Most industrial operations discharge storm water into a receiving water body from a single point of discharge from the permitted area. The water leaving the site will have many chemical constituents, some of which are considered to be pollutants (or contaminants) by statute. States differ in their water quality standards, but all require permit compliance monitoring. How the reported results are analyzed can make a huge difference to the permit holder’s operations. This newsletter uses a real example to explain how wrong analytical results can result in unwarranted financial penalties.