1.   There are high levels of benzene in groundwater monitoring wells directly adjacent to Little Eagle Creek.  Data from June 2012 indicated that benzene was as high as 2,800 micrograms per liter (ug/L) in DHW-96 and 1,170 ug/L in OW-32.  Both wells are located within feet of the creek banks.

2.   LNAPL has been detected in measurable thickness at two different locations at the facility.  The LNAPL plume associated with Tank 6 has been observed in DHW-84, less than 150 feet from the creek.

3.   The current remediation system consists of a pump and treat system, interceptor trench, and extraction wells.  The aquifer testing data presented in the report shows that several wells adjacent to the creek with high concentrations of benzene are outside the capture zone of the remediation system and/or the remediation system is not effectively preventing contaminant migration.

4.   Benzene was detected in sediment samples from Little Eagle Creek, with one sediment sample above the Region 5 Ecological Screening Level at 143 micrograms per kilogram (ug/kg) and lower concentrations detected downstream.   

5.   Benzene has been detected in the surface water of Little Eagle Creek.

6.   Benzene appears to be migrating from the facility into the sediments and surface water of Little Eagle Creek.

• Continued pump and treat system operation;
• Conducted semi-monthly O&M on the LNAPL recovery system installed at DHW-110 on May 31st;

• Made modifications to the remediation system recirculation line to allow for greater flow control on May 31st;

• Inspected the carbon vessels and discovered that the influent screens were fouled on June 7th;

• Commenced corrective measures to modify the carbon system in order to eliminate the effect of the fouled influent screens on June 13, 2013;

• Conducted 2^nd quarter groundwater sampling event beginning the week of May 21st;

• Submitted a response to EPA's comment on the Investigation Report on June 14th; and

• Submitted the First Quarter 2013 Groundwater and Surface Water Monitoring Report on June 11th.

2.1.3 Enforcement Activities, Identity of Potentially Responsible Parties (PRPs)
EPA executed Docket No. V-W-11 C-984, an AOC with BP on November 14, 2011.

2.1.4 Progress Metrics
Below is a schedule of items included in the AOC.  BP requested a deadline extension for submittal of the Investigation Report.   

• Continue to provide oversight and documentation support to EPA's On-Scene Coordinator (OSC); 
• Conduct Little Eagle Creek monthly surface water sampling; 
• Continue to operate the pump & treat system;  and
• Prepare monthly surface water monitoring report.

The treatment system remained down for supplemental services necessary to operate the system using carbon only (i.e., bypassing the air stripper). Re-start of the system is anticipated in late June. During the system down time, the The transfer pump recirculation plumbing was modified to allow for greater flow control upstream of the carbon vessels; carbon vessels were inspected and the influent screens were observed to be fouled; and corrective measures to address this condition are underway and should be completed in late June.