The staff at SCS Engineers (SCS) has talked at length about how changing the parameters of a coal ash remediation project impacts the eventual outcome of that project. That involves not only the factors present at a particular site but also the regulatory environment in which that site operates, certainly as rules evolve regarding the disposal of coal combustion residuals (CCRs).
Two primary means of coal ash remediation are closure-in-place, or cap-in-place, of an existing coal ash storage site, and closure-by-removal. Closure-in-place involves dewatering the storage site, or impoundment, in effect converting from wet storage to dry storage of ash. A cover system is then used to prevent more water from entering the site.
Closure-by-removal involves dewatering of the coal ash, and then excavating it, and transporting it to a lined landfill or a recycling center.
“There are lots of technical reasons and site-specific factors that can influence a project’s outcome,” said Eric Nelson, vice president of SCS and an experienced engineer and hydrogeologist. “These might include the type and volume of CCR, the geologic setting [e.g., groundwater separation], presence and proximity of receptors [e.g., drinking water supply], and physical setting [e.g., constraints such as access, available space onsite for re-disposal, proximity/availability of offsite re-disposal airspace, etc.].”
Sherren Clark, an SCS team member with experience in civil engineering and environmental science, said “risk evaluation is a key component of remedy selection. A CCR unit undergoing an assessment of corrective measures [ACM] could be a 100-acre ash impoundment containing 30 feet of fly ash, but it also could be a 2-acre bottom ash pond. It could have numerous groundwater constituents exceeding drinking water standards by a significant margin, or it could have a single parameter slightly above the limit at a single well. And there could be water supply wells nearby in the same aquifer, or none for miles around. All of these factors play into the selection of a remedy that addresses the existing risks, without creating other negative impacts such as site disturbance, dust, or truck traffic.”
Tom Karwoski, a hydrogeologist and project manager for SCS who has designed and managed investigations and remediations at landfills as well as industrial, Superfund, and other waste storage sites, noted the challenges inherent to individual sites and stressed careful planning is needed to achieve the desired result. At some sites, “given the size and the nature of the impoundments, transport of CCR off-site may not be the best option.” When moving from the ACM to the remedy [selection], it’s extremely important to have multiple meetings with the client to set the schedule. Based on the way the [CCR] rule is written, things have to progress logically. There’s time available for careful planning. The last thing we want to do is start making assumptions without input from the client and other interested parties. Regulatory compliance and concern for the surrounding community and the environment are important to us and our clients.
“If the nature of the site in its current condition allows it, capping of the site will reduce surface water moving through the waste and significantly cut down on the risk of groundwater contamination,” Karwoski said. “At sites where you have CCRs that may be distributed across a site, to consolidate that onsite and then the cap will address CCRs impacting groundwater.”
Jennifer Robb, vice president and project director with SCS’s Solid Waste Services Division, and the company’s Groundwater Technical Advisor for the Mid-Atlantic region said her group has “done corrective measures for cobalt, arsenic, and thallium,” all contaminants found in coal ash. “There are some in situ bio-remediation that can be done, where basically you’re trying to alter the chemistry to immobilize the metal.” Jennifer noted that there are also more physical remedies where contaminated groundwater is extracted from the subsurface by pumping or the groundwater plume is contained or treated in-situ with the construction of “cut off trenches.”
Karwoski said, “we have no preconceived notions about what is best for all sites, but if you consolidate [waste] onsite and then cap, it will certainly take care of a lot of situations where you have CCRs impacting downgradient groundwater.” This approach may not be appropriate in every situation, but, if arrived at after thoughtfully navigating the remedy selection process defined in the current Federal CCR rules (40 CFR 257 Subpart D—Standards for the Disposal of Coal Combustion Residuals in Landfills and Surface Impoundments), should result in an approach that is effective based on the site-specific factors present.
Read last month’s blog “Many Factors Influence Remedies for CCR Control and Disposal.”
The U.S. Environmental Protection Agency (EPA) has identified 1, 2, 3 – Trichloropropane (TCP), which does not occur naturally in the environment, as an emerging chemical of concern that can threaten drinking water supplies. It states that TCP is a persistent pollutant in groundwater and has classified it as “likely to be carcinogenic to humans.” California State Water Board member Steven Moore called TCP an “insidious chemical” because it persists in the environment, sinks in water and is harmful in even tiny doses. Currently, there is no federal maximum contamination level (MCL) for TCP; however, there is a federal non-enforceable health-based screening level of 0.00075 ug/L.
Since 2012, TCP has been on the emerging Contaminant Candidate List (CCL), which is a watch list of unregulated contaminants that are known to, or anticipated to, occur in public water systems and may require regulation under the Safe Drinking Water Act (SDWA). The EPA has required, under the Unregulated Contaminant Monitoring Rule (UCMR), that large water systems test for TCP every five years with a minimum reporting level of 0.03 μg/L. This rule allows for the EPA to monitor contaminants suspected to be in drinking water that are unregulated under the SDWA. As a result of the testing, TCP has been identified across the US in drinking water sources. Currently, there is no federal maximum contamination level (MCL) for TCP; there is a federal non-enforceable health-based screening level of 0.00075 ug/L.
The author continues the paper with an examination of what TCP is and how it impacts our environment and our health. She then discusses regulatory policies and how California’s mandatory TCP standard could be a blueprint for other state water agencies currently investigating how to enhance their own drinking water protections from emerging contaminants.
Lyn covers some of the legal aspects, risks to businesses, detection, and treatment options to conclude her white paper. She also provides plenty of resources to start the journey toward sustainable treatment solutions that communities can afford.
About the Author: Lynleigh Love is a Senior Project Geologist with SCS Engineers. She has been a professional geologist for more than 22 years with extensive technical expertise in environmental assessment, remediation, and regulatory compliance. Her experience includes groundwater/soil vapor monitoring, excavation work plans, and remedial action plans.
PFAS are also key components in aqueous film-forming foam (AFFF), which is used to fight petroleum-based fires at aviation and manufacturing facilities. For decades, AFFF containing PFAS has been used extensively at airports throughout the world to protect the safety of passengers, crew, and others. The FAA requires that commercial airports train with, calibrate equipment with, and use the best performing AFFF fire suppression systems. AFFF is required to be used at airports and must be certified to meet strict performance specifications, including those mandated by the U.S. Department of Defense Military Specifications.
Lynleigh Love and Chris Crosby of SCS Engineers discuss the risks and issues with PFAS-based firefighting foam used at airports. The authors cover the regulatory climate, contamination investigations, operational and environmental management and litigation, along with alternatives to using traditional AFFF. There are some possible alternatives that can mitigate health risks in your community.
Read this article to help inform your mitigation plan and strategies to minimize risk.
According to the U.S. Geological Survey Circular 1344, the United States uses 79.6 billion gallons per day of fresh groundwater for public supply, private supply, irrigation, livestock, manufacturing, mining, thermoelectric power, and other purposes. This blog is intended for businesses that must meet groundwater monitoring regulatory compliance according to EPA and state mandates, which are becoming increasingly stringent.
Have you had a regulatory compliance issue due to the condition of your groundwater monitoring wells or adequacy of your monitoring network? Are you confident compliance issues won’t arise in the future? Groundwater monitoring networks—including wells and dedicated sampling equipment—are often:
What if you managed your groundwater monitoring network like your other equipment assets? By taking a systematic asset management approach to maintaining your groundwater monitoring network you can:
Not concerned? Consider the likely results of the “if it ain’t really broke, don’t fix it” approach:
Regulatory Non-Compliance: Failure to comply with state and federal monitoring well regulations may result in a notice of non-compliance, fines, or legal action.
Repair and Maintenance Costs: Ignoring minor repairs and maintenance can lead to significant well repair or replacement costs. Simple repairs like lock replacement or ground surface seal repair are quick and low cost. Don’t let these minor items put you at risk for notification of non-compliance due to neglect. Other repairs such as protective casing or near-surface well casing repair may cost more but are a fraction of the cost of replacing a well that becomes unstable due to neglect.
Well Replacement Costs: Abandoning and replacing a single well that can no longer be repaired can cost $3,000 to $10,000+ depending on the depth and construction of the well.
As with many assets, you save time and money in the long run by addressing problems before they arise. So what does monitoring well asset management look like? It doesn’t have to be complicated, costly, or time-consuming. We recommend starting with a simple inventory following these basic steps:
1. Identify needed repairs and replacements of existing wells
2. Develop a plan to repair, replace, or abandon wells as needed
3. Identify deficiencies in the coverage of your well networks
Schedule inventory Steps 1-3 yearly. Download SCS Engineers’ useful well inspection checklist to record monitoring well conditions, identify well maintenance needs and identify the regulatory status of each well. Your trained staff or your environmental consultant can perform the yearly well inventory.
Contact SCS at for a groundwater expert near you.
About the Authors: Tom Karwoski, PG, has 30 years of experience as a hydrogeologist and project manager. He has designed and managed investigations and remediations at existing and proposed landfills; and industrial, Superfund, military, and petroleum sites. Mr. Karwoski was a hydrogeologist with the Wisconsin Department of Natural Resources prior to becoming an environmental consultant.
Meghan Blodgett, PG is a project professional with over eight years of experience in the environmental consulting field, including soil, groundwater, and soil vapor investigation and remediation; brownfield redevelopment; and solid waste landfill development. She is experienced in planning and performing soil and groundwater contamination investigations, monitoring well design and installation, hydraulic aquifer testing, and soil and groundwater sampling.
Per- and poly-fluoroalkyl substances (PFAS) are receiving increasing attention from regulators and the media. Within this large group of compounds, much of the focus has been on two long-chain compounds that are non-biodegradable in the environment: PFOS (perfluorooctane sulfonate) and PFOA (perfluorooctanoic acid).
Long detected in most people’s bodies, research now shows how “forever chemicals” like PFAS accumulate and can take years to leave. Scientists have even tracked them in biosolids and leafy greens like kale. Recent studies have linked widely used PFAS, including the varieties called PFOA and PFOS, to reduced immune response and cancer. PFAS have been used in coatings for textiles, paper products, cookware, to create some firefighting foams and in many other applications.
Testing of large public water systems across the country in 2013 through 2015 found PFAS detected in approximately 4 percent of the water systems, with concentrations above the USEPA drinking water health advisory level (70 parts per trillion) in approximately 1 percent (from ITRC Fact Sheet). Sources of higher concentrations have included industrial sites and locations were aqueous film-forming foam (AFFF) containing PFAS has been repeatedly used for fire fighting or training. Source identification is more difficult for more widespread low-level PFAS levels.
With the EPA positioned to take serious action on PFAS in 2020 and beyond, regulators in many states have already started to implement their own measures, while state and federal courts are beginning to address legal issues surrounding this emerging contaminant. State actions have resulted in a variety of state groundwater standards for specific PFAS compounds, including some that are significantly lower than the USEPA advisory levels. These changes mean new potential liabilities and consequences for organizations that manufacture, use, or sell PFAS or PFAS-containing products, and also for the current owners of properties affected by historic PFAS use. If you operate a landfill or own a site with PFAS history this may be something you need to discuss and plan now.
Questions for property owners, property purchasers, and manufacturers include:
If PFAS treatment or remediation is required, a number of established options to remove PFAS from contaminated soil and groundwater are available, including activated carbon, ion exchange or high-pressure membrane systems. On-site treatment options, including in-situ or ex-situ alternatives, the management of reject streams with concentrated PFAS waste where applicable, are also available.
Do You Need Help?
Need assistance with PFAS or have an idea that you would like to discuss? Contact , or find the SCS Engineers location nearest you.
Following the release of the U.S. Environmental Protection Agency’s PFAS Action Plan, many states have begun to draft plans and take action to address per- and polyfluoroalkyl substances (PFAS).
PFAS have been used in the production of a wide range of industrial and household products, including fire suppressant foam (Aqueous Film-Forming Foams or AFFF) stored and used at airports and aviation facilities for example. Peripatetic in water, PFAS are in the environment and detected in humans.
Nationwide PFAS Sampling and Analyses Plans
States and the federal government are launching programs to sample stormwater, groundwater, and wastewater for the more common PFAS substances at aviation facilities, firefighter training facilities, military bases and training centers, petroleum refineries and terminals, and petrochemical production facilities.
Other secondary sources, such as landfills, wastewater treatment plants, and where biosolids are used in agricultural applications, are preparing for more aggressive water and environmental testing to help the states determine the potential exposure through drinking water due to the tendency of the substances to accumulate in groundwater.
Many states, such as California are focusing on PFAS analytes including PFOA and PFOS. Massachusetts, for example, is focusing on a subset of PFAS compounds – PFOA, PFOS, PFHxS, PFHpA, and PFNA, because these compounds are considered a threat to human health at high levels. According to the Center for Disease Control (CDC), blood levels of both PFOS and PFOA have steadily decreased in U.S. residents since 1999-2000, but only water and soil-sampling plans can help narrow down potential sources and those facilities that may have accumulated PFAS historically. Although not an exhaustive list, they are a sound and reasonable start, which accredited laboratories are capable of detecting, analyzing, and can be treated with available technology.
Focus on California’s Phased Plan – Phase I for Airports, Aviation Facilities, Landfills
In our blog, we’ll focus on California and the State Water Resources Control Board’s (SWRCB) PFAS Phased Investigation Approach published on March 6, 2019. On March 20, 2019, the SWRCB initiated Phase I of its investigative plan by issuing orders to 31 airports, over 250 landfills, and over 900 drinking water wells to obtain PFAS data across the state. The order issued to airports entitled “Water Code Section 13267 Order for the Determination of the Presence of Per- and Polyfluoroalkyl Substances – Order WQ 2019-0005-DWQ,” requires source investigation and sampling at airports. We’ve linked to the PDF for airports here. Phase II will cover refineries, bulk terminals, non-airport fire training areas, and 2017-2018 urban wildfire areas. Phase III will cover secondary manufacturers, wastewater treatment plants and pre-treatment plants, and domestic wells.
The Order requires the facilities to submit a Technical Report to the Regional Water Board upon notification. For example at aviation facilities, an “Airport Operator Questionnaire” is due to the Regional Water Board within 30 days and other requirements including a Work Plan for a one-time preliminary site investigation within 60 days of receiving order notification. Submission of the final sampling and analysis report for each facility is due 90 days following the State or Regional Water Board acceptance of the facility’s Work Plan.
Hire a State-licensed Professional Geologist or Professional Engineer
While the schedule is aggressive, professional engineers familiar with these investigations and reporting requirements can meet the timetable. What should facility owners and managers expect from their professional geologist or engineer? A complaint investigation of possible PFAS releases at your site will include all of the following:
Preparation of the state required documents including a work plan for the preliminary site investigation.
A site map with sample locations, PFAS material storage and use areas, probable release areas including firefighting training areas, crash sites, and spills from handling.
The report needs to identify sensitive receptors such as municipal supply wells, domestic wells, and surface water bodies within a one-mile radius of a suspected source area.
Proposed surface and subsurface soil sampling locations to delineate the surficial and vertical extent of impacts where PFAS were applied to land.
Proposed representative groundwater sample locations in proximity to a suspected source area.
Existing monitoring wells for your facility may be used if located in proximity to PFAS source(s), and groundwater samples would be representative of groundwater conditions. If the groundwater gradient is unknown, at a minimum, three groundwater samples will be collected around the source area.
The sampling and analysis plan for compounds and parameters specified by the state that includes quality assurance and quality control procedures necessary to ensure valid and representative data is obtained and reported. Your engineer or geologist will determine the appropriate sampling procedures, including sampling equipment, sampling containers, the quality of water used for Blank preparation and equipment decontamination, sample holding times, and quantities for sampling PFAS compounds.
Best practices will minimize contamination, so all sampling materials, equipment, blanks, containers, and equipment decontamination reagents used in sampling must be PFAS free, to the maximum extent practicable.
Include all reporting limits for PFAS.
The signature, stamp, and contact information of the California-licensed Professional Geologist or Professional Engineer responsible for the content of the Work Plan.
The Final Report should include the final sampling and analysis report, submitted no later than 90 days following the State or Regional Water Board acceptance of the Work Plan. This report should include a description of the sampling activities; a summary table of analytical results; the Chain of Custody; the field sampling log; and boring logs and any temporary/permanent monitoring well construction details.
The report will also contain the site map showing the sampling/monitoring locations, and a copy of the laboratory analytical results of the monitored media.
The Questionnaire is to be completed and submitted within 30 days if your facility has not discharged, disposed of, spilled, or released in any way, AFFF or other PFAS containing materials to the land at your facility, or if you have already conducted sampling for these constituents in compliance with the minimum work plan requirements.
The Questionnaire, the Work Plan, and all other reports and analytics are submitted in a searchable electronic format, with transmittal letter, text, tables, figures, laboratory analytical data, and appendices in Portable Document Format (PDF) format and in electronic data deliverable (EDD) format to state’s GeoTracker website via the Electronic Submittal of Information (ESI) Portal.
SCS Engineers’ professional engineers, geologists, and hydrogeologist are available to answer questions. SCS samples, oversees analyses, writes environmental reports, and designs-builds treatment for landfill, industrial, and aero facilities nationwide. Visit our website or contact SCS at-1-800-767-4727 or . SCS will match your industry need with a local professional to assist you.
For more information use the links in the blog, or visit the USEPA PFAS website.
About the Authors:
Chris Crosby is a Project Manager at SCS Engineers and has over thirteen years of professional experience in the environmental consulting field. He successfully manages complex environmental site assessments, subsurface investigations, and remediation projects to help navigate regulatory requirements and meet client objectives. He routinely investigates a variety of constituents of concern at properties with soil, groundwater, and vapor intrusion impacts due to releases from historical site use and implements appropriate remediation technologies to restore properties to be protective of human health and the environment.
Diane Samuels is the Corporate Communications Director at SCS. She writes blogs and articles about environmental challenges and the technologies available to design solutions for waste management and other industries responsible for safeguarding the environment.
According to the U.S. EPA, approximately 561,000 underground storage tanks (USTs) nationwide store petroleum or hazardous substances. The greatest potential threat from a leaking UST (LUST) is contamination of groundwater, the source of drinking water for nearly half of all Americans. EPA, states, and tribes work in partnership with industry to protect the environment and human health from potential releases.
Randy Bauer, a project director with SCS Engineers in Arizona stated, “We have seen a significant increase in the number of storage tank failures nationwide, primarily from single-walled fiberglass tanks installed in the 1990s.” He went on to say, “Some fuel additives, such as ethanol, are known to eventually dissolve the epoxy used in the fiberglass tanks, leading to cracks and failures.”
SCS currently has seven soil and groundwater remediation systems in operation in Arizona because the Arizona Department of Environmental Quality (ADEQ) has a proactive program. As the state’s environmental regulatory agency under the Environmental Quality Act of 1986, ADEQ is a separate, cabinet-level agency that directs all of Arizona’s environmental protection programs. Their mission is to protect and enhance public health and the environment in Arizona. The department does this by overseeing the state’s environmental laws and authorized federal programs to prevent pollution of the air, water, and land, and to ensure clean up of pollution, such as LUSTs when it occurs.
About Randy Bauer:
Mr. Bauer has nearly 30 years of experience conducting environmental site assessments, subsurface investigations, groundwater monitoring programs, soil and groundwater remediation, and geotechnical investigations at industrial hazardous waste and solid waste facilities. His responsibilities include supervision, planning, and conducting of numerous Phase I and Phase II environmental site assessments (ESAs) and underground storage tank (UST) removals. Mr. Bauer has planned and directed the characterization and remediation of several large projects involving soil and groundwater contamination. He also directed several hydrogeologic characterizations, including the collection of soil and groundwater samples and interpretation of aquifer tests. He has prepared several Remedial Investigation/Feasibility Study (RI/FS) reports, and prepared, designed, and implemented treatability studies, Remedial Action Plans (RAPs), and groundwater monitoring programs. He has been directly responsible for the preparation of several Aquifer Protection Permits (APPs) for wastewater treatment plants and solid waste disposal facilities. Mr. Bauers duties included
Mr. Bauer has planned and directed the characterization and remediation of several large projects involving soil and groundwater contamination. He also directed several hydrogeologic characterizations, including the collection of soil and groundwater samples and interpretation of aquifer tests. He has prepared several Remedial Investigation/Feasibility Study (RI/FS) reports, and prepared, designed, and implemented treatability studies, Remedial Action Plans (RAPs), and groundwater monitoring programs. He has been directly responsible for the preparation of several Aquifer Protection Permits (APPs) for wastewater treatment plants and solid waste disposal facilities. Mr. Bauers duties included
He has been directly responsible for the preparation of several Aquifer Protection Permits (APPs) for wastewater treatment plants and solid waste disposal facilities. Mr. Bauer’s duties include the senior technical review of documents, as well as negotiation and coordination with the Arizona Department of Environmental Quality (ADEQ).
At the upcoming USWAG CCR Workshop Feb 22-23 in Arlington, VA, Steve Lamb and Floyd Cotter of SCS Engineers will present a session about the advantages and disadvantages of emerging alternative capping options, and how different regulatory agencies are viewing these options.
About this Session: Traditional final cover and capping design for coal combustion residual (CCR) surface impoundments and landfills have included compacted soil liner, geomembrane liner, drainage layer, and a vegetative soil cover. But coal-fired plants oftentimes don’t have the large volumes of soil that it takes to implement these options.
Alternative capping options have recently emerged in the industry such as exposed geomembrane liners or synthetic turf/geomembrane liner systems. Some of these alternative capping options have many advantages over their traditional counterparts. These advantages include faster installation times, minimal need for soil, improved storm water quality, and reduced maintenance and post-closure costs. For surface impoundments, alternative capping designs can also greatly reduce the amount of disturbance of the existing CCR material within the impoundment.
About Steve Lamb: Steve Lamb, PE provides SCS with over 27 years of experience in solid and hazardous waste management, environmental engineering, civil engineering, hydrology and hydraulics, landfill engineering, remedial design, and regulatory compliance. Mr. Lamb is a Vice President and director of SCS’s Charlotte, NC office.
About Floyd Cotter: Floyd Cotter specializes in solid waste management projects. His project work involves all areas of solid waste management including planning, permitting, transportation, landfill design, construction, and monitoring. Mr. Cotter is also experienced in general civil engineering, construction oversight, environmental site assessments, closure and post-closure plans, and permit and contract document preparation.
