Water Quality (v1)
Version 1.0.0 · Published 2026-06-10
What this is
Water Quality joins the Environmental Feature Inventory as a 9th category alongside TRI, contaminated sites, RCRA hazardous waste, major roadways, traffic noise, golf courses, phosphate, CAFOs, and ag fields. The category produces one feature per address with a tier in {severe, moderate, minor, none} based on the public water system (PWS) serving the address.
PWS resolution waterfall
We resolve which PWS serves a given (lat, lon) by point-in-polygon against three boundary layers, in confidence order:
- HIGH confidence: EPA SDWIS service-area polygon
- MEDIUM confidence: FDEP Water Management District public-water-supply boundary
- LOW confidence: derived from the county polygon (one county = dominant PWS)
- If no match: unresolved (treated as likely-on-well; see below)
v1.0 ships the LOW-confidence fallback for all 20 curated FL PWS. EPA SDWIS polygons (HIGH) and FDEP WMD boundaries (MEDIUM) land in v1.1.
Tier-firing rules
| Tier | Trigger | Source |
|---|---|---|
| SEVERE | Active MCL violation OR confirmed lead service line (LSL) in PWS | EPA SDWIS + EPA LSL Inventory |
| MODERATE | Monitoring or treatment violation OR boil-water advisory within last 3 years | EPA SDWIS + FDEP ACMR (pair captures admin violations SDWIS alone misses) |
| MINOR | Utility has a recent or open compliance record that is not a tier-firing health-based, monitoring, treatment, or boil-water violation (e.g., an administrative or public-notification record). PFAS detections are excluded here, see below. | EPA SDWIS + FDEP ACMR |
| none | No recent violations | n/a |
PFAS handling at v1.0
EPA finalized enforceable MCLs of 4 ppt for PFOA and PFOS in April 2024, but the compliance timeline runs out for years (initial monitoring through ~2027, MCL compliance later still), and in 2025 EPA announced it would reconsider parts of the rule, so an enforceable, settled bright line is not yet in force. UCMR 5 (2023-2025) is detection data, not enforcement data, and a detection is not a violation. v1.0 surfaces a PFAS detection as a metadata flag in the BLUF prose and methodology callout but does not use it to modify the tier letter. A genuine PFAS MCL exceedance (a formal violation), by contrast, arrives as an MCL violation and tiers as severe like any other health-based violation. Tier-firing on a bare PFAS detection waits for a settled compliance standard, and v1.1 will revisit. [ref:our-water-quality-v1]
Well-water addresses at v1.0
When no PWS polygon matches an address, the category returns no feature (none tier) and the BLUF surfaces a flag: "This address is likely on a private well; well-water signal lands in v1.1." v1.1 will add a Well Water category powered by USGS aquifer vulnerability + FDEP well water DB + county disclosure requirements.
v1 limitations (honest callouts)
- Curated snapshot of 20 large FL PWS. v1.1 will replace with bulk EPA SDWIS + FDEP ACMR fetches for all ~3,900 active FL PWS.
- Boundary confidence is LOW for all PWS at v1.0. The county-polygon approximation overstates service-area extent. EPA + FDEP polygon ingest in v1.1.
- FDEP impaired waters (303(d) list) not yet integrated. The schema is in place; ETL lands in v1.1.
- Deterministic tier rules, not Bayesian. Per the 2026-06-09 triangulation, deterministic ships at v1.0; Bayesian hierarchical model considered for v1.1 when missing data handling needs upgrading.
Sources (2-source consensus rule)
- EPA SDWIS (Safe Drinking Water Information System) , EPA Office of Water, accessed 2026.
- FDEP Annual Compliance Monitoring Report (ACMR), FDEP Division of Water Resource Management, 2024.
- EPA UCMR 5, Unregulated Contaminant Monitoring Rule, EPA Office of Ground Water and Drinking Water, 2023-2025.
- EPA Lead and Copper Rule Revisions (LCRR), LSL inventory mandate effective October 2024.
Changelog
1.0.0 (2026-06-10): Initial. 20-PWS curated snapshot + deterministic tier rules + PFAS-as-flag + well-water flag. Per the 2026-06-09 DeepSeek triangulation consensus on Decisions 1-3 (PFAS flag-only, deterministic over Bayesian, well-water defer to v1.1).