What a community water system charges, regardless of water use. It is meant to recover costs of utility overhead such as reading and maintaining meters, carrying out billing, or other expenses. All water users incur this fee, although prices may vary by account type, meter size, location, zoning type, or use. Sometimes, base service fees include a built-in amount of usage (e.g., the base service fee might include 5,000 gallons of water before additional usage charges are incurred). Source: Understanding Your Water Bill | US EPA.