Clean Water Act discharge permit · NPDES WA0020729

DAYTON STP, Dayton, WA: NPDES WA0020729 discharge permit, effluent exceedances, inspections, penalties

Administratively continuedPermit status
MinorDischarger class
0Pollutants under a numeric limit
7Pollutants with an effluent exceedance
0Inspections on file
0Formal enforcement actions

DAYTON STP, held by City Of Dayton, holds NPDES permit WA0020729. EPA’s file records it issued September 1, 2011 and expiring September 29, 2016.

DAYTON STP, Dayton, Washington: Individual permit WA0020729, held by City Of Dayton; Publicly owned treatment works; Administratively continued (past its expiration date and still in force until reissued); issued September 1, 2011, term to September 29, 2016, by State.

pH: 0 limits, 18 violations of any kind, 12 effluent exceedances, latest July 31, 2025.
Solids, total suspended: 0 limits, 33 violations of any kind, 9 effluent exceedances, latest June 30, 2018, largest 99,999% over the limit.
pH, minimum: 0 limits, 7 violations of any kind, 7 effluent exceedances, latest August 31, 2010.
Coliform, fecal general: 0 limits, 15 violations of any kind, 6 effluent exceedances, latest July 31, 2014, largest 650% over the limit.
Fecal coliform, MPN, EC med, 44.5 C: 0 limits, 5 violations of any kind, 5 effluent exceedances, latest January 31, 2011, largest 100% over the limit.
Solids, suspended percent removal: 0 limits, 5 violations of any kind, 2 effluent exceedances, latest August 31, 2007, largest 20% over the limit.
pH, maximum: 0 limits, 1 violation of any kind, 1 effluent exceedance, latest January 31, 2010.
BOD, 5-day, 20 deg. C: 0 limits, 128 violations of any kind, 0 effluent exceedances.
BOD, percent removal [total]: 0 limits, 75 violations of any kind, 0 effluent exceedances.
Flow: 0 limits, 16 violations of any kind, 0 effluent exceedances.
Nitrogen, ammonia total [as N]: 0 limits, 10 violations of any kind, 0 effluent exceedances.
Temperature, water deg. fahrenheit: 0 limits, 6 violations of any kind, 0 effluent exceedances.
Oxygen, dissolved [DO]: 0 limits, 6 violations of any kind, 0 effluent exceedances.
Alkalinity, total [as CaCO3]: 0 limits, 6 violations of any kind, 0 effluent exceedances.
Hardness, total [as CaCO3]: 0 limits, 6 violations of any kind, 0 effluent exceedances.

Washington holds 238 Publicly owned treatment works coverages of this permit type in EPA’s file; 50 were issued before WA0020729.

Coverages issued nearest WA0020729

June 16, 2011: SPOKANE RIVERSIDE PARK WATER RECLAMATION FACILITY, Spokane, WA0024473, held by City of Spokane RPWRF
June 23, 2011: LIBERTY LAKE SEWER & WATER DIST, Liberty Lake, WA0045144, held by Liberty Lake Sewer & Water District
July 7, 2011: YELM WATER RECLAMATION FACILITY, Yelm, WA0040762, held by Yelm Water Reclamation Facility
July 8, 2011: WILBUR STP, Wilbur, WA0044920, held by Town of Wilbur
August 9, 2011: TONASKET POTW, Tonasket, WA0052337, held by City of Tonasket
September 12, 2011: WAPATO, CITY OF - WAPATO WWTP, Wapato, WA0050229, held by WAPATO, CITY OF
September 14, 2011: LEWIS COUNTY WATER & SEWER DIST 6, Mossyrock, WA0037141, held by Lewis County Water & Sewer District #6
September 30, 2011: YAKIMA POTW, Yakima, WA0024023, held by Yakima Regional POTW
October 25, 2011: CHEWELAH WWTP, Chewelah, WA0023604, held by City of Chewelah
November 16, 2011: WASHOUGAL STP, Washougal, WA0037427, held by City of Washougal

DAYTON STP among its neighbors

EPA’s permit file holds 2 discharge permits in the Payne Hollow-Touchet River subwatershed (HUC 170701020401), WA0020729 among them. Its county holds 4, 0 of them major permits; WA0020729 is a minor permit.

Other permits in the Payne Hollow-Touchet River subwatershed (HUC 170701020401)

ROCK HILL CONCRETE CO LLC, Dayton: WAG507041, minor permit, permit term to March 31, 2026

Identity

Facility as filed	DAYTON STP
Permittee as filed	City Of Dayton
NPDES ID	WA0020729
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	September 1, 2011
Expiration date	September 29, 2016
Issuing agency	State
Address	Dayton, WA 99328
Receiving water impaired	303(D) Listed
Subwatershed	Payne Hollow-Touchet River (HUC 170701020401)

Effluent limits and exceedances

15Pollutants on file
0Under a numeric limit
15With a violation of any kind
7With 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
pH	18	12	July 31, 2025
Solids, total suspended	33	9	June 30, 2018	99,999% over the limit
pH, minimum	7	7	August 31, 2010
Coliform, fecal general	15	6	July 31, 2014	650% over the limit
Fecal coliform, MPN, EC med, 44.5 C	5	5	January 31, 2011	100% over the limit
Solids, suspended percent removal	5	2	August 31, 2007	20% over the limit
pH, maximum	1	1	January 31, 2010
BOD, 5-day, 20 deg. C	128	0
BOD, percent removal [total]	75	0
Flow	16	0
Nitrogen, ammonia total [as N]	10	0
Temperature, water deg. fahrenheit	6	0
Oxygen, dissolved [DO]	6	0
Alkalinity, total [as CaCO3]	6	0
Hardness, total [as CaCO3]	6	0

Inspections, violations and enforcement

0Single-event violations

EPA’s single-event violation file, as loaded, holds no violation for NPDES WA0020729.

Inspections

EPA’s inspection file holds no inspection for NPDES WA0020729.

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 WA0020729.

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

This public-records page covers the NPDES discharge permit WA0020729 for the DAYTON STP in Dayton, WA, held by City Of Dayton, with a status of administratively continued and a discharger class of Minor Discharger. The facts list 15 pollutants on file, 7 with an effluent exceedance, and 0 under a numeric limit, within the Payne Hollow-Touchet River (HUC 170701020401) subwatershed.