It’s no secret in 2018 that dental unit waterline (DUWL) cleanliness is important. Every trade publication, tradeshow and continuing education summit offers some sort of crash course on the subject. The bacteria problem is widespread and omnipresent regardless of the practice type or equipment employed. If it runs water, the potential to be a problem exists. Given their nature, dental waterlines will grow bacteria beyond the 500 colony forming units per milliliter drinking water standard without some level of shock and maintenance.