Clay, SD
A PlainEnviro-computed score from reported facility/violation counts, not an official EPA rating, health forecast, or population-adjusted rate. See methodology.
Environmental data for Clay in South Dakota · Population: 15,133
Clay, SD is tracked across three EPA datasets covering 0 Toxics Release Inventory (TRI) facilities, 7 Safe Drinking Water Act systems, and 0 Superfund National Priorities List sites. Together these generate an environmental burden score of 6/100 (Low Risk), calibrated against national distributions for facility density, chemical release volume, Superfund concentration, and water-system health violations.
Industrial disclosures inside the county total 0 lbs of reported toxic releases under EPCRA Section 313, while 2 water systems carry an active health-based violation in the SDWIS record. EPA Air Quality System monitors logged a median AQI of 39 and a peak AQI of 137 in 2024, with 79% of observed days rated "Good" (0–50).
All figures below draw directly from federal EPA records, TRI self-reported emissions, SDWIS compliance history, NPL Hazard Ranking System scores, and AQS daily AQI summaries, and are not adjusted, weighted, or forecast. A past violation or elevated score does not itself indicate current unsafe conditions; it documents the regulatory and disclosure history publicly filed with the U.S. Environmental Protection Agency through the most recent reporting cycle.
Air Quality History (2022–2024)
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 |
|---|---|---|---|---|
| 2024 | 289 (79%) | 75 | 2 | 137 |
| 2023 | 244 (67%) | 103 | 15 | 173 |
| 2022 | 320 (88%) | 45 | 0 | 87 |
Source: EPA Air Quality System (AQS) Annual AQI by County 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 South Dakota, see the EPA's AirNow.gov.
Water Systems (7)
| System | Population | Violations |
|---|---|---|
| VERMILLION | 11,695 | 0 |
| CLAY RURAL WATER SYSTEM | 4,780 | 0 |
| CLAY RWS/SOUTH UNION | 1,447 | 0 |
| WAKONDA | 276 | 3 |
| MASKELL, VILLAGE OF | 86 | 10 |
| LEWIS AND CLARK REGIONAL WATER SYSTEM | 25 | 0 |
| LEWIS AND CLARK REGIONAL WATER SYSTE | 0 | 0 |
Frequently Asked Questions
What is the environmental risk level in Clay, South Dakota? ▼
Are there Superfund sites in Clay? ▼
How many toxic release facilities are in Clay? ▼
What is the air quality in Clay? ▼
Is the drinking water safe in Clay? ▼
What environmental agencies cover Clay? ▼
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.