Thanks Bruce for your question. This issue is common in parts of the Perth coastal plain in Western Australia. Iron in groundwater delivered via bore systems can produce red coloured rust stains on buildings, paths, fences and plants. The stain is a precipitate, ferric hydroxide (rust); this builds up causing discolouration to light coloured surfaces.
Iron may also be present in slimes, or sludges, which can induce severe equipment corrosion over time. Iron deposits can cause problems in irrigation systems, especially those that rely on small orifices for pressure control or delivery via water drippers.
It is difficult to remove the iron at source as it is present in dissolved form in the groundwater. If irrigating with iron-rich groundwater, the system design should use large droplet (low pressure) sprinklers should to limit overspray
and water aeration. Aeration will cause the dissolved iron to precipitate out, and clog sprinklers. I hope this helps you.
