Have you ever wondered what happens to the water after you flush the toilet or drain the sink?
In the Greater Nashville area, this process involves an intricate system which is designed to ensure that wastewater is treated and safely returned to the environment. Understanding this journey helps us understand the importance of maintaining and upgrading our sewage infrastructure. Let’s delve into the current model, planned updates, and how YOU can stay informed and involved in the management of Nashville’s wastewater.
The Greater Nashville Area Sewage System
Current Sewage System Model
The Greater Nashville area’s sewage system is a complex network of pipes, pumps, and treatment facilities designed to manage and treat wastewater from homes, businesses, and industries. The system is operated by the Metro Water Services (MWS), which oversees the collection, treatment, and discharge of wastewater.
Parts of the sewage infrastructure utilize a combined sewer system (CSS). A combined sewer system is designed to collect rainwater runoff, domestic sewage, and industrial wastewater in the same pipeline. Under normal conditions, the combined sewage is transported to a wastewater treatment plant where it is treated and then discharged into local water bodies. However, during periods of heavy rainfall or snowmelt, the combined volume of wastewater and rainwater may exceed the capacity of the combined sewer system or treatment plant. When this happens, combined sewer overflows (CSOs) occur, releasing untreated or partially treated sewage directly into rivers, streams, and other bodies of water.
To mitigate the environmental and public health impacts of CSOs, MWS in Nashville has implemented various strategies. These include:
- the construction of retention basins to temporarily hold excess water
- the expansion of treatment plant capacities
- and the separation of stormwater and sanitary sewers in critical areas.
Additionally, green infrastructure solutions, such as rain gardens and permeable pavements, are being introduced to reduce the volume of stormwater entering the combined sewer system. These efforts aim to decrease the frequency and severity of CSOs, ensuring a cleaner and safer environment for the Nashville community.
Storm Sewer vs.
Sanitary Sewer
How Is Wastewater Actually Treated?
Understanding the complexities of Nashville’s sewage system, including the challenges posed by combined sewer systems, naturally leads to a crucial question: How is wastewater actually treated? Delving into the treatment process reveals the sophisticated methods and technologies used to transform wastewater into safe, clean effluent before it is released back into the environment.
Before we begin, let’s define that word, effluent. Effluent refers to the treated water that flows out of a wastewater treatment plant. After undergoing various stages of treatment, effluent is released back into local water bodies, such as rivers or lakes.
This water should meet environmental standards established by the Tennessee Department of Environment and Conservation to ensure it is safe for the local ecosystem and public health.
Let's learn about this process with a video!
Planned Updates to the Sewage System
Planned Updates to the Sewage System
As Nashville grows, so does the demand on its sewage infrastructure. Recognizing this, the Metro Water Services has several plans for updates and improvements:
- Capacity Expansion With the city’s rapid growth, increasing the capacity of existing treatment plants is a priority. This involves upgrading equipment, expanding facilities, and enhancing treatment processes to handle more wastewater efficiently.
- Infrastructure Renewal Aging infrastructure poses significant challenges. Plans include replacing outdated pipes, pumps, and other components to reduce leaks, overflows, and maintenance costs.
- Green Infrastructure Incorporating green infrastructure, such as rain gardens, permeable pavements, and green roofs, helps manage stormwater runoff, reducing the load on the sewage system and preventing overflows during heavy rains.
- Advanced Treatment Technologies Adopting cutting-edge technologies like membrane bioreactors and UV disinfection can enhance the effectiveness of wastewater treatment, ensuring cleaner effluent and better protection for the environment.
The journey of wastewater from our homes to its return to the environment is a fascinating and vital process. In the Greater Nashville area, the sewage system is an essential part of maintaining public health and environmental quality. As the city grows, so does the need for a robust and updated sewage infrastructure.
Staying informed and involved in wastewater management is crucial for Nashville residents. You can attend public meetings held by Metro Water Services to stay updated on sewage system projects and improvements.
Additionally, organizations like Harpeth Conservancy offer educational programs and volunteer opportunities focused on water conservation and quality. HC actively engages in initiatives like advocating for responsible water withdrawal permitting, conducting water quality testing, and advocating for proper sewage system design.
By participating in these programs and adopting sustainable practices at home, such as proper disposal of waste and reducing water usage, we all can play a vital role in protecting Nashville’s water resources and ensuring a cleaner, healthier environment.