2.1 Chapter Introduction This chapter provides a detailed literature synthesis that focuses on the environmental impacts of street waste and the benefits of street sweeping in mitigating those impacts. The chapter covers the following three primary areas: • The characteristics of street waste and how these characteristics may impact water quality and street sweeping efficiency. • The potential water quality benefits provided by street sweeping. • The co-benefits of street sweeping, such as air quality improvements, improved roadway and stormwater system condition, wildlife protection, and traffic safety. The sources for this chapter included journal articles, government reports, case studies of municipal street sweeping programs, and guidance materials from across the United States. The following subsections discuss these findings: • 2.2.1 Sources of Street Waste • 2.2.2 Physiochemical Characteristics • 2.2.3 Removal Efficiency • 2.2.4 Street Pollutant Transport • 2.2.5 Water Quality Benefits