Understanding the Different Types of Sewage Systems

When you think of sewage you likely think of a putrid sludge moving through the pipes under the road outside, and you wouldn’t be totally wrong. However, there are a few different types of sewer systems and they each have a unique purpose for catching waste and wastewater.

The three types of sewers are sanitary sewers, storm sewers, and combined sewers. All three of these sewer systems play important roles in ensuring that the waste we produce is transported and treated properly.

Sanitary Sewer System

The main purpose of a sanitary sewer is to carry waste away from homes and businesses to wastewater treatment plants. These systems are specifically designed to handle human waste and easily degradable manufactured solids such as toilet paper and tissues. These systems consist of many miles of piping, manholes, and pumping stations to propel the waste through the system.

How these sanitary sewage systems work is by carrying human waste through small plumbing pipes in the home, to gradually bigger pipes outside, until it reaches the main sewer line in the street. From here the sewage is transported to a wastewater treatment plant to be treated and returned safely to the environment.

Storm Sewer System

Storm sewers, also known as surface or runoff sewers, are designed to collect and carry rainwater, snowmelt, and irrigation runoff into storm drains located in parking lots, streets, and gutters. These drains are connected through a series of underground pipes that carry this water directly to rivers, lakes, and other bodies of water without having been treated at a treatment plant.

Unlike the sanitary sewer that carries waste to a treatment plant, the storm sewer system carries untreated runoff water straight into our environment. All the water that goes into that storm drain is discharged into our waterways.

Combined Sewer Systems

These types of sewer systems are exactly what they sound like. They are a combination of sanitary sewer systems and storm sewer systems. They typically aren’t used anymore due to their potential health hazards to people and the environment. 

How combined sewers work is by collecting all the water from rain and snow into a pipe and then adding human waste into the same pipe. In ideal circumstances, this system would pump these combined wastes to a treatment plant where it would then return safely to the environment.

However, in times of extreme rainfall or flooding, these systems can back up and overflow causing untreated wastewater to flow directly into the environment. This allows for dangerous pathogens and pollutants to make their way into the environment, posing a serious threat to people’s health.

SCADA Monitoring: Sewage and Wastewater

In order to ensure that these sewer systems operate properly and minimize the overall risk of overflow and malfunction, a supervisory control and data acquisition (SCADA) system can help. A SCADA system can be implemented at multiple levels in the wastewater collection and treatment process.

Whether it’s booster pump monitoring or treatment tank monitoring, a SCADA system can help mitigate equipment damages, overflows, and quickly report any malfunctions. Check out High Tide Technologies to learn more about the applications of SCADA in wastewater treatment and how it can help make your system more efficient.