Always try to split sample with the agency. In other words, take a portion of the sample they are collecting and have this analyzed by a different analytical laboratory.
Always ask for and carefully review quality control data for analytical results received from the agency and the analytical laboratory of your choice. In particular, examine matrix spiked sample results and percent recoveries. These values are critical for any meaningful interpretation of data.
When collecting field data for volatile organics, prepare a field blank and trip blank to provide indication of any field and laboratory contamination, respectively.
Discuss results with the analytical laboratory, especially quality control and quality assurance protocols.
All labs are not created equal! Unfortunately, too many labs simply record quality control data without actually using it.
