Case Study: Street Sweeping
2025
Chesapeake Bay Story Link
Water pollution control with street sweepers. A Washington County study.
Our Schwarze street sweepers are not only helping keep the streets clean but are helping to protect local watersheds across America. Washington County, Maryland has found a way to fight pollutants from entering the rainwater runoff. Excessive amounts of phosphorus and nitrogen in storm water runoff is the leading cause of eutrophication in the Chesapeake Bay. Eutrophication occurs when there is an excessive amount of nutrients in a body of water, causing algae blooms, oxygen depletion, and ecosystem damage.
Washington County was just one of many state and local governments in Maryland, Virginia and the District of Columbia facing a US Environmental Protection Agency (EPA) mandate to reduce their total daily maximum load (TMDL) of such nutrients in their storm water runoff by at 20% to reduce eutrophication in Chesapeake Bay.
When researching alternatives to address the EPA mandate, they discovered that frequent use of air sweepers was far more cost effective and provided continuing benefits compared to investments into expensive infrastructure projects. John Swauger, who serves as storm water management coordinator, said it comes down to the numbers; “We looked at some of the other BMPs (best management practices) and many of those are quite expensive to install.” Their initial goal was to meet the 20% TMDL reduction mandate at a cost of no greater than $20,000 per acre of treatment. What they found was that by adding advanced air sweepers and increasing sweeping frequency to every two weeks, they could achieve the target for a cost of $731 per acre of treatment.
“We really had to look at ways to become innovative; that’s where the street sweeps options came in” said Alex Reed, watershed specialist Washington County. Alex Reed would go on to say that the Schwarze sweepers provided the “best bang for the buck” when compared to other watershed protection projects.