Many projects or operation involve geochemistry: chemicals in water, sediments, soils, or rocks. Most people are not concerned with chemicals like magnesium sulfate or sodium chloride, but they are seriously concerned with toxins that effect human and environmental health. These toxins can be inorganic metals such as arsenic, cadmium, and zinc or organic compounds such as polychlorinated dioxins, furans, biphenyls, and pesticides. These toxins are most commonly present in very low concentrations, frequently not detectable. They are censored data.
The consequences of incorrectly analyzed and interpreted geochemical data can range from fines through remedial actions to cease-work orders. It is important to appreciate the potential for environmental and economic harm, to recognize when geochemical data are incorrectly analyzed, and understand how they should be analyzed.
This paper will not teach you statistics or ecology, only to recognize how nondetected chemical values should be analyzed in permit applications and compliance reports.