H2NOW Chicago's sensor-laden, real-time water monitoring platform provides public updates on the Chicago River’s quality. 

Chicago River sensor project gives the public real-time water quality data

This week is Chicago Water Week, led by water innovation nonprofit Current. Water Week features a series of events to highlight the resource’s critical role in Chicago’s environment, economy, and society; many discussions focus on advanced technologies for clean water distribution, management, and conservation. Fittingly, Current recently launched a flagship project: H2NOW Chicago. The sensor-laden, real-time water monitoring platform provides public updates on the Chicago River’s quality. 

Specifically, the system collects and displays real-time data on fecal coliform bacteria levels. This allows river users to decide if they want to proceed with their plans or wait until another time.

“We talk about it like a weather app for the Chicago River,” Alaina Harkness, executive director of Current, told Centered. “We want it to help people — kayakers, boaters, people who want to take a walk along the river — plan and understand if it is a good day to do that.”

The real-time detection and reporting system is touted as the first of its kind in an urban waterway, and numerous technologies are being tested and evaluated during a pilot project. Until now, river quality monitoring typically involved manually taking water samples, sending them to a lab, and waiting at least a day for results.  

“Testing and monitoring our water is the first step in instituting protections for the environment and our residents,” Chicago Mayor Lori Lightfoot said in a news release. “Being the first of its kind, this platform and the water monitoring technology it is testing in our city are very exciting and helpful not only to our residents, but can no doubt be used by other cities in the future.” 

More than 20 partners collaborated on the project, including the Metropolitan Water Reclamation District of Greater Chicago and the city’s Department of Water Management. Much of the capital comes from Our Great Rivers, which is funded by The Chicago Community Trust. The local utilities have helped with in-kind support such as technology installation and maintenance.

“There’s a willingness on the part of our leadership here in the city and on our utilities to … be part of this collaborative innovation. We’re so grateful for their ongoing support,” Harkness said.

The problem

Fecal bacteria themselves are not necessarily harmful to humans, but they are a key indicator of the presence of other harmful bacteria and viruses. The Chicago River also has multiple branches and the water quality differs among them even during the same time period, so looking at data from just one location is not a universally accurate measure.

“You could have a great day to kayak on the main stem and a bad day to kayak on the North Branch,” Harkness said. “Understanding how geography matters and where you are in the river — upstream or downstream — matters and is a key thing we’re hoping to help inform people about.”

The effects of climate change — especially warmer air and water temperatures and more extreme precipitation events — affect the river’s bacteria levels in ways like increased stormwater runoff and sewer overflows. That makes the project timely as climate change concerns become more prominent.

“A lot of it comes down to more and more intense storm events and rainfall, and those are the types of things in particular that we are concerned about when we think about what happens to the river and its overall health,” Harkness said. “It’s a great time to start … rolling this out to the public and getting people more activated and engaged and paying attention to how the river water quality changes in real time.”

Current's approach includes connecting discrete technologies to monitor water quality in real-time.
Current’s approach includes connecting discrete technologies to monitor water quality in real-time. Credit: Current / Courtesy

The technology

No comprehensive system exists to measure real-time microbial levels in river surface water, Harkness said, so Current developed its own approach by purchasing and connecting discrete technologies.

Current installed solar-powered Proteus probes with optical sensors at three points on the Chicago River — north, south, and main. They measure data including water temperature, haziness, and tryptophan-like fluorescence, a measure of microbial contamination. 

The gathered data is transmitted to IOSight’s iGreen analytics system, which filters out unuseful data, organizes valuable data, and presents river quality information in clear visual representations such as graphs and diagrams. The results are publicly displayed on the H2NOW digital platform with explanations of whether the bacteria levels are good, low caution, or high caution in addition to information about previous readings. The data is updated every 15 minutes.

The team installed a Wavelet data logging and transmission system on the river’s main stem. It connects with probes and shares readings over communication networks. Current also is using a TECTA “lab-in-a-box” mobile microbial detection system. It identifies the presence of fecal coliform and helps with calibrating the probe measurements and providing trustworthy real-time estimates.

What’s next

The sensors will be removed for the winter, November through March, partly because few people interact with the river in the winter so project partners see little value in leaving the expensive equipment in the winter elements. In addition, the sensors are solar powered and sunlight is harder to come by during winter’s gray days and long nights. 

Current will use the downtime to find areas for improvements and possible new platform features for the relaunch next spring.

“In this phase, where we just initially launched, we’re collecting a bunch of ideas about how to make both the front-facing platform better and also what new technologies we might want to test,” Harkness said. “We are always interested in adding new technology components to the platform.”

Already this year, they tested a sampling technology that could help to clarify exactly where fecal coliform bacteria is coming from. For example, it could help determine if the bacteria is coming from people or animals. 

Current is also deciding whether and where to add more sensors because “every data point enriches our understanding about the dynamics of the different [river] branches.” However, the sensors are still pretty expensive so the project partners have to plan and budget.  

“Once we have really robust pilot results and understand how much value there is to the public using this — whether or not it’s actually achieving the goals of improving and enriching public understanding of the river — I think we’ll have a better sense of how to do sustainability planning for these efforts,” Harkness said. “There’s so much potential to use these data as ways to engage the public and help them understand why infrastructure investments matter so much.”