CHICAGO (WLS) — The I-Team got an exclusive behind-the-scenes tour of the largest conventional water treatment plant in the world, the Jardine Water Purification Plant near Navy Pier.

Cameras haven’t been allowed inside since before 9/11, when new security measures were enacted. ABC7 got an exclusive look at how your drinking water is kept safe, and protected from cyber threats.

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The Jardine Plant doesn’t only service the city of Chicago, but also delivers safe water to more than 5 million people across 120 area suburbs. The I-Team was granted exclusive access for the first time in over 20 years deep into the inner parts of the water plant to see how your water is treated and protected.

The plant is the largest in the world of its kind ,and one of two in Chicago pumping water to 4,300 miles of water mains.

The plant treats Lake Michigan water and converts it into drinking water. Workers and engineers like Ed Salinas showed how massive infrastructure is required to distribute the water.

“So we’re lifting about 500 million gallons a day and we can add another pump if the demand was higher,” Salinas said.

In one room, water is lifted 20 feet from the lake and collected.

“There’s water from two miles out,” Salinas said.

MORE COVERAGE: See the I-Team’s complete coverage of lead contamination in Chicago’s water system

Underneath are the pumps, one of which can pump 300 million gallons of water a day. They are turned on and off based on demand. Typically there are two in service, but the warmer summer months mean there’s more usage.

“We might have three pumps in service, but there’s redundancy. There’s a total of eight pumps that are available,” Salinas said.

The purified water, the final product as such, are held in pools and goes through the sand filters.

“Then from there it gets collected and it goes to the reservoir and now to distribution,” Salinas said. “It has all the chemicals and meets all the requirements to be safe to drink from this point.”

The water is vigorously tested in a room with dozens of running faucets.

“Every day they perform like 900 tests and their schedule every hour to do certain tests to ensure that they have the right chlorine, the right fluoride, of chloric acid and all these other chemicals,” said Salinas.

Commissioner of the Chicago Department of Water Management Randy Connor said beside making sure the water is safe to drink, his team also ensures it’s safe from other outside threats.

“We also take a look at our cybersecurity as well. And we run different tests and different diagnostics daily. And we work with the FBI, CIA, Homeland Security,” he said.

But the water plant is not connected to the outside internet, lowering the risk of cyberthreats.

“Because we’re not connected to the Internet. But we must always be leery of people who come in and bring their own computers, people who come in and bring their own flash drives, things of that nature to bring in their own malware,” Conner said. “So we’re always constantly running our computer diagnostics.”

The valves that help control water flow are only on an internal internet connection on a network that lies only in the property of this facility. Conner said if the system was breached, it could put the water in danger.

“If they’re able to get in there, able to change the dosages or the chemicals we put in the water, they’ll be able to access a lot of the chemicals that we use and be able to manipulate them. They’ll be able to shut down pumps.”

Salinas also showed us the room where a blended phosphate chemical is added to water to protect people from lead contamination from old home service lines. It provides a coating inside the pipes to prevent the metal from leaching into the water.

Chicago’s drinking water meets all U.S. Environmental Protection Agency standards and is lead-free.

However, the city has the most lead pipes in the nation – an estimated 400,000 of them – connected to people’s homes which were mostly built before 1986. The city has a lead line replacement program which has so far updated 6,500 of the 400,000 lines.

Connor said the city is asking the state to extend the timeline to replace lines from 20 to 40 years and he’s hoping Chicago qualifies for more federal funds.

“Seeing that we have 400,000 led service lines, we need a lot more money than most states combined. We have more lead service lines in the city of Chicago than 44 of the other states put together,” he said.

There are several programs you can qualify for to potentially get lead service lines replaced or get a discount on the job. For more information on free lead water testing or programs to get lead service lines replaced. The CDC says no amount of lead is safe for children.

Click here to learn more about Chicago’s lead service replacement programs

Click here to learn more about city-issued test kits