Federal Register / Vol. 77, No. 49 / Tuesday, March 13, 2012 / Proposed Rules 14717 

NAEMS began in the summer of 2007 

and consisted of 24 monitoring sites 

located in nine states. In addition, 

Tyson Foods, Inc. collected data from 

two broiler sites, which are also 

included in the NAEMS dataset. 

Academic researchers from various 

universities conducted the NAEMS 

study with EPA oversight. At the animal 

confinement sites, the study was 

designed to collect process and 

emissions data for ammonia (NH3), 

hydrogen sulfide (H2S), total suspended 

particulate matter (TSP), particulate 

matter with aerodynamic diameters less 

than 10 micrometers (PM10), PM with 

aerodynamic diameters less than 2.5 

micrometers (PM2.5), and volatile 

organic compounds (VOCs). For lagoons 

and basins, the study was designed to 

collect NH3, H2S and VOCs. 

In accordance with the Agreement’s 

monitoring protocol, the EPA developed 

draft EEMs for animal housing 

structures and manure storage and 

treatment units using the emissions and 

process data collected under the 

NAEMS and other relevant information. 

Once the draft EEMs are final, the EPA 

expects that the AFO industry will use 

the EEMs to estimate daily and annual 

emissions for use in determining AFOs’ 

regulatory responsibilities under the 

Clean Air Act, the Comprehensive 

Environmental Response, Compensation 

and Liability Act, and the Emergency 

Planning and Community Right-toKnow Act. 

The draft documents describe the 

sites monitored, the statistical 

methodology used to analyze the data, 

and the EEMs. 

The agency is requesting comment on 

the draft documents with particular 

emphasis on the statistical methodology 

used to develop the emissions 

estimating methodologies. Please submit 

comments within 90 days of the date of 

this notice. Electronic copies of the 

documents are available at 

www.epa.gov/airquality/agmonitoring. 

On February 17, 2012, EPA’s Office of 

Air Quality Planning and Standards sent 

a memorandum to the EPA Science 

Advisory Board Staff Office titled, 

‘‘Animal Feeding Operations Air 

Emissions Estimating Methodologies 

from the National Air Emissions 

Monitoring Study’’ asking the Science 

Advisory Board to review and provide 

comments on these documents. 

In response to EPA’s memorandum, 

the EPA’s Science Advisory Board has 

formed an expert panel to review and 

provide comments on these documents. 

The Science Advisory Board review 

process is an independent process. 

Information on submitting comments to 

the Science Advisory Board can be 

found at www.epa.gov/sab. Additional 

information about the Science Advisory 

Board process can be found at: http:// 

yosemite.epa.gov/sab/sabproduct.nsf/0/ 

ae6639dd6b79360e852579a4004e5529

!OpenDocument. The Science Advisory 

Board anticipates multiple meetings of 

the expert panel to cover the documents 

in this notice. 

The EPA will consider public 

comments received in response to this 

notice, public comments submitted to 

the Science Advisory Board, and the 

Science Advisory Board panel 

recommendations as the final emissions 

estimating methodologies are 

developed. 

Dated: February 29, 2012. 

Janet McCabe, 

Acting Assistant Administrator. 

[FR Doc. 2012–5550 Filed 3–12–12; 8:45 am] 

BILLING CODE 6560–50–P 

ENVIRONMENTAL PROTECTION 

AGENCY 

40 CFR Part 300 

[EPA–HQ–SFUND–1990–0011; FRL–9646–1] 

National Oil and Hazardous 

Substances Pollution Contingency 

Plan; National Priorities List: Partial 

Deletion of the Ellsworth Air Force 

Base Superfund Site 

AGENCY: Environmental Protection 

Agency. 

ACTION: Proposed rule; notice of intent. 

SUMMARY: The Environmental Protection 

Agency (EPA) Region 8 is issuing a 

Notice of Intent to Delete Operable Unit 

(OU) 1 the former Fire Protection 

Training Area (FPTA), along with two 

other Areas of Concern (AOC): The 

Gateway Lake Ash Study Area and the 

Pride Hangar Study Area of the 

Ellsworth Air Force Base (AFB) 

Superfund Site located in Meade and 

Pennington Counties, South Dakota, 

from the National Priorities List (NPL) 

and requests public comments on this 

proposed action. The NPL, promulgated 

pursuant to section 105 of the 

Comprehensive Environmental 

Response, Compensation, and Liability 

Act (CERCLA) of 1980, as amended, is 

an appendix of the National Oil and 

Hazardous Substances Pollution 

Contingency Plan (NCP). The EPA and 

the State of South Dakota, through the 

Department of Environment and Natural 

Resources, have determined that all 

appropriate response actions at these 

identified parcels under CERCLA other 

than five year reviews have been 

completed. However, this deletion does 

not preclude future actions under 

Superfund. 

This partial deletion pertains to the 

surface soil, unsaturated subsurface soil, 

surface water and sediments of Operable 

Unit (OU) 1, the Gateway Lake Ash 

Study Area, and the Pride Hangar Study 

Area. The groundwater medium 

associated with OU–11, Basewide 

Groundwater, will remain on the NPL 

and is not being considered for deletion 

as part of this action. The other OUs 

associated with Ellsworth AFB were 

deleted in 2006. 

DATES: Comments must be received by 

April 12, 2012. 

ADDRESSES: Submit your comments, 

identified by Docket ID No. EPA–HQ– 

SFUND–1990–0011, by one of the 

following methods: 

• http://www.regulations.gov. Follow 

on-line instructions for submitting 

comments. 

•

Email: dalton.john@epamail.epa.gov. 

• Fax: 303–312–6961. 

• Mail: Mr. John Dalton, Community 

Involvement Coordinator (8OC), U.S. 

EPA, Region 8, 1595 Wynkoop St., 

Denver, CO 80202. 

• Hand delivery: 1595 Wynkoop St., 

Denver, CO 80202. Such deliveries are 

only accepted during the Docket’s 

normal hours of operation, and special 

arrangements should be made for 

deliveries of boxed information. 

Instructions: Direct your comments to 

Docket ID No. EPA–HQ–SFUND–1990– 

0011. EPA’s policy is that all comments 

received will be included in the public 

docket without change and may be 

made available online at http:// 

www.regulations.gov, including any 

personal information provided, unless 

the comment includes information 

claimed to be Confidential Business 

Information (CBI) or other information 

whose disclosure is restricted by statute. 

Do not submit information that you 

consider to be CBI or otherwise 

protected through http:// 

www.regulations.gov or email. The 

http://www.regulations.gov Web site is 

an ‘‘anonymous access’’ system, which 

means EPA will not know your identity 

or contact information unless you 

provide it in the body of your comment. 

If you send an email comment directly 

to EPA without going through http:// 

www.regulations.gov, your email 

address will be automatically captured 

and included as part of the comment 

that is placed in the public docket and 

made available on the Internet. If you 

submit an electronic comment, EPA 

recommends that you include your 

name and other contact information in 

the body of your comment and with any 


emcdonald on DSK29S0YB1PROD with PROPOSALS
14718 Federal Register / Vol. 77, No. 49 / Tuesday, March 13, 2012 / Proposed Rules 

disk or CD–ROM you submit. If EPA 

cannot read your comment due to 

technical difficulties and cannot contact 

you for clarification, EPA may not be 

able to consider your comment. 

Electronic files should avoid the use of 

special characters, any form of 

encryption, and be free of any defects or 

viruses. 

Docket: All documents in the docket 

are listed in the http:// 

www.regulations.gov index. Although 

listed in the index, some information is 

not publicly available, e.g., CBI or other 

information whose disclosure is 

restricted by statute. Certain other 

material, such as copyrighted material, 

will be publicly available only in the 

hard copy. Publicly available docket 

materials are available either 

electronically in http:// 

www.regulations.gov or in hard copy at: 

U.S. EPA Records Center, Region 8, 

1595 Wynkoop Street, Denver, CO 

80202–1129, (303) 312–6312, Hours: 

Mon–Fri, 8:30 a.m. to 5 p.m. 

South Dakota Air & Space Museum, 

2890 Davis Drive, Building 5208, 

Ellsworth AFB, SD 57706, (605) 385– 

5188, Hours: Mon–Fri, 7 a.m. to 4 p.m. 

FOR FURTHER INFORMATION CONTACT: 

Mark Aguilar, Remedial Project 

Manager, U.S. Environmental Protection 

Agency, Region 8, 1595 Wynkoop 

Street, Denver, CO 80202–1195, (303) 

312–6251, email: 

aguilar.mark@epamail.epa.gov. 

SUPPLEMENTARY INFORMATION: 

Table of Contents 

I. Introduction 

II. NPL Deletion Criteria 

III. Deletion Procedures 

IV. Basis for Partial Site Deletion 

I. Introduction 

EPA Region 8 announces its intent to 

delete OU–1, the Gateway Lake Ash 

Study Area, and the Pride Hangar Study 

Area of the Ellsworth AFB Superfund 

Site, from the National Priorities List 

(NPL) and requests public comment on 

this proposed action. The NPL 

constitutes Appendix B of 40 CFR part 

300 which is the National Oil and 

Hazardous Substances Pollution 

Contingency Plan (NCP), which EPA 

promulgated pursuant to section 105 of 

the Comprehensive Environmental 

Response, Compensation and Liability 

Act (CERCLA) of 1980, as amended. 

EPA maintains the NPL as the list of 

sites that appear to present a significant 

risk to public health, welfare, or the 

environment. Sites on the NPL may be 

the subject of remedial actions financed 

by the Hazardous Substance Superfund 

(Fund). This partial deletion of the 

Ellsworth AFB Site is proposed in 

accordance with 40 CFR 300.425(e) and 

is consistent with the Notice of Policy 

Change: Partial Deletion of Sites Listed 

on the National Priorities List, 60 FR 

55466 (Nov. 1, 1995). As described in 

300.425(e)(3) of the NCP, a portion of a 

site deleted from the NPL remains 

eligible for Fund-financed remedial 

action if future conditions warrant such 

actions. 

EPA will accept comments on the 

proposal to partially delete this site for 

thirty (30) days after publication of this 

document in the Federal Register. 

Section II of this document explains 

the criteria for deleting sites from the 

NPL. Section III discusses procedures 

that EPA is using for this action. Section 

IV discusses OU–1, the Gateway Lake 

Ash Study Area, and the Pride Hangar 

Study Area of the Ellsworth AFB 

Superfund Site and demonstrates how 

they meet the deletion criteria. 

II. NPL Deletion Criteria 

The NCP establishes the criteria that 

EPA uses to delete sites from the NPL. 

In accordance with 40 CFR 300.425(e), 

sites may be deleted from the NPL 

where no further response is 

appropriate. In making such a 

determination pursuant to 40 CFR 

300.425(e), EPA will consider, in 

consultation with the State, whether any 

of the following criteria have been met: 

i. Responsible parties or other persons 

have implemented all appropriate 

response actions required; 

ii. All appropriate Fund-financed 

response under CERCLA has been 

implemented, and no further response 

action by responsible parties is 

appropriate; or 

iii. The remedial investigation has 

shown that the release poses no 

significant threat to public health or the 

environment and, therefore, the taking 

of remedial measures is not appropriate. 

Pursuant to CERCLA section 121(c) 

and the NCP, EPA conducts five-year 

reviews to ensure the continued 

protectiveness of remedial actions 

where hazardous substances, pollutants, 

or contaminants remain at a site above 

levels that allow for unlimited use and 

unrestricted exposure. EPA conducts 

such five-year reviews even if a site is 

deleted from the NPL. EPA may initiate 

further action to ensure continued 

protectiveness at a deleted site if new 

information becomes available that 

indicates it is appropriate. Whenever 

there is a significant release from a site 

deleted from the NPL, the deleted site 

may be restored to the NPL without 

application of the hazard ranking 

system. 

III. Deletion Procedures 

The following procedures apply to 

deletion of OU–1, the Gateway Lake Ash 

Study Area, and the Pride Hangar Study 

Area of the Site: 

(1) EPA consulted with the State 

before developing this Notice of Intent 

for Partial Deletion. 

(2) EPA has provided the state 30 

working days for review of this notice 

prior to publication of it today. 

(3) In accordance with the criteria 

discussed above, EPA has determined 

that no further response is appropriate. 

(4) The State of South Dakota, through 

the Department of Environment and 

Natural Resources, has concurred with 

the deletion of OU–1, the Gateway Lake 

Ash Study Area, and the Pride Hangar 

Study Area of the Ellsworth AFB 

Superfund Site, from the NPL. 

(5) Concurrently, with the publication 

of this Notice of Intent for Partial 

Deletion in the Federal Register, a 

notice is being published in a major 

local newspaper, the Rapid City Journal. 

The newspaper announces the 30-day 

public comment period concerning the 

Notice of Intent for Partial Deletion of 

the Site from the NPL. 

(6) The EPA placed copies of 

documents supporting the proposed 

partial deletion in the deletion docket 

and made these items available for 

public inspection and copying at the 

Site information repositories identified 

above. 

If comments are received within the 

30-day comment period on this 

document, EPA will evaluate and 

respond accordingly to the comments 

before making a final decision to delete 

OU–1, the Gateway Lake Ash Study 

Area, and the Pride Hangar Study Area. 

If necessary, EPA will prepare a 

Responsiveness Summary to address 

any significant public comments 

received. After the public comment 

period, if EPA determines it is still 

appropriate to delete OU–1, the 

Gateway Lake Ash Study Area, and the 

Pride Hangar Study Area of the 

Ellsworth AFB Superfund Site, the 

Regional Administrator will publish a 

final Notice of Partial Deletion in the 

Federal Register. Public notices, public 

submissions and copies of the 

Responsiveness Summary, if prepared, 

will be made available to interested 

parties and included in the site 

information repositories listed above. 

Deletion of a portion of a site from the 

NPL does not itself create, alter, or 

revoke any individual’s rights or 

obligations. Deletion of a portion of a 

site from the NPL does not in any way 

alter EPA’s right to take enforcement 

actions, as appropriate. The NPL is 


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designed primarily for informational 

purposes and to assist EPA 

management. Section 300.425(e)(3) of 

the NCP states that the deletion of a site 

from the NPL does not preclude 

eligibility for future response actions, 

should future conditions warrant such 

actions. 

IV. Basis for Partial Site Deletion 

The following information provides 

EPA’s rationale for deleting OU–1, the 

Gateway Lake Ash Study Area, and the 

Pride Hangar Study Area of the 

Ellsworth AFB Superfund Site from the 

NPL. 

Site Background and History 

The Ellsworth AFB Superfund Site 

(CERCLIS ID #SD2571924644), is a 

United States Air Force Air Combat 

Command installation located 12 miles 

east of Rapid City, South Dakota, and 

adjacent to the small community of Box 

Elder. Ellsworth AFB is located within 

the following Sections, Townships, and 

Ranges, in Pennington and Meade 

Counties, South Dakota: 

Sections 35 and 36, Township 3 

North, Range 8 East, Meade County; 

Section 31, Township 3 North, Range 

9 East, Meade County; 

Sections 1, 2, 11, 12, 13, Township 2 

North, Range 8 East, Pennington and 

Meade Counties; and 

Sections 5, 6, 7, 8, 17, 18, 19, 

Township 2 North, Range 9 East, 

Pennington and Meade Counties. 

The main Air Base covers 

approximately 4,858 acres within 

Meade and Pennington counties and 

includes runways, airfield operations, 

industrial areas, housing, and 

recreational facilities. 

The site was officially activated in 

July 1942 as the Rapid City Army Air 

Base, a training facility for B-17 bomber 

crews. Ellsworth AFB has been the 

headquarters of operations for a variety 

of aircraft, the Titan I Intercontinental 

Ballistic Missile system and the 

Minuteman I and Minuteman II missile 

systems. Ellsworth AFB has historically 

provided support, fueling, training, 

maintenance, and/or testing facilities. 

Operations at Ellsworth AFB over the 

years generated a variety of waste 

materials including municipal solid 

waste, wastewater treatment plant 

sludge, industrial wastes including 

waste oils, solvents, paints, spilled 

fuels, waste pesticides, shop waste, 

metal remains from ordnance disposal 

(shell casings and bomb fragments but 

not unexploded ordnance) and 

radiological wastes. Contaminants of 

concern at Ellsworth AFB include 

chlorinated solvents, waste fuels, and 

metals. 

Ellsworth AFB was proposed for 

listing on the NPL October 26, 1989 (54 

FR 43779), placed on the NPL August 

30, 1990 (55 FR 35509), and is therefore 

subject to the provisions of Section 120 

of CERCLA, 42 U.S.C. 9620. At that 

time, the entire base, approximately 

4,858 acres, was included in the listing 

(‘‘fence line to fence line’’). The 

Department of Defense, EPA and the 

State of South Dakota entered into a 

Federal Facilities Agreement (FFA) 

which formalizes the process for 

environmental response actions and the 

relative roles of the Air Force, EPA and 

the State of South Dakota under 

CERCLA and the Installation 

Restoration Program (IRP). The FFA was 

signed by the Air Force, the EPA, and 

the State of South Dakota in January 

1992 and became effective on April 1, 

1992. 

Upon listing, the facility began 

identifying sites where activities 

involving hazardous substances may 

have occurred. The sites requiring 

further investigations were grouped into 

Operable Units (OUs). Twelve OUs were 

identified at Ellsworth AFB. The OUs 

include: OU–1, Fire Protection Training 

Area; OU–2, Landfills Nos. 1 and 6; 

OU–3, Landfill No. 2; OU–4, Landfill 

No. 3; OU–5, Landfill No. 4; OU–6, 

Landfill No. 5; OU–7, Weapons Storage 

Area; OU–8, Explosive Ordnance 

Disposal Area; OU–9, Old Hobby Shop 

Area; OU–10, North Hangar Complex; 

OU–11, Basewide Groundwater; and 

OU–12, Hardfill No. 1. Records of 

Decision (RODs) were finalized for all of 

these OUs between October 1995 and 

April 1997. 

Surface soil, unsaturated subsurface 

soil, surface water, and sediments at 

OU–2, OU–3, OU–4, OU–5, OU–6, OU– 

7, OU–8, OU–9, OU–10 and OU–12 

(approximately 542 acres) and the 

surface soil, unsaturated subsurface soil, 

surface water and sediment media of an 

additional 4,300 acres not associated 

with an operable unit were deleted from 

the NPL December 4, 2006 (71 FR 

70318). 

Four areas not deleted in 2006 were 

OU–1 (all media), OU–11 (Basewide 

Groundwater) [including all 

groundwater plumes located within the 

Base boundary and those described as 

emanating from the Base], and two 

Areas of Concern: the Gateway Lake Ash 

Study Area and the Pride Hangar Study 

Area. Appropriate response actions for 

soil media have since been completed at 

OU–1, the Pride Hangar Study Area and 

the Gateway Lake Ash Study Area. The 

remedial investigation/feasibility study 

(RI/FS) process did not identify any 

unacceptable risks for surface water and 

sediment at these areas. Therefore, 

remedial actions were not required for 

surface water and sediment. 

The portions of the Ellsworth AFB 

Site to be deleted from the NPL are: 

• Surface soil, unsaturated subsurface 

soil, surface water and sediment media 

at OU–1 [generally described by the 

following coordinates: N667749.88/ 

E1242611.11; N667496.84/E1242812.29; 

N667330.75/E1242852.01; N666933.49/ 

E1242558.40; N667158.53/E1242265.75; 

N667787.47/E1242276.80; N667749.88/ 

E1242611.11] 

• Gateway Lake Ash Study Area 

[generally described by the following 

coordinates: N667944.01/E1248056.74; 

N667694.15/E1248058.87; N667695.57/ 

E1247811.84; N667947.55/E1247834.49; 

N667944.01/E1248056.74] 

• Pride Hangar Study Area [generally 

described by the following coordinates: 

N673538.32/E1243066.96; N673267.45/ 

E1243270.27; N673228.21/E1243223.95; 

N673113.04/E1243308.87; N673021.04/ 

E1243204.65; N673409.00/E1242911.91; 

N673538.32/E1243066.96]. 

OU–1 consists of the former Fire 

Protection Training Area (FPTA), Pond 

001, and a portion of the drainage 

channel that leads into Pond 001. The 

former FPTA is approximately 10 acres 

in size and is located in the 

southwestern portion of Ellsworth AFB. 

The FPTA was operated by the 

Ellsworth AFB at this location from 

1942 to 1990. The location of the burn 

area within the former FPTA has 

changed several times over the years. 

Aerial photographs of Ellsworth AFB 

show numerous areas of staining 

presumed to be a result of the fire 

training activities within the former 

FPTA. The training exercises conducted 

at the FPTA involved simulation of 

aircraft fires and spills and consisted of 

dispersing various fuels, oils and 

solvents within the burn pit area and 

subsequently igniting and extinguishing 

the fire. Extinguishing chemicals used 

during the fire-training exercises have 

included aqueous-film-forming-foam, 

halon, protein-foams, carbon dioxide, 

dry chemicals and 

chlorobromomethane. 

The Gateway Lake Ash Study Area is 

located in the southeast portion of 

Ellsworth AFB. The site is located in a 

low area approximately 400 feet south 

of Gateway Lake and north of the 

Ellsworth AFB wastewater treatment 

facility. The area is generally level open 

terrain that is grass covered and 

bounded on the north by trees and on 

the east by an unnamed creek. To the 

west is the entrance road to the Base’s 

wastewater treatment plant and to the 

south is the wastewater plant. 

The open land that contains the 

Gateway Lake Ash Study Area had come 


emcdonald on DSK29S0YB1PROD with PROPOSALS
14720 Federal Register / Vol. 77, No. 49 / Tuesday, March 13, 2012 / Proposed Rules 

under consideration for construction of 

a new building when soils at the 

proposed building site were assessed. 

Two exploratory geotechnical borings 

were drilled in August 2002 that 

encountered ash debris and glass 

material. Further evaluation provided 

information that the area was once an 

open ravine which had been filled with 

ash and debris. An incinerator to the 

south was identified as a potential 

source of the fill debris. Over time, the 

area had been graded and a portion 

within the fenced boundary of the 

wastewater treatment facility had been 

seeded with grass. Except for the 

planted trees to the north, the remaining 

area has since grown over with natural 

grass and shrubs. 

The Pride Hangar Study Area is 

located at the northwest corner of the 

Pride Hangar within OU–11 and covers 

approximately 1.7 acres. Two former 

side-by-side waste solvent underground 

storage tanks located on the northwest 

corner of the Pride Hangar were the 

primary source of a TCE plume known 

as the Pride Hangar plume. These tanks 

were removed in 1992. 

A map identifying the areas to be 

deleted is available in the partial 

deletion docket. The groundwater 

medium at the Ellsworth AFB Site (OU– 

11, Basewide Groundwater) will remain 

on the NPL and response activities will 

continue for that OU. 

Operable Unit 1 

An extensive RI was conducted to 

characterize site conditions at OU–1 in 

1993 and 1994. The program included 

completion of boreholes, installation of 

monitoring wells, geotechnical analysis 

of soil samples, ecological 

investigations, assessment of human 

health risks, and review and 

compilation of previous IRP 

investigations. Collection and laboratory 

analysis of soil, groundwater, surface 

water, and sediment samples were 

included in the RI field program. 

Soil impacted by past activities at 

OU–1 extends from the surface to the 

capillary fringe beneath the former 

FPTA. The nature of the soil 

contamination at OU–1 soils included 

JP–4 (jet fuel), benzene, toluene, 

ethylbenzene and xylene (BTEX), and 

chlorinated volatile organic compounds 

(VOCs). JP–4 contamination was in a 

range of hundreds of thousands to 

millions of micrograms per kilogram 

(mg/kg) in vadose zone and capillary 

fringe soils. Total BTEX contamination 

was in a range of non-detect (ND) to 

hundreds of thousands of mg/kg in 

vadose zone soils, and thousands to tens 

of thousands of mg/kg in capillary fringe 

soils. Total chlorinated VOCs 

contamination was in a range of ND to 

tens of mg/kg in vadose zone soils, and 

ND to hundreds of mg/kg in capillary 

fringe soils. 

A baseline risk assessment indicated 

that the soils of the burn-pit area posed 

an unacceptable risk, primarily from the 

potential for contaminating the 

underlying groundwater. Risks from 

exposure to pesticides and dioxins/ 

furans in surface and subsurface soils at 

OU–1 were well below the acceptable 

range and did not warrant remediation. 

Contaminants in surface water and 

sediment included VOCs, semi-volatile 

organic compounds (SVOC), pesticides, 

one phthalate, one polynuclear aromatic 

hydrocarbon and inorganics including 

cyanide, thallium, mercury, arsenic, 

manganese and nickel. However, it was 

determined in the risk assessment that 

the levels of these contaminants fell 

within the acceptable risk range, and 

therefore, no remedial action was 

warranted for surface water or sediment. 

A Final ROD for an Interim Remedial 

Action (IRA) for OU–1 was signed in 

May 1995. The objective of the IRA at 

OU–1 is to reduce the immediate risks 

posed by the contaminants in the deeper 

subsurface soils of the burn-pit areas of 

the FPTA and to prevent the movement 

of contaminants to shallow groundwater. The interim remedy included soil 

vapor extraction (SVE), groundwater 

removal using wells and an existing 

interceptor trench, treatment of 

groundwater, condensate, and soil gas, 

and surface water discharge of treatment 

effluent. Only the SVE system pertains 

the media being proposed for deletion. 

The SVE system consisted of four dual 

phase extraction wells and eight soil 

vapor extraction wells, and a soil vapor 

blower with soil gas treated by thermal 

oxidation before discharge. 

The OU–1 SVE system began 

operation in March 1996 and operated 

until the final remedy was 

implemented. The thermal oxidizer was 

operated from March 1996 to November 

1996 when blower discharge 

contaminant levels were low enough to 

discharge to the atmosphere. 

The 1995 Feasibility Study for OU–1 

recommended expanding the IRA SVE 

system to remove volatile organic 

chemicals from source area soils. A 

Final ROD for Remedial Action at OU– 

1 was signed in May 1996. The remedial 

action objectives (RAOs) are: (1) The 

cleanup of ground water to regulatory 

levels and, for contaminants where 

regulatory levels are not available, to 

levels considered safe for public 

drinking water, and (2) the cleanup of 

source area soils to levels that would 

not pose a threat of contaminating 

ground water. The selected remedial 

action included: continued operation of 

the IRA SVE system to remediate a 

portion of the source area soils; use of 

groundwater wells and an existing 

collection trench to remove 

contaminated groundwater in the source 

area; installation and use of additional 

SVE wells, groundwater wells and/or 

collection trenches; treatment of soil gas 

and contaminated groundwater at the 

IRA treatment plant; implementing 

institutional controls (deed and land use 

restrictions) to restrict the future use of 

the area while the remedy is being 

implemented; and providing for longterm monitoring and maintenance. Only 

the SVE system and the institutional 

controls apply to the media being 

proposed for deletion. 

The Final ROD set cleanup goals for 

four VOCs identified for remediation in 

soil: benzene (10 mg/kg), 1,2- 

dichloroethylene (DCE) (41 mg/kg), 

tetrachloroethylene (PCE) (10 mg/kg), 

and trichloroethylene (TCE) (10 mg/kg). 

Cleanup goals for these four VOCs were 

based on model estimates for the 

protection of groundwater. Where 

model estimates were less than standard 

detection limits, remediation cleanup 

goals were based on standard detection 

limits. Remediation of jet fuel in the soil 

at OU–1 was also required because 

concentrations of jet fuel and related 

components exceeded State of South 

Dakota regulations. Cleanup goals for 

petroleum related contamination were 

set at: JP–4 (500,000 mg/kg), toluene 

(15,000 mg/kg), ethylbenzene (10,000 mg/ 

kg), xylene (300,000 mg/kg), and 

naphthalene (25,000 mg/kg). 

An additional SVE blower, seven dual 

phase extraction wells, a dual phase 

extraction trench and four soil vapor 

extraction wells were installed as part of 

the Final Remedial Action. The IRA 

system was incorporated into the final 

remedy. Construction of the remedial 

action was completed in June 1997. 

This alternative included institutional 

controls, implemented August 27, 1997, 

to prevent human exposure to 

contaminated soil and groundwater. 

These controls include: (1) Issuing a 

continuing order to restrict on-site 

worker access to contaminated soil, and 

to restrict or control temporary 

construction activities unless proper 

protective equipment is worn; (2) filing 

a notice with the State to recommend 

denial of water appropriation permit 

applications to install groundwater 

wells within the area of contamination 

and any area which may be effected by 

potential contaminants; (3) filing a 

notice to the deed detailing the 

restrictions of the continuing order and 

groundwater well restrictions; and (4) a 

covenant to the deed in the event of 


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property transfer. The continuing order 

is reissued with 5-year reviews and the 

most recent is dated August 5, 2010. 

Operation and maintenance of the 

SVE system included collecting samples 

at the blower stacks and calculating 

mass removals, measurements of 

individual well vacuums and 

contaminant levels, and blower vacuum. 

Based on these measurements, operation 

of the SVE wells and the SVE 

component of dual phase wells were 

optimized by applying vacuum to the 

points of highest contaminant 

concentration. Based on system 

monitoring, one SVE blower was shut 

off in March 2000 and operation of one 

SVE blower was focused on wells with 

the highest contaminant concentration. 

Two additional dual phase extraction 

wells were installed in June 2003 and 

began operation in October 2003 to 

address free product and improve 

groundwater plume containment. 

SVE operation continued until July 

2007. SVE operation was suspended in 

2007 because monitoring data showed 

that SVE contaminant mass removal 

rates had diminished significantly and 

the removal rates remained low. 

A high vacuum extraction system 

(HVE) was operated from May to 

November 2007 and from May to 

November 2008. The HVE system 

operated at 15 wells (nine monitoring 

wells and six dual extraction wells) 

with the primary purpose of removing 

residual free product. Operation and 

maintenance of the HVE system 

included measuring hydrocarbon 

concentrations in the vapor discharge, 

measurement of vacuum at individual 

wells and at the vacuum blower, and 

drawdown at individual wells. 

Operation of the HVE system was 

suspended in November 2008 after free 

product was no longer observed at any 

of the wells on site. 

A bioventing system was operated at 

OU–1 from November 2008 through 

August 2010 to enhance the biological 

degradation of fuel-related contaminants 

BTEX; naphthalene; and total petroleum 

hydrocarbons as gasoline-range organics 

[GRO] and diesel-range organic [DRO]) 

in the vadose zone soils. Bioventing was 

designed to replace the SVE system and 

utilized existing SVE wells, dual 

extraction wells, and associated piping. 

Fifteen SVE and dual extraction wells 

were used in the bioventing system. 

Operation and maintenance of the 

bioventing system included measuring 

oxygen and carbon dioxide levels in 

bioventing wells, and recording 

pressure, temperature and flow from the 

blower. 

Post one year bioventing soil samples 

were collected in January 2010 at six 

boring locations where soil samples 

collected in 1989 or 1993 had exceeded 

OU–1 soil cleanup goals. Analytical 

results from vadose zone soils for 

ethylbenzene, naphthalene, toluene and 

xylene at the six borings were all below 

reporting limits (6.9 mg/kg maximum) 

and below cleanup goals based on State 

Regulations for each compound 

(ethylbenzene 10,000 mg/kg, 

naphthalene 25,000 mg/kg, toluene 

15,000 mg/kg, and xylene 300,000 mg/ 

kg). The maximum DRO result from the 

vadose zone soil samples was 210,000 

mg/kg and the maximum GRO result 

from the vadose zone soil samples was 

1,700 mg/kg, both below the cleanup 

goal of 500,000 mg/kg for JP–4 in soil 

based on State Regulation. 

With respect to the contaminants of 

concern cis-1,2–DCE, benzene, PCE, and 

TCE, the analytical results in the vadose 

zone showed the concentrations were 

all below reporting limits, which were 

below the cleanup goals established in 

the Final ROD. These data demonstrate 

the cleanup goals have been met. 

The 2010 5-year review recommend 

evaluating existing data to determine if 

partial deletion of surface soil, 

unsaturated subsurface soil, surface 

water and sediment from OU–1 is 

appropriate. Subsequent data evaluation 

indicated that unsaturated soils met the 

cleanup levels documented in the ROD 

and is protective of groundwater. The 

next five year review is scheduled for 

the year 2015. 

Gateway Lake Ash Study Area 

Electromagnetic survey data from the 

August 2003 Draft Preliminary 

Assessment/Site Investigation (PA/SI) 

Report indicated the areal extent of the 

ash and debris was approximately 1⁄3

acre. Field observations and soil borings 

indicated the ash and debris were 6 to 

7.5 feet in thickness and typically 

encountered within one foot of the 

surface. 

The PA/SI reported contaminants in 

the ash and debris and soils including 

VOCs, SVOCs, metals and dioxins/ 

furans. Detected results were compared 

to the USEPA Region 3 Risk Based 

Concentrations (RBCs). The industrial 

soil screening value at a 1x 10–6 risk 

level was used for dermal and 

inhalation risk and the dilution 

attenuation factor (DAF) of 20 was used 

for evaluating the soil to groundwater 

migration pathway. Detected metal 

concentrations were compared to 

regional concentration ranges as 

established in the RI Report for nearby 

OU–6. 

Three VOCs were detected in the ash 

and debris but concentrations did not 

exceed industrial or DAF 20 values. 

Five SVOCs (1,4-dichlorobenzene, 2,4- 

dintrotoluene, 4-nitrophenol, Nnitrosodi-N-propylamine, and 1,2,4- 

trichlorbenzene) exceeded DAF 20 

standards and one SVOC (N-nitrosodiN-propylamine) exceeded industrial soil 

standards in the ash and debris. Four 

VOCs and one SVOC were detected in 

the soil beneath the ash and debris but 

concentrations did not exceed industrial 

or DAF 20 screening levels. Low 

concentrations of VOCs and SVOCs in 

the underlying soils indicated the 

contaminants in the buried ash and 

debris did not greatly impact the 

underlying soils. 

Metals were detected in the ash and 

debris with arsenic exceeding RBCs but 

within the range of background 

concentration in surrounding soils. 

Arsenic and mercury exceeded both 

industrial and DAF 20 screening levels. 

Manganese exceeded the DAF 20 

screening level in the underlying soil 

but was considered to be within 

background ranges. Toxicity 

Characteristic Leaching Potential metals 

and pH analysis indicated the ash and 

debris material was non-hazardous. 

Results for dioxins/furans indicated the 

maximum concentration in the ash and 

debris was below screening criteria and 

similar to background concentrations. 

Based on the characterization of the ash 

and debris and no evidence of 

contaminant migration under the debris 

or outside the buried debris limits, no 

further actions were recommended. No 

RI or FS was completed for the Gateway 

Lake Ash Study Area soils. 

The Air Force, independent of 

CERCLA, determined that the ash 

material should be removed from the 

site and disposed properly at a licensed 

land disposal facility (the Rapid City 

Landfill). In January 2007, 4,310 cubic 

yards of ash material was hauled to the 

Rapid City Landfill and used as daily 

cover material. Confirmation sampling 

of underlying soils for SVOCs detected 

one SVOC compound, bis(2- 

ethylhexyl)phthalate, at 74 mg/kg, that 

was below the DAF 20 value of 

2,889,000 mg/kg for that compound. The 

excavated area was restored by 

backfilling with clean soil from 

stockpiles and excavations on Base, and 

reseeding the site. The characterization 

of the ash and debris, removal of the ash 

debris from the site, and results from 

confirmation sampling in the 

underlying soil demonstrate that the site 

is clean. 

The Gateway Lake Ash Study Area 

overlies OU–11, Basewide Groundwater. 

As a result, the institutional controls for 

OU11 apply to this area. The ICs 

selected in the 1997 OU11 ROD 

included (1) issuing a continuing order 


emcdonald on DSK29S0YB1PROD with PROPOSALS
14722 Federal Register / Vol. 77, No. 49 / Tuesday, March 13, 2012 / Proposed Rules 

(by the Installation Commander) to 

restrict or place limitations on the 

installation of any new groundwater 

wells; (2) filing a notice in 

environmental and real estate records at 

the Base or Installation, detailing the 

restrictions of the continuing order and 

groundwater well restrictions; and (3) 

compliance with the provisions of 

CERCLA Section 120(h)(3) or other 

applicable statutory requirements in the 

event of property transfer. These ICs 

were implemented August 27, 1997. 

The Gateway Lake Ash Study Area 

was addressed in the 2010 Five Year 

Review as an area not deleted during the 

previous partial deletion. No 

recommendations were made regarding 

the Gateway Lake Ash Study Area in the 

2010 Five Year Review. The next five 

year review is scheduled for the year 

2015. 

Pride Hangar Study Area 

The Pride Hangar Study Area is 

located at the northwest corner of the 

Pride Hangar within OU–11 Area 1 and 

covers approximately 1.7 acres. Two 

former side-by-side waste solvent 

underground storage tanks located on 

the northwest corner of the Pride 

Hangar were the primary source of a 

TCE plume known as the Pride Hangar 

plume. These tanks were removed in 

1992. A soil sample was collected from 

near the floor of the tank excavation (10 

feet below ground surface) in1993 and 

analyzed for VOC. TCE was reported at 

0.09 mg/kg. 

During the 1994 RI for OU–11 

Basewide Groundwater, a groundwater 

sample collected near the tank site 

contained total 1,2–DCE at 11 mg/L, 

chloroform at 1,580 mg/L, TCE at 6,800 

mg/L and JP–4 at 270 mg/L. A soil boring 

at that same location was non-detect for 

VOCs and SVOCs in the capillary fringe. 

The FS for OU–11 Basewide 

Groundwater Area 1 recommended, and 

the OU–11 ROD specified groundwater 

extraction and treatment in OU–11 Area 

1. A vacuum extraction system was 

installed to extract contaminated 

groundwater and operated southeast 

(downgradient) of the Pride Hangar from 

1997 to 2006. No RI or FS was 

completed for soils at the Pride Hangar 

Study Area. 

Additional soil sampling was 

completed at the Pride Hangar Study 

Area in 2002. In eleven vadose zone soil 

samples, TCE results ranged from <5 mg/ 

kg to 120 mg/kg and cis-1,2–DCE was 

detected in only one sample at 40 mg/ 

kg. The September 3, 2003 Serial Letter 

1–54–RA–301, Pride Hangar Source 

Remediation Recommendation, 

recommended SVE to remove 

chlorinated VOCs in the vadose zone at 

the Pride Hangar Study Area. This 

action was implemented and consisted 

of SVE pilot testing in May 2004 and 

intermittent operation of the SVE 

system from July to November 2004. 

The SVE system consisted of an SVE 

blower, eight SVE wells, and temporary 

above-ground piping. Operation and 

maintenance of the SVE system 

included monitoring vacuum at the 

wells and blower, and vapor flow rate 

at the blower. The SVE system was shut 

down due to the potential aeration of 

groundwater and its detrimental effect 

on anaerobic groundwater treatment 

implemented in 2004. A 2007 

Explanation of Significant Differences 

allowed for continued use of the SVE 

system at the Pride Hangar Study Area 

even but the SVE system was not 

operated again. 

Vadose zone soil samples were 

collected from direct push borings in 

the Pride Hangar Study Area in 2010. 

Soil samples included samples collected 

in the vadose zone at the depths where 

chlorinated VOC concentrations were 

highest in 2002. TCE concentrations in 

vadose zone samples were all nondetect except for three detections at 

concentrations of 0.58, 0.52 and 0.52 mg/ 

kg. These TCE contaminant 

concentrations are above the most 

conservative EPA Regional Screening 

Level for protection of groundwater for 

TCE but are within the acceptable risk 

range given the change in the TCE 

toxicity value. Cis-1,2–DCE 

concentrations in vadose zone samples 

were all non-detect except for one 

detection of 0.81 mg/kg. This cis-1,2– 

DCE concentration is below the EPA 

Regional Screening Level for protection 

of groundwater for cis-1,2–DCE of 21 mg/ 

kg for a DAF of one. These vadose zone 

soil sample results, reported in the 

August 2011 Pride Hangar Vadose Zone 

Soil Sample Results technical 

memorandum, indicated a significant 

source of contaminated soil no longer 

existed. 

The Pride Hangar Study Area overlies 

OU–11, Basewide Groundwater. As a 

result, the institutional controls for 

OU11 apply to this area. The ICs 

selected in the 1997 OU11 ROD 

included (1) issuing a continuing order 

(by the Installation Commander) to 

restrict or place limitations on the 

installation of any new groundwater 

wells; (2) filing a notice in 

environmental and real estate records at 

the Base or Installation, detailing the 

restrictions of the continuing order and 

groundwater well restrictions; and (3) 

compliance with the provisions of 

CERCLA Section 120(h)(3) or other 

applicable statutory requirements in the 

event of property transfer. These ICs 

were implemented 27 August 1997. 

The Pride Hangar Study Area was 

addressed in the 2010 Five Year Review 

as an area not deleted during the 

previous partial deletion. No 

recommendations were made regarding 

the Pride Hangar Study Area in the 2010 

Five Year Review. The next five year 

review is scheduled for the year 2015. 

Community Involvement 

Community involvement activities 

that have taken place include 

publishing the FFA and RODs for public 

comment, establishing and maintaining 

an Administrative Record, and 

formation of a Restoration Advisory 

Board (RAB) to facilitate input in the 

cleanup process. The RAB includes 

Ellsworth AFB, EPA and SDDENR 

oversight personnel as well as 

community leaders and local 

representatives from the surrounding 

area. RAB meetings are held twice each 

year, normally in May and November. 

Determination That the Criteria for 

Deletion Have Been Met 

EPA, with concurrence from the State 

of South Dakota, through the 

Department of the Environment and 

Natural Resources, by a letter dated 

November 22, 2011, has determined that 

no additional response is necessary at 

Ellsworth AFB for surface soil, 

unsaturated subsurface soil, and surface 

water and sediment media at OU–1, the 

Gateway Lake Ash Study Area and the 

Pride Hangar Study Area. Responsible 

parties have completed all appropriate 

response actions required and the 

unsaturated subsurface soil is cleaned 

up at OU–1 and the Pride Hangar Study 

Area. Investigation of the Gateway Lake 

Ash Study Area showed that it posed no 

significant threat to public health or the 

environment and removal of the debris 

eliminated any potential threat, 

therefore, the taking of remedial 

measures is not appropriate. Therefore, 

EPA is proposing to delete these 

portions of the Ellsworth AFB Site. 

EPA Region 8 has followed the 

procedures required by 40 CFR 

300.425(e). The EPA has consulted with 

the State of South Dakota and provided 

the state 30 working days for review of 

this notice prior to publication. The 

State, through the Department of 

Environment and Natural Resources has 

concurred with the deletion of surface 

soil, unsaturated subsurface soil, and 

surface water and sediment media at 

OU–1, the Gateway Lake Ash Study 

Area and the Pride Hangar Study Area 

from the Ellsworth AFB Superfund Site. 

Concurrent with the publication of the 

Notice of Intent for Partial Deletion in 


emcdonald on DSK29S0YB1PROD with PROPOSALS
Federal Register / Vol. 77, No. 49 / Tuesday, March 13, 2012 / Proposed Rules 14723 

the Federal Register, a notice is being 

published in The Rapid City Journal. 

The EPA placed copies of documents 

supporting the proposed partial deletion 

in the deletion docket, and made these 

items available for public inspection 

and copying at the Site information 

repositories. 

List of Subjects in 40 CFR Part 300 

Environmental protection, Air 

pollution control, Chemicals, Hazardous 

waste, Hazardous substances, 

Intergovernmental relations, Penalties, 

Reporting and recordkeeping 

requirements, Superfund, Water 

pollution control, Water supply. 

Authority: 33 U.S.C. 1321(c)(2); 42 U.S.C. 

9601–9657; E.O. 12777, 56 FR 54757, 3 CFR, 

1991 Comp., p. 351; E.O. 12580, 52 FR 2923, 

3 CFR, 1987 Comp., p. 193. 

Dated: February 8, 2012. 

James B. Martin, 

Regional Administrator, Region 8. 

[FR Doc. 2012–6031 Filed 3–12–12; 8:45 am] 

BILLING CODE 6560–50–P 


emcdonald on DSK29S0YB1PROD with PROPOSALS