Owners of the Downtown Aquarium, whose tanks have been leaking thousands of gallons of saltwater for several months, have not responded to an order to begin installing monitoring wells and to obtain a permit to discharge the water, state officials said.

The aquarium has until the end of business today to respond to the state's request or face disciplinary action, including fines.

State health officials said the leaking water is not a public health threat.

"This is not a huge problem with regard to water quality or the public health. But it's gone on too long," said Mark Salley, a spokesman for the Colorado Department of Public Health and Environment.

Neither Scot Hulgan, an aquarium manager, nor Jeff Cantwell, senior vice president of development for Landry's Restaurants Inc., the aquarium's owner, responded to repeated requests for interviews this week.

Steve Gunderson, director of the water quality control division for the state, said the aquarium has taken several steps to find the leak and has reduced the amount of water being discharged onto its site, which is adjacent to the South Platte River.

"The leak was 3,000 gallons a day. That's been reduced to 1,000 gallons," Gunderson said. "They've done a lot of work looking for the leak. Our engineers have been there. The problem is that the plumbing is incredibly complicated."

Problems at the aquarium surfaced in January, after news reports revealed the leak at the popular tourist attraction and restaurant.

In addition to the leak, the state found that the aquarium was improperly discharging "filter backwash water" onto a wetlands next to the aquarium. Gunderson said the aquarium has since obtained a permit for that activity, as required by law.

But the new state order, sent in July, has failed to elicit a response.

"Our letter to them says they need a discharge permit for the 1,000 gallons a day of saltwater they're losing," Gunderson said. "And they need monitoring wells. We want to see how much of a problem this is creating."

smithj@RockyMountainNews.com or 303-954-5474