PHASE II ENVIRONMENTAL SITE ASSESSMENTS

The first step toward the solution of any environmental problem is to determine the site conditions, the nature of the contaminants, and the extent of existing and potential contamination. Smith-Emery performs comprehensive site assessments designed to define the existing site conditions in terms relevant to environmental issues and regulations. Smith-Emery can use that information to identify remedial alternatives that may be applicable at the site, evaluate those alternatives, and recommend an environmentally sound and cost-effective solution.

Smith-Emery has performed site assessments and remedial investigations for a wide range of environmental problems. These projects have been directed at both manmade and natural environmental media including groundwater, surface water, soil sediments, and building materials. Compound types addressed have included environmental contaminants such as solvents, volatile organics, metals, PCBs, asbestos, and pesticides.

The information-gathering process of the Phase I environmental assessment serves to identify areas of potential environmental concern and to define the scope of any Phase II assessment work. The information gathered in the Phase I details the areas to be sampled and the chemicals or other substances for which the samples should be analyzed. The Phase II site assessment will identify areas where problems are, while a site characterization determines the magnitude of those problems so that remedial measures can be assessed.

WORKPLAN PREPARATION

When a site assessment is to be performed under the auspices of a regulatory agency or must gain regulatory approval at some point, negotiations and detailed work plans are required. Smith-Emery obtains the approvals necessary throughout the investigation to keep the process moving smoothly. If the project is to be performed under the client's direction, Smith-Emery GeoServices can negotiate with the agency to achieve the project goals as quickly as possible.

Quality control is an extremely important element of every Smith-Emery investigation work plan. Smith-Emery field crews follow quality control procedures that address sample collection and handling as well as calibration of field instrumentation and appropriate documentation. Each sample is documented on a chain-of-custody form. Smith-Emery carefully decontaminates sampling equipment as necessary.

An equally important element of every work plan is health and safety planning. A qualified Smith-Emery health/safety officer prepares a site-specific health and safety plan based on the expected physical and chemical hazards that may be encountered. A site-safety officer is responsible for verifying that all employees strictly adhere to the procedures outlined in the health and safety plan.

FIELD INVESTIGATION

Smith Emery performs field investigations to obtain detailed information on potential problems identified by the Phase I Site Assessment. The field investigations will establish the following site characteristics, as necessary:

SITE CHARACTERIZATION

Based on the information required, Smith-Emery develops a focused site characterization work plan which includes a sampling plan detailing sampling procedures, locations, and frequency, and an analytical plan detailing analytical procedures and analyses. The Smith-Emery field investigation may employ a number of investigative techniques such as:

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SAMPLING TECHNIQUES & TOOLS

Soil Gas Survey  |  Soil Borings / Test Pits  |  Geophysical Surveys
Air Monitoring  |  Modeling  |  Groundwater Monitoring  |  Hydrologic Studies

Soil Gas Survey

In some instances, a soil gas survey may be used as a preliminary investigative tool for assessing subsurface contamination of a site where volatile organic compounds are involved. Soil gas from the shallow subsurface is collected and analyzed, enabling detection of volatile contaminants in the soil or shallow groundwater.

Soil Borings / Test Pits

Soil borings and/or test pits serve as mechanisms to investigate site stratigraphy, soil properties, and the spatial extent of contamination within the soil. In general, we use soil borings when a relatively large area must be investigated and test pits when the extent of contamination has already been roughly identified and is contained within a relatively small area. Prior to performing work involving the disturbance of the site subsurface, we locate underground utilities and piping through interviews with utility companies and reviews of existing as-built drawings.

Geophysical Surveys

Our staff has experience in the application of geophysics--the science of measuring the physical properties of the earth to determine subsurface composition and structure. During a site investigation, we may use one or more of the following nondestructive geophysical techniques to aid in defining subsurface conditions:

In addition, Smith-Emery utilizes borehole geophysical logging. Geophysical information is obtained from boreholes using logging probes that measure resistivity (electrical logging) and electrical potential (spontaneous or self-potential logging). The information obtained from these probes can frequently define soil and rock layering more accurately than a soil-sampling program. Borehole geophysics also helps to identify zones of differing permeabilities, which is beneficial when considering future remedial needs.

Air Monitoring

Through the course of a field investigation, Smith-Emery performs air sampling and monitoring for several purposes including:

It is important to note the difference between air sampling and air monitoring. Air samples can be collected and analyzed for specific compounds in a laboratory, while air monitoring is done in real-time in the field by portable instruments. Smith-Emery performs air monitoring to detect general types or classes of contaminants or determine gas levels in the field. Smith-Emery takes occasional field readings as a check on the adequacy of or need for respiratory protection and to offer a preliminary assessment of site contamination.

Modeling

To better meet the needs of our clients, Smith-Emery GeoServices has made a substantial investment in state-of-the art computer equipment and software. Utilizing advanced computer aided design (CAD) techniques enables Smith-Emery's Project Managers to easily visualize complicated physical situations such as aquifer properties, hydraulic gradients, and contaminant distribution. Sophisticated computer assisted modeling (CAM) software allows our Project Managers to design the optimum placement for additional monitoring wells and soil borings on a parcel of land, resulting in obtaining the needed data at the lowest cost to our clients.

Groundwater Monitoring

Smith Emery has extensive experience in monitoring contaminated aquifers. With the installation of a network of groundwater monitoring wells, we can determine ground-water and aquifer characteristics and monitor the movement of contaminant plumes. Smith-Emery bases the design of the monitoring well system on several variables:

Hydrologic Studies

To begin a study for contaminated groundwater, Smith-Emery performs a detailed analysis of the following factors:

Most of this information can be obtained through a network of groundwater monitoring wells. We design and strategically place monitoring wells to obtain accurate data regarding volumes, flow rates, and hydrogeological characteristics. Smith-Emery collects samples from the wells for analysis for contaminants and solids levels. Laboratory analysis is then performed to assist in selecting a treatment regime.

The hydraulic properties of concern are the transmissivity and storativity of the aquifer. These properties are best determined through pumping tests. During the pumping tests, Smith-Emery monitors the response of the water level in the well being pumped and in nearby observation wells. Water levels before, during, and after pumping are analyzed as functions of time and distance from the pumped well to determine transmissivity and storativity. This data is then used for fate and transport studies, design of dewatering systems, and design of contaminant plume containment systems.

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