The Interstate Natural Gas Association of America is expected to ask the US Treasury Department for a ruling that gas intertie payments do not have to be reported by interstate pipelines or gas utilities as taxable income. It wants a ruling similar to a ruling the US government issued last December on electric intertie payments. Treasury officials report receiving no contact yet from the trade association . . . . A power company in Pennsylvania is appealing a federal district court decision that culm is not “biomass” for tax purposes. “Culm” is the dirt, rock and other debris that is deposited above ground outside underground coal mines. If the material were “biomass,” then a power plant that burns it would qualify for faster tax depreciation. A federal district court said earlier this year that it is not . . . . The Joint Tax Committee staff is spending its free time studying tax returns filed by Enron. The staff hopes to make a report to the tax-writing committees in Congress by year end on what Enron did to reduce its US income taxes. Senate hearings are possible next year.