By JAMES MacPHERSONBISMARCK, N.D. (AP) â¿¿ A Republican-backed measure aimed at closing loopholes enjoyed by oil companies in exchange for lower tax rates in North Dakota could hurt future funding for such things as schools and state employees, education and public worker groups told lawmakers Tuesday. "We know that the cost of education will continue to increase and this decreases future revenue," North Dakota Education Association spokesman Kayla Pulvermacher said of the proposal. Oil industry officials told the Senate Finance and Taxation Committee Tuesday that the state's dynamic tax policy adds more risk to an already risky and costly business and could cause drillers to move rigs elsewhere. Oil officials also cautioned lawmakers to not become overly reliant on oil revenues because of the boom-bust nature of the industry. Sen. Dwight Cook, R-Mandan, who chairs the committee, told fellow lawmakers that his proposal is an attempt to bring tax certainty to the oil industry and the state, while closing loopholes and adding drilling incentives. The measure would charge oil companies an effective tax rate of 9.5 percent on wells drilled after 2017 instead of the 11.5 percent tax rate they're charged now. Democrats have called the measure radical and reckless, saying it would cost the state more than $595 million in lost revenue in the first five years. Lynn Helms, director of the state Department of Mineral Resources, said the state does not have a position on the measure. Cook's proposal, which he crafted with the help of oil companies, would cut the exemption for so-called stripper wells that the state Tax Department says is costing North Dakota about $50 million in revenue each year. The 1980s-era law cuts taxes for low-producing oil wells to keep them pumping but it also has been applied in recent years to some gushers in North Dakota because they are near the weaker wells.