Site Report: Jualpa Tunnel
| Site Name: | Jualpa Tunnel |
|---|---|
| Address: | Gold Creek Basin, Juneau, AK 99801 |
| File Number: | 1513.38.011 |
| Hazard ID: | 406 |
| Status: | Cleanup Complete - Institutional Controls |
| Staff: | IC Unit, 9074655229 dec.icunit@alaska.gov |
| Latitude: | 58.306189 |
| Longitude: | -134.410053 |
| 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.
Problems/Comments
Mining tunnel was formerly used as underground sluice for gold extraction, now transports water supply source into Juneau water distribution system. In 1987, metallic mercury was observed on the tunnel floor. Mercury has not been detected in routine drinking water sampling. Seepage water collecting in the upper tunnel has contact time with raw mercury in the sediments. The water is discharged from a pipe directly into Gold Creek at the terminus of the Jualpa Tunnel. Analysis of sediment and water by ADEC detected low levels of mercury in sediments but not in the water to detection limit of 0.2 parts per billion (ppb). Measures used to mitigate the risk of exposure of the drinking water supply to the raw mercury were placement of an impervious liner and concrete to cover sediment on the floor of the tunnel. A concrete bulkhead was built at the upper end of the lower tunnel sealing in the riffle blocks and acting as a barrier to limit contact between mercury in the upper tunnel and the drinking water in the lower tunnel. A high density polyethylene pipe transports water through the upper tunnel to assure contact with drinking water and the mercury laden sediments in the upper tunnel.
Action Information
| Action Date | Action | Description | DEC Staff |
|---|---|---|---|
| 5/22/1989 | Preliminary Assessment Approved | "Preliminary Assessment Report for Jualpa Tunnel" prepared by Ecology and Environment, Inc. recieved by DEC. | Former Staff |
| 2/12/1993 | Site Characterization Report Approved | Beth Potter submitted report in January 1993: "Site Inspection Report for Jualpa Tunnel." | Former Staff |
| 8/26/1993 | Site Added to Database | Metals. | Former Staff |
| 11/10/1994 | Site Ranked Using the AHRM | Initial ranking. | Former Staff |
| 3/20/2008 | Update or Other Action | Ledger code requested; ongoing research into current status | Bruce Wanstall |
| 5/23/2013 | Update or Other Action | File Review. | Erik Norberg |
| 5/30/2013 | Site Visit | Site visit with staff Denise Elston and CBJ Water Utility Supervisor Ken Huddlestun inspecting the upper tunnel site across Gold Ck near the bridge up Perseverance. | Erik Norberg |
| 5/31/2013 | Site Visit | Site visit with CBJ Water Utility Supervisor Ken Huddlestun inspecting the Lower tunnel site near Cope Park. | Erik Norberg |
| 9/11/2013 | Update or Other Action | Staff changed from Erik Norberg to Denise Elston. | Kristin Thompson |
| 10/15/2013 | Conceptual Site Model Submitted | Consultant submitted a conceptual site model to evaluate potential exposure pathways. | Denise Elston |
| 12/3/2013 | Potentially Responsible Party/State Interest Letter | PRP letter notification issued to CBJ Public Works, Water Utilities Division. | Sally Schlichting |
| 6/28/2014 | Final Cleanup Report Reviewed | Final report from Joiner Engineering LLC dated July 2013 reviewed. | Sally Schlichting |
| 6/30/2014 | Cleanup Complete Determination Issued | Risks at the site are controlled by engineering measures. Site is closed with institutional controls. | Sally Schlichting |
| 6/30/2014 | Institutional Control Record Established | Reporting to DEC on a five year basis required to verify integrity of engineering controls installed to prevent exposure to tunnel sediments. | Sally Schlichting |
| 7/14/2014 | Update or Other Action | Staff name changed from Schlichting to IC Unit for IC tracking purposes. | Evonne Reese |
| 7/14/2014 | Institutional Control Update | Received the signed copy of the IC Agreement from the property representative. | Evonne Reese |
| 3/10/2017 | Institutional Control Compliance Review | IC compliance review conducted. Reminder system set to follow-up on the five-year reporting requirements in 2019. | Kristin Thompson |
| 8/22/2019 | Institutional Control Compliance Review | An Institutional Controls reminder letter e-mailed to the facility operator on this date. | Mossy Mead |
| 11/21/2019 | Institutional Control Compliance Review | An e-mail received from the City and Borough of Juneau reporting that all IC requirements are being met at this site as of this date. | Mossy Mead |
| 7/10/2024 | Institutional Control Compliance Review | IC compliance review completed on this date. An IC reminder letter was e-mailed to the landowner. The next review will be in five years’ time. | Gaige Robinson |
Contaminant Information
| Name | Level Description | Media | Comments |
|---|---|---|---|
| Mercury - Total | < Table C | Groundwater | |
| Lead - Dissolved | < Table C | Groundwater |
Control Type
| Type | Details |
|---|---|
| Signed CS Determination | Agreement to five year reporting. |
Requirements
| Description | Details |
|---|---|
| Advance approval required to transport soil or groundwater off-site. | Standard condition. |
| Maintenance / Inspection Of Engineering Controls | Report every 5 years on integrity and as they occur, any changes, improvements or repairs. |
| Movement or use of contaminated material (including on site) in a manner that results in a violation of the water quality standards is prohibited (18 AAC 70) | Standard condition. |
No associated sites were found.