When choosing a pump station, the installation type plays an important role: above ground (dry installed) or underground (wet well with submersible pumps). In this article, we compare both configurations on maintenance, safety, costs and uptime — so you can make an informed decision for your sewage, wastewater or water management situation.
What is an above-ground pump station?
An above-ground pump station, also known as a dry-installed pump chamber or dry-installed pump station, positions the pumps above liquid level. The liquid is drawn in via a suction line. Maintenance, inspection and repair take place above ground, without personnel needing to enter a wet well or confined space.
With an underground configuration, submersible pumps are placed directly in the liquid in a wet well. Maintenance requires the pump to be hoisted up, including the associated safety measures for working in confined spaces.
Comparison: above ground vs underground
| Criterion | Above ground (dry installed) | Underground (wet well) |
|---|---|---|
| Maintenance | Above ground, safe, fast | In the sump, lifting required |
| Safety | No confined space | Confined space procedures required |
| Inspection | Visual and auditory, direct | Only after retrieving pump |
| Downtime | Shorter (faster maintenance) | Longer (more complex procedures) |
| Civil works | Pump house/frame above ground | Wet well with guide rails, lifting facility |
| Footprint | Above ground | Underground (smaller footprint) |
| Noise | Audible (attenuation possible) | Muffled by underground placement |
| Life cycle costs | Often lower (fewer labour hours) | Often higher (more complex maintenance) |
Advantages of above-ground pump stations
Safety and working conditions
The most important advantage are safety and hygiene. Maintenance on pumps in a wet well requires working in a confined space — with risks of gas exposure (H₂S), slipping and drowning. An above-ground installation eliminates these risks. Personnel work at ground level in a dry, easily accessible space. Also, since the above ground installed pumps remain clean on the outside, the inspection and maintenance work adds to pleasant and hygienic working conditions.
Faster maintenance, higher uptime
At an above-ground pump station, pumps are directly accessible. Inspection covers, shimless adjustment and cartridge seals make maintenance fast and simple. No crane or hoisting equipment is needed. The result: shorter maintenance stops and higher uptime of the pump station.
Lower Total Cost of Ownership
Although the initial investment in an above-ground installation is sometimes higher, the TCO over the service life is often lower. This is due to shorter maintenance time, less deployment of specialist equipment and fewer emergency measures during failures. Read more in the article on costs and TCO of self-priming pumps.
Condition monitoring and early detection
An above-ground pump is not only easier to maintain, but also easier to monitor. Vibrations, temperature and noise are directly observable. And with the addition of suction and discharge gauge reading, pump operation and efficiency can be monitored real-time. This makes early detection of wear or deviations simpler than with a pump that is submerged.
When to choose above ground?
An above-ground pump station is in many cases the best choice for:
- Permanent sewage pump stations and lift station applications
- Locations where safety and working conditions are a priority
- Applications with high uptime requirements
- Situations where TCO outweighs purchase price
An underground wet well may be preferred when above-ground space is very limited, noise is unacceptable (and attenuation is insufficient), or when the application is simple enough to serve with a submersible pump.
Gorman-Rupp solutions for above-ground pump stations
Gorman-Rupp Europe supplies self-priming pumps designed for dry-installed installations. The Super T-Series®, Super U-Series® and Ultra V-Series® are suitable for wastewater, sewage and industrial applications.
The Reliasource / SCS system offers a complete modular pump station concept with self-cleaning sump, maintainable above ground and suitable as a replacement for traditional wet wells. View the full overview of self-priming pumps.
In addition, Gorman-Rupp Europe provides support with the selection, design and commissioning of above-ground pump stations, from system analysis to pre-assembled delivery.
Frequently asked questions
The purchase costs can be higher due to the above-ground construction. However, the lower maintenance and downtime costs over the service life often result in a more favourable TCO.
Above-ground pumps produce more noise than underground installations. This can be resolved with a sound attenuated enclosure. Electrically driven pump sets (such as the E-Line) are particularly quiet in operation.
In many cases, yes. Gorman-Rupp Europe supports retrofit projects, including system analysis and advice on the most suitable configuration. Contact us to discuss the possibilities.
Want to know more about above-ground pump stations for your situation? Our pump specialists are happy to assist. Contact us.