A water pump in combination with groundwater that contains iron / rust
A groundwater source that contains large amounts of iron / rust may damage not only your pump's interior but also its exterior if it comes into contact with water when you spray your garden.
Excessive amounts of iron / rust may significantly reduce your pump's lifespan, because these particles wear down the seal, as a result of which the pump loses its power and will eventually start leaking.
Unfortunately, it is not possible to filter these particles and prevent them from entering the pump. Special 'deironing filters' are available, but they have such a low passage capacity that they do not filter effectively enough to keep the water with particles from entering the pump. They are suitable only for protecting particular domestic applications such as washing machines.
Unfortunately, there is no solution with regard to deironing deep wells for which borehole pumps are being used.
Purifying a water source
We would advise you to contact your regional dewatering contractor to discuss the possibilities of purifying your water source. Although groundwater sources can be flushed, you may need to drill for a clean-water source at a different location on your grounds.
In brief, clean your water source or drill for a new one if you need to pump water that has a high iron / rust content.