Marine
Marine Vapor Control & Degassing Services
Loading, offloading, tank cleaning, and maintenance at marine terminals and vessels all generate hydrocarbons and volatile organic compounds (VOCs) that require controlled capture and destruction under federal and state regulations. When those vapors are not properly managed, your terminal faces permit violations, forced shutdowns, and real safety exposure for your crew.
Envent deploys mobile Marine Vapor Control Systems (MVCS) and Dock Safety Units (DSUs) built to meet U.S. Coast Guard (USCG) 33 CFR Part 154 Subpart P and EPA 40 CFR Part 63 Subpart Y requirements. Envent has run marine vapor control operations across North America since 1992, covering inland river terminals, Gulf Coast bulk liquid facilities, barge loading, and LNG vessel degassing.
Why Choose Envent?
Envent’s engineers manage every permit, agency submission, and compliance document your marine vapor control project requires. Your team receives a complete documentation package that holds up under agency review.
Every marine deployment uses USCG-approved MVCS and DSU equipment, achieving greater than 99% VOC and H2S destruction efficiency across barge loading, vessel offloading, tank cleaning, and LNG degassing operations.
Envent operates the largest mobile fleet of thermal oxidizers and vapor control systems in North America. OQ-qualified technicians run every deployment from setup through final documentation.
Our Marine Services
Your tanks, vessels, storage tanks, pipelines, and barges all require controlled vapor removal before inspection, maintenance, or product changeover. Envent’s degassing and vapor control services cover all of these asset types across refining, midstream, and industrial facilities, with VOC and H2S destruction at greater than 99% efficiency on every project. Every deployment follows OSHA confined space entry standards under 29 CFR 1910.146 with a site-specific safety plan in place before field work begins. Envent has completed degassing projects for ExxonMobil, Shell, Chevron, and Valero since 1992.
When your facility handles H2S, ammonia, mercaptans, or other chemical vapor streams, releasing them without treatment creates permit violations and community complaints. Envent’s scrubbers and odor control services handle these vapor streams through chemical treatment, keeping your operation within EPA BACT compliance requirements. Envent has managed vapor scrubbing operations at refineries, chemical plants, and marine terminals since 1992. OQ-qualified technicians run every deployment with a site-specific safety plan and full compliance documentation through project close.
When your terminal or refinery generates contaminated water from hydrotesting, tank cleaning, or groundwater remediation, offsite disposal adds cost and schedule risk to your operation. Envent’s water treatment services cover mobile wastewater remediation, pipeline and tank hydrotest water treatment, and groundwater remediation at terminals, refineries, and industrial sites. Treatment is handled directly on your site, removing the need to transport contaminated water offsite. Envent has completed water treatment projects across Texas, California, and broader North America since 1992, with full compliance documentation through project close.
MARINE VAPOR CONTROL FAQS
What federal regulations apply to marine vapor control at U.S. terminals?
Marine vapor control at U.S. terminals falls under two federal rules that apply simultaneously. The U.S. Coast Guard requires compliance with 33 CFR Part 154 Subpart P, which covers marine vapor control system design and certification. The EPA requires compliance with 40 CFR Part 63 Subpart Y under NESHAP, which governs emissions from marine vessel loading operations. Envent’s systems meet both sets of requirements on every project.
Does Envent hold active USCG certification for marine vapor control operations?
Yes. Every Envent marine deployment runs under active USCG certification, which means your terminal does not carry compliance exposure from Envent’s side of the operation. The National Maritime Center publishes the full USCG certification standards if you need to review them with your compliance team. See Envent’s marine vapor recovery services for more on how this applies to your specific operation.
What types of marine operations does Envent support?
Envent supports vapor control and degassing across cargo vessel loading and offloading, barge operations, tank cleaning, LNG vessel degassing, and railcar loading at marine terminals. Envent has completed projects across all of these operation types since 1992. View the full project portfolio for examples across vessel types and terminal configurations.
How does Envent manage permitting and agency coordination for marine projects?
Envent’s engineers handle all permit applications, agency submissions, and field documentation from project start through close. At project completion, your team receives a full documentation package covering system performance, destruction efficiency records, and agency correspondence. This matters most at facilities where USCG or EPA inspectors review vapor control logs during audits. See Envent’s compliance page for more on how projects are documented.
What VOC destruction efficiency do Envent's marine vapor control systems achieve?
Envent’s marine vapor control systems achieve greater than 99% VOC and H2S destruction efficiency on every project. This meets EPA NESHAP requirements and exceeds USCG minimum standards, giving your terminal a clear margin against emission exceedances during loading and transfer operations. The EPA publishes national VOC emission trends and benchmarks at epa.gov if you need supporting data for your permit records.
Can Envent manage marine vapor control projects in Canada?
Yes. Envent has completed marine and terminal vapor control projects in Canada, including operations requiring compliance with VOC regulations under the Canadian Environmental Protection Act (SOR/2025-88). Envent handles cross-border permitting and agency coordination on both sides of the border. The Canadian barge and railcar loading case study covers how Envent managed benzene emission controls across a multi-phase Canadian terminal operation.
What is the difference between marine vapor recovery and marine degassing?
Marine vapor recovery captures VOCs generated during active loading and transfer operations and routes them through a destruction system, keeping emissions within permit limits while the transfer is running. Marine degassing removes residual hydrocarbon vapors from a vessel’s cargo tanks before it enters drydock, undergoes hot work, or switches between product types. Both require USCG-approved equipment and OQ-qualified personnel on-site. Envent provides both marine vapor recovery and degassing and vapor control for details.
Has Envent completed LNG vessel degassing operations?
Yes. Envent completed the world’s first LNG cargo container ship degassing and has since completed additional LNG-powered freight vessel projects. LNG vessel degassing requires vapor control configurations built to handle cryogenic residuals and the vapor characteristics specific to LNG cargo, work that most mobile providers cannot support. Read the LNG freight vessel case study for a full account of how that project was managed.
How quickly can Envent mobilize for a marine vapor control project?
Envent operates the largest mobile fleet of vapor control systems in North America, so equipment availability is rarely the limiting factor on a project schedule. Mobilization timelines depend on site-specific permit requirements and logistics. Envent’s team works on permit coordination in parallel with equipment staging to keep deployment time as short as possible. Call 888-997-9465 or request a quote to discuss scheduling for your terminal.
What safety standards does Envent follow on marine vapor control projects?
Envent carries a 0.0 TRIR across its full project history. Every marine project involving enclosed or restricted spaces follows OSHA confined space entry standards under 29 CFR 1910.146, along with hot work protocols and personal gas monitoring. A site-specific safety plan is in place before any field work begins. Envent’s full safety record is documented on the safety page.
Ready to discuss your marine vapor control requirements?
Envent has managed marine vapor control operations across North America since 1992, from Gulf Coast bulk liquid terminals to inland river facilities and Canadian ports. Your project gets USCG-certified equipment, OQ-qualified technicians, and a documentation package that holds up under agency review.
