Stormwater flowing across an impervious surface, such as a paved road, can pick up pollutants, organic material (such as leaves), or spilled liquids and carry them to the sewer inlet. This additional pollutant loading can increase wastewater treatment costs. It is usually more cost-effective to clean the streets regularly to remove these pollutants before they reach the sewage treatment plant, than to have to upgrade sewage treatment processes to remove the pollutants at the back end of the water cycle, before the treated wastewater is discharged into a waterway.
Regularly scheduled street sweeping is an effective pollution prevention strategy that can increase the effective treatment capacity of a sewage treatment plant without having to upgrade its capital facilities. Clean streets also provide aesthetic benefits.
Despite its cost-effectiveness, regularly scheduled street sweeping imposes additional costs on a community that its residents may not want to assume.
Example 1: Madison, Wisconsin
Description: A study done by the USGS and the City of Madison examining the impacts of increased street sweeping as a tool for improving water quality.
Example 2: Minnesota
Description: The linked document includes several pollution prevention strategies. Street sweeping is addressed on page 15 of the PDF.
Example 3: Minnesota
Description: A report on the state of the street sweeping practice. Document can be used to make capital and operating cost decisions for an organization.