Pure water is used for dialysis. Water should not contain contaminants like particles, trace elements, chemicals, organic matter, bacteria or bacterial fragments. Since this water is in direct contact with the blood stream any impurities in the dialysis water has the potential to pass to the patient. Dialysis water treatment should remove chemical and microbial contaminants to allowable limits. Purified water for dialysis is then distributed to individual dialysis machines to produce dialysate solution that remains free of contaminants.