Modern American sewer systems were first built in the mid-nineteenth century as a reaction to the worsening of sanitary conditions brought on by massive industrialization and urbanization. But even after decades of advancements in many other aspects of industrialization and, still an average U.S water pipe is 77 years old, a great many were laid in the 19th century. Sewers are even older. Most should have been replaced decades ago.
The vast majority of the country’s water systems are in urgent need of repair and replacement. Climate change and the heavier rainfall is expected to make things worse. Unexpected heavy rainfalls introduce too much water into the system and can cause pump stations and treatment plants to break down, as well as untreated sewage to overflow from manhole covers and pour into water bodies. The overflow is so significant that the storm water-and-sewage mixture backs up into the streets. As treatment plants age across the United States and as the country’s population grows, these sewage floods are becoming more problematic, contributing to the severe surface-water problems. Experts say this could create a sewage burden that cities need to plan for.
We’ve seen this sort of burden in recent days with the extensive flooding experienced in Baton Rouge. Experts say Baton Rouge’s sewage system was unable to handle the extensive and long lasting downpour, leading to “sanitary sewer overflow.” This happens when too much water is introduced into the treatment facility causing sewage backups and overflow which can be very hazardous to human life.
Increased rainfall could lead to dangerous overflows in cities that have combined sewer systems. Cities that don’t have combined systems still end up with storm water in their sewers through infiltration and inflow.
A combined sewer is a sewage collection system of tunnels and pipes also designed to collect surface runoff. They can cause serious water pollution problems when wet weather flows exceed the sewage treatment plant capacity. This type of sewer scheme is no longer used in building new communities. Many cities in the United States still have combined sewer systems. It’s difficult to estimate the number of overflows they lead to, but a 2004 U.S. EPA report pegged it at about 850 billion gallons being discharged into American waterways.
Municipalities across the country are employing different approaches to deal with the issue. Broadly, they fall into two categories:
Investing in pre-existing “gray” infrastructure like updating, expanding, redesigning, and, in many cases, reinventing the sewage infrastructure for 21st-century challenges.
The second option is opting for green infrastructure, which mainly tries to keep rainwater out of sewage systems and allow for reuse of treated effluent.
According to experts, the first option is not much sustainable as pipes, storage tunnels and treatment plants are designed with fixed volumes in mind, meaning increased precipitation patterns could pose a problem over time. But the second solution, i.e. green infrastructure, has flexibility and resilience as it is a more adaptable system.
The municipal authorities in different cities of United States are constructing additional capacity in treatment plants and storage facilities but are also trying to find ways to use natural solutions. There are technologies that allow for communities to expand their capacity without the costly infrastructure. Technology companies like Active Water Solutions have the ability to lower the risk of sewage backup and overflow. The technology also allows for water reuse for agriculture purposes as well as industrial process.
The reality is the global climate change is making us reevaluate how we must look at the future of our infrastructure. We have to take action now in an effort to mitigate risks in the future.
Are you interested in learning more about advanced technologies in wastewater treatment? Contact us today.