StateImpact PA: Dimock Action Memo

0.21 MB·

UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION I
4860 Arch Street
Philadelphia, Porneylvania 19108-2028

Subject: Action Memorandum - Request for Funding for a Removal Action at the Dimock
‘Residential Groundwarer Site, Intersection of PA Routes 29 & 2034
Dimiock Township, Susquchanna Connty, Pennsylvania

Centr Hit.
rom f-mESE Gti on Sen Corner
Tasos Regen Dra SS

JAN 19 208

To: Dennis ¥, Camey, Associate Division Director
Hazardous Site Cleanup Division (3H830)

1 PURPOSE

‘The purpose of this Action Memorandum is to request and document approval of an
emergency reunoval actiou to prevent, limir, or mitigate the threats posod by the presence of
azardons substances at the Dmock Residential Groundwater Site (the “Site"), pursuant fo
Section 104(a) af the Comprehcasive Envisoumental Response, Componsation and Liability Act,
42USC. § $6042) (CERCLA). ‘The Site is located in Dimock Township, Susquehanna
‘County, Pennsylvania, ‘The OSC has initiated a rernoval site evaluation in accordance with the
‘National Oil and Hazardous Substances Pollution Contingency Plan (NCP), 40 C.E-R, Patt 300.
‘The O8C has decermined, based on Pennsylvania Department of Enviromental Protection
{PADEP} and Cabot Oil and Gas Corporation (Cabot) sampling information, consultation with
An EPA toxicologist, the Agency for Toxic Substances and Discase Registry (ATSDR) Record
Of Activity (ARUA), issued 12728/11, and the recent EBA well survey effor, that a number of
‘home wells in the Dimock arca contain hazardons substances, some of which aro not naturally
ound in the environment, Inorgamc hazardous substances are present in four home wells at
Jevels thet present a public health concern, These four specific homes have bosu depudet upon
donated water for drinking andor household use and the reliability ofthe sources for donated
‘water is at tis point uncertain

swore diling activities in the Dimock asea may have used materials containing hazardous
substances. Spills and other releases have beeu documented by PADEP tram these dilling
activities, These is reason to believe that a release of hazardous substances has oceuted. The
presence af hazardous substances ia the four home wells constitutes a release or substantil
threat aa celease and the situation meets the exteria for conducting a seanval actin wader
Section 300.415 af the NCP. The OSC tas determined that tueds in the amount of $100,000 ate
needed ta mitigate the human heallh cancers inilally at four Homes acd therefore propases The
actions included inthis Action Memurandurm. This action includes provision af alternate water
(four homes und home well sampling af approximuely 6) homes within the Site wea,
TL _ SITE CONDITIONS AND BACKGROUND

A, Background
1, Site Description - The Site area 1s located in Dimock, a curl area of northeastern
Pennsylvania ia Susquehianna Caunly. map of the aren i included below,
History-Cabot beg iam -
ddifing for nscual gas
in the Dimock area in
2008. Methane
‘contamination was
detected in private
wells thereatter in
concentrations
exceeding those
previously found
PADEP had the lead
in investigating the
envizouziental
complaints ia
Dimock, PADEP

entered into a Consent

Onder and Agreement
(CORA) with Cabo

‘which required

erenanet restoration

‘of replacement of the

affected water supply. A publie waler line wa initially vonsidered, PADEP later
modilied the CORA w require installation of ges mitigation” systems for 19
Inames served by 18 private sells in the Site area," Until the ges mitigation
ystems were insllled, Cabot was ta provide a termporary water source Some well,
‘owotery, within the scope of the PADEP CO&S, have gas mitigation systems
‘installed, but others do not. While the gas mitigation systems were designed to
remove methane, a potential exists that (acy may remove some hazardous
substances as «by-product oftheir operation. Regardless, KPA does not know
what, if any, hazardous substanocs these “gas mitigation” systems, originally
designed to address methane, ate removing. ‘Therefore, EPA is including both pre-
‘and post-treatment sampling inthe scope of this action. Furthermore, there are

Tt had originally heon reported that 19 homies were served by the 18 wells included within the
svope of the CO&A but the daor-ta-door home well survey conducted to date by EPA has
identified that there are currenily 21 homes served by 20-wells on those same properties
other homes served by private wells thet were wot covered by the seope ofthe
PADEP COMA, but are within this Site aro,

TIL Quantities’ Types «af Subtamess Present

1

Arsenic ~ Arsenic is a naturally occurring element widely distributed inthe
eats crust, Arsenio may also he present at elevated eonentratiems in the
groundwater due to the use and effects af drilling fluids. Arsenic is clasified
az a known buman carcinogeo. This clasitiation is hased an animal and
toaovan studies, which indicate an increased risk for developing cancers of the
skin, lung, bladder, kidney, liver, and prostate frara consuming arsenic
containing water. Noo-cancer health effects associated with ingestion of
arsenic include eirculasory probleras and skin damage.

Barium Bariura isa silvery-swhite metal tht exists in nature only in ores
containing mixtures of elements. Ic combines with other vhemivals yuch as
sulfur or carbon and oxygen to form harium compounds. Tarium sulfate is
sometimes used by doctors to perform medical texte und tp lake x-rays of the
gastrointestinal tact. Ingesting drinking water eontaining levels of barium
above die EPA drinking water guidelines for relatively short periods of time
can cause pastrofntestinal disturbances and muscle weukress. Ingesting high
Ievels for along time can damage the kidneys. Barium iy known to be 8
‘common constituent of drilling fluids,

Bis(2-ethythexyl)phthalate (DEHP)* - DEYIP isa manufactured chemical that
is commonty added to plastics wo make them flexible. The phlbslates are
generally considered co be of slight to moderate loxicity. DEHP may be
fnrtatiog to the eyes, ski, andl mucous membranes. Mild gastric disturbances
and diarrhea may occur following ingestion of larger doses. Central nervous
system (CNS) depression may occur if Targe amounts of phthalnte acid esters
fre absorbed. EPA has determined that DEITP is a probable human
carcinogen. These determinations were based entirely on liver concer ja ras
and mice. DEHP is known to he associated with drilling activities.

Glycol Compounds (including Ethylene Glyeal® md 2-Methexyethanol) —
Glycol compounds are a class af organic compounds belonging ta the sleohol
amily. Exposure ta large amounls of ethylene glycol can damage the
Kidneys, nervous system, lungs, and heart. Exposure te high concentrations of
2-rmethoxyethanol is usscciated with testicular damage, impaired nervous
system, and anemia. Glyeols are known ta be common in drilling dvids
“Mangimese* ~ Mangmnesc is naturally oocurting substance found in many
lypes of rock and soil. Manganeveis alsa known to be a constituent of some
specialized drilling Quid, Eating small amouat of manganese from food oF
‘water iy needed to stay healthy. At high levels, it can cnuse damage to the
nervous system,
6. Phenol - Phenol is both» manufsetured chemical and a natural substance
Phenol is used as a disinfeotant and is found ia a number af cemsumer
products, Skin exposure to high amounts can produce skin burns, liver
smug, deck uring, and iegular heart beat. Various phenols nre commonly
sssovinted with drilling fluids

7. Sodium ~ Sodium is an essential nmtient and accu aaturally ia most foods,
Fxeossive sodium intake is associated with high blood pressure, Various
solium containing compounds are sociated with driling fluids

A hacardous substanes, as defined uader CERCLA Section 101(24) and designated ia
Section 302.4 of the Nacional Contingency Plan (NCP), 40 CFR. Section 302 4

B. National Priovitiew Lint

‘The Dimock Resideotial Groundwater Site ix not en the CERCLA National Priorities Lint
APL).

C. State and Local Authorities’ Roles

‘Cabot had been sampling the home wells and providing bottled drinking water and
alternate waler for non-potable use, through a Canseak Ordes ard Ayreememl (COSA) with
PADEP. The COMA supplies only ta specific list of homes, and does not inclule other homes,
also located within the sume geographic arca, Some ofthese addiviual humes have had limited
sampling conducted by Cabot and/or PADEP, PADEP determined thal Cabot hus complied With
the terms of the COMA, as it applies to the provision of temporary water, and subseuuently
approved Cabos request ta stop the delivery of alternate wate.

AV, THREATS TO PUBEIC HEALTH OR WELFARE OR THE ENVIRONMENT

Seetion 300.415 of the NCP lists the factory ts be considered in determining the
appropriateness of a Removal Action. Paragraphs (b)(2)6), (i), aud (vi) of Section 300.415
directly apply to the conditions found st the Dirmack Residential Groundwater Site

{In evaluating the situation, the OSC fies considered whether hazardous substances were
present io a home well. The levels of those hazardous substances were then coosidered ugainst
primary Maximum Contaminant Levels (MCLs), ‘They were also considered lor non-cuncer risk
to determine ifthe levels uemerate a hazard quoticnt greater than 2. The presence of inorganic
and organi chemsieas in 2 number of wells supports the need for this ction.
300415 (b\2)()__ “Actual oF potential exposure to nearby human populations,
tamimals or the food chatn fram hazardous substances ar
pollutants cr contaminants”

‘The hazardous substances listed above, present in water frou home wells a tis Site
based on sampling data described below, onuld cause adverse health impacts when chronic
exposure [bough drinking water or other unex of water in the home occurs, There sre other
contaminants discussed in the Agency for Toxie Substances und Disease Registry"s (ATSDR)
Reoard of Activity (AROA) issued on Decemher 28, 201 |, which could also cause adverse
health impsets. ATSDR has concluded for the area originally included wth the PADEP‘Cabot
CORA. which includes the four homes being considered lere for altemate watcr, that a chrouic
heath risk exists for most tells ani thal the siluation supports « "Do Not Use the Water” action
including the consideration af alterative home water supplies until further characterization i
completed. Au BPA Regioa Il toxicologists opiion is that, of the homes evahated to date in
an on-going cffor, hat four home wells coneain comamunants ac levels that present a public
hhealth concem. Ione home, manganese was detected at 628 ugiL. Exposure to this
concentration would yield a Hazard Quotient of approximstcly 2, Tn snother home, mangaucse
(1360 uyyD) wats detected ata level that yenerates a Havard Quotient of appronimately 4. Note
that children reside at dus location. In the third horne, arsenic was observed ata eoncentation
(37 ng/L) that exceeds its MCL of (10 ug/L} aud would pose a long-term cancer risk of Sk-D4.
‘Note that children roside at this Jncarion, ln tho fourth home, manganese was detoeted at 669
ugiT. Fapaure to thiy concentration would yieul a Hazard Quotient of approximately 2.3,
‘Available data also indicate that hazardous substances may he ptesent in a mumher af other
hhomes, Because the available daa is nor comaplete and is of uncertain quality, additional
sampling is nocded to Tacilitte a rther cvalustion of any poceutial health conoetus from the
drinking wer at home sells in the Site en

RPA ix providing water hase upoo a risk of expasune to hazardows substances shove
hhealth-hased levels, Turlhermore, the OSC notes thul fr those homes where the UPA
‘oxicologist has not identified contaminants thar present a public health concern, thatthe limited
data available does identify the existence of hazardous substances, 1n addition, PADED"s CORA
determined that 18 home wells were impactod by drilling activities; veh impact may be
cevidlenve uf Due migration of huzardowy substances,

Again, ite noted that this determination ix haved upon dala which was culleved by
pauties other than EPA (Cabot sad PADEP). The quality assuranceiquality vontral (QA/QC)
infomation bas not been verified. However, what is cleat is that this data stungly suggests that
luxzardous substances have been released anc are present in some home wells at levels that may
prescat « public health concern. Current data docs show arsenic and muuganese at higher levels
‘than may be typically found, in post duilling samples, Since arsenic and manganese are naturally
oveuring substances, PA'S assesment will include compurisons af hackgrounl ecncentrations
‘nd post delling concenttations present, EPA mutinely aot under CERCLA ta protect public
health frst while ic act to further define convaraination. Thus, within this aetioa, EPA vill
complete an assessment ofthe warer quality of the home wells in the Site area to close
information gaps as soon as possible. ‘This sampling will be focused intially on evaluating
those homes inthe Site arce that have been sempled inthe past, Beyond tha, sampling st homes
will he bused upon a sermpling rationale wing information regarding alleged health impacts and
<data gaps. In addition, KPA will contime to evaluate the updated dats, and may revise ity uctions
lo provide water to any of the additional homes, or to cease provision of water, as warranted hy
‘he data

300.415 (h)@2)Gi) “Actual or potential contamination of driuking water supplies
oF sensitive ecosystems”

‘The discussion of 300.415 (H) (2) (f) ahove applies to thy fuclor. Roth organic and
inorganic contaminants have been detected in home Wells. Although thia action is predominantly
‘brsed upon inorganic data at the four homes, ic should be noted that organic compounds have
been deiected wl other homes as detailed in the ATSOR AROA. Glycol detections included
ethylene glycol, triethylene glycol, and 2,2"oxybisethanol (diethylene glycol), Some wells had
all tee reported glycols present in their wells bul no excordanees of risk based serceuing
‘uteri (note: the aualytical detectiva level used appeared to be higher Ihan screening levels),
Bis@2-cthylhexyl) phthalate (DEHP) was detected in tive samples and ranged ftom 0.14 wy. to
22 upil.. -methoxyethanel concentrations (ranging dram 880 ug/L to 1,200 ug/L) were detected
‘in each of six wells

300-415 () (2) (vi) “The availabilty of other appropriate federal or state response
mechanisms co respond tothe release”

‘The four homes being vonsidevel fr alerts wat under this action were all dependent
‘upon donated water, either bottled, water bullaloes {tamporury storage tanks) or both, Tt isthe
O8C's understanding thatthe lst delivery of bulk water Gram ose organalom veased on
January 3,2012. In any case the reliability of sources for donated wate is at best uacertin

PROPOSED ACTIONS AND ESTIMATED COSTS.
A. Proposed Action
1. Proposed Action Description

‘Throughout dhe duration oF Site activities, all personnel involved wth cxecntion of this
proposed action will comply sith the requirements of CERCLA and with al athcr applicable
Federal and Stale regulation to the extent practicable cpasidering the cxigencies of the situation,
in acwordance with 40 CFR § 300.415(). Available data indicate that « number af homes in the
trea have havandous substances prescat in the home wells, bur only four indicate concenteations
‘identified hy the EPA toxicologist ata level of eonec, Thus, those four homes will be
‘icrmedliately supplied sith wafer. At the same time, approximately 61 hone wells will be
srupled by EPA to obtain data of known quality assurance to support future evalualions and
respanse decisions. EPA will continue to evaluste the updated daca, and may revise its uetiums
provide water to any of the additional homes, orto cease provision of water, ax warranted by the
sta, The Removal activites atthe Site will iuelude the following:
L.— Mobilize and demohitize personnel und eyuipment te coilucl the action;

2 Delivery of a temporary souree of elean water for houschold use to the
‘owe (4) Homes with wells that comlain contaminants levels of public
bbealdh caneer. This provision of temporary water vill continue until,
potential expaures are further understnnil and mitigated a4 needed

3. Theaampliny program will include anulysin tor a broad range of
parameters with a special priority heing placed on quick turearound for
those pararneters which are most frequently observed inthe data available
to FPA at this time. The Ayency val! alsa da some Himited sampling for
‘methane und bacteriological conetitusnts, Home woll water sampling will,
dhe performed by TPA in the Site area using the following assigned
privrity:

3, The four (4) homes considered for provision of altemate water, 0
assess the potential exposurc to hszardous substances aud to determine
‘whether vontinued temporary provision of clean water for household
vse is required,

fi. The seventeen (17) zemaining homes located on properties included in
the PADEP/Cabot CO&A?, which were identified as being impacted
by drilling activities,

Jif. Approximately thity (30) additional homes in the immediate area that
‘wave hee sump nthe past

fv. Additional homes io the Site area where ume or mare of the fastory
below supports sampling,

1. Ditost abservation or acher evidence (hame well surveys} of
adverse health effeors potentially attributable to contaminated
groundwater vse,

2, ‘Where data gops in groundwater measurement or sampling
need to be filled to gain an adequate understanding of Site
eondifions.

Approximately teo (J0) homes are currently identified from well
survey, bul more enuld be aided bayed upon data review.
4. Maintain necessary documentation of Site netivities.
5, Develop and implement appropriate health und vafely profuvols forthe
removal activity.

11 hac originally been reported that 19 homes were served by the 18 wells included within the
scope of the CORA but the door-to-door home well survey conducted to date by EPA has
identifi that there are currently 21 homes servod by 20 wells on those same propertics.
2, Contefbution to Remedial Perfarmance

A remedial action is not anticipated and therefore this removal action is not neonsisteat
‘with any proposed romedial action

3. Applicable nr Relevant nd Appropriate Requirements (*ARAR#”)
Actious will be conducted in curoptiance with Applicable or Relevant and Approptiste

Regulations (ARARs) tothe exsent practicable considering the exigencies of Ihe situation, in
accordance sith 40 CFR 300.4154),

B. Estimated Couts
Extramural Costs Total

Regional Allowance Chste: (ERRS $ 50,000
Contactors and Subeomtraetors)

Other Extramural Costs Not Funded 525.000
From the Regional Allowauce:

START Contractor

Subtotal, Extramural $75,000

Extramural Costs Contingency $ 25,000

‘Tutal Removal Action Project Ceiling ss100.000

YL EXPKCTED CHANGE IN SITUATION SHOULD ACTION BE DELAYKD OR
NOT TAKEN

If'ne action ia taken, the residents may utilize well water which poses a potential public
wealth vonern,

VO. OUTSTANDING POLICY ISSUES

‘Because this response action could be considered mations significant or rosedent
setting, itrogpires the prior concurrence of the Assistant Administrator, Office of Solid Waste
and Frmergency Response (AA-OSWER), Furthermore, because the action uppears lo be
nationally significun! andor precedent-stting, the Region will continue ta coordinate closely
wath Headquarers. EPA also will maintain evordination and commnaicationa with PADEP. In
(alung this action, EPA is aware of and has considered the potential applicability of the natural
gs exclusion under CERCLA, the Bentsen Amendment under Ihe Resouroe Conservation and
Recovery Ast (RCRA), aud the exclusions to the definition of ‘underground injection’ wuder the
Safe Drinking Water Act (SDWA). BPA has concluded that this uclion is appropriate under
CERCTA al this time,
VOI. ENFORCEMENT

‘The total FPA eosts for this removal astion based opon full-cost aocounting practices that
will he eligible for eon! reanvery are estimated below wy follows!

Direct Berramucal Costs 100,000
Direct Intramural Costs S 25,000
Total Direct Costs 125.000
Indirect Cost (67.13% x Direct Costs) $83,012
Total Costs (Direct and Indirect) $208,912

1X, RECOMMENDATION

‘This Action Memerandum represents the seloctod Removal Action for the Dimack
Residential Groundwater Site In Dinnock Township, Susuetuarma County, Peemsylvania,
developed in accordance with CERCLA, as amended, and is consistent with the NCP. This
decision is based on the administrative record forthe Site, The administrative record consists of
the following documents

1, 1/13/12 “Dimack Home Well Data” memo from PPA Toxieologist Dawn Joven,
ATSDR AROA Issued 1228/11
Summary af Portions of data reccived by FPA and reviewed by the OSC
PADEP Conseat Order ancl Agreement. dated December 15, 2010.

EPA Data Revieve Memo, Ianusry 13, 2012
TPA 104 request to Cabot, January 6. 2012

Conditious at the Site mest the Removal Action requirements ot Section 300.4150) af
the NCP aud 1 recommend your approval of the proposed removal sction and exemption fren
the statutory limits, The total project ceiling, if approved, will be $100,000. OF this, as much as,
$350,000 comes from the Regiemal removal allomance, Please indicate your approval oF
‘disapproval below.

> Direct Costs include direct extramural coats and direct intramural casts. Tndineut enste are
caleulated based on an estimated indirect cost rate expressed as a percentage of site-specific
dlreet costs consistent with the full cost accounting methodology cffective October 2, 2000,
‘Those catiates do not include pre-judgment interest, da not take into account other enforcement
cots, including Department of Jusice costs, and may be adjusted during the course of removal
action. ‘The estimates ate for Mustrative purposes anly and thefr use in nol inerved to erente any
1ights tor responsible partes. Neither the lack of a tote enst estimate ane deviation of avLual
total costs from this estimate will affect the United States’ right to cost eevevery.
Action by the Approving Omi!

Thave reviewed the above-stared facts and, bined upon thove fauts and the information
camped in the documents described above, [hereby approveldisapprove the selected removal
action,

aprnoven: cena (ens parn__/s/zera

‘Dennis P, Camoy, ASsociate Division Ditector
Hazurdous Site Cleanup Division
EPA Region 3

DISAPPROVED: DATE,

Deanis P. Caney, Associate Division Director
Hazardous Site Cleump Division
TPA Region 3