TMDL Stormwater Management

Brudis & Associates, Inc. (BAI)was responsible for Stormwater Water Management System Retrofits in Carroll, Frederick, and Howard Counties. This project was to retrofit the 20 SHA stormwater ponds into Best Management Practices (BMP) sites to the Maximum Extent Practicable (MEP) in order to treat the roads impervious runoff and improve water quality of the receiving ponds and streams. The retrofits included converting the dry ponds into extended detention, wet ponds, bioswales, micro bioretentions, and shallow wetland. The retrofits help SHA take TMDL Credits for the reduction of pollutants such as Total Nitrogen, Total Phosphorous and Total Suspended Solids in the streams, and improve the water quality of the streams and Chesapeake Bay. The project included developing concepts to final design plans, JPA and coordination with SHA/MDE on all permitting requirements.

BAI was responsible for the following activities:

• Review of Existing Conditions Information and Desktop Analysis: BAI’s team reviewed as-built information and reports for the existing ponds. The information was supplemented with the desktop analysis in the Geographic Information System environment.
• Field Investigation: BAI’s team conducted field investigations of the 20 SHA dry ponds to visually confirm information on available plans/reports, drainage patterns, and document other existing conditions.
• Concept SWM Retrofit Report for MDE submittal: BAI’s team prepared concept SWM retrofit reports based on the sketch approvals from SHA.
• Joint Permit Application (JPA) and Other Permit Coordination: This task included preparing a Joint Federal State Permit Application with impact plates for the Retrofit sites that incorporate the wetland and waterway boundaries and preliminary SWM/drainage/ESC designs.
• Final Design: BAI’s team developed Final Design construction documents for the retrofits.