SCADA System Guides Santa Clara Forward

Santa Clara invests in a new SCADA system and builds distribution efficiency with in-house repair and replacement.
SCADA System Guides Santa Clara Forward
City of Santa Clara Water and Sewer Utilities Director Chris de Groot stands in front of the utility’s new water storage tank under construction in Santa Clara, California. (Photography by Lezlie Sterling)

The Santa Clara, California, water system could serve as a snapshot of the history of water utilities in the United States.

In 1895, the utility began delivering water from two wells to 400 connections and 45 hydrants. Water was stored in four elevated redwood tanks.

Then, in 1906, the San Francisco earthquake destroyed the tanks. The city was without emergency water until a ground-level cistern was constructed along with three steam-driven turbines to pump water into the mains. The distribution system was improved through a bond issue approved by voters in 1920, and the system was further modernized through the 1930s and 40s.

Following World War II, the population skyrocketed and the area became host to the high-tech industries of Silicon Valley. Storage tanks, booster pumps, additional wells and imported water connections were added to the system to keep pace with growing demand.

Today, facing the challenges of aging infrastructure like other cities across the country, Santa Clara has invested in state-of-the-art SCADA technology to optimize operations while ensuring security.

The city has agreements with two other utilities for imported water if necessary, while reclaimed water now makes up 18 percent of the water usage in the system. Water reclamation, along with improved efficiencies, have reduced overall residential water consumption, forcing the utility to become very cost conscious as it moves ahead.

“Despite increases in population, we’re seeing a steady decrease in water sales — the turnover of older housing stock and more efficient plumbing,” says Chris de Groot, director of water and sewer utilities. “Plus, some of our more water-intensive industries have left the area.”


Santa Clara operates 28 groundwater wells, which supply about 65 percent of the city’s water consumption. Agreements with the Santa Clara Valley Water District and the City of San Francisco supply the remainder. Average production is 15.7 mgd, although the system has a production capacity of 72 mgd if all wells are pumping and all turnouts are at full capacity.

The utility maintains six storage tanks with 26.8 million gallons of storage capacity, and is currently building a new 2-million-gallon storage tank and booster station. The distribution system consists of 334 miles of mains and three booster pumps. The connected population is just over 122,000.

Currently, 18 percent of the water used in Santa Clara is reclaimed water. The city is part owner of the South Bay Water Recycling system, which takes water from the San Jose Regional Wastewater Treatment Facility. The recycled water is used in paperboard manufacturing and irrigation. “It takes some of the pressure off our potable supply,” de Groot says. “It also cuts down on our peaking factor.” He adds, though, that the state-mandated recycled water target for the future is 30 percent.

Cost cutting

Santa Clara works feverishly to keep costs low, especially where internal talents can help the utility avoid the need to bid work to outside contractors. “We rely a lot on keeping internal costs low,” de Groot says.

His department maintains its own engineering staff and construction crews. Main replacements — except those above 16 inches (O.D.) — are done in-house. “Our engineering staff does all the design work for us,” de Groot explains. “Our water engineers hold certification in distribution, plus they work hand in hand with the construction crews. They know how the system operates. It’s not like a private company where the two groups may be off in separate departments somewhere.

“When developers come in and need main extensions, we’ll bid the job, but our crews generally undercut outside contractors by as much as 40 percent. Plus it’s quicker and it gets our crews paid.”

When a line leaks or breaks, Santa Clara’s team takes that on, too. “We fix it,” de Groot says. “Our two crews do really high-quality work, and there’s no issue of a one-year warranty.”

The use of internal staff has helped the utility save money and accomplish more work, de Groot says. “We really have the best of both worlds.”

But cost cutting doesn’t solve the problem of needing to invest in aging infrastructure.

“A number of our wells are 60 years old. Currently we have plans for two new wells, and we have spaces for those,” he says, explaining that one well will be installed on property the utility already owns, and the second will be built at a fire station. Drilling depth will be between 600 and 1,000 feet.

“Land in Silicon Valley can go for as much as $4 million an acre. Finding land for new wells is very challenging,” de Groot adds, noting that the utility needs five new wells and has plans for developing a new well every two years for the next decade.

Total cost for the two new wells is approximately $5 million and the new storage tank currently under construction is budgeted at $3.5 million.

Another $3 million is ticketed for open-cut main replacement, with all engineering and construction work to be done in-house. “We don’t do lining,” de Groot explains. “Most of our work is in-kind replacement, with upsizing where necessary.”

Approximately 70 percent of the pipe is cast iron, installed during the 1950s and ‘60s. Most of the pipe installed in the 1970s and ‘80s was ductile iron. ACP, or asbestos cement pipe, installed between 1940 and 1980 makes up 16 percent of the system, with the remainder a mixture of PVC, RCP and welded steel. Most of the system is 12-inch-diameter pipe or smaller.

Automation provides another answer

In an even bigger project, Santa Clara is finishing up the installation of a state-of-the-art SCADA system that will serve its supervisory control and data needs for the next 25 years, while providing security that rivals that found in nuclear facilities. Even better, the utility’s operators played a major role in designing the $10 million system.

“Our old SCADA was simply outdated,” de Groot says, noting the utility continuously struggled to find parts for the system. It was also limited to monitoring various sites around the system. “We could not control our pump stations or modify existing parameters.”

Security was a major concern, as well. “We don’t want any outside party gaining control of the system,” he says. The system is so tight there is no remote access; the only control points are the control room and the city’s emergency response center.

“We looked at other examples,” de Groot says. They also brought in a consultant. “Our operators, engineers and construction crews all sat down in one room. We wiped the slate clean and started from scratch on a SCADA master plan. ‘What would you want it to do; what do you want to see?’”

Operators need to be able to drill down and run operational scenarios, de Groot says, while engineers want data, and management wants to be able to see the big picture all at once.

“Everybody in that room had input,” he says. “As director, I just sign the checks. The operators are the ones who have to run the system. They have the operational expertise. We wanted their buy-in as well as their insight.”

For example, when operators thought 24-inch screens might be adequate, they were challenged to think bigger. As a result, the new system has a pair of 60-inch screens that show the entire city and all the water and wastewater control and data points.

“Everybody can see everything,” de Groot says.

The operators also recommended a larger than normal control room. It’s 900 square feet, with space enough for half a dozen people in case of emergencies. “It’s more expensive, but it’s more functional.”

Trimark/Westin Associates of Folsom, California, was awarded the contract for development and installation of the new system.

Construction started last year, and progress was halted temporarily while Santa Clara prepared for and hosted Super Bowl 50 in February.

When finished sometime later this year, the SCADA improvements will be deployed at 28 potable water well sites, seven sewer pump stations, three booster pump stations, one turnout, three operational control centers, and a kiosk at City Hall to display data in real time.

The system has a great degree of redundancy, with dual backup generators, dual HVAC systems and redundant encrypted communication systems.

Future challenges

The improvements will certainly help Santa Clara provide high-quality water to the community for years to come. But de Groot and his team continue to wrestle with costs and rates, especially as water use continues to decline even as the population increases.

Since 2004, the population has risen from 109,000 to over 122,000. At the same time, however, residential water sales have dropped by about 35 percent — from 3,900 million gallons per year to 2,400 million gallons.

“Our modeling shows more efficient buildings, many with dual plumbed systems to provide recycled water for toilet flushing,” de Groot says.

Nonetheless, the utility must recover fixed costs.

“It’s a constant push and pull, but improving efficiencies through investments in technology and infrastructure will help us meet those challenges.”


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