yep same here , but have it emptied every 2 years , so about say 100£ quid per year and get our water from wales , it always tasted bit like old mutton to me as well haha , only joking lol,
do'es it need emptying that often bird ,ive got two septic tanks one for a four bed farmhouse that's never been emptied since I bought the house 11 years ago and one that services two barn conversions that I have not emptied yet and that has been in 6 years and in my last house was there 15 years and did not empty it once