The 'Big Pour': 60 Cement Trucks To Line Highway 29 In St. Helena

ST. HELENA, CA — The City of St. Helena reminded its community that the "Big Pour" — a critical step in upgrades to the city's Wastewater Treatment Plant — starts at 3 a.m. Wednesday and will last 17-18 continuous hours. The pour consists of 60 cement trucks that will be parked along Highway 29 with premixed concrete known as "redi-mix" or "ready-mix."

"It is essential to note that once the pouring begins, work cannot be halted until all 60 trucks have fully poured the concrete," the city said. "Residents can contact the Public Works Department with questions by calling 707-968-2658."

Upgrades to the Wastewater Treatment Plant are continuing to progress. The "Big Pour" is a critical step in the process as the city prepares to accept new wastewater treatment equipment that will elevate its ability to treat wastewater and produce both reclaimed and recycled water to customers for landscape and crop irrigation. In addition, the treated water from the plant will meet all quality standards suitable for direct discharge into the Napa River — if required, city official said in a news release.

"The City of St. Helena is committed to the environment and to delivering a state-of-the-art wastewater treatment facility that not only meets current regulatory requirements but also ensures the long-term sustainability of our environment," said Eric Janzen, assistant director of Public Works. "We appreciate the community's understanding and cooperation throughout this project."

Critical Milestone

The "Big Pour" is a critical milestone. All the concrete delivered from 60 trucks used will be pre-mixed, commonly known as "redi-mix" or "ready-mix," and the curing process will commence as each truck is emptied. It is essential to note that once the pouring begins, work cannot be halted until the concrete has been fully poured. To that end, the 60 trucks will stage on Highway 29 in order to be in position to continually pour.

Once the "Big Pour" is completed the cement will cure for nearly a month to achieve sufficient strength to accommodate the weight of the equipment. To ensure proper strength, concrete samples will be taken during the pour and tested periodically during the curing process.

As the concrete cures, two members of the Public Works staff will visit the equipment manufacturer, Cloacina, in Arroyo Grande. While at Cloacina staff will conduct "factory acceptance testing" of each piece of equipment. Successful completion of these tests will lead to the City's acceptance of the equipment, after which it will be shipped to St. Helena for installation.

The current schedule has the new equipment beginning to arrive in St. Helena later this summer. The equipment will then be installed and should be fully operational before the end of the year.

According to a news release from the city, while this project will not increase the wastewater plant's capacity or promote additional development within the city it does elevate the wastewater treatment standards beyond what the current plant can achieve. Currently, the wastewater treatment plant produces "secondary" treated water, which is unsuitable for use on crops or ornamental landscaping. The city currently disposes of this water by spraying it on a large grass field that is inaccessible to the public. During the winter months, a portion of the treated water is discharged into the Napa River under strict regulations. However, there have been instances where the plant has had to discharge water that did not meet the state's standards for natural waterway discharge. As a result, the city is under a state order to rectify this issue and the new wastewater treatment plant will enable the city to address the issue.

Additional information about the project will be released as further details and information are available. Residents can contact the Public Works Department with questions by calling 707-968-2658.