The NYT is reporting on the potential for increased smog due to oil and gas operations: "Thousands of natural gas wells are expected to be drilled in Pennsylvania over the next few years, requiring a fleet of construction equipment, diesel engines and compressor stations. Together, they could be a large new source of smog-forming emissions along the Northeast corridor, much of which still struggles with old air quality standards at a time when U.S. EPA is preparing to make the rules stricter."