Do they really mean town sewer hookups instead of septic? If so my guess is that the real reason is they just don’t want people living in the countryside. I looked it up and Costilla County is only 3,500 people in 1,200 square miles. It looks to be more or less empty desert. No way are they going to run sewer and water lines across that large an area for so few people. 100% of my town is on septic and private wells, even in the village itself.