My mother-in-law has problems with her household pipes running from her sink to the septic tank, for they are 40+ years old, and full of mineral deposit, and rust. It is like running two inches of water through a half in pipe, although it is only the hot water, and not the cold. Any help, possible solutions would be very helpful, for she has had a few look at it with astronomical offers, and she is 71 yr’s old with a fixed income. Thank you