Ohio officials have asked to avoid crossing the Big Darby Creek in Pickaway County and the Little Miami River in Warren County within Caesar Creek State Park because of the risk of harming fish and other wildlife posed by drilling the pipeline beneath the rivers.
[11] It has a 5-mile (8.0 km) long 24-inch (610 mm) branch connecting pipeline with the Williams Energy owned Echo Springs Processing Plant.
On 31 May 2006, the Rockies Express Pipeline filed an application to construct and operate this section.
The construction approval was issued by the Federal Energy Regulatory Commission (FERC) on 20 April 2007.
[11] The Rockies Express Pipeline filed an application to construct and operate this section on 30 April 2007 and the FERC issued approval on 30 May 2008.
[9][14] In June 2014, REX placed the Seneca Lateral into initial service and in January 2015, the Seneca Lateral was placed into full service with the ability to move approximately 0.6 billion cubic feet per day (6.2 billion cubic metres per annum) onto the REX mainline in Zone 3.
On August 1, 2015, REX placed its Zone 3 East-to-West Project into service, making Zone 3 of the mainline fully bi-directional with the ability to move approximately 1.8 billion cubic feet per day (19 billion cubic metres per annum) of Appalachian production to Midcontinent markets.