An East Hampton man who was charged on Sunday with driving while intoxicated, his third such arrest in eight years, could face “significant” jail time if convicted of the felony charges he is facing.East Hampton Town police stopped Dalton D. Donegal, 39, a little before midnight on Three Mile Harbor Road in East Hampton, saying he was speeding and swerving across the double yellow line. Back at Wainscott headquarters his breath test reportedly produced a reading of .18.Because Mr. Donegal was convicted of misdemeanor D.W.I. here in 2008, and of felony D.W.I.