Green Infrastructure Design
In 2009, the City of Huntington adopted a Long-Term Control Plan (LTCP) to help reduce its combined sewer overflow (CSO) discharges into waterways. The $64 million capital improvement plan included $2 million for green infrastructure to either reduce stormwater entering the combined sewers or improve the quality of the runoff. However, the original LTCP did not address how to spend this set aside.
Huntington hired Lochmueller Group (Lochgroup) to find the most cost-effective uses of sustainable design. The resulting study evaluated several options and recommended $2.3 million in green projects that would improve water quality, as well as projects to provide energy savings at the wastewater treatment plant. Lochgroup also advised Huntington on opportunities for grants and other financial incentives to further stretch their infrastructure investment.
Sustainable alternatives were evaluated in part by weighing the amount of time it would take for the investment to pay for itself via cost savings and whether a project would simultaneously meet other city initiatives, such as downtown revitalization or expanding its greenways.
Throughout the development of this Green Infrastructure Study, Lochgroup worked closely with city personnel to ensure that its recommendations were specifically tailored to Huntington’s needs.
Recommendations included the following:
- Replacing the wastewater treatment plants 4 aging centrifugal blowers with high-efficiency turbo blowers that provide energy savings, lower maintenance costs, quieter operation, and a smaller footprint. Lochgroup’s calculations found replacement of the blowers would pay for itself with cost savings in 8 years.
- Incorporating sustainable infrastructure such as rain gardens, vegetated swales, and permeable pavement into construction of the 5 CSO interceptors already planned for installation by the LTCP to reduce the volume and increase the quality of stormwater runoff.
- “Green street” improvements such as infiltration planters and vegetated curb extensions, for the interceptor proposed through the City’s downtown. This would not only help to manage stormwater runoff but would also beautify the streetscape, making the downtown area more aesthetically appealing and helping to create a greater sense of community pride.
Lochgroup also evaluated the City’s LTCP for potential cost savings. By recommending a unique design for its wet weather treatment facility, Lochgroup was able to reduce the size of several components and eliminate the need for an expensive high-rate clarification process. This cut the overall cost of implementing the LTCP by $10.9 million.