Programs in the Stormwater Management Plan

The National Pollutant Discharge Elimination System Permit is a requirement of the federal Clean Water Act, and it requires the City of Philomath to implement the Stormwater Management Plan (SWMP) contained in the NPDES MS4 Phase II General Permit issued by the Oregon Department of Environmental Quality.

Control Measures in the Stormwater Management Plan include programs for:

  • Public Education and Outreach
  • Public Involvement and Participation
  • Illicit Discharge Detection and Elimination
  • Construction Site Runoff Control
  • Post Construction Site Runoff for New Development and Redevelopment
  • Pollution Prevention and Good Housekeeping of Municipal Operations

Benton County is currently overseeing the Construction Site Runoff Control and the Post Construction Site Runoff measures for the City of Philomath under an Inter-Governmental Agreement. (I.G.A.) Any projects with a land disturbance of 10,800 square feet or more in size is required to submit an erosion control and post construction plan that is reviewed and  inspected by an inspector from Benton County.

Allowable Non-Stormwater Discharges:

The permit does not authorize the discharge of non-stormwater from the MS4, except where such discharges satisfy one of the following conditions:

  • The non-stormwater discharge is regulated under a separate NPDES permit.
  • The non-stormwater discharge originates from emergency firefighting activities.

The non-stormwater discharge is categorized as an authorized or allowable non-stormwater discharge listed below:

  • Uncontaminated water line flushing.
  • Landscape irrigation. For permit registrant owned or operated areas, landscape irrigation will be considered allowable only if pesticides and fertilizers are applied in accordance with manufacturer’s instructions.
  • Diverted stream flows.
  • Uncontaminated groundwater infiltration (as defined at 40 CFR § 35.2005(20)) to separate storm sewers.
  • Rising groundwaters.
  • Uncontaminated pumped ground water.
  • Potable water sources (including potable groundwater monitoring wells and draining and flushing of municipal potable water storage reservoirs).
  • Start up flushing of groundwater wells.
  • Foundation, footing and crawlspace drains (where flows are not contaminated [i.e., process materials or other pollutant]).
  • (J) Uncontaminated air conditioning or compressor condensate.
  • Irrigation water.
  • Springs.
  • Lawn watering.
  • Individual residential car washing.
  • Charity car washing (provided that chemicals, soaps, detergents, steam or heated water are not used. Washing is restricted to the outside of the vehicle, no engines, transmissions or undercarriages).
  • Flows from riparian habitats and wetlands.
  • Dechlorinated swimming pool discharges including hot tubs (heated water must be cooled for at least 12 hours prior to discharge).
  • Fire hydrant flushing.
  • Street and pavement wash waters (provided that chemicals, soaps, detergents, steam or heated water are not used).
  • Routine external building wash-down (provided that chemicals, soaps, detergents, steam or heated water are not used).
  • Water associated with dye testing activity.
  • Discharges of treated water from investigation, removal and remedial actions selected or approved by DEQ pursuant to Oregon Revised Statute (ORS) Chapter 465.