Chesapeake Bay TMDL Support Services
Wallace Montgomery is currently providing support services to Maryland Transportation Authority (MDTA) and the Maryland State Highway Administration (SHA) in support of their requirement to meet Chesapeake Bay Total Maximum Daily Load (TMDLs) for nutrients and sediment.
The Chesapeake Bay TMDL, established by the Environmental Protection Agency (EPA), is a comprehensive “pollution diet” for the Bay intended to initiate actions to improve water quality in the waterway. The Bay’s TMDL applies to Delaware, Maryland, Pennsylvania, New York, Virginia, West Virginia, and the District of Columbia. Local jurisdictions have developed, and are refining, Watershed Implementation Plans (WIPs) to facilitate the required efforts.
Key measures included in the WIPs to achieve TMDL goals include programs to construct stormwater management/best management practices (SWM/BMP’s) for water quality enhancement facilities to treat runoff from highway pavement that is currently untreated. Objectives of these programs are to design and construct cost-effective and sustainable practices through a process of streamlined retrofit recommendations and developing final design plans for selected sites.
WM is currently providing these services in conjunction with such programs for two agencies.
For the MDTA, WM is designing new SWM/BMP’s to treat runoff from MDTA pavement along I-95 in Cecil County. Current efforts are focused on retrofitting SWM facilities in the I-95 median. To the extent feasible, the new SWM facilities are being designed in accordance with recent Maryland Department of the Environment criteria for Environment Site Design (ESD) practices. Work involves field view to screen potential sites for water quality enhancement facilities along the highway including consideration of access, conflict with utilities, topographic constraints and maintenance concerns. Facilities are designed for selected sites including preparation of construction plans. Support information includes reports documenting the SWM design and the acreages treated to demonstrate compliance with TMDL requirements. Work also includes cursory geotechnical investigations.
For the SHA, WM is part of a team involved in efforts to identify, analyze, design and permit SWM/BMP facilities to provide water quality treatment for 10 Ac. of SHA owned, untreated impervious surfaces along seven selected interchanges of I-95. The scope of work being performed for the SHA is similar to the efforts performed for the MDTA.
WM is also providing similar services to design SWM/BMP facilities on along SHA roadways in Cecil County.
For both the MDTA and SHA efforts, construction is being performed by on-call contractors selected particularly for the required work. The overall process involves generating a continuous flow of retrofit designs for construction by the on-call contractors. When needed, design/consultation facilities will be provided during construction.