David Hogue, Senior Professional, Kleinfelder
Introduction
Landfills have long stood at the crossroads of necessity and environmental compromise. From their earliest incarnation as open dumping grounds to today’s carefully engineered waste repositories, they reflect both our reliance on disposable culture and our evolving commitment to environmental protection. But now, a new chapter is being written—one in which landfills not only manage waste but actively support renewable energy initiatives.
This paper explores the historical development and environmental impact of landfills while spotlighting a current methane recovery and pipeline project at Juniper Ridge Landfill in Old Town, Maine. Central to this effort is Kleinfelder’s role in providing independent review of a complex horizontal directional drilling (HDD) design intended to connect captured landfill gas to Unitil Corporation’s pipeline system. The project reflects a promising transformation: turning waste into energy, pollution into opportunity, and environmental oversight into ecological stewardship.
From Rudimentary Dumps to Regulated Facilities
In 1935, waste disposal in California involved little more than digging a hole and burying trash. This rudimentary approach provided no protection against leachate or disease, and the environmental consequences went largely unexamined. In 1959, the first “sanitary landfill” guidelines introduced a new standard: compacting waste and covering it regularly with soil. This was a pivotal shift, and it continued with landmark federal regulations, including the Solid Waste Disposal Act of 1965 and the Resource Conservation and Recovery Act (RCRA) of 1976.
By 1991, the Environmental Protection Agency (EPA) implemented comprehensive standards for municipal solid waste landfills (MSWLFs), requiring:
- Groundwater monitoring
- Closure and post-closure care
- Corrective actions for contamination
- Enhanced liner and cover systems
These changes redefined the landfill from an uncontrolled hazard to a managed system designed to limit its environmental footprint.
Environmental Hazards: Leachate and Methane
Despite improvements, landfills remain sources of environmental risk. One of the most serious issues is leachate, the toxic liquid formed when water filters through waste. Leachate can contaminate groundwater with:
- Heavy metals
- Carcinogenic organic compounds
- Nutrients that cause algal blooms
- Pathogens
- Dissolved solids and salts
- Xenobiotic chemicals with unknown long-term effects
In response, modern landfills employ containment and treatment technologies such as impermeable liners, leachate collection systems, and chemical immobilization methods like redox reactions and sorption.
In the atmosphere, the principal concern is methane (CH₄)—a greenhouse gas 80 times more potent than CO₂ over 20 years. Methane from landfills accounts for approximately 30% of global warming since the pre-industrial era and contributes to ground-level ozone, linked to respiratory illness.
But methane is also a renewable resource—and one increasingly targeted for energy recovery.
Juniper Ridge Landfill: From Emission Source to Energy Producer
The Juniper Ridge Landfill has served Maine’s waste disposal needs since 1996. Today, it is undergoing a transformation driven by environmental responsibility and technological innovation. Methane generated by decomposing waste will be captured, processed, and delivered to Unitil Corporation’s regional distribution system via a newly proposed 4-inch coated steel natural gas pipeline. The 9,000-foot pipeline represents more than a utility upgrade; it marks the landfill’s emergence as a clean energy contributor.
At the heart of the initiative is a horizontal directional drilling (HDD) installation designed to traverse sensitive wetland environments with minimal disruption. The proposed pipeline crosses a wetland complex with diverse hydrological features and sensitive habitats, including culverts, groundwater-fed zones, and migratory bird ecosystems. In response, the design team selected Horizontal Directional Drilling, a trenchless construction method that enables the pipe to be installed beneath the surface—at depths ranging from 48 inches to over 17 feet—without excavating from above.
This approach protects wetland hydrology and habitat connectivity by:
- Preserving root systems and soil structure
- Avoiding surface disturbance
- Minimizing runoff and sedimentation
- Supporting continued use by avian and aquatic wildlife
The design balances infrastructure development with ecosystem preservation—demonstrating the potential for “low-impact” engineering solutions in environmentally sensitive zones.
Kleinfelder’s Role: Third-Party Review for Environmental and Technical Integrity
To ensure that the HDD plan meets stringent environmental and regulatory requirements, Unitil retained Kleinfelder as an independent reviewer. Kleinfelder’s role is to assess the project’s feasibility, environmental soundness, and regulatory compliance. This includes coordination with the Maine Department of Environmental Protection (DEP), adherence to federal pipeline safety rules, and local shoreland zoning ordinances.
Kleinfelder’s technical review covers:
- HDD Alignment and Burial Depth – Assessing the technical adequacy of the bore path to minimize disruption to subsurface wetland conditions.
- Regulatory Compliance – Reviewing permit conditions and confirming the design aligns with DEP and federal wetland protection standards.
- Stormwater and Erosion Control – Ensuring drainage plans prevent sediment transport and preserve water quality.
- Drilling Fluid Management – Evaluating containment, reuse, and disposal plans to prevent inadvertent releases of bentonite and other drilling compounds.
- Wildlife Protection Measures – Verifying that the project limits disturbance to wetland species and complies with seasonal and spatial restrictions.
Through this review, Kleinfelder supports the project’s environmental mission—serving as both a technical advisor and a steward of ecological integrity.
Landfill Gas Recovery: A Model for Renewable Transition
The methane recovery project at Juniper Ridge represents a broader shift in landfill philosophy—from containment to conversion. Rather than merely managing emissions, the facility will produce renewable natural gas, offsetting fossil fuel demand and contributing to Maine’s clean energy targets. Closed and capped landfills, once symbols of environmental degradation, are now being repurposed as:
- Solar arrays
- Green parks and golf courses
- Wildlife habitats
- Gas-to-energy sites
Juniper Ridge is leading this trend, supported by a coalition that includes Casella Waste Systems (the landfill operator), Unitil Corporation (the utility), and Kleinfelder (the independent reviewer). The project is an example of how cross-sector partnerships can yield infrastructure that meets both economic and environmental goals.
Conclusion: Landfills as Gateways to Sustainability
Historically, landfills symbolized a reactive approach to waste – a place to bury problems. As our environmental understanding has matured, so too have our landfills. Today’s facilities are more than repositories; they are complex systems designed to prevent pollution, capture emissions, and even produce energy.
The methane recovery and HDD pipeline project at Juniper Ridge demonstrates this transformation in action. By leveraging innovative design and third-party oversight, the project avoids sensitive environmental impacts while contributing to Maine’s energy resilience. Kleinfelder’s involvement ensures that every aspect – from engineering feasibility to wetland protection – is addressed with rigor and transparency.
In this way, landfills are no longer endpoints. They are launchpads for environmental progress – turning the legacy of waste into a foundation for a cleaner, more sustainable future.
References
- Atmospheric Pollution from Landfills. Retrieved from Landfill air pollution: how it affects air quality – Kunak
- EPA. Understanding Global Warming Potentials (2023, April 6). Retrieved from https://www.epa.gov/ghgemissions/understanding-global-warming-potentials
- EPA. Basic Information about Landfill Gas. Retrieved from https://www.epa.gov/lmop/basic-information-about-landfill-gas
- Elizabeth Ward, The Lender’s Guide to Developing an Environmental Risk Management Program. https://archive.fdic.gov/view/fdic/7450/fdic_7450_DS2.pdf
- Wikipedia contributors. Landfill. Wikipedia, The Free Encyclopedia. https://en.wikipedia.org/wiki/Landfill
- EPA. Basic Information about Landfills. https://www.epa.gov/landfills/basic-information-about-landfills
- RMI. Turning Trash into Treasure. https://rmi.org/turning-trash-into-treasure
- Aria Energy & Casella Waste Systems Renewable Energy Project. SolidWaste.com. https://www.solidwaste.com/doc/aria-energy-casella-waste-systems-renewable-energy-project-0001
- Unitil Corporation Completes Acquisition of Bangor Natural Gas Company. Unitil Newsroom. https://unitil.com/news/unitil-completes-purchase-bangor-natural-gas-compa