...continued from page 8
"We own the stormwater system and are required to manage it in a way that protects health and the environment," he said. "We banned phosphorus fertilizer in 2006, and we got a lot of pushback then. But the market changed, and there are other products out there, even if its not as effective. That's secondary to the environmental burden that is placed on us."
Christie Alwin, an environmental quality specialist with the Michigan DEQ, said the department is coordinating with the USGS to look at coal tar sealants.
"From our perspective, there is a potential for there to be runoff on parking lots that have been resurfaced and sealed, and that could make its way to a stormwater pond or detention basin," she said. "Over time, we want to understand the quality of those sediments and the requirements of those. Looking at it from a stormwater program perspective, 'How do we make sure those sediments are properly disposed, and what do we know about the impacts of PAHs?'"
Additionally, the federal EPA, as part of a recent court settlement with several environmental groups, has agreed to consider comments restricting the use of coal tar sealants in certain industrial stormwater permits issued by the agency.
Oakland County Water Resources Commissioner Jim Nash said he is not aware of any testing of stormwater basins for PAH in Oakland County, but said he would be in favor of such testing and investigating the issue further.
"In Oakland County, we depend on our lakes for our economy," he said. "Anything we can do to make our lakes more pure would be a great thing in our mind. I think, maybe, we should do some testing. I think it's a very good idea."
The use of coal tar sealants at the county and local level isn't always known.
Whether local school districts are using coal tar sealants on parking lots or playgrounds isn't entirely clear. Officials at Birmingham Public Schools said the district uses a "polymer-based sealant." However, experts in the sealant industry said sealant bases are either made from coal tar or asphalt emulsion, which is a petroleum-based product. However, some asphalt-based products do have a polymer additive, which is used to increase durability. Officials in the Rochester Community Schools district said the district doesn't use sealants. Likewise, the use of asphalt sealants in the Bloomfield Hills Schools district is very limited.
"Typically, we only use sealants to black out old traffic markings to make changes," said Brian Goby, director of physical plant services for the Bloomfield Hills district. "This is rare, usually a very small area, and that hasn't been done in quite a few years."...continued on page 10