L (Average) | System-wide | 2 ug/L (Public health goal) | Within the limit |
| Boron | Metals | 140 ug/L (Average) | Purchased Surface Water | 1000 ug/L (NL) | Detected — no federal limit |
| Calcium | Metals | 70.15 mg/L (Average) | Groundwater | No federal limit | Detected — no federal limit |
| Chromium, Hexavalent | Metals | Not detected ug/L (Average) | System-wide | 0.02 ug/L (Public health goal) | None detected |
| Copper | Metals | 330 ug/L (90th percentile) | At the tap | No federal limit | Within the limit |
| Lead | Metals | 1.6 ug/L (Average) | System-wide | No federal limit | Within the limit |
| Lithium | Metals | 40 ug/L (Average) | Purchased Surface Water | No federal limit | Detected — no federal limit |
| Magnesium | Metals | 26 mg/L (Average) | Purchased Surface Water | No federal limit | Detected — no federal limit |
| Potassium | Metals | 5 mg/L (Average) | Purchased Surface Water | No federal limit | Detected — no federal limit |
| Sodium | Metals | 105 mg/L (Average) | Purchased Surface Water | No federal limit | Detected — no federal limit |
| Escherichia coli (E. coli) | Microbial | 0 % (Maximum) | Percentage of Positive Samples Collected | 0 % (Public health goal) | None detected |
| Total Coliform | Microbial | 0 % (Maximum) | Percentage of Positive Samples Collected | 0 % (Public health goal) | None detected |
| Alkalinity | Physical & aggregate | 190.65 mg/L (Average) | Groundwater | No federal limit | Detected — no federal limit |
| Hardness | Physical & aggregate | 272 mg/L (Average) | Purchased Surface Water | No federal limit | Detected — no federal limit |
| pH | Physical & aggregate | 8.2 (Average) | Purchased Surface Water | No federal limit | Detected — no federal limit |
| TOC | Physical & aggregate | 2.4 mg/L (Average) | Purchased Surface Water | No federal limit | Detected — no federal limit |
| Combined Radium | Radionuclides | Not detected pCi/L (Range) | System-wide | 0.019 pCi/L (Public health goal) | None detected |
| Gross Alpha | Radionuclides | Not detected pCi/L (Range) | System-wide | 0 pCi/L (Public health goal) | None detected |
| Gross Beta Particle Activity | Radionuclides | Not detected pCi/L (Average) | System-wide | 0 pCi/L (Public health goal) | Detected — no federal limit |
| Uranium | Radionuclides | Not detected pCi/L (Average) | System-wide | 0.43 pCi/L (Public health goal) | Detected — no federal limit |
| Dichlorodifluoromethane | VOCs & pesticides | Not detected ug/L (Average) | Groundwater | 1000 ug/L (NL) | 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.
- **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.
- **Perchlorate** — A chemical used in rocket fuel and fireworks that can also form during disinfection. Can interfere with thyroid hormone production; has no national enforceable limit but is regulated in some states.
- **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.
- **Bromochloroacetic acid** — A mixed-halogen haloacetic acid disinfection byproduct. Part of the broader HAA9 group; monitored without its own enforceable limit.
- **Chlorodibromoacetic acid** — A brominated haloacetic acid disinfection byproduct. Part of the broader HAA9 group; monitored but without its own enforceable federal limit.
- **Dibromoacetic acid** — A brominated haloacetic acid disinfection byproduct. Part of the broader HAA9 group; monitored without its own enforceable limit.
- **Dichloroacetic acid** — A haloacetic acid disinfection byproduct. One of the five haloacetic acids regulated together as HAA5 for cancer risk.
- **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.
- **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.
- **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.
- **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.
- **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.
- **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 2026-06-04 from thewatermap.com._