Site Report: Municipal Light & Power, Plant No. 2, Spill 1

Site Name:	Municipal Light & Power, Plant No. 2, Spill 1
Address:	8670 Glenn Highway, Frontage Road, Anchorage, AK 99504
File Number:	2100.38.356
Hazard ID:	9
Status:	Cleanup Complete - Institutional Controls
Staff:	IC Unit, 9074655229 dec.icunit@alaska.gov
Latitude:	61.230833
Longitude:	-149.713889
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

A transformer oil spill of "several hundred gallons" occurred in the 1970's when vandals shot a transformer. The location was evaluated during a transformer upgrade in 2002 and soils impacted by oil were removed; PCBs were not present in the soils.

Action Information

Action Date	Action	Description	DEC Staff
6/13/2002	Update or Other Action	Approved request of 6/12/2002 to transport and thermally remediate approximately 170 cubic yards of contaminated soil.	Eileen Olson
6/26/2002	Update or Other Action	Received a site characterization report dated June 17, 2002 for transformer upgrade. No PCBs detected but excavation sidewall samples showed that DRO concentrations are elevated, with the maximum result 5,550 mg/kg DRO. Conclusions propose borings to characterize contamination.	Eileen Olson
12/30/2002	Update or Other Action	ADEC received a letter report on December 30, 2002 indicating that the soil had been successfully remediated and would be used in the construction industry. Prior to disposal the soil was in two separate stockpiles. Both stockpiles (approximately 180 cubic yards) were sent to ASR.	Beatrice Egbejimba
12/31/2002	Site Characterization Report Approved	Letter sent to Lena Saville of Municipal light and Power with information regarding ADEC's approval of report and a request for additional site characterization of the north sidewall of the excavation. The report describes a previous field investigation involving the upgrade of an 8,000-gallon transformer that is located in an area of known transformer oil spills that may have contained polychlorinated biphenyls (PCB). Transformer No. 5 was temporarily relocated while a secondary containment basin was constructed and impacted soil removed from its former location. The confirmation sample results identified a maximum concentration of 5,550 mg/Kg diesel-range organic (DRO) hydrocarbons and 724 mg/Kg residual-range organic (RRO) hydrocarbons remaining in the northern sidewall of the transformer upgrade excavation. PCBs were not detected in any of the confirmation samples. Approximately 180 cubic yards of soil and 35 cubic yards of concrete was excavated and sent to Alaska Soil Recycling in June for thermal remediation.	Beatrice Egbejimba
12/31/2002	Update or Other Action	ADEC sent state letter of interest.	Beatrice Egbejimba
1/6/2003	Update or Other Action	Site address is 8670 Glenn Highway, Anchorage, 99504, based on information provided by Lena Saville. Database updated to reflect new information.	Beatrice Egbejimba
2/5/2003	Update or Other Action	ADEC met with Lena Saville of ML&P to discuss proposal for a work plan.	Beatrice Egbejimba
2/6/2003	Update or Other Action	ADEC visited site with Lena Saville of ML&P to discuss the possible use of data from on-site wells (MWB10 and B6). After the site visit it was agreed that site conditions were not similar and a work plan with inferred data from MWB10 and B6 would not be acceptable.	Beatrice Egbejimba
2/26/2003	Site Added to Database	Spill date uncertain but the year of the spill is correct.	Former Staff
3/6/2003	Update or Other Action	ADEC received site characterization work plan. The work plan proposes to install a monitoring well adjacent to the location with the highest concentration of DRO identified during the 2002 investigation.	Beatrice Egbejimba
3/25/2003	Update or Other Action	ADEC sent letter to Lena Savile of ML&P with approval of site characterization work plan.	Beatrice Egbejimba
5/20/2003	Update or Other Action	ADEC sent approval letter regarding Additional Environmental Assessment report to Lena Savile of ML&P. Additional wellls were requested to delineate the nature and extent of groundwater contamination at the site. A work plan is requested by June 24, 2003.	Beatrice Egbejimba
6/11/2003	Update or Other Action	Staff received a report entitled "August 2001 Environmental Assessment Report, plant Two, Unit *, Pipeline Closure” and a work plan entitled “Corrective action Plan” from former PM. The August 2001 Environmental Assessment, documents a field activity in which two soil samples were collected and analyzed at 5 to 7 feet and 7.5 to 9.5 feet from Boring B1. A maximum concentration of 1330 mg/kg DRO was reported at 7.5 to 9.5 feet. A corrective action plan (CAP) was submitted to DEC for approval in October 2001. No documentation of CAP approval letter was found in file.	Beatrice Egbejimba
6/17/2003	Update or Other Action	ADEC received work plan to install 2 additional monitoring well in the visinity of tranformer #5.	Beatrice Egbejimba
6/19/2003	Meeting or Teleconference Held	ADEC met with Lena Savile of ML&P to discuss proposed work plan received June 17, 2003. The work plan proposes to install two additional wells adjacent to the transformer. Based on two reports received from former project manager on 6/11/03, staff advised ML&P to relocate one monitoring well. Reports indicate that contaminated soil is present adjacent to Unit 8. Unit 8 is in close proximity to transformer #5 and contaminated soil from this area may be contributing to the high level of DRO in the groundwater. It was agreed that a well will be installed in the approximate location of Boring B1. Boring B1 was advance by Shannon & Wilson during an investigation in 2001. A maximum concentration of 1330 mg/kg DRO was reported at 7.5 to 9.5 feet. A revised work plan to investigate the groundwater beneath this area will be submitted for ADEC’s approval.	Beatrice Egbejimba
6/24/2003	Update or Other Action	ADEC revised workplan for the investigation of groundwater beneath transformer #5 and unit 8 areas.	Beatrice Egbejimba
6/26/2003	Update or Other Action	ADEC sent letter to Lena Savile of ML&P with approval of work plan for the installation of monitoring wells MW2 and MW3. ADEC suggested that MW 2 be relocated further up gradient of its current location, so that the groundwater direction can be more accurately determined. If relocation is not feasible because of underground utilities or other constrains the current location is acceptable. A report should be submitted by September 1, 2003.	Beatrice Egbejimba
9/5/2003	Update or Other Action	ADEC sent letter to Lena Savile of Municipal Light & Power Plant with information regarding report received 9/4/03. The report provided information regarding the installation and sampling of monitoring wells MW-2 and MW-3 and sampling of previously existing MW-1. The report shows that monitoring well MW1 has shown an increase since the April 2003 groundwater monitoring event from 3.80mg/ L diesel-range organics (DRO) and 2.62 mg/L residual-range organics (RRO) to 9.40mg/L DRO and 6.18 mg/L RRO. Results obtained from the newly installed groundwater monitoring wells MW-2 and MW-3 did not indicate the presence of any contaminant of concerns above the applicable groundwater cleanup level of 1.5 mg/L DRO and 1.1 mg/L RRO. However, impacted soil above the applicable cleanup level of 250 mg/kg DRO was encountered during the installation of monitoring well MW-3. 956mg/kg DRO was the maximum concentration reported. This soil sample was collected at a depth of 15 -17 feet below ground surface (bgs). Groundwater was encountered at 23.5 feet bgs with no detectable concentration of DRO at the groundwater interface. Based on the information provided in the report ADEC has determined that quarterly groundwater monitoring is necessary to establish the concentration trend. A workplan indicating a schedule was requested by ADEC by September 30, 2003.	Beatrice Egbejimba
9/5/2003	Long Term Monitoring Established	Decision was based on the information provided in the Additional Site Characterization of the Transformer No. 5 and Unit No. 8 Area, Plant 2 report received by ADEC on 9/4/03.	Beatrice Egbejimba
9/17/2003	Update or Other Action	ADEC approved work plan for quarterly monitoring of the three wells associated with the impacted groundwater in the transformer area. Beginning September 2003, these wells will be monitored for DRO and RRO. A report was requested within 60 days of completing site characterization activities.	Beatrice Egbejimba
10/20/2003	Update or Other Action	ADEC received September 2003 Groundwater Monitoring report.	Beatrice Egbejimba
10/27/2003	Cleanup Complete Determination Issued	The Alaska Department of Environmental Conservation, Contaminated Sites Program (ADEC) has completed review of the environmental records associated with the ML&P Plant 2, Spill 1, located at 8670 Glenn Highway in Anchorage. Based on this information, the ADEC has determined a Cleanup Complete Determination with Institutional Controls shall be granted. The hazardous substance contamination has been adequately addressed and does not pose an unacceptable risk to human health or the environment. (This action entered 9/17/09)	Bill O'Connell
10/27/2003	Institutional Control Record Established	Institutional Controls established and entered into the database.	Bill O'Connell
2/5/2004	Update or Other Action	File number changed from CS69.28-1 to 2100.38.356.	Sarah Cunningham
8/24/2004	Meeting or Teleconference Held	CSP staff met with Lena Savile of ML&P to discuss the recent excavation around a key box near the formerly identified contamination. The excavation around the key box removed DRO contaminated soil that was estimated to be part of the previously identified contamination and the result of the 1964 earthquake. Soil was stockpiled nearby and the highest DRO level was measured at 1,600 mg/kg. Options were discussed how to address the contamination. ML&P will provide a workplan to CSP for review. It is possible that ML&P may propose a Method 3 determination or higher levels of contamination be excavated and landfarmed on the property coupled with monitoring.	Rich Sundet
9/2/2004	Update or Other Action	On 9/2/04, DEC approved ML&P's 9/2/04 request to transport about 10 cubic yards of DRO contaminated soil excavated from around a waterline keybox to ASR for thermal treatment. The soil was generated during parking lot improvements at Plant 2 north of Unit 8.	Rich Sundet
6/13/2008	Exposure Tracking Model Ranking	Initial ranking with ETM completed.	Eileen Olson
7/21/2008	Document, Report, or Work plan Review - other	Reviewed July 2008 Groundwater Monitoring Report. Samples were collected from wells MW-1, MW-2, and MW-3 on two occasions in 2008 and analyzed for DRO and RRO. Only RRO was detected above the clenaup level on one occasion in MW-1 at 1.34 mg/l.	Bill O'Connell
9/18/2009	Document, Report, or Work plan Review - other	Reviewed January 2009 Groundwater Monitoring Report. Samples were collected from wells MW-1, MW-2, and MW-3 in January 2009 and analyzed for DRO and RRO. Contaminants were not detected above cleanup levels.	Bill O'Connell
9/21/2009	Document, Report, or Work plan Review - other	Reviewed July 2009 groundwater monitoring report. Samples were collected from MW1, MW2, and MW3. Contaminants were not detected above cleanup levels.	Bill O'Connell
9/22/2009	Update or Other Action	Based on recent data, groundwater monitoring is no longer required at this site. All other conditions of the closure decision remain in effect.	Bill O'Connell
10/12/2009	Document, Report, or Work plan Review - other	Monitoring well decommissioning report received. MW-2 and MW-3 were decommissioned in accordance with ADEC guidance, MW-1 was in an area of overhead utilities so the well casing was cut off 2.5 feet below ground surface and filled with bentonite.	Bill O'Connell

Action Date

Action

Description

DEC Staff

6/13/2002

Update or Other Action

Approved request of 6/12/2002 to transport and thermally remediate approximately 170 cubic yards of contaminated soil.

Eileen Olson

6/26/2002

Update or Other Action

Received a site characterization report dated June 17, 2002 for transformer upgrade. No PCBs detected but excavation sidewall samples showed that DRO concentrations are elevated, with the maximum result 5,550 mg/kg DRO. Conclusions propose borings to characterize contamination.

Eileen Olson

12/30/2002

Update or Other Action

ADEC received a letter report on December 30, 2002 indicating that the soil had been successfully remediated and would be used in the construction industry. Prior to disposal the soil was in two separate stockpiles. Both stockpiles (approximately 180 cubic yards) were sent to ASR.

Beatrice Egbejimba

12/31/2002

Site Characterization Report Approved

Letter sent to Lena Saville of Municipal light and Power with information regarding ADEC's approval of report and a request for additional site characterization of the north sidewall of the excavation. The report describes a previous field investigation involving the upgrade of an 8,000-gallon transformer that is located in an area of known transformer oil spills that may have contained polychlorinated biphenyls (PCB). Transformer No. 5 was temporarily relocated while a secondary containment basin was constructed and impacted soil removed from its former location. The confirmation sample results identified a maximum concentration of 5,550 mg/Kg diesel-range organic (DRO) hydrocarbons and 724 mg/Kg residual-range organic (RRO) hydrocarbons remaining in the northern sidewall of the transformer upgrade excavation. PCBs were not detected in any of the confirmation samples. Approximately 180 cubic yards of soil and 35 cubic yards of concrete was excavated and sent to Alaska Soil Recycling in June for thermal remediation.

Beatrice Egbejimba

12/31/2002

Update or Other Action

ADEC sent state letter of interest.

Beatrice Egbejimba

1/6/2003

Update or Other Action

Site address is 8670 Glenn Highway, Anchorage, 99504, based on information provided by Lena Saville. Database updated to reflect new information.

Beatrice Egbejimba

2/5/2003

Update or Other Action

ADEC met with Lena Saville of ML&P to discuss proposal for a work plan.

Beatrice Egbejimba

2/6/2003

Update or Other Action

ADEC visited site with Lena Saville of ML&P to discuss the possible use of data from on-site wells (MWB10 and B6). After the site visit it was agreed that site conditions were not similar and a work plan with inferred data from MWB10 and B6 would not be acceptable.

Beatrice Egbejimba

2/26/2003

Site Added to Database

Spill date uncertain but the year of the spill is correct.

Former Staff

3/6/2003

Update or Other Action

ADEC received site characterization work plan. The work plan proposes to install a monitoring well adjacent to the location with the highest concentration of DRO identified during the 2002 investigation.

Beatrice Egbejimba

3/25/2003

Update or Other Action

ADEC sent letter to Lena Savile of ML&P with approval of site characterization work plan.

Beatrice Egbejimba

5/20/2003

Update or Other Action

ADEC sent approval letter regarding Additional Environmental Assessment report to Lena Savile of ML&P. Additional wellls were requested to delineate the nature and extent of groundwater contamination at the site. A work plan is requested by June 24, 2003.

Beatrice Egbejimba

6/11/2003

Update or Other Action

Staff received a report entitled "August 2001 Environmental Assessment Report, plant Two, Unit *, Pipeline Closure” and a work plan entitled “Corrective action Plan” from former PM. The August 2001 Environmental Assessment, documents a field activity in which two soil samples were collected and analyzed at 5 to 7 feet and 7.5 to 9.5 feet from Boring B1. A maximum concentration of 1330 mg/kg DRO was reported at 7.5 to 9.5 feet. A corrective action plan (CAP) was submitted to DEC for approval in October 2001. No documentation of CAP approval letter was found in file.

Beatrice Egbejimba

6/17/2003

Update or Other Action

ADEC received work plan to install 2 additional monitoring well in the visinity of tranformer #5.

Beatrice Egbejimba

6/19/2003

Meeting or Teleconference Held

ADEC met with Lena Savile of ML&P to discuss proposed work plan received June 17, 2003. The work plan proposes to install two additional wells adjacent to the transformer. Based on two reports received from former project manager on 6/11/03, staff advised ML&P to relocate one monitoring well. Reports indicate that contaminated soil is present adjacent to Unit 8. Unit 8 is in close proximity to transformer #5 and contaminated soil from this area may be contributing to the high level of DRO in the groundwater. It was agreed that a well will be installed in the approximate location of Boring B1. Boring B1 was advance by Shannon & Wilson during an investigation in 2001. A maximum concentration of 1330 mg/kg DRO was reported at 7.5 to 9.5 feet. A revised work plan to investigate the groundwater beneath this area will be submitted for ADEC’s approval.

Beatrice Egbejimba

6/24/2003

Update or Other Action

ADEC revised workplan for the investigation of groundwater beneath transformer #5 and unit 8 areas.

Beatrice Egbejimba

6/26/2003

Update or Other Action

ADEC sent letter to Lena Savile of ML&P with approval of work plan for the installation of monitoring wells MW2 and MW3. ADEC suggested that MW 2 be relocated further up gradient of its current location, so that the groundwater direction can be more accurately determined. If relocation is not feasible because of underground utilities or other constrains the current location is acceptable. A report should be submitted by September 1, 2003.

Beatrice Egbejimba

9/5/2003

Update or Other Action

ADEC sent letter to Lena Savile of Municipal Light & Power Plant with information regarding report received 9/4/03. The report provided information regarding the installation and sampling of monitoring wells MW-2 and MW-3 and sampling of previously existing MW-1. The report shows that monitoring well MW1 has shown an increase since the April 2003 groundwater monitoring event from 3.80mg/ L diesel-range organics (DRO) and 2.62 mg/L residual-range organics (RRO) to 9.40mg/L DRO and 6.18 mg/L RRO. Results obtained from the newly installed groundwater monitoring wells MW-2 and MW-3 did not indicate the presence of any contaminant of concerns above the applicable groundwater cleanup level of 1.5 mg/L DRO and 1.1 mg/L RRO. However, impacted soil above the applicable cleanup level of 250 mg/kg DRO was encountered during the installation of monitoring well MW-3. 956mg/kg DRO was the maximum concentration reported. This soil sample was collected at a depth of 15 -17 feet below ground surface (bgs). Groundwater was encountered at 23.5 feet bgs with no detectable concentration of DRO at the groundwater interface. Based on the information provided in the report ADEC has determined that quarterly groundwater monitoring is necessary to establish the concentration trend. A workplan indicating a schedule was requested by ADEC by September 30, 2003.

Beatrice Egbejimba

9/5/2003

Long Term Monitoring Established

Decision was based on the information provided in the Additional Site Characterization of the Transformer No. 5 and Unit No. 8 Area, Plant 2 report received by ADEC on 9/4/03.

Beatrice Egbejimba

9/17/2003

Update or Other Action

ADEC approved work plan for quarterly monitoring of the three wells associated with the impacted groundwater in the transformer area. Beginning September 2003, these wells will be monitored for DRO and RRO. A report was requested within 60 days of completing site characterization activities.

Beatrice Egbejimba

10/20/2003

Update or Other Action

ADEC received September 2003 Groundwater Monitoring report.

Beatrice Egbejimba

10/27/2003

Cleanup Complete Determination Issued

The Alaska Department of Environmental Conservation, Contaminated Sites Program (ADEC) has completed review of the environmental records associated with the ML&P Plant 2, Spill 1, located at 8670 Glenn Highway in Anchorage. Based on this information, the ADEC has determined a Cleanup Complete Determination with Institutional Controls shall be granted. The hazardous substance contamination has been adequately addressed and does not pose an unacceptable risk to human health or the environment. (This action entered 9/17/09)

Bill O'Connell

10/27/2003

Institutional Control Record Established

Institutional Controls established and entered into the database.

Bill O'Connell

2/5/2004

Update or Other Action

File number changed from CS69.28-1 to 2100.38.356.

Sarah Cunningham

8/24/2004

Meeting or Teleconference Held

CSP staff met with Lena Savile of ML&P to discuss the recent excavation around a key box near the formerly identified contamination. The excavation around the key box removed DRO contaminated soil that was estimated to be part of the previously identified contamination and the result of the 1964 earthquake. Soil was stockpiled nearby and the highest DRO level was measured at 1,600 mg/kg. Options were discussed how to address the contamination. ML&P will provide a workplan to CSP for review. It is possible that ML&P may propose a Method 3 determination or higher levels of contamination be excavated and landfarmed on the property coupled with monitoring.

Rich Sundet

9/2/2004

Update or Other Action

On 9/2/04, DEC approved ML&P's 9/2/04 request to transport about 10 cubic yards of DRO contaminated soil excavated from around a waterline keybox to ASR for thermal treatment. The soil was generated during parking lot improvements at Plant 2 north of Unit 8.

Rich Sundet

6/13/2008

Exposure Tracking Model Ranking

Initial ranking with ETM completed.

Eileen Olson

7/21/2008

Document, Report, or Work plan Review - other

Reviewed July 2008 Groundwater Monitoring Report. Samples were collected from wells MW-1, MW-2, and MW-3 on two occasions in 2008 and analyzed for DRO and RRO. Only RRO was detected above the clenaup level on one occasion in MW-1 at 1.34 mg/l.

Bill O'Connell

9/18/2009

Document, Report, or Work plan Review - other

Reviewed January 2009 Groundwater Monitoring Report. Samples were collected from wells MW-1, MW-2, and MW-3 in January 2009 and analyzed for DRO and RRO. Contaminants were not detected above cleanup levels.

Bill O'Connell

9/21/2009

Document, Report, or Work plan Review - other

Reviewed July 2009 groundwater monitoring report. Samples were collected from MW1, MW2, and MW3. Contaminants were not detected above cleanup levels.

Bill O'Connell

9/22/2009

Update or Other Action

Based on recent data, groundwater monitoring is no longer required at this site. All other conditions of the closure decision remain in effect.

Bill O'Connell

10/12/2009

Document, Report, or Work plan Review - other

Monitoring well decommissioning report received. MW-2 and MW-3 were decommissioned in accordance with ADEC guidance, MW-1 was in an area of overhead utilities so the well casing was cut off 2.5 feet below ground surface and filled with bentonite.

Bill O'Connell

Contaminant Information

Name	Level Description	Media	Comments
DRO	Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation	Soil

Name

Level Description

Media

Comments

DRO

Between Method 2 Migration to Groundwater and Human Health/Ingestion/Inhalation

Soil

Control Type

Type	Details
Other	CS database notation and letter to landowner/RP (added during a QC check 4/9/2014).

Type

Details

Other

CS database notation and letter to landowner/RP (added during a QC check 4/9/2014).

Requirements

Description	Details
Advance approval required to transport soil or groundwater off-site.
Groundwater Monitoring	Semi-annual groundwater monitoring required

Description

Details

Advance approval required to transport soil or groundwater off-site.

Groundwater Monitoring

Semi-annual groundwater monitoring required

Record of Decision

No associated sites were found.

Missing Location Data

Because the GIS location data for this site has not been entered, we cannot direct you to its position on the map. Click "Continue" to proceed to the Contaminated Sites Web Map or "Close" to return to the site report.

Continue Close

Site Report: Municipal Light & Power, Plant No. 2, Spill 1

Site Chronology

IC / Closure Details

Documents

Associated Sites

Problems/Comments

Action Information

Contaminant Information

Control Type

Requirements

Record of Decision

Missing Location Data

State of Alaska Department of Environmental Conservation