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

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

- Page: https://www.thewatermap.com/water/ca/mountain-house-mountain-house-ca/2023
- JSON API: https://www.thewatermap.com/api/water/ca/mountain-house-mountain-house-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: 38
- Contaminants with a federal limit: 32
- 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 |
|---|---|---|---|---|---|
| Chloramine | Disinfectants | 2.3–3 mg/L (Range) | System-wide | No federal limit | Within the limit |
| HAA5 | Disinfection byproducts | 23–26 ug/L (Range) | System-wide | No federal limit | Within the limit |
| TTHM | Disinfection byproducts | 38–46 ug/L (Range) | System-wide | No federal limit | Within the limit |
| Nitrate | Inorganic chemicals | Not detected mg/L (Range) | System-wide | 10 mg/L (MCL) | None detected |
| Copper | Metals | 0.2 mg/L (90th percentile) | At the tap | 1.3 mg/L (Action level) | Within the limit |
| Lead | Metals | 0 ug/L (90th percentile) | At the tap | No federal limit | Within the limit |
| Lithium | Metals | Not detected (Reported level) | System-wide | 9 (NL) | None detected |
| Escherichia coli (E. coli) | Microbial | 0 (Highest single sample) | No. of Detections | 0 (MCLG) | None detected |
| Nitrate Nitrite | Other | Not detected mg/L (Range) | System-wide | 10 mg/L (MCL) | None detected |
| 11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.005 (NL) | None detected |
| 4,8-Dioxa-3H-perfluorononanoic acid (ADONA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| 4:2 Fluorotelomer sulfonic acid (4:2 FTS) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| 6:2 Fluorotelomer sulfonic acid (6:2 FTS) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.005 (NL) | None detected |
| 8:2 Fluorotelomer sulfonic acid (8:2 FTS) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.005 (NL) | None detected |
| 9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.002 (NL) | None detected |
| Hexafluoropropylene oxide dimer acid | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.005 (NL) | None detected |
| N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.005 (NL) | None detected |
| N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.006 (NL) | None detected |
| Nonafluoro-3,6-dioxaheptanoic acid | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.02 (NL) | None detected |
| Perfluoro-3-methoxypropanoic acid (PFMPA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.004 (NL) | None detected |
| Perfluoro-4-methoxybutanoic acid (PFMBA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| Perfluorobutanesulfonic acid | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| Perfluorodecanoic acid (PFDA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| Perfluoroheptanesulfonic acid (PFHpS) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| Perfluoroheptanoic acid | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| Perfluorohexanesulfonic acid | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| Perfluorohexanoic acid | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| Perfluorononanoic acid | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.004 (NL) | None detected |
| Perfluoropentanesulfonic acid (PFPeS) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.004 (NL) | None detected |
| Perfluoropentanoic acid | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.003 (NL) | None detected |
| Perfluorotetradecanoic acid (PFTeDA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.008 (NL) | None detected |
| Perfluorotridecanoic acid (PFTrDA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.007 (NL) | None detected |
| Perfluoroundecanoic acid (PFUnA) | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.002 (NL) | None detected |
| PFBA | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.005 (NL) | None detected |
| PFOA | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.004 (NL) | None detected |
| PFOS | PFAS ("forever chemicals") | Not detected (Reported level) | System-wide | 0.004 (NL) | None detected |
| TOC | Physical & aggregate | 1.28–2.1 mg/L (Range) | System-wide | No federal limit | Detected — no federal limit |
| Turbidity | Physical & aggregate | 100 (Reported level) | System-wide | No federal limit | Detected — no federal 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.
- **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.
- **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.
- **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.
- **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.
- **11-Chloroeicosafluoro-3-oxaundecane-1-sulfonic acid (11Cl-PF3OUdS)** — 11-chloroeicosafluoro-3-oxaundecane-1-sulfonic acid, a chlorinated PFAS compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **4,8-Dioxa-3H-perfluorononanoic acid (ADONA)** — ADONA, a newer-generation PFAS replacement compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **4:2 Fluorotelomer sulfonic acid (4:2 FTS)** — 4:2 fluorotelomer sulfonic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **6:2 Fluorotelomer sulfonic acid (6:2 FTS)** — 6:2 fluorotelomer sulfonic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **8:2 Fluorotelomer sulfonic acid (8:2 FTS)** — 8:2 fluorotelomer sulfonic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **9-Chlorohexadecafluoro-3-oxanonane-1-sulfonic acid (9Cl-PF3ONS)** — 9-chlorohexadecafluoro-3-oxanonane-1-sulfonic acid, a chlorinated PFAS compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **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.
- **N-ethyl perfluorooctanesulfonamidoacetic acid (NEtFOSAA)** — N-ethyl perfluorooctanesulfonamidoacetic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **N-methyl perfluorooctanesulfonamidoacetic acid (NMeFOSAA)** — N-methyl perfluorooctanesulfonamidoacetic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **Nonafluoro-3,6-dioxaheptanoic acid** — Nonafluoro-3,6-dioxaheptanoic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **Perfluoro-3-methoxypropanoic acid (PFMPA)** — Perfluoro-3-methoxypropanoic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **Perfluoro-4-methoxybutanoic acid (PFMBA)** — Perfluoro-4-methoxybutanoic acid, a PFAS-related compound. Monitored under EPA rules as part of broad PFAS surveillance.
- **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.
- **Perfluorodecanoic acid (PFDA)** — Perfluorodecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluoroheptanesulfonic acid (PFHpS)** — Perfluoroheptanesulfonic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluoroheptanoic acid** — Perfluoroheptanoic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluorohexanesulfonic acid** — Perfluorohexanesulfonic acid, a PFAS 'forever chemical.' Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- **Perfluorohexanoic acid** — Perfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and widely detected.
- **Perfluorononanoic acid** — Perfluorononanoic acid, a PFAS 'forever chemical.' Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
- **Perfluoropentanesulfonic acid (PFPeS)** — Perfluoropentanesulfonic acid, a PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluoropentanoic acid** — Perfluoropentanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment.
- **Perfluorotetradecanoic acid (PFTeDA)** — Perfluorotetradecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluorotridecanoic acid (PFTrDA)** — Perfluorotridecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **Perfluoroundecanoic acid (PFUnA)** — Perfluoroundecanoic acid, a longer-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent and bioaccumulative.
- **PFBA** — Perfluorobutanoic acid, a shorter-chain PFAS 'forever chemical.' Monitored under EPA rules; persistent in the environment and the human body.
- **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.
- **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.
- **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.

## 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._