A three-way agreement among Buda, the Guadalupe Blanco River Authority (GBRA) and the Sunfield Municipal Utility District (MUD) could allow for the future expansion of the city’s wastewater treatment plant (WWTP).
The agreement, approved unanimously by the Buda City Council June 20, would call for the total discharge of 3.5 million gallons per day of treated effluent into an unnamed tributary of Plum Creek.
Council members shared little discussion on the agenda item before it was approved. City Engineer John Nett said the agreement “is a proactive measure.”
“We are nearing the point where we will have to plan on expanding (the wastewater treatment plant) to accommodate for future growth,” Nett said.
Nett said the expansion of the wastewater treatment plant has been in the city’s capital improvement projects (CIP) plan for a while. He said council members were aware the city was planning on locating an additional place to discharge the increased volume of effluent based on the expansion.
According to Nett, the current volume of discharged effluent cannot exceed 1.5 million gallons per day (mgd). Buda is currently discharging 1.1 to 1.2 mgd.
“When we realized that we were nudging up to that 1.5 mgd threshold, we knew we needed to begin the construction process,” Nett said.
Nett said the city retained the services of AECOM, a consulting firm with previous experience in wastewater plant expansions, to assist it in plans and requirements of expansion.
Nett said the wastewater treatment plant has been at its current location between City Park and Garison Park in the Public Works complex for 15 to 20 years. It currently discharges treated effluent into a tributary of the Plum Creek basin south of Robert S. Light near the Meadows of Buda area.
Nett said the reason behind the agreement is the need for another point of discharge for the effluent produced by the expanded wastewater treatment plant, which will amount to 3.5 mgd.
Buda filed the draft permit for expansion with TCEQ in January 2016 and the final comment period ended this week. According to city documents, the process for TCEQ to evaluate permits is approximately 18 to 24 months.
Nett said the draft permit would allow the city to split the flow of discharge between the two discharge points without exceeding the 3.5 mgd limit.
According to city documents, Sunfield will be able to use the effluent for irrigation purposes at no charge and Sunfield will provide the necessary easements to Buda at no cost.
Nett said the agreement is perpetual and the next step in the process will be for 2428 Partners, owners of the Sunfield development, to approve the agreement, as well as the MUDs.
Nett said that the city does not discharge into Onion Creek due to recharge concerns since Onion Creek feeds into the Barton Springs Edwards Aquifer.
He added a study would have to be performed at the proposed discharge site in Sunfield to determine if the waterway can support the additional pollutant loading the discharged effluent will cause.
Nett said the pollutant loading in the treated effluent water is monitored and measured to higher standards than TCEQ requires. TCEQ enforces those requirements and imposes steep penalties on entities that discharge effluent bellow the set standards, Nett said.
“The additional pollutant loading from ‘urban runoff’ like businesses and houses in aggregate, is worse because it’s not sampled and tested for quality,” Nett said.
Buda Public Information Officer David Marino said construction on the expansion of the wastewater treatment plant will not begin until the additional draft discharge permit is approved by TCEQ.
Marino said the plant expansion would be complete 12 to 16 months after construction begins.