Many of the EPA test methods used for air monitoring were developed decades ago when emission levels were orders of magnitude higher than they are today. We now measure many pollutants at or near the detection limit of these methods. Method biases that were once insignificant compared to the pollutant concentrations of 40 years ago are now very significant at today’s extremely low levels.
Increasingly, our clients have been asking for better quantification of method performance at these low levels. Not only do they want to know “How low can you go?” but also what the method biases and uncertainties are at or near the method detection limit.
In response, Clean Air has conducted many method assessments both for clients and for trade organizations such as the Electric Power Research Institute (EPRI). Some of these are simply a review of existing literature to identify potential method biases and other issues. Others involve detailed uncertainty analysis and development of best practice standards such as the report “Filterable Particulate Matter Stack Test Methods: Performance Characteristics and Potential Improvements” we prepared for EPRI. Still others involve extensive laboratory testing with our Flue Gas Simulator such as the work we did on low level HCl measurement “Laboratory Evaluation of EPA Methods 26 and 26A for Analysis of Halogens and Halides in Stack Gas” also for EPRI.
Sometimes, we find that an existing test method simply doesn’t work for a particular application. In those situations, we have developed alternative or modified test methods. This may involve alternative sampling approaches and even custom sampling equipment. We also work with our in-house laboratory team as well as recognized experts in the field to develop alternative analytical approaches that provide better precision and lower detection limits.
Whether your need is for a better understanding of the data quality from an existing test method or development of a new method Clean Air can help.