Clean Water Act discharge permit · NPDES OR0023493

TWIN ROCKS WWTP, Twin Rocks, OR: NPDES OR0023493 discharge permit, effluent exceedances, inspections, penalties

EffectivePermit status
MinorDischarger class
13Pollutants under a numeric limit
2Pollutants with an effluent exceedance

TWIN ROCKS WWTP, held by TWIN ROCKS SANITARY DISTRICT, holds NPDES permit OR0023493, which discharges to Watseco Creek (Rm 0.2). EPA’s file records it issued January 10, 2018 and expiring January 31, 2023. The status and dates are as EPA’s permit file stood when Velarion loaded it (October 14, 2026); EPA’s free Detailed Facility Report on ECHO carries the permit’s current standing.

Identity

Facility as filed	TWIN ROCKS WWTP
Permittee as filed	TWIN ROCKS SANITARY DISTRICT
NPDES ID	OR0023493
Permit status	Effective
Permit type	Individual permit
Discharger class	Minor discharger
Facility type	Publicly owned treatment works
Program	Publicly owned treatment works
Issued	January 10, 2018
Expiration date	January 31, 2023
Address	Twin Rocks, OR 97136
Receiving water	WATSECO CREEK (RM 0.2)
Subwatershed	Spring Creek-Frontal Pacific Ocean (HUC 171002030904)
SIC	4952 – Sewerage Systems

Cited to the EPA ICIS-NPDES permit file (ECHO download) and EPA’s NAICS/SIC and component files, the same download.

Effluent limits and exceedances

14Pollutants on file
13Under a numeric limit
2With a violation of any kind
2With an effluent exceedance

An effluent exceedance is a discharge monitoring report value over the permit’s numeric limit (EPA’s violation code E90). A violation of any kind also counts a report not filed. Each row is EPA’s own count for that pollutant.

Pollutant or measure	Limits	Violations, any kind	Effluent exceedances	Latest exceedance	Largest exceedance, as filed
Coliform, fecal - % samples exceeding limit	1	1	1	September 30, 2024	10% over the limit
Enterococci - % samples exceeding limit	0	1	1	September 30, 2024	10% over the limit
BOD, 5-day, 20 deg. C	11	0	0
Solids, total suspended	11	0	0
pH	4	0	0
Nitrogen, ammonia total [as N]	2	0	0
Flow, in conduit or thru treatment plant	2	0	0
Chlorine, total residual	2	0	0
Enterococci	2	0	0
Coliform, fecal general	2	0	0
Temperature, water deg. centigrade	1	0	0
BOD, 5-day, percent removal	1	0	0
Solids, suspended percent removal	1	0	0
Chlorine usage	1	0	0

Cited to the EPA ICIS-NPDES limits and effluent violations files (ECHO download); up to 60 rows shown, most exceedances first.

Inspections, violations and enforcement

0Single-event violations

EPA’s single-event violation file, as loaded, holds no violation for NPDES OR0023493.

Velarion’s copy of EPA’s ICIS-NPDES files does not include the inspections, formal enforcement actions and informal enforcement actions files, so this page shows none of them. EPA’s free Detailed Facility Report on ECHO lists this permit’s inspections, enforcement actions and penalties.

Cited to the EPA ICIS-NPDES violation, inspection and enforcement files (ECHO download); up to 50 rows of each shown, newest first.

Watch this permit

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EPA publishes a free Detailed Facility Report for every permit on ECHO: its compliance status quarter by quarter, its inspections, and its enforcement actions and penalties. EPA also sends free notices of new inspections and enforcement actions through ECHO Notify; enter NPDES ID OR0023493 there.

Nearby on the register

Figures from EPA’s ICIS-NPDES download, loaded October 14, 2026.

This page covers Clean Water Act discharge permit NPDES OR0023493 for TWIN ROCKS WWTP in Twin Rocks, OR, held by TWIN ROCKS SANITARY DISTRICT, which discharges to WATSECO CREEK (RM 0.2) in the Spring Creek-Frontal Pacific Ocean subwatershed (HUC 171002030904). The permit is listed as Effective, with a Minor discharger class, an issue date of January 10, 2018, and an expiration date of January 31, 2023, and the page lists 14 pollutants on file, 13 under a numeric limit, and 2 with an effluent exceedance.