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Site Report: Kaltag School Oil Seep

Site Name: Kaltag School Oil Seep
Address: Near Kaltag School, Kaltag, AK 99748
File Number: 850.38.001
Hazard ID: 289
Status: Active
Staff: Jim Fish, 9074512117
Latitude: 64.324662
Longitude: -158.723811
Horizontal Datum:WGS84

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.


Residents of Kaltag informed ADEC in 1991 that oil seeps were appearing every spring at the Kaltag School. Probable sources include the Alaska Village Electric Cooperative (AVEC) and Yukon-Koyukuk School District (YKSD) tank farms, which occupy the same gravel pad south of the Kaltag School. A BIA former tank farm serving the Kaltag school (located immediately east of the former AVEC and YKSD tank farms) is also a suspected source. There is a history of fuel oil spills beginning in 1985. Outdated equipment and poor fuel transfer procedures also contributed to chronic leaks and spills from overfills. Site characterization in 1998 and 2000 show heavy soil staining at all three tank farm locations, and that diesel range organics (DRO) and benzene are the primary contaminants of concern. The suprapermafrost groundwater underneath the school has been impacted, and the contamination has migrated via this pathway underneath the school, along the ditches of the school road, and onto the neighboring Semaken property. General groundwater flow is to the north, parallel to the Yukon river. In 1998 Shannon & Wilson performed site characterization and installed as an interim corrective action a roadway seepage control measure and a product recovery trench. Soil samples showed DRO present up to 67,300 milligrams per kilogram (mg/kg), gasoline range organics (GRO) up to 1,330 mg/kg, and benzene, toluene, ethylbenzene, and xylenes (BTEX) above ADEC cleanup levels. Groundwater analysis showed benzene contamination well above ADEC cleanup levels. Soil data for benzene was not conclusive, as the Practical Quantitation Limit (PQL) was above ADEC cleanup levels for all samples. The seepage filtration system (SFS) was to intercept water flow at the site's northern boundary, and to treat and dispose of collected seep water; however, low levels of groundwater have limited the effectiveness of the system. Groundwater monitoring has also been limited by low groundwater levels, and by traffic damage to wellpoints. Vapor intrusion assessment has been conducted in the school, but was confounded with indoor air cources of contamination; e.g., school boiler and other possible sources of VOCs). School is located on state land. Also see file numbers 850.38.005, 850.02.002, and 850.02.003. Name of tank farm was Alaska Village Electrical Coop in 1989. Known spills at site: 200 gallons heating oil (1989), report of oil saturated ground at the tank farm (1987), unknown amount of fuel spilled near school (1986), overfilled diesel tanks next to school (1985). 2010 Update: Fuel handling continues to be problematic at the school fuel transfer tank and above-ground piping areas. The YKSD is in the process of updating the entire fuel system at the school (boiler and transfer tank and pumps). DRO contamination remains in the soil around the school, the new teacher housing (across the street), and at fuel tank farm areas (both AVEC and YKSD). A new contaminant (1-Chloro-octadecane) was also found during soil scrrening and sampling during October, 2010. A cleanup plan (based on soil excavations and land farming) was compiled by a DEC term contractor for implementation in 2014-15.

Action Information

Action Date Action Description DEC Staff
8/21/1991 Site Added to Database DRO contamination. No Longer Assigned
10/14/1991 Site Ranked Using the AHRM Initial ranking by staff. Score = 78. No Longer Assigned
2/23/1994 Update or Other Action (Old R:Base Action Code = RPL2 - Site Information Request Letter). Staff sent PRP-CS Database Notification Letter to RP requesting update and more environmental information concerning contamiated site. As of this "complete date" no response has been received. Jeff Peterson
4/15/1994 Update or Other Action (Old R:Base Action Code = CORR - Correspondence (General)). Staff received a Revised Scope of Work, Preliminary Site Assessment by Shannon and Wilson term contractor. Work includes a file review, site recon, limited sampling and SA work plan. ADEC will issue Notice to Proceed soon. Site work should occur in June. Cindy Thomas
6/28/1994 Update or Other Action (Old R:Base Action Code = RECN - Site Reconnaissance (CS)). Staff conducted site inspection with Term Contractors (Shannon and Wilson) to oversee performance of site investigation. The following was noted: Soil/water seep coming from the top of an access road which runs down into nearby yard, area smelled of diesel fumes, gravels near two tank farms and next to school were saturated with fuel, liners questionable at both tanks, and a small drainage runs underneath the school, probably moving fuel through the area. Problem more considerable than originally thought. Will try to work with school district and AVEc and TCC to develop cleanup plan. Cindy Thomas
1/10/1995 Update or Other Action (Old R:Base Action Code = RPS - Responsible Party Search). Appears to be two owner/RPs for this site: 1)Yukon Koyukuk School District, P.O. Box 80210, Fairbanks, Alaska 99708-0210, contact is Terrie Irwin and 2)Alaska Village Electric Corporation, 4831 eagle Street, Anchorage, Alaska 99503, contact is John Lyons. Cindy Thomas
1/23/1995 Update or Other Action SITE SUMMARY: Two adjacent tank farms show considerable soil and perched ground water contamination. Oily water seep runs down road next to school each year. ADEC granted legislative appropriation to conduct assessment and cleanup. Term contractor S&W hired last year to do brief assessment. 55K remains. ADEC should write RFP to do soil removal and long term stockpile from within tank farm and along oil seep. Possibly install interception trench too. Work should happen in fall 1995 after impacted area drains. YKSD has no funds to upgrade system. Cindy Thomas
2/26/1996 Update or Other Action (Old R:Base Action Code = SI - Site Investigation). Shah Alam
3/5/1996 Update or Other Action The legislative Appropriation (AR 48035-94) for the contaminated site at Kaltag was a one year appropriation and was not available for spending in 1996. Alaska Village Electric Corporation (AVEC) rebuilt their tank farm during summer 1995 (phone conversation with John Lyon, February 6, 1996). Alaska Division of Energy improved the piping systems of Yukon Koyukuk School District's (YKSD) tank farm. The Division of Energy forwarded a memorandum to ADEC outlining their 1995 work. Shah Alam
1/7/1997 Update or Other Action On 10/9/1996, ADEC project manager, Shah Alam, visited the site. Shah Alam
5/21/1998 Update or Other Action ADEC project manager for this contaminated site changed from Alam to Mazzitello. Shah Alam
8/13/1998 Interim Removal Action Approved ADEC approved workplan for ADEC contractor to conduct interim corrective active work. Tasks include: Select Site For Biocell; Construct Biocell; Install roadway seepage control test section. Action conducted to reduce oil seep which is migrating across school grounds and into roadway area. John Mazzitello
8/13/1998 Site Characterization Workplan Approved ADEC approved workplan for ADEC contractor to conduct contamination assessment activities which included soil and groundwater sampling in the area of the AVEC and YKSD tank farms. John Mazzitello
12/23/1998 Site Characterization Report Approved ADEC approved report entitled "Site Assessment and Interim Corrective Action" conducted by Shannon and Wilson, dated December, 1998. Report describes fuel contamination in the active layer above permafrost around the Kaltag School, at the AVEC and YKSD tank farms, downgradient of the YKSD tank farm and the southern portion of the a nearby residence. POL concentrations measured at the private residence was found to be below cleanup levels (see ADEC letter dated 5/24/1999). Water contaminated fuel was observed on puddles and ponded water on two sides of the school building. Groundwater contamination identified in 5 well points. Assessment determines that scope of POL contamination is broader than originally documented. John Mazzitello
12/28/1998 Update or Other Action Biocell created with excavated soil from the seep location. Approximately 170 cubic yards were stockpiled in an older gravel pit located immediately north of the City of Kaltag Maintenance Garage and south of a slough. Stockpile is 15 feet wide, 8 feet tall, and approximately 40 feet in length. Shannon Oelkers
4/11/2001 Update or Other Action ADEC staff along with DEC's contractor traveled to the site to observe site conditions and meet with city council members. David Pikul
5/16/2001 Update or Other Action This site has been funded under CIP funds in the past, however, AVEC has recieved Denali funds to upgrade and cleanup their tank farm and these funds should be used for cleanup, not CIP funds. CSRP is coordinating with AVEC and Denali Commishion personnel to shift to the appropriate funding source. ADEC will continue project management of the site. David Pikul
6/19/2001 Update or Other Action extend the end date for NTP 1820121002 to 9/30/01. David Pikul
7/11/2001 Meeting or Teleconference Held Meeting with AVEC to discuss tank construction plans. David Pikul
8/24/2001 Update or Other Action Funding approved for 2001/2 water quality monitoring and scrubber filtration system (SFS) maintenance David Pikul
1/31/2002 Update or Other Action In June of 2001 the biocell was sampled. One sample reported DRO above ADEC cleanup levels at 553 mg/kg. BTEX analytes were not detected above cleanup levels. Added to the database in 2007 to reflect administrative file. Shannon Oelkers
4/15/2002 Meeting or Teleconference Held Meeting with AVEC. David Pikul
4/22/2002 Meeting or Teleconference Held ADEC and AVEC traveled to the site to discuss agency plans with the community. David Pikul
6/5/2002 Update or Other Action Sump pumps have been installed in the SFS by local personnel. S&W will be traveling to the site for SFS maintenance and sample collection. David Pikul
2/9/2004 Update or Other Action CIP RFP forwarded for maintenance of the SFS by consultant. RFP also includes potential sampling of onsite well head. Mike Jaynes
1/16/2007 Update or Other Action Staff reassigned from Jaynes to Oelkers. Aggie Blandford
1/25/2007 GIS Position Updated Shannon Oelkers
1/25/2007 Update or Other Action Review of data collected to date reveals significant data gaps in both groundwater monitoring and SFS system. Unable to determine effectiviness of SFS system due to low groundwater flow. Vapor intrusion has not been evaluated at this site, and benzene levels from 2004 are above the EPA action levels. Shannon Oelkers
2/14/2007 Update or Other Action ADEC approves the stockpile for landspreading. Shannon Oelkers
7/27/2007 Update or Other Action Site transferred from Oelkers to Farris. Shannon Oelkers
9/6/2007 Update or Other Action Staff met with personnel from YK School district to discuss Huslia and Kaltag site characterization work that was completed by ADEC in summer 07. The results are not in yet for Kaltag, but staff spoke with Shannon and Wilson, who indicated the report would be completed by the end of October. They indicated that preliminary results did not indicate a vapor intrusion problem at the Kaltag school. Ann Farris
1/31/2008 Update or Other Action Staff has received and is in the process of reviewing the Site Characterization report on the Kaltag School Oil Seep. Ann Farris
3/6/2008 Update or Other Action Review of the site characterization report and the historical investigations indicates surface and subsurface contamination from the former tank farms, generator sheds, and storage of drums and a few transformers. Water from surface infiltration (primarily snowmelt) flows above the permafrost and seasonally causes seeps. Samples of this water through borings 4-5 feet deep indicate BTEX contamination above ADEC 18AAC 75 Table C values. Additionally sheen was noted on several of the seeps. This water flows generally north following the surface topography and permafrost topography. A filtration system was installed in 1998 and operated for a few years. It is no longer functional, but there have not been any sheen noted since 2004. The Yukon River is approximately 50 ft horizontally from the site, but approximately 30 to 50 ft vertically down. Soil sampling along the piping to the river, the topography, and the extent of the permafrost indicates contamination from this site is extremely unlikely to reach the river. Contamination in surface soil is a concern in various locations across the site, particularly the former YKSD tank farm. Additional sampling for PCBs in the area of former transformer storage must be completed. Staff is meeting with the YKSD next week and will discuss the additional sampling needs and excavation of the contaminated soil. The filtration system should also be removed as it no longer is serving a purpose. Ann Farris
3/13/2008 Update or Other Action Staff met with a representative from the Yukon-Koyukuk School District regarding the Kaltag School Oil Seep Site. They will know by May if they their capital improvement request for environmental cleanup is approved by the Legislature. In the meantime, they will check to see if the biocell is still intact and able to receive additional soil. DEC will write a scope of work describing the work that must be completed. If the YKSD appropriation does not get approved, other funding sources through the DEC CIP funds or through the Brownfield Grant process will be sought. The amount of surface soil that needs to be tested and removed is believed to be small, but it is beneath the playground facilities so may represent a significant risk. Ann Farris
5/12/2009 Exposure Tracking Model Ranking Initial ranking with ETM completed for source area id: 78317 name: vicinity of school Ann Farris
2/1/2010 Update or Other Action DEC project manager changed from Ann Farris to James Fish. Janice Wiegers
3/11/2010 Update or Other Action RFP issued for contaminant screening, characterization, and cleanup plan proposal. Jim Fish
7/1/2010 Update or Other Action RFP awarded & NTP issued to consultant Jim Fish
8/2/2010 Meeting or Teleconference Held DEC Project Manager and Shannon & Wilson met with David Pratt (YKSD Maintenance Superintendent) to discuss new teacher housing construction on former YKSD Tank Farm in 2008, and site assessment activities planed for this fall. Jim Fish
8/23/2010 Meeting or Teleconference Held Attempted Stakeholder Meeting Teleconference (no call-ins) but discussed project and additional areas of concern in Kaltag with David Prat (YKSD). Jim Fish
11/10/2010 Meeting or Teleconference Held A stakeholder teleconference was held to explain field screening and sampling efforts of October, 2010 near the Kaltag school, to identify and delineate fuel contamination and possible PCB contamination (based on stained soils near electrical equipment storage). Results from immuno-assay field screening initially indicated widespread PCB contamination, but were later determined to be false-positive; analytical soil samples did not indicate PCB contamination. The compound 1-Chloro-octadecane was found to interfer with field screening test kits, and is another COC (alond with diesel fuel) near the site. YKSD will upgrade all fuel handling components and the boiler in the school during 2011, and will coordinate with DEC during such activities. DEC and consultants plan to monitor surface runoff during spring break-up and do additional site assessment, and evaluate the potential for future remedial action after fuel system upgrades at the school. Jim Fish
4/8/2011 Report or Workplan Review - Other Draft report for 2010 site characterization received from Shannon & Wilson Jim Fish
4/19/2011 Report or Workplan Review - Other Comments sent to S&W for draft report - along with notes for upcoming spring sampling Jim Fish
5/9/2011 Site Characterization Report Approved Final Site Characterization report recieved from Shannon & Wilson Jim Fish
12/22/2011 Report or Workplan Review - Other Report addendum received and reviewed - additional DRO delineation, 1-COD correlation, & spring run-off control Jim Fish
7/13/2012 Cleanup Plan Approved Received and approved cleanup plan Jim Fish
10/18/2012 Update or Other Action Discussed RSA with UAF and pending cleanup plans Jim Fish
2/26/2013 Update or Other Action CIP discussion of scope for cleanup plan Jim Fish
8/12/2013 Update or Other Action Hazard ID 26101 / File No. 850.38.005 / Kaltag School Former BIA Tank Farm split out as separate site from Hazard ID 289 / File No. 850.38.001 / Kaltag School Oil Seep per management request. Source Area ID 78318, ETM ranking, and other associated information transferred to Hazard ID 26101. Mitzi Read
12/23/2013 Cleanup Plan Approved CIP Funding for soil cleanup (summer 2014) approved today. Jim Fish
5/2/2014 Site Visit Site visit to Kaltag for stakeholder meeting with community and to walk around the site. Jim Fish
7/17/2014 Site Visit Site visit to Kaltag to locate utilities (with ACS rep), define inaccessible areas with AK Demo, and to develop local hire plans with the City Jim Fish
7/17/2014 Site Visit Site visit to Kaltag to locate utilities (with ACS rep), define inaccessible areas with AK Demo, and to develop local hire plans with the City Jim Fish
7/28/2014 Meeting or Teleconference Held Met with Doyon to discuss laibility of contaminated soils and subsurface rights of gravel pit area. Final landfarm work plan submitted for Doyon review. Addressed ADNR concenrs on permafrost disturbacne and SWPP best managament practices in work plan, for Temporary land Use Permit (TLUP). Jim Fish
7/31/2014 Update or Other Action Temporary Land Use Permit approved & received from ADNR today Jim Fish
8/4/2014 Update or Other Action Cleanup by S&W and subcontractor (Alaska Demo) begins today. Jim Fish
8/12/2014 Cleanup Plan Approved Received approval from Doyon on land farming plan Jim Fish
8/18/2014 Update or Other Action Contractor estimated up to 1,500 cubic yards of additional contaminated material may be present in the area between the former BIA tank farm and Outlying Areas 2 and 3 (and deeper than 5-ft bgs); contractor advised that excavating, transporting, and placing this soil into expanded treatment cells would require a project cost amendment. DEC decide not pursue the amendmnet because this additional contaminated material is likely associated with the former BIA Tank Farm (which is not being addressed under this particualr cleanup effort). Jim Fish
8/20/2014 Site Visit DEC and contractor visited site to inspect cleanup and final grading/recontouring of soils around the school, and to view the land farm & phytoremediation plot. Final total volume of soils excavated was approx. 1,700 cu yds. Land farm and phyto plot are 18" thick; phyto plt 100' x 150', same for landfarm plot, but with a 50'extension. Jim Fish
8/28/2014 Update or Other Action Received water manangment plan from contractor to reduce pooling of water from heavy rainfall and to direct runoff from land farm and phyto-polt in a controlled manner. Will be implmented next visit to Kaltag (mid-Sept), overlapping with sampling trip; no addtional cost to project. Jim Fish
9/16/2014 Update or Other Action Contractor visited the site during the week of Sept 8th to implement the drainage improvements/control plan (for the land farm and phyto-plot), and to collect baseline pore water samples and land farm soil samples. Jim Fish
11/5/2014 Meeting or Teleconference Held Stakeholder Teleconference held today to give summary overivew of 2104 Cleanup efforts and plans for Spring/summer 2015. UAF also gave update on phytoremediation efforts and plans. Jim Fish
5/26/2015 Meeting or Teleconference Held Stakeholder meeting held in Kaltag, attended by DEC and its contractor (S&), City and tribal representatives, and residents. Status of cleanup actions and planned work for summer 2015 was discussed. Also discussed was the issue of remaining contamination at the former BIA Tank Farm. Jim Fish
5/26/2015 Site Visit Site visit conducted after stakeholder meeting to view land farm & phytoremediation plots, stash of willow cuttings, and school site for runoff and status of erosion control. Observed new Cell phone tower SW of former AVEC and YKSD tank farms (clear cut lot). Jim Fish
12/22/2016 Update or Other Action Received status update report from contractor - 2016 field season landfarm soil sample results indicate DRO concentrations may be decreasing; no petroleum COCs have been detected in pore water (exterior of treatment cells). Additional soil tilling and sampling will occur in spring/summer of 2017. Jim Fish
6/15/2017 Update or Other Action A project update and anticipated summer field schedule was drafted by the term contractor and sent to the City of Kaltag. Jim Fish
9/8/2017 Update or Other Action Received cleanup (phytoremediation) update from UAF; samples collected during 2017 summer field season and analysis of soils is underway. Growth of willows and grass has been very good this growing season. Landfarming also continued in 2017 via City operator contracted by term contractor. Soil and water samples related to landfarming also collected at end of 2017 field season for evaluation of cleanup. Jim Fish
2/6/2018 Update or Other Action Landfarm treatment and monitoring summary report received today. Jim Fish
5/18/2018 Exposure Tracking Model Ranking A new updated ranking with ETM has been completed for source area 78317 school and near vicinity. Jim Fish
12/14/2018 Update or Other Action Kaltag Landfarm 2018 Summary Report received from contractor - DRO, ethylbenzene, o-xylenes, 1-methylnaphthalene, and 2-methylnapthalene were detected above ADEC cleanup levels in a soil sample and field-duplicate collected at a depth of approximately 14 inches near the center of the landfarm. DRO were also detected above cleanup levels in 2 soil samples collected near the landfarm margins at depths of approximately 12 inches. No contaminants were detected above the limit-of-quantitation (LOQ) in porewater samples (although toluene was detected below the LOQ in one porewater sample, but not its duplicate). Contractor recommends continued landfarm tilling during 2019. Jim Fish

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