B&N is helping the City of Columbus, Ohio, take a new, greener approach to remedy sanitary sewer overflows (SSOs). To lessen the impact of SSOs on the environment, the City is operating under directives from the U.S. EPA and Ohio EPA using a multi-step approach to address the SSOs.
Blueprint Columbus is the City’s pilot program to implement environmentally sound Green Infrastructure (GI) solutions that can reduce SSOs. B&N is leading a Blueprint Columbus project in a 115-acre Clintonville neighborhood to evaluate, develop, design and implement GI solutions.
Bio-Basins to Improve Stormwater Management
When stormwater runoff from private properties goes to building foundation drains and/or low lying yard areas, the runoff can enter the sanitary sewers. B&N proposed a series of bio-basins (also known as rain gardens) within the neighborhood right of way, between the curb and property boundary or sidewalk.
Stormwater runoff will be routed to the bio-basins through openings in the roadway curb. The bio-basins filter the runoff through a top layer of permeable engineered soil and plants and a layer of gravel. An under drain at the bottom will route the runoff to the storm sewer. The bio-basins will provide additional storage for stormwater runoff and also improve the quality of stormwater being discharged into streams.
Private Property Enhancements to Reduce I/I
A key component of the plan to reduce SSOs includes reducing the amount of rainfall-induced I/I to the sanitary sewer from private sources, such as roof runoff and sewer laterals. I/I can be decreased through rehabilitating sanitary main lines and enhancing private property drainage systems and sanitary sewers.
B&N is assisting with private property enhancements, including lateral lining, redirecting downspouts and sump pump program implementation to remove flows from the sanitary sewers and reroute them to the stormwater system. Because the rerouted flows could overburden the stormwater system, the bio-basins that will provide additional storage and treatment will be built first.
Key features of the Blueprint Columbus project include:
- Cleaning and televising sanitary laterals and storm sewers
- Performing detailed field investigations and locating downspouts
- Hydrological and hydraulic modeling of the study area stormwater system to identify Green Infrastructure storage and treatment capabilities
- Identifying and recommending cost-effective improvements
- Leading the downspout redirection and lateral rehabilitation for private properties
The project started in May 2013 and currently is underway.