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Published in the May 2020 Focus on the Environment Newsletter
Per-and polyfluoroalkyl substances (PFAS) compounds are man-made chemicals that have been used in numerous industrial processes and many consumer products such as cookware, stain resistant carpets, grease resistant food packaging, raincoats, makeup, and many others. PFAS compounds are persistent in the environment and have been shown to accumulate in people and animal tissues. They have been shown to induce tumors, disrupt hormones, and cause damage to the immune system and organs like kidneys and the liver. They are widespread in the environment, and have been found throughout the world in soil, groundwater, surface water and air.
In 2016, EPA established health advisory levels (HALs) for PFOA and PFOS, two of the most prevalent PFAS compounds, at 70 parts per trillion (ppt). Although the HALs are intended to offer a margin of protection from adverse health effects from exposure to PFOA and PFOS in drinking water, they are non-regulatory and non-enforceable. In late 2019, the EPA finally signaled their intention to establish MCLs for PFOS and PFOA in drinking water, beginning a process that will likely take multiple years before a federal drinking water standard is finalized. With the federal government lagging-behind in the establishment of regulated standards, states are left alone to develop their own policies to regulate these chemicals, a process leaving them open to challenges, legal and otherwise, regarding their authority to establish standards and require corrective action.
As with drinking water MCLs, the lack of federally regulated cleanup standards has left states with little leverage to force responsible parties to remediate PFAS contaminated sites. Because PFAS chemicals were a key ingredient in firefighting foams used widely by the military during training and emergencies, the federal government is responsible for large number of PFAS contaminated sites across the country. The Pentagon estimates environmental and legal liabilities in the billions of dollars to investigate and remediate PFAS releases at hundreds of military bases. To date, the US Department of Defense (DoD) has proactively initiated short-term actions (e.g. provided bottled water, point of use filters) and long-term actions (e.g. municipal connections, filtration systems) such that no one is drinking water above the HAL of 70 ppt at sites where the DoD is the known source of PFOA and PFOS. However, for those states with either proposed MCLs and/or Health Based Guidance Levels for PFOA and PFOS at concentrations less than the 70 ppt HAL, there exists a gap between what the DoD will provide treatment for versus what the state contends is safe to drink. As more and more states attempt to force the military to investigate and clean up PFAS related contamination, the DoD has begun pushing back, contending that PFAS contamination falls under Federal cleanup law, in this case CERCLA, and challenging the authority of states to require corrective action.
In April of this year, New Jersey proposed MCLs for PFOA and PFOS at 14 ppt and 13 ppt, respectively, as well as adding both to the List of Hazardous Substances. The proposed MCLs are considerably stricter that the EPA HAL of 70 ppt and could set the standard for other states looking to emulate New Jersey’s proactive stance. As with New Hampshire, New Jersey likely will face legal challenges after the rules become final; however, the robust process New Jersey used to develop their MCLs potentially places them on firmer footing.
The NJDEP employs a panel of the state’s leading water experts under its Drinking Water Quality Institute (Institute) for the sole purpose of developing MCLs for hazardous contaminants in drinking water. In the case of PFOA and PFOS, three subcommittees were established within the Institute to address the essential considerations for development of MCLs as outlined in the New Jersey Safe Water Drinking Act. The Health Effects Subcommittee was responsible for recommending health-based levels, the Testing Subcommittee was responsible for revaluating and recommending appropriate laboratory analytical methods and the Treatment Subcommittee was responsible for evaluating best available treatment technologies. Recommendations from each of the three subcommittees formed the basis for the recommended PFOA and PFOA MCLs. Using this approach, the Institute ensures that the recommended MCLs are protective of human health, can be reliably quantified within acceptable limits of uncertainty and are attainable using current available treatment technologies.
Published in May 2020 Focus on the Environment Newsletter
On October 9, 2019, the President of the United States signed Executive Order 13891, titled “Promoting the Rule of Law Through Improved Agency Guidance Documents.” The Executive Order (EO) is the Trump Administration’s noteworthy effort to address the long-running problem of the use of guidance as regulation. We all know that guidance lacks the force and effect of law, but unfortunately it is sometimes presented as a requirement and even when accompanied by a disclaimer, may carry the implicit threat of enforcement action if the regulated community does not comply.
The EO essentially does two things. First, it directs each federal agency to place all its active guidance documents into a single online guidance document portal. Second, the Executive Order requires agencies to finalize or amend existing regulation on how guidance documents are issued, including a public notice and comment period and approval by the agency head or someone simply appointed by the president.
Shortly after publication of the EO, and without an opportunity for public review and comment, the Office of Management and Budget (OMB) issued instructions for implementing the EO through an October 31, 2019 memo titled Guidance Implementing Executive Order 13891. The OMB memo specifically requires “… each agency by February 28, 2020 to establish a single, searchable, indexed website that contains, or links to, all of the agencies’ respective guidance documents currently in effect. If an agency determines that it failed to include on its new guidance portal a guidance document that existed on October 31, 2019 it may reinstate the guidance document provided it does so by June 27, 2020. Any rescinded guidance document that has not been reinstated by June 27, 2020, may be reinstated only by following all the necessary steps associated with the issuance of a new guidance document.” The OMB guidance also requires that the following information be clearly visible on agency guidance portals:
“Guidance documents lack the force and effect of law, unless expressly authorized by statute or incorporated into a contract.”
“The agency may not cite, use or rely on any guidance that is not posted on the website existing under the executive order, except to establish historical facts.”
The EPA guidance portal is located at https://www.epa.gov/guidance. Guidance documents on the new guidance portal are organized by EPA offices such as Office of Air and Radiation, Office of Chemical Safety and Pollution Prevention, Office of General Council, Office of Land and Emergency Management, and Office of Water. The portal also allows for selection of guidance by EPA regional office. After clicking on a particular EPA office or regional office, the resulting page displays a list of all the guidance documents within the particular office or region in table format. Information provided on the table includes document name, issue date, date added to portal list, EPA identifier, topic, and a description/summary. A very basic search function allows simple searches of key words to help limit the number of entries. The search results can then be sorted by date. A May 22, 2019 search of the Office of Land and Emergency Management guidance portal page for the word “closure” reduced the original list of 3,690 documents to 184. Beyond sorting the list from newest to oldest or oldest to newest, the user is left scanning the title and description field to find the desired document. A similar search for “RCRA Online” resulted in 2,729 documents of the 3,690 total entries, indicating that at least some of the critical RCRA Online guidance was considered “in effect” and has been moved to the portal.
Each page of the portal provides a link to submit a petition for Agency modification or withdrawal of guidance documents as well as the following statement:
“EPA’s guidance documents lack the force and effect of law, unless expressly authorized by statute or incorporated into a contract. The agency may not cite, use, or rely on any guidance that is not posted on this website, except to establish historical facts.”
The guidance portal also indicates that EPA is continuing to inventory guidance documents and anticipates providing updates prior to the June 27, 2020 deadline. If you utilize guidance that you consider critical to your business, I suggest that you verify it is included, and if not, contact the respective EPA office to determine why. Otherwise, after June 27, 2020 you may no longer be able to rely on it.
Although convenient to have all of EPA’s guidance in one searchable location, the real reason for the new single access point is only, in a small way, related to convenience or the user experience. One only needs to scan the EO to understand that the real reason for this effort is to crack down on the overuse and reliance on guidance. The simple requirement to place all agency guidance in one location makes clear in a less than subtle manner that the information is only guidance and should be used, or not used, with this in mind. It is important to remember, however, that not all guidance is bad or should be ignored. Guidance can and does, in many cases, perform an important role in providing clarification on how an agency interprets complicated regulations. Many in the regulated community rely on guidance to provide consistency both across the country and through time as regulators and administrations change. Without clear guidance, every regulator is free to interpret complicated or poorly written regulations as they see fit.
It will be interesting to see how some EPA programs will function in the future, given the reliance on guidance. Take the RCRA Corrective Action program for example. RCRA Corrective Action is the site-wide cleanup program for hazardous waste treatment, storage, and disposal facilities (TSDFs). The multimillion-dollar program is implemented nearly entirely through guidance. And why is that? Because stakeholders could not agree on regulations. EPA tried multiple times through the proposed Subpart S regulations in 1990 and the 1996 Advanced Notice of Proposed Rulemaking (ANPR) to promulgate RCRA Corrective Action regulations. In both cases, the regulated community argued that the proposed regulations were too inflexible and burdensome, while environmental groups and public argued that the rules were not detailed or strict enough. Without regulation, guidance was forced to fill the void. If we are going to reduce the reliance on guidance, we should expect to see comprehensive and detailed regulations in the future, which in turn is going to make stakeholder agreement and promulgation of new rules more difficult. This, after all, may be the long-range unstated goal of the Executive Order.
Published in the May 2020 Focus on the Environment Newsletter
On May 20, 2020, Ohio EPA Division of Environmental Response and Revitalization (DERR) Geologist Group announced that they have posted a draft revision of the Ground Water Sampling chapter (Chapter 10) of the Technical Guidance Manual (TGM) for Hydrogeologic Investigations and Ground Water Monitoring. The DERR Geologist Group maintains Ohio EPA’s TGM and provides support for geologic and ground water issues related to the investigation and cleanup of contaminated sites, including:
Resource Conservation and Recovery Act (RCRA) Subtitle C facility corrective actions and closures
Comprehensive Environmental, Response, Compensation and Liability Act (CERCLA or Superfund) sites and federal facilities
State-lead remedial response sites, properties regulated under Ohio’s Voluntary Action Program (VAP) and brownfield properties
The Ohio EPA TGM was first finalized in 1995 and subsequently updated in February 2006 (Revision 1) and May 2012 (Revision 2). This guidance document represents an update (Revision 3) to Chapter 10 (Ground Water Sampling). Listed below are the technical changes from the 2012 version of Chapter 10.
Updated formula for calculating water volume in a one-foot section of well casing and associated table.
Updated sampling mechanisms and associated table.
Added general information related to sampling PFAS.
Updated Field Conditions section for additional conditions that could affect sample representativeness.
Updated water level measurements section and associated table.
Updated existing references and added new references.
The Ohio EPA will accept comments on the revised chapter until June 19, 2020. Comments should be emailed to Doug.Switzer@epa.ohio.gov
Published in the May 2020 Focus on the Environment Newsletter
On May 19, 2020 EPA released its May 2020 update to their “Regional Screening Levels for Chemical Contaminants at Superfund Sites.” Screening levels (SL) are risk-based concentrations derived from standardized equations combining exposure information assumptions with EPA toxicity data. The EPA website is the source of screening levels for all the EPA regions, thus the term Regional SLs or RSLs.
SLs are used for site “screening” and as initial cleanup goals, if applicable. SLs are not de facto cleanup standards and should not be applied as such. The SL’s role in site “screening” is to help identify areas, contaminants, and conditions that require further attention at a particular site. Generally, at sites where contaminant concentrations fall below SLs, no further action or study is warranted under the Superfund and RCRA Corrective Action programs, so long as the exposure assumptions at a site match those considered by the SL calculations. Chemical concentrations above SLs would not automatically designate a site as “dirty” or trigger a response action; however, exceeding a SL suggests that further evaluation of the potential risks by site contaminants is appropriate.
SLs can be obtained on the RSL website from either the generic summary tables or using the RSL calculator. The generic summary tables are presented at a target cancer risk (TR) of 1E-06, and at either target hazard quotients (THQ) of 1.0 or 0.1.The generic summary tables provide a list of contaminants, CAS number, toxicity values and chemical-specific information, MCLs, and the lesser (more protective) of the cancer and noncancer SLs for resident soil, industrial soil, resident air, industrial air, tapwater, and leaching to groundwater exposure scenarios. The summary tables are available as PDF or Excel files. The web calculator provides users considerably more flexibility to develop site-specific SLs using a combination of user-defined and default input variables.
SLs are usually updated twice a year, typically in November and May. The prior update occurred in November 2019. Changes to the RSLs tables are summarized in the “What’s New” page, including spreadsheet files comparing the newly updated RSLs and toxicity information to the previous version. Only the chemicals for which changes occurred are included in the comparison files. This is a good way to see if an RSL for a contaminant of interest changed and if it went up or down. Some of the more common constituents we run into at our sites for which a change in RSL occurred during the May 2020 update include dibenzofuran, naphthalene, and tetrahydrofuran. RSL changes with this update for these three compounds in industrial soil and tap water at TR 1E-06 and THQ 0.1 are as follows:
One of the more problematic issues associated the use of RSLs is what happens when RSLs change. This always seems to happen in the middle of putting together a large report or risk assessment. What do you do? Many practitioners feel that you are obliged to use the most recent screening levels in every case; others feel that screening levels identified in an approved plan or agreement become set in stone. To best manage the change, the workplan or agreement should clearly state how this will be addressed. Also, do not count on EPA or states informing you of new updates, especially if a critical screening level has gone up. I recommend signing up to automatically receive notification when new releases are available.
Published in the May 2020 Focus on the Environment Newsletter
USEPA and others in the vapor intrusion field have been evaluating a variety of Indicators, Tracers, and Surrogates (ITS) to assess their use in predicting the best time to collect representative indoor air samples for vapor intrusion studies (Schuver, et. al., 2018). The idea is that if a predictive combination of easily obtainable, low cost ITS can be identified, they could be used to improve the collection of actionable analytical data at a lower cost.
For vapor intrusion assessments, typical indicators include seasons of the year, wind speed, the difference between the indoor and outdoor temperatures (differential temperature), barometric trends, and the difference between sub-slab and indoor air pressure (differential pressure). In this article, I will focus on differential pressure.
Differential pressure is a useful indicator for a number of reasons and is “baked in the cake” when it comes to designing and assessing the performance and long-term monitoring of sub-slab depressurization systems.
If the pressure beneath the slab is greater than the indoor air space, there will be a tendency for sub-slab air to migrate into the indoor air space through advection. The reverse situation should also occur if the pressure beneath the slab is less than the pressure of the indoor air space. This is why vapor intrusion and radon mitigation can be accomplished through the use of sub-slab depressurization systems. In fact, the differential pressure required is surprisingly low. In Ohio, the standard differential pressure for radon mitigation systems is only -0.020 inches of water.
Differential pressure is generally measured with a hand-held manometer. Recently, however, sensitive differential pressure sensors have become available as part of the “Internet of Things” (IOT) revolution. These sensors can be connected to permanent sub-slab monitoring points, such as the Vapor Pin®, to collect and transmit differential pressure readings to the web at preset intervals. They can also be used to set alarm point that will notify users of system faults or other unacceptable conditions.
I have been experimenting with one of the sensors at my home, which has a radon mitigation system. The graph below plots a segment of the collected data (differential pressure measured in inches of water). The graph clearly demonstrates that my radon mitigation system is producing a differential pressure of approximately -0.050 inches of water, which exceeds the minimum standard of -0.020 inches of water. The graph also indicates minimal day-to-day fluctuation with the system running over a period of approximately 10 days. To test how fast the system responds to a system fault, I turned off the radon system for a period of approximately 24 hours. As you can see differential pressure responded very quickly after the system was turned off and again when it was turned back on.
The sensors connect wirelessly to a data hub that feeds data through the internet to a website. The cost of a sensor and a data hub is approximately $500. Data housing and reporting plans through the website can be very inexpensive. The plan I have been using costs less than $40 per year.
I believe that over the next year or so, sensors like these will become common place and used by field crews to monitor conditions leading up to and throughout sub-slab and indoor air sampling campaigns. They will also be used to collect and record the results of pressure field testing, whole building pressurization studies, long-term sub-slab depressurization system monitoring, and during high volume sub-slab sampling tests.
Differential pressure is a very powerful and easily obtainable indicator of conditions that drive vapor intrusion. However, what underlying factors cause the pressure differential. In the next article, I will review two of these potential drivers – temperature and barometric pressure?
Schuver, H, Lutes, C, Kurtz, J, Holton, C, Truesdale, RS. Chlorinated vapor intrusion indicators, tracers, and surrogates (ITS): Supplemental measurements for minimizing the number of chemical indoor air samples—Part 1: Vapor intrusion driving forces and related environmental factors. Remediation. 2018; 28: 7– 31. https://doi.org/10.1002/rem.21557
Published in the March 2020 Focus on the Environment Newsletter
On February 13, 2019, U.S. EPA (EPA) announced its annual enforcement and compliance results for fiscal year (FY) 2019 ending September 30, 2019. The FY 2019 report is presented online in two ways: as a “story map” and as a series of graphs. Both the story map and press release highlight an increase from last year in civil and administrative penalties, criminal prosecutions, and self-audits by industry. Overall, however, most of the enforcement metrics are down relative to last year and prior years.
decreases were on the cleanup front where:
through enforcement actions, for future cleanup of contaminated soil and water
decreased by approximately 95 percent from 2018, to the lowest amount since
tracking of this metric began.
through enforcement actions, to treat, minimize, or properly dispose of
hazardous and non-hazardous waste decreased more than 90 percent from 2018, to
the lowest amount since tracking of this metric began.
One of the more telling of the enforcement metrics provided in the report is the number of facility inspections and evaluations conducted by EPA in a given year. Since most enforcement actions begin with an inspection, this metric serves as a leading indicator and unlike most of the metrics presented in the report, the number of facility inspections and evaluations conducted in a given year is relatively free of spin and is easy to track and understand. This is due in part to the fact that facility inspections do not take years to conclude as major enforcement actions often do. In FY 2019, EPA conducted approximately 10,320 inspections and evaluations, a reduction of approximately 4 percent. This follows a 13 percent reduction during FY 2018. It should be noted, however, that this decrease in the number of inspections/evaluations began in FY 2010 and has continued each year since then. To some degree, this decrease in Federal inspections and evaluations is due in part to increasing delegation of programs to states. On the whole, the number of federal inspections and evaluations conducted each year is a fraction of that conducted by the States. For example, based on EPA’s Enforcement and Compliance History Online (ECHO) website, EPA conducted 968 hazardous waste inspections in FY 2019 while the combined state programs conducted over 15,106 hazardous waste inspections.
Clearly, the single metric the Trump admiration is most proud of is the increase in the use of the self-auditing program that allows facilities to voluntarily report violations and return to compliance possibly in return for lighter penalties. According to the 2019 story map, “In 2019 OECA (Office of Enforcement and Compliance Assurance) continued to see an increase in the number of entities, including new owners, utilizing its self-disclosed violation policies that encourage regulated entities to voluntarily discover, disclose, and correct violations of federal environmental laws and regulations. Specifically, in FY 2019, 635 entities with over 1,900 facilities voluntarily disclosed violation pursuant to self-disclosure polices, expediting return to compliance, an estimated 20% increase compared to FY 2018.” Unfortunately, the true environmental benefits of self-disclosure and informal enforcement actions (e.g. warning letters) have proven difficult to track as indicated by the March 2, 2020 Government Accountability Office (GAO) Report titled “Additional Action Needed to Improve EPA Data on Informal Enforcement and Compliance Assistance Activities.”
Published in the March 2020 Focus on the Environment Newsletter
Cox-Colvin & Associates personnel routinely provide vapor
intrusion (VI) training to regulators, attorneys, environmental professionals,
and the regulated community; and have helped in the development of VI guidance
within the US and throughout Latin America and Europe. As a result, we have had the opportunity to
review a large number of VI guidance documents over the years.
The Ohio EPA VI Guidance, initially released in 2010, was
developed for sites under the oversight of the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980 (CERCLA), the Resource
Conservation and Recovery Act (RCRA), and the Voluntary Action Program (VAP),
carried out under the supervision of Ohio EPA Division of Environmental
Response and Revitalization (DERR). The 2020 Version is the second
update. In May 2016, Ohio EPA rescinded Chapters 10 (data evaluation) and 11
(modeling the VI pathway using the Johnson and Ettinger [J&E] model). Ohio
EPA considered Chapters 10 and 11 out of date and no longer appropriate for
projects seeking cleanup under any of the DERR programs.
The 2020 Guidance has been significantly expanded and improved in
many ways. We can appreciate the difficulty and effort that went into the
rewrite, given the continued rapid evolution in the science of VI and in the
underlying human health toxicity factors for which there seems to be little
The general approach to sites is similar to other modern
guidance documents for VI: understand the history of volatile compound uses
and/or releases at your site, develop a robust conceptual site model (including
preferential pathway analysis), base decisions on multiple lines evidence
(sampling of various environmental media), compare results to applicable
standards and mitigate as necessary.
Provided below are some of the more significant changes to the
incorporates Ohio EPA’s somewhat controversial imminent hazard indoor air
action levels published by Ohio EPA in the August 2016 as a standalone document
titled “Recommendations Regarding Response
Action Levels and Timeframes for Common Contaminants of Concern at Vapor
Intrusion Sites in Ohio.” In the 2016 document, Ohio EPA
established response actions and timeframes for common chemicals (TCE and
others) encountered during VI investigations when receptors are present. The response actions, tied to specific indoor
air and/or sub-slab soil gas concentrations, include removal of occupants until
a remedy can be put in place. If you are
a VI practitioner, you need to be aware of these limits and have a frank
discussion with your client about potential actions that may be advised
following the receipt of the analytical results.
environmental samples to support multiple lines of evidence is a common theme
in the guidance. The 202 guidance
incorporate a welcomed and fundamental shift in the significance of sub-slab
sampling, placing greater emphasis on the use of sub-slab data, and less
emphasis on groundwater, bulk soil, and exterior soil gas data. It is encouraging to see that Ohio EPA has included
significant warnings against using bulk soil samples. We have reviewed many assessments that have
incorrectly concluded that VI pathway was incomplete based on the results of
bulk soil samples. The most important
message we provide during VI training is that if you want to understand VI, you
must collect soil gas samples.
The Guidance includes
a section devoted to VI from petroleum releases, based in part on the 2015 US EPA Technical Guide for
Addressing Vapor Intrusion at Leaking Underground Storage Tank Sites. Once released, petroleum hydrocarbons behave
differently in the environment and are generally less toxic and less mobile
than chlorinated solvents. Because of the effectiveness and speed of
aerobic biodegradation in biologically active soils, Ohio EPA recommends,
consistent with US EPA and ITRC Guidance, reduced lateral and vertical
investigation distances at relatively small petroleum releases compared to
chlorinated solvent sites.
The Guidance includes
the following critical statements related to the evaluation of VI data in Ohio. “For Ohio EPA DERR RP (remedial program) sites, when considering
concentrations measured in sub-slab, soil gas, or ground water, the VISLs
should be applied corresponding to an excess lifetime cancer risk (ELCR) of
1E-5 and a hazard quotient (HQ) of 1. If the measured concentrations in
the sampled media are less than the appropriate VISLs set at an ELCR of 1E-05
and a HQ of 1 for the appropriate exposure scenario, Ohio EPA DERR considers
the pathway to be ‘incomplete’ and additional investigation or risk estimation
of this pathway is not warranted.” Although Ohio EPA
DERR has consistently utilized an ELCR of 1E-5 and a HQ of 1 in VI work, we believe
this is the first time this has been clearly stated in the guidance. A
similar comment is included for Ohio VAP sites which includes reference to the
VAP-required multiple chemical adjustment.
The Guidance presents
Ohio EPA’s position on the Ohio EPA/OSHA jurisdiction issue when it comes to
indoor air contamination derived from vapor intrusion. You may or may not
agree with the position, but at least it’s out in the open.
The Guidance includes
a section devoted to remedies (Section 13) organized largely around the concept
of risk level and time frame, including imminent, acute, chronic, and unknown. Included in Section 13 are discussions of
monitoring requirements for engineering controls (mapping of the
depressurization field and indoor air sampling) and post-mitigation sampling
(pressure and/or indoor air sampling to demonstrate system effectiveness
through seasonal variation).
The Guidance covers,
as Section 14, the critically important topic of long-term management and exit
strategies at VI sites where mitigation measures are installed.
Included as appendices
to the Guidance are special considerations for evaluating residential
properties, a VI conceptual site model checklist, Ohio EPA’s standard operating
procedures and field data collection forms, comparison of tubing type to vapor
absorption, and soil gas analytical methods and reporting limit ranges.
Although the Guidance is very comprehensive, we do suggest that
practitioners may want to keep a few things in mind going forward.
The Guidance suggests
that you limit the COC for indoor air to those compounds detected in sub-slab
soil gas so that you can more easily eliminate the compounds associated with
indoor sources. We believe this is a bit
too conservative. Sanitary sewers are
probably the most important preferential pathway and as such, you should expand
the indoor COC list a bit to include compounds such as chloroform, carbon
disulfide, bromoform, and tetrahydrofuran.
If these compounds are detected in indoor air, the VI issue may be
related to poor plumbing connections, which can be easily and inexpensively
resolved. Without this data, you may end
up installing a more expensive sub-slab system and still have a VI issue.
The Guidance is silent
to PFAS and PFOS. These compounds may
become risk drivers for indoor air in the future.
US EPA is placing a
renewed emphasis on how to predict the most opportune time to collect an indoor
air sample. Expect new guidance on using
surrogates such as sub-slab differential pressure reading, indoor radon
concentration, outdoor temperature, and barometric pressure to predict timing
of air sampling.
monitoring over a brief period (2 weeks or less) can help sort out the
complexities and temporal variability of COC concentrations in indoor air. The Guidance is silent on this as an
approach; however, we are confident if you proposed it for your site, Ohio EPA
would not resist its use.
Published in the March 2020 Focus on the Environment Newsletter
For years, owners/operators of
solid waste landfills in Ohio were under the false impression that after thirty
years of post-closure care and maintaining financial assurance, they could just
stop. Several years ago, when the 30-year periods for early landfill closures
were approaching, Ohio EPA began informing the owners/operators that this was a
misconception, and that they could not just stop post-closure activities;
owners/operators had to demonstrate that their landfills no longer posed a
threat to human health and the environment prior to ending post-closure care. Until
recently, the process of doing that was not well defined. On February 28, 2020,
the Ohio EPA released guidance regarding the process for ending post-closure
care at solid waste landfills.
The new guidance document summarizes the Ohio EPA’s process for municipal solid waste landfill owners and operators that request to end the post-closure care period. This information also applies to industrial and residual solid waste landfills. To request an end to the post-closure care period, a sanitary, industrial, or residual waste landfill owner/operator must submit a written certification that all post-closure care activities have been completed in accordance with the appropriate rule. The certification documentation must include the following, and must be signed and sealed by a professional engineer registered in Ohio:
A summary of changes to leachate quality and
The rate of leachate generation and quantity of
leachate in the landfill, with an explanation of how these figures were derived
A summary of any on-going groundwater assessment
or corrective measures
A summary of explosive gas migration and
generation by the landfill
An assessment of the integrity and stability of
the cap system if post-closure care activities cease
The Ohio EPA requests that the
leachate, groundwater, and explosive gas summaries all include data trends for
the past ten (10) years so that they can properly assess compliance with
post-closure care requirements. It is evident that putting together the required
demonstration, documentation, and certification will take some time, so
owners/operators should not wait until the 30 post-closure care period is up
prior to starting. It is suggested that owners/operators start at the 25-year
mark so that there is time to go through the process. The guidance document
states that the demonstration may require controlled field tests to see what
happens if the leachate collection system is shut down, or if the explosive gas
collection system is shut down. These tests should be accomplished by competent
geologists and engineers. The guidance document suggests that owners/operators
establish a close working relationship with Ohio EPA to efficiently demonstrate
that their landfills no longer pose a threat to human health and the
Decision of the Director
The Director of the Ohio EPA may
either discontinue or extend the post-closure care period based on the data and
information provided, and whether human health and safety and the environment
will be protected into the future. The Director can determine that only some
post-closure care activities must continue rather than all of them. If it is
determined that some or all post-closure care activities can end, the landfill
owner/operator will receive a letter from the Director ending those post-closure
care requirements. Upon receipt of this letter, if all post-closure care is
approved to end, the owner/operator can request the termination of the
financial assurance instrument. If the Director determines that some
post-closure care activities must continue, the financial assurance instrument
should be adjusted accordingly.
The guidance also discusses continuing obligations regardless
of the post-closure status, stressing that the landowner is required to ensure
that the landfill will not threaten public health, safety, or the environment
in the future. These continuing obligations include:
Obtaining authorization in accordance with Rule
3745-513 prior to any to disturbance of the landfill cap
Maintaining the integrity of the landfill to
ensure that it does not pollute waters of the state (under Chapter 6111 of the
Ohio Revised Code)
Controlling explosive gas migration
Adhering to institutional controls
Voluntary Action Program
An interesting side note is that
once a landfill is no longer subject to all of the closure requirements of
Chapter 3734 of the Ohio Revised Code (i.e., the Director has determined that
no further monitoring or maintenance is required, and the permit is no longer
in effect), the property is eligible for the Ohio EPA’s Voluntary Action
Program, and, if desired, redevelopment may occur under that program.
waste landfills – 3745-27-14; industrial waste landfills – 3745-29-14; and
residual waste landfill – 3745-30-10. It should be noted that the Ohio EPA is
currently in the process of consolidating the industrial and residual waste
landfill rules, so the rule citation for industrial waste landfills will likely
change in the next year or so.
Published in March 2020 Focus on the Environment Newsletter
As the name implies, pump
and treat (P&T) is a relatively simple remediation technology where groundwater
containing dissolve contaminants is pumped from the aquifer and directed to
some form of treatment. The advantages
of P&T are two-fold, it provides hydraulic containment and control of the
contaminated groundwater plume while simultaneously reducing the dissolved contaminant
attributes made P&T an attractive and popular alternative back in the
1980’s and early 1990’s when groundwater remediation was in its infancy. As a result, P&T systems were routinely recommended,
approved and implemented, via the technology screening process, as both the interim
and final groundwater remedial measure.
Following startup, most P&T systems performed as predicted and proved successful at both containing and reducing source concentrations. Over time, however, the nice linear contaminant removal trends became asymptotic as the contaminant removal rate decreased. These asymptotic or “tailing” concentration trends became synonymous with P&T and marked where the system reached the point of diminishing returns. Adding insult to injury, the concentration where the tailing contaminant trend plateaued often exceeded the site cleanup level or remedial action objective (RAO). As a result, the original estimated times to achieve the RAOs came and went, and it became evident that most P&T systems would need to operate much longer than expected. To be fair, this was less a failure in the technology than it was in the failure to understand and account for the complex mass transfer processes that govern contaminant transport – a hindsight that provides little if any solace to those faced with operating their P&T systems in perpetuity.
Along with the extended
time projections to attain RAOs came ever increasing operation and maintenance
(O&M) requirements and costs. P&T
systems installed as interim measures were often designed based on
incomplete/inadequate site characterization and understanding, which often
resulted in flawed P&T design and poor system performance. This subsequently made them ill-suited to
serve their subsequent long-term role as the final remedy. In addition, system design was often focused
solely on the target contaminant(s), with little thought given to the natural
groundwater quality. P&T system
design typically did not account for the operational challenges resulting from
the physical, chemical or biological encrustation/plugging of the well screen, pump,
discharge line, and treatment system from naturally occurring minerals and
bacteria. As a result, P&T system
performance typically decreases with time and use, resulting in increased energy
use and lower pumping rates. Declining
performance and increased operational costs are especially troublesome for P&T
systems because they are typically required to operate continuously at
designated pumping rates to maintain adequate plume capture.
It is important to
realize that much of the stigma associated with P&T as an O&M nightmare
is born out of the poor design and operation of P&T systems and not the
technology itself. After all, the water
supply industry has successfully utilized P&T technology for over 100 years
to provide groundwater as a reliable source of drinking water for their
customers. And although they face the
same challenges with regard to mineral precipitation and biofouling, they have
learned to successfully design, manage and operate their systems to achieve
maximum long-term efficiency.
If you currently own or operate a P&T system and are faced with the ongoing expense and hassle of operating it over the long term, then it may be time to take a fresh look at the problem. The first step in this process is to evaluate whether the P&T system can be replaced with an alternative treatment technology. For example, in-situ oxidative and bioremediation technologies have been utilized successfully at many petroleum hydrocarbon and chlorinated solvent sites as cost-effective replacement technologies for original P&T systems.
technologies aren’t an option, there are still some steps you can take to
potentially improve the overall efficiency of the P&T system. The process begins with a simple reassessment
of the site conceptual model. The data
collected since system startup can be reviewed to refine/update the site
conceptual model and identify modifications (pumping rates, well locations)
that will improve the P&T system performance, while still maintaining
The P&T system should
be inspected to identify and replace any faulty or inefficient equipment. In addition, any components that are not used
and/or no longer necessary should be removed.
Remediation wells that require frequent cleaning to maintain required
pumping rates are candidates for replacement when the maintenance costs exceed
the cost for a replacement well. Any new
replacement wells should be installed in the best location to intercept/capture
the plume and designed for the site-specific aquifer conditions and minimum pumping
rate to maximize efficiency.
Finally, because well
performance typically decreases with time and use, a simple, regularly
scheduled data collection and analysis plan should be implemented to track system
performance with time. The resultant
data trends provide the operator with the ability to better forecast P&T
system maintenance requirements, thereby minimizing the cost and inconvenience
of unscheduled down-time and repairs and improving the cost effectiveness and
efficiency of the maintenance efforts.
Unfortunately, P&T as
a remediation strategy is not going away anytime soon. If you are currently operating a P&T
system, however, it may be time to take a fresh look and see what if anything
can be done to optimize the system and reduce long-term O&M requirements
and costs. Please feel free to contact
me if you feel a fresh look may be warranted.
Published in March 2020 Focus on the Environment Newsletter
On March 2, 2020, U.S. EPA released for public comment the draft 2020 National Pollutant Discharge Elimination System (NPDES) general permit for stormwater discharges associated with industrial activity, also referred to as the Multi-Sector General Permit (MSGP). Some of the proposed revisions streamline the ability to interpret and comply with the permit, while others will likely increase both the level of effort and costs to maintain permit compliance. The proposed permit, once finalized, will replace the existing U.S. EPA MSGP, which is set to expire on June 4, 2020.
Although the proposed permit has near-term implications for industrial facilities where U.S. EPA is the NPDES permitting authority, many NPDES-delegated states (including Ohio) mirror the federal permit language when updating their state permit. Therefore, you can expect significant changes to many state-authored MSGPs in the coming years. EPA’s website and the Proposed 2020 MSGP Fact Sheet list the proposed changes from the 2015 MSGP and note areas where the agency is seeking comment. Majority of the changes incorporate recommendations from the National Academy of Sciences (NAS) and a 2016 agreement with industry groups and environmentalists. The fact sheet is particularly useful as it provides background discussions to better understand the context of each proposed change and request for comment. Some of the noteworthy proposed changes include:
Requiring all facilities to conduct universal
benchmark monitoring for pH, total suspended solids, and chemical oxygen demand
on a quarterly basis (currently only certain industry sectors are required to
perform benchmark monitoring for select constituents a total of four times
during the 5-year permit term);
Revising or removing benchmark values for some
constituents based on the latest toxicity information;
Addition of benchmark monitoring
requirements for various industrial sectors that previously had no benchmark
Consideration of major storm control
measure enhancements for facilities that are located within a flood-prone area,
such as the FEMA 100-year flood zone; and
A new tiered “additional implementation
measures” (AIM) that are triggered by benchmark monitoring exceedances (the
proposed AIM is more prescriptive and may incur greater costs than the
generalized response actions of the current permit).
Cox-Colvin routinely assists industrial facilities
with management of their MSGP and associated storm water pollution prevention
plan (SWPPP). Contact us if you need
assistance or would like to discuss possible changes that may affect your
Published in the May 2020 Focus on the Environment Newsletter Per-and polyfluoroalkyl substances (PFAS) compounds are man-made chemicals that have been used in numerous industrial processes and many consumer products such as cookware, stain resistant carpets, grease resistant food packaging, raincoats, makeup, and many others. PFAS compounds are persistent in the environment and have been […]
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Published in March 2020 Focus on the Environment Newsletter As the name implies, pump and treat (P&T) is a relatively simple remediation technology where groundwater containing dissolve contaminants is pumped from the aquifer and directed to some form of treatment. The advantages of P&T are two-fold, it provides hydraulic containment and control of the contaminated […]
Published in March 2020 Focus on the Environment Newsletter On March 2, 2020, U.S. EPA released for public comment the draft 2020 National Pollutant Discharge Elimination System (NPDES) general permit for stormwater discharges associated with industrial activity, also referred to as the Multi-Sector General Permit (MSGP). Some of the proposed revisions streamline the ability to […]