Water Quality Report · Updated May 12, 2026
VENTURA WWD NO. 8 - SIMI VALLEY
VENTURA WWD NO. 8 - SIMI VALLEY delivers tap water graded D (64/100) by TapWaterSafety.org. The utility serves approximately 94,738 residents in SIMI VALLEY, California using surface water (purchased). The most significant water quality concerns are: Haloacetic acids (HAA5) significantly above health guideline; Radon* significantly above health guideline; Haloacetic acids (HAA9) significantly above health guideline; Arsenic detected. For questions, the utility can be reached at 805-583-6808.
Is SIMI VALLEY tap water safe to drink?
VENTURA WWD NO. 8 - SIMI VALLEY delivers tap water that earns a grade of D (64/100) from TapWaterSafety.org — a below-average rating, with multiple concerns including haloacetic acids (haa5) significantly above health guideline.
The utility serves 94,738 residents in SIMI VALLEY, drawing from surface water (purchased).
Public testing data identifies 18 contaminants in this water above EWG's health-based guidelines, including: Haloacetic acids (HAA5), Radon*, Haloacetic acids (HAA9), Total trihalomethanes (TTHMs), Arsenic, Dibromoacetic acid, Dibromochloromethane, Bromodichloromethane, Bromoform, Uranium, Bromochloromethane*, Dichloroacetic acid, Chromium (hexavalent), Chloroform, Nitrate and nitrite, Radium, combined (-226 and -228), Nitrate, Trichloroacetic acid. For most residents, a properly certified home filter at the kitchen tap is the most cost-effective way to reduce exposure to whatever's in your water. See our filter recommendations below, matched specifically to this utility's contaminant profile.
Quick actions for SIMI VALLEY residents
Top concerns in this water
Based on the most recent EPA and EWG data, these are the most significant water quality issues for VENTURA WWD NO. 8 - SIMI VALLEY.
Haloacetic acids (HAA5) significantly above health guideline
Moderate concernHaloacetic acids (HAA5) detected at 36.2 ppb, 362x above the EWG health guideline of 0.1 ppb.
Radon* significantly above health guideline
Moderate concernRadon* detected at 258.72 pCi/L, 172x above the EWG health guideline of 1.5 pCi/L.
Haloacetic acids (HAA9) significantly above health guideline
Moderate concernHaloacetic acids (HAA9) detected at 10.2 ppb, 171x above the EWG health guideline of 0.06 ppb.
Arsenic detected
Moderate concernArsenic detected at 0.494 ppb.
Contact VENTURA WWD NO. 8 - SIMI VALLEY
Reach the utility directly for service issues, water quality concerns, or to request your Consumer Confidence Report.
General Contact
Treatment Plant
Recommended water filters for SIMI VALLEY
Filters matched to the specific contaminants in this water supply.
Carbon block (NSF/ANSI 42 + 53)
$40-$750Activated carbon is highly effective for disinfection byproducts like TTHM and HAA5.
Reverse Osmosis
$249-$750Arsenic is most effectively removed by reverse osmosis. Some specialized adsorptive filters also work.
Disclosure: TapWaterSafety earns a commission from purchases made through these links. This does not influence our scoring methodology or filter selection.
Score breakdown
This utility's overall score of 64/100 breaks down across five weighted components. Read the full methodology →
Contaminants detected — international standards comparison
Every contaminant detected, compared side-by-side against US EPA legal limits, the EU Drinking Water Directive (2020/2184), WHO Guidelines, and California's Public Health Goal (the strictest US benchmark). Why we show multiple standards →
| Contaminant | Detected | EWG US health-based |
EPA US legal |
EU DWD Europe |
WHO global |
CA PHG strictest US |
Tested sample year |
Status |
|---|---|---|---|---|---|---|---|---|
| Haloacetic acids (HAA5) Disinfection byproduct |
36.2 ppb | 0.1 | 60.0 | 60 | — | — | — | 362× over |
| Radon* Radiological |
258.72 pCi/L | 1.5 | — | — | — | — | — | 172× over |
| Haloacetic acids (HAA9) Disinfection byproduct |
10.2 ppb | 0.06 | — | — | — | — | — | 171× over |
| Total trihalomethanes (TTHMs) Disinfection byproduct |
22.3 ppb | 0.15 | 80.0 | 100 | — | — | — | 149× over |
| Arsenic Heavy metal |
0.494 ppb | 0.004 | 10.0 | 10 | 10 | 0.004 | — | 124× over |
| Dibromoacetic acid Disinfection byproduct |
3.31 ppb | 0.03 | — | — | — | — | — | 110× over |
| Dibromochloromethane Disinfection byproduct |
8.24 ppb | 0.1 | — | — | — | — | — | 82× over |
| Bromodichloromethane Disinfection byproduct |
4.06 ppb | 0.06 | — | — | — | — | — | 68× over |
| Bromoform Disinfection byproduct |
8.06 ppb | 0.5 | — | — | — | — | — | 16× over |
| Uranium Radiological |
5.95 pCi/L | 0.43 | 20.0 | 30 | 30 | 0.43 | — | 14× over |
| Bromochloromethane* Other |
0.698 ppb | 0.06 | — | — | — | — | — | 12× over |
| Dichloroacetic acid Disinfection byproduct |
1.56 ppb | 0.2 | — | — | — | — | — | 7.8× over |
| Chromium (hexavalent) Heavy metal |
0.117 ppb | 0.02 | — | — | — | — | — | 5.9× over |
| Chloroform Disinfection byproduct |
1.91 ppb | 0.4 | — | — | — | — | — | 4.8× over |
| Nitrate and nitrite Inorganic |
0.663 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 4.7× over |
| Radium, combined (-226 and -228) Radiological |
0.22 pCi/L | 0.05 | 5.0 | — | — | — | — | 4.3× over |
| Nitrate Inorganic |
0.442 ppm | 0.14 | 10.0 | 11.3 | 11.3 | 10 | — | 3.2× over |
| Trichloroacetic acid Disinfection byproduct |
0.324 ppb | 0.1 | — | — | — | — | — | 3.2× over |
| Chlorate Disinfection byproduct |
99.1 ppb | 210.0 | — | — | — | — | — | Below guideline |
| Selenium Heavy metal |
8.39 ppb | 30.0 | 50.0 | 20 | 40 | 30 | — | Below guideline |
| Vanadium Other |
3.73 ppb | 21.0 | — | — | — | — | — | Below guideline |
| Molybdenum Other |
6.88 ppb | 40.0 | — | — | — | — | — | Below guideline |
| Dichloromethane (methylene chloride)* Volatile organic compound |
0.323 ppb | 4.0 | 5.0 | — | — | — | — | Below guideline |
| Aluminum Heavy metal |
16.8 ppb | 600.0 | — | 200 | — | 600 | — | Below guideline |
| Barium Heavy metal |
16.4 ppb | 700.0 | 2000.0 | — | 1300 | 2000 | — | Below guideline |
| Monochloroacetic acid* Disinfection byproduct |
1.07 ppb | 53.0 | — | — | — | — | — | Below guideline |
| Monobromoacetic acid Disinfection byproduct |
0.235 ppb | 25.0 | — | — | — | — | — | Below guideline |
| Manganese Heavy metal |
0.387 ppb | 100.0 | — | 50 | 80 | — | — | Below guideline |
| Strontium Radiological |
0.268 ppb | 1500.0 | — | — | — | — | — | Below guideline |
| Xylenes (total)* Volatile organic compound |
0.0318 ppb | 1800.0 | 10000.0 | — | — | — | — | Below guideline |
| Dibromomethane* Other |
1.33 ppb | — | — | — | — | — | — | Below guideline |
| Fluoride Inorganic |
0.324 ppm | — | 4.0 | 1.5 | 1.5 | — | — | Below guideline |
| Nitrite* Inorganic |
0.0128 ppm | — | 1.0 | — | — | — | — | Below guideline |
All values in the unit of the detected level. Red cells indicate the detected level exceeds that standard. Some contaminants have limits in some jurisdictions but not others (shown as —). The "Tested" column shows the year each contaminant sample was collected.
Sources: US EPA, EU Drinking Water Directive 2020/2184, WHO Guidelines (4th ed.), California OEHHA PHGs, EWG Tap Water Database.
VENTURA WWD NO. 8 - SIMI VALLEY service area
This water system serves 1 community in Ventura County, California. Click any city for its dedicated tap water quality page.
Find the right filter for SIMI VALLEY water
Browse filter categories by water-quality concern. Each option below is NSF-certified for the matched contaminant type.