Philadelphia

After three years of exponential growth, the Marcellus Shale is showing signs of plateauing this year.

An environmental group is challenging how Pennsylvania combines air emissions from interconnected Marcellus Shale infrastructure for regulatory purposes.

Cabot Oil & Gas Corp. and GSI Environmental Inc. are questioning a Duke University study that found a link between hydraulic fracturing and increased cases of gas migration in northeastern Pennsylvania.

The public debate over shale gas came to a head in Philadelphia last week, as industry executives touted their achievements, government officials praised and criticized those developments, and protestors shouted from the street outside the two-day Shale Gas Insight 2011 conference hosted by the Marcellus Shale Coalition (MSC).

The need for higher standards in emerging shale plays could push some companies out of the business, a Talisman Energy Inc. executive told a Philadelphia audience Thursday.

NRG Energy Inc. will acquire Philadelphia-based retail natural gas and electricity provider Energy Plus Holdings LLC for $190 million in cash, the companies said Tuesday.

The debate over taxing shale gas production in Pennsylvania is increasingly focusing on where the money would go, as two Philadelphia-area Republican lawmakers proposed severance taxes last week designed to ease the tax burden on individuals.

With Philadelphia temperatures expected to peak around 90 Wednesday, the combination of a mini-heat wave in the East, a 15.8-cent advance by July futures on the previous Friday and the restoration of industrial demand that had been missing during a long holiday weekend caused double-digit price gains across the board Tuesday in the launch of the June aftermarket.

Revenue raised through a proposed impact fee that would cost Marcellus Shale drillers a minimum $10,000 per well annually is needed to help close a project $4.2 billion budget gap in Pennsylvania, according to state Senate President Pro Tempore Joe Scarnati (R-Jefferson).