State: Covanta needs a plan to discharge less mercury into Willamette River


Tracy Loew, Salem Statesman Journal
Wed, December 22, 2021, 4:52 PM·3 min read

State environmental regulators want the Covanta Marion garbage incinerator to reduce the amount of mercury it discharges into the Willamette River.

The Oregon Department of Environmental Quality is asking for public input on the company’s renewed water quality permit. It includes a new provision that gives Covanta two years to provide DEQ with a plan to reduce mercury emissions.

The incinerator, located in Brooks, takes most of Marion County’s waste. It burns about 550 tons of municipal waste per day, and an additional 250 tons of medical and industrial waste per month.


Covanta uses about 88,000 gallons per day of well water for flushing built-up minerals from the boiler and cooling tower. That water is then is treated and discharged to a 12-inch pipe that runs six miles into the Willamette River at milepost 72.1, immediately downstream of the Wheatland Ferry.

The Covanta Marion facility in Brooks.

Covanta’s federal permit to discharge wastewater to the river expired on Nov. 30, 2009. It has been allowed to continue operating under its previous permit because it filed a timely application with DEQ, which has been delegated authority over the permits.

DEQ had taken public input on a proposed permit renewal in March 2016, but that proposal was put on hold while regulators awaited federal rule changes governing mercury levels in the Willamette River. Those changes were final early this year.

The Willamette exceeds water quality standards for mercury at the company’s outfall.

The new permit does not have a mercury limit, but requires Covanta to show how it will monitor and minimize mercury releases.

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The mercury comes from sulfuric acid, which the company uses to adjust the water’s pH.

Covanta already has taken one step to reduce the amount of mercury it releases to the river. During the summer months, it uses some of the wastewater to irrigate landscaped areas on the facility’s 17-acre property.

The 2016 proposal also included a lower limit for chlorine releases, with a requirement to install a dechlorination system if the limit could not be met.

That provision was removed after Covanta showed that samples taken near the river outfall, rather than next to the plant, had lower chlorine levels, DEQ spokesman Dylan Darling said.

The facility uses chlorine as a biocide to control algae buildup in its cooling towers.

Both chlorine and mercury are toxic to aquatic life, and mercury bioaccumulates in fish tissue, which could pose a health risk to people eating fish from the river.

The public is invited to comment on the proposal. Comments must be received by 5 p.m. Jan. 25.

They can be faxed to 503-378-7944; emailed to Jennifer.Maglinte-Timbrook@deq.state.or.us; or mailed to Jennifer Maglinte-Tombrook, permit coordinator, 4026 Fairview Industrial Drive, Salem, OR 97302-1142.

A virtual public hearing is scheduled for 4 p.m. Jan. 18. More information about the permit and hearing is available at https://www.oregon.gov/deq/get-involved/documents/012521covanta.pdf.

Tracy Loew is a reporter at the Statesman Journal. She can be reached at tloew@statesmanjournal.com, 503-399-6779 or on Twitter at @Tracy_Loew.

This article originally appeared on Salem Statesman Journal: Oregon proposes Covanta dump less mercury in the Willamette River