Drinking water quality · 2023
· Verified
· PWSID CA3610004
What's in West Valley Water District — Rialto, Ca, CA tap water
5 contaminants in West Valley Water District — Rialto, Ca, CA's water sat at or above a federal limit, led by Lead at 2.7x the limit.
- !5 contaminants at or above a federal limit — worst is Lead at 2.7x
- !16 of 27 core regulated contaminants reported — 11 never appear in this report
- ✓No open federal violations
+How this score is calculated
Every system starts at 100. Points come off for measured levels, for the federal violation record, and for how much of the core regulated set the utility actually reported. All three inputs are the utility's own published numbers and EPA's own records.
- −60 contaminants at or above a federal limit
- −0 contaminants within 20% of a limit
- −0 open health-based violations
- −0 open monitoring / reporting violations
- −0 health-based violations resolved in the last 5 years
- −5 core regulated contaminants never reported (16/27)
A 90–100 · B 80–89 · C 70–79 · D 60–69 · F below 60. A system reporting under a third of the core set is capped at C however clean its numbers look — a short report is not a clean bill of health.
Full grading methodology, constant for constant →What to worry about
- Lead2.7× the federal limit40 ug/L · limit 15 ug/L
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.
Higher than 95% of CA systems that report it · higher than 95% of U.S. systems
- Perfluorohexanesulfonic acid2.2× the federal limit0–22 ng/L · limit 10 ng/L
Regulated by the EPA at 10 parts per trillion and included in the PFAS Hazard Index.
Higher than 85% of CA systems that report it · higher than 90% of U.S. systems
- PFOS2.1× the federal limit0–8.3 ng/L · limit 4 ng/L
Linked to cancer, thyroid disease, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
Higher than 70% of CA systems that report it · higher than 75% of U.S. systems
- Turbidity1.8× the federal limit1.8 NTU · limit 1 NTU
High turbidity can shelter microbes from disinfection; the EPA enforces it through a treatment-technique standard.
Higher than 85% of CA systems that report it · higher than 90% of U.S. systems
- PFOA1.3× the federal limit0–5.3 ng/L · limit 4 ng/L
Linked to cancer, liver damage, and immune effects; the EPA set an enforceable limit of 4 parts per trillion.
Higher than 70% of CA systems that report it · higher than 75% of U.S. systems
+32 contaminants were measured and came in below the limitShow all
| Contaminant | Measured | Federal limit |
|---|---|---|
| Arsenic | 0.38–7.6 ug/L | 10 ug/L |
| Nitrate | 2–7.4 mg/L | 10 mg/L |
| Chlorine | 1.08–2.51 mg/L | 4 mg/L |
| TTHM | 0–46.4 ug/L | 80 ug/L |
| Combined Radium | 2.4 pCi/L | 5 pCi/L |
| HAA5 | 0–16.6 ug/L | 60 ug/L |
| Gross Alpha | 3.7 pCi/L | 15 pCi/L |
| Tetrachloroethylene | 0–0.51 ug/L | 5 ug/L |
| Fluoride | 0.22–0.36 mg/L | 4 mg/L |
| Copper | 90 ug/L | 1300 ug/L |
| Trichloroethylene | 0–0.31 ug/L | 5 ug/L |
| Chromium | 0.58–3.1 ug/L | 100 ug/L |
| Chloride | 43 mg/L | — |
| Sulfate | 29 mg/L | — |
| Aluminum | 46–380 ug/L | — |
| Calcium | 48 mg/L | — |
| Magnesium | 8.6 mg/L | — |
| Manganese | 7.4–34 ug/L | — |
| Sodium | 38 mg/L | — |
| Total Coliform | 1 % | — |
| Perfluorobutanesulfonic acid | 2.5–13 ng/L | 500 ng/L |
| PFAS | 0–2.5 | — |
| Alkalinity | 130–170 mg/L | — |
| Color | 5 | — |
| Hardness | 150 mg/L | — |
| Odor | 1 | — |
| pH | 7.1–7.8 | — |
| Specific Conductance | 360 | — |
| TOC | 0.26–2 mg/L | — |
| Total Dissolved Solids | 220 mg/L | — |
| Uranium | 1.8–3.2 pCi/L | 20 pCi/L |
| MTBE | 0–0.83 ug/L | — |
What this report doesn't tell you
11 of the 27 contaminants a community water system normally reports do not appear anywhere in West Valley Water District — Rialto, Ca, CA's data. Absent is not the same as absent-from-the-water — it means nobody published a number.
+Full detail: PFAS testing, water source, historical monitoring, and the federal violation record
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-based4 violations on record · most recent May 1987resolved
Source: EPA SDWIS / ECHO. View the full federal record on EPA ECHO ↗