My Township in Pa. also requires a 3 year max pump out and inspection with proof required. They started that about 10-12 years ago. I have a small 500 gal. tank, easy access lid and get a once a year pump out. Household of two. The cost seems to vary, but it's usually $150. I'm sure it will be higher this year. At the time of the that pumping ordinance, two of the larger unincorporated villages were forced onto new public sewer systems. The largest town is a borough not part of the township. They have their own sewer system. I once lived in another borough for 8 years. That was the only time in my long adult life that I ever paid a sewer bill. By the time I left there, 17+ years ago, the sewer bill had already gone crazy. As I recall, they demanded payment for the entire year in advance in Jan. It used to aggravate me that I paid the same sewer rate as a one person home that a 6 person home paid.
Some years back a local Amish farmer refused to comply with the pumping and the fines increased exponentially. When it got up to something like $120k, a friend of his negotiated on his behalf and got it reduced to something like $80k. Not sure if he paid it, but he must have.
I'm dreading the cost of them coming through with public sewer. There's a 7 acre lot beside me that I know will be eventually sold and broken up when the elderly gentleman passes. At 1/2 acre plots that's 14 houses, or if it's the normal 1/4 acre people get that can be 28. Not looking forward to that mess...