HARRISBURG (AP) – A major natural gas producer is partnering with the PA Department of Environmental Protection to collect in-depth data on air emissions and water quality at well sites. CNX Resources Corp. will conduct environmental monitoring at two future well sites throughout all stages of the drilling and fracking process. The collaboration is an intensive data-collection exercise that could be used to drive future policy changes. State officials are touting the partnership as the first of its kind. The reaction from environmental groups is mixed. The company has drilled more than 500 wells in the vast Marcellus Shale natural gas field. PA is the nation’s No. 2 gas-producing state.