Aquila ( ILA), an electricity and natural gas service provider, said that it received approval from the Iowa Utilities Board for a 1.8% rate increase to recover the costs of investments made in the company's natural gas transmission and distribution operations. Operating costs and system improvements made by the company include construction of new gas main lines, individual gas service lines and equipment to serve customers' energy demand in the state. The new rates for the company's 147,000 gas customers in the state are expected to be effective on or before April 1, 2006 With the new rates, a typical residential customer using 903 therms (one therm equals 100 cubic feet of gas) a year will have an increase over current rates of about 60 cents per month, or about two cents a day. A typical commercial customer using 3,498 therms annually would have an increase over current rates of about $2.53 a month, or about eight cents a day. The Kansas City, Missouri-based company had originally filed for a 2.7%, or $4.1 million, increase in annual revenues. The approved rates will increase annual revenues by $2.9 million for Aquila in Iowa. The company said, new rates are applied to the delivery of gas to its customers and are not related to the gas cost portion of customers' bills. ''We are currently reviewing the order to determine if there are other aspects of the case we might ask the IUB to reconsider,'' the company said.