Black water likely caused by Alaskan quake

Published Tuesday, November 5, 2002 10:57:02 AM Central Time

DES MOINES, Iowa (AP) -- Shock waves from the earthquake that rocked Alaska shook loose sediment beneath the earth's surface in Iowa, causing black water to flow from wells in the northeastern part of the state.

"Anybody would be worried if they opened up the tap and saw dirty, black water," Sean Hauser, owner of Hauser's Water Conditioning in Manchester. "A couple of them said it had a rotten egg smell."

The Iowa Department of Natural Resources said the powerful effects of Sunday's Alaskan earthquake likely caused the strange phenomena almost 2,500 miles away.

"The shock waves from a major earthquake will travel all over and be detected across the world," said Bob Libra, a geologist with the Iowa Geological Survey in Iowa City. "The big ones get the whole world ringing like a bell and gets everything rolling."

There also were reports of cloudy or dark water in western Wisconsin, Libra said.

He said the underground shock waves, which in some cases affected private wells less than 200 feet deep, shake sediment, mineral deposits loose in underground aquifers and from well casings.

"It's very powdery, mud colored to yellow to almost black in some cases," Libra said.

In most cases, the water settles and clears within a few days, he said.

In some private wells, leaving an outdoor hydrant or faucet run for a few hours usually clears the water, Libra said.

Reports of the dark water began coming in within minutes of the earthquake, which hit Sunday at 4:21 p.m. CST, Libra said.

Natural resource officials warned well-owners not to drink the discolored water, which may contain high levels of manganese -- a naturally occurring element of the soil.

"In higher concentrations there are some health effects of some concern," said Joe Sanfilippo, an environmental program supervisor for the Department of Natural Resources.

Officials advised farmers to contact their veterinarians before giving the water to their animals.

Dr. John Schiltz, the Iowa State veterinarian, said he was unaware of the problem and would be checking with experts to determine what, if any, health risk the dark water poses to livestock.

Reports of black water came from areas around Riceville, Waterloo, Waverly, Manchester and Guttenburg.

"Many of them didn't have any idea what had caused it," said Sanfilippo. "This is the first time it has happened that I'm aware of since 1964."

The DNR said the water can range from a lime green to black.

"When people first see it, they think it's a petroleum product," said Mike Wade, an environmental specialist with the DNR. "Manganese suspended in water is almost soluble and can have a greasy appearance."

Hauser said he got eight calls at his water conditioning shop from concerned well owners who discovered the murky water.

He recommended the customers flush out and chlorinate their wells. Most of them are able to take care of it on their own, he said.

A 4.3 magnitude temblor that struck Nebraska earlier Sunday -- also felt in parts of Iowa and South Dakota -- just wasn't strong enough to cause the problems being seen in northeast Iowa, Libra said.

He said similar problems followed the 1964 Alaska earthquake, which in some areas, also altered well levels and springs.

Libra said he doesn't know why similar phenomena hasn't occurred following some of the big earthquakes in California.

"That's a good question," he said "It may well be the big tectonic picture and that energy doesn't transmit this way, while Alaska has a direct line to us."

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On the Net:

Iowa Department of Natural Resources: http://www.state.ia.us/government/dnr/