Clean Water Act discharge permit · NPDES WA0037290

TAMOSHAN STP, Olympia, WA: NPDES WA0037290 discharge permit, effluent exceedances, inspections, penalties

Administratively continuedPermit status
MinorDischarger class
0Pollutants under a numeric limit
3Pollutants with an effluent exceedance
1Inspections on file
0Formal enforcement actions

TAMOSHAN STP, held by Thurston County Public Works, holds NPDES permit WA0037290. EPA’s file records it issued October 26, 2017 and expiring November 30, 2022.

TAMOSHAN STP, Olympia, Washington: Individual permit WA0037290, held by Thurston County Public Works; Publicly owned treatment works; Administratively continued (past its expiration date and still in force until reissued); issued October 26, 2017, term to November 30, 2022, by State.

Solids, total suspended: 0 limits, 50 violations of any kind, 6 effluent exceedances, latest March 31, 2014, largest 258% over the limit.
BOD, 5-day, 20 deg. C: 0 limits, 46 violations of any kind, 2 effluent exceedances, latest November 30, 2011, largest 58% over the limit.
pH: 0 limits, 1 violation of any kind, 1 effluent exceedance, latest September 30, 2018.
Coliform, fecal general: 0 limits, 11 violations of any kind, 0 effluent exceedances.
Flow: 0 limits, 11 violations of any kind, 0 effluent exceedances.
BOD, percent removal [total]: 0 limits, 1 violation of any kind, 0 effluent exceedances.

April 14, 2026: Evaluation (S).

Washington holds 238 Publicly owned treatment works coverages of this permit type in EPA’s file; 170 were issued before WA0037290. Thurston County Public Works holds 9 permits in Washington.

Other permits held by Thurston County Public Works

BOSTON HARBOR STP, Olympia: WA0040291, issued December 15, 2011
GRAND MOUND STP, Rochester: WA0042099, issued February 16, 2010
THURSTON COUNTY PW RAINIER PIT, Rainier: WAG501275, issued February 17, 2021
THURSTON COUNTY PW WALDRICK PIT, Olympia: WAG501276, issued February 17, 2021
THURSTON COUNTY PW OWL HILL PIT, Tenino: WAG501278, issued February 17, 2021
LITTLEROCK RD. SW AND 113TH AVE. SW, Olympia: WAR314478, issued November 18, 2020
OLD HIGHWAY 99/SARGENT/201ST RAB, Centralia: WAR315330, issued November 19, 2025
183RD AVE. SW PHASE 1, Rochester: WAR315340, issued November 19, 2025

Coverages issued nearest WA0037290

September 7, 2017: LYNDEN WWTP, Lynden, WA0022578, held by LYNDEN CITY OF
September 22, 2017: LEAVENWORTH POTW, Leavenworth, WA0020974, held by City of Leavenworth
September 26, 2017: ZILLAH POTW, Zillah, WA0020168, held by City of Zillah
September 26, 2017: QUINAULT INDIAN NATION - MOCLIPS RIVER ESTATES WWTP, Moclips, WA0026603, held by MOCLIPS RIVER ESTATES WWTP
October 6, 2017: LAKE STEVENS SEWER DISTRICT WWTP, Lake Stevens, WA0020893, held by Lake Stevens Sewer District
November 1, 2017: MARYSVILLE STP, Marysville, WA0022497, held by City Of Marysville Wastewater Treatment Plant
November 9, 2017: ANACORTES WWTP, Anacortes, WA0020257, held by City of Anacortes
November 13, 2017: CARBONADO STP, Carbonado, WA0020834, held by City of Carbonado
December 31, 2017: HARTSTENE POINTE STP, Shelton, WA0038377, held by Hartstene Pointe Water-Sewer District
January 12, 2018: BURLINGTON WWTP, Burlington, WA0020150, held by BURLINGTON CITY

TAMOSHAN STP among its neighbors

Its county holds 207, 1 of them major permits; WA0037290 is a minor permit.

Other permits in the county

2021 U10 POND IMPROVEMENTS, Lacey: WAR314009, minor permit, permit term to December 31, 2025
22ND AVENUE SIDEWALK PROJECT, Olympia: WAR301843, minor permit, permit term to December 31, 2015
9816 MARINER DR NW, Olympia: WAR302777, minor permit, permit term to December 31, 2015
ABERNETHY COURT, Olympia: WAR314783, minor permit, permit term to December 31, 2025
ALLEN ORCHARD, Tumwater: WAR012336, minor permit, permit term to January 1, 2015
ALPINE S & G RIXIE RD, Olympia: WAG501037, minor permit, permit term to September 30, 2015
AMCOR PACKAGING, Tumwater: WAR012411, minor permit, permit term to January 1, 2015
AURORA OAKS PRD, Olympia: WAR314118, minor permit, permit term to December 31, 2025
BAY HILL PLAT, Olympia: WAR303379, minor permit, permit term to December 31, 2015
BELLEFIELD OFFICE PARK, Olympia: WAG994611, minor permit, permit term to June 13, 2029

Identity

Facility as filed	TAMOSHAN STP
Permittee as filed	Thurston County Public Works
NPDES ID	WA0037290
Permit status	Administratively continued (past its expiration date and still in force until reissued)
Permit type	Individual permit
Discharger class	Minor discharger
Facility type	Publicly owned treatment works
Program	Publicly owned treatment works
Issued	October 26, 2017
Expiration date	November 30, 2022
Issuing agency	State
Address	Olympia, WA 98502

Effluent limits and exceedances

6Pollutants on file
0Under a numeric limit
6With a violation of any kind
3With 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	Violations, any kind	Effluent exceedances	Latest exceedance	Largest exceedance, as filed
Solids, total suspended	50	6	March 31, 2014	258% over the limit
BOD, 5-day, 20 deg. C	46	2	November 30, 2011	58% over the limit
pH	1	1	September 30, 2018
Coliform, fecal general	11	0
Flow	11	0
BOD, percent removal [total]	1	0

Inspections, violations and enforcement

0Single-event violations

EPA’s single-event violation file, as loaded, holds no violation for NPDES WA0037290.

Inspections

Date	What EPA recorded	Agency
April 14, 2026	Evaluation	S

Formal enforcement and penalties

0 formal actions, 0 of them with a penalty assessed. Federal and state penalties are separate figures from separate authorities and are shown as each was filed, never added together.

Informal enforcement

EPA’s informal enforcement file holds no action for NPDES WA0037290.

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Figures from EPA’s ICIS-NPDES download, loaded September 15, 2026.

This public-records page covers NPDES permit WA0037290 for TAMOSHAN STP in Olympia, WA, held by Thurston County Public Works, with a status of administratively continued and a minor discharger class. The page lists 6 pollutants on file, 0 under a numeric limit, 6 with a violation of any kind, and 3 with an effluent exceedance.