As a child Mark Jakubauskas was scolded for playing in the mud.
Now he gets paid for it.
Officially he's a Kansas Biological Survey associate research professor.
In common terms, he's a "muckologist."
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"In this sediment we can trace a lot of the history of this lake," Jakubauskas said as he lifted a hockey-puck-sized slice of sediment from Kanopolis Reservoir. "There's really a lot to be learned about the past and what to expect in the future."
Jakubauskas has been taking core samples from Kansas reservoirs and lakes for about five years.
The Kansas Water Office is helping fund the research that's largely designed to study the state's drinking water supply. Earl Lewis, Water Office assistant director, said the grant is for about $155,000 annually.
The fee generally gets in-depth testing on about three reservoirs and five or 10 smaller lakes.
"That's a great deal," Lewis said. "They do a great job and we get a lot from it."
As a comparison, Lewis and Jakubauskas said the U.S. Army Corps of Engineers has been paying about $100,000 per Kansas reservoir to an out-of-state group for samplings.
Modern sonar technology lets biologists quickly measure sediment, which can be up to 20 feet deep in some lakes.
Jakubauskas and a crew of three biologists take the research several steps further.
Aboard a pontoon boat they stop at predetermined locations on a lake and run steel tubes into the muck. A vibrating motor helps the tube work through the sediment.
Back on the surface, the sample is pushed from inside the tube and tested for a variety of elements, including plutonium.
"We know that plutonium levels in the U.S. were highest in 1963, the last year they did A-bomb testing," Jakubauskas said.
Finding the highest level within a core allows biologists to know how much sediment had gathered before and since that time.
Trace amounts of lead, which was added to gasoline before being outlawed in the 1970s, are another indication of time.
Jakubauskas said both lead and plutonium amounts are well below harmful levels in Kansas waters.
The majority of Kansas lakes, especially those that provide drinking water, are relatively free of elements directly harmful to humans.
But most of our muck holds growing amounts of nitrogen and phosphorous, which contribute to Kansas' blue-green algae concerns. Agricultural runoff isn't the only source for the nutrients.
Locally, Jakubauskas and his crew did research on Augusta City Lake.
For decades the lake showed moderate nutrient levels, then sudden spikes came when housing developments replaced prairie.
"All the nutrients put on those yards went right into the lake," Jakubauskas said. "Green lawns by the lake equal green lakes, unfortunately."
Most sediment is washed into lakes during floods, like the legendary rains of 1993 and some of a few years ago.
And all lakes aren't created equal.
Cheney Reservoir has lost only about 10 percent of its capacity to sediment. Augusta City Lake also has accumulated relatively little sediment, considering it was made about 80 years ago.
Fall River Reservoir has lost far more.
Jakubauskas calls John Redmond Reservoir, east of Emporia and a valuable water supply, "a sad lake" because of its massive buildup of sediment and its shallowness.
What he hasn't learned, however, is how to put billions of tons of sediment to good use.
"That's the real problem with the stuff is that it's not good for anything," he said. "It's a real fine clay. It's not soil, so it's not really good for growing anything. When it dries it's kind of pretty. Maybe you could make some nice pots out of it."