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Portland vacuums tear gas residue from storm drains downtown

The Portland Bureau of Environmental Services cleaned tear gas residue out of several downtown storm drains Wednesday in an effort to prevent pollutants from reaching the Willamette River.

Six drains around the Multnomah County Justice Center and the Mark O. Hatfield U.S. Courthouse were cleaned after weeks of heavy tear gas deployment by federal officers and the Portland Police Bureau. The officers used the tear gas to discourage and disperse protesters in the area.

To safely clean out the storm drains, crews used a vacuum to remove everything — including the sediment — from catch basins. The waste is being sent to a commercial landfill. No flushing was done.

“Our primary goal is pollution prevention,” BES Compliance Manager Matt Criblez said. “We know that a certain amount of these chemicals have settled into the city’s storm drains.”

BES has received numerous reports from the public and has documented several instances of power washing during protest clean-up that flushed contaminants from the streets into the storm drains.

“I can’t guarantee that nothing has reached the river… We are doing our best to prevent and keep the pollutants at the source as much as possible from entering our system,” Criblez said. “Most of that stuff is a material of some kind that has to be flushed with water. It’s hard to get into our system without it being flushed by water.”

BES spokesperson Diane Dulken said the tear gas residue that has been washed into the storm drains is technically an illegal discharge. Only rainwater is allowed to be flushed through the storm drain system. She said with rain in the forecast, their goal is to capture what they can.

In some parts of the city, storm drains lead into the sewer system and flows to a wastewater treatment plant.

“In this area (downtown), that is not the case,” Dulken said.

The six storm drains that were cleaned out lead directly to the Willamette River. The agency is working on getting permission to clear out a seventh storm drain that is located behind the courthouse fence.

“In some cases, we were ahead of the curve and that was helpful for people to prevent discharges. In a couple of cases, we believe those discharges already happened, which again is why we are cleaning out the storm drain of the debris we can recover,” Dulken said.

Depending on what they find, sewer line cleaning may be warranted.

The clean-up is currently planned as a one-time event, but BES is also taking samples from the storm drains for analysis. Criblez said they’re testing for zinc, lead, copper, and chromium — contaminants found in crowd control agents like tear gas, but also commonly found in stormwater due to motor vehicles and other sources.

The samples will also be analyzed for substances specific to tear gas use: hexavalent chromium, perchlorate, barium, and cyanide.

“This isn’t CSI. We can’t just say, ‘What is all in this sediment?’ That will cost a lot of money,” Criblez said. “So, what we’re basically doing is paring it down to what specific pollutants we expect to find or what we understand to be the primary pollutants from the tear gas.”

The sampling results are expected to be available later this month and will help inform the city if further cleaning is necessary.

BES is also working with Portland Parks & Recreation to prevent chemicals and tear gas residue from dirt and trees from reaching storm drains. PP&R is also coordinating with their staff to ensure personal and environmental safety in cleaning up the downtown parks.

PP&R spokesperson Mark Ross said the city’s efforts will follow guidance from state and local health authorities. Parks workers will place bags full of wood chips in front of storm drains. He said this will help absorb any residue out of the runoff water before it enters the storm drains.

Meanwhile, U.S. Sen. Ron Wyden, D-Ore., sent a letter Thursday to U.S. Attorney General William Barr and Department of Homeland Security Acting Secretary Chad Wolf, expressing concern about the federal agencies’ sustained use of tear gas in Portland and its negative impact on human health. Late last month, OPB reported that several protesters claimed tear gas has caused irregularities with their periods.

“Your agencies deployed a number of federal agents to Portland last month. They weren’t invited, they weren’t needed, and their presence fomented the very violence you claim they were there to prevent,” Wyden stated in the letter. “The agents responded to largely peaceful demonstrations by firing ‘less-lethal’ rounds at protesters and by using tear gas on them night after night. Residents of Downtown Portland, including the houseless community, were exposed to these dangerous chemicals regardless of whether they took part in the protests.”

Wyden included a series of questions ranging from what chemicals agents were used by federal officers in Portland to whether or not federal agencies conducted an examination of the impact that tear gas or riot control agents has on human physiology.

Map of storm drains to be cleaned on August 5, 2020, by the Portland Bureau of Environmental Services.
Portland Bureau of Environmental Services /
Map of storm drains to be cleaned on August 5, 2020, by the Portland Bureau of Environmental Services.

Copyright 2020 Oregon Public Broadcasting