Pittsboro, NC – On Tuesday, May 10, 2022, routine sampling of the water entering the Town of Pittsboro system revealed a higher-than-normal amount of free ammonia present in the sample. Upon discovery, Town staff reached out to the City of Greensboro to find out if there had been a release of contaminants. City of Greensboro staff notified the Town that between 62 and 106 gallons of Bardac 208M, a cleaning and disinfecting chemical, had spilled at a manufacturer last Monday (May 2nd, 2022), which the city could not process before entering the river. Upon this notice, Town staff took a sample of raw water from the river and found a free ammonia level of more than 2.5 mg/L. Out of an abundance of caution, Town staff shut down the water plant to stop the flow of water into the town system to attempt to allow the free ammonia to pass the Town’s water intake.
The water plant remained offline throughout the day, and town staff continued sampling. The samples taken from the finished water leaving the Water Plant showed 0.93 mg/L of free ammonia at its highest. Town staff also drained the water from the sediment removal basins and clear well to remove, as much as possible, the impacted water before it entered the system.
Test results taken this morning indicate a lower amount of the substance in the river. Finished water entering the system showed a result of 0.10 mg/L, and numbers within the system were normal (at or below 0.01 mg/L).
For Chapel Ridge, test results this morning showed concentrations of 0.28 mg/L at the Booster, 0.09 mg/L at the tank, and 0.05 mg/L within the distribution system.
There is no EPA limit for free ammonia in water systems. Higher levels of free ammonia can lead to poor taste and odor for water, but concentrations the Town is experiencing do not have adverse effects on the health of water consumers. If the water has a high level of free ammonia, you are likely to experience a moldy or earthy taste or smell when the ammonia removes too much oxygen from the water. For more information regarding the effects of free ammonia, please CLICK HERE.
Town staff will continue to sample and closely monitor the situation and issue another release as soon as we have more information about this event.