HUTCHINSON, Kan. (AP) — Earthquakes appear to be striking Kansas less frequently but officials say it’s too early to say whether new rules are the reason.

The Hutchinson News  reports the Kansas Corporation Commission issued an order on March 20 that set a new maximum daily amount of waste saltwater injection amounts in Harper and Sumner counties.

State scientists and regulators have suggested the injections, which dispose of the saltwater byproduct of oil and gas production from hydraulic fracturing, are likely triggering the tremors along existing but previously unknown fault lines in the region.

The order, which went into effect March 30, will cut injection in some wells by up to 60 percent when fully implemented by late June.

According to the commission’s documents, more than 110 million gallons of wastewater were injected beneath Harper and Sumner counties in 2014.