Saturday, March 17, 2012

Water, sewage, and Climate Change in the Rochester, NY region


Uninteresting and unappealing as the subject of sewage can oftentimes seem, two news items this week about a couple of our New York State cities’—New York City and Buffalo—sewer systems caught my attention. New York City’s new sewer system plan was hailed as a model of how combined sewer overflows can be significantly reduced and Buffalo was excoriated by the Environmental Protection Agency (EPA) for failing to comply with federal Clean Water Act requirements for combined sewer systems.

What is a combined sewer overflow system (CSO) and why should I care? Glad you asked.

A combined sewer is a type of sewer system that collects sanitary sewage and stormwater runoff in a single pipe system. Combined sewers can cause serious water pollution problems due to combined sewer overflows, which are caused by large variations in flow between dry and wet weather. This type of sewer design is no longer used in building new communities, but many older cities continue to operate combined sewers. Combined sewer - Wikipedia, the free encyclopedia

We here in Rochester, NY were not in the news this week over our sewer system, but just for the record we have a CSO with a lot of storage tunnels. And, that works pretty well in most cases:

“Out of 50-70 wet weather events per year, only 1-2 extreme events generate flows that exceed tunnel capability. However, even during these extreme events, the system still captures more than 99 percent of the total volume of CSOs generated.” THE MONROE COUNTY PURE WATERS PROGRAM … A HISTORY

This all becomes interesting and more meaningful as you pull away from our short-term interests and concerns and get a bigger picture of what might be coming down the tube—so to speak. It’s not good. According to the New York State Department of Environmental Conservation “About ten percent of the CSOs in the United States are found in NYS,” Combined Sewer Overflow (CSO) - NYS Dept. of Environmental Conservation. Add that to the findings of the recent Climate Change study funded by New York State Energy Research and Development Authority (NYSERDA):

Within the state’s urban areas, two other critical water related equity concerns include siting and operation of waste treatment facilities and the widespread use of combined sewer systems. Wastewater treatment facilities are often located in lower-income, minority communities. Under climate change, such facilities may need to be relocated due to rising sea levels or expanded to address new threats to water quality. Combined sewer systems, which collect and treat both municipal wastewater and storm water, are disproportionately concentrated in the state’s older, urban areas (and particularly in neighborhoods with high concentrations of low-income, minority residents). Combined sewer systems contribute to localized flooding and serious water quality problems during periods of heavy rainfall. These flooding events, known as combined sewer overflows (CSOs), are likely to become worse with more frequent heavy rainfall events under climate change. Adaptation planning needs to take into account the concerns of environmental justice communities that are affected by siting decisions and/or CSOs. (Pages 67-68) Report 11-18 Response to Climate Change in New York State (ClimAID).

This means that as our region becomes inundated by the Likely Changes coming with Climate Change, most of the sewer systems around the Great Lakes may be dumping a lot of sewage into the water we drink, bathe, and fish in. This map (the little black dots are CSOs) gives you a nice visual:


Photo from: EPA - CSO Demographics “Combined sewer system are remnants of the country's early infrastructure and so are typically found in older communities. Combined sewer systems serve roughly 772 communities containing about 40 million people. Most communities with combined sewer systems (and therefore with CSOs) are located in the Northeast and Great Lakes regions, and the Pacific Northwest”.

BTW: The ClimAID report mentions our fair city:

The degree to which combined sewer overflows may increase in frequency in a changing climate is dependent on the rainfall threshold at which a combined sewer overflow is initiated in a given sewage system. For instance, the City of Rochester reduced combined sewer overflows by constructing 34 miles of 12-to-16-foot diameter tunnels that can store sewage until it can be treated. While these tunnels will store the combined sewage generated by most rainfall events, Environmental Protection Agency regulations allow up to four combined sewer overflow events per year. An EPA study of the upgraded systems concluded that daily combined sewer overflow discharges could increase by 50 percent with climate change due to two additional large storm events (USEPA, 2008). However, as is often not clearly noted, this 50-percent increase assumes that only four combined sewer overflows currently occur each year. (Page 95) Report 11-18 Response to Climate Change in New York State (ClimAID).

If you are starting to get alarmed, you’re getting my point: We might be doing OK if Climate Change were not in the picture. But it is. Extreme weather events, including large storms, can very well happen with more frequency than our present CSOs can handle. Our Great Lakes could become extremely polluted.

NYS Senator Schumer gets it on how we need to update our aging sewer systems and knows it’s going to cost a lot of money:


But our senior senator from New York does not mention Climate Change in his press release. So, the money he’s talking about probably won’t cover the kind of change that needs to be made to our waste water infrastructure as large storms threaten to overwhelm our sewage systems. Our county doesn’t mention Climate Change in their description of our waste water system: pure waters. The NYS DEC does mention Climate Change, including a spot on reference:

“Klaus Jacob, from Columbia University, and Betsy Blair, from the Hudson River National Estuarine Research Reserve described the expected impacts of sea level rise in the Hudson. The predicted sea level rise of between 4 and 33 inches in the Northeast by the end of the century, coupled with increases in extreme weather events, pose a threat to low lying transportation and sewage treatment plant infrastructure” Hudson Valley Climate Change Conference, December 4, 2006 - NYS Dept. of Environmental Conservation

Yet, this issue where our waters might easily become inundated by sewage overflows as Climate Change worries our environment has found little traction with the public. That matters because without public awareness of this issue, coupled with the Climate Change element, few funds are going to be squeezed by an already financially stricken public who’d rather not think about sewage at all.

However, it makes little sense to make recommendations for buttressing our wastewater infrastructure without mentioning Climate Change because not only are our sewer systems getting old, they were planned for a planet that doesn’t exist anymore. This planet, the one we plan to get drinking water from for some time into the future, is warming up, and your grandmother’s sewage system just won’t do.

* To learn more about water quality issues in our Rochester, NY area, check out these two events:

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