America’s stewardship of one of its most precious resources, groundwater, relies on a patchwork of state and local rules so lax and outdated that in many places oversight is all but nonexistent, a New York Times analysis has found.

The majority of states don’t know how many wells they have, the analysis revealed. Many have incomplete records of older wells, including some that pump large volumes of water, and many states don’t register the millions of household wells that dot the country.