2009_Post_Closure_Plan_Final.pdf

Prepared for:

366 CES/CEAN

Mountain Home Air Force Base Mountain Home, Idaho

FINAL

Municipal Solid Waste Landfill Post-Closure Plan

Contract No. QYZH 02-5682AA

April 2009

Hamilton Builders Inc.

Sunrise Engineering Inc.

1650 South Topaz Way

Meridian, Idaho 83642

Hamilton Builders Inc.

5751 Fortress Court

Boise, Idaho 83703

MOUNTAIN HOME AIR FORCE BASE

FINAL

MUNICIPAL SOLID WASTE LANDFILL

POST-CLOSURE PLAN

CONTRACT NO.: QYZH 02-5682AA

April 2009

Project Number: 0208-01-03

Prepared For:

CES/CEAN

1100 Liberator Street, Bldg 1297

Mountain Home Air Force Base, Idaho

Mountain Home AFB i 8/18/2009

Table of Contents Title Page

1 INTRODUCTION ............................................................................................................................. 1-1

1.1 Location Description .................................................................................................................. 1-1

1.2 Objective ..................................................................................................................................... 1-1

2 SCHEDULE ....................................................................................................................................... 2-1

2.1 Post-Closure Care Requirements of 40 CFR §258.61: ............................................................... 2-1

3 FINAL LAND USE ........................................................................................................................... 3-1

3.1 Access ......................................................................................................................................... 3-1

3.2 Signage and Security .................................................................................................................. 3-1

3.3 Future Use .................................................................................................................................. 3-1

4 ROUTINE MONITORING .............................................................................................................. 4-1

4.1 Inspection and Maintenance ....................................................................................................... 4-1

4.1.1 Cover System ..................................................................................................................... 4-1

4.1.2 Leachate Collection System ............................................................................................... 4-2

4.1.3 GW Monitoring .................................................................................................................. 4-2

4.1.3.1 Exemption Demonstration from Groundwater Monitoring Feb 1996 ................... 4-2

4.1.3.2 Base-wide Long-Term Monitoring ........................................................................ 4-2

4.1.4 Landfill Gas Monitoring .................................................................................................... 4-3

5 POST-CLOSURE CERTIFICATION ............................................................................................ 5-1

6 POST-CLOSURE COSTS ................................................................................................................ 6-1

6.1 Financial Assurance for Closure, Post-Closure Care and Corrective Action ............................. 6-1

REFERENCES .......................................................................................................................................... R-1

APPENDICES

A VICINITY MAP

B SITE LOCATION MAP

C CDHD CLOSURE INSPECTION APPROVAL/SITE PHOTOS

D MSWLF SITE INSPECTION FORM

TABLES

2-1 MSWLF 30-YEAR SCHEDULE OF POST-CLOSURE ACTIVITIES

3-1 POST-CLOSURE CARE POC AND EMERGENCY CONTACT LIST

Page 1-1 8/18/2009

1 INTRODUCTION

1.1 Location Description

The Mountain Home Air Force Base (“MHAFB”) occupies approximately 5,800 acres and is located in Elmore County; approximately 40 miles southeast of Boise, Idaho

(see Appendix A – Vicinity Map). Operations began in 1943 and remained active until the end of WWII. From 1945 through 1953, MHAFB was only intermittently active;

however, it has been continuously active since 1953.

The Municipal Solid Waste Landfill (“MSWLF”) occupies approximately 105 acres at the southeast corner of the base (see Appendix B – Plan Set). It is the third landfill that has been operated by MHAFB with operations beginning in 1969. In 2009 the

MSWLF was formally closed (see Appendix C – Final Closure Notice). Post-closure inspection(s) and care will be completed in 2039. Until formal closure, the MSWLF was open to base residents only and excluded the general public. The MSWLF received an estimated 3,816 tons of waste per year (qualifying it for the small community exemption). The landfill site also has cells that contain asbestos, composting, and non-municipal solid waste (construction and demolition debris). (JJ

Howard Engineering, p.1)

Previously active cells are lower than the surrounding grade; no surface water runs off from the cells to the surrounding land. In addition, all closed cells have no surface drainage or runoff from the active landfill area. Waste unloading was performed within the contained areas of the active pits. There are no liners or leachate collection systems at the landfill. Due to the arid climate, very little leachate has been produced.

Heavy equipment used at the landfill is stored and maintained in a storage shed near the landfill office.

1.2 Objective

The post-closure care period begins with completion of all closure activities. Post-closure care requirements specified in 40 CFR §258.61 and Idaho Code 39-7416

Page 1-2 8/18/2009 require the owner or operator of all MSWLF units to prepare a written post-closure plan. MHAFB is responsible for all post-closure activities on the site. Idaho Code references the federal standards for post-closure care without modification. The purpose of this post-closure plan is to comply with these regulations.

This plan documents the activities that will occur during the 30-year post-closure care period at three MSWLF cells closed in 1995, 1998, and 2003; and the two MSWLF cells closed in 2009 (see Appendix B). The Construction & Demolition Waste Cell and the Asbestos Cell were also closed in 2009 and are documented on the plan. This post-closure plan is organized into the following sections:

Schedule

Final Land Use

Routine Monitoring

Post-Closure Certification

Post-Closure Costs

Page 2-1 8/18/2009

2 SCHEDULE

2.1 Post-Closure Care Requirements of 40 CFR §258.61:

Following closure of each MSWLF unit, the owner or operator must conduct post-closure care. Post-closure care must be conducted for 30 years and consist of at least the following:

1) Maintaining the integrity and effectiveness of any final cover, including making repairs to the cover as necessary to correct the effects of settlement, subsidence, erosion, or other events, and preventing run-on and run-off from eroding or otherwise damaging the final cover;

2) Maintaining and operating the leachate collection system in accordance with the requirements in §258.40, if applicable. The Director of an approved State may allow the owner or operator to stop managing leachate if the owner or operator demonstrates that leachate no longer poses a threat to human health and the environment;

3) Monitoring the ground water in accordance with the requirements of Subpart E and maintaining the groundwater monitoring system, if applicable; and

4) Maintaining and operating the gas monitoring system in accordance with the requirements of §258.23.

The small landfill exemption status of the municipal landfill exempts the Mountain

Home Air Force Base (MHAFB) from the requirements for a leachate collection system, and a groundwater monitoring system.

The State Director can reduce the length of the post-closure care period if the owner or operator demonstrates there would be no adverse impact to human health and the environment. Conversely, the post-closure care period can be increased if the State

Page 2-2 8/18/2009

Director determines that the lengthened period is necessary to protect human health and the environment.

In accordance with 40 CFR 258.61(b)(1), MHAFB would like to revisit the post-closure care period in 5 years. MHAFB will request the CDHD to evaluate the quarterly methane monitoring data collected to determine if post-closure care of the landfill should be continued if it is demonstrated that there has been no adverse impacts to human health and the environment.

Following completion of the post-closure care period for each MSWLF unit, the owner or operator must notify the State Director that a certification, signed by an independent registered professional engineer or approved by the Director of an approved State, verifying that post-closure care has been completed in accordance with the post-closure plan, has been placed in the operating record.

Table 2-1 demonstrates the 30-year post-closure care period schedule for each of the

MSWLF cells that have been closed.

Page 3-1 8/18/2009

3 FINAL LAND USE

3.1 Access

Residents of the base no longer have access to the MHAFB landfill. Access to the

MHAFB MSWLF will be controlled to prevent damage to the final cover. Access to the front entrance of the landfill has a gate to inhibit access. The entire landfill is also encompassed within the larger Base perimeter fence, which is patrolled by Base

Security on a 24 hour – 7 day rotation.

3.2 Signage and Security

A well-maintained, conspicuous sign identifies the point of access to the solid waste facility. The sign offers the following information:

Facility name

Emergency phone numbers.

MHAFB will be responsible for maintaining the site security system throughout the closure and post-closure period. Table 3-1 lists the POC and emergency phone directory for the facility.

3.3 Future Use

The MHAFB and MSWLF will continue to be fenced and will not be actively used after closure. The area will be returned to a natural setting, planted to native vegetation similar to the surrounding environment. Perimeter fencing will remain to discourage the use of the area and disruption of the final cap.

Table3-1 Post-Closure Care Point-of Contact Listing and Emergency Directory

Title Address Phone Solid Waste Program Manager

366 CES/CEAN

1100 Liberator ST, Bldg 1297

Mtn Home A.F. Base, ID

(208) 828-1853

Operations Flight Commander

366 CES/CEO

1030 Liberator ST, Bldg 1300

Mtn Home A.F. Base, ID

(208) 828-6501

Central District Heath Department 520 E. 8 th

St. North

Mountain Home, ID 83647

(208) 587-9225

Idaho Department of Environmental Quality

Boise Regional Office

1445 N. Orchard

Boise, ID

(208) 373-0550

Idaho Department of Environmental Quality Solid

Waste Program Coordinator

1410 N. Hilton

Boise, Idaho

(208) 979-0416

Page 4-1 8/18/2009

4 ROUTINE MONITORING

4.1 Inspection and Maintenance

Inspections by MHAFB personnel will be conducted on a semiannual basis (biannual inspection) for the first year of post-closure care, and annually thereafter for the 30-year period. Inspections by the Central District Health Department (“CDHD”) will occur as requested, or as provided by law. Records of inspections detailing observations will be kept in a log book so that changes in any of the MSWLF cells can be monitored; in addition, records will be kept detailing changes in post-closure care personnel to ensure that changing personnel will not affect post-closure care due to lack of knowledge of routine activities. The inspection forms that will be used can be found in Appendix D and will serve to guide the inspections of the area.

The condition of the facility will be documented with notes, maps and photographs.

Monitoring of the landfill will include an examination of access, signage, surface water controls, concrete structures, final cover integrity, vectors and gas emissions.

Maintenance activities will be implemented as needed to remedy potential or real problem situations identified during routine inspections.

4.1.1 Cover System

Inspections will be performed and documented by MHAFB personnel and will include an overall assessment of the closed portion and specific evaluation of needed repairs, erosion or damage. Inspection of the final cover will be performed on the ground and through aerial photography, if available. The inspection will include a record of eroded banks, patches of dead vegetation, animal burrows, uneven settlement, erosion related to storm water, subsidence, and cracks along the final cover cap.

MHAFB is responsible for any reconstruction, notification and placement of documentation that may be required. Should reconstruction be required, work must begin within sixty (60) days and include notice of completion to, and

Page 4-2 8/18/2009 approval by, the CDHD and MHAFB. All documentation resulting from any construction activity shall be placed in the operating record.

4.1.2 Leachate Collection System

The MHAFB MSWLF does not have a bottom liner system or a leachate collection system. Therefore, no leachate management or system operational requirements are necessary during the post-closure care period.

4.1.3 Ground Water Monitoring

The MHAFB MSWLF is exempt from the 40 CFR §258 Subpart E requirements to conduct groundwater monitoring.

Data has been collected over several years at different landfill sites. The following are monitoring events that have occurred:

4.1.3.1 Exemption Demonstration from Groundwater Monitoring, February 1996

This demonstration concluded that groundwater monitoring is not appropriate for the MSWLF. The Base MSWLF is located in a semi-arid region that receives less than 10 inches of precipitation annually. Fate and transport modeling done using site-specific data indicate that vadose transit-times for any hazardous chemicals that may be leached from the Base MSWLF will exceed the operational life of the facility plus the 30-year post-closure care period. For a conservative transport scenario for a mobile VOC, the vadose transit-time is estimated to be about 150 years. (Woodward-Clyde,

p. 4-1).

Because of the types of waste that the MSWLF receives, it is not expected to have an adverse impact on regional groundwater at any time. There has been no indication of degradation of groundwater for future use.

Page 4-3 8/18/2009

4.1.3.2 Base-wide Long Term Monitoring

May 2, 1994 letter from DEQ indicated the following:

“We would like to point out that tricholoroethylene (TCE) contamination has been detected within the general limits of the

Mountain Home Air Force Base documentation appears to indicate that no detection of this contamination was found within monitor well No. 17 (MW17) which is located to the south and down gradient of the MSWLF. We recommend that continued monitoring of this well be performed until such time that you have an approved groundwater monitoring plan.”

The groundwater LTM program at the Base began in May 1996 and consists of sampling groundwater from selected wells. Monitoring well No. 17 (MW17) is a 4-inch diameter monitoring well installed to a depth of 387 feet bgs. The well was installed in the late 1980s to early 1990s. Between May 1996 and April 2000, the well was successfully sampled eight times for volatile organic compounds

(VOCs) by Method SW8260 with TCE not detected above the method detection limit of 0.5 µg/L (Foothill, p. 9-8).

4.1.4 Landfill Gas Monitoring

MHAFB has an established program of quarterly monitoring at and around the landfill facilities for methane. Operating and testing standards and equipment meet or exceed all applicable industry standards and are performed in a workmanship-like manner. Testing is performed at the landfill structures and boundaries. The results obtained during each quarterly monitoring event, along with documentation indicating the areas sampled, are entered into a designated section of the daily operating record for the facility.

Page 4-4 8/18/2009

MHAFB has not, however, installed the type of landfill gas monitoring system that is required by 40 CFR §258.23. The small landfill exemption status of the

MSWLF exempts the MHAFB from this requirement.

Page 5-1 8/18/2009

5 POST-CLOSURE CERTIFICATION

Following completion of the post-closure care period, the State Director will be notified that an independent registered professional engineer has verified and certified that post-closure care has been completed in accordance with the post-closure plan and that this certification has been placed in the operating record. Certification of post-closure care will be submitted for each MSWLF cell.

Page 6-1 8/18/2009

6 POST-CLOSURE COSTS

6.1 Financial Assurance for Closure, Post-Closure Care and

Corrective Action

39-7417, Idaho Code:

1. Applicability. These requirements shall apply to new MSWLF units, existing

MSWLF units and lateral expansion except as exempted in 40 CFR §258.1(d) and §258.70(a).

2. The requirements of this section are effective October 9, 2008, or at such later date upon subsequent amendment of 40 CFR §258.70. Note: As of this date, the requirements of this section are effective October 9, 1995.

40 CFR §258.70. Applicability and Effective Date:

1. The requirements of this section apply to owners and operators of all MSWLF units, except owners or operators who are State or Federal government entities whose debts and liabilities are the debts and liabilities of a State or the United

States.

MHAFB is exempted under §258.70(a) as a State or Federal entity whose debts and liabilities are those of the U.S. Government.

Page R-1 8/18/2009

REFERENCES

Bionomics Environmental, Inc. Municipal Solid Waste Landfill Post Closure Plan. August 2003.

Code of Federal Regulations. Title 258. Subpart F. Landfill Closure and Post Closure.

Foothill Engineering Consultants, Inc. Final Five-Year Remedy Review Report, Mountain Home

Air Force Base, Idaho. March 2001.

Idaho Administrative Procedures Act, IDAPA 58, Title 01, Chapter 06. Solid Waste Management

Rules.

Idaho Code. Title 39. Chapter 74. Idaho Solid Waste Facilities Act.

J.J. Howard Engineering, Inc. Mountain Home Air Force Base Municipal Solid Waste Landfill –

Standard for Operation, Closure Plan and Post-Closure Care. March 27, 1997.

RMC Consultants, Inc. Technical Memorandum, Groundwater and Vapor Sampling Results.

April 2003.

Woodward-Clyde. Solid Waste Management Mountain Home Air Force Base 366 th

Wing –

Exemption Demonstration for Groundwater Monitoring. February 21, 1996.

ID Task Name Start Finish 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2026 2027 2028 2029 2030 2031 2032 2033 2034 2035 2036 2037 2038 2039 2040 165 MSWLF 2009 Landfill Cell #1 Tues 3/9/2009 Tues 3/8/2039

166 Official Closure Approval Tues 3/9/2009 Tues 3/9/2009

167 Post-Closure Care Period Tues 3/9/2009 Tues 3/8/2039

168 Bi-Annual Inspection 1, Year 1 Tues 3/9/2009 Wed 9/9/2009

169 Bi-Annual Inspection 2, Year 1 Tues 3/9/2010 Thurs 9/9/2010

170 Annual Inspections Year 2-30 Wed 3/9/2011 Tues 3/8/2039

171 Topographic Survey Year 12 Mon 2/7/2020 Mon 2/7/2020

172 Topographic Survey Year 17 Mon 2/7/2025 Mon 2/7/2025

173 Topographic Survey Year 22 Mon 2/8/2030 Mon 2/8/2030

174 Topographic Survey Year 27 Mon 2/9/2035 Mon 2/9/2035

175 Final Closure Certification Wed 3/9/2039 Wed 3/9/2039

176 MSWLF 2009 Landfill Cell #2 Tues 3/9/2009 Tues 3/8/2039

177 Official Closure Approval Tues 3/9/2009 Tues 3/9/2009

178 Post-Closure Care Period Tues 3/9/2009 Tues 3/8/2039

179 Bi Annual Inspection 1, Year 1 Tues 3/9/2009 Wed 9/9/2009

180 Bi-Annual Inspection 2, Year 1 Tues 3/9/2010 Thurs 9/9/2010

181 Annual Inspections Year 2-30 Wed 3/9/2011 Tues 3/8/2039

182 Topographic Survey Year 12 Mon 2/7/2020 Mon 2/7/2020

183 Topographic Survey Year 17 Mon 2/7/2025 Mon 2/7/2025

184 Topographic Survey Year 22 Mon 2/8/2030 Mon 2/8/2030

185 Topographic Survey Year 27 Mon 2/9/2035 Mon 2/9/2035

186 Final Closure Certification Wed 3/9/2039 Wed 3/9/2039

187 Asbestos Landfill Cell Tues 3/9/2009 Tues 3/8/2039

188 Official Closure Approval Tues 3/9/2009 Tues 3/9/2009

189 Post-Closure Care Period Tues 3/9/2009 Tues 3/8/2039

190 Bi Annual Inspection 1, Year 1 Tues 3/9/2009 Wed 9/9/2009

191 Bi-Annual Inspection 2, Year 1 Tues 3/9/2010 Thurs 9/9/2010

192 Annual Inspections Year 2-30 Wed 3/9/2011 Tues 3/8/2039

193 Topographic Survey Year 12 Mon 2/7/2020 Mon 2/7/2020

194 Topographic Survey Year 17 Mon 2/7/2025 Mon 2/7/2025

195 Topographic Survey Year 22 Mon 2/8/2030 Mon 2/8/2030

196 Topographic Survey Year 27 Mon 2/9/2035 Mon 2/9/2035

197 Final Closure Certification Wed 3/9/2039 Wed 3/9/2039

198 Construction and Demolistion Waste Landfill Cell Tues 3/9/2009 Tues 3/8/2039

199 Official Closure Approval Tues 3/9/2009 Tues 3/9/2009

200 Post-Closure Care Period Tues 3/9/2009 Tues 3/8/2039

201 Bi Annual Inspection 1, Year 1 Tues 3/9/2009 Wed 9/9/2009

202 Bi-Annual Inspection 2, Year 1 Tues 3/9/2010 Thurs 9/9/2010

203 Annual Inspections Year 2-30 Wed 3/9/2011 Tues 3/8/2039

204 Topographic Survey Year 12 Mon 2/7/2020 Mon 2/7/2020

205 Topographic Survey Year 17 Mon 2/7/2025 Mon 2/7/2025

206 Topographic Survey Year 22 Mon 2/8/2030 Mon 2/8/2030

207 Topographic Survey Year 27 Mon 2/9/2035 Mon 2/9/2035

208 Final Closure Certification Wed 3/9/2039 Wed 3/9/2039

198 MSWLF 2003 Landfill Cell Tues 3/9/2009 Tues 3/8/2039

199 Official Closure Approval Tues 3/9/2009 Tues 3/9/2009

200 Post-Closure Care Period Tues 3/9/2009 Tues 3/8/2039

201 Bi Annual Inspection 1, Year 1 Tues 3/9/2009 Wed 9/9/2009

202 Bi-Annual Inspection 2, Year 1 Tues 3/9/2010 Thurs 9/9/2010

203 Annual Inspections Year 2-30 Wed 3/9/2011 Tues 3/8/2039

204 Topographic Survey Year 12 Mon 2/7/2020 Mon 2/7/2020

205 Topographic Survey Year 17 Mon 2/7/2025 Mon 2/7/2025

206 Topographic Survey Year 22 Mon 2/8/2030 Mon 2/8/2030

207 Topographic Survey Year 27 Mon 2/9/2035 Mon 2/9/2035

208 Final Closure Certification Wed 3/9/2039 Wed 3/9/2039

187 MSWLF 1998 Landfill Cell Tues 3/9/2009 Tues 3/8/2039

188 Official Closure Approval Tues 3/9/2009 Tues 3/9/2009

189 Post-Closure Care Period Tues 3/9/2009 Tues 3/8/2039

190 Bi Annual Inspection 1, Year 1 Tues 3/9/2009 Wed 9/9/2009

191 Bi-Annual Inspection 2, Year 1 Tues 3/9/2010 Thurs 9/9/2010

192 Annual Inspections Year 2-30 Wed 3/9/2011 Tues 3/8/2039

193 Topographic Survey Year 12 Mon 2/7/2020 Mon 2/7/2020

194 Topographic Survey Year 17 Mon 2/7/2025 Mon 2/7/2025

195 Topographic Survey Year 22 Mon 2/8/2030 Mon 2/8/2030

196 Topographic Survey Year 27 Mon 2/9/2035 Mon 2/9/2035

197 Final Closure Certification Wed 3/9/2039 Wed 3/9/2039

187 MSWFL 1995 Landfill Cell Tues 3/9/2009 Tues 3/8/2039

188 Official Closure Approval Tues 3/9/2009 Tues 3/9/2009

189 Post-Closure Care Period Tues 3/9/2009 Tues 3/8/2039

190 Bi Annual Inspection 1, Year 1 Tues 3/9/2009 Wed 9/9/2009

191 Bi-Annual Inspection 2, Year 1 Tues 3/9/2010 Thurs 9/9/2010

192 Annual Inspections Year 2-30 Wed 3/9/2011 Tues 3/8/2039

193 Topographic Survey Year 12 Mon 2/7/2020 Mon 2/7/2020

194 Topographic Survey Year 17 Mon 2/7/2025 Mon 2/7/2025

195 Topographic Survey Year 22 Mon 2/8/2030 Mon 2/8/2030

196 Topographic Survey Year 27 Mon 2/9/2035 Mon 2/9/2035

197 Final Closure Certification Wed 3/9/2039 Wed 3/9/2039

Acronyms