The construction of a ...

The construction of a borehole usually creates a lot of sediment, due to pulverised rock (assuming that the borehole penetrates into rock and is not terminated in unconsolidated deposits). If the rock is mainly sandstone and the borehole is newly constructed, this is the most likely source of the reddish-brown colouration. The remedy is to pump the borehole water to waste until it runs clear, which could take several days but maybe only a few hours. This will remove the sediment that has been forced into the rock fissures and pore spaces by the construction process. However, if this has already been done and the discolouration persists, it could signal a source of local contamination of the groundwater (e.g. from a nearby quarry) or that the source water has a high iron content. High iron content may be removed by simple aeration, which causes precipitation of the iron as a red sediment, but often the addition of a backwashing filter is needed to produce a clean water low in suspended solids.