Chemicals From A Mine In Mexico Contaminate Water Supply 25 Miles From U.S. Border

CIUDAD HIDALGO, MEXICO - AUGUST 02: The sun rises over Guatemala and the Suchiate River which separates it from Mexico on August 2, 2013 in Ciudad Hidalgo, Chiapas, Mexico. Thousands of undocumeted Central Americans pass illegally into Mexico, many of them immigrants on the first leg of their long and perilous journey north to the United States. (Photo by John Moore/Getty Images) (2013 Getty Images)

About 10 million gallons of contaminated wastewater have spilled into rivers from a mine in northern Mexico, and federal officials announced Sunday they are restricting water supply to cities and towns in the country's north, including the Sonora state capital of Hermosillo.

The National Water Commission said it was monitoring chemicals in the Bacanuchi and Sonora rivers following this week's spill at the Buenavista copper mine in Cananea, about 25 miles south of the U.S. border.

The state's civil defense office issued a statement on its Facebook page denying rumors that the contamination includes cyanide, which it said it not used in copper mining.

The water agency says towns affected include Arizpe, Banamichi, San Felipe de Jesus, Aconchi, Baviacora and Ures, as well as Hermosillo. However, it said the state capital receives only 3 percent of its water from the river.