Community partnership uses LID to meet storm water management goals
In 2015, Prince George’s County, Md., pursued a community-based public-private partnership (CBP3) model developed by the U.S. EPA Region 3, and selected Corvias as its private partner to retrofit an initial 2,000 acres of storm water infrastructure with low impact development (LID) and green infrastructure best management practices (BMPs). The Clean Water Partnership (CWP) is the first jurisdiction in the U.S. to successfully implement and complete a CBP3 model solution to storm water management at such a large scale.
As part of the larger partnership, a CWP Schools Program was designed as a pilot to assist Prince George’s County Public Schools (PGCPS) with treating and managing storm water runoff from impervious sites by utilizing LID and green infrastructure BMPs. Schools are selected to receive new, green storm water retrofits to help with managing untreated runoff from impervious areas and reduce the impact of sediments and pollution that flow into natural waterways. This collaborative effort between PGCPS and CWP will guarantee that the county’s federal storm water standards are met while providing an educational legacy of future generations committed to managing the water quality in their communities.
The LID Center is one of the partners assisting the CWP in developing the planning approach, BMP technology selection and public outreach to support CWP in completing its goals. In a planning and design role, the LID Center also understands local site conditions, permitting requirements and design standards.
LID is utilized heavily across CWP projects to include the ACP and Schools Programs. Some of the more visible installations are done in collaboration with stakeholders from the Prince George's County communities to include local municipalities, schools, libraries and churches.
Micro-bioretention cells capture and treat storm water runoff.
Partnership in Action
The program has kicked off its third year with 12 schools on the schedule for retrofits during the 2018 construction season. One of the schools receiving the benefit of LID practices includes Parkdale High School in Riverdale, Md. This school was the catalyst for the pilot schools program. The CWP Parkdale High School project will include a retrofit of seven BMPs. This will include seven micro-bioretention retrofits and remove one impervious surface to provide water quality treatment, reduce total maximum daily load and receive 1.86 impervious area restoration credits for the Chesapeake Bay. Micro-bioretention, bioswales, submerged gravel wetland and various other device types allow treatment of previously untreated areas, while providing an opportunity for education, community outreach and aesthetic appeal.
Particular challenges with Parkdale High School are the school’s property aesthetics creating potential flood or drainage issues; a lack of or limited awareness of health and safety around the negative impacts of storm water runoff; and the need to meet federal and state storm water standards. The CWP was able to provide a solution to help the school with its storm water retrofit.
During the initial phase of the program, Parkdale High School received an individual plan, which included a customized package with pictures and concept designs, as well as a dialogue to help the school understand the purpose of the BMP devices. The school’s students, faculty and maintenance staff identified the school’s needs. The industry solutions for those needs then were customized to fit the needs of the facility. The CWP team included design engineers, community outreach, and maintenance personnel who worked together to develop a scope of work to improve storm water runoff at the school and educate students on the importance of storm water management, all while meeting state and federal mandates.
Parkdale High School’s existing site was constructed in 1968, with an addition to the school made in the 1980s. The existing onsite storm drain system had outfalls through a drainage swale in the woods to the east of the football field with runoff from the site flowing to the Brier Ditch and then into the Anacostia River. Parkdale High School has large onsite areas of impervious pavement, which does not allow water to infiltrate the ground. To address this issue, the CWP decided to remove a portion of unneeded impervious pavement, while seven new micro-bioretention cells that will capture and treat storm water runoff are installed in remaining area.
The devices collect storm water from the remaining impervious surfaces and allow it to pool temporarily. Sediments then are deposited on the surface and water filters through the natural media, which removes the remaining pollutants. Upon completion, students will help install native plants that are adaptable to wet and dry soil conditions as part of the engagement and educational components of the project.
The CWP is a model for addressing aging infrastructure.
Reaping the Benefits
Through projects like Parkdale High School’s, the CWP successfully has proven and validated this concept and achieved the goals of the 18-month pilot program to include 100 storm water infrastructure projects—including 250 devices covering 2,000 acres—done in a manner that resolved to be more cost-effective in an abbreviated timeline, creating local capacity, and, ultimately, delivering on promises.
Many communities throughout the U.S. are improving their storm water systems, especially with the benefits that green infrastructure and other low-impact designs have on the broader community. Beyond managing storm water, green infrastructure provides environmental and social benefits, including improving air quality, providing jobs in construction and maintenance, and increasing green space across the county.
Prince George’s County is the first to implement a CBP3 as a solution to focus on its socio-economic and local capacity issues through an infrastructure program. As a result, many jurisdictions are looking at the CWP and its results as a model to address their specific needs and to tackle aging infrastructure.