In case you’ve been procrastinating looking in to the reason your tap water has been coming out a cloudy, milky color—relax, it’s most likely nothing to worry about. More often than not the white-ish color is actually produced by a bunch of tiny air bubbles that enter the water from the pressure in the pipes when you turn on the faucet.
United Utilities has a page dedicated to determining if your problem is simply these harmless bubbles or something else that should be looked into further. Check out the site for a simple test you can do in your own kitchen. If you haven’t run into this, then at least you’ll be prepared if it ever comes up!