Erin go blecchh

Chicago River. Photo: Hu Guangyao/Xinhua/NEWSCOM

The Christian Science Monitor yesterday ran a brief article on their blog questioning the environmental safety of dyeing the Chicago River green for St. Patrick's Day. Apparently, when the St. Paddy's Day Parade committee was required to replace the toxic fluorescein back in 1966, they chose a vegetable-based alternative whose ingredients remain a closely guarded secret. Like the recipe for Coke Classic.

Well if Chicago isn't willing to be forthcoming about what they're dropping into the river, just head north to the Wisconsin River where, for the homeowners on Petenwell-Castle Rock Lakes, every summer day is Saint Patrick's Day! And they're more than willing to tell you a thing or two about what will turn a river green. This, too, is a vegetable-based dye - a carpet of algae fed on a rich diet of too much phosphorus sloughing into the Wisconsin River.

Virgil Miller, waterfront resident and PACRS member, goes for the green on the Wisconsin River, August 2008.

But unlike with green beer, you don't want your lips getting anywhere near this stuff...