Modesto celebrates wastewater plant upgrade

Modesto officials celebrated Thursday the completion of a $133 million upgrade to the city’s Jennings Road Wastewater Treatment Plant, which will clean the water to such a state that it can be used to irrigate fields growing food for people.

The city was required to upgrade the plant in order to meet new state standards that take effect in 2018 for discharging treated wastewater into the San Joaquin River. But Modesto aims to sell the highly treated water to drought-stricken farmers on the West Side.

Modesto is working with Turlock, the Del Puerto Water District, Ceres and Stanislaus County on the $100 million North Valley Regional Recycled Water Program, in which Modesto and Turlock will provide Del Puerto’s farmers with highly treated wastewater for their crops.

The two cities plan to build pipelines and other infrastructure to transport the water from their treatment plants to the Delta-Mendota Canal, which will deliver the water to farmers. The farmers will pay for the cost of the project and provide Turlock and Modesto with a premium for the recycled water. Construction could be completed by the end of 2017.

Mayor Garrad Marsh told an audience of several dozen people gathered at the city’s Jennings plant that the city is on the cusp of transforming something once considered having little value into an asset that will produce jobs and economic benefits for the region.

“We used to figure out how to get rid of it,” he said in an interview. “Now we are partnering with the Del Puerto Water District to provide it to their farmers.”

He and other city officials also praised the Jennings plant upgrade for coming in on time and on budget.

Utilities Department engineering division manager Will Wong said the Jennings plant upgrade is the most expensive project in city history. He said construction started in May 2012. He said the construction is essentially done, except for minor items. He said the next step is for the city to start testing the upgrade and get the certifications needed to operate it. The upgrade is expected to be operational in June.

The project involves providing what is called tertiary treatment of the wastewater. That involves the use of membranes to provide microfiltration of the wastewater and disinfecting it to kill harmful bacteria.

Modesto operates two waste-water treatment plants – one on Sutter Avenue in west Modesto and the Jennings Road facility, which is about 10 miles southwest of downtown and along the San Joaquin River.

The Sutter plant provides primary treatment of the wastewater before it is sent by pipeline to the Jennings plant. There the water undergoes secondary treatment. This water is released into the San Joaquin River during the rainy season. In other months, it is used to irrigate the city’s roughly 2,500-acre ranch on Jennings Road, where animal feed is grown. The water also is stored in ponds.

Wong said the Jennings plant treats an average 20 million gallons of sewage per day. The upgrade will allow the plant to provide tertiary treatment to 12.6 million gallons per day. The city completed a roughly $25 million tertiary upgrade in 2010 that can treat 2.3 million gallons per day. So with the two projects, the plant can provide tertiary treatment to 14.9 million gallons each day. Modesto also receives cannery wastewater that is used at the Jennings ranch.

Modesto borrowed the money for the most recent tertiary upgrade from the state at an interest rate of 2.6 percent. The city’s sewer customers are paying off that debt and the cost of other wastewater projects through higher monthly bills. Wong said sewer bills have more than doubled since 2008. He said in 2008 a single-family home paid about $14 month for sewer service and now pays about $32.

But he said Modesto’s rates are competitive. The city’s most recent Comprehensive Annual Financial Report shows that as of July 2013, Modesto charged a single-family home $30.40 a month compared with $25.75 per month in Fresno, $24.11 in Lodi, $37.31 in Stockton, $34 in Tracy and $37.10 in Turlock.

This story was originally published September 17, 2015 at 3:45 PM with the headline "Modesto celebrates wastewater plant upgrade."