The Environmental Legacy of a Working River

NW Natural and a group of businesses and public agencies – in concert with state and federal regulators – are working to clean up sediments contaminated from more than 150 years of industrial activity around Portland Harbor.



The Portland Harbor – the Willamette River from about the Fremont Bridge to Sauvie Island – has been the site of industry and jobs for most of Portland’s history. This area has been central to both Portland’s and Oregon’s economy – as well as to the nation’s military strength.

Over many decades property along the river housed lumber mills, creosote facilities and other forest products manufacturing. During World War II, hundreds of military ships were built on this stretch of the river. And between 1913 and 1956, the gas company manufactured gas on land near the St. Johns Bridge, property now called the Gasco site.

Industrial activity, plus stormwater and agricultural runoff, left contaminants in the sediments at the bottom of the Willamette.

In 2000, the U.S. Environmental Protection Agency declared Portland Harbor a Superfund site.

What is the Superfund?

In 1980, Congress passed the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA). CERCLA created a clean-up “Superfund,” paid for by taxes on certain industries. The fund was intended to cover clean-up costs of “orphan sites”: polluted sites for which the EPA cannot identify a party to pay for cleanup. That’s usually because the property owner has gone out of business.

However, the tax expired in the1990s, so there is no actual “Superfund” anymore: no pot of government money to pay for site cleanup where there is no PRP. That means the remaining “potentially responsible parties” (PRPs) must cover all cleanup costs for the designated Superfund site.

The EPA and others have identified more than 150 PRPs, including NW Natural, for the Portland Harbor Superfund site. Many of the companies originally responsible had long-since gone out of business by the time EPA declared the area a Superfund site.

Lower Willamette Group

NW Natural also participated in the Lower Willamette Group. The LWG formed in 2001 as a working group of the 10 parties that signed an agreement with the EPA to conduct and support the Remedial Investigation and Feasibility Studies necessary for cleanup of the site. Four other parties chose to contribute financially to the project.

From 2001 to 2016, the LWG worked cooperatively with EPA and its partners, spending more than $115 million on technical studies and costs incurred by the federal, state and Tribal governments to oversee the project.

Through this work, the LWG provided agencies more than a million data points of sampling and analysis, making Portland Harbor one of the most intensely studied of any Superfund site in the nation.

The LWG actively engaged with the community to build awareness and encourage public involvement. It shared updates on its work and perspectives on the best approaches to an effective cleanup of the Portland Harbor.

Moving forward

In January 2017, the EPA released its Record of Decision for the Portland Harbor, detailing steps necessary to clean up contaminated areas of the river bottom in the 10-mile stretch of the lower Willamette River.

Gasco site cleanup. In parallel with the Portland Harbor effort, NW Natural is developing plans for the Gasco site in North Portland, where a predecessor company manufactured gas. The company has installed control systems to prevent contaminants in groundwater at the Gasco property from reaching the Willamette River. NW Natural continues to work closely with the Oregon Department of Environmental Quality on this project.

Investing for a cleaner river. Through 2015, NW Natural has spent $119.6 million on remediation planning and cleanup for both the Gasco site and the Portland Harbor Superfund site. The company will continue to work on environmental cleanup until it has met the expectations of regulatory agencies and the people of Portland.

How clean is the river?

Here’s what the Public Health Division of the Oregon Department of Human Resources says about health risks in the Portland Harbor:*

  • The levels of chemicals found in the water, dirt and sediment do not pose a health risk for recreational users, including children.
  • Eating resident fish from the harbor continues to be the main health hazard from the site. Resident fish are those that live their entire lives in the harbor. However, salmon and other fish that migrate through the river are safe to eat, according to the health authority.
  • Bacterial contamination in the river could potentially cause bacteria-related illnesses, especially if swimming near a combined sewer overflow area after a heavy rainfall. Bacterial contamination continues today and will not be resolved by the Superfund cleanup process. However, conclusion of work by the City of Portland on the Combined Sewer Overflow Program will reduce these overflows to no more than four a year, most of which will occur during the winter.

* From the Public Health Division’s Portland Harbor Superfund Site Recreational User Health Assessment Recreational User Health Assessment summary

Page updated Jan. 6, 2017