Hill Air Force Base Restoration Advisory · PDF fileHill Air Force Base Restoration Advisory Board Meeting Minutes Oct. 29, 2015 ... Ms. Grunewald said all cleanup documents from the

The minutes were approved by the RAB on January 5, 2016.

Hill Air Force Base Restoration Advisory Board

Meeting Minutes

Oct. 29, 2015

Members Present: Organization: Members Present: Organization: Loren Allen Davis County Health Dept. Tim Lane Roy Community At-Large Robert Becker Sierra Club TJ Mitchell Clinton City Travis Bonsteel Clinton Community Vern Phipps Clearfield Community Sandra Bourgeois Environmental Protection

Agency Ivan Ray Davis & Weber Canal

Company Summer Day Weber-Morgan Health Dept. Muhammad Slam Utah Department of

Environmental Quality Buck Ekstrom Clearfield City Ed Sorensen Roy City Bambi Gibson Sunset Community Jan Ukena South Weber Community Randy Hilton South Weber City Brian Wesoloski Riverdale Community Clint Holm Layton Community Darrin Wray Hill AFB RAB Co-chair Stephen Jackson Layton City Scott Zigich Davis County School District Douglas Johnson Hill AFB Community Alternate

Facilitator: Organization: Tim Sueltenfuss RAB Facilitator Members Absent: Organization: Members Absent: Organization: Jeff MacFarlane North Davis Sewer District Brad Nelson Weber Basin Water Peter Matson Layton City Brett Nelson Central Weber Sewer District Joe Maylin Sunset City Rich Sirken Weber State University Other Attendees: Organization: Other Attendees: Organization: Dave Allison UDEQ Mark Loucks AFCEC-Hill Kathleen Bradley AFCEC Armando Perez AFCEC Public Affairs Carly Brown Ageiss Brent Poll South Weber Coalition Angelina Casarez AFCEC Public Affairs Mike Reynolds CH2M Hill Jarrod Case AFCEC-Hill Mark Roginske AFCEC-Hill Jeremy Cox CH2M Hill Corey Schwabenlander CH2M Hill Ann Driechciarz CH2M Hill Kalem Sessions AEEC Barbara Fisher Hill AFB Public Affairs Seth Smith AFCEC Randy Gates CH2M Hill Shannon Smith AFCEC-Hill Britt Grunewald AFCEC Sandy Staigerwald EA Engineering Dave Harris Ageiss Ed Zuelke AFCEC

Handouts Distributed at Meeting: Handouts:

Updated Hill AFB Basewide Plume Map

Page 2 of 11

Agenda Item #1. Welcome

Mr. Darrin Wray, the RAB Air Force co-chair, called the meeting to order and welcomed RAB members to the meeting. He welcomed the representatives from the Air Force Civil Engineer Center (AFCEC), and introduced several new RAB representatives: Mr. TJ Mitchell (Clinton City); Mr. Douglas Johnson (Hill AFB Community Alternate), filling in for Mr. Jason Bowers; and Mr. Alan Arnold (Riverdale Community Alternate). Mr. Wray introduced Mr. Tim Sueltenfuss, the new RAB Facilitator. Mr. Sueltenfuss said he specializes in conflict analysis and resolution. His bio was provided to the RAB via email prior to the RAB meeting. He offered to meet with RAB members the following day, if anyone was interested. Agenda Item #2. RAB Business

Mr. Sueltenfuss briefly went through the packet distributed at the meeting. The meeting agenda is attached (Attachment 1). Action Item List. Mr. Sueltenfuss said that a current action item list was included in the packet (Attachment 2). He encouraged RAB members to look through the action items and noted that many of the action items would be addressed at the meeting. He asked if there was any discussion needed about the action items. None of the RAB members responded. Schedule. A schedule of upcoming RAB meetings and a list potential future training and tour events was provided to the RAB (Attachment 3). Mr. Sueltenfuss said future RAB meeting dates are included for the RABs awareness and encouraged them to mark their calendars now. Mr. Johnson said he would like an opportunity to see injections into the soil, if there are other sites using either the enhanced bioremediation or enhanced reductive dechlorination (ERD) remedies. Mr. Loucks said there will be more sites using these technologies. Mr. Sueltenfuss said it would be added to the list of potential tour requests. RAB Membership. Ms. Carly Brown said that the term of every community RAB member will expire at the end of 2015, so the RAB will need to go through the confirmation and solicitation process as outlined in the RAB Operating Procedures. Ms. Brown said before the January RAB meeting, she will be contacting the community members to ask if they would like to continue on the RAB. If so, an email vote will be conducted to either confirm them in their position or to open the position to additional applications. If not, a full solicitation will be conducted. Ms. Brown said there are some differences in the RAB Operating Procedures and how the RAB and Air Force currently operates, so they will need to modified and brought up-to-date. She said suggested revisions will be made internally and the changes will be circulated via e-mail so the RAB can decide whether or not to approve the changes at the January RAB meeting. Contact Information Consent. Mr. David Harris passed out a form for RAB members to provide up-to-date contact information. The form also allows RAB members to check a box for which groups they consent to allowing the Air Force to provide this information (other RAB members, the public, both or neither). Mr. Harris said RAB members are not required to allow public access to their contact information, but without the RAB website, there is no other way for the public to contact them. If someone from the public contacts the Air Force requesting RAB member information, this form will

Page 3 of 11

provide the level of consent each RAB member has approved. If consent is not given, the Air Force will contact the RAB member to address contact information requests on a case-by-case basis. Updated Hill Staff List. Mr. Mark Loucks said a current staff list and site assignment sheet was provided in the handouts (Attachment 4). Contact information for each site manager was available in the breakout packets, if needed. Mr. Loucks said that due to staffing shortages, Hill AFB has recruited Ms. Britt Grunewald and Ms. Sharon Stone (both from Peterson Air Force Base in Colorado Springs, Colorado), and Mr. Ed Zuelke (Fairchild AFB in Spokane, Washington) to fill in until positions are filled. Mr. Loucks said a new staff member will join the team in mid-November, so the staff assignment list will change again soon. Administrative Record. Ms. Grunewald said all cleanup documents from the last year have been uploaded to AFCEC’s online administrative record. She said now that a support contract is in place, the remaining 300 documents should be completed within the next month. She asked RAB members if they had a chance to try the website, and if so if they had any questions or issues with the website. Following a question from Mr. Johnson about historical documents (from more than a year ago) and whether they are available on the website, Ms. Grunewald said the remaining 300 are from prior to a year ago and will be loaded within a month. She said in the meantime, those 300 documents are available on a disc at the Weber State University-Davis Campus Library. Agenda Item #3. Operable Unit 15 (Indoor Air Sampling Program) Update

Mr. Mark Roginske and Mr. Corey Schwabenlander provided an update on Operable Unit 15 (OU15), the indoor air sampling program (Attachment 5).

Slide 2 showed a timeline for the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) process at OU15. Mr. Roginske said OU15 has been well-studied and documented since the basewide air sampling program began in 2003. Based on the data that has been gathered over the past 12 years, the Air Force will be making changes to the 2015/2016 Indoor Air Sampling Program, which will be detailed in this presentation. Mr. Roginske said the RAB will notice similarities and differences between the interim remedies over the past years and the final remedy that will be

selected in a Proposed Plan (PP) and Record of Decision (ROD), scheduled for completion in 2016. Mr. Roginske noted that RAB members will have an opportunity to provide early input at the Feasibility Study (FS) phase planned for Spring 2016, and formal input at the PP phase. Mr. Schwabenlander said the updates to the program are designed to optimize time and funds, which will be good news to participating residents. Contacting Participants. Mr. Schwabenlander said at the August RAB meeting, the RAB brainstormed ways for the Air Force to contact participants for the upcoming program. Slide 3 compiled the feasible ideas with previous methods used by the Air Force, which will be used to contact participants in the 2015/2016 air sampling program. The Air Force will contact the approximately 400 residents sampled the previous year and residents on a periodic sampling schedule (due to an existing vapor removal system or detection in the recent past). In addition, Mr. Schwabenlander said the Air Force will be working to identify residents that have recently moved to the area, by identifying parcels with recent transactions (through county and city databases) and comparing them to parcels in the defined affected areas. Mr. Roginske said the Air Force already has processes in place to obtain this information, as they routinely access this type of data for new leases. Mr. Mitchell suggested that the base use utility information

Page 4 of 11

through the cities. Mr. Schwabenlander said they will try the parcel comparison first, as they already have easy access to the information.

Long-duration Samples. Slide 7 was provided to remind the RAB of the challenge of accounting for variability in indoor air contaminant concentrations over time, as was proven during the intensive indoor air studies at the Arizona State University (ASU) house in Layton. New guidance from the Environmental Protection Agency (EPA), shown on Slide 8, recognizes variability and suggests a solution: long-duration samples. Mr. Schwabenlander said data shows that a 24-hour sample, such as those collected by the Summa canisters used for the past 12 years, is not representative of average concentrations in a home. To assess risk and exposure, looking at an average concentration over 26 days would be much more helpful in understanding the condition in the home, as shown on Slide 9. Slide 10 provided pictures of the passive diffusion samplers that will be used in the 2015/2016 indoor air sampling program. Mr. Schwabenlander said that while the passive samplers have been around for a while, there are now multiple studies showing success in gathering accurate and reliable long-term data from homes. Following a question from Mr. Ivan Ray about how the samplers are tested, Mr. Schwabenlander said the manufacturer conducts quality control checks before sending them to the sampling contractor. Mr. Schwabenlander said the sampling contractor will also continue to take duplicate samples and field blanks as part of their own routine quality

control in the field. Mr. Brian Wesoloski asked if the passive samplers have a quicker lab turnaround. Mr. Schwabenlander said they are similar to the Summa canisters; samples are overnighted to the lab and preliminary data is received within five days. Mr. Schwabenlander said that now the sampling methodology has been selected, the next step is to determine the sample duration. To account for variability, longer-duration samples are better. He said current studies indicate reliability over a 14-day period, but another study is under way to test reliability up to 26 days. Results from the 26-day test are expected in mid-December. Mr. Schwabenlander said that the EPA and Utah Department of Environmental Quality (UDEQ) have given verbal approval to the change in sampling methodology, and written approval is expected any day. He said that the 2015/2016 sampling program begins on Monday (November 2) in the approximately 120 homes with vapor removal systems (VRSs). Until results of the 26-day reliability test are known, a 14-day duration sample will be used. If the 26-day duration study proves reliable, in mid-December the sampling contractor will implement 26-day duration samples. If the study determines the 26-day duration sample is not reliable, the sampling contractor will continue with the 14-day duration sample. Following a question from Mr. Robert Becker, Mr. Schwabenlander said that homes with VRSs are sampled annually to test the performance of the VRS, so the VRS will continue operating for the duration of the sample. Mr. Buck Ekstrom asked about the cost of the passive diffusion samplers. Mr. Schwabenlander said that the Summa canisters were approximately $150 for the sampler and analysis at the lab, and the passive diffusion samplers are approximately double that cost. Mr. Schwabenlander said

Page 5 of 11

that the passive diffusion samplers will provide better, long-term data and will ultimately make the program better by providing more accurate average concentrations in homes. Mr. Tim Lane suggested that the new method also seems to be less intrusive to the resident. Since sampling was beginning the week following the RAB meeting, Mr. Schwabenlander said that some residents have already heard about the changes to the sampling methodology, which has been met with a positive response. He said it will take a little more scheduling coordination with the residents, since it will be at least two weeks in between the placement and pick-up of the sampler. A fact sheet detailing the new sampling method will be emailed to residents that have provided an email address, and a hard copy will be provided when the sampler is placed in the home. The fact sheet will also be posted on the Hill AFB website soon. Mr. Schwabenlander said that air sampling results will be handled similarly as in previous program years. If a home has a detection above the Mitigation Action Level (MAL), and if an indoor source investigation confirms vapor intrusion, a VRS will be offered to residents. OU10 (Clearfield) Discontinued Sampling. Slide 16 showed a map of OU10 in Clearfield and Sunset. Mr. Schwabenlander noted that the northern lobe in Sunset was very deep (230-300 feet) and there has never been a vapor intrusion concern associated with it. The bolded box shows the approximate sampling

area in the shallow trichloroethene (TCE) and shallow tetrachloroethene (PCE) plume. Mr. Schwabenlander said there are multiple lines of evidence to demonstrate that vapor intrusion is not occurring at OU10. He said extensive groundwater data indicates there is a clean water lens overlying the shallow OU10 plumes which acts as a barrier, preventing contaminant vapors from evaporating off the water table and entering homes.

Mr. Ekstrom asked why other Operable Units (OUs) do not have a clean water lens. Mr. Schwabenlander said it is possible there are localized areas of clean water lenses in the other OUs, but not like at OU10 where the lens covers the entire shallow plume. Mr. Schwabenlander said the shallow TCE and PCE plumes sit in a paleo-sand channel, which causes the contaminated groundwater to drop below the water lens. In addition to the clean water lens identified through groundwater and soil gas samples, 12 years of indoor air sampling show that vapor intrusion is not occurring in OU10. Of the more than 700 samples collected in OU10, all samples exceeding the MAL were due to indoor sources. Mr. Schwabenlander said there is one home in OU10 with a VRS. This home had a detection above the MAL, a VRS was installed, but the home continued to have detections above the MAL. Ultimately, an indoor source was identified and removed, and has been non-detect ever since. The EPA and UDEQ are reviewing the supporting documentation to remove OU10 from the indoor air sampling program. If they concur, homes in OU10 will not be sampled during the 2015/2016 air sampling round. Mr. Schwabenlander said residents will be notified with either a phone call or letter and fact sheet to explain the change. If the regulators do not concur, homes in OU10 will be sampled toward the end of the current round of sampling. Graduating Homes Without Vapor Intrusion. Slide 22 detailed the indoor air dataset collected over the last 15 years.

Page 6 of 11

Mr. Schwabenlander said it has been proposed that homes with four consecutive non-detect samples collected during the heating season be graduated from the indoor air sampling program. He said this

suggested change was based on the existing data collected around Hill AFB with the 24-hour Summa canister and compared against intensive studies conducted at the ASU house and other study houses in the United States. He said their comparison determined that four non-detect samples was the magic number. In the communities surrounding Hill AFB, there more than 400 homes where four consecutive non-detect samples are followed by one additional heating season sample. Only eight showed a detection in the fifth sample. Only one of those eight homes was attributed to vapor intrusion and received a VRS. Mr.

Schwabenlander said the results from this one home may be due to increased contaminant concentrations in the groundwater and indicated a need for continued plume evaluation to detect migration of the “hot spots” or areas of high concentration within the plume. Mr. Clint Holm asked about the confidence interval at the ASU house and other study houses in the United States. Mr. Schwabenlander said he would get back to Mr. Holm with that answer. Mr. Ekstrom said he would like to look at the detailed methodology to see how they came to the magic number of four non-detect samples. Mr. Schwabenlander said that once the report has been reviewed by the regulators and is approved for the public, it can be made available to the RAB. Mr. Holm suggested that it may be beneficial to wait one more year before removing OU10 from the program until samples can be collected with the longer-duration passive samplers, rather than basing it on the 24-hour samples. He said that since longer-duration sampling is now part of the EPA guidance to avoid the variability it could be construed as biased to make the decision on past data. Mr. Schwabenlander said there is a solid case for removing OU10 because of the thousands of groundwater, soil gas and air sampling samples that have been collected over the past 15 years. Mr. Wray said the Air Force’s primary concern is protecting the public, but also has a stewardship to spend public funds responsibly. Mr. Wray said that the Air Force has spent a lot of time and money at OU10 and there is still not one home with evidence of vapor intrusion so it is time to make that decision. The EPA and UDEQ are reviewing the supporting documentation to graduate homes without vapor intrusion from the indoor air sampling program. If they concur, homes that have not shown vapor intrusion will not be sampled during the 2015/2016 air sampling round. Mr. Schwabenlander said residents will be notified with either a phone call or letter and fact sheet to explain the change. If the regulators do not concur, homes can still be added to the 2015/2016 sampling program. Mr. Ekstrom asked about the RAB’s role regarding the decisions outlined in the presentation, as it seems decisions have already been made in the report. Mr. Sueltenfuss said the RAB is a forum for RAB members to provide advice to the Air Force that may influence cleanup decisions. Mr. Wray said the Air Force has to ensure the science is right in the report, followed by a review by the EPA and UDEQ specialists, before it can be made available to the public. Mr. Wray said the RAB is briefed on such topics before the reports are finalized so they can be informed and provide input into the decision documents such as the Proposed Plan. There were no additional comments or questions on this presentation.

Page 7 of 11

Agenda Item #4. Break/Breakout Sessions

RAB members broke into small groups, by community, to meet with Hill project managers to discuss items in more detail and any other issues of concern. Informational material provided during the breakout sessions is attached (Attachment 6). Agenda Item #5. Operable Unit 12 (Roy) Update

Mr. Mark Roginske and Mr. Jeremy Cox provided an update regarding the status of Operable Unit 12 (OU12) and the Permeable Reactive Barrier (PRB) in Roy (Attachment 7). Slide 2 showed a timeline for the CERCLA process at OU12. Mr. Roginske noted the installation of the PRB in 2004 and ROD signed in 2008. An Explanation of Significant Differences (ESD), to address changes to the remedy at OU12, is planned for 2016.

OU12 is primarily comprised of TCE-contaminated groundwater that flows from the base into a portion of Roy, shown on a map on Slide 5. The remedy for OU12 included the following components:

Extraction wells at the base boundary – actively pumping contaminated groundwater and discharging to approved location to prevent further migration off-base

Monitored natural attenuation (MNA) throughout the plume – allowing natural processes to reduce TCE concentrations

Groundwater restrictions Measures to address vapor intrusion – addressed in OU15 Permeable reactive barrier (PRB) – installed near the “rail

trail” near 2700 West in Roy, the 30-foot deep trench is filled with sand and iron filings that allows contaminated groundwater to flow through and breaks down TCE when it comes into contact with the iron filings (illustrated on Slide 7). PRB Performance. Mr. Cox said the PRB was intended to reduce, not completely prevent, the westward migration of the plume. The iron in the PRB, however, was affected by nitrate in the groundwater (unrelated to Hill AFB and most likely from fertilizer use in the area), and is no longer able to break down the TCE to the expected efficiency. Mr. Cox said the PBR treatment efficiency is measured by sampling wells up- and down-gradient of the PRB and was operating as expected at first but is now treating at less than a 30 percent efficiency (shown on Slide 10). Progress of MNA. In 2007, a groundwater model was created to estimate how the OU12 plume might change over time. The model incorporated groundwater flow rate, contaminant concentrations and geology based on the data available at the time and took a very conservative look at how OU12 might evolve. Slide 12 illustrated how the 2007 groundwater model predicted the westward migration of the plume in 2018, with treatment at the PRB.

Page 8 of 11

Mr. Cox also noted that the model predicted that high concentrations of TCE (shown by the yellow gradient) would continue to flow into the PRB for decades.

Slide 13 illustrates the difference between the predicted plume in 2018 (from the 2007 model) and the actual plume in 2011. The actual 2011 plume map shows that the yellow, higher concentration areas of the plume have receded and are no longer reaching the PRB. The “toe” of the plume is also receding which is more evidence that MNA is occurring much more quickly throughout OU12 than predicted by the 2007 model. Mr. Cox noted that other than the PRB, MNA and the base boundary system, there have been no additional remedies applied at the site.

Due to the significant difference between the prediction and the actual map, the groundwater model was revised and refined in 2013-2014 using a larger data set (data from 2004 to 2011). Mr. Cox said the revised model was calibrated to overestimate the plume extent and to assume that the PRB was not in place, so that the Air Force could make some conclusions about the need for the PRB. He said the revised model predicts that TCE concentrations will decrease sooner than the old model.

The map on Slide 15 illustrates how the previous model differs from the revised model. Mr. Cox noted that the revised model used conservative assumptions, so conditions are not expected to even reach the extent shown on this map. With this new conservative model, Mr. Cox said the maximum westward extent is expected to occur by approximately 2016 (give or take a few years), even without treatment at the PRB. Conclusions. Mr. Cox said the revised model has helped to conclude that, even if the PRB was operating as expected (and it is not), the PRB is no longer required to achieve the goal of reducing down-gradient migration because MNA is occurring faster than expected. The Air Force is preparing an ESD to document the removal of the ROD requirement for treatment at the PRB. The ESD will also declare that MNA will be relied upon to decrease TCE concentrations in the groundwater at OU12. The ESD will be submitted to regulators this fall and, once approved, will be available to the public. Future of the PRB. Mr. Cox said they have been collecting groundwater and surface water data in the vicinity of the PRB to help determine how best to address the future of the PRB. Results from surface water samples collected up-gradient of the PRB, some in residential backyards, were provided on Slide 21. In one location, TCE was detected at low levels near a culvert in a resident’s backyard, but TCE concentrations have been measured here historically because of an old drainage system. Mr. Cox said a total of 12 samples were collected from three locations and all have either been non-detect or below the acceptable risk range determined in the remedial investigation report.

Page 9 of 11

Results from shallow groundwater wells in the vicinity of the PRB were shown on Slide 23 and results from deeper groundwater wells were shown on Slide 24. Mr. Cox said the results are consistent with MNA and are shown to be significantly decreasing when compared with previous results. Based on the results, the Air Force is evaluating in-place decommissioning of the PRB. Mr. Cox said that leaving the PRB in place makes sense, as it would cause the least disruption to residents and, even though it isn’t treating as expected, it is still providing some treatment. Mr. Cox said the Air Force does not foresee any modifications to the actual PRB as part of the decommissioning.

Mr. Cox said that the Air Force is investigating means to improve the surface water drainage at the PRB, even though surface water accumulation occurred at the location prior to the installation of the PRB. He said existing drainage features may be enhanced or improved, or soil may be added to particular areas to raise the ground surface near the PRB, as shown on Slide 27. This work is expected to begin in 2016 and stakeholders and affected residents will be asked for input. There were no additional comments or questions on this discussion.

Agenda Item #6. Accomplishments in Fiscal Year 2015 Mr. Mark Loucks provided the RAB with an overview of the accomplishments in Fiscal Year 2015 (FY15) (Attachment 8). Mr. Loucks said FY15 was a banner year for the Air Force, as there has been a lot of activity and progress at the environmental sites at Hill AFB. He said the Air Force uses three metrics to measure success:

Remedy in Place (RIP) – ROD signed and all remedies constructed and operating Response Complete (RC) – All active remedial/cleanup actions have been completed Site Closure (SC) – Site is remediated to residential risk standards

Mr. Loucks said a ROD is a significant step in the CERCLA process because it indicates that a remedy has been selected and is legally agreed upon by all stakeholders. The following Operable Units had RODs signed in FY15:

1. Operable Unit 11 (on-base gas station site) 2. Operable Unit 9 (multiple on-base sites, including base golf course, and in small portion of

Sunset) 3. Operable Unit 10 (Clearfield) 4. Operable Unit A (Little Mountain Test Annex)

Mr. Loucks said that the Air Force could not have accomplished this much without the help of the EPA and UDEQ regulators. He said they reviewed countless documents and worked with the Air Force to

ensure the documents were meeting all requirements and ensuring the remedies were protective of human health and the environment. Remedy in Place (Slide 8). Five sites reached this milestone at Hill AFB in FY15. They are:

1. Operable Unit 11 (on-base gas station site) 2. Operable Unit 9 (on-base golf course area) 3. Operable Unit 9 (1100 Area) 4. Operable Unit 9 (800/900 Area)

Page 10 of 11

5. Operable Unit 10 (Clearfield) Response Complete (Slide 9). One site reached this milestone at Hill AFB in FY15. ST061 is a fuel spill in a tank farm area, under base housing. Mr. Loucks said that other than a few land-use controls, this site

is remediated. Sites Closed (Slide 10). Four sites reached this milestone at Hill AFB in FY15, bringing the Hill AFB total to six sites in site closure (of sites included in the Performance-Based Remediation contract). They are:

1. Oil/Water Separator OW510 (on-base) 2. Oil/Water Separator OW529 (on-base) 3. Pond 7 (on-base) 4. Underground storage tank ST066 (Little Mountain)

Other Accomplishments (Slide 11). Mr. Loucks said it has been a very active year and the Air Force and its contractors have accomplished a lot. In addition to the sites listed above, the Air Force has, among other things, taken steps to reduce cleanup timeframes and remove source area contamination at several sites. They include the following:

Operable Unit 6 (on-base and Riverdale) – Installed additional extraction wells on-base and now discharge to the sanitary sewer for treatment. Mr. Loucks said this saves money while still meeting the same cleanup objectives.

Operable Unit 8 (on-base and Layton) – Installed system and began soil vapor extraction in source area in industrial area on-base.

Military Munitions Response Program (on-base) – Completed Feasibility Study and Proposed Plan at firing range, disposal pit and burn pit (Sites SR502, DA503 and BP504). Mr. Loucks said two of these sites will be in SC within a year.

Operable Units 5 (Sunset and Clinton) and 12 (Roy) – Installed injection points and completed injections in high concentration source areas.

Mr. Sueltenfuss congratulated the Air Force and regulators for the progress made at Hill AFB in FY15. He said the RAB’s role in these accomplishments is also significant. There were no additional questions or comments on this presentation. Agenda Item #7. Public Comment Opportunity

Mr. Sueltenfuss asked if there were any members of the public in the audience who would like an opportunity to comment. Mr. Brent Poll from the South Weber Coalition brought an article from the August 12, 2015 Deseret News titled, “Colorado contested Superfund status for mine, fearing stigma.” He said that the article states that Superfund sites, such as Hill AFB, have a stigma associated with them, such as potentially having an effect on property values and tourism. But, he said the article states that studies have shown it is worth being classified as a Superfund site because it is the best way of resolving contamination. He then said that although Hill AFB has done a lot of good things, the community would have been better off being polluted by a company such as Kennecott Copper, who acts not in a discretionary function, but in

Page 11 of 11

an arbitrary one. Mr. Poll provided a copy of the article to Mr. Sueltenfuss and encouraged RAB members to read it. Mr. Ray said the Davis and Weber Canals Company received a $3 million grant that will be used over the next two years to improve and expand the canal using pre-cast box culvert. He said he was notifying RAB members because it will affect Interstate 15 bridges near the base and potentially in cities represented on the RAB, such as Roy and Sunset. He said care will be taken to minimize disruptions to the community. Agenda Item #8. Potential Agenda Items for Next Hill AFB RAB Meeting

OU15 Risk Assessment Enhanced Reductive Dechlorination (ERD) Sites Update on OU12 Explanation of Significant Differences Community Representative Elections (if necessary) Revised RAB Operating Procedures

Item #9. Adjournment

Meeting adjourned at 9:00 p.m.

Attachments:

1. Agenda 2. Action Item List 3. RAB Schedule 4. Updated Staff List 5. Presentation Slides – Operable Unit 15 Update 6. Breakout Materials 7. Presentation Slides – Operable Unit 12 Update 8. Presentation Slides – Accomplishments in Fiscal Year 2015

Hill AFB Restoration Advisory Board

Meeting 6:30 p.m., Oct. 29, 2015

Sunset City Building (Sunset Room) 200 West 1300 North

Sunset, Utah

Pre-RAB Meeting Training Session 6 p.m. Vapor Intrusion ................................................................... Jarrod Case, Hill AFB

RAB Meeting Agenda

6:30 � 6:35 Welcome ..................................................... Darrin Wray, RAB Air Force Co-Chair

6:35 � 6:55 RAB Business ...................................................... Tim Sueltenfuss, RAB Facilitator Action Items

- Action Item List - RAB Schedule - RAB Membership � Carly Brown, Ageiss

Contact Information Consent � Dave Harris, Ageiss Updated Hill Staff List � Mark Loucks, Hill AFB Administrative Record � Follow-up Questions � Britt Grunewald, Hill AFB

6:55 � 7:40 Operable Unit 15 (Indoor Air Sampling Program) BASAP Revisions 25 minutes Presentation ............................................................................................................. ........................ Mark Roginske (Hill AFB) and Corey Schwabenlander (CH2M Hill) 20 minutes RAB Questions and Discussion

7:40 � 8:10 Break/Breakout Sessions

8:10 � 8:30 Operable Unit 12 (Roy) Update 15 minutes Presentation ............................................................................................................. ........................... Mark Roginske (AFCEC-Hill AFB) and Jeremy Cox (CH2M Hill) 5 minutes RAB Questions and Discussion

8:30 � 8:50 Accomplishments in Fiscal Year 2015 15 minutes Presentation ........................................................................ Mark Loucks, Hill AFB 5 minutes RAB Questions and Discussion

8:50 � 8:55 Public Comment Opportunity

8:55 � 9:00 Agenda Items for January 28, 2016 Meeting

9:00 Adjourn

Acronym DefinitionsThe following acronyms are commonly used in cleanup program reports and documents.

AFB: Air Force Base AFCEC: Air Force Civil Engineering Center ARA: Alliance for Risk AssessmentARARs: Applicable or Relevant and Appropriate Requirements ASTP: Air Stripper Treatment Plant ASU: Arizona State UniversityATSDR: Agency for Toxic Substances and Disease RegistryBTEXN: Benzene, Toluene, Ethylbenzene, Xylenes, and Naphtalene BRA: Baseline Risk Assessment CE: Civil Engineering CERCLA: Comprehensive Environmental Response, Compensation and Liability Act CRP: Community Relations Plan CWSID: Central Weber Sewer Improvement District DCA: Dichloroethane DCE: Dichloroethene DNAPL: Dense Non-aqueous Phase Liquid DOD: Department of Defense EA: Enhanced Attenuation EA: Environmental Assessment EE/CA: Engineering Evaluation/Cost Analysis EPA: Environmental Protection AgencyERA: Environmental Restoration Account ERD: Enhanced Reductive Dechlorination ERP-O: Environmental Restoration Program Optimization EVO: Emulsified Vegetable Oil EUL: Enhanced Use Lease FFA: Federal Facilities Agreement FS: Feasibility Study FY: Fiscal Year FYR: Five-Year Review GIS: Geographic Information SystemIRA: Interim Remedial ActionIRP: Installation Restoration Program IST: Installation Support Team IWTP: Industrial Wastewater Treatment Plant LNAPL: Light Non-aqueous Phase Liquid LTM: Long-term monitoringLUST: Leaking Underground Storage TankMAL: Mitigation Action Level MCL: Maximum Contaminant Level MD: Munitions Debris MEC: Munitions and Explosives of Concern MMRP: Military Munitions Response Program MRS: Munitions Response Site MTBE: Methyl Tertiary Butyl Ether MNA: Monitored Natural Attenuation

MPO: Minimum Performance Objectives MRL: Minimal Risk LevelNAS: National Academies of ScienceNIT: North Interceptor Trench NDSID: North Davis Sewer Improvement District NPL: National Priorities List O&M: Operations and MaintenanceOU: Operable Unit OES: Optimized Exit Strategy PA/SI: Preliminary Assessment/Site Inspection PBR: Performance-Based Remediation PCB: Polychlorinated BiphenylsPCE: Perchloroethylene (tetrachloroethene) PMP: Performance Monitoring Plan PP: Proposed Plan PPB: Parts per billion PPBV: Parts per billion by volumePPM: Parts per millionPRB: Permeable Reactive Barrier PSVR: Performance Standard Verification Report QA/QC: Quality Assurance/Quality ControlRAB: Restoration Advisory Board RCRA: Resource Conservation and Recovery Act RA: Remedial ActionRC: Response Complete RD: Remedial DesignRfC: Reference ConcentrationRFP: Request for Proposal RI: Remedial Investigation RIP: Remedy in Place ROD: Record of Decision RPM: Remedial Project ManagerRSL: Regional Screening LevelSC: Site Closeout SRS: Source Recovery System SVE: Soil Vapor Extraction SVOC: Semi-volatile Organic CompoundTAG: Technical Assistance Grant TARS: Tooele Army Rail Shop TCA: TrichloroethaneTCE: TrichloroetheneTPH: Total Petroleum Hydrocarbons UDEQ: Utah Department of Environmental Quality UTTR: Utah Test and Training Range VI: Vapor Intrusion VOC: Volatile Organic CompoundVRS: Vapor Removal System ZVI: Zero-Valent Iron µg/L: Micrograms per liter

Item No. Action Item Requester Date Requested Action Taken Responsible

PartyTarget

Completion Date Status

2015-1

Request for information (cleanup site info, RAB schedule, RAB mtg material, etc.) easily accessible from web

Various RAB members

8/27/15 RAB Mtg

M. Loucks B. Fisher

D. Harris

10/29/2015 In progress

2015-2

Provide OU site summary spreadsheet at RAB mtgs

Various RAB members

8/27/15 RAB Mtg

C. Brown 10/29/2015 In progress

2015-3

Provide calendar w/upcoming meeting, training and tour dates

Various RAB members

8/27/15 RAB Mtg

C. Brown 10/29/2015 In progress

2015-4

Email or post RAB agendas in advance of RAB mtgs

B. Ekstrom 8/27/15 RAB Mtg

9/29: Emailed RAB members final agenda for Oct. 29 RAB meeting. Will continue for upcoming meetings.

C. Brown 10/1/2015 Complete

Hill Air Force Base 2015 RAB Action Items

Restoration Advisory Board CalendarOctober 2015

RAB Meetings 2015 Thursday, Oct. 29 Sunset City Building

2016 Thursday, Jan. 28 Sunset City Building Thursday, April 28 Sunset City Building

Thursday, July 28 Sunset City Building Thursday, Oct. 27 Sunset City Building

RAB Training Oct. 29 Pre-RAB Training Vapor Intrusion

Potential Future Trainings Cleanup Technologies – Pre-meeting Training

o Enhanced Reductive Dechlorination (ERD) o Zero-Valent Iron (ZVI)/Clay Soil Mixing o Bio-reactors

Geology/Hydrogeology

RAB Tours

Potential Future Tours Installation of OU-1 gravity drain at Trench D (Oct/Nov 2015) Annual Operable Unit Tour (Early Spring 2016) OU-2 ZVI Implementation (Spring 2016) OU-4 Bio-reactors (Spring/Summer 2016)

Project Managers Operable Unit/Site CommunityJarrod Case Operable Unit 9 Sunset/On-base

Britt Grunewald* Operable Unit 1 South Weber

Mark Loucks Operable Unit 3 On-baseOperable Unit 7 On-baseOperable Unit 8 Layton

Mark Roginske Vapor Intrusion Program (Operable Unit 15) Communities surrounding baseOperable Unit 12 RoyOperable Unti A Little Mountain Test Annex

Sharon Stone** Operable Unit 2 South WeberOperable Unit 14 (3 munitions sites) On-base

Ed Zuelke*** Operable Unit 4 South Weber and RiverdaleOperable Unit 5 Sunset and ClintonOperable Unit 6 RiverdaleOperable Unit 10 Sunset and ClearfieldOperable Unit 11 On-base

* Britt is located at Peterson AFB in Colorado Springs, CO** Sharon is located at Peterson AFB in Colorado Springs, CO*** Ed is located at Fairchild AFB, Spokane, WA

Current Hill AFB Restoration Project Team -- Staff Assignments

1

Air Force Civil Engineer CenterI n t e g r i t y - S e r v i c e - E x c e l l e n c e

1

Operable Unit 15 –Indoor Air Program Updates

Mark Roginske, P.E. – AFCEC/CZOM Hill SectionCorey Schwabenlander, P.G. – EA Team

October 29, 2015

I n t e g r i t y - S e r v i c e - E x c e l l e n c e 2

OU 15 – CERCLA Process

1992-2000LimitedSampling

2000Standard Methods

2004First Sampling Plan Finalized

2010, 2012Sampling Plan

Revisions

2015RI, Sampling

Plan Revision

2016FS, PP, ROD,

RD/RA Workplan

2003TCRA,

Start Basewide Air Sampling

Estimated Schedule for Final Docs:

Winter 2015/2016: RI Report

Spring 2016: FS Report (RAB)

Summer 2016: Proposed Plan

Fall 2016: ROD

Winter 2016: RD/RA Work Plan

Interim Remedy Final Remedy

2013Indoor Air Program

Designated as Operable Unit 15

ACRONYMSFS = Feasibility StudyPP = Proposed PlanRAB = Restoration Advisory BoardRD/RA = Remedial Design/Remedial ActionRI = Remedial InvestigationROD = Record of DecisionTCRA = Time-Critical Removal Action

2


Indoor Air Program Updates

Key Optimizations:

Contacting participants

Long-duration samples to address variability

Discontinue OU 10 (Clearfield) sampling (no VI found)

Criteria for graduating residences without VI



Contacting Participants

3


Contacting Participants

Residences that were sampled last year

Residences that are on a periodic monitoring schedule

Existing VRS

Detection in recent past

Identify and contact new residents in targeted areas where VI may be occurring

Notice posted to Hill AFB website (in progress)



Long-duration Samples

4



Challenge: Accounting for variability in indoor air contaminant concentrations over time

ASU Study House



New EPA VI Guidance (2015):

“..a longer collection period for each individual sample would be expected to yield a more reliable basis for estimating long-term, time-average exposure than would a one-day sample collection period.”

5



Long-duration samples provide better average exposure concentrations than 24-hour samples



Solution:

Deploy passive diffusion samplers for multi-day durations during the heating season

Several studies show reliability of samplers

6



How long of a sample duration?

To account for variability, the longer the better

Technology limitations

Current studies demonstrate reliability over a period of 14 days

Another study underway to test reliability up to 26 days (study complete in December)

30 days correlates well with some underlying assumptions in TCE toxicity values

Potential developmental effects over 24-26 day exposure period may be significant



Implementation

EPA and UDEQ have verbally approved the change in sampling methodology

Use long-duration samples in the upcoming 2015/2016 event

November thru mid-December

Homes with VRSs (~120)

14-day sample duration

Mid-December thru March

Homes without a VRS

Use 26-day duration if proof-of-technology test supports

Use 14-day duration if not

7



Communication

Change explained to residents during scheduling (response so far has been positive)

Fact sheet

Email (if possible)

Handed to residents during sampling

Posted to www.hill.af.mil


Decision making during 2015/2016 event:

VRS for detections above MAL (not indoor source)

Results to residents

Above MAL – within 10 days

Below MAL – 6-8 weeks

Same care taken to account for indoor sources

TBD: number of long-duration samples needed to graduate residents from the program


8



OU 10 Discontinued Sampling



Clinton Sunset

Clearfield

Sunset City Office

Hill AFB West Gate

Approximate Area Sampled

Main Street

9



Multiple lines of evidence demonstrate that VI is not occurring at OU 10

Groundwater samples

Soil gas samples

Indoor air samples



Clean water lens overlies OU 10 plumes

Layer of uncontaminated water at the water table that is a barrier to VI

Evidenced by multiple water table and soil gas samples over the plume

Precipitation

Infiltration

Clean Water Lens

VOC Groundwater Plume

Acts like a barrier to VI

10



12 years of indoor air monitoring 201 of 287 residences sampled (70%)

More than 700 samples collected

All MAL exceedances due to indoor sources

No VI detected in homes

Indoor source removed



Implementation

EPA and UDEQ to review supporting documentation

If they concur:

Graduate homes starting with the 2015/2016 sampling event

Call and send letters/fact sheets to residents explaining the change

If not:

Homes can still be added to the 2015/2016 sampling event

11



Graduating Homes Without VI



Indoor air dataset summary

More than 15 years of monitoring

2000 homes, more than 8500 samples

TCE not detected in 80% homes (1700)

More than 90% homes (1800) less than MAL for TCE

6% homes (120) have a VRS (not all were VI)

12



Based on existing data (24-hr samples)

Graduate homes with 4 consecutive non-detects collected during the heating season

Over 400 cases where there are 4 NDs followed by another heating season sample

Only 8 with detections

Only 1 of those 8 was attributed to VI and got a VRS

Not a significant risk (RI Report Risk Assessment)

Detection after 4 NDs possibly due to increase in groundwater concentration beneath residence

Continued plume evaluation to detect migration –homes added back if concentrations increase



Implementation and Communication

EPA and UDEQ to review supporting documentation

If they concur:

Graduate homes starting with the 2015/2016 sampling event

Call and send letters/fact sheets to residents explaining the change

If not:

Homes can still be added to the 2015/2016 sampling event

13


Questions?

RAB Breakout Session

Packet

Clearfield & Layton

Quarterly Operable Unit Update October 2015 RAB Breakout Session

Operable Unit 8 (Layton) Project Manager � Mark Loucks, (801) 777-6299

Site Status Record of Decision signed in 2005

Since Previous RAB (August 27, 2015)

Optimized the monitoring well sampling in the off-Base area o Used a computer program to determine which wells could be removed from the sampling

program while maintaining estimates of plume mass and area within 10%

Continued the Soil Vapor Extraction (SVE) treatability study to address a potential trichloroethene (TCE) source area in the on-base industrial area

o Initial 30-day test results showed successful removal of TCE from the subsurface o Based on the results, the test is being extended

Continued system optimization test of the Base Boundary Hydraulic Containment System �1 year test o Groundwater extraction was stopped from the two remaining operational wells in the East

System while the West System continued normal operation o The capture of the contaminant plumes by the West System is being evaluated o If the West System continues to successfully capture the groundwater contaminant plume at

the Base boundary, the East System will remain off

Next Six Months Complete SVE treatability study at on-base TCE source area Complete system optimization test of the Base Boundary Hydraulic Containment System

Schedule

Date ItemDec 2015 Conclude SVE treatability studyFeb 2016 Conclude BBHCS optimization study

Challenges None noted at this time

RAB Q&A None at this time Please notify Barbara Fisher, 75th Air Base Wing Public Affairs, at (801) 775-3652, or the project

manager listed above if you have a question that you would like addressed during the breakout session at the next RAB meeting. If you have a question between meetings, please contact Ms. Fisher or the project manager.


Operable Unit 10 (Clearfield/Sunset) Project Manager � Ed Zuelke, (509) 247-8152

Site Status Record of Decision signed in 2015 Remedy in place in 2015

Since Previous RAB (August 27, 2015) Record of Decision signed (September 2015) Completed construction of remedial action � targeted carbon substrate injections on and off-base for

PCE and shallow TCE plumes Interim-Remedial Action Completion Report finalized (September 2015) Continued groundwater sampling and soil gas sampling in treatment areas

Next Six Months Monitor progress of full-scale remedy

o Includes quarterly sampling of performance monitoring wells and monthly soil gas monitoring Optimization of the number of monitoring wells sampled annually

Schedule

Date ItemWinter 2016 Annual Remedial Action-Operation Report

Challenges None noted at this time.

RAB Q&A None at this time. Please notify Barbara Fisher, 75th Air Base Wing Public Affairs, at (801) 775-3652, or the project


Hill AFB


Operable Unit 11 (Hill AFB) Project Manager � Ed Zuelke, (509) 247-8152

Site Status Record of Decision signed in 2015 Remedy in place in 2015

Since Previous RAB (August 27, 2015) Completed construction and began operation of remedial system � soil vapor extraction at source area

and groundwater extraction system with treatment for the dissolved phase plume Interim-Remedial Action Completion Report finalized (September 2015) Routine groundwater sampling completed Routine removal of floating fuel from groundwater monitoring wells. Fuel-related contaminants are

lighter than water and will float allowing for removal.

Next Six Months Continue operation of the soil vapor extraction and groundwater extraction systems Monitor progress of remedy

Schedule


Challenges None at this time




Operable Unit 13 (Hill AFB) Project Manager � Mark Loucks, (801) 777-6299

Site Status Record of Decision completed in 2013. No additional remediation can be planned until the existing, older homes are demolished in about

2020.

Previous Year (July 2014 � July 2015)

Delineated PCB-contaminated soil beneath the roadways of Charlestown Loop, Charlestown Circle and Trenton Circle.

Final After Action Report submitted and approved by the US EPA and UDEQ.

Next Six Months Maintain land use controls over area No further efforts (until 2020 � see below).

Schedule

Date ItemApproximately 2020 Remove any remaining PCB-contaminated soil upon return

of property to Air Force control and demolition of the homes and road

Challenges Not able to coordinate any early PCB removal with recent road construction. However, road repairs

were completed without impacting any PCB�s. .




Operable Unit 14 (Hill AFB) Project Manager � Sharon Stone, 719-554-5819

Site Status Awaiting regulatory approval of Record of Decision and Remedial Action Work Plan

Since Previous RAB (August 27, 2015) Address regulatory comments on ROD Currently awaiting regulatory concurrence on responses to comments on Draft Remedial Action Work

Plan for BP504/BP504A.

Next Six Months Complete Record of Decision Compete Remedial Action Work Plan for site BP504/BP504A Mobilize for field work at OU14

Schedule

Date ItemNovember 2015 Final Record of DecisionNovember 2015 Final Remedial Action Work PlanApril 2016 Field Work MobilizationJune 2016 Field Work Completion

Challenges Final Record of Decision approval is delayed while EPA and Air Force deliberate on appropriate

language regarding potential munitions and explosives of concern should they be discovered during implementation of the remedy



Clinton, Sunset & Roy


Operable Unit 5 (Clinton/Sunset) Project Manager � Ed Zuelke, (509) 247-8152


Since Previous RAB (August 27, 2015) Routine groundwater sampling completed Routine operation of OU 5 Aeration Curtain Routine operation and maintenance of OU 5 Groundwater Extraction Trench Quarterly Treatability Study Performance Monitoring (October 2015)

Next Six Months Bioaugmentation of target treatment zone at off-Base TARS Quarterly Treatability Study Performance Monitoring Optimization of Remedial Action-Operations groundwater monitoring to limit life-cycle costs of

groundwater monitoring Zone 16 Treatability Study Technical Memorandum

ScheduleDate ItemFall 2015 Bioaugmentation of off-Base TARS target

treatment zone Fall 2015 Optimization of Remedial Action-Operations

Groundwater Monitoring Technical Memorandum Fall 2015 Zone 16 Treatability Study Technical MemorandumWinter 2015 Quarterly Treatability Study Performance

Monitoring





Operable Unit 9 (Sunset/Hill AFB) Project Manager � Jarrod Case, (801) 777-3943

Site Status Record of Decision � signed September 2015 Completed Site Closeout Letter for Pond 7 Area (Sep 2015) Achieved �remedy in place� at 800/900 area, 1100 area, and Golf Course area

Since Previous RAB (August 27, 2015) Routine groundwater sampling completed Completed second round of injections of carbon substrate at the 1100 Area (on Hill AFB near the West

Gate) as part of the full-scale treatment Completed construction of final remedy at the Golf Course Area

o Source area � Bioreactor � recirculation of contaminated groundwater through a carbon rich mulch to promote breakdown

o Groundwater plume � Carbon substrate injections

Next Six Months Conduct removal action at Pond 1 Area � stormwater retention pond on-base near south gate

o Remove contaminated sediment and restore pond Monitor progress of remedial actions Optimize the number of groundwater wells sampled annually

Schedule

Date ItemWinter 2015/2016 Pond 1 Removal Action Completion ReportWinter 2016 Annual Remedial Action-Operation Report





Operable Unit 12 (Roy) Project Manager � Mark Roginske, (801) 775-3651


Since Previous RAB (August 27, 2015) Routine groundwater sampling completed Continued routine operation and maintenance of the OU 12 Base Boundary Hydraulic Containment

System and Permeable Reactive Barrier (PRB) in Roy. Began Source Area Treatability Study Activities

o New injection wells installed. o Began carbon substrate injections. o Began soil vapor extraction system installation.

Next Six Months PRB Evaluation

o Prepare Explanation of Significant Difference to remove requirement for treatment at the PRB. o Monitor new monitoring wells to aid in the evaluation of in-place decommissioning options.

Source Area Treatability Study o Performance monitoring of carbon substrate injection. o Operation and maintenance of soil vapor extraction system.

Base Boundary Hydraulic Containment System o Evaluate and implement system optimizations to reduce power consumption and O&M costs.

Schedule

Date ItemFall 2015 Source Area Treatability Study Field ActivitiesWinter 2015/2016 Explanation of Significant Difference for PRB

Challenges None

RAB Q&A None at this time. Please notify Barbara Fisher, 75th Air Base Wing Public Affairs, (801) 775-3652 or the project manager

listed above if you have a question that you would like addressed during the breakout session at the next RAB meeting. If you have a question between meetings, please contact Ms. Fisher or the project manager.

Riverdale & South Weber


Operable Unit 1 (South Weber) Hill AFB Project Manager � Britt Grunewald, (719) 556-8060


Since Previous RAB (August 27, 2015) OU-1 Groundwater Extraction System Modifications � Purpose to reduce system power and O&M costs

o Began construction activities. OU-1 Hot Spot Treatment � Purpose to reduce contamination in non-source area dissolved phase

plume o Continue performance monitoring.

Explanation of Significant Differences (ESD) finalized in June 2015 to document results of the Supplemental Human Health Risk Assessment.

Next Six Months Continue operations and maintenance and routine monitoring. Continue Hot Spot Treatment and performance monitoring. Complete construction of groundwater extraction system/gravity drain modifications. Prepare Memo to the Site File to document groundwater extraction system modifications.

Schedule Date ItemFall 2015 Groundwater Extraction System ModificationsWinter 2016 Memo to the Site File � to document

modifications to the OU1 groundwater extraction system remedy

Challenges Changes in access to off-Base private property. Hill AFB had limited access to properties along the

steep hillside north and east of the source area to conduct the 2015 seeps and spring survey. This did not impact operations or maintenance of the extraction trench system.

RAB Q&A None at this time Please notify Barbara Fisher, 75th Air Base Wing Public Affairs, (801) 775-3652 or the project manager



Operable Unit 2 (South Weber) Project Manager � Sharon Stone, (719) 554-5819


Since Previous RAB (August 27, 2015) Routine groundwater, seep and spring sampling completed Routine operation and maintenance of all treatment systems

Next Six Months Treatability Study Work Plans will be developed, outlining plans to implement and evaluate zero valent

iron (ZVI)/clay soil mixing and Enhanced Reductive Dechlorination (ERD) technologies at this site. The purpose of this evaluation is to determine if these technologies will reduce the overall remedial timeframe for this site.

Schedule

Date ItemFall 2015 Development of Treatability Study Work PlansWinter 2016 Annual Remedial Action-Operation ReportSpring 2016 Field implementation of treatability studies

including ZVI/clay soil mixing, injection well installation and carbon-based substrate injection into groundwater for ERD


RAB Q&A None at this time Please notify Barbara Fisher, 75th Air Base Wing Public Affairs, (801) 775-3652, or the project manager



Operable Unit 4 (South Weber/Riverdale) Project Manager � Ed Zuelke, (509) 247-8152


Since Previous RAB (August 27, 2015) Routine operation and maintenance of the OU 4 Horizontal Drain Upgrade System Public Comment Period for Revised Proposed Plan

o Maintain current remedies o Install bioreactor within capped portion of Landfill 1 to treat ongoing TCE source o Shallow soil excavations and installation of soil vapor extraction systems at uncapped Landfill 1

and 2 o Install enhanced reductive dechlorination biobarriers on-Base to treat TCE-contaminated

groundwater Optimization of Remedial Action-Operations groundwater monitoring network Pre-Design Data Collection Letter Work Plan for remedial design

Next Six Months Pre-Design Data Collection Field Work Record of Decision Amendment Remedial Design/Remedial Action Work Plan

Schedule

Date ItemFall 2015 Record of Decision AmendmentFall 2015 Pre-Design Data Collection Field WorkWinter 2015/2016 Remedial Design/Remedial Action Work Plan





Operable Unit 6 (Riverdale) Project Manager � Ed Zuelke, (509) 247-8152

Site Status Record of Decision signed in 1997 Explanation of Significant Difference (ESD) signed in 2013 (allowing direct discharge to North Davis

Sewer District)

Since Previous RAB (August 27, 2015) Routine operation and maintenance of the OU 6 Groundwater Containment System off base Completed modifications to on-base system that added two additional extraction wells and changed the

discharge to the sanitary sewer.

Next Six Months Continue operation of the on-base and off-base groundwater treatment systems.

Schedule





1/5/2016

1

I n t e g r i t y - S e r v i c e - E x c e l l e n c e

Air Force Civil Engineer Center

Update Regarding OU 12 Permeable

Reactive Barrier

Mark Roginske – AFCEC/CZOM Hill Section Mike Reynolds – OU 12 Site Manager, EA Team

Jeremy Cox – Environmental Engineer, EA Team

October 2015

1


OU 12 – CERCLA Process

2008ROD

Signed

2016PRB ESD Approval

2003Source Area

Removal Actions

2010Source Area

Removal Actions

ACRONYMSBBHCS = Base Boundary Hydraulic Containment System RI = Remedial Investigation ESD = Explanation of Significant Differences ROD = Record of Decision PRB = Permeable Reactive Barrier

2006Proposed

Plan

2004PRB and BBHCS Installed

1998-2005Remedial

Investigation

2015Additional

Source Area Treatment

2

1/5/2016

2


OU 12 Overview • Remedy for TCE Plume

Performance of the Remedy• PRB Performance• Progress of MNA• OU 12 Model Update• Conclusions

Future of the PRB• Summary of Recent Testing • In-place Decommissioning

Introduction


Operable Unit 12Overview

4

1/5/2016

3


OU 12 Overview

Operable Unit 12 (OU 12) consists of TCE in groundwater in Roy.


Remedy for TCE Plume

(1) Extraction wells at the Base boundary

(2) Monitored natural attenuation (MNA) throughout plume• MNA: natural processes that reduce TCE

concentrations

• Includes biological or physical processes

(3) Restrictions on groundwater use

(4) Measures to address vapor intrusion• Indoor air sampling

• Mitigation systems when needed

1/5/2016

4


Remedy for TCE Plume

(5) A permeable reactive barrier (PRB) near the west end of plume

Conceptual representation of PRB operation

(A Citizen’s Guide to Permeable Reactive Barriers [EPA, Sept. 2012])


Performance of the Remedy

1/5/2016

5


PRB Performance

PRB was intended to reduce (not to completely prevent) further spread of contamination to currently unaffected residents in Roy

Iron in PRB affected by nitrate in groundwater

Nitrate not related to Hill AFB releases; may be due to fertilizer use off-Base


PRB Performance

Example of PRB treatment efficiency near center of PRB:

1/5/2016

6


Progress of MNA

Model created for OU 12 plume in 2007

Model is an estimate of how the plume might change over time• Incorporates groundwater flow rate, contaminant

concentrations, geology• Limited data available in 2007

However, MNA occurring much more quickly throughout the plume than predicted by the model


Progress of MNA

Predictions of the 2007 model: • Contaminated groundwater would continue to flow

into the PRB for decades • Downgradient plume would migrate westward for

decades, even with treatment at the PRB• Predicted plume in 2018:

1/5/2016

7


Progress of MNA

Predicted plume in 2018:

Actual plume in 2011:


OU 12 Model Update

Model updated in 2013–2014 • Groundwater data from 2004 through 2011 used to

calibrate the model

The revised model predicts TCE concentrations will decrease sooner than the old model• Better matches actual observations• Actual extent of plume expected to be less than

predicted.

1/5/2016

8


OU 12 Model Update

- - - Previous Model: Maximum Predicted Extent with PRB Operation

- - - Current Model: Maximum Predicted Extent (Worst Case)


OU 12 Model Update

Predictions of current model: • Maximum downgradient plume extent will occur

around 2015/2016 without treatment at PRB• Downgradient TCE plume will gradually shrink without

any treatment at the PRB

1/5/2016

9


Conclusions

PRB not operating as expected

MNA occurring faster than expected

PRB operation no longer required


Conclusions

The Air Force is preparing an Explanation of Significant Differences (ESD) to document:• Relying upon MNA to decrease TCE concentrations

in groundwater • Removing the ROD requirement for treatment at the

PRB

Draft in progress.

Expected to go to EPA and UDEQ this fall.

1/5/2016

10


Future of the PRB


Summary of Recent Testing

More samples collected to better understand TCE concentrations at PRB• Surface water• New shallow groundwater wells• Existing monitoring wells

1/5/2016

11





–2015

Surface Water:• Total of 12 samples collected from 3 locations in

2014–2015 (so far)

1/5/2016

12



Shallow Groundwater (4 to 6 feet below ground surface) upgradient of PRB:• Total of 11 samples collected from 10 locations in 2015



Deeper Groundwater (up to 36 feet below ground surface) upgradient of PRB:• Total of 13 samples collected from 13 locations so far

in 2015

1/5/2016

13


In-Place Decommissioning

In-place decommissioning being evaluated.

The Air Force is investigating means to improve the surface water drainage at the PRB• Surface water accumulated at the location of PRB

before construction; continues presently• In-place decommissioning may include steps to the

reduce the occurrence of surface water at the PRB



In-place decommissioning may include:• Leaving iron/sand mixture left in place without

modification• Enhancing/improving existing drainage features

near PRB • Adding soil to raise ground surface near the PRB

Expected to begin in 2016

Will solicit input from stakeholders and affected residents

1/5/2016

14


PRB

Existing Drainage

Piping

Possible Fill Area


27


Questions?

28

1


1

Accomplishments in FY 15

Mark D. LoucksChief Environmental Restoration AFCEC/CZOM Hill Section [email protected]


How does AF measure success

Records of Decision completed

Remedial Actions implemented

Sites where response is complete

Sites that were closed

Other accomplishments

Overview

2


Remedy In Place (RIP) -- Means Record of Decision is signed

All remedies are constructed and in operation

In FY 15 -- 5 sites have reached this Milestone

Response Complete (RC) -- Means All active remedial/cleanup actions have been completed

Only Land Use Controls and possibly GW monitoring continue

In FY 15 -- 1 site reached this Milestone

Site Closure (SC) -- Means Site has been remediated to residential risk standards

In FY 15 -- 4 sites reached this Milestone

How The AF Measures Success


OU11 Record of Decision

• Contamination is all on base

• Petroleum, TCE, MTBE

• Signed in August 2015

• Components of remedy• Institutional controls• Light Non Aqueous Phase Liquid

(LNAPL) removal (i.e. gasoline on the water table)

• Soil Vapor Extraction in source area• Ground water extraction from 4 wells• Monitored natural attenuation (MNA)

OU11

3



• Contamination on and off base• Contaminants-TCE, PCE, carbon tetrachloride• Signed September 2015

• Components of remedy• Institutional Controls for all sites• 1100 Area

• Contaminant - TCE• Enhanced bioremediation - Injections of

additives across much of site

• Golf Course• Contaminants - TCE and PCE• Limited excavation• Install mulch bioreactor • Enhanced bioremediation - Injections of

additives • Monitored Natural Attenuation

• 800/900 Area • Contaminant - carbon tetrachloride• Monitored Natural Attenuation

OU 9 multiple locations

1100 Area

Golf Course

Area

800/900 Area



• Contamination mostly off base• TCE and PCE• Signed September 2015

• Components of remedy• Institutional controls over entire

areaShallow Plume Area (TCE & PCE)• Enhanced bioremediation -

Injection of additives in high concentration areas

• Monitored natural attenuation

Deep Plume Area (TCE Only)• Monitored natural attenuation

OU10 West Gate Area

Deep Plume area

4


OUA Record of Decision (Little Mountain)

OUA

• Contaminants mostly on base, some off base

• Multiple solvents (TCE is main one)• Fuels in the Former Tank Farm Area• Signed September 2015

• Components of Remedy• Land Use Controls in each area • Sludge Drying Beds

• “Green” soil vapor extraction (Passive fans run by solar power)

• Monitored natural attenuation• North Disposal Area

• Monitored natural attenuation• Former Tank Farm Area

• Soil removal• Monitored natural attenuation

Sludge Drying Beds

Former Tank Farm Area

North Disposal Area


Remedy In Place (RIP)

OU11

OU9 Golf

Course

OU11• Groundwater extraction system

installation completed• Started operating in late Sep 15• SVE system installed prior to RODOU9 (Golf Course Area)• Removed contaminated soils• Installed mulch bioreactor • Installed injection points and

completed the injectionsOU9 (1100 Area)• Installed injection points • Completed a couple of rounds of

injectionsOU9 (800/900 Area)• Monitoring in placeOU10• Installed injection points and

completed the injections

OU91100 area

OU10

OU9 800/900

area

5


Response Complete (RC)(active remedial activities completed)

ST061 – fuel spill in tank farm area, under base housing area

• Removed all possible LNAPL at this site

• Only monitoring of land use controls remain

ST061


Sites Closed (SC) in FY 2015

Pond 7

Oil Water Separator

Oil Water Separator

= sites closed this fiscal year

= sites closed in previous years

ST 066

• Two Oil Water Separator sites• OW510 – Jan 2015• OW529 - July 2015

• Pond 7 - Sept 2015

• Underground Storage Tank • ST066 - Sept 2015

6


Other Accomplishments

OU6

OU8

OU6• Installed additional extraction wells on-base• Discharge to sanitary sewer for treatment

• Objective; reduce cleanup time

OU8• Installed system and began soil vapor

extraction in significant source area• Objective; remove source area contamination

Military Munitions Response Program• Completed RI/FS and Proposed Plan at

• SR502, DA503 and BP504

OUs 5 and 12• Installed injection points and completed the

injections • Objective; reduce cleanup time frames

• At OU12 installed and started soil vapor extraction system

• Objective; remove source area contamination

BP504

DA502

SR502

OU12

OU5


4 Records of Decision signed (overall 6 sites)

5 sites have reached Remedy In Place (RIP)

1 site reached Response Complete (RC)

4 sites reached Site Closure (SC)

Plus a whole bunch of other stuff completed many will reduce cleanup time frames

Recap

7


Questions?

13

1


1

Jarrod Case, P.E.AFCEC/CZOM Hill Section

October 29, 2015

Vapor Intrusion: Overview


Outline

What is Vapor Intrusion? And why is it important?

Why does it happen?

Testing for Vapor Intrusion

Fixing Vapor Intrusion

2


What is Vapor Intrusion?

“Vapor intrusion is the general term given to migration of hazardous vapors from any subsurface contaminant source, such as contaminated soil or groundwater or contaminated conduit(s), into an overlying building…via any opening or conduit.”*

Why is Vapor Intrusion Important?“Vapor intrusion is a potential human exposure pathway -- a way that people may come into contact with hazardous vapors while performing their day-to-day indoor activities.”*

* U.S. EPA, 2015. OSWER Technical Guide For Assessing And Mitigating The Vapor Intrusion Pathway

From Subsurface Vapor Sources To Indoor Air. OSWER Publication 9200.2-154. June 2015.


Why Does Vapor Intrusion Happen?

Like water, air moves through soil, following the path of least resistance

Vapor-forming chemicals (evaporate easily)

Unlike water, air (vapors) can move both up and down

Differences in pressure (moves from high to low)

3




Vapor-forming chemicals (evaporates easily)









4



Like water, air moves through soil following the path of least resistance




Difference in concentration (moves from high to low)



“All types of buildings, regardless of foundation type (e.g., basement, crawl space, slab-on-grade), have openings that render them potentially vulnerable to vapor intrusion.”*

Some examples include:

Cracks or holes

Expansion joints

Utility piping (conduits)

Sumps

* U.S. EPA, 2015. OSWER Technical Guide For Assessing And Mitigating The Vapor Intrusion Pathway From Subsurface Vapor Sources To Indoor Air. OSWER Publication 9200.2-154. June 2015.

5


Testing for Vapor Intrusion

Summa® canisters

Evacuated, stainless steel

Draws in air over time (e.g. 24 hr)

Sorbent tubes

Glass or metal tube containing sorbent material

Active (i.e. pumped air) or passive

*Note - Sampling indoor air doesn’t distinguish between sources.


Indoor Sources

Homes have numerous sources of indoor air contaminants. Examples:

Chemicals

Building materials

Home furnishings/décor

Attached garages/storage areas also contribute

Detection levels for sampling are very low

Need to determine where detections are coming from

6


Fixing Vapor Intrusion

Pre-emptive:

Sealants/vapor barriers

Sub-slab venting (passive)

Post-construction:

Sub-slab venting (active) – fan pulls vapors out from beneath slab(Sub-membrane venting for dirt crawl spaces)

Remove the source

Cleanup soil/groundwater


Questions?

Hill Air Force Base Restoration Advisory · PDF fileHill Air Force Base Restoration Advisory Board Meeting Minutes Oct. 29, 2015 ... Ms. Grunewald said all cleanup documents from the

Documents