It’s a common sight in many public schools across the city: a small child tiptoes to lean over a metal basin as cool water spouts out from the mouth of a water fountain.

Most parents and teachers don’t think twice about it, assuming that the water is clean to drink. But according to a Toronto District School Board (TDSB) sprinkler fitter, students should avoid quenching their thirst at the water fountain.

“I would send them (to school) with bottled water,” Stephen Sampson told CTV Toronto.

Sampson – who admits he doesn’t drink the water from water fountains – said the TDSB is behind in installing backflow preventers, putting drinking water at risk.

“It’s not very good when you have water coming from areas that are stagnant and being back-siphoned into the water you consume,” Sampson said.

Backflow preventers stop the reversal of the normal flow of water which can lead to the potential contamination of drinking water if chemicals, pollutants, toxic substances, bacteria or pathogens enter back into the public water supply system.

In Toronto, backflow preventers have been mandated in public schools since 2008, but many buildings are still waiting to have them installed.

Out of a total of approximately 600 public schools, about 145 have backflow preventers, while 35 have them installed but still need to be inspected.

According to the TDSB, backflow preventers are being installed in phases due to budget constraints.

It costs between $10,000 and $15,000 to install one backflow preventer – meaning the entire project will run the school board $15 million to $18 million.

“School boards are responsible for the safety and well-being of staff and students and for maintaining their educational facilities,” Lauren Ramey, spokesperson for the minister’s office of the Ministry of Education, explained in an email to CTV Toronto.

She said maintenance funding for TDSB schools comes from the School Renewal Allocation fund which has increased by $3.16 million to a total of $472 million since 2003. But despite the more generous budget, Ramey admits the cash-strapped school board still faces many hurdles.

“The TDSB has faced challenges in the past in ensuring repairs and maintenance were done in a cost-effective manner,” she said.

Every school in the city is expected to have a backflow preventer in a few years but until then, many students, such as those at Forest Hill Junior and Senior Public School will have to wait.

But the delay doesn’t mean water safety is not a top priority, according to the TDSB.

The school board said the water at all TDSB schools is tested daily by the city and annually by staff members.

And every week, school caretakers will also turn on all the taps to flush out sediments.

Drinking water at schools where a backflow preventer has not been installed is not dangerous but it’s not completely safe either, said Lawson Oates, the director of business operation at Toronto Water.

Oates compared the situation to riding a bicycle. “You can ride a bike without a helmet…but with a helmet you are safer.”

With a report from CTV Toronto’s Naomi Parness