A new U.S.

California has failed to spend $455 million of federal money meant to improve water infrastructure in the state, while thousands of people rely on groundwater laced with nitrates and other contaminants, federal regulators said Friday.

The Chino copper mine near Silver City, New Mexico is one of the longest-operating mines in the West. The mine’s current owner, Freeport-McMoRan, just started mining there again in 2011 and the company is on the hook to restore thousands of acres of heavy metal-contaminated groundwater.

Denver’s southern suburbs, dependent on shrinking supplies of groundwater, could get a new surface water supply as soon as 2015, heading off the specter of expensive water bills choking off economic growth.

Energy companies are being allowed to pollute drinking water aquifers with oil and gas drilling and fracking waste in Northern Colorado and Denver. Over the past 13 years, the U.S.

Groundwater and surface-water systems are connected, and groundwater discharge is often a substantial component of the total flow of a

Groundwater provides drinking water for millions of Americans and is the primary source of water to irrigate cropland in many of the nations most productive agricultural settings. Although the benefits of groundwater development are many, groundwater pumping can reduce the flow of water in connected streams and rivers -- a process called streamflow depletion by wells.

On what Colorado chief oil regulator Matt Lepore called an “auspicious day,” the state began hearings Wednesday on a proposal to make the state the first in the nation to require groundwater testing before and after all new oil and gas drilling operations.