The rule applies to public water systems that use surface water or ground water under the direct influence of surface water and serve at least 10,000 people.
(The rule; applies; to public water systems) (public water systems; use; surface water or ground water) (public water systems; serve; at least 10,000 people)
The rule public water systems public water systems
applies use serve
to public water systems
surface water or ground water
at least 10,000 people