Water Quality Permits

MS4 Phase II General Permit

As part of its efforts to protect and improve Oregon's water quality, DEQ issues stormwater discharge permits to small municipal storm sewer systems that discharge stormwater into streams, rivers, lakes and streams. DEQ currently regulates municipal stormwater discharges from 19 regulated small MS4s under “Phase II” MS4 individual permits. In 2017 DEQ proposed to permit existing and future Phase II communities under a general permit, the MS4 Phase II Stormwater general permit.

Current Action

On November 30, 2018, DEQ issued a NPDES general permit for discharges from small MS4s. This permit is Oregon’s first MS4 Phase II general permit issued after EPA’s revision to the Phase II Stormwater Rule in 2016.
For additional information please visit DEQ’s Municipal Stormwater Permits webpage.
If you are interested in receiving updates about the Phase II General Permit development, please email your name, affiliation and email address.