| Action Date |
Action |
Description |
DEC Staff |
| 9/2/2003 |
Update or Other Action |
DEC log shows receipt on this date of two reports prepared by Shannon & Wilson, Inc.: "Limited Phase II Environmental Site Assessment, Tract J, Block 5, Tudor Centre Subdivision, Anchorage, Alaska, July 2003" and "Additional Site Characterization, Tract J, Block 5, Tudor Centre Subdivision, Anchorage, Alaska, July 2003". The Limited Phase II report documents work done in June 2003 including field screening and sampling of ten test pits; completion and sampling of 4 soil borings, and the collection of screening level groundwater samples from temporary monitoring wells. The borings were advanced in the northwest area of the property. The Additional Site Characterization report documents work done in July 2003 including advancing 3 borings that were completed as monitoring wells, soil screening, and soil and groundwater sampling. (These reports were not located in the file and were requested and resubmitted by the responsible party on 6/10/2010). |
Eileen Olson |
| 7/1/2004 |
Document, Report, or Work plan Review - other |
DEC approved transport of investigation derived waste (IDW) for disposal, including 2 cubic yards of soil and an unidentified volume of groundwater. |
Eileen Olson |
| 6/3/2010 |
Update or Other Action |
ADEC received "Work Plan for Site Characterization, 4000 Ambassador Drive, Tract J, Block 5, Tudor Centre Subdivision". |
Eileen Olson |
| 7/14/2010 |
Site Added to Database |
A new site has been added to the database |
Mitzi Read |
| 7/16/2010 |
Document, Report, or Work plan Review - other |
DEC approval letter issued for plan received 6/3/2010. Response delayed while ADEC sought additional site information not in ADEC files. Letter also includes DEC cost recovery requirement notification. |
Eileen Olson |
| 7/21/2010 |
Exposure Tracking Model Ranking |
Initial ranking with ETM completed for source area id: 78918 name: Petroleum Contaminated Soil & Groundwater |
Mitzi Read |
| 7/28/2010 |
Potentially Responsible Party/State Interest Letter |
DEC letter notifying landowner ANTHC of status as a potentially responsible party and requesting additional information, including the Phase I report for the property, field notes by environmental consultants who have worked at the site, photographs, workplans and reports not previously submitted. |
Eileen Olson |
| 8/16/2010 |
Update or Other Action |
DEC received previously unsubmitted report "Phase I Environmental Site Assessment for Blk 4, Tract H and Blk 5, Tract J, Tudor Centre Subdivision, Anchorage, Alaska 99508...July 2002" for site from ANTHC. Report was requested in DEC letter dated July 28, 2010 with the expectation that it might contain site history information that would provide information regarding the source of contamination encountered at the site, but it did not. |
Eileen Olson |
| 9/7/2010 |
Update or Other Action |
Received report titled "Site Characterization, 4000 Ambassador Drive, Tract J, Block 5, Tudor Centre Subdivision, Anchorage, Alaska, September 2010" prepared by Shannon & Wilson, Inc. The report describes the installation of six borings completed as monitoring wells. The accompanying email states that ANTHC intends to follow the recommendations by the consultant to install additional monitoring wells along both the western and southern property lines to attempt to determine if the contamination found is a result of migration from an off-site source.
|
Eileen Olson |
| 9/20/2010 |
Update or Other Action |
ADEC received an informal plan (i.e. as email text with attachments) by ANTHC's consultant for additional work to be conducted according to the June 3, 2010 "Work Plan for Site Characterization, 4000 Ambassador Drive, Tract J, Block 5, Tudor Centre Subdivision" including installing four new borings/monitoring wells in the vicinity of Monitoring Well B10MW at tentative locations shown on a figure provided with the request, with several additional modifications described that included collecting soil samples at the soil/groundwater interface. |
Eileen Olson |
| 9/29/2010 |
Document, Report, or Work plan Review - other |
ADEC conditionally approved the revised "Work Plan for Site Characterization, 4000 Ambassador Drive, Tract J, Block 5, Tudor Centre Subdivision" originally submitted on 6/3/2010, with revisions submitted on 9/20/2010. |
Eileen Olson |
| 12/3/2010 |
Update or Other Action |
ADEC received "Additional Groundwater Investigation...November 2010" report for groundwater investigation done from October 13 - 28, 2010, including completing 4 borings as monitoring wells and sampling the groundwater, installing piezometers, and conducting a relative elevation survey of the well casings and piezometers. (Note: This report was re-submitted on 3/3/2011 with additional information not included in the appendices). |
Eileen Olson |
| 1/7/2011 |
Update or Other Action |
Received email and diagram regarding Environmental Management Plan (EMP) for site from Shannon & Wilson. |
Eileen Olson |
| 1/13/2011 |
Meeting or Teleconference Held |
Met with consultants S&W 10:00 AM-11:30 AM to discuss Environmental Management Plan (EMP) for site. |
Eileen Olson |
| 3/2/2011 |
Meeting or Teleconference Held |
Meeting with landowner/responsible party ANMC re process to follow with respect to construction work and cleanup. |
Eileen Olson |
| 3/2/2011 |
Update or Other Action |
Received from consultant Shannon & Wilson Environmental Management Plan (EMP) for site. (Note: This is the first of 3 EMPs submitted through May 2011). The plan described a foundation design that entails removing an estimated 35,000 cubic yards of soil from the proposed building footprint and replacing it with gravel fill material to the bottom of the footings elevation, and discharging up to 110,000,000 gallons (110 million) into the adjacent pond that overflows to University Lake. Evaluation and handling of potentially contaminated soil is discussed in detail in the EMP. |
Eileen Olson |
| 3/3/2011 |
Update or Other Action |
ADEC received 3 reports, all prepared by Shannon & Wilson, on this date: the Revised "Additional Groundwater Investigation ... November 2010" (originally submitted by ANTHC on 12/3/2010; revised version provided by Shannon & Wilson); the "Geotechnical Data Report, ANTHC Healthy Communities Building ... September 2010"; and the letter report "Groundwater Characterization, 4000 Ambassador Drive" dated Febraury 8, 2011.
|
Eileen Olson |
| 3/12/2011 |
Update or Other Action |
ADEC received from ANTHC by email survey drawings of Tract H of the same Block that the site (Tract J) is in, showing proposed soil storage locations as part of discussions of handling of very large quantities of excavated potentially contaminated soil. |
Eileen Olson |
| 3/18/2011 |
Document, Report, or Work plan Review - other |
ADEC issued a letter to ANTHC with subject line "Notice of applicable ADEC Contaminated Sites Regulations" following notification by the RP on 3/17/2011 that consultant Montauk Environmental
Engineering and/or Watterson Construction had begun contaminated site soil characterization activities on March 16,2010, without submitting a work plan to ADEC. Montauk used an auger to drill and sample 50 borings on 10’ on center grids, collecting field screening samples at 18 inches and 4 feet below the ground surface. Field notes and any analytical results that may exist not yet provided to ADEC. ADEC's letter notified the RP that ADEC regulations 18 AAC 75.335. "Site characterization" require that a responsible person submit a site characterization workplan to ADEC for approval before beginning site characterization work. |
Eileen Olson |
| 3/29/2011 |
Update or Other Action |
Contaminated Sites staff copied on notification by ADEC Division of Water to ADNR that ADEC's excavation dewatering general permit will not be used for the dewatering activity at the site as the discharge will be approved by DEC as part of the clean-up of a contaminated site. |
Eileen Olson |
| 4/5/2011 |
Update or Other Action |
ADEC received a second, revised Environmental Management Plan (EMP) prepared by Shannon & Wilson; this version includes the original foundation design that entailed removing an estimated 35,000 cubic yards of soil from the proposed building footprint and replacing it with gravel fill material to the bottom of the footings elevation, but also included treating water pumped from the excavation during dewatering before it is discharged to the adjacent pond, with water traveling through an 18,100 gallon weir tank as the initial holding tank, etc. |
Eileen Olson |
| 5/2/2011 |
Update or Other Action |
ADEC staff received a request for comment by DNR with a deadline of May 16, 2011 on a temporary water use application from Sullivan Water Wells to withdraw 1,000 gallons of water per minute for up to 3 days (subject to a maximum 1,440,000 for the test) sometime between May 20, 2011 and August 31, 2011 from a drilled well 140 to 200 feet deep at a location just south of the new Healthy Communities Building (HCB). Planned use of the water includes a pump test for yield; the pumped water is to be discharged into the Lake Tract pond. According to Sullivan Drilling representatives, the well to be pump-tested will be a cooling water injection well, with cooling water pumped from an existing production well some 1000 feet away and reinjected into the same aquifer after being used to cool buildings. According to Sullivan, the yield from the pump test is used to determine the volume of water the aquifer the injection well is completed in will accept. |
Eileen Olson |
| 5/2/2011 |
Update or Other Action |
ADEC received a request for comment on a temporary water use application from Sullivan Water Wells to withdraw 1,000 gallons of water per minute for up to 3 days (subject to a maximum 1,440,000 for the pump test) May 20, 2011 through August 31, 2011 from a drilled well 140 to 200 feet deep at the site, with the pumped water to be discharged into the Lake Tract pond. The deadline for written comments was May 16, 2011. ADEC staff replied to the email indicating that the Contaminated Sites Program would have comments on the application. |
Eileen Olson |
| 5/10/2011 |
Update or Other Action |
ADEC received "Revised Environmental Management Plan, 4000 Ambassador Drive, Tract J, Block 5, Tudor Centre Subdivision, Anchorage, Alaska, ADEC File No. 2100.38.516, May 2011" for the construction of the proposed Healthy Communities Building (HCB) with the major change that the design in now for a pile-supported foundation that does not entail excavating up to 35,000 cubic yards of soil and dewatering up to 110 million gallons from the excavation. The change in foundation design appeared to follow ADEC informing ANTHC through Shannon & Wilson that environmental analytic samples from auger cuttings could not be considered as definitive accurate results for the purposes of determining whether soil is or is not contaminated. ANTHC sought to eliminate double-handling of soil by characterizing in place, prior to excavation, the 35,000 cubic yards to be excavated. (Note that this is the third EMP submitted). |
Eileen Olson |
| 5/11/2011 |
Update or Other Action |
ADEC staff requested and received from Sullivan Drilling the well log completed to date for the future injection well. The log shows Sand & Gravel to 33 feet below ground surface (bgs),
Silt Sand Gravel W/Clay from 33 to 51 ft. bgs, Sand & Gravel 51 to 93 ft. bgs; Silt Sand Gravel Dense 93 - 106 bgs; Silt Sand Gravel 106 - 135 bgs; Sand & Gravel 135 - 180 bgs; and Sand Silt Gravel 180 - 192 bgs. This indicates that the confining layer if present is from 33 - 51 feet bgs; however, the information reported for the piezometers drilled to 36.5 feet in August 2010 indicate soil was saturated to the bottom of the holes. |
Eileen Olson |
| 5/11/2011 |
Update or Other Action |
Staff spoke to Bill Sullivan on 5/5/2011 and Cole Sullivan on 5/11/2011 (both of Sullivan Drilling) regarding the potential for the pump testing of the injection well at the ANTHC property to spread existing groundwater contamination, and the potential for the well, once functioning in the injection mode, to impact near-surface contaminated water. In particular, attempted to gain some certainty regarding whether there is an aquitard between the uppermost aquifer and the aquifer the injection well taps into at and above the 189 foot below ground surface (bgs) depth of the well. Soil in the piezometer borings were wet to the maximum depth drilled (36.5 ft. bgs) and the static water level in the injection well was 32 feet bgs as per the well log received 5/11/2011. Could not determine whether aquifers might be connected; observation wells should be used during massive pump-testing. |
Eileen Olson |
| 5/19/2011 |
Update or Other Action |
DEC received from DNR a copy of a memo by DNR Hydrologist Roy Ireland commenting on injection well and noting there are three cooling wells for the ANTHC already in the area. |
Eileen Olson |
| 5/20/2011 |
Document, Report, or Work plan Review - other |
DEC staff provided review comments to DNR on DNR temporary water use authorization for pump test of up to 2 million gallons from a future injection well, with discharge to the adjacent pond and lake system. |
Eileen Olson |
| 5/27/2011 |
Update or Other Action |
DEC received copy of Temporary Water Use Authorization TWUP A2011-46 issued by DNR to Sullivan Water Wells. The Authorization includes Contaminated Sites Program conditions recommended to DNR. |
Eileen Olson |
| 6/3/2011 |
Meeting or Teleconference Held |
On 6/3/2011, Sundet met with Steven Weaver and Paul Morrison of ANTHC to discuss their consultant Shannon & Wilson's Environmental Management Plan and overall concerns whether they can implement the plan and continue constuction work on their proposed Healthy Communities Building (HBC) located within the contaminated site in Tract J. The EMP was received at DEC on May 10, 2011. The plan was developed to address pre-construction activities at the location of the proposed ANTHC Healthy Communities Building (HBC). The EMP is essentially a work plan as required by ADEC’s “Site Cleanup Rules”, 18 AAC 75.325 – 75.390, but differs somewhat from a standard plan in that it is intended for use to assist in complying with a broad range of environmental regulations during pre-construction activities such as water well pump testing and excavation for underground utilities. During the conversation, Sundet reiterated that DEC had no objection with ANTHC continuing on its plans to drive pilings on the site. However, Sundet also noted that the "site" has not been fully characaterized both horizontally or vertically. In follow-up to the meeting, a draft letter was issued to ANTHC conditionally approving the Environmental Management Plan. |
Rich Sundet |
| 6/3/2011 |
Meeting or Teleconference Held |
On 6/3/2011, Sundet met with Steven Weaver and Paul Morrison of ANTHC to discuss their consultant Shannon & Wilson's Environmental Management Plan and overall concerns whether they can implement the plan and continue constuction work on their proposed Healthy Communities Building (HBC) located within the contaminated site in Tract J. The EMP was received at DEC on May 10, 2011. The plan was developed to address pre-construction activities at the location of the proposed ANTHC Healthy Communities Building (HBC). The EMP is essentially a work plan as required by ADEC’s “Site Cleanup Rules”, 18 AAC 75.325 – 75.390, but differs somewhat from a standard plan in that it is intended for use to assist in complying with a broad range of environmental regulations during pre-construction activities such as water well pump testing and excavation for underground utilities. During the conversation, Sundet reiterated that DEC had no objection with ANTHC continuing on its plans to drive pilings on the site. However, Sundet also noted that the "site" has not been fully characaterized both horizontally or vertically. In follow-up to the meeting, a draft letter was issued to ANTHC conditionally approving the Environmental Management Plan. |
Rich Sundet |
| 6/6/2011 |
Site Characterization Workplan Approved |
In followup to its 6/3/2011 meeting with Steven Weaver and Paul Morrison of ANTHC and verbal approval of ANTHC's consultant Shannon & Wilson Environmental Management Plan, DEC issued an approval letter for the EMP on 6/6/11. The EMP was received at DEC on May 10, 2011. The plan was developed to address pre-construction activities at the location of the proposed ANTHC Healthy Communities Building (HBC). The EMP is essentially a work plan as required by ADEC’s “Site Cleanup Rules”, 18 AAC 75.325 – 75.390, but differs somewhat from a standard plan in that it is intended for use to assist in complying with a broad range of environmental regulations during pre-construction activities such as water well pump testing and excavation for underground utilities. The letter reiterated points from the 6/3 meeting including that DEC had no objection with ANTHC continuing on its plans to drive pilings on the site. However, Sundet also noted that the "site" has not been fully characaterized both horizontally or vertically. |
Rich Sundet |
| 6/22/2011 |
Site Visit |
DEC visted site to discuss the status of the dewatering effort with Watterson Construction personell. Dan Piascowski requested a quick review of the dewatering cleanup plan since he anticipates excavating next week. |
Todd Blessing |
| 6/28/2011 |
Update or Other Action |
DEC reviewed and approved of Shannon and Wilson’s (S&W's) Groundwater Cleanup Plan for ANTCH Healthy Communities Building Titled “Excavation Dewatering General Permit 20009DB0003, 4000 Ambassador Road, Anchorage, Alaska; ADEC File 2100.38.516”, Dated March 7, 2011. The cleanup plan defined S&W's approach to construction dewatering at the Alaska Native Tribal Health Consortium (ANTHC) Healthy Communities Building.
Construction dewatering will be conducted using a series of shallow sumps which will pump at steady rate of 200 to 250 gallon per minute (gpm). It is estimated that the pumps will depress the groundwater table by 10 feet. Initial dewatering (up to 50 gpm) will be discharged to the Alaska Water and Waste Water Utility (AWWU) sewer and excess water will be held in a 18,000 gallon weir tank. Water held in the tank will be visually inspected for sheen and odor and analyzed for DRO, total aromatic hydrocarbons (TAH), and total aqueous hydrocarbons (TaqH). If sample results suggest that the held water does not exceed surface water quality standards, held water will be discharged to a storm drain via the pond adjacent to the eastern project boundary. Water that exceeds surface water quality standards will be diverted through a BF 400 filter equipped with activated carbon filters. The filters will be changed when they reach 90 percent of the calculated capacity. Water samples will be collected from the weir tank and the outlet of the filter on a weekly basis. After a month of dewatering and no surface water exceedences are noted, sampling can be reduced to a monthly occurance.
|
Todd Blessing |
| 7/11/2011 |
Document, Report, or Work plan Review - other |
DEC reviewed Montauk Environmental Engineering's project report for stockpiles 1,2, A, and B. Stockpile 1 and 2 were excavated from Tract J, suspected clean and contained rougly 1,000 cubic yards and 800 cubic yards of soil, respectively. Stockpiles A and B were roughly 50 cubic yard suspected claean stockpiles excavated from tract I. Stockpiles 1 and 2 were tested fro DRO and BTEX as well as the field sheen test. Methylene chloride was the only contaminant detected at elevated levels and since it was also detected in the trip blank, it is believed to be a laboratory contaminant. Stockpiles A and B were also sampled to be analyzed for GRO, DRO, RRO, PCB, and PAHs, and VOCs, and metals. In stockpiles A and B, DRO was detected at elevated levels and ranged from 191 mg/kg to 623 mg/kg. Methylene chloride, arsenic and chromium were also detected at elevated levels. |
Todd Blessing |
| 7/13/2011 |
Update or Other Action |
DEC recieved an update from Watterson construction regarding their dewatering acitivities. At this time, all groundwater has been disposed of in the sanitary sewer and Watterson predicts they will not need to discharge groundwater into the adjacent pond. |
Todd Blessing |
| 9/9/2011 |
Update or Other Action |
Staff reviewed the boring logs for wells used to observe groundwater levels during the aquifer test of the cooling re-injection well. Well B9MW is approved for observation; however piezometer D2 was not. Staff requesteed ANTHC contractor (Sullivan Water Wells) replace piezometer D2 with a monitoring well installed in accordance with DEC’s February 2009 monitoring well guidance. Staff also Sullivan water wells notify us 48 hours before they begin the draw down and injection testing. |
Todd Blessing |
| 9/12/2011 |
Update or Other Action |
Staff approved of Superior Plumbing and Heating's proposal to install a new observation well for the healthy communities building's re-injection well aquifer test. The new observation well will be installed adjacent to the reinjection well. Staff notified Superior Plumbing and Heating's that we will inspect the draw down and injection well testing. |
Todd Blessing |
| 9/28/2011 |
Site Visit |
Staff conducted a site visit to inspect the aquifer test of the cooling re-injection well. Jim Ridgeway of Anchorage Well and Pump services initated draw down of the cooling injection well over a 24 hour period and monitored shallow groundwater levels during the pumping. Staff viewed the data results during the intitial pumping and did not note any drawdown of shallow groundwater. The aquifer test is slated to continue for next few days and results in a spreadsheet format will be provided to staff. |
Todd Blessing |
| 1/30/2012 |
Update or Other Action |
DEC staff reviewed Montauk's 24 October report regarding the cleanup and treatment of contaminated soil on Tract I, Block 5, Tudor Center Subdivision. Tract I was used in the past as a dumping area for asphalt and other miscellaneous debris that may have been associated with a former asphalt plant that operated on Tract C-2. Visual evidence of contamination was noted in October 2010 by Watterson Construction Company. Cleanup of contaminated soil was performed in accordance with a May 2011 DEC approved work plan. Confirmation soil sample results within the excavation and floor sidewalls confirmed DRO levels remaining on-site were below 18 AAC 75.341 Table B2 migration to groundwater cleanup levels. |
Todd Blessing |
| 4/19/2013 |
Meeting or Teleconference Held |
DEC met with representatives of ANTHC to discuss project status. On Tract J a groundwater monitoring program needs to be established and the potential impacts of the groundwater plume on the nearby surface needs to be determined. A new site will be opened to for Tract I, where debris and TCE and DRO contaminated soil were found. |
Jacob Gano |
| 4/25/2013 |
Update or Other Action |
Letter sent to ANTHC requesting groundwater monitoring work plan and surface water assessment. |
Jacob Gano |
| 4/25/2013 |
Update or Other Action |
Notify ANTHC that Tract H is not part of this contaminated site, therefore DEC approval is not required to conduct work on that property. ANTHC had previously provided a Geotechnical Investigation and Environmental Sampling Plan for the Tract H property to DEC for approval. |
Jacob Gano |
| 5/20/2013 |
Site Characterization Workplan Approved |
Conditional approval letter |
Jacob Gano |
| 9/27/2013 |
Site Visit |
ADEC staff conducted a site visit to observe groundwater monitoring at the Tract J site. |
Meghan Dooley |
| 7/31/2014 |
Document, Report, or Work plan Review - other |
Reviewed the June 2014 ground water monitoring report for sampling events in September 2013 and April 2014. Two wells B5(A)MW and B10(A)MW were installed. The two new wells and two existing wells B13MW and B11MW were sampled for diesel range organics (DRO) and residual range organics (RRO) during both events. None of the analytes were detected in B13MW and B11MW in either event. DRO and RRO were not detected in B5(A)MW in the September 2013 event. In the June 2014 event RRO was detected in B5(A)MW below cleanup levels. In both events DRO was detected above cleanup levels in B10(A)MW. RRO was detected both times but was above cleanup levels during the second event. Based on this report, the ADEC requested a decommissioning plan for B13MW and B11MW. |
Lisa Krebs-Barsis |
| 9/26/2014 |
Update or Other Action |
Monitoring well decommissioning work plan approved for wells B13MW and B11MW. |
Lisa Krebs-Barsis |
| 7/14/2015 |
Site Characterization Report Approved |
Monitoring well B10(A)MW was sampled in October 2014 and April 2015 and B5(A)MW was sampled in April 2015. The sample collected from B5(A)MW was analyzed for residual range organics (RRO) and diesel range organics (DRO). Neither analyte was detected in the sample. The samples collected from B10(A)MW, during the two sampling events, were analyzed for RRO and DRO. The samples exceeded cleanup levels for DRO and RRO in both sampling events. However, concentrations of contaminants at B10(A)MW are stable within a small range. Monitoring wells B13MW and B11MW were decommissioned. Based on this report, ADEC recommended decommissioning of wells B10(A)MW and B5(A)MW. |
Lisa Krebs-Barsis |
| 8/12/2015 |
Exposure Tracking Model Ranking |
A new updated ranking with ETM has been completed for source area 78918 Petroleum Contaminated Soil & Groundwater. |
Lisa Krebs-Barsis |
| 2/2/2016 |
Cleanup Complete Determination Issued |
DEC has determined that the site has been adequately characterized and further cleanup action is not required, subject to institutional controls. |
Lisa Krebs-Barsis |
| 2/2/2016 |
Institutional Control Record Established |
Institutional Controls established and entered into the database. |
Lisa Krebs-Barsis |
| 9/23/2016 |
Update or Other Action |
The Notice of Environmental Conservation (deed notice) was submitted to the Anchorage District Recorder's Office on this date. |
Kristin Thompson |
| 10/24/2016 |
Update or Other Action |
The official recorded deed notice was received today. Document No. 2016-040565-0 filed in the Anchorage Recording District. |
Kristin Thompson |
| 12/30/2016 |
Institutional Control Compliance Review |
IC compliance review conducted. Staff had already been changed from Lisa Krebs-Barsis to IC Unit. Information was added to the Closure/IC Details. Reminder system set to follow-up on land use conditions every three years. |
Kristin Thompson |
| 4/20/2017 |
Institutional Control Update |
A letter was issued this date requesting ANTHC report and decommission any groundwater wells remaining on site. Reminder system set to follow-up on the reporting of onsite wells in one month, and on the decommissioning of wells in one year. |
Kristin Thompson |
| 5/24/2017 |
Institutional Control Periodic Reporting |
Received confirmation by email that there are no remaining groundwater monitoring wells associated with this site. |
Kristin Thompson |
| 5/11/2020 |
Institutional Control Update |
A geotechnical investigation is being planned on this property during the current field season. The subsurface investigation will be limited to cone penetrometer testing (CPT). Normally the holes collapse on themselves, but sometimes when the material is cohesive or silty, it will stay open. Any holes left open will be decommissioned by backfilling with bentonite chips, followed by a cement grout at the surface. No soil or groundwater will be brought to the surface during the investigation, therefore no work plan is needed.
|
Evonne Reese |
| 7/17/2020 |
Institutional Control Compliance Review |
Landowner and contact at ANTHC updated. IC Compliance Review sent to the landowner on this date to verify ownership and site use. Next review is due in three years, in 2023. |
Cascade Galasso-Irish |
