Meet SCS Engineers professionals at the Iowa Society of Solid Waste Operations (ISOSWO)’s Recycling & Solid Waste Management Fall Conference, October 2-4, at the Waterloo Convention Center in Waterloo, Iowa.
The conference will feature networking opportunities, a solid waste tour and a sustainability walking tour, exhibits, and auction, and educational sessions.
We hope you were able to join SCS Engineers for our follow-up presentation to Black Goo I. In this live session, we welcomed Dr. Craig Benson, who is studying black goo for the Environmental Research & Education Foundation. Joining Dr. Benson were landfill and leachate engineers and an expert who brings in-field expertise for a holistic presentation.
Landfills are experiencing a phenomenon called “black goo,” solids that make their way into leachate and gas collection systems, clogging equipment and impairing the management and extraction of leachate and gas. The viscosity differs between facilities, hardening like concrete or staying pliable. It attaches to pumps and check valves and settles in sumps, causing problems for leachate collection system cleanouts and landfill operations.
With funding from the Environmental Research & Education Foundation, Craig Benson provided information from his team’s studies, and our panelists discussed how goos move through waste into the infrastructure and how to remove it or keep your systems functioning. Ultimately, this and a growing base of information will help us to prevent the goo problem from happening in the first place.
Who Should Watch and What You’ll Learn?
Goo II is for those in wastewater operations, landfill owners, operators, technicians, field personnel, engineers, and regulators interested in learning more about goos. We covered these topics:
SCS forums are strictly educational.
On March 23, 2023, EPA hosted a live webinar entitled “Listening Session: CERCLA PFAS Enforcement.” EPA is currently preparing a CERCLA PFAS Enforcement Discretion Policy, and they presented an overview of their current thoughts on the topic. Following EPA’s 15-minute presentation, live comments from registered speakers (e.g., Anne Germain with National Waste and Recycling Association, Robin Wright with Delaware Solid Waste Authority) were provided.
SCS’s National Expert on Emerging Contaminants and on Innovative Technologies Jeff Marshall, provides these highlights from EPA’s presentation, delivered by Ken Patterson (EPA Office of Site Remediation Enforcement):
The policy discretion document is still being developed by EPA. The recording of the March 14 and 23, 2023, listening sessions will be posted soon on EPA’s CERCLA PFAS Enforcement Listening Sessions web page.
Follow SCS on your preferred social media site for updates. Please share this update with others whose operations will be impacted.
Solutions: Liquids Management and Sequestration
Deep Well Disposal for PFAS Attracts Heightened Interest as New Regulations Loom One thing that landfills, airports, wastewater treatment facilities, chemical companies, and other entities needing to manage liquid PFAS waste will not have to worry about is competing for deep well …
$2 Billion in EPA Grant Funding to Address PFAS in Drinking Water On February 13, 2023, the EPA announced the availability of $2 billion of grant funding to address emerging contaminants, like Per- and Polyfluoroalkyl Substances (PFAS) in drinking water across the …
USEPA Effluent Guidelines Program Plan, Including PFAS Limits & Nutrient Study USEPA recently issued Effluent Guidelines Program Plan 15, which includes a focus on PFAS discharges from multiple categories. In conjunction with Plan 15, EPA has determined that revisions to the …
Biosolids and PFAS – What’s in my Fertilizer? Many original PFAS compounds were phased out of production in the early 2000s, but they were replaced with other compounds still being evaluated for safety. Tony Kollasch looks at the …
PFAS Discharges: EPA Issues NPDES Guidance to States While the Office of Water works to revise Effluent Limitation Guidelines (ELGs) and develop water quality criteria to support technology-based and water quality-based effluent limits for PFAS in NPDES permits, this memorandum describes steps permit writers can implement under existing authorities to reduce the discharge of PFAS…
Landfill operators forever work to stay on top of a diverse and complex mix of leachate contaminants—heavy metals, ammonia, and biochemical oxygen demand, among them. But lately, they have more to think about, for one: how to keep concentrations of these contaminants within the wastewater treatment plant’s tightening discharge limits. Add to this concern the possibility of more compliance pressure as the list of constituents on regulators’ radar grows. Some operators are preparing for what may be down the pike, from microplastics to PFAS and PFOA—with the latter sometimes called the “elephant in the room.”
Among the strategies, some are exploring on-site leachate treatment options, and there are several. Finding the most fitting, sustainable, and cost-effective one takes vetting. Here is the study of a Florida landfill’s informed decision-making process.
A landfill serving an exploding residential and commercial population recently found itself in a predicament when the overburdened municipal wastewater treatment plant stopped accepting leachate from all county waste operations. Pressed to find a credentialed treatment facility quickly, this SCS Engineers client contracted with a private plant, but the arrangement came with a steep price tag. Overnight, the site’s leachate hauling and disposal costs rocketed from just over three cents a gallon to almost 16 cents a gallon. So, the operator turned to SCS Engineers for help vetting a robust and financially sustainable solution. Ultimately, the client wants to eliminate dependence on a third party and better control its destiny to avoid landing in the same predicament.
In answer, SCS is looking into the feasibility of a system that would clean leachate to drinking water standards to be discharged directly to groundwater. The team is wrapping up a comprehensive study of the site’s current operations, system, and leachate composition as it prepares the client to go out to bid.
“Our goal is to position the landfill to be as independent as possible while providing a cost-effective solution to their leachate treatment,” says SCS Engineers Project Lead Kollan Spradlin. He and the SCS liquid management experts backing him have kicked into high gear because time is money. Right now, the landfill generates about 70,000 gallons a day of leachate through much of the year. In the wet season, that figure spikes to about 150,000 gallons a day. At roughly 16 cents, the landfill can shell out over $24,000 a day for leachate disposal during the wet season.
SCS Engineers’ preliminary work begins with compiling crucial information around current leachate generation and future projections and around site-specific characteristics of the liquids. Next, the team vets multiple leachate treatment systems, sizing up each one against the client’s individual needs to ultimately make a recommendation. And, as important, the team makes sure the operator is very clear on how much upfront capital they need to build an effective, reliable system to do the job.
Spradlin and SCS’s liquid management experts are working on an interim solution while developing a long-term plan. The interim remedy is an evaporator fueled by landfill gas, heats and evaporates water molecules.
“With the evaporator, our client’s private disposal volume is reduced by 50,000 gallons a day, significantly cutting disposal costs. But that’s not enough. We want to reduce that expense further and to manage all or the vast majority of the leachate on-site,” Spradlin says.
The ultimate plan is to design a plant that can treat almost 120,000 gallons a day to a quality that can discharge across a spray field at the facility to groundwater. The landfill saves on disposal costs and owns the system rather than paying for an outside operator’s treatment technology.
This Florida landfill relies on SCS’s site knowledge and its past liquids management experience. SCS’ understanding of the systems and daily operations helped the team develop operational measures already reducing leachate generation to make on-site treatment an option.
“We have completed plan design and construction of their collection, storage, treatment, and disposal systems. And that helped to provide insight into reliable, long-term leachate disposal recommendations,” says Bob Gardner, a 41-year veteran of SCS and part of the team supporting this particular project.
“We had knowledge of site fill sequencing, site conditions, and constraints. And this sped up the process of coming up with a modification that works within their operations and infrastructure,” he says.
All of this foundational background is key to identifying client-centered solutions and presenting a comprehensive data package to vendors. “We give bidders the details they need so they can size their equipment appropriately and provide a more accurate budget estimate. We are trying to eliminate bidder change orders resulting from inadequate background information,” Spradlin says.
The team is thinking ahead, evaluating treatment processes that address a wide range of leachate properties and consider constituents that may be regulated in the future.
“We may put in a reverse osmosis system, a membrane bioreactor, or ultrafiltration to reduce constituent concentrations and take out particulates. We design for flexibility to add more treatment technology on the front end or back end to save the client infrastructure costs in years to come,” Spradlin says.
What differentiates SCS from some other environmental engineering firms is its full-service model and deep bench.
“We touch everything at this landfill. And we have a multidisciplinary team, including national liquid management experts whose knowledge we can tap into at any time. So, we can be one-stop, saving the client from having to go to multiple vendors,” Spradlin says.
Sam Cooke is the lead liquid management expert for this Florida landfill. Like his colleague, Gardner, he knows the wastewater treatment problems landfill operators face; he knows the vendors and their technology. And he understands the importance of relationships—with the client, the state agencies, and every party who is key to the client’s success and the community they serve.
“We fully realize that the wastewater-leachate treatment system we design needs to do its job close to 24/7/365. Moreover, it must do it effectively, sometimes under difficult conditions. So, as we design treatment systems and work with equipment suppliers, facility owners, environmental managers, and treatment system operators, we strive to provide added value and support,” Cooke says.
“In this case, we’re using our knowledge to help our client develop a bid package that addresses specific technical requirements but also meets and helps protect their business and financial goals.”
The team has already met with the regulatory agencies to develop a clear permitting path to accelerate plant deployment and ensure the landfill is fully compliant before making the large transition to direct discharge.
By working with vendors and regulatory representatives well before releasing bid documents, SCS has paved a path to leachate treatment independence.
SCS periodically prepares Technical Bulletins to highlight items of interest to our clients and friends. We publish these on our website.
Our most recent Bulletin summarizes and updates the TCEQ’S New Rules Implementing Compliance and Registration Requirements for Coal Combustion Residuals (CCR) Management. In addition, this Bulletin covers TCEQ’s development of a program for implementing the Federal rules governing CCR facilities in Texas. While TCEQ’s CCR program needs to be as protective as the federal CCR rules, there are important distinctions in Chapter 352.
SCS’ Texas-based professionals are experts on TCEQ’s new program for registering coal combustion residue (CCR) sites. We are currently working to support multiple sites needing to meet the application deadline. Our engineers and geologists know how to use site-specific design and related technical documents to complete TCEQ’s detailed application for a registration consistent with TCEQ’s new regulatory program.
For additional information on the updated regulations, deadlines, and compliance requirements, contact:
SCS periodically prepares Technical Bulletins to highlight items of interest to our clients and friends. We publish these on our website.
Our most recent Bulletin summarizes and updates the TCEQ’S New Rules Implementing Compliance and Registration Requirements for Coal Combustion Residuals (CCR) Management. In addition, this Bulletin covers TCEQ’s development of a program for implementing the Federal rules governing CCR facilities in Texas. While TCEQ’s CCR program needs to be at least as protective as the federal CCR rules, there are important distinctions in Chapter 352.
SCS’ Texas-based professionals are experts on TCEQ’s new program for registering coal combustion residue (CCR) sites. We are currently working to support multiple sites needing to meet the December application deadline. Our engineers and geologists know how to use site-specific design and related technical documents to complete TCEQ’s detailed application for a registration consistent with TCEQ’s new regulatory program.
For additional information on the updated regulations, deadlines, and compliance requirements, contact:
When Melissa Russo’s boss Phil Carrillo told her he thought she should get her drone pilot license, she thought he was kidding. At the time, she worked on SCS’s Remote Control (RMC) team; selling drone services was a part of her job, but she had not thought of flying these unmanned vehicles herself.
Her thirst for competition kicked in when he turned the proposition into a bet. He was going after his pilot license himself; she bet she’d beat his score. They finished in a dead heat, but what started as friendly rivalry ended up bringing a new dimension to Russo’s job— a job that continues to expand in breadth as new opportunities turn up.
Today she not only flies, sells drone services, and teaches others how to sell and fly, but she’s helped bring geographical information systems (GIS) into RMC’s portfolio. How these technologies fit together is RMC remotely collects data from drones and different landfill systems. Then the GIS translates that data into maps, capturing a visual picture of how clients’ facilities’ systems are performing. The GIS piece is one of the latest chapters in the story of Russo’s evolving role (more to come on that).
Piloting is what especially gets her juices going.
“I love working with my team, supporting them in what they do. But when it comes to drones, I like the hands-on experience of flying myself more than telling other people how to do it.”
She controls these small aircraft from a device on the ground, sharply focused on her surroundings while keeping the drone in her sight at all times.
“You have to make sure there are no manned vehicles around; they have the right of way. And there’s a lot of continuous movement on landfills. You’re constantly aware of your surroundings. Is a truck coming? Am I in line with where dumping is going on?”
Flying drones takes muscle and mechanical aptitude.
The drone and case can weigh 45 pounds. And there are a lot of moving parts to assemble and calibrate.
Sometimes it’s manual work, pointing and rotating a remote controller to send a radio signal to tell the drone what to do. But more often, she pilots automated flights that she maps in advance and uploads the flight path specs into software that interfaces with the drone.
“When I’m flying drones, I can access areas where if I had boots on the ground, I couldn’t. I can go and explore just about anywhere, similar to when I dream— only it’s real,” she says.
With any task, she’s laser-focused, concentrating on one part of the picture at a time to grasp the details. She steps back and uses critical thinking, accumulated knowledge, and imagination to take on what’s before her.
The innovation process
“We’re pretty lucky with our timing; new and proven technologies are emerging quickly. I’m one of many SCSers with a deep knowledge of technology and practical experience in the solid waste industry. Together, we can make a difference because we understand the business and operational challenges very well. When I need an expert in another industry, I just reach out to a colleague. The learning process never ends, and each project helps me and my team constantly find better answers.
“My boss is more of a big-picture person; his ideas are huge and amazing. He comes to me with new ideas, and I figure out how to make them work and implement them,” Russo says.
She points to his idea to use proven GIS technology within RMC. She was already using GIS to map methane data, process topographic maps, and stockpile calculations. For instance, she integrates methane values into the GIS and overlaps them with imagery so her clients can zoom in on one well or get a large-scale view of the overall health of the gas collection system. But integrating GIS in new ways to incorporate multiple landfill systems would solve some expensive problems and, better yet, prevent even more expensive mitigation and repairs.
Expanding GIS applications to illustrate multiple landfill systems
“I know drones and how to process drone data. But now that we are expanding applications, I add more layers of landfill data, such as liquids, soil, the gas collection and control system (GCCS), SCADA, and surface emissions, to bring them into the RMC GIS platform. My colleagues are demonstrating these technologies at the SCS June Client Webinar.”
“I created a team of hand-picked SCS staff with both GIS and waste management backgrounds (and a whole lot of drive) to make the vision come to life,” she says. “That’s how we innovate, tight teams with access to nationwide expertise.”
Within six months of the project’s genesis, Russo and her team had integrated gas and liquid collection systems, other landfill systems, and asset management into the RMC GIS platform. She and her team now sell these applications nationwide.
Russo’s come a long way since joining SCS at age 21
In her mind, she grew up at the company. Before coming on board, she managed a shop in Manhattan Beach, California, while she began thinking about what to do next.
“I learned a lot about business and people. It was a stepping-stone – I discovered how to earn trust, build rapport, and sell. But in time, I decided I wanted a more professional job,” she recalls.
She went to work for a real estate company managing the SCS Engineers Long Beach office, where she would soon take an entry-level Accounts Payable position in SCS Field Services.
In time, she transitioned to the Health and Safety group, assisting in creating training material and managing truck fleets. Soon she was managing assets, among other firsts for her. By this point, she had developed enough software, accounting, and other administrative skills to step up fast.
Part of the job was keeping up with vehicle maintenance, so she often spoke with field staff. Many of them she already knew from her days working in the accounting department.
Growing with her SCS colleagues
“When I was in my first administrative roles, I supported many colleagues who were field techs or supervisors; they are project managers now. It feels as though we’ve grown up together, and we know and trust each other. We collaborate well and know that when we bring projects to each other that we will take care of each other,” Russo says.
She especially likes the RMC concept because remote control and automation enable her, her clients, and her team to work smarter, not harder because they leverage the technology to work for them.
“That means we can usually work from anywhere, giving all of us more time for family, friends, or allocating the time saved towards other needed to-dos. I’m up at five a.m. and, at times, may not finish work until nine at night. Somehow, us working women find the balance in between meetings, writing proposals, and answering emails; I have lunch with my two boys or take them to a park,” she says.
Bambi Lance, a veteran SCSer and her mother, works in the same business unit as Melissa does. “Mom’s been here for 16 years, and it’s interesting to have her perspective not only as my mom but as someone who knows SCS. She knows my department, and she knows me. She sees what I am doing and she along with management encourage me to do more and believe in myself.”
Russo reflects again on the concept of stepping-stones on the way to knowledge and maturity. I’m competitive and take on challenges, which has been a driving force in all I do today. It’s helped me take a personal inventory of how I am now versus the young Melissa,” she says.
She uses it to gauge her direction. And she uses it to connect to her staff. “I try to help them see you can turn almost any experience, into a positive. I want my team to see we are all learning and growing. They can, as I can, comfortably bring new ideas to the group and company, which often turn into new ways to help clients.”
She circles back to her decision to fly drones, explaining how it aligns with her career path from her first steps to today. “Becoming a pilot was a natural fit because it’s a new challenge. The craving to take on new tasks is how I grew from an accounting administrator to a project coordinator up to a business manager. It’s wanting to expand my knowledge, tackle new feats, and accomplish what I was not sure I could do. I like the challenge.”
The SCS Culture is Driven by Client Success
Managing oil and gas waste is challenging, even when practicing due diligence. The job requires impeccable skill and attention and sometimes outside support, which Colorado operators recently learned when they found high oil content in leachate coming out of their sump. They turned to SCS, knowing through their longstanding relationship with the engineers and that their liquids management team could deal with oil-laden wastewater.
Ensuring sustainable outcomes begins with collecting and analyzing comprehensive data that become the building blocks for a feasibility study. The study helps with immediate challenges and builds a more holistic approach to tackle increasingly expensive operation challenges at landfills.
“First, we talk about the site’s leachate history, including quality and quantity. What is the source of the waste generating the leachate, and where is it deposited? How are liquids used in current operations? The current practice used the liquids on the landfill surface for dust control, leaving an unsightly oily sheen.
Once we talk about how the site currently manages these liquids, we discuss options for future handling for improvement,” says Neil Nowak, SCS Engineers project director. “You’ve got to have a holistic understanding of day-to-day operations with the data to solve the problem cost-effectively.”
Neil’s preliminary research led to one recommendation to meet all the criteria – separate oil and water from leachate as the liquid exits the pump. The separation process can reduce the oil-laden leachate volume by 70 percent.
The technology works by separating the leachate into oil and water portions using an oil/water separator, such as a gun barrel tank, which is low cost and effective. After piping the water to an evaporation pond, the collected oil is sent offsite for future handling, usually disposal.
“This method gives the operator a better option for dealing with the leachate over the current practice of spraying it on the landfill surface for dust control,” Nowak says.
Spraying usually provides an alternative for liquids while reducing disposal time and cost. However, he explains, oil-laden leachate is a different beast than typical MSW liquids and calls for a more creative solution to remain within regulatory compliance.
Oil and water separation eliminates the aesthetics issues at the site with its previous practice. The greater value is that this method gives operators full control of oil’s movement, which can otherwise be very hard to accomplish.
“Oily leachate can adhere to the wheels of equipment that move dirt over the landfill surface; consequently, it ends up in places operators do not want it to go. Oil and water separation technology is a reliable way to keep it out of surface drainage areas and ensure it does not infiltrate into groundwater outside of the lined space,” Nowak explains.
Operators avoid short- and long-term consequences springing from compliance issues, but beyond today, the technology that SCS sizes operates for 20-plus years and helps prepare them for the long haul.
This option enables waste pros who take on growing demand from the oil and gas industry to protect the environment and public health, even as volumes increase. Oily liquids are particularly challenging for wastewater plants. Separation technology provides greater assurance that the landfill will still have a home for their leachate as wastewater treatment plants raise the bar on what they will allow.
The remaining question…
What is the most cost-effective and safe way to eliminate the filtered oil?
The solution for the immediate need is straightforward and simple. Depending on geology, local regulatory policy, and cost factors, solidification or injection are the most common, safe practices now, but reuse options are under development. Reuse and prevention are part of a longer-term landfill strategy, so Neil draws on his colleagues’ expertise.
Nowak’s expertise comes from years of experience supporting the oil and gas industry. Backing him is national liquid management expert Nathan Hamm, who lends technical expertise and insight on best practices for reducing leachate.
Commonly the best bang for your leachate management dollar is to reduce the volume of leachate or wastewater to treat in the first place. Operators can begin by diverting stormwater away from active portions of the landfill, then installing a better cover system. Depending on the landfill’s need and location, reducing the size of new cells and timing those new cells to come online during low precipitation seasons is practical. Leachate minimization practices such as these directly reduce the treatment system capital and ongoing operational costs.
The Colorado operator now has oil and gas waste management options and has a comprehensive, site-specific review of leachate management with a clear understanding of where there is room for improvement.
As far as their immediate priorities, says Nowak, “We have left them with enough thought-out information to make informed decisions, and for now, they are leaning toward the oil and water separation technology. Though they can keep operating without it, they are looking to get ahead of possible compliance issues by making changes voluntarily, which are usually less costly in the end and demonstrates social responsibility to the Colorado Department of Public Health and Environment and the EPA.
Not too long ago, SCSer Gomathy Radhakrishna Iyer thought she’d become a mechanical engineer but decided to go down another path at her father’s coaxing, and she’s never looked back. Today she is a Civil & Environmental Engineering Ph.D. and has become deeply entrenched in the world of landfills—human-made formations that she calls “beautiful.”
Dr. Iyer’s work spans research and engineering projects in landfill gas emissions reduction, landfill design, and leachate management. She’s also keeping up with PFAS to be ready for what may lie ahead around these emerging contaminants. “What I’m most into these days is researching and helping clients select leachate treatment systems and doing landfill expansion designs. It’s so mentally rewarding when you find solutions for the client’s problems. They are happy, and you are happy,” says the SCS staff professional.
She is known by more than her work family. Gomathy is a published researcher and speaker, most recently presenting at the Global Waste Management Symposium in February 2020. Her presentation covered one of her pet topics, her Ph.D. focus: using grass clippings and biosolids as biocovers to remove methane from landfills.
Pre-COVID, she spent many of her days in the field. Lately, she spends a little more time anchored to her computer in her home office. There she typically works on a few spreadsheets at a time, maybe as part of a gas emissions report, a stability analysis, or settlement analysis. Then she shifts her focus to her design drawings. Dr. Iyer still manages to break away to put on her PPE – her hardhat, safety vest, and steel-toed boots. She happily drives off in a company truck to the landfill, lugging field parameter testing probes and a 10-pound ISCO to collect leachate samples; or do other fieldwork like locating LFG wells and pipes or other features that help her design.
In the summers, it gets scorching hot. And the winters can be bone-chilling cold, especially for a woman who spent most of her life in India, where she was born and raised. In her last years there, she studied the transport of heavy metals through groundwater. Then, it was on to the University of Texas, Arlington, where she earned her Ph.D. and became set on finding work at SCS, coming on board in 2019.
Among her earliest challenges was communication. “Sometimes I would be in a meeting or having lunch with my colleagues, and they would bring up baseball or other games or a Netflix series. They were new concepts to me, and I couldn’t relate. While I speak English, I was unacquainted with the vernacular. I was like, what is Super Bowl? I thought maybe it was something very big that people eat from,” she recalls. That does not stop a researcher.
Finding a way to become better acclimated became a project of sorts. She started spending weekend downtime in front of the TV to learn about these American pastimes. Baseball still isn’t her first love, but she’s happy to say, “In 2019, I went to my first Washington Nationals game with a big group from SCS, and I had at least some knowledge of what was going on.”
The ambitious civil engineer has pushed past another on-the-job challenge—one brought on by the impulse to know every detail she can nail down before setting to work. “Since I’m from a research background, I tend to dig to the very bottom to try and know the problem completely. Sometimes it’s a good thing. But I’ve had to be conscious of time constraints, gain an understanding of the minimum required to do the job well, and move on,” she says.
What first brought her to the United States was her husband, Ramesh Padmanabhan. He was working on a Ph.D. at the University of Texas at Dallas while she was studying in India, so the relationship truly began as a long-distance one. They got to know each other through a combination of old-world traditions and 21st Century channels. “Ours was an arranged marriage. Our parents introduced us, and for the first year, we met up and talked on SKYPE,” Dr. Iyer recollects. He’s a molecular and cell biologist and sometimes her consultant too.
“In my job, I need to know the biology and chemistry of microbes as they are responsible for breaking down waste, and he is my encyclopedia. I don’t have to Google as much when he’s around.” She adds: “I can’t complete my story without talking about my brother who has given me unconditional support and career advising through my life. These two men are pillars of my life.”
As a woman civil engineer who’s all about waste, she’s in the minority, but she doesn’t feel as if she is because women are moving into waste engineering. She’s one of four women on an eight-person team, who she says is “like my family. And my supervisor is a great supporter of women in STEM (science technology, engineering, and math).”
She hears from many newly degreed civil engineers, including “young ladies” with questions about waste management. They read blogs about her work that originated on SCS’s website and are on social media. “These graduates want to take their career to the next level, and they have a lot of questions about how to start solving waste issues,” she says. She tells them that solid waste management is one of the best and most stable industries they can choose and that the pandemic has driven that point home. “We are reminded through COVID that waste management is an essential business, and there will always be jobs to support it,” she says.
What Dr. Iyer loves most about her job is what she and her team imagine and draft in drawings, keeps developing, and in time, is built. “It’s like giving birth to a baby. Very exciting,” she says. Her groundwater contamination remediation work got her interested in PFAS, even before she finished her studies. “I had a lab mate in school who did PFAS research. That got me curious about these emerging contaminants. I’ve stayed vigilant to keep up with what’s happening with regulations and treatment options under research. If regulations now under consideration are implemented, our clients will have to start thinking more proactively about addressing PFAS. So, we need to learn more on a holistic level about what these contaminants can do and the best way to treat them.”
She tells the story of how her venture into civil engineering started with her father. “He wanted to be a civil engineer himself but was the eighth son, so his parents couldn’t afford tuition, and in India, you don’t go to college once you are grown with a family,” she explains. He wanted his daughter, already drawn to engineering, to pursue what had been his dream and said he thought it would suit her better than the direction she was leaning. “Had I studied mechanical engineering as I’d been thinking of doing, I would not have come into waste.” She is happy with where she’s landed.
“When you work all day and still are not tired –you still enjoy it and are happy to contribute to something good—that’s how you know it’s the right fit.”
Lately, landfill operators are putting stock in onsite landfill leachate treatment systems as a strategy to stay on top of increasing requirements in their already demanding regulatory world. Leachate treatment systems help meet tightening restrictions on liquids that landfills send to municipal wastewater treatment plants or discharge directly. And onsite leachate treatment gives operators a leg up should they one day have to deal with any emerging contaminants found on an expanding list.
With their eyes on compliance, landfill owners and operators are looking to leachate treatment systems that can ease the impact of soaring leachate disposal costs. Of course, the more contamination, the harder the hit since higher contaminants can mean higher municipal treatment plant surcharges or the landfill having to haul its leachate longer distances to a treatment plant that will accept it. Both examples usually result in higher treatment, disposal, and hauling costs.
A spike in its ammonia concentrations was enough impetus for one Oregon landfill operator to turn to SCS Engineers a few months ago. At its highest levels, the ammonia climbed to 50-fold what many small wastewater treatment plants, like the one in the Northwest, will take over the long-term.
Project Director Shane Latimer and Technical Lead Sam Cooke got on the stick to figure out how their client could keep hauling and disposing of leachate at the local wastewater treatment plant it has routinely relied on for years.
Coming up with a plan is a complex, multi-step process that requires looking through many lenses. To design a cost-effective, efficient treatment facility, Latimer and Cooke use an in-house multidisciplinary team of co-workers from Project Management, Chemical Engineering, Civil Engineering, and Geotechnical Engineering. The team performs in-depth analyses to identify the most economical and feasible technology. A design that in this case not only addresses ammonia but prepares the operator for emerging contaminants, such as the possible need for per and polyfluoroalkyl substances (PFAS) reduction, which Cooke describes as a train that has not yet arrived in Oregon but has left the station and is heading down the track.
Starting with the most immediate concern, Cooke says, “Our client had seen ammonia concentrations between 500 and 1,500 mg per liter, which is high. Acceptable ammonia levels can vary depending on the type of facility and how much leachate they expect to get compared to their total flow. But small treatment plants like the one our client depends on will set ammonia limits of about 25 or 30 mg per liter,” he says.
SCS begins with a leachate pretreatment options analysis to dive into details beyond ammonia levels – spikes in ammonia call for close attention. Still, there’s more to consider in masterminding a robust and fitting plan to manage the complex process.
“These are biological treatment systems, and there is no one-size-fits-all answer. You need to know how these systems will react to whatever is in your leachate, so you have to account for more than ammonia, or whatever your constituents of concern are,” Latimer says.
SCS’s leachate contaminant analyses use the landfill’s historical data along with what they learn from tests that SCS orders to understand alkalinity, pH, and carbon, among other leachate chemistry puzzle pieces.
“We look at concentrations of raw leachate, flow rate, pretreatment requirements, and other factors. We want to get a comprehensive picture of the problem and ultimately make the best treatment decision to get compound concentrations down to acceptable discharge levels,” Latimer explains.
What customized solution did the team design for the client in Oregon? The system of choice is a membrane bioreactor (MBR), which combines membrane separation technology with traditional activated sludge technology with optional reverse osmosis treatment. The design is a compact, efficient, biological wastewater treatment plant.
“An MBR is an elegant solution. We found it to be a good choice for this application for several reasons. It takes up relatively little space and fits well within the available plant footprint. It produces a relatively low-volume waste sludge stream. And it can cost-effectively treat multiple constituents of concern, so should new leachate chemistry issues arise, an MBR can address many of them,” Cooke says.
Being able to handle multiple concerns if and when they arise is key here. Cooke and Latimer wanted not only to get the immediate problem in check but see that the client has a dynamic and robust system to tackle whatever new challenges may be down the road.
When SCS goes into design mode, they plan ahead by engineering modular systems to add additional treatment methods if and when they’re necessary.
“For instance, MBR treats the leachate to reduce ammonia, other nutrients, organics, and suspended solids. By leveraging this treatment method first, you eliminate a lot of the bulkier constituents. But we left room for a modular addition such as reverse osmosis for “polishing,” treating MBR discharge for other minor constituents including PFAS,” Cooke says.
The client who came to SCS for a relatively inexpensive remedy for an ammonia problem now has a feasible, economical asset for leachate management.
“These investments are good security for landfill operators,” says Latimer. “If a municipal wastewater treatment plant is struggling to meet its standards, eliminating one contributing source of wastewater, like a landfill, could potentially solve several issues, such as ammonia, biochemical oxygen demand, and total suspended solids.”
But these treatment systems provide added security for more than the landfill.
“When disposal sites invest in sound leachate treatment systems, it’s also good for municipal wastewater treatment plants. It assures them that landfill operators will help them with the overall regulatory burden. We are helping them both to prepare for present and future challenges,” says Latimer.