Environmental Standards from a Statistical Point of View

The most common way for governments to protect the population from environmental insults, such as air or water pollution, is to set a standard. Most standards consist of two parts: a cutoff value beyond which health risks are deemed unacceptable, and an implementation rule, specifying how compliance with the standard will be ascertained. We illustrate the concepts with two US environmental standards, one for air pollution and one for water pollution. From a statistical point of view, the US EPA implementation rules in these examples have poor performance characteristics. We present a statistician's first stab at improving the implementation. Complications such as spatial and temporal dependence, and network design bias, are discussed.