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Site Report: Kenai Gas Field Pad 41-18

Site Name: Kenai Gas Field Pad 41-18
Address: MP 10.5 Kalifornsky Beach, Kenai, AK 99611
File Number: 2320.38.033
Hazard ID: 3189
Status: Active
Staff: Peter Campbell, 9072623412 peter.campbell@alaska.gov
Latitude: 60.442500
Longitude: -151.247222
Horizontal Datum:NAD83

We make every effort to ensure the data presented here is accurate based on the best available information currently on file with DEC. It is therefore subject to change as new information becomes available. We recommend contacting the assigned project staff prior to making decisions based on this information.

Problems/Comments

Petroleum hydrocarbons were observed in a well cellar during a Marathon environmental audit performed in July 1999. Diesel range organics (DRO) and Natural Gas Condensate above ADEC cleanup levels contaminate soil and groundwater. Further site assessment has been required to determine horizontal and vertical extent of contamination. A site remediation plan will follow.

Action Information

Action Date Action Description DEC Staff
7/5/2000 Site Ranked Using the AHRM Initial ranking. Donald Seagren
7/28/2000 Site Added to Database DRO and Natural Gas Condensate. Former Staff
11/22/2000 Meeting or Teleconference Held Site inspection with Marathon and consultant to discuss proposed additional site assessment and select MW locations Donald Seagren
2/5/2001 Update or Other Action Modification to proposed assessment work plan approved. Letter sent with approved/required changes. Entire work plan needs to be submitted for review and approval prior to commencement of the field work, since only the proposed changes were submitted Donald Seagren
2/13/2001 Update or Other Action Discussed proposed change to assessment work plan due to the buried reserve pit. Work plan to be submitted shortly. Donald Seagren
2/15/2001 Site Characterization Workplan Approved Reviewed and approved Analysis and Sampling work plan. Requested notification so site inspection could be conducted during assessment activities. Donald Seagren
5/29/2001 Site Characterization Report Approved Reviewed Additional Site Assessment Report dated 16 May 01; soil and GW contamination exceeding Method 2 cleanup levels is present. Continued GW monitoring Donald Seagren
8/2/2001 Update or Other Action Review Beneficial Re-Use Draft workplan for SW program. Left message for Mark Susich to call and discuss prior to commenting to SW program. Donald Seagren
8/6/2001 Update or Other Action Review beneficial re-use plan and discuss with Mark Susich of Marathon. Discuss with Jim Frechione and provide comments. Recommend non-objection to proposal. Donald Seagren
9/27/2001 Update or Other Action Review Quarterly Groundwater Monitoring Report - May 2001. Donald Seagren
8/26/2002 Update or Other Action Review Quarterly monitoring reports for 3rd &4th quarter 2001. Donald Seagren
5/20/2003 Update or Other Action Reviewed 4th Quarter 02 & October 02 Groundwater Monitoring reports. Donald Seagren
1/21/2004 Update or Other Action Reviewed Semiannual GW Monitoring report , April 2003, dated 14 July 03 with cover letter dated 19 January 04. Donald Seagren
1/23/2004 Meeting or Teleconference Held Met with Eric Ward (Marathon). concern over MW4. Establish at least 2 SW monitoring points downgradient of MW4. Will further investigate anomaly @ MW4. Donald Seagren
1/28/2004 Update or Other Action Reviewed October 2003 monitoring report. Conditionally approved requested changes to monitoring plan. Donald Seagren
3/10/2004 Update or Other Action File number assigned and entered into the Fileroom DB and CS DB. Alyce Hughey
6/7/2004 Update or Other Action Reviewed and approved GW monitoring plan. Marathon will examine well logs for 2 water wells on site. If they are in the same aquifer as MW4, they will be sampled also to attempt to determine the anomaly at MW4. Donald Seagren
6/24/2004 Update or Other Action Site inspection, examined MWs, discussed development of future assessment/monitoring plans. Donald Seagren
8/24/2005 Update or Other Action Reviewed 2004 annual monitoring report. It appears that contamination may be migrating based on the results from MWA. Requested Marathon develop contaminated soil stockpiling/ remediation plan to remove contaminated soil encountered during normal site activities to remove contaminant source areas. Donald Seagren
8/30/2005 GIS Position Updated Using Figure 1 from a 2004 Annual Groundwater Monitoring Report-Final, Kenai Gas Field Pad 41-18, from OASIS Environmental, dated August 10, 2005, in conjunction with TopoZone Pro and the KPB Parcel Lookup, entered the coordinates for this site. Metadata includes No Topo Basemap, TopoZone Pro Street Maps, Black and White Aerial Photo, on a Medium Size Map, View Scale 1:10,000, Coordinated Datum NAD83. High degree of confidence in accuracy of location. Alyce Hughey
12/21/2005 Update or Other Action Reviewd 05 monitoring report with sampling events in July & October. No appreciable chnge in contaminant concentrations. Contaminant plume appears to migrating across pad. Surface water off pad exceeded benzene cleanup level in Juy but not October. Marathon will be required to continue quarterly surface water monitoring and yearly GW monitoring on pad. Contaminant levels are not declining after 6 years. Marathon will be required to investiagte and develop an in-situ remediaiton plan to address the contamination on site. Either the contamination is not decreasing or there is a continuing leak somewhere on the pad. Donald Seagren
2/13/2006 Update or Other Action telephone call from Chick Underwood. One of the monitor wells was damaged during pad expansion. The MW will be properly abandoned and a report generated. The pad will be reevaluated and new MW installe dthis summer. Donald Seagren
4/4/2007 Exposure Tracking Model Ranking Donald Seagren
7/11/2007 Update or Other Action Reviewed 06 monitoring report and discussed comments with Tom Beckman. Delaying on-site work until operations has completed on-site pad work is approved. Figure 2 shows a possible change in GW flow direction. If this change is corrects, the Sw samples were not downgradient of the pad. Therefore, for the next sampling event, 4 or 5 Sw samples ar eto be taken in what is now the apparent downgradient direction. this is important since MWA & MW4 at the edge of the pad exceed cleanup levels for DRO. Further assessment and verification of GW flow directin will be conducted in the winter 07/08. Donald Seagren
11/7/2007 Site Characterization Workplan Approved Reviewed & approved work plan for additional site assessment at the pad. The proposed work will be conducted during the winter 07 thru summer 08, with LTM continuing after that. The soil borings and MW installations in the adjacent wetlands must be done during the winter when the ground is frozen to prevent damage to the wetlands habitat. The additional site work will provide data on the current site conditions both on and off the pad in the adjacent wetlands. Soil, GW and SW samples will be collected. Addtional data/information will be collected to assist in determining the best remediation approach for the site. Donald Seagren
6/12/2008 Update or Other Action Site transferred from Don Seagren to Paul Horwath per Linda Nuechterlein. Alyce Hughey
1/14/2009 Exposure Tracking Model Ranking A new updated ranking with ETM has been completed for source area 74164 Various Pad releaases. Alyce Hughey
8/10/2009 Document, Report, or Work plan Review - other Reviewed the Site Assessment and Remedial Evaluation Report Kenai Gas Field Pad 41-18, from OASIS Environmental, dated April 17, 2009 for Paul Horwath. The Site Assessment soil sampling performed during the drilling of nine additional groundwater monitoring wells (on pad and off pad) indicated that DRO soil contamination above the soil cleanup levels exists at the site from one to eleven feet below ground surface, and RRO soil contamination exists, but below the soil cleanup levels. The groundwater sampling performed indicated that DRO and RRO groundwater contamination is present beneath the production pad and the western portion of the production pad above the groundwater cleanup levels. Of the two samplings performed of three surface water samples taken, appears that the surface water in the area of the shallow groundwater wells is not affected with the contaminated groundwater. The Monitored Natural Attenuation results indicated that both aerobic and anaerobic degradation pathways are active at the site. The readings indicate that the site is in transition from aerobic to anaerobic conditions. Further assessment is needed to determine if biodegradation and natural attenuation can be used to passively cleanup the site. Alyce Hughey
7/15/2010 Document, Report, or Work plan Review - other Reviewed the Additional Site Assessment Report, Kenai Gas Field Pad 41-18, from OASIS Environmental, dated April 16, 2010 for Paul Horwath. During the additional site assessment performed in 2009 to further characterize the petroleum impacts at the northern edge of the pad, two additional soil borings were drilled and made into monitoring wells. Soil analytical results indicated that Benzene and DRO was detected above the soil cleanup levels and GRO and RRO being detected below the soil cleanup levels. All of the groundwater monitoring wells were then sampled other than three off-pad and downgradient wells because they were frozen and two on-pad wells because they were buried by snow berms. The groundwater sampling results reflected expected concentrations based on the past analytical results within the monitoring wells previously sampled other than DRO was detected at about three times higher than the groundwater cleanup levels in one of the newly installed monitoring wells, indicating that the DRO plume boundary reaches the pad edge. The proposed surface water samples were not conducted because the surface water was frozen. The surface water sampling is scheduled to be performed in April or May of 2010. Alyce Hughey
2/6/2012 Document, Report, or Work plan Review - other Reviewed the Kenai Gas Field Pad 41-18, 2010 Annual Groundwater Monitoring Report, dated April 11, 2011, from OASIS Environmental. The two 2010 groundwater and surface water sampling events planned for 2010 were changed due to scheduling conflicts and the presence of nesting Terns. Spring sampling was performed in June and the fall sampling was postponed until spring of 2011. All monitoring wells were sampled other than for MW-6 because it was found destroyed. DRO was detected in monitoring wells MW-3, MW-4, MW-9, MW-10 and MW-15 above the groundwater cleanup levels at concentrations ranging from 2.3 to 4.8 mg/L. The DRO groundwater contamination remains next to the Wastewater Building, and along the northern and western edges of the pad. Surface water sampling was performed on August 24, 2010 with Toluene being detected in sample SW-5, and PAHs being detected in SW-4, SW-5, SW-6, and SW-7 all below the surface water quality standards. No sheens were noted on the surface. Alyce Hughey
7/5/2012 Document, Report, or Work plan Review - other Reviewed the Groundwater Monitoring Report, Kenai Gas Field Pad 41-18, dated April 13, 2012, prepared by OASIS Environmental. The 2011 groundwater sampling event was conducted on October 17th and 18th of 2011, with DRO being detected in monitoring wells MW-3, MW-4, MW-9, MW-10 and MW-15 above the groundwater cleanup levels at concentrations ranging from 2.0 to 8.2 mg/L. Monitoring wells not sampled included MW-1 because it was damaged, MW-6 because it was destroyed and MW-5 and MW-7 because they are being proposed for decommissioning. Surface water sampling was performed on October 15, 2011 with BTEX not being detected and TAqH was detected in sample SW-4 at 0.001734 mg/L, SW-5 at 0.0009 mg/L and in SW-7 at 0.000069 mg/L all below the surface water quality standards. No sheens were noted on the surface. Alyce Hughey
10/19/2012 Document, Report, or Work plan Review - other Review and approve Groundwater and Surface Water Monitoring and Sampling Work Plan KGF 41-18 Dated October 5, 2012 with conditions that have been detailed in the project file. Reviewed in Horwath’s absence. Peter Campbell
2/5/2013 Document, Report, or Work plan Review - other Reviewed the Kenai Gas Field Pad 41-18 Groundwater Monitoring and Additional Site Assessment Report, dated January 10, 2013, prepared by Weston Solutions. The annual 2012 groundwater and surface water sampling was conducted on September 29th and 30th of 2012. The additional assessment activities and new monitoring well sampling was conducted between October 23rd and 26th, 2012, and MW-18 was re-sampled on November 5, 2012 because the October sample was misplaced. DRO groundwater contamination ranged from 1.7 mg/L to 10.0 mg/L in wells sampled. On September 30, 2012 surface water samples were collected with TAH at 0.00518 mg/L in all surface water samples collected and TAqH ranging from 0.005718 to 0.006799 mg/L in surface water samples collected, with no sheens observed. On October 22, 2012 four test holes (one on each side of the building) were advanced to the first encountered groundwater using a “super sucker” next to the former Waste Water Building. Each boring was 36 inches bgs. Field screened to approximately 24 inches, with PID readings of 0.0 ppm. Groundwater slowly charged to a static water level of approximately 18 inches bgs. The test holes were left open for 3 days to observe for the presence of LNAPL. During these three days the holes were checked several times, with no odor, sheen or LNAPL evident. Eight monitoring wells were scheduled to be decommissioned; however, only three were decommissioned due to inaccessibility (MW-1, MW-3 and MW-11). The other five wells (MW-A, MW-5, MW-6, MW-7 and MW-8) are scheduled for decommissioning in January or February of 2013. Three replacement and four new monitoring wells were installed in October of 2012 (MW-3R, MW-8R, MW-11R and MW-16, MW-17, MW-18 and MW-19. Well MW-3R was installed to replace MW-3, MW-8R was installed to replace MW-8 and MW-11R was installed to replace MW-11. The four newly installed monitoring wells were installed to better delineate the groundwater plume at the site. Replacement wells MW-5R and MW-6R were scheduled for installation on the northwest portion of the pad as close to the pad/wetland without being in the wetland. Due to the steepness of the pad grade and the desired well locations, access with the Geoprobe would need to be from the wetland during frozen periods. The installation of these two wells is scheduled for January or February of 2013. Alyce Hughey
9/18/2013 Long Term Monitoring Established Annual long term monitoring of GW quality established within Weston Solutions' 2012 Groundwater Monitoring and Sampling Work Plan. Paul Horwath
6/29/2015 Update or Other Action Send an e-mail communication to Drew Anderson of Hilcorp Alaska, Inc., requesting the identity of the current Hilcorp Project Manager for Pad 41-18, and requesting an update on any additional assessment work that may have been completed since 2012 by Weston Solutions. Paul Horwath
6/29/2015 Exposure Tracking Model Ranking A new updated ranking with ETM has been completed for source area 74164 Various Pad releaases. Paul Horwath
7/21/2016 Document, Report, or Work plan Review - other Review Brice Environmental's 2015 Groundwater and Surface Water Monitoring Report, dated May 2016, and received June 21, 2016. Need to obtain signatures on this report from Brice. Paul Horwath
9/27/2017 Document, Report, or Work plan Review - other Issued conditional approval of the 2017 GW Monitoring Work Plan, which was prepared for Hilcorp by Brice Environmental. Paul Horwath
10/6/2017 Document, Report, or Work plan Review - other Approved Brice's 2017 Groundwater Monitoring Work Plan (amended). Paul Horwath
12/12/2017 Document, Report, or Work plan Review - other Review Hilcorp's 12-4-2017 letter to ADEC's Lori Aldrich (SW Program), covering the trenching across KGF Pad 41-18, to install underground power lines. No contamination encountered, per Hilcorp's Kelly Nixon. Paul Horwath
7/2/2019 Document, Report, or Work plan Review - other ADEC approved the 2019 Groundwater Monitoring Program Work Plan, which was prepared by Brice Environmental, as amended by the Brice Environmental June 24th response to ADEC's June 21st work plan review comments. Paul Horwath
3/16/2020 Document, Report, or Work plan Review - other Review the 2019 Groundwater Monitoring Program Report Peter Campbell
9/8/2021 Document, Report, or Work plan Review - other Review and approve 2021 work plan. Peter Campbell
6/28/2023 Site Visit Pad inspection with DEC staff, Hilcorp Safety and consultant. Peter Campbell
3/14/2024 Meeting or Teleconference Held Meet with Hilcorp to discuss 2024 cathodic protection actions that will involve trenching across 41-18. Hilcorp presented the planned pathway of the trenches. Hilcorp plans on managing excavation with the same methods established in previous digs. Excavate soils and place next to open trench. If grossly impacted soils are encountered notify DEC. Place impacted soils back into excavation in the order they were removed from the ground ("dirty soils first in and covered with clean soils"). Water will be sent to the Grind and Inject facility. If significant product is encountered, they have been advised to berm the source area trench to stop product from moving over the entire trench. A construction report has been requested to document impacts. Peter Campbell
8/13/2024 Update or Other Action Hilcorp reported a new discovery of stained, odorous soils approximately 100 feet west of the Grind and Inject facility during some pad trenching activity. Peter Campbell

Contaminant Information

Name Level Description Media Comments

Control Type

Type Details

Requirements

Description Details

No associated sites were found.

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