IWEA Abstract
Upper Pogues Run CSO Abatement
“Fitting large tanks into sensitive environments”
Authors:
Ben Reed, P.E., Project Manager, Citizens Energy Group, Indianapolis, IN
Martin Brungard, P.E.,D.WRE, DLZ *
*Corresponding Author:DLZ, 157 E. Maryland St, Indianapolis, IN 46204
Presentation Abstract:
Citizens Energy Group (Citizens) is responsible for abating combined sewer overflows from the Upper Pogues Run basin on the near-eastside of Indianapolis. The project area is predominantly residential with some areas being over 100 years old. A string of city parks straddle the Pogues Run Creek and interceptor sewers draining the area, parallel that creek. Concern for the historic community and city parks resulted in unique solutions for reducing overflows.
An Advanced Facility Plan developed for the project area, evaluated alternatives including green infrastructure construction, building new sewers and tanks, and sewer regulator improvements. The local community’s concern with aesthetics, community disruption, and damage to their parks led to a plan to construct two storage tanks in the city parks with limited new sewer work.
To aid the city park aesthetics, the tanks will be completely buried. Only the equipment buildings for each tank will be above ground and those buildings are designed with architectural features similar to other park buildings. The tanks are situated below the local sewer inverts to enable gravity inflow. This avoids the need for redundant or backup power for high-rate inflow pumping systems.
Conventional construction of these deep tanks would have required large and disruptive excavations that would have destroyed dozens of large trees and occupied large swaths of the parks. Relatively shallow bedrock depth made it more feasible to construct deep tanks and anchor them to bedrock. Therefore, circular shaft-style tank construction was recommended and designed. The resulting shafts are 110 feet deep with 63-foot diameter and 150 feet deep with 30-foot diameter to provide 2.0 and 0.6 MG capacity, respectively. Tangential inlets convey flow into the deep tanks. Effluent depths will be 90 and 120 feet, when the tanks are full. Wet-weather inflows will be stored for up to 2 days before being returned to the local interceptors for conveyance to the treatment plants. Because the tanks can be emptied slowly, small pump sets with 1 and 0.3 MGD capacity will return the stored effluent to the sewers.
Four new diversion structures accept wet-weather inflow while keeping normal dry-weather flow out of the tanks. Eight existing sewer regulator structures will be either modified or replaced to control overflows from the local sewers.
The project design weighed the impacts to the parks and community while keeping capital costs similar to that for the other conventional CSO abatement measures proposed in the facilities plan. While the destruction of mature park lands has quantifiable costs, the effect on the local neighborhoods was incalculable. The limited construction footprint substantial reduces the community impact. The elimination of major sewer construction in the community also reduces community disruption.
The project will be placed in service prior to December 2021 and is anticipated to cost about $35 million to construct.
75 words or less: WHAT ARE THE MAIN PURPOSE AND CONCLUSIONS OF YOUR WORK?
The Upper Pogues CSO Abatement project illustrates how innovative construction features can be employed to avoid disrupting communities and sensitive features while delivering sewer overflow reduction. The deep tank construction methods reduce the tree and habitat loss in the parks and provide fail-safe acceptance of all wet-weather inflows.
References & sources
None
Speaker Bios:
Benjamin Reed is a Professional Engineer with Citizens and he serves as the Project Manager for the Upper Pogues project. He has over 10 years experience with wastewater engineering services.
Martin Brungard is a Professional Engineer with DLZ in Indianapolis withMasters in both Civil and Environmental Engineering. He has provided wastewater treatment and collection engineering services for clients across the country for over 30 years. He served as the planning and design Project Manager for the Upper Pogues project.