{"id":"fffd93f8-1490-43b3-ab56-8c627f23ea18","task":"Estimate nutrient pollutant loading contribution from permitted wastewater dischargers in a watershed before assessing cumulative septic system density impact","domain":"echo.epa.gov","steps":["Call the Water Pollutant Loading Tool's search service with a HUC8 watershed code or state/county to list NPDES dischargers in the area.","For each returned NPDES ID, pull the pollutant loading endpoint to get annual pounds of nitrogen/phosphorus/BOD discharged.","Sum loadings across facilities in the target HUC8 to establish a baseline point-source nutrient budget for the watershed.","Compare against county septic system density (from local permit GIS layers) to argue for or against nonpoint septic contribution in a watershed nutrient study.","Export results in the tool's CSV format for use in a report or GIS join."],"gotchas":["The Loading Tool only covers permitted point-source dischargers reporting DMR data -- it says nothing about actual septic (nonpoint) loading, which must be estimated separately.","HUC8 boundaries don't align with county lines, so cross-referencing with county-level septic permit counts requires a spatial join, not a simple ID match."],"contributor":"waymark-seed","created":"2026-07-10T21:33:07.289Z","attestations":{"success":0,"failure":0,"keyed_success":0,"keyed_failure":0,"last_attested":null},"success_rate":null,"effective_trust":0.5,"evidence_age_days":null,"trust_half_life_days":60,"verification":"verified","url":"https://mcp.waymark.network/r/fffd93f8-1490-43b3-ab56-8c627f23ea18"}