City of Burlington, Vermont

City of Burlington, Vermont

CEDO / City Hall Room 32
802-865-7144 / cedofd@burlingtonvt.gov
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Assessment Process

Environmental Site Assessments (ESA’s) are conducted by professional consultants, with Vermont DEC oversight, and for all EPA funded studies, EPA Quality Assurance screening. Thus there is a “hands-off” system whereby the client commissioning the ESA cannot influence the findings.

There are two levels of assessment:

Phase I ESA

The initial study performed at a site suspected to have contamination issues is called a “Phase I Environmental Site Assessment (ESA)”. The Phase I ESA is mostly a desktop study, combining historical and deed research, interviews with past and present owners/tenants and neighbors, site walkovers, database reviews of areas of concern, and reviews of any available records, resulting in an opinion as to whether or not there is the potential for contamination at the site. If the Phase I ESA concludes that past activities on or near the site could have led to contamination, the report must be submitted to Vermont DEC, which will issue a so-called “First Letter” to the site owner indicating that that a workplan for a Phase II ESA be submitted within a specified timeframe.
 

Phase II ESA

Phase II ESA’s establish the type, degree, and extent of contamination through soil and groundwater testing using drill rigs, soil sampling, sophisticated sampling techniques, and lab analysis. These assessments are highly standardized and prescriptive, ensuring a consistent format.

Before any assessment work can take place, a Phase II ESA Workplan must prepared by a qualified consultant, and be approved by Vermont DEC. If USEPA Brownfields grant money is to used, the workplan must undergo a rigorous EPA Quality Assurance review before the Phase II ESA can be performed.

Once a Phase II ESA Workplan is approved by Vermont DEC and EPA Quality Assurance, consultants can commence field work, which is in turn tracked and overseen by the Vermont DEC Site Manager. The Phase II ESA may include soil sampling, groundwater sampling, and in some cases, indoor air sampling, asbestos and lead analyses. Once the Phase II ESA is completed, a draft report is submitted to Vermont DEC. The report, and soil and water sample results are reviewed by the Vermont DEC Site Manager assigned to the site. In some cases, Vermont DEC may ask for additional sampling, or for a re-write of portions of the report. Using tables of “Preliminary Remediation Goal” levels for each hazardous substance, the Site Manager reviews the recommendations made in the completed report, and issues a “Second Letter” to the site owner indicating whether or not the site needs additional work, and if warranted, orders that a Corrective Action Plan for site cleanup be submitted, also within a specific timeframe.
 

Corrective Action Plan

With the Phase I and II ESA’s complete, and the Second Letter in hand, consultants craft a draft Corrective Action Plan for the site. This plan covers all cleanup and future monitoring activities, and is the working document for remediation. 
There are generally three options is dealing with soil and groundwater contamination, and many Corrective Action Plans employ a combination of the below methods:

 

Leave Contamination in Place and Monitor

This can involve monitoring only, or capping impacted areas with clean soil, and often a Notice to Land Records is placed that permanently documents contamination, and refers to the appropriate Vermont DEC file.. This option is far more common with petroleum compounds, which break down over time, and in areas where there are municipal water and sewer systems.

Conduct On-Site (“in situ”) Remediation

This could mean pumping and treating groundwater, using injected air (“sparging”) to introduce oxygen to subsurface contaminants to promote degradation, stockpiling soils to allow for natural atennuation, phytoremediation (the use of plants for remediation), or other emerging technologies – provide they receive approval from Vermont DEC before use in the field.

Remove Contaminated Soils

Depending on the type, amount, and toxicity of the contamination, soils can be removed and used for landfill cover, recycled at an asphalt plant (petroleum soils), incinerated, or placed in a lined landfill.
 

In almost all cases, post-cleanup monitoring is required to ensure the effectiveness of a remedy. This can be taking water samples from a monitoring well, soils samples from stockpiled soils, and/or other measures. If contamination is left in place, it is common practice to register a Notice to Land Records to permanently document the presence of contamination.

For more information, contact:

Gillian Nanton, Assistant Director of CEDO, 802-865-7179, or 
Kirsten Merriman-Shapiro, Project and Policy Specialist, 802-865-7284