Biogas Collection Systems

Biogas Collection Systems

Plastic Fusion Fabricators designs and installs complete biogas collection systems for anaerobic digesters, covered lagoons, wastewater treatment facilities, and landfill gas recovery projects. We build the full infrastructure — from gas collection covers and HDPE header piping to condensate management, pressure control assemblies, and flare or energy system tie-ins — engineered as an integrated system that captures methane reliably and delivers it where it needs to go.

A biogas collection system is more than a cover on a lagoon. It’s a methane collection system — a network of gas pickup points, lateral and header piping, condensate traps, pressure/vacuum relief devices, and gas conveyance infrastructure that must work together under variable gas production rates, temperature swings, and corrosive conditions. When any one component fails or underperforms, you lose gas capture efficiency, create safety hazards, and put regulatory compliance at risk.

With 40+ years in environmental containment and a track record as a pioneer in anaerobic digester lagoon systems, Plastic Fusion brings the field experience to design, fabricate, and install biogas collection infrastructure that performs from day one — and holds up for decades.

System Components We Design, Fabricate, and Install

• Biogas collection covers — floating and fixed-mount geomembrane covers for gas capture
• Anaerobic digester covers — gas-tight HDPE, XR-5, and RPP membrane systems
• Gas collection piping — HDPE headers, laterals, and manifolds fabricated in-house
• Condensate management — low-point drains, condensate traps, and drain-back systems
• Pressure and vacuum relief assemblies
• Gas-tight pipe penetrations through covers and containment walls
• Flare station and CHP generator tie-ins
• RNG upgrading system interconnections
• Heat retention covers with integrated gas collection for cold-climate digester performance
• Ballast systems, rainwater drainage, and cover tensioning infrastructure

Methane Collection System Integration

The methane collection system is the core of any biogas project’s performance. We engineer gas collection infrastructure that accounts for variable methane production rates across seasonal and operational cycles, H₂S and moisture content in the raw gas stream, pressure management under the cover and through the conveyance system, condensate accumulation and removal at low points in the piping network, and safe tie-in to downstream equipment — whether that’s a flare, combined heat and power (CHP) unit, or RNG upgrading facility.

Our industrial pipe fabrication shop builds custom HDPE spools, manifolds, reducers, and fittings for biogas piping systems — so your gas collection infrastructure arrives site-ready, fusion-welded, and dimensionally matched to your system design. This in-house fabrication capability eliminates the lead time, cost, and fit-up problems that come with sourcing biogas piping components from third parties.

Applications

• Municipal wastewater treatment plant biogas recovery
• Dairy and livestock manure digester gas collection
• Covered lagoon digester systems for agricultural operations
• Food and beverage processing waste-to-energy projects
• Industrial anaerobic digestion facilities
• Landfill gas collection and control systems (GCCS)
• Renewable natural gas (RNG) production infrastructure
• Co-digestion facilities handling mixed organic feedstocks
• Biomethane collection systems for carbon credit and energy recovery programs

Why Contractors and Engineers Specify Plastic Fusion

• 40+ years in environmental containment — pioneer in anaerobic digester lagoon and biogas systems
• Complete system capability: covers, piping, condensate, pressure control, and flare/energy tie-ins
• In-house HDPE fabrication shop for custom gas collection piping, manifolds, and fittings
• Certified thermoplastic welders trained in HDPE, XR-5, RPP, PVC, and polypropylene
• Material selection matched to gas chemistry — H₂S concentration, temperature, UV exposure
• Gas-tight seam welding with full destructive and non-destructive QA/QC testing
• Nationwide mobilization with experienced biogas project field crews
• Direct coordination with engineers, developers, energy companies, and regulatory agencies
• Ongoing maintenance and repair services to protect system performance long-term

Industries Served

Plastic Fusion installs biogas collection systems for municipal utilities, wastewater treatment districts, dairy and livestock operations, food processors, renewable energy developers, landfill operators, and industrial facilities managing organic waste streams. We work under EPA, state air quality, NSPS Subpart XXX (landfill gas), and NESHAP regulations — and deliver the documentation your compliance team, investors, and carbon credit verifiers require.

Biogas Collection System FAQs

What is a biogas collection system?

A biogas collection system is the complete infrastructure that captures, conveys, and delivers biogas produced during anaerobic digestion or landfill decomposition. It typically includes a gas-tight cover or cap over the digestion source, gas collection piping (headers and laterals), condensate management components, pressure and vacuum control devices, and conveyance piping to downstream equipment — a flare, engine-generator, or RNG upgrading facility. The system must be designed and installed as an integrated unit, because a failure at any point — a leaking cover seam, a blocked condensate trap, a pressure imbalance — degrades gas capture efficiency across the entire system.

What is the difference between a biogas collection system and a biogas collection cover?

The cover is one component of the system. A biogas collection cover is the gas-tight geomembrane that sits over the digester, lagoon, or tank and contains the biogas in the headspace. The biogas collection system includes the cover plus everything downstream: gas pickup points, header and lateral piping, condensate drains, pressure relief, and tie-ins to utilization equipment. Plastic Fusion designs and installs both — the cover and the complete collection infrastructure — as an integrated scope, which eliminates the coordination problems that arise when covers and piping are handled by separate contractors.

How does a methane collection system work?

A methane collection system captures the methane-rich biogas produced during anaerobic digestion (or landfill decomposition) and routes it to a point of use or destruction. Under the cover, biogas accumulates in the headspace and flows to gas pickup points connected to lateral piping. The laterals feed into header pipes that convey the gas to a central manifold. Along the way, condensate traps remove moisture from the gas stream. Pressure and vacuum control devices maintain safe operating conditions. The gas is then delivered to a flare (for destruction), a CHP engine (for electricity and heat generation), or an RNG upgrader (for pipeline-quality biomethane). The entire system operates under slight negative pressure to ensure continuous gas flow and prevent cover uplift.

What materials are used for biogas collection piping?

HDPE (high-density polyethylene) is the standard material for biogas collection piping due to its chemical resistance to methane, CO₂, H₂S, and condensate, along with its fusion-weldable joints that create leak-free, gas-tight connections. Plastic Fusion fabricates all biogas piping components — headers, laterals, manifolds, reducers, and custom fittings — in our HDPE fabrication shop, delivering fusion-ready assemblies that integrate cleanly with the cover system and downstream equipment.

What size biogas projects does Plastic Fusion handle?

We install biogas collection systems ranging from single-tank municipal digesters to multi-lagoon dairy operations and large-scale RNG production facilities. Our nationwide field crews mobilize to any site — and our in-house fabrication capability means we can turn around custom piping and cover components without third-party delays, regardless of project scale.

How do biogas collection systems support RNG and carbon credit programs?

Methane captured through a biogas collection system can be upgraded to renewable natural gas (RNG) for injection into the natural gas pipeline — generating revenue through RIN credits, LCFS credits, or voluntary carbon markets. The collection system’s gas capture efficiency directly impacts project economics: higher capture rates mean more RNG produced and more credits generated. Plastic Fusion’s integrated approach — cover, piping, and gas management installed as a single system — maximizes capture efficiency and minimizes the fugitive emissions that reduce credit value.

Request a Quote

If you’re developing, expanding, or retrofitting a biogas collection system, Plastic Fusion delivers complete infrastructure — from cover to flare tie-in — engineered for your specific application. Contact us for project-specific pricing, material recommendations, and installation timelines.