Non-Compliance Clean Air Act Clean Water Act RCRA

MERRIMACK WWTF

Quick Summary

•Currently out of compliance in at least one environmental program (CAA, CWA, or RCRA).
•Assessed $0 in total penalties since records began.

Address: 36 MAST RDD W HWY
MERRIMACK, NH 03054
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County: HILLSBOROUGH County
Industry: Utilities
NAICS (North American Industry Classification): 221320
Inspections: 5 · last Sep 25, 2025
Total Penalties: $0
Registry ID: 110001522086

Compliance Status (Last 12 Quarters)

Number of calendar quarters, out of the last 12, in which this facility was in violation of its permit. Zero means no recorded violations in that program over the past three years.

Air (CAA)
Qtrs Non-Compliant

Water (CWA)
Qtrs Non-Compliant

Hazardous Waste (RCRA)
Qtrs Non-Compliant

Compliance Violations

Individual permit violations recorded by the EPA across air, water, and hazardous waste programs. Open violations are unresolved as of the most recent ECHO data update.

Program	Type	Violation Date	Return to Compliance	Status
cwa	Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment	Apr 28, 2025	—	Open
cwa	Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment	Apr 30, 2024	—	Open
cwa	Wet-weather SSO discharge to waters of the U.S. that may endanger health or the environment	Apr 16, 2024	—	Open
cwa	Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment	Mar 8, 2024	—	Open
cwa	Dry-weather SSO discharge to waters of the U.S. that may endanger health or the environment	Jan 29, 2024	—	Open
cwa	Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment	Jan 22, 2024	—	Open
cwa	Dry-weather SSO, no discharge to waters of the U.S., not permit compliant, no endangerment	May 2, 2023	—	Open
cwa	Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment	Mar 16, 2023	—	Open
cwa	Dry-weather SSO, no discharge to waters of the U.S., that may endanger health or the environment	Aug 16, 2022	—	Open
rcra	Standards Applicable to Generators of HW: Manifest Requirements Applicable to Small and Large Quantity Generators	Dec 9, 2014	Jun 21, 2015	Resolved
cwa	Schedule Event achieved late but reported	Feb 19, 2005	—	Open
rcra	Standards Applicable to Generators of HW: Pre-Transport Requirements Applicable to Small and Large Quantity Generators	Jul 11, 1995	Nov 16, 1995	Resolved

Discharge Limit Exceedances

Instances where this facility's reported discharge monitoring results exceeded its permitted limits under the Clean Water Act. Exceedance percentage shows how far over the permit limit the discharge was.

Pollutant	Violation	Reported	Limit	Exceedance	Period	Status
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,413.60 MPN/100mL	406.00	+248%	Apr 2025	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,268.80 MPN/100mL	406.00	+213%	Mar 2025	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	461.10 MPN/100mL	406.00	+14%	Jan 2025	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	980.40 MPN/100mL	406.00	+141%	May 2024	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	640.50 MPN/100mL	406.00	+58%	Dec 2023	Open
Chlorine, total residual	DMR, Limited - Numeric Violation	1.22 mg/L	1.00	+22%	Nov 2023	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	658.60 MPN/100mL	406.00	+62%	Apr 2023	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	2,419.60 MPN/100mL	406.00	+496%	Aug 2022	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	2,419.60 MPN/100mL	406.00	+496%	Feb 2022	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	437.40 MPN/100mL	406.00	+8%	Jan 2022	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	547.50 MPN/100mL	406.00	+35%	Nov 2021	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	547.50 MPN/100mL	406.00	+35%	Mar 2021	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,011.20 MPN/100mL	406.00	+149%	Jan 2021	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,299.70 MPN/100mL	406.00	+220%	Jan 2020	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	461.10 MPN/100mL	406.00	+14%	Dec 2019	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,413.60 MPN/100mL	406.00	+248%	Jan 2019	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,986.30 MPN/100mL	406.00	+389%	Sep 2018	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,119.90 MPN/100mL	406.00	+176%	Apr 2018	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,299.70 MPN/100mL	406.00	+220%	Apr 2017	Open
Chlorine, total residual	DMR, Limited - Numeric Violation	0.87 mg/L	0.85	+2%	Aug 2016	Open
E. coli, colony forming units [CFU]	DMR, Limited - Numeric Violation	1,046.20 MPN/100mL	406.00	+158%	Feb 2015	Open

Enforcement Actions

Formal enforcement cases brought by the EPA or state agencies, including administrative orders and civil penalties assessed. Penalty amounts reflect what was formally assessed, not necessarily what was collected.

WRITTEN INFORMAL

RCRA (Hazardous Waste) · Case RCRA-NHD986483386-001 · Jul 2, 2015

INFORMAL WRITTEN NOTIFICATION

RCRA (Hazardous Waste) · Case RCRA-NHD986483386-000 · Nov 16, 1995