Holistic Vision Brings Lasting Solution to Reducing CSOs

Combined sewer overflows (CSOs) are a chronic problem for many communities in the Northeast. When a consent decree arrives at a municipality’s doorstep, a common reaction is to immediately start making changes to achieve compliance, but I have seen how a long-term, holistic approach is the only way to truly fix the underlying problem.  Embarking on a long-term strategy can be a daunting endeavor, but when implemented correctly it can produce significant cost savings and lasting results.   

The ten-year-long project the Town of Madawaska, Maine began in 2008 is a great example of how such a strategy is a possible and powerful approach for any municipality, no matter their size. Madawaska, which sits in America’s most northeastern county, has a population just north of 4,000 and an average snowfall of 112 inches a year. Before their project began, the town’s combined sewer collection system, composed of 100-year-old vitrified clay and asbestos-cement pipes, had an average of ten overflow events per year and substantial infiltration. Since the improvements began in 2011, the town has had only three CSO events and average daily flow to the wastewater treatment facility has been reduced by approximately 230,000 gpd. While the project is discussed in detail in the latest edition of the NEWA Journal, I wanted to outline some of the aspects of this project that made it successful. 

Holistic vs. End of Pipe Approach

Due to the age and condition of the pipes, our initial engineering evaluation recommended that the town take a holistic approach to fixing the problem instead of an end-of-pipe solution. Through TV inspections and smoke and dye testing, the town uncovered high priority areas to focus their efforts. With the high priority areas identified, the project was broken up into distinct phases: initial phases focusing on the Fraser pump station collection system area, as this area of the collection system had a high concentration of I/I due to sewer pipe and manhole deficiencies and the following phases focusing on the Main pump station collection area with the goal of maximizing the amount of extraneous flow removed early in the implementation.  

In both stages, mechanical issues, as well as sewer pipe and manhole deficiencies, were addressed.  Addressing just the mechanical issues would have had a large impact on the mitigation of future overflows; however, the aging pipes and poor condition of the collection system would continue to let in a high volume of I/I and eventually fail, requiring expensive emergency repairs. Using the findings of TV inspection, smoke and dye testing, and the staff’s historical knowledge to prioritize replacement, Madawaska undertook an ambitious series of sewer system upgrades. Approximately 47,000 feet of sewer lines have been replaced to date, meaning approximately 45 percent of the system has been upgraded since the original CSO master plan was approved.

Funding the entire vision

We developed the town’s ideal plan for the project before going out and pursuing funding opportunities. As many of us who work with municipal utilities understand, coming up with a project design is not nearly as difficult as finding the funding to make that project a reality. However, with our experience with funding, we understand how important it is to go after the full amount necessary for lasting change. We pursued several different funding sources from state and federal agencies. The largest funding was a $1.98 million loan and a $4.72 million grant from the United States Department of Agriculture Rural Development program. An additional $2 million came from an Economic Development Administration grant, with a further $1 million loan from MEDEP with $300,000 in principal forgiveness. This total package allowed the work to be completed in a few years, rather than over a much longer period, and leveraged the town’s share of the cost.

Community Outreach for Lasting Change

In addition to the physical upgrades, the project included a public engagement program and the establishment of an ordinance to address illegal connections and support the system long-term. This began with a house-to-house inspection program to locate sump pumps, roof drains, and floor drains that were connected illegally and public outreach about the new sewer ordinance’s penalties for non-compliance. The inspections were overseen by the engineer, but were conducted by local high school students with an interest in engineering, with engineering interns performing much of the data management. This helped control costs, created a valuable educational opportunity, and helped connect local students with municipal leaders, staff, citizens, and the community infrastructure.

 

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Brent Bridges

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