Topeka ? A system to monitor mercury pollution in Kansas has taken longer than expected to set up, and more data need to be collected before reaching any hard conclusions, a state environmental official said Friday.

“It has been a bit of a challenge,” said Tom Gross, who is section chief of the Kansas Department of Health and Environment Bureau of Air and Radiation.

The Kansas Legislature in 2007 passed a law to monitor mercury levels as part of a system that would coincide with a growing national network aimed at pinpointing areas of high amounts of the toxic pollutant.

Gross told the Senate Natural Resources Committee that it has taken longer than expected to establish six monitoring stations in Kansas because officials were trying to do it as inexpensively as possible by soliciting free access to the land.

And, he said, setting up a site at the Cimarron National Grassland near Elkhart in far southwest Kansas took a lot of negotiating with the federal government because of liability concerns.

But now the sites are established, he said.

The monitoring station in Reserve in Brown County has been up and running the longest with 10 months worth of data recorded, he said. That data at that site show that mercury levels in precipitation are the same range as levels at sites in the region in other states.

He said it was too early to tell if mercury levels are alarmingly high in any areas of Kansas.

Gross said human activities produce about half of the mercury in the atmosphere, and most of that comes from coal-burning electric power plants.

State Sen. Marci Francisco, D-Lawrence, said the mercury monitoring will be helpful.

“This information needs to be combined with information about the sources of the pollutant and then we might get some idea how far is mercury traveling from the site,” Francisco said.

The other monitoring stations are near West Mineral, Cawker City, near Scott City and near Burlington.