Aquarion Engineering Services
222 St. John St.
Portland, ME 04102
207-828-1272
Fax 207-774-6907
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CSO Mitigation
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Infrastructure Design | Stormwater Phase II Compliance | CSO Mitigation

Combined Sewer Overflow (CSO) mitigation is a challenge that faces many municipalities. Aquarion has been involved in numerous CSO facility plan studies, as well as the sewer separation designs and wet weather mitigation master plans resulting from such studies. Plus, we have served as liaison to the Departments of Environmental Protection for many of our clients.

Aquarion has coordinated detailed mapping programs, isolated night flow gauging, and TV monitoring of sewer collection systems. The results of the data collected serve as a basis for designing remedial actions to abate CSOs. Actions range from flow slipping, elevating overflow weirs, and installation of backflow preventers to upgrading of pump stations and treatment facilities to accept projected wet weather flows.

For more information contact Stephen Bradstreet. sbradstreet@aquarion.com

  
CSO Mitigation Case Study
Fairfield Combined Sewer Overflow Study—Fairfield, Maine
Typical of Maine communities, Fairfield’s sewers were constructed on the combined sewer principal and carry both sanitary wastewater and street drainage. Recently, heightened concern with the water quality impacts of these discharges has resulted in regulations that require elimination or treatment of such overflow. Aquarion’s Phase I study was directed at development of a cost effective program of phased stormwater separation from the sanitary sewer system.

Aquarion conducted a field reconnaissance of stormwater drainage areas to delineate catch basin and culvert catchment areas. Our report presented the methods for determining stormwater drainage areas and calculating stormwater volumes, costs of separation projects, and the comparison of separation costs to the volume of stormwater being removed. Aquarion is now contracted to prepare construction documents for the separation of stormwater and sanitary sewer for seven of the projects recommended in the report.