When is Clean Not Clean? A Critical Environmental Issue

The discovery of thousands of discarded chemical drums on the Hooker Chemical Company property near Montague, Michigan in the 1970s helped spur Michigan’s toxic cleanup program.

Now retired, Andrew Hogarth was the respected longtime chief of the Remediation and Redevelopment Division – in charge of toxic cleanup – in the State Department of Environmental Quality. Despite over 30 years of effort by state government and more than $1 billion of state taxpayer money invested to deal with toxic contamination, thousand of toxic sites remain. Recent publicity about chemical contamination across the state prompted FLOW to ask Hogarth for perspective.

Can you give a little history of how Michigan’s cleanup program has evolved? 

In the early days of Michigan’s cleanup program, our objective was to clean contaminated sites up to naturally occurring conditions, making them safe for all uses. Since groundwater is a public trust resource, part of the commonwealth of our citizens, the approach was that only the Michigan Attorney General, on behalf of the people of the state, could accept less in a settlement involving contaminated groundwater. It was a fairly simple approach that was relatively easy to discuss and implement on some sites.

However, it soon became clear, given the large number of contaminated sites and the costs involved, that the natural background level was often not practical or sometimes not even possible to achieve. This led to a need for another way to establish cleanup goals for contaminated sites. “How clean is clean?” became a question posed by experts in many fields across the country to signify the challenge we faced. It led to what we now call risk based cleanup criteria.

Criteria needed to be developed for the full range of potential migration and exposure pathways and the health, environmental, and safety risks they might pose. The new approach also made it unnecessary to meet criteria if exposures through that pathway could be reliably controlled. [For example, a community might pass an ordinance banning new well installation in contaminated aquifers.]

What are the implications of this change?

Over the period of my career, the biggest change has been going to risk based cleanup criteria with the option of imposing use restrictions on future use of the property. This now happens frequently, as responsible parties choose not to clean up a site sufficiently to make it safe for unrestricted residential use. This change has been one that the regulated community has favored in an effort to reduce cleanup costs, but it has created program complexity and poses potential health and safety problems for the future.

A number of different exposure pathways or hazards need to be considered for every site, such as drinking of groundwater, direct contact with soil, runoff into surface waters, vapor intrusion into buildings, and fire and explosion hazards, to name a few. Other important factors such as chemical toxicity, variations in likely exposures associated with differing land uses, and what kind of use restrictions are reliable are critical matters that need to be built into the regulatory scheme. To be protective into the future, the use restrictions must be effective in perpetuity.

Is there anything going on in Lansing to address these concerns?

Michigan’s Part 201 Cleanup Criteria Rules set forth what the criteria are and how they are to be applied. The last major update to these rules was in 2002. Much of the science supporting those criteria is now decades old, and in some cases outdated. Consequently, many criteria are no longer protective, and some are too restrictive. Some chemicals now of serious concern are not even included. MDEQ staff have been working for several years with various stakeholder groups, to develop a revised rules package. Those revisions are now out for public comment.

Although not all members of the regulated community agree with all the changes, it is a good package that includes updated exposure and toxicity information, where available, and an improved process for addressing vapor intrusion. It should provide a much improved program for dealing with contaminated sites and the hazards they pose. Of particular importance is the vapor intrusion pathway, which if not dealt with properly, can pose serious health and safety hazards for an unsuspecting public.

It is very important that the rules be promulgated soon. I am very concerned that the few stakeholders that continue to object to certain aspects of the package will use the legislative process to delay or block its implementation. Recently proposed Senate bills, if passed, could provide unnecessary platforms for creating confusion about the science and delaying progress.

Is there a way of protecting people in the future from the risk of exposure to contaminants that have not been cleaned up from some sites?

It is critically important that the land use restrictions and engineering controls placed on properties as part of a site remedy be properly installed, maintained in perpetuity, and be recorded with the deed. Such sites also need to be properly monumented to reduce the potential for accidental breaching of exposure barriers or land use activities inconsistent with the use restrictions. As properties change hands in the future, the likelihood of such problems increases.

There are already thousands of properties in Michigan with land use restrictions as part of a contaminated site cleanup project. There are many more sites that are known to be
contaminated where a remedy has not been implemented. At these sites, even if the owners or operators are not the party liable for causing the contamination, owners and operators are obligated to exercise due care to assure that people do not get exposed to unsafe conditions. However, MDEQ does not have the resources to assure that these sites are being effectively monitored.

Political efforts to deregulate and shrink the size of government leave agencies like the MDEQ underfunded and understaffed to accomplish their missions. If sufficient resources are not available to monitor compliance with these obligations, 20, 50, maybe 100 years from now, once again people may be asking: Why did they let this happen? What were they thinking?