On-site Analysis: A Rapid, Cost-effective Alternative for Site and Waste Characterization
Environmental laboratories spend enormous amounts of time and money in an effort to maximize analytical efficiency without compromising services or increasing fees. In an industry where time is money, low costs and quick turnaround are factors desired by industrial/hazardous waste generators and remediation/site investigation firms when selecting fixed laboratory services.
However, even the most efficient analytical facility can expect occasional delays in production. A lack of instrument availability, for example, can lead to a hefty backlog of samples. Quality control samples must be analyzed with each batch and, when QC results fall outside the established criteria limits, the source of the problem must be identified and corrected, and the samples must be reanalyzed. Instruments and laboratory information management systems (LIMS) require routine maintenance and occasionally experience unexpected downtime. Even under optimum operating conditions at the fixed laboratory, it still requires some amount of time to ship the samples there. All of these variables can separately or in concert serve to delay the reporting of results. Project costs accumulate quickly when remedial contractors and disposal firms are kept waiting for work to proceed pending the outcome of critical sample data.
In recognition of the need for timely analytical results, Environmental Resources Management of Exton, Pa., has developed ERM-Field Analytical Services Technology® (ERM-FAST®), a fully self-supported mobile field analy-tical unit which brings laboratory-quality instrumentation, methods, and degreed chemists to the field to provide real time analytical results for a variety of targeted analytes in solid, liquid, and air matrices. This article describes the applicability of on-site analysis as an alternative to fixed laboratory services for a wide range of projects.
Advantages of Utilizing a Mobile Analytical Unit
The advantages of utilizing a mobile analytical unit are threefold: results are available in real time; the analyses can be customized (greater flexibility); and the total costs incurred can be less than that for comparable fixed laboratory services. The ERM-FAST service has performed on-site analyses with EPA approval on RCRA RFI and CERCLA RA projects. This service is capable of providing organic and inorganic data within an hour after arrival on the site. All EPA-regulated volatile organic compounds (VOCs) and semivolatile organic compounds (SVOCs) including pesticides, PCBs, and petroleum hydrocarbons can be detected using transportable gas chromatograph/mass spectrometer (GC/MS) instrumentation. Additionally, any non-regulated organic compounds can be identified by referencing sample mass spectra to the NIST mass spectral database of over 75,000 organic compounds. Target Analyte List (TAL) metals (except beryllium) can be determined in solid matrices using an Energy Dispersive X-Ray Fluorescence (EDXRF) spectrometer. Unsaturated VOCs (aromatics and alkenes) can be determined by headspace analysis utilizing a portable gas chromatograph with photoionization detection (GC/PID).
These instruments, housed in a specialized vehicle, are powered by rechargeable batteries, house current (through shoreline), or from large onboard gasoline-powered generators. All of these capabilities combine to provide an arsenal of services dedicated to performing sophisticated environmental analyses in the field, with real-time results.
Timely Results, Analytical Flexibility
Real-time data affords project management the luxury of making timely decisions which can help minimize a site investigation, remedial activity, or waste characterization project and associated costs. For example, total project costs for contractors (drillers, excavators) can be limited to one mobilization as field screening data can be used to rapidly and thoroughly delineate a contaminated site. A field screening unit may also perform many analyses covering a wide variety of sample locations and matrices in an effort to locate hot spots or investigate areas of concern. Used in this way, sample results obtained in real time can serve to drive the project toward its intended objectives in a very timely manner.
With fixed laboratory operations, for specific instances such as site restoration and hazardous waste characterization, agency regulations may require the use of federally promulgated methods such as those in USEPA SW-846 and CLP programs. These method protocols must be rigidly followed by the fixed laboratory with tight quality assurance/quality control measures and analytical performance criteria. These methods are intended to provide the highest level of data quality since the fixed lab results are usually relied upon as legally defensible; however, these regulatory methods may extend beyond the data requirements of many environmental projects.
Data quality objectives for on-site analyses can be structured to meet the intended level of usage of the data. The analytical design is usually configured such that the methods selected are suited to the requirements for utilizing the data.
For example, a large number of samples can be analyzed on site very quickly with a minimum of constraints on data quality. Concurrently, a percentage of the total number of samples can be selected with confidence for fixed laboratory confirmation. Such flexibility in analytical procedures lends itself to "yes/no" qualitative investigations as well as "pass/fail" analyses for determining sample concentrations near a targeted cleanup level. If required, higher levels of data quality can be achieved on-site by performing modified SW-846 methods (such as 8081, 8021, 8260, and 8270), implementing a Quality Assurance Project Plan with site-specific Data Quality Objectives, and providing extended and electronic data deliverables in the field.
Real-time results and analytical method flexibility are advantages to on-site screening which facilitate the judicious selection of a limited number of samples to be sent to a fixed laboratory for confirmatory analyses. Typically, a minimum of ten percent of the total number of samples screened on-site are submitted to the fixed lab. The total analytical costs for a large site investigation or remedial activity involving hundreds of sample locations requiring analysis for multiple fractions can be greatly reduced by employing a mobile analytical service in this fashion.
Other Applications for On-Site Analytical Services
In addition to the site investigation and remediation applications for mobile analytical services mentioned throughout this article, unlimited opportunities for field screening present themselves throughout all levels of industry.
In cases where a large base of sample data can be acquired and used purposefully for real-time decision making, process stream optimization, fugitive emissions, waste stream characterization, and regulatory compliance, an on-site analytical unit can provide a rapid, cost effective, and flexible alternative to fixed laboratory services.
David R. Catherman is the ERM-FAST technical manager for Environmental Resources Management in Exton, Pa.