DEQ awarded nearly $23M to Virginia localities for stormwater improvement projects in the first phase of the SLAF program. HRPDC staff conducted a desktop analysis of the projects and examined the types of best management practices (BMPs) used and the cost effectiveness of the BMPs at removing total phosphorous. DEQ awarded grants to all of the projects that came under $50,000 per pound of total phosphorous removed per year. Our analysis also led to the development of recommendations on selecting and tracking projects for the next phases of the SLAF program.
Fifteen different categories of BMPs were included in the project submittals. Stream restoration was the most commonly used BMP, and all 24 of those projects submitted received funding. The most cost effective projects used dry ponds, extended dry detention, and stream restoration. The most expensive BMPs were permeable pavement and bioretention.
The recommendations are aimed at more closely aligning the grant program with the draft Chesapeake Bay TMDL MS4 Action Plan Guidance. Staff recommends that the SLAF application use the draft Action Plan Guidance methodology to calculate the pollutant loading rates and evaluate the removal of nitrogen and sediment in addition to phosphorus. Lastly, HRPDC staff suggests that DEQ dedicate a portion of the SLAF resources to encourage innovative projects. The summary report is available here.