From forklifts to catch basins, protecting water quality at industrial sites

Proposed updates will improve monitoring, and better define who needs this permit

We regulate stormwater at nearly 1,200 industrial facilities across Washington through the Industrial Stormwater General Permit. This permit covers businesses like log yards, tank farms, rail yards, trucking facilities, auto recyclers, marine cargo handling facilities, and manufacturing facilities. The goal is cleaner stormwater going into rivers, streams, Puget Sound and marine waters.

While some industries create waste water from cleaning equipment, processing materials, or manufacturing process and discharge the water through a pipe, this permit regulates the stormwater or rain that comes in contact with materials and pollutants at industrial facilities. Ecology has a series of stormwater general permits that are guided by federal and state laws and help to protect clean water by using best management practices, requiring sampling and monitoring, and operation and maintenance requirements.

We update our general permits on five-year cycles. We now have a draft of the updates for the Industrial Stormwater General Permit out for public comment and wanted to share more about some of the proposed changes.

Our permit tackles stormwater pollution

The day-to-day activities at industrial facilities, from operating industrial machinery to transporting goods, to recycling or manufacturing, have the potential to pollute when rain contacts pollutants on the property and flows into local waterbodies. 

Examples of possible pollution include:

  • Sediment/turbidity (cloudy water) from degraded pavement, potholes, dirt, and dust
  • Copper from brake pads, pesticides, vehicle washing, bulk materials
  • Petroleum from fuel, lubricants, hydraulic fluid
  • Zinc from tire wear, motor oil, hydraulic fluid, galvanized metal surfaces/products, exterior paint
  • 6PPD from automobile, truck, and heavy equipment tires

Clarifying protections for transportation facilities at material handling and storage areas

Image Showing Rail Mounted Gantry Cranes at a Port

Rail Mounted Gantry Cranes at a Port

Facilities that have something to do with transportation is a specific sector of the Industrial Stormwater Permit. Nearly 300 transportation facilities are covered under the permit. This includes ports, railroads, bus barns, truck transportation facilities, air transportation, and bulk petroleum facilities. 

Since 2010, the permit has required transportation facilities to manage and monitor stormwater in all areas of their industrial operations. Many transportation facilities have implemented the permit as intended by Ecology, and performed this monitoring. When facilities found stormwater issues they changed practices and worked to improve stormwater quality facility-wide. We often call these corrective actions, which can include designing and implementing treatment systems that remove sediment, metals, and other pollutants. However, not all facilities have applied the permit facility-wide. 

A recent ruling by the Washington State Court of Appeals supported Ecology’s approach to permit coverage. The permit applies to all industrial transportation areas, not just in areas where vehicle maintenance, equipment cleaning, and airport deicing occur (which comes from a federal definition from the 1990’s). Appellants have petitioned the State Supreme Court to reconsider the lower court decision. 

For this 2024 permit update, using our state authority (Chapter 90.48 RCW), we are proposing a new definition to clarify that at transportation facilities the permit requirements apply to all areas of industrial operations.
Also, at transportation facilities, cargo and materials are moved between ships, trains, trucks, and storage areas. We are proposing to clarify the definition of “industrial activity” to ensure transportation facilities apply the permit, sampling, and best management practices (BMPs) facility-wide, including areas where material is handled and stored. 

Example of permit coverage area

Example of Permit Coverage area showing a variety of industrial facilities  occupying a port waterfront. Those facilities include vehicle maintenance areas, ship to shore cranes, container handling and storeage, Cargo Storage.

This example from the Port of Everett shows the small areas where they do vehicle and equipment maintenance areas, versus the entire marine cargo handling facility where they have already implemented the permit.

How can moving and storing materials generate pollution?  

Stormwater pollution in these “Material Handling Areas” can come from a few sources. Cargo generally falls into three categories: shipping containers, bulk materials (like paper pulp, grain, metal ore, etc), and break-bulk cargo (such as automobiles or other large machinery). If rain falls on these materials it can pick up dirt, chemicals, and other pollutants, and flow into waterbodies.

Image Showing reach stackers loading cargo containers

These reach stackers do the hard work of moving and stacking heavy cargo containers, so their tires have more zinc to prevent wear and ensure safety.

The handling and storage of cargo often involves heavy duty equipment such as reach stackers repeatedly managing the containers and materials in tight turns. As with cars and trucks, material handling equipment may release pollutants to stormwater such as copper from brake pads, and zinc and 6PPD-quinone (6PPD-q) from tire wear. Certain cargo handling equipment may have tires that are not approved for road use and contain a higher concentration of zinc per tire to help prevent wear and increase stability for safe performance. This equipment and activity can also generate pollution from dust, spilled materials, degraded pavement, potholes, and hydraulic fluid.

Stormwater monitoring data collected by permittees over the last decade confirms that these areas generate pollution. Therefore, we are clarifying in the draft permit that stormwater management and monitoring is required in material handling and storage areas.

Supporting marine cargo facilities in protecting local water

Image showing port shipping containers stacked on one another

Out of the 300 transportation facilities, 54 facilities fall within the marine cargo handling facility category. Ships are often loaded and unloaded onto wharves and piers, which are typically flat, over-water structures or are next to waterbodies. Rain that falls on these wharves and piers drains through holes (called scuppers or wharf drains) that allow stormwater and associated pollutants to flow directly into freshwater, tidelands, and marine waters.

We support Washington industries and the need for goods to move around our region. We also have a responsibility to ensure that facilities are protecting water quality in their daily operations. We know these overwater structures have some logistical issues to overcome as they improve their stormwater management. We plan to work with transportation facilities, including ports, to ensure a practical and durable path to protect Washington’s water. As we have seen at some ports in Washington and in other states like Oregon, Virginia, and Maryland, it is possible to have both a thriving port and protect water quality.  

More proposed changes

Protecting local water from toxic chemicals

Per- and polyfluoroalkyl substances (known as PFAS) are a large group of chemicals. They are often called “forever chemicals” because they never disappear from the environment. This permit currently does not have any PFAS requirements. We are proposing to add PFAS sampling requirements for specific types of facilities: airports and landfills, as these operations are more likely to have PFAS contamination. Learn more about PFAS at

6PPD-quinone from tire wear particles is lethal to coho salmon and causes water pollution.  We are proposing to add sampling starting in year three of the permit for larger transportation facilities. Learn more about this chemical at

Removing the automatic approval for areas not exposed to rain

Also called Conditional ‘No Exposure’ exemption, as proposed Ecology would now only grant this exemption after inspection to confirm that there is no possible exposure to pollutants.

Adding flexibility on where sampling can occur

Recognizing the potential challenges of sampling stormwater on wharves and piers, we are proposing to allow facilities to propose an adjustment to where they sample their stormwater discharge. This is intended to help with safety and logistical issues of sampling wharves and piers at marine cargo handling facilities. We would review and process these waiver requests as a modification of permit coverage with a public notice.

We want your feedback

This permit update is a part of the typical process for general permits. In 2023, we held a series of listening sessions in person and virtually to help us prioritize updates to make to the permit. The current Industrial Stormwater General Permit expires Dec. 31, 2024. All documents are available online, including the fact sheet which includes a detailed list all of the proposed changes in the draft permit.


Graphic showing the Industrial Stormwater General Permit

Please submit comments on the draft permit from May 15 – June 28, 2024. More information is on our webpage.

You can submit comments:

Workshops and hearings

At the workshop we will share information about the permit followed by a hearing where people can provide verbal testimony. The public hearings will begin immediately following the public workshops and will conclude when public testimony is complete. Verbal testimony will receive the same consideration as written comments.

Workshops held on Zoom:

After Ecology receives and considers all comments (comments are due June 28, 2023), we will make any changes needed and make a final decision on the permit. We plan to make a decision on the general permit by December 2024.

How does this permit work with the Municipal Stormwater Permit?

Some facilities, such as some ports, need to have both a municipal stormwater permit and an industrial stormwater permit because of the wide range of activities and potential pollutants at their facilities. For example, some ports have public spaces, such as parks, farmers markets, and public parking lots. If the community is under a Municipal Stormwater Permit, then these types of spaces would fall under the municipal permit.

However, areas where there are industrial activities – like loading and unloading shipping containers, would require the industrial stormwater permit. The pollution generated (or the pollution concentration and type) at industrial facilities is different than a municipal setting. Municipal streets are set up for traffic driving in mostly straight directions. At transportation facilities, vehicles move in tight turns to navigate around and load/unload cargo. The size and scale of vehicles and equipment at many of these facilities is more than you would see on the busiest road.