Prep for river cleanup to start
By Kathie Marchlewski
Preparation for the dredging of the Tittabawassee River to remove dioxin hot spots will begin next week.
Contractors hired by The Dow Chemical Co., which is responsible for completing the work as a requirement of its operating license, plan to hydraulically dredge two stretches of river this summer.
One is a 1,200-foot section near the Dow dam found to have levels of dioxin as high as 60,000 parts per trillion -- hundreds of times the state's allowable level -- along with volatile and semivolatile compounds such as chlorinated benzenes. The area once was home to an active wastewater discharge from the Dow plant into the river, last used in the 1970s.
The second spot is a 2,400-foot section near Caldwell Boat Launch with dioxin levels around 30,000 ppt.
The state's direct contact criteria for dioxin, the level it considers safe for human contact, is 90 ppt.
"They are contaminants directly in the river, directly impacting the resource," Michigan Department of Environmental Quality Geologist Allan Taylor said of the river's contamination, which also has spread onto the flood plain. Removing hotspots is expected to keep high levels from further contaminating land, especially residential property, when the river moves and floods.
Dow spokesman John Musser said the company agreed the levels of dioxin in the areas to be dredged are "uncharacteristically high," and agreed to begin removing contaminated sediment once winter was over and river conditions allowed.
That time is now.
Dow remediation leader Steve Lucas said the final resting place for the removed material will be Dow's Salzburg landfill. Before it gets there, it will have to be dried out, something that will take place on Dow property on land near its wastewater treatment plant. The soils first will be placed in "Geotubes," which are large bags -- 200 feet by 30 feet -- that will keep them contained until they are ready for disposal.
Peter Simon of Ann Arbor-based ATS, which has been studying the river for Dow, said the undertaking is a large one. "The amount of water you have to handle is tremendous," he said. He compares hydraulic dredging to vacuuming, where a lot of air moves through the machine in order to snag a relatively small amount of dirt; dredging has to move a lot of water.
Another 800-foot section of river about six miles downriver from Midland's Tridge also is slated for cleanup of levels as high as 87,000 ppt of dioxin, though plans aren't yet final and work likely won't take place this year.
That project could be a bit trickier, because it could require some private property owners to grant access to their land -- land ownership extends from adjacent properties to the middle of the river. This summer's dredging will take place primarily on Dow property, so permission from outsiders isn't needed.
Most who heard about the upcoming dredging at a DEQ/Dow-sponsored meeting at Horizons Conference Center in Saginaw were glad to see action.
"We're happy to see that they're cleaning up the river," said Shirley Salas, a riverside resident and co-founder of Tittabawassee River Voice, a traditionally anti-DEQ regulation group. "It's always good to get things cleaned up."
The founder of Bay City-based environmental activist group Lone Tree Council, Terry Miller, called the plan "excellent."
But Midlander Bill Egerer, founder of Midland Matters, a group of concerned property owners, questions the decision to begin sediment removal. "I don't know all of the options," he said, "but some are encapsulate it, leave it alone or study it some more." He wondered how the decision was made.
Sygo said the DEQ, Dow and the U.S. Environmental Protection Agency, which also oversees the project, agreed the material should be removed.
"The (hot spots) need to come out," he said. "The EPA would have liked to have seen them out by now."
Odors not likely in community
Some of the compounds that will be pulled from the Tittabawassee this summer have the potential to stink. But The Dow Chemical Co. and state Department of Environmental Quality say the process of dredging -- hydraulic -- paired with careful air monitoring will prevent odors from making it into town.
"Everything is done to prevent that scenario. We are not going to allow odors downtown," said Dow remediation leader Steve Lucas.
The potential for smells would come not from sediment, but from compounds such as chlorinated benzenes, which are in the soil and have accumulated near a wastewater discharge last used in the 1970s.
DEQ Geologist Allan Taylor said Dow will have to seek air quality permits for the project.
İMidland Daily News 2007
For additional articles like this one, go to the Tittabawassee River Watch web site www.trwnews.net for complete coverage of the Tittabawassee River Dow Chemical dioxin contamination saga. . The Newspaper / Media page of our site contains an extensive archive of media articles dating back to January 2002. The source organization's web site link is listed to the right of the article, visit often for other news in our area. The Newspaper / Media page may be accessed by scrolling down to the bottom of the CONTENTS section and clicking on the Newspaper/Media link.