An energy company using coal (many still do as they transition to renewable energy sources) uses desulfurization for its flue gas, preventing air pollution and creating gypsum as a by-product. Fly ash, another by-product of creating energy, is sold to concrete companies for a profit. The wastewater used in these green processes has high chloride. It is pretreated to ensure the chemistry of the wastewater is safe before injecting it into an EPA and state regulatory agencies-approved Class I well below drinking water aquifers.
Pretreatment helps to ensure the energy company does not decrease the capacity of the well to accept wastewater. Chemical characterization of the wastewater in the permitting process and regular sampling during operations helps ensure the fluid is non-hazardous and unchanged.
Using green practices, this energy company prevents air and water pollution, protects drinking water resources, and qualifies as a zero-discharge facility. The bottom line is that they provide energy at a reasonable cost; the company is profitable from its green practices and protects health and human life.
That’s sustainability that empowers the safety of electric utilities as they provide for our energy needs.
You are welcome to make use of SCS Engineers’ extensive library of papers, blogs, and videos for the power sector. Here are a few suggestions:
Professional Geologist Jake Dyson is responsible for permitting, drilling, regulatory compliance, and operating Class I, II, V, and VI UIC wells. Dyson manages permitting, testing, and workovers of UIC wells and serves his clients as a technical advisor on developing and executing well construction material, formation fluid, and well testing programs, including managing drilling and construction costs, interpreting geologic data for model inputs, and developing static geologic models. You can reach Jake at SCS Engineers or on LinkedIn.
The EPA proposes updated effluent limitation guidelines (ELGs) for meat and poultry product facilities, aiming to reduce wastewater pollution, particularly nitrogen and phosphorus discharged from meat and poultry processing facilities. These changes affect meat and poultry industry facilities, including those that would apply to additional direct and indirect dischargers.
There is growing concern as local and state ELGs are also beginning to appear. These new guidelines can impact the meat and poultry industry and the food and beverage industry. In summary, the federal guidelines are influencing state and local plans.
Meat:
Poultry Processing:
Overall, the proposed changes in effluent limitation guidelines by the EPA represent a significant shift in regulatory expectations for the meat and poultry industry. SCS Engineers provides webinars and resources that provide crucial insights and guidance for industry stakeholders to navigate these changes effectively.
SCS Engineers provides these free resources:
Hydrogen sulfide (H2S) is often identified as a potential culprit of odors and nuisance complaints near municipal solid waste (MSW) landfills. Some base their complaints on information found on the Internet as fact. As experts, let’s start by saying data from other landfills or pulled from an AI browser summary online will not provide accurate answers. H2S concentrations vary widely and are unique to individual landfills.
How is H2S generated in an MSW landfill, and why do concentrations vary?
Calcium sulfate (CaSO4•2H2O, aka gypsum), the primary ingredient in wallboard (aka drywall), can be biologically converted to H2S under select and somewhat rare conditions. Specifically, seven conditions are required for the biodegradation of gypsum to H2S. See (Gypsum Association, Industry Technical Paper: Treatment and Disposal of Gypsum Board Waste (Jan. 1991); Gypsum Association, Treatment and Disposal of Gypsum Board Waste, Part II, Technical Paper (Mar. 1992).
Condition 1 – Liquid Water. The biological conversion of sulfate to H2S occurs in the aqueous phase—i.e., sufficient free liquids must be present, and sulfates must dissolve into the free liquids. Modern landfills with leachate collection systems may experience intermittent perched and discrete zones of saturation within the waste mass, particularly following periods of extended precipitation. Low-permeability confining layers (e.g., clay or clay-like soil used for intermediate cover) may temporarily trap water/leachate in discrete pockets within the landfill.
Condition 2 – Source of Soluble Sulfate. Gypsum, having the chemical formula CaSO4•2H2O, is a source of soluble sulfate. Gypsum sources include wallboard (aka drywall), flue gas desulfurization (FGD) material from coal-fired power plants, and some industrial wastes. Sulfates and sulfur compounds can also be present in lower concentrations in other waste streams, depending on what the MSW landfill accepts.
Condition 3 – Sulfate-reducing Bacteria. Sulfate-Reducing Bacteria (“SRB”) use dissolved sulfate as an electron acceptor in the oxidation of carbon. Primary SRB include Desulfovibrio and Desulfotomaculum. These SRBs, as well as many other bacteria, are commonly present in MSW landfills. However, the presence of SRB within a landfill may not be ubiquitous, and may be limited to regions where the other required conditions favor their existence and survival.
Condition 4 – Organic Material. SRBs use organic material as a food source to multiply and degrade sulfate to H2S. Carbon serves as a source of energy for the bacteria. Typical MSW has a high organic content due to a wide variety of organic materials such as wood, paper, cardboard, food, vegetative waste, and fabrics. Many communities with recycling programs help divert these waste materials for reuse and recycling.
Condition 5 – Anoxic Environment. SRBs thrive under anoxic (without oxygen) conditions. The presence of oxygen can kill SRBs. While anoxic conditions are typically not present in areas where MSW was recently disposed, they are typical in portions of MSW landfills where organic wastes have been present for at least a few months and decompose to produce methane and carbon dioxide.
Condition 6 – Appropriate pH Range. SRB reduction of sulfate to H2S is reportedly optimum within a pH range of about 7 to 8, and does not occur outside a pH range of about 4 to 9. The pH range within a typical MSW landfill falls within this activity range.
Condition 7 – Appropriate Temperature Range. SRB reproduction and H2S generation are reportedly optimum within a range of about 30 °C to 38 °C (86 °F to 100 °F). Many MSW landfills are within or a little above this optimum range. Studies of SRB in geologic environmental settings found reduced activity above about 60 °C (140 °F), and no activity above about 80 °C (176 °F). Similarly, SRB activity ceases in freezing conditions.
In summary, although the necessary conditions for H2S generation are likely intermittently present within some discrete pockets within many MSW landfills, the conditions are not likely ubiquitous throughout the waste. MSW landfill conditions and waste composition are typically highly heterogeneous with respect to both location within the landfill and time. Thus, there are zones within landfills where many, but not all of the seven required conditions are present, and H2S generation does not occur. For example, there are undoubtedly many regions within landfills where free liquids (i.e., saturated conditions) are not present and, therefore, SRB conversion of sulfates to H2S does not occur, despite the presence of the other six conditions.
Similarly, a landfill may have pockets where bulk sulfate-containing waste has been disposed of but where the internal portion of the pocket is not exposed to moisture, organics, or SRB—each a necessary condition for converting sulfate to H2S.
Considering these seven conditions and heterogeneous landfill conditions, there are too many variables to provide a reliable and defendable quantitative model for H2S generation at all MSW landfills.
Monitoring and Treating Landfill H2S Conditions
We invite you to use our free resource library to learn more about how monitoring and data collection can protect your workers and the surrounding environment.
About the Author: Jeff Marshall, PE, is a Vice President of SCS Engineers and our National Expert on Emerging Contaminants (e.g., PFAS) and Innovative Technologies. He has over four decades of experience emphasizing environmental chemistry (e.g., hydrogen sulfide generation at MSW landfills), environmental permitting and compliance (e.g., fumigation facilities), hazardous materials/waste management, site assessment/remediation, treatment technologies, and human health risk issues. Hydrogen sulfide experience includes dozens of facilities, including landfills, coal-fired power plants, and paper mills.
Join SCS Engineers as Sponsors and Exhibitors at the 2025 SDHF Annual Affordable Housing and Community Development Conference in San Diego, CA on October 16th, 2025. The San Diego Housing Federation’s annual Affordable Housing and Community Development Conference brings together more than 600 developers, builders, architects, lenders, property managers, service providers, elected and agency officials and staff, community, and business leaders to share innovative approaches to affordable housing, community, and economic development. We are proud sponsors of the event and we look forward to seeing you there.
Follow the link to find more information about the conference: https://www.housingsandiego.org/events-2/2025-affordable-housing-amp-community-development-conference
Join SCS Engineers at the 2025 National Brownfields Training Conference at McCormick Place in Chicago, August 5–8, 2025.
Brownfields 2025 brings together professionals from government, industry, and the community to explore best practices for the remediation and redevelopment of brownfield sites. As the premier event focused on transforming contaminated properties into community assets, Brownfields 2025 offers more than 180 interactive sessions, mobile workshops, and networking events. Attendees will connect with peers and decision-makers, discover new resources and technical assistance, and explore the latest innovations in brownfields cleanup and sustainable redevelopment.
Stop by and visit SCS Engineers at Booth 314 to connect with our experts, learn more about our work in brownfields remediation, and explore how we help communities turn environmental challenges into revitalization opportunities. Don’t miss this opportunity to connect with SCS Engineers and the broader brownfields community in the heart of the Windy City – register now!
Look for these special presentations:
Let Me Tell You a Story – Brownfields and StoryMaps with Megan Husic, a Nevada Certified Environmental Manager and a Project Manager at SCS Engineers. Megan’s presentation explores the power of Geographic Information Systems (GIS) and ESRI StoryMaps in transforming how we engage with stakeholders and communities, particularly in the context of brownfield projects. StoryMaps is a dynamic tool that integrates maps with narrative text, images, and multimedia to create compelling and interactive stories. StoryMaps are valuable for educating the audience about Brownfields, showcasing the potential of Brownfields revitalization, providing background and current site information, and outlining plans and community benefits. Learn the essential steps and considerations for creating an effective StoryMap, including the importance of assembling a skilled team, and discover how it can revolutionize brownfield project communication and stakeholder engagement.
Transforming Brownfield Redevelopment with GIS: A Comprehensive Approach with Kayla Ouellette, GIS Manager at SCS Engineers. Kayla’s presentation explores the transformative role of Geographic Information Systems (GIS) in managing and communicating the complexities of brownfield projects. Kayla delves into leveraging GIS technology to enhance project planning, data management, and stakeholder engagement. Key topics include an overview of the GIS environment, access to GIS software, and practical applications, including site selection and ranking, demographic analysis, data management, and community outreach. Her presentation emphasizes the importance of starting with the end in mind, ensuring that you tailor GIS solutions to meet specific project needs and reporting requirements. By utilizing GIS, project teams can improve accuracy, efficiency, and communication, ultimately leading to more successful brownfield redevelopment efforts.
Melissa Schick joins Alyssa Kuhn and Aditi Chakravarty of EPA, Richard Jenkins of Pasco County, FL, for a Topic Talk on Brownfields Challenges Created through Increasing Frequency and Intensity of Hurricanes. U.S. EPA Region 4 had a challenging hurricane season with Hurricanes Helene and Milton which made landfall on Florida’s Gulf Coast on September 26 and October 9, respectively. Helene’s total costs were $78.7 billion in damages and an estimated total of $59.6 billion in damage and needs were attributed to North Carolina, alone. When we add in other disasters such as wild fires, tornados, and floods the amount of debris to manage is a major challenge for states and the waste industry too.
Eric Williams is a trainer for the Brownfields University pre-conference training event, designed to provide a curriculum of core brownfield concepts and practices before the full educational program content. Eric will be providing his “Stack & Sequence – Strategically Using Multiple Sources of Brownfields Funding” training module, which is the subject of multiple papers and presentations. Public agencies and non-profits will benefit by learning how to best promote redevelopment through utilizing multiple capital sources.
Join us for a relaxed evening of networking, drinks, and city views as we celebrate our shared commitment to Brownfields Redevelopment. Taking place Thursday, August 7, 2025 from 7 – 9PM at the VU Rooftop Lounge.
SCS Engineers proudly sponsors the 2025 CALED Annual Conference, taking place May 7–9 at the DoubleTree by Hilton Hotel Ontario Airport in Ontario, CA. Project Director Eric William will present “Repositioning Environmentally Challenged Urban Infill Redevelopment Sites,” where he’ll share strategies to transform underutilized properties into productive community assets. The conference brings together economic development professionals from across the state to celebrate those who are “Growing Economies from the Ground Up” and provide valuable opportunities to learn, connect, and collaborate. Register now!
A third of the food raised or prepared does not make it from farm or factory to fork. Producing uneaten food squanders a whole host of resources—seeds, water, energy, land, fertilizer, hours of labor, and financial capital—generating greenhouse gases at every stage, including methane when organic matter lands in the global rubbish bin. The food we waste is responsible for roughly 8 percent of global emissions. Greg McCarron discusses how composting and anaerobic digestion turn organic waste into a beneficial product in Waste Management & Research, Volume 43, Issue 4.
The trend in the United States is towards using ASP systems to process food scrap materials. Recent examples by private companies involve the composting of food processing residuals. One company implemented a turned windrow compost project for sustainability reasons and to produce organic fertilizer to grow organic food products, which continue to grow in demand. Another company is pursuing an ASP compost project as land application regulations are changing, which are affecting America’s farms and farmers, and requiring enhanced organic management practices.
Anaerobic Digestion (AD) involves decomposing organic waste in an oxygen-deficient atmosphere, producing methane-rich biogas. Historically, AD has been used to process low solids/wet organic materials, such as manure, biosolids, and liquid industrial waste. To manage food waste, three types of AD facilities are increasingly being utilized in the United States: (1) stand-alone food waste digesters, (2) on-farm digesters that co-digest food waste and manure, and (3) digesters at water resource recovery facilities that co-digest food waste and biosolids.
About the Author: As a Vice President, Greg McCarron oversees SCS Engineers’ nationwide organics management initiative, which includes edible food rescue, composting, and anaerobic digestion. Greg is SCS’s National Expert on Organics and works closely with national, regional, and local clients. His experience includes the design, planning, permitting, regulatory support, construction oversight, system start-up, economic analysis, and technology assessment projects for municipal and private clients. His turn-key projects typically involve feasibility studies, due diligence evaluations, facility siting, site investigations, environmental studies, permitting, design, and construction and operation services. Facilities include compost facilities, landfills, landfill gas control facilities, and support facilities (e.g., roadways, stormwater, utilities). Other projects include waste composition studies, compliance reports, and preparing various procurement documents. Reach out to Greg at or on LinkedIn.
Additional Composting Resources:
Join SCS Engineers and San Diego Environmental Professionals for a case study of a real PFAS investigation at a commercial airport, Santa Maria public airport. Speaker and SCS Engineers Project Manager Chuck Houser will be sharing some of the experiences, pitfalls, and takeaways from doing this investigation.
SCS Engineers is a proud sponsor of the 2025 California Rural Water Expo. Join fellow water professionals for a week of training, networking, and fun in the beautiful setting of Lake Tahoe. Attendees will get an opportunity to learn from industry experts, like SCS Engineers Project Manager Chuck Houser, and get a look at current technology and vendors. Highlights include our annual banquet, Brew fest, raffle, Mardi Gras Bead Game, and more fun! Registration is open for exhibitors and attendees. Visit the link for more information.
The Role of Environmental Engineering
As we celebrate Earth Day and honor the natural systems that sustain life—our forests, oceans, and atmosphere—it’s also an opportunity to reflect on how professionals across the environmental sector contribute to protecting our planet. Some efforts are highly visible, such as preserving endangered habitats or advancing renewable energy. Others, however, operate quietly in the background, confronting the more complex legacy of industrial development, which provides the products and services we use.
At SCS Engineers, some of our work resides in this less visible space. This work includes landfill engineering, site remediation, infrastructure development, and regulatory compliance. These aren’t the areas typically highlighted on Earth Day, but they are vital in maintaining environmental and public health—and in many ways, they represent a different kind of stewardship.
The Invisible Side of Environmental Work
To some, environmental engineering tied to waste management or development may seem counterintuitive to environmental protection. Some view landfills, brownfields, and infrastructure projects as necessary evils—problems to be managed rather than contributions to sustainability.
But that perspective overlooks our work’s critical role in restoring damaged environments, protecting communities from exposure, and shaping how to implement future development responsibly.
Our work doesn’t always look like conservation—but it is. It’s conservation through control, balance, and careful planning – sustainability.
Redemption Through Engineering
Earth Day is a time to recognize that not all environmental progress begins in pristine ecosystems. Much of it starts in places where damage has already been done—on contaminated sites, aging landfills, or underserved communities with high environmental risk.
At SCS Engineers, we work with public and private sector clients to:
It isn’t just reactive work—it’s strategic, science-driven, and essential to reducing long-term environmental risk.
A Balanced Approach to Environmental Protection
We recognize that those professionals working in the environmental sector may not always get the spotlight. It’s easy to look at a landfill and see only the waste—or at development and see only the disruption. But behind the scenes are engineers, scientists, and planners working to harmoniously ensure that our built environment coexists with our natural one.
The challenges we face today—climate change, pollution, population growth—require a wide range of solutions; some focus on protection, others on prevention, and many, like ours, on restoration and resilience.
Celebrating All Contributions the Week of Earth Day
Environmental progress is not linear. It often involves confronting the consequences of past decisions and building a path forward that prioritizes sustainability at every stage. Our work may be less visible, but it is no less critical. We are proud to be part of the team, ensuring that human advancement doesn’t come at the cost of our shared environment.
We invite you to recognize the full spectrum of environmental work this week of Earth Day. From protecting endangered species to restoring contaminated land, every contribution matters. And for those working to manage what others might overlook—we see this as our responsibility and our opportunity for impact.
If your organization is navigating complex environmental challenges or seeking ways to manage growth, waste, or remediation responsibly, we’re here to help. If you want a satisfying career where your work matters, join us!
About the Author: Rafael Aberle is an environmental professional responsible for coordinating and performing site assessment activities including soil and groundwater sampling. Rafael works closely with SCS’s clients across the Southeastern U.S. Rafael has extensive experience overseeing construction projects including methane gas management and capture systems.
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