Edgewater swimming advisory posted after Thursday night sewer overflow
Heavy, sudden storm burst triggers combined sewer overflow at Edgewater Beach, second this month
The Northeast Ohio Regional Sewer District has posted a public advisory this morning at Edgewater Beach due to a combined sewer overflow (CSO) event around 9:45 last night, the result of elevated storm levels that briefly exceeded the capacity of the sewer system, discharging a combination of sewage and stormwater into Lake Erie.
Visitors — particularly children, the elderly, and those in ill health — are advised to avoid contact with the water and wood debris while the advisory is posted.
Last night’s overflow at this location is the third of the 2025 swimming season, the others occurring on June 14 and July 16. While the number of combined sewer overflow events at this location continues to decrease annually, every event raises logical questions about the response, causes, and system improvements — both ongoing and future plans.
The answers are worth talking about.
How we respond to overflow events
When our crew’s overflow alarms sound, no matter the hour, staff respond to the beach to verify the event, document the visible details, and secure the area for the safety of beachgoers using temporary fencing until the restoration work is completed with the help of Cleveland Metroparks. We also post additional signs to notify visitors of the overflow and the resulting advisory.
Regarding water quality, Sewer District crews sample water twice daily (collecting afternoon samples in addition to the already daily morning collection) at 10 locations at Edgewater Beach — five locations close to the beach, and five further from the shore but still within common swimming range — beginning today.
The samples will be tested to determine if E. coli bacteria levels are elevated. Results will be available 24 hours after the sample is collected. Once these daily samples are below the federal and state advisory standards of 235 (which equates to colony counts of E. coli per 100 milliliters of water), the advisory will be lifted, and the Sewer District will discontinue the twice-daily sampling.
You can learn more about Edgewater water quality daily predictions and E. coli test results at neorsd.org/beaches.
What causes combined sewer overflows
Much of Cleveland exists atop a combined sewer system, a network of sewers that carry sanitary sewage (waste from your house) and stormwater in the same pipes to maximize the volume of water being collected, moved, and eventually treated.
When heavy storms produce large volumes of surface runoff, combined sewers may not be able to handle the increase. For this reason, rather than having sewage back up into homes or treatment plants, relief points were designed in the system years ago to release the combined flow to the environment. Those points are called combined sewer overflows, or CSOs.
While state of the art in the late 1800s (the outfall at Edgewater Beach dates back to 1898), combined sewers and their outfalls became a challenge as development advanced in the first half of the 20th century. More frequent overflows were the result, and changes were needed.
The large hinged flap gate at the Edgewater Beach that keeps the outfall closed in dry conditions weighs thousands of pounds and is not actuated by any mechanism or armature. The only thing that causes the flap gate to open during an overflow event is the sheer force of flow and volume behind it as can be seen in this 2023 Edgewater overflow footage.
Learn more about combined sewers, weather patterns, and solving legacy environmental problems like combined sewer overflows in these select episodes from our Clean Water Works Podcast.
Improvements to the Edgewater sewer system
Built in the late 1880s, the combined sewer outfall at Edgewater discharged a mixture of sewage and stormwater into Lake Erie approximately 40 to 50 times per year through the mid-1970s. That’s no longer the case.
Since its inception in 1972, the Sewer District has invested billions in sewer and stormwater projects across the entire service area. Early work included improving and building new infrastructure, such as the Northwest Interceptor, which resulted in combined sewer overflow discharges significantly decreasing, particularly here at the Edgewater outfall where events now occur an average of less than twice a year.
A closer look at the annual totals, the Edgewater outfall had one event in each of the years 2021 and 2022, three overflows in 2023, and one in 2024.
Built in the late 1880s, the combined sewer outfall at Edgewater discharged a mixture of sewage and stormwater into Lake Erie approximately 40 to 50 times per year through the mid-1970s. That’s no longer the case.
The Edgewater portion of the Northwest Interceptor begins at W. 117 and ends at the Westerly Wastewater Treatment Plant located by the Edgewater Marina, collecting sewage from homes and businesses on the west side of Cleveland to Kamm’s Corner.
Eliminating other combined sewer overflows in the region
One of the Sewer District’s largest capital expenditures is Project Clean Lake, a $3 billion 25-year infrastructure investment program addressing combined sewer overflows, a legacy challenge in nearly 800 cities across the country — including Cleveland, Columbus, Akron, and Cincinnati.
Combined sewers were once a state-of-the-art waste management system. Now, they must be addressed to reduce the volume of pollution entering waterways. In the Sewer District’s service area, CSO discharge points are in Cleveland and inner-ring suburbs, including Garfield Heights, Maple Heights, Brooklyn, and East Cleveland.
Since the start of Project Clean Lake in 2011 when combined sewer overflow totals were 4.5 billion gallons per year, the Sewer District has eliminated 2 billion gallons of annual overflow volume. More than 2 billion additional gallons will be captured annually once Project Clean Lake construction is completed in 2036.
Because of Project Clean Lake and other capital investments, the Sewer District has successfully reduced the number of permitted combined sewer overflow discharge points from 126 to 112.
Project Clean Lake includes, in part, the construction of seven large-scale storage tunnels large enough for a semi-truck to drive over 20 miles:
- Euclid Creek ($213M, now online)
- Dugway ($155M, now online)
- Doan Valley ($155M, now online)
- Westerly ($146M, now online)
- Shoreline ($223M, complete in 2025)
- Southerly ($358M, now under construction, complete in 2029)
- Big Creek ($239M, design and construction 2027–2033)
