100,000 gallons of raw sewage down the Platte

Todd Hartman, Rocky Mountain News

Friday, July 13, 2007

A large spill at the Littleton-Englewood Wastewater Treatment Plant this week sent 100,000 gallons of raw sewage into the South Platte River but did little damage to water quality, officials said today.

The spill happened Tuesday after a mechanical failure led to tank overflows that sent sewage flooding into the plant and storm drains that lead to the river. It lasted about 20 to 25 minutes, said plant manager Dennis Stowe.

A regulator at the Colorado Department of Public Health and Environment said the sewage was quickly diluted by strong flows in the river. Bacterial levels in the river were actually higher upstream of the plant than a half-mile downstream of the spill, he said.

"It's important to note (Littleton-Englewood's) response to the situation was exceptional," said Brad Simons, engineering section manager for the state's Water Quality Control Division.

He said Littleton-Englewood officials quickly notified both regulators and the city of Thornton, which takes drinking water out of the river downstream. Thornton, in turn, shut off its intake valves so the contaminated water passed it by.

Even so, state regulators consider 100,000 gallons a significant spill, Simons said. More typically, spills total a few hundred or a few thousand gallons. But it's too soon to know if the spill will bring a financial penalty to the wastewater plant, Simons said.

Figures provided by Stowe indicate that the spill amounted to less than 2 percent of the river's flow over a 25-minute period. Stowe said the spill was the largest in recent years at the plant. He said another of comparable size happened 12 to 15 years ago.