Making It: The Giant Underground Tunnels Cleaning Up the Lake
MAKERS: The Northeast Ohio Regional Sewer District
PROJECT: Project Clean Lake
POLLUTION PAST AND PRESENT: Cleveland’s earliest sewer systems emptied raw sewage – from houses, industries, and rainwater on the street – directly into Lake Erie. Even after facilities to treat the water were built in the 1910s, the city of Cleveland continued this practice – and it still happens today during heavy storms. When it rains too much for the sewer system to handle, excess rainwater will overflow into the environment. They’re called combined sewer overflows and, in 2000, more 4.5 billion gallons of combined sewage reached Lake Erie.
TUNNELING FOR A CLEANER LAKE: In 2010, the Northeast Ohio Regional Sewer District launched Project Clean Lake, a 25-year program designed to cut combined sewer overflows by 98%. The plan includes investments in green infrastructure, but at the heart of the project is the storage tunnel project. The Northeast Ohio Regional Sewer District is currently constructing seven tunnels, ranging in length from two to five miles, which will store excess sewage until it can be treated – rather than emptying it into Lake Erie.
DIGGING THE DUGWAY: One of the seven tunnels is the Dugway – which lies on Cleveland’s east side, 200 feet underground. The Dugway is 3 miles long, and digging it out requires the use of a powerful 300-foot-long drilling and conveyor system. “The machine,” as program manager Doug Lopata calls it, inches through the underground shale at five foot increments, and workers help place a concrete lining around the tunnel as it goes.
INVISIBLE CONSTRUCTION: Because these projects are happening below ground, most of the public are completely unware of their existence. “Ultimately, we’re doing a lot of work and effort that no one sees,” said construction supervisor Ryan Sullivan. “But the impact that it has on the lake and the city of Cleveland is so great, that it really makes the job worth it.”