25th Annual Energy, Utility & Environment Conference (EUEC), Tucson

August 1, 2022

Join SCS Engineers at the 25th Annual Energy, Utility & Environment Conference (EUEC), October 5-7, 2022, in Tucson, Arizona.

EUEC offers 10 tracks with over 300 speakers on everything from Renewable Energy to Utility Regulations to CO2 Emissions and Wastewater.  Several SCS Engineers professionals are speaking at the conference, including:

Pat Sullivan, Senior Vice President, on Air Quality Permitting Issues for Landfill Gas to Energy Projects
[Track E: MSW, LFG, RNG, Biofuels, WTE, Climate, GHG, Carbon Credits, Environmental Justice]

Pat’s Abstract: Landfill gas to energy projects can have some unique air permitting issues that complicate efforts to obtain permits and to keep permitting and pollution control costs affordable. These issues include assessing best available control technology (BACT)/lowest achievable emission rate (LAER), finding cost effective control options that meet BACT/LAER, managing impurities in the gas that can impact emissions and controls, gas treatment technologies necessary to remove contaminants in the gas or to create renewable natural gas (RNG), avoiding or reducing costs for emission reduction credits (ERCs), and determining whether third party plants are under common control with the landfill. The presentation will cover the following energy recovery technologies: reciprocating engines, gas turbines, microturbines, boilers, and treatment plants that create renewable natural gas (RNG). Several case studies of recent projects will be included to illustrate the key themes.

Jeff Pierce, Senior Project Director, on “Flip or Flop: Conversion of Biogas Power Generation to RNG
[Track E: MSW, LFG, RNG, Biofuels, WTE, Climate, GHG, Carbon Credits, Environmental Justice]

Jeff’s Abstract: Landfill gas and digester gas are currently widely used in the United States to produce renewable power; however, solar and wind have generally become more cost-effective sources of renewable power. The value of biogas as a source of renewable power has receded. Credits under the Federal Renewable Fuel Standard (RFS 2) Program and the California Low Carbon Fuel Standard (LCFS) Program now combine to create a market value for renewable natural gas (RNG) exceeding $30/MMBtu. RNG’s link to these programs is that RNG is dedicated for vehicle fuel use in the form of compressed natural gas (CNG). Large to moderately sized biogas power plants are now being shut down, and RNG plants are being constructed, using the freed-up biogas. The payback on the RNG plants is generally less than two years. The presentation will address: 1) An overview of the workings of the RFS 2 and LCFS programs – explaining how the credits are monetized, and reviewing the historic and possible future trend of RNG prices; 2) An overview of the technologies used to convert biogas to RNG – a natural gas equivalent. The RNG can then be injected into natural gas pipelines for transport to CNG users; 3) The pipeline interconnection process and governing pipeline quality standards will be briefly discussed; and 4) Construction cost, operation/maintenance cost and performance of a typical RNG plant will be presented.

Alex Stege, Senior Project Advisor, will present “Understanding the Uncertainty in LFG Recovery Forecasts Used for Planning RNG Projects”
[Track E: MSW, LFG, RNG, Biofuels, WTE, Climate, GHG, Carbon Credits, Environmental Justice]

Alex’s Abstract: LFG generation and recovery forecasting is critical for evaluating suitable RNG project sizes and potential revenues. Yet the forecasts struggle to overcome large uncertainties arising from limitations that will be discussed in this paper, including: the lack of measurements of methane generation or moisture conditions in the landfill impacting generation, limited data on the types of wastes disposed, reliance by the LFG industry on regulatory LFG emissions models without knowledge of how to adjust them for site-specific conditions, and the inability of the models to account for expected changes in waste composition as organics diversion programs expand.

Kacy Garber is presenting on “Developing Testing and Monitoring Plans for CO2 Storage Projects: Lessons Learned from MSW and CCR”
[Track H: CCR, CCS, ELG, Coal Ash, WWM, ponds, Liners, and Cement]

Kacey’s Abstract: To protect underground sources of drinking water, it is essential to develop effective testing and monitoring plans for carbon capture and storage (CCS) projects. The regulatory framework and practice for CCS are similar to Municipal Solid Waste (MSW) and Coal Combustion Residual (CCR) disposal sites; however, the risk and related cost implications of monitoring network errors in CCS projects are significantly higher. In this talk, we discuss key considerations for developing testing and monitoring plans for CCS projects based on our understanding of MSW and CCR regulatory frameworks and in the context of lessons learned from those mature monitoring programs.

Charles Hostetler will speak about “Considerations for CCUS Site Selection:  Satisfying Local Siting Conditions and Impacts on Project Financials”
[Track A: Utility Regs, Policy, Strategies, Permits, Compliance]

Charles’s Abstract: A number of generalized tools and concepts exist to assess the capacity for carbon dioxide storage on a regional scale.  An issue for assessing carbon dioxide storage capacity for local point-source emitters is gathering enough data from readily available sources to determine the potential for carbon sequestration on a local scale, particularly in geologic settings that are not thought of as traditional; e.g., depleted oil fields or coal beds.  In this talk we examine some methods for assessing carbon sequestration capacity at local scales and in non-traditional terrains, and consider the impacts of characterization uncertainty on project financials. 1) What are ancillary CO2 project factors that increase risk and can have adverse financial impacts? 2) What tools do you need to avoid these factors? 3) What locations and geologic terrains are going to be most favorable for local sequestration and what type of conditions should be avoided?


The EUEC conference includes over 100 Exhibitors and plenty of networking opportunities.

Click here for more details and registration information.  Hope to see you there!



Posted by Laura Dorn at 2:34 pm

SCS Advice from the Field: Considerations for the Piping Network

March 5, 2018

An essential part of landfills accepting organic matter is the gas collection and control system (GCCS) for controlling odors and landfill gas (LFG) emissions into the environment; the piping network. GCCS design and construction have evolved significantly over the past four decades, from passive venting trench systems to a sophisticated and elaborate piping systems with specialized components for handling LFG, landfill liquids, and condensate flowing through the piping network.

This detailed article discusses best practices and recommendations that GCCS designers keep in mind; careful attention to these details can potentially save  landfill operators significant modification costs and inconveniences prior to and during construction of the final covers.

Read the full article published in MSW Magazine.

About the Authors: Ali Khatami, Ph.D., PE, LEP, CGC, is a Project Director and a Vice President of SCS Engineers. Srividhya Viswanathan, PE, is a Senior Project Manager with over 10 years of engineering experience. David Fisher is an SCS National OM&M Compliance Manager with 18 years of environmental experience.



Posted by Diane Samuels at 6:01 am

“Landfills are living, breathing beasts …

September 12, 2016

…and as waste settles, it can have an effect on equipment,” according to Pat Sullivan of SCS Engineers in this ClimateWire article. As the U.S. EPA focuses on pushing landfill owners into cutting down on methane emissions some worry that a combination of tightening regulations and poor cost analysis might put some smaller landfills out of business.

Read the full article here.

LANDFILL EMISSIONS: Going to the dump? You might make electricity
Kavya Balaraman, E&E reporter

Reprinted from ClimateWire with permission from E&E Publishing, LLC. Copyright 2016. 

Posted by Diane Samuels at 6:00 am

SCS Advice From the Field: Everything you ever wanted to know about siloxane removal.

September 6, 2016

An informative and complete discussion from Jeffrey L. Pierce of SCS Engineers, Energy Practice of siloxanes and landfill gas (LFG) utilization. Plus, presentations on the economics and performance of siloxane removal from biogas; advice on siloxane sampling, analysis and data reporting recommendations on standardization for the biogas utilization industry.

Read more


Posted by Diane Samuels at 6:00 am

Letter to US EPA: Renewable Fuel Standard Program: Standards for 2017 and Biomass-Based Diesel Volume for 2018 (Proposed Rule)

July 13, 2016

On July 11, 2016, multiple organizations representing the full value chain of cellulosic waste feedstock conversion to transportation fuel sent a letter to Gina McCarthy, Administrator of the U.S. Environmental Protection Agency (EPA). The letter supporting the Renewable Fuel Standard Program: Standards for 2017 and Biomass-Based Diesel Volume for 2018 (Proposed Rule) noted that additional information and factors need to be considered.

Read or share a copy of the letter here, contact SCS Engineers, or one of the organizations below:

  • The Coalition for Renewable Natural Gas (RNG Coalition)
  • NGV America (NGVA)
  • The Canadian Gas Association (CGA)
  • Energy Vision (EV)
  • The National Waste and Recycling Association (NWRA)
  • The Solid Waste Association of North America (SWANA)
  • Transportation Energy Partners (TEP)
  • Virginia Clean Cities (VCC)
  • Clean Fuels Ohio (CFO)
  • Lone Star Clean Fuels Alliance (LSCFA)





Posted by Diane Samuels at 11:28 am

SCS Advice From the Field: Carbon Monoxide (CO) Readings At Landfill Gas Extraction Wells

June 8, 2016

Question: I have a small oxidation event at my landfill and am continually testing for carbon monoxide (CO) in the surrounding landfill gas (LFG) extraction wells. Using colorimetric tubes, I am monitoring the readings which range from 5-10 parts per million (ppm). Is there an accepted standard for background carbon monoxide in LFG? Moreover, how much inaccuracy is expected using the colorimetric tube testing?

Answer: Carbon monoxide (CO) can be found in small quantities even when there is no landfill fire. If your concern is landfill fire, most reputable resources state that a landfill fire generates readings of at least 100 ppm CO and more typically in the 500-1000 ppm range with 1000 ppm a reliable indicator that a landfill fire event may be present.

CO readings on colorimetric tubes are inherently less accurate and tend to run higher than laboratory results. Colorimetric tubes do provide value as a real-time indicator versus subsequent lab results, and can be used as an index reading, calibrated by lab results later. If you’ve had a landfill fire event before, with CO levels greater than 100 ppm, the lab confirmed 5-10 ppm CO could be residual left over from the earlier event.

Although some people believe that the presence of CO at almost any level is an indicator of landfill fire, recent laboratory tests show that CO can be generated at values up to and over 1000 ppm by elevating refuse temperatures without the presence of combustion (fire). Other tests have shown that high values of CO are found in some landfills with no current landfill fire and no indication of a past landfill fire. This information supports that it is possible that Elevated Temperature (ET) Landfills can have CO levels over 1000 ppm CO without the presence of combustion or landfill fire.

In the end, CO can be an indicator of landfill fire, but not always, as described here. Low methane, high carbon dioxide, and even landfill temperatures above 131 degrees F may or may not be indicators of past or current landfill fire. Physical indicators of a landfill fire may include rapid settlement in a localized area, cracks and fissures, smoke and flame, melted landfill gas system components, and char on the inside of LFG headers and blower/flare station components such as a flame arrester. However, most of these indicators can occur at ET landfills as well without the presence of fire or combustion.

A professional landfill gas engineer is needed to assess these conditions as a whole, and make a judgment on the underlying driver, condition, and resolution.

Have a question for our SCS Professional Engineers or Field Staff? Just ask here.

Landfill and Landfill Gas Services at SCS Engineers.


Posted by Diane Samuels at 6:00 am

SCS Engineers in ENR’s Top 100 Design Firms for Eighth Consecutive Year: Ranked Second Largest Environmental Engineering Firm

May 12, 2016

“Our clients enable SCS to build, grow, and sustain an engineering firm dedicated to solving environmental challenges,” said Jim Walsh, President and CEO of SCS. “We sincerely thank our friends, colleagues and, in particular, our clients for helping us achieve a highly regarded ranking each year.”

Firms are ranked in terms of revenue by Engineering News-Record magazine (ENR), as reported in the May 2, 2016, issue of the “ENR Top 500 Design Firms Sourcebook.” SCS has made the Top 500 list since its publication in 2002 and has ranked in the top 100 of that list since 2008.

When sorted by firm type, SCS Engineers is ranked the second largest environmental engineering firm (ENV) and is ranked in the “Top 20 Sewerage and Solid Waste” service firms in the nation. SCS has made this top 20 list since 2002.

Later in the year, ENR will publish additional resources and lists, including the “Top 200 Environmental Firms” issue, typically published in the month of August.

Vision, Mission, Values

Learn more about our latest innovation, SCSeTools

Posted by Diane Samuels at 6:00 am

SCS Engineers’ David P. Hostetter PE, LEED AP, CEM, Named a Waste360 Young Professional Award Winner

May 10, 2016

Penton’s Waste360 Unveils the Next Generation of Leaders in the Waste and Recycling Space Award

Dave Hostetter, SCS Engineers
Dave Hostetter, SCS Engineers

The Waste360 “40 Under 40” awards program recognizes inspiring and innovative professionals under the age of 40 whose work in the waste, recycling, and organics industry has made a significant contribution to the industry. Dave Hostetter focuses on designing landfill gas systems and landfill gas flare systems.  Although still considered a young professional himself, he serves as a mentor to other engineers, providing guidance with hands-on design as well as professional guidance.

Dave is a LEED® Accredited Professional (LEED AP) and a Certified Energy Manager (CEM).  He brings to SCS Engineers an abundance of expertise and fresh ideas. Dave has a keen eye for troubleshooting and diagnosing control system issues. He serves SCS clients wholeheartedly and goes out of his way to provide assistance as well as the expertise needed to make their day-to-day operations run as smoothly as possible.  Dave has participated in a multitude of landfill gas and leachate system designs, including designs for blower and flare stations, wellfields, gas conveyance piping, leachate pumping systems, and groundwater extraction systems.  His vast and varying experience, honest and hard-working approach to projects, and his positive attitude make him a respected resource within the firm.

Dave lives the SCS mission, and clients trust him for his honest and comprehensive approach to their challenges. Dave takes ownership of his work and puts in the time and effort to deliver excellent results and maintain a great relationship with his clients. “Dave Hostetter sets the example of how an honorable, dynamic, and experienced engineer should act at SCS,” said Paul Mandeville, Senior Vice President and Director of SCS’s offices on the east coast. “Dave serves as a model of what young professionals and students should strive to become in their professional and personal careers; we are very proud of him.”

Please join SCS in congratulating Dave Hostetter on his recent recognition by Waste360.

Posted by Diane Samuels at 6:00 am

The NWRA and SWANA React to EPA Region 2 Common Control Issue

January 29, 2016

The National Waste & Recycling Association (NWRA) and the Solid Waste Association of North America (SWANA) returned comments and recommendations on the Environmental Protection Agency’s (EPA) draft Part 71 Operating Permit for Ocean County Landfill and MRPC Holdings LFGTE Operations, Permit Number: P71-0CMH-001 (Draft Permit) to EPA  Region 2 Permitting Section, Air Programs Branch. The letter was sent on January 28, 2016, to Mr. Steven C. Riva of the EPA.

NWRA and SWANA expressed concerned that the EPA’s issuance of the Draft Permit, and the circumstances under which it has been prepared, represent a significant departure from practical permitting policies and will constitute a disincentive to expand existing and develop future landfill gas-to-energy (LFGTE) projects around the country.

The jointly submitted comments from both not-for-profit Associations on the Draft Permit were intended to convey their members’ strong interest in these projects, which represent an economic investment in alternative renewable energy sources and the reduction in greenhouse gas (GHG) emissions. Both Groups have expressed concern that the EPA’s actions should not undermine those investments and the benefits derived from these LFGTE projects.

The main points of the letter cover the Associations’ disagreement with the EPA’s approach to common control. NWRA and SWANA support the position that the OCL and MRPC are two separate sources that are not under common control, and they oppose the position proposed by EPA Region 2 in the Draft Permit. Both Groups are urging EPA to re-evaluate this decision and utilize an environmentally beneficial approach when making common control determinations for landfills and third-party LFGTE plants both now and in the future. Other portions of the letter address the uncertainty that EPA’s position would create for affected facilities and how it could re-open already settled compliance expectations.

Members of NWRA and SWANA have access to the letter and may continue directing comments and questions through either Association.

Questions directed to SCS Engineers should be addressed to Pat Sullivan, Senior Vice President and the SCS National Expert on the Clean Air Act.

Learn more about SCS Clean Air Act Services, or Greenhouse Gas Services, or
Landfill Gas to Energy Services

Posted by Diane Samuels at 5:18 pm

DDC Journal – Winter Edition – Waste to Energy

November 9, 2015

DDC Journal recently published an interesting article by Pat Sullivan, “Developing power plants that reduce environmental impacts.” http://viewer.zmags.com/publication/097d62a6#/097d62a6/24


Pat Sullivan, BCES, CPP, REPA, is a Senior Vice President of SCS Engineers and our National Expert on the Landfill Clean Air Act and the New Source Performance Standard (NSPS). Mr. Sullivan has over 25 years of environmental engineering experience, specializing in solid and hazardous waste-related issues.

Posted by Diane Samuels at 7:22 pm