Regulatory movement around PFAS is picking up; this year and next could be monumental around managing these toxic compounds in landfills and leachate. Operators should look out for proposed U.S. Environmental Protection Agency (EPA) rules in 2022 and final rules in 2023. Most notably, two PFAS categories, PFOA and PFOS, could be classified as hazardous wastes under the Resource Conservation and Recovery Act (RCRA) and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), aka Superfund. Also, expect rules on monitoring and limiting PFAS in drinking water.
Amidst this regulatory activity, PFAS treatment research advances, which will be critical to landfill operators when they are charged with managing this very challenging stream. With existing options, it’s near impossible to destroy these “forever chemicals,” known for their carbon-fluorine bond, considered one of the strongest in nature.
SCS Engineers’ Gomathy Radhakrishna Iyer advises operators on what to look for to brace for regulatory change and advises them on their best defense—the treatment piece. She explains current options and potential technology breakthroughs on the horizon.
“On the legislative front, standardized guidance might not happen overnight. There’s much to learn, as leachate is not the same, including as it pertains to PFAS. Concentrations and compounds vary. So, EPA is gathering data and knowledge to inform policy and mitigation options moving forward,” Iyer says.
Today’s focus entails developing and validating methods to detect and measure PFAS in the environment. The EPA is evaluating technologies to reduce it and is trying to understand better the fate and transport of PFAS in landfills (including landfill gas, leachate, and waste).
While PFAS concentrations in leachate sent to publicly owned treatment plants (POTW) are unknown, the EPA 2023 rule aims to fill in the missing pieces. What is learned and subsequent decisions will be critical to landfill operators who depend on POTWs as a final destination for leachate and at a time when POTWs meet stringent guidelines on what they can accept. The EPA’s focus will begin with guidance on monitoring and reporting figures, including a list of PFAS to watch for in 2022.
In the meantime, the agency published interim guidance on destroying and disposing of PFAS, which it plans to update in fall 2023. The interim guidance identifies the information gap with regard to PFAS testing and monitoring, reiterating the need for further research to address the FY20 National Defense Authorization Act NDAA requirements. Operators can also look to SWANA treatment guidelines to help prepare for new rules.
Get ahead of the game by doing your homework on treatments, Iyer advises. POTWs have discharge limits, and once PFAS in leachate is weighed in with the existing constituent limits on permits, ensuring a disposal destination will call for proactive measures.
The discussion on treatments will be important. Iyer advises on staying up with expectations that may be in the pipeline, beginning by focusing on today’s commercially available options:
Comparing these methods, Iyer says, “Biological treatments work better simply as a pretreatment method, removing PFAS to some extent. Their performance may also only apply to non-biodegradable organic matter. Considering these limitations, the alternative of physical-chemical treatments is most often recommended by industry experts; they appear to be more effective as supported by data,” Iyer says.
Her preference is RO, the membrane-enabled separation process, which many treatment plants already use, or are considering, to remediate other constituents. “Because we know RO to be effective with other contaminants and PFAS, I think it’s a great gainer, especially if plants already use this method to treat leachate for other contaminants successfully,” she says.
RO requires relatively little operational expertise, while other physical-chemical methods, such as GAC and ion exchange, require some chemistry knowledge.
“With granular activated carbon and ion exchange, resins attach to contaminants in leachate. These approaches require pretreatment for organics removal, process understanding, and operator involvement. Conversely, with RO, you learn a fairly straightforward process and move through the steps,” she says.
But while physical-chemical treatments are the best readily available options today, each has limitations. RO leaves a residue requiring further treatment; then, the material is typically recirculated in landfills as a slurry or hauled to a POTW, meaning there is no guarantee they will not need to be addressed later. Other methods, such as GAC, are more energy-intensive and have limited sorbent capacity. Ion exchange, in particular, has difficulty removing short-chain PFAS, which persist in the environment.
When the time comes that PFAS have stringent discharge limit requirements, no one of these technologies may work as a standalone, so the search is on for more robust systems.
Several new treatments are under research; unlike their predecessors, they appear to break the chemical bond.
Iyer shares her take on each option:
“I’m especially interested in seeing how plasma treatment works in the real world versus the lab. The building costs can be higher, and leveraging electricity to break the bond is expensive. But the maintenance should be easy and relatively inexpensive compared to other technologies. It will be interesting to see how economical it would be for landfills over the long run.”
There is more to learn about each of these new technologies. Researchers are working to identify the adsorbents that best suit PFAS compound removal, whether short or long chains. With photocatalytic reaction, a research direction is exploring combining UV rays, a catalyst, and an oxidant to degrade PFAS.
“We know that the absorption options and photocatalytic concepts work well on strong contaminants,” Iyer says. She moves on to her thoughts on thermal treatment. She wants to know more about this particular option before weighing in. “I’m not sure how feasible this method will be for the operators. PFAS get destroyed at a temperature greater than 1,000 degrees Celsius. But for high quantities of leachate, this option could be expensive.”
Most EPA-funded research is based on these developing treatment processes. But there is plenty to evaluate to identify the best solutions in a given scenario. With that understanding, the agency is trying to understand the types and volumes of PFAS generated, how they change or degrade as they enter landfills, and where they originate. EPA is building a database to track this information to consider key characteristics of individual PFAS to help guide forthcoming guidance on treatments.
In the meantime, Iyer advises operators to pay close attention to evolving developments and communications from EPA.
We recently saw the memorandum from EPA on addressing PFAS discharges in EPA-issued NPDES permits. We will look for guidance to the state permitting authorities to address PFAS in NPDES permits soon and more information from the EPA’s roadmap.
At SCS, we use our time to learn about technologies, including what’s still under investigation and explore what seems to work. In addition, watch for guidance documents, not just from EPA but from research organizations such as EREF and universities. Do your due diligence and keep your eyes and ears open for EPA and your state regulatory authority announcements. Staying informed is the best strategy for landfill operators at this point.
Liquids and wastewater management resources.
SCS Engineers is expanding its Phoenix, Arizona, office to meet the growing demand for sustainable environmental consulting and engineering. Recent employee-owners joining the firm are pictured upper left to right, including Samantha Montgomery, a technical associate; Mike Bradford, senior professional engineer; Cynthia Neitzel, a professional engineer; and Taylor Goins, field services working as part of SCS’s comprehensive team.
Montgomery’s focus is to prepare monthly, semi-annual, and annual greenhouse gas reports, along with processing and analyzing the data associated with those reports. She specializes in air quality compliance and permitting, particularly for landfills.
Bradford brings more than 20 years of experience in civil engineering and project management. He has been the principal engineer and engineer of record for a wide range of public and private sector capital projects in Arizona and across the country for solid waste landfills and other public works civil projects.
As a landfill project manager focusing on landfill gas collection and control systems and compliance reporting, Neitzel brings more than 20 years of experience. She has a background in landfill design, construction quality assurance, and air quality permitting and compliance.
Goins provides clients with landfill gas monitoring and other related environmental monitoring services, helping them reduce operational costs and protect air quality. He also operates and maintains other environmental pollution control systems.
“Mike and Cynthia bring invaluable experience creating and overseeing environmental solutions for municipalities and businesses, which provide essential services in our region,” said Pat Sullivan, senior vice president of SCS Engineers. “They, along with the rest of the team, join SCS to serve our clients who are actively seeking to protect public health and the environment as part of doing business, whether that’s remediating property, operating a landfill, lowering their carbon footprint, or running a fuel station.
SCS Engineers’ environmental solutions and technology directly result from our experience and dedication to our clients responsible for safeguarding the environment as they deliver their services and products. For more information about joining this remarkable national firm, please visit SCS Engineers Careers.
(l) Liquids addition. The owner or operator of a designated facility with a design capacity equal to or greater than 2.5 million megagrams and 2.5 million cubic meters that has employed leachate recirculation or added liquids based on a Research, Development, and Demonstration permit (issued through Resource Conservation and Recovery Act (RCRA), subtitle D, part 258) within the last 10 years must submit to the Administrator, annually, following the procedure specified in paragraph (j)(2) of this section, the following information:
(1) Volume of leachate recirculated (gallons per year) and the reported basis of those estimates (records or engineering estimates).
(2) Total volume of all other liquids added (gallons per year) and the reported basis of those estimates (records or engineering estimates).
(3) Surface area (acres) over which the leachate is recirculated (or otherwise applied).
(4) Surface area (acres) over which any other liquids are applied.
(5) The total waste disposed (megagrams) in the areas with recirculated leachate and/or added liquids based on on-site records to the extent data are available, or engineering estimates and the reported basis of those estimates.
(6) The annual waste acceptance rates (megagrams per year) in the areas with recirculated leachate and/or added liquids, based on on-site records to the extent data are available, or engineering estimates.
(7) The initial report must contain items in paragraph (l)(1) through (6) of this section per year for the most recent 365 days as well as for each of the previous 10 years, to the extent historical data are available in on-site records, and the report must be submitted no later than June 21, 2022.
(8) Subsequent annual reports must contain items in paragraph (l)(1) through (6) of this section for the 365-day period following the 365-day period included in the previous annual report, and the report must be submitted no later than 365 days after the date the previous report was submitted.
(9) Landfills in the closed landfill subcategory are exempt from reporting requirements contained in paragraphs (l)(1) through (7) of this section.
(10) Landfills may cease annual reporting of items in paragraphs (l)(1) through (6) of this section once they have submitted the closure report in § 62.16724(f).
If you need assitance meeting the regulations, please contact your project manager or send a request to
Engineering News Report publishes the ENR Top 500 List, which ranks global design/engineering firms by revenue. SCS Engineers again ranks in the top 100, moving up this year from #73 to #59. We thank our clients and our employee-owners for helping SCS continue to rank as a top-tier environmental services engineering, consultanting, and construction firm.
ENR is one of the premier companies tracking the A&E industry, and these rankings are closely followed as they publish throughout the year. SCS Engineers is also recognized in the Sewer & Waste List of Top 20 companies globally, ranking at #5, up from #10 the previous year.
Climate change and reducing our nation’s carbon footprint are important challenges facing our planet. SCS Engineers remains a leader in recovering and utilizing methane from landfills, a potent greenhouse gas. In the last decade, we’ve been expanding our role to include more utilization of biogas from agriculture, carbon sequestration, management of other greenhouse gas and environmental impacts for multiple sectors while reducing methane production in landfills by diverting organics.
SCS designs and supports innovative environmental solutions with our in-house award-winning technologies to help our clients. With more data and control available 24/7, our clients can make more informed decisions, operate more efficiently, running cleaner and safer while delivering essential services, products, and properties.
If you thrive in a friendly, collaborative, and client-focused company, SCS Engineers is the place for you, and we’re growing! We’re looking for field technicians to work collaboratively on our Field Services teams nationwide. Specific information is posted for each open position. Use our job search to find your desired location.
Under general supervision, our technicians operate, monitor, and maintain gas migration control and recovery systems, including gas well monitoring and adjustment, troubleshooting, and system repairs. These systems capture emissions that keep our planet cleaner. SCS clients entrust us with the management of more than 35 million metric tons of anthropogenic CO2e greenhouse gases every year. We collect and beneficially use or destroy enough to offset greenhouse gas emissions from 7.4 million passenger cars annually.
Become one of the growing engineers, consultants, scientists, and technicians helping private and public entities run cleaner and more efficiently. A very rewarding place to have a career!
Co-Authors Joseph Duckett and Jeffrey Pierce argue that we should “Hold It” long enough to follow facts and science before accepting environmental misconceptions. History shows popular beliefs about environmental hazards and health risks – alarmist or dismissive – are sometimes wrong.
We recommend their new book, Hold It! The Case for Hard Thinking, Honesty and Humility when Assessing Environmental Health Risks. It’s the #1 new release in Amazon’s Pollution Engineering category. Both authors take an objective look at some of today’s and yesterday’s most controversial environmental topics.
You can read a review here and buy the book on Amazon.
SCS Engineers has built an impressive history, set of accomplishments and qualifications in designing, building and operating Renewable Natural Gas (RNG) facilities. SCS creates the RNG by removing almost all other gas constituents except the methane. These other constituents include carbon dioxide, hydrogen sulfide (H2S), sulfur compounds, and volatile organic compounds (VOCs), siloxanes, oxygen, nitrogen, and waste.
Leaders such as Jeff Pierce of SCS Engineers employ decades of energy systems expertise to analyze and evaluate the effects of variations in processes and the parameters important to successful facilities. They model and evaluate complex systems and processes to evaluate plant performance. They account for project objectives and requirements while considering technical, business, energy, and environmental objectives.
Biogas recovery systems are feasible for landfills, large dairy, hog, poultry, and beef operations. In short, using science and facts to make sustainable decisions has a much greater impact on addressing climate change.
These are a few words to describe our 2022 Conrad Quality Award Recipients. Celebrating the accomplishments of these SCS employee-owners, the Conrad Award highlights the level of quality we seek as a company.
Click here to read about our colleagues.
Conrad Quality Focus Awards recognize SCSers for their sustained quality performance above and beyond what is required by their job. The Awards Program helps keep our attention on quality every day — something we all strive for to meet and exceed our clients’ needs and expectations.
The City Council of the City of Lincoln, Nebraska, recently approved a four-year service agreement with SCS Engineers for comprehensive environmental solutions and technology supporting the Solid Waste Management Division and Lincoln Water System.
The contract provides professional engineering and technical support for the City’s two Solid Waste Management Facilities, located on Bluff Road and North 48th Street in Lincoln. Modern landfills such as these contain complex systems to protect the health of nearby communities and the environment. Lincoln’s Solid Waste Management Division uses SCS professionals’ expertise and proprietary software for air quality and gas collection and control systems (GCCS), operations, monitoring, and maintenance. These environmental services keep the landfills fully compliant with regulatory requirements while aligning with the City’s system performance goals and anticipated operational and maintenance activities.
The City is using SCSeTools® software designed for landfills to support managing the monitoring data to gauge operational health continually. The firm’s comprehensive environmental services include sampling and monitoring groundwater, stormwater at both facilities, and leachate analysis at the Bluff Road Landfill.
SCS assists with scheduled testing and reporting to federal, state, and local agencies, including the Environmental Protection Agency, Nebraska’s Department of Environment and Energy, and the Lincoln-Lancaster County Health Department. Primarily these public reports cover monitoring summaries, statistical analyses of analytical results, and review of emission sources, factors, and calculations associated with the GCCS. They also include greenhouse gas reports, estimates, Title V permit requirements and documentation, NPDES General Permit support, and Stormwater Pollution Prevention Plans.
Michael Miller, an SCS vice president and one of the firm’s environmental due diligence experts, said,” We’re privileged that the City of Lincoln entrusts us to partner with its professionals to maintain the landfills’ safe and efficient operations. The Solid Waste Management Division and Lincoln Water System support the citizens with essential services and the environment; we’re honored to assist.”
SCS Engineers shows you in this short video featuring SCS Remote Monitoring & Control technology built for landfill owners and operators, solar farms, and for use on pipelines by SCS Engineers, landfill and environmental practitioners.
Introduction
Contamination at thousands of shopping centers across California from previous business operations presents problems for property owners who wish to continue commercial use, redevelop, and maintain property value. Commercial property remediation targets returning these buildings and land to predevelopment conditions, presenting opportunities for reuse and redevelopment.
One property owner discovered that securing adequate funding and working closely with state and regional regulatory agencies leads to success despite changing regulations and oversimplifying regulatory health risk assessment methods. The Draft Cal-EPA Supplemental Vapor Intrusion Guidance (DSVIG) suggests changes to the methods in which vapor phase transport and potential health risks are modeled and calculated for occupants of buildings with known soil or groundwater contamination beneath them. These changes, the result of a multi-year working group collaboration, recommend an arguably more conservative calculation of indoor air quality. The changes rely on EPA work and guidance, with empirically derived attenuation factors (AFs), which will increase the number of sites requiring additional environmental assessment and mitigation to achieve health risk standards. Although the DSVIG is currently draft guidance, there is evidence that regional regulatory agencies have already adopted AFs in calculating indoor air quality.
Diamond Bar Commercial Center Assessment and Mitigation
Drucker Survivors Trust owns and operates a multi-tenant commercial building in Diamond Bar, California, including a dry cleaner at one time. The former cleaners caused an unauthorized release of dry cleaning solvent containing chlorinated volatile organic compounds to the subsurface during its operation.
Financing for this all too common situation requires environmental due diligence in the form of research commonly completed in a Phase I Environmental Site Assessment followed by an assessment to characterize potential liabilities associated with chlorinated solvent releases before lenders provide funding.
Regulatory oversight in California can either be voluntarily engaged or involuntarily if assessment activities on an adjacent or nearby property indicate the presence of chlorinated volatile organic compounds in the subsurface linked to dry cleaning operations in the vicinity.
The Drucker Survivors Trust sought approval from the applicable regulatory agency, Los Angeles Regional Water Quality Control Board (LARWQCB), to assess and mitigate the chlorinated solvent release to ensure the protection of human health and reduce environmental liabilities associated with the property.
Regulatory closure is the acceptance of assessment and remediation activities by the governing regulatory entity to bring the site into compliance. Compliance, in this case, required assessment and mitigation of beneficial use groundwater underlying the property impacted by the solvent release and completing soil vapor assessment and health risk screening calculations under current state and federal guidelines.
Guidance on vapor assessment and associated health risk screening methods have changed rapidly in California state environmental regulations. As environmental engineers and consultants, SCS professionals manage an extensive list of vapor assessment, health risk assessment, and vapor intrusion mitigation projects resolving these vapor–related issues.
To start this project, the SCS team prepared a successful grant application securing more than $650,000 in funding from the California State Water Resources Control Board’s Site Cleanup Subaccount Program (SB 445, established in 2014). This state-provided grant money enables the assessment and mitigation necessary to close with the LARWQCB.
Subsurface assessment activities defined the extent and scale of chlorinated solvent impacts to soil vapor, soil, and groundwater, enabling the design of a remediation program. To reduce the groundwater contamination to cleanup levels set by the LARWQCB, SCS Engineers designed and implemented an injection program to deliver engineered chemicals directly to the groundwater plume. The injected chemicals destroy the chlorinated solvents via in situ chemical reduction and stimulation of biological degradation.
While challenging drilling conditions precluded previous consultants from attempting groundwater remediation, SCS industry experts safely achieved up to a 99 percent concentration reduction within the groundwater plume. SCS designed a soil vapor assessment that relied more on site-specific data collection and less on conservative default assumptions while conforming to the most current regulatory guidance targeted at minimal impact on the building tenants.
SCS managed all aspects of the project, including grant requirements and communication between the client, regional and state water board staff, city staff, and subcontractors. Obtaining and managing entrance under state waste discharge requirements is necessary, and SCS completed all necessary permitting and reporting requirements to facilitate the groundwater mitigation activities. Careful planning and experience with similar projects minimized impacts on tenants and kept the project on a strict timeline with no missed regulatory deadlines. SCS continues working with the LARWQCB to conclude the client’s final closure requirements and is in the process of applying for an additional $900,000 in SCAP funding to implement the final stages of the project targeted at obtaining final regulatory closure.
Changes Coming to Regulatory Guidance
Recent changes to regulatory guidance in California are arguably making obtaining closure on sites with vapor intrusion health risk concerns more difficult to achieve. The Draft Cal-EPA Supplemental Vapor Intrusion Guidance (DSVIG) suggests changes to the methods in which vapor phase transport and potential health risks are modeled and calculated for occupants of buildings with known soil or groundwater contamination beneath them. These changes, which result from a multi-year working group collaboration, recommend a more extensive and site-specific data collection effort. They include indoor air quality calculation methods relying on EPA work and guidance and empirically derived attenuation factors (AFs) which some would argue lead to overestimating potential health risks.
The consequences of the DSVIG are potentially significant if adopted as is and appear likely to result in more sites being “screened in” with vapor intrusion issues and more sites requiring mitigation. The impact, resultant costs, and possibly detrimental secondary effects such as decreases in affordable housing production, particularly in urban infill areas. And while none would argue with appropriate protection of health risk, the question is whether the studies and empirical data used to support the DSVIG represents the best available science and is truly representative and predictive of risk.
The DSVIG adopts an attenuation rate of 0.03 for the flux of both soil and sub-slab vapor to indoor air based on a previous 2012 EPA Study comprised of empirical data collected from buildings arguably not representative of modern construction in California.
The development of a reliable screening level attenuation factor for California based on high-quality, recent, California-specific data:
1) Will be protective of human health, as no toxicological imperative or basis supports a call for accelerated or immediate action (as evidenced by the fact that the DSVIG workgroup commenced its work in 2014 and issued the review draft in 2020).
2) Will ensure California’s environmental policy satisfies the gold standard for data quality and insightful analysis in which the state once took pride.
3) Will not unnecessarily decimate the California housing development market. The empirically derived screening level AF in the DSVIG is overly conservative based on the available data. More accurate empirical data and measurement methods for site-specific measurement are available.
With respect, oversimplifying the VI health risk assessment methods has constrained the environmental community’s ability to apply science-based health risk screenings, often resulting in costs associated with additional environmental assessment and mitigation. An additional revision to the DSVIG to utilize a screening level AF more reflective of the current California data and building specifications could save state resources, increase infill development by reducing urban sprawl, promote housing development, all while protecting human health.
About the Author: Keith Etchells is a professional geologist and hydrogeologist with over two decades of experience assisting clients in managing environmental risks associated with ownership, transfer, or operation of commercial, industrial, and waste disposal properties. His particular technical expertise involves aspects of groundwater science and engineering relevant to contaminated sites and landfills, including supervision and conduct of subsurface data acquisition, remedial design and implementation, conceptual site model development, aquifer testing, extraction well design, groundwater quality evaluation and treatment, vapor intrusion health risk assessment and mitigation, predictive modeling, and contaminated soil and groundwater remediation design.
He is responsible for designing analytical, geotechnical, and hydrogeological data collection programs to complete subsurface assessment and remediation. He has prepared subsurface assessment documents, property mitigation plans, vapor intrusion risk assessment documents, soil management plans, aquifer characterization documents, conceptual site models, and groundwater remedial design and implementation documents.
