 At the present time, no such flights are authorized from the airport; in fact, the only hazardous materials presently used and stored at the airport are those associated with the underground gasoline fuel storage tanks.Surface runoff and groundwater flow is generally to the northeast toward the San Joaquin River.Rinse water from maintenance operations flows into a storm drainage system and pesticide chemicals, which have previously contaminated soil and groundwater on the site, may have been introduced to the environment via this route.