Usage of zip code to define application and sales locations created a number of problems. Zip codes represent postal delivery locations. Large wilderness areas or farmland may have few if any delivery points. Since mail is not delivered to these locations, they are technically not located in a zip code. Determination of what zip code to report for an application or intended application in one of these locations was problematic for the businesses and applicators.
Some zip codes represent more than one contiguous location.
Without more accurate address data than is currently collected, there is no way to divide application or intended application quantities between the separate locations represented by these zip codes. Data reported for selected zip codes have not been reported under that zip code. These selected zip codes are unique to a location and could be used to identify where an application or intended application occurred. Identification of the specific location of a pesticide application is not allowed by the Pesticide Reporting Law. In these instances, if the zip code was located entirely within a single enclosing zip code, the data were reported under that enclosing zip code.