Pflugerville City Council approved the purchase of new filters for the city's water treatment plant Oct. 28 at a cost of $1.35 million.

In 2006 the city installed 20 of the filters, formally called membrane cassettes, made by General Electric. Those filters are approaching the end of their lifespan, according to city documents.

"[The filters] have a life of about 10 years and we are rapidly approaching that life," Assistant City Manager Tom Word said. "We took a strategy to split the purchase and replacement into three years to spread out the economic impact to our budget."

Pflugerville's water treatment plant can accommodate 25 of the specialized filters, and the city plans to install them in three phases.

In phase 1 the city purchased 10 filters, which were installed in fiscal year 2014. Council's Oct. 28 approval will lead to the installation of 10 more filters in FY 2015. Five more filters are expected to be purchased and installed in FY 2016, city documents state.

Word said particles in the water have accumulated in the filters and reduced their capacity.

With a total of 25 new filters the treatment plant's capacity should increase from about 13.5 million gallons per day to about 18 million gallons per day, city documents state.

General Electric is the sole provider of the filters, Word said.