How does nonpoint source pollution and impervious surfaces affect water quality and quantity?
Water Quality Differences in stormwater and baseflow water quality are often a result of surrounding land uses. For example, urbanization and agriculture contribute nonpoint source pollutants such as oil, fertilizers, herbicides, pesticides, sediment, salt, bacteria, and wastes. Nonpoint source pollution comes from an array of sources making its exact origin difficult to determine. Water Quantity Water quantity or stream flow, frequently differs between base flow and stormwater conditions when rainfall and snowmelt are diverted to the streams by impervious surfaces such as pavement and compacted soils. Under natural conditions, precipitation is filtered through the soil, recharging the groundwater.