Site Report: Cordova Electric Coop. - Eyak Lake

Site Name:	Cordova Electric Coop. - Eyak Lake
Address:	West End of Eyak Lake, NE of LeFevre Rd & CR Hwy, Cordova, AK 99574
File Number:	2215.38.007
Hazard ID:	27
Status:	Active
Staff:	Mollie Dwyer, 9074651076 mollie.dwyer@alaska.gov
Latitude:	60.541389
Longitude:	-145.738611
Horizontal Datum:

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.

Site Chronology
IC / Closure Details
Documents
Associated Sites

Problems/Comments

Waste oil and diesel spills from 1960's and later resulted in soil and groundwater contamination at the site. Contamination migrating into Eyak Lake has been controlled by the installation and operation of a groundwater pump-and-treat system. Long term monitoring of the groundwater and operation of the remediation system continues.

Action Information

Action Date	Action	Description	DEC Staff
1/19/1981	Site Added to Database	Waste oil and diesel contaminants.	Former Staff
3/20/1991	Update or Other Action	(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Letter was sent requesting a site cleanup plan.	Former Staff
6/24/1991	Preliminary Assessment Approved	A preliminary assessment was received by ADEC and is under review.	Former Staff
8/13/1991	Site Ranked Using the AHRM	New information from Jane Tokin caused site to be reranked.	Former Staff
8/13/1991	Update or Other Action	Additional site information sent by Cordova Field office.	Former Staff
2/14/1992	Update or Other Action	(Old R:Base Action Code = SA1 - Phase I Site Assessment (General)).	Former Staff
4/10/1992	Update or Other Action	(Old R:Base Action Code = SA1R - Phase I SA Review (CS/LUST)).	Former Staff
10/29/1993	Update or Other Action	(Old R:Base Action Code = SA1R - Phase I SA Review (CS/LUST)).	Former Staff
10/29/1993	Update or Other Action	(Old R:Base Action Code = SA2R - Phase II SA Review (CS)).	Former Staff
1/13/1994	Update or Other Action	(Old R:Base Action Code = CORR - Correspondence (General)). Granted request for time extension of COBC.	Former Staff
1/26/1994	Update or Other Action	(Old R:Base Action Code = MS - Monitoring/Sampling). Groundwater conditions improving in some wells, degrading in others.	Former Staff
3/8/1994	Update or Other Action	(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). The proposed pilot scale in-situ soil and groundwater treatment system was conceptually approved.	Former Staff
4/22/1994	Update or Other Action	(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Plan to incorporate contaminated soil into road bed approved.	Former Staff
5/4/1994	Update or Other Action	(Old R:Base Action Code = CORR - Correspondence (General)). Sampling plan for proposed soil treatment/disposal plan approved.	Former Staff
11/9/1994	Update or Other Action	(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). If monitor well G-2 TPH level remains high, information regarding a possible source of contamination must be provided. In addition, Gilfilian Engineering has recommended that ground water treatment be performed in the vicinity of MW-5.	Mike Krieber
11/10/1994	Update or Other Action	(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). No further soil cleanup appears needed in the proximity of the fuel shed. The excavated soil was disposed of on the 1994 road paving project.	Mike Krieber
3/1/1995	Update or Other Action	(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). January water samples could not be obtained due to frozen monitor wells. Proposed sampling within 30 days is acceptable to the Department. Future monitoring events should provide information on whether the excavated contaminated soil was the primary source of GW contamination.	Mike Krieber
3/1/1995	Update or Other Action	(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Reviewed remedial action workplans for tasks 4 and 5. Task 4 could be postponed. The soil investigation / sampling plan, required by item #2, needs to be submitted for Department review and approval, no later than 4/3/95. Task 5, proposal to use the PetroTrap (a passive product collection device) is appropriate.	Mike Krieber
4/17/1995	Update or Other Action	(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Sampling at the interface could provide somewhat better information on contaminant mobility and will provide for better guidance in ground water treatment needs, if any. Subject to minor revisions, the task 4 plan is approved. The proposed SWAP system is acceptable to the Department. The task 5 plan revision is approved.	Mike Krieber
5/3/1995	Update or Other Action	(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). Reviewed a ground water monitoring report. GW contamination levels in the vicinity of monitor wells G1 and G2 appear to have significantly dropped since the last sampling events. Surmised that this is due to excavation of contaminated soils on the south side of the building in the summer of 1994. There is a slight increase in contaminant levels in the cooling pond which is probably due to the movement of a the contaminant slug downgradient.	Mike Krieber
8/8/1995	Update or Other Action	(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). Reviewed a remedial action preliminary report.	Mike Krieber
9/12/1995	Update or Other Action	(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). To better observe the GW contamination trends, the department requests that the cooperative provide a graphical presentation of the results in the future monitoring reports.	Mike Krieber
10/5/1995	Update or Other Action	(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). Reviewed a Remedial Action Report. Continue sampling the downgradient monitor wells to determine if contamination levels drop. Active remediation could be required if levels do not drop.	Mike Krieber
11/22/1995	Update or Other Action	(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). Reviewed a ground water monitoring report. Contamination levels are approaching acceptable limits except in monitor well #5.	Mike Krieber
1/7/1997	Update or Other Action	Reviewed a GW Monitoring Report. MWs 1 and 3 have had continuous reports of contamination being within acceptable limits. Therefore, these 2 monitor wells do not require further analytical sampling now. However, when project closeout is contemplated in the future, these 2 wells may need to be sampled then. I ask that you continue to measure the static level in these wells, which may provide useful data for site modeling. The July 1995 sample results were slightly above the acceptable contamination levels in monitor wells #4 and G1, but results have been good since. Sampling of these 2 wells is still needed through the 2nd quarter of 1997. Provided that the sample results for these 2 wells stay within acceptable limits through then, no further sampling will be required until project closeout is anticipated. Monitor wells G2 and #5, along with the cooling pond, still have contamination levels above allowable limits. These locations will still need to be sampled quarterly.	Mike Krieber
10/16/1998	Update or Other Action	ADEC requested additional information related to Cordova Electric Corporation’s (CEC) intentions and/or workplan development to address on-site contamination, including a sampling program schedule.	David Pikul
12/18/1998	Update or Other Action	ADEC reviewed the 1998 groundwater monitoring data and commented on the need for site characterization.	David Pikul
2/16/1999	Meeting or Teleconference Held	Meeting between ADEC and CEC. Discussion topics - proposed locations for the incoming power line from the hydroelectric plant, workplan preparations for groundwater sampling of the on-site monitoring wells and put together the information of the oil-water separator discharge system.	David Pikul
3/1/1999	Update or Other Action	ADEC review and comment on the information that provided related to the proposed alignment for the power line connection at the Eyak Lake Plant.	David Pikul
4/5/1999	Update or Other Action	Workplan review for Power Line Sampling.	David Pikul
6/24/1999	Update or Other Action	ADEC site visit to Eyak Lake Power Plant.	David Pikul
6/25/1999	Update or Other Action	Oil seepage along the shoreline of Eyak Lake, ADEC requested CEC to initiate response action to contain and cleanup contamination at the Eyak Lake Plant site and any adjacent land and waters that may be impacted from its migration.	David Pikul
7/13/1999	Update or Other Action	Test pits that were excavated along the underground power line route did not identify any contamination and, therefore, ADEC has no objection to its installation.	David Pikul
8/23/1999	Meeting or Teleconference Held	ADEC meeting with Gilfilian regarding workplan to address oil seepage into Eyak Lake.	David Pikul
10/15/1999	Update or Other Action	ADEC reviewed workplan for the abatement of oil seepage into Eyak Lake, approval not granted.	David Pikul
10/19/1999	Update or Other Action	PERP responding to waste oil spill from the site tanks. It appears that several factors lead to the spill. Unseasonably heavy rains overwhelmed the oil water separator system. The separator pump failed to shut off, filling the used oil tank with water. The high level alarm and the shut off valve on the used oil tank failed, allowing the tank to overflow. Accumulated rain water in the containment dike allowed the oil to overflow the containment and flow to the lake. Remove one of these factors and the spill may not have occurred, or at least may have been much smaller. On the fortunate side, the wind forced the oil against the shore and back into the containment pond, keeping it from spreading across the lake.	David Pikul
11/2/1999	Site Ranked Using the AHRM	Air Exposure Index Value changed from 0.1 to 0.2, oil seepage into lake visible at shoreline.	David Pikul
1/5/2000	Update or Other Action	Provided PERP RP contact iformation for billing.	David Pikul
5/12/2000	Meeting or Teleconference Held	CSRP staff held a meeting/teleconference with the RP and their consultant to discuss the workplan submitted to address seepage of oil into Eyak Lake. ADEC requested that additional effort be employed during this phase on site work.	David Pikul
7/5/2000	Interim Removal Action Approved	Interim Action workplan approved to advance soil test pits and install vertical culverts for the purpose of product recovery to mitigate the seepage of oil into Eyak Lake.	David Pikul
7/14/2000	Update or Other Action	Interim action implemented with exception of the installation of the product recovery skimmer devices. To be installed as soon as they arrive from the factory.	David Pikul
7/25/2000	Update or Other Action	Comment letter issued requesting additional site characterization and reporting of interim action progress.	David Pikul
8/30/2000	Update or Other Action	Received Eyak Lake Interim Corrective Action Report prepared by Gilfilian Engineering and Environmental Testing, Inc.	David Pikul
9/26/2000	Update or Other Action	Received Work Plan Addendum - Site Characterization/Plant Demolition Portion, prepared by Gilfilian Engineering.	David Pikul
10/5/2000	Site Characterization Workplan Approved	Phase I Site Characterization Work Plan Approved. Phase II to be conducted spring 2001.	David Pikul
1/25/2001	Meeting or Teleconference Held	Met with Bob Gilfilian, Kris Ivarson and Danny Ackmann (via telephone) at Gilfilian Engineering offices. Discussed status of Phase I site report, potential interim actions and addition characterization. Received request for authorization to transport and dispose of drums.	Scott Pexton
2/2/2001	Meeting or Teleconference Held	Meeting held at ADEC offices in Anchorage with Scott Pexton, Jim Frechione, Danny Ackmann, Bob Gilfilian and Kris Ivarson to discuss drum removal, site characterization and potential interim removal actions. Received Eyak Lake Phase I Site Characterization and Site Demolition report, prepared by Gilfilian Engineering.	Scott Pexton
2/15/2001	Update or Other Action	Sent email message to Kris Ivarson of Gilfilian Engineering regarding the February 2 meeting and the drum disposal plan.	Scott Pexton
2/22/2001	Update or Other Action	Received copy of letter from the EPA Region 10 RCRA Compliance Unit to Danny Ackmann of Cordova Electric Cooperative that granted a 30-day extension (to March 5, 2001) for the time frame to dispose of hazardous waste generated during October 2000.	Scott Pexton
3/5/2001	Update or Other Action	Received fax transmittal from Gilfilian Engineering with copies of the generator's waste manifests. Also received a fax copy of a Phase II Site Characterization Work Plan (dated February 21, 2001), prepared by Gilfilian Engineering.	Scott Pexton
4/11/2001	Meeting or Teleconference Held	Meeting at ADEC offices in Anchorage with Danny Achmann, Bob Gilfilian, Kris Ivarson, Jim Frechione, Renee Evans and Scott Pexton to discuss Interim Removal Action Work Plan.	Scott Pexton
5/10/2001	Interim Removal Action Approved	Interim corrective action approved with conditions.	Renee Evans
5/22/2001	Update or Other Action	Revised workplan received from Gilfilian addressing conditions from 5/10/2001 ADEC letter.	Renee Evans
5/30/2001	Update or Other Action	Fax from CEC and approval for biocell placement.	Renee Evans
7/11/2001	Meeting or Teleconference Held	Meeting and site visit to CEC. Attended City Council meeting to provide update and answer questions regarding site status.	Renee Evans
7/24/2001	Update or Other Action	Fax to CEC regarding 18 AAC 80 requirements for separation distance waivers and status request for sorbent placement/free product recovery.	Renee Evans
7/25/2001	Update or Other Action	Status report received regarding boom, leachate in biocell, etc.	Renee Evans
8/2/2001	Update or Other Action	Biocell leachate sample results received.	Renee Evans
8/19/2001	Update or Other Action	Teleconference with CEC regarding site status and planned actions. CEC will address separation distance waiver for additional biocell proposed to be located less than 200 feet from Eyak Lake and additional removal actions for this summer (2001). Sorbents are continued to be used on lake, cooling pond, in sump (oil separator building). Free product continues to be removed from sumps.	Renee Evans
2/20/2003	Update or Other Action	DEC completed review and comment to the work plan for recovery trench installation.	David Pikul
11/9/2003	Meeting or Teleconference Held	DEC attended a meeting with CEC and their consultant to discuss current data and to project the next activities at the site. Treatment cell data indicated soil was ok for on-site spreading. Groundwater monitoring was suspended.	David Pikul
11/18/2003	Update or Other Action	DEC staff traveled to the site for an on-site meeting and subsurface investigation. In order to evaluate the on-site product collection system, several soil test pits were advanced upgradient of the collection sumps. From the information gathered, it was clear that the liner installed to "funnel" groundwater flow into the sumps was acting as a barrier wall and groundwater flow is being diverted around the system. More product was noticed at the edges of the system than was previously observed when the collection sumps were installed. Without further action, DEC believed that the product would flow around the collection system and result in additional seeps into Lake Eyak. It was determined that a large trench, positioned parallel to the current system would act to create relief and allow product collection. Plans for such a system are to be forth coming from CEC.	David Pikul
2/23/2004	Meeting or Teleconference Held	DEC attended a meeting following review of the proposed plan for installation of the recovery trench. Details were finalized and a revised workplan forthcoming. CEC would like to begin work ASAP while the lake water is down.	David Pikul
3/2/2004	Update or Other Action	DEC completed review of the revised plan and provided comment.	David Pikul
3/8/2004	Interim Removal Action Approved	DEC approved the second revision of the work plan to install an open trench for product recovery that includes pump and treat of groundwater with reinjection of treated water into the sites groundwater. Approval was achieved through consult and buy-in of the States Water Quality Program.	David Pikul
3/9/2004	Update or Other Action	CS staff consulted Div. of Water regarding required pemits for water discharge to the subsurface and received the following response: thanks for checking with me yesterday on this clean up plan and whether a wastewater disposal permit is needed. According to your description and schematic, a trench will intercept the contaminant plume, pump then treat, then inject down a Class V well for which the responsible party has already applied to EPA Region 10. The injection is to groundwater below the site area and into groundwater already affected by contamination. Our section does not need to issue a permit for these activities as they will be done in accordance with a DEC Corrective Action Plan for SPAR/C-Sites approval. However, our wastewater regs can require an engineered plan review even if a permit will not be issued. Under 18 AAC 72.600 "A person who constructs, alters, installs, modifies, or operates any part of a nondomestic wastewater treatment works or disposal system must first have written department approval of engineering plans..." In this case, SPAR's review of the engineering plans satisfies this requirement.	David Pikul
7/21/2004	Meeting or Teleconference Held	DEC staff met with MWH and Danny Ackmann of CEC to discuss site activities and modifications to the remedial system currently in operation at the site.	David Pikul
7/29/2004	Update or Other Action	DEC completed review of the request for approval for modification to the work plan. DEC issued approval letter for changes to the system and for perfomance monitoring.	David Pikul
9/16/2004	Update or Other Action	MW-4 has been found.	David Pikul
1/12/2005	Update or Other Action	DEC provided the RP a comment letterto the RP's contractor’s e-mail of November 29, 2004 informing DEC of the status of the soil treatment cell, request to dispose of that soil in the cooling pond, requesting approval for using MW-4 for performance monitoring, sand point installation and notification of a forthcoming monitoring and sampling report. Issues pointed out by DEC included: missplacement of the treatment system infiltrator, use of monitoring well G-R2 for performance monitoring and not MW-4 as it is outside of the free product plume, lack of system performance monitoring data, DEC's request for installation of groundwater monitoring wells, DEC expressed disapproval for the use of test hole observation points as monitoring wells, and DEC's objection to the use of treated soil in the filling of the cooling pond, but non-objection to reviewing a detailed plan for filling the cooling pond. Plan must also include provisions for closing the oil/water separator sump and pipe connecting to the cooling pond.	David Pikul
4/7/2005	Update or Other Action	DEC participated in a teleconference with the RP's new MWH project manager, Doug Quist. DEC provided an overview of the site history and outstanding issues.	David Pikul
4/11/2005	Meeting or Teleconference Held	DEC attended a meeting with Doug Quist to discuss additional work which included: performance monitoring for the treametn system, additional characterization of tank farm area, closure of the cooling pond and separator shed, record keeping of free product collected and spreading on-site of treated soil.	David Pikul
2/16/2006	Update or Other Action	Cordova Electric Cooperative Eyak Lake Power Plant, Cordova, Alaska. A determination has been made regarding the status of the former cooling pond at the site. Alaska Department of Natural Resources (ADNR) has reviewed the information for the Cordova Electric cooling pond and have determined that a portion of the pond is state land. ADNR has no objections to the pond being filled by Cordova Electric, however, they have been advised to apply for a lease of the site. Alaska Department of Environmental Conservation Water Quality Program has determined that Water Quality Standards don't apply to the cooling pond since it is a treatment works, so no permit will be required to fill in the pond. The Department of Environmental Conservation Contaminated Sites Program has suggested to the Responsible Party’s contractor to proceed with work plan preparation for filling in the cooling pond.	David Pikul
12/5/2006	Update or Other Action	Project management transferred from Pikul to O'Connell. Letter sent to Ken Gates about timeliness of future reports and possible meeting in early 2007.	Bill O'Connell
12/6/2006	Update or Other Action	Received 2005/2006 Remediation System Monitoring Events Report. This report details activitites conducted from summer 2005 until fall 2006 including: Installation of 4 boreholes and completion of three of the boreholes as monitoringng wells (MW-5r, MW-6, MW-7), installation of 3 wellpoints between the interceptor trench and Eyak Lake, decommissioning and spreading of the soil from teatment cell #2 and backfilling of the cooling pond. Groundwater monitoring conducted in June 2005, November 2005, and November 2006. Contaminant levels are still above Table C cleanup levels, but are below historic highs. Product recovery continues in MW-6 and MW-7 using absorbent socks. Free product continues to be present in MW-5r, which replaced MW-5. No sheen was noted on Eyak Lake, or on the cooling pond during filling.	Bill O'Connell
1/31/2007	Exposure Tracking Model Ranking		Bill O'Connell
2/8/2007	Meeting or Teleconference Held	Meeting with CEC and MWH to discuss site status and future action at the site. Monitoring will continue, 2 or 3 additional well points will be installed along Eyak Lake and habitat restoration will occur along the shore of the lake in conjunction with Cordova Waterhsed Goup.	Bill O'Connell
11/20/2008	Document, Report, or Work plan Review - other	Received 2007/2008 monitoring and corrective action report for CEC. In 2007, the former oil/water separator (OWS) was removed and an investigation was conducted to see if there was a drain line from the OWS shed to the former cooling pond that was filled in in 2006. No drain line was found and it was concluded that there had never been one, despite drawings to the contrary. The excavation of the sump encountered free product at the groundwater interface, so a stainless steel well point was installed as the excavation was backfilled. Soil samples collected from the excavation contained DRO up to 3,740 mg/kg at 8-10 feet bgs. A skimmer was installed in the well point at the former sump, however recoverable quantities of product were never present in the wellpoint, so the skimmer was moved to MW-5R. Groundwater monitoring events were conducted in 2007 and 2008. In 2007, floating product was found in wells G-2R, MW-6, and MW-7, in 2008, floating product was only found in MW-5R. Analytical results from both of the monitoring events indicated DRO and RRO concentrations were above Table C cleanup levels in wells G-2R, MW-5R, MW-6, MW-7, and wellpoints WP2, and WP3 with a maximum DRO concentration of 73.7 mg/L found in well MW-5R in 2007. The inlet and outlet of the groundwater treatment tank were sampled in 2007 and 2008 and sample results indicate contaminated water is being effectively treated in the tank prior to discharge to the subsurface.	Bill O'Connell
1/11/2010	Document, Report, or Work plan Review - other	Reviewed 2008/2009 Monitoring Report. Events were conducted in October 2008 and June 2009. In 2008, groundwater samples were collected from Well Points WP-1, WP-2 and WP-3 and the product skimmer in MW-5r was serviced. The well points were sampled to evaluate previous data that indicated an increase in the DRO concentration at WP-2. The 2008 sampling found that DRO in WP-2 had decreased from 12.1 mg/l to 8.97 mg/l and RRO was detected above the cleanup level in WP-1 at 1.95 mg/l. WP-3 was dry. The spill buster product collection device installed at MW-5r has not recoverd any product as product levels, while consistent, are not enough to activate the device. In 2009, samples were collected from WP-1,WP-2, WP-3, WP-4, WP-5, and the inlet and outlet of the treatment tank. Samples were not collected from G-2r, MW-5r, MW-6 ans MW-7 due to the presence of a thin layer of floating product. Samples collected from well points did not contain copntaminants above ADEC groundwater cleanup levels except at WP-2, which contained DRO at 2.6 mg/l, a decrease from 2008 levels. Samples collected from the inlet and outlet of the treatment tank did not contain contaminants above cleanup levels, but they also did not indicate a significant reduction in DRO levels after treatment. An assessment of the remediation system found it to be in good working condition and is typically operated from May to October each year.	Bill O'Connell
6/29/2010	Document, Report, or Work plan Review - other	Reviewed 2010 Work plan for CEC. One groundwater monitoring event will be conducted during which samples will be collected from wells G2-R, MW-5R, MW-6, MW-7, and WP1, WP2, WP3, WP4, and WP5. Water samples will also be collected from the inlet and outlet of the treatment tank. Samples will be analyzed for DRO, RRO, GRO, and BTEX. The spill buster will be removed from MW-5R due to unrecoverable quantities of petroleum in the well.	Bill O'Connell
12/9/2010	Document, Report, or Work plan Review - other	Reviewed 2010 Remediation System Monitoring Events Report for Cordova Electric. Groundwater samples were collected from well points WP-1, WP-2, WP-3, WP-4, WP-5, and monitoring wells MW-5R, MW-6, MW-7, G2-R and the inlet and outlet of the treatment system tank in July 2010. In October 2010, well point WP-7 was sampled and the entire contents of the treatment system tank was flushed through the infiltration trench. The Magnum Spill buster deployed in MW-5R was removed due to the lack of floating product and will not be re-deployed at the site due the consistent lack of floating product in available wells. Of the 9 wells sampled, 5 had DRO or RRO above the Table C cleanup level and one well, MW-5R contained 0.01’ of floating product. DRO was detected up to 9.11 mg/l in well G2R and RRO was detected up to 15.4 mg/l in the same well. Samples collected from the inlet and outlet of the treatment system contained detectable concentrations of contaminants, but below cleanup levels, and the DRO and RRO concentrations were reduced in the treatment tank by approximately 10-15%.	Bill O'Connell
10/24/2014	Exposure Tracking Model Ranking	A new updated ranking with ETM has been completed for source area 71007 ASTs.	Bill O'Connell
11/3/2014	Exposure Tracking Model Ranking	Initial ranking with ETM completed for source area id: 71007 name: ASTs	Bill O'Connell
3/23/2015	Document, Report, or Work plan Review - other	Reviewed 2012/2013 Remediation system and Monitoring Report for Cordova Electric. Activities conducted during these efforts include groundwater sample collection from monitoring wells and well points, water sampling from the inlet and outlet of the treatment tank and monitoring well decommissioning. In October 2012, groundwater samples were collected from well points WP1, WP2, WP4, and WP5. The monitoring wells were not available for sampling due to cold weather. In June 2013, samples were collected from monitoring wells MW-5R, MW-6, MW-7, G2-R, and well points 1-5, WP3 was replaced with WP3R because no water was present in WP3 in 2012. Samples from the inlet and outlet of the treatment tank were collected during both sampling events. In the well points located along the edge of Eyak Lake, DRO was detected at 3.55 mg/l and RRO was detected at 2.29 mg/l in WP-2 during the June event. At WP-3R, RRO was detected at 2.46 mg/l during the June event; the PQL for DRO was elevated to 2.61 mg/l in this sample. Monitoring well MW-5R is located just upgradient from the interception trench and contained DRO at 53.5 mg/l and RRO at 16.6 mg/l in the June event. In October 2012, this well had 0.01 feet of free product and was not sampled. MW-7 located near the former waste oil and fuel tanks contained DRO at 11.2 mg/l and RRO at 2.17 mg/l. Monitoring well G2R located just downgradient from the infiltration trench contained DRO at 3.43 mg/l and RRO at 7.02 mg/l. Samples from the inlet and the outlet of the treatment tank did not contain contaminants above cleanup levels however DRO concentrations were lower in the outlet samples than the inlet samples suggesting the treatment system continues to reduce contaminant concentrations. The well points along Eyak Lake continue to show contaminant concentrations above groundwater cleanup levels, however there have been no reports of sheen or other impacts to the Lake so it does not appear that contaminants are migrating into the lake in any significant amount. MW-5R located just upgradient from the interception trench shows the highest levels of petroleum contamination at the site, however the water in the interception trench does not appear to be as contaminated based on the inlet samples from the treatment system. Report recommends biennial sampling of WP-1, WP-2, WP-3R, G2-R, MW-5R, MW-6, MW-7, and the inlet and outlet of the treatment system. Monitoring wells G-1, G-3, G-4, G-5, G-6, and G-7 were decommissioned in accordance with ADEC guidance in June 2013.	Bill O'Connell
1/17/2017	Update or Other Action	Communication with RP and consultant regarding work plan for 2017 monitoring	Bill O'Connell
10/19/2017	Document, Report, or Work plan Review - other	Reviewed 2017 work plan. Samples will be collected from monitoring Wells G2-R, MW-5R, MW-6, MW-7 and sand points WP1, WP2, WP3R, WP4, and WP5 as well as the treatment tank inlet and outlet. Samples will be analyzed for DRO, GRO, RRO, and PAHs.	Bill O'Connell
11/2/2017	Exposure Tracking Model Ranking	A new updated ranking with ETM has been completed for source area 71007 ASTs.	Bill O'Connell
6/18/2018	Document, Report, or Work plan Review - other	Reviewed 2017 Monitoring report for Cordova Electric. Samples were collected from monitoring wells MW-6, MW-7, and G-2R; well points WP-1, WP-2, WP-3R, WP-4 and WP-5. MW-5R could not be sampled due to the presence of 0.01 feet of product and the inlet and outlet of the treatment tank were not sampled because the tank had already been winterized for the season. Samples from Well points WP-1, WP-2, and WP-3 contained DRO and or RRO above cleanup levels, with DRO detected up to 7.5 mg/l in WP-2. Samples from monitoring wells MW-7 and G-2R also contained DRO and RRO above the cleanup level, with DRO detected up to 73.5 mg/l in well G-2R. Benzo(a)anthracene, benzo(a)pyrene, and benzo(b)fluoranthene were also detected above cleanup levels in groundwater. 2017 sampling results indicate a significant increase from previous results. To evaluate if these concentrations represent a trend or an anomaly, Stantec proposes to sample the available monitoring wells, well points, and the inlet/outlet of the system three times in summer 2018.	Bill O'Connell
4/5/2019	Update or Other Action	Teleconference today with CEC and Stantec to discuss monitoring network and remedial optimization	Bill O'Connell
2/3/2020	Site Characterization Report Approved	On this date, ADEC received the Former Eyak Lake Power Plant July 2019 Remediation System Monitoring Report submitted by Stantec and dated December 2019. Work included groundwater monitoring of: well points WP-1, WP-2, WP-3R, WP-4, WP-5 and monitoring wells MW-6, MW-7 and G-2R. MW-5R could not be sampled due to the presence of 0.01 feet of free product. Additionally the inlet and outlet of the remediation system treatment tank were not sampled because it was undergoing maintenance and not operational at the time. A very slight, yet sporadic sheen was noted on the surface of the interceptor trench. Samples from the well points WP-1, WP-2, and WP-3R adjacent to the lake contained DRO and RRO above cleanup levels up to 19.5 mg/Land 12.1 mg/L respectively. This is an increase in DRO and RRO concentrations from the last three sampling events (2013, 2017, and 2019). Well point WP-3R also contained benzo(a)pyrene above cleanup levels at 0.288 ug/L. Samples from monitoring wells MW-7 and G-2R contained DRO and RRO above the cleanup levels up to 16.1 mg/L and 32 mg/L respectively. Monitoring well MW-7 contained benzo(a)pyrene above cleanup levels at 0.288 ug/L. During the summer of 2020, Stantec proposes to replace the infiltration system with activated carbon in the trench and injecting carbon in five locations. Additionally, the three wells points adjacent to the lake will be replaced to provide better quality water quality data and all the monitoring wells will be sampled.	Grant Lidren
5/4/2020	Meeting or Teleconference Held	On this date, ADEC attended a teleconference with CEC, City of Cordova, and Stantec. The purpose of the meeting was to discuss proposed 2020 field work.	Grant Lidren
8/25/2020	Site Characterization Workplan Approved	ADEC received and approved the 2020 Work Plan - Cordova Electric (Former Eyak Lake Power Plant)Eyak Lake, Cordova submitted by Stantec and dated August 25, 2020. The three well points adjacent to the lake (WP-1, WP-2, and WP-3R) will be removed and replaced with three new pre-packed well points. The existing remediation system will be decommissioned and the trench will be filled with approximately 1,000 lbs of granular activated carbon (GAC). Groundwater and surface water will be sampled twice in 2020. Surface water samples will be collected adjacent to WP3R/WP3R2. Groundwater samples will be collected from monitoring Wells G2-R, MW-5R, MW-6, MW-7 and sand points WP1R, WP2R, WP3R2, WP4, and WP5. Samples will be analyzed for DRO, GRO, RRO, PAHs, TAH, and TAqH.	Grant Lidren
6/8/2021	Document, Report, or Work plan Review - other	On this date, ADEC approved the “Former Eyak Lake Power Plant September and October 2020 Remediation System Monitoring Event Report”, dated December 2020 and received on February 25,2021. The report describes the September and October 2020 groundwater and surface water monitoring events as well as the application of activated carbon to the interceptor trench, and attempted installation of replacement well points at WP-1, WP-2 and WP-3R. Contaminant exceedances above the 18 AAC 75.345 Table C Groundwater Cleanup Levels were detected during the September and October 2020 sampling events. In September diesel range organics (DRO) and residual range organics (RRO) were detected above cleanup levels at WP-2 and MW-6. In October DRO was detected above cleanup levels at WP-2, WP-3, G2-R and RRO was detected above cleanup levels at WP-1, WP-2, WP-3, and G2-R.	Brandi Tolsma
6/8/2021	Meeting or Teleconference Held	On this date, ADEC met with Stantec to discuss the conclusions and recommendations outline in the December 2020 report. The ADEC concurs with the recommendation for additional groundwater monitoring at the site and recommends sampling for volatile organic compounds (VOCs) in addition to gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), and polycyclic aromatic hydrocarbons (PAHs).	Brandi Tolsma

Action Date

Action

Description

DEC Staff

1/19/1981

Site Added to Database

Waste oil and diesel contaminants.

Former Staff

3/20/1991

Update or Other Action

(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Letter was sent requesting a site cleanup plan.

Former Staff

6/24/1991

Preliminary Assessment Approved

A preliminary assessment was received by ADEC and is under review.

Former Staff

8/13/1991

Site Ranked Using the AHRM

New information from Jane Tokin caused site to be reranked.

Former Staff

8/13/1991

Update or Other Action

Additional site information sent by Cordova Field office.

Former Staff

2/14/1992

Update or Other Action

(Old R:Base Action Code = SA1 - Phase I Site Assessment (General)).

Former Staff

4/10/1992

Update or Other Action

(Old R:Base Action Code = SA1R - Phase I SA Review (CS/LUST)).

Former Staff

10/29/1993

Update or Other Action

(Old R:Base Action Code = SA1R - Phase I SA Review (CS/LUST)).

Former Staff

10/29/1993

Update or Other Action

(Old R:Base Action Code = SA2R - Phase II SA Review (CS)).

Former Staff

1/13/1994

Update or Other Action

(Old R:Base Action Code = CORR - Correspondence (General)). Granted request for time extension of COBC.

Former Staff

1/26/1994

Update or Other Action

(Old R:Base Action Code = MS - Monitoring/Sampling). Groundwater conditions improving in some wells, degrading in others.

Former Staff

3/8/1994

Update or Other Action

(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). The proposed pilot scale in-situ soil and groundwater treatment system was conceptually approved.

Former Staff

4/22/1994

Update or Other Action

(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Plan to incorporate contaminated soil into road bed approved.

Former Staff

5/4/1994

Update or Other Action

(Old R:Base Action Code = CORR - Correspondence (General)). Sampling plan for proposed soil treatment/disposal plan approved.

Former Staff

11/9/1994

Update or Other Action

(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). If monitor well G-2 TPH level remains high, information regarding a possible source of contamination must be provided. In addition, Gilfilian Engineering has recommended that ground water treatment be performed in the vicinity of MW-5.

Mike Krieber

11/10/1994

Update or Other Action

(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). No further soil cleanup appears needed in the proximity of the fuel shed. The excavated soil was disposed of on the 1994 road paving project.

Mike Krieber

3/1/1995

Update or Other Action

(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). January water samples could not be obtained due to frozen monitor wells. Proposed sampling within 30 days is acceptable to the Department. Future monitoring events should provide information on whether the excavated contaminated soil was the primary source of GW contamination.

Mike Krieber

3/1/1995

Update or Other Action

(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Reviewed remedial action workplans for tasks 4 and 5. Task 4 could be postponed. The soil investigation / sampling plan, required by item #2, needs to be submitted for Department review and approval, no later than 4/3/95. Task 5, proposal to use the PetroTrap (a passive product collection device) is appropriate.

Mike Krieber

4/17/1995

Update or Other Action

(Old R:Base Action Code = RAPR - Remedial Action Plan Review (CS)). Sampling at the interface could provide somewhat better information on contaminant mobility and will provide for better guidance in ground water treatment needs, if any. Subject to minor revisions, the task 4 plan is approved. The proposed SWAP system is acceptable to the Department. The task 5 plan revision is approved.

Mike Krieber

5/3/1995

Update or Other Action

(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). Reviewed a ground water monitoring report. GW contamination levels in the vicinity of monitor wells G1 and G2 appear to have significantly dropped since the last sampling events. Surmised that this is due to excavation of contaminated soils on the south side of the building in the summer of 1994. There is a slight increase in contaminant levels in the cooling pond which is probably due to the movement of a the contaminant slug downgradient.

Mike Krieber

8/8/1995

Update or Other Action

(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). Reviewed a remedial action preliminary report.

Mike Krieber

9/12/1995

Update or Other Action

(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). To better observe the GW contamination trends, the department requests that the cooperative provide a graphical presentation of the results in the future monitoring reports.

Mike Krieber

10/5/1995

Update or Other Action

(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). Reviewed a Remedial Action Report. Continue sampling the downgradient monitor wells to determine if contamination levels drop. Active remediation could be required if levels do not drop.

Mike Krieber

11/22/1995

Update or Other Action

(Old R:Base Action Code = RARR - Remedial Action Report Review (CS)). Reviewed a ground water monitoring report. Contamination levels are approaching acceptable limits except in monitor well #5.

Mike Krieber

1/7/1997

Update or Other Action

Reviewed a GW Monitoring Report. MWs 1 and 3 have had continuous reports of contamination being within acceptable limits. Therefore, these 2 monitor wells do not require further analytical sampling now. However, when project closeout is contemplated in the future, these 2 wells may need to be sampled then. I ask that you continue to measure the static level in these wells, which may provide useful data for site modeling. The July 1995 sample results were slightly above the acceptable contamination levels in monitor wells #4 and G1, but results have been good since. Sampling of these 2 wells is still needed through the 2nd quarter of 1997. Provided that the sample results for these 2 wells stay within acceptable limits through then, no further sampling will be required until project closeout is anticipated. Monitor wells G2 and #5, along with the cooling pond, still have contamination levels above allowable limits. These locations will still need to be sampled quarterly.

Mike Krieber

10/16/1998

Update or Other Action

ADEC requested additional information related to Cordova Electric Corporation’s (CEC) intentions and/or workplan development to address on-site contamination, including a sampling program schedule.

David Pikul

12/18/1998

Update or Other Action

ADEC reviewed the 1998 groundwater monitoring data and commented on the need for site characterization.

David Pikul

2/16/1999

Meeting or Teleconference Held

Meeting between ADEC and CEC. Discussion topics - proposed locations for the incoming power line from the hydroelectric plant, workplan preparations for groundwater sampling of the on-site monitoring wells and put together the information of the oil-water separator discharge system.

David Pikul

3/1/1999

Update or Other Action

ADEC review and comment on the information that provided related to the proposed alignment for the power line connection at the Eyak Lake Plant.

David Pikul

4/5/1999

Update or Other Action

Workplan review for Power Line Sampling.

David Pikul

6/24/1999

Update or Other Action

ADEC site visit to Eyak Lake Power Plant.

David Pikul

6/25/1999

Update or Other Action

Oil seepage along the shoreline of Eyak Lake, ADEC requested CEC to initiate response action to contain and cleanup contamination at the Eyak Lake Plant site and any adjacent land and waters that may be impacted from its migration.

David Pikul

7/13/1999

Update or Other Action

Test pits that were excavated along the underground power line route did not identify any contamination and, therefore, ADEC has no objection to its installation.

David Pikul

8/23/1999

Meeting or Teleconference Held

ADEC meeting with Gilfilian regarding workplan to address oil seepage into Eyak Lake.

David Pikul

10/15/1999

Update or Other Action

ADEC reviewed workplan for the abatement of oil seepage into Eyak Lake, approval not granted.

David Pikul

10/19/1999

Update or Other Action

PERP responding to waste oil spill from the site tanks. It appears that several factors lead to the spill. Unseasonably heavy rains overwhelmed the oil water separator system. The separator pump failed to shut off, filling the used oil tank with water. The high level alarm and the shut off valve on the used oil tank failed, allowing the tank to overflow. Accumulated rain water in the containment dike allowed the oil to overflow the containment and flow to the lake. Remove one of these factors and the spill may not have occurred, or at least may have been much smaller. On the fortunate side, the wind forced the oil against the shore and back into the containment pond, keeping it from spreading across the lake.

David Pikul

11/2/1999

Site Ranked Using the AHRM

Air Exposure Index Value changed from 0.1 to 0.2, oil seepage into lake visible at shoreline.

David Pikul

1/5/2000

Update or Other Action

Provided PERP RP contact iformation for billing.

David Pikul

5/12/2000

Meeting or Teleconference Held

CSRP staff held a meeting/teleconference with the RP and their consultant to discuss the workplan submitted to address seepage of oil into Eyak Lake. ADEC requested that additional effort be employed during this phase on site work.

David Pikul

7/5/2000

Interim Removal Action Approved

Interim Action workplan approved to advance soil test pits and install vertical culverts for the purpose of product recovery to mitigate the seepage of oil into Eyak Lake.

David Pikul

7/14/2000

Update or Other Action

Interim action implemented with exception of the installation of the product recovery skimmer devices. To be installed as soon as they arrive from the factory.

David Pikul

7/25/2000

Update or Other Action

Comment letter issued requesting additional site characterization and reporting of interim action progress.

David Pikul

8/30/2000

Update or Other Action

Received Eyak Lake Interim Corrective Action Report prepared by Gilfilian Engineering and Environmental Testing, Inc.

David Pikul

9/26/2000

Update or Other Action

Received Work Plan Addendum - Site Characterization/Plant Demolition Portion, prepared by Gilfilian Engineering.

David Pikul

10/5/2000

Site Characterization Workplan Approved

Phase I Site Characterization Work Plan Approved. Phase II to be conducted spring 2001.

David Pikul

1/25/2001

Meeting or Teleconference Held

Met with Bob Gilfilian, Kris Ivarson and Danny Ackmann (via telephone) at Gilfilian Engineering offices. Discussed status of Phase I site report, potential interim actions and addition characterization. Received request for authorization to transport and dispose of drums.

Scott Pexton

2/2/2001

Meeting or Teleconference Held

Meeting held at ADEC offices in Anchorage with Scott Pexton, Jim Frechione, Danny Ackmann, Bob Gilfilian and Kris Ivarson to discuss drum removal, site characterization and potential interim removal actions. Received Eyak Lake Phase I Site Characterization and Site Demolition report, prepared by Gilfilian Engineering.

Scott Pexton

2/15/2001

Update or Other Action

Sent email message to Kris Ivarson of Gilfilian Engineering regarding the February 2 meeting and the drum disposal plan.

Scott Pexton

2/22/2001

Update or Other Action

Received copy of letter from the EPA Region 10 RCRA Compliance Unit to Danny Ackmann of Cordova Electric Cooperative that granted a 30-day extension (to March 5, 2001) for the time frame to dispose of hazardous waste generated during October 2000.

Scott Pexton

3/5/2001

Update or Other Action

Received fax transmittal from Gilfilian Engineering with copies of the generator's waste manifests. Also received a fax copy of a Phase II Site Characterization Work Plan (dated February 21, 2001), prepared by Gilfilian Engineering.

Scott Pexton

4/11/2001

Meeting or Teleconference Held

Meeting at ADEC offices in Anchorage with Danny Achmann, Bob Gilfilian, Kris Ivarson, Jim Frechione, Renee Evans and Scott Pexton to discuss Interim Removal Action Work Plan.

Scott Pexton

5/10/2001

Interim Removal Action Approved

Interim corrective action approved with conditions.

Renee Evans

5/22/2001

Update or Other Action

Revised workplan received from Gilfilian addressing conditions from 5/10/2001 ADEC letter.

Renee Evans

5/30/2001

Update or Other Action

Fax from CEC and approval for biocell placement.

Renee Evans

7/11/2001

Meeting or Teleconference Held

Meeting and site visit to CEC. Attended City Council meeting to provide update and answer questions regarding site status.

Renee Evans

7/24/2001

Update or Other Action

Fax to CEC regarding 18 AAC 80 requirements for separation distance waivers and status request for sorbent placement/free product recovery.

Renee Evans

7/25/2001

Update or Other Action

Status report received regarding boom, leachate in biocell, etc.

Renee Evans

8/2/2001

Update or Other Action

Biocell leachate sample results received.

Renee Evans

8/19/2001

Update or Other Action

Teleconference with CEC regarding site status and planned actions. CEC will address separation distance waiver for additional biocell proposed to be located less than 200 feet from Eyak Lake and additional removal actions for this summer (2001). Sorbents are continued to be used on lake, cooling pond, in sump (oil separator building). Free product continues to be removed from sumps.

Renee Evans

2/20/2003

Update or Other Action

DEC completed review and comment to the work plan for recovery trench installation.

David Pikul

11/9/2003

Meeting or Teleconference Held

DEC attended a meeting with CEC and their consultant to discuss current data and to project the next activities at the site. Treatment cell data indicated soil was ok for on-site spreading. Groundwater monitoring was suspended.

David Pikul

11/18/2003

Update or Other Action

DEC staff traveled to the site for an on-site meeting and subsurface investigation. In order to evaluate the on-site product collection system, several soil test pits were advanced upgradient of the collection sumps. From the information gathered, it was clear that the liner installed to "funnel" groundwater flow into the sumps was acting as a barrier wall and groundwater flow is being diverted around the system. More product was noticed at the edges of the system than was previously observed when the collection sumps were installed. Without further action, DEC believed that the product would flow around the collection system and result in additional seeps into Lake Eyak. It was determined that a large trench, positioned parallel to the current system would act to create relief and allow product collection. Plans for such a system are to be forth coming from CEC.

David Pikul

2/23/2004

Meeting or Teleconference Held

DEC attended a meeting following review of the proposed plan for installation of the recovery trench. Details were finalized and a revised workplan forthcoming. CEC would like to begin work ASAP while the lake water is down.

David Pikul

3/2/2004

Update or Other Action

DEC completed review of the revised plan and provided comment.

David Pikul

3/8/2004

Interim Removal Action Approved

DEC approved the second revision of the work plan to install an open trench for product recovery that includes pump and treat of groundwater with reinjection of treated water into the sites groundwater. Approval was achieved through consult and buy-in of the States Water Quality Program.

David Pikul

3/9/2004

Update or Other Action

CS staff consulted Div. of Water regarding required pemits for water discharge to the subsurface and received the following response: thanks for checking with me yesterday on this clean up plan and whether a wastewater disposal permit is needed. According to your description and schematic, a trench will intercept the contaminant plume, pump then treat, then inject down a Class V well for which the responsible party has already applied to EPA Region 10. The injection is to groundwater below the site area and into groundwater already affected by contamination. Our section does not need to issue a permit for these activities as they will be done in accordance with a DEC Corrective Action Plan for SPAR/C-Sites approval. However, our wastewater regs can require an engineered plan review even if a permit will not be issued. Under 18 AAC 72.600 "A person who constructs, alters, installs, modifies, or operates any part of a nondomestic wastewater treatment works or disposal system must first have written department approval of engineering plans..." In this case, SPAR's review of the engineering plans satisfies this requirement.

David Pikul

7/21/2004

Meeting or Teleconference Held

DEC staff met with MWH and Danny Ackmann of CEC to discuss site activities and modifications to the remedial system currently in operation at the site.

David Pikul

7/29/2004

Update or Other Action

DEC completed review of the request for approval for modification to the work plan. DEC issued approval letter for changes to the system and for perfomance monitoring.

David Pikul

9/16/2004

Update or Other Action

MW-4 has been found.

David Pikul

1/12/2005

Update or Other Action

DEC provided the RP a comment letterto the RP's contractor’s e-mail of November 29, 2004 informing DEC of the status of the soil treatment cell, request to dispose of that soil in the cooling pond, requesting approval for using MW-4 for performance monitoring, sand point installation and notification of a forthcoming monitoring and sampling report. Issues pointed out by DEC included: missplacement of the treatment system infiltrator, use of monitoring well G-R2 for performance monitoring and not MW-4 as it is outside of the free product plume, lack of system performance monitoring data, DEC's request for installation of groundwater monitoring wells, DEC expressed disapproval for the use of test hole observation points as monitoring wells, and DEC's objection to the use of treated soil in the filling of the cooling pond, but non-objection to reviewing a detailed plan for filling the cooling pond. Plan must also include provisions for closing the oil/water separator sump and pipe connecting to the cooling pond.

David Pikul

4/7/2005

Update or Other Action

DEC participated in a teleconference with the RP's new MWH project manager, Doug Quist. DEC provided an overview of the site history and outstanding issues.

David Pikul

4/11/2005

Meeting or Teleconference Held

DEC attended a meeting with Doug Quist to discuss additional work which included: performance monitoring for the treametn system, additional characterization of tank farm area, closure of the cooling pond and separator shed, record keeping of free product collected and spreading on-site of treated soil.

David Pikul

2/16/2006

Update or Other Action

Cordova Electric Cooperative Eyak Lake Power Plant, Cordova, Alaska. A determination has been made regarding the status of the former cooling pond at the site. Alaska Department of Natural Resources (ADNR) has reviewed the information for the Cordova Electric cooling pond and have determined that a portion of the pond is state land. ADNR has no objections to the pond being filled by Cordova Electric, however, they have been advised to apply for a lease of the site. Alaska Department of Environmental Conservation Water Quality Program has determined that Water Quality Standards don't apply to the cooling pond since it is a treatment works, so no permit will be required to fill in the pond. The Department of Environmental Conservation Contaminated Sites Program has suggested to the Responsible Party’s contractor to proceed with work plan preparation for filling in the cooling pond.

David Pikul

12/5/2006

Update or Other Action

Project management transferred from Pikul to O'Connell. Letter sent to Ken Gates about timeliness of future reports and possible meeting in early 2007.

Bill O'Connell

12/6/2006

Update or Other Action

Received 2005/2006 Remediation System Monitoring Events Report. This report details activitites conducted from summer 2005 until fall 2006 including: Installation of 4 boreholes and completion of three of the boreholes as monitoringng wells (MW-5r, MW-6, MW-7), installation of 3 wellpoints between the interceptor trench and Eyak Lake, decommissioning and spreading of the soil from teatment cell #2 and backfilling of the cooling pond. Groundwater monitoring conducted in June 2005, November 2005, and November 2006. Contaminant levels are still above Table C cleanup levels, but are below historic highs. Product recovery continues in MW-6 and MW-7 using absorbent socks. Free product continues to be present in MW-5r, which replaced MW-5. No sheen was noted on Eyak Lake, or on the cooling pond during filling.

Bill O'Connell

1/31/2007

Exposure Tracking Model Ranking

Bill O'Connell

2/8/2007

Meeting or Teleconference Held

Meeting with CEC and MWH to discuss site status and future action at the site. Monitoring will continue, 2 or 3 additional well points will be installed along Eyak Lake and habitat restoration will occur along the shore of the lake in conjunction with Cordova Waterhsed Goup.

Bill O'Connell

11/20/2008

Document, Report, or Work plan Review - other

Received 2007/2008 monitoring and corrective action report for CEC. In 2007, the former oil/water separator (OWS) was removed and an investigation was conducted to see if there was a drain line from the OWS shed to the former cooling pond that was filled in in 2006. No drain line was found and it was concluded that there had never been one, despite drawings to the contrary. The excavation of the sump encountered free product at the groundwater interface, so a stainless steel well point was installed as the excavation was backfilled. Soil samples collected from the excavation contained DRO up to 3,740 mg/kg at 8-10 feet bgs. A skimmer was installed in the well point at the former sump, however recoverable quantities of product were never present in the wellpoint, so the skimmer was moved to MW-5R. Groundwater monitoring events were conducted in 2007 and 2008. In 2007, floating product was found in wells G-2R, MW-6, and MW-7, in 2008, floating product was only found in MW-5R. Analytical results from both of the monitoring events indicated DRO and RRO concentrations were above Table C cleanup levels in wells G-2R, MW-5R, MW-6, MW-7, and wellpoints WP2, and WP3 with a maximum DRO concentration of 73.7 mg/L found in well MW-5R in 2007. The inlet and outlet of the groundwater treatment tank were sampled in 2007 and 2008 and sample results indicate contaminated water is being effectively treated in the tank prior to discharge to the subsurface.

Bill O'Connell

1/11/2010

Document, Report, or Work plan Review - other

Reviewed 2008/2009 Monitoring Report. Events were conducted in October 2008 and June 2009. In 2008, groundwater samples were collected from Well Points WP-1, WP-2 and WP-3 and the product skimmer in MW-5r was serviced. The well points were sampled to evaluate previous data that indicated an increase in the DRO concentration at WP-2. The 2008 sampling found that DRO in WP-2 had decreased from 12.1 mg/l to 8.97 mg/l and RRO was detected above the cleanup level in WP-1 at 1.95 mg/l. WP-3 was dry. The spill buster product collection device installed at MW-5r has not recoverd any product as product levels, while consistent, are not enough to activate the device. In 2009, samples were collected from WP-1,WP-2, WP-3, WP-4, WP-5, and the inlet and outlet of the treatment tank. Samples were not collected from G-2r, MW-5r, MW-6 ans MW-7 due to the presence of a thin layer of floating product. Samples collected from well points did not contain copntaminants above ADEC groundwater cleanup levels except at WP-2, which contained DRO at 2.6 mg/l, a decrease from 2008 levels. Samples collected from the inlet and outlet of the treatment tank did not contain contaminants above cleanup levels, but they also did not indicate a significant reduction in DRO levels after treatment. An assessment of the remediation system found it to be in good working condition and is typically operated from May to October each year.

Bill O'Connell

6/29/2010

Document, Report, or Work plan Review - other

Reviewed 2010 Work plan for CEC. One groundwater monitoring event will be conducted during which samples will be collected from wells G2-R, MW-5R, MW-6, MW-7, and WP1, WP2, WP3, WP4, and WP5. Water samples will also be collected from the inlet and outlet of the treatment tank. Samples will be analyzed for DRO, RRO, GRO, and BTEX. The spill buster will be removed from MW-5R due to unrecoverable quantities of petroleum in the well.

Bill O'Connell

12/9/2010

Document, Report, or Work plan Review - other

Reviewed 2010 Remediation System Monitoring Events Report for Cordova Electric. Groundwater samples were collected from well points WP-1, WP-2, WP-3, WP-4, WP-5, and monitoring wells MW-5R, MW-6, MW-7, G2-R and the inlet and outlet of the treatment system tank in July 2010. In October 2010, well point WP-7 was sampled and the entire contents of the treatment system tank was flushed through the infiltration trench. The Magnum Spill buster deployed in MW-5R was removed due to the lack of floating product and will not be re-deployed at the site due the consistent lack of floating product in available wells. Of the 9 wells sampled, 5 had DRO or RRO above the Table C cleanup level and one well, MW-5R contained 0.01’ of floating product. DRO was detected up to 9.11 mg/l in well G2R and RRO was detected up to 15.4 mg/l in the same well. Samples collected from the inlet and outlet of the treatment system contained detectable concentrations of contaminants, but below cleanup levels, and the DRO and RRO concentrations were reduced in the treatment tank by approximately 10-15%.

Bill O'Connell

10/24/2014

Exposure Tracking Model Ranking

A new updated ranking with ETM has been completed for source area 71007 ASTs.

Bill O'Connell

11/3/2014

Exposure Tracking Model Ranking

Initial ranking with ETM completed for source area id: 71007 name: ASTs

Bill O'Connell

3/23/2015

Document, Report, or Work plan Review - other

Reviewed 2012/2013 Remediation system and Monitoring Report for Cordova Electric. Activities conducted during these efforts include groundwater sample collection from monitoring wells and well points, water sampling from the inlet and outlet of the treatment tank and monitoring well decommissioning. In October 2012, groundwater samples were collected from well points WP1, WP2, WP4, and WP5. The monitoring wells were not available for sampling due to cold weather. In June 2013, samples were collected from monitoring wells MW-5R, MW-6, MW-7, G2-R, and well points 1-5, WP3 was replaced with WP3R because no water was present in WP3 in 2012. Samples from the inlet and outlet of the treatment tank were collected during both sampling events. In the well points located along the edge of Eyak Lake, DRO was detected at 3.55 mg/l and RRO was detected at 2.29 mg/l in WP-2 during the June event. At WP-3R, RRO was detected at 2.46 mg/l during the June event; the PQL for DRO was elevated to 2.61 mg/l in this sample. Monitoring well MW-5R is located just upgradient from the interception trench and contained DRO at 53.5 mg/l and RRO at 16.6 mg/l in the June event. In October 2012, this well had 0.01 feet of free product and was not sampled. MW-7 located near the former waste oil and fuel tanks contained DRO at 11.2 mg/l and RRO at 2.17 mg/l. Monitoring well G2R located just downgradient from the infiltration trench contained DRO at 3.43 mg/l and RRO at 7.02 mg/l. Samples from the inlet and the outlet of the treatment tank did not contain contaminants above cleanup levels however DRO concentrations were lower in the outlet samples than the inlet samples suggesting the treatment system continues to reduce contaminant concentrations. The well points along Eyak Lake continue to show contaminant concentrations above groundwater cleanup levels, however there have been no reports of sheen or other impacts to the Lake so it does not appear that contaminants are migrating into the lake in any significant amount. MW-5R located just upgradient from the interception trench shows the highest levels of petroleum contamination at the site, however the water in the interception trench does not appear to be as contaminated based on the inlet samples from the treatment system. Report recommends biennial sampling of WP-1, WP-2, WP-3R, G2-R, MW-5R, MW-6, MW-7, and the inlet and outlet of the treatment system. Monitoring wells G-1, G-3, G-4, G-5, G-6, and G-7 were decommissioned in accordance with ADEC guidance in June 2013.

Bill O'Connell

1/17/2017

Update or Other Action

Communication with RP and consultant regarding work plan for 2017 monitoring

Bill O'Connell

10/19/2017

Document, Report, or Work plan Review - other

Reviewed 2017 work plan. Samples will be collected from monitoring Wells G2-R, MW-5R, MW-6, MW-7 and sand points WP1, WP2, WP3R, WP4, and WP5 as well as the treatment tank inlet and outlet. Samples will be analyzed for DRO, GRO, RRO, and PAHs.

Bill O'Connell

11/2/2017

Exposure Tracking Model Ranking

A new updated ranking with ETM has been completed for source area 71007 ASTs.

Bill O'Connell

6/18/2018

Document, Report, or Work plan Review - other

Reviewed 2017 Monitoring report for Cordova Electric. Samples were collected from monitoring wells MW-6, MW-7, and G-2R; well points WP-1, WP-2, WP-3R, WP-4 and WP-5. MW-5R could not be sampled due to the presence of 0.01 feet of product and the inlet and outlet of the treatment tank were not sampled because the tank had already been winterized for the season. Samples from Well points WP-1, WP-2, and WP-3 contained DRO and or RRO above cleanup levels, with DRO detected up to 7.5 mg/l in WP-2. Samples from monitoring wells MW-7 and G-2R also contained DRO and RRO above the cleanup level, with DRO detected up to 73.5 mg/l in well G-2R. Benzo(a)anthracene, benzo(a)pyrene, and benzo(b)fluoranthene were also detected above cleanup levels in groundwater. 2017 sampling results indicate a significant increase from previous results. To evaluate if these concentrations represent a trend or an anomaly, Stantec proposes to sample the available monitoring wells, well points, and the inlet/outlet of the system three times in summer 2018.

Bill O'Connell

4/5/2019

Update or Other Action

Teleconference today with CEC and Stantec to discuss monitoring network and remedial optimization

Bill O'Connell

2/3/2020

Site Characterization Report Approved

On this date, ADEC received the Former Eyak Lake Power Plant July 2019 Remediation System Monitoring Report submitted by Stantec and dated December 2019. Work included groundwater monitoring of: well points WP-1, WP-2, WP-3R, WP-4, WP-5 and monitoring wells MW-6, MW-7 and G-2R. MW-5R could not be sampled due to the presence of 0.01 feet of free product. Additionally the inlet and outlet of the remediation system treatment tank were not sampled because it was undergoing maintenance and not operational at the time. A very slight, yet sporadic sheen was noted on the surface of the interceptor trench. Samples from the well points WP-1, WP-2, and WP-3R adjacent to the lake contained DRO and RRO above cleanup levels up to 19.5 mg/Land 12.1 mg/L respectively. This is an increase in DRO and RRO concentrations from the last three sampling events (2013, 2017, and 2019). Well point WP-3R also contained benzo(a)pyrene above cleanup levels at 0.288 ug/L. Samples from monitoring wells MW-7 and G-2R contained DRO and RRO above the cleanup levels up to 16.1 mg/L and 32 mg/L respectively. Monitoring well MW-7 contained benzo(a)pyrene above cleanup levels at 0.288 ug/L. During the summer of 2020, Stantec proposes to replace the infiltration system with activated carbon in the trench and injecting carbon in five locations. Additionally, the three wells points adjacent to the lake will be replaced to provide better quality water quality data and all the monitoring wells will be sampled.

Grant Lidren

5/4/2020

Meeting or Teleconference Held

On this date, ADEC attended a teleconference with CEC, City of Cordova, and Stantec. The purpose of the meeting was to discuss proposed 2020 field work.

Grant Lidren

8/25/2020

Site Characterization Workplan Approved

ADEC received and approved the 2020 Work Plan - Cordova Electric (Former Eyak Lake Power Plant)Eyak Lake, Cordova submitted by Stantec and dated August 25, 2020. The three well points adjacent to the lake (WP-1, WP-2, and WP-3R) will be removed and replaced with three new pre-packed well points. The existing remediation system will be decommissioned and the trench will be filled with approximately 1,000 lbs of granular activated carbon (GAC). Groundwater and surface water will be sampled twice in 2020. Surface water samples will be collected adjacent to WP3R/WP3R2. Groundwater samples will be collected from monitoring Wells G2-R, MW-5R, MW-6, MW-7 and sand points WP1R, WP2R, WP3R2, WP4, and WP5. Samples will be analyzed for DRO, GRO, RRO, PAHs, TAH, and TAqH.

Grant Lidren

6/8/2021

Document, Report, or Work plan Review - other

On this date, ADEC approved the “Former Eyak Lake Power Plant September and October 2020 Remediation System Monitoring Event Report”, dated December 2020 and received on February 25,2021. The report describes the September and October 2020 groundwater and surface water monitoring events as well as the application of activated carbon to the interceptor trench, and attempted installation of replacement well points at WP-1, WP-2 and WP-3R. Contaminant exceedances above the 18 AAC 75.345 Table C Groundwater Cleanup Levels were detected during the September and October 2020 sampling events. In September diesel range organics (DRO) and residual range organics (RRO) were detected above cleanup levels at WP-2 and MW-6. In October DRO was detected above cleanup levels at WP-2, WP-3, G2-R and RRO was detected above cleanup levels at WP-1, WP-2, WP-3, and G2-R.

Brandi Tolsma

6/8/2021

Meeting or Teleconference Held

On this date, ADEC met with Stantec to discuss the conclusions and recommendations outline in the December 2020 report. The ADEC concurs with the recommendation for additional groundwater monitoring at the site and recommends sampling for volatile organic compounds (VOCs) in addition to gasoline range organics (GRO), diesel range organics (DRO), residual range organics (RRO), and polycyclic aromatic hydrocarbons (PAHs).

Brandi Tolsma

Contaminant Information

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Comments

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Type

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2020 letter Workplan

2019 Monitoring Report

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Site Report: Cordova Electric Coop. - Eyak Lake

Site Chronology

IC / Closure Details

Documents

Associated Sites

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Contaminant Information

Control Type

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2020 letter Workplan

2019 Monitoring Report

Missing Location Data

State of Alaska Department of Environmental Conservation