Drinking water quality · 2023
· Verified
What's in Ucmr5 — East Bay Mud (2023), CA tap water
29 contaminants were measured in the Ucmr5 — East Bay Mud (2023), CA water system's 2023 annual report. Each is shown below against its federal limit.
- Reporting year
- 2023
- Contaminants measured
- 29
- Over federal limit
- 0
- Approaching the limit
- 1
- Service area
- CA
PFAS — EPA UCMR5 (2023–2025)
1 PFAS compound detected in Ucmr5 — East Bay Mud (2023), CA
The EPA finalized the first-ever federal drinking-water limits for six PFAS compounds in April 2024. These numbers come straight from EPA's UCMR5 lab dataset — every U.S. system serving more than 3,300 people tested every PFAS sample at an entry point to its distribution system. PFAS not listed below were either tested and not detected, or not yet sampled.
PFBA
● Detected (no federal limit)Where your water comes from · EPA SDWIS
Ucmr5 — East Bay Mud (2023), CA's drinking water comes from surface water, drawn from 9 sources.
Source
- BRIONES RESERVOIR
- LAFAYETTE WTP INTAKE
- ORINDA WTP INTAKE
- PARDEE RESERVOIR
- + 5 more
Treatment
- LAFAYETTE WTP
- ORINDA WTP
- SOBRANTE WTP
- + 3 more
Distribution
Also buys water from CONTRA COSTA WATER DISTRICT.
Compliance history
Federal Safe Drinking Water Act violation & enforcement records (EPA SDWIS). A violation is a regulatory determination by the state or EPA — separate from the measured levels above.
- Maximum contaminant level exceededHealth-based1 violation on record · most recent Aug 1995resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗
Disinfection byproducts
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| HAA5Haloacetic acids — a group of five disinfection byproducts formed when disinfectants react with organic matter. | 50 ug/LAverageSystem-wide | None set | Approaching the limit |
+By source (2)— Walnut Creek, USL
| |||
| TTHMTotal trihalomethanes — a group of four chemicals (including chloroform) formed when chlorine reacts with natural organic matter. | 57 ug/LAverageSystem-wide | None set | Within the limit |
+By source (2)— Walnut Creek, USL
| |||
| BromateA disinfection byproduct formed when bromide-containing water is treated with ozone. | 0–1.7 ug/LReported levelSobrante | 0.1 ug/LPublic health goal | Within the limit |
| ChlorateA byproduct that can form during disinfection, especially when hypochlorite solutions degrade. | 108 ug/LAverageEBMUD Results System | 800 ug/LNL | Detected — no federal limit |
+By source (3)— USL, EBMUD Results System, Walnut Creek
| |||
| NDMA | 3.9 ng/LAverageEBMUD Results System | 10 ng/LNL | Detected — no federal limit |
+By source (3)— USL, EBMUD Results System, Walnut Creek
| |||
Disinfectants
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| ChloramineA longer-lasting disinfectant made by combining chlorine with ammonia. | 2.4 mg/LAverageSystem-wide | 4 mg/LPublic health goal | Within the limit |
+By source (2)— Walnut Creek, USL
| |||
Inorganic chemicals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| FluorideA mineral often added to drinking water to help prevent tooth decay. | 0.7 mg/LAverageSystem-wide | 1 mg/LPublic health goal | Within the limit |
+By source (2)— Walnut Creek, USL
| |||
| ChlorideA naturally occurring salt compound. | 6 mg/LAverageSystem-wide | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| SulfateA naturally occurring mineral from rock and soil. | 7 mg/LAverageSystem-wide | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
Physical & aggregate
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| TurbidityA measure of cloudiness from suspended particles in the water. | 0.02 NTUAverageSystem-wide | 1 NTUMCL | Within the limit |
+By source (2)— USL, Walnut Creek
| |||
| AlkalinityA measure of the water's capacity to neutralize acids. | 130–140 mg/LReported levelUSL | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| HardnessA measure of dissolved calcium and magnesium minerals. | 140–160 mg/LReported levelUSL | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| pHA measure of how acidic or basic the water is. | 9.1–9.4Reported levelOrinda | None set | Detected — no federal limit |
+By source (2)— Walnut Creek, USL
| |||
| Specific ConductanceA measure of how well water conducts electricity, which tracks dissolved mineral content. | 127AverageSystem-wide | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| TOCTotal organic carbon — a measure of organic material dissolved in the water. | 5.1–6.6 mg/LReported levelUSL | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| Total Dissolved SolidsTotal dissolved solids — the combined content of all dissolved minerals and salts. | 65 mg/LAverageSystem-wide | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
Radionuclides
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Gross AlphaGross alpha particle activity — a combined measure of alpha-emitting radioactive substances. | Not detected pCi/LAverageSystem-wide | 0 pCi/LPublic health goal | Within the limit |
+By source (2)— USL, Walnut Creek
| |||
| Gross Beta Particle ActivityGross beta particle activity — a combined measure of beta-emitting radioactive substances. | 6.1 pCi/LAverageSystem-wide | 0 pCi/LPublic health goal | Detected — no federal limit |
+By source (2)— Walnut Creek, USL
| |||
Metals
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| AluminumA common element sometimes used as a treatment coagulant. | Not detected ug/LAverageSystem-wide | 600 ug/LPublic health goal | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| BoronA naturally occurring element from rock and soil. | Not detected ug/LAverageEBMUD Results System | 1 ug/LNL | Detected — no federal limit |
+By source (3)— USL, EBMUD Results System, Walnut Creek
| |||
| CalciumA naturally occurring mineral that contributes to water hardness. | 33–34 mg/LReported levelUSL | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| Chromium, HexavalentHexavalent chromium ('chromium-6') — the more toxic form of chromium. | Not detected ug/LAverageSystem-wide | 0.2 ug/LPublic health goal | Detected — no federal limit |
+By source (2)— Walnut Creek, USL
| |||
| MagnesiumA naturally occurring mineral that contributes to water hardness. | 13–14 mg/LReported levelUSL | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| PotassiumA naturally occurring mineral from rock and soil. | 2 mg/LReported levelUSL | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| SilicaA naturally occurring compound from sand and rock. | 10–12 mg/LReported levelSobrante | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
| SodiumA naturally occurring salt component. | 32–35 mg/LReported levelUSL | None set | Detected — no federal limit |
+By source (2)— USL, Walnut Creek
| |||
Microbial
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Total ColiformA group of bacteria used as an indicator of overall water-system sanitation. | 0.3 %Reported levelWalnut Creek | 0 %Public health goal | Detected — no federal limit |
+By source (2)— Walnut Creek, USL
| |||
PFAS ("forever chemicals")
| Contaminant | Measured | Federal limit | Status |
|---|---|---|---|
| Perfluorohexanoic acidPerfluorohexanoic acid, a shorter-chain PFAS 'forever chemical.' | Not detected ng/LAverageEBMUD Results System | 1 ng/LNL | Detected — no federal limit |
+By source (3)— USL, EBMUD Results System, Walnut Creek
| |||
People also ask about Ucmr5 — East Bay Mud (2023), CA's water
+Is Ucmr5 — East Bay Mud (2023), CA tap water safe to drink in 2023?
Every one of the 29 contaminants measured in Ucmr5 — East Bay Mud (2023), CA's 2023 Consumer Confidence Report is below its federal limit. "Safe" under the EPA's drinking-water standards is health-based, not aesthetic — but by those standards, no measured contaminant in this report exceeds its enforceable threshold. Individual health concerns (e.g. immunocompromised, infant, pregnancy) may warrant additional filtering regardless of compliance.
+What contaminants are in Ucmr5 — East Bay Mud (2023), CA tap water?
29 contaminants were measured in Ucmr5 — East Bay Mud (2023), CA's 2023 Consumer Confidence Report, spanning metals, physical & aggregate, and disinfection byproducts. 13 have an enforceable federal limit; the rest are detected but unregulated. Every measured value, in the utility's own units, is on this page.
+Are any contaminants in Ucmr5 — East Bay Mud (2023), CA tap water approaching the federal limit?
One contaminant is between 80% and 100% of the federal limit in this report: HAA5. Approaching means measured but not in violation — a margin that can close quickly if conditions change.
+Where does the data on this page come from?
Every value is transcribed from Ucmr5 — East Bay Mud (2023), CA's 2023 Consumer Confidence Report — the annual drinking-water report every U.S. public water utility is required by federal law to publish. The original source document is archived and viewable on this site. A water-quality report covers an entire service area, not a single address.
+How often is Ucmr5 — East Bay Mud (2023), CA's water quality data updated?
Each U.S. public water utility publishes one Consumer Confidence Report per year, covering the prior calendar year's measurements. This page reflects the 2023 report; a new report will replace it once the utility publishes its next annual update.