Dr. Brindha Subramanian’s job is a lot harder than it should be, thanks to the Santa Clara Valley Water District.

Subramanian is the chief managing dentist for the Health Trust’s Children’s Dental Center in San Jose’s East Side at King and Story roads. Her office sees nearly 300 children every week, and because most of San Jose does not have fluoridated water, she sees a far higher than usual number with painful cavities when they walk through the door.

“It’s sad. It’s the first thing that stood out about Silicon Valley when I moved here from Texas,” said Subramanian.

This is not what’s supposed to jump out at newcomers.

It’s a long-standing embarrassment that not all cities in the valley have fluoridated water. San Jose is the largest city in the country that does not, although it does fluoridate its own municipal water system, which serves a small part of the city. For the rest of San Jose and other parts of the county, it’s up to the Water District, which serves 1.8 million customers as the water wholesaler.

On Tuesday, children’s advocates and others will ask the district to finally provide fluoridated water, which is considered to be one of the 10 greatest public health achievements of the 20th century. The board should be unanimous in authorizing staff to develop a policy.

The scientific evidence is overwhelming.

A study of third-graders found that in Santa Clara County, 13.2 percent have an urgent need for dental treatment, as opposed to 2.6 percent in the Bay Area who drink fluoridated water. Repeated studies over the years have shown that fluoridation reduces tooth decay 20 to 40 percent.

The American Dental Association supports fluoridation. So do the U.S. Centers for Disease Control and Prevention, the American Medical Association and the U.S. Surgeon General.

It isn’t cheap — the startup costs are about $18 million — but the American Dental Association reports that every $1 spent on fluoridation saves $38 in dental procedures. The Health Trust plans to help raise money for the project, though public agencies typically finance the public benefit.

For children, especially those who struggle in school, tooth decay is serious. Kids who are in pain are distracted in class, if they show up at all.

This proposal will rile opponents of fluoridation, a highly vocal but small minority. Their latest rallying point is the federal recommendation to lower the standard for optimally fluoridated water to 0.7 parts per million from the previous range of 0.7 to 1.2 parts per million. The change was made because some children experienced spotting on their teeth at higher levels, not because fluoride was found to be unsafe.

Fortunately, the latest poll shows in Santa Clara County, only 13 percent of residents oppose fluoridation. It’s no surprise. Silicon Valley prides itself on embracing beneficial technologies.

With the water district’s decision Tuesday, it can emerge from the Dark Ages of dental care and embrace water fluoridation.