In this Feb. 13, 2012 photo, six and half miles of canal bring water from the Rio Grande to the Donna Reservoir in Donna, Texas. State and federal researchers have found the highest chemical ... more 
In this Feb. 13, 2012 photo, six and half miles of canal bring water from the Rio Grande to the Donna Reservoir in Donna, Texas. State and federal researchers have found the highest chemical contamination levels in a section of the canal. (AP Photo/Chris Sherman) less 
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Associated Press | Photo By Chris Sherman
Sat, Mar 3, 2012 6:19 PM EST