The EPA's Office of Underground Storage Tanks (OUST) reports the number of cases of Leaking Underground Storage Tanks remaining unresolved exceeds 70,000 across the U.S. The EPA data also indicates the average cost of cleanup as US$130,000. As with any data, it's important to look at the distribution of data, not just averages. A vivid (maybe too vivid) example of this “flaw of statistics” is the fact that the average age of diaper wearer is somewhere near middle age, let’s say 45 years old. Drilling down into the data available from individual state UST cleanup funds, we find many examples of cleanup costs exceeding US$1.0M, sometimes with no end in sight. We can reasonably infer from the OUST data that the less complex sites have been resolved at a lower cost of cleanup, leaving the more complex sites yet to be addressed. This begs the question – WHY?
Mature groundwater plumes for environmental contaminants pose a complex challenge with regards to accurate delineation of sources, vertical and lateral extent, dominant pathways, and likely storage zones for residual contaminants. It is not uncommon for plumes from multiple sources to commingle and diffuse across a relatively large distance and a varied hydrogeological spatial volume. As a result, uncertainty in the accuracy of the conceptual site model (CSM) increases, and in turn the associated risk assessment, and the costs contemplated for cleanup alternatives. Better data resolution and scale are required to reduce these uncertainties. Low-Level Membrane Interface Probe Technology with Hydraulic Profiling (HPT) provides one approach for obtaining cost-effective and reliable high-resolution data, at a more informative scale in order to improves CSMs and enable better decision-making.
COLLABORATIVE TEAM EFFORT HELPS MONETIZE THE COST OF LNAPL CLEANUP FOR TDEC
COLUMBIA Technologies was selected by PM Environmental to support a high-resolution assessment of a former retail gas station with persistent LNAPL contamination. The goal of the assessment was to evaluate for the Tennessee Department of Environment & Conservation the impact of better information on monetizing the cost of long-term correctives action at these types of sites. The site is one of 246 remaining "difficult to resolve" sites in Tennessee and is typical of the many of over 16,000 remaining Leaking Underground Storage Tank sites in the U.S. The project involved a careful review of historical documents, cleanup activities, and extended field activities after hours and at night.
Detailed information gained through this effort delineated an extensive amount of residual gasoline within difficult soil conditions highlighting the need for careful consideration of remedial alternatives. The team employed the guidelines of the ITRC Technical and Regulatory Guidance for Evaluating LNAPL Remedial Technologies for Achieving Project Goals.
It is safe to say that 99% of all site assessments are either conducted through traditional sampling, groundwater monitoring wells, or direct sensing methods. As a leading site investigation partner to environmental consultants throughout North America and Hawaii, COLUMBIA Technologies specializes in soil and groundwater contamination assessments.
Since 1999, we have completed over 750 site assessments for some of the most discriminating clients including oil companies, government agencies, commercial real estate owners, developers, as well as architectural and engineering firms. Throughout all of our testing and experiences to date, we believe that using a comprehensive High Resolution Vertical Profiling approach seems to be the most cost-effective and accurate method to assess a contaminated site. This consists of direct sensing technologies to delineate the vertical and horizontal extent of the contamination to pinpoint the location. Once this information is known, following up with confirmation soil and groundwater samples would take place to validate the contaminant of concern.
The direct sensing technologies may cost more up front, however they assure that accurate information is being collected to move forward with designing remediation plans. In addition, our patented real-time data services platform, SmartData Solutions®, is able to produce high resolution visualizations through a secured website for online review of project data.
John Sohl, COLUMBIA Technologies' CEO, attended the 8th Symposium on the Design and Construction of Hazardous Waste Sites hosted by the Philadelphia Post of the Society of Military Engineers (www.samephildelphiapost.org). The focus of the symposium was how to incorporate performance based contracting into the environmental restoration of complex sites covered by the nation's Superfund Program.
John's key take-a-ways from the symposium were:
- The remaining Superfund sites are extremely complex. Successful restoration will be driven by detailed characterization built upon multiple lines of evidence and the best available science and technologies.
- Successful participants in future cleanups will be characterized by highly collaborative teams with aligned goals, risk, and reward.
- Information will drive clarity and successful communication with all stakeholders involved in the restoration efforts. Even after restoration efforts begin, there will be a continuing need for adaptive management using data-driven performance metrics.
The PBC contracts will be procured across multiple EPA regions in three major groups: Design Environmental Services (DES), Remediation Environmental Services (RES), and Environmental Services and Operations (ESO). Procurements will be open to both large and small businesses. The new contracting acquisition framework is being handled through EPA's Office of Superfund Remediation Technology and Innovation (OSRTI) (http://www.epa.gov/superfund/partners/osrti/) and FedBizOpps (www.fbo.gov).
One of the most critical points to remember when developing a site closure work plan is that it simply costs too much to assess, remediate, and make decisions on information that is incomplete, inaccurate, and too late. Traditional approaches to characterizing subsurface conditions by drilling, soil sampling, and monitoring wells screened over large intervals are too incomplete to accurately deal with site heteregoneity.
Therefore, a high resolution site characterization approach is a more attractive option as it enables projects to move forward with remediation focused activities such as corrective action, free product recovery efforts, and site closure.
Let’s face it, the heterogeneity geology of a site is going to impact the migration of subsurface contamination opposed to the age old myth that it always follows the direction of groundwater. Introduction of the Hydraulic Profiling Tool (HPT) for site investigation and remediation efforts supports contaminant mapping activities to provide a greater understanding of subsurface conditions. By measuring direct pressure response, HPT develops weighted lines of evidence indicating the tight (or loose) grains and low (or high) flow zones in order to determine the migration pathways, remediation injection regions, and placements for monitoring wells. With an integrated Soil Electrical Conductivity (EC) array this tool also defines zones of lower conductivity which allows for the movement of contaminants into the subsurface.
Since 2008, our team at COLUMBIA Technologies has supported site managers in evaluating petroleum contamination at 125 and growing projects using direct sensing or imaging tools. These projects include a wide-range of application from gasoline and diesel fuel retail stations to Superfund sites, as well as petroleum terminals, petroleum storage facilities, pipeline terminals, railyards, oil refineries, complex underground storage tank (UST) sites, military installations, and truck refueling facilities. These sites have spanned across 28 states in the United States including Hawaii, and multiple provinces in Canada. One primary technology deployed at these sites is the Laser Induced Fluorescence, specifically LIF-UVOST® to determine the LNAPL distribution at these facilities. These experiences have provided us with a number of lessons learned about accurately, rapidly, and cost-effectively characterizing these sites using this technology.
COLUMBIA Technologies is currently supporting our first high-resolution direct sensing project in Mexico City. COLUMBIA’s direct sensing team landed in Mexico City in August to make a difference in the environmental industry on a global level and prove that real-time information can drive a project to satisfy regulatory requirements for investigation of contaminated sites.
Following the proven concept of stakeholder and regulatory involvement, systematic work planning, and dynamic work execution, these site investigations focused on providing a better understanding of how the results would impact the overall remediation scope and property disposition.
Would a comprehensive site assessment and better data with multiple technology integration make a difference in your overall scope? Before you answer that question, think about whether or not having better, more accurate, and real-time information would motivate you to change your investigation technique on your next project. Are you actually interested in having data that accurately depicts the plume, delineates your source area, and multiple lines of evidence on your subsurface contamination? Or, would you rather “drill blind” and continue to sample areas where you think there may be contamination and install monitoring wells at the wrong depth and location incurring additional costs and time?
If having better data would actually change the way you would execute your project, design a remediation plan, or install monitoring wells, please read on. If you disagree, you may also continue to read, but the thoughts below may conflict with your perspective. Just saying, we warned you.
Data which is collected with advanced direct sensing tools (such as the Membrane Interface Probe (MIP), Laser Induced Fluorescence (LIF), or Hydraulic Profiling Tool (HPT)) provide a greater level of detail for characterizing the local site geology, a more in depth understanding of the hydrology, and deeper insight into the contaminant chemistry of your site. Wouldn’t all of this allow you to make more informed decisions?
Article originally featured in the Environmental Protection Agency (EPA) CLU-IN Technology News and Trends March 2011 Issue
Most recently, the March 2011 issue of Technology and Trends highlighted a project where COLUMBIA Technologies worked closely with the property owner, the Virginia Department of Environmental Quality (VA DEQ), and the City to address the site's environmental and economic issues.
Efforts to better delineate contamination and accelerate remediation of the former Fannon Petroleum Services site in Alexandria, VA, were initiated in the early 2000s as part of a plan to redevelop the site for residential use.
For this project, the VA DEQ initiated the Triad approach including the development of a conceptual site model and consensus on specific investigative methods and tools, with a focus on using:
- Membrane Interface Probe (MIP) to characterize distribution of volatile organic compounds (VOCs) in discrete hydrologic units and soil stratigraphy at offsite locations;
- Direct-sensing geophysical tools rather than groundwater and soil sampling for initial screening; and
- A dynamic work strategy to allow real-time decision making that could identify specific locations for direct-sensing locations as work proceeded.
Click the following link to read the full article, Revised Characterization Plan Accelerates Petroleum Brownfield Cleanup and Redevelopment.