How to Keep TICs from Ruining your Remedial Investigation

16 Oct How to Keep TICs from Ruining your Remedial Investigation

Collecting samples for laboratory analysis is part of most remedial investigations. A classic example is testing soil and groundwater to determine the contents of an underground storage tank (UST); the laboratory looks for hydrocarbons and volatile and semi-volatile compounds, including Tentatively Identified Compounds (TICs). So, when lab results report elevated concentrations of volatile organic compounds (VOCs) — specifically benzene, xylene, toluene, ethylbenzene, and methyl tert-butyl ether (MTBE), plus TIC concentrations — the data indicates the UST formerly contained gasoline. ESA then compares the specific VOC concentrations to New Jersey Department of Environmental Protection (NJDEP) regulatory standards for each compound. But the laboratory report also includes a list of the TIC concentrations. So, what are TICs, and why are they important?

TICs are compounds, usually with lengthy and unusual names, reported at estimated concentrations that appear in the laboratory report after the list of targeted volatile and semi-volatile compounds. NJDEP regulations define a TIC as a non-targeted compound, detected in a sample using a gas chromatograph/mass spectrometer analytical method, tentatively identified along with its estimated concentration. NJDEP regulations require that the person responsible for conducting the remediation evaluate the chemical composition for individual and total combined TIC concentrations to determine the significance of TICs as a remediation trigger.

Let’s simplify this a bit. TIC compounds are present per the laboratory report, but the identity and concentration of each TIC cannot be confirmed without further study. Here is a useful analogy presented in NJDEP guidance: Imagine that we take your photo. You, the subject, are in sharp focus. However, the photo also captures other people, out of focus, in the background. Who are they, how did they get in the picture, and is their presence problematic? NJDEP wants to know the same things about TICs. And this is why TICs can complicate a project.

Depending on the nature and concentrations of TICs, further investigation may become necessary. In some instances, TICs will linger in groundwater long after the targeted compounds have been remediated, inhibiting timely regulatory site closure. And, of course, that costs more money and consumes more time for something that, in our client’s mind, wasn’t part of the original scope of work. ESA understands how frustrating and upsetting this can be.

At ESA, we DO NOT automatically do this extra work without first looking for ways to minimize the impact on our clients. Remediation standards for TICs vary based on chemical composition and health risk; therefore, to determine the appropriate action level, ESA evaluates each identified TIC to ascertain if the compound is carcinogenic or non-carcinogenic and what remediation standards to apply. If we can demonstrate that the TICs are present at non-actionable concentrations, they are no longer an issue. If they are present at actionable concentrations, we then seek to determine if the TICs are chemical breakdown products of the original targeted compounds. Over time, compounds in the soil and groundwater degrade into what we call breakdown compounds. This happens via biodegradation and weathering. If the TICs are degradation compounds of the targeted chemicals of concern and the Preliminary Assessment demonstrated that there are no other sources of those compounds on site, then addressing the TICs becomes far easier because the work needed to address the TICs can be blended with the remedial work required for the targeted compounds.

At ESA, we get that you don’t like having to do environmental studies — they cost you time and money. That’s why, while we must adhere to all state and federal environmental regulations, we always seek strategic ways to use those regulations to your benefit.