Author: Alex Miller

EPA Adds West Vermont Street Site to Superfund List

Posted on by Alex Miller

Following nearly a year of speculation, an 18-acre groundwater contaminant plume on Indianapolis’ West Side, has landed the area on the U.S. Environmental Protection Agency’s new Superfund list.  Superfund is a federal program that aims to address some of the most contaminated land and waterways in the country.

In September 2015, the EPA made the proposal to put the West Vermont Street groundwater site on the National Priority List. In 2009, Marion County Health Officials had discovered high concentrations of vinyl chloride (a breakdown product of drycleaning solvents) in the drinking water of three homes near the Allison Transmissions plant, just south of the Indianapolis Motor Speedway.

Proposal Map for West Vermont Street Superfund Site. Courtesy: United States Environmental Protection Agency
Proposal Map for West Vermont Street Superfund Site. Courtesy: United States Environmental Protection Agency

 

According to EPA officials, there were at least 20 other potentially affected homes in the area, and immediate action was taken to ensure the health and safety of these homeowners. Utility workers diverted the water service from the underground water wells in the area to municipal water.

Even with this measure in place, EPA officials determined the potential danger of the groundwater plume was too much to ignore. Investigations confirmed the migration of the plume could put as many as 18 thousand people at risk of becoming exposed to the contaminant.

EPA officials are now conducting further investigations to delineate the horizontal and vertical nature of the plume, filling in data gaps, and identifying all potential exposure pathways including vapor intrusions. A few potential responsible parties have been identified as a result of their historic operation and known individual contaminant releases on their properties.

EnviroForensics has been involved in SuperFund sites like this one around the Indianapolis area, including the Keystone Corridor Project, and we know how important this work is. We look forward to providing additional information as new developments arise regarding this project.

Where There is Exposure, There is a Problem: Identifying Exposure Pathways

Posted on by Alex Miller

It may seem like the objective of every project is to completely wipe out contamination, but it’s a little more nuanced than that. Sure, we want to make certain that a client’s property is as clean as it can be for future use, but it’s also important to consider where actual risks to human health occur in situations where a thorough site cleanup isn’t possible. That’s why, when we develop a Conceptual Site Model (CSM) a key component is the identification of potential exposure pathways and receptors. Once we can prove there’s no possible way a human can come in contact with the contaminant, we’re one step closer to obtaining the coveted “No Further Action” letter from the regulatory body with which we’re working.

It all starts with the investigation. In short, we use the data collected from soil and groundwater tests to delineate and characterize the horizontal and vertical nature of the contamination plume. The size, shape, and location gives us a general idea of which structures and buildings may be impacted, and, using this information, we can draw up our CSM.

In the Conceptual Site Model (seen in the simplified figure below) you can see we’ve labeled the actual dry cleaner machine (the established source of contamination) the buildings resting above the contaminated soil and groundwater, the different types of impacted soils,  groundwater and all identified migration pathways.  The contaminant migration pathways are indicated by the arrows in our figure.

Conceptual Site Model Example

The next step is to test those pathways to determine if there’s a potential for exposure, because where there’s exposure, there’s a problem.  We start at the established source, and work our way down and up from there, checking surrounding structures for possible vapor intrusions, and testing soil and groundwater impacts and the possible receptors they could come in contact with (sewer laterals, sewer mains, groundwater wells, and the like.)

Once we’ve determined the existing pathways, it’s time to figure out what (if anything) needs to be done. We conduct an exposure assessment based on the type of receptors being impacted. Those receptors can be humans, utility corridors, drinking water wells, and the like. As an environmental consultant, we want to wipe out any contamination, but we are also beholden to both the institutional constraints and the client’s legal obligations. Identifying the potential exposure pathways at a Site can help us pin-point our focus as we draw up our site closure strategy.

 

 

Thermal Remediation: How to put VOCs on the Hot Seat

Posted on by Alex Miller

We know that chlorinated solvents tend to volatize on their own, so what happens if we use the chemical’s physical properties to cause them to volatilize even more? That’s the concept behind Thermal Conductive Heating (TCH) or Electric Resistance Heating (ERH). The idea is to heat the subsurface to such a temperature that any present contaminant becomes volatized and can be removed from the soil and groundwater. Using super-heated metal rods (TCH) or an electric current (ERH) along with some familiar applications from remedial techniques we’ve touched on in the past, a “thermal” approach can make for an effective remediation strategy for sites where other techniques are less feasible.

Excavation might not be an option if above ground structures are in the way or if contamination is too deep. Soil Vapor Extraction Systems (SVE) can prove to be an effective solution, but can prove to be equally ineffective if the contaminant plume is too deep or the concentration of the contaminant is too great. In other cases, the contamination could be resting in a patch of more dense clay soil, making it more difficult to extract contaminants. Contamination in saturated clay soil can be slowly released into groundwater over time in a process known as “back diffusion,” which makes it more difficult to achieve cleanup goals. In all these scenarios, TCH or ERH can be a viable option.

Thermal Conductive Heating
Figure Courtesy of: Terratherm

 

 

 

 

 

 

 

 

 

 

 

 

A thermal remediation system has a set of components that, working together, can effectively remove contamination from a cleanup site. The first component is the heat itself. In a TCH application, several heating rods are placed into the impacted areas to effectively raise the temperature of the ground. Additionally, a vacuum component will be installed into these wells to extract the vapor generated by the heat. If necessary, groundwater extraction wells will be installed near the heating wells to collect impacted groundwater. Treatment systems are used to remove contaminants from the water and vapor that has been extracted.

Once the thermal remediation process is started, the components operate like workers on an assembly line. Heat is applied to the subsurface, chemicals become volatized, and contamination is collected in the vapor phase by the vacuums in the heating wells. The vapors are put through a treatment component, then released into the atmosphere.  Groundwater is extracted from the subsurface as well and goes through a treatment process of its own.

“Thermal” applications are considered “in-situ”, or in-place, and are perfect for sites in which demolition or excavation are not possible, or the contamination cannot be addressed by any other means.

Bloomberg: Struggles Persist to Enhance Vapor Data Innovations

Posted on by Alex Miller

Reproduced with permission from Daily Report for Executives, 153 DER (Aug. 9, 2016). Copyright 2016 by The Bureau of National Affairs, Inc. (800-372-1033) <http://www.bna.com>

Public and regulatory concerns are steadily rising over the risk of health detriments linked to vapor intrusion that seeps into the floors of buildings.

The Environmental Protection Agency continues to warn short-term exposure to trichloroethylene (TCE), a degreaser and primary contaminant spread through vapor intrusion, among pregnant mothers may cause fetal cardiac defects.

And the agency is moving forward with nearly surefire finalization of a rule to add vapor intrusion, the process of volatile compounds migrating through sub-surface groundwater or soil to air in above-ground structures, to the Superfund Hazard Ranking System.

But high-tech developers and vendors are struggling to overcome hurdles in vapor intrusion sensor development, leaving potentially affected communities in the lurch with unreliable or inaccessible data.

Mobile technology isn’t yet sophisticated enough to detect contaminants at necessary precision, even with the historical help of some government agencies, according to recent Bloomberg BNA interviews with consultants and advocates.

That’s leaving vapor intrusion assessment at a deficit. Sensor technology is advancing at breakneck speed in other regulatory areas prone to hazard, such as occupational safety and health and climate change.

 

Need for Improvement

The EPA nationwide and private industry rely on largely passive sampling of air, groundwater, soil and sub-slabs to model the likely threat posed by a vapor intrusion pathway, the agency says.

That approach traditionally involves canister sampling with gas chromatography/mass spectrometry analysis and other methods to assess indoor air concentrations of common vapor intrusion contaminants, such as TCE and tetrachloroethene (PCE), as well as benzene, toluene, ethylbenzene and xylenes, a chemical group known as BTEX.

Those technologies and tactics, however, fail to effectively diagnose short-term risks, contamination spikes and variability, because they target time-weighted averages, rather than continuous monitoring, experts told Bloomberg BNA.

“There’s a lot of evidence that indoor air concentrations vary enormously, daily, seasonally and by weather. Soil/gas concentrations may also vary seasonally,” Lenny Siegel, executive director of the Center for Public Environmental Oversight, told Bloomberg BNA.

Traditional devices passively sample over the course of 24 hours to several weeks.

 

Health Concerns

Concerns over contaminants, coupled with a lack of trusted analysis, has even led to the closure of schools nationwide after EPA Region 9 released Superfund guidance in 2014 to highlight the need to safeguard pregnant mothers from TCE exposure.

The guidance points to conclusions outlined in a 2011 EPA toxicity assessment held in a compendium called the Integrated Risk Information System.

“This and other findings in the IRIS assessment of TCE indicates that women in the first trimester of pregnancy are one of the most sensitive populations to TCE inhalation exposure,” the guidance said. “For fetal cardiac malformations, a specific developmental effect, the critical period for exposure is considered to be the approximate 3-week period in the first trimester of pregnancy during which the heart develops.”

 

Public Disruptions

The Magnolia Elementary School in El Cajon, Calif., which is part of EPA Region 9, shut down for the 2015-2016 school year due to perceived vapor intrusion risks.

A class action lawsuit pointed to a TCE plume in the vicinity brought on by a former aerospace manufacturing plant.

Local school officials took similar action in recent months in Winston Salem, N.C. and Millis, Mass.

States such as New York, Connecticut and Massachusetts also have moved forward with their own revisions to TCE and other contaminant concentration standards, and state agencies have shut down sites due to excessive contamination.

Moreover, the Massachusetts Department of Environmental Protection is likely to dive into revisitation needs for roughly 200 sites already closed after remediation of TCE contamination, agency officials announced in April.

The state’s 2011 revised standards slashed appropriate toxicity levels for residential indoor air TCE exposure more than 14 times, from 85 micrograms per cubic meter (µg/m3) to 6 µg/m3.

 

‘No Consensus’ Exists

 

Interested parties continue to debate, however, the TCE exposure linkage with cardiac birth defects.

“There’s no consensus on this [TCE] issue. You put 10 scientists in a room, it’s five and five. It’s like Republicans and Democrats; its split down the middle,” Blayne Hartman, vapor intrusion expert with Hartman Environmental Geoscience, told Bloomberg BNA.

The Silicon Valley Leadership Group contested the guidance in 2015, arguing industry is shouldering drastically increased compliance costs despite the region’s failure to properly roll out the policy change.

The EPA, however, rejected that complaint.

“There are no significant uncertainties that have arisen since 2011 that were not considered prior to the release of EPA’s final toxicity assessment as to whether TCE causes fetal heart defects,” Region 9 Superfund Director Enrique Manzanilla told the group in November 2015.

Meanwhile, the EPA’s 2015 release of national vapor intrusion guidance already pushes site managers and risk assessors to consider sub-surface hazards.

 

 

Emerging Technology

A handful of developers are spearheading sensor innovation and other technology tied to vapor intrusion assessment.

The challenge is to deploy user-friendly, continuous monitoring, mobile devices with parts per billion precision at prices around $1,000 each.

A Palo Alto, Calif., startup named Entanglement Technologies is one potential vendor pushing the envelope.

The company’s lead product, dubbed the Autonomous Rugged Optical Multigas Analyzer, is a mobile, rapid response device.

“It can be costly to screen large areas to determine when that [vapor intrusion] pathway is important, to what degree it’s a concern to health and to be able to cheaply and efficiently either determine that mitigation is required or to determine that mitigation is not required,” Tony Miller, Entanglement chief executive officer, told Bloomberg BNA. “Our instrument allows you to quickly determine where it is important to measure so you can get that study done more quickly, and when it’s done more quickly, it’s done more cheaply because a significant fraction of costs is associated with labor.”

The product, however, isn’t yet on the market. Miller predicted he’d start selling the device in 2017.

 

 

Fusion Technology Being Deployed

Another trailblazer already deployed nationwide is a fusion of a traditional gas chromatography instrument with more precise, customized data intake capacity and analysis, created by Hartman and Mark Kram, founder and chief technology officer at Groundswell Technologies.

“I firmly believe that continuous monitoring, regardless of whether it’s with a sensor or an analytical system, is the only way to be able to understand appropriate dynamics and risks and then respond in a timely fashion,” Kram told Bloomberg BNA. “That in and of itself would allow me to confidently classify this as the most innovative option out there.”

The Hartman-Kram device, which costs roughly $35,000-$60,000 each, is similar in size to a small suitcase.

Other groups like the North Carolina-based RTI International are moving forward with their own products.

 

 

Agency Assistance/Marketability

The Entanglement product received development funding from the National Science Foundation and the National Institutes of Health.

Entanglement’s Miller said enhancement is the only thing keeping his product off the market.

“We have a set of technologies which are fundamentally new, and there has been time required to develop the technology. It hasn’t been a market force issue,” he told Bloomberg BNA. “We’re now at the point where we have successfully demonstrated these technologies, so now it’s just making the transition to commercialization.”

Despite Miller’s 2017 pledge, some experts say developers as a whole are at least a half dozen years away from marketing a product en masse.

But other agencies don’t seem to be weighing in with real resources despite the apparent risks at play.

 

 

EPA Unaware of Assistance

The EPA’s Office of Research and Development said it is unaware of any ongoing research development or private sector assistance for vapor intrusion.

The National Aeronautics and Space Administration (NASA), an agency involved heavily in sensor innovation, also isn’t sponsoring or developing environmental contamination innovation, a spokesman said.

The National Institute of Standards and Technology and the Environmental Security Technology Certification Program, an agency that has traditionally funded vapor intrusion assessment research, didn’t respond to Bloomberg BNA requests for comment.

But other experts questioned whether a lack of demand is restraining innovation.

“What we have is a chicken and egg problem,” the Center for Public Environmental Oversight’s Siegel said. “The regulators don’t require these technologies because they aren’t quite on the market yet, and the companies aren’t pushing, at least, the portable ones; they’re reluctant to develop them because there’s no requirement for them.”

On top of that, the possibility remains that the EPA may reverse its cardiac defect guidance, Hartman said.

“That may take away the demand, or [threshold standards] might go up enough that maybe some of these sensors can get low enough.

That’s all speculation,” he said.

 

 

Superfund Connection?

 

 

The EPA’s looming finalization of the rule (RIN:2050-AG67) to add vapor intrusion to the Hazard Ranking System under Comprehensive Environmental Response, Compensation and Liability Act, better known as Superfund, is generating more interest in and concern for sub-surface hazards.

And while the EPA Region 9 TCE guidance is the most potent precipitator, the Superfund listing may in part drive the push for technological innovation, the experts said.

“This [regulatory development] is not likely to be the last one. With each additional incremental step in the regulation and highlighting of the exposure pathway, you’re going to see more and more developments in the science and technology,” Jeff Carnahan, a vapor intrusion expert with EnviroForensics, an environmental engineering company that represents dry cleaners, told Bloomberg BNA.

Technological improvements may actually, however, unveil a smaller risk posed by sub-surface contaminants, Siegel said.

 

 

Source of Contamination

“If [the source of contamination] turns out to be a can of gun cleaner, than you know where it’s coming from. If it’s a crack in the floor, you know where it’s coming from,” he said, referring to household items that may emit contamination. “This is actually a major issue at a lot of sites where they find something but they don’t know whether it’s really vapor intrusion.”

The rulemaking doesn’t call for revisitation of current Superfund sites or those proposed and deleted.

A decision to include revisitation mandates would have been a game-changer for innovation demand though, Kram said.

“The regulators have to adopt a balanced position, as they do not want to unnecessarily burden the regulated community with high compliance costs,” he said. “Their current policies indicate that they are convinced that acute TCE exposures of low concentrations can be harmful. In addition, they acknowledge that conditions are dynamic. This creates a significant challenge regarding the methods they are currently accepting for acute TCE related risk characterization.”

EnviroForensics Attending MWDLA Annual Convention This Weekend

Posted on by Alex Miller

It’s been a whirlwind couple of days at EnviroForensics. In the midst of the major move from our current headquarters to our new one, we’re also getting ready for one of the biggest weekends of the year, the annual Midwest Drycleaning and Laundry Association Convention!!

Over the next two days, dozens omidwestdrycleaningf drycleaners from Indiana, Kentucky and Ohio will converge on the Belterra Casino Resort and Spa in Florence, Indiana, to talk about new technologies and emerging challenges in the industry. But, of course it won’t just be strictly for business.

We’re excited to meet up with our partners and friends in the industry who have played a major role in our 20 year existence. Environmental consulting is very much, at its core, a people business. We’re brought in to clean up contamination that can threaten human health, but we’re also there to provide a safety net to the business owner, who likely never knew of the potential for pollution.

Some of these drycleaners have been our clients, but we also consider them our friends. This weekend we’ll be hitting the golf course with them, catching up over a few drinks at happy hour, and talking shop while dining on some delicious food.  We take pride in our customer service, and it’s events like these that give us a better understanding of the drycleaner experience and help us cultivate a more personal connection with our clients. If you’re heading down to Florence today, we’ll see you there!

 

Taking on an Environmental Challenge Thousands of Miles Away

Posted on by Alex Miller

EnviroForensics is based in Indianapolis, but we don’t let our central location get in the way of addressing environmental issues across the country. Our project managers are equipped with years of experience leading investigations and remediation projects from both out in the field and behind a desk. In that time, we have also cultivated trusting relationships with outside vendors from all over the country, and have a keen understanding of individual state environmental regulations, making geographic proximity virtually irrelevant.

Recently, EnviroForensics did a project on the West Coast with an unusually tight deadline. A client in California needed soil and groundwater data collected, analyzed, and reported within a week. We received the phone call late on a Friday afternoon. Ordinarily, coordinating the logistics for a such a project would be a Herculean task, but due to the hard work of our staff and connections we have built in the Bay Area, we were able to line up a private utility locate contractor, a drilling contractor, an environmental equipment vendor, and a California-certified analytical laboratory by the end of business that same day. Our personnel caught a flight early the next week and we were well on our way.

EnviroForensics was founded in California in 1996, so we understand the unique regulatory challenges regarding permitting and sample collection. We worked with our partners in the Bay Area to ensure all appropriate permits were obtained prior to the start of work. Our field team advanced hand augers in a tight space within the site building and direct push borings within the site parking lot. Soil and groundwater samples were collected within one (1) day, minimizing the disturbance to the property owner’s on-site business. The samples were hand-delivered to the laboratory and the testing results were received and reported to the client on-time, within one week of his initial request.

When taking on a project, whether it’s right around the corner, or thousands of miles away, a steady, well-seasoned team is needed to lead the operations. Additionally, a knowledge and familiarity with the local rules and regulations and trustworthy partnerships in the area make a big impact. For this project and countless others, our project managers have proven they possess the ingenuity and the expertise to effectively manage environmental investigations and cleanups both locally and nationally.

‘Tis the season for Vapor Intrusion Testing!!

Posted on by Alex Miller

LEARN WHY THE WINTER AND SUMMER MONTHS ARE THE BEST TIMES OF YEAR TO TEST FOR VAPOR INTRUSION

Indoor air sampling canister used to measure subsurface soil gas during a vapor intrusion assessment

The schedule at EnviroForensics during the summer and winter months are jam-packed with indoor air and soil gas assessments. During these time frames every year, field staff head out with sampling canisters and equipment in tow, checking businesses and homes for Vapor Intrusion impacts. This includes looking for cracks and other structural fallacies where volatilized chemicals present in the subsurface can sneak into the indoor air of buildings and homes. This is no mere coincidence. The winter and summer months are optimal times to test for Vapor Intrusion due to both indoor and subsurface conditions, as well as state-mandated testing parameters.

SAMPLING AND MEASURING INDOOR AIR IS COMPLICATED
Indoor air concentrations can be difficult to measure given the many variables that need to be considered. Outside barometric pressure and temperatures, soil temperature and moisture content, ground water levels, building construction, the integrity of the foundation, potential preferential pathways, and indoor-outdoor air exchange rates can all affect vapor migration through the ground and into a building. Due to the high variability in indoor air and soil gas sampling results, and the limited amount of data collected for analysis, industry experts consider it to be more efficient and health protective to collect vapor samples under what are considered “worst-case conditions” in order to determine if vapor intrusion is indeed occurring. Collecting samples during “worst-case conditions” provide a better understanding as to just how high the chemical concentrations can get in the indoor air.

TWO MAIN REASONS WHY TESTING FOR VAPOR INTRUSION HAPPENS IN THE SUMMER AND WINTER 

  1. Windows and Doors are Closed
    Vapor Intrusion is more likely to occur during the Summer and Winter months because doors and windows tend to remain shut, and tenants are using their heating, ventilating, and air conditioning (HVAC) systems during these time periods exclusively for the circulation inside the building. These factors alone promote a higher risk of vapor intrusion. Keeping the windows and doors shut allow any chemicals entering the building or house to accumulate due to the decreased air circulation and decreased air dilution from fresh outside air. Additionally, the HVAC system can create a pressure differential that actually pulls vapors up from the subsurface.
  2. The Water Table Declines
    Below the subsurface, where the chemical contamination is located, conditions are ripe for “worst case conditions.” Since the water table tends to drop during the Summer and Winter months in Indiana and the soil moisture content decreases, more pore space is created in the vadose zone, allowing more vapors to collect below the foundation. With a higher probability of vapors sneaking into a building, the summer and winter conditions tend to provide us with the most accurate measuring stick for the worst case scenario than the rest of the year.

WORST CASE CONDITIONS REQUIRED BY REGULATORY COMMUNITY
Most state regulators make collecting samples during “worst-case conditions” a requirement in Vapor Intrusion investigations. For example, The Indiana Department of Environmental Management (IDEM) will not give a “no further action” on a site unless sampling data has been collected during the window of time when conditions are ideal for Vapor Intrusion to occur and the concentration of the volatile organic compound (VOC) is below levels that could prove dangerous to human health.

UNDERSTANDING YOUR VAPOR INTRUSION RISK GIVES YOU A BETTER UNDERSTANDING OF THE AIR YOU BREATHE
The concept of Vapor Intrusion and the study of its environmental impacts is still in its relative infancy. With each passing year we’re learning more about this type of exposure pathway and what we can do to better detect it. Science has taught us that the summer season isn’t just for baseball, barbecues, and beaches, and the winter time isn’t just for scarves, snowmen, and skating. The two seasons are also the optimal times to get the best possible understanding of the air quality inside your home or business.  The better we understand the air we breathe, the more likely we can protect it from chemicals that pose a potential risk to our health.

Learn more about our Vapor Intrusion Assessment and Mitigation Services.

Enhanced Reductive Dechlorination Showing Positive Returns at Indiana Dry Cleaning Site

Posted on by Alex Miller

While the surrounding Mooresville, Indiana community applauds Crest Cleaners for proactively cleaning up a previously unidentified hazardous mess that was left behind from historic dry cleaning practices, the workhorses remediating the contamination are grinding away below the subsurface.  Tiny microorganisms are destroying the PCE in the groundwater and reducing the concentration of the contaminant. It’s all a part of the “Enhanced Reductive Dechlorination,” process, which is the primary approach of the Remedial Work Plan (RWP) being implemented by EnviroForensics.

Air quality test canister placed in adjacent to determine Vapor Intrusion impact.
Air quality test canisters placed in adjacent building to determine Vapor Intrusion impact.

In addition to the potential for human health risks at the Site as a result of soil or groundwater exposure, the contaminant plume in the groundwater represented a potential vapor intrusion risk to an offsite building.  The project team debated between two viable options:

1.      Install, monitor, and maintain a Sub-Slab Depressurization System (SSDS) at the offsite location to mitigate the potentially harmful vapors underneath the building, which would have required years of maintenance and groundwater sampling; or

2.      Implement an ERD application to reduce the concentration of the groundwater plume, and eliminate potential vapor intrusion issues.

Based on the overall benefit to the community and to reduce stress and aggravation to adjacent property owners that comes with long-term monitoring, the project team chose option two.

Fences being put up around one of the injection sites.
Fences being put up around one of the injection sites.

Here’s how the remediation at this site worked. Naturally occurring bacteria called Dehalococcoides ethanogenes (DHC) are in the groundwater completing a process called reductive dechlorination where the chlorine molecules are cleaved off and replaced by hydrogen particles.  This process continues until the resulting compound is no longer dangerous.   At this site, the process was occurring, but not at a rate that would make the cleanup cost effective for the client.  In order to complete this cleanup we utilized a process called bioaugmented enhanced reductive dechlorination (ERD) and in-situ chemical reduction (ISCR).  The process begins by sampling the groundwater across the remediation area for contaminant concentrations and geochemical parameters including DHC populations to determine the dosage of injected materials required in each area of the site.  Different areas received modified doses of materials based on the calculations completed by our geochemist.  The ERD agent (3D-Microemulsion or 3DMe) was injected along with Chemical Reducing Solution (CRS), an ISCR augmentation.  The ISCR agent immediately begins hydrolysis reactions directly destroying the PCE contaminant while producing reduction reactions with the natural chemistry that will allow the 3DMe to better complete its work.  The two work synergistically, increasing the cost effectiveness of the injection.  The pre-sampling of DHC revealed that the population of DHC needed to be augmented.  10 gallons of a DHC enhanced fluid was injected at each of the 92 injection locations used for the ERD/ISCR.   The combination of these three injected materials allows for minimal site disturbance and a high level of effectiveness for the cleanup of drycleaning solvents.

Intrinsically safe fan installed on building
Intrinsically-safe fan installed on building to manage potential methane production.

An often overlooked byproduct of the ERD process is methane. As a preventative measure, the field staff upgraded the Site building SSDS with an intrinsically-safe fan and installed an intrinsically-safe SSDS at the offsite building as an interim measure.  Soil gas points were also installed between the injection areas and the adjoining properties to the east.  Additionally, EnviroForensics has extra intrinsically-safe fans and piping ready to be installed, should there be a methane issue at the surrounding properties.

The results from the first injection event were very promising. Groundwater contaminant concentration went down from thousands of micrograms per liter before the injection to single digits of micrograms per liter one month after the injections. Quarterly groundwater sampling will continue for a year or two to demonstrate that the contaminant plume is retreating or remediated. The ultimate goal of the ERD approach is to reach Site closure quickly, and reduce the costs and health risks of this contamination.

 

Click here to learn more about how Enhanced Reductive Dechlorination works.

Similarities Between “Manhattan Project” Site Cleanup, Chlorinated Solvent Site Cleanup

Posted on by Alex Miller

More than fifty years after its final nuclear test, federal contractors are proceeding with a massive undertaking to clean up a site in New Mexico made famous by the “Manhattan Project.” The Los Alamos National Laboratory, which opened in 1943, was used to test and develop the atomic bombs that would later be dropped on Hiroshima and Nagasaki, Japan, during the final months of World War II. Projects to address this enormous environmental liability had been moving at a slow pace until last month.

The Trinity bomb was the first test explosion of the famed "Manhattan Project," and the first explosion of its kind in history.
The Trinity test was the name of the first nuclear detonation conducted on July 16, 1945, as part of the famed “Manhattan Project,” and the first explosion of its kind in history.

In June, the New Mexico Environmental Department (NMED) and the U.S. Department of Energy (DOE) agreed on a Consent order to expedite all remaining work on legacy waste management from the laboratory. With this new Consent Order in place, federal contractors are now working on remediating the south facing slopes of the Los Alamos Canyons. Although this project involves a different type of contamination than the dry cleaning solvents we at EnviroForensics manage on a daily basis, there are similarities that we couldn’t help but notice.

Nuclear explosion tests at the site halted in 1965, and very little has been done up to this point to address the public health risks left behind by the years of nuclear testing. At the time of the nuclear testing, there wasn’t much known about the adverse effects of being exposed to high concentrations of radiation and nuclear fallout. As medical researchers eventually realized the dangers of these toxins, the concern for public health increased, as well as the necessity for a remedial solution. Similarly, PCE was once the leading solvent used in commercial dry cleaning. After 2007 when it was classified as a Group 2A carcinogen by the International Agency for Research on Cancer, it started losing momentum and began to be replaced by less toxic solvent alternatives.  Like the nuclear scenario described above, commensurate health studies on PCE didn’t come until long after its widespread use. Past handlers of these toxic substances in both cases had no way of knowing their practices could have such long-lasting potential health effects.

J. Robert Oppenheimer and Leslie Groves at remains of the Trinity test in September 1945. Courtesy: TIME
J. Robert Oppenheimer and Leslie Groves at remains of the Trinity test in September 1945. Courtesy: TIME

The DOE has chosen excavation to help complete this part of the legacy waste cleanup. As we’ve mentioned in previous blogs, excavation is one of the most straight-forward ways to rid a Site of many contaminants, including PCE.  Crews at the “Manhattan Project” site will dig in five separate zones in a 1 acre area along the south facing slopes, with the objective of removing 125 cubic yards of contaminated soil. Similar to the manner PCE contaminated soil is handled, the crews in New Mexico will prepare the soil and approve it for transport to a hazardous waste facility.

The south facing slopes of the Los Alamos Canyon is not considered a residential area, but the ultimate goal of this cleanup is to reduce the concentration of the contaminants (in this case Arsenic and Plutonium) to the EPA’s mandated “residential” levels. The hope is to redevelop the area around the Los Alamos National Laboratory site with commercial and residential real estate. Often times, the aim of a PCE site cleanup is also to remove the potential health risks for future tenants that have redevelopment on their minds.

Los Alamos National Laboratory, Los Alamos, New Mexico. Courtesy:alphascientific.com
Los Alamos National Laboratory, Los Alamos, New Mexico. Courtesy:alphascientific.com

NMED estimates the rest of the Los Alamos National Laboratory legacy cleanup will take another 19 years to finish and cost up to $3.8 billion. Chlorinated solvent cleanups often take years and cost hundreds of thousands or millions of dollars. In both cases, it seems an immediate or proactive approach is always the best way to go about addressing these problems.  Quicker action leads to more cost-effective solutions and a healthier environment for all.

 

Vapor Intrusion or Process Emissions – Help Me, Help You

Posted on by Alex Miller

Written by Stephen R. Henshaw, President & CEO, EnviroForensics

As seen in the August 2014 issue of Cleaner & Launderer

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I’ve talked a lot about vapor intrusion over the past few years. Vapor intrusion occurs when volatile organic compounds (VOCs) in soil and groundwater off-gas and migrate into occupied buildings and store fronts. The need to conduct vapor intrusion sampling is often times the result of VOCs in the soil and groundwater. Typically a vapor intrusion assessment will include collecting sub-slab soil gas samples along with the collection of indoor air samples. This paired sampling, as it is often times referred to, is designed to show two things: 1) whether or not there is contamination in the subsurface soil gas sample that could create a vapor intrusion issue; and 2) whether or not there are concentrations of VOCs in the breathing air that could be attributable to the subsurface contamination.

I want to tell you this because if it is determined that vapor intrusion exists and VOCs are migrating from the subsurface into occupied building structures, you as the responsible party for the subsurface impacts, would also be responsible for mitigating those vapors. Additionally, the identification of a vapor intrusion issue in buildings not owned by you could lead to the potential for third party litigation should it be determined that people have been breathing contaminated air. Continue reading “Vapor Intrusion or Process Emissions – Help Me, Help You”