Ohio Cities to Check Sewers in Effort to Curb CSOs

The Ohio Environmental Protection Agency approved an agreement with more than 20 suburban communities whose sewer collection systems tie into the city of Columbus' sewer system and wastewater treatment plants, according to a Feb. 17 press release.

The goal of the agreement is to protect public health and the environment by reducing the inflow of clean stormwater into the sanitary sewer system. Excessive stormwater causes sewer overflows, backed-up sewers, and bacterial contamination throughout the metropolitan area.

"This plan will allow Ohio EPA and the communities to work collaboratively to help solve the problems created by aging sewer systems, while improving water quality and reducing the user fees that Columbus would otherwise have to charge to treat this water," said Ohio EPA Director Chris Korleski.

Participating suburbs and sewer districts include: Bexley, Dublin, Gahanna, Grandview Heights, Grove City, Groveport, Hilliard, Jefferson Water and Sewer District, Marble Cliff, Minerva Park, New Albany, Obetz, Reynoldsburg, Riverlea, Shawnee Hills, Urbancrest, Upper Arlington, Westerville, Whitehall, and Worthington. Franklin County also has participated in this effort and intends to take the agreement to the county commissioners for final approval in March. The villages of Brice and Valleyview did not actively participate in the process of crafting the agreement and have yet to formally approve the plan. While Ohio EPA hopes to still secure an agreement with these communities, the agency will seek other enforcement avenues if necessary to ensure that all communities are doing their part to address their respective share of the system.

"I want to express my appreciation to the mayors, village administrators, city council members, and many others for their extraordinary support of this plan," Korleski said. "This will be a great achievement when all communities involved implement the work under this agreement."

These "satellite" communities don't treat their own sewage. Instead, they send it through the Columbus sanitary sewer system for treatment at the city's Southerly and Jackson Pike plants. During large storms, rainwater enters the sewers through cracks and improper connections and overloads the sewers or the treatment plants.

Under the agreement, the suburbs will investigate their own sewers over the next several years to determine where excess stormwater and groundwater enters their systems and develop plans for correcting any deficiencies. Each community will submit its evaluation study plan within six months. This work will help Columbus meet its commitment to Ohio EPA to improve water quality in the region.

Ohio EPA has just approved Columbus' wet weather management plan. When the plan is implemented, there will be a dramatic decrease in sewer overflows and basement backups that occur in the city of Columbus' service area after rains and snowmelt. The total cost for the projects in the wet weather management plan is $2.5 billion (in 2005 dollars).

Interim projects currently under way are expected to reduce sewage discharges by approximately 540 million gallons in a typical year by 2010. The Columbus sewer system currently discharges approximately 1.65 billion gallons of sewer overflow in a typical year. By 2025, these overflows will be reduced to a total of approximately 250 million gallons. Once all projects are complete, remaining overflows from the system may be reduced to approximately 100 million gallons per year on average.

This remaining overflow volume will not violate the water quality standards that protect human health and aquatic life. This is primarily due to the relatively short duration of the discharge (approximately 15 hours total in an average year) and because the discharge will be to the Scioto River during high flows, allowing significant dilution of the remaining overflow.

Ohio EPA's approval letter for Columbus' wet weather management plan is at www.epa.state.oh.us/dsw/cso/columbus_ltcp.html. The orders that embody the agreements with the suburban communities are also online at www.epa.state.oh.us/dsw/enforcement/enf_actions_2009.html.