Cities Are Racing to Replace Aging Sewer Systems

By Emily Newton

Cities all over the U.S. are rushing to replace aging sewer systems, and there are a few critical reasons why. The nation’s sewer development boom in the early to mid-twentieth century is no longer meeting infrastructure needs.

Aging sewer systems all over the country are simultaneously reaching the end of their reasonable lifetimes, causing serious concerns for city infrastructure managers. In addition to aging pipes, climate change and population growth are putting excessive pressure on systems already struggling to keep up.

Older Sewer Systems Are Aging Out

One major source of the race to replace aging systems is the age of most American sewer infrastructure. Studies have found that most underground pipes in the U.S. have already reached the end of their useful life or are nearly there. This includes lines laid in the early and mid-twentieth century and even as far back as the 1800s. They pose a greater risk of cracking, breaking and releasing toxins into water supplies as they age.

Additionally, the age of pipes themselves, even those that are still safe and functional, impacts their effectiveness today. The American population has more than doubled since 1950. Lines built in the post-WWII era were made for a population significantly smaller than today. This means the nation is working with sewer systems that were simply not built to handle the amount of traffic they are getting.

Overburdened sewer systems combined with old and deteriorating pipes create a recipe for disaster in many urban areas. These factors increase the risk of sanitary sewer overflow (SSO) and combined sewer overflow (CSO) events, which seriously threaten public health and the environment. Older pipes are also at a higher risk of experiencing cracks and breakage. It is no surprise that there are an estimated 240,000 water main breaks annually in the U.S., costing billions of dollars in repairs and lost water.

Repairing and replacing pipes is no quick job, either. Teams of utility experts and construction personnel are needed to conduct the actual pipe work. Plus, they need time to excavate and trench the area to dig out and replace the broken pipes. This requires high amounts of work, time and money.

The Lead and Copper Problem

Anyone familiar with the water and sewage industry knows the serious risks of lead and copper in public water supplies. It is one of the main factors influencing the current race to replace aging sewer systems. Experts predict that most lead and copper pollution in drinking water comes from the corrosion of home plumbing systems rather than water supplies themselves. However, service lines may still pose a contamination risk.

Lead and copper were much more common in the early and mid-twentieth century. Today we know those materials are dangerous for building, especially residential infrastructure. Unfortunately, most of the nation’s sewer systems were built a hundred or more years ago. They are aging and losing structural integrity and are also more likely to contain dangerous materials that pose a public health threat.

Pipes nearing or surpassing their useful life spans are more likely to begin experiencing corrosion, releasing lead and copper into residential water supplies. Since so much of the nation’s sewer infrastructure was made when lead pipes were still common, this threat is now occurring on a massive scale, further compounding the problem. It’s no surprise that many cities are hurrying to replace their sewer systems before corrosion occurs.

The Role of Climate Change

Climate change may not sound like it has anything to do with sewer systems, but it is actually causing serious issues. Over the past few decades, it has led to significantly higher than average rainfall in many U.S. cities. EPA data shows that extreme single-day precipitation contributes to these rising numbers.

This means urban areas in parts of the country are experiencing more days with extreme rainfall, which leads to intense traffic in sewer systems. As a result, pipes and drainage systems are overflowing more often due to this rise in excessive precipitation rates.

Increased rates of SSOs and CSOs can be dangerous and cause serious damage. For instance, numerous videos went viral in 2022 when extreme rainfall caused flooding in the New York City subway and highways. Flooding of this intensity poses a health and safety risk and leads to infrastructure and property damage.

This extreme precipitation trend will likely continue as climate change issues persist. Aging sewer systems are already overburdened today. Population growth and ever-increasing rainfall rates will only speed up the process and worsen current flooding and overflow issues.

Solutions for Aging Sewer Systems

In the face of these challenges, city leaders are stepping up with innovative solutions for aging sewer systems. It will take massive amounts of time and money to completely replace old infrastructure, so many of today’s urban solutions are focused on alleviating stress on these systems to protect public health and local environments.

For example, architects and construction leaders are beginning to adopt eco-engineering in new urban infrastructure. It utilizes principles that prioritize minimizing a structure’s environmental impact, including on local sewer systems. An eco-engineering approach for development will reduce strain on aging infrastructure, helping to protect local wildlife and plant life from pollution.

Additionally, some cities are using large-scale, ambitious projects to address sewer system challenges. For instance, Philadelphia uses “greened acres” to soak up rainwater before it can get into sewer systems. These are areas of land designed to absorb rainfall or direct the flow of it to rain gardens, which are like natural basins for collecting excess precipitation and soaking it into the soil.

Even individual homeowners can help. Some Philadelphia residents are using porous materials in their driveways to soak up rainwater coming off their roofs. This captures precipitation before it can get into sewer systems. More people using strategies like this could potentially alleviate a significant amount of stress on sewer systems.

Moving Toward Safer Sewer Systems

Creating safer sewer infrastructure will take time, investment and innovation, but it isn’t impossible. Cities all over the U.S. are already demonstrating creative solutions to these challenges by focusing on reducing the amount of liquid these pipes have to handle. Modern, green updates will make U.S. sewer systems safer and healthier for people and the planet.

Emily Newton is a construction and industrial journalist. She is also the Editor-in-Chief for Revolutionized Magazine. Keep up with Emily by following her by subscribing to Revolutionized’s Newsletter.

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