Former Conoco Pipeline (Abandoned) Site


Site Background

The Conoco Pipeline (Abandoned) Site (Site) is approximately two acres and is in the 7100 block of N. Clarence Avenue of Valley Center along the former location of an abandoned Conoco crude oil pipeline. A former Conoco crude oil pipeline crossed through the neighborhood and was abandoned in place by water displacement in 1977.

Conoco (now Phillips 66), entered into Consent Order 95-E-0047 with KDHE to complete a Comprehensive Investigation and Corrective Action Study (CI/CAS) related to impacts suspected to have been caused by a leak in the abandoned pipeline.

A water main was installed in December 1999, and groundwater monitoring was reduced to semiannual. In November of 2000, free product was observed in two wells prompting the evaluation of additional remedial actions.

In October 2001 Conoco performed a vacuum-enhanced fluid recovery event from 4 monitoring wells, which ultimately removed 2,645 gallons of liquid, including 72 gallons of petroleum hydrocarbons.

In December 2011, ConocoPhillips delineated the extent of light non-aqueous phase liquid (LNAPL using laser-induced fluoresce (LIF), and a resulting baildown testing showed that the LNALP transmissivity was below the benchmark for Maximum Extent Practicable (MEP) for recovery. A November 2012 Indoor Air Evaluation indicated that the vapor intrusion pathway was incomplete. Long term monitoring of groundwater was continued on site until being suspended in 2015 due to a lack of dissolved petroleum constituents above the KDHE RSK outside of the four wells that contained product.

Phillips 66 purchased the property at 7117 N. Clarence Avenue, and subsequently razed all the above-ground structures. On July 14, 2020 Phillips 66 recorded Environmental Use Control Agreements (EUCs) with the Sedgwick County Register of Deeds for 7112 and 7032 N. Clarence Avenue (19-EUC-0018) and 7059 N. Clarence Avenue (19-EUC-0019).

A public comment period regarding the Agency Decision Statement and the recommended closure will be held from July 15, 2021 to July 30, 2021 with a notice published in the Ark Valley News on July 15, 2021 advertising the comment period, and physical copies of the Agency Decision Statement will be available at the Valley Center Public Library, as well as the KDHE Offices in Topeka, during the public comment period.


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KDHE Site Documents