Interstate Power and Light Company (IPL), a subsidiary of Alliant Energy Corporation the Iowa Office of Consumer Advocate and the Iowa Consumers Coalition have filed a unanimous settlement proposal with the Iowa Utilities Board addressing all issues among these three parties in IPL’s natural gas base rate case filed in May, 2012.

The parties have agreed to an increase in IPL’s annual natural gas service revenue requirement of approximately $10.5 million and the settled return on common equity was established at 10 percent.

The parties have also agreed to a Cost Management Plan, proposed by IPL, which would use tax benefits to credit customer bills and mitigate any impact of the revenue requirement increase for a period of three years.

This would result in customers per therm expense dropping below the current interim level if approved by the IUB.