The U.S. Environmental Protection Agency's new lead and copper rules require water services to replace lead pipes by 2037.

This program is about safeguarding Amarillo’s future,” Shannon Tolleson, the city's assistant director of utilities, said.

The city investigated 98% of its water lines and found no lead pipes, but some were made of galvanized steel that "may have absorbed lead" and some were designated "unknown," according to the letters.