Jan's sister lives in a palatial place oop int' 'ills near Burrrnlih. They are so far away from civilisation they have neither mains water nor sewerage. Further up the hill is a shallow pit fenced off from the sheep and that's where their water comes from. There's a large and expensive treatment plant in the house to make sure it's suitable for human consumption - although they tend to buy vast quantities of bottled water from the supermarket for that purpose. I do recall, when they had a simple ultra-violet light to treat the water, washing my hands in it and the soap forming a very pretty blue scum around the sink.
Down the hill, buried in the farmer's field, is a soakaway for all the sewage. They have lived in that house for well over 20 years and haven't had a problem.