Vapor Intrusion of Contamination
Viewpoints from a Public Hearing
Assemblyman Thomas P. DiNapoli, Chairman
Contamination of indoor air by volatile chemicals from contaminated soil and groundwater is an emerging area of public health concern. Vapor intrusion occurs when contaminants vaporize and rise up through cracks, gaps, or pores in soil and foundations into homes and other buildings. Vapor intrusion is known to have occurred at several Superfund sites in New York State and has the potential to be a problem at brownfield sites as well. While the New York State Department of Environmental Conservation (DEC) and the Department of Health (DOH), as well as the United States Environmental Protection Agency (EPA), have issued draft guidance pertaining to various aspects of vapor intrusion, none have been finalized.
On November 15, 2004 the Assembly Environmental Conservation Committee convened a public hearing in Endicott, New York to examine issues concerning vaporization and resulting human exposure. The primary purpose of the hearing was to determine what lessons can be learned from past experience in order to properly address vapor intrusion in the future. The Committee received testimony from panels of witnesses including federal, state and local government officials, public health and environmental experts, and citizens representing affected communities. This report provides a summary of testimony received at the hearing and recommendations for future action.
While federal and state agencies have been aware of the potential for vaporized contaminants to enter into homes and buildings for over a decade, conventional wisdom held that levels of indoor air contamination would not be of concern due to dilution and attenuation. Experts in environmental health and engineering have only recently come to realize the true potential for vapor intrusion to result in widespread human exposures. Indoor air sampling performed at a site in Colorado in 2000-2001 found significant levels of the contaminant trichloroethylene (TCE) in homes where the computer model recommended by EPA had predicted little or no contamination. As a result, EPA and state agencies began a national effort to understand vapor intrusion and to revisit sites where cleanup has occurred but the potential for vapor intrusion is high.
Here in New York, this effort led to the discovery of widespread contamination in Endicott, which now has mitigation systems in place in over 450 homes and businesses. Vapor intrusion has also been discovered in Hopewell Junction, which EPA proposed for listing on the National Priorities List (NPL) on September 23, 2004 pursuant to federal Superfund. At Hopewell, EPA collected soil gas samples at 206 homes and found detectable concentrations of TCE at 65 of those homes. Sub-slab ventilation systems have been installed at 42 of the 65 homes. Vapor intrusion problems have also been identified in Hillcrest, at the Jackson Steel site in Long Island, at the Morse Industrial Corporation site in Ithaca, as well as at several other sites around the state.
The issue of vapor intrusion poses serious challenges for sound public policy making in New York State as well as nationally. The biggest of these challenges is the lack of clear health and environmental standards for indoor air pollution. This is especially true for TCE, the most common volatile chemical found at thousands of contaminated sites across the country. TCE is the chemical of greatest concern at the Endicott, Hopewell Junction, and Hillcrest sites. The level of TCE contamination considered protective of human health varies widely across EPA regions and states, causing concern to citizens and regulatory agencies alike.
A number of other challenges posed by vapor intrusion must also be addressed. They include:
Status of Current Standards and Regulation
EPA is in the process of developing guidance for evaluating vapor intrusion. This guidance was designed only to determine if there is a potential for an unacceptable risk, not to provide recommendations on how to delineate the extent of risk or how to eliminate the risk. The guidance will not resolve the lack of national standards for contaminants in indoor air. EPA’s Office of Solid Waste and Emergency Response released the draft guidance in the November 29, 2002 Federal Register and is currently reviewing the numerous comments received. Two technical sessions have been held to review the draft guidance and a third is planned for March 2005. It is uncertain when the guidance will be finalized.
In 2001, EPA released a draft toxicity assessment for TCE based on current information regarding toxicity and health effects. Significantly, the draft assessment found that children are more susceptible to TCE exposure than adults and that TCE is five to 65 times more toxic than was previously believed. The TCE toxicity assessment was peer reviewed by EPA’s Science Advisory Board, which recommended finalization of the assessment with some revisions. In response to concerns raised by the Department of Defense, however, EPA requested additional external peer review by the National Academy of Sciences. The Academy officially initiated its review of the draft assessment in December 2004. It is expected to take about 15 months.
In the meantime, some states and EPA regions have adopted more stringent TCE exposure and remediation guidelines based on the analysis provided in the draft assessment. In the absence of a definitive toxicity assessment, the TCE guidelines adopted by Regions and states vary significantly, by an order of magnitude or more. For example, EPA Regions 3 and 6 adopted TCE air guidelines based on the most conservative assumptions provided in the draft toxicity assessment. At 0.016 micrograms per cubic meter (mcg/m3) and 0.017 mcg/m3 respectively, these guidelines are among the most stringent in the country, and correspond to one excess lifetime (30-year) cancer among a million people. Colorado has adopted 0.016 mcg/m3 as the level at which screening will occur and 1.6 as the level at which cleanup will be required. EPA Region 9 presented two values, 0.017 and 0.96, in their "Preliminary Remediation Goals Table" published in October 2004. An explanation of the 2004 Table states, "Region 9 has shown both [TCE values] on this Table, rather than choosing one over the other, to give Table users as much information as possible in the absence of a final EPA toxicity value." The State of California has a "Target Indoor Air Concentration" of 1.22 mcg/m3 based on a much less conservative toxicity assumption than those contained in EPA’s draft assessment (See Appendix F for a table showing the range of TCE values employed by various EPA Regions and states).
In October of 2003, DOH established an air guideline for TCE of 5 mcg/m3, which is significantly higher than California, Colorado, and several EPA Regions. This guideline is the subject of much debate, and DOH is currently in the process of establishing a panel of experts to provide peer review for the guideline. The promulgation of the new TCE guideline has resulted in the inconsistent treatment of homes in Endicott. Before October 2003, vent systems were installed in homes where TCE was detected at levels above 0.22 mcg/m3. However, under the new guideline, homes tested after October 2003 only qualify for vent systems if TCE is detected at levels above the 5 mcg/m3 threshold. This has led to confusion and frustration within the affected community.
In late 2004, DEC issued a draft Program Policy titled "Evaluating the Potential for Vapor Intrusion at Past, Current, and Future Sites." This draft policy states that DEC has compiled a list of 400 State Superfund sites at which chlorinated volatile organic compounds (CVOCs) have been disposed or detected in groundwater and 750 sites with groundwater contaminated by volatile organic compounds (VOCs). Under the policy, these sites would be evaluated and ranked for further investigation and potential remediation. The public comment period on the draft policy ended on January 24, 2005. The draft policy left several concerns that will hopefully be addressed before the policy is finalized, including the number of sites to be investigated, how long it will take, and what level of exposure will trigger remediation (See Appendix D for the full text of Assemblyman DiNapoli’s comments on the draft policy).
DOH has also issued draft guidance on vapor intrusion titled "Guidance for Evaluating Soil Vapor Intrusion in the State of New York." The draft was released on February 21, 2005. The public comment period ends April 23, 2005.
In New York State, a new Brownfield Cleanup Program (BCP) was enacted in October of 2003. The law provided for the voluntary cleanup of brownfield sites, refinancing of the State Superfund program, and the creation of a comprehensive program for the long-term restoration of groundwater. Under the BCP statute a new Groundwater Protection and Remediation Program was created, the provisions of which are based on experience under the Superfund and Oil Spill cleanup programs. The program provides for the long-term pursuit and remediation of groundwater contamination that has migrated off-site. The law also requires the provision of opportunities for meaningful public participation, and establishes a Technical Assistance Grants Program for both Superfund and brownfield sites, something that will be particularly important at vapor intrusion sites.
Summary of Testimony
The following are summaries of testimony presented at the hearing or submitted for the record. These summaries were prepared either by the witness or by staff using their written testimony. Copies of the written testimony may be obtained by contacting the Committee.
Honorable Maurice Hinchey, Congressman, 22nd District
This hearing is an important step towards assessing how regulatory agencies have dealt with Endicott’s toxic contamination and how to improve procedures for dealing with the emerging threat that vapor intrusion presents in communities statewide.
As I learned of the extensive toxic plume beneath Endicott, I immediately pushed for a comprehensive health study as well as expedited remedial action. While progress has been made on both these fronts -- a health study is underway and the site has been reclassified from Class 4 (site which has been properly closed but requires continued management) to Class 2 (site which poses a significant threat to public health or the environment and requires action) on the New York State Registry of Inactive Hazardous Waste Sites -- there is more to be done.
Some of the unresolved issues concerning this site include:
TCE inhalation and drinking water standards are presently under review by the federal government. The progress of this review should be followed closely and may have a profound impact on remediation efforts in Endicott and elsewhere.
Honorable Joan Pulse, Mayor, Village of Endicott (Edited by staff)
The Village of Endicott has encountered numerous trials and tribulations throughout the years. Although we have faced challenges, we were still able to seize and capitalize on every opportunity that was presented before us.
During my campaign and since election, I have had three primary goals for the Village of Endicott: fiscal responsibility, economic development (which will create and secure the future for our children), and safety (specifically addressing any and all environmental concerns in our community). Protecting our community, and holding accountable those responsible for the contamination, is fundamental to my beliefs-THOSE WHO DID IT; CLEAN IT UP!
Five years ago, no one had ever heard of vapor intrusion. A situation in Colorado shed new light on our understanding of vapor intrusion. EPA continues to work diligently to help others understand the environmental impacts of this emerging issue.
State and local agencies have met with residents on numerous occasions, provided information, conducted investigations, and where appropriate, ensured that responsible parties are held accountable for cleanup. I, and the residents of the Village of Endicott, would accept no less. I would argue that Endicott, from the environmental perspective, is one of the most highly scrutinized municipalities in the State, if not the Nation.
I welcome and endorse the need to protect our citizens. I personally have said and will continue to say, "I will hold IBM’s feet to the fire" when it comes to protecting our environment - but I refuse to accept the portrayal by the media that every effort isn’t being made to address the situation. Yes, there are environmental concerns in Endicott and they do need to be resolved. There needs to be oversight, to ensure the protection of citizens - and that is being done by the DEC and the State and County DOH.
I rely on and thank the DEC and the State and County DOH. Moving forward, protecting residents, improving the quality of life, and providing opportunities are the responsibilities of my administration. I encourage those present to join me in accomplishing these goals, and I again thank the committee for taking up this issue.
Carl Johnson, Deputy Commissioner, Office of Air and Waste Management, NYS Department of Environmental Conservation (Edited by staff)
Along with the New York State Department of Health (DOH), the Department of Environmental Conservation (DEC) is committed to protecting public health and environmental quality from the potentially serious effects of vapor intrusion into homes and businesses.
Vapor intrusion is a rapidly developing field of science and policy. While chemical concentrations of vapors are typically low, in some instances they can accumulate to levels which pose safety hazards, including the potential for explosions or acute health effects. Even in low concentrations, these vapors may lead to chronic health effects.
Determining the exact concentrations of contaminants in a building resulting from vapor intrusion may be difficult. For example, the use of other substances (including gasoline and cleaning solvents) in or around a building may complicate our ability to effectively determine the precise level and source of contaminants stemming from vapor intrusion. Through modeling and direct measurements, DEC makes the best possible estimate of actual contamination levels resulting from vapor intrusion. In partnership with DOH, we then search for means to resolve the problem.
DEC recognizes that vapor intrusion cannot be resolved simply through ventilation at the buildings where hazardous or potentially hazardous levels of vapors are discovered. Elimination of the source is our ultimate objective. We view the use of vapor mitigation systems as a short-term solution to the vapor intrusion problem. By addressing the source of the contamination, and ensuring that steps are taken to remediate and monitor the soil and groundwater which provides a pathway for the migration of these chemicals, DEC can provide effective long-term protection of the public health from vapor migration.
The standards with which cleanups must comply are determined by DOH, not DEC. Our responsibility involves establishing a cleanup plan which ensures that contamination is cleaned up to the level established by DOH.
DEC has developed a program policy to deal with all sites in all the remedial programs where vapor intrusion may be an issue. The strategy in the policy divides the universe of sites into two groups: 1) sites where remedial decisions have already been made (legacy sites) and 2) sites where remedial decisions have yet to be made. The guidance in this document primarily applies to the first group - sites where decisions have already been made - and outlines a process to be used to identify and prioritize those sites for further action. A prioritization approach has been developed to focus efforts on evaluation of legacy sites with the greatest potential for vapor intrusion first. DEC is in the process of working through the universe of legacy sites in order to identify the sites of concern. The sites in group 2 have already been evaluated and, where necessary, vapor intrusion is being added as part of a routine investigation. All future sites will include a vapor intrusion investigation component.
The remediation of vapor intrusion sites is complex, and these comments only provide a brief synopsis of the actions which DEC undertakes.
Nancy Kim, Ph.D., Director, Division of Environmental Health Assessment, NYS Department of Health (Edited by staff)
The New York State Department of Health (DOH), in conjunction with other state and federal agencies, is carrying out a number of activities related to vapor intrusion, including the performance of environmental health investigations and health studies; the development of remedial guidance, guidelines for chemicals in air, and soil cleanup objectives for brownfields; and the provision of public health information.
Environmental health investigations at vapor intrusion sites follow an approach consistent with that for other environmental media. Since no two sites are exactly alike, the approach is dependent on site specific conditions, including site use history, geological and other physical characteristics, and potentially exposed populations. Existing information is reviewed and new data is gathered until questions regarding current and potential exposures and the actions needed to prevent or mitigate exposures and remediate the source of vapor contamination can be answered.
DEC and DOH are drafting guidance right now for investigating and evaluating exposure pathways, an early draft of which is attached to our testimony.
DOH is also developing an approach to making remedial decisions based on soil vapor and indoor air concentrations. The approach is outlined in a matrix and to date matrices have been developed for trichloroethylene and tetrachloroethylene. Drafts are being provided with our testimony for you to comment on however you want to. The form of the matrix is evolving as we learn more and apply it at different sites.
In addition, DOH has developed indoor air guidelines for the drycleaning chemical tetrachloroethylene (also known as perc), dioxin, PCBs and TCE. The TCE guideline was established after an extensive evaluation of scientific information using methods consistent with those used by other agencies and scientific bodies. We looked at both cancer and non-cancer effects and focused most on inhalation studies. We developed potential guidelines or criteria for evaluating TCE toxicity for all the different health effects, and in general, those guidelines range from one to ten micrograms per cubic meter of air. The guideline adopted is five micrograms per cubic meter of air.
We developed the TCE guideline based on our understanding of the science. We reviewed EPA’s draft Toxicity Assessment for TCE and the Science Advisory Board’s review, which provided many recommendations for improving the document and many more details about the uncertainties involved in estimating TCE’s cancer risks. Depending on the various aspects of TCE at issue, we came up with a slightly different answer than the Assessment. We also looked at critiques of the Assessment by some other EPA scientists who are aware of California’s work on TCE.
Some EPA regions have taken a lower figure and some reference concentrations are higher. It depends on which guideline you look at. For example, the cancer potency factor for TCE in air recommended by EPA Region 3 is the highest recommended by EPA in the draft Assessment. It is based on an epidemiological study with the following limitations: the study did not have individual exposure measurements; the study population was exposed to other chemicals besides TCE; and the routes of exposure for the study were ingestion, and probably dermal absorption and inhalation, as compared to inhalation alone.
Our guideline corresponds to an excess cancer risk of between one in one million and one in one hundred thousand, depending on the risk extrapolation relied upon. But it is generally probably a little bit greater than one in one million.
We have committed to a peer review process for the TCE guideline and expect to ask various stakeholders to recommend scientists for the peer review. For the peer review, we are completing an extensive scientific document about the key issues related to TCE toxicity and risks. We also recognize the need to continue to update, review and refine our evaluation of the potential health risks associated with TCE using good science.
Matthew Hale, Director, Office of Solid Waste, US Environmental Protection Agency (Edited by Staff)
EPA considers vapor intrusion from contaminated soils or groundwater into homes and other buildings to be a significant environmental concern and one where the science is still evolving. We have long recognized that volatile organics contaminating soils or groundwater can migrate into nearby buildings, resulting in indoor air levels that may present a human health threat. Within recent years, however, we have come to recognize that the occurrence of vapor intrusion into buildings is more widespread than previously thought. For example, in some cases, volatile organics have migrated further from their source than was expected; in others, vapor intrusion was not originally identified as an exposure pathway of concern, but later proved to be one.
Because we now recognize the potential for vapor intrusion to be a significant exposure pathway at certain remediation sites, EPA and state environmental agencies have paid increased attention to indoor air concerns at cleanup sites where soil or groundwater is contaminated with volatile organics. For example, in the Resource Conservation and Recovery Act (RCRA) corrective action cleanup program, we routinely screen sites for potential vapor intrusion where there is a possible concern. Where concerns are identified, EPA (or more frequently under RCRA, the authorized state agency) requires corrective action - for example, the installation of vapor removal systems beneath a building.
Perhaps the most difficult challenge relating to vapor intrusion is determining with reasonable certainty whether there is likely to be a problem or not when buildings are in the vicinity of soil or groundwater contaminated with volatile organics. A complicating factor in evaluating vapor intrusion and the risks it may pose is the potential presence of some of the same chemicals at or above background concentrations from the ambient (outdoor) air and/or emission sources in the building e.g., household solvents, gasoline, cleaners. Because of the large number of sites where vapor intrusion could potentially be a concern, because the science is still evolving in this area, and because of the technical difficulties in determining whether there actually is a problem at a given location, the EPA Office of Solid Waste and Emergency Response developed draft screening guidance, which it published for comment on November 29, 2002 (Federal Register November 29, 2002: 67 FR 71169-71172).
In this draft guidance, EPA recommends a tiered approach to screening sites for vapor intrusion potential - that is, to determine whether vapor from volatile organics is likely to be entering buildings, and if so whether it would likely be a health concern. The guidance recommends that regulators and responsible parties use a conservative modeling approach in determining whether there is likely concern at a given location, and that they conduct sub-slab and indoor air sampling when the possibility of vapor intrusion at levels of concern can’t be ruled out. The guidance also notes that when indoor air sampling is conducted, that it be conducted more than once and the sampling program be designed to identify ambient and indoor air emission sources of contaminants.
EPA received numerous comments on this guidance, which it is now reviewing. We have held technical working sessions with the states, academia, and external stakeholders to discuss this guidance in San Diego, California and Amherst, Massachusetts, and will be returning to San Diego next March for our third technical working session. After that meeting, we will determine how best and over what time period to finalize the guidance.
When it published this draft guidance, EPA recommended its use at RCRA, Superfund, and Brownfield cleanup sites. However, we emphasize that it is only guidance and is still in draft form, and that other approaches may also be appropriate. Furthermore, the State of New York is authorized to run the RCRA cleanup program in lieu of EPA, and therefore the New York State Department of Environmental Conservation is generally responsible for overseeing and regulating RCRA cleanups within the state. New York-like any authorized state under RCRA-may choose to follow this guidance, or may adopt other approaches that achieve protective results.
Joseph Graney, Ph.D., Assistant Professor, Dept. of Geological Sciences and Environmental Studies, State University of New York at Binghamton (Edited by staff)
I have been fortunate to have been involved in some of the scientific research related to the Hillcrest problems. Much of my work at Hillcrest has been related to the emission and transport of vapor phase mercury. I believe that similarities in the chemical and physical properties of mercury to volatile organic compounds (VOCs) may allow findings from mercury monitoring studies to act as a potential surrogate for designing future studies of VOCs in brownfields as well as residential exposure studies.
The methods for detecting indoor air concentrations of organic compounds such as trichloroethylene (TCE) and other VOCs typically require use of Summa canisters and relatively long sampling times (typically 24 hours). Collection and analysis of such samples is expensive, but needed for regulatory purposes including exposure assessments. However, short term monitoring times and in-situ sampling methods would be of major benefit to better determine shorter term variation in VOC concentrations from exposure perspectives. Such instrumentation is available for monitoring low level mercury concentrations in indoor air exposure settings, and further development of similar instrumentation for low level VOCs is needed. Such instrumentation could be used to quickly screen large numbers of residences in a cost effective manner.
The times of year when samples should be collected for indoor and ambient air exposure assessments need further study. I am not convinced that the major indoor air exposure to contaminants associated with vapor intrusion occurs during the winter months (i.e. during the heating season when forced air furnaces are in operation). Sampling during all seasons should be carried out to document temporal trends in VOC concentrations specific to the climatic conditions in the Southern Tier of New York State.
The complex terrain of the Southern Tier (characterized by incised river valleys and surrounding hilltops) may make ambient air quality from venting of VOCs in residential areas a concern, due to the likelihood of pollutants being preferentially channeled within the river valleys. Methods should be devised and tested to lower the VOC emissions to ambient air. For example, the installation of in-situ VOC vapor adsorption cartridges inside ventilation ductwork may lower emissions to ambient air.
Groundwater contamination problems are proving to be difficult to rectify. There may be need for a further evaluation of innovative groundwater remediation approaches above and beyond conventional pump and treat methods. The study of preferential pathways of groundwater and vapor phase pollutant transport in relation to underground utility services (gas, sewer, cable, electric, telephone) is also in need of further study.
Lenny Siegel, Executive Director, Center for Public Environmental Oversight
U.S. EPA’s 2001 draft toxicity assessment found that TCE is five to sixty-five times more toxic than previously believed, largely because of the risk to children. Consequently, most EPA Regions have adopted a new "provisional" standard of .017 micrograms per cubic meter (mcg/m3). However, New York has no clear plan for responding at concentrations below 5 mcg/m3. Because people who live and work above volatile pollution cannot replace the air they breathe, policy-makers should take a more precautionary approach.
Vapor intrusion is usually viewed as the rise of toxic fumes directly into structures. However, contamination may escape over a large area, elevating ambient concentrations above the screening level. Therefore, investigations should be based upon conceptual site models that consider all sources, pathways, and receptors.
Cleanup should be accelerated to ensure that mitigation measures will remain effective in the long run, reduce outdoor exposures, and enable safe reuse of vapor-impacted properties. Today there are cheaper, faster technologies that can protect against vapor intrusion and restore groundwater resources.
Theodore J. Henry, M.S., Toxicologist and Community Involvement Specialist, Henry and Associates, LLC
Trichloroethylene (TCE) is one of the top 8 percent most toxic compounds based on EPA Region 3 data. The data available show that the current national debate over adequate vapor intrusion criteria is economic and not the result of a lack of data. This is unfortunate given America’s past lessons involving lead and smoking, where we ignored science for decades at the cost of many lives and young minds.
EPA has started addressing vapor intrusion, but investigation of this pathway is in its infancy. Furthermore, the financial and technical expertise limitations at the state and local level will impact the Nation’s ability to protect communities from TCE. Nevertheless, community members will try to apply political pressure where they can to get adequate testing and remediation despite a regulatory process that is financially strapped, technically challenged and conflicted. Some policies and regulations will be implemented to help, but this will take years and will differ drastically from state to state. While communities work hard to bring this change, they will need the support from political leadership to allow them to participate effectively. All participating agencies must involve communities through HEART (Honesty, Empathy, Accessibility, Responsiveness and Transparency). Technical issues needing to be addressed include: source definition, correlation of known contamination with records, groundwater flow, soil gas data, indoor air data over time, biomonitoring, etc.
In the end, science must prove itself with empirical data from the affected communities, not just with modeling and risk assessment. If the affected communities do not get this type of community involvement and technical support, contamination will be missed, misjudgments will be made regarding true exposure levels, and the remedial actions selected will fall short of protecting neighborhoods.
Bernadette Patrick, Citizens Acting to Restore Endicott’s Environment (Edited by staff)
I am a resident in the Town of Union and co-founder of the citizens’ action group C.A.R.E. On October 31, 2002 my daughter at the age of 17 during her senior year of High School was diagnosed with Hodgkin’s Lymphoma.
On that same day in October the DEC, DOH, and IBM representatives agreed upon a mitigation decision matrix to be protective of public health and to be used to determine which houses in my neighborhood, located in a 300-acre toxic plume, will be eligible for a mitigation system. To date there are 480 properties with mitigation systems installed.
There are hundreds of people in this community that share these same stories. What is worse, knowing or not knowing? The level of fear and anxiety is the same for everyone living within this plume. Test or no test, system or no system.
Think about the scenarios I just mentioned. They are real. There are about 200 more homes in the area near the mapped plume that have TCE under them. They are not qualifying for testing or mitigation systems. The only way we can ensure the safety of the people in this designated area is to lower the acceptable levels of TCE vapor intrusion and vent their homes.
Based on this testimony I am here today asking that the EPA set a standard for TCE at nothing greater than .017 micrograms per cubic meter. It is your fiduciary duty to ensure that this community and every community nationwide be protected from vapor intrusion stemming from soil and groundwater contamination caused by industries that jeopardize our health and well being.
Alan Turnbull, Coordinator, Resident Action Group of Endicott (Edited by staff)
Some two years ago, my wife was diagnosed with squamous cell carcinoma, a cancer of the throat. Oncologists will never venture any statement as to its cause, but it is generally thought to have origins by inhalation of air or drinking of liquids (water). In an effort to determine what may have caused this illness, I began to ask questions from a multitude of sources, such as the Cancer Society, the NYS-DOH, and private oncologists. Needless to say, I was confronted with more questions than answers. To my dismay, I found that there were no safe guidelines or standards that addressed residential indoor air standards for toxic intrusions. Therefore, safe guidelines and standards must be established to protect the citizenship of our community as well as other communities around the country. These guidelines and standards must be put into place as soon as possible to ensure productive and healthy lives for all.
It is crucial that a commission of scientists and medical personnel undertake extended studies for low dose ingestion of toxins in humans without delay. Results of this toxic/human hypothesis of low dose exposure must be made available to the general public at the earliest timeframe possible.
Pressure should be placed on EPA to have their science committees present the lowest possible threshold level for remediation. While some scientists admit that any air/vapor TCE reading qualifies to institute remediation, we must not accept any guideline threshold level higher than .175 micrograms per cubic meter (a guideline of .017 micrograms per cubic meter would be preferable).
Remediation must be vigorously undertaken by any and all means at our disposal. However, mitigation via venting systems installed in homesteads is, at best, only a temporary "stop-gap" measure.
Last, and most importantly, I request that the following be given serious consideration: That in order to expedite residential VOC/toxic testing by the NYS-DOH/NYS-DEC to determine toxicology levels:
As it now stands, a team of technicians must take an inventory of any and all items within a basement to remove anything that would possibly influence air sampling. This elimination process alone takes approximately four hours. Thus the team is able to test approximately two residences per day. However, by performing sub-slab sampling, approximately six houses could be accomplished per day. By reducing time, costs would likewise be reduced, and overall area testing would be accelerated.
Donna Lupardo, Resident Action Group of Endicott (Edited by staff)
The residents of the Village of Endicott and surrounding entities have been exposed to contaminants from multiple exposure routes including air pollution, contaminated drinking and bathing water, soil gas, and vapor intrusion. Health studies need to take into consideration the combined effects of these various exposure routes. In looking at places like Endicott, there is a need to create models that take all of these routes into consideration.
As far back as 1989, reports were being published indicating that the IBM facility led the United States in chlorofluorocarbon emissions and other pollutants. Most of us here are interested in knowing what the current emission levels are from the plant; how the current ambient air is affected by hundreds of venting units; and what we can learn from historic air emission levels. After much delay, the Agency for Toxic Substances and Disease Registry (ATSDR) is now in the process of surveying residents to gather information about the historic pre-1987 air emission levels where there seems to be some kind of information gap.
We’ve now been witness to the evolution of the science of vapor intrusion. Communities around the State are grappling with the reality of this new exposure route. I join my friends in saying that we want the State to thoroughly examine the issue of putting in place stricter TCE air standards, which should be stricter than the current standard of five micrograms per cubic meter.
Many of these standards are set for adults over short exposure time periods. We’re especially concerned that the standards also take into consideration young children who are more sensitive to contaminants of this kind.
I’d like to point your attention to something that our Press and Sun Bulletin reported back in August. They reported that water samples from a well installed in the IBM cafeteria building back in 1963 showed evidence of pollution in the bedrock two hundred and fifty feet below the site and evidence suggests industrial solvents may have reached a deep aquifer that feeds a network of wells along the Susquehanna River Valley. Collectively these wells serve at least eighty thousand residents in Vestal, Johnson City and in Endicott. Obviously, there could be a potential need for more aggressive remediation efforts given the sheer number of people affected.
Finally, we are grateful that ATSDR has a mixtures work group investigating the water contamination issue. While we’ve been assured that there are low levels of various compounds in the water, what is not clear is what happens when these low levels interact with one another. Further scientific inquiry may show that such commingling of these contaminants represents a potential threat to public health.
Bruce K. Oldfield, Hillcrest Environmental Action Team (edited by staff)
I am a resident in Hillcrest, NY and part of a citizens’ action group, the Hillcrest Environmental Action Team, HEAT.
In 1992, a discharge of TCE into a dry well at the former Singer-Link facility (now owned by CAE Electronics) was mapped, indicating movement of this material into the surrounding neighborhood. Since then, TCE has spread throughout portions of the residential area and even shows up in a monitoring well 1700 feet from the source, on a direct path towards our drinking water well field.
Recently, the DEC began monitoring TCE levels in our homes. Levels above 5 micrograms/cubic meter were discovered. I had been following a similar problem in Endicott and was told that the standard for mitigation there was 0.22 micrograms/cubic meter. In Endicott, just under 500 homes were vented. In Hillcrest, only three homes were vented although many more were above the .22 micrograms/cubic meter action level used in Endicott.
The EPA proposed guideline for TCE in residential buildings is 0.017 micrograms/cubic meter. This is roughly 300 times lower, that is, more stringent, than the standard set by New York’s DOH. Although the DOH acknowledges the range of estimates for TCE (for one excess cancer per million persons) is 0.2 to 4 micrograms/cubic meter, our standard was set arbitrarily higher at 5 micrograms/cubic meter. The orders of magnitude difference between the provisional EPA standard and DOH standard concerns me and many of my fellow residents.
I am also concerned that the venting of TCE from the subslab of our homes is moving the pollutant from one area to the next. When temperature inversions form in these valleys, the air that we are venting from the ground is trapped in the valley so not only are we breathing it in our homes, we are breathing it in the outdoor air also. We find this unacceptable.
I would like the NYS Assembly to consider using its influence on the NYS Department of Health to change the NYS standards for TCE in our homes to match the EPA provisional guidelines. I would also like to see outdoor air standards set that are going to insure that breathing this air is safe for our children.
Debra Hall, Hopewell Junction Citizens for Clean Water
All I know is that living in the United States, paying my taxes and living an honest life, the least my family and I deserve is clean air to breath and clean water to drink. Imagine knowing that your water and air are contaminated. You go to the health agencies, the so called experts, who are there to help you. But instead of getting the help you need you get untruths and false information. And then you ask why? Is it financial? Is it that if the person tells you what they know they will get in trouble? Is it that they really do not know?
Whatever the reason is, my family should not be at risk of getting cancer or some other deadly disease. I see it all around me, so many sick people, especially children. It has been known that my site was contaminated since 1979, but the correct investigation never took place. The Hopewell Junction Citizens for Clean Water ask to stop making us victims. Give us air standards that will protect us. It can be done. It’s possible. No more excuses. The technology is here. It’s only common sense that this issue gets dealt with correctly and morally.
Philip J. Landrigan, M.D., M.P.P, Director, Center for Children’s Health and the Environment, Mount Sinai School of Medicine
Leonardo Trasande, M.D., M.S., Assistant Director, Center for Children’s Health and the Environment, Mount Sinai School of Medicine (Edited by staff)
TCE is an organic chemical that has been used for dry cleaning, metal degreasing and as a solvent for oils and resins. It evaporates easily in the open air but can stay in the soil and groundwater for years afterwards. In the body, TCE may break down into multiple other chemicals such as dichloroacetic acid, trichloroacetic acid, chloral hydrate, and 2-chloroacetaldehyde. These products have been shown to be toxic to animals and are probably toxic to humans, especially young children with developing bodies.
The most well-studied and significant health effect of TCE is its link to cancer. Studies of workers exposed to TCE are sometimes complicated to interpret because many of these workers are exposed to other solvents that also can cause health effects. However, TCE has been found to cause cancer in both mice and rats, which suggests that it also causes cancer in humans. The World Health Organization has classified TCE as a Class IIA carcinogen, meaning that TCE is probably carcinogenic to humans. The EPA has also stated that TCE may have the potential to cause cancer in humans, and has set a maximum contaminant level for TCE of five parts per million in drinking water.
Other effects that can result from heavy TCE exposure include damage to the liver, kidneys, gastrointestinal system, and skin. TCE has been linked to birth defects. Chronic exposure to TCE can also affect the human central nervous system. Case reports of intermediate and chronic occupational exposures included effects such as dizziness, headache, sleepiness, nausea, confusion, blurred vision, facial numbness, and weakness.
For all of these reasons, all occupational exposures to TCE should be thoroughly investigated. Not only do the workers who have been exposed to TCE deserve to know the potential health effects they have suffered, but further research into the health effects of TCE will help clarify important questions that remain about its health effects.
In addition, we also need to consider the effects of TCE contamination on people in the broader community. For example, children are especially vulnerable to the health effects of TCE, just as they are to many other chemicals. The health and economic consequences of children’s present-day exposures to environmental toxicants will be experienced by our society throughout much of the twenty-first century.
Unfortunately, we have learned this lesson the hard way, in part because of exposures to chemicals such as TCE. A very high rate of childhood cancers in Toms River, New Jersey was found to be linked to the amount of drinking water that women ingested during their pregnancies. Even though the water was never found to have levels higher than EPA’s contamination standard for TCE, the researchers’ analysis demonstrated that exposure to TCE in the fetus was associated with cancer, especially leukemia, in these children. The epidemiologists who studied this cluster of cancer suggested that the developing fetus might be especially vulnerable to TCE and other chemicals that were found in the drinking water in Toms River. As the exposure to TCE was removed, researchers found that the cancer rates in Toms River decreased significantly.
One way to prevent and treat children’s exposures to environmental contaminants, such as TCE, is through the development of a statewide system of Children’s Environmental Health Centers of Excellence.
David Ozonoff, M.D., M.P.H., Professor of Environmental Health, Boston University School of Public Health (Edited by staff)
I have had a long interest in the health effects of the chlorinated ethylenes TCE and its very close relative, tetrachloroethylene (PCE), and have authored numerous peer-reviewed epidemiological studies on these chemicals. TCE has been implicated in at least four kinds of adverse health effects: effects on the central nervous system; cancer; birth defects; and autoimmune disease, such as lupus. For historical reasons and force of circumstance much of our knowledge of the effects of TCE are based on occupational exposures. While it is not easy to determine what effects might be expected, if any, at the substantially lower levels normally encountered from vapor intrusion, I am concerned about effects even at these levels for two main reasons.
First, we have been studying the effects of TCE in drinking water for almost 15 years and have seen substantial increased cancer risks at exposures orders of magnitude lower than occupational exposures. Residential exposures to drinking water come from a combination of ingestion, inhalation (from air stripping) and dermal absorption, with the latter two being of roughly the same order of magnitude as ingestion. The current maximum contaminant limit (MCL) for drinking water is 5 micrograms per liter. This corresponds (roughly) to an indoor air exposure of 1 microgram per cubic meter of air. The MCL is an old standard based on outdated cancer estimates. Thus the level of 5 micrograms per cubic meter proposed by the NYS DOH is not consistent with the current (now fairly old) water standard.
In addition, there is reason to believe that the exposure level corresponding to an excess cancer risk of one in one million is considerably lower than previously thought. To be health protective one normally chooses the most conservative estimates. Considerable uncertainty in the correct parameter estimates for important physiological processes, like the rate of absorption between species, can lead to very large differences in dose-response modeling. W.J. Cronin and colleagues use Monte Carlo analysis in conjunction with physiologically-based pharmacokinetic (PBPK) modeling to determine the impact of different parameter values on estimates of the risks posed by TCE. There is a wide range of legitimate estimates using PBPK models when coupled with the linearized multistage model used by DOH. Cronin, for example, has estimates as low as 0.02 micrograms per cubic meter as the one in one million risk for TCE in air.
The choice of a linearized multistage model, as used by DOH, is not the only possible choice, and choosing a different biologically plausible model can result in a large variation in estimated risks. C.R. Cothern and colleagues investigated the variations between four different models, including the model chosen by DOH. The difference in estimated risks among the models was almost a factor of 10,000, i.e. the most protective model (the Weibull model) predicted risks from TCE in drinking water to be 10,000 times higher than the risks from the least protective model (the multistage model chosen by DOH). There are no biologically based criteria for choosing one model over another.
My second concern is that adverse health effects can be expected to result from extremely tiny exposures where some kind of biological amplification of damage occurs. The classic example is cancer, where a tiny alteration in DNA makes a cell into a cancer cell. The original damage is biologically reproduced and the offending tiny amount of chemical no longer need be present. This is essentially the reason we believe there is some cancer risk at every level of exposure.
There are other biological systems where such intrinsic amplification might be expected, including the immune system (eg. bee stings and the dramatic, sometimes fatal effect of tiny exposures); the nervous system (where tiny signals are amplified into large responses); and human reproduction (where an entire organism comes from a single fertilized egg). Thus the health effects seen in occupational environments are plausibly present, although at a much lesser frequency, at much lower exposures as well.
Daniel Wartenberg, Ph.D., M.S., Director, Division of Environmental Epidemiology, Robert Wood Johnson Medical School (Edited by staff)
I have been studying the health effects of TCE for about 8 years and am increasingly concerned about the likely carcinogenicity of TCE and its impact on the health of those exposed to even low levels of this chemical.
In 1997 I was awarded a grant by the EPA to evaluate the epidemiologic evidence for making inferences of cancer hazards and risks for exposure to TCE. With colleagues, I conducted a detailed review of more than 80 relevant scientific publications. We concluded that evidence of excess cancer rates among occupational cohorts with the most rigorous exposure assessment is found for kidney cancer, liver cancer, non-Hodgkin’s lymphoma, cervical cancer, Hodgkin’s disease, and multiple myeloma. In 2000, I again summarized the data and made similar conclusions. One notable report published since my review in 2000 was on a new cohort in Denmark that uses measures of biological material to document exposure to TCE. In general, the results of that study provided additional support for the findings we presented in 2000, which suggested that TCE exposure causes cancer in humans.
I acknowledge the limitations of some of these studies, and imprecision of the assessments of exposures, but I believe that the evidence points strongly towards carcinogenicity and that exposure should be minimized to the degree reasonably possible unless and until evidence to the contrary can be developed. In short, based on the evidence, we believe that TCE should be considered a human carcinogen until proven otherwise.
In general, any exposure to a carcinogen increases an individual’s risk of developing cancer. Therefore, on the basis of the available evidence, and in the interest of preventing unnecessary cases of cancer, I urge you to limit exposures to the minimum amounts reasonably achievable.
Because the studies conducted did not collect sufficient data on length and magnitude of exposures for rigorous modeling of the likely carcinogen, we should err on the side of overprotection rather than underprotection. In addition, the research on other outcomes is somewhat limited, again suggesting the need for more stringent rather than less stringent exposure limits.
Conclusions and Recommendations
The evidence gathered through this hearing underscores the high level of uncertainty and controversy associated with all of the issues raised by vapor intrusion including the screening and testing of sites, the setting of indoor air quality standards, and determining the appropriate mitigation, and remediation measures. Policies and guidelines to address these issues are still in the developmental stage in New York State and across the country.
An overarching principle to remember as New York proceeds to address the challenges posed by vapor intrusion is that the degree of uncertainty associated with these challenges is an issue in itself. Living with uncertainty is one of the most difficult aspects of living at a contaminated site. It is a source of incredible stress and frustration. This uncertainty is a given, at least for the foreseeable future. In the face of such uncertainty, government must strive to take a precautionary and transparent approach.
A precautionary approach holds that where threats of harm to human health or the environment exist, lack of full scientific certainty about cause and effect should not be viewed as sufficient reason for government to postpone precautionary measures to protect public health and the environment. We must use the knowledge we have today to take a preventive approach to eliminating exposures from vapor intrusion.
Government must also provide citizens with complete and accurate information on the potential health and environmental impacts associated with different policy choices. The policy making process should be open and transparent, and provide citizens with opportunities for meaningful participation.
In addition, the degree of scientific complexity associated with a decision should not be used to obscure the nature of the decision at hand. For example, the scientific evidence regarding TCE supports a range of toxicity estimates, largely based on the protectiveness of underlying assumptions. This has led to the adoption of indoor air guidelines by EPA Regions and states that vary by an order of magnitude or more. These guidelines are all scientifically plausible and supported by "sound science." The choice between them is largely a policy choice, not one of science alone.
The following recommendations are based on information gathered through this hearing. These actions should be taken as part of developing a comprehensive policy for addressing vapor intrusion in New York State:
New York State is in the beginning stages of developing policies to address vapor intrusion and should work with citizens and public policy makers to tackle the important challenges ahead in addressing the threat to public health posed by vapor intrusion. This hearing was one effort to provide transparency and encourage participation.
ASSEMBLY STANDING COMMITTEE ON ENVIRONMENTAL CONSERVATION
NOTICE OF PUBLIC HEARING
|SUBJECT:||Vaporization of contamination from soil and groundwater into indoor air|
|PURPOSE:||To examine the human health impact of vapor intrusion stemming from soil and groundwater contamination|
Chapter 1 of the Laws of 2003 establishing the Brownfield Cleanup Program (BCP) provided for the refinancing of the State Superfund program and a comprehensive program for the long-term restoration of groundwater. The groundwater provisions of the new program are based on experience at various sites under New York’s Superfund and Oil Spill cleanup programs. The intent was to address the shortcomings of those programs by providing for the investigation and pursuit of off-site migration of contamination, particularly through groundwater plumes, in order to eliminate human exposure.
The vaporization of contaminants from soil and groundwater impacting indoor air has occurred at several State Superfund sites and has the potential to be a problem at brownfield sites. While both the New York State Department of Environmental Conservation and United States Environmental Protection Agency are considering draft guidance that sets standards for vapor intrusion, neither agency have issued final guidance. Vapor intrusion should also be considered during the development of generic soil cleanup standards under the BCP.
The purpose of this hearing is to examine issues concerning the vaporization of contamination from soil and groundwater and resulting human exposure, and to determine what lessons can be learned from experience in order to properly address vapor intrusion in the future. The Committee will take testimony from various witnesses including panels of federal, state and local government officials, public health and environmental experts and citizens representing affected communities.
Oral testimony will be accepted by invitation only and limited to 5 minutes duration. 10 copies of any prepared testimony should be submitted at the hearing registration desk. The Committee would appreciate advance receipt of prepared statements. Written testimony will also be accepted and may be sent to the contact person listed on the reply form. In order to further publicize the hearing, please inform interested parties of the Committee’s interest in receiving written testimony from all sources.
In order to meet the needs of those who may have a disability, the Assembly, in accordance with its policy of non-discrimination on the basis of disability, as well as the 1990 Americans with Disabilities Act (ADA), has made its facilities and services available to all individuals with disabilities. For individuals with disabilities, accommodations will be provided, upon reasonable request, to afford such individuals access and admission to Assembly facilities and activities.
October 26, 2004
Honorable Erin M. Crotty
Dear Commissioner Crotty,
On November 15, 2004 the New York Assembly Standing Committee on Environmental Conservation will hold a public hearing to examine issues concerning the vaporization of contaminants from soil and groundwater into indoor environments and human exposure to such contaminants. Specifically the Committee is interested in receiving testimony addressing both the state of the science and as well as the policy implications of vapor intrusion. You are invited to appear before the Committee on this date to more formally explore these issues.
Witnesses participating in the hearing may be grouped into panels consisting of individuals with similar backgrounds and/or expertise. Each witness will be asked to make a formal presentation for 5 minutes, followed by questions for the panel as a whole, as well as for individual witnesses.
The hearing will be held on November 15th at the Endicott Visitor Center in Endicott, New York and will begin at 11:00 a.m. More detailed information is included in the enclosed Hearing Notice. Your response by November 4, 2004 will be appreciated. If you have any questions, or would like further information, please contact Jeff O’Donnell or Alex Roth at 518-455-4363. Thank you and we look forward to hearing from you.
Honorable Mauric Hinchey
Honorable Joan Pulse
Carl Johnson, Deputy Commissioner
Dr. Nancy Kim, Director
Matthew Hale, Director
Joseph Graney, Assistant Professor
Lenny Siegel, Director
Theodore J. Henry, Toxicologist and Community Involvement Specialist
Alan Turnbull, Coordinator
Bruce K. Oldfield, Member
Debra Hall, Member
ADDITIONAL EXPERT TESTIMONY WAS SUBMITTED BY
Leonardo Trasande, M.D.
Philip J. Landrigan, M.D.
David Ozonoff, M.D., M.P.H.
Daniel Wartenberg, Director
January 24, 2005
Commissioner Erin Crotty
Dear Commissioner Crotty,
Thank you for the opportunity to comment on the Department’s proposed vapor intrusion policy. I appreciate that the Department has acted quickly in drafting this policy in an area that experts in environmental health and engineering have only recently come to realize has significant potential to result in significant risks to human health from exposures.
As you know, the Assembly’s Environmental Conservation Committee recently held a hearing on vapor intrusion in Endicott, NY. The difficulty associated with setting indoor air quality standards underscores the need to proceed cautiously, yet to ensure that actions taken protect the health of residents. Testimony from citizens impacted by contaminated sites here in New York made it clear that living with uncertainty is one of the most frustrating and stressful things about living near a contaminated site.
The vapor intrusion policy being formulated by the Department has the potential to ease much of this stress and frustration. To be successful, the vapor intrusion policy that is finally adopted by the Department must be protective of human health and the environment and be transparent. People must be able to see and understand why the Department has made the decisions it has in ranking and investigating contaminated sites.
It is with recognition of the great work being done and tremendous efforts being put forth at the Departments of Environmental Conservation and Health to develop a protective vapor intrusion policy as well soil cleanup program and standards that I offer the following comments. I encourage DEC to consider them and re-issue another draft before finalizing this policy.
Assemblyman Thomas P. DiNapoli
Thank you for this opportunity to comment on the Department of Environmental Conservation’s (DEC’s) Draft Policy on Vapor Intrusion. DEC’s intention to evaluate all contaminated sites to determine whether the vapor intrusion pathway is complete is commendable. I am also looking forward to reviewing the draft "Guidance for Evaluating Soil Vapor Intrusion in the State of New York" when it becomes available.
While I commend DEC for issuing this draft policy is such timely manner, I believe that there is a lack of transparency that makes it impossible to assess fully the adequacy of the policy as a whole and its specific components. I hope that the following comments will be useful in focusing attention on areas that need additional explanation.
The Draft Policy Needs to Clarify How Many Sites will be Investigated and the Timeline for Investigation. Page two of the Draft Policy states that DEC estimated that solvents or other volatile chemicals have been disposed of at over 750 sites resulting in contaminated soil or groundwater. Page three notes that there are more than 400 sites where chlorinated volatile organic compounds (CVOCs) were disposed of or detected in soil or groundwater. The draft report states a "manageable number of sites" will be initially targeted for further study to determine whether impacts associated with vapor intrusion exist. Once initial investigations are complete and any necessary revisions to the procedures are made, DEC will then begin to investigate the remaining sites identified as having potential vapor intrusion impacts. Each year several previously investigated sites will be selected from each Region for further vapor intrusion investigations until all sites requiring further study have been completed.
There is concern that it will take DEC a very long time to investigate all known sites at which public health threats may exist. DEC should state what it believes to be a manageable number of sites that will be targeted initially for further study, and identify how long it estimates it will take to investigate all sites that may be causing vapor intrusion problems.
The Draft Policy needs to state the trigger for actual investigation of contaminated sites. While the summary of the draft policy notes that all past, present and future contaminated sites will be evaluated, the section on screening criteria (p.3) notes that sites will be prioritized based on the ranking and considered for further evaluation. Due to the uncertainties that exist in assessing vapor intrusion, the fact that site characteristics determine how vapors migrate and that understanding of soil vapor migration and intrusion is still evolving, I believe that on-site inspections will be necessary at all sites. In addition, DEC should state clearly whether it intends to investigate all sites or some percentage of sites and what actions will be taken when vapor intrusion impacts are found to exist.
Additional Public Outreach Needed
Numerous Questions Remain Concerning Complete Pathways
It is not clear how DEC will determine the current location and extent of the groundwater plumes, which is necessary to determine completed pathways. Without this information, it is impossible to establish a safe distance for measuring adjacent site use or for determining what structures should be evaluated for completed pathways - as is called for in the draft policy. This needs to be clarified.
While this policy deals directly with existing vapor intrusion problems, I am also concerned with how DEC will address situations where no complete pathway is currently identified, but migrating groundwater with levels of contamination exist that may ultimately result in vaporization problems when the plume reaches inhabited areas. If DEC will be relying on existing, dated, information on sites, an additional concern exists as to how DEC will ensure that new pathways have not developed/evolved over time.
As defined, a complete pathway means that humans are exposed to vapors that originate from site contamination. By this definition, vapor intrusion is not limited to indoor air. I support the inclusion of outdoor vapors from contamination being incorporated into DEC’s vapor intrusion policy.
Prioritization of Contaminated Sites Needs More Explanation
According to the draft policy, prioritization of contaminated sites will drive additional investigation. It is not clear how DEC will determine if impacts associated with vapor intrusion exist. DEC should clarify how many site-specific conditions and what numerical weighting they believe will have to be present to trigger further action. Will one completed pathway be sufficient to trigger additional investigation?
It Is Unclear Why Soil and Groundwater Contamination are to be Prioritized Separately
Additivity should be Considered
Lack of Information Should Not be Assumed to Mean No Impacts Exist
Screening for Chlorinated Volatile Organic Compound (CVOC) Vapor Intrusion
Concern that Potentially Significant Sites Will Not Triggering Action
The Trigger for Further Investigation at Sites with Contamination Deep Underground Needs Further Explanation. The background section of the draft policy notes that past assumptions that drove investigation into vapor intrusion were flawed, including the assumption that if an off-site dissolved contaminant plume flowing beneath a home or business was deep, then the concentration of vapors entering buildings above would be so low that they would not represent indoor air concerns. As drafted, this policy places the lowest possible weight on sites where contamination is deep underground. This seems to be inconsistent with DEC’s acknowledgement that the potential impacts of such contamination were previously underestimated. It is unclear that the proposed weighting of depth to groundwater proposed in this policy will provide adequate protections for human health. An explanation of how this determination was made needs to be provided.
Information is Needed for Sites with Source Remediation Complete and Remaining Groundwater Contamination. The section on vapor intrusion investigation does not cover those cases in which the initial source of contamination has been remediated, but contaminated groundwater remains either on or off-site. The draft policy notes (p.5) that if groundwater within 100 feet of or beneath an occupied building is contaminated with VOCs, then a characterization effort will be required. If groundwater quality data is unavailable, a limited groundwater investigation may be required to evaluate current groundwater conditions downgradient of any remaining on-site sources of VOCs in order to make this determination. DEC needs to ensure that sites where the source has been remediated but groundwater remains contaminated are covered in its final policy.
Additionally, for sites at which groundwater contamination has existed for some time, contaminated groundwater plumes may have migrated further than 100 feet from the original source. Provisions for addressing this should be included in the draft policy.
I hope these comments are useful in formulating a final, transparent vapor intrusion policy. If you have any question, please feel free to contact my office.
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