Hi-tech sewers can help safeguard public health, environment and economies

In the wake of the coronavirus, economic recovery is top of mind for all city leaders, the majority of whom believe that investing in infrastructure and technology can spur a rebound. Yet current analyses indicate that we only have funding available to cover approximately 57 percent of infrastructure system improvements through 2029, leaving an investment gap of $2.6 trillion. Cities are in the midst of some of their toughest-ever budget constraints and are faced with stressed infrastructure badly in need of renewal. Against a backdrop of rising needs and limited resources, officials are grappling to identify the investments that do more with less and deliver superior performance in the areas that matter most for their communities. One solution runs under our feet.

While sewer system investment doesn’t always make the headlines, new approaches to sewer and watershed management are delivering a big impact for cities across the country.

Making sewers smarter

When considering projects that define a “smart city”—using cutting-edge technology to improve quality of life—sewers are sometimes an afterthought. But tech-enabled, smart sewer systems that improve a city’s wastewater network can deliver far-reaching societal and environmental benefits to communities. For many cities, smart sewers deliver pay-back that should put them at the top of the smart city investment agenda.

Consider road transportation infrastructure as a metaphor to illustrate what’s possible. Designed to maximize efficiency, roads are managed with a network of stoplights and traffic sensors, with police directing and diverting traffic according to demand. Advanced wastewater technology works the same way, with coordinated sensors and virtual stoplights that adjust and direct flow to avoid congestion (in this case sewer overflows) and identify potholes (blockages and excessive infiltration and inflow). Smart sewer tech works just like GPS-enabled traffic apps, guiding flow based on live traffic conditions. Managing our sewer infrastructure is every bit as critical and, with new technology, as doable, today as managing our roads.

And smart sewer investments make sound economic sense for all segments of society. Citizens in economically depressed areas are often disproportionately affected by outdated and failing infrastructure, along with the financial burden to fix these problems. Digitally driven sewers help level the playing field for disadvantaged communities. Wastewater network assessment technologies, real-time monitoring, data analytics and system modeling allow utilities to target investment where it is needed most, minimizing the cost of maintaining compliance, and delivering solutions that are more sustainable and efficient.

Smart sewers can also deliver additional benefits to communities. For example, smart sewers can leverage innovative wet weather management systems, known as green infrastructure, that control and combat overflows integrate with public space, providing safer, greener areas for recreation. These systems can also improve and renew roadways, replacing sections with permeable asphalt, which allows rain and snowmelt to pass through, instead of flooding at curbs.

Take one case in point: South Bend, Ind., my hometown. The smart sewers project in this Midwestern city delivered multi-faceted, transformational outcomes. Virtually every time it rained heavily, the City of South Bend faced sewer overflows into the landmark St. Joseph River. South Bend’s aging infrastructure—in this case, its sewer system—would discharge excess flows into the river. One to two billion gallons of sewage-polluted water was being dumped into the river annually, and the cost of a long-term control plan to manage the overflow was estimated at more than $860 million. To put that number in perspective, South Bend has a total population of 100,000 people with a median household income of $39,000 per year—meaning residents would see a big impact in their tax increases.

South Bend turned to Xylem’s BLU-X wastewater network optimization technology to solve the problem with dramatically less investment. The system consists of smart sensors and smart valves, located throughout the network. Those sensors trade available conveyance capacity in real-time, like an underground stock market, and shift water to areas of spare capacity, avoiding sewer overflows.

By equipping the sewer system with technology that allowed for real-time sensing, monitoring and alerting, the system has eliminated dry weather overflows and reduced combined sewer overflow into the St. Joseph River by more than 70 percent. Since it was implemented, South Bend has reaped the benefits of approximately $1.5 million in annual operating and maintenance cost savings and close to $500 million in capital work savings.

Kieran Fahey, director of long term control planning for the City of South Bend, has noted that “the success that we’ve had in South Bend using the BLU-X smart sewer technology has allowed us to improve the water quality in the St. Joseph’s River at a cost that is achievable for the community.”

It is time to look beneath the surface of our cities’ ailing infrastructure and make the investments that maximize outcomes for our communities. Smart infrastructure solutions can deliver the digital insights needed to provide cost savings, superior system performance, and regulatory compliance. Innovative city and utility leaders can deliver a better way to manage wastewater systems and make a lasting difference in the lives of the communities they serve.

Luis Montestruque is vice president of advanced infrastructure analytics digital solutions at Xylem, a water technology solutions provider.