Cleaner Water Ahead as Skokie Plant Breaks Ground on $400 Million Upgrade

A water treatment plant near Chicago just took a big step toward cleaner rivers and safer water for more than a million people. On October 8, the Metropolitan Water Reclamation District of Greater Chicago (MWRD) broke ground on a nearly $400 million upgrade at its Terrence J. O'Brien Water Reclamation Plant in Skokie, Illinois. The project, called Battery E, will add new tanks and equipment to help clean water much more thoroughly before it flows back into local rivers. Officials say the upgrade is one of the largest investments in the district's 137-year history.

The O'Brien plant has been running for almost 100 years, opening back in 1928. Because so much of its equipment is very old, it needs repairs and modern upgrades. Aruch Poonsapaya, a managing engineer at the plant, explained that aging infrastructure needs regular maintenance. He also said the biggest reason for Battery E is to remove a nutrient called phosphorus from the water.

Phosphorus is a natural substance that living things need to survive. But when too much phosphorus gets into rivers and lakes, it causes big problems. It can make algae grow out of control, lower the oxygen levels in the water, and hurt fish and other wildlife. MWRD Board President Kari K. Steele said the effects can travel all the way from the North Shore Channel of the Chicago River south to the Des Plaines River and even the Mississippi River.

The O'Brien plant serves about 143 square miles of the Chicago area, treating water that drains from about 5.19 million people's homes. That is roughly 90% of Cook County. Water goes through a two-step cleaning process before it is released back into the environment. The first step, called primary treatment, removes about 60 to 70 percent of contaminants, or harmful materials, in the water.

Battery E will support the second step, known as secondary treatment, which cleans water to about 97 to 99 percent purity. Poonsapaya said the water that goes back into the river is very safe for human contact, even though it is not quite clean enough to drink. Battery E will also help the plant meet new government rules about phosphorus discharge that go into effect in 2027 and 2030. These rules are part of stricter environmental standards being set across the country.

Steele said the plant must be ready for many challenges ahead, including unpredictable water flows, changing weather, and new types of pollution. She told officials at the groundbreaking ceremony that the district's water treatment systems must keep evolving to meet those challenges. 'Our infrastructure must evolve with that,' she said. 'This project reminds us that we are all tied together by water.'

Skokie Mayor Ann Tennes spoke at the groundbreaking and called the project an important step in keeping the village's water safe. She noted that Skokie and MWRD have worked together on sustainability goals for many years. One shared goal is to cut the village's community-wide water use by 7.5%, or nearly 200 million gallons per year, by 2030. Mayor Tennes added that even though most people do not think about wastewater systems every day, they are absolutely essential.

Battery E is expected to take about four years to complete, and hundreds of tradespeople will work on the project during that time. The new system will help the plant serve its community for another century. Officials hope it will set a strong example for water districts across the region. Clean water, they say, depends on investing in the pipes, tanks, and technology that most people never see.