The primary source of water for rangeland reticulation of water
will be from groundwater bores. Depending on the location of
the bore, either subartesian or artesian bores may be
developed. Typically subartesian bores will not pose major
problems with temperatures. Artesian bores may experience
high temperature and pressures and require special
consideration. Two components where problems may occur
are:
Casing is required to prevent bore collapse and to act as a safe
house for any pump installed in the bore. Choice of material will
depend on strength requirements, corrosion resistance, ease of
handling, cost considerations, type of formation, method of
drilling, bore design, construction techniques and licence or
permit requirements. Casing materials include:
- steel;
- PVC;
- thermoplastic (ABS); and
- fibreglass reinforced plastic (FRP)
Well heads will protect the underlying aquifer from the ingress
of surface water which may contain contaminants in subartesian
wells and will allow flow to be controlled from artesian wells. For
artesian wells special consideration will need to be made for
pressure and flow testing without interfering with the pump or
reticulation system. Headworks shall be flanged jointed
construction. Lead annular seals and screw jointed headworks are
not acceptable.
In more corrosive environments where temperatures and pressures are
higher only first grade quality material should be used for the
well head and valves and should be rated to handle the temperature
and pressure of the bore. Typically stainless steel is used,
although advances in epoxy coatings and electroplating has allowed
materials such as cast iron and bronze to be considered. For
temperatures exceeding 50ºC or flow exceeding 15 litres per
second, a main isolating valve of equivalent diameter to the inner
casing shall be incorporated into the headworks between the bore
casing and the distribution outlets (NMBSC, 2003)
The “Minimum Construction Requirements for Water Bores in
Australia, 2003” provides drillers in Australia information
and a technical standard for construction of water bores. The
Australian Drilling Industry Association is the professional
organization for the drilling industry. Drilling contractors,
suppliers and consultants can be accessed through their website:
www.adia.com.au
Further information on evaporation and dam covers available in
Review of Water Reticulation Equipment for Rangelands
pastoral Applications Review compiled by Ralph
Williams UniSA (information on this page extracted from review)
Further information on bore maintenance available in
Download GAB Well Maintenance
Field Guide for Artesian Wells - SAAL NRM
Board
