Microbiologists study the life (biology) of organisms that are too small to see without a microscope. Some of these microscopic organisms can cause serious or deadly diseases in people. Keeping these organisms out of the water supply is a major concern for water agencies. Microbiologists use microscopes, chemical tests, and other diagnostic techniques to screen the water for dangerous microorganisms. Their duties include:

• conducting microbiological and chemical tests for monitoring and controlling water quality in reservoirs, lakes, treatment plants, and the drinking water distribution system;
• isolating and identifying bacteria found in the water;
• interpreting and evaluating the results;
• preparing technical reports about their findings;
• developing new and improved biological and microbiological analyses;
• keeping up to date with ever changing state and federal regulations.