The U.S. Department of Defense (DoD) is responsible for hundreds of sites with potential drinking water contamination. The process of measuring lead contamination at these sites is both costly and time-consuming. The purpose of this ESTCP project was to validate the field performance of the MetalyzerTM 5000, a new instrument that measures lead concentrations in water. Use of the MetalyzerTM 5000 could reduce analytical costs, speed DoD compliance with drinking water standards, and permit a more rapid, thorough sampling procedure. The MetalyzerTM 5000 has been validated for lead and a new project is underway to validate its performance in detecting other metals.
The MetalyzerTM 5000 measures toxic metal concentrations in water using an electrochemical technique called Potentiometric Stripping Analysis (PSA). PSA is capable of analyzing multiple metals simultaneously and calculating subparts-per-billion concentrations in on-the spot measurements of a building's plumbing system, in reservoirs and harbors, or anywhere contamination is a concern. The device is controlled by a computer and can be left alone to monitor water supplies or waste streams for extended periods of time. Such accuracy and flexibility could allow DoD to quickly characterize sources of water contamination at installations and more rapidly bring them into compliance with Safe Drinking Water Act regulations. Rigorous testing of the system was conducted at the San Diego Naval Submarine Base, and the MetalyzerTM 5000 is commercially licensed and began commercial production in 1998.
The main strengths of the MetalyzerTM 5000 include instantaneous results, accuracy, sensitivity, versatility, and simplicity. During the demonstration, correlation between PSA and the standard graphite furnace atomic absorption spectrometry (GF-AA) analysis was 95 percent. The traditional laboratory analytical cost of a single measurement for lead in drinking water ranges from $20 to $75. In a cost comparison of GF-AA analysis and PSA analysis, the GF-AA cost per sample was $64.37 while the PSA cost per sample was $15.64. The capital cost of the Metalyzer is $25,000 for over 20,000 samples. The capital cost breakdown is $1.25 per sample compared with the weighty GF-AA's $50.00 cost per sample. Unlike laboratory tests that typically take two to four weeks to process, this system completes its analysis in approximately 15 minutes - dramatically reducing the time required to complete an accurate site contaminant characterization.
Those responsible for testing drinking water supplies, distribution systems, and effluent waste streams will benefit from this simplified method through lower analytical costs and rapid response times. If the MetalyzerTM 5000 gains Environmental Protection Agency (EPA) acceptance for drinking water monitoring, a process currently underway, DoD could benefit from greatly simplified regulatory compliance procedures.
Use of the MetalyzerTM 5000 would allow DoD facilities to quickly and inexpensively monitor drinking water supplies in order to comply with regulations. The MetalyzerTM 5000 is commercially available, but the complexity and length of the process of gaining EPA approval for new monitoring procedures prevents DoD from immediately reaping the potential benefits of using the technology. (Project Completed - 1998)