What Is the Civil Engineer’s Role in Wastewater Treatment?

Civil engineers tackle projects associated with numerous structures that people see every day — such as bridges, buildings and roads. However, they also apply their skills and insight to wastewater treatment. People don’t typically notice wastewater and its treatment facilities as often as those other buildings and infrastructure, but it is just as important.

Civil engineers frequently work with environmental planners on such projects, and some even specialize in water engineering while pursuing their degrees. Here are some of the fascinating ways civil engineers assist with the wastewater treatment industry.

Building New Plants or Upgrading Existing Systems

Any plans for new wastewater treatment plants must take into account an area’s current and future needs, as well as any applicable regulatory requirements. The same is true when a plant is upgraded so it aligns with modern needs. Civil engineers frequently contribute to and oversee those projects at every stage.

For example, Sally Walters is a civil engineer with more than 15 years of experience. She specializes in water engineering and ranks an upgrade to a sewage treatment plant as one of her proudest achievements.

Some of today’s civil engineers also use a tool called GPS-X, a wastewater treatment plant simulator. A team building a new wastewater treatment plant in Iraq used it to model all the facility’s processes before moving ahead with the project. That approach allowed examining proposed treatment types and selecting the most purifying, efficient options based on the model’s output.

Identifying the Link Between Wastewater and Public Health

Wastewater treatment is something many everyday individuals take for granted. Without the processes and chemicals used in those specialized plants, untreated wastewater could exacerbate public health threats.

Sometimes, civil engineers confirm wastewater treatment failures that make people sick.

One recalled having to tell a Guatemalan hospital director that his system discharged into a river that people used to source drinking water. Since that news came during a typhoid outbreak, it was timely but devastating information.

Civil engineering students at Ohio University are tracking COVID-19 in wastewater on campus. They use a machine called an autosampler to collect water once an hour for a day. Then, they analyze the samples to look for trends.

Elsewhere, a civil engineering research paper examined whether wastewater infrastructure could spread the virus. Researchers previously found a link between wastewater system defects and the spread of SARS in the 2000s. The author learned it might affect COVID-19 transmission, too.

Finding Better Wastewater Treatment Options

All water treatment plants deploy primary and secondary processes. Some also use tertiary treatments, particularly if regulations require meeting stringent standards. Primary treatments use gravity and continued physical processes to remove solids from the water. The secondary methods use beneficial microorganisms to break down more of the liquid’s impurities. Tertiary treatments provide additional purification and disinfection.

Wastewater treatment plant managers continually seek better ways to carry out each of those stages. Civil engineers often assist with related research. 

A team of civil and environmental engineers from the National University of Singapore recently found a new bacteria strain that could make wastewater treatment methods more efficient. It removes both nitrogen and phosphorus from sewage. That’s a significant outcome because most wastewater treatment plants use separate reactors to eliminate each one. That approach is expensive and takes up a lot of space. Plants that use single reactors that remove both can also be inefficient because multiple microbes compete for resources.

Exploring Possibilities to Make Wastewater Potable

Civil engineers use their expertise to develop safe ways to turn wastewater into drinking water in areas of the world that consistently experience water scarcity. For example, one facility in Orange County, California, treats wastewater and stores it in an aquifer to dilute and cleanse it before the public consumes it. After completing an expansion in 2023, the facility will generate 130 gallons of drinking water daily through this setup.

Additionally, engineers at Rice University used Houston as a model to determine the best ways to increase the amount of potable liquid from wastewater. One identified possibility was to create a water delivery system with several distribution points based on the existing wastewater treatment network. If the water does not travel as far between destinations, it will not pick up so many contaminants, making it faster to purify. The team also explored technologies to see which one worked the best and fastest while being the least expensive to implement.

This study examined direct potable reuse, considered the best choice for cities with established systems. However, the researchers clarified that better options could exist for engineers tasked with building entirely new infrastructures. For example, they might create a distribution system that separates the delivery of potable and non-drinkable water. That approach could streamline the processing time and make water available for use faster than other methods.

Facilitating Better Resilience While Fighting Pollution

Civil engineers play crucial roles in making destinations more resilient against disasters or regular bouts of inclement weather. Storms can cause overflows at wastewater treatment plants that lead to pollution. Ordinarily, stormwater holding tanks hold what comes from homes, businesses and road runoff during heavy rainfall. Moreover, civil engineers must make sure the infrastructure is built to last through generations.

The overflow is too much for a wastewater plant in a suburb of Dublin to handle. Figures indicate that the incoming wastewater is from approximately 2.3 million people, but the system can only manage liquid from 1.6 million individuals. This problem leads to hundreds of millions of litres of wastewater discharged into Dublin Bay and the River Liffey. It doesn’t help that the surrounding sewer system dates back to the 1900s.

Ireland gets frequent rainfall, but wastewater overflows can also happen if an area sustains a severe storm, such as a hurricane. That’s one of the reasons why civil engineers in the United States strongly supported the Safeguarding Tomorrow Through Ongoing Mitigation (STORM) Act. Tom Smith, the executive director of the American Society of Civil Engineers, explained, “As civil engineers, we’re thinking about building infrastructure that will last 50 to 100 years or more. The opportunity to build strategically is now.”

Crucial Input for Essential Infrastructure

These examples show why civil engineers possess expertise that leads to advancements in wastewater treatment. Their suggestions and project management capabilities create healthier, more productive communities that facilitate the highest possible amounts of wastewater properly treated and reused. The alternatives potentially harm people and the environment and mean water is not being effectively repurposed.