Montgomery County P3 MS4 Pilot Program

Montgomery County P3 MS4 Pilot Program

Client: Montgomery County Government, Division of Capital Projects, Department of Environmental Protection

Location: Montgomery County, MD

Supporting on this P3 Pilot Program for MS4 Compliance in Montgomery County, Soltesz supported the County in fulfilling the requirements of the Municipal Separate Storm Sewer System (MS4) permitting needs as mandated by the Federal and State governments. The intent of this program was to secure the highest amount of water quality credits per the Maryland Department of the Environment (MDE) criteria most cost-effectively by July 1, 2020.

Under this contract, Soltesz oversaw two projects securing a total of 181 Impervious Acres of water quality credit—TPC Potomac at Avenel Farm and B’Nai Israel, where existing private stormwater management ponds had been constructed providing treatment to large contributing drainage areas. Both ponds were designed pre-2000 stormwater management criteria and offered opportunities for water quality credits by retrofitting the facilities to meet current standards.

The extended detention pond at TPC Avenel was retrofitted with an innovative forebay enhancement that will lessen the runoff’s impacts to local streams by filtering out contaminants, recharging the groundwater, and protecting against storm surges. Soltesz has constructed nearly 1,000 environmental site design features that will significantly improve the output from the pond, aiding in the ongoing restoration of our nation’s treasured Chesapeake Bay. The reconstructed pond’s forebay specifically helps by trapping trash and sediment within a pre-treatment area, reducing the cost and frequency of pond maintenance, while increasing the pond’s effectiveness in removing sediment, phosphorus, and nitrogen from entering nearby streams. It will also improve conditions for the aquatic life and provide a longer life cycle to the pond.

We provided a pond retrofit to the existing Stormwater Management Extended detention pond at the B’Nai Israel site. For this project, we added wet storage volume through means of dredging and excavating a deeper pond volume, increased the wet storage volume by 185% (3.4 ac-ft. to 6.29 ac-ft.), and implemented a Riprap Diversion Barrier directing 1” storm flow into newly excavated forebay.

Soltesz participated in community meetings, providing exhibits and material to educate residents about the clean water program, and answered questions about how the work would be done.