Residential Assessment and Monitoring

SCOPE OF WORK: LSP services supporting assessment and monitoring of chlorinated VOC in bedrock aquifer system           

Omni Environmental Group is providing Licensed Site Professional (LSP) services to property owners in central Massachusetts who acquired a vacant parcel of land with scenic views in order to construct a new home. Historical uses of the Site included light industrial manufacturing, which led to a release of chlorinated VOC (CVOC) to the environment, discovered through the detection of CVOC in a nearby private drinking water well. Once the former owner ceased funding, work response actions terminated and the Site fell into non-compliance under the Massachusetts Contingency Plan (MCP – 310 CMR 40.0000).

In order to acquire the land, the current property owners consented to an Administrative Consent Order (ACO) with the Massachusetts Environmental Protection (MassDEP), which requires assessment and monitoring activities to support a Temporary Solution Statement or Permanent Solution Statement under an ACO timeline.

Omni Environmental Group evaluated the extensive historical data set and prepared a field program for geophysical borehole logging at four (4) existing bedrock wells to further characterize fractured bedrock in support of: 1) dissolved and/or free phase fate and transport; 2) further defining the Conceptual Site Model (CSM); and 3) forthcoming MCP Regulatory submittals under the ACO.

Borehole logging data gathered during the field assessment program allowed Omni Environmental Group to identify rock fabric dip angle, bedding/foliation planes, fracture orientation, breakouts, and flow regimes (e.g. areas of inflow, outflow, vertical gradients, etc.) under steady state and stressed conditions. This fostered the selection of multiple discrete vertical sampling points at each well to quantify CVOC concentrations and monitor natural attenuation parameters indicative of reductive dechlorination, support contaminant fate and transport evaluation, and to update the CSM.

Omni Environmental Group communicated directly with the MassDEP, presenting detailed findings of the recent borehole logging leading to approval of a request to amend the ACO on behalf of the Client to establish new deadlines for regulatory reporting under the MCP.

Ongoing services for the Client include continued LSP services, quarterly bedrock groundwater and local private drinking water well sampling activities, and forthcoming preparation of a Phase II Comprehensive Site Assessment, Phase III Remedial Action Plan, and Phase IV Remedy Implementation Plan.