The purpose of this guide is to provide you with a complete overview of what phase two environmental site assessment entails and how it compares to other site assessments. Phase two environmental site assessment is the second of three types of site assessments that can get conducted, and it is the most comprehensive.

Phase 2 Environmental Site Assessment is a process that often gets overlooked for due diligence and can be one of the most critical components of an environmental assessment. 

What Triggers It?

Here are a few factors that can trigger the need for a Phase 2 Environmental Site Assessment (ESA). 

  • One is if the results of a Phase 1 ESA indicate the presence of potential contamination. 
  • Another is if there has been a release or spill of hazardous materials on the property. 
  • If there is reason to believe that there may be contamination present due to the property’s past use, a Phase 2 ESA may be warranted.
  • This assessment usually gets done when there has been a spill or release of hazardous materials, if there is suspected contamination, or if there is new construction on the site. The purpose of it is to determine if there are any potential risks to human health or the environment.

What Is The Goal?

The goal of Phase 2 environmental assessment is to determine whether a significant contamination or health concern exists on a property. Phase I assesses the probability of contamination of a site first, using visual observations, a review of past uses, and regulatory records, whereas Phase II evaluates if there is pollution. A Phase I assessment involves research to determine whether there is any reason to suspect materials are present, based on historical records on the site, state and agency databases, reviews of site plans, photographs and other documents with past uses, and site. 

What Are The Benefits?

The benefits of a Phase 2 ESA study cost are that it can provide more accurate and detailed information about the efficacy of a drug. 

It is beneficial in many ways, including determining whether the drug is safe for patients with similar symptoms to those found in the study. It also helps to determine how effective the drug is, compared to other drugs on the market.

  • It can determine If there are any adverse effects on the patients who are taking the drug or treatment.
  • It can help to find if there are any interactions with other drugs a patient may be taking.
  • It helps to determine how well the drug or treatment works and how it should get used in different populations, such as children, adults, the elderly, etc.

How Long Does It Take?

Depending on the size and complexity of the site, a Phase 2 ESA can take anywhere from several weeks to several months to complete. The first step is to collect all available information about the property. It includes looking at historical records, aerial photographs, and other data that can give clues about potential contamination. 

Next, a site visit gets conducted to collect soil samples, water, and air. These samples are then analyzed in a laboratory to determine if there are any harmful chemicals. If contamination gets found, additional testing may be needed to assess the extent of the problem.

Who Pays For Phase II Investigations?

Phase II Investigations are typically paid for by the party who stands to benefit from the report. In most cases, this is the current property owner or the prospective buyer. If the assessment is for lending purposes, the lender will usually require that their name get included on the report. Occasionally, it will get conducted at the request of a governmental agency.

How Much Does It Cost?

The cost of a phase 2 ESA study depends on the country, the type of study, and the number of participants.

Phase 2 ESA studies are more expensive than phase 1 studies because they require more time, more participants, and more complex experiments.

The cost of a Phase 2 ESA Study can vary depending on the type of study, but it can be anywhere from $10,000 to $150,000.

Differences Between Phase I and Phase III ESA

While the Phase 1 Environmental Site Assessment follows standard procedures, Phase 2 ESAs are more tailored to the property, its environmental condition, and whatever is found during Phase 1. Phase I Environmental Site Assessments (ESAs) and Phase II environmental site assessments are federally standardized procedures used by an environmental professional (EP) to examine a property’s history and present uses and analyze potential impacts. 


Now you know, Phase II ESA aims to develop reliable, scientifically valid data regarding actual conditions of the property by collecting samples of groundwater, soil, and soil vapors for laboratory analysis. Phase II ESAs involve sampling soil, soil vapor, and groundwater that will assist in determining whether or not there are hazardous substances and petroleum products in site media.