Eisenback & Ruhnke - Phase II Site Investigation

5.0 Phase II Site Investigation (Phase II SI) Process

5.1 Purpose

The Phase II Site Investigation (SI) is defined as an intrusive study of the Site’s soil, sludge, water, groundwater, and waste material to evaluate both the location and the extent of impacts from historical uses. SI’s are performed to verify the presence of environmental contaminants alleged to be on site, as determined by the Phase I ESA.

According to the ASTM Standard (E1903-00) the SI has four main components:

¨ The development of the scope of work;
¨ The investigation methods and activities;
¨ The evaluation and presentation of the data;
¨ The preparation of the findings and conclusions.

ASTM requirements for each of these elements is discussed detail in the following sections.

5.2 Defining Objective and Scope of Work

A scope of work should be defined that states what the areas of concern are, how they will be investigated, and what they will be investigated for. All parties should agree on this scope and objective prior to performing the investigation.

5.3 Identifying the Potential Contaminants

A list of the contaminants believed to be on site should be developed. This list is based the contaminants and chemicals used on site and should be identified in the Phase I ESA

5.4 Migration Pathways

Once a list of potential contaminants has been developed and areas of concern have been defined, migration pathways can be predicted. A migration pathway is a route a contaminant may have traveled and entered into the soil and groundwater of the Site, or how it has been dispersed throughout the Site. For example a historical disposal of contaminants into an on-site septic system will allow the contaminants to migrate from the septic system, via the leach field piping, into the soil and leach into the groundwater. The contaminants could then migrate in the groundwater towards a domestic well.

5.5 Sampling Strategy

The sampling strategy is developed to achieve the objective of the SI. The types of samples to be collected, laboratory analysis, areas of sampling, the depth and number of samples to be collected are determined. The sampling strategy should effectively evaluate the areas of concern to determine what environmental contaminants are present, what concentrations they are at, and define the source of the contaminants.

5.6 Investigation Methods and Activities

The methods of the investigation to be used are based on the required sampling strategy, geology of the Site, and the requirements of the sampling (depth, surface cover, location of suspect contaminants, etc.).

Some methods of investigations include collection of soil samples by hand augering, direct push sampling, rotary drill technology and excavation.

5.7 Site Investigation Work Plan

Before any work is completed an investigation work plan should be developed by the consultant. The objective of the work plan is to attain a consensus from all parties involved on the work to be performed. Note, the scope of work included in a proposal may be sufficient to satisfy the requirements of a work plan. The purpose of the work plan according to the ASTM Standard is to:

¨ Explain what and where the environmental conditions are
¨ Outline the objectives of the SI.
¨ Explain the reasoning in the development of the sampling strategy and the analytical program.
¨ Specify the sampling strategy, technologies, and analytical methods to be used.
¨ Present QA/QC programs
¨ Provide all pertinent details and information concerning implementation of the SI.
¨ Detail the deliverables
¨ Provide locations of sampling
¨ Specify equipment decontamination
¨ Analytical methods for each sample
¨ List health and Safety requirements

5.8 Health and Safety Plan

A Site Health and Safety Plan (HASP) are prepared to protect the health of the on-site employees and provide protection to the surrounding community from the hazards of the SI. The HASP should be prepared by a health and safety professional.

5.9 Interpreting Sampling Data

If the SI discovers contaminants on site then consultant can typically determine if the contaminants present a problem by comparing the concentrations of contaminants to federal and state Standards, Criteria, or Guidelines (SCGs).

If contaminants detected on site are not listed in the SCGs than a risk assessment may need to be performed by the consultant to assess the significance of the findings.

5.9.1 Standards, Criteria, and Guidelines

Standards, Criteria, and Guidelines (SCGs) are the published allowable levels of contaminants in a particular medium (soil, water) and are set by the federal or state authorities. Standards are legally enforceable regulatory levels that must be complied with under specified conditions. Criteria or guidelines are not typically enforceable by law.

5.10 Site Investigation Report

The SI report should fully describe the work performed, document the information gathered, and provide an evaluation of the data. According to the ASTM Standard, in preparing the report the consultant must review all data collected, correlate it to the list of recognized environmental conditions, and determine if any contamination actually exists. If any investigation work was completed different than outlined in the work plan then the changes and reasons for the changes need to be discussed. The ASTM Standard suggests the SI report follow the following format:

I. Introduction
II. Background Information
III. Phase II SI Activities
IV. Evaluation and Presentaion of Results
V. Discussion of Findings and Conclusions
VI. Recommendations

Attachments: Tables, figures, photographs, boring logs, laboratory results, chain of custody forms.

Upon conclusion of the SI, the environmental conditions of the property will have been assessed and a determination made as to whether any contamination is present. If no contamination is discovered and reasonable inquiry has been made, then the consultant may recommend no further environmental evaluation for the Site. If contamination is discovered, then the parties may withdraw from the transaction, or negotiate the cost of remediation for the Site. If remediation cost estimates are needed, then additional investigation may be necessary to define the extent of the contamination and gather information for remediation alternatives and development of remediation cost.