Part-timers are part-timers by choice. Governments don't typically make any distinctions, and the water/sewer rates are a government function, not an OPA function.

 LOT of money has been paid for water and sewer lines

The total yearly costs include for infrastructure cost, sewage treatment, water treatment, salaries, trucks, etc. etc. The service area prepares a budget every year and it is approved by the County Commissioners. Have you seen it so as to know why the numbers are what they are?

Anyway, given your position, maybe you should also ask the county for a reduction on your other taxes as well. Good luck.

If I were to purchase a second home say in the greater Baltimore area would the county give me special tax consideration because I was a part-timer? I doubt it. Does Ocean City give special consideration to part-timers? I doubt it.

As an aside, what you probably don't remember is the sewage moratorium in Ocean Pines when those who owned lots could not even build a home -- full-time or part-time.