What is a shallow well and how does it work?

by admin | Oct 25, 2021 | Uncategorized

With the countrywide drought and strict water restrictions in the Western Cape and other regions still fresh in our memory, several homeowners have resorted to – or are considering – installing shallow wells to access groundwater close to the surface. This water, if available in your area, is a great resource to supplement or even replace municipal water to irrigate your garden, or as an emergency water supply. 

People have been digging wells all over the world for thousands of years and many of the best constructed wells are still in use today. 

– What is a shallow well? 

A shallow well is typically just a hole in the ground for water to seep into. It differs from a borehole in that it is much shallower and doesn’t attempt to tap into an underground aquifer. These wells can be created in a variety of different ways, depending on your soil type, from digging it with a shovel or excavator to drilling or ramming pipes into the ground. The cost of digging a shallow well is much less than drilling a deep borehole. 

Water from these wells will typically have a lower level of total dissolved mineral solids compared to most boreholes, but shallow wells are more prone to bacterial contamination from above and the opening should always be covered for safety.

The sidewalls should also be lined with either plastic or metal piping to prevent it from collapsing. 

– How do I get the water out?

Water can be extracted from a shallow well with a jet pump up to a depth of around 6 metres. The pipe going down the well should be as wide in diameter as possible to reduce friction and there must be a spring-loaded non-return valve at the bottom of the pipe to keep the pump primed. The water extracted by the jet pump can be stored in a water tank to use later, or it can be used directly to irrigate your garden. 

The size of the jet pump you need will depend on the depth of your well, how fast it recharges, and how far you want to pump the water once it is above ground. The recharge rate of your well is the time it takes to refill with water after pumping all the water out. It is advisable to never let the inlet of your suction pipe hang right at the bottom of the well where it can suck in sand or debris, as this will very quickly wear the pump’s impeller down. 

– How do I know if a well will work in my area?

The simplest way to know if a well will work in your area is to ask people in your community if they have a working well. Unfortunately, there is no fail-safe way of predicting exactly where you will find water when you start digging. It depends on the soil type, typography and even the rainfall of the recent past. 

Pascali stocks a range of jet pumps suitable for shallow well applications and the technical team at Pascali is ready to answer any questions you may have.

What is hard water and why is it important?

by admin | Oct 25, 2021 | Uncategorized

What is commonly referred to as hard water is water that contains a significant amount of dissolved minerals, especially calcium and magnesium. This isn’t a situation associated with rainwater or municipal water, but borehole water can potentially contain a range of dissolved minerals, depending on the rock formations the water travels through.  

– Why is it important? 

Hard water can influence pumps, pipes, and fittings in the long run. Calcium carbonate deposits – or lime scale – can build up inside pumps, pipes and fittings over time and restrict the flow of water. In the most extreme cases this buildup can cause a pump’s impeller to become stuck inside the pump casing. 

The deposits will mainly be located at warmer surfaces and areas where the flow of water is high. In a pump this is typically around the mechanical seal, at the impeller and around the cooling mantle or stator housing. The problems caused by the deposits include mechanical seal failure, unbalance on the impeller and overheating in the motor.

This should be avoided by opening the pump housing, inspecting, and cleaning the impeller, seals and housing with a wire brush regularly. There are chemicals that can remove the build-up, but it is recommended that a professional do this. 

Deposits that have built up inside water pipes will cause a reduction in water pressure because they restrict the flow. Over time, water pressure may slow to a trickle or stop flowing altogether.

Hard water will also have an influence on the efficacy of soap, detergents, and shampoo.

– What can be done about it?  

If you are reliant on borehole water for domestic use the water should be tested every year by an accredited water laboratory. These tests will give you an indication of the total dissolved solids, pH, possible E. coli count, and a breakdown of the different minerals in your water. There are different thresholds of acceptable levels of dissolved solids in water for domestic use and for irrigation. 

If your water has high levels of dissolved solids, it could be worthwhile to install a filtration system. Filtration systems should always be installed in the water system after a booster pump. The pump should push the water through the filter and not have to suck the water through the filter.  

Be aware that if you have hard water, regular mechanical cleaning of the pressure pump is the most practical solution.

For the best possible advice contact the professionals at Pascali who are standing by to answer all your questions. 

How does a pressure tank work?

by admin | Oct 25, 2021 | Uncategorized

You will often see a pressure pump sit on top of a small pressure tank in domestic setups. This tank is not just to keep the pump and motor off the ground but plays an important role in the way your pressure pump system functions. 

– How does it work?

Air can be compressed, water cannot. The pressure tank, which is typically 24 litres in capacity stores water and compressed air, separated by a rubber membrane or bladder. The air pressure inside the pressure tank can be adjusted to the desired level at which the system should operate. A pressure tank is usually installed with a mechanical pressure switch, which will switch the pump on if the pressure drops after a tap is open for long enough and will switch off again when a pre-determined pressure is reached. 

– What a pressure tank does

When a tap is opened for a short while, like filling a glass of water, the air pressure in the tank will push the water out and the pump won’t have to switch on. If a tap is kept open for longer, like running a bath, the pressure will drop and the pump will switch on to restore the pressure to the pre-set level. 

– Benefits of a pressure tank

Some of the benefits of a pressure tank is that your pump won’t have to switch on every single time someone opens a tap. This saves electricity and reduces wear and tear on the pump motor. Another benefit is that there is a larger amount of water that is already under pressure compared to a system without a pressure tank. This pressurised water is available even in the event of a power failure. 

Because water cannot compress there is a phenomenon called the water hammer effect. This happens when fast flowing water comes to a sudden stop, like a closed tap. The water crashes into this obstruction with a significant force. There is a massive amount of energy locked up in moving water and the water hammer effect can really cause some damage. The pressure tank with an air compartment serves as a shock absorber, alleviating the hammer effect on your entire system, because the air can be compressed to dissipate the energy. 

If you have any more questions or you need a qualified professional to install your pressure pump system, don’t hesitate to contact the technical people of Pascali for assistance.