LAS CRUCES, N.M. (AP) — Every spring, shortly after the water arrives, islands of foam bob down the Rio Grande. They make parts of the river look like a vile root beer float.
“It looks nasty, that’s for sure,” said Phil King, a civil and geological engineering professor at New Mexico State University.
But, what is it?
Like every other expert reached Wednesday by the Sun-News, he did not know for certain. King said he has not run a chemical analysis of the annual foam globs, and doesn’t know anyone who has. He did, however, offer a theory.
King said that throughout the year materials — likely organic — settle on the riverbed. In the spring, flowing water whips up those materials creating a froth. Each year, he has observed, the amount of foam varies.
“I was surprised to see how little there was this year,” he said.
Bert Cortez, of the U.S. Bureau of Reclamation, said the foam may arise from “leftover chemicals coming from the farms.”
King and Cortez joined officials from the city of Las Cruces, the Elephant Butte Irrigation District and the Southwest Environmental Center in saying the river foam is unlikely to be toxic.
Biologists did not return phone messages from the Sun-News seeking comment.
Even if it is safe, the foam remains unappealing.
King said he avoids contacting it and doesn’t let his dog play in it when they walk along the river or irrigation paths.
“She can play in it when that stuff’s gone,” King said.
Copyright 2013 The Associated Press.