‘PETKOCH’: The U.S. EPA and Illinois attorney general will investigate growing piles of petroleum coke along Chicago’s Calumet River, which BP confirms are from its nearby refinery. (Chicago Tribune)

ICYMI: Here’s Kari Lydersen’s report on the “PetKoch” piles from Monday. (Midwest Energy News)

***SPONSORED LINK: Register today for the FREE Great Plains Clean Energy Transmission Summit, taking place October 21 in Saint Paul. Join public and private sector leaders — along with moderators from Midwest Energy News — in a debate over the future of clean energy and the electric grid. Breakfast and lunch included.***

EFFICIENCY: Early pilot programs show consumers are changing their habits as smart meters enable variable pricing for electricity; and Wal-Mart opens its first store lit entirely by LEDs, just outside Cleveland. (Midwest Energy News, Cleveland Plain Dealer)

COAL: A federal judge raises questions about the legality of Minnesota’s statute restricting new imported coal power, but neither side in the dispute with North Dakota is willing to predict an outcome. (Minneapolis Star Tribune)

PIPELINES: The federal agency that oversees pipeline safety has sharply increased research funding amid a series of high-profile spills; and a Canadian study finds that although they tend to release more oil, pipelines are generally safer that trucks or rail. (Wall Street Journal, The Hill)

NORTH DAKOTA: Another oil leak spills 10 barrels of crude, state officials try to determine whether Tesoro know about problems with a pipeline that spilled 20,000 barrels last month, and the the state’s chief regulator says it’s time to step up pipeline oversight. (Dickinson Press, Associated Press, KFGO)

ALSO: Holders of mineral rights are suing drilling companies over natural gas that is flared instead of being captured and sold, and farmers resist plans to build new landfills for drilling waste. (Associated Press, New York Times)

FRACKING: The agency that oversees an Ohio reservoir fights efforts to drill nearby. (Youngstown Vindicator)

WIND: Omaha’s public utility will double its renewable energy portfolio with a 400 MW wind purchase, and Xcel Energy wins regulatory approval for four new wind farms in Minnesota and North Dakota. (Omaha World-Herald, Minneapolis Star Tribune)

OHIO: An attorney for an industrial group explains why he supports Sen. Bill Seitz’s proposed changes to the state’s efficiency law. (Columbus Business First)

FRAC SAND: A new 650-acre frac sand mine is proposed in Wisconsin. (Associated Press)

MICHIGAN: A renewable energy business group wants the state to raise the bar on its renewable energy standard. (CBS Detroit)

***SPONSORED LINK: Register today for the Midwest’s largest energy efficiency event, the Midwest Energy Solutions Conference, taking place January 14-16 in Chicago. Use Code MWEN25off for $25 off just for Midwest Energy News readers.***

HYDROPOWER: A Boston company abandons its plan to install hydropower turbines on the bottom of the Mississippi River, and will focus on existing dams instead. (Associated Press)

UTILITIES: Why microgrids pose a new threat to utility business models, and experts at a Minnesota investors conference warn utilities need to redefine their roles. (Bloomberg, POWER Magazine)