Here's a drinking water warning for the Windward side.

The Board of Water Supply says water samples from the Waihee Tunnel tested positive for E. coli bacteria. The Waihee Tunnel serves communities from Kahana Valley to Waimanalo.

E. coli indicates the water may be contaminated with human or animal waste. This can cause health effects like, headaches or diarrhea.

The Board of Water Supply says the water is safe to drink because it's continuously disinfected before it reaches customers.