Introduction to Stormwater Pollution Prevention For Your Business

What is stormwater pollution runoff?

It is the rain and melting snow that flows off streets, rooftops, lawns, and farmland. The flowing water carries salt, sand, soil, pesticides, fertilizers, leaves and grass clippings, oil, litter, and many other pollutants into nearby waterways. Since these pollutants are washed off a wide area and cannot be traced to a single source, they are called non-point source or runoff pollutants.

Why is your awareness and participation so important?

Washington state’s water resources — its streams, lakes, wetlands, groundwater, and Puget Sound — play an important role in the quality of life we enjoy. They provide us with recreation and drinking water, support tourism and salmon, and are used by industry. These waters, however, are vulnerable to pollution from a wide variety of human activities.

Many of our water pollution problems are due in large part to pollutants that are washed off from land by storms. The quality of "stormwater" from residential properties, public facilities, commercial and industrial businesses, and agricultural lands is an increasing concern nationwide. Many people believe that stormwater is "clean" and does not harm water quality. This perception is understandable since the amount of pollution from any one place is not usually significant by itself. But when all these small amounts are combined, they can cause significant water quality problems.

How will stormwater pollution issues affect your business?

Stormwater may become contaminated by industrial activities as a result of contact with materials stored outside, spills and leaks from equipment or materials used on site, contact with materials during loading, unloading or transfer from one location to another, and from airborne contaminants.

Many of the potential pollutants in stormwater discharges are industry specific, but there are also significant commonalities among various industrial activities. Motorized equipment, cars, trucks, and heavy equipment are typically used at industrial sites. They represent a source of contamination by petroleum products and metals that are common to most facilities with coverage under this permit. Industrial activities are typically associated with impervious surfaces and the collection of dirt and other debris that stormwater may mobilize. This can result in high levels of suspended solids and turbidity in the stormwater discharge. Metals are also common contaminants at industrial sites. Sources of metals pollution include oils and lubricants from motor vehicles, tire dust, brake pad dust, raw material and products, and exposed galvanized metal surfaces on buildings, fences, and equipment.

As a business, you can do your part to protect our waters by taking steps to prevent storm water pollution. To protect our water resources, many small businesses must obtain National Pollutant Discharge Elimination System (NPDES) permits and develop a Storm Water Pollution Prevention plan (SWPPP).

What is an NPDES permit?

NPDES permits intend to protect water resources by preventing various pollutants from entering lakes, streams and other bodies of water. In general, the permit lasts five years and sets limitations on what can be discharged to a lake or stream.

Who needs a stormwater permit?

Stormwater Management is now the law. Federally mandated stormwater permits require many industries and cities to control stormwater runoff. Even communities without stormwater permits require erosion controls on construction sites and better stormwater management in new development. Storm water discharges are generated by runoff from land and impervious areas such as paved streets, parking lots, and building rooftops during rainfall and snow events that often contain pollutants in quantities that could adversely affect water quality. Most storm water discharges are considered point sources and require coverage by an NPDES permit. The primary method to control storm water discharges is through the use of best management practices.

Does your business need an NPDES stormwater permit?

Certain businesses are subject to the Industrial Stormwater General permit and is based on their Standard Industrial Classification (SIC) code. Regulated businesses include, but are not limited to, the following:

  • Paper and chemical producers
  • Fabricated metal operations (except producers of machinery and transportation equipment)
  • Lumber and wood producers
  • Mineral industries
  • Leather tanning and finishing industries
  • Material recyclers such as junkyards and metal scrap yards
  • Stone, clay, glass and concrete producers
  • Transportation facilities that have vehicle maintenance shops and equipment cleaning

Note - Significant Materials can include:

  •  Fuels, solvents, coolants, lubricants and cleaners
  •  Metallic materials
  • Raw, intermediate and final products
  •  Machining fluids
  •  Wastes and scrap materials
  •  Dust or residuals
  •  Processing or production operations
  •  Hazardous substances
  •  Chemicals

**Visit the following web page at to determine your SIC code and whether your business is subject to the Industrial Stormwater General permit**

What if my business does not store materials or perform operations outside?

If raw materials, manufacturing processes and wastes are managed in ways that prevent exposure to storm water, your business may qualify for a no exposure certification and therefore not require an NPDES permit.

Next Steps:

Now that you have a better understanding for stormwater runoff and pollution and have determined if your business qualifies for a stormwater permit, the next step will be to file your application with the Department of Ecology. Whether filing for an Industrial, Construction or other specialty stormwater permit as well as a No Exposure Certification, the Washington Stormwater Center is here to assist your needs. Please take some time to familiarize yourself with this valuable resource. You will find access to training for your business, aggregated online resources designed to provide you with all of the information required to comply to your permit and the latest news and videos pertaining to stormwater runoff.