The biggest risk is that it was never designed to hold water system pressures. It will probably bulge, distort, or split when subjected to pump system pressures.: I am rehabilitating an old well system in which the previous owner : installed rigid ABS DVW pipe. I would like to know if DVW pipe can safely : carry fresh water, or are there health risks by leaving it as part of the : water system? It has never been used in a DVW capacity; its been spliced : to a flexible water pipe. Thank you.