Ohio officials have again asked federal regulators to require the builders of a natural-gas pipeline to avoid crossing the Big Darby Creek altogether and to avoid crossing the Little Miami River within Caesar Creek State Park.

The Big Darby in Pickaway County and the Little Miami in Warren County are designated scenic rivers by Ohio and the U.S., and Caesar Creek is one of the busiest state parks.

The Ohio Power Siting Board on Monday asked the Federal Energy Regulatory Commission to rehear the suggested alternative routes and amend its May 30 order authorizing construction of Rockies Express East.

The project is the final stretch of a 1,679-mile pipeline carrying natural gas from Colorado across Ohio.

State officials are worried about the risk to fish and other wildlife posed by drilling the pipeline beneath the rivers. The board's proposed alternative routes would add 5.8 miles to avoid crossing beneath the Big Darby and 12.3 miles to cross the Little Miami at a different location.

If the pipeline must cross under the Little Miami, the crossing should be made away from Caesar Creek State Park to minimize the environmental impact, state officials wrote.

Also, federal regulators should require the pipeline builders to file a detailed contingency plan explaining what will be done if the drilling goes wrong and damages the waterways, state officials wrote.

It is not known when the federal commission might decide on the state's request to reconsider the alternative routes.

A spokesman for Rockies Express Pipeline, the energy partnership building the pipeline, has said that construction is highly regulated and will be "environmentally friendly and safe."

Copyright (c) 2008, The Columbus Dispatch, Ohio. Distributed by McClatchy-Tribune Information Services.