New sewer plant will allow Rio Vista to expand

July 17, 2006

New sewer plant will allow Rio Vista to expand

By Mike Corpos


The new waste water plant in Rio Vista is set to handle 1 million gallons of raw sewage per day, but has room to expand. (Zachary Kaufman/Daily Republic)

RIO VISTA - When a town grows, everything grows with it, including the amount of sewage generated.

To accommodate such an increase, construction crews in this town of about 7,000 are putting the final touches on the city's new wastewater treatment plant.

Built north of town, near the junction of Church and Airport roads, the new plant gives the city nearly double the waste-treatment capacity of the current plant, which is nearly 30 years old.

The plant should be online by the end of July, and it should begin treating its first sewage in early August, said construction manager Larry Timmer of Harris and Associates, an engineering and management firm.

Originally budgeted at $24.7 million, the project will likely run closer to $26 million when completed mainly because of skyrocketing costs for construction materials.

Once completed, the new plant will provide Rio Vista with the ability to treat up to 1 million gallons of wastewater per day, nearly doubling the 600,000-gallon-per-day capacity of the existing plant on Beach Drive.

"The old plant's too small to treat all the sewage," Timmer said, adding the new construction leaves space for expansion up to three times the initial capacity.

"It will enable us to continue with community growth," Vice Mayor Ron Jones said. "All the other projects would not be possible without the new plant."

At its initial size, the new plant will be able to serve about 5,000 homes. It will start serving the Trilogy housing development and another subdivision now under construction. Eventually, the city will phase out Beach Drive plant.

At that point, the new plant will take on the whole city's sewage and the old plant will be converted into a lift station, pumping sewage across town to the new plant.

Before the plant can be brought online, it needs to be "seeded," meaning a small amount of sewage will be brought in and allowed to sit while colonies of bacteria that break down solid waste are allowed to develop, Timmer said.

Employing newer microfiltration technology, the new plant will be one of the more cutting-edge sewer plants in the area.

"It's not a conventional plant - they're usually much bigger," he said.

Along with new treatment facilities, the new plant will have state-of-the art electronics, touch-screen controls and monitoring systems, housed in the new office and lab building, just to the west of the main treatment facilities.

"In the lab, they'll do all the in-house testing to make sure the water quality meets the permit requirements," Timmer said.

After the wastewater is filtered, it is sent to a pair of ultraviolet disinfection units to kill off any remaining bacteria.

"Nobody likes chlorine these days, even though it's very effective," Timmer said, noting the UV units do pretty much the same job without added chemicals. "All of the water here can actually be reclaimed."

Although the discharged water is cleaner than most drinking water, using reclaimed wastewater is still a hard sell in communities.

"The water we'll dump will actually be cleaner than the water in the Sacramento River," Timmer added.

Once the plant is done purifying the wastewater, it will be pumped through a $2 million pipeline, about 300 feet out into the Sacramento River.

In case of backup, the plant also has a 2 million gallon holding pond to store untreated wastewater.

On the south end of the property are several greenhouses which will be used to dry out the solid waste sludge. Once that sludge is dry, Timmer said it will be trucked to landfills.

When construction is completed, the city has contracted Houston-based Veolia Water, which currently operates the Beach Drive plant, to run the new plant.

Construction began in December 2004. The plant will begin processing sewage in August.

Reach Mike Corpos at 427-6977 or mcorpos@dailyrepublic.net.