Water Bore Construction
Water Bore Construction…..what is it exactly? A Water Bore is not something everyone has experience with, especially not the construction side of things. Many people purchase a property with an existing bore so do have some experience with using a Water Bore, however the complete Water Bore Construction phase is the most critical aspect. If your considering having a bore drilled then there are several potential issues to be aware of, thus this post on our website.
The unaware seem to assume that a bore is just a hole in the ground with some pipe in it. To a very small degree this is true, however there are, or should be, many other factors taken into consideration and most definitely put into practise during Water Bore Construction.
Firstly is the location of the water bore. We are firm believers in our water divining skills, so much to say that we put our money where our mouth is, not only with a “No Water No Charge” policy, but a signed written guarantee of a bare minimum flow rate of at least 15 lts per minute. Any less than 15lts per minute and we will declare the bore to be “No Water No Charge”, at which point we will select another site to drill, with the same 15lt per minute minimum flow requirements. Some drillers say they offer a “No Water No Charge” policy, however if they find you 5 lts per day they declare it as “water” and you will be charged in full! Centre State Drilling does not operate in such a way, we believe in doing the right thing by our clients, thus a signed written guarantee.
The drilling of the water bore to appropriate depth commences, then it is lined (or SHOULD BE) to the FULL depth of the hole, all the way to the bottom. This bore lining is referred to as “bore casing”, and in most bores 125mm class 9 pvc bore casing is the minimum construction requirement. The key part of the minimum construction standard is the “Class 9”. This denotes the wall thickness (strength) of the casing. There is a vast array of bore casing available, some Australian made and some cheaper imports from Asia. We only use Certified Australian made bore casing of at least class 9. Its more expensive than the imported casing, however it complies to Australian standard, is certified lead free and in our case, comes with a lifetime warranty.
The following pictures are of a bore that was constructed “cut price”. Some contractors on arriving on site, ask to see any other quotes and promise to “get under it”….. the following is the type of result many unsuspecting people receive.
Looking at these pictures we can see that the bore has collapsed and caused significant subsidence around the surface of the bore. The large piece of “bore casing” was retrieved from the bore hole. This section of the bore “imploded” thus causing the bore to collapse. Needless to say the bore is now beyond remediation and a new bore now needs to be constructed. Looking closely at the third picture we can clearly see the word “sewer” on the casing. This is cheap sewer pipe that was used instead of the required class 9 pressure pipe bore casing!
After the correct casing is installed, the bore should be “developed”, that is pumped clean with an air lift technique, to remove and drilling slurry or sediment in the hole as a result of the drilling and construction process. In certain geological formations an “gravel pack” is used, that is the annulus of the hole, or the space between the outside of the bore casing and the walls of the hole, is lined with fine gravel to support the formation and filter any sediment, then the developing process can begin. Bore development is an important step for two reasons, firstly it ensures a CLEAN stable water inflow into the bore and secondly, its during this phase, that the driller can make an accurate determination of the bore flow rate, thus the correct sized pump can be installed.
A bore needs to be pumping clean water immediately the pump is installed. If the water is full of slurry and sediment, the pump, if it can, has to move that sediment, thus causing significant wear issues on the pump, firstly on the pump impellors, but secondly on the pump motor. Submersible pumps and their motors are designed to move clean water and trying to move slurry will cause a pump motor to draw significantly more amperage than they are designed for, which will cause the pump motor to overheat/seize/burn out.
Many pump suppliers and installers are refusing to install pumps on bores drilled by certain contractors, without first having another driller clean and flow test the bore. We get asked to perform this many times per year on some supposedly “cheap” bores, the results are often quite disappointing for the unsuspecting bore owners, however the old saying applies “you pay peanuts you get monkeys”.
So to sum up, bore location, bore construction and bore development are very important factors. The client should receive from the driller, a “Bore Completion Report”. This is mandatory as per regulations set down by the water authority. The report gives all details pertaining to the bore, depth, yield, water quality, type of bore casing used, geology, development time, standing water level etc etc. All these details are necessary for both the land owner and the pump installer. We always recommend or suggest to our clients that they are most welcome to observe the drilling and construction process first hand and are happy to answer any question and explain exactly what is happening at any stage of the process. It can be confusing if you have not seen a bore drilled before. Its your money being spent and you have every right to be as fully informed as possible. I also suggest people watch our Water Bore Drilling tutorial https://www.youtube.com/watch?v=cKweHAwj9-A&t=8s its 8 minutes in length and well worth watching. We also offer a free groundwater database search and report http://www.centrestatedrilling.com.au/free-groundwater-database-search/ based on bores in your immediate vicinity we can give our clients a good idea as to what to expect from a bore on their property.
We take pride in our work, in our reputation and our results and we work hard to constantly improve in all areas. Our reputation and reviews speak for themselves https://www.facebook.com/pg/borewaterdrillers/reviews/?ref=page_internal but please feel free to google us and check all our online reviews, not just the ones on our FB page. We also have plenty of videos online https://www.youtube.com/channel/UCDCpgHk4uGpJzoU6wzH0mNQ?view_as=subscriber displaying the whole water bore construction process.