Understanding the Different Types of Lift Stations
Municipal water systems must move millions of gallons of potable water and wastewater daily. While the force of gravity handles much of the work, there are times when the flow must travel uphill. Lift stations are the primary solution to this problem. Choosing the right pump and station design for a given situation is critical for consistent operation.
What is a lift station?
In a typical lift station, water enters a holding chamber or well. A pump then forces the water to a higher elevation. Valves in the system open and close to prevent backflow and allow elevated water to move through the system.
The Different Types of Lift Stations
Lifting stations in the water industry break down into two types. The primary difference is the location of the pump in the facility.
Dry Well Lift Station
Every sewage lift station has a wet well for collecting wastewater. Once there is a predetermined volume in the tank, the pump activates to move the liquid. In a dry well station, the pump and other controls sit in a separate well apart from the liquid.
The advantage of this arrangement is that the equipment is easy to access. Maintenance and repairs can happen without dealing with the wastewater in the wet well. Dry well pumps are generally more energy efficient than their submersible counterparts.
Because they require two compartments, dry well lift stations are larger, more noticeable facilities than wet well stations. This added size increases the cost of building the station.
Submersible Wet Well Lift Station
In a submersible station design, the pump sits in the wet well with the wastewater. Pumps in this type of station often have solids-handling capabilities that make them more robust. While performing maintenance may be inconvenient, submersible pumps are designed to need less attention.
Wet well stations cost less to implement. Submersible pumps are often less expensive, and the simple design of the station requires less labor.
Considerations When Choosing Lifting Stations
Once a water utility recognizes the need for a lift station, it must choose a design that meets its needs. Several factors may come into play.
Flow Rate
Building a station that will accommodate the area’s flow rate is a practical concern. If wastewater sits too long in the wet well, it can promote the growth of dangerous bacteria and release unpleasant odors. If the capacity is too small, the pump will run frequently, leading to higher maintenance and replacement costs.
Ease of Maintenance
Systems with several stations or fewer technicians may find that ease of access to station components is an important factor. Submersible pump maintenance may result in a long pause in operation as well as exposing technicians to wastewater.
Operating Costs
The difference in installation and operating costs may be a deciding factor when choosing the design of a sewage lift station. Dry well station pumps can be more efficient, but the facility costs more to install than a wet well.
Solids-Handling Capacity
Wastewater often contains solids that can impact the performance of a pump. A submersible pump with solids-handling capacity may be the right choice if clogs are a concern.
Other Water Conditions
Certain water conditions may demand the use of a dry well model. A submersible pump is not feasible in industrial settings where it would operate in hot or caustic water.
Pairing SCADA Technology with Sewage Lift Stations
System control and data acquisition technology can help incorporate a lift station into the larger water system. Sensors connected to the SCADA system send performance information to a central hub and alert the utility of sudden changes. Sensor data will also allow maintenance teams to see changes in performance over time, giving them a better sense of when the station needs attention.
A Partner for Cloud-Based SCADA in the Water Industry
Could-based SCADA systems designed by High Tide Technologies are an ideal solution for asset management in municipal water collection, distribution, and treatment systems. By utilizing cloud storage, performance data becomes available in any location through a laptop, phone, or tablet. The result is a system with higher efficiency and greater responsiveness. Contact High Tide Technologies today to learn more about the advantages of incorporating SCADA technology in your water system.