Look up NPDES-permitted water dischargers by name, city+state, or NPDES permit number - use this before any other ECHO tool that takes a facility, since they all need an npdesId (or a name they resolve internally).

ID SOUP: ECHO exposes at least two IDs per facility - npdesId (the NPDES permit number, e.g. "GA0038202") and registryId (EPA's cross-program facility ID). Pass npdesId to the other ECHO tools, never registryId.

Provide at least one of: name, city+state together, or npdesId. name and city are matched SERVER-SIDE as a substring by ECHO itself (city requires state alongside it - city alone is rejected as too broad). nameContains is a SEPARATE, CLIENT-SIDE substring filter applied AFTER the server-side search returns, narrowing further - it does not go to ECHO and cannot be used to broaden a search that came back empty.

When npdesId is given, that value IS the identifier and is always returned - ECHO is only asked to CONFIRM and enrich it (name, registryId, lat/lon, permit status). If that confirm lookup finds nothing (typo, unindexed permit, or a transient ECHO error), the response still contains the npdesId you passed, with every other field null and confirmed:false - this is not a failure, and the note explains why. Never treat confirmed:false as proof the permit is invalid.

A name/city+state search can match more than one facility - the response is never guessed down to one. Multiple matches produce a note saying so; narrow with nameContains, add state, or switch to npdesId once you have it.

permitStatus can be "Effective", "Terminated", "Expired", "Admin Continued", and others - a facility appearing in results does NOT mean it is currently permitted to discharge; check permitStatus before assuming so.

Results are capped at maxResults (default 50, max 500); when more match, truncated:true and totalMatched show how many were found in total.

Find NPDES-permitted water dischargers (majors AND minors) in a geographic area - answers "what's permitted to discharge near/on this reach," not "what IS being discharged" (pair with get_dmr_values per facility for that).

Exactly one spatial filter is required: bBox {west, south, east, north} in decimal degrees, OR lat+lon+radiusMiles together (radiusMiles capped at 25). Providing zero, both, or a partial lat/lon/radiusMiles set is rejected with a clear error naming what's missing.

Results are FACILITY PERMIT LOCATIONS (the address/coordinates on file for the permit), not the physical location of a discharge pipe or outfall - a facility's outfall can be meaningfully upstream/downstream/offset from the permit address. Do not treat a facility appearing in radius/bbox results as proof it discharges exactly at that point.

Each result includes permitStatus and majorMinor - a "Terminated" or "Expired" facility can still appear (it was permitted here at some point); check permitStatus before assuming it currently discharges. majorMinor is "M" (major) or "N" (minor) per ECHO's convention.

Results are capped at maxResults (default 50, max 500); when more match, truncated:true and totalMatched show how many were found in total. A dense urban area within even a 2-mile radius can return hundreds of stormwater/general-permit facilities alongside majors - narrow the radius or bbox rather than raising maxResults if you want a smaller, more relevant set.

Get the effluent limits ECHO has on file for a facility's outfall(s) - one row per (outfall x parameter x statistical basis x limit type). "DAILY AV" vs "DAILY MX" for the same parameter are DISTINCT limits, not duplicates - and a parameter routinely carries BOTH a mass limit (limitType "Q1"/"Q2", e.g. lb/d) AND a concentration limit ("C1"/"C2", e.g. mg/L) at the SAME statistical basis, which are also distinct limits, not duplicates.

Identify the facility with npdesId (preferred) or name (resolved internally - ambiguous names return a note asking you to call find_facility first). Omit startDate/endDate for the CURRENT permit's limits (the common case). A permit reissuance changes limits: pass a historical startDate/endDate (YYYY-MM-DD) to see a PRIOR permit's limits instead - verified live against real historical ECHO data (see get_dmr_values for the same date-range mechanism). The response's note always states which permit window (permitStart-permitEnd) the returned limits belong to.

limitValue:null for a parameter means monitoring is required but no numeric limit is assigned (a real, meaningful distinction from "no limit information exists") - do not treat it as missing data.

Optionally filter to one outfall with outfall (e.g. "001"); omit to see limits for all outfalls.

Get measured Discharge Monitoring Report (DMR) values for a facility - the actual reported effluent values, not just limits (use get_permit_limits for that).

Identify the facility with npdesId (preferred) or name (resolved internally - ambiguous names return a note asking you to call find_facility first).

THE WINDOWING TRAP, SOLVED: omitting startDate/endDate returns ONLY the facility's CURRENT permit window - which can be as narrow as the last few years, hiding older discharges entirely. The response ALWAYS notes this when no date range is given, even if current-window rows come back. To reach historical discharges (e.g. a pre-2023 permit), pass startDate/endDate (YYYY-MM-DD) - ECHO honors these and returns REAL DATA from the facility's OLDER permit(s), verified live (a 2011-2012 query against a real facility returned 360 real historical report rows). There is no separate historical endpoint to call - passing the date range through to this same tool IS the fix.

If a date range IS given but zero rows come back, the response explains the returned permit window rather than implying "no discharge occurred" - a range outside any permit ECHO has data for looks identical to a genuinely clean period unless you check the window ECHO actually returned.

dmrValue:null with a populated nodiFlag means ECHO recorded a specific reason no value was reported (e.g. monitoring not required that period) - this is NOT the same as a missing/unreported value; nodiFlag:null with dmrValue:null on an overdue report means the value is simply missing. Values may be provisional and subject to revision.

Optionally filter with parameter - matches EITHER an exact parameter code (e.g. "00530") OR a case-insensitive substring of the parameter name (e.g. "suspended"). Results are capped at maxResults (default 50, max 500); when more match, truncated:true and totalMatched show how many were found in total.

Get DMR-derived violations for a facility - effluent/compliance flags ECHO computed from Discharge Monitoring Reports. This is DIFFERENT from get_enforcement_actions: a facility can have violations here with no formal case ever filed, and a single enforcement case can resolve violations from several different reporting periods - the two tools do not correspond 1:1.

Identify the facility with npdesId (preferred) or name (resolved internally - ambiguous names return a note asking you to call find_facility first).

SAME WINDOWING TRAP AS get_dmr_values, same fix: omitting startDate/ endDate returns only the CURRENT permit window, and the response ALWAYS notes this, even when current-window violations come back. Pass startDate/endDate (YYYY-MM-DD) to reach historical violations - verified live: a 2011-2012 query surfaced real "DMR, Limited - Numeric Violation" flags for a BOD exceedance that the current-permit view alone would never show.

A row is included here ONLY when ECHO itself recorded a violation (NPDESViolations) - a NODI ("no data") code alone, even one that looks violation-adjacent, is NOT treated as a violation on its own; verified live that real NODI codes (e.g. "Conditional Monitoring Not Required") never co-occur with an actual violation flag in practice. Two distinct kinds of violation appear, both carrying violationCode/violationDescription/ severity, and neither is "more real" than the other:

• Reporting/monitoring violations (e.g. code D80, "DMR, Monitor Only - Overdue") - a required report wasn't submitted on time, independent of whether effluent was ever out of spec.

• Effluent/numeric violations (e.g. code E90, "DMR, Limited - Numeric Violation") - a reported value exceeded its limit; exceedancePct is populated when ECHO computed by how much.

If a date range returns zero rows, the response distinguishes "no monitoring reports at all in this window" from "reports came back, none were flagged as violations" - the second is a genuinely clean compliance result, not missing data, and is reported as such rather than implied to be an error.

Results are capped at maxResults (default 50, max 500); when more match, truncated:true and totalMatched show how many were found in total.

Get FORMAL ICIS-NPDES enforcement cases for a facility - consent orders, administrative orders, and their penalties. DIFFERENT from get_violations: a facility can accumulate DMR violations with no case ever filed, and one case can resolve violations spanning multiple years - do not assume a 1:1 relationship between the two tools, and do not assume "no cases here" means "no violations" (check get_violations separately).

Identify the facility with npdesId (preferred) or name (resolved internally - ambiguous names return a note asking you to call find_facility first). Enforcement cases are looked up by the facility's ECHO Registry ID, NOT the NPDES permit number - verified live: case_rest_services.get_cases links via p_facility_id=<RegistryID>; p_id, p_pid, p_reg, and several other plausible-looking param names all silently no-op on this service (they fall through to a whole-database row-limit error instead of filtering). If this facility's Registry ID could not be confirmed (see find_facility's confirmed:false), this tool cannot look up cases and says so rather than guessing at a param that won't work.

Penalties are frequently penalty:0 (the FEDERAL penalty field) even for cases with real financial consequences - many enforcement actions are STATE-level consent orders, and their penalty shows up in stateLocalPenalty instead. Verified live against an 11-case real enforcement history where EVERY federal penalty was $0.00 but state penalties ranged from $2,900 to $150,000 - checking penalty alone would have reported that facility's entire enforcement history as penalty-free, which was false. Check both fields; a $0 in one is not evidence of "no penalty at all."

Optional startDate/endDate (YYYY-MM-DD) filter to cases with a filed OR settlement date in range, applied CLIENT-SIDE (ECHO's case search does not support server-side date filtering - p_daterange and similar guesses were tried and silently ignored). A case with no date on file at all is excluded when a range is given, since it can't be confirmed to fall inside it.

Results are capped at maxResults (default 50, max 500); when more match, truncated:true and totalMatched show how many were found in total.