In most cases discoloured water is not harmful and can be cleared by running the first incoming cold water tap (usually in the kitchen) at a trickle until it clears. Very occasionally customers have noticed “tiny particles” or “bits” in their tap water. This can be caused by planned or unplanned work to the water supply network which causes natural sediment in the pipes to shift (quite often this is a dark red, brown colour).
Small dark grey or black particles can occasionally be caused if your pipework is made from lead. This is most likely if your house was built before 1970. For more information see our Lead and Your Water pages.