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Combined sewer overflows

The Board organized a meeting of officials from the thee levels of government on the U.S. and Canadian sides of the border for a discussion regarding combined sewer overflows (CSOs) in Calais and St. Stephen, which occasionally overflow and discharge a mixture of sewage and stormwater into the St. Croix River.

Combined sewer systems are designed to transport both sanitary sewage and stormwater in a single pipe to a treatment facility. The capacity of these systems may be exceeded in periods of heavy rainfall or wet weather resulting in direct discharges of untreated wastewater to receiving environments. These overflows are referred to as combined sewer overflows or CSOs.

Presentations regarding CSOs and actions being taken to eliminate them from their respective sewer systems were given by Anna Leis Hafford (Olver Associates) on behalf of City of Calais and Grant Godfrey, a consultant to the Town of St. Stephen.

Presentations were also given by Ed Logue from the Maine Department of Environmental Protection (MDEP) regarding the State´s CSO program and by Carol Wood from the U.S. Environmental Protection Agency (EPA), Region 1 (New England) regarding the U.S. Federal approach to the elimination of CSOs. Tim LeBlanc from the New Brunswick Department of the Environment described the Province´s approach to CSOs.

The major conclusion of these presentations and discussions is that eliminating CSO´s is an extremely costly venture that competes for limited resources with other essential services, e.g., maintaining safe and secure supplies of drinking water. Consequently, efforts to deal with this issue are necessarily being made over a long term planning horizon.

See the following documents related to this part of the meeting:

• CSO meeting summary
• Appendix 1: key points from the presentations
• Appendix 2: handout provided by Olver Associates on Calais
• Appendix 3: overview of the CSO issue provided by MEDEP and EPA.

August meetings and site visits

• The next Board meeting, Public Meeting and site visits will take place week of August 18-22.
• Board Meeting and Public Meeting will take place in McAdam, NB.
• The Board will visit the Grand Falls dam on the Saint John River following the St. Croix activities.

Work planning

Status of 2004-2007 Work Plan:

• GIS mapping completed
• Modelling completed
  • Add an Executive Summary to the HMS Model report
• State of the Watershed Report:
  • First draft out for review
  • Remove estuary section at end of the report but ensure that relevant data is retained as appropriate.
  • Prepare Press Release prior to August release at Public meeting
  • Prepare a cover letter from the Board Chairs

2008 - 2011 Work Plan:

• Potential water quality projects, e.g.:
  • Update and interpret the watershed´s long term lake quality database
  • Assess impacts of Combined Sewer Overflows
  • Possible public education project re: non-point sources of pollution
• Bathymetric mapping of major reservoirs
• Update Watershed Directory
• Others?

Actions/next steps

• Secretaries to work with FB Environmental to finalize revisions to the State of the Watershed Report
• Corps to prepare Executive Summary for HMS Report provide to Board Secretaries for review
• All to bring project ideas forward for 2008-2011 Work Plan

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