Client: Hammond Sanitary District

Location: Hammond, Indiana

The Hammond Sanitary District retained Donohue to update its Long Term Control Plan (LTCP). The District serves approximately 100,000 residents and its collection system contains over 100 CSO diversion structures, 13 CSO outfalls, and combined, separated, and partially separated portions of the collection system.

Donohue has developed a robust MIKE URBAN hydrologic/hydraulic model capable of simulating dry and wet weather flows from the varied service areas including direct runoff and rainfall dependent inflow and infiltration. The calibrated model includes 350 subcatchments, 1,136 nodes, 109 CSO diversion structures, 13 CSO pump stations, and 9 sanitary/collector pump stations.

Other tasks include updating dynamic HEC-RAS models of the receiving streams to simulate the water quality impacts of CSO discharges, a Stream Reach Characterization Evaluation Study (SRCES), evaluating pump station SCADA data, assessing financial capability, preparing an implementation schedule, developing post-construction monitoring program, coordinating public and regulatory agency involvement, and assisting with negotiating a new Consent Decree with the U.S. EPA Region V.

The CSO abatement alternative analysis included single-event and long-term simulations and includes the following alternatives: sewer separation, remote storage/treatment, increased conveyance, centralized storage, increased treatment capacity, and combinations thereof.