In the 1960's, farmers began to rely on chemical pesticides to control insects, weeds, and grasses. During the 1970's, ag chemical usage increased at an exceptionally rapid rate as more and more producers incorporated chemicals into their agronomic production practices. With this increase in demand, numerous local input and supply firms added ag chemicals and chemical application services to their product lines. Washing and mixing sites sprang up to service the growing demand for ag chemical application services. Little thought was given to the effects (either short term or long term) that accumulating concentrations of chemicals at these sites might have on ground water supplies.