PORTSMOUTH CITY OF
NPDES ID: NH0100234
S — SNC: Compliance schedule violation
The facility missed a deadline in its compliance schedule by more than 90 days.
Violations
March 31, 2026
Coliform, fecal general
7% over limit
Discharged 15 MPN/100mL against a permitted limit of 14 MPN/100mL (MO GEO)
DMR, Limited - Numeric Violation
Coliform, fecal - % samples exceeding limit
287% over limit
Discharged 38.71 % against a permitted limit of 10 % (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2026
Coliform, fecal - % samples exceeding limit
150% over limit
Discharged 25 % against a permitted limit of 10 % (DAILY MX)
DMR, Limited - Numeric Violation
January 31, 2026
Coliform, fecal - % samples exceeding limit
61% over limit
Discharged 16.1 % against a permitted limit of 10 % (DAILY MX)
DMR, Limited - Numeric Violation
December 31, 2025
Coliform, fecal general
0% over limit
Discharged 0 MPN/100mL against a permitted limit of 0 MPN/100mL (MAXIMUM)
DMR, Monitor Only - Overdue
Enterococci
0% over limit
Discharged 0 MPN/100mL against a permitted limit of 0 MPN/100mL (MAXIMUM)
DMR, Monitor Only - Overdue
October 31, 2025
Enterococci
282% over limit
Discharged 396.8 MPN/100mL against a permitted limit of 104 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
June 30, 2025
Arsenic, total [as As]
0% over limit
Discharged 0 mg/L against a permitted limit of 0 mg/L (DAILY MX)
DMR, Monitor Only - Overdue
Enterococci
318% over limit
Discharged 435.2 MPN/100mL against a permitted limit of 104 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
March 31, 2025
Coliform, fecal - % samples exceeding limit
126% over limit
Discharged 22.6 % against a permitted limit of 10 % (DAILY MX)
DMR, Limited - Numeric Violation
February 28, 2025
Coliform, fecal - % samples exceeding limit
7% over limit
Discharged 10.7 % against a permitted limit of 10 % (DAILY MX)
DMR, Limited - Numeric Violation
September 30, 2024
Enterococci
2227% over limit
Discharged 2419.6 MPN/100mL against a permitted limit of 104 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
August 31, 2024
Enterococci
490% over limit
Discharged 613.1 MPN/100mL against a permitted limit of 104 MPN/100mL (DAILY MX)
DMR, Limited - Numeric Violation
First flagged
April 14, 2026 (3 months ago)
Last confirmed
August 1, 2026 (4 days ago)