
Below 15, the level that requires action
4 public water companies list Westerlo as a place they supply. The biggest is Westerlo Town Water Supply, with about 220 people. The highest latest result among Westerlo's water companies is 5.3 parts per billion, at Mapletree Apts. None of the 4 with results was above 15 at its latest test. 3 are small systems serving fewer than 500 people each, such as a mobile home park, a subdivision or a business with its own well.