FOG are the fats, oils, and grease substances, primarily from food processing and manufacturing, requiring wastewater treatment.
Not long ago, a Utah food manufacturer turned to SCS with a persistent problem: high concentrations of fats, oils, and grease (FOG) in its wastewater— high enough to clog the city’s sewer line, knock it out of compliance, and cost it a steep surcharge year after year. As the plant worked toward a solution, its customers’ demand was growing; it reached a point where it had to expand to keep up, and that’s when the quandary came to a head. The meat processor couldn’t get a permit for expansion until the FOG was in check.
Within 18 months, SCS Project Director Mark Pearson and his team of liquid management gurus had their client within acceptable discharge limits for the first time in years. Actually, the plant’s doing a lot better than meeting the city’s requirements. Its FOG concentrations, which had spiked to thousands of mg/L, are consistently down below the established discharge limit of 200 mg/L.
The scenario Pearson walked into is that the wastewater generation and pollutant loading were highly variable as flows fluctuated. Due to hydraulic limitations, the treatment system couldn’t keep up with volumes during peak flows. As a result, the influent (untreated wastewater) was discharged from the plant to the sewer to the municipal wastewater treatment plant. And because the system was overtaxed, it did not sufficiently break down the FOG, which exacerbated the problem, wreaking havoc with the city’s collection pipes.
After completing the initial assessment, Pearson’s team developed a multifaceted approach to debottleneck the system’s hydraulics and make other improvements to increase FOG removal efficiency.
Pearson; Dean Free, senior project manager; and Nathan Hamm, program lead for wastewater and liquids management, came up with a design that achieves two main goals: It eliminates uncontrolled discharge from the plant; it greatly reduces concentrations of FOG—cutting the contaminant load to the city. Not only is the client within discharge limits, but it’s also pushed through its most immediate barrier to expansion permit approval. And it’s improved its relationship with the city.
The solution is a complex one involving chemistry, mechanical engineering, and electrical engineering. But to pare a lot of fine details down to the nitty-gritty, Pearson says:
“We put in screens that remove solids in the wastewater. We constructed a 60,000-gallon tank to equalize the flow coming to the plant. We adjusted pH to help optimize the wastewater treatment chemicals’ effectiveness. We separated the influent tank from the effluent (treated water) pipes to solve a problem where the influent would overflow into the effluent through a perforated wall. The new piping setup makes overflow impossible. And to further fortify the system, we installed a lift station to capture previously untreated wastewater.”
As a bonus, the team installed a tank that the separated FOG residual is pumped to, then hauled to a compost facility for beneficial use.
Besides adding these system enhancements, the SCS team took capabilities further with a process control and instrumentation component. The technology monitors flow rates, temperatures, tank levels, and other conditions. It processes the data and automatically makes adjustments to achieve treatment goals, avoid production downtime, and enable operators to respond proactively should they see a red flag.
Comparing the old to the new way of monitoring and analyzing, Pearson says, “What our client had before was rudimentary information. And while they could monitor conditions, they had to walk around the plant. All of the operational data can be viewed on a screen now from one location. They have more data at their fingertips and more capability to make adjustments to avoid discharge exceedances.”
The wastewater treatment system upgrade was done as a design-build to speed the timeframe while also increasing efficiency. “We could immediately start rather than put it out to bid. We could do construction as we designed. And there was one entity and one point of responsibility. So what’s cool is we leverage both SCS engineering and construction capabilities to solve problems,” Hamm says.
He and his colleagues have the know-how to pivot on a dime if they have to, and there were a couple of times it was necessary, including when the client brought new management on board midway through the installation process. The new team preferred different instrumentation and had a specific scheme in mind.
“We were in the process of installing the original instruments. But we were able to incorporate their equipment preference midstream. We had to figure out how to get new instruments installed and ensure they were perfectly integrated with the computer control system that takes readings from the instruments. It was what they wanted, so we saw that they got it,” Pearson says.
While he and his co-workers’ jobs as project design and build engineers are done, they have not faded from the picture. They provide ongoing technical support when the client needs assistance with troubleshooting. The automated control system has helped.
“This is a robust and complex mechanical treatment system. If by chance, something was wrong, our client can transmit data that comes out of the process controller so we can work remotely to determine if process changes are needed. If they are, we can often make those changes from offsite, and quickly,” Hamm says.
But the SCS team also plans so that its client is equipped to ensure its success moving forward. They provide operator training. And they developed a standard operating and maintenance procedures manual and a checklist to track data and activities transferred from shift to shift, providing operators a standard and seamless way to communicate.
The busy Utah plant is on a good trajectory, with solid footing.
Says Pearson: “Before, they could not expand the plant or even continue their operations much longer if they did not get the FOG under control. Now they can operate continuously, discharge to the city, and they have potential to expand their plant because they are showing the regulators they can stay within their permit limits.”
Complementing the Interstate Technology and Regulatory Council’s – ITRC, PFAS Technical and Regulatory Guidance, the website now has ITRC Per- and Polyfluoroalkyl Substances – PFAS, and Risk Communication Fact Sheets available. The site and updated content replace older fact sheets with more detailed information and useful for those who wish to understand the discovery and manufacturing of PFAS, information about emerging health and environmental concerns, and PFAS releases to the environment with naming conventions and federal and state regulatory programs.
SCS Engineers’ professionals recommend further reading to understand specific chemicals or subgroups of chemicals under study to comprehend PFAA behavior in the environment. There are appropriate tools to develop a site-specific sampling and analysis program and considerations for site characterizations following a PFAS release.
Firefighting Foams – Aqueous film-forming foam (AFFF) users and those who manage AFFF releases.
The Interstate Technology and Regulatory Council (ITRC) is a state-led coalition working to reduce barriers to the use of innovative air, water, waste, and remediation environmental technologies and processes. ITRC documents and training can support quality regulatory decision making while protecting human health and the environment. ITRC has public and private sector members from all 50 states and the District of Columbia and is a program of the Environmental Research Institute of the States (ERIS), a 501(c)(3) organization incorporated in the District of Columbia and managed by the Environmental Council of the States (ECOS).
ITRC Goals
National paradigm shifts for using new technology
Harmonized approaches to using innovative technology across the nation
Increased regulatory consistency for similar cleanup problems in different states
SCS Engineers
Reduce the review and permitting times for innovative and proven approaches to environmental prevention and mitigation programs
provides Prevention with Risk Management, Process Safety, and Spill Prevention Plans
Can help reduce the possible impact on environmental insurance
Faster cleanup with less environmental impacts
Decrease compliance costs
Provides technical and regulatory expertise for public outreach
Regularly engages with state and federal regulators and compliance enforcement as a trusted engineering firm.
The industry is designing and building more substantive drainage features and larger collection systems from the bottom up, that maintain their integrity and increase performance over time, thus avoiding more costly problems in the future.
Waste360 spoke with three environmental engineers about what landfill operators should know about liquids’ behavior and what emerging design concepts help facilitate flow and circumvent problems such as elevated temperature landfills, seeps, and keep gas flowing.
The engineers cover adopting best practices and emerging design concepts to facilitate flow. They cover topics such as directing flow vertically to facilitate movement to the bottom of the landfill, drainage material, slope to the sump percentages, vertical stone columns, installing these systems at the bottom before cells are constructed, and increasing cell height to prevent the formation of perched zones.
Ali Khatami, one of the engineers interviewed, has developed standards for building tiered vertical gas wells that extend from the bottom all the way up. He frequently blogs about landfill design strategies that his clients are using with success. His blog is called SCS Advice from the Field. Dr. Khatami developed the concept of leachate toe drain systems to address problems tied to seeps below the final cover geomembrane. These seeps ultimately occur in one of two scenarios, each depending on how the cover is secured.
Landfill Gas Header: Location and BenefitsBy continuing to design gas header construction on landfill slopes, all of the components end up on the landfill slope as well. You can imagine what type of complications the landfill operator will face since all of these components are in areas vulnerable to erosion, settlement, future filling, or future construction. Additionally, any maintenance requiring digging and re-piping necessitates placing equipment on the landfill slope and disturbing the landfill slope surface for an extended period.
AIRSPACE, the Landfill Operators’ Golden EggAirspace is a golden egg, the equivalent to cash that a waste operating company will have overtime in its account. With each ton or cubic yard of waste received at the landfill, the non-monetary asset of airspace converts positively to the bottom line of the …
Gas Removal from Leachate Collection Pipe and Leachate SumpKeeping gas pressure low in and around the leachate collection pipe promotes the free flow of leachate through the geocomposite or granular medium drainage layer to the leachate collection pipe and improves leachate removal from the disposal cell. Using gas removal piping at leachate sumps is highly recommended for warm or elevated temperature landfills where efficient leachate removal from the leachate collection system is another means for controlling landfill temperatures.
Leachate Force Main Casing Pipe and Monitoring for LeaksLandfill operators may add a casing pipe to their leachate force main for additional environmental protection. Consequently, the leachate force main is entirely located inside a casing pipe where the leachate force main is below ground. In the event of a leak from the leachate force main, liquids stay inside the casing pipe preventing leakage …
Pressure Release System Near Bottom of LandfillsPressure Release System Near Bottom of Landfills – Essential Component for Proper Functioning of the Landfill Drainage Layer. Landfill designers are generally diligent in performing extensive leachate head analysis for the design of the geocomposite drainage layer above the bottom geomembrane barrier layer. They perform HELP model analyses considering numerous scenarios to satisfy all requirements …
Landfill Leachate Removal Pumps – Submersible vs. Self-Priming PumpsSelf-priming pumps can provide excellent performance in the design of a landfill leachate removal system. Landfill owners and operators prefer them to help control construction and maintenance costs too. A typical system for removing leachate from landfill disposal cells is to have a collection point (sump) inside …
In this Waste Today article, Sam Cooke discusses the factors, treatment options, analytical methods, and identifying PFAS sources to most effectively reduce the concentrations of ammonia and PFAS in landfill leachate.
Reducing these concentrations help meet discharge permit requirements for direct discharge of treated leachate to surface waters and to meet publicly owned treatment works (POTW) discharge permit standards.
Sam points out that accomplishing ammonia and PFAS reduction with established wastewater treatment technologies works, but the right treatment depends on each site’s specific parameters. He suggests conducting bench-scale and pilot-scale testing for any feasible nitrogen removal or treatment system. Testing the wastewater helps to identify any changes in the concentration of nitrogen compounds. Thus, necessary changes to the treatment processes, such as additional aeration or chemical additions are easier to identify and less costly to implement.
About the Author: Mr. Cooke, PE, CEM, MBA, is a Vice President and our expert on Industrial Waste Pretreatment. He has nearly three decades of professional and project management experience in engineering with a concentration in environmental and energy engineering. Mr. Cooke works within SCS’s Liquids Management initiative to provide services to our clients nationwide.
Pilot-Testing a Novel “Concentrate-&-Destroy” Technology for ‘Green’ and Cost-Effective Destruction of PFAS in Landfill Leachate
One of the recent recipients of EPA’s latest round of small business research grants is investigating a novel technology for treating PFAS in leachate. This project could fill a key technology gap for cost-effectively treating PFAS in landfill leachate. The technology would provide landfill field engineers and decision-makers with a cost-effective solution and mitigate the health impacts as the relevant regulations are rapidly evolving.
Per EPA:
The technology is based on an innovative adsorptive photocatalyst (Fe/TNTs@AC) synthesized by modifying low-cost activated carbon (AC) with a cutting-edge photocatalyst, iron-doped titanate nanotubes (Fe/TNTs). The technology works by first concentrating PFAS in water onto Fe/TNTs@AC, and then completely degrading PFAS under UV or solar light. Bench-scale studies indicated that Fe/TNTs@AC can remove >99% of PFOA or PFOS from water via adsorption within 1 hour and degrade nearly 100% of the adsorbed PFAS within 4 hours of UV irradiation. Complete destruction of PFOA also regenerates the material, allowing for repeated uses.
While conventional AC or resins do not degrade PFAS, and while PFAS-saturated AC or resins are hardly regenerable, PFAS on Fe/TNTs@AC are amenable to efficient photocatalytic degradation, which not only destroys PFAS, but regenerates the material. While direct photochemical treatment of PFAS-laden water is often cost-inhibitive, the new technology employs photocatalytic treatment only for spent Fe/TNTs@AC, which is only a fraction of the raw water volume, and thus consumes much less energy.
Phase I commenced on March 1 and runs through August 31, 2020
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. They persist even when excreted through urine. 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. For example, in Madison, Wisconsin, PFAS have been detected in 14 of 23 municipal water supply wells, but the detected concentrations were below the USEPA’s health advisory levels for PFOA and PFOS. A study of potential PFAS sources near two of the Madison wells identified factories, fire stations, landfills, and sludge from sewage treatment plants as possible sources, but did not identify a specific source.
With the EPA positioned to take serious action on PFAS in late 2019 and 2020, 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.
Questions for manufacturers, property owners, and property purchasers include:
Should we test for PFAS?
If so, where and how?
To what standards should we compare our results?
What will we do if we find PFAS?
If 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 the management of reject streams where applicable, are also available.
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Need assistance with PFAS or have an idea that you would like to discuss? Contact for more information.
Use these resources to explore more about PFAS each is linked to helpful articles and information.
SCS Engineers welcomes Mark Pearson, P.E, to the firm’s environmental engineering practice. As a Project Director, he and his team will provide water and wastewater engineering and consulting to public and private entities in the region and the U.S. from SCS’s Overland Park office.
Mark brings decades of expertise in environmental engineering, with an emphasis on wastewater design for water treatment plants, wells, pumping stations, and including sewers and waterlines. His experience includes project management through facility planning, design, and construction phases; a good fit for SCS’s comprehensive solutions.
A Professional Engineer licensed in three states, he supports clients with the design, construction, and implementation of environmental treatment systems for water and wastewater plants and post-industrial use, reuse, and the disposal of liquids. Mark helps support industries and landfills facing increasing regulatory policies, higher standards required by water treatment plants, and the rising costs associated with protecting water supplies.
Mark has worked on a wide range of projects around the world and in the United States. He is a certified Envision Sustainability Professional (ENV SP) and a member of the National Council of Examiners for Engineering and Surveying (NCEES). He earned his bachelor’s degree in civil engineering from the Missouri University of Science and Technology, and his master’s degree in environmental engineering from California State University-Long Beach.
“Mark’s expertise and knowledge enhance SCS’s ability to provide sustainable process treatment design and wastewater solutions to industrial and landfill clients who are responsible for leachate and liquids management, which is a significant operational expense for them,” stated Nathan Hamm, a Vice President of SCS Engineers and Central region lead in the Liquids Management program.
This EREF Summit will bring together practicing engineers, academics, industry professionals, government personnel and policymakers to facilitate discussion and provide various perspectives on the management, issues, and policies related to PFAS.
Per- and polyfluoroalkyl substances (PFAS) are a group of compounds that are man-made and are commonly used in industrial processes and consumer products such as food packaging, fire-fighting foams, metal plating, outdoor gear, popcorn bags, food wrappers, facial moisturizers, mattresses, carpeting, and cookware. Despite the widespread use of PFAS in everyday products, there are still significant knowledge gaps associated with the management of these compounds.
Understanding the entire range of wastewater management and disposal alternatives can be a daunting task, particularly as increasingly stringent surface water discharge standards take effect or as zero discharge facilities find the management of their waste liquid needs changing over time. Former solutions are no longer options or may be too costly. One alternative that is rapidly gaining traction is deep injection wells.
Deep well injection is a viable leachate management option in many parts of the United States, yet it is often screened out as a possible alternative due to a lack of understanding of the technology or gross misconceptions about its acceptance or applicability. The purpose of the Monte Markley’s paper The Basics of Deep Well Injection as a Leachate Disposal Option is to present the basic technical, economic and regulatory considerations of deep well injection as a technology a facility should evaluate when considering the applicability of geologic sequestration of leachate.
Technical criteria discussed are potential disposal volumes, geologic suitability, chemical compatibility, pre-treatment requirements, and leachate chemistry. The economic considerations are evaluated based on the technical criteria noted above, management of public perception/relations, current leachate management expenditures, the service life of the asset and risk to develop accurate capital, O&M costs, and return on investment. Regulatory considerations include the role of state vs. federal primacy for each state, the general stance of regulatory acceptance in specific areas of the United States, and a discussion of the permitting process and typical reporting requirements.
These key considerations are then integrated into an overall suitability evaluation that an owner can utilize to accurately determine if deep well injection is a viable option and, if so, how to educate other stakeholders and manage the process of implementation as a project moves forward.
Comments were submitted to the EPA from NWRA/ SWANA regarding the EPA’s Advance Notice of Public Rule Making (ANPRM) for revisions to Subtitle D, and in particular potential revisions regarding the bulk liquids addition. Subtitle D prohibits bulk liquids additions with the exception of leachate recirculation, and the RD&D permit process allows bulk liquids. Bob Gardner of SCS Engineers was involved in the development of the joint NWRA/SWANA comment letter.
EPA has indicated that they are considering adding a “wet landfill” definition to Subtitle D; however, the Industry strongly advised against doing so. The letter addresses this issue and the reasons for recommending against a separate “wet landfill” definition.
About the Author: Mr. Cooke, PE, CEM, MBA, is a Vice President and our expert on Industrial Waste Pretreatment. He has nearly three decades of professional and project management experience in engineering with a concentration in environmental and energy engineering. Mr. Cooke works within SCS’s Liquids Management initiative to provide services to our clients nationwide.
