If you need the best Precast Concrete Sump Pit Supplier, you’re in the right place.
A sump pit is supposed to capture water at the lowest point on a site or building and maintain its level until it can be pumped out, doesn’t float in the ground or work up to the point where the pump gets flooded or runs dry.
When it works, people don’t even consider it.
In the event it does not, then it is likely not the concrete, but the supplier who designed and cast the pit.
This guide explains how to do a detailed review of a precast concrete sump pit supplier for a pump station to perform its function.
The Decision to Select a Supplier Is More Dependent on the Process They Use Than on the Spec Sheet
Buyers typically begin by assessing the cost per unit, depth and pit diameter.
The above is a good starting point, but it doesn’t include the specifics of sizing the wet well to meet your pump’s cycling needs or how the supplier seals the pit against groundwater and provides a detailed base design to prevent flotation when the pit is dry and the surrounding water table exerts pressure.
Sump pits are located in the wettest ground conditions on site and are generally below the water table for most of the year in coastal areas of the UAE.
A supplier that considers sump pits as a hydraulic structure, whose size is based on the pump cycle time and whose buoyancy and floatation conditions are verified, creates these items accordingly.
If it is treated as a simple concrete cylinder without the hole in the bottom, then he will give a pit that will either float out of the ground when it is empty or will fill up quicker than the pump can.
Be Sure You’re Ordering What You Need
It’s important to understand the type of sump pit that the project requires before comparing suppliers as not all precast manufacturers produce every type of sump pit.
Simplex Sump Pits
Simplex Sump Pits contain just one pump and are typically used in small applications such as basement dewatering, plant room drainage, or one building’s stormwater sump.
Duplex and/or Triplex Pump Station Sumps
A Duplex and/or Triplex Pump Station Sumps will have two or three pumps in succession or in parallel, and these pumps are sized up for larger flows where redundancy is important – having one pump go out of action does not mean that the site floods.
Wet Well / Dry Well Combination Pits
Wet Well / Dry Well Combination Pits are designed to isolate the water holding space from a dry compartment with the pump controls and valves to completely provide a dry environment for electrical / mechanical components.
Submersible Pump Sumps
The size of Submersible Pump Sumps is calculated specifically to accommodate the dimensions of the submersible pump, having as its base the pump cradle or guide rail system.
With this knowledge you may narrow your supplier search to those who design for pump station applications and not a general precast manufacturer who may make a modified manhole for use as a sump.
For Wet Well Sizing and Pump Cycle Calculations, Ask
The water flows through an undersized sump pit too often, causing the pump to wear out prematurely, and an oversized sump pit allows the water to stagnate and allows the sediment to settle.
Find out how they determine the wet well size; by the smallest cycle time of the pump you’re purchasing, and the manufacturer’s minimum start-stop flow rate, or by a standard series of sizes that they sell based on the type of pump you select?
Suppliers that want to know your pump curve and the rate you expect to draw in will be designing for your equipment; those who quote a size from a catalog are just shooting in the dark.
Take a Look at Their Waterproofing and Flotation Resistance
This is what makes the most costly mistakes.
Questions to pose to the supplier are how they prevent infiltration of groundwater, if they add an external waterproofing membrane, and how they determine if the pit floats when empty and the water table is high — a critical question.
Typically, it’s the weight of the base slab, anti-flotation collars, or the ballast (specific to the groundwater level at your site).
If you can get a supplier to show you how to perform their flotation check on your actual site conditions, they are giving you something you can check; if they don’t provide numbers, they’re not.
Check on Their Manufacturing Quality Control
Two sump pits can be identical on paper and yet end up with different characteristics when constructed.
Question about the method of casting and curing base slabs, sealing of pipe and cable penetrations at wall and what inspections are conducted prior to shipping out a unit.
A dense (good cured) base will repel water and will be able to bear compressive forces from resisting flotation forces and will be the first place that a pit begins to leak in poorly sealed penetrations.
Request Engineered Drawing and Structural Calculations
A good supplier will be able to draw something that is specific to your project rather than a cut sheet.
For sump pits it includes specific pump size and mounting information, the volume of the wet well based on your pump cycle needs, and a flotation test to your site’s water level.
If a supplier is not able to generate calculations specific to your pump and site requirements, you are likely purchasing a generic pump’s size that is appropriate for another project.
Discuss the Similarities and Differences Between Access and Maintenance Provisions
A sump pit must be maintained as long as it remains in the ground – clean debris, adjust floats, replace pumps.
Ask the supplier how it will be designed to provide access:
- Will a cover be large enough for a person to lift the pump out without entering a confined space where possible?
- Will the pump have some rails for pulling and reinstalling without draining the pit?
- Will the pump have enough clearance for a person to actually reach the components that need to be serviced?
When a pit cannot be accessed via confined space other than full entry, it adds to the cost and risk associated with every maintenance visit of the system over its lifetime.
Look Into Their References and Track Record
What a supplier can provide you is determined by sizing calculations and flotation checks.
Placed pits are a truthful indicator of what they actually delivered.
Request specific examples of sump pits provided to sites with similar pump duty and groundwater conditions and pictures or maintenance history well after installation, not at delivery.
After a couple of years in the ground, a pit that is still dry and level and running well is a reflection of a supplier’s product design rather than any spec sheet.
The Following Is a List of Red Flags to Watch for in a Relationship
Here are a few warning signs that may occur simultaneously when a supplier isn’t familiar with pump station applications:
- Vague answers regarding wet well sizing or calculation of pump cycles.
- Unwillingness to provide a flotation check for your location’s groundwater level.
- No clear answer on how pipe and cable penetrations are sealed.
- Price significantly lower than the rest of the market with no explanation of the difference.
None of these is in itself disqualifying, but two or three together are worth stopping to ponder.
Pupil Progress Data: Bringing It All Together
The key to selecting the right precast concrete sump pit supplier is knowing which pit configuration is actually needed for your project, verifying the pit is sized to accommodate your actual pump, verifying flotation resistance is sufficient to handle your project site’s groundwater, and verifying practical access for maintenance — and let’s be honest — the actual pit will have to do all of these things, and will have to do them well — not just on a drawing — after it is installed.
If you get this right, the pit performs exactly as it is supposed to: it supports the pump to maintain water stability; it keeps the pump running properly; and it doesn’t come into contact with you for decades.
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