Portland Gas Manufacturing Site Cleanup

Capping begins using gravelly sand containing activated carbon to support on-going remediation of the area.

What’s Happening?

Starting in July 2020, NW Natural began work to clean up contaminated sediment at the former Portland Gas Manufacturing site along the Willamette River in downtown Portland. This work is addressing historical contamination resulting from gas manufacturing operations along the west bank of the river from the mid-1800s to early 1900s.

Cleanup activities include removal of some contaminated sediment, capping with clean sand and gravel, and enhanced natural recovery. Activated carbon will be added to a portion of the cap to increase effectiveness. Work is being completed using barges and small boats in an area between the Steel and Burnside Bridges, offshore of Tom McCall Waterfront Park.

Project Status

Last updated: Sept. 1, 2020

  • August: Based on the discovery of WW II-era munitions during dredging, NW Natural’s cleanup team expanded fencing in Tom McCall Waterfront Park during the second half of August, restricting public access to the park. The cleanup team implemented additional safety measures to protect workers completing the cleanup action. The team has completed dredging, and returned the fencing returned to its original location near the edge of the seawall. Fencing will remain in place until work is completed (see below). More information is in the FAQ below.
  • NEW Sept. 1: The cleanup team has completed all of the dredging and capping work has begun. The cleanup team removed all dredged sediment from the work area, and a final barge load of material is being screened for munitions. Approximately 4,700 cubic yards of contaminated sediment were removed. Experts from the Portland Air National Guard facility picked up all WW II-era munitions discovered during dredging for disposal.
  • September – October: Place clean capping materials (sand and gravel, some amended with activated carbon).
  • October 12-16: Portland seawall walkway closed for removal of equipment and fencing.


DEQ Project Managers:
Sarah Greenfield
(503) 229-5245  |  greenfield.sarah@deq.state.or.us

Dan Hafley
(503) 229-5417 

Media: Lauren Wirtis
(503) 229-6488  |  wirtis.lauren@deq.state.or.us

Useful Resources

In The News


Frequently Asked Questions

What is this project and why is this cleanup project important?

This is the last large legacy contamination site in the downtown reach of the Willamette River. The cleanup effort will remove areas of contamination in the river sediments adjacent to the Portland seawall. It is important that these contaminants be removed from the river to ensure long-term protection of human health and the environment. To learn more about the Downtown Reach, see the factsheet about cleanup in this area.

What happened with the munitions? Am I safe?

On July 23, NW Natural and the consultant team discovered two World War II-era military shells and a small bullet during dredge work for the PGM cleanup. Work immediately ceased so the work team could establish a plan to proceed safely. During this time, there was no risk to public safety. Explosive ordnance disposal personnel from the 142nd National Guard base in Portland picked up the munitions for disposal.

It is unclear how these munitions came to this part of the river. However, the area was used for docking naval ships under repair during World War II.

NW Natural, in consultation with a firm experienced in munitions disposal, developed a plan to resume work. DEQ has approved this plan. Previously dredged sediment was taken by barge to an area where it could be safely sorted and screened for additional munitions. This work began the week of Aug. 10, 2020 and as of Sept. 1 is nearly complete. Screening of previously-dredged sediment identified additional munitions. These munitions have also been picked up by National Guard personnel for disposal.

NW Natural’s cleanup team resumed dredging work the week of Aug. 17, 2020 with additional precautions, including protective barriers aboard the barges and further restriction to the area, both in-water and in Tom McCall Waterfront Park, to ensure public safety.

As of Sept. 1, 2020, dredging work is complete. All dredged sediment has been removed from the work area and a final barge load of material is being screened. Approximately 4,700 cubic yards of contaminated sediment were removed in total.

Why are there restrictions to the walkway and the river area?

In order for staff to safely conduct and monitor the work along the Portland seawall, river navigational restrictions and walkway restrictions are necessary. There will be signs at either end of the project area along the walkway to ensure that people know how to move around the site. The project team has been coordinating with local, state and federal agencies and groups to communicate these closures with all impacted parties.

Is this cleanup related to the Portland Harbor Superfund Site?

No. This site is upriver of the Portland Harbor Superfund Site and is not a part of that cleanup effort. Project represents the last significant cleanup of legacy contamination in the downtown reach of the river.

How are you making sure workers remain protected from COVID-19?

DEQ, NW Natural and contractors hired to assist with the cleanup have all established health and safety plans that include protocols for minimizing person-to-person exposure, which can lead to the spread of COVID-19.

I see an oily sheen on the water, has there been a spill?

You may see an oily sheen on the water surface within the work area during the removal of contaminated sediment, as old petroleum material is being dredged that could create a sheen. Dredging will be completed within an enclosure, called a moon pool, to prevent the release of contaminants to the river. Water quality will be monitored throughout both dredging and placement of clean fill. DEQ will be on-site regularly to oversee the work being done. If you do have any concerns, please contact DEQ Project Manager, Dan Hafley, at (503) 229-5417 or hafley.dan@deq.state.or.us.

I can smell the chemicals being dug up, is that something dangerous?

The smell, something like mothballs or driveway sealer, is coming from the waste products from the contamination being removed from the river, including naphthalene and benzene. Naphthalene is especially noticeable; it has the distinct odor of mothballs and can be smelled at very low concentrations.

You can smell naphthalene and benzene at concentrations much lower than DEQ levels of concern. The health-risk level of naphthalene is approximately 10 to 50 times higher than the level at which most people can smell it. For this project, the concentration of naphthalene is not expected to reach unhealthy levels. Benzene will also be at levels that are significantly lower than the levels considered to be unhealthy.
NW Natural will provide multiple layers of air monitoring for naphthalene and benzene – including handheld and static monitors in the project area – to help ensure the safety of residents, workers and visitors in the area, as well as on-site project crews.

Although it’s not unsafe at low levels, the odor of some materials being removed is unpleasant. NW Natural has developed a vapor management approach that strives to limit these unpleasant odors.

How long will this cleanup work take?

The cleanup work is currently scheduled to begin in early July 2020 and will continue through the in-water work window that closes at the end of October. This includes removing the contaminated sediment and placing clean soil on top of it.

Once cleanup work is completed, long-term monitoring will occur to confirm the integrity of the sediment cap and natural recovery of the cleanup area.

What kind of traffic impacts will there be during construction?

Traffic impacts should be minimal since the removal work will be completed using barges and small boats. Navigational restrictions on the river may have a small impact depending on the level of boat traffic.

Will this make it unsafe to swim or boat in the river?

This cleanup will not affect recreational safety on the river.

How can I get more information?

This project website contains the most recent information and additional resources are listed at the top of the page on the righthand side. Additionally, you can contact project managers at DEQ or NW Natural below:

  • DEQ: Dan Hafley | (503) 229-5417 | hafley.dan@deq.state.or.us
  • NW Natural: Dave Santen | (503) 610-7505 | Dave.Santen@nwnatural.com

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