Rubber materials used in plumbing fixtures are the most common cause of black particles in tap water. The use of chloramine as a disinfectant may cause some types of plumbing fixtures to break down faster than normal. If you experience rapid o-ring or gasket disintegration within a few years of installation, install chloramine-resistant plumbing fixtures.
Carbon filters attached to plumbing fixtures or used in water pitchers can also cause the presence of black particles. The small carbon particles in these filters are black and can pass through in your water. Black particles can also come from iron and manganese in the water, which may come loose from pipe walls after a large main break or major construction.
Flushing the system and your taps should resolve the issue of black particles caused by plumbing fixtures or construction. If black particles are from your filter, you should replace the filter as recommended by the manufacturer.