Public Health Considerations for Improperly Identified Reclaimed Water

For more than 30 years, utilities have been using purple pipe to designate high-quality municipally or privately treated domestic reclaimed water. Reclaimed water might be of different quality from one community or state to another, but uniformly, a utility oversees and provides control of the quality of reclaimed water that meets regulatory standards for the intended use. Utility workers and reclaimed water users are acquainted with the purple pipe designation and have come to expect consistent high-quality water that–in urban applications–has usually been filtered and received high levels of disinfection, producing water with low bacteriological content and clear appearance (color and turbidity). Recently, property owners have started to recognize onsite reuse of non-utility produced multiple source waters as a move to increase conservation of potable supplies, be environmentally responsible, and potentially gain Leadership in Energy and Environmental Design (LEED) points for commercial developments.This movement has led to changes in plumbing codes and state regulations to allow use of such non-utility produced water on a private property. The result is distribution of untreated or minimally treated wastewater on private property in purple pipe for indoor (toilet flushing) and outdoor (surface irrigation) applications that were previously not permitted. This accentuates the public health risk of exposure to untreated or undertreated wastewaters potentially containing high bacterial population counts (including pathogens), particularly since users may trust that the purple pipe carries highly treated, municipally controlled reclaimed water.This paper identifies efforts over the last 3 years to resolve onsite pipe color codes, public health concerns, and actions being taken by individual utilities and state public health organizations to influence proper public health protective measures.