INSIGHTS on Brownfield Assessment and Remediation
Brownfield sites—mainly abandoned or soon-to-be abandoned industrial facilities—pose huge challenges to governments, communities, and engineering firms charged with restoring them to common uses. At issue are contaminants—chemicals and metals—that if not remediated pose public health concerns.
Tangled Web of Custody, Access, and Analysis
As the U.S. moves toward a postindustrial economy, revitalization of land occupied by factories strains current legal, regulatory, and funding resources. As is so common these days, laboratories and engineering firms rise to the task.
Brownfield sampling and analysis require logistical juggling. Engineering firms take initial samples from soil and groundwater to estimate the type and extent of contamination. They often hire mobile labs to collect samples over weeks or months. Couriers transport samples to brick-and-mortar chemical analysis laboratories.
The majority of samples processed by Geosyntec Consultants (Boca Raton, FL) are analyzed by contract labs. The company reserves its own SiREM analytical laboratory for specialized tests to support out-of-the-ordinary cleanups or remediations.
Based on knowledge of the property and its probable use, engineers will have a good idea of what compounds to look for. Geosyntec, for example, orders predetermined analyses based on the facility type. Where contamination is suspected, they cast a wider net, of perhaps half a dozen analysis suites, while homing in on locations with the highest contaminant concentration.
“The Florida laboratory community is pretty dialed in to the different types of contaminants to expect from most brownfields,” says David Latham, Geosyntec’s senior geologist. Most common and troublesome are petroleum residues, pesticides, herbicides, and metals.
Rich Information Sources
While the U.S. Department of Environmental Protection (DEP) still participates in brownfield assessment and remediation, states hold enormous sway.
Brownfield assessments in Texas involve two phases. Phase 1 includes a review of the current and historical operations at a property. Included in the review are invoices, bills, and company documentation—some filed with local authorities, some stored in archives—cataloging the chemicals or materials that entered and left the property.
Interviews with current and former owners or operators, and current and past employees, are a rich information source. The Texas Commission on Environmental Quality (TCEQ; Austin, TX) analyzes historical photographs to determine when and where the property was developed, or razed, and when ‘subfacilities’ such as underground tanks were installed or removed. “We sometimes have access to aerial photos dating to when the land was undeveloped,” says Ann Strahl, quality assurance specialist at TCEQ. She says knowledge of operations, and chemical handling, storage, and disposal related to those activities, helps focus the overall assessment. “If the property was an ink factory or a wood-treating plant, we’d have a good idea as to the types and classes of chemicals of concern at the property,” she adds.
Phase 2 assessment involves development of a fieldwork plan for environmental sample collection. Based on the current and historical operations, TCEQ conducts a literature search to determine the appropriate analytical methods for sample analysis. When historical information about the property is limited, TCEQ turns to broad-spectrum methods, including full-scan gas chromatography mass spectrometry such as SW-846 8260 for volatile organic compounds and SW-846 8270 for semivolatiles. The goal is to assess the presence or absence of the most common organics.
Similarly, TCEQ uses inductively coupled plasma mass spectrometry or atomic emission spectrometry mass spec (ICP/MS or ICP/AES) to assess metal concentrations. At times the organization turns to specialized analytical tests, such as GC with an electron capture detector to analyze pentachlorophenol below the regulatory level of 0.006 milligrams per liter (mg/L) in groundwater.
Because regulatory levels of proscribed chemicals are already low (and falling), analytical instrument sensitivity can challenge phase 2 brownfields assessments. In Texas, protective concentration levels (PCLs)— concentrations above which follow-up action is often required—tax and stretch the capabilities of today’s instrumentation and methods. For example, the PCL for vinyl chloride in groundwater is 0.002 mg/L, and the value for ethylene dibromide is 0.00005 mg/L. “Sometimes we have difficulty finding methods and analytical labs capable of achieving the sensitivity levels we need to reach,” Strahl says. “Laboratories are continually improving their methods to achieve better detection and quantitation limits and to generate data of known and documented quality, but limitations on analytical technologies can be a factor.”
The EPA has established, and is encouraging the use of, the performance-based measurement system (PBMS) in some programs to allow laboratories flexibility in method selection, including methods not found in EPA-published manuals. To be valid, the quality of PBMS data must equal or surpass the quality of data generated by a standard reference method. “Many laboratories are beginning to implement PBMS,” according to Strahl, “but it can take a lot of time.” Issues the laboratories must deal with on a regular basis include matrix interference, especially when the regulatory level is low. The PBMS approach allows the laboratory to work with the method to resolve some, if not all, of the matrix interference.
Headache Miscellany
Brownfield assessment and remediation are large, complex, wide-area problems with issues that most lab managers don’t ever consider.
Negotiating site access is the biggest headache for John Hargraves, regional manager at PM Environmental (Decatur, AL). “Bringing property owners to a certain comfort level regarding what is involved, and what their responsibilities will be under the assessment and remediation proposals, is a challenge.”
Some owners are more educated about the concept, and readily agree to terms with engineering and municipalities. But others find themselves facing the process at the wrong time and from the wrong perspective. Owners’ hands may have been forced by governments, or their main goal is to sell the property quickly, and they do not understand that the sale cannot proceed without an assessment.
“Many owners lack that critical motivation,” Hargraves adds. “When we approach them we try to present the advantages to them of assessment.”
PM Environmental does its own assessment, planning, and remediation, but outsources analytical work to contract environmental laboratories. Labs must hold appropriate state certifications, including for specific analytes, for their work to be considered valid. Which lab gets the business depends on the brownfield location and the PM Environmental office responsible for the project.
Finding an owner at all is not always straightforward. With most long-abandoned facilities built in the first half of the 20th century, taxing authorities become the owners of last resort. In some instances this facilitates assessment and cleanup. States and cities have rules in place and incentives to move projects along at minimum cost, for example, by making brownfield sites attractive to developers. Municipalities also use their imagination in this regard, especially with the possibility of returning properties to the tax rolls.
Bankrupt companies have no incentive to participate in brownfield projects, and generally make unreliable partners. Then there is the gray area of companies in a variety of financial situations that prefer to clean up their site themselves and not participate in brownfield programs.
Regulatory issues are most easily avoided by long-term planning and communicating with stakeholders, particularly government officials and regulators. Engineering firms that do not give themselves enough lead time to answer critical questions may find regulators stepping in and stopping a project abruptly. “This usually occurs when regulators weren’t made aware of the full picture at the front end,” Hargraves says. “But even some states are more flexible than others. Engineering firms have to know each state they operate in, and how best to plan for how regulators work.”
Surprise!
Environmental contract companies should be prepared for surprises, both pleasant and unpleasant. “There are surprises everywhere, but they can go both ways,” Hargraves says. The presence—or absence—of underground storage tanks constitutes a major source of unexpected revelation. More tanks than anticipated, particularly those holding dangerous chemicals, are a main reason for cost overruns.
Sites that Hargraves terms “scary-looking” sometimes require only straightforward or no remediation, while facilities that appear clean on initial inspection may turn out to be disasters after the drilling, sampling, and analysis results come back.
"Sites may appear to have environmental impact, but they don't. That's why we do these assessments," Hargraves says. PM Environmental does not normally encounter difficulty in hiring those with the appropriate skills for remediation work, but here is where geography plays a role. Depending on the geographic location, finding subcontractors with the right credentials may be difficult. Lacking experience with companies in a particular region exacerbates the problem. “Finding the right crew might take doing research and asking questions.”
Geography also affects how involved PM Environmental becomes with a job, or whether it takes it on at all. The firm often sends engineers to a site for a walkthrough and initial evaluation, but subsequently outsources nonsupervisory work to subcontractors. It comes down to resource allocation, according to Hargraves. “When the customer is just looking for numbers, we have certain restrictions. Our travel time is so expensive, we can’t compete with local bids. We’re already at a disadvantage because [the cost for] their mobilization efforts will be so much lower than ours.”
Access to funding can haunt both public and private brownfield projects. “Minimizing costs is a top priority,” Latham says.
He explains that the first step in a public brownfield project consists of obtaining a brownfield designation through the applicable state or municipality. The project then waits in a queue for funding, which surprisingly is more difficult to come by for a public project than for a private site. “It’s not uncommon to begin work under a grant given to a municipality, then stop because the money runs out.” The project then reenters the applicant pool in search of additional resources.
Some engineering firms have entered the grant-writing business to help smooth out rough financial circumstances. These companies have become savvy in the art of selling states and local nonprofits on the cause of turning blighted, contaminated, hazardous, unoccupied public sites into oases of recreation and commerce. “Communities often jump on board, but convincing them takes creativity,” Latham says.
The situation is somewhat more complicated for sites intended for strictly commercial development, such as a large corporate campus. Here the government tries to lure corporations or developers with existing infrastructure (water, sewer, electric, transportation) and nearby amenities to convince them of the value of the location—if they will only invest in rehabilitating it. Potential buyers acquire the property at a deep discount, often with tax breaks added on. But the environmental cost comes directly off the bottom line. Addressing contamination issues is not an insignificant hurdle.
Florida’s brownfield program is “very organized” and “top tier in this regard with its case review and documentation,” Latham says. “The Florida DEP does a great job in approving funding in a timely fashion, generating cleanup documents, and laying out the remediation plan from A to Z.”
Contamination may reach depths of only several feet at many sites, or may remain inert within soil for decades. Replacing soil with clean fill often solves the first issue, although soil that is removed must be incinerated. In some instances merely paving the site, creating a parking lot on some of it, or installing deep concrete flooring (think big-box stores) renders a site safe for human habitation. These are among the sites most easily redeveloped at the lowest cost.
“States have built cleanup tax credits and other perks into programs,” says Geosyntec’s Latham. “These incentives make economic sense because everyone agrees that in the end the property and neighborhood improve, and [they] often lead to the entry of a profitable, tax-paying enterprise.”
Sometimes all the sampling, analytical work, planning, and funding result in a dead end. As Maria LeBron, assistant division director for remediation at TCEQ , notes, “Cost-effective cleanup technologies may not exist for some sites, because when the assessment and the feasibility study are completed, cleanup of the site may not be practical based on the site conditions and technologies currently available.”