Pumping away combined sewer overflows

摘要

Age and location have conspired against Cleveland. The city's century-old combined sewer system discharges into Lake Erie, a state EPA-designated "sensitive receiving water." The end result: a 2011 consent decree giving the Northeast Ohio Regional Sewer District 25 years to lower illegal discharges from 4.5 billion gallons to 494 million gallons a year. Begun in 2012, the second major component of the district's $3 billion Project Clean Lake long-term control plan is a rather unusual solution to the problem of undersized wastewater facilities: a pump station 240 feet below ground that stores combined sewer overflows during peak wet weather events. Once flows subside, the facility will dewater the storage tunnels and pump flows into the Easterly Interceptor where it will be conveyed by gravity to the Easterly Wastewater Treatment Plant.