Drinking water for 400,000 people is contaminated

The excess of the chemicals, known as trihalomethanes (THMs), has been present in many public water supplies for years, and is caused by chlorine, added to purify water, mixing with organic matter such as leaves, timber, and peat.
Long-term exposure to THMs include an increased risk of certain cancers, such as bladder and colon; reproductive problems such as miscarriages, birth defects, and low birth rates; and damage to the heart, lungs, liver, kidney, and central nervous system.