If so, make sure the proper authorities know. Look in your phone book under county or city government for the agency responsible for water quality. It may be called the department of the environment. Call information for the city or county if you cannot find the address. Or try the Internet.
Many counties have extensive Internet information on their agencies.
Have the students write letters reporting their findings and asking if there are programs in place to improve water quality. Research the sources of nitrate in drinking water in your area by contacting local water suppliers, agricultural agents, environmental organizations, etc. Collect information and share it with each other. Have student groups write informational material specific to your area and distribute it to parents and others who can help reduce nitrate use. Have students talk to schoolyard maintenance people.