Glens Falls sewer line split yields clean results

The city has been separating some of its water from the rest of the flow. Over the last several years, a $17 million project has separated stormwater from the Glens Falls sewer line - and the change has gone on to pay dividends.

GLENS FALLS, N.Y. (NEWS10) - The city has been separating some of its water from the rest of the flow. Over the last several years, a $17 million project has separated stormwater from the Glens Falls sewer line - and the change has gone on to pay dividends.

This week, the city released data on why the separation matters. The process has reduced the amount of sewage to bypass (overflow) through the Glens Falls Wastewater Treatment Plant and into the Hudson River by as much as 85%. 50% fewer bypasses have been seen overall, according to Mayor Bill Collins. Sewage that does make it into the plant is blended with treated water and let into the Hudson River, at what the city says is a minimal impact on the water.

The short version: Separating the flows into their own sets of pipes means less sewage getting caught up in the stormwater flow and making it into the Hudson River. That's good as it is on a day with clear skies, but quite another when it rains.

“Glens Falls and the surrounding area have experienced an increase of intense rain events over the last couple of years," said Water and Sewer Department Superintendent Bill Norton. "When we receive a large amount of rain in a short period of time, the result is the collection system experiencing a rapid increase in flow, that peaks, and then quickly dissipates."

Sewage is most likely to bypass the wastewater treatment plant when rain falls at a rate of more than 0.1 inches in a 15-minute span, putting more stress on the plant. The more rainfall is spread out over multiple hours, the less likely it is for anything from the sewage pipes to end up touching the Hudson.

The reduction of sewage overflow is gradual, with fewer bypass events being seen over recent periods of rainfall. Sewage flow also enters the Glens Falls wastewater plant via tributaries from Queensbury, Moreau and South Glens Falls, which together contribute about 32% of what the plant handles in a day. And the city hopes to keep improving the way its water flows, especially in regard to new projects on South, Broad, Elm, Warren, Glen, Bay, and Ridge Streets.

"Additional efforts to reduce the stormwater impact on the sanitary sewer line have been made by using bio-retention basins, rain gardens, and dry wells to collect the runoff and allow the water to seep into the ground after receiving any amount of rainfall,” said Collins. “The City of Glens Falls has concentrated on separating the combined sewer systems while performing road construction and repair projects."