Over the past several decades, regulatory requirements related to combined sewer systems have changed several times, and it can be hard for most municipal governments to stay informed of the changes and their requirements to comply. This is why HRG’s relationship with Steelton Borough has been so valuable. For more than a decade, we have guided them through the regulatory requirements, culminating with the separation of a portion of their combined sewer system in the eastern section of town.
Beginning in 2002 when the Pennsylvania Department of Environmental Protection issued its Combined Sewer Overflow Policy, we helped the borough meet its requirements by:
- Obtaining an NPDES General Permit;
- Implementing a Nine Minimum Controls (NMC) Plan that reduced the pollution caused by CSOs with quick measures requiring no construction or major engineering studies; and
- Implementing a Long Term Control Plan (LTCP), which ensured that combined sewer system effluent met Clean Water Act standards (thereby protecting watersheds, aquatic life, and human health).
In developing the LTCP for Steelton, we identified the need to separate a portion of their combined sewer system known as the “T” Street Drainage Basin. The “T” Street diversion chamber was the second largest drainage basin in the borough with the largest volume of overflow during storm events, and it did not achieve the required 85 percent capture for the five storm events we evaluated.
Therefore, we designed 7,200 feet of new storm sewer, ranging from 15 to 48 inches in diameter, which would be installed adjacent to the existing combined system and would carry stormwater exclusively. We also rehabilitated the old combined system to carry sanitary system flows only. By separating the storm and sanitary flows, we were able to abandon the diversion chamber.
This project completely eliminated overflow events in the borough and removed Steelton from the list of approximately 130 CSO communities in Pennsylvania. It also significantly decreased the flow conveyed to the borough’s three pumping stations and the local water treatment facility during precipitation events.
Well aware of the budgetary limits municipalities must face, HRG took special care to phase the timing of this work, to complete the LTCP as an Act 537 Plan so that the borough would be eligible for partial reimbursement of the cost, and to expedite the completion of design plans for the sewer separation project in order to meet deadlines for several grant and loan programs. Thanks, in part, to this effort, the borough obtained a low-interest loan for $4.7 million from PENNVEST.
