Public Notification - City of Pflugerville Monitoring/Reporting Violation
January 14, 2020
Manville WSC is mandated by the state to perform routine water sampling throughout our system monthly, including the water received from the City of Pflugerville, and has had no quality issues. Because the City of Pflugerville is wholesale water provider to Manville Water Supply Corporation PWS ID TX2270033, this public notice is being provided to our customers to meet TCEQ’s public notification requirements.
City Violation Notice;
The City of Pflugerville received a Notice of Violation on January 10, 2020 from the Texas Commission on Environmental Quality (TCEQ) as the result of a computer programming error at the Surface Water Treatment Plant. As a result of the computer error, during a period of approximately 2.5 hours, the filtration membrane had a decay rate of .35 pounds per square inch (PSI) per minute which exceeds the state and federal guideline of .33 PSI per minute.
During a routine Membrane Integrity Test (MIT) on December 24, the Surface Water Treatment Plant alert notification software incorrectly indicated that a plant filtration membrane’s integrity was within acceptable levels and “passed” the automated test. As a result of the computer programming error, a filtration membrane that failed its MIT remained in service producing water for a period of 2.5 hours or less.
While reviewing the daily reports approximately 5 hours later, the City’s water operator discovered the computer programming error. The filtration membrane was immediately shut down, assessed and manually tested. The membrane was put back online after a successful retest showed all filtration measurements within state and federal guidelines.
As a result of this MIT computer programming error, less than 2% of the City’s daily gallon water usage, approximately 80,000 gallons out of six million produced that day, was potentially impacted. There were no issues indicated in other filtration or water treatment protocols. Immediately following this incident, the turbidity level, which is measure of the clarity of the water and a secondary measure of the membrane effectiveness, was compliant with TCEQ, state and federal requirements.
Additional information, frequently asked questions and City water reports are available online at www.pflugervilletx.gov/water. If you have questions regarding this matter, you may contact City Manager Sereniah Breland at 512-990-6115.
MWSC is an equal opportunity provider and employer.