District 7 TMDL Stormwater Management Facilities Retrofits


  • MDOT SHA
  • Howard, Carroll, and Frederick Counties, Maryland
  • $5.9M


BAI was responsible for Stormwater Management System Retrofits in three counties. Designed the retrofit of 20 SHA stormwater ponds into best management practices (BMP) sites to the maximum extent practicable (MEP) 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 the client take TMDL credits for the reduction of pollutants such as total nitrogen, phosphorous and suspended solids in the streams, and improve the water quality of the streams and Chesapeake Bay. Developed concepts to final design plans, completed JPAs and coordinated all permitting requirements, and provided construction phase services.