Published on April 01, 2021
Fort Worth is required to notify all customers in the Westside pressure planes about a non-acute drinking water treatment violation. This includes all cities and entities that purchase drinking water from Fort Worth, who in turn must notify their customers.
The Westside Water Treatment Plant failed to meet the minimum treatment technique requirements for the month of March 2021. The Texas Commission on Environmental Quality classifies the violation as a failure to maintain microbial treatment.
The official public notice is available online. It contains details about what happened and is being mailed to all Fort Worth retail water customers in the westside pressure planes.
The Westside plant uses the membranes to achieve removal credits for Cryptosporidium, Giardia lamblia and viruses. To receive the removal credits, TCEQ requires that each membrane rack pass a direct integrity test (DIT) every seven days.
The DIT is performed by pressurizing air through the membrane modules and holding that pressure for a pre-established duration. If the pressure drops below a minimum value, the test fails. Then the utility places the rack off line and inspects each module, looking for broken fibers that may impact the filtration effectiveness.
The treatment technique violation occurred because eight days elapsed between the successful integrity test and membrane rack #5 was in service for three days after a failed test.
The Westside Water Plant is the only Fort Worth plant to use membranes in the treatment process. Unlike most drinking water membrane filtration plants, the Westside plant has a full conventional treatment process upstream of the membrane filters. The pre-membrane treatment includes using ozone for taste and odor control and disinfection, chemical mixing, settling and granular media filtration. After the membranes, final disinfection occurs prior to being pumped to the water distribution system for use by customers.
The other four membrane racks had successful DIT performed within the required timeframe and without any failures. Both the conventional granular filters and membrane filters recorded exceptionally good water quality levels throughout the period in question. The effectiveness of filters is measured by the turbidity (clarity) of the water. All routine bacteriological samples taken in the westside pressure planes on March 2, 3, 8, 10, 11, 15 and 25 passed.
The utility retrained all of the Westside plant’s operations staff on how to respond to alarms pertaining to the membrane system.
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