Wetlands Assessment, Remediation and Replication

SCOPE OF WORK: LSP services, assessment, and remediation at a public school, residence and wooded wetland

A release of an estimated 800 gallons of #2 fuel oil occurred at a public-school system resulting from the over-pressurization of a 6,000-gallon underground storage tank (UST). Fuel oil infiltrated an adjacent clay tile drain leading to a municipal stormwater system and off-Site migration, impacting approximately 700 linear feet of drainage channel and 53,000 square feet of wetlands.

Omni Environmental Group was retained by the oil vendors' insurance company to provide Licensed Site Professional (LSP) services and supervision and oversight of Immediate Response Action (IRA) activities under the Massachusetts Contingency Plan (MCP – 310 CMR 40.0000).

Initial response actions included: coordination with federal, state, and local authorities; oversight to stabilize the release, cleanout and inspection of the stormwater system; tank system testing and removal; soil excavation and dewatering; soil boring/monitoring well installation; confirmatory sampling; and property access agreements.

We prepared and submitted a Notice of Intent (NOI) identifying the type and boundaries of resource areas, anticipated remedial actions and the measures designed to meet the performance standards of the Wetlands Protection Act regulations pursuant to 310 CMR 10.00. Our staff represented the Client through numerous communications and at public hearings to review the NOI with the conservation commission, affected property owners, regulators, and involved parties, resulting in an approved Order of Conditions (OOC).

Omni Environmental Group provided for project management and field oversight under the NOI over a continuous twenty-five-week program between fall and mid-winter. NOI activities included: erosion and sedimentation control installation and maintenance; clearing and temporary roadway installation; operation of a stormwater retention and bypass system; removal and proper management of approximately 1,000 tons of impacted soil/sediment and 66,000-gallons of impacted liquids; comprehensive confirmatory media sampling; summary communications and interim submittals to involved parties and regulators; and backfilling and wetlands replication to restore native vegetation.

Post remedial activities will include post remedial inspections; continued confirmatory media sampling to demonstrate the effectiveness of response actions and facilitate a Stage I Environmental Screening under the MCP; continued regulatory compliance; public involvement notifications; and activities necessary to achieve a Certificate of Compliance under the OOC.

The expected outcome of these activities will be the submission of an IRA Completion and Permanent Solution Statement in accordance with the MassDEP IRA approvals, regulations of the Massachusetts Contingency Plan (MCP – 310 CMR 40.0000), and approved OOC.