CSO/SSO Information Page

Public Advisory and Sign-up Information

Click Here for the CSO Notification/Public Advisory Page, where notice will be posted in the event of a combined sewer overflow (CSO) event.

Updated 2023 NPDES Permit

Town of Montague NPDES Permit No. MA0100137


1. During wet weather, the permittee is authorized to discharge combined storm water and wastewater from the CSO outfalls listed below:

Outfall Latitude Longitude Description

01 42° 34' 45" N 72° 34' 24" W Greenfield Road near WPCF

02 42° 36' 16" N 72° 33' 38" W Adjacent to Power Canal

2. The effluent discharged from these CSOs is subject to the following limitations: a. The discharges shall receive treatment at a level providing Best Practicable Control Technology Currently Available (BPT), Best Conventional Pollutant Control Technology (BCT) to control and abate conventional pollutants and Best Available Technology Economically Achievable (BAT) to control and abate non-conventional and toxic pollutants. The EPA has made a Best Professional Judgment (BPJ) determination that BPT, BCT, and BAT for combined sewer overflows (CSOs) include the implementation of the Nine Minimum Controls (NMC) specified below. (1) Proper operation and regular maintenance programs for the sewer system and the combined sewer overflows. (2) Maximum use of the collection system for storage. (3) Review and modification of the pretreatment program to assure CSO impacts are minimized. (4) Maximization of flow to the POTW for treatment. (5) Prohibition of dry weather overflows from CSOs. (6) Control of solid and floatable materials in CSOs. (7) Pollution prevention programs that focus on contaminant reduction activities. (8) Public notification to ensure that the public receives adequate notification of CSO occurrences and impacts. NPDES Permit No. MA0100137 Page 8 of 17 (9) Monitoring to effectively characterize CSO impacts and the efficacy of CSO controls.

CSO Outfall Locations/Map

Potentially Affected Communities

CSO Long Term Control Plan Summary

Click Here for the most recent LTCP update. Note that this document and related appendices can also be downloaded through the file module on the CSO Public Advisory/Notification Page. Please scroll down on that page to access this archive.

Public Advisory and Sign-up Information

Click Here for the Public Advisory Page

Blending Information

The Town of Montague practices blending, which involves the use of a special tank at the wastewater facility during high flow/wet weather events to help buffer the CSO discharge, mitigating untreated sewage from exiting the CSO. The tank is equiped wth an automatic valve and chlorine dosage system in order to disinfect and partially treat the wastewater before it is blended with the normally treated final effluent and discharged to the recieving waters. This is done in order to reduce pathogens and protect public health.

CSO/SSO Reports and Files

Montague's CSO outfalls are located along the Connecticut River, adjacent to Power Street (downstream of the Turners Falls Dam) and Greenfield Road (below the Poplar Street put-in) in Turners Falls. CSO events may impact these area and any areas downstream as deicted in the mas above.

CSO overflows include stormwater that include, or likely include, some quantity of untreated or partially treated sewage and waste.

Precautionary measures to be taken by the public following a CSO discharge event:

Avoid contact with these water bodies for 48 hours after the discharge or overflow ceases due to increased health risks from bacteria and other pollutants. See above for more information on whether specific resource areas, such as bathing beaches, are affected.

Report of Recent CSO Events:

05/27/2024 CSO Event at the Greenfield Road (MON001) Duration of 0 hour and 40 minutes beginning at 2:00PM with released quantity estimated volume of 8,201 gallons. Water body affected: Connecticut River.

05/21/2024 CSO Event at the Greenfield Road (MON001) Duration of 1 hour and 10 minutes beginning at 6:20PM with released quantity estimated volume of 8,201 gallons. Water body affected: Connecticut River.

03/07/2024 PARTIALLY TREATED discharge through wastewater facility's final effluent outfall (CWF001.)Duration of 1 hour and 20 minutes beggining at 02:20AM, ending at 03:40AM with released quantity estimated volume of 12,000 gallons. Water body affected: Connecticut River. (CL)


Note: Immediate public notifications present the three-year average discharge associated with each of our three CSO regulators, as in the table below. Because these represent historical averages, they may over- or under-state the quantity released for any given event. Amended values are presented in the CSO Event Log, which appears in the file module, further below. Those values are as follow:

Montague 3yr CSO Overflow Average per Incident 

2020 - 2022 (gallons)







Previous Monthly CSO Reports and Discharge Data Appear in Reports Provided Below