About This Project

ABSTRACT

The subject facility is an active pipeline and petroleum storage site in the Gulf Coast Region where a leaking aboveground storage tank (AST) created a large dissolved and LNAPL plume. BOS 200+®, a modified version of BOS 200®, was applied over a large area during a 6-month period in 2017. Results to date indicate that LNAPL levels have been eliminated or significantly reduced. In addition, benzene and TPH levels have decreased an average of 96.3% and 97%, respectively. A No Further Action determination has been requested and is pending.

PROJECT SNAPSHOT

Key Dates

• February 2017 – Remedial Design Characterization (RDC)
• Summer/Fall 2017 – Injection of BOS 200+®
• No Further Action (NFA) Determination: Pending

Treatment Area: 93,000 ft2
Lithology: Varied across the large area but consisted mainly of silty clay to clay over weathered shale with some sand and gravel.
Depth to Water: 5 to 25 ft bgs (variable)
Contaminants: LNAPL and TPH
Implementation Method: Direct push and Pre-Drill injection

CHALLENGES

The subject facility is an active pipeline and petroleum storage site in the Gulf Coast Region where a leaking aboveground storage tank (AST) created a large dissolved and LNAPL plume. BOS 200+®, a modified version of BOS 200®, was applied over a large area during a 6-month period in 2017. Results to date indicate that LNAPL levels have been eliminated or significantly reduced. In addition, benzene and TPH levels have decreased an average of 96.3% and 97%, respectively. A No Further Action determination has been requested and is pending.

APPROACH

• 1,110 soil samples were collected as part of a large RDC in early 2017. The sample results were used to create an optimized and surgical BOS200+® design. All samples were analyzed at the RPI Project Support Laboratory at no cost.
• Injection specifications:
  • 93,000 ft2 Treatment Area
  • >1,000 Injection Locations
  •  361,000 lbs BOS 200+®
• The majority of the injection locations were completed using direct push injection techniques. In one area, shallow refusal was encountered (weathered shale), so the Pre-Drill technique was used to reach the target treatment depth.

RESULTS (5 Years Post Application)

• LNAPL
  • The total number of wells with measurable LNAPL prior to
    remediation: 15
  • Post-remediation LNAPL statistics
    • No measurable LNAPL: 12
    • Sheen: 2
    • Measurable LNAPL: 1 (current max LNAPL thickness = 0.02 ft)
• Dissolved Total Volatile Petroleum Hydrocarbons
  • The average dissolved TPH concentration in the monitoring wells
    prior to remediation: 20.9 mg/L
  • Post-remediation average concentration: 0.38 mg/L (97% reduction)
• Post treatment analytical support provided by the RPI Project Support Laboratory at no cost.

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