Clean Water Act discharge permit · NPDES NH0100277

CITY OF SOMERSWORTH, Somersworth, NH: NPDES NH0100277 discharge permit, effluent exceedances, inspections, penalties

Administratively continuedPermit status
MajorDischarger class
23Pollutants under a numeric limit
14Pollutants with an effluent exceedance
0Inspections on file
0Formal enforcement actions

CITY OF SOMERSWORTH, held by SOMERSWORTH W P C F, holds NPDES permit NH0100277, which discharges to Salmon Falls River. EPA’s file records it issued September 29, 2000 and expiring October 31, 2005.

CITY OF SOMERSWORTH, Somersworth, New Hampshire: Individual permit NH0100277, held by SOMERSWORTH W P C F; Publicly owned treatment works; Administratively continued (past its expiration date and still in force until reissued); issued September 29, 2000, term to October 31, 2005; discharges to SALMON FALLS RIVER.

Solids, total suspended: 19 limits, 68 violations of any kind, 63 effluent exceedances, latest September 30, 2019, largest 848% over the limit.
BOD, 5-day, 20 deg. C: 19 limits, 60 violations of any kind, 60 effluent exceedances, latest January 31, 2021, largest 99,999% over the limit.
Phosphorus, total [as P]: 4 limits, 50 violations of any kind, 50 effluent exceedances, latest June 30, 2024, largest 385% over the limit.
E. coli, thermotol, MF, MTEC: 2 limits, 48 violations of any kind, 48 effluent exceedances, latest February 28, 2026, largest 99,999% over the limit.
Chlorine, total residual: 2 limits, 23 violations of any kind, 23 effluent exceedances, latest December 31, 2024, largest 1,271% over the limit.
pH: 6 limits, 21 violations of any kind, 21 effluent exceedances, latest May 31, 2024.
Oxygen, dissolved [DO]: 1 limit, 9 violations of any kind, 9 effluent exceedances, latest July 31, 2025, largest 72% over the limit.
Solids, suspended percent removal: 1 limit, 9 violations of any kind, 8 effluent exceedances, latest March 31, 2013, largest 87% over the limit.
Nitrogen, ammonia total [as N]: 7 limits, 10 violations of any kind, 5 effluent exceedances, latest August 31, 2014, largest 146% over the limit.
LC50 Static Renewal 48Hr Acute Ceriodaphnia dubia: 1 limit, 2 violations of any kind, 1 effluent exceedance, latest September 30, 2003, largest 83% over the limit.
LC50 Static Renewal 48Hr Acute Pimephales promelas: 1 limit, 2 violations of any kind, 1 effluent exceedance, latest September 30, 2003, largest 56% over the limit.
NOEL Static Renewal 7Day Chronic Ceriodaphnia dubia: 1 limit, 2 violations of any kind, 1 effluent exceedance, latest September 30, 2017, largest 54% over the limit.
Noel Statre 7Day Chronic Pimephales: 1 limit, 2 violations of any kind, 1 effluent exceedance, latest September 30, 2002, largest 8% over the limit.
BOD, 5-day, percent removal: 1 limit, 1 violation of any kind, 1 effluent exceedance, latest April 30, 2005, largest 6% over the limit.
Lead, total recoverable: 1 limit, 3 violations of any kind, 0 effluent exceedances.
Chromium, total recoverable: 1 limit, 3 violations of any kind, 0 effluent exceedances.
Hardness, total [as CaCO3]: 1 limit, 1 violation of any kind, 0 effluent exceedances.
Nickel, total recoverable: 1 limit, 1 violation of any kind, 0 effluent exceedances.
Zinc, total recoverable: 1 limit, 1 violation of any kind, 0 effluent exceedances.
Aluminum, total recoverable: 1 limit, 1 violation of any kind, 0 effluent exceedances.
Cadmium, total recoverable: 1 limit, 1 violation of any kind, 0 effluent exceedances.
Copper, total recoverable: 1 limit, 1 violation of any kind, 0 effluent exceedances.
Flow, in conduit or thru treatment plant: 2 limits, 0 violations of any kind, 0 effluent exceedances.

June 30, 2025: PR: Failure to enforce standards, local limits, and reporting requirements (>15% SNC SIU) (Level II) (EP6).

New Hampshire holds 48 Publicly owned treatment works coverages of this permit type in EPA’s file; 11 were issued before NH0100277. SOMERSWORTH W P C F holds 2 permits in New Hampshire.

Other permits held by SOMERSWORTH W P C F

SOMERSWORTH W P C F, Somersworth: NHL100277, issued January 1, 2021

Coverages issued nearest NH0100277

December 15, 1999: DURHAM WWTP, Durham, NH0100455, held by DURHAM W W T F
February 8, 2000: MILFORD TOWN OF, Milford, NH0100471
May 31, 2000: NASHUA WASTEWATER TREATMENT FACILITY, Nashua, NH0100170, held by NASHUA CITY OF
August 8, 2000: PEASE WASTEWATER TREATMENT FACILITY, Portsmouth, NH0090000, held by PEASE DEVELOPMENT AUTHORITY
September 27, 2000: DOVER/HUCKLEBERRY HILL W W T F, Dover, NH0101311, held by DOVER-HUCKLEBERRY HILL W W T P
December 5, 2000: FARMINGTON WWTP, Farmington, NH0100854, held by FARMINGTON W W T P
January 31, 2002: GREENVILLE W W T F, Greenville, NH0100919
June 7, 2002: MERIDEN VILLAGE WATER DISTRICT, Plainfield, NH0101168, held by Meriden Village Water District
September 25, 2002: PITTSFIELD WASTEWATER TREATMENT FACILITY, Pittsfield, NH0100986, held by PITTSFIELD W W T F
November 20, 2002: TROY WASTEWATER TREATMENT PLANT, Troy, NH0101052, held by TROY W W T P

CITY OF SOMERSWORTH among its neighbors

EPA’s permit file holds 17 discharge permits in the Lower Salmon Falls River subwatershed (HUC 010600030507), NH0100277 among them. Its county holds 69, 5 of them major permits; NH0100277 is a major permit.

Other permits in the Lower Salmon Falls River subwatershed (HUC 010600030507)

ACLARA METERS LLC, Somersworth: NH0023558, minor permit, discharging to Salmon Falls River, permit term to November 30, 2019
ACLARA METERS, LLC, Somersworth: NHNOEJ023, minor permit, permit term to May 17, 2026
BERWICK SEWER DISTRICT, Berwick: MEL101397, minor permit, permit term to December 31, 2025
GREEN MOUNTAIN POWER - LOWER GREAT FALLS (SOMERSWORTH) HYDROELECTRIC PROJECT, Somersworth: NHG360028, minor permit, discharging to Salmon Falls River, permit term to December 31, 2014
HEAVY TRUCK SALES OF NEW ENGLAND, Berwick: MER05B835, minor permit, discharging to Unnamed Wetland, permit term to April 25, 2016
MULTI-FAMILY DEVELOPMENT PROJECT - 85 ELM STREET, Somersworth: NHR10021F, minor permit, permit term to February 16, 2027
ROLLINSFORD HYDROELECTRIC PROJECT, Rollinsford: NHG360030, minor permit, discharging to Salmons Falls River, permit term to December 31, 2014
ROLLINSFORD W W T F, Rollinsford: NHL100251, minor permit, permit term to December 31, 2025
SOMERSWORTH W P C F, Somersworth: NHL100277, minor permit, permit term to December 31, 2025
SOMERSWORTH WASTE WATER TREATMENT PLANT, Somersworth: NHNOE3163, minor permit, permit term to September 13, 2026

Identity

Facility as filed	CITY OF SOMERSWORTH
Permittee as filed	SOMERSWORTH W P C F
NPDES ID	NH0100277
Permit status	Administratively continued (past its expiration date and still in force until reissued)
Permit type	Individual permit
Discharger class	Major discharger
Facility type	Publicly owned treatment works
Program	Publicly owned treatment works
Issued	September 29, 2000
Expiration date	October 31, 2005
Address	Somersworth, NH 03878
Receiving water	SALMON FALLS RIVER
Receiving water impaired	303(D) Listed
Subwatershed	Lower Salmon Falls River (HUC 010600030507)
Other EPA IDs (FRS)	RCRA handler NHD510067671; ICIS-AIR source NH0000003301790287

Effluent limits and exceedances

23Pollutants on file
23Under a numeric limit
22With a violation of any kind
14With 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
Solids, total suspended	19	68	63	September 30, 2019	848% over the limit
BOD, 5-day, 20 deg. C	19	60	60	January 31, 2021	99,999% over the limit
Phosphorus, total [as P]	4	50	50	June 30, 2024	385% over the limit
E. coli, thermotol, MF, MTEC	2	48	48	February 28, 2026	99,999% over the limit
Chlorine, total residual	2	23	23	December 31, 2024	1,271% over the limit
pH	6	21	21	May 31, 2024
Oxygen, dissolved [DO]	1	9	9	July 31, 2025	72% over the limit
Solids, suspended percent removal	1	9	8	March 31, 2013	87% over the limit
Nitrogen, ammonia total [as N]	7	10	5	August 31, 2014	146% over the limit
LC50 Static Renewal 48Hr Acute Ceriodaphnia dubia	1	2	1	September 30, 2003	83% over the limit
LC50 Static Renewal 48Hr Acute Pimephales promelas	1	2	1	September 30, 2003	56% over the limit
NOEL Static Renewal 7Day Chronic Ceriodaphnia dubia	1	2	1	September 30, 2017	54% over the limit
Noel Statre 7Day Chronic Pimephales	1	2	1	September 30, 2002	8% over the limit
BOD, 5-day, percent removal	1	1	1	April 30, 2005	6% over the limit
Lead, total recoverable	1	3	0
Chromium, total recoverable	1	3	0
Hardness, total [as CaCO3]	1	1	0
Nickel, total recoverable	1	1	0
Zinc, total recoverable	1	1	0
Aluminum, total recoverable	1	1	0
Cadmium, total recoverable	1	1	0
Copper, total recoverable	1	1	0
Flow, in conduit or thru treatment plant	2	0	0

Inspections, violations and enforcement

1Single-event violations

Date	What EPA recorded	Agency
June 30, 2025	PR: Failure to enforce standards, local limits, and reporting requirements (>15% SNC SIU) (Level II)	EP6

Inspections

EPA’s inspection file holds no inspection for NPDES NH0100277.

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 NH0100277.

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

This public-records page covers Clean Water Act discharge permit NPDES NH0100277, held by CITY OF SOMERSWORTH in Somersworth, NH, with its status listed as administratively continued. The page lists 23 as the discharger class count, 14 pollutants under a numeric limit, and 14 pollutants with an effluent exceedance.