The City of Bartlesville is assuring residents that drinking water remains safe, despite temporary discoloration that may appear as the City performs routine circulation and maintenance on the water distribution system.
“Earlier this week, the City implemented temporary changes to water chemistry to improve the overall health of the water distribution system,” said Water Utilities Director Terry Lauritsen. “While the water is still safe to drink and use as normal, these changes can potentially impact the appearance of the water in areas that are served by older water lines.”
This discoloration is cosmetic only. The water remains safe to drink and use as normal.
Why This Is Happening
Bartlesville’s raw water naturally contains relatively high levels of dissolved calcium. During treatment, a small amount of this calcium is intentionally left in the water to form a thin protective scale inside pipes. This scale helps prevent metals from leaching into the water and works alongside the City’s primary corrosion‑control treatment, a polyphosphate additive.
Over many years — especially in older metal pipes with cement linings — natural mineral deposits can build up inside these pipes. It can also create additional surface area where a harmless biofilm can form, something present in water systems worldwide. While safe, this buildup can affect taste or odor during warmer months if not managed.
What the City Is Doing
To improve water quality and system performance, the City has recently made slight adjustments to water chemistry, including lowering the pH from approximately 8.2 to 7.6. This change reduces the rate at which scale forms, helping remove excess buildup in older pipes. The water remains within safe, scale‑forming conditions, as measured by the Langlier Index.
In addition, the City performs annual fire hydrant flushing — running water at high speeds through pipes — to physically remove accumulated deposits. This work is typically scheduled in late winter or early spring, when warmer temperatures reduce the risk of ice on roadways.
However, Lauritsen said these measures are becoming less effective for areas served by older water pipes.
“Although we have a long-term program in place to replace these aging water lines, the work is scheduled over the next 10 to 15 years,” said Lauritsen. “In the meantime, we have made slight adjustments in water chemistry to lower this scale-forming potential, which combined with system flushing, will reduce buildup, protect pipe integrity and maintain adequate fire flow capacity.”
What Residents May Notice
- Temporary discoloration in some areas, especially where older metal pipes are present
- Cloudy, yellowish, or brownish water caused by loosened mineral deposits
- Short‑term changes that typically resolve within a few days
Residents with plastic service lines are unlikely to experience any discoloration.
“The discoloration is the dislodged scale and biofilm that has formed on the pipe,” Lauritsen said. “These components do not pose any health risk, but influence our perception of the safety of the water. While crews have flushed general areas that are known to have this older water pipe, more targeted flushing may be necessary in areas that have more of this scale present.”
If residents notice any water discoloration, call the water department at 918.338.4104 or after hours at 918.338.4055 so that crews can flush the impacted areas.
Commitment to Safety
“Even when discoloration occurs, the water remains safe,” said Lauritsen. “These maintenance activities are essential for keeping the system healthy and ensuring long‑term reliability for all Bartlesville residents.”
For more information, residents may contact the Water Utilities Department at 918.338.4104 or visit www.cityofbartlesville.org.