Willamette upriver study seeks to identify contaminant source
The Oregon Department of Environmental Quality has launched an intensive study of pollution in the 10-mile stretch of the Willamette River from the Sellwood Bridge to the falls at Oregon City.
The study will look for pesticides and industrial pollution in river sediments throughout the area. It will focus on sediments near storm-sewer outfalls in Milwaukie, Lake Oswego, Gladstone, West Linn and Oregon City, which for decades have been contaminated with urban runoff.
"If we find elevated levels of contamination," said Madi Novak, project coordinator for the DEQ, "the next step would be for DEQ to try to identify
the source of the contamination."
The DEQ's plan is to then enlist responsible parties for assistance in conducting a further investigation, she said, as well as assess the risk to human health and the environment. A cleanup, if warranted, would follow.
Travis Williams, director of the river advocacy group Willamette Riverkeeper, said the study will follow up on concerns initially raised during the evaluation of the Portland Harbor Superfund Site, which found high levels of pollution in the river much farther downstream.
"People really felt we needed to look upstream," Williams said.
However, Novak emphasized that the upriver reach of the Willamette is not officially part of the heavily contaminated Portland Harbor Superfund Site, at least not yet. But the upriver study is expected to add relevant new information about the health of the lower river.
"For this initial work, which is intended to discover previously unknown contamination, we'll compare concentrations with Portland Harbor Superfund Site cleanup levels," she said. "We will also compare conditions that are typical of background conditions, i.e., concentrations that are found in the Willamette River without a nearby source of contamination."
Although the upriver reach is not as massively polluted as the Portland Harbor, it does contain several highly polluted "hot spots," though likely not as severe as the Superfund site. And it contains some of the same highly dangerous chemicals of concern, though at lower concentrations, Novak said.
Over the past 25 years, scientists have been collecting samples from the upriver reach showing that, just like in the Portland Harbor, several locations are riddled by polychlorinated biphenyls, a highly toxic compound also known as PCBs. They also found that several other dangerous chemicals, such as petroleum-based hydrocarbons, lead and mercury, also lurk in the sediments. Traces of the long-banned pesticides DDT and chlordane also have been found in the sediments.
Many of these chemicals were also found in the tissues of smallmouth bass and carp that live in the river.
One of these studies is a 2013 investigation by the U.S. Geological Survey. The USGS study of pollution in creeks entering the upriver stretch of the Willamette found 33 pesticides, including insecticides, fungicides and herbicides in the sediment. The contamination exceeded U.S. Environmental Protection Agency benchmarks in 40 percent of the streams sampled. Nearly all streams contained at least one insecticide at levels exceeding an aquatic-life benchmark, most often the insecticides bifenthrin and fipronil, the USGS found.
The pesticides were found to reduce the abundance of aquatic insects that are food for young salmon and steelhead, as well as for birds and bats, the study said.
But beyond these studies, the existing data are limited. Novak said the new study will fill important data gaps.
The project, called, the Willamette Watershed Toxics Reduction Partnership, is being run jointly by the DEQ and the U.S. Environmental Protection Agency, which will fund the $100,000 investigation. The project is being guided by a citizen-based steering committee that met in May and October and plans to meet again in January.
Based on the limited amount of data collected from this stretch of river since the 1900s, the known hot spots are located near the:
Sellwood Bridge: The city of Portland collected samples of sediment and tissue from smallmouth bass near the bridge in August, in order to evaluate sewer outfalls as a source of PCBs. It found PCB concentrations of 262 parts per billion in sediment samples, and concentrations of up to 634 ppb in tissue from smallmouth bass.
The EPA has set a limit of 0.5 ppb of PCBs in drinking water. The Food and Drug Administration (FDA) requires that infant foods, eggs, milk and other dairy products, fish and shellfish, poultry and red meat contain no more than 200 to 300 parts per billion in food.
Waverley Country Club: A carp sample collected by DEQ in 1994 near the golf course showed PCB concentrations of 360 parts per billion, as well as DDT and other pesticides.
Confluence of Johnson Creek: Johnson Creek contains PCB contamination for the first several miles upstream from the mouth in downtown Milwaukie. A carp sample collected nearby in the Willamette River had elevated levels of PCBs and pesticides.
Confluence of Kellogg Creek: Surface sediment samples collected from Kellogg Creek located near the mouth in 2012 contained PCB levels of up to 58 parts per billion. A historical carp sample collected nearby in the Willamette River had elevated levels of PCBs and pesticides.
Confluence of Tryon Creek: United States Geological Survey sediment sampling indicates the presence of pharmaceuticals in this area.
Lake Oswego/Lake Oswego industrial area: Multiple polluted sites are located in the Lake Oswego industrial area, including Martin Electric, which the DEQ says stored, transferred and sold electrical transformers from 1968 to the late 1970s. In 1987, the Lake Oswego Fire Department found drums containing PCBs on the site. EPA later found PCB contamination in soil ranging up to 172,000 parts per million. In addition, elevated concentrations of PCBs and DDT were detected in a smallmouth bass sample.
West Linn: A few chemicals, including PCBs, petroleum-based substances and pesticides, were collected near and in the lagoon at Cedar Island, a 14-acre park. An elevated concentration of PCBs and dioxin were found in the channel west of Goat Island, the last island in the Willamette north of Oregon City Falls.
Oregon City: Multiple DEQ cleanup sites are located on both shores, including the Blue Heron Paper Mill, a 22-acre site above the falls thought to be contaminated with PCBs, petroleum hydrocarbons and metals.