The City of Big Shoulders is also the City of Big Water.

Chicago’s Department of Water Manage-ment is capable of producing 2.1 billion gallons of potable water per day, serving 490,000 accounts and 5.3 million customers throughout Chicago and 125 neighboring suburbs. That’s over 40% of the population of the entire state of Illinois.

The department is responsible for over 4,000 miles of water mains, 48,500 fire hydrants and two of the largest water treatment plants in the world.

And the capital improvement plans and programs for this vast system are just as big. The department is in the midst of a 10-year campaign that includes replacing aging distribution lines and installing new water meters throughout the customer base.

Total cost of these improvements is estimated at $6 billion when the plan is completed.  

“The capital plan is a huge investment in Chicago’s future,” says Randy Conner, Department of Water Management commissioner. “It creates a foundation for our future growth, attracting new business and expanding our regional water distribution services.”

Lake Michigan water

Chicago’s source water is Lake Michigan, which borders the city along a 45-mile-long shoreline. Two intake cribs are located 2 miles offshore, and freshwater is pumped from these structures to either the Jardine treatment plant (rated at 1.44 billion gallons a day) or the Sawyer treatment plant (rated at 0.72 bgd).

The treatment scheme at both locations is the same: Raw water is chlorinated and fluoridated, and alum and polymer are added as the water flows into rapid mix tanks. Solids are flocculated and settled, and the water is filtered before final disinfection with chlorine. A phosphate blend is added to line pipes and prevent corrosion.

A series of 12 pumping stations move the water through the distribution system to customer sites. Some of the pumping stations are being converted to green processes; more efficient electricity is replacing steam as the main power source, with green roofs, solar panels to produce supplemental power and permeable landscaping also being added. Total savings from these changes are estimated at $4.5 million annually.

The system operates on a pump-on-demand basis; there are no elevated storage tanks.

Capital improvement plan

The Department of Water Management’s 10-year capital improvement plan aims to:

Dramatically reduce the miles of old water mains, some of which date to the 1880s.

Upgrade over 200,000 manually read water meters and add meters to unmetered accounts.

Convert three of the 12 pumping stations to sustainable status.

And investigate the potential to replace lead service lines throughout the city.

To help fund these improvements, the Chicago City Council, as well as the Department of Water Management’s partners and constituencies, unanimously agreed to incremental water rate increases totaling 75% over a four-year period, 2012-16.

Water mains

According to department data, over half of the city’s water mains were installed in 1946 or earlier. The department began replacing them in 2012. The goal has been to install at least 90 miles of new pipe each year since, and Conner says the installation rate has actually been increased because of efficiencies the department has developed over the period.

“Most of the old lines are ductile or cast iron — some reinforced concrete — although we’ve encountered some old wooden pipes, as well,” he says. “Average depth of excavation is 6 feet, and we’re using crawlers and backhoes and open-trench construction throughout the replacement project. Most of the new lines are ductile iron.” Diameters range from 6 inches for feeder lines to 48 inches for larger distribution mains.

While the department focuses on areas where leaks have been detected using TriCorr ultrasonic devices (Fluid Conservation Systems) and unusually high or constant flow rates noted on customer meters, much of the replacement has been in conjunction with other infrastructure projects like street reconstruction or utility replacement.

“We’ve become more efficient at replacing water mains as we’ve gone along,” Conner says. “We have been able to save money and increase the mileage of new pipe by grouping projects in specific areas of the city and by leaving some of the old pipe in the ground and disconnecting it rather than trying to remove it.”

The department uses in-house city employees for about 35% of the work — mainly the trenching — and outside contractors for the rest of the work including the connections.

Conner notes that the department goes the extra mile to keep affected customers informed of the work. He says it’s important to make sure the elected officials in a neighborhood know about the scheduled work ahead of time.

“We also send letters to property owners, put out informational flyers throughout the neighborhood and place notices in community newspapers.”

Conner adds that customers can also sign up to stay informed electronically, via email.

In sum, Chicago is well on pace to meet its target of reducing and replacing over 1,000 miles of its pre-World War II pipe by 2021.

Meters

Dr. Andrea Holthouse Putz, deputy commissioner, describes the city’s ambitious metering project.

“We had been using manual-read meters before, and although 80% of our revenue was metered, over 300,000 of our 490,000 accounts were nonmetered,” she says. Billing for nonmetered accounts was estimated, based on the size of the building or house on the property and the number of occupants. Bills were sent every six months, in advance.

“All the nonmetered accounts are getting new Badger ORION AMR meters,” Holthouse Putz says. “These have 900 MHz transmitters that we can drive by and read from the street.” She says it’s “a huge change,” both for the city as well as customers. “They appreciate being able to see actual and accurate usage,” she says. “Plus, a red flag pops up if there’s a problem like a broken sewer or unusually high flow rate.”

A website (www.metersave.org) serves as a clearinghouse of information. The website describes how the new meters are available free to residents who own single-family houses and two-flats and are current on their bills. The program also guarantees that residential customers installing new meters will not pay more than they were before for seven years.

As part of the meter installation process, the department offers customers a free test for lead levels and a water pitcher and six water filters that are NSF-certified to remove lead if used correctly. If a home does test over the U.S. Environmental Protection Agency’s action level of 15 parts per billion for lead in drinking water, the department will also inspect a customer’s system and make a recommendation regarding lead abatement. Other features of the program include indoor and outdoor water conservation tips.

The department is 10 years into the replacement program and has installed approximately 130,000 new meters thus far.

Lead service lines

Like most of the older cities across the country, the Department of Water Management is investigating potential problems caused by lead service lines from the street to the customer’s site and lead plumbing inside the building.

“We actually started studying the issue before the crisis in Flint (Michigan),” Conner says.

The water produced by the department meets or betters all federal and state regulations, and the city aggressively tests to ensure water quality. Both water treatment plants add a phosphate blend to coat pipes and prevent corrosion. Still, there is the possibility that lead service lines and in-house plumbing could be leading to lead levels that exceed guidelines, particularly in homes built before 1986.

To that end, the department has commissioned a study by the firm of CDM Smith to evaluate the total cost and multiple factors involved in replacing lead service lines connecting water mains to homes.

“We’re doing the study to get a better understanding of what’s going on in the city, what are the technologies that might be employed, and the funding that might be available,” Conner says. Addressing this issue would make Chicago the largest city in the nation to explore a complete lead service line replacement program, and Conner estimates that costs to remove lead lines could be $4 to $8 billion over multiple decades.

Conner says the study report should be available sometime this spring and will recommend one or two pilot studies the city can conduct to further understand any problems, as well as identify solutions, such as the feasibility of splitting costs with property owners 50-50.

Also, the department has launched what it describes as a first-of-its-kind study to determine the possible impact of water main construction and meter installation on water quality.

No comprehensive scientific study has previously explored the topic, the department states. “While the study is ongoing, preliminary data indicate the water main replacement program is not producing large changes in lead concentrations. As such, no changes are warranted to the city’s 10-year capital plan to replace century-old water mains and aging sewer mains that is in progress.”

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Greening the water infrastructure

The Chicago Department of Water Management may be big, but it’s also going green, and that includes the water distribution pump stations. Four of the stations are being converted from steam power to solar electric power to reduce CO2 emissions and save on operating expenses.

The Springfield Avenue pump station is a good example. The station is responsible for distributing 45-60 million gallons of water daily to local residents and businesses. 

“The conversion is a great example of how we can incorporate sustainable solutions while saving money and creating more reliable infrastructure for our future,” says Randy Conner, water management commissioner. The move is expected to save $4.5 million in power costs annually and prevent the emission of 17,000 tons of carbon emissions.

In addition to the installation of solar panels manufactured by SolarWorld and the move away from steam power, the Springfield station features permeable pavers, an underground retention basin and green roof.

An additional 12,000 square feet of new park space for use by the community was created through the demolition of unused city property and further enhances the environmental benefits of the conversation. Conner says Department of Water Management expects the pumping station will receive silver LEED certification.

Similar conversions are planned for three more pumping stations as part of the city’s “Building a New Chicago” infrastructure improvement plan, initiated by former Mayor Rahm Emanuel.