Drinking-water exposure across Texas counties.
Health-based Safe Drinking Water Information System (SDWIS) violations and the population served by affected public water systems, aggregated to county footprints. This is the seed layer for a full Drinking Water Risk Score (DWRS) + EJ overlay; EJScreen burden index integration is wired in the data lib but lives behind the next-up queue.
EJ exposure choropleth
Toggle between violation count (procedural pressure) and people served (exposure footprint). Atlas frames both as burden / exposure indicators, not harm.
Cached SDWIS health-based violation rows per county since 2023-04-01.
- 0
- 1-9
- 10-29
- 30-99
- 100+
- No data
- •Flip between metric modes to see which counties stay bright across unrelated burdens versus which only flare in one layer.
- •Use overlays to isolate counties where the highlighted pattern may explain why a metric spikes or refuses to move.
- •Check the top list for repeat names, then trace whether they cluster geographically or break the regional pattern.
SDWIS rows are self-reported by primacy agencies; recent quarters lag. Snapshot is filtered to TX health-based violations after 2023-04-01. EJ outputs derived from this should be framed as exposure / burden, not harm.
- 1Lubbock CountyTop PWS · FRANKLIN WATER SYSTEMS 31,00712,041 ppl
- 2Midland CountyTop PWS · MARGIES MHP506148,669 ppl
- 3Harris CountyTop PWS · GEO SPECIALTY CHEMICALS4842,345,070 ppl
- 4Brazoria CountyTop PWS · VILLAGE OF SURFSIDE BEACH36427,622 ppl
- 5Burnet CountyTop PWS · CASSIE WATER SYSTEM35819,120 ppl
- 6Comal CountyTop PWS · RAMBLE RIDGE SUBDIVISION30951,602 ppl
- 7San Augustine CountyTop PWS · LA PLAYA SUBDIVISION WATER SYSTEM2685,031 ppl
- 8Orange CountyTop PWS · CITY OF ROSE CITY24045,399 ppl
- 9Mclennan CountyTop PWS · CITY OF RIESEL21310,620 ppl
- 10Polk CountyTop PWS · TEMPE WSC 119020,909 ppl
- EJScreen burden indexEPA EJScreen by block group with buffer geocoding around PWS service areas.
- ACS demographic contextBlock-group race / income / language overlays beyond the current 3-county snapshot.
- DWRS composite scoringpopulationServed × recency × violation severity tier per `docs/contracts/dataset-registry.md`.
- EJ overlap signalMismatch detection between burden density and procedural responsiveness.
- • SDWIS rows are self-reported by primacy agencies; recent quarters lag.
- • Snapshot is filtered to TX health-based violations after 2023-04-01; widen via fetchSdwis({since: undefined}) and write to data/ (gitignored) for analysis runs.
- • county is sourced from GEOGRAPHIC_AREA (area_type_code=CN); some PWSs are missing this row.
- • EJ outputs derived from this should be framed as exposure / burden, not harm.