HENNIKER WASTEWATER TREATMENT FACILITY
NPDES ID: NHG580018
E — SNC: Effluent violation (monthly average limit)
The facility discharged more of a pollutant than its permit allows, based on a monthly average.
This quarter: 9 effluent violations.
Violations
May 31, 2026
Copper, total [as Cu]
255% over limit
Discharged 0.011 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
338% over limit
Discharged 0.0105 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
E. coli
1% over limit
Discharged 410 MPN/100mL against a permitted limit of 406 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
Phosphorus, total [as P]
98% over limit
Discharged 4.55 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
April 30, 2026
Copper, total [as Cu]
203% over limit
Discharged 0.0094 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
292% over limit
Discharged 0.0094 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
March 31, 2026
Copper, total [as Cu]
384% over limit
Discharged 0.015 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
67% over limit
Discharged 0.004 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
February 28, 2026
Copper, total [as Cu]
469% over limit
Discharged 0.01365 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
384% over limit
Discharged 0.015 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2026
Nitrogen, total [as N]
0% over limit
Discharged 26.9 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 26.9 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 13.61999989 kg/d against a permitted limit of 0 kg/d (DAILY MX)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 13.61999989 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.126 MGD against a permitted limit of 0.51 MGD (ROLL AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
433% over limit
Discharged 0.0128 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
433% over limit
Discharged 0.0128 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
BOD, 5-day, 20 deg. C
0% over limit
Discharged 2.99639997 kg/d against a permitted limit of 96.70199919 kg/d (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
323% over limit
Discharged 0.0131 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
323% over limit
Discharged 0.0131 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2025
Nitrogen, total [as N]
0% over limit
Discharged 9.67019992 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.127 MGD against a permitted limit of 0.51 MGD (ROLL AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
352% over limit
Discharged 0.014 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
352% over limit
Discharged 0.014 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
471% over limit
Discharged 0.0137 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
471% over limit
Discharged 0.0137 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, total [as N]
0% over limit
Discharged 21.5 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 9.67019992 kg/d against a permitted limit of 0 kg/d (DAILY MX)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 21.5 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
November 30, 2025
Nitrogen, total [as N]
0% over limit
Discharged 26.7 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.128 MGD against a permitted limit of 0.51 MGD (ROLL AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
558% over limit
Discharged 0.0158 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
558% over limit
Discharged 0.0158 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
426% over limit
Discharged 0.0163 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
426% over limit
Discharged 0.0163 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Nitrogen, total [as N]
0% over limit
Discharged 26.7 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 12.93899989 kg/d against a permitted limit of 0 kg/d (DAILY MX)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 12.93899989 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
October 31, 2025
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.128 MGD against a permitted limit of 0.51 MGD (ROLL AVG)
DMR, Limited - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 24.9 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Copper, total [as Cu]
632% over limit
Discharged 0.0227 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
632% over limit
Discharged 0.0227 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
815% over limit
Discharged 0.02195 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
815% over limit
Discharged 0.02195 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, total [as N]
0% over limit
Discharged 9.14355992 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 9.14355992 kg/d against a permitted limit of 0 kg/d (DAILY MX)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 24.9 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Phosphorus, total [as P]
171% over limit
Discharged 6.24 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Overdue
Phosphorus, total [as P]
171% over limit
Discharged 6.24 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
September 30, 2025
Nitrogen, total [as N]
0% over limit
Discharged 17.8 mg/L against a permitted limit of 0 mg/L (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 6.76459994 kg/d against a permitted limit of 0 kg/d (MO AVG)
DMR, Monitor Only - Overdue
Nitrogen, total [as N]
0% over limit
Discharged 6.76459994 kg/d against a permitted limit of 0 kg/d (DAILY MX)
DMR, Monitor Only - Overdue
Copper, total [as Cu]
642% over limit
Discharged 0.023 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
642% over limit
Discharged 0.023 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.128 MGD against a permitted limit of 0.51 MGD (ROLL AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
754% over limit
Discharged 0.0205 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
754% over limit
Discharged 0.0205 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Phosphorus, total [as P]
191% over limit
Discharged 6.7 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Nitrogen, total [as N]
0% over limit
Discharged 17.8 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
August 31, 2025
Copper, total [as Cu]
796% over limit
Discharged 0.0215 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Overdue
Copper, total [as Cu]
796% over limit
Discharged 0.0215 mg/L against a permitted limit of 0.0024 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Phosphorus, total [as P]
143% over limit
Discharged 5.6 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Overdue
Phosphorus, total [as P]
143% over limit
Discharged 5.6 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
Copper, total [as Cu]
626% over limit
Discharged 0.0225 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Overdue
Copper, total [as Cu]
626% over limit
Discharged 0.0225 mg/L against a permitted limit of 0.0031 mg/L (DAILY MX)
DMR, Limited - Numeric Violation
Flow, in conduit or thru treatment plant
0% over limit
Discharged 0.129 MGD against a permitted limit of 0.51 MGD (ROLL AVG)
DMR, Limited - Overdue
July 31, 2025
Phosphorus, total [as P]
114% over limit
Discharged 4.92 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
June 30, 2025
Phosphorus, total [as P]
1209% over limit
Discharged 30.1 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
May 31, 2025
Phosphorus, total [as P]
158% over limit
Discharged 5.93 mg/L against a permitted limit of 2.3 mg/L (MO AVG)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
July 13, 2026 (24 days ago)