OWASA said Tuesday it is increasing the release of water from hydrants throughout the utility’s 380 miles of pipes which began last week in the continuing work to address taste and odor in drinking water.
The musty or earthy taste and odor reported by customers since mid-May results from algae in the Cane Creek Reservoir and University Lake. OWASA’s treatment process removes algae from drinking water, but some organic compounds may remain and may cause a musty or earthy taste and odor.
Regular testing of drinking water throughout the water system continues to show that OWASA water is safe to drink and use for all purposes.
Water leaving the Jones Ferry Road Water Treatment Plant in Carrboro has close to normal taste and odor, but water with taste and odor remains in the water system. Releasing water from hydrants, or “flushing,” accelerates the replacement of water that has a noticeable taste and odor with water that has a better, less noticeable taste and odor. However, the transition will be gradual and customers may continue to experience taste and odor for some time. We ask for your continued patience and understanding as we work through these difficult and persistent issues.
OWASA sought the assistance of the Town of Cary’s water laboratory, which used a gas chromatograph-mass spectrometer to identify MIB (2-Methylisoborneol) as the organic compound which is the primary source of taste and odor in OWASA water. The treatment changes OWASA has taken to remove taste and odor from MIB have been appropriate according to other experts in water treatment with whom OWASA has consulted.
While it is not a health concern, some people can notice taste and odor caused by MIB in drinking water at levels as low as 5 parts per trillion. One part per trillion is like one drop of water diluted into 20 Olympic-size swimming pools.
“We deeply appreciate the use of the Town of Cary’s specialized equipment and assistance” said Katie Harrold, Laboratory Supervisor.
On May 12, OWASA increased the use of powdered activated carbon at the Jones Ferry Road Water Treatment Plant to help resolve taste and odor.
On May 25, OWASA began adding a chemical (sodium permanganate) to help remove taste and odor in water being pumped from the Cane Creek Reservoir.
OWASA and other utilities routinely use powdered activated carbon and permanganate in water treatment.
OWASA will keep the community informed. OWASA invites customers to contact OWASA’s laboratory staff at the Jones Ferry Road Water Treatment Plant at 919-537-4228 or firstname.lastname@example.org for more information about taste and odor or to request to have their water tested at no charge.