The Portland Bureau of Environmental Services on Wednesday removed residual tear gas from several downtown drains to prevent pollutants from reaching the Willamette River.
Six drains around the Multnomah County Justice Center and Mark O. Hatfield’s U.S. Courthouse have been cleaned of tear gas by federal officials and the Portland Police Bureau after weeks of use. Officials used the tear gas to discourage and disperse protesters in the area.
To safely clean the storm sewers, the crews used a vacuum to remove everything – including sediment – from the catch basins. The waste is sent to a commercial landfill. No rinsing was performed.
Green water from the purge flows down a storm drain near Lownsdale Park across from Federal Court Mark O. Hatfield in Portland, Oregon on July 30, 2020, the morning after law enforcement officers used tear gas to disperse protesters. Environmental specialists know little about the long-term effects of tear gas on plants, water and wildlife.
Monica Samayoa / OPB
“Our main goal is to prevent pollution,” said BES compliance manager Matt Criblez. “We know that a certain amount of these chemicals have settled in the city’s storm sewers.”
BES has received numerous reports from the public and has documented several cases of electricity laundering during the protest cleanup, in which pollutants were washed from the streets into the storm sewers.
“I cannot guarantee that nothing has reached the river. … We are doing our best to prevent the pollutants from getting into our system as far as possible at the source, ”said Criblez. “Most of it is a material that needs to be rinsed with water. It’s hard to get into our system without water flushing it. “
BES spokeswoman Diane Dulken said the tear gas residue washed into storm sewers was technically an illegal discharge. Only rainwater may be flushed through the drainage system. With rain in the prediction, she said her goal was to capture what she can.
In some parts of the city, storm sewers lead into the sewer system and flow to a sewage treatment plant.
“That’s not the case in this area (downtown),” said Dulken.
The six cleaned storm surges lead directly to the Willamette River. The agency is working to get permission to clear a seventh storm drain that is behind the courthouse fence.
“In some cases we were ahead of the curve and that was helpful for people in preventing discharges. In some cases, we believe these discharges have already taken place, so we are again cleaning the storm drain from the debris that we can reclaim, ”said Dulken.
Depending on what they find, the sewer line may need cleaning.
The cleanup is currently planned as a one-off event, but BES is also taking samples from storm sewers for analysis. Criblez said they test for zinc, lead, copper, and chromium – contaminants found in mass control agents like tear gas, but also commonly found in rainwater from automobiles and other sources.
Connected: “It’s like testing it on us”: Portland protesters say tear gas caused irregularities in their periods
The samples are also tested for substances specific to tear gas use: hexavalent chromium, perchlorate, barium, and cyanide.
“This is not a CSI. We can’t just say, “What’s in this sediment?” It’s going to cost a lot of money, ”said Criblez. “So we basically reduce it to what specific pollutants we expect or what we understand to be the main pollutants from tear gas.”
Map of storm sewers to be cleaned by the Portland Bureau of Environmental Services on August 5, 2020.
Portland Environmental Services Bureau / Portland Environmental Services Bureau
The sampling results are expected to be available later this month and will inform the city if further cleaning is required.
BES is also working with Portland Parks & Recreation to prevent chemicals and tear gas residue from dirt and trees from entering storm sewers. PP&R also coordinates with its employees to ensure personal and environmental safety when cleaning the parks in the city center.
PP&R spokesman Mark Ross said the city’s efforts would follow directions from state and local health officials. Park workers put sacks full of wood chips in front of the storm sewers. He said this would help absorb debris from the runoff water before it gets into the storm sewers.
Meanwhile, U.S. Senator Ron Wyden, D-Ore., On Thursday sent a letter to U.S. Attorney General William Barr and Acting Secretary of Homeland Security Chad Wolf expressing concerns about the continued use of tear gas Expressed by federal agencies in Portland and its negative effects on human health. Late last month, the OPB reported that several protesters alleged tear gas caused irregularities in their periods.
Connected: Oregon lawmakers are calling for an investigation into the health and environmental effects of tear gas
“Your agencies sent a number of federal agents to Portland last month. They weren’t invited, they weren’t needed, and their presence fueled the very violence you claim was there to prevent it, ”Wyden said in the letter. “The agents responded to largely peaceful demonstrations by firing less fatal shots at demonstrators and using tear gas on them night after night. Downtown Portland residents, including the homeless, were exposed to these dangerous chemicals whether or not they participated in the protests. “
Wyden asked a number of questions ranging from the use of chemicals by federal officials in Portland to whether federal agencies had conducted an investigation into the effects of tear gas or riot control agents on human physiology.
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