Which statement defines a public water system?

Which statement defines a public water system?

• A. It has at least 15 service connections OR regularly serves 25 individuals daily (60 days a year)
• B. It serves more than 1000 customers
• C. It supplies non-potable water
• D. It is owned by a private company

Answer: (A)

The key idea is the regulatory threshold that makes a system a public water system. A system becomes a public water system if it provides drinking water to the public and meets either of these size criteria: it has at least 15 service connections or it regularly serves 25 individuals per day for at least 60 days in a year. This threshold matters because it determines whether the system falls under drinking-water regulations and monitoring requirements, regardless of who owns it. So why this one is the best choice: it exactly matches the official criteria used to define a public water system—the two size-based conditions (15 service connections or 25 people daily for 60 days). The other statements aren’t defining features: serving more than 1,000 customers isn’t the cutoff, the water being non-potable disqualifies it from being a drinking-water system, and ownership by a private company does not, by itself, determine whether a system is public.

The key idea is the regulatory threshold that makes a system a public water system. A system becomes a public water system if it provides drinking water to the public and meets either of these size criteria: it has at least 15 service connections or it regularly serves 25 individuals per day for at least 60 days in a year. This threshold matters because it determines whether the system falls under drinking-water regulations and monitoring requirements, regardless of who owns it.

So why this one is the best choice: it exactly matches the official criteria used to define a public water system—the two size-based conditions (15 service connections or 25 people daily for 60 days). The other statements aren’t defining features: serving more than 1,000 customers isn’t the cutoff, the water being non-potable disqualifies it from being a drinking-water system, and ownership by a private company does not, by itself, determine whether a system is public.