THE U.S. NAVY AND THE ALASKA DEPARTMENT OF …Explain the reasons for the recommendation of the...

PROPOSED PLAN FOR PETROLEUM SITES WITH NO UNACCEPTABLE RISKSFORMER ADAK NAVAL COMPLEX - ADAK ISLAND, ALASKA

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PROPOSED PLAN FOR PETROLEUM SITESWITH NO UNACCEPTABLE RISK

Former Adak Naval Complex, Adak Island, Alaska September 2004Former Adak Naval Complex, Adak Island, Alaska September 2004Former Adak Naval Complex, Adak Island, Alaska September 2004Former Adak Naval Complex, Adak Island, Alaska September 2004Former Adak Naval Complex, Adak Island, Alaska September 2004

INTRODUCTION

THE U.S. NATHE U.S. NATHE U.S. NATHE U.S. NATHE U.S. NAVY AND THE ALVY AND THE ALVY AND THE ALVY AND THE ALVY AND THE ALASKA DEPASKA DEPASKA DEPASKA DEPASKA DEPARTMENT OFARTMENT OFARTMENT OFARTMENT OFARTMENT OFENVIRONMENTENVIRONMENTENVIRONMENTENVIRONMENTENVIRONMENTAL CONSERVAL CONSERVAL CONSERVAL CONSERVAL CONSERVAAAAATION announce theTION announce theTION announce theTION announce theTION announce the

This Proposed Plan proposes the preferred cleanup alternatives for the10 free-product recovery petroleum sites (hereafter referred to as petro-leum-contaminated sites) at the former Adak Naval Complex, Adak Is-land, Alaska, that pose no risk to human health or the environment abovetarget health goals. This Proposed Plan was developed in accordancewith State of Alaska regulations governing petroleum-release sites, theAlaska Department of Environmental Conservation (DEC) Oil and OtherHazardous Substances Pollution Control Regulations (18 Alaska Adminis-trative Code [AAC] 75). This document is being issued by the Navy, thelead agency for site activities, and the Alaska DEC, the lead regulatoryagency. This document summarizes information that can be found ingreater detail in the Site Characterization Report, Part 1 and Part 2, andother relevant documents referenced in this Proposed Plan. The Navyand the Alaska DEC encourage the public to review the Site Characteriza-tion Report and other relevant documents to increase their understandingof the site and the activities that have been conducted there. The SiteCharacterization Report and other relevant documents cited in this Pro-posed Plan are available in the information repositories listed on the sidebar of this page.

The public is encouraged to review and comment on this Proposed Plan.The Navy, in consultation with the Alaska DEC, may modify any of thecleanup alternatives, including the preferred cleanup alternatives basedon new information or public comments. Final decisions for 10 petro-leum-contaminated sites will be presented in the Record of Decision (ROD).The ROD will include a responsiveness summary describing how publiccomments were addressed.

The Proposed Plan has the following purposes:

Provide basic background informationDescribe the cleanup options that were evaluatedIdentify the preferred cleanup alternatives for remedial actionExplain the reasons for the recommendation of the preferredcleanup alternativesSolicit public review of and comment on all of the cleanupalternatives including the preferred cleanup alternativeProvide information on how the public can be involved in theremedy selection process

(Technical terms used in this plan are italicized where they are first used and defined in the Glossary section at the end of the plan.)

Dates to Remember

PUBLIC COMMENT PERIODOctober 1 throughNovember 1, 2004The U.S. Navy and the Alaska Departmentof Environmental Conservation will acceptwritten comments on the Proposed Planduring the public comment period.

PUBLIC MEETING DATESeptember 20, 2004The U.S. Navy and the Alaska Departmentof Environmental Conservation will hold apublic meeting to explain the ProposedPlan and briefly summarize the activitiesperformed to date. Oral and writtencomments will also be accepted at themeeting. The meeting will be held at theAdak City Offices at 6:00 p.m.

For more information, see the informationrepositories at the following locations:

Library Reserve RoomUniversity of Alaska, Anchorage3211 Providence DriveAnchorage, AK 99501(907) 786-1871

Engineering Field Activity, NorthwestNaval Facilities Engineering Command19917 Seventh Avenue NEPoulsbo, WA 98370-7570

Bob Reeve High SchoolAdak, AK 99546


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Introduction.....................................................1Site Background...............................................2Site Regulatory History..................................... 5Site Characteristics.......................................... 5Cleanup Levels.................................................7Extent of Contamination....................................8Summary of Site Risks..................................... 9Remedial Action Objectives............................. 10Remedial Action Alternatives........................... 10Evaluation of Alternatives................................11Preferred Cleanup Alternatives........................ 13Additional Activities........................................ 15Community Participation................................. 16Acronyms......................................................17Glossary........................................................ 17Comment Form............................................. 19

CONTENTS The 10 sites that pose no risk to human health or the environ-ment above target health goals that are addressed in thisProposed Plan are the following:

GCI Compound, Underground Storage Tank(UST) GCI-1 (GCI Compound)Source Area (SA) 80, Steam Plant No. 4, USTs 27089and 27090 (SA 80)Tanker Shed, UST 42494 (Tanker Shed)SA 78, Old Transportation Building, USTs 10583 and10584 and Above-ground Storage Tanks (ASTs)(SA 78)SA 82, P-80/P-81 Buildings, USTs 10579 and 10587 andAST 10333 (SA 82)SA 88, P-70 Energy Generator, UST 10578 (SA 88)Solid Waste Management Unit (SWMU) 58, HeatingPlant No. 6 (SWMU 58/SA 73)SA 73, Heating Plant No. 6 (SWMU 58/SA 73)Yakutat Hangar, UST T-2039A (Yakutat Hangar)NORPAC Hill Seep Area (NORPAC Hill)

It should be noted that although SWMU 58 and SA 73 wereestablished as separate sites, they are both located at Heat-ing Plant No. 6, and are addressed as a single site.

The former Adak Naval Complex is located on Adak Island,which is approximately 1,300 air miles southwest of Anchor-age, Alaska, in the Aleutian Island chain (Figure 1). Figure 2shows the location of each of the 10 sites addressed in thisProposed Plan. The former U.S. Navy base occupied 76,800

SITE BACKGROUNDacres on the northern half of the island, and the U.S. Fish andWildlife Service manages the southern portion of the island,which is a designated wilderness area within the Alaska Mari-time National Wildlife Refuge System.

Figure 1Adak Island

Vicinity


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All operations ceased at the former Adak Naval Complex onMarch 31, 1997, after the active Navy mission ended. FromApril 1997 through September 2000, critical facilities such asthe power plant, airfield, and environmental cleanup systemswere operated by the Navy through a caretaker contractor. InJune 1998, the Navy entered into a lease with the Adak ReuseCorporation (ARC). In October 2000, ARC commenced op-eration of community facilities such as the airfield and utilitysystems.

In September 2000, the federal government entered into aland transfer agreement with The Aleut Corporation, a Nativecorporation. This agreement set forth the terms and condi-tions for the conveyance of approximately 47,000 acres of theformer Adak Naval Complex property to The Aleut Corpora-tion. The actual conveyance or transfer of property occurredon March 17, 2004. The land transfer includes all of the down-town area, housing units, and industrial facilities. The AlaskaDepartment of Transportation currently owns the Tanker Shedsite, and The Aleut Corporation owns the remaining nine sitesaddressed by this Proposed Plan.

The transferred land has institutional controls currently in placethat prevent exposure to petroleum-related chemicals. Theinstitutional controls include land use restrictions (primarilyrestricted to areas designated for commercial or industrialuse); notification of intrusive soil excavation activities; andgroundwater restrictions that prohibit use of the downtownaquifer as a drinking water resource.

The Navy established a community involvement program in1994 to provide interested Alaska citizens and Adak residentswith timely and updated information on the environmentalcleanup and the transfer and reuse of Navy land and facilities.The community involvement program also provides a mecha-nism for public input on environment cleanup decisions. In-formation is conveyed to the public via fact sheets and news-letters, Restoration Advisory Board (RAB) meetings and otherformal public meetings, web site announcements(www.adakupdate.com), information repositories on AdakIsland (Bob Reeve High School building, second floor) and inAnchorage (University of Alaska library’s reserve room), andthe Administrative Record file located at Naval Facilities Engi-

neering Command, Engineering Field Activity,Northwest, Poulsbo, Washington. In addition, amailing list is maintained and updated to informconcerned citizens of upcoming meetings andsignificant activities, such as public comment pe-riods. Public input is obtained through RABmeetings and other formal public meetings, com-munity interviews, requests for public comments,and a telephone hotline.

Various environmental field investigations wereperformed by the Navy at the 10 petroleum-con-taminated sites between 1991 and 2002. Theseinvestigations included, but were not limited to,site assessments conducted to evaluate site con-ditions during tank removals, site investigationsto evaluate subsurface conditions and investi-gate potential sources of contamination, andgroundwater investigations to evaluate concen-trations of petroleum compounds and naturalattenuation parameters. Based on these inves-tigations, the media impacted by petroleum hy-drocarbon releases at the 10 petroleum-contami-nated sites include soil, groundwater, sediment,and surface water.

The suspected and known sources of petroleumhydrocarbons in soil, groundwater, sediment,and surface water at these 10 sites, the releasehistory, and previous cleanup activities are sum-marized in Table 1. In most cases, releases ofpetroleum hydrocarbons at the 10 sites appearto be related to USTs, ASTs, or piping associ-ated with the USTs and ASTs historically usedat the site. Other potential sources of petro-leum hydrocarbon contamination are oil/waterseparators located at SWMU 58/SA 73 andTanker Shed, a vehicle wash rack located at

Figure 2Location of Petroleum-Contaminated Sites with No Unacceptable Risk, Adak, AK


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Tanker Shed, and fuel pipelines (unre-lated to site USTs and ASTs) located atthe GCI Compound, SA 80, and NORPACHill. Documentation of releases wasfound for only five of the 10 sites: GCICompound, SA 80, SA 78, and SWMU58/SA 73. The source of the petroleumhydrocarbons released to the environ-ment at the other five sites is not docu-mented.

Cleanup activities that have been imple-mented include UST, AST, oil/waterseparator, and associated piping remov-als; contaminated soil excavation; re-covery of groundwater/free product dur-ing tank removals; free-product remov-als; annual groundwater monitoring, andnatural attenuation monitoring. In ad-dition, corrective actions were imple-mented at SWMU 58/SA 73 and YakutatHangar. French drains were installed indrainage ditches affected by free prod-uct at both sites, and the drainageditches were then backfilled. These cor-rective actions eliminated human andecological exposures to contaminatedsurface soils.

Table 1Site Summary Information

USTs

ASTs

Othe

rNo

. UST

s Re

mov

edNo

. AST

s Re

mov

ed

Gallo

ns o

f Fr

ee

Prod

uct

Rem

oved

Cubi

c Ya

rds o

f So

il Re

mov

ed

No. o

f Well

s Mo

nito

red

Annu

ally

Natu

ral

Atte

nuat

ion

Moni

torin

gOt

her C

leanu

p Ac

tiviti

es G

CI C

ompo

und

10

Main

Road

Pipe

line a

nd fo

rmer

avga

s pip

eline

Durin

g UST

remo

val, 2

,000 g

allon

s of w

ater a

nd pe

troleu

m

relea

sed i

nto ex

cava

tion

1NA

~522

02

Y~9

0% of

wate

r and

petro

leum

relea

sed t

o exc

avati

on re

cove

red

SA

802

0Ma

in Ro

ad P

ipelin

eFil

l hos

e rup

tured

whil

e ser

vicing

two U

STs a

t site

, app

rox.

50 to

70

gallo

ns of

petro

leum

relea

sed,

trace

amou

nts of

fuel

dripp

ed

from

ends

of M

ain R

oad P

ipelin

e sec

tion t

empo

rarily

remo

ved

durin

g one

UST

remo

val

2NA

~25

290

2Y

Pipin

g ass

ociat

ed w

ith U

ST 27

089 r

emov

ed, 4

50 ga

llons

of w

ater a

nd

prod

uct r

emov

ed fr

om U

ST 27

089 e

xcav

ation

Tan

ker S

hed

10

Oil/w

ater s

epar

ator,

vehic

le wa

sh ra

ckNo

relea

ses d

ocum

ented

1NA

~530

~55

2Y

None

repo

rted

SA

782

2No

neSo

il con

tamina

tion a

nd/or

fuel

leakin

g fro

m pip

ing co

nnec

ted to

tw

o AST

s and

one U

ST ob

serve

d dur

ing ta

nk re

mova

ls 1a

20

02

YNo

ne re

porte

d

SA

822

1No

neNo

relea

ses d

ocum

ented

21

< 1

Unkn

own

1Y

Durin

g AST

remo

val p

etrole

um-im

pacte

d soil

s abo

ve 3

feet b

gs w

ere

remo

ved.

SA

881

0No

neNo

relea

ses d

ocum

ented

1NA

~26

01

YNo

ne re

porte

d S

WMU

58/S

A 73

61

Oil/w

ater s

epar

ator

JP-5

spille

d fro

m AS

T Ja

n-89

61

~50

3Y

Oil/w

ater s

epar

ator r

emov

ed, fr

ench

drain

insta

lled i

n dra

inage

ditch

es

and d

raina

ge di

tches

back

filled

Yak

utat H

anga

r1

1No

neNo

relea

ses d

ocum

ented

11

~690

~500

2Y

Petro

leum

prod

uct in

terce

ptor t

renc

h ins

talled

for f

ree p

rodu

ct re

mova

l, fre

nch d

rain

instal

led in

drain

age d

itch a

nd di

tch ba

ckfill

ed N

ORPA

C Hi

ll0

2Un

derg

roun

d fue

l pipe

lines

No re

lease

s doc

umen

tedNA

0~1

00

NbTh

e 2 A

STs d

raine

d and

pipe

lines

asso

ciated

with

2 AS

Ts dr

ained

and

purg

ed

AST

- abo

vegr

ound

stor

age t

ank

bgs -

below

grou

nd su

rface

JP -

jet pe

troleu

mNA

- no

t app

licab

leSA

- so

urce

area

SWMU

- so

lid w

aste

mana

geme

nt un

itUS

T - u

nder

grou

nd st

orag

e tan

k

b Monit

ored

natur

al att

enua

tion p

aram

eters

monit

ored

only

once

at th

is sit

e.

Susp

ecte

d or

Kno

wn S

ourc

esCl

eanu

p Ac

tiviti

es

a The r

emov

al of

the se

cond

UST

loca

ted at

this

site c

ould

not b

e con

firmed

. How

ever

, the s

econ

d UST

was

not fo

und d

uring

on-si

te ac

tivitie

s.

Site

Docu

men

ted

Relea

ses


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Investigation and cleanup of petroleum-contaminated sites atthe former Adak Naval Complex have been ongoing since 1986.Adak was initially proposed for placement on the National Pri-orities List in 1992 and was officially listed in 1994. The Navy,as lead agency, entered into a three-party Federal FacilitiesAgreement (FFA) with the U.S. Environmental ProtectionAgency (EPA) and Alaska DEC and a two-party State-AdakEnvironmental Restoration Agreement (SAERA) with the AlaskaDEC to facilitate investigation and cleanup activities.

In 1993, the Navy, EPA, and Alaska DEC signed the FFA, whichincorporates the EPA’s cleanup process under the Compre-hensive Environmental Response, Compensation, and Liabil-ity Act of 1980 (CERCLA) as amended by the Superfund Amend-ments and Reauthorization Act of 1986 (SARA). The CERCLAexclusion of petroleum as a hazardous substance requiredthat cleanup of petroleum-related chemicals would follow Stateof Alaska regulations. Therefore, the FFA stated that petro-leum-contaminated sites, such as those containing USTs andleaking underground fuel lines, would be evaluated under aseparate two-party agreement between the Navy and the Stateof Alaska. This agreement, the SAERA, was signed in April1994.

In May 1997, the Navy and Alaska DEC agreed to integrate thecleanup decision process for petroleum-contaminated siteswith the cleanup decision process being conducted for haz-ardous-substance-release sites under CERCLA. As a result,the Record of Decision (ROD) for Operable Unit A (OU A) was

SITE REGULATORY HISTORY

prepared for both the petroleum-contaminated sites and thehazardous-substance-release sites and signed by the Navy,the EPA, and the Alaska DEC in 2000.

The ROD for OU A selected final or interim remedies for eachof the 128 petroleum-contaminated sites identified on AdakIsland. The interim remedy, free-product recovery, was se-lected for 14 sites that contained measurable quantities offree-phase petroleum product. In addition, the ROD for OU Aspecified that these 14 sites would require future remedy se-lection pursuant to the two-party SAERA. To clarify regula-tory authority, the ROD for OU A was amended in 2003 toremove these petroleum sites from CERCLA authority. There-fore, final remedies for the 14 petroleum-contaminated siteswill be selected in accordance with Alaska State regulation 18AAC 75.325 through 18 AAC 75.390 which provides the regu-latory procedures and requirements for petroleum cleanupdecisions.

This Proposed Plan addresses 10 of the 14 sites. These 10sites (listed in the Introduction) are the sites where the re-maining petroleum-related chemicals pose no risk to humanhealth or the environment above target health goals, pro-vided that institutional controls prohibiting the use of ground-water as a drinking water source remain in effect. The re-maining four sites are those where petroleum-related chemi-cals pose a potential risk to human health or the environmentabove target health goals, and these sites will be addressedin separate documentation.

Physical Characteristics that ImpactRemedy SelectionAdak Island experiences a polar maritime climate character-ized by persistently overcast skies, high winds, frequent andoften violent storms, and a narrow range of temperature fluc-tuation throughout the year. The average total annual pre-cipitation for Adak Island is about 60 inches, most of whichfalls as rain in the lower elevations. Average monthly precipi-tation varies from a low of about 3 inches during June andJuly to a high of 7 to 8 inches during November and Decem-ber. Snowfall averages over 100 inches a year at sea level.

Adak Island consists primarily of volcanic and sedimentaryrocks with a relatively thin mantle of unconsolidated material(generally less than 10 feet) covering much of the bedrock.Only the downtown area is known to have a thick sequence ofunconsolidated material (greater than 100 feet). Surficialdeposits across the island were formed primarily by threegeologic processes: glaciation, volcanic activity, and erosionand deposition. The northern region of Adak is dominated bythe remnants of three volcanoes.

The hydrogeology of northern Adak Island is limited by thelow permeability of native surface materials and bedrock, steepslopes, and discontinuity of sporadically located permeable

SITE CHARACTERISTICSzones. Most undisturbed areas are mantled by tephra (ash)deposits. Combined with steep slopes, these conditions offerlittle opportunity for infiltration. Additionally, the combinationof a thin mantle of unconsolidated material over poorly jointedbedrock results in groundwater that is intermittent and notlaterally extensive. The most notable exception is the later-ally extensive flat area with permeable soil located in thedowntown area.

Groundwater levels are generally 5 to 20 feet below landsurfaces in different areas within the downtown area. Waterlevels in wells typically vary 0 to 2 feet during different sea-sons. Water table responses to tidal fluctuations are mostapparent near tidally affected surface water bodies such asKuluk Bay, Sweeper Cove, and South Sweeper Creek. Tidaleffects in groundwater levels can typically be measured withina couple hundred feet of the surface water body.

Land UseThe former Adak Naval Complex had two main developedareas: Naval Air Facility (NAF) Adak and Naval Security GroupActivity (NSGA). Land uses at NAF Adak, located in the devel-oped downtown area, include aviation, port operations, lightindustrial, administrative, commercial/recreational, and resi-dential. NSGA is located approximately 5 miles northeast of


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NAF Adak, on the northwestern shore of Clam Lagoon. Theprimary land uses during operations at the facility includedlight industrial, administrative, and residential.

Historical, current, and future land use information for the 10petroleum-contaminated sites is summarized in Table 2. ARC,the designated local redevelopment authority, has establishedthe acceptable future uses of land transferred from the mili-tary to The Aleut Corporation. These land uses are commer-cial reuse, aviation reuse, residential reuse, and public facili-ties reuse. The sites classified as commercial reuse includeGCI Compound, SA 78, SA 82, SA 88, and SWMU 58/SA 73.The sites classified as aviation reuse include SA 80, TankerShed, and Yakutat Hangar. A portion of NORPAC Hill is classi-fied as residential reuse, and the remainder is classified aspublic facilities reuse. Locations of the 10 petroleum-con-taminated sites are provided on Figure 2.

Groundwater UseGroundwater has not historically been used as a drinking watersource on Adak Island, nor is it currently being used. Futurehuman use of groundwater on Adak Island as a drinking wa-ter source is not expected because of the following:

Surface water from Lake Bonnie Rose is used as the soledrinking water source on Adak Island.The Interim Conveyance document issued by the UnitedStates to The Aleut Corporation imposes institutional con-trols that prohibit the future use of the downtown ground-water aquifer as a drinking water source.

However, according to Alaska regulations (18 AAC 65.350),groundwater is considered to be a drinking water source un-less it can be demonstrated that the groundwater is not cur-rently being used as a drinking water source and groundwa-ter is not a reasonably expected potential future source ofdrinking water. As stated above, groundwater is not currentlybeing used as a drinking water source on Adak. In addition,institutional controls are in place to prevent the use of thedowntown aquifer as a future drinking water resource. Welldrilling and excavation for the purpose of installing a privateor public domestic use well are strictly prohibited. In addi-tion, any excavation at these sites will require excavation no-tification. The downtown area will be periodically inspectedby driving existing roads to see if there is evidence of domes-tic wells in use. If there is evidence of domestic use of thegroundwater, the Navy will notify the regulatory agencies.

Although institutional controls are in place preventing the useof the downtown aquifer, groundwater is still considered tobe a reasonably expected potential future source of drinkingwater if all of the following conditions apply: 1) the site islocated within the downtown area where groundwater yieldis sufficient to support a water supply well, 2) the occurrenceof groundwater is more than 10 feet below ground surface (ftbgs) (i.e., the minimum well protection and source water pro-tection requirements established for public water systems byAlaska regulations [18 AAC 80.015] could be met), and 3) salt-water would not be drawn into a hypothetical municipal wa-ter supply well during pumping. The sites where groundwa-ter is considered to be a reasonably expected potential futuresource of drinking water are GCI Compound, SA 80, and TankerShed.

Table 2 Land and Groundwater Use Summary

Land Use

Potential Future Groundwater Use As Drinking Water

Site Historical Current Future Yes No GCI Compound

Gasoline station/motor pool Telecommunications facility

Commercial reuse (telecommunications facility)

•

SA 80 Steam plant (1940s-1995) Not used Aviation reuse • Tanker Shed

Aviation-related facility (air transport depot, base operations office, and maintenance facility for tanker trucks)

Not used Aviation reuse •

SA 78 Fire station /transportation garage (1950-1991), office space/storage (1992-1995), vehicle refueling (1960s-1993)

Not used Commercial reuse •

SA 82 Building P-80-NSGA community center and automated data processing and training center, Building P-81-function unknown


SA 88 Auxiliary power generator/storage facility Not used Commercial reuse • SWMU 58/ SA 73

Heating/power plant for the NSGA complex (1950s–1995)


Yakutat Hangar

Airplane hangar/automotive hobby garage Automotive hobby garage

Aviation reuse •

NORPAC Hill

Army barracks, mess halls, Kuluk Housing (constructed in 1960s)

Kuluk Housing Residential reuse (Kuluk Housing), public facilities reuse (remainder of site)

•


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The sites where groundwater is not considered a reasonablyexpected potential future drinking water source are SA 78,SA 82, SA 88, SWMU 58/SA 73, Yakutat Hangar, and NORPACHill. SA 78, SA 82, SA 88, and SWMU 58/SA73 are locatedoutside of the downtown area, where groundwater yield isnot sufficient to support a water supply well. The depth togroundwater at Yakutat Hangar is less than 10 feet; there-fore, the minimum well protection and source water protec-

tion requirements for public water systems established byAlaska regulations [18 AAC 80.015] could not be met at thesite. Finally, NORPAC Hill is adjacent to Kuluk Bay, and watersupply wells located at this site would draw in saltwater fromthe bay. Additional information on groundwater can be foundin the 1995 Groundwater Study Report. Future groundwateruse as drinking water is summarized in Table 2 for all 10sites.

Groundwater Cleanup Levels

Chemical Drinking

Watera (mg/L) Not Drinking Waterb (mg/L)

GRO 1.3 13 DRO 1.5 15 Benzene 0.005 0.05

aTable C values applicable to GCI Compound, SA 80, and Tanker Shed bTen times the Table C values applicable to SA 78, SA 82, SA 88, SWMU 58/SA 73, Yakutat Hangar, and NORPAC Hill Notes: DRO - diesel-range organics GRO - gasoline-range organics mg/L - milligram per liter

CLEANUP LEVELS

Chemical-specific cleanup criteria have been established forcleanup of petroleum-contaminated sites at the former AdakNaval Complex in accordance with Alaska DEC regulation 18AAC 75. The Alaska regulations establish four methods fordetermining cleanup levels for soil [18 AAC 75.340] and threemethods for determining cleanup levels for groundwater [18AAC 75.345]. The Alaska DEC Method Two cleanup levelsestablished to prevent migration of contaminants from soil togroundwater in the over 40 inches of rainfall zone (18 AAC75.341, Tables B1 and B2) were used to estimate the poten-tial extent of soil impacted by petroleum contamination ateach site. The Alaska DEC Method Four cleanup levels [18AAC 75.340(a)(4)], which are based on site-specific risk as-sessments, were used to evaluate what soil cleanup actionsmight be needed at each site. The tabulated groundwatercleanup levels [18 AAC 75.345(b)(1), Table C] or 10 timesthese values were used to estimate the potential extent ofgroundwater impacted by petroleum contamination at eachsite and were used to determine whether groundwater cleanupactions are required at each site, as appropriate.

Under the Alaska DEC Method Four cleanup levels for soil,site-specific alternative cleanup levels (ACLs) may be pro-posed based upon results of the risk assessment conductedfor an individual site. Proposed ACLs are submitted to theAlaska DEC for approval. These ACLs are designated for anindividual site if the Alaska DEC agrees that they are protec-tive of human health, safety, and welfare and of the environ-ment [18 AAC 75.340(f)]. Because the risk assessments forthese 10 sites established that the concentrations in soil donot pose a risk to humans or the environment above targethealth goals at their present contamination level, no separateACLs were calculated and, by default, the existing contami-nant levels at each site become the site-specific ACLs. Therisk assessment findings of no unacceptable risk remain valid

Table 3Alaska DEC Groundwater Cleanup Levels

Cleanup levels specified for groundwater at petroleum-con-taminated sites on the former Adak Naval Complex are basedon the use of groundwater as a drinking water source [18AAC 75.345(b)(1), Table C], or 10 times these levels if thegroundwater is not reasonably expected to be a potential fu-ture source of drinking water [18 AAC 75.345(b)(2)]. As dis-cussed in the previous section, only groundwater at GCI Com-pound, SA 80, and Tanker Shed is considered to be a reason-ably expected potential future source of drinking water. Thegroundwater cleanup levels are provided in Table 3.

providing that the assumed land uses for the site, as per theAdak Reuse Plan (see Summary of Site Risks Section), do notchange. Since the Interim Conveyance document agreementbetween the Navy and the new land owners prohibits resi-dential use of the 10 sites addressed in this plan, the land useassumptions used in the risk assessments are at least as healthprotective as the future uses allowed under the Interim Con-veyance document.


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EXTENT OF CONTAMINATIONVarious environmental field investigations were performed atthe 10 petroleum-contaminated sites between 1991 and 2002.Based upon the results of these field investigations, the po-tential extent of contamination at these 10 sites was esti-mated for free product, soil, groundwater, surface water, andsediment. Extent of contamination for soil and groundwaterwas estimated by comparing site concentrations to the AlaskaDEC cleanup levels as discussed in the previous section. Moredetailed information for each of the 10 petroleum-contami-nated sites is provided in Part 2 of the Site CharacterizationReport.

Free ProductMonitoring wells at the 10 petroleum-contaminated sites havebeen gauged for the presence of free product at regular in-tervals between September 1996 and October 2002. Thedates of free-product monitoring, the number of wells moni-tored, the number of wells in which free product was de-tected, the maximum measured free-product thickness, thedate of the maximum measured free-product thickness, andthe date that free product was last observed are provided inTable 4 for each of the 10 sites. Information provided inTable 4 shows that, for most sites, free product was detectedinitially in relatively few wells, and in some cases has notbeen seen in any on-site wells for several years. Specifically,

free product has not been detected in any of the wells at GCICompound, SA 82, Yakutat Hangar, and NORPAC Hill duringthe most recent year of monitoring for these sites (either2001 or 2002, depending on the site). The extent of freeproduct at the other six sites has been significantly reducedas a result of free-product removal at these sites. Free-prod-uct recovery has been completed to the maximum extent prac-ticable at all sites, except Tanker Shed.

Soil and GroundwaterThe extent of soil and groundwater impacted by petroleumcontamination at each site was estimated by comparing ana-lytical results to the Alaska DEC cleanup levels. For ground-water, only the most recent analytical result available for eachchemical at each location is compared to the groundwatercleanup levels to determine the extent of groundwater con-tamination, because this data represents the current condi-tions at the site. As shown in Table 5, diesel-range organics(DRO), gasoline-range organics (GRO), naphthalene, benzene,ethylbenzene, toluene, and total xylenes were detected atconcentrations above the applicable Alaska DEC cleanup lev-els in soil and groundwater. Concentrations of petroleum hy-drocarbons did not exceed the applicable Alaska DEC ground-water cleanup levels at four sites: SA 82, SA 88, YakutatHangar, and NORPAC Hill. The exceedances above cleanup

Table 4 Extent of Contamination - Free Product

Table 5 Contaminants Detected in Soil and Groundwater at ConcentrationsGreater Than Applicable Alaska DEC Cleanup Levels

Notes:DRO - diesel-range organicsGRO - gasoline-range organicsGW - groundwaterS - soil

a Free product recovery activities are ongoing at the Tanker Shed site.

a


9

levels do not represent a human or ecological health risk asdetermined by the risk assessments (see Summary of SiteRisks section).

Surface Water and SedimentPetroleum hydrocarbons were detected in surface watersamples collected from SWMU58/SA 73. Petroleum hydro-carbons were also detected in freshwater sediments at SA

78 and SWMU 58/SA 73, and in marine sediments at SA 78and NORPAC Hill. These four sites (SA 78, SWMU 58/SA 73,and NORPAC Hill) were the only sites where surface waterand sediment could potentially become impacted by petro-leum hydrocarbons. The detected petroleum hydrocarbonsdo not represent a human or ecological health risk as deter-mined by the risk assessments (see Summary of Site Risksbelow).

Nine human health and ecological risk assessments were con-ducted to determine if residual petroleum at the free-productrecovery sites would pose an unacceptable risk to human healthor the environment if no cleanup actions were to take place.Note that a single risk assessment was performed for thecombined SWMU 58 and SA 73 sites. Sites pose no unac-ceptable risk if the cumulative risk is less than or equal to thetarget health goals established by Alaska DEC.

Risks (human health only) and hazards from ex-posure to petroleum compounds in soil, sediment,surface water, and groundwater were estimatedfor each complete exposure pathway. For humanhealth, risks and hazards were estimated basedon current land use patterns (presented on Table2) and groundwater not being used as drinkingwater because institutional controls prohibiting theuse of groundwater are in place. The completeexposure pathways for human health and the typesof human populations evaluated in the risk assess-ments (e.g., worker populations with only healthyadults versus residential populations that includechildren and the elderly) are presented on Table6. There were no risks or hazards above targethealth goals at any of these sites; therefore, exist-ing petroleum-related chemicals pose no risks pro-vided that institutional controls prohibiting the useof groundwater as a drinking water source remainin effect. Consequently, the only actions neces-sary to protect human health are those related toensuring that the groundwater does not become asource of drinking water.

SUMMARY OF SITE RISKS

Table 6 Summary of Human Health Exposure Routes Evaluated

There were no ecological hazards above the target healthgoal for plants and animals exposed to petroleum compoundsin soil, surface water, or sediment. There are no threatenedor endangered species affected by any of the petroleum re-leases. Therefore, no actions are necessary to protect eco-logical health at any of these sites.


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REMEDIAL ACTION OBJECTIVES

REMEDIAL ACTION ALTERNATIVES

Prevent exposure to petroleum-related chemicals in soiland groundwater at the site

The preferred cleanup alternatives for the 10 petroleum-con-taminated sites are Alternative 2, Limited Groundwater Moni-toring; Alternative 3, Monitored Natural Attenuation and In-stitutional Controls; and Alternative 4, Product Recovery. Al-ternative 2 is the preferred cleanup alternative for SA 82, SA88, Yakutat Hangar, and NORPAC Hill. Alternative 3 is thepreferred cleanup alternative for GCI Compound, SA 80, SA78, and SWMU 58/SA 73. Alternative 3 and Alternative 4 arethe preferred cleanup alternatives for Tanker Shed.

A comprehensive array of remedial alternatives was previ-ously identified, developed, and evaluated by the Navy forthe 128 petroleum-release sites, including the 14 free-prod-uct recovery sites, at the former Adak Naval Complex duringthe 1998 Focused Feasibility Study (FFS), as amended in 1999.The 1998 FFS, as amended, provided the information re-quired to select the preferred remedies for the 128 petro-leum release sites in the ROD for OU A, which was signed in2002. For the 14 free-product recovery sites, the ROD forOU A selected an interim remedy, which consisted of free-product recovery. The ROD for OU A also specified that these14 sites were designated for future final remedy selection.Final remedy selection for 10 of the 14 petroleum-contami-nated sites is described in this Proposed Plan.

The list of cleanup alternatives developed for petroleum-re-lease sites during the 1998 FFS, as amended, was used asthe starting point for identifying alternatives for the 10 petro-leum-contaminated sites addressed in this Proposed Plan.These alternatives are as follows:

Alternative 1, No Action. This alternative is included as abaseline to represent current conditions. No remedial ac-tions are included with this alternative. It is used for com-parison to the other alternatives.

Alternative 2, Limited Groundwater Monitoring.Groundwater monitoring would be conducted to confirm thatpetroleum-related chemicals in groundwater are declining.This approach to cleanup relies on naturally occurring pro-cesses to reduce petroleum concentrations in groundwater.Microorganisms present in soil and groundwater break downpetroleum compounds into harmless chemicals.

Alternative 3, Monitored Natural Attenuation and In-stitutional Controls. Groundwater monitoring would beconducted to evaluate whether petroleum-related chemicalsin groundwater are attenuating to concentrations below ap-plicable Alaska DEC groundwater cleanup levels. Petroleum-

related chemicals that currently exceed applicable Alaska DECcleanup levels would be monitored, as well as natural attenu-ation indicator compounds. This approach to cleanup relieson naturally occurring processes to reduce petroleum con-centrations in groundwater. This alternative also includes in-stitutional controls as an additional means of reducing poten-tial exposure to petroleum contamination.

Alternative 4, Product Recovery. Free product on thegroundwater surface would be collected to the maximum ex-tent practicable using skimmers.

Alternative 5, Limited Soil Removal/Source Removaland Thermal Desorption. Petroleum-contaminated soilwould be excavated and then heated to drive off the petro-leum compounds.

Alternative 6, Ex Situ Bioremediation of Soil. Petroleum-contaminated soil would be excavated and placed in a linedpile for treatment. Air, water, and nutrients would be addedto the soil to encourage microorganisms to break down thepetroleum compounds to harmless chemicals.

Alternative 7, In Situ Bioremediation of Soil, MonitoredNatural Attenuation, and Institutional Controls. Petro-leum-contaminated soil would be treated in the ground. Thisalternative relies on the same naturally occurring microor-ganisms as natural attenuation. However, the growth of themicroorganisms is encouraged by increasing air flow in groundby either blowing air into the ground or by pulling air throughthe soil. This alternative would also include institutional con-trols.

Alternative 8, Soil Cover, Monitored Natural Attenua-tion, and Institutional Controls. Contaminated surface soilwould be covered with a layer of clean soil to prevent contactwith petroleum. Institutional controls would be used to fur-ther limit contact with petroleum chemicals in soil and ground-water. Natural attenuation would cause the petroleum con-centrations to decrease.

Alternative 9, Soil Vapor Extraction/Air Sparging, Moni-tored Natural Attenuation, and Institutional Controls.A vacuum system is used to cause light petroleum compoundsto move to vapor extraction wells. It is only effective for lighterpetroleum materials such as those present in gasoline. Insti-tutional controls would be used to limit potential contact withpetroleum.

The remedial action objectives (RAOs) to be achieved by the preferred cleanup alternatives for these sites are:

Over the long term, reduce concentrations of petroleum-related chemicals in groundwater to levels below AlaskaDEC groundwater cleanup levels


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EVALUATION OF ALTERNATIVESThe results of the 1998 FFS, as amended, were applied tothe selection of the final remedy for the 10 petroleum-con-taminated sites addressed in this Proposed Plan. The criteriaused to complete the alternative evaluation in the 1998 FFS,as amended, were based on EPA guidance, which encom-passes ADEC guidance, and are summarized in Table 7. Stateacceptance and community acceptance are evaluated afterpublic and state comments on the proposed cleanup actions.Therefore, these two criteria were not evaluated in the 1998FFS, as amended, or in this Proposed Plan.

An evaluation of alternatives using the EPA criteria was per-formed separately for each of the 128 petroleum-release sitesat the Former Adak Naval Complex in the 1998 FFS, asamended. In order to summarize the results of the evalua-tions for the 128 petroleum-release sites, the January 1998Proposed Plan for Cleanup Action at Petroleum Sites on AdakIsland presented the evaluations for nine categories of sites.Sites that had similar characteristics were grouped togetherinto the nine categories and a single alternative evaluationwas presented for each category. The categories applicableto the 10 petroleum-contaminated sites presented in this Pro-posed Plan are:

Category 1 – Free-product sitesCategory 6 – Diesel sites, soil concentrations above screen-ing levels (Alaska DEC Method Two Cleanup Levels), with-out buildings over the source area, groundwater risk be-low acceptable risk (groundwater risk is acceptable if con-centrations are less than the Alaska DEC Cleanup Levels -Alaska DEC Table C or 10 times the Alaska DEC Table Cdepending on the site [see Cleanup Levels section])Category 7 – Diesel sites, soil concentrations above screen-ing levels (Alaska DEC Method Two Cleanup Levels), with-

out buildings over the source area, groundwater risk aboveacceptable risk (groundwater risk is not acceptable if con-centrations are greater than the Alaska DEC Cleanup Lev-els - Alaska DEC Table C or 10 times the Alaska DECTable C depending on the site [see Cleanup Levels sec-tion])

The alternative evaluation that was performed for the Cat-egory 6 Sites in the January 1998 Proposed Plan for CleanupAction at Petroleum Sites on Adak Island is applicable to SA82, SA 88, Yakutat Hangar, and NORPAC Hill. The evaluationfor the Category 6 Sites is applicable to SA 82, SA 88, YakutatHangar, and NORPAC Hill because the petroleum concentra-tions in soil at these sites are above the Alaska DEC MethodTwo cleanup levels and the petroleum concentrations ingroundwater are less than the Alaska DEC cleanup levels.The alternative evaluation that was performed for the Cat-egory 7 Sites in that same document is applicable to GCI Com-pound, SA 80, SA 78, and SWMU 58/SA 73. The evaluationfor the Category 7 Sites is applicable to GCI Compound, SA80, SA 78, and SWMU 58/SA 73 because the petroleum con-centrations in both soil and groundwater are above the AlaskaDEC cleanup levels. Finally, a combination of the alternativeevaluations that were performed for the Category 1 Sites andthe Category 7 Sites in the January 1998 Proposed Plan isapplicable to Tanker Shed. A combination of these evalua-tions is applicable to Tanker Shed because free product hasnot been recovered to the maximum extent practicable at thissite and the petroleum concentrations in both soil and ground-water are above the Alaska DEC cleanup levels. It should benoted that Alternatives 8 and 9 are not applicable to any ofthe sites addressed in this Proposed Plan because there areno ecological risks and because gasoline is not the only con-taminant present at any of these sites.

Table 7 CERCLA Criteria


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The alternative evaluations presented in the January 1998Proposed Plan were modified slightly for this Proposed Plan.First, Alternative 2, Limited Groundwater Monitoring, was notevaluated in the January 1998 Proposed Plan. It was addedin the 1999 Focused Feasibility Study Amendment, and anevaluation was never performed for this alternative. There-fore, an evaluation of this alternative was added during prepa-

Figure 3 Figure 4

Figure 5

ration of this Proposed Plan. Furthermore, the site-specificcosts presented in the January 1998 Proposed Plan are notdirectly applicable to the sites addressed in this Proposed Plan.Therefore, the cost evaluation was also modified to providerelative costs. The resulting modified figures are included asFigures 3, 4, and 5.


13

The preferred cleanup alternatives for the 10 petroleum-con-taminated sites that do not pose a risk above target healthgoals are identified in Table 8. In order to maintain consis-tency with cleanup decisions made in the ROD for OU A, the1998 FFS (as amended), the January 1998 Proposed Plan,and the ROD for OU A were reviewed to determine what fac-tors or criteria were used to select the preferred remedy forthe 128 sites addressed in these documents. These factorsor criteria are the suitability criteria listed in Table 9. Becausesite conditions do not pose a risk to human health or theenvironment at any of these 10 sites, remedial alternativesdeveloped for sites that do pose a risk above target healthgoals (Alternatives 5, 6, and 7) were eliminated as potentialpreferred remedial alternatives. Therefore, the list of pre-ferred remedial alternatives that may be selected for each ofthese 10 sites is limited to Alternatives 1, 2, 3, or 4. Productrecovery has already been completed to the maximum extentpracticable at all sites except Tanker Shed. Therefore, Alter-native 4 is potentially applicable only to Tanker Shed.

The preferred cleanup alternative(s) for each of these siteswas selected based on a comparison of site-specific condi-tions to the criteria used to determine the suitability of analternative, as presented in Table 9. A solid bullet in thistable adjacent to a suitability criterion indicates that site-spe-cific conditions match the alternative’s suitability criterion. Analternative is identified as the preferred remedy when site-specific conditions most closely match the alternative’s suit-ability criteria.

Based on these comparisons, Alternative 2, Limited Ground-water Monitoring; Alternative 3, Monitored Natural Attenua-tion and Institutional Controls; and Alternative 4, Product Re-covery are the selected preferred remedial alternatives forthe 10 petroleum-contaminated sites addressed in this Pro-posed Plan. These alternatives will provide appropriate, cost-effective remedies that protect human health and the envi-ronment and that can be implemented at the earliest possibletime. The Alaska DEC concurs with the selection of thesealternatives as the Preferred Alternatives.

Alternative 2, Limited Groundwater Monitoring, is selected asthe preferred remedial alternative for the SA 82, SA 88, YakutatHangar, and NORPAC Hill sites. Alternative 2 is selected forthese sites because groundwater concentrations are not abovethe Alaska DEC cleanup levels (10 times the Alaska DEC TableC values [see Cleanup Levels section]) and monitored naturalattenuation is therefore not required to reduce groundwaterconcentrations to below cleanup levels. Limited groundwatermonitoring will ensure that conditions at these sites do notchange, and concentrations of petroleum compounds continueto decrease. Therefore, Alternative 2 is protective of humanhealth and the environment and complies with Alaska regula-tions. In addition, it provides excellent long-term and short-term effectiveness at a low cost. Finally, Alternative 2 is readilyimplementable.

Alternative 3, Monitored Natural Attenuation and InstitutionalControls, is selected as the preferred remedial alternative forthe GCI Compound, SA 80, Tanker Shed, SA 78, and SWMU58/SA 73 sites. Alternative 3 is selected for these sites be-cause groundwater concentrations are above the Alaska DECcleanup levels. Monitored natural attenuation is needed toreduce concentrations to below the Alaska DEC cleanup lev-els and institutional controls are needed as long as concen-trations are above Alaska DEC cleanup levels. Therefore,Alternative 3 is protective of human health and the environ-ment and complies with Alaska regulations. In addition, itprovides good long-term and short-term effectiveness at arelatively low cost. Finally, Alternative 3 is readilyimplementable. Alternative 4, Product Recovery, is also se-lected as a preferred remedial alternative at the Tanker Shedsite. Alternative 4, Product Recovery, will be performed con-currently with Alternative 3, Monitored Natural Attenuation.Further product recovery will comply with the Alaska regula-tions and will reduce the source of petroleum dissolving intogroundwater.

Site

Limited Groundwater Monitoring

Monitored Natural Attenuation and

Institutional Controls

Product Recovery

GCI Compound • SA 80 • Tanker Shed • • SA 78 • SA 82 • SA 88 • SWMU 58/SA 73 • Yakutat Hangar • NORPAC Hill •

PREFERRED CLEANUP ALTERNATIVES

Table 8 Preferred Cleanup Alternatives for Each Site


14

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15

At SA 82, the Navy will perform a limited soil removal. Thegoal of this limited soil removal is to remove shallow soilspotentially containing elevated concentrations of DRO. Theanticipated volume of soil proposed for removal at this loca-tion will be approximately 22 cubic yards. One soil samplewill be collected from the bottom of the excavation for chemi-cal analyses to demonstrate the effectiveness of the removalactivity. The sample will be analyzed for DRO only. The pro-posed excavation will be performed in conjunction with largersoil removal actions scheduled at other sites on Adak Island.

At SA 80, SA 88, SWMU 58/SA 73 the Navy will perform an-nual free product monitoring as a part of scheduled monitor-ing activities already being performed on Adak. The Navy willremove free product observed in monitoring wells during thescheduled groundwater monitoring activities. The goal of thisadditional free-product removal is to reduce the quantity offree product at these sites to a minimal thickness.

In addition, assessment activities will be performed at SA 80,Tanker Shed, SWMU 58/SA 73, and Yakutat Hangar to sup-port the selection of the preferred remedial alternatives. The

additional assessment activities to be performed by the Navyinclude the collection of additional soil, groundwater (from anew well), and surface water samples as summarized in Table10. Additional soil samples will be collected at SA 80; addi-tional soil and groundwater samples will be collected at TankerShed; additional soil and surface water samples will be col-lected at SWMU 58/SA 73; and additional surface watersamples will be collected at Yakutat Hangar.

Finally, additional remedial activities may be necessary at thesesites in accordance with the Interim Conveyance document, ifthese sites undergo future site development. In the event offuture site development, the Navy will be responsible for ad-ditional remedial actions found to be necessary to properlymanage contaminated materials that have been removed aspart of site development and exceed Alaska DEC tabular val-ues. The Navy will perform the remedial activities providedthat the contaminants were released prior to conveyance ofthe land and that the future site development is consistentwith land uses allowed under the Interim Conveyance docu-ment.

ADDITIONAL ACTIVITIES

Table 10 Additional Assessment Activities


16

The Navy and the Alaska DEC provide information regardingthe 10 petroleum-contaminated sites to the public throughpublic meetings and the information repositories for the site.The Navy and the Alaska DEC encourage the public to gain amore comprehensive understanding of the site and the activi-ties that have been conducted at the site by attending a publicmeeting or reviewing documents in the information reposito-ries. The dates of the public comment period; the date, loca-tion, and time of the public meeting; and the locations of theinformation repositories are provided on the front page ofthis Proposed Plan.

Comments from the public will be used to help determinewhat action to take. We invite you to comment on this Pro-posed Plan. You may communicate verbally or in writing atthe public meeting. If you prefer, you may submit writtencomments during the public comment period by sending themto:

Mark Wicklein, P.E.Engineering Field Activity, NorthwestNaval Facilities Engineering Command19917 Seventh Avenue NEPoulsbo, WA 98370-7570Phone: (360) 396-0226Fax: (360) [email protected]

COMMUNITY PARTICIPATION

After considering public comments, the Navy and the AlaskaDEC will select the final cleanup remedies. The preferredcleanup remedies may be modified from those presented inthe Proposed Plan based on public comments or new infor-mation. The chosen remedy will be described in a Record ofDecision. The Navy will respond to comments on the Pro-posed Plan in a responsiveness summary. The responsive-ness summary will be part of the Record of Decision, whichwill be available for review in the information repositories atthe locations listed on the front page of this plan.

For further information on the Petroleum-Contaminated Sites, please contact:

Mark Wicklein, P.E.Engineering Field Activity,

Northwest Naval Facilities Engineering Command19917 Seventh Avenue NEPoulsbo, WA 98370-7570Phone: (360) 396-0226Fax: (360) 396-0857

[email protected]

Jason WeigleAlaska Department of Environmental Conservation

555 Cordova St.Anchorage, AK 99502Phone: 907-269-7528Fax: 907-269-7649

[email protected]


17

AAC Alaska Administrative CodeARC Adak Reuse CorporationAST above-ground storage tankCERCLA Comprehensive Environmental Response,

Compensation, and Liability Actcu yd cubic yardsDEC Department of Environmental ConservationDRO diesel-range organicsEPA Environmental Protection AgencyFFA Federal Facilities AgreementFFS focused feasibility studyft bgs feet below ground surfaceGRO gasoline-range organics

NAF Naval Air FacilityNSGA Naval Security Group ActivityOU Operable UnitRAB Restoration Advisory BoardRAO remedial action objectiveROD Record of DecisionSA source areaSAERA State-Adak Environmental Restoration AgreementSARA Superfund Amendments and Reauthorization ActSWMU solid waste management unitTPH total petroleum hydrocarbonUST underground storage tank

ACRONYMS

GLOSSARYAdministrative Record. A compilation of documents sup-porting an administrative action. The administrative recordcontains all documents, data, and descriptions of site-specificactions or observations that are used to make decisions aboutthe site.

complete exposure pathway. A path from source(s) ofcontaminant to humans and other species (animals and plants)via soil, water, air, or food. A complete exposure pathwayconsists of the following four elements: (1) a source andmechanism of chemical release (e.g., a leaking undergroundstorage tank), (2) a retention or transport medium (e.g.,groundwater), (3) a point of potential human/ecological con-tact with the affected medium, and (4) a means of entry intothe body at the contact point. If any of these four elements ismissing, the pathway is incomplete and there is no exposureto the chemical.

Comprehensive Environmental Response, Compensa-tion, and Liability Act of 1980 (CERCLA). A federal lawauthorizing action to respond to the release, or substantialthreat of release, into the environment of hazardous sub-stances, pollutants, or contaminants that may present an im-minent and substantial danger to public health or welfare.CERCLA’s emphasis is on the cleanup of old/inactive hazard-ous substance sites; it does not include spills of petroleum,oil, and lubricants.

contamination. Any physical, chemical, biological, or radio-logical substance or matter that is present in soil, groundwa-ter, air, or a combination of these media at a concentrationthat is greater than regulated levels.

diesel-range organics. See the total petroleum hydrocar-bons definition.

ex situ. A method of cleaning up sites where soil and ground-water are removed from the ground and treated above ground.

Federal Facilities Agreement. An agreement between theNavy, EPA, and the Alaska DEC that ensures that the environ-mental impacts associated with past and present activities atthe facility are thoroughly investigated and that appropriateremedial actions are taken as necessary to protect the publichealth, welfare, and the environment.

free-phase petroleum. Petroleum that is present at a siteas a separate liquid, which is usually found as a floating layeron groundwater. Does not include petroleum adsorbed ontosoil or dissolved in groundwater.

free product/free-product. See free-phase petroleumdefinition.

free-product recovery petroleum sites. Sites wherefree-phase petroleum was historically detected and wherepetroleum recovery activities have been implemented.

free-product thickness. A measure of thickness of thefloating layer of petroleum on groundwater.

gasoline-range organics. See the total petroleum hydro-carbons definition.

hazard index. The sum of hazard quotients.

hazard quotient. A measure of the non-carcinogenic haz-ard from exposure to a chemical from a site, which is calcu-lated as the ratio of estimated exposure to a chemical from asite to the estimated safe dose level of that chemical.

hydrocarbons. A large group of chemical compounds com-posed of only carbon and hydrogen.

in situ. A method of cleaning up a site without excavatingsoil or extracting groundwater. Soil and groundwater aretreated in place.


18

institutional controls. Administrative controls that preventhuman exposure to contaminated soils through communityeducation, soil excavation restrictions, groundwater use re-strictions, etc.

Interim Conveyance document. Legally binding documentthat transfers land ownership from one party to another. Mayinclude restricting certain activities on the transferred land.

land transfer agreement. An agreement to transfer theland ownership from one party to another. May include re-strictions on certain activities on the transferred land.

maximum extent practicable. Capable of being designed,constructed, and implemented in a reliable and cost-effectivemanner, taking into consideration existing technology, site lo-cation, and logistics.

moisture regime. Amount of moisture present in the imme-diate vicinity.

National Priorities List. A federal listing of hazardous wastesites requiring cleanup through the CERCLA program.

natural attenuation. The process by which the concentra-tion of contaminants in the environment is reduced by naturalprocesses such as volatilization, dispersion, and microbialdegradation.

Operable Unit (OU). A separate unit or geographic subareaof a site based on geography, geology, or type of contami-nants which is investigated and evaluated separately fromother units at the site.

permeable. Allows water to pass freely through.

Proposed Plan. A document used to facilitate public in-volvement in the remedy selection process. The documentpresents the lead agency’s preliminary recommendation con-cerning how best to address contamination at the site, pre-sents alternatives that were evaluated, and explains the rea-sons the lead agency recommends the preferred alternative.

Record of Decision (ROD). A legal document describingthe remedial actions selected for a site by the lead regulatoryagency.

risk. A measure of the probability that damage to life, health,property, and/or the environment will occur as a result of agiven hazard.

risk assessment. A process for characterizing the currentand potential threats to human health and the environmentthat may be posed by contaminants migrating to groundwa-ter or surface water, being released to air, leaching throughsoil, remaining in the soil, and bioaccumulating in the foodchain. The primary purpose of a risk assessment is to providerisk managers with an understanding of the actual and poten-tial risks to human health and the environment posed by asite and any uncertainties associated with the assessment.This information may be useful in determining whether thereis a current or potential threat to human health or the envi-ronment that warrants remedial action.

State-Adak Environmental Restoration Agreement(SAERA). An agreement between the Navy and the AlaskaDEC to implement site characterization and remediation ofpetroleum sites on Adak.

Superfund Amendments and Reauthorization Act of1986 (SARA). Modifications to CERCLA enacted on October17, 1986.

target health goals. Maximum numeric risk levels estab-lished by a regulatory agency as allowable risks that do notrequire further action. When a risk assessment is conducted,the numeric site-specific risk estimates must be equal to orbelow regulatory target health goals in order for the risk to beconsidered “acceptable”. In Alaska, the target health goal fora carcinogenic compound is 1 x 10-5 (a risk of contractingcancer of 1 in 100,000), and the target health goal for non-cancer chemicals is a hazard quotient or hazard index of one.

total petroleum hydrocarbons (TPH). Total petroleumhydrocarbons is a term used to describe a large family ofseveral hundred chemical compounds that originally come fromcrude oil. Because there are so many different chemicals incrude oil and in other petroleum products, it is not practical tomeasure each one separately. However, it is useful to mea-sure the total amount of TPH at a site. TPH is a mixture ofchemicals, but they are all made mainly from hydrogen andcarbon, called hydrocarbons. Scientists divide TPH into groupsof petroleum hydrocarbons that act alike in soil or water. Thesegroups are called petroleum hydrocarbon fractions. Each frac-tion contains many individual chemicals. The grouping of rela-tively heavier petroleum hydrocarbon chemicals is often re-ferred to as “diesel-range,” whereas the grouping of lighterpetroleum hydrocarbon chemicals is often referred to as “gaso-line-range.” These two ranges of petroleum hydrocarbonsare typically analyzed separately in the laboratory, using slightlydifferent methods.

vadose. Above the water table.


19

COMMENT FORM

Name/Address

Comments

Please mail or fax comments on this Proposed Plan to:Mark Wicklein, P.E.Environmental Operations Team 2, Code 05ER.2Engineering Field Activity, NorthwestNaval Facilities Engineering Command19917 Seventh Avenue NEPoulsbo, WA 98370-7570Fax: (360) 396-0857

If you have special needs or require this document in alternate form,please call Mark Wicklein at (360) 396-0226.


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