ROCHESTER, N.Y. (WROC) — In his own words, Mike Garland, Director of the Monroe County Department of Environmental Services, calls our sewage system the envy of other municipal areas. Namely for its efficiency and its protection of our local waterways.
In the 1970s, Monroe County was just one of three major metropolitan areas to use federal funding to update their sewer systems to minimize the amount of raw sewage that was dumped in local waterways and improve water quality.
Even with today’s increasingly heavy rain, the system is still performing as designed.
“CSOAP is a Combined Sewer Overflow Abatement Program tunnel system,” said Garland. “So, when there’s significant rainfall, those pipes can overflow, and in most cities these they would overflow to local water bodies. In this case, here in Monroe County they would overflowed Genesee River or Irondequoit Bay and out into the Lake Ontario embayment, so it was roughly ten years in the planning and design before construction began.”
Combined sewer systems, where storm water and raw sewage enter the same network of pipes are common in many older cities across the United States. Including Rochester, Buffalo, Syracuse, Albany, and New York City. In Rochester, prior to the implementation of CSOAP 60-90 overflows occurred each year now even after one of our wettest summers on record it remains a fraction of that.
“We had nine very significant wet weather events that exceeded the capacity of our tunnel system. Typically, we see maybe three to four on average about three instances where we have a wet weather event that exceeds the capacity of the system.” said Garland.
This is all as we continue to see the higher daily rainfall totals on the wettest day of the year in Rochester according to Climate Central. Adding further strain to not only our system but others across New York State.
In Rochester, with C-SOAP in place, the sewer system can process approximately 2 inch an hour rainfall rates depending on how widespread the rainfall is before an overflow could occur.
“[A] quarter of inch of rain per hour, depending on how widespread it is in the duration, will generally convey water into the tunnel system, and after about two inches per hour, depending on how widespread it is in the duration, it could challenge the capacity of the tunnel system. Which has a storage capacity of 175 million gallons,” said Garland.
To further alleviate the strain on these systems, Dr. Shirley Clark, a professor of environmental engineering at Penn State, suggests that more green infrastructure along with other abatement techniques could be a long-term solution if the work is done fast enough.
“[Combined sewer systems] don’t overflow until you get a rain event, so they’re not overflowing on a daily basis. It is these heavy rain events, so the problem is, they’re putting a lot of investment into, you know, a combination of this green infrastructure, rain gardens […] on the top of the surface. As well as then also looking at where they could put in storage or bigger piping etc,” said Dr. Clark. “[But] can that work be done to get that additional capacity and treatment faster than the weather is changing?”
Green infrastructure, and other storm water diversion techniques such as rain barrels, are highlighted in Rochester’s 2019 Climate Change Resilience Plan with several test projects underway. Another major boon for greenspace may also come from the forthcoming Inner Loop North project which under the preferred concept could add an additional 8 acres or so of greenspace to the city of Rochester.