"For 100 years, Mexico City has flushed its wastewater north to irrigate the farmland of Hidalgo State. This foul cascade, which the farmers call 'the black waters,' flows through a latticework of canals and then trickles over the fields.
So when word got out that the government was finally going to build a giant wastewater treatment plant, one might have expected the farmers around here to be excited. Instead, they were suspicious.
'Without that water, there is no life,' said Gregorio Cruz Alamilla, 60, who has worked his family’s 12-acre farm since he was a boy.
Mr. Cruz knows the water is loaded with toxic substances, including chemicals dumped by factories, and he tires of clearing his field of plastic bottles and wrappings every time he irrigates.
But like many others here, he worries that treating the water, though it may remove harmful contaminants, will also strip away some of the natural fertilizers that even the authorities here say have helped make this valley so productive."