Phase Two Environmental Site Assessment

Phase II Environmental Site Assessment (Investigation)

The Phase II Environmental Site Assessment (Phase II Investigation) is conducted on a site that has a suspected or known Recognized Environmental Condition (REC) such as a spill, a leak, or a facility that handles hazardous materials and doesn’t have proper records. The Phase II Investigation is generally considered the second step in the process of environmental due diligence. If a REC is identified, by the conclusions of a Phase I Environmental Site Assessment, by a Regulatory Agency Inspection, or by general knowledge, a more detailed investigation involving chemical analysis for hazardous substances and/or petroleum hydrocarbons is needed. The goal of the Phase II Investigation (which may include several field investigations and multiple reports) is to define the type, concentration, and size of the contamination, as well as the affected media. Additional research may be necessary, such as nearby receptors (wells), to help define the type and speed of cleanup necessary (Phase III) at the site. A Phase II typically includes: drilling at the site, collecting soil, and possibly water samples, from the surface and at depth, and analyzing the samples for a range of chemicals which may be present at the site. These analytical results are typically compared to State Cleanup Levels.

Work performed by Enviro Assessment, PC is conducted by staff engineers and/or geologists with many years of experience in the field. The Three Main Areas of Study are Soils, Soil Vapors and Groundwater.

These areas are discussed below in greater detail:

Phase II – Soil Sampling

Phase II Investigations will include soil sampling if the source area of a chemical spill or leak is suspected to be on the Subject Property, the soils at the spill location are expected to be impacted with these chemicals. Soil samples will be collected from both the source area and from areas adjacent to the source area that would define the size (both vertically and horizontally). Understanding the amount of soil impacts are important in order to determine the best method available to remove or remediate the impacted soils.

All soil samples are analyzed at State certified Laboratories for Chemicals of Concern. The results of these analysis are typically compared to either the EPA Tier 1 levels or the states, which ever is more stringent.

If the full extent of the soil impacts are not defined, additional investigations will be needed in order to define the size of the impacts, the concentration of the impacts and the types of chemicals impacting the soils.

Phase II – Soil Vapor Sampling

Phase II Investigations will include soil vapor sampling if the source area of a chemical spill or leak is unknown or records of past leaks, or uses of chemicals at the property is not available. The soil vapor testing will help evaluate what if any volatile chemicals are located in the immediate area of the testing locations. Soil vapor samples will be collected from several locations in around around possible spill or leak locations in order to attempt to identify any source areas (higher concentration of impacts) Soil vapor sampling is not typically used to define the size (both vertically and horizontally) of impacts as vapors transmit through the subsurface in complex patterns. Once the location of the most concentrated chemical soil vapors are located, soil samples are collected in order to verify impacts at the property to the soils.

Understanding the amount of soil vapor impacts are important in order to determine the best method to locate the area of impacted soils.

All soil vapor samples are analyzed at State certified Laboratories for Chemicals of Concern. The results of these analysis are typically compared to either the EPA Tier 1 levels or the states, which ever is more stringent.

If the full extent of the soil vapor impacts and soil impacts are not defined, additional investigations will be needed in order to define the size of the impacts, the concentration of the impacts and the types of chemicals impacting the soils.

Phase II – Groundwater Sampling

Phase II Investigations will include groundwater sampling if the source area of a chemical spill or leak is suspected to be significant enough to allow transportation of the chemicals through the soils into the groundwater beneath the Subject Property, the groundwater at the subject property will need to be evaluated for impacts via grab samples. If these samples are impacted will chemicals of concern, then a network of monitoring wells will be required to be installed to monitor the direction of groundwater flow, the speed of the flow, the concentrations in the groundwater and the location of the chemical plume in the groundwater. Groundwater samples will be collected multiple locations in order to define the extent of impacts in the groundwater (both vertically and horizontally). Understanding the amount of groundwater impacts are important in order to determine the best method available to remove or remediate the impacted groundwater.

All groundwater samples are analyzed at State certified Laboratories for Chemicals of Concern. The results of these analysis are typically compared to either the EPA Tier 1 levels or the states, which ever is more stringent.

If the full extent of the groundwater impacts are not defined, additional investigations will be needed in order to define the size of the impacts, the concentration of the impacts and the types of chemicals impacting the groundwater.

Ground Penetrating Radar

Ground Penetrating Radar (GPR) is used to attempt to located buried metal objects. Sometimes GPR is able to even locate the edge of former excavations due to the change in soil types. This tool is almost always used as part of our due diligence in locating underground objects prior to drilling during a Phase II Investigation.