While more than $4 million in wastewater treatment plant improvement funds were on the Pflugerville City Council's docket Thursday, less than a quarter of that number was ultimately approved.

Council members voted to award a construction contract for the Pflugerville Central Wastewater Treatment Plant for "interim improvements" to the tune of $832,142, but tabled more than $3 million in engineering and design costs for a full expansion.

Instead, council members asked that Freese and Nichols Inc., the consulting firm hired by the city to design the wastewater treatment plant expansion, come back to the dais in two weeks with alternative plant expansion options.

Concerns arose over the total flow capacity of the proposed expansion design. Freese and Nichols' proposed expansion would have a maximum capacity of 10 million gallons per day (MGD) at the end of its full build out in 2028. The plant has a current maximum capacity of 5.3 MGD.

Pflugerville City Engineer Amy Giannini added that an additional 2 MGD could be diverted to other city treatment plants if needed.

Kendall King, group manager for Freese and Nichols' Treatment, Transmission and Utilities team, reported that the existing plant uses specific operations and the proposed expansion would mirror the existing treatment processes. To expand beyond 10 MGD, the plant expansion would require different treatment processes, which would require additional training and staffing at the plant, according to King.

Council members opted to table the resolution requesting funds for engineering costs related to the proposed Central Wastewater Treatment Plant expansion and asked Freese and Nichols and city staff to return in two weeks with alternative plans with larger maximum capacity thresholds.

The Pflugerville Central Wastewater Treatment Plant reached 75 percent of its permitted capacity in 2016.

At some point in the next 18 months the city will break ground on a new wastewater treatment facility in New Sweden. That facility, located on a small parcel of city property surrounded by the city’s extraterritorial jurisdiction, is planned to serve the utility needs of residents and potential developments to the east of Lake Pflugerville.