Grid operator PJM Interconnection's efforts to fix what it believes to be an error in its\xa0December auction is now dividing regulators, consumer advocates and power providers. PJM believed power prices for customers were artificially inflated, so it decided to delay posting the auction results and asked\xa0federal regulators\xa0to allow it to change the auction rules. But critics say that move could generate a potential windfall for power producers. POLITICO\u2019s Catherine Morehouse breaks down the messy fight. Plus, EPA rejected applications to keep unlined coal ash ponds open at six power plants.