Final answer:
Septic tanks must be a minimum of 100 feet from water supply wells to prevent contamination. This regulation is crucial for maintaining the safety of the water supply in areas where homes use individual septic systems for sewage treatment.
Step-by-step explanation:
The question asks for the minimum distance that septic tanks must be from water supply wells. This is an important consideration in environmental health to prevent contamination of the water supply. Septic tanks are part of an individual sewage treatment system used where centralized sewage systems are not available, and they include a septic tank and a drain field. When a septic system malfunctions, it can lead to water pollution, which is why the distance from water wells is regulated. The correct answer to the question is c. 100 feet. This distance is the minimum recommended to prevent potential contamination of the water supply by the septic tank system.