KALAMAZOO, MI -- The state official who oversees regulation of oil and gas wells says he is certain that Saturday's earthquake in Kalamazoo County is unrelated to fracking or other drilling in the area.

"I am extremely confident there is no connection," said Hal Fitch, a geologist who is director of the Michigan Department of Environmental Quality's Office of Oil, Gas, and Minerals.

That opinion is echoed by David Barnes, professor of geosciences at Western Michigan University.

"I'm as certain as a scientist can be" that there is no connection, Barnes said.

Hydraulic fracturing -- also known as fracking -- is a process that involves pumping water at high pressure to create fractures in rock, allowing the oil or natural gas to flow more freely to the well bore.

Class II wells are those associated with oil and gas development. Here is a key to the well types: BDW: Brine Disposal Well, for disposal of waste fluids associated with oil and gas drilling and production, including hydraulic fracturing flowback water; WIW: Water Injection Well, for injection of water for enhanced oil recovery (i.e., flooding of an oil field to push unrecovered oil toward production wells); GBD: Gas & Brine Disposal (for disposal of waste fluids and unusable gas); OTI : Other Injection.

Scientists, including those at the U.S. Geological Survey, recently have connected an increase in seismic activity to high-pressure injection wells used to dispose of wastewater that is the byproduct of fracking. The link has been seen in Colorado, Texas, Arkansas, Oklahoma and Ohio.

However, Fitch and Barnes said the earthquake here appears to be a natural phenomena versus one induced by human activity.

"The nearest hydraulic fracturing activity is more than 50 miles away and took place several years ago," Fitch said.

The closest oil and gas development to the quake epicenter is about three miles southeast of the epicenter of the earthquake, Fitch said.

The U.S. Geological Survey has placed the quake epicenter along 34th Street just north of East Q Street in the Kalamazoo County community of Scotts. The new oil wells are on Pease Farm off East R Avenue.

"Three producible wells and one dry hole have been drilled in the field, all within the past 18 months," Fitch said. "None used hydraulic fracturing. There are no injection wells in the field."

Fitch said the new oil wells are part of the so-called Climax oil field in southeast Kalamazoo County that has had numerous wells since the 1950s.

"There's probably been a 1,000 wells there" over the years, Fitch said.

RELATED: Complete coverage of the Michigan earthquake

Barnes said he and his colleagues, including Bill Harrison and John Yellich, have been looking at the state maps of oil drilling and injection wells since the earthquake occurred. The Michigan Geological Survey, a state program that maps, evaluates and researches geological resources, is based at WMU and Yellich is the program's director.

This map from the Michigan Department of Environment Energy, and labeled by scientists at Western Michigan University, shows the location of the earthquake epicenter to nearby oil wells as well as the wastewater injection wells used by the Pfizer manufacturing facility. The important point, the WMU scientists say, is that the quake originated much deeper in the Earth than the wells, which eliminates a connection between the two.

While there are the new oil wells near the epicenter, it is important to note "they aren't injecting anything into the ground. They're pulling stuff out," Barnes said.

And it's the injecting, rather than extraction, that's linked to quakes, he said.

In addition, the depth of drilling in the new oil wells is still considerably above the basement rock where the quake originated, Barnes said. That's the "slam dunk" the quake and the drilling are not connected, Barnes said.

"This drilling activity has nothing to do with the seismic activity because the rock break occurred 15,000 feet deeper," Barnes said.

Like Barnes, Fitch said the depth of Saturday's quake -- 5.9 kilometers below the Earth's surface -- is "key" to ruling out the possibility that the quake was induced by human activity.

Barnes said there's "no question" that seismic activity has been triggered elsewhere in the country by injecting wastewater at high pressure deep in the Earth near a fault line.

"You inject the fluid in a fault, it gets slippery," making it easier for movement to occur, he said.

But that's not what happened here, he said.

However, Barnes said there is a connection the Climax oil fields and the quake: The same fault that caused the quake also contributed to the formation of oil.

"The reason people drill there is because of formation of the fault, which is the kind of place where you find oil," Barnes said. "But that doesn't mean the drilling caused the earthquake.

"People are jumping all over it because it's interesting," Barnes said. "But it just doesn't wash."

Julie Mack is a reporter for Kalamazoo Gazette. Email her at jmack1@mlive.com, call her at 269-350-0277 or follow her on Twitter @kzjuliemack.