Challenge
A 150,000-barrel storage tank with an external floating roof was experiencing seal leakage around the perimeter. During rain events, stormwater would leak into the tank, resulting in significant rainwater accumulation. Over time, the rainwater displaced valuable product storage capacity, leading to lost revenue and creating the need for a compliant water removal strategy.
In total, approximately 650,000 gallons of water had settled at the bottom of the tank, mixed with hydrocarbons and a visible oil rag layer. The customer required a safe, efficient, and environmentally compliant method for water removal, hydrocarbon recovery, and vapor control, followed by tank degassing to prepare for return to service.
Solution
Envent Corporation deployed a custom-engineered water treatment system, including:
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Activated carbon scrubbers and oil-water separation equipment to treat hydrocarbons and remove the oil rag layer
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Frac tanks placed strategically to isolate solids and settled hydrocarbons, minimizing cross-contamination
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A follow-up mobile tank degassing operation using an EMTOS (Envent Mobile Thermal Oxidizer System) to safely eliminate VOCs
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Real-time vapor monitoring to ensure non-detect VOC concentrations, meeting all air quality permit limits
The project was completed ahead of schedule, with no regulatory exceedances and full control of hazardous vapors throughout the operation.
Benefit
Envent’s turnkey water treatment and vapor control solution enabled the customer to:
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Recover valuable hydrocarbons, adding cost savings compared to hauling off contaminated product
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Minimize downtime by returning the tank to service quickly and safely
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Maintain full compliance with air and water discharge regulations
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Eliminate VOC emissions during degassing, protecting workers and the environment
This project highlights Envent’s expertise in external floating roof tank recovery, hydrocarbon-contaminated water treatment, and refinery vapor control—delivering efficient, compliant, and cost-saving solutions tailored to complex tank storage challenges.
Project: Condensed Water Removal from Storage Tank Location: Victoria, Texas Product: Water contaminated with gasoline range organics.
