The nation's 55,000 community water systems must make significant investments to install, upgrade, or replace infrastructure to ensure the provision of safe drinking water to their 243 million customers. The US Environmental Protection Agency's first-ever national drinking water infrastructure needs survey, conducted in 1995, estimates that these systems must invest a minimum of $138.4 billion in the next 20 years? Of this total, $76.8 billion is for infrastructure improvements needed now to protect public health. A portion of the total, $12.1 billion, is for infrastructure improvements related to standards established under the Safe Drinking Water Act.