What are USEPA’s New PCE Toxicity Values About?

It has been a year since the USEPA issued its new toxicological profile for tetrachloroethylene (PCE).  The new profile resulted in the revision of PCE’s toxicity values in EPA’s Integrated Risk Information System (IRIS).  Despite their obscurity, IRIS toxicity values carry great importance because they are at the heart of the risk assessment process and thus play a central role in determining the extent of waste site cleanups.

What was unusual about the PCE toxicity value change is that the new values indicate PCE is less toxic than previously thought; this is a rare occurrence because most IRIS values changes have gone the other way.  EPA did not come up with the idea of lowering its estimate of PCE toxicity by itself; it received “encouragement” from a National Research Council (NRC) expert advisory committee.  To EPA’s credit, they solicited the input from NRC, even if not all at the agency were happy with the recommendations they received.  It turned out that NRC placed greater emphasis on higher quality scientific studies (those with more controls and less ambiguous toxicity endpoints) and urged EPA to discount studies of lesser scientific quality.  The higher quality studies indicated that PCE was in fact less toxic than previously thought

Very Interesting, but why is this Important?

EPA’s old PCE toxicity values suggested that PCE was so toxic that even concentrations in air that were too low to measure could pose a serious health risk.  As a result, PCE became a significant driver of cleanup actions at many waste sites where vapor intrusion was a pathway of concern.

As you likely know, vapor intrusion is an exposure pathway whose significance many environmental scientists and regulators consider to have been underestimated in the past. Remedial actions to address vapor intrusion have thus become more common, even in situations previously thought to have been satisfactorily closed-out.  In many of these vapor intrusion situations it has been the presence of PCE in air that drives remedial actions.  With PCE now recognized as being less toxic, some of these remedial actions may not be necessary.

Have State Agencies Adopted the New PCE Toxicity Values?

Much of the waste site cleanup work in the US takes place at the direction of state governments.  Most states and political bodies with waste site cleanup laws specifically cite EPA’s IRIS database as the first choice for all risk assessment toxicity values.  However, some states take an à la carte approach with IRIS; reserving their right to use their own toxicity values when they see fit.  Massachusetts is just such a state and its PCE toxicity values date back to the early 1980s (and have evolved since then), a time when there were no federal standards for PCE in drinking water.  MassDEP (then DEQE for the nostalgic) was responding to a big PCE problem in drinking water pipes and in the absence of federal criteria, it took a commendable DIY approach.

What about New Jersey?

But, this post is not about Massachusetts, it’s about New Jersey and its January, 2013 adoption of EPA’s new toxicity values for PCE. Like Connecticut, New Jersey tried to adopt a semi-privatized waste site cleanup law (modeled on the Massachusetts Contingency Plan), but neither state had the much success with their program..  Some place the blame for this lack of success on the inflexibility of NJ DEP and CT DEEP; I am not quite close enough to either situation to comment.

Now the New Jersey DEP seems intent on getting its privatized waste site cleanup program back on track.  It is breathing new life into its LRSP program and in January of this year it issued final guidance to address vapor intrusion sites.   As part of its vapor intrusion guidance, NJDEP has adopted the new EPA IRIS toxicity values for PCE.  By adopting the EPA values, New Jersey raises the threshold at which remedial action is required at sites with PCE.

Among the states, New Jersey is generally perceived to err on the side of environmental cautiousness and its adoption of the new EPA PCE toxicity factors can only add to the momentum in favor of  nation-wide adoption.   New Jersey is off to a good fresh start with its privatized cleanup program.

Impacts to indoor air quality from volatile organic compounds (VOCs) have been receiving greater attention recently due to a growing awareness of vapor intrusion (VI) from underground oil and chemicals.   VI occurs when chemicals spilled on the ground migrate under structures and then volatilize up into indoor air.  After a recent residential basement oil spill I was called in to provide a second opinion on why high indoor air VOC concentrations persisted in the home after the cleanup had been completed.  Some of the results were very surprising.

Locating VOCs in the Basement

Following the release, a well qualified response contractor had conducted a thorough cleanup.  The remediation included removing portions of the floor slab, wall board, wood framing and most other building materials that had been contacted by the oil.  Despite the cleanup, indoor air concentrations in the basement and first floor of the house exceeded the Massachusetts Department of Environmental Protection criteria.

The contractor suspected the problem was the first course of concrete chimney blocks, which had likely absorbed oil in the aftermath of the spill.  The oil in the blocks was now likely volatilizing into the air.  Removing and replacing the contaminated  blocks presented an obvious structural challenge so initially an epoxy sealant was applied to the entire chimney to prevent further oil volatilization.  However, indoor air testing conducted after the epoxy had cured showed that indoor air concentrations remained stubbornly high.

To assess the cause of the indoor air levels, I visited the subject home with a ppbRAE to see if it would help me locate the source of the organic vapors.  Once in the basement, it did not take long to discover that the epoxy sealant was not preventing VOC migration out of the concrete chimney blocks; the blocks were still off-gassing VOCs to the basement air.  While there were also a few pieces of previously unidentified wood framing off-gassing VOCs, the concrete blocks looked to be the main culprit.

But What’s Going on Upstairs?

With the basement VOC source identified, I went upstairs to check on first floor; what I found there was completely unexpected.  While ambient basement air VOC readings had been just above zero (at some distance from the chimney), ambient levels on the first and second floors were about 200 ppb!  How could this be?  I walked through the house with the home owner trying to identifying potential VOC sources.  After an hour of looking I hadn’t been able to identify a source and almost everywhere in the occupied space I was measuring 200 +/- 40 ppb of VOCs in the breathing zone air; there were no odors.  Big mystery!

Finally, on a high book shelf in the living room I noticed two glass hurricane lamps; each containing several ounces of clear liquid lamp oil.  When I held the tip of the ppbRAE probe over the glass lamp chimneys the instrument’s numerical readout shot up; the mystery of the upstairs VOC source was seemingly solved!  And the source was completely unrelated to the basement oil spill.

What is in lamp oil that causes such a strong response on the ppbRAE?  From my limited on-line research, there does not appear to be a commonly accepted formula for lamp oil.  At one time kerosene was used, but this now seems less common except in outdoor settings.  Whale oil was also once used, a practice now thankfully in the past.  The oil in these lamps had no odor, but beyond that I do not have any information on what it was.  I did not collect a sample for lab testing, so I do not know specifically what the ppbRAE was responding to.

Lessons Learned

This experience was a good reminder of just how sensitive today’s air monitoring equipment has become.  Even very small contributions from sources that do not seem particularly volatile can have a dramatic impact on indoor air testing measurements.  It is important to keep a watchful eye out for unanticipated VOC sources when conducting indoor air testing.

Transforming CT’s Cleanup Regs. – Problems and Opportunities

There is a consensus among stakeholders working with Connecticut’s environmental cleanup programs that change is needed. The rigid framework of the Remediation Standards Regulations (RSRs) combined with DEEP’s lack-luster support for the LEP program and a reluctance to accept site-specific risk assessment has resulted in bogged down remediation programs. This regulatory bottle-neck may be contributing to the slow the pace of the state’s economic recovery.

Under CEEP Commissioner Dan Esty’s vision and Graham Steven’s management, I participated in one of six workgroups set up to tackle questions including: evaluating the effectiveness of the current 16 remediation programs; incorporating liability relief into the remediation system; and surveying successful programs in other states. This was public participation on a grand scale and a great value to state’s taxpayers – six workgroups of 16 people, that’s 96 stakeholders (representing business, industry, legal, environmental groups, consultants/LEPs, and government) contributing their 1,400 years of collective experience to the task of clarifying problems and offering solutions. Each group has met five or six times, and together expended over 3,000 hours of effort in five weeks. At normal billing rates, I’d estimate the professional effort donated to the State of Connecticut during this exercise to be worth over $400,000.

Click on this link to read the Remediation Transformation Work Group reports, see the summary of the problem and an attempt at proposed solutions.

Common threads that run through the workgroup recommendations include:
1. The current system is not working in a manner that benefits the citizens; the Transfer Act is particularly problematic and needs to be fixed.
2. Moving to a unified system has clear benefits.
3. A revised system needs to have site specific risk-based on-ramps and exit points.
4. Other states have successful risk-based models to emulate.
5. Incentives must be included to help unclog the system, protect the environment and re-vitalize the real estate market.

Don’t let Connecticut’s best value go unread. Download the six reports to your Kindle and read up on them this weekend. In a future post, I’ll key – out sections which I found illuminating. Do you have experience with other programs in other states that work well to remediate sites to a reasonable and risk-based level of protection of public health and the environment? Now is the time to have your voice heard. The public comment period on the reports ends on November 7. The DEEP is inviting comment at DEP.Cleanup.Transform@ct.gov .

Under the leadership of Commissioner Daniel Esty, the Connecticut Department of Energy and Environmental Protection (DEEP) is continuing its drive to satisfy the legislature’s directive to transform the state’s waste site cleanup laws.   The first phase of this effort is scheduled to culminate with a December 15, 2011 report to the General Assembly.  DEEP has developed a detailed plan for putting the disparate pieces of the report together and has been working quickly to involve the range of public stakeholders.

As part of this effort, the Department held a public meeting on August 9, 2011 at DEEP Headquarters in Hartford to solicit topics for different work groups to focus on.  Graham Stevens  (Commissioner Esty’s point man for the program transformation) used a PowerPoint presentation that included twenty-nine possible topics for work group consideration.  Four of the twenty-nine were identified as the “DEEP Topics” and those correlated well with some of the ones specifically required by the legislature in Public Act No. 11-141.

Actually, the legislature included eight specific topics it wanted addressed in the report; the first seven of these could be interpreted as requests for specific information and analysis, but the eighth item was: “recommendations that will address issues identified in the report or improvements that may be necessary for a more streamlined or efficient remediation process”.  Clearly the legislature’s goal is to reshape the cleanup program to at a minimum make it more streamlined and efficient; a tacit acknowledgement that the existing program lacks those qualities.

The specific issues where the legislature seems to believe their attention is warranted include:

  1. The length of time it takes for a contaminated site to work its way through the program;
  2. Whether the number of properties going through the system is appropriate;
  3. The role of Licensed Environmental Professionals (LEPs) in the program;
  4. Information about the auditing of LEP decisions by DEEP;
  5. Whether the liability relief extended to property owners is working to get the legislative goals accomplished;
  6. An analysis of how DEEP’s complicated 16 program cleanup system is compares to state’s (such as Massachusetts) that have a single program cleanup system; and
  7. To what extent DEEP is making use of scientific and engineering precedent by the federal government and the CT Academy of Science and Engineering and developing and implementing its cleanup program.

The legislature presumably wants the report because they believe there is an opportunity to improve the DEEP’s cleanup program by a close examination and by a rigorous comparison Connecticut’s system to other state programs.  It’s never easy or comfortable for a person or an agency to closely examine itself and to compare itself critically to others.  DEEP deserves credit for its commitment to undertake this difficult process and we are proud to have the opportunity to work with them to make it happen.

As described in an earlier post, the Connecticut DEEP (Department of Energy and Environmental Protection) is working to transform its 16 separate site cleanup programs to make the overall system more efficient and productive.  Many of the program problems are due to regulatory inflexibility; and that inflexibility reflects a fear that without close state agency involvement, cleanups will not conducted to the standards needed to protect public safety.  Despite good intentions, this fear has hindered Connecticut’s ability to develop waste site cleanup momentum.  By creating regulatory road blocks and amplifying financial risks, DEEP has depressed developer’s appetite for site cleanups.  So instead, dirty sites fester for decades.

Enter the relatively new DEEP Commissioner Daniel C. Esty.  On-leave from Yale where he is a joint professor at the Law School and the School of Forestry and Environmental Studies, he joins DEEP with a long list of accomplishments.   A champion of “next generation” regulation, he looks to private companies to take the initiative on environmental issues.  He is also an advocate of data-based environmental decision making; a principle we at OTO fervently applaud.   Esty has taken on the job of evaluating and transforming the state’s cleanup programs and his schedule is aggressive; a report is due to the State Legislature by December 15, 2011.

Commissioner Esty’s point man for managing the transformation of the cleanup regulations is Graham Stevens.  In addition to his job at DEEP, Stevens, a 1998 graduate of Clark University is also pursuing graduate studies at UConn.  After demonstrating strong leadership ability at the Department, he moved up quickly and was named Chief of Staff to former DEP Commissioner Gina McCarthy.  He now serves as the Department’s Brownfields Coordinator.  Stevens has developed a network of relationships throughout state government from the legislative to the municipal level.  As former hockey player, Esty sees Stevens as a team member who can score an important goal.

Stevens’s biggest challenge will be getting the report on transforming the site cleanup program into the net by the December 2011 deadline; a similar process in New Jersey took 18 months.  And not everyone involved necessarily wants to see him succeed. Arrayed in front of him are a group of influential players in government, legal and technical professions with vested interests in limiting the cleanup program changes.

We at OTO are fully supportive of the Commissioner’s goals.  OTO has two senior people contributing to the process.  Among our recommendations for change will be the incorporation of site specific risk assessments as a vital tool for demonstrating when a cleanup is sufficient. Whether meaningful change can ultimately be realized remains to be seen, but we are pleased to see this initiative moving forward.

When it comes to Brownfields cleanups, there may be something new in the Land of Steady Habits.  Up until quite recently, Connecticut’s efforts to encourage the cleanup of contaminated properties has been frustrated by three forces:

  1. Lack of Predictability – Parties seeking to cleanup contaminated properties are unable to see through to the end of the project because the state’s regulatory programs are just too unpredictable.    Promising redevelopment plans are tabled because when the potential economic return for a project can not be estimated, there is little chance the project will be started in the first place.
  2. Regulatory Inflexibility – In Connecticut there is a perception that enforcing the letter of the cleanup regulations is more important than achieving meaningful cleanup.  This is unfortunate, because every contaminated site is different, and the ability to craft creative solutions that reduce or eliminate risk to people and the environment should be more important than meeting strict regulatory requirements.
  3. Liability Exposure – A friend’s favorite expressions is: “no good deed goes unpunished”.   How right he is!  In Connecticut a property owner trying, but failing to cleanup a contaminated property to the state’s satisfaction can be saddled with more liability than they bargained for.  Look at this article regarding the Norwich Hospital for how the Town of Preston got saddled with $40 million in liability by the state.

Is anything changing? Maybe.  First, as part of new Brownfields legislation, the state is now offering  liability protection to innocent landowners trying to cleanup properties.   How successful this new legislation will be remains to be seen, but it is good to finally get some incentives in place to encourage positive action.

Second, the new Commissioner of the Department of Energy and Environmental Protection is seeking ways to improve the various Connecticut site cleanup programs.  If he is successful in reforming the current programs by making them easier to understand and  more predictable, then we may see more parties willing to take the risk of trying to cleanup contaminated property in Connecticut.


Connecticut Department of Energy and Environment Protection (DEEP) Commissioner Daniel Esty has begun an ambitious initiative to transform the state’s environmental cleanup programs; in the opinion of many citizens, this initiative is long overdue.  As environmental consultants practicing in Connecticut and neighboring Massachusetts, we see the similarities and the differences between the two state cleanup programs on a daily basis, and they are quite striking.  The Massachusetts program delegates more authority to their Licensed Site Professionals (LSPs) than Connecticut DEEP does to their equivalent Licensed Environmental Professionals (LEPs).   In Massachusetts, DEP selectively audits the cleanup work of LSPs, but has moved away from direct involvement in site specific decision making.  By contrast, the Connecticut DEEP’s program uses rigid state-wide standards and then conducts a very high percentage of  audits.  DEEP’s process delegates less authority to LEPs, increases cleanup costs, and reduces the predictability of a favorable outcome.

The differences in the success of the two programs speaks volumes.  In Massachusetts there is strong public support for the cleanup program by concerned citizens and the business community; what’s more approximately two thirds of reported sites have reached closure.  The Connecticut cleanup program does not enjoy a comparable level of popularity and has achieved satisfactory cleanups on only about 10% of all so-called “transfer” sites.  While at one time considered promising, the Connecticut program has not achieved the level of success originally envisioned.

Three steps that Connecticut DEEP could take to improve their cleanup program include:

  1. Delegate more responsibility for cleanup decision making to LEPs;
  2. Place greater emphasis on the use of site specific risk assessment as the preferred tool for determining when site cleanup is sufficient; and
  3. Revise the current groundwater protection classification system by differentiating between long term water quality objectives and realistic shorter term expectations for water quality given historic land use.

OTO is participating in the discussions that are part of the Connecticut program’s transformation.  Commissioner Esty is to be applauded for taking on the challenge of transforming the state’s cleanup program; we wish him the best of luck in this endeavor.