HomeMy WebLinkAboutIR 9711 INFORMAL REPORT TO CITY COUNCIL MEMBERS No. 9711
To the Mayor and Members of the City Council March 3, 2015
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•a SUBJECT: PUBLIC NOTIFICATION TO WATER CUSTOMERS REGARDING A
rrn DRINKING WATER TREATMENT TECHNIQUE VIOLATION
Purpose:
The purpose of this informal report is to brief the City Council on the public notification
requirement to water customers regarding a treatment technique violation involving the water
treatment disinfection process at the Eagle Mountain Water Treatment Plant.
Background:
The Eagle Mountain Water Treatment Plant uses ozone for primary disinfection and mono-
chloramines for secondary disinfection. In the water treatment process, the effectiveness of
inactivation of Giardia and viruses is measured by the concentration of the disinfectants multiplied
by the contact time, known as CT. The TCEQ has strict requirements regarding disinfectant
concentrations and contact time that must be met within the plant in order to obtain pathogen
inactivation credit.
For approximately 21 hours from February 16 through February 17, errors in the operation of the
ozone system resulted in a bypass of the ozone disinfectant process, leaving only the secondary
disinfection process for inactivation credits. It was determined after the event that the secondary
disinfection process did not provide sufficient CT, requiring a public notice of the treatment
technique violation. The Water Department self-reported the violation to TCEQ.
The department conducted routine distribution system microbiological monitoring in areas served
by the Eagle Mountain plant on Feb. 17 and 19. None of the sampling results showed problems
with the water quality. In addition, the Tarrant County Public Health Department's surveillance
data indicates the level of gastrointestinal cases has remained well below its action threshold.
There are three levels of violations, and this is a Tier 2 violation. Tier 1 violations are acute
violations where there is the potential for human health to be immediately impacted. Tier 1
violations require notifying customers within 24-hours of occurrence and usually include a boil
water notice. Tier 2 violations do not pose an immediate risk to human health. Examples of Tier 2
violations may include treatment technique violations as well as providing water with levels of a
contaminant that exceed EPA or state standards. Tier 2 violations require notifying customers as
soon as possible but within 30 days. Tier 3 violations are those that do not have a direct impact
on human health and have a 90-day notification period.
The Water Department has taken steps to re-train employees on standard operating procedures
and updated that procedure to include additional checks and balances.
If you have questions, please contact Interim Water Director Andy Cronberg at 817-392-5020.
David Cooke
City Manager
ISSUED BY THE CITY MANAGER FORT WORTH, TEXAS