MADISON, Wis. -- Runoff pollution into lakes and streams can be a problem in the spring, and a concerned citizen took action after discovering that the city of Madison was pumping out some pollution of its own.

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Environmental biologist David Zaber was walking his dog along Wingra Creek across from Quann Dog Park when he said he saw an old pipe flowing down the urban waterway.

The next day he brought his camera to document the pollution, WISC-TV reported.

"This is a plume of contaminated stormwater -- polluted runoff that's flowing into the lake -- into Wingra Creek and into Lake Monona," Zaber said. "This is carrying a host of pollutants, including phosphorous, which is the core of why we have such bad algae problems."

And about 30 feet upstream, Zaber found and photographed another old pipe stuffed with an absorbent boom, which was apparently leaking oil.

Zaber said he called the city last fall about pollution coming from the city's Goodman Pool Park Maintenance Facility. But this time, he called the Department of Natural Resources, WISC-TV reported.

"I was irritated. This is a completely unnecessary, unacceptable illegal discharge into a waterway that's already seriously damaged by pollution," Zaber said.

WISC-TV visited the site and found the two pipes disintegrating in the water. Later, the DNR and Zaber arrived and helped each other pull out the boom, which was so soaked with oil that it started leaking again.

Zaber said he suspects it violates the city's federal stormwater discharge permit.

"I wouldn't be surprised that there is a violation of the stormwater discharge permit," he said. "I don't know what those permit levels are, so I can't really tell you whether or not that that's the case. At this time of the year for short periods of time a lot of places are exceeding those permits."

A city parks official first said the problem was a dilapidated stormwater drain at the facility that crews fixed after Zaber's complaint by installing a berm.

But later, officials said they discovered a second problem. Due to site construction, they said the city inappropriately hooked into one of the drainage pipes that hadn't been used in years and was probably loaded with sediment.

City Parks Development Manager Si Wystrand said that late last week crews cleaned some "gunk" out of the one pipe leaking oil but that only part of the second pipe could be cleaned.

It is not supposed to be used, but it will be for another month until a permanent stormwater basin can be installed to collect pollutants, WISC-TV reported.