Phase II Environmental Site Assessment (ESA) 

While a Phase I ESA identifies a recognized environmental condition, usually a request to evaluate the potential impact is done by doing a Phase II ESA. The purpose of Phase II work is to determine whether harm was done to the enivronment.

The scope of work focuses on the area of the site that are most likely to exhibit detectable contaminates based on knowledge of how the property has been used. Spartan Environmental can provide a full range of field services including groundwater, soil, and sub-slab soil gas sampling. Geophysical surveys are employed to identify potential underground storage tanks, drain lines, disturbed soil, or buried debris. 

If there is no significant contamination after the phase II evaluation, often  no further work is required. If contamination is found to be at levels of concern, additional site characterization to delineate the extent of impacts are done. We may have to do cleanup if the risk is high enough. 

The cost of a Phase 2 ESA varies depending on the type of lab analyses required, access subsurface, drilling method needed, overhead constraints, and groundwater testing required.


The following are some of the things Spartan does in a phase II ESA:


Soil Sampling and site characterization:

Spartan’s professional geologists have successfully completed soil sampling and characterizations of many sites. To reduce cost and ensure accuracy, Spartan typically uses direct-push sampling technology to obtain core soil samples, when available. Once the sample results are received, Spartan scientists are able to determine if the sample results collect from the site present human and/or ecological risks. If they do further action is taken.

Soil Testing, Profiling, and Disposal:

Spartan’s geologist and environmental scientists are well experienced in soil testing & profiling of soil for disposal and/or reuse in accordance with regulatory requirements. To reduce the cost of disposal, Spartan’s soil sampling enables the soil to be reused or segregated and disposed of in a way that is cost efficient. 

Groundwater remediation, sampling, and plume migration:

Groundwater remediation and characterization is perform by obtaining groundwater samples. If we find contamination, our geologic experts will evaluate the texture, nature, and concentration of the contaminant plume. Following assembly of the data, computer modeling techniques enable Spartan’s scientists to determine the plume of the contamination and it’s migration.

Risk Assessment:

Risk Assessment is used to determine potentially adverse environmental conditions and contaminates. If these create safety or health concerns. In order to get a conceptual understanding of a site. Spartan roughly assesses and models the key elements of the project including the source, the potential Receptors, and the exposure pathways. 

If testing confirms contaminates, the concentrations of contaminants in the soil and groundwater are compared to the Oregon DEQ Risk-based Concentration (RBCs). An RBC is the condition of a harmful substance in water, soil, air, or sediment that is determined to be destructive of human health and the environment under specified exposure conditions. RBCs are identified for particular harmful substances at a site, and they specify areas of pathways, such as land or water, where humans and other living things could be exposed.

Exposure pathways are the means by which contamination may impacting  human health or the surrounding environment. These pathways include the air, water, and soil. If a pathway determined to be “contaminated” then the potential Receptors must be considered. 

The following is the list of Risk-Based Concentration (RBCs) for Oregon:

  • Underground Storage Tank – RBC
  • RBC – Soil & Indoor Air
  • RBC – Complete list

Receptors include the current and future potentially exposed population and the environment. In order for Risk to be present at the site, a source must be present and a receptor must be present. If any of these key things are missing, there is no risk.

Vapor Intrusion studies:

Vapor intrusion refers to what happens when chimerical vapors migrate form the soil or groundwater into a home or other building. Many chemical that move into buildings this way are considered to be volatile organic compounds (VOCs). 

VOCs can move easily through the soil and tend to migrate from high-pressure to low-pressure areas. Since a basements tend to have lower pressure than the soil underneath, these VOCs are likely to enter the basement (or other first level) through cracks in the foundation, wall, or floors. Some heating and air conditioning systems can pull the gases into the structures. Once these are inside, natural air flow, and ventilation allow the vapors to spread throughout the building. Vapor intrusion can cause air to become polluted and unhealthy. 


How do I know if I have vapor intrusion?

You can collect soil vapor samples in the ground nearby a structure or in the ground right next to your foundation, or you might collect indoor air samples. 

If you learn of a toxic spill or leak, you might call the owners or government officials to request a test for vapor intrusions. The EPA provides information about vapor intrusions and safe chemical levels. 


What should I do?

If test indicate that chemicals are intruding into your home or commercial structures, you could have a mitigation and/or remediation system installed. 

Geophysical surveys:

Geophysical surveys sometimes may be more cost effective or ecologically viable to do. These surveys are generally conducted when attempting to determine whether subsurface structures, such as underground storage tanks or other features that may surface on hazardous materials usages/storage, may be present.

A geophysical survey can determine if a subsurface features not visible at the surface exist at the site. It can also identify evidence of former subsurface feature by identifying evidence such as germinated piping, as well as disturbed soil in the shaped and depth of subsurface features. 

If you are in need of a Phase 2 ESA in the Oregon or Washington area or would just like to talk to someone about your situation call Spartan at 971-600-3983.