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

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

- Page: https://www.thewatermap.com/water/ca/lathrop-lathrop-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/lathrop-lathrop-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: 31
- Contaminants with a federal limit: 6
- Contaminants at or above the federal limit: 2
- Part of The Water Map — https://www.thewatermap.com

## Contaminants measured

| Contaminant | Category | Measured level | Sampling context | Federal limit | Status |
|---|---|---|---|---|---|
| Chlorine | Disinfectants | 0.2–1.2 mg/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Within the limit |
| Bromodichloromethane | Disinfection byproducts | 2–5 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Detected — no federal limit |
| Bromoform | Disinfection byproducts | 0–8 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Detected — no federal limit |
| Chloroform | Disinfection byproducts | 7–49 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Detected — no federal limit |
| Dibromochloromethane | Disinfection byproducts | 0–7 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Detected — no federal limit |
| HAA5 | Disinfection byproducts | 22–51 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Approaching the limit |
| TTHM | Disinfection byproducts | 22–51 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Within the limit |
| Dibromoacetic acid | Inorganic chemicals | 0–5 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Within the limit |
| Dichloroacetic acid | Inorganic chemicals | 6–22 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Within the limit |
| Nitrate | Inorganic chemicals | 2.6–5.2 mg/L (Range) | City Wells-Raw GW | 10 mg/L (MCL) | Within the limit |
| Trichloroacetic acid | Inorganic chemicals | 6–21 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Within the limit |
| Arsenic | Metals | 6–12 ug/L (Range) | LAWTF-Treated GW | No federal limit | At or above the limit |
| Barium | Metals | 0.4 mg/L (Reported level) | City Wells-Raw GW | 2 mg/L (MCL) | Within the limit |
| Calcium | Metals | 46–70 mg/L (Range) | City Wells-Raw GW | No federal limit | Detected — no federal limit |
| Chromium, Total | Metals | 12 ug/L (Reported level) | City Wells-Raw GW | No federal limit | Within the limit |
| Copper | Metals | 0.13 mg/L (90th percentile) | At the tap | 1.3 mg/L (Action level) | Within the limit |
| Magnesium | Metals | 11–16 mg/L (Range) | City Wells-Raw GW | No federal limit | Detected — no federal limit |
| Sodium | Metals | 40–50 mg/L (Range) | City Wells-Raw GW | No federal limit | Detected — no federal limit |
| Vanadium | Metals | 14 ug/L (Reported level) | City Wells-Raw GW | No federal limit | Detected — no federal limit |
| Mcaa | Other | 0–4 ug/L (Range) | Distribution System (Combined GW and SW) | No federal limit | Detected — no federal limit |
| Perfluorobutanesulfonic acid | PFAS ("forever chemicals") | 0–7.5 ng/L (Range) | City Wells-Raw GW | No federal limit | Detected — no federal limit |
| Perfluorohexanesulfonic acid | PFAS ("forever chemicals") | 0–4.7 ng/L (Range) | City Wells-Raw GW | No federal limit | Within the limit |
| PFOA | PFAS ("forever chemicals") | 3 ng/L (Reported level) | City Wells-Raw GW | No federal limit | Within the limit |
| PFOS | PFAS ("forever chemicals") | 0–23 ng/L (Range) | City Wells-Raw GW | No federal limit | At or above the limit |
| Alkalinity | Physical & aggregate | 200–210 mg/L (Range) | City Wells-Raw GW | No federal limit | Detected — no federal limit |
| Bicarbonate | Physical & aggregate | 250 mg/L (Reported level) | City Wells-Raw GW | No federal limit | Detected — no federal limit |
| Hardness | Physical & aggregate | 164–240 mg/L (Range) | City Wells-Raw GW | No federal limit | Detected — no federal limit |
| pH | Physical & aggregate | 8 (Reported level) | SSJID-Treated SW | No federal limit | Detected — no federal limit |
| Combined Radium | Radionuclides | 0.8 pCi/L (Reported level) | City Wells-Raw GW | 5 pCi/L (MCL) | Within the limit |
| Gross Alpha | Radionuclides | 3.7–8.3 pCi/L (Range) | City Wells-Raw GW | 15 pCi/L (MCL) | Within the limit |
| Uranium | Radionuclides | 2.1–6.4 pCi/L (Range) | City Wells-Raw GW | 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.
- **Bromodichloromethane** — A trihalomethane disinfection byproduct. Counted within regulated total trihalomethanes; long-term exposure is associated with cancer and reproductive effects.
- **Bromoform** — A trihalomethane disinfection byproduct. Counted within regulated total trihalomethanes; long-term exposure is associated with liver and kidney effects.
- **Chloroform** — A trihalomethane formed when chlorine reacts with organic matter in water. A component of regulated total trihalomethanes; long-term exposure is linked to liver and kidney effects.
- **Dibromochloromethane** — A trihalomethane disinfection byproduct. Part of regulated total trihalomethanes; long-term exposure is linked to nervous-system, liver, and kidney effects.
- **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.
- **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.
- **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.
- **Trichloroacetic acid** — A haloacetic acid disinfection byproduct. One of the five haloacetic acids regulated together as HAA5.
- **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.
- **Chromium, Total** — Total chromium — the sum of all chromium forms, from natural deposits and industrial discharge. Long-term exposure above the federal limit can cause allergic dermatitis; includes hexavalent chromium.
- **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.
- **Magnesium** — A naturally occurring mineral that contributes to water hardness. Not federally regulated for health; affects scaling and taste.
- **Sodium** — A naturally occurring salt component. Not federally regulated for health; relevant for people on sodium-restricted diets.
- **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.
- **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.
- **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.
- **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._