Turlock moves ahead with river treatment plant. Big rate hikes are already under way
Turlock is pressing forward with a new water treatment plant on the Tuolumne River, aimed at reducing its use of wells.
The City Council voted 5-0 on June 11 to continue partnering with Ceres on the project, which could be ready in 2023. Both cities have already launched the series of rate hikes that will cover most of the $202 million cost.
The Turlock council had taken several votes in recent years in favor of the project. It met again last week to consider an alternative offered by Modesto.
The larger city proposed selling surplus water from the treatment plant that has operated on the Tuolumne since 1995. Demand on this plant has been less than projected, thanks to water conservation efforts and slowing population growth.
The Turlock council declined the offer, which would have cost more and taken longer to deliver than the new treatment plant. A rough estimate put the cost at $495 per acre-foot from the new plant and $557 from the existing plant, said William Wong, director of utilities for Modesto. An acre-foot is 326,000 gallons.
His estimate did not account for the 10-mile distance between the existing plant and the proposed plant, meaning extra pipeline costs.
The Turlock council decision cleared the way for a June 29 vote by the Stanislaus Regional Water Authority to move into detailed design and construction, said Robert Granberg, the project’s general manager. Its board is made up of two council members each from Turlock and Ceres.
The authority has already chosen CH2M Hill, part of a Colorado-based company, to do this work. Construction could start in February 2021 and finish in June 2023, Granberg said.
Project discussed since 1980s
Turlock and Ceres are among the many Central Valley cities that get their water entirely from wells. The groundwater can run short during drought. Wells also can be shut down if they fail to meet state standards for drinking water.
Modesto officials credit the existing Tuolumne treatment plant with helping to recharge aquifers in and near the city. It was built by the Modesto Irrigation District, and also supplies farmers in the surrounding area.
A plant for Ceres and Turlock has been pursued off and on since the late 1980s, sometimes with other cities in their vicinity. Cost and other concerns put off the idea.
The Turlock Irrigation District has already agreed to sell some of its Tuolumne supply to the plant, to be built near the Geer Road bridge over the river. The intake system – perforated pipes under the streambed – are already in place.
The plant will filter and sanitize the river water, then send it through a pair of new pipelines. One will go about five miles south to Turlock, the other about four miles west to Ceres.
Rate hikes already under way
Turlock and Ceres approved multi-year water rate increases to cover most of the treatment plant cost. A typical customer in Turlock, using an average of 300 gallons a day, will see an increase from $30.76 in 2017 to $68.54 in 2022.
Rate increases could be reduced or canceled in the future thanks to the lower-than-expected cost of the plant, originally set at $278 million. Granberg said this resulted from the detailed analysis by engineers involved in the project.
Both cities will put some of the rate hikes into upgrading the wells that will remain part of their systems.
The cities also are using $35 million in state and federal grants on the treatment plant. They continue to seek grants and expect to soon line up a low-interest loan from the state.
More water for salmon
The partners note another benefit: Higher flows for salmon. Water for TID farmers is diverted at La Grange Reservoir. The project will allow some of that water to run for about 25 more miles before being taken for human use.
Turlock and Ceres had other partners in the treatment plant that came and went over the years, such as Hughson, Keyes, Denair, Hilmar and Delhi. Granberg said they could get back into it in the future by covering their share of the costs.
Modesto also had been part of the Ceres-Turlock project, to supply customers just south of the river. Reduced demand projections prompted it to withdraw.
This story was originally published June 18, 2020 at 5:00 AM.
