Water Borehole Maintenance

Don’t let your water well fall into a state of disrepair

Water borehole maintenance is essential to maximise the long term life of this resource. The first step, and the easiest, is to ensure that the water is tested regularly. Testing your well water regularly ensures that that if the water quality is starting to change, which often happens, you can catch this at the early stages and resolve this quickly and effectively as bacteria grow exponentially and cause the well to fail.

Iron and manganese water

Bore holes accumulating iron oxide deposits is very common and occurs from iron salts within the water and from the action of naturally occurring bacteria which thrive in an iron-rich environment.

This contamination in the well looks like rust-red deposits which gradually block the bore hole pump. The bacteria stick to the pumps impellers, slowly building up till the pump fails. The bacteria also clog up the piping further down the well system, causing loss of flow due – This is often the first sign you will see of this problem occurring.

Signs of iron at the surface

If the water appears to be crystal clear, but on standing takes on a brown tinge, it contains dissolved ferrous salts which are oxidising to the insoluble ferric form. With less oxygen available below ground, this process will be very gradual at the level of the pump but a hard, rusty, layer will slowly build on hard surfaces and start to choke the waterways.

Should the water be rusty and cloudy looking on start-up and have an unpleasant smell, there will be iron related bacteria at work in the depths. These grow as an orange slime while also oxidising the ferrous salts into ferric solids which will, again, cause blockage of the water passages.

Each borehole is different but many “iron affected” wells will suffer both direct oxidation and bacteriological contamination to some degree.

Our maintenance packages have been designed to identify these problems early so rectification is easier and cheaper than if the well is left to choke.

How the cleaning process works

If we can TND Drilling like to inspect the Water Well with a Bore Hole camera prior to works commencing so that we can see the extent of the blockages (sliming) clogging of the slots if the well has a slotted liner.

The solution is then added to the well in liquid form containing a powerful, naturally occurring chemical, which will combine with the Iron Oxide deposits in the well to form a solution which can be pumped clean away from the borehole carrying with it all bacteria and foul deposits. The solution doesn’t, react with or damage any metallic or man-made material generally used in borehole pumps or pumping systems.

Cleaning the borehole can take up to 48 hours depending on the severity of contamination so it is essential that if the bore hole is to be taken off line this is scheduled in so other resource planning can be made. The water well pump and rising main will need to be recirculated and as much of the system as possible to ensure that the whole system is treated.

Things to consider before bore hole cleaning

The well cleaner removes a very large percentage of iron build up but it is not to be used as a one hit long term problem solver the contamination will reappear in the borehole as it is an entirely natural process with water movement. Experience will dictate the frequency of treatment necessary to keep the problem in check with a minimum of down-time, regular water testing is essential.

One other problem that can happen is that the well clearance works so effectively that as the iron oxide (slime) is removed it actually uncovers the true condition of the steel works (rising main etc) and this then causes minor leakage holes. it is imperative that this is assessed as it is possible that the pump becomes disconnected in the hole, this then becomes very costly to rectify.