Napa, CA
Transparent derived index from EPA TRI / SDWIS / Superfund extracts: not an official EPA rating. Fixed caps: facilities ≤25 pts (50+ = max), log10 releases ≤25 pts, Superfund ≤25 pts (5/site), health-violation systems ≤15 pts (3/system), high-chemical facilities ≤10 pts. Bands: High ≥60, Moderate ≥30. See methodology.
Environmental data for Napa in California · Population: 136,070
TRI sites such as Westlake Royal Stone LLC - Napa; Vulcan Materials Co Napa Quarry; Foley Products Co - Napa; SDWIS systems such as NAPA, CITY OF; AMERICAN CANYON, CITY OF; ST. HELENA, CITY OF anchor Napa, CA's EPA extract. Derived burden score 28/100 (Low Risk) uses fixed national caps on density, log release volume, Superfund count, and health-flagged systems - not an official EPA rating.
Health-flagged SDWIS rows in Napa include NAPA, CITY OF; AMERICAN CANYON, CITY OF; ST. HELENA, CITY OF, while Westlake Royal Stone LLC - Napa leads reported TRI pounds among local Form R filers. AQS median AQI 41 / peak 77 in 2021.
Burden score 28/100 (Low Risk) is the only weighted composite on this page. The tables below list every TRI facility, SDWIS system, and Superfund site EPA has on record for Napa -- not just the names called out above -- reproducing the disclosure history as filed, not a current-safety verdict. Extract current as of 2026-08-25.
Release-over-release change
What changed for Napa, CA: EPA TRI 2023 reporting year
Same facilities, both years
-4.5%
2 facilities that filed in 2022 and 2023
Whole inventory
-4.5%
712 lb → 679 lb, every facility that filed
Between the two reporting years, 0 facilities filed for the first time and 1 stopped filing. Facilities entering or leaving the inventory are excluded from the same-facility comparison above.
- Napa, CA's total reported releases fell from 712 lb in 2022 to 679 lb in 2023, based on EPA TRI filings.
- Napa, CA's off-site transfers fell from 711 lb in 2022 to 679 lb in 2023, based on EPA TRI filings.
Air Quality History (2020–2021)
EPA Air Quality Index (AQI) data showing how many days per year fall into each air quality category.
| Year | Good | Moderate | Unhealthy (SG) | Max AQI |
|---|---|---|---|---|
| 2021 | 108 (77%) | 32 | 0 | 77 |
| 2020 | 259 (71%) | 91 | 7 | 224 |
Source: EPA Air Quality System (AQS) Annual AQI by County AQI categories: Good (0-50), Moderate (51-100), Unhealthy for Sensitive Groups (101-150), Unhealthy (151-200), Very Unhealthy (201-300), Hazardous (301+)
For real-time air quality readings and pollutant breakdowns in California, see the EPA's AirNow.gov.
Water Systems (28)
| System | System pop (SDWIS) | Violations |
|---|---|---|
| NAPA, CITY OF | 84,804 | 3 |
| AMERICAN CANYON, CITY OF | 21,437 | 18 |
| ST. HELENA, CITY OF | 5,386 | 27 |
| TOWN OF YOUNTVILLE | 2,787 | 0 |
| PACIFIC UNION COLLEGE | 1,958 | 0 |
| HOWELL MOUNTAIN MUTUAL WATER COMPANY | 1,240 | 65 |
| VETERANS HOME OF CALIFORNIA | 1,000 | 1 |
| ADVENTIST HEALTH - ST. HELENA HOSPITAL | 817 | 0 |
| BERRYESSA HIGHLANDS | 715 | 38 |
| CIRCLE OAKS WATER DISTRICT | 500 | 0 |
| BERRYESSA ESTATES (LBRID) | 474 | 12 |
| BERRYESSA PINES WATER SYSTEM | 261 | 3 |
| MEYERS WATER CO. | 250 | 2 |
| HESS WINERY | 250 | 1 |
| SPANISH FLAT WATER DISTRICT | 230 | 1 |
| SPINDRIFT MARINA | 100 | 0 |
| LINDA VISTA MUTUAL WATER CO | 90 | 0 |
| NAPA RIVER RANCH | 70 | 3 |
| LA TIERRA HEIGHTS MUTUAL | 67 | 1 |
| RIVER RANCH FARM WORKER CENTER | 66 | 0 |
| MONDAVI FARM WORKER CENTER | 66 | 0 |
| CALISTOGA FARM WORKER CENTER | 65 | 0 |
| EDDY DRIVE | 48 | 0 |
| MILTON ROAD WATER COMPANY | 44 | 7 |
| BUCKTAIL MUTUAL WATER COMPANY | 42 | 1 |
| LINDA FALLS TERRACE MUTUAL | 35 | 0 |
| R RANCH AT THE LAKE | 28 | 1 |
| VAILIMA ESTATES MUTUAL WATER | 25 | 0 |
TRI Facilities (4)
| # | Facility | Total Releases |
|---|---|---|
| 1 | Westlake Royal Stone LLC - Napa | 2.6K lbs |
| 2 | Vulcan Materials Co Napa Quarry | 1 lbs |
| 3 | Foley Products Co - Napa | 0 lbs |
| 4 | Cmc Rebar - Ca - Napa | 0 lbs |
Cities in Napa (5)
Frequently Asked Questions
What is the environmental risk level in Napa, California? ▼
Are there Superfund sites in Napa? ▼
How many toxic release facilities are in Napa? ▼
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What does this county environmental profile show?
This county environmental profile rolls up EPA Toxics Release Inventory facility reports, Safe Drinking Water Information System public-water-system filings, and Superfund National Priorities List sites for the county boundary defined by the U.S. Census Bureau. Facility counts reflect facilities with a reporting address inside the county, not where downstream environmental effects may be observed. Population figures are from the most recent Census ACS 5-year estimate. The county detail page is updated whenever the upstream EPA programs publish revised data; see the methodology page for the documented ingest cadence and the editorial choices governing how aggregations are computed.
Read our methodology - how this data is sourced, computed, and verified.