The theme of water for this year’s Doors Open Waterloo Region drew many to a treatment plant with a history.

Greenbrook Water Treatment Plant took part in the annual event on Saturday that allows people to tour places not normally open to the public.

In 2014, an explosion rocked the building when ammonia was pumped into a chlorine tank.

“We have taken all the measures and the ministry has come in,” said Kaoru Yajina of Region of Waterloo Water Services. “They have done their checks.”

No sign of damage remains at the facility that pumps millions of litres of water to about 20,000 people in Waterloo Region.

“[It pumps] 140 litres per second,” said Yajina. “I would say about five per cent of the region’s water supply.”

Kitchener resident Rhonda MacKinnon says she was reminded of the Walkerton Water Crisis as she visited the plant.

“I knew people that passed away and heard the helicopters going in and out of town,” she said. “[They were] always wondering who was going to be taken away next.

“I can see now that things are being done to a specific standard and that the province is requiring that treatment plants be up to a certain code.”

Yajina adds that these steps were explained during the tour.

“We show them where their water comes from, what we do with the water, and how it gets to the tap,” she said.

The Greenbrook Water Treatment Plant was the first of its kind in the region and dates back to the 1890s.

“I want to understand how the engineers manage the plant,” said Waterloo Region resident Derek Shaw. “I want to know the mechanics maintain the plant.”

The Grand River Conservation Authority and Reid’s Chocolate Factory are two other sites for Doors Open that are focusing on the theme of water.