The Village of DePue: Mmm....TACOs - Part 8

I'm still trying to support Cleanup DePue's Press Release claim that:

Contaminated debris blows onto public and private property throughout the village and surrounding natural areas, exposing residents -- more than a quarter of whom are children under the age of 16 -- and local wildlife to arsenic and heavy metals such as lead, mercury and cadmium. Visit www.CleanUpDePue.org to see an interactive map that details the way-above-normal concentrations of pollutants at hundreds of contaminated sites.

I did visit their site and I have been looking at the data to see where these "way-above-normal concentrations of pollutants at hundreds of contaminated sites."

I thought possibly that it might be arsenic and chromium leading this charge since every single one of the samples in OU-4 - where the people of DePue live, work, and play, were above the screening levels for these two compounds.

Then I remembered that Chemicals of Concern (CoCs) that are carcinogens are calculated differently and calculate considerably lower levels than background concentrations making them impracticable to use for remediation goals.

On the Cleanup DePue's website they write about background concentrations:

"For each parameter whose sampling results demonstrate concentrations above those , the [responsible party] shall develop appropriate soil remediation objectives in accordance with this Part." The Illinois EPA considers these background standards an appropriate measure by which to compare soil samples.

Yes that is true.  But background levels are not the sole remediation goal, and I believe that may be where the confusion lies and why Nancy Loeb, director of the Environmental Advocacy Clinic at Northwestern University School of Law’s Bluhm Legal Clinic states in the Press Release:

“The companies spent millions of dollars on consultants in an attempt to show that this SuperFund site poses no significant risks, and they delivered a superficial plan that barely touches many of the contaminated areas, leaves the slag pile and other waste in place, does nothing to stop contamination from seeping into the groundwater, and leaves backyards, playgrounds and Lake DePue without real remediation.” 

The issue, as I think I am now coming to understand, is twofold.

1. They are leaving the contaminated areas in place and moving contaminated media to these areas.
2. They are not remediating the area, specifically OU-4, to background levels in Section 742 Appendix A, Table G of Title 35 of the Illinois Administrative Code or groundwater down to MCL/MCLG levels.

Loeb also criticized CBS and ExxonMobil for their totally unrealistic methods for looking at risk:

“In determining whether a person is exposed to potentially harmful levels of toxic pollutants, CBS and ExxonMobil are counting each exposure as if it were an isolated incident, and pretending that residents are exposed only to a single contaminant and only in one area of the town. The reality is that children are growing up here, eating from home gardens, playing in parks and ball fields, boating in the lake, and later working and living as adults in DePue. Any realistic assessment of health risks has to take these multiple, constant and long-term exposures into account.”

I do not have access to the plan, but I am pretty sure that the Illinois EPA is making CBS and ExxonMobil cleanup to a level consistent with the "Tiered Approach to Corrective Action Objectives":

Source

...or more affectionately called "TACOs"

I know nothin' about this thing called TACOs.  All I know is what any other person reading up on this topic and trying to understand it gets to look at on the interwebs.  What I do know about my industry, including the regulators that oversee it, is that they overkill everything when you attach the words "Superfund" and "Town" together.

I am pretty sure that the remediation plan CBS and ExxonMobil put together meets TACOs.  If Cleanup DePue thinks it does not, I will need to see their reasoning.  All I have is a Press Release stating that the plan is not a "realistic assessment of health risks," and a bunch of analytical data.

So let's get back to the question of are there "way-above-normal concentrations of pollutants at hundreds of contaminated sites?"  And, are the levels found high enough to present a concern?

TACOs tells us this:

The purpose of these procedures is to provide for the adequate protection of human health and the environment based on the risks to human health posed by environmental conditions while incorporating site related information.

With that in mind, we must assume that meeting TACOs meets adequate protection of human health and the environment.  If one wants to make an argument that it does not, let me know why in the comments.  For the most part, TACOs gets you to the same place that EPA's soil screening level calculations do.  They will spit out basically the same remediation goals.

Here is how TACO is designed to work:

Source

You can read more about TACOs by going here.

OU-4 will be samples collected in residential areas so that's the path we will go down.  This requires Appendix B Table A and Table E objectives.  Based on the values in Table A, the new CoC list looks like this:

I still show that some of the OU-4 CoCs exceed the Table A objectives (the one's in purple).  Also note how Illinois goals match closely in some cases with EPA's SSLs.

So, based on the data in the Excel files I downloaded from the Cleanup DePue website, six contaminants were found in OU-4 - the area where people have access to - that were above the Illinois cleanup objective concentrations in Appendix B, Table A.

My next quest will be to see by how much over the objectives as well as how many sample points are elevated.


Next post: he Village of DePue:  By how much and how many  - Part 9


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