T. M. Gates, Inc

T. M . Gates, Inc.

Environmental and Sanitary Wastewater Consultants

Investigation and Characterization

After the determination is made that soil or groundwater contamination exists at a site, it is then important to investigate and characterize the contaminant plume. This can be achieved by performing and/or installing a series of strategically placed soil borings and/or groundwater monitoring wells. After the soil borings or monitoring wells are completed and the data is collected and analyzed, a treatment or disposal strategy can be determined. T. M. Gates, Inc. uses the following techniques to determine a treatment or disposal strategy:

2-DIMENTIONAL AND 3-DIMENTIONAL GEOLOGIC CROSS SECTIONS

Geologic cross sections provide the client with a visual representation of the subsurface geology. By knowing the lithology of the site, T. M. Gates, Inc. can determine the behavior and path of the contaminant. After the contaminant pathways have been established, and the extent of the plume has been established using a modeling program, a remedial or disposal strategy can be proposed and implemented to eliminate the contamination.

CAPTURE ZONE AND CONTAMINANT PLUME MODELING

Capture zone and contaminant plume modeling are two additional tools that can be used to develop a remedial strategy. By utilizing simple computer aided modeling programs, the full extent and concentration of the contamination can be determined. T. M. Gates, Inc. uses this information in conjunction with geologic cross sections and other data to determine the most effective and economically viable treatment alternative.

Risk Based Corrective Action (RBCA) can be used as a treatment strategy at specific sites. A RBCA is generally used at sites were low levels of contamination pose no immediate or future risk to human health. T. M. Gates, Inc. has used RBCAs to obtain No Further Action (NFA) documents from various state and federal agencies. Depending of site location and contaminant concentration, a RBCA can be used either before remedial technologies are proposed and installed, or after a remedial system has lowered the soil and/or groundwater contamination to an acceptable level. RBCAs are generally more cost effective than conventional treatment strategies. However, a RBCA does not eliminate the contamination, and most government agencies will not accept a RBCA if any potential threat to human health exists or the contamination has moved off-site.

RISK BASED CORRECTIVE ACTION (RBCA)