Hermosillo, Mexico - Authorities imposed restrictions on the water supply to several towns and cities in northwest Mexico, after toxic substances from a nearby mine reportedly turned a river orange, killing fish and livestock.

The wastewater came from the Buenavista copper mine in Cananea, Mexico, situated only about 25 miles from the US border, and contaminated the Bacanuchi River, a tributary of the Sonora River. Approximatel 10 million gallons of leached copper was spilled into the river according to the National Water Commission (Conagua.)

The restrictions affect seven municipalities, fed by the 260-mile river, including the Sonora state capital, Hermosillo, which is home to nearly 800,000 people.

Local media broadcast pictures of orange water, which reports said had killed fish and cattle, and is affecting milk production.

PROFEPA, Mexico's federal agency charged with environmental protection, is monitoring water quality at multiple points along the river and has already ordered that the company, Buenavista del Cobre, part of the mining giant Grupo Mexico, provide "full remediation" for the spill.

Sonora state, which accounts for 27 percent of all Mexican mining, is the country's leading producer of gold, copper, graphite, and a number of other mined products.

In August last year, a trailer-truck carrying cyanide for a Sonora gold and sliver mine overturned, contaminating the Yaqui River. This caused a shortage of drinking water, human illness, and the death of reptiles and birds.