PA DEP Renews Borough Stormwater Permit
The Clean Water Act prohibits anybody from discharging "pollutants" through a "point source" into a "water of the United States" unless they have an NPDES permit. The permit will contain limits on what you can discharge, monitoring and reporting requirements, and other provisions to ensure that the discharge does not hurt water quality or people's health.
Public comments on the permit are currently being accepted. You can view the draft application here.