United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R01 -92/070
September 1992
PB93-963705
Superfund
Record of Decision:
Town Garage Radio Beacon,
-------
50272.101
REPORT DOCUMENTATION 11. REPORT NO. 1 ~ 3. Reclplent'e Acce88lon No.
PAGE EPA/ROD/ROl-92/070
4. TItle and Subtitle 5. Report Dete
SUPERFUND RECORD OF DECISION 09/30/n
. Town Garage Radio Beacon, NH
6.
First Remedial Action - Final
7. Aulhor(e) 8. Perlonnlng OrgeniDtion Rept. No.
9. Perlonnlng Orgelnizatlon Name end Address 10. ProjecllTuklWork Unit No.
11. Contrsc1(C) or Grsnt(G) No.
(C)
(G)
12. Sponaorlng OrgenizeUon Name end Address 13. Type 01 Report & Period Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. SUpplementary Notee
PB93-963705
16. AbetreC1 (Umlt: 200 worde)
The Town Garage Radio Beacon, NH, site includes the Holton Circle residential
development of 23 homes, a town garage area, and an undeveloped hillslope and wetlands
area in Londonderry, New Hampshire. Excluding the town garage, land use in the area is
predominantly residential. Drinking water is obtained via private bedrock wells, with
the exception of nine residents on Holton Circle and residents of the adjacent Isabella
Drive development who are connected to a public water supply. The site overlies a
Class IIb aquifer, which is a potential source of drinking water. From 1940 to 1968,
the area was owned by the Department of Defense (DOD), who reportedly used it as a
radio beacon facility from 1940 to 1947. In 1968, the property was transferred to the
Town of Londonderry. Eight acres of the property were used as a garage to store town
vehicles, along with road sand and salt, and to perform routine maintenance on the
vehicles; 12 more acres were given to the Londonderry Housing and Redevelopment
Authority. Site contamination was discovered in 1984 when Holton Circle residents
requested that the state sample their bedrock wells. Resulting investigations. showed
VOCs at levels above federal and state drinking water standards. The state has
continued to monitor the wells onsite and notes that decreasing concentrations of
(See Attached Page)
17. Document Anelyele L Deecrlptors
Record of Decision - Town Garage Radio Beacon, NH
F~rst Remedial Action - Final
Contaminated Medium: gw
Key Contaminants: VOCs, metals (chromium)
b. Identifier8l0pen-End8cf T IIrII18
c. COSA 11 FIeIdIGroup
18. AveilebiMty Sletement 18. Security CI..e (Thie Report) 21. No. 01 Pell"
None 120
20. Security Cle.. (Thle Pager 22. PrIce
None
See AN~Z38. 18 ~e Instrucuons on R..,.t8B )
(Formetty NTlSo35)
-------
o
EPA/ROD/ROl-92/Q70
Town Garage Radio Beacon, NH
First Remedial Action - Final
Abstract (Continued)
l,l,l-TCA and increasing concentrations of 1,I-DCE and 1,1-DCA demonstrate that a
degradation process is occurring. This ROD provides a final remedy for the contaminated
onsite ground water. No further remedial actions are anticipated for the site. The
primary contaminants affecting the ground water are VOCs; and metals, including chromium.
The selected remedial action for this site includes allowing the contaminated ground
water in the overburden and bedrock aquifers to naturally attenuate; implementing
institutional. controls including deed restrictions to prevent future use of ground water;
monitoring ground water; and implementing a contigency remedy to provide an alternate
water supply to affected residences in the event that contaminants in the drinking water
wells reverse their historical trend and concentrations begin increase beyond the
clean-up levels. There are no capital costs associated with this remedy; however the
estimated present worth O&M cost for this remedial action is $1,250,000.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific interim ground water clean-up levels.
are based on SDWA MCLGs and state standards and include 1,1-DCE 7 ug/l; 1,1,1-TCA
200 ug/l; antimony 6 ug/l; beryllium 4 ug/l; chromium 100 ug/l; and barium 2,000 ug/l.
Three years after these levels have been achieved, a riSk assessment will be performed to
-------
DECLARATION FOR THE RECORD OF D~~ISION
Holton Circle Groundwater Contamination site
Londonderry, Hew Hampshire
STATEMENT OF PURPOSE
This decision document presents the selected remedial action for
the Holton Circle Groundwater Contamination Site in Londonderry.,
New Hampshire, developed in accordance with the Comprehensive
Environmental Response, Compensation and Liability Act o~ 1980
(CERCLA), as amended by the Superfund Amendments and.
Reauthorization Act of 1986, and to. the extent practicable, the
National oil and Hazardous Substances contingency Plan (NCP), 40
CFR Part 300 et sea., as amended. The Region I Administrator has
been delegated the authority to approve this Record Of Decision.
The State of New Hampshire has concurred on the selected remedy.
STATEMENT OF BASIS
This decision is based on the Administrative Record which has
been developed in accordance with Section 113 (k) of CERCLA and
which is available for public review at the Leach Public Library
in Londonderry, New Hampshire and at the Region I Waste
Management Division Records Center in Boston, Massachusetts. The
Administrative Record Index (Appendix F to the ROD) identifies
each of the items comprising the Administrative Record upon which
the selection of the remedial action is based.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous. substances from this
Site, if not addressed by implementing the response action
selected in this ROD, may present an imminent. and substantial
endangerment to the public health or welfare or to the
environment.
DESCRIPTION OF THE SELECTED REMEDY
This ROD. sets forth the selected remedy for the Holton Circle
Groundwater Contamination Site, which involves natural
attenuation of contaminated groundwater in the overburden and
bedrock aquifers, with institutional controls to prevent future
ingestion of contaminated groundwater. The selected remedy is a
comprehensive approach which addresses all potential future risks
caused by the groundwater contamination at the Site. There are
no current risks posed by the site. The remedial measures will
-------
u.s. ENVIRONMENTAL PROTECTION AGENCY
REGION J:
- --
9/30/9~ -'
-
RECORD OF DECISION
Holton Circle Groundwater-contamination site
Londonderry, New'Hampshire
-.
.
-------
2
groundwater and will restore the overburden and bedrock aquifers
to their beneficial uses.
The selected remedy includes four main components:
1.
restoration of contaminated groundwater in the
overburden and bedrock aquifers by natural attenuation:
2.
institutional controls:
3.
groundwater monitoring: and
4.
an alternate water supply contingency.
-..
DECLARATION
The selected remedy is protective of human health and the
environment, attains Federal and state requirements that are
applicable or relevant and appropriate for this remedial action
and is cost-effective. .
The selected remedy relies on natural attenuation to restore the
contaminated groundwater to its beneficial uses, therefore the
selected remedy does not satisfy the preference for treatment
which permanently and significantly reduces the toxicity,
mObility or volume of the hazardous substances as a principal
element. Treatment will not be utilized to restore the
contaminated groundwater because it was determined not to be
warranted or cost effective considering the conditions at the
site. Active restoration does not afford a significant cleanup
time advantage i~oeither the bedrock or the overburden aquifer.
The selected remedy is as protective of public .health as active
restoration.
.-
OSWER Directive 9355.7-02 states that five-year reviews will be
conducted at sites where cleanup levels will take' five or more
years to achieve (policy review). Therefore, a review will be
conducted within five years after commencement of this remedial
action to ensure that the remedy continues to provide adequate
protection of human health and the environment.
-
ulie Belaga
Regional Administrator
u.s. EPA, Region I
¥c,3lJ
Date J
1172/
-------
Contents
II.
zzz.
ZV.
VI.
VII.
VIII.
IX.
XI.
XII.
nzz.
Holton Circle Groundwater
. Contamination Site
TABLE OF CONTENTS
I.
SITE NAME, LOCATION AND DESCRIPTION.
SITE HISTORY' ENFORCEMENT ACTIVITIES
. . . . . . . .
. . . .
. . . .
A.
B.
Land U.e , Response Bis1:ory . . . . . . .
Enforcement History. . . . . . . . . . .
. . . .
. . . .
t'Y\tfMm1I1'Y PU1'ZCJ:PUZOJl . . . .
. . . . .
. . .
. . .
SCQRS ~ ~ lJE n~~:a~I,B 1D1Z1' oa UBPOJIQ: 16C:rJ:OJJ
. .
V.
SUMMARY OF SI~E CHARACTERISTICS. . .
. . . .
. . . .
SUMMARY OF SITE RISKS. .
. . . . .
. . .
. . . . . .
DEVELOPMENT AND SCREENING OF ALTERNATIVES.
. . . . '.
A.
'B.
statutory Requirements/Response Objectives
~.ChDOlo9Y aDd U'ternative 2)eyeJ.opm8D1:
and screening. . . . . . . . . . . . . .
. . .
. . . .
DESCRIPTION OF ALTERNATIVES. . . . . . . . .
. . . .
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES.
X.
THE SELECTED REMEDY. . . . . .
. . . . . . .
. . . .
A.
B.
Interim Cleanup Levels. . . . . . . .
Description of the Remedial Components
. . . . .
. . . . .
STATUTORY DETERMINATIONS
. . .
. . .
. . . . .e
. . .
A.
The selected Remedy is Protective of Human
Health and the EDYiranmen't ... . . . . . . . .
The Selected Remedy Attains ARARs . . . . . . . .
The Selected Remedial Action is Cost Effective.
The Selected Remedy utilizes Permanent Solutions
and Alternative Treatment or Resource Recovery
Technologies to the Maximum Extent Prac~icable .
The Selected Remedy Does Not satisfy the Preference
for Treatment as a principal Element. . . . . .
B.
c.
D.
E.
DOCUMENTATION OF NO SIGNIFICANT CHANGES
. . . . . .
EAR ROLB
. . . .
......
. . . .
. . . . . . .
paae Number
1
1
1
2
2
3
4
14
21
21
22
22
27
34
34
38
41
41
42
43
44
45
46
-------
APPENDICES
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
APPENDIX
A - Fiqures
B - Tables
C - ARAR tables
D - New Hampshire Letter of Concurrence
E - Responsiveness summary .
F - Administrative Record Index
-------
I.
SITE NAME, LOCATION AND DESCRIPTION
The Holton' Circle Groundwater Contamination Superfund Site (Site)
is located north of Pillsbury Road near the intersection of
Pillsbury and High Range Roads in Londonderry, New Hampshire.
The Site study area includes a residential development of 23
homes (Holton Circle), the Londonderry townqaraqe area located
on High Range Road, and an undeveloped hillslope and wetland area
between the town garage and Holton Circle (see Appendix A, Figure
~ - Site Location Map).
The Holton Circle residential development, and the adjacent
Isabella Drive development, are located on a knoll which is
surrounded by wetlands on three sides. 4fhe IDndonderry'town
garage and radio beacon areas are also located on a knoll which
is situated ap~'roximately 500 feet to the west, and upgradient of
Holton Circle. Betwee:1 the town garage and Holton Circle exists
approximately 20 acres 'f an undeveloped hillslope area and a
wetland. Excluding tt. town garage, land use in the immediate
Site area is predominG~,~ly residential. Drinking water in the
area is obtained via private bedrock wells except for nine
residents on Holton Circle and the residents of Isabella Drive,
all of whom use public water from the Southern New Hampshire
Water Company. A more complete description of 'the Site can be
found in the Remedial Investigation Report (March 1992) on pages
1-1 to 1-2 of Volume I.
II.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
A.
Land Use and Response History
The Site was discovered in 1984 following a request to the State
by residents of the Holton Circle development to sample their
bedrock wells. Sampling results from the New Ham[1ire
Department of Environmental Se~lices (NHDES) reve". "d the
presence ot volatile organic compounds (VOCs) in several of the
residential drinking water wells and the nearby town garage well.
The major contaminants detected include ~,1 dichloroethene (1,1-
DCE) and 1,1 dichloroethane (l,l-DCA) at levels above federal and
state primary drinking water standards.
A Preliminary Assessment (PA) completed by EPA in 1985 confirmed
the presence of VOCs but did not determi~e a source for the
contamination, though several potential source areas were
identified. From 1985 to 1989, the NHDES continued to monitor
residential wells in the area on an informal basis. During 1988
and ~989, the Southern New Hampshire Water ~plpany extended
public water supply service to Holton Circle and the adjacent
Isabella Drive develop~ nt. S:vteen of the 23 residents of
Holton Circle remain on priva-; :irinking water we.lls while there
are no private wells on Isabel. Drive. In March 1989, the Site
. .. '-..-
-------
Holton Circle Groundwater Contamination site
Record of Decision - september 30, 1992
2
was placed on the National Priorities List (NPL) to conduct
further studies and to potentially remediate the contamination at
the site using federal funding.
To date, VOCs have been detected in 12 of the 23 residential
wells on Holton Circle, five of which were above federal primary
drinking water standards at one time. CUrrently, no residential
wells have concentrations above federal drinking water standards.
Six of the 17 monitoring wells and two of the 14 microwells have
levels of VOCs above federal drinking water standards.
Additionally, elevated levels of inorganics (inclwHnq sodiwn and
other metals) and chloride have been found in both the overburden
and bedrock aquifers.
A more detailed description of the Site history can be found in
the Remedial Investigation Report (March 1992) on pages. 1-2 to 1-
8 of Volu~e I.
B.
Enforcement History
Though a specific source for the groundwater contamination has
not been identified, the Remedial Investigation concluded that
the town garage area is the likely source area of the
contamination. The Town of Londonderry reportedly has used and
uses the town garage area primarily for the storage and routine
maintenance of Town vehicles, as well as the storage of road sand
and salt. The town garage area was formerly owned by the
Department of Defense (DOD) from 1940 until 1968, at which time
eight acres of the property was transferred to the Town of
Londonderry and twelve acres to the Londonderry Housing and
Redevelopment Authority. The DOD reportedly used' the property as
a radio beacon facility for the Grenier Air Field between 1940
and 1947. .
In July 1992, EPA notified the Town of Londonderry of their
potential liability at the Site as the current owner of the town
garage area.
III. COMMUNITY PARTICIPATION
Throughout the Site's history, community concern and involvement
has been moderate to high. EPA has kept the community and other
interested parties apprised of the site activities through
informational meetings, fact sheets, press releases and public
meetings. .
During August 1990, EPA released a community relations plan which
outlined a p!:og!:Ui 'to address community concerns and keep
-------
Holton Circle Groundwater Con~amination Site
Record of Decision - September 30, 1992
, 3
March 27, 1990, EPA held an informational meeting at the
Londonderry Junior High School in Londonderry, New Hampshire to
describe the plans for the Remedial Investigation and Feasibility
Study (RI/FS). The meeting was attended by approximately 50
people, most of whom were residents of Holton Circle. The major
concerns voiced were the Site name, the Site's impact on property
. values in the Holton Circle subdivision and adjacent properties,
the cost of private water hook-ups, and the potential duration
required for the study/clean-up process. .
On June 30, 1992, EPA made ~ ~cminj&trative record available
for public review at ~A's offices in Boston and at Leach Public
Library located at 276 Mammoth Road in Londonderry. EPA
published a notice and brief analysis of the Proposed Plan in the
Derry News on June 24, 1992, and made the plan available to the
public as part of the Administrative Record.
On June 30, 1992, EPA held an informational meeting to discuss
the results of the Remedial Investigation and the cleanup
alternatives presented in the Feasibility study, and ~o present
the Agency's Proposed Plan. Also during this meeting, the Agency
answered questions from the pUblic. From June 30, 1992 to July
30, 1992, the Agency held a thirty (30) day public comment period
to accept public comment on the alternatives presented in the
Feasibility Study and the Proposed Plan and on any other
documents previously released to the public. FOllowing a written
request received by EPA from the Town of Londonderry on July 23,
1992, the public comment period was extended an additional thirty
(30) days to August 31, 1992. On July 21, 1992, the Agency held
a public hearing to discuss the Proposed Plan and to accept any
oral comments. A transcript of this meeting, the comments, and
the Agency's response to comments are included in the attached
responsiveness summary in Appendix C.
IV.
SCOPE AND ROLE OF RESPONSE ACTION
Though a source area was identified, the results of the RI
indicate that there is no ongoing source presently contributing
to groundwater contamination at the Site. As such, no principal
or low level threat wastes are known to exist at the Site.
Therefore, 'EPA's expectations at the Site are to return usable
groundwater to its beneficial uses in a time frame that is
reasonable given the particular circumstances at the Site. This
remedial action is a comprehensive approach and no other operable
mu:ts are anticipated.
-------
Holton Circle Groundwater contamination site
Record of Deg~sion - September 30, 1992
4
V.
SUMMARY OF SITE CHARACTERISTICS
sections 1.2.4 to 1.2.6
contains an overview of
significant findings of
below by media.
of Volume I of the Feasibility Study
the Remedial Investigation. The
the Remedial Investigation are summarized
~
BOXLS
In connection with RI field work conducted from Jwgust to October
1991, surface and subsurface sp~~s were collected from test pits
and soil borings during excavation and drilling activities. A
total of 11 test pits and 17 soil borings were used to obtain 72
soils samples from across the site. All of. the soil samples .were
analyzed for volatile organics, semivolatile organics~ metals,
and petroleum hydrocarbons.
Surface and Subsurface Soils. A summary of the chemicals
detected in test pit and 60il boring samples are presented in
Appendix S, Tables 1. 2, J and 4 of this ROD.
organics. Volatile organics and semivolatile organics were found
primarily in the town garage area and, to a lesser extent, the
area east of the wetland. Several aromatic volatiles, including
toluene and ethylbenzene, were detected in trace amounts well
below federal and state drinking water standards in the radio
beacon area of the site.
Volatile organics. Volatile organics detected in soil samples
consisted of chlo~;nated volatiles, aromatic volatiles, ketones,
and carbon disulf!q~. with the exception of acetone (up to
65,000 ug/kg), the:other volatile organics detected in soil
samples were found~~t concentrations less than 40 ug/kg. Other
volatile organics detected above sample detection limits inc~ude
te~rachloroethen~~(PCE), trichloroethene (TCE), 1,1,1-
tr1chloroethane (l,l,l-TCA), toluene, and 2-butanone. 1,1-
Dichloroethene (l,l-DCE), l,2-dichloroethane (1,2-DCA),
ethylbenzene, xylenes, and carbon disulfide were each detected in
one or two soil samples at concentrations less than sample
detection limits. .
In comparison to other volatile organics, acetone was detected
more .often and in higher concentrations (47 to 65,000 ug/kg) in
soil samples located throughout the immediate town garage area.
~emi~l~i~~ o~~~ii~. Semivolatile orqanics, including
13 polynuclear arQ~atichydrocarbon (PAH) compounds, bis(2-
ethylhexyl) phthalate, benzyl alcohol, and 4-methylphenol were
-------
Holton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
5
limits (48 to 2,400 ug/kg) in several soil samples, primarily in
the northern portion of the town garage ar~a.
Petroleum Hydrocarbons. Petroleum hydrocarbons were reported in
varying concentrations Cup to 4900 mgJkg) in many of the soil
samples collected from locations in the town garage area. Lower
concentrations (up to 730 mg/kg) were also found in other boring
locations throughout the area, most often in soil sa~les
collected from a depth of 0 to 2 feet.
zaorg"ldca. Inorganic concentrations found in soll samples
varied over large ranges across the Site. ~ommon mineral-rorming
metals (aluminum, iron, calcium, magnesium, potassium, and
sodium) were generally reported in the highest concentrations.
Barium, beryllium, and ten other heavy metals were also reported.
Heavy metals consisted of arsenic, chromium, cobalt, copper,
lead, manganese, nickel, vanadium, and zinc. In comparison to
naturally-occurring metals found in typical soils of New
Hampshire and the eastern u.S. (Appendix B, Table 5),
concentrations of heavy metals found at the Si~ were similar~
with the possible exceptions of arsenic, chromium and lead in the
radio beacon area.
Summary of Soil Contamination. In the town garage area, the
detection of petroleum hydrocarbons, PAH compounds, and other
fuel and combustion products such as benzoic acid in surficial
soils are consistent with typical town garage activities such as
the constant operation and maintenance of large vehicles.
Chlorinated volatiles and acetone were the major chemicals
detected in soils and are widely dispersed throughout the Site.
Since chlorinated volatiles are largely limited to shallower
soils, the presence of these chemicals are believed to be
representative of residual concentrations remaining in soils from
the scattered disposal of spent solvents, cleaners, or other
products containing organic chemicals. Acetone is a common
solvent with many maintenance-~ype applications.
The impact of past activities in the former radio beacon area
appears to be minimal near the former radio beacon tower.
However, low levels of organic chemicals were detected in soils
southeast of the former tower. The absence of organic chemicals,
and the presence of metals which appear to be at naturally-
occurring levels in relatively undisturbed soils in the former
radio beacon area, is consistent with information obtained during
the geophysical survey.
A source of chlorinated volatiles ~ound in the qroundwater was
not identified in soils during ~i. investigation.
L.
-------
~olton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
6
During RI field activities conducted during the Summer/Fall of
1991, nine overburden and eight bedrock monitoring wells were
installed across the Site, primarily in the hillslope area.
Following the discovery of contamination in the overburden
aquifer in the town garage and hillslope areas, 14 microwells
were installed between March and May 1991 to determine the full
extent of the plume. Groundwater samples were collected from the
overburden and the bedrock monitoring wells during two rounds of
sampling in December 1990 and June 1991. The samples were"
analyzed for volatile organics, semivolatile organics, metals,
and il1organics. Groundwater samples from the microwells were
collected during two s8Epling rounds in April 1991 and June 1991.
Microwell samples were analyzed for volatile organics only.
1.
Overburden Groundwater
Overburden refers to the groundwater which exists in the
subsurface material overlying bedrock. A summary of the
chemicals detected in groundwater samples collected from
overburden wells during the re~edial investigation is presented
in Appendix B, Table 6. Microwell sampling results are inc~uded "
in Appendix B, Tables 7 and S. "
Volatile Organics. No volatile or semivolatile organics were
found above the sample detection limits in samples collected from
the overburden and bedrock wells in the radio beacon area of the
Site. In the town garage and hillslope areas, volatile organics
detected in groundwater samples consisted primarily of
chlorinated volatiles. PCE, 1,1,1-TCA, 1,1-DCE, and 1,1-DCA were
each detected in groundwater samples, although 1,1,1-TCA was
detected more often and at higher concentrations than the other
chlorinated volatiles, particularly in the hillslope area.
Carbon tetrachloride, 1,1,2-trichloroethane (1,1,2-TCA),
ethylbenzene, and xylenes were each detected in one or two
groundwater samples in trace amounts well below federal and state
drinking water standards. Total chlorinated volatile
concentrations were highest in groundwater samples from wells
MW-2S (939 ug/L) and MW-SS (229 ug/L), which are located north-
northeast of the town garage area along the hillslope.
Chlorinated volatiles were not detected in overburden groundwater
samples collected from east of the wetland.
Results of samples collected from the microwells confirmed the
presence of similar contaminants detected in the overburden
monitoring wells. Chlorinated volatiles were detected in
groundwater samples collected from all but the one background
well (Mi-14), which is located in the western portion of the town
garage area at a higher elevation. The highest concentration of
total chlorinated volatiles (298 ug/l) waa collected from Mi-04
-------
Holton Circle Groundwater Contamination Site
Record of Decision - Septe~~~r 30, 1992
. 7
western edge of the wetland.
Semivolati1e Organics. Semivolatile organics were not detected
in any groundwater samples collected fram the overburden
monitoring wells.
znorqanics. Mineral~forming metals were fOund more often and in
higher concentrations than other inorqanics in both filtered
(dissolved) and unfiltered (total) groundwater sa~ples. Barium,
beryllium. and 13 heavy metals including arsenic. chromium
(total) and lead were a1se ~tected in u~fi1tered groundwater
samples. In general, conc~~~rations de~ :ed in unfiltered.
samples were much higher ti:~~ those det ~d in filtered samples
and in some cases, contaminants found -, .iltered samples were
not detected in unfiltered samples. Elevated concentrations of
sodium were found throughout the hillslope area and are believed
to be the result of an open salt pile which existed in the town
garage area until the mid 1980's.
Among other inorganics detected at the Site were chloride and
nitrate. Chloride was detected in the highest ~oncentrations
(2880 to 3550 mg/l) in samples collected direc' r downg~adient of
the area in the town garage area formerly usee )r ste. 'ge of an
open salt pile. Chloride concentrations measu~-d in 'j. ~s east
of the wetland were substantially less than the levels west of
the wetland in the hills10pe area. The patterns of elevated
chloride are similar to that of sodium and are believed to be the
resul t of leaching f:' :n the former sal t pile. Elevated
conductivity reading~ also coincide with the elevated levels of
chloride.
Summary of OVerburden Groundwater Contamination. The most
evident results seen in groundwater collected from the overburden
aquifer are the elevat.a concentrations of chlorinated volatiles,
and salt-associated solutes including chloride, sodium, and other
cations. Geological and hydrogeological results demonstrate that
groundwater flows from the town garage area, with a predominant
northeast-east direction. As shown in Appendix A, Figure 2,
groundwater data confirms that a plume of chlorinated volatiles
occurs from the town garage area and extends northeast-east
towards the wetland. Groundwater in wells along the northeast
and eastern hillslope immediately downgradient of the town garage
area exhibited the highes~ chlorinated volatile concentrations.
Analytical data, coupled with geological and hydrogeological
results from this investigation, indicate that ~e town garage
area is the source area from which chlorinated volatiles
originated in overburden groundwater. l,l,l-~ was the
-------
Holton circle Groundwater contamination site
Record of Decision - september 30, 1992
8
groundwater. There is evidence that the degradation
chlorinated volatiles is occurring in the subsurface
l,l,l-TCA can be a degradation product of PCE, which
surface soils in the town garage area.
of the
media.
was found in
Elevated chloride, sodium, and other cation concentrations in
wells downgradient of the town garage area indicate that the
re~e o~ .these solutes from the former salt pile has occurred.
The shape and direction of the chloride and sodium plumes are
similar to the plume exhibited by chlorinated volatiles.
2.
Bedrock GrouDawa~er
A summary of the chemicals detected in groundwater samples
collected f~om bedrock wells during the field investigation is
presented in Appendix B, Table 9.
Volatile organics. Volatile organics were detected in
groundwater samples collected from bedrock monitoring wells which
consisted primarily of chlorinated volatiles. The three
chlorinated volatiles which were detected most frequently and in
the highest concentrations were l,l,l-TCA, l,l-DCA, and l,l-DCE.
Similar to. overburden groundwater samples, l,l,l-TCA was usually
found in higher concentrations than other chlorinated volatiles.
In contrast, l,l-DCE and l,l-DCA concentrations tended to be much
higher in groundwater samples collected from the bedrock aquifer
than from the overburden aquifer, suggesting that l,l,l-TCA may
be transforming into l,l-DCE and l,l-DCA through degradation
processes-. other volatile organics detected in groundwater
samplesi~including PCE, TCE, 1,2-DCA, chloromethane, carbon
tetrachloride, chlorobenzene, benzene, toluene, and 2-butanone,
were each detected in some samples in trace amounts well below
federal and state drinking water standards.
The highest concentrations of chlorinated volatiles were
generally detected in groundwater samples collected from MW-2D
(up to 497 ug/L), MW-5D (up to 87 ug/L), and MW-4D (up to
133 ug/L), all of which are located in the hillslope area.
chlorinated volatiles were detected in groundwater samples from
east of the wetland at concentrations which were much lower than
groundwater west of the wetland.
In June 1991, multi-level sampling devices were installed in
existing monitoring wells which isolated the suspected fracture
zones in bedrock. This allows samples to be taken from specific
depths from within the well. conceDtrations of chlorinated
volatiles were found to vary lIiqn.ificantcw in qroundwater s8.1DPles
collected from several of the is~lated ~nes. In general,
chlorinated concentrations werehigbest near the surface of the
-------
Holton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
, 9
the contamination was introduced from the ov~~burden aquifer into
the bedrock aquifer.
_i..-018t11. orqanics. 4J.'wo semi volatile orqanics (phenol and
bis(2-ethylhexyl)phthalate) were detected in groundwater samples
collected from MW-5D and MW-7D respectively in December, 1990.
%DCrqaniea. Mineral-forming metals were found more often and in
higher concentrations than other inorganics in both filtered and
unfiltered qroutJdwater smnpl"es. Bariumr berylliumr and 10 heavy
metals including arsenic, chromium (total), and lead were also
detected in unfiltered groundwater samples. . Similar to the
overburden aquifer, concentrations of several metals, and
particularly sodium, tended to be higher in groundwater samples
collected from wells downgradient of the location of the former
town garage salt pile.
Concentrations of these metals were also significantly higher
than those found in off-site wells within ~wo miles of the Site
(see Appendix B, Table 10).
Similar to the overburden aquifer, chloride and nitrate were"
consistently detected in groundwater samples collected from the
bedrock aquifer. The highest concentrations (1,110 to 23,500
mg/l) were found in groundwater samples collected from
" downgradient of the former salt pile along the hillslope.
Bedrock groundwater from wells east of the wetland had lower
concentrations (35 to 740 mg/L). Chloride concentrations in
groundwater samples collected from bedrock wells were higher in
comparison to samples collected from the associated overburden
wells. As with the overburden, elevated conductivity readings
corresponded with elevated levels of chloride.
Summary of Bedrock Groundwater Contamination. Elevated
concentrations of chlorinated volatiles (primarily l,l,l-TCA,
1, I-DCA, and l,l-DCE) and salt-associated solutes (chloride,
sodium and other cations) in groundwater from the bedrock aquifer
are similar to those observed in the overburden aquifer.
The highest concentrations in bedrock groundwater occur in wells
directly downgradient of the town garage area. Decreases in
concentrations with lateral migration are probably due to
dilution with bedrock groundwater of background quality. Unlike
the overburden aquifer. the traDSpor~ of these ~mi~ls extends
into 'the Bol'ton Circle subdivision. ~be detection of elevated
concentrations found in wells east of the wetland is attributed
to 'the natural flow of grou.ndwater beneath the wetland. and/or
-------
Holton Circle Groundwater Contamination site
Record of Decision - September 30, 1992
10
Concentrations in the residential and the town garage ~edrock
wells have decreased sharply since their discovery in 1984.
However, at present changes in chlorinated volatile
concentrations over time appear to be relatively minor. This may
be due to the low flow rates of groundwater through the bedrock
aquifer and the dissipation of the contaminants at the source.
Degradation processes are apparently occurring as suggested by .
the increasing concentrations of l,l-DCA and l,l-DCE coupled with
the decreasing concentrations of l,l,l-TCA in groundwater, as
distan~e9 from the town garage area increases. Decreases in
chloride and salt-related cations i~dicates that dilution is also
occurring.
The extent of contamination and concentrations of individual
contaminants suggest that the mass of chemical materials
remaining in source areas is limited or non-existent. If
present, this mass most likely occurs as adsorbed or residual
liquid (ganglia or droplets). Significant quantities of DNAPL
(~ense non-aqueous phase liquids) are not i~ieated by the data.
3.
Residential Well Water
During the field investigation, residential well water samples
were collected by an EPA contractor (Metcalf and Eddy, or M&E) in
April 1990 and quarterly by the NHDES from March 1990 to July
1991. The April 1990 samples were split with the NHDES. Results
were consistent. All residential wells in the Holton Circle
subdivision are bedrock wells of approximately 200 feet in depth.
Several residential wells in the Holton Circle subdivision found
to have detectable levels of organic chemicals continue to be
monitored by the NHDES on a regular basis. .
A summary of chemicals detected in groundwater samples from
residential wells is presented in Appendix B, Tables 11 and 12.
Volatile organics detected in the residentiaf wells consisted of
chlorinated and aromatic volatiles. Volatile organics including
acetone, chloromethane, bromochloromethane, and methyl-t-butyl
ether were detected in the M&E sampling in trace amounts well
below federal and state drinking water standards and were not
detected. in the NHDES sampling.
The NHDES and M&E April 1990 data results showed similar
concentrations of the chlorinated volatiles detected, including
l,i-DCA and 1.1-DCE.
orqanics. Since 1984, l,l-DCA and 1,1-DCE were detected during
every sampling. periocl and were usually found in higher
-------
Holton Circle Groundwat~r Contamination site
Record of Decision - September 30, 1992
11
volatiles including l,l,l-TCA, PCE, 1,2-DCA, chloroform,
chloromethane, and bromochloromethane were also detected, yet
less often and at concentrations near or below the sample
detection limits.
The highest concentrations were detected in residential wells RW-
lID, RW-14D, and RW-lOD, located along the western side of the
Holton Circle subdivision closest to the wetland. Chlorinated
volatiles were also found to a lesser extent in groundwater
samples collected from nine other lots in the Holton Circle
subdivision. Groundwater samples collected from residential
wells in the southern portion of the Bolton ~ircle subdivision
did not have detectable concentrations of chlorinated volatiles.
Since 1984, chlorinated volatile concentrations in the
residential wells have decreased over time. The largest changes
in concentrations appear to have occurred prior to 1990. Similar
to trends exhibited in on-site monitoring wells to the east of
the subdivision, changes in concentrations from 1990 to 1991 were
much smaller. In addition, a similar decrease in chlorinated
volatile concentrations in the town garage bedrock well coincides
with those seen in the residential wells.
other Organics. Semivolatile organics, pesticides, and PCBs were
not identified in any of the samples collected from residential
wells during the field investig~tion.
Inorganics. Inorganics detected in samples collected from
residential wells included mineral-forming metals (including
sodium, calcium magnesium and potassium), barium, and five heavy
metals. The heavy metals consisted of arsenic, copper, lead,
manganese, and nickel. Mineral-forming metals were present in
the highest concentrations in unfiltered samples and were
elevated in residential wells in the Holton Circle subdivision as
compared to off-site residential wells within two miles of the
Site (see Appendix B, Table 10).
Conductivity values measured in several residential wells between
April 1990 and December 1991 ranged from 165 to 3200 mho/cm.
This is consistent with elevated values measured in on-site
bedrock monitoring wells. The highest conductivity values
measured were found in residential wells (RW-11D, RW-14D, and
RW-10D) along the western side of the Holton Circle subdivision.
Summary of Residential We11 Contamination. Chlorinated volatiles
were detected in 12 of the 23 residential bedrock wells in the
Holton Circle subdivision. The most likely source of chlorinated
volatiles appears to be the town garage area to the east of the
wetland. Fiqure 3 in Appendix A shows the bedrock plume of
-------
Holton Circle Groundwater contamination site
Record of Decision - September 30, 1992
12
extending into the Holton Circle subdivision. The residential
wells with the highest chlorinated volatile concentrations are
located in the western, sections of the subdivision, c~osest to
the town garage area. The absence of chlorinated volati~es in
residential wells in the east and southern sections OI the
subdivision suggests that the extent of the plume diminishes in
the northwestern section of the subdivision.
The types of chlorinated volatiles detected in residential. wells
are generally the same as seen in the overburden and bedrock
monitoring wells located throughout the Site. The predominance'
of 1,I-DCA and l,l-DCE is indicative of the degradation of the
larger chlorinated volatiles such as PCE and l,l,l-TCA, which are
present in low concentrations in the residential wells and town
garage well but in higher concentrations in the on-site
monitoring wells. As discussed earlier, the decrease in
chlorinated volatile concentrations as groundwater flows from the
town garage area through the Holton Circle subdivision most
likely results from the dilution of chlorinated volatile
concentrations as groundwater comes in contact with
uncontaminated groundwater.
Overall there has been a considerable reduction in chlorinated
volatile concentrations found in the residential wells at Holton
Circle between 1984 and 1990.
~
SURFACE WATER
Two surface water samples were collected during the field
investigation, a sample from the wetland and a sample from an
area of ponded drainage water located adjacent to and
downgradient of the town garage area. A summary of chemicals
detected in surface water samples is presented in Appendix B,
Table ~3.
organics. Two volatile organics, l,l,l-TCA and carbon disulfide,
and one semivolatile organic, diethylphthalate, were measured in
both surface water samples at trace concentrations well below
federal and state drinking water standards.
Inorqanics. Inorqanics detected in surface water collected from
the wetland include the mineral-forming metals (aluminum, iron,
calcium, magnesium, sodium, and potassium), barium, manganese and
five heavy metals. In addition to these metals, beryllium and'
nickel were also found in surface water samples taken from the
ponded drainage water only. Mineral-forming ~etals were present
in the highest concentrations. OVerall, 'metals ccmc.ellat.~~tions
were ,higher in the surface water sample taken from the ponded
drainage wa1:er. Eleva1:ed sodium CDnCdaua1:ions were also
-------
Holton Circle Grcundwater Contamination Site
Record of- Decisi-:n - E Jtember 30, 1992
L
Similar to groundwater collected from overburden wells, elevated
chloride concentrations (1160 to 2080 mg/L) were detected in both
surface water samples. Orthophosphate concentrations ranged from
40.5 to 44 mg/L. Conductivity values in both surface water
samples were elevated in ccmparison to average conductivity
values for the Londonderry area.
SWlUlary of Surface Watez CODt"lII~ D4UoA. Samplinq results
indicate that qroundwater discharge into the wetland and the
ponded drainage water is likely occurring. This is further
supported by flof-' gradients established froa groundwater and
surface water el~vation Eeasurements. The wetland and ponded
drainage water also likely receive s~ ace water run-off from
higher elevations where the town gar..: -~ area is located.
Similarly, contaminated soils could po~entially be transported to
the wetland or ponded drainage water through surface water run-
off. However, the sampling results indicate that surface water
quality does not appear to be significantly impacted by organic
chemicals at the Site.
Elevated chloride concentrations and conductivity values
consistent with findings in overburden groundwaters, and
to be related to the leaching of salt-associated solutes
former open salt pile.
are
appear
from the
~
SEDIMENTS
Nine sediment samples were collected in December 1990 and eleven
additional samples in June 1991. Samples were taken from the
wetland, the ponded drainage area, and a drainage ditch located
at a discharge pipe within the town garage area. Samples
collected in June 1991 were evaluated for volatile organics and
total combustible organics only. Because of the low soil content
retrieved in the sediment saEples, especially during the December
1990 sampling, analytical results are interpreted on a qualified
basis only. A summary of chemicals detected in sediment samples
is presented in Appendix B, Table 14.
Volatile Organics. Volatile organics were consistently detected
in sediment samples collected in December 1990 and June 1991.
Chlorinated volatiles including PCE, 1,1,1-TCA, and 1,1-DCA were
detected. Acetone, 2-butanone, methylene chloride and carbon
disulfide were also detected. Toluene was detected only in
December 1990. Of the chlorinated volatiles detected, 1,l-DCA
and l,l,l-TCA were found in higher concentrations than PCE.
Non-chlorinated volatiles were usually present at higher
concentrations 'then chlorinated volatiles.
Concentration_. of all volatile organics varied qreatly in samples
-------
Holton Circle Groundwater contamination site
Record of Decision -September 30, 1992
14 -
(64 to 1,100 ug/kg) were usually found in samples collected from
the wetland. Ac~tone was also found at elevated concentrations
in many sediment samples and was generally detected in locations
where chlorinated volatiles were also reported.
other orqanics. While most of the semivolatile organic results
were rejected during data validation, benzoic acid,
4-methylphenol, benzo(a)pyrene, and bis(2-ethylhexyl)phthalate
were detectecl in several samples. Elevated concentrations of
petroleum hydrocarbons (21.7 to 669 mg/kq) were also apparent in
sediment samples collected from each location. Neither
pesticides ~or PCBs were identified in any sedi~ent samples.
Elevated levels of total combustible organics ranging from 13,800
to 892,000 mg/kg were measured in sediment samples.
Inorqanics. Inorganics were detected in all sediment samples at
varying concentrations. Mineral-forming metals were detected in
the highest concentrations and more often than other metals.
B-ary ~ 8ecti.m~ CODtam:buat:11:1D. More types of volatile and
semivolatile organics were found in sediment samples than in
surface waters. The organics detected were also identified in
soils and groundwater in the town garage area. The presence of
elevated organic concentrations (including petroleum
hydrocarbons) in the wetland sediments indicate that sediments
provide a retaining area for chemicals that were apparently
released from upqradient sources in the town garage area.
Elevated concentrations of volatile and semivolatile organics are
apparent in sediment near the outlet of the drainage pipe. The
organic chemicals detected in sediment are consistent with the
types of organic chemicals detected in soils and groundwater.
At.
AXIL
In accordance with the Holton Circle Health and Safety Plan,
health and safety air monitoring was performed with a
Photoionization Detector (PID) during all phases of the field
investigation to screen for organic vapors. No organic vapor
levels were detected above background in ambient air screened
with the PID. Therefore, additional air quality monitoring was
not performed as part of the field investigations.
A complete discussion of Site characteristics, can be fouhd in
-------
Holton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
15
VI.
SUMMARY OF SITE RISKS
A Risk Assessment (RA) was performed to estimate the probability
and magnitude of potential adverse human health and environmental
effects from exposure to contaminants associated with 'the Site.
The public health risk assessment followed a four step process:
1) contaminant identific~tion, which identified those hazardous
substances which, given the specifics of the Site, were of
significant concern: 2) exposure assessment, which identified
actual or potential exposure pathways, characterized the
potentially evposed popw.ationa, ancl det~n.miqed the extent of
possible exposure: 3) toxicity assessment, whicb considered the
types and magnitude of adverse health effects associated with
exposure to hazardous substances, and 4) risk characterization,
which integrated the three earlier steps to summarize the
potential and actual risks posed by hazardous substances at the
Site, including carcinogenic and non-carcinogenic risks. The
results of the public health exposure assessment for the Holton
Circle Groundwater Contamination Superfund Site are discussed
below, followed by the conclusions of the ecological assessment.
Sixty-six contaminants of concern, listed in tables 6-2 to 6-26
of Volume II of the RI, were selected for evaluation. in the risk
assessment. Because of the relatively limited number of
contaminants detected at the Site, these sixty-six contaminants
of concern represent all contaminants identified at the Site with
the exception of inorganics in' soils. Inorganics were compared
to maximum background concentrations derived from literature
values. As a result, eight inorganic chemicals were selected as
contaminants of concern in soils. A summary of the health
effects of each of the contaminants of concern can be found in
Section 6.0 of Volume I of the RI on pages 6-53 to 6-96.
Potential human health effects associated with exposure to the
contaminants of concern were estimated quanti~ativel7 or
qualitatively through the development of several hypothetical
exposure pathways. These pathways were developed to reflect the
potential for exposure to hazardous substances based on the
present uses, potential future uses, and location of the Site.
For the purpose of developing pathways, the Site consists of
three areas.
The first area is the town garage and radio beacon areas, which
are completely enclosed by a fence. This area is not currently
open to the public and is used by town workers. Therefore,
current exposure pathways were developed to estimate potential
risks to workers only (i.e., non-residential). However,
development of the property .for residential p\lJ:~ is possible.
Therefore, future exposure pathways were developed to estimate
-------
. .
Holton Circle Groundwater Contamination site
Record of Decision - September 30, 1992
16
~
1he second area consists of the undeveloped hillslope and wetland
areas. Current exposure pathways were developed to estimate
risks to trespassers (i.e., adults and children) who may access
the area on occasion. Residential development within this area
is also possible. Therefore, future exposure pathways were
developed to estimate potential risks to future residents.
The third area evaluated was the Holton Circle subdivision
i tsel f. CUrrent and future exposure pathways were developed to
estimate risks to residents.
The following
evaluated. A
6.0 of Volume
27.
is a brief summary of the exposure pathways
more thorough description can=be found in section
I of the Remedial Investigation on pages 6-21 to 6-
The following exposure pathways were evaluated quantitatively
under current land-use conditions:
. .
Incidental ingestion
surface soils in the
town garage workers,
exposed 250 days per
and dermal abscrption of chemicals in
town garage and radio beacon areas by
assuming the individual worker may be
year for 25 years.
Incidental ingestion and dermal absorption of chemicals in
surface soils in the hillslope area and east of the wetland
area by trespassers assumed to be a.years or older and who
may be exposed an average of 33 days per year for 22 years.
Incidental ingestion and dermal absorption of chemicals in
sediments in the hillslope area and wetland area by
trespassers assumed to be a years or older and who may be
exposed an average of 33 days per year for 22 years.
.
Dermal absorption of chemicals in the hillslope area ponded
drainage water and in the wetland area surface water by
trespassers assumed to be a years or older and who may be
exposed an average of 33 days per year for 22 years.
.
Direct ingestion of chemicals in bedrock groundwater by town
garage area workers assuming the individual worker with an
average body weight of 70 kg may ingest 1 liter of water per
day, 250 days per year for 25 years.
Direct ingestion of chemicals in bedrock groundwater by
BoltOD Circle residents assuming the average resident with
a body weight of 70 kg may ingest 2 li'tentlCf wa'ter per day,
-; 350 days per year for 30 years.
The following exposure pathways were evaluated quantitatively
-------
Holton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
17
under fu~~re land-use conditions:
.
Incidental ingestion and dermal absorption of chemicals in
soils by future town garage, radio beacon, and hillslope
area residents assuming the average ~ident may be exposed
350 days per year for 30 years.
Incidental ingestion and dermal absorption of chemicals in
hillslope and wetland area sediment by future residents who
may be exposed an average of 350 days per year for 30 years.
.
.
Dermal absorption of chemicals in hillslope a:.:..ea ponded
drainage water by future residents assuming the average
resident may be exposed 191 days per year for 30 years.
- Direct ingestion of chemicals in overburden groundwater by
future town garage, radio beacon, and hillslope area
residents assuming the average resident with a body weight
of 70 kg may ingest 2 li~ of water per day. 350 days per
year for 30 years.
.
Direct ingestion of chemicals in bedrock groundwater by
future town garage, radio beacon, and hillslope area
residents assuming the average resident with a body weight
of 70 kg may ingest 2 liters of water per day, 350 days per
year for 30 years.
.
Direct ingestion of chemicals in overburden groundwater east
of the wetland area by future Holton Circle resident~
assuming the average resident with a body weight of kg
may ingest 2 liters of water per day, 350 days per YE r for
30 years.
Direct ingestion of chemicals in bedrock groundwater east of
t ~ wetland area by future Holton Circle residents assuming
t ,average resident with a body weight ~f 70 kg may ingest
2 _iters of water per day, 350 days per year for 30 years.
For each pathway evaluated, an average and a reasonable maximum
exposure estimate was generated corresponding to exposure to the
average and the maximum concentration of contaminants detected in
that particular medium.
Excess lifetime cancer risks were determined for each eX~osure
pathway by multiplying the exposure level with the cbemi. ~l-
specific cancer potency factor. cancer potency factors :. ive been
developed by EPA from epidemiological or animal studies ~J
reflect a conservative "upper bound" of the riJak posed by
-------
Holton Circle Groundwater Contamination site
Record of Decision - september 30, 1992
18
very unlikely to b~ greater than the risk predicted. The
resulting risk estimates are expressed in scientific notation as
a probability (e.g. 1 x 10.6 for 1/1,000,000) and indicate (using
this example), that an individual is not likely to have greater
than a one in a million chance of developing cancer over 70 years
as a result of site-related exposure as defined to the compound
at the stated concentration. CUrrent EPA practice considers
carcinoqen.ic risks to be additive when assess.ing exposure to a,
mixture of hazardous substances.
The hazard index (HI) was also calculated for each pathway as
EPA's measure of the potential for non-carcinogenic health
effects. The hazard quotient is calculated by dividing the
exposure level by the reference dose (RfD) or other suitable
benchmark for non-carcinogenic health effects for an individual
compound. Reference doses have been developed by EPA to protect
sensitive individuals over the course of a lifetime and they
reflect a daily exposure level that is likely to be without an
appreciable risk of an adverse health effect. RfDs are derived
from epidemiological or animal studies and incorporate
uncertainty factors to help ensure that adverse health effects
will not occur. The hazard quotient is often expressed as a
single value (e.g. 0.3) indicating the ratio of the stated
exposure as defined to the reference dose value (in this example,
the exposure as characterized is approximately one third of an
acceptable exposure level for the given compound). The hazard
quotient is only considered additive for compounds that
have the same or similar toxic endpoint and the sum is referred
to as the hazard index (HI) (for example: the hazard quotient for
a compound known to produce liver damage should not be added to a
second whose toxic endpoint is kidney damage).
Tables '15 to 20 of Appendix B depict the carcinogenic and non-
carcinogenic total risk summaries for each current and potential
future exposure pathway identified above. Tables which depict
the carcinogenic and non-carcinogenic risks for each contaminant
of concern can be found in Section 6.0 of Volume II of the
R~medial Investigation.
None of the exposure pathways listed above for current land-use
conditions were found to pose an unacceptable carcinogenic or
noncarcinogenic health risk.
Under future ,land-use conditions, the following exposure pathways
were found to generate carcinogenic risks which exceed EPA's
acceptable cancer risk level of ~x~O~ and non-carcinogenic
hazard ind~ of 1. With the exception of non-carcinogenic risks
generated from average groundwater exposure scenarios, all future
potential risks shown below occur 'for 1:I1e worst case sC'enarios'
-------
Holton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
,19
The chemicals listed below ~ontribute the overwhelming majority
of the overall risk for each respective exposure pathway.
Carcinogenic Risks -- puture Land-Use Conditions
c
2xl0-4
,
Arsenic
n
radio beacon area overburden
groundwater by residents.
ax10-4
Beryllium
,
Arsenic
Beryllium
e 1
overburden and bedrock qroundwater
by future Holton Circle residents.
overburden
2x10-4 for
bedrock
l.~-DCE
Arsenic
Non-Carcinogenic Risks -- Puture Land-Use Conditions
n
and
<3
rsen1c
Chromium
Thallium
9 s 0 a s
hillslope area overburden and
bedrock qroundwater by residents.
and
<3
n
Arsenic
Barium
and
<4
n
1 to 6
2
Arsenic
The noncarcenogenic hazard index of 2 estimated for the potential
future soil exposure pathway is entirely attributable ~o arsenic
concentrations in soil at the town garage area. This hazard
-------
Holton Circle Groundwater contamination site
Record of Decision - september 30, 1992
20
soil. The hazard index for the aver~ge arsenic concentration in
town garage area soils is below 1. Arsenic is a naturally
occurring metal in soils which varies greatly with geographic
location. Due to the lack of site-specific background samples,
there is considerable uncertainty concerninq naturally occurring
levels of arsenic at the site. In light of these factors, and
because a hazard index of two is not significantly different than
a hazard index of one. soil cleanup of arsenic in the town gaJ;'age
area is not warranted. at this time.
As shown in the tables above, J;)ariwn. chromium (total).
beryllium, thallium, antimony, and arsenic were found "to
contribute to the overall risk at the site. Of these inorganics,
barium, chromium, beryllium and antimony were detected slightly
above their respective federal primary drinking water standards
(maximum contaminant levels, or MCLs). Given the low frequency
of inorga~ic hits, it is expected that these inorganic
concentrations are not representative of actual conditions at the
site. Therefore additional inorganic sampling will be conducted
under.the selected remedy.
Of the inorganics detected at the site, arsenic was found to be
the main contributor of potential future risk. However, arsenic
was not detected in groundwater above its MCL of 50 parts per
billion (ppb), a level at which the carcinogenic risk posed by
arsenic in groundwater is 2x10-03. Recent studies indicate that
many skin tumors arising from oral exposure to arsenic are non-
lethal, and that the dose-response curve for the skin cancers may
be sublinear (in which case the cancer potency factor used to
generate risk estimates will be overstated). Consequently, it is
EPA policy to manage arsenic-based risks downward by a factor of
ten, i.e., as if the risks were 2xlO-~ at 50 ppb. Because the
concentrations of arsenic detected at the site were below the
MCL, and because the risks for groundwater ingestion are based
upon a 3o-year exposure duration for this site as opposed to a
70-year exposure duration used for development of the MCL, the
risk. for arsenic should be considered reasonably lower than EPA's
acceptable carcinogenic risk of lxlO.~.
Based on the risk calculations, l,l-DCE is the only VOC which
contributes to the future potential risk at the Site. Though
1,l,l-TCA was consistently found in groundwater above its MCL, it
does not. contribute significantly to the potential risks as
calculated. l,l-DCA was detected above New Hampshire's.
nonenforceable drinking water Health Advisory (HA) standards, but
not above the federal or state MCL. Based upon results from the
la"tes"t sampling round, there are no residential drinking water
wells ~uthe ar~known to have contaminant concentrations which
exceed - rederal ar state drinking water standards. including MCLs
-------
Holton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
21
which exhibited contaminant concentrations ab~ve MCLs during the
RI are no longer used as drinking water sources. These residents
now obtain public water from the Southern New Hampshire Water
Company (SNHWC). .
'BCOLOG%C1L JaR S1JKHARY
A qualitative survey of terrestrial wildlife, aquatic resources,
wetland and wildlife habitats, and vegetation was conducted
during the field investigation. Important potential exposure
pa1:hways identified at the Si1:e were exposure of aquatic or semi-
aquatic species to chemicals in surface water and sediment and
exposure of vegetation and soil-dwelling organisms to chemicals
in surface soil. .
None of the chemicals present at the Site have been shown to
accumulate through the food chain. Impacts from bioaccumulation
are therefore not expected. The ecological assessment concluded
that most terrestrial wildlife species at or near the Site are
not likely to be adversely impacted. However. fluctuations in
natural conditions in the wetland add a degree of uncertainty to
this conclusion.
CONCLUSIONS REGARDING RISKS
Actual or threatened releases of hazardous substances from this
Site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
Several contaminants, particularly l,l-DCE and l,l,l-TCA, are
above federal drinking water standards in both the overburden and
bedrock groundwater aquifers. These aquifers are in an area of
residential development and may be utilized for consumption
purposes. .
VII. DEVELOPMENT AND SCREENING OF ALTERNATIVES
A. statutory Requirements/Response Objectives
Under its legal authorities, EPA's primary responsibility at
Superfund sites is to undertake remedial actions that are
protective of human health and the environment. In addi~ion,
Section 121 of CERCLA establishes several other statutory
requirements and preferences, including: a requirement that
EPA's remedial action, when complete, 1IIUst comply with all
federal and more stringent state environmental standards,
requirements, criteria or limitations, unless a waiver is
-------
Holton Circle Groundwater contamination site
Record of Decision - september 30, 1992
22
cost-effective and that utilizes permanent solutions a~d
alternative treatment technologies or resource recovery
technologies to the maximum extent practicable; and a preference
for remedies in which treatment which permanently and
siqnificantly reduces the volume. toxicity or mobility of the
hazardous substances is a principal element over remedies not
involving such treatment. Respons~ alternatives were developed
to be consistent with these conq~~~ional mandates.
Based on preliminary information relating to types of
contaminants, environmental media of concern, and potential
exposure pathways, remedial action objectives were developed to
aid in the development and screening of alternatives. These
remedial action objectives were developed to mitigate existing
and future potential threats to public health and the
environment. The response objectives are:
1.
Prevent ingestion of water which contains compounds in
concentrations that exceed federal and state
en£crceable drinking water standards; and
Prevent ingestion of water containing compounds which
have no enforceable federal or state drinking water
standards but which pose an unacceptable health risk.
2.
B. Technoloqy and Alternative Development and screening
CERCLA and the NCP set forth the process by which remedial
actions are evaluated and selected. In accordance with these
requirements, a range of alternatives ~ere developed for the
site.
with respect to the groundwater response action, the RI/FS
developed a limited number of remedial alternatives that attain
site specific remediation levels within different timeframes
using different technologies; and a no action alternative.
As discussed in section 3.0 of Volume I of the Feasibility Study,
the RI/FS identified, assessed and screened technologies based on
implementability, effectiveness, and cost. section 4.0 of Volume
I of the Feasibility Study presented the remedial alternatives
developed by combining the technologies identified in the.
previous screening process in the categories identified in
section 300.430(e) (3) of the NCP.
Because of the nature and limited extent of contamination at the
site, only £ive remedial alternatives ~ available for detailed
evaluation, including the no action alternative. Therefore, in
accordance with 'the RCP and current Feasibility Study guidance,
-------
Holton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
.23
alternatives, as described below, were retained for detailed
evaluation.
VIII.
DE6<'RIftIOJl 01' UaTEItIlATrvES
This Section provides a narrative summary of each alternative
evaluated. A detailed tabular assessment of each alternative can
be found in Table 5-25 of Volume II of the Feasibility study. .
~l~erna~ive 1 - _0 ~~iOB
.
Natural attenuation of overburden groundwater
Natural attenuation of bedrock groundwater
Groundwater monitoring
.
Evaluation of Alternative 1, the No Action alternative, is
required by the NCP and serves as a baseline for comparison with
~he other remedial alternatives under consideration. Under
Alternative 1, groundwater in both the overburden and bedrock
aquifers would na~urally attenuate. Natural attenuation is a
process where groundwater is allowed to remediate naturally
through dilution, dispersion, and/or degradation mechanisms
without intervention or treatment. Factors affecting the time
required for clean-up by natural attenuation include the physical
and chemical properties of the contaminants as well as the
geological characteristics of the subsurface environment.
Subsurface fate and transport modeling was conducted in the
Feasibility Study to estimate clean-up times. No. effort would be
made to restrict potential human exposure to groundwater
contaminants through institutional controls and no contingency
for an alternate water supply is provided. A groundwater
monitoring program would be conducted under this alternative to
last approximately 30 years. Basad on calculations presented in
Appendix A of Volume III of the FS, natural attenuation of the
overburden and bedrock groundwater plumes is expected to occur in
2 to 3 years and 7 to 25 years respectively. .
Estimated
Estimated
Estimated
Estimated
Estimated
Time for Design and Construction:
Period for Overburden Cleanup:
Period for Bedrock Cleanup:
Capital Cost:
Operation and Maintenance Cost
°
2 to 3 years
7 to 25 years
None
$1,246,000
~.4 ~U1 eo8t:
$.1,~.,.ooo
-------
Holton circle Groundwater contamination site
Record of Decision ~ september 30, 1992
- -
24
Alterna~ive 2 - Limited Action
.
Natural attenuation of overburden groundwater
Natural attenuation of bedrock groundwater
Institutional controls
Groundwater monitoring
Alternate water supply contingency
.
.
.
.
Alternative 2 relies upon the natural attenuation processes to
remediate both the overburden and bedrock groundwater aquifers,
as described in Alternative 1. Additionally, Alternative 2
includes institutional controls to prevent -ingestion of
contaminated groundwater, either through a local zoning ordinance
and/or property deed restrictions.
Institutional controls ~ be implemented ~ ~e Si~ include
restriction of future groundwater use in ~he town garage and
hillslope areas of the Site and a drainage restriction in the
town garage area to prevent potential future releases of
contaminated water into the subsurface. The town garage
currently has an open floor drain in the main garage building
which discharges directly into the ground. Implementation of the
drainage restriction will prevent future use of this drain and
prevent the installation of new ones. These restriction serve
collectively to reduce the potential for human exposure to
contaminants. Restrictions on groundwater use would remain in
effect until the quality of the groundwater meets cleanup levels.
Groundwater monitoring will be conducted to track migration of
the plume, the progress of natural attenuation, the success of
the remedy, and to confirm water quality in residential wells.
The monitoring program to be implemented at the site will include
continuous groundwater sampling of Holton Circle residential
wells and monitoring wells for volatile organic compounds (VOCs)
and metal compounds (inorganics).' Following implementation of
the groundwater monitoring program, the program may be re-
evaluated by EPA and the state and as a result, sampling
frequencies and locations may change. Additional wells may be
installed or eliminated from the monitoring program if necessary.
Groundwater monitoring will continue until such time as EPA and
the State jointly determine that groundwater cleanup levels
'The ini tial two sampling rounds of metal compounds
(inorganics) will seek to determine levels which are representative
-------
.
o
Holton Circle Groundwater Contamination site
Record of Decision - September 30, 1992
25
established in this Record of Decision have been met. The
monitoring program is described in detail on pages 40 to 42 of
this Record of Decision.
Analysis of the residential groundwater data will be continually
evaluated to determine the need for an alternate water supply.
. In 'the event (which EPA considers unlikely based on the current
information) tha't contaminan'ts in drinking water wells reverse
their historical trend ~nd begin increasing to 'the point that
they exc-eea cl~T!Up It s. an al teznate vater supply contingency
is available to reside.. .;s. The alte:.-:-,ate water supply
contingency includes either providing ~ hookup to t~e SNHWC
supply or use of a point-of-use in-home filter sy~ ~. Hookup to
the SNHWC supply is preferred because it is as prr ~tive of
public health yet more cost-effective than a filt, 3ystem.2
Estimated Time for. Design and Construction:
Estimated Period for Overburden Cleanup:
Estimated Period ~or Bedrock Cleanup:
Estimated Capital Cost:
Estimated Operation and Maintenance Cost
o
2 to 3 years
, 'to 25 years
None
$1,246,000
$1,246,000
Estimated Total Cost:
*All costs are net present worth. Estimates do not include
potential costs associated with implementing institutional
controls or the alternate water supply contingency.
Potential costs for the contingency are shown in table 21 of
Appendix E.
Alternative 3 - .imited Action - Active OVerburden Remediation by
Air striDDina
Treatment of the overburden aquifer by air
stripping/activated carbon filtration
Natural attenuation of the bedrock aquifer
Institutional controls
Groundwater monitoring
Alternate water supply contingency
Alternative 3 involves treatment of the overburden aquifer using
groundwater extraction and treatment technology. Under this
alternative, groundwater from the overburden aquifer would be
collected in a subsurface collection trench and pumped to a
.
.
.
.
2Should this contingency arise, EPA will review the
protectiveness of 'the selected remedy 1:hrough 'the prt"("@ss Outlines
-------
Holton Circle Groundwater Contamination Site
Record of Decision- September 30, 1992
26
metals pretreatment system. This step may be necessary to reduce
the levels of naturally-occurring iron in the groundwater which
may otherwise impede the efficiency of the VOC treatment system.
During this step, the extracted groundwater would be pretreated
so that the dissolved iron precipitates, or settles, out of the
water. After pretreatment, the groundwater would be pumped to an
air stripping and activated carbon filtration system to remove
the VOC contaminants. Treated groundwater would then be returned
to the overburden aquifer through a recharge trench. Natural.
attenuation would be relied upon to remediate the bedrock
aquifer.
As described in Alternative 2, institutional controls to prevent
future groundwater ingestion in the town garage and hillslope
areas of the Site would be implemented. Further, a contingency
to provide an alternate water supply for on-site residents would
be available. The groundwater monitoring plan described under
Alternative 2 would also be utilized under this alternative.
Estimated Time for Design and Construction:
Estimated Period for Overburden Cleanup:
Estimated Period for Bedrock Cleanup:
Estimated Capital Cost:
Estimated Operation and Maintenance Cost
Estimated Total Cost:
'1 to 2 years
1. 5 to 2. 5 yrs
7 to 25 years
'$ 823,750
$1,641,000
$2,464,750
*AII costs are net present worth. Estimates do not include
potential costs associated with implementing institutional
controls or the alternate water supply contingency.
Potential costs for the contingency are shown in table 21 of
Appendix B.
Alternative 4 - Limited Action - Active Overburden Remediation by
UV/Chemica1 Oxidation
.
Treatment of the overburden aquifer by ultraviolet
(UV)/chemical oxidation
Natural attenuation of the bedrock aquifer
Institutional controls
Groundwater monitoring
Alternate water supply contingency
.
.
.
Alternative 4' is identical to Alternative 3 except that it
involves treatment of tbe overburden aquifer using ultraviolet
(UV)/chemical oxidation as the treatment technology. Under this
alternative, groundwater from the overburden aquifer would be
-------
Holton Circle ~roundwater Contamination Site
Record of Decision - September 30, 1992
, .
. 27
described in Alternative 3. After
treated by (UV)/chemical oxidation
contaminants. Treated groundwater
overburden aquifer. '
pretreatment, water would be
to remove the VOC
would be re-injected to the
As described in Alternative 2, institutional controls to prevent
future groundwater ingestion would be implemented and a
, contingency to provide an alternate water supply £or on-site
residents would be available. The qroundwater monitoring plan
described under Alternative 2 would also be utilized under this
alternative.
The times required to complete remediation of the overburden and
bedrock aquifers under Alternative 4 are expected to be the same
as Alternative 3.
Estimated
Estimated
E,stimated
Estimated
Estimated
Time for Design and Construction:
Period for Overburden Cleanup:
Period for Bedrock Cleanup:
Capital Cost:
Operation and Maintenance Cost
1 to 2 years
1. 5 to 2. 5 yrs
7 to 25 years
$ 927,500
$1.601,000
$2,528,500
Estimated Total Cost:
*All costs are net present worth. Estimates do not include
potential costs associated with implementing institutional
controls or the alternate water supply contingency.
Potential costs for the contingency are shown in table 21 of
Appendix B. '
Alternative 5 - ,Active Overburden and Bedrock Groundwater
Remediation .
Treatment of the overburden aquifer by ultraviolet
(UV)/chemical oxidation
Treatment of the bedrock aquifer by ultraviolet
(UV)/chemical oxidation
Institutional controls
Groundwater monitoring
Alternate water supply contingency
Alternat~ve 5 involves treatment of groundwater from both the
overburden and bedrock aquifers using ultraviolet (UV)/chemical
oxidation as the treatment technology. Under this alternative,
groundwater from the overburden aquifer would be captured in a
subsurface drainage collection trench, similar to those described
in Alterna'tives 3 and 4. Contaminated bedrock groundwater would
be removed by pumping from bedrock extraction wells. The
combined qroundwa'ters would be pre--treated, as in Alternatives 3
and 4, then would be treated by UV/chemical oxidation technology,
.
.
.
.
-------
Holton circle Groundwater Contamination site
Record of Decision - September 30, 1992
28
as described in Alternative 4.' Treated groundwater would be
re-injected to both the overburden and bedrock aquifers.
As described in Alternative 2, institutional controls to prevent
future groundwater ingestion would be implemented* and a
contingency to provide an al~ernate water supply for on-site
residents would be available. The groundwater monitoring plan
described under Alternative .2 would also be utilized wu:ler this
alternative. ---
. ~.~-'
Estimated Time for Design and construction:
Estimated Period for Overburden Cleanup:
Estimated Period for Bedrock Cleanup:
Estimated capital Cost:
Estimated operation and Maintenance Costs
Es~ima~ed To~al Cost:
:t'~ 2 years
1. 5 to 2.5 yrs
5 to 21 years
$1,590,000
$2,359,000
$3,949,000
~All costs are net present worth. Estimates do not include
potential costs associated with implementing institutional'
controls or the alternate water supply contingency.
potential costs for the contingency are shown in table 21 of
Appendix B.
IX.
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
-
section l21(b) (1) of CERCLA presents several factors that, at a
minimum, EPA is required to consider in its assessmen~=of
alternatives. Building upon these specific statutory mandates,
Section 300.430(e) (9) of the National contingency Plan,
articulates nine evaluation criteria to be used in assessing the
individual remedial alternatives.
A detailed analysis was performed on the alternatives using the
nine evaluation criteria in order to select a Site remedy. The
following is a summary of the comparison of each alternative's
strengths and weaknesses with respect to the nine evaluation
criteria. These criteria and their definitions are as follows:
Threshold cri~eria
The two threshold criteria described below must be met in order
for the alternatives to be eligible for selection, in accordance
with the NCP.
1.
overall protection of human health and the environment
addresses whether or 1101: a remedy provides adequa'te
-------
.
c
Holt:::: Circle Groundwater Contamination Site
Reco=~ of Dec:sion - September 30, 1992
.29
pathway are eliminated, reduced or controlled through
treatment,. engineering controls, or institutional
controls.
2.
CompJ.i8DC8 witJa applicabl.8 or raJ.8vant &Dd approprjate
requirements (ARABs) addresses whether or not a remedy
will meet all of the ARARs of other federal and state
environmental. laws and/or provide qrow:ads for invoking
a waiver.
Primary Balancina Criteria
The following five criteria are utilized to compare and evaluate
the elements of one alternative to another that meet the
threshold criteria.
6.
7.
3.
Long-term effectiveness and permanence addresses ~he
criteria that are utilized to assess alternatives for
the long-term effectiveness and permanence they afford,
along with the degree of certainty that they will prove
successful.
4.
Reduction ot toxicity, mobility, or volume through
treatment addresses the degree to which 'ternatives
employ recycling or treatment that redu:- - toxi,ity,
mobility, or volume, including 'how treat..~ent is .lsed to
address the principal threats posed by the Site.
Short term ettectiveness addresses the period of time
needed to achieve protection and any adverse impacts on
human health and the environment that may be posed
during the construction and implementation period,
until cleanup goals are achieved.
5.
Zmplementability addresses the technical and
administrative feasibility of a remedy, including the
availability of materials and services needed to
implement a particular option. .
Coat includes estimated capital and Operation and
Maintenance (O&M) costs, .as well as net present-worth
costs. .
JlQ4ir"iDCJ Crit:eria
The modifying criteria are used on the final evaluation of
remedial alternatives qeJ1era}ly after EPA bas received public
-------
Holton Circle Groundwater Contamination Site
Record of Decision- September 30, 1992
30
8.
state ao=eptance addresses the State's position and key
concerns related to the preferred alternative and other
alternatives, and the State's comments on ARARs or the
proposed use of ARARswaivers.
9.
C~YDi~ acceptance addresses the pUblic's general
response to the alternatives described in the Proposed
Plan and lUfFS report. .
A detailed tabular assessment of each alternative according to
the nine criteria can be found in Table 5-25 of Volume II of the
Feasibility Study.
Following the detailed analysis of each individual alternative, a
comparative analysis, focusing on the relative performance of
each alternative against the nine criteria, was conducted. This
comparative analysis can be found on pages 5-50 to 5-59 of Volume
I of ~e Feasibility Study.
The section below presents the nine criteria and a brief
narrative summary of the alternatives and the strengths and
weaknesses according to the detailed and comparative analysis.
1.
Overall Protection of Human Health and the Environment
Alternatives 2, 3, 4, and 5 would provide overall reduction of
risk by preventing access to, and therefore ingestion of,
contaminated groundwater through the use of institutional
controls. These four alternatives would reduce the levels of
contamination in the groundwater in similar timeframes, either by
natural attenuation or by direct treatment, and therefore provide
equal protection of human health and the environment.
Alternative 5 would achieve cleanup levels in bedrock groundwater
slightly faster than Alternatives 2, 3 or 4. However, the time
to complete remediation of the overburden groundwater is
virtually the same for all four alternatives. Additionally,
drainage restrictions which may require the removal or sealing of
the town garage floor drain would prevent potential future
discharge of contaminants through that pathway under Alternatives
2 through 5.
Only Alternative 1 would not meet this criterion because it
contains no provision to prevent exposure to the groundwater
contaminants.
Because no construction activities would occur, neither
Alternative 2 nor 1 would adversely impact 'the nearby wetland.
-------
Holton Circle Groundwater Contamination site
Record of Decision - September 30, 1992
31
impacts to the wetland during construction and remediation
activities. Though none of the alternatives includes planned
construction or other disruption in the wetland area,
Alternatives 3, 4, and particularly 5 may generate adverse
impacts to the wetland due to hydrologic changes caused by the
treatment system which could cause a dewatering of the wetland.
Camp~i&Dc. with AppUcab.l. or JteJ..v~t &D4 Appropriate
bquiremenu (SV~R8)
Each of the alternatives woW.d attain chemical-specific ARARs
(primarily federal drinking water standards ur.~~r the Safe
Drinking Water Act) in relatively the same ti: frame. In the
overburden aquifer, all five alternatives wou. meet chemical-
specific ARARs (MCLs) in approximately 1.5 .to ~ years. .
Alternatives 1 through 4 would meet chemical-specific ARARs in
the bedrock aquifer in 7 to 25 years, while Alternative 5 would
achieve those ARARs in. a slightly faster time frame of 5 to 21
years.
. 2.
Alternatives ~ and 2 would meet action-specific ~ because no
remediation activities would occur on-site which would result in
the handling of RCRA hazardous wastes, the release of
contaminants to the air, or which might potentially impact nearby
wetland areas. Alternatives 3, 4 and 5 would have to minimize
any potential impacts to the wetland, comply with certain RCRA
requirements, and control air releases from on-site treatment
units in order to achieve action-specific ARARs.
Alternatives 1 and 2 would meet all location-specific ARARs
because no on-site remediation activities are necessary which
would have any impact on a water body (including the wetland) or
their associated resources (fish and wildlife). Alternatives 3 -
5 would have to minimize impacts to the wetland and associated
resources in order to meet all location-specific ARARs .
Appendix C lists all ARARs for this Site, and describes the
manner in which each alternative would attain each such ARAR.
3.
Long-term Effectiveness and Permanence
Alternative 1 (no action) provides the least amount of long-term
effectiveness since there would be no institutional controls
implemented to prevent ingestion of contaminated drinking water
from the overburden and bedrock aquifers by future residents.
Additionally, Alternative 1 would not include a drainage
restriction 'to prevent potential future relea1!es of contaminarrts
into the subsurface soils and/or groundwater.
-------
Holton Circle Groundwater Contamination site
Record of Decision - September 30, 1992
32
provides the greatest adequacy and ~eliability of controls.
Alternatives 3 through 5 provide equal adequacy and reliability
of controls.
Alternatives 2 - 5 provide similar degrees of long-term
effectiveness and permanence as they each attain qroundwa~er
ARARs in approximately the same time period. At the point in
which ARABs are attained under each of those alternatives, the
contaminant plume would have dispersed (either naturally or
through treatment) irreversibly and thus permanently. .
. -
For all five~.lternatives. long-term monitoring and
reviews would be required until groundwater cleanup
met to assure the remedy would remain protective of
and the environment. .
five-year
levels are
public health
4.
Reduction of Toxicity, MObility, or Volume through
. Treatment
For Alternatives]. and 2, there would be no reduction of
toxicity, mobility, or volume of contamination ~hrough treatment.
However, because these alternatives would not require treatment
technologies, no process residuals would be generated which would
require further disposal. Under these alternatives, reduction of
toxicity and volume of contamination is expected by natural
attenuation in both the overburden and bedrock aquifers.
Alternatives 3, 4, and 5 use treatment technologies to achieve
groundwater cleanup levels in th& overburden aquifer at the Site.
Under-these alternatives, the toxicity, mobility and volume would
be reduced in the overburden aquifer through the use of an
extraction, treatment and recharge system. Additionally,
Alternative 5 would reduce the toxicity, mobility and volume of
contaminants in the bedrock aquifer. However, Alternatives 3, 4,
and 5 would generate process wastes which would require on-site
temporary storage as well as off-site disposal. These process
wastes would include metals sludge from the groundwater
pretreatment system, spent activated carbon, and spent
uv/oxidation lamps. Moreover; Alternatives 3, 4, and 5 would
likely cause the release of VOCs to the air due to operation of
the groundwater treatment system.
5.
Short-term Effectiveness
All five alternatives remediate the overburden aquifer at
approximately the same rate: between 1.5 to 3 years.
Alternatives 1 'through 4 Temediate 'the bedrock aquifer in 7 ~o 25
years: Alternative 5 would remediate bedrock groundwater slightly
-------
Holton Circle Groundwater Contamination site
Record of Decision - September 30, 1992
33
Remedial activities associated with Alterna~~ves 1 and 2 pose no
risks to workers, community members or the environment, as no
remedial construction -activities would occur. Alternatives 3, 4
and 5 would pose the risk of releasing VOC vapors to the air
during the treatment process. Risk associated with such
potential releases are anticipated to be low.
Alternatives 3, 4 and 5 would also pose potential short term
.risks to nearby wetland during remediation activities.
For all :five alternatives~ workers may be exposed to qZ'OW1dwater
contaminants during DCnitoring operations. Additionally, for
Alternatives 3, 4, and 5, workers may be exposed to groundwater
contaminants during remedial construction activities. Workers
would be equipped with proper personal protection to reduce the
potential for exposure.
6.
Implementability
Each of the alternatives considered in the Feasibility Study
would be technically feasible to implement. Alternatives 1 and 2
would be the easiest to implement as they would not include
treatment technologies and would not generate process residuals
that require disposal.
Alternatives 3, 4, and 5 would .require contractors with
specialized experience. The treatment technologies for
Alternatives 3, 4, and 5 are, however, readily implementable by
several vendors. Alternative 5 would be the most difficult of
the alternatives to implement due to the complexity associated
with the extraction of bedrock groundwater.
The institutional controls included in Alternatives 2 through 5
have similar administrative feasibilities. Alternative 1 would
be somewhat easier to implement administratively than the other
alternatives as no institutional controls would be employed. The
alternate water supply conti~gency included as part of
Alternatives 2 through 5 is readily implementable.
7.
Cost
The total estimated costs for each alternative are broken into
capital costs and operation and maintenance (O&M) costs. Capital
costs include items such as equipment purchases, engineering
designs, and site preparation work. O&Mcosts include activities
such as groundwater monitoring and equipment maintenance. All
costs include 8 25% contin9ency. '!'hese costs aTe summarized in
the table below and were .estimated for each alternative assuming
-------
Holton Circle Groundwater contamination site
Record of Decision - September 30, 1992
34
5
Alternative 5 has the highest net present-worth cost (NPW) due to
proposed treatment of both the overburden and bedrock aquifers.
Alternatives 3 and 4 have similar NPW costs. Alternatives 1 and
2 have identical NPW costs which are associated with anticipated
monitoring costs. .
~e costs listed here for Al ternati yes 2, 3, 4, and 5 do not
include any costs associated with institutional controls or the
alternate water supply contingency. Some administrative costs
may be associated with the implementation of institutional
controls.
Because of decreasing contamination levels, it is anticipated
that implementation of the alternate water supply contingency
will not be necessary. However, the costs associated with the
alternate water supply contingency, should it be required, are
included in Appendix B, table 21, on a per household basis.
8.
state Acceptance
The New Hampshire Department of Environmental Services (NHDES)
has been involved with the study of the site since its discovery
in 1984. The NHDES has reviewed this ROD and concurs with the
selected remedy.
A copy of the declaration of concurrence is enclosed as Appendix
D of this ROD.
9.
community Acceptance
The comments received from the community on the RI/FS and the
Proposed Plan during the public comment period (June 30 to August
31, 1992), the public meeting (June 30, 1992), and the public
hea~incJ (July 21. 1992). EPA"s responses to those ccuaments are
included in the Responsiveness Summary in Appendix E.
-------
Holton Circle Groundwater Contamination Site
Record of Decision - September 30, 1992
, 35
local citizens expressed several concerns at the pUblic hearinc;.
The concerned public 'include local residents, particularly those
of Holton Circle and Isabella Drive, and the Town of Londonderry
administration. The Town of Londonderry is the only party to
receive an EPA notice letter of potential liability.
Additionally, Congressman William Zeliff and State Representative
Karen Hutchinson raised concerns. The predominant view expressed
by the community is that any action taken at the Site is
"excessive" due to 'the fact that no residential well currently
exceeds federal MCLs.
Several issues raised by the public are not related to the
specific selected remedy or other alternatives, but rather to EPA
policy and the site in general. Such issues include the site
name, site "boundary", estimated time period for remediation, and
res~dential and lender liability.
%.
~KB BBLEC~ED RRMBD~
Alternative 2 is the selected remedy for the Site and involves
natural attenuation of overburden and bedrock groundwater, with
institutional controls to prevent future ingestion of
contaminated groundwater in the town garage and hillslope areas.
The selected remedy is a comprehensive approach which addresses
all potential future risks caused by the groundwater
contamination at the Site. There are no current risks posed by
the Site.
A.
Interim Groundwater CleanuD Levels
Interim cleanup levels have been established in groundwater for
contaminants of concern identified in the Baseline Risk
Assessment found to pose an unacceptable risk to either public
health or the environment. Interim cleanup levels have been set
based on the ARARs (e.g., Drinking Water Maximum Contaminant
Level Goals (MCLGs) and MCLS) as available, or other suitable
criteria described below. Periodic assessments of the protection
afforded by remedial actions will be made as the remedy is being
implemented and at the completion of the remedial action. At the
time that Interim Groundwater Cleanup Levels identified in the
ROD and newly promulgated ARARs and modified ARARs which call
into question the protectiveness of the remedy have been achieved
and have not been exceeded for a period of three consecutive
years, a risk assessment shall be performed on the residual
groundwater contamination to determine Whether the remedial
action is protective. ~isrisk assessment of ~he residual
groundwater contamination shall follow EPA procedures and will
assess the cumulative carcinogenic and non-carcinogenic risks
-------
Holton Circle Groundwater contamination Site
Record of Decision- September 30, 1992
36
assessment, the remedial action is not determined to be
protective by EPA, the remedial action shall continue until
either protective.levels are achieved, and are not exceeded for a
period of three consecutive years, or until the remedy is
otherwise deemed protective. These protective residual levels
shall constitute the final cleanup levels for this Record of
Decision and shall be considered performance standards for any
remedial action.
Because the aquifer under the site is a Class XXB aquifer, which
is a potential source of drinking water. MCLs and non-~o HCLGs
established under the Safe Drinking Water Act are ARARs.
Interim cleanup levels for known, probable, and possible
carcinogenic compounds (Class A, B, and C) have been established
to protect against potential carcinogenic effects and to conform
with ARARs. Because the MCLGs for Class A & B compounds are set
at zero and are thus not suitable for use as interim cleanup
levels, MCLs and proposed MCLs have been selected as the interim
cleanup levels for these Classes of compounds. ~cause the MC:U;s
for the Class C compounds are greater than zero, and can readily
be confirmed, MCLGs and proposed MCLGs have been selected as the
interim cleanup levels for Class C compounds.
Interim cleanup levels for Class D and E compounds (not
classified, and no evidence of carcinogenicity) have been
established to protect against potential non-carcinogenic effects
and to conform with ARARs. Because the MCLGs for these classes
are greater than zero and can readily be confirmed, MCLGs and
proposed MCLGs have been selected as the interim cleanup levels
for these classes of compounds.
In situations where a promulgated state standard is more
stringent than values established under the Safe Drinking Water
Act, the state standard was used as the interim cleanup level.
In the absence of an MCL, proposed MCL, MCLG, proposed MCLG,
state standard, or other suitable criterion to be considered
(e.g., health advisory, state guidelines), an interim cleanup
level was derived for each compound having carcinogenic potential
(Classes A, B, and C compounds) based on a 10-6 excess cancer
risk level per compound, considering the ingestion of
groundwater. In the absence of the above same standards and
criteria, interim cleanup levels for all other compounds (Classes
D and E) were established based on a level that represents an
acceptable exposure level to which the human population
(including sensitive subgroups) may be exposed without adverse
affect during a 1ifeti~e or part of a lifetime, incorporating an
adequate margin of safety (hazard quotient = 1), considering the
ingestion of groundwa1:er. If a value described by any of the
-------
"
Holton circle Groundwater Contamination Site
Record of Decision - September 30, 1992
, 37
pr(~ision and accuracy or was below what was deemed to be the
background value, then the practical quantification limit or
background value was used as appropriate for the interim
groundwater cleanup level. .
Several inorganic compounds including arsenic, chromium (total),
barium, beryllium, lead, thalliur. ~nd ant:~ony were detected at
the Site during the one round of ~ .oundwat~- sampling that :
included inorganics. Barium, chromium, beryllium and antimony
were each found in one or two monitoring wells at concentrations
slightly in excess of current federal drinking water standards.
Although arsenic was not detected above federal drinking water
standards ,50 ppb), it is one of the major contributors to
overall risk at the Site. Thallium was detected only once, at
its MCL, in the overburden groundwater in the radio beacon area.
The national primary drinking water regulations establish a 15
ppb action level for lead, and specify treatment techniques that
are ~o be implemented when the action level is exceeded at ten
percent of the consumer taps sampled in a public water system.
The regulations do not require the attainment of a specific
cleanup level (e.g., an MCL): rather, EPA can set cleanup levels
for lead at Superfund sites based upon on a site-specific
analysis. The lead action level was not exceeded in any of the
residential taps sampled at this Site, although it was exceede~
in 6 if 18 monitoring wells. As with several other inorganics,
lead ' ~s not detected in any filtered samples, and the highest
unfil~ered concentration detected was 31.5 ppb (below the lead
MCL of 50 ppb). Although the treatment requirement is not
triggered in this case, EPA has deemed the lead regulations as'
to-be-considered (TBC) in setting cleanup goals for this Site.
Inorganic contaminants of concern were, for the most part,
detected at low concentrations. Overall, the occasional elevated
concentrations are probably due to sampling artifacts and are not
representative of actual conditions at the Site. The monitoring
program to be implemented as part of the selected remedy will
include additional groundwater sampling to confirm the actual on-
-------
Holton Circle Groundwater Contamination Site
Record of Decision- September 30, 1992
38
Table I below summarizes the Interim Cleanup Levels for
carcinogenic and non-carcinogenic contaminants of concern
identified in groundwater.
~ABLE I:
IIr.I'ER:IK GROUlIDWA1'ER CLEAJIUP LEVELS
C&rc::~qenic:: :Interim Basis Level
COD't-~ Dalats o~ CODC!8rD Cleanup of Risk
Class ( ) Level (uqfl)
Beryllium (B.,) 4 MCLG 2. ~XIO-06
1,1 Dichloroethene (C) 7 MCLG 5. OXIO'OS
'U"
SUM - 2.6XIO
Non-carcinoqenic Interim Basis Target Hazard
Contaminants Cleanup Endpoint Quotient
~ COncen! LeYel(uqfl)
Antimony (D) 6 MCLG blood 0.41
chemist.
Barium (D) 2000 MCLG increase 0.77
blood
pressure
Beryllium (B2) 4 MCLG no 0.02
adverse
effect
Total Chromium (D) 100 MCLG no 0.54
effect
observed
1,1 Dichloroethene 7 MCLG liver 0.02
(C)
1,1,1 Trichloroethane 200 MCLG liver 0.06
(D)
HAZARD INDEX SUM FOR LIVER = 0.08
BLOOD = 1.18
.
micrograms per liter (ug/l) = parts per ~illion (ppb)
The exposure factors used for the calculation of risk levels
and hazard quotients are 1.2XlO-02 l/kgjday and 2.7XlO-02
l/kg/day for carcinogens and non-carcinogens respectively,
based on standard exposUre parameters for residential
qroundwater ingestion (OSWER Directive 9285.6-03.).
-------
Holton Circle Groundwater Contamination Site
Record of Decision ~ September 30, 1992
39
While these interim cleanup levels are consistent with ARARs, a
cumulative risk that could be posed by these compounds may exceed
EPA's goals for remedial action. Consequently, these levels are
considered to be interim cleanup levels for groundwater. At the
time that these Interim Groundwater Cleanup Levels identified in
the ROD, and newly p:ramulqated DARB and modified ARARs which
call into question the protectiveness of the remedy, have been
achieved and have not been exceeded for a period of three
consecutive years, a risk assessment shall be performed on the
residual groundwater contamination to determine whether the
remedial action is protective. This risk assessment of the
residual groundwater cc:mtmnination shall follow EPA procedures
and shall assess the cumulative carcinogenic and non-carcinogenic
risks posed by ingestion of groundwater. If, after review of the
risk assessment, the remedial action is not determined to be
protective by EPA, the remedial action shall continue until
either protective levels are achieved and not exceeded for a
period of three consecutive years, or until the remedy is
otherwise deemed protective. These protective residual levels
shall constitute the final cleanup levels for this ROD and shall
be considered performance standards for any remedial action.
All Interim Groundwater Cleanup Levels identified in the ROD and
newly promulgated ARARs and modified ARARs which call into
question the protectiveness of the remedy, and the protective
levels determined as a consequence of the risk assessment of
residual contamination, must all be met at the completion of the
remedial action throughout the aquifers under the Site (the
groundwater plume). EPA has estimated that these levels will be
obtained within 2 to 3 years in the overburden aquifer and 7 to
25 years in the bedrock aquifer.3
B.
DescriDtion of Remedial ComDonents
The selected remedy, Alternative 2, contains four main remedial
components:
1.
restoration of contaminated qroundwater in the
overburden and bedrock aquifers by natural attenuation;
institutional controls;
2.
3It is expected that cleanup levels' in the overburden for VOCs
and most inorganics will be attained within 3 years. If resampling
shows that inorganics concentrations are in fact elevated, then
cleanup levels for antimony and chromium will be attained in a
slightly longer time frame (6 to 11 years), but still within the,
overall estimated time frame far achievinq cll!ll.JIIl'iup ~ J 51 at this
-------
Holton Circle Grounqwater contamination site
Record of Decision - September 30, 1992
40
3.
groundwater monitoring; and
4.
alternate water supply contingency
The goal of the selected remedy is .to restore contaminated
groundwater to its beneficial uses in 2 to 3 years in the
overburden aquifer and 7 to 25 years in the bedrock aquifer. .
These estimated cleanup times are calculated in Appendix A of the
FS and are based on geologic, hydrogeologic, and sampling data
coJ.l.ected as part of the p,.1ft"~ial Investigation.
During performance of the remedy and until such a time as cleanup
levels are attained, institutional controls will be implemented
at the Site to protect human health and the environment. The
objectives of the institutional controls are to prevent ingestion
of contaminated groundwater by potential future residents and
prevent releases of contaminated liquids into the environment
from a drainage pipe(s) in the town garage portion of the Site.
These controls will involve 1:bree parcels of property. 'the fermer
radio beacon area and the town garage area which are owned by the
Town of Londonderry, and the hillslope area which is owned by a
private party. These properties are identified as lots 6-1, 6-2,
and lot 13-4 respectively, on the Town of Londonderry tax map
included in figure 5 of Appendix A.
Groundwater will be monitored to track the migration
plume, to assess water quality in residential wells,
determine the success of the remedy~~~The monitoring
include the following components: --
of the
and to
program will
.
An initial groundwater monitoring event will be
conducted to sample the following wells:
1.
Microwells M7-01 to MI-14 (see figure 6 of
Appendix A for locations).
Overburden monitoring wells MW~1S to MW-9S.
Bedrock monitoring wells MW-1D to MW-8D. Bedrock
wells MW-2D,. 4D, 5D, .and 6D are multi-level wells
as depicted in figure 7 of Appendix A.
Collectively they represent 17 sampling ports.
Residential bedrock wells RW-5D and RW-10D through
RW-23D.
Town garage wells RW-GS (overburden) and RW-GD
C bedrock) . .
2.
3.
4.
5.
-------
Holton Circle Groundwater :ontamination site
Record of Decision - September 30, 1992
,41
.
organic compounds (VOCs), sodium
major ionss (to include CI, HC03'
and filtered samples for Ca, Mg,
total dissolved solids).
The microwells and monitoring wells will be sampled for
inorganics (unfiltered) during the first two rounds of
samplinq and subaequently, as determined necessary by
EPA. If cleanup levels for Ba, Be, Cr, and Sb are
attained following initial sampling rounds, these
levels must be confirmed during the next 3 yaars of
monitoring.
and chloride', and
So" NOz' N03' NH"
Na, K, Fe, Mn, and
.
Subsequent sampling rounds will be performed semi-
annually at all microwells and monitoring wells and at
the residential wells listed under item (4) above. All
samples will be analyzed for VOCs, sodium and chloride.
The number of sampling wells may be adjusted, fOllowing
the initial monitoring results, as deemed appropriate
by,EPA.
.
If any contaminants are found above levels protective
of human health in any residential well, that well
shall be immediately resampled to verify the
concentration(s). If the elevated concentration(s) is
verified through additional sampling and the well is
used as a drinking water source, that resident will be
supplied with an alternate water supply, preferably
hookup to the Southern New Hampshire Water Company
(SNHWC) supply line. If hookup to the supply line is
not possible, that resident will be supplied with an
in-home filter system. The alternate water supply
contingency will remain in effect until all cleanup
levels are met throughout the plume.
The balance of the residential wells, as listed below,
include eight (8) wells which have never had a
detection of contamination to date. Rather than
sampling each of these wells on a semi-annual basis,
each well will be sampled every five years, prior to
each five-year review, to verify the groundwater
quality.
4Sodium and chloride will be sampJ.ed to help 'track migration
of the plume.
~ese are standard pa%A1ueters which are 'typically sapled and
-------
Holton Circle Groundwater Contamination Site
Record of Decision- September 30, 1992
42
RW-1D
RW-2D
RW-3D
RW-4D
RW-6D
RW-7D
RW-8D
RW-9D
The monitoring pr:oc;ram will continue un~il completion of the
remedial action has been verified. ~he monitoring program will
be reviewed initially after the first two years and then during
each subsequent five-year review. 7'he program may be modified'
and sampling frequencies may be adjusted as deemed necessary by
EPA.
To the extent required by law, EPA will review the site at least
once every five years after the initiation of remedial action at
the Site if any hazardous substances, pollutants or contaminants
remain at the Site to assure that the remedial action continues
to protect human health and the environment.
XI.
STATUTORY DETERMINATIONS
The remedial action selected for implementation at the Holton
Circle Groundwater contamination site is consistent with CERCLA
and, to the extent practicable, the NCP. The selected remedy is
protective of human health and the environment, attains ARARs and
is cost effective.
A.
The Selected Remedy is Protective of Human Health and
the Environment
The remedy at this Site will permanently reduce the risks posed
to human health and the environment by eliminating, reducing or
controlling exposures ~o human and environmental receptors
through natural attenuation of the groundwater and through
institutional controls.
Moreover, the selected remedy will achieve potential human health
risk levels that attain the 10-' to 10-6 incremental cancer risk
range and a level protective of non-carcinogenic endpoints, and
will comply with suitable ARARs and to be considered (TBC)
criteria. At the time that the Interim Groundwater Cleanup
Levels identified in the ROD and newly promulgated ARARs and
modified ARARs which call into question the protectiveness of the
remedy have been achieved and have not been exceeded for a period
of ~hree consecutive years, a risk assessment shall be per£ormed
on the residual groundwater contamination to determine whether
'the remedial action is protective. This risk assessment of the
-------
'.
-.- ","--" - -
Holton Circl~ Groundwater contamination Site
Record of Decision - September 30, 1992
, 43
and will assess the cumula~ive carcinogenic and non-carcinogenic
risks posed by ingestion of groundwater. If, after review of the
risk assessment, the remedial action is not determined to be
protective by EPA, the remedial action shall continue until
protective levels aTe achieved and have not been exceeded for a
period of three consecutive years, or until the remedy is
otherwise deemed protective. These protective residual levels
shall constitute the final cleanup level~ for this Record of '
Decision and shall be considered performance standards for any
remedial action. '
B.
~e Selected Remedy ~ttaiDS ~s
This remedy will attain all applicable or relevant and
appropriate federal and state requirements (ARARs) that apply to
the Site. Environmental laws from which ARARs for the selected
remedial action are derived, and the specific ARARs include:
Cbemica~-SDeci£ic
.
Clean Water Act - Ambient Water Quality Criteria (AWQC)
Safe Drinking Water Act - Maximum Contaminant Levels and
Maximum Contaminant Level Goals (MCLs and MCLGs)
Resource Conservation and Recovery Act - Maximum
Concentration Limits (MCLs)
Clean Air Act - National Ambient Air Quality Standards
(NAAQS)
New Hampshire - Primary Drinking Water Standards
.
.
Location-SDecific
.
Clean Water Act - Dredge or Fill into Wetlands (Section 404)
Federal Executive Orders 11988 and 11990 - Floodplain
Management and Wetlands Protection
Fish and Wildlife COordination Act
New Hampshire Dredging Rules
New Hampshire Wetlands Rules
.
.
.
.
Action-SDecific
.
New Hampshire Antidegradation POlicy
New Hampshire - Rules re Abandonment of Wells
.
The following policies, criteria, and quidancewere also
considered in development of the remed ,1 action.
To Be Considered (TEC)
.
EPA carcinoqen Assessment Slope Factors
-------
Holton Circle Groundwater Contamination site
Record of Decision - September 30, 1992
44 .
.
EPA Risk Reference Doses
EPA Groundwater Protection Strategy and Groundwater
Classification Guidelines
EPA Action Level for Lead
New Hampshire Proposed Groundwater Protection Regulations'
New Hampshire Secondary Drinking Water Standards
.
.
A comprehensive listing of ARARs for the selected re~edy as well
as the other alternatives can be found in Appendix C of this
Record of Decision. This table gives a brief synopsis of the
ARARs and an explana'tion of the actions necessary to attain the
ARARs. The table also indicates whether the ARARs are applicable
or relevant and appropriate to actions at the site. In addition,
the table describes policies, guidance, and criteria that are to
be considered (TBC) with respect to the remedial action. .
C.
. The Selected Remedy is cost-Effective
In EPA's judgment, the selected remedy is cost effective, i.e.,
the re~edy affords overall effectiveness proportional to its
costs. In selecting this remedy, once EPA identified
alternatives that are protective of human health and the
environment and that, attain, or, as appropriate, waive ARARs, EPA
evaluated the overall effectiveness of each alternative by
assessing the relevant three criteria -- long term effectiveness
and permanence: reduction in toxicity, mobility, and volume
through treatment: and short term effectiveness -- in
combination. The relationship of the overall effectiveness of
this remedial alternative was determined to be proportional to
its costs. The costs of this remedial alternative are:
Component capital Costs 0 , M Costs Total NPW Cost
Monitoring 0 $1. 25 million $1. 25 million
Institutional * * *
Controls
Alternate
Water Supply * * *
contingency
T9tal Cost 0 $1. 25 million $1. 25 million
* Costs assoc1ated w1th 1nst1tut10nal controls are expected to be
minimal. Further, EPA anticipates that the alternate water
contingency will not need to be implemented and thus will have no
cost. In the event that the contingency is implemented, the per
household costs are inc~udecl in table 2~ ox Appendix B.
-------
Holton Circle Groundwater Contamination Site
Record of Decision ~ September 30, 1992
45
including active restoration (Alternative 5), yet the cost is
approximately $2.8 million less than the most expensive
alternative. Additionally, the time required for natural
attenuation is estimated to be only slightly longer than the time
required for active restoration of the bedrock. Furthermore. all
the alternatives evaluated, except for No Action, would require
institutional controls and an alternative water supply
contingency to be fully protective.
Therefore, since natural attenuation is as protective as the
other u'ternatives and requires a similar tiae period of
operation, yet at a much lower cost, there is no advantage to
active restoration and the selected is the most cost-effective.
~
D.
The Selected Remedy Utilizes Permanent Solutions and
Alternative Treatment or Resource Recovery Technologies
to the Maximum Extent Practicable
Once EPA identified those al~ernatives that attain or, as
appropriate, waive ARARs and that are protective of human health
and the environment, EPA identified which alternative utilizes
permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable.
This determination was made by deciding which one of the
identified alternatives provides the best balance of trade-offs
among alternatives in terms of: 1) long-term effectiveness and
permanence; 2) reduction of toxicity, mobility or volume through
treatment; 3) short-term effectiveness; 4) implementability; and
5) cost. The balancing test emDhasized long-term effectiveness
and permanence and the reduction of toxicity, mobility and volume
through treatment; and considered the preference for treatment as
a principal element, the bias against off-site land disposal of .
untreated waste, and community and state acceptance. The
selected remedy.provides the best balance of trade-offs among the
alternatives in the manner described below.
All five alternatives comply with ARARs,. however only
alternatives 2 through 5 provide fully for the protection of
human health by requiring the implementation of institutional
controls. The institutional controls to be implemented are the
same for the selected remedy as for the other three alternatives,
and are therefore equally protective of human health.
Based on the results of monitoring activities and hydrogeological
studies which have been conducted at the Site, it 1. expected
that the selected remedy, na'tuTal at'te~ion, will provide
similar long-term effectiveness and permanence as the other three
alternatives which rely on treatment to reduce c:cmt:.aDi.nation at
-------
Holton circle Groundwater contamination site
Record of Decision - September 30, 1992
46
Though the selecteq remedy does not reduce toxicity, ~obility, or
volume through treatment, reduction of toxicity~ and to some
extent volume, of the contamination is expected through natural
attenuation processes. Based on data collected during the RI,
calculations in the FS indicate that the selected remedy will
attain cleanup levels in the overburden aquifer within three
years. Alternatives 3, 4, and 5 would achieve the same goal in
essentially the same time period (2.5 years). similar '
calculations ]DacIe for the bedrock aquifer indicate that the
selected remedy and alternatives 3 and 4 will require 7 to 25
years to attain cleanup levels through natural attenuation.
Active restoration under alternative 5 would not attain cleanup
levels appreciably faster, requiring 5 to 21 years. Given the
similar time frames necessary to attain cleanup levels between
the selected remedy and alternatives 3, 4, and 5, it was
determined that the reduction in contaminant mobility provided by
alternative 5, and to a lesser extent by alternatives 3 and 4, '
has no advantage in preventing future migration of the '
contaminant plume than does the selected remedy.
The selected remedy does not involve any construction activities
and is readily implementable. Alternatives 3 through 5 each
require construction activities, to varying degrees, in an area
of wetland and residential development. Therefore, only the
selected remedy was determined to be more effective in the short
term as to not adversely impact the local community or, the
wetland. with respect to the other three alternatives, the
selected remedy is by far the easiest and least expensive to
implement, yet the selected remedy is as effective and protective
as the other alternatives, including active restoration. All
four alternatives demand the same degree of institutional
controls and involve an alternate water supply contingency.
Therefore, based on these criteria, it was determined that use of
a treatment technology is not warranted at the Holton Circle Site
given that the selected remedy was found to be as effective and
protective as active restoration, but more cost effective and
easier to implement.
The Selected Remedy Does Not satisfy the Preference for
Treatment Which permanently and significantly Reduces
the Toxicity, Mobility or Volume of the Hazardous
Substances as a principal Element
The 'selected remedy relies on natural attenuation to restore the
contaminated groundwater to its beneficial uses. Treatment will
not be utilized to restore the corrta1llinatet! groundwater because
it was determined not to be warranted or cost effective
considering the conditions at
-------
Holton Circle Groundwater Contamination site
Record of Decision - September 30, 1992
. 47
bedrock or.the overburden. Additionally, a review of the
analytical sampling results to date indicate that significant
natural attenuation has already occurred at the Site and is
expected to continue. Unlike active restoration, there is no
potential impact to the nearby wetland or J.ocaJ. community by
natural attenuation because no construction activities are
needed. Moreover, while the selected remedy does not employ
active treatment, the natural attenuation process wi~~ result in
the permanent and significant reduction in contaminant toxicity.
%1:1:. DO\;U~""'A!r%01l O? 110 S1:cnn:nCMft' CDBGES
EPA presented a Proposed Plan (preferred alternative) for
remediation of the Site on June 30, 1992. No changes of
significance have been made between the Proposed Plan and
Record of Decision. .
this
%1:1:1:. ~'l'E ROLE
The New Hampshire Department of Environmental Services (NHDES)
has reviewed the various alternatives and has indicated its
support for the selected remedy. The State has also reviewed the
Remedial Investigation, Risk Assessment and Feasibility study to
determine if the selected remedy is in compliance with applicable
or relevant and appropriate state environmental laws and
regulations. The State of New Hampshire concurs with the
selected remedy for the Holton Circle Site. A copy of the
-------
APPmtDU A
-------
UPDmZX A
-------
, / '-';::';"';
~ r~ ~ '" I, ..' ~ sly' #'~'"
P'¥ 'YJ ~rd', / 'iI.-.,~ &~\ \ '~ ,/ 1) '\" ~,-~Q ~ ~
~., p I::- ~~ ,\ \ ~ ~"~ f~ ~
", °J:~4 ' ~ "'- I .
: ><~ ~~" .O~ 'b - 11,\ .'" I 'E' yA'1j"~~" /
. ~ <9.r:. / .. I \ II I ~ 1.'11 1j''f. 0-'
'~~ 'iP, - . / >\ ' I I : ..: ~" /' '",
. .(~ ....~ ---.... .. (, ; 'if I ~ UI"".,
., ~ - ) I.. '. ~'
~' -~, .\~. l\s"~/,,~'I\~ ~v*{-s' '~;-!i3f
- . '~II -';::::::'''''T VrJlfl (.~\: II - I I' V,. -'......
(~ ~~) ~ \ ..~"'". /rOW.".' ria r51 ~~~
: . HILL SLOPE 'THEWETlANDS J)\(t! \ ,!,'. ~
J './ ' AREA 'N ' '3
~; :T"--, ~ . , " " '~., " \. '. I / \ .'>, '1 ~t2 ~ '
y "'Ib ~ .0-i'lf'- _J , ;u:: " '..) '-. ~. '1',),' '~~J RW-'~ J .~~~~~~
, ,. i / ' .. .. "'. ~ " ~ ~ - ~ ,I '~,r ~.), ." (1) ~-/
,/ )~1,' ~~ ~- ~ '....' }t~ I. ~: " \ ~-, ~ ~ ~g~:%'
«i:- ~ / '.., ~::t.RAGE "'IiI: ~ ' \' ~, 14;' I... S \~ H ,
' : ' ~ ' I .,s ~ . HOLTON CIRCLE -'
'( /. \1 ~ ~ ~ ~J ~~.t~' ",~
~ ,7:fi ~. ~ t;/-,9"\~ ~.\ ~ ~ ~.~ - .'!.,. ....:... ')$
; .' ~'j '-~<.. ~(2j'i ~~~ ~~] "W6}.v \}~'" 1?'
'. ..~ -' -:::," 1'< , " ~ ,#' v ~N i;;Q .lb>J. ~ (\. 1'"
- '-: ' , - , ' - O~'/ ./ )\ 0
'I i;" l) ,,-{ \t I 'kI (~~,) , a5~.2 'A ~ h . ,1 ~
.... ",' 1\)': . -'. .. - l\ 1"~: ,,~, :
~~~ . ~ :', "". .j/ ~ -::::; 1 ,'\~i~ -- "...- J ~rx"A
2~ -~ I - ".. :~~~~~\';:~ '>. ~ - .
'SCAlEINFEET '..;:' I'/~. Figure 1 SITEMAP
-------
~
./
(
I
LC>CaIOIID
ChlDml1Bd
Vol8ti1es
(ugl\.)
ND . NO. DeIeCle
-------
,.~
ii\)i ...'~<> '. '\..
" . "-. '" . : i iti I '\..
' . . .'i> . ,. 0
-""'-'" '. 0M;i,
! "<; <: ,i:?:' "'.' Y",., , : '. '<> ',.. "", ", ' "'')"
I. ," ," Ji""'/" .'\.'- /~.' ,.,'" , , , '" '" "
fl .. ':"4!t:~ \;;" ".,< / u ,..\. ,. " ., .. ; ,riIC, //', ,,!:~)..
. ' " .~.{: /, " /'...,., ,> ~" " ' ',":' '.._~! y . " ":~::"c. 1,< i , '
.C ''J'~<>iH': " ',/ '-C,,' ~. ..' \'i(' i " Jlgc:-:' /, -- ',- ,,' :~;f', , ""a
';J'::"~ (:~{<,.,/ ,~':",;o,~- :tL~ -,:""',.,~,;~,>~::.,;,'.,,, '000
tm/..~'- '-...: - - - - I:::: I /"" s...,,"~ -""""~i-' : ~._l,_,_".. 0
...... -." ", .:. " , . ~'" pW.", '.... ' , , ,
. ".. " SI"'..." ~ , '.... I ' " . ..
' , ,'<~ /",:, " " Pc'.. .1Iw,,, ':<' "'''. . '~.,' "'" "-"'{.'.. ';;:/ "'.
-' - ',. " .~...... 0, .JI.:. . .~ 'JO, 0 0 ']~ 0
r-' ...... ", "," , , '. -\, .- .,..."",- '".. ~ " , " ''', ".
//, . , ......' ~< '.., "">;",.cL ~1' . "'it """"'." '1 -"J ~.. ~. " '.
' ", , ' ,.''';''<-, ,'",-,. _.m " "", '~.. '.. ,~"
./ '. -, ...... ,," '," ',' ',,' ~ /"-.. ."""'" ,,' -" 9.'00 .. , , /, ~W-12D .... ,,-- -,
.-j '.. - -..' "- ,., '.,,,. .,' '" ""''''''. ft, '- , ,!. '. , '.
: ..... ': " 0 ";'0 ". ';.,". '/' '~",' '...OS , c. -,' ,.~ ~W"13 .-
., ':,-. 'DRAINAGE -', j ~"" ", ". ", ,
. .0 0 . 0,," D. ITCH , . 10-415 . "" ~'7D o. - ,I ,< ~..',/ : 18.800
.. " I,' '.. .... " "/ ',m,- ..... "", '- /. " ,
/, ~. -X." ' =' .. ~\t ,\ "'''J -" " ,..... ".,' :,' j,' 'j
. . , 1t>WH GAAAGE .~, '''', '" ~- 5'" "."'''''. . ,T'/' / riOL r.-::! ./ .
' -- , ..~ '. ..... ",.. . , ! ii.' , '.' ,~, C'RC"
. '. '" MAN, .... - - "" SUBC"";i!'.,
I , ~ ',. B''''''"'' -"-', , . . , "",
o -'. ~ - , .' " ..... . '" ~ RW-19D . ". ,.. 0
'.. ". "" , ""'. " ,'( -'. ,
'- ,i' . ::~"" .. " . - - _..;:. -.- - ...;. ..:. - . -' '"::' .- '...' "
... -"''''. ,: / l-"'" -- ' , . ',' ..~- - :... - ..,.. -::, ~> -''''''.:., ~'.' , ,
'. , / - - - - - - - - .', '.. , , --, .
"""" ~-'''''''' ':,' , . " ", .,' ,-' "'. '" ""', ' ",.
1 CONCENTRA'" . . - ", ." -,'/. . "'t ' .. , ''',', .,... .' ,.
-,-- ",:,::,<' - " ...,;j . ,: "'-. ',' ' '" '" . . ,,' / ,"C<, , ",' ,
=::::D:::R --, :,-'-'~:~~ . ~~~'" :..., ""j . . '. #.'., Fig~re 4 '
'-'- 'i ,#) " ", ;", " ' {', . D EXW.TOF TOTAL (UNnLTER£DI
",..,,"'" w '" '0, ". , ' , " .-'" , ", <, "'~'.. £S11MATE DROCK GROUNDWA-
' '..'H. "", , , . .OD"'MIN 8E , ONDERRY NH
"';;;""." ""'~ ,"",. '~-' .. ./ :' , " HOL TO' OReLL LOND .: . ,
,..., " ""'/'-'" ,':,. '- '! " ..- '
NS:'NOTSAMPLED '." . ...-. - /. '. . led. ImG.andllsidontialwellssampte POOR QUALITY
200 I -' ~ . Ir1Im mOflllanng web lamp OJ.
't, ~.J , '\ '\!WI'.. "'""'=::="""-~""'._"'ORJGJNAl
- "CAlE IN FEET . ,..;,
~ , T~Mop(PIa181),I'.COOh.
SOURCE: Hollon Circle . 1990
eaSI8m TopogrIIIIics.
----
'~
'.
"
-
--..b.
---- ,.,'
-------
. Figure
10 SHERWOOD ROAD
5
...
68...,
3"". l..
1'3-4
TOWN OF
LONDONDERRY
GARAGE
$14.'
.oj
\II
4\
\0 ,. S' \~
..
.z 0
~
1'i0 192k@
(I f#IJ
'9n (I.C) (It") C'~')
~S
\02 0\00
fOS -...;, 0..
~~
o .~~~~
,~~~ ~~
102 A
~~
:>G:> POOR QUALITY
ORIGINAL
~...-:"I
..
409
-------
C:,
100
L...
IIW-4S ~ MONITORING WEll
111-13. MICROWEll
;oURCE. Hollon Circte Topographic Map (Plate I), 1". .oDh.
Ea'lIn Topogr8P/1iCl, 1990
Figure 6
LOCA TIONS OF MICROWELLS.
-------
HOLE DIAMETER. IN INCHES HOLE DIAMETER. IN INCHES HOLE DIAMETER. IN INCHES . HOLE DIAMETER. IN INCHES
6 6 LEGEND
o 0 0
-)... InllalBd Pacl.,1 looI8Ied Zone
20 20 20 'v.~~~'1 Unmonitored Zone
25 I
30 30 30 USGS Catiper Log
35 BOC BOlIDm 01 Casing
40 40 ~O Vertical Scale 1. . 25'
45
50. ",; 50 50
S5
60 IAW.2O.5 60 60
I- 65
70 70 70 w
W
I- U.
W
W I- ~. 75
u. w (j
80 Z 80 w 80
u. Z
(j ~ U) 85
;!; c.
90' (j
-------
I "
APPDmU B
-------
Table
1
SUMMARY Of CHEMIC ALl DI!11ICfED IN TEST prr SOILI AT THB FORMER RADIO BEACON AREA, HOLTON CIRCLB RI
NUMBER OF
, . RANQE OF POSITIVE HITS RANGE Of a.DCATlOtt OF
PBTECTION LIMITS PER AVERAGE(I) CONCENTRATIONS (2) ~AXIMUM
MltUMUtot tdAXIMUM NUMBER OF SAMPLES CONCENTRATION MINIMUM MAXIMUM COttCENTRATIOtt
VOLATILE ORGANICS (ullka) Chemical. wero DOt ddoded
".
SEMIVOLATILE ORGANICS (8&"&) Chemical. wero DOt detectod
METALS (malk&>
Aluminum J.4,. 41.1 2 I 2 6,300 4,150 1,610 TP-4-1 (II 1\)
Iron J.4 ,. 41.1 2 I 2 6,200 UIO 1,570 TP-4-B (II 1\)
Calcium J.4,. 47.1 2 I 2 650 425 171 TP-4-B (II 1\) .
~'anCilum J.4,. 41.1 2 I 2 1,400 121 1,190 .". TP-4-1 (II 1\)
., Pot8l1ium U.. 47.1 2 I 2 1,200 410 1,910 TP-4-1 (II ft)
Sodium :1.4.47.1 I I 2 43 62.6 TP-4-1 (II ft)
Bulum 3.4.. 41.1 2 I 2 23 1.6 36.6 TP-4-8 (II ft)
BelyUlum 3.4.41.8 2 I 2 0.34 0.21 0.4 TP-4-B (II 1\)
Anenlc 3.4 "41.8 2 I 2 4.1 3.6 5.1 J TP-4-8 (II 1\)
Claromlum J.4 ,. 47.8 2 I 2 7.9 5.9 9.' TP-4-8 (II ft)
Cabalt 3.4,. 47.8 2 I 2 3.5 2.6 4.4 ,P-4-B (II ft)
I.c8d 3.4.47.8 2 I 2 3.8 3.3 4.2 J TP-4-a (II 1\)
Man.- 3;4.41.8 2 I 2 110 63 155 J TP-4-B (II ft)
VlUl8dlum 1.4 .. 47.8 2 I 2 10 5.6 14.3 TP-4-1 (II 1\)
Zinc 1.4.41.8 2 I 2 14 8.2 19.4 TP-4-a (II ft) .
PETROLEUM HYDROCARBON' (malka} 10 I I 2 22 38J TP-4-B (II ft)
NOTES:
..
J - Quantltatlon II Ipproal_to duo to Ilmlta"on III - quality control review.
I. An arlthmdlc Iverlgo WII calcullted Ulln. 112 1M ..mplo detection limit If" ..wyte WII not ddected.
-------
Table
2
HUMBER OF
RNfOB OP roSITIVE HITS RANOB OF LOCATION op
DETECTION UMITS PER AVERAOE (I) CONCENTRATIONSP) MAXIMUM
t.fINIMU., MAXIMUM NUMBER OP SAMPLEs CONCENTRATION MINIMUM MAXIMUM CONCBHTRATION
VOLATILE OROANICS (u<a)
TctrachiorocdJeno 1-6 , I 5 4.6 11.51 MW-,S (0-2 ft)
Trlehloroahcno 1-6 2 I 6 5.2 6.5 13 1 MW-II (5-7 ftJ
Toluene 1-6 I I 5 2.5 . 2.51 MW-I' (0-2 ft)
Ethylbcazeno '-6 , I 5 2.0 . 21 MW-,. (0-2 ft)
Total X,ICAe8 1-6 2 I 6 . 2.' 1.5 4 1 MW-fl (5-7 ft)
SEMIVOLATILE OROANICS (8a1k1)
Bazole Acid 730-3600 2 I 6 ~. 72 905 1 MW-,. (0-2 ft)
8b(2-cthYlbeayl)phthalato 730-3600 2 I 6 1.3 . 69 1.3 1 MW-,. (0-2 ft)
MET AI..S (malt&)
AlumJaum J.f - 47.' 6 I 6 13,000 6,750 22,600 ... MW-I. (22-24 ft)
1r0ll J.f - 47.' . I 6 IJ,SOO . 5,'90 IJ,SOO 80-4-' (32-34 ft)
,Calcium J.f - 47.' 6 I 6 1,200 300 3,320 MW-I' (22-24 ft)
MapcalulII J.f - 47.' '6 I 6 3,900 1,190 13,700 '5 (22-24 ft)
Potaulum J.f - 47.' 6 I 6 2,400 102 7,110 '12-24 ft)
Sodium J.f .. 47.' 4 I 5 7] 30.6 157 '. I (32-]4 A)
B8r1ulII J.f .. 47.' 6 I 6 36 14.4 62.' 80+' (32-]f ft)
DeryUlum J.f .. 47.' , I 6 0.S2 0.25 0.74 MW-I' (22-24 ft)
ArIClllc 3.. .. 47.' 6 I 6 II 3.2 41.6 MW-II P2-24 ft)
C8dmlum J.f .. 47.' 8 I 6 0.37 0.6 MW-I. (5-7 a)
Chromlu. J.f .. 47.' , I 6 25 10 78 MW-,. (22-24 ,,)
Cobalt J.f .. 47.8 6 I 6 6.4 2.9 '17 MW-,. (22-24 ft)
Copper J.f .. 47.' .s I 6 10 U 30.5 MW-,I (22-24 ft)
Lad J.f .. 47.8 6 I 6 8.1 U 16.1 MW-I' (0-2 ft)
M8II,8Ae88 J.. .. 47.' 6 I 6 180, 69.4 467 MW-,S (22-24 ft)
Nlchl J.. .. 47.' .s I 6 14 6.4 49.7 MW-I. (22-24 ft)
V8ll8dlum J.. .. 47.' 6 I 6 27 9.5 75.2 MW-,S (22-24 ft).
Zinc. J.f .. 47.' 6 I 6 29 13.9 63.2 1 MW-,S (22-24 fa)
PETROLEUM HYDROCARBONS (mllk&) ,O .. I 9 26 15.1 74 1 80-4-' (0-2 ft)
SUMMARY Oil CHEMICALS DBJECTED IN BORINO SOQ..S AT niB FORMER RADIO BBACON AREA, IIOLTON CIRCLE RI
NOTES:
,- Qow...... . .......-... 10 '-' .. ... ,""ft, ....,,. ""low. .
.. . - .... "'''''.m ....""" ..... . .... .. IN ....... ....'" ... aI,......, -.. .... .'- .... ... "''''''m ...~ d~ 10 d""", ....".. d"",... UmB..
I. An arithmetic averalo wu ealc:ulated ualn. an IN "mple detection IImlll! "'lJIaIyte waa not detCded.
'2. Preaenll the minimum 8IId lIItalmum v8luea ror poaltive deteclions.
-------
Table
3
~
. SUMMARY OF CIIBMICAU DSTEC11!D IN TEST PIT SOILS AT THE TOWN OARAGE AREA AND EAST OP THB WHTI.ANDS, HOLTON CIRCLB RI
NUMBER OF
RANGE Of POSITIVE HITS RANGE Of J,DCATION Of
DETECTION UMITS' PER AVERAGE (I) CONCENTRATIONS (2) IotAXIMUM
MINIMUM MAXIMUM NUMBER Of SAMPLES CONCENTRATION MINIMUM MAXIMUM CONCENTRATIO"
VOLArlLE ORGANICS (uglkg)
T etrechloroethene 5 - 21 " 9 3.0 3J TP-12-8 (4 1')
Acetone 5 -21 J 1 9 15 47 51 TP-12-1t (41\)
SEMIVOL~TILE ORGANICS (u<t) . I 9. . " . ~ ~. ~.., :':. i. ,".
Acenaphthylene S50 - 910 J 1 9 290 . 120 290 J TP-12-A (9 ft)
Fluorene S50 - 910 " 9 170 . 110J TP-12-8 (4 ft)
Phenan~rene 350 - 110 J I 9 960 . 860 960 J TP-12-A (9 ft)
Anthracene 3SO - '10 J I 9 330 . 190 330 J TP-12-A (9ft)
Fluoranthene J50 - 910 .. 2 I 9 2,400 . 930 2,400 J TP-12-A (9 ft)
Pyrene 150 - 910 'll 9 2.300 . 730 2,300 J TP-12-A (9 ft)
Benzo(l)anthncene 1$0-910 2' 9 1,000 . 340 1,000 J TP-I2-A (9 ft)
ChrylCno ISO - 910 2 I 9 1.600 . 450 1,600 J TP-I2-A (9 ft)
Benzo(b)nuorantheno ISO - '10 2 I 9 1,200 . 230 1,200 J TP-12-A (9 1\)
Benzo(k)nuorantheno '.;' lSO-'IO 2' 9 1,100 . 290 1,100 J TP-12-A (9 1\)
Benzo(l)pyreno 'SO - '10 2 1 9 1.200 . 290 1,200 J TP-I2-A (9 1')
Indeno( 1,2.3-ed)pyreno 150 - '10 1 I 9 580 . SIOJ TP-12-A (91\)
Benzo(g,h,l)perylena 150 - 110 2 1 9 6SO . 140 6SO J TP-12-A (91\)
MET AtS (mglk&)
Aiumlnum 0.4 - 0.7 ., 9 4.300 1,930 6,845 TP-I2-A (9 ft)
Iron 311 -'84 9 1 9 4.700 2,010 8,950 TP-12.., (11\)
Calcium ; 0.9 - ,.7 7 I 9 1.100 436 3,100 TP-12-11 (10 ft) .
Magnellum 3.1 - '.4 . 1 9 1,100 3n 1,845 TP-12-A (9 ft)
Potailium 1.4 - 47.8 . 1 9 590 19. 1.230 TP-12-A (9 1\)
Sodium 26.5 - 46.3 6 I 9 71 54.9 169.5 TP-I2-A (9 1\)
Barium I.S - 19.2 " 9 II U 2S TP-I2-A (9 ft)
BeryUlum 0.2 - 0.3 ., 1 9 0.24 0.18 0.43 TP-12'" (1 1')
ArlCnlc 2.3 - 'M 9' 9 12 2.4 55.5 J TP-12-8 (4 1\)
Chromium 0.2 - 0.3 " 9 6.2 2.3 13.5 TP-I2-' (11\)
Cobalt 0.5 -'.2 9 1 9' 2.0 0.91 3.J TP-12-' (1 ft)
Leod 3.6 9 I 9 7.5 1.9 21 J TP-12-A (91\) .
Manganese 2.0 - '.5 9' 9 74 24.' 179 J TP-I2-8 (4 ft)
N Ick.el 12.7 - 32.1 I 1 9 2.4 6.7 1'P-12-A (9 ~)
Vanadium 0.6 - '.0 9 I 9 6.8 2.5 14.2 1P-12-' (11\)
Zinc '.1 - 27.8 9 1 9 16 5 36 TP-12-8 (41\)
PETROLEUM IIYDROCARBONS (mg/ltg) 10 . I 9 760 II 4.900 J 1P-12-J (4 ft)
NOTES:
J -'Qullnljlelion II epproxlmale due 10 IImltalloniln the quality control review. .
. - The maximum dr~ected value II Uled a. the averege because the calculated everaSII WI. greater than the madmum value due to elevated Amplc detection limite.
I. An arithmetic a..~rage WI. calcullted usin, In the .....ple detection limit If an 8II8Iyte wal not detected.
2. Presents the noinimum and mulQlum values (or positive detections.
-------
Table
4
SUMMARY Op CHEMICALS DETIICTED IN BORINO SOILl AT TIlE TOWN OARAOE AREA AND EAST Of THE WETLANDS, HOLTON ClltCLE au
NUMBER OF
RANOE OF fOSlTIVE lilTS RANOE oF' LOCATION OF
DETECTION LIMITS PER AVERAOE (I) CONCENTRATIONS (2) t.tAXIMUM
t.tINIMUt,f MAXIMUM NUMBER OF SAMPLES CONCENTRATION MINIMUM MAXIMUM CONCENTRATION
VOLATILE OROANICS (u&f18)
Tdrachloroetheno 1-21 II 1 44 U 2 36' MW-6S (0.2 ft)
Trk:hloroetheno .-21 10 1 44 4.0 I 25 , HW-6S (0.2 ft)
1,1,1- Trlchlorodhano '-21 .. 1 44 3.1 3 12 . 80-$-3 (0.2 ft)
I,I-Dlchloroetheno '-21 2 1 44 3.3 1 1 , t.tW--6S (0.2 ft)
1,2-Dlchloroedlano II-54 I 1 44 2.0 . 21 tttW-1S (2-4 ft)
Acetono '-21 201 44 2,900 65 65,000 80-12-3 (4-6 ft)
2-Butanone '-21 I 1 44 1.1 331 80-12-2 (10-12 ft)
Tolueno '-21 1 1 44 4.0 2 19' 80-12-2 (12-14 It)
Ethylbenzeno. '-21 2 1 44 3.0 . I 3 , 8O-S-3 (0.2 11)
ToCaI Xylenel '-21 I 1 44 3.0 . 31 t.tW-9S (0.2 ft)
Carbon Dlaulfldo '-21 I 1 44 3.5 51 t.tW-6S (1"" ft)
SEMIVOLATILE OROANIC. (.alka)
Benzyl Alcohol 140 - 4400 I 1 40 260 3151 80-12-2 (1-12 It)
Benzoic Acid 310 - 910 II 1 40 180 . 48 180 , MW-1S (0-2 ft)
4-Methylphenol 350 - 910 I 1 40 145 . 145 1 ..., 80-12-2 (1-12 ft)
I:'- BI8(2-ethylhellyl)phthalate 310 - 910 3 1 40 260 52 .t40 , MW-2S (0-2 1')
' Acenaphthyleno 350 - 910 I 1 40 81 . 811 80-12-1 (0.2 It)
.~
J "'. "nanthreno 350 - 910 2 1 40 290 240 290 , 80-12-1 (0.2 ft)
')'8CenC 350 - 910 I 1 40 120 . 1201 80-12-1 (0-2 It)
Fluorantheno 350 - 910 2 1 40 290 380 480 , a1Q-12-1 (0-2 ft)
Pyreno 350 - 910 2' 40 300 365 520 . a1Q-12-1 (0-2 ft)
Benzo(a)anthraceno J50 - 910 2' 40 220 . 145 220 , 110-12-1 (0.2 It)
Chryleno 150 - 910 2' 40 260 235 380 , 80-12-1 (0.2ft)
Benzo(b )Ouorantheno ISO - 910 2' 40 250 190 300' 110-12-1 (1-12 ft)
BClUo(k)Ouorantheno ISO - 910 2' 40 260 280 335 , 80-12-1 (1-12 ft)
Benz.o(a)pyrene 850 - 910 2 1 40 250 230 310 , 80-12-1 (1.-12 It)
Indeno( 1,2,3-cd)pyrene 850 - 910 I' 40 260 2101 Bo-12-1 (8-12 1')
Benzo(g,h,l)perylene 850 - 910 2' 40 250 160 215 I Bo-12-1 (1-12 It)
MET ALS (11':.;ka)
Aluminum 0.4 - 0.1 40' 40 10,000 2,280 26,100 MW-6S (0-2 It)
Iron S21 - 384 401 40 11,000 2,840 33,800 MW-3S' (10.12 1')
Calcium 0.9 -1.1 35' 40 900 139 3,600 tdW-3S (1()'-12 1')
Magnellum J.I- 8.4 40' 40 3.400 318 11,600 MW-3S (1()'-12 It)
Potailium 1.4 - 41.8 40' 40 2,400 152 . 14,600 tdW- 35 U().-12 ft)
Sodium 26.5 - 46.3 28' 36 330 13 1,230 tdW-95 «()'-2 It)
Barium 1.5 - 19.2 40' 40 36 4.1 191 MW-6S (6-10 It)
Beryllium 0.2 - 0.3 26' 40 0.31 0.24 0.1 tdW-3S (UH2 ft)
-------
SUMMARY OF (:IIEMICALI DETECTED IN BORING SOILS AT TilE TOWN OARAGE AREA AND EAST OF THE WETLANDS. HOLTON CIRCLE AI
NUMBER OF
POSITIVE lilTS
fER
NUMBER OF SAMPLES
Table
4
(cont..)
. ~ANGE OF
DETECTION LIMITS
MINIMUM MAXIMUM
AVERAGE (I)
CONCENTRATION
RANOE OF
CONCENTRATIONS (2)
MINIMUM MAXIMUM
a mum
Chromium O.~ - 0.3 361 40 28 4.5 157 .
Cobalt 0.5 - 2.2 401 40 5.3 1.2 18.8
Copper 0.4 - 0.7 311 40 7.1 1.3 24.8 .
Lead 1.6 351 40 6.7 1.7 13 .
M_canClO 3.0 - 3.5 40 1 40 ISO 22.3 421 1
Nlc:kd 13.1 - 22.1 3J 1 40 14 2.6 69.6
Sdver 204-7.0 I 1 40 0.61 1.001
Thallium 223 .. 296 I 1 40 0.30 0.43
V ....dlum 0.6 - 1.0 401 40 19 13.2 n.6 .
Zinc 1.1" 27.1 301 40 19 6.00 63.6 .
10
19 1 41
27
570.
II
;.
PETROLEUM HYDROCARBONS (mclk )
NOTES:
. - Quantltatlon la approxlmato due 10 IImltatlonl'" die quality c:onlrol review.
. - Tho maximum cletec:tod val... II uled II "0 aver..e bec:auae the c:alc:ulatedlVCra.o w.a creater than the maximum valuo due 10 elovated IImpie detection IImltl.
I. All arithmetic averalo waa ellculated uIIII, 1/2'" IImple detec:tlon limit If 8ft aaalyte wal not detected.
2. Preaentl tho minimum and maximum valu.. ror poaltlve detoc:tIona.
'J.
~.
.".
" ,
.'
LOCATION OF
MAXIMUM
CONCENTRATION
I
MW-3S (10-12 n)
MW-3S (10-12 n)
MW-'S (10-12 n)
BO-12-2 (24-27 n)
MW-'S (10-12 n)
MW-'S (10-12 n)
MW-9S (o-a ft)
BO-12-2 (24-27 n)
MW-'S (10-12 ft)
MW-3S (10-12 n)
-------
tble
5
..,
I EASTERN UNITED ST4TES (I) NEW IIAMPSIllRE (2) NEW HAMPSIllRIi (3)
ARlTHMBTIC ARITHMETIC
AYERAOE IAHOB AYERAOB RANOB
(1IIJIk&) (~ (aal'&) (m&lk&) 10,000 30,000 - 100,000 -
IRON 25,000 100 -. 100,000 20,000 - 50,000 - -
CALCIUM 6,300 100 .. 280,000 8,000 - 18,000 - -
MAONESIUM 4,600 50 - > 50,000 3,000 - 10,000 - -
POT ASSIUt.t 15,010 SO.. 37,000 . 9,500 - ~5,ooo -
SODIUM 7,800 < SOO - 50,000 10,000 - 15,000 -- -
BARIUM 420 10 - 1,500 JOO - 1,000 - -
BERYLLIUM. 0.'5 <1-7 '.0- 3.0 - -
.1"
ANTIMONY 0.16 C I - 8.8 - - -
ARSENIC 7.4 0.' - 73 '.6 - 6.0 4.9 1 - 12.
CADMIUM - - - 0.58 0.15 - 8.9
CIIROMIUM 52 I.. I.OM 1$.0 - 30.0 11.8 4-47
COBALT 9.2 c 0.3 - 70 3-10 - -
COPPER 2a <1-700 7.0 - 15.0 - -
LEAD 11 c 10 - 300 20-30 29.8 2 - 160
MANOANESB 640 < a - 7,000 500 - 700 - -
MERCURY 0.12 0.o, - 3.4 O.OJ - 0.23 0.08 0.01 - 0.61
NICKEL 18 < S - 700 7 - 15 8.2 U-28
SELENIUM 0.45 < ().. ., 0.1-0.5 - -
TIIALUUM .., 2.3-23 - - -
VANADIUM 66 <7-](1) ]0-70 - -
llNC 5~ < S - 2,900 200 - 300 - -
METAL CONCENTRATIONS IN SURFICIAL SOILiIN TilE EASTERN U.S. AND NEW HAMPSHIRE
.5.
NOTES:
-- - No data IVlilable
I. Schaklctle IIId Bocrnl8ll, 1984
2. Bocrnlen IIId Shacklclle, 1981
3. CavUler, 1991; basccl on .urface 8011, coUlt:tcd throu&hout New Hlmp8hlre by the ~HDES.
;
,.
[
I
-------
Table
6
SUMMARY OP CHEMICALS DBTECTBD IN OVERBURDEN GROUNDWATER IN THB TOWN OARAOE AREA AND BAST OP ntB wm.ANDS,
HOLTON CIRCLB RI
NUMB~R OF
R~aE OP POSITIVE HITS RANOE OF LOCATION Of
DETECTION LIMITS PUR AVERAOE (I) CONCENTRATIONS (2) MAXIMUN
MINIMUM tdAXIMUM NUMBER Of SAMPLES CONCENTRATION MINIMUM MAXIMUM CONCENTRATION
. VOLATILE OROANICS (uJIL) - Dec:elllber 1990
T etrac:hloroetheno 10 - so I I . 3.0 . ]I MW-5S
1,1,1- Trlc:hlorodhaoo 10 5 I I 120 :J 740 MW-2S
1,1,2- T rlc:h1orocthano 10 - so 2 I I 1.0 . I I J NW-2S
I,I-Dlc:hloroetheno 10 2 I . 1.6 II ' 21 MW-SS
I,I-Dlc:hloroethane 10 3 I . 15 6 14 MW-2S
Carbon Tetrachloride 10 - SO I I . 2.0 . 2J ==U,
Elhylbeazeno 10 - SO I I . 1.0 . IJ
Total XylC11C8 10 - 50 I I I 2.0 . 2J MW-7S
VOLATILB OROANICS (uJIL) -Iune 1991
Tdrachloroetheno S -25 I' . 3.9 41 MW-5S
1,1,1- T rlchlorocthano 1-25 5' . 3.9 3 700 MW-2S
1,l-DlchJoroctheno I 2' . 1.5 19 26 tttW-5S
1,I-Dk:h1oroCdwae . ' 3' . 33 1 220 tttW-2S
SEMIVOLATILB OROANICS (uaIL) - December 1990 .~,
Cbcaalc:8l. were DOl detected
TOTAL METALS (uaIL) - December 1t90
AlulDlauia " - 20 I " . 49,000 10,400 13,000 MW-2$
Iron '-11 8 , , . 47,000 10,500 n,700 MW-2$
Calcium 10 - I' 8' . 180,000 21,400 191,000 MW-5$
Mapellum ,,- 21 8' . 31,000 6,480 103,000 MW-5$
,Sodium 19-50 8' . 750,000 16,700 1,930,000 MW-4'
poca..lum 68 - 101 I' . 26,000 9,350 49,200 MW-5S
Barium 1-2 8' . 400 92 911 1 MW-5S
BeryUlum I 6 I . 2.1 I 4.2 MW-88
Antimony. 14 - 11 2 I ., 8.7 10.5 15.5 MW-I$
ArIellJc ',',. , . . 7 I . 24 14.2 41.1 MW-3S
Cadmium: ;:' .. I-I 2 I . 2.1 3.5 4.1 1 MW-8S
Chromium 4 8 I . 130 25.9 396 MW-3S
Cobalt.., 2-4 8 I . 29 1.1 69.8 MW-2S
C' 11.' 7 I . 43 28.6 104 1 MW-21
opper '~" "
Lead:~~' :" ," "" " J I I . '20 5.9 36.3 MW-21
M ,,,..,;r,."~'i" .' t-f I I . 1,600 412 3.040 MW-21
. UI~I~~":"':~';" ....'
;0.' 0.2 2 I . 0.25 0.52 0.84 1 MW.....I
Mercary~."," ',:' ,
-------
Table
6
(cont..)
SUMMARY OF CHEMICALI DETECTIiD IN OVERBURDEN OaotlNDW ATER IN THE TOWN OARAOE AREA AND EAST OP TUB WliTLANDI,
IIOL TON CIRCLB II
NUMBER OF
RANOEOF POSITIVE HITS RANOI! OP &.OCATION OP
DETECTION LIMITS 'ER AVERAOE (I) CONCENTRATIONS (2) . MAXIMUM
MINIMUM MAXIMUM NUMBEIt OF SAMPLES CONCENTRATION MINIMUM MAXIMUM CONCENTRATION'
TJiiffium ~ I', 6 1.2 21 MW.)S
Vanadium 2 -3 . I 8 92 19.5 234 MW,"",S
Zinc 27.3 , I 7 130 107 245 , MW,"",S
DISSOLVED MET AU (u&fL). December 1190
,
,A!U.InUID It - 94.4 2 I 8 230 187 ' 1,470 MW-2I -'
hoa 11.2 - ..8 J I 8 420 192 1,740 MW-JI
Calcium 19 ' 1 I 8 210,000 21,200 191,000 MW-f.
Ma&ne.lum 17 . I 8 24,000 1.800 98,400 MW-SI
Sodium SO . I 8 810,000 16,500 2,120,000 MW-2I
Potuslvm 68 ' I' 8 14,000 5,430 31,700 MW-,.
Barium 25.4 - 'lA1I J, 8 150 31.6 586 MW.5S
Araenlc 2 I I 8 1.2 2.6 MW..lI
Coball '';' . 4 I 8 5.4 3 18.9 MW.....
Copper 2-3.2 ., 8 3.8 2.1 8.4 MW-JI
Man&aneae M.' 7 I 8 840 47.6 2,730 MW.....
Mercury 0.2 2 I 8 0.22 0.4 0.74 , MW.....
Nickel . " 8 10 6.6 21.1 MW.as
WAT~R QUALITY PARAMETER' (IDWL).. Dece...., 1990
Chloride I " 8 1,700 42 3,550 MW.JI
Nltrale/Nitrlle 0.01 - G.Of ., 8 0.93 0.31 4.2 , MW..... .
.
Sulfale 0.01 I I . 0.05 0.4' MW.7.
Orthopholphale I " 8 44 1.5 178 MW.JS
Bicarbonate 2 ., 8 48 6.7 110 MW-SI
NOTES: '
J - QuanUlallon I. approJdm.te due 80 1IIDllaUOII8 In the .1111'1 conlrol review.
. - The mulmulD detecled value I. .8ecI .. the Ivcr.,. IItc:aV80 the calculaled avera. wa, Irealer than the maxlmulD value due 10 elevated ample detection 11mb.
I. An arithmetic average wu calculated v.lnl 1/2 III. ample detection limit If an anal)1. wu not detecled.
2. Presenl. the minimum and mulmum value. for po.ltl". detecllon..
-------
--,-'--- - ,- -,-
Table
7
HOLTON CIRCLE
MICROWELL OAT A
--------------
--------------
Well location
1,1,1 TCA
1,10CA
..
1,1 OCE .
CA
Toluene
Carbon
disulfide
------------------------------------------------------------------------
MI-l 38.9 7.2 3.4 SO 1.2 7.8
M1-2 48.9 175.0 2.6 20.~ aD SD
MI-3 10.1 4.1 80 80 80 SO
MI-4. 275.0 23.0 80 80 80 80
M1-S 107.0 12.0 2.4 SO SO SO
M1-6 13.2 80 8t) SO 1.4 SO
MI-7 9.4 1.2 80 SO SO so
""1-9 ~.9 BD BD SD SD BD
MI-9 21.0 10.0 1.4 SD SD SO
MI-10 87.0 21.0 5.9 80 80 80
MI-11 22.0 80 1.8 80 TRACE 80
MI-12 2.5 < 1.0 80 8D SO 80
MI-13 1.9 80 80 80 80 80
MI-14 80 80 80 80 80 80
------------------------------------------------------------------------
* Above data analyz~ by NHDES lab.
MI-l to MI-7 sampled in 4/91.
M1-8 to M1-14 sampled in 5/91.
MI-14 is background well.
* All quantities reported in ppb.
* 1,1.1 TCA = trichloroethane
* 1.1 DCA = dichloroethane
* 1,1 DCE = dichloroethene
* CA = chloroethane .
* 80 = below detection limit
* < = less than
-..---'. ...- - --.--"
-------
Well location
Table
B
-
HOLTON CIRCLE
MICROWELL DATA
--------------
--------------
*SAMPLED IN Jun~/July 91
~
1,1,1 TCA
Trichloro. Carbon Carbon
1,1 DCE fluorome.tetrachl. disulfide
------------------------------------------------------------------------
1,1 DCA
M!-l
MI-2
M!-3
MI-4
MI-5
MI-6
MI-7
MI-8
MI-9
MI-10
MI-11-
MI-12
MI-13
MI-14
ND 12.0 8D 8D 8D 8D
NOT SAMPLED----------------------------------------------
2.5 6.3SD aD SD 8D
98.0 50.0 2.6 6.4 16.0 8D
22.0 37.0 8D 8D 3.7 BD
12.0 1.5 BD 22.0 1.8 SD
DRY WELL -------------------------~~ ---------------
3.8 8D 8D 8D 8D BD
27.0 18.0 8D 8D 4.4 1.6
20.0 19.0 8D 8D 3.3 1.0
8D 8D 8D 8D BD 8D
8D BD 8D BD 8D BD
. 1.20 8D 8D 8D 8D 8D
DRY WELL ----------------------------------------------
-------------------------------------------------
* Above data analyzed by NHDES lab.
MI-3 to MI-6, MI-9 to MI-12, MI-14 were sampled on 7/18/91
MI-1, MI-4, MI-6 to MI-8, MI-12, MI-14 were sampled on 6/26/91
MI-13 was sampled on 7/26/91. MI-14 is background well.
* All quantities reported in ppb.
* 1,1,1 TCA = trichloroethane
* 1,1 DCA = dichloroethane
* 1,1 DCE = dichloroethene
* CA = chloroethane
* 8D = below detection limit
* < = less than
-------
Table
9
. ';.'~'f."~"'~ '\::.:."
. . ,'". O"~.. ''tA.'''~
. . ~ '. .
SUMMARY OP CHEMICALS DET&; IIUI ... lED ROCK OItOUNDW ATER ... niB TOWN OARAOB ARBA ANIJ BAST oP THB W811..ANDS, HOLTON ClRa.s RI
RANOEoP
DETECTION UMITS
MINIMUM MAXIMUM
NUMBER OF
POSITIVE lilTS
PER
NUMBER OF. SAMPLES
. AVERAOB (I)
toNcENTRAnON
aMOB 0'
t:oN~TION. (2)
"'NIMUM MAXIMUM
LOCAnON OP
MAXIMUM
CONCENTRATION
VoLATILI OROANICS (galL) - December 1990
TelnchioroelheM .
TtlchlOl~
I.' .1- TrIdtlotOllltt..
I.I':DIeMIIMfIlal8
I.I-D~
l.t-DleWIIMfhu8
C8ltJoR Tdnchlorllle
~
TaI-
2-a.......
c... D"".....
votATIUI ORoANICS (.aIL) -,.. 1991 (3) ,
Tel...""",..... UI. , - 25
M.I-Trldtlotoee'" S
1.I-DIe~ 5
I.I-DkhlC11t1ed1a8 ,- 9
~~. '-25
cNor~ '-25
~ 5-25
Tell.... 5 - 25
ettllo8 DW'¥- I " . 5 - 25
SENIVOLAtiLE OIOANICS e.aIL) - ~ 1990
"-d 10
118{2~")pI.IW... 10 - 47
TOtAL MEtALS ettatL) - DeceIIIIIer 1990
AhaIa...
,..
ealcl...
M'pal..
Wlu.
'CIt...I...
a.tlalll
AIIII_1
..'
10
10
10
10
10
10
10
10
10
10
10
I' 7 1.0 . II MW-2D
I' 7 1.0 . II MW-ID
4' 7 16 t " MW-SD
5' 7 16 ' 41 MW-2D
5' 7 21 t 4. MW-ID
I' 7 5.0 51 . MW-3D
I' 7. 2.0 . 2J MW-ID
I' 7 2.0 . 2J MW-SD
I , 3' 7 4.0 . 1 .. , MW-4D
I' 7 U I' MW-3D
2' 7 4.0 . I 4 MW-ID
I' 7 2.1 . 2.11 MW-5D (LEVEL 4)
4' 7 21 10 14' MW-2D (LBVEL 6)
5' 7 1 U 19 MW-2D (LEVEL 4)
5' 7 14 .e.' 39 MW-2D (LEVEL 6)
2' 7 U U 35 MW-ID (LBVEL 6)
I' 7 U. 2." MW-4D (LEVEL 2)
I' 7 2.1 . . 2.11 MW-SD (LBVEL 3)
4' 7 3.0 1.1 4.5 MW-6D (LBVEL I)
2.' 7 U .. 1.1 MW-2D (lBVEL 2)
"
~ lOt
I' 1 4.0 . 4' . MW-5D
I' 7 18 44 . MW:,,~....
''''',;'.-' .
" 7 840 1M 1.420 ,MW-m
" 7 1,000 488 ";700 MW-1D '
7' 7 370,000 IS.. 69t.CIOG MW-2D
7' 7 110.000 . 1.900 S2J.CIOG MW-4D
" 7 1,270.000 24,. 6,140,CIOG MW-4D '
7' 7 41,000 5,t. 1 34 ,ClOG MW-4D
" 7 900 29.1 ".910' 'MW-4D'
I I 7 '.2 14 MW-5D
19 - 20
1-17
10 - 19
17 - 27
39-50
68 - 101
1-2
14 - 17
-------
Table
9
( con t. . ) ,
SUMMARY OP CHEMICALS DI!'I1I:I'EO IN IEDIOCIt OROUNDWATER IN mB TOWN GARAaB ARBA AND BAST OP mB WB'I'LANDS,IIOLTON ClRCUlIi
'"
I
NUMBER OF
IANOS OF POsmVE HITS RAN~E OF a.or'.' "'OP
DPECTION , IMITS PER A VERAOB (I) CONCENTItATIONS (2) to! \
MINIMUM "AXIMUM NUMIIp OP SAMPLES CONCENTRATION MINIMUM MAXIMUM CQtfCENTaATION
ArIeAlC ~-IU I' I ~.J J.;) MW-IU
Chrollllu. 10 I I 1 ],I 4.4 9.7 MW-3D
Cob8h 2-4 . I 1 2.4 5.5 MW-4D
Copper 1.2 . I 2 2.4. U MW-ID
Lad 1.1-"' . I 7 7.4 7.1 16.1 " ID
M........ '.t 7 I 7 550 34.2 I," MW-4D
Mema" 0.1 J I 1 0.34 0.3 0.' . MW--4D
NIeUi . I I 3 5.9 11.6 MW-JD
Zinc '1.2 I I 2 13 20 MW-ID
DiSSoLVED MET AU (.aIL) - Dece8ber 1990
IRIII . .8.4 - '8.4 . I 7 1,400 285 7,190 M\V-1D
C"elu. II 7 I 7 350,000 36.400 567,000 'M\V""D
tot'.....I.. n 7 I 7 130,000 1,150 a,ooo. M\V""D
Sodl.. so 7 I 7 1,410.000 24,200 ',190,000 . M\V-4D
'ot..... .. 7 I 1 44,000 6,150 155,000 . MW-4D
1a,1.. 41.7 - ,1.5 4 I 7 680 24.9 3,500 . MW-4D
Ar" " I 7 3.1 15.5 MW-JD
Capper ' J I 7 1.7 2.1 J.2 MW-JD
MM..... 4.. 7 I 7 530 25,4 2,190 MW-4D
MemIIJ 0.2-0.6 J I 7 0.22 0.3 0.5 . MW-4D
Hie'" . I I 7 2.5 5.5 MW-5D
WATER QUALITY PARAMETEU (.aIL) - P8ca~JJ 1990
ChlorIde " I 7 4.400 35.0 23,500 MW-.tD ,
NII,II""II.. 0.01 4 I 7 0.79 0.2 2.7' MW-JD
s..rll. 0.01-0.12 2 I 1 0.02 0." MW-4D
Ortllaphoaph...l. , " 7 45 U 1(.' MW-4D
IIe.rbonet. I 1 I 7 47 26 100 MW-1D
NOTES:
. - QaMllllloa I. approll"', ... ID I......... .. ... quII", control mrlc..
. - The -II... cldected .... II .... .. ... nerep bee8.lIIthe eaJe....ed 'YCrIae II 1,e8fer I"'" the ...IDlu. value due 10 deviled 1UIpI. detectloa Ilmll..
' t.;.. .rllhadlc .YCrI..... aIaI.ed -. 1/2 !he .8IpI. detedloa 11811 Jr.. "'JI' ... aot detected.
' 2. Praen8. !he ....... ,ad ...... "'...Ior pII8IIlYe detect"'. ,
-------
Table
(cont..)
9
SUMMARY OP CHEMICAU DETBCTED IN BEDROCK OROUNDWATER IN mB TOWN OARAGB AREA AND BAST OP THB WI!11.AHDS, HOLTON CIRCLB..
".
I
NUMBER OF
IANOI! OF POSITIVE HITS RANGE OF a.or'~' "op
D~TECTION UMITS PER AVERAGE (I) CONCENTRATIONS (2) ~~ t
MINIMUM ",AXIMUM NUMBP Of SAMPLES CONCENTRATION MINIMUM MAXIMUM COtICEN1RATlON
ArKAlc ~-IU II 7 "l.J oJ.) MW-7D
Chromium 10 J I 7 3.8 4.4 9.7 MW-3D
Cobalt 2-4 8 I 7 2.4 5.5 MW-4D
Copper 7.2 8 I 2 2.4 . 2.4 t.fW-8D
Lead 1.1-'.4 . I 7 7.4 7.1 16.1 ,. 'D
Manlanao 9.9 7 I 7 5SO 34.2 1,960 MW""'D.
Mercury O.a J I 7 0.34 0.3 0.1 J MW""'D
Nickel 4 1 I 3 5.9 13.6 MW-3D
Zinc 11.2 ' I 2 13 20 MW-ID
DISSOLVED MET AU (ua/L) - December 1990
Iron '8.4 - '8.4 ., 7 1,400 285 7,190 MW-7D .
Calcl!!m II 1 I 7 3SO,OOO 36,400 567,000 MW-4D
Mesnellum n 7 I 7 130.000 1,8SO 606,000.. MW""'D
Sodium 50 '" 7 1.470,000 24,200 1,190.000 J MW""'D
Potailium 68 '" 7 44.000 6,ISO ' 155,000 J MW""'D
Barium 43.7 - ".5 4' 7 680 24.9 3,500 J MW""'D
ArlCl\lc 2 8' 1 3.1 1S.5 MW-JD
Copper 2 J' 7 1.1 2.1 U MW-~D
ManIUl.. 4.8 7 I 7 .530 25.4 2,190 MW""'D
Mercury 0.2 - 0.6 J, 1 0.22 0.3 0.5 J MW-4D
Nickel 4 ' I 1 2.5 5.5 MW-$D
WATER QUALITY PARAMETERS (maIL) - Deco..., 1990
Chloride S 6 I 1 4.400 35.0 23,500 MW-4D .
Nltrlte/Nltrato 0.01 4' 7 0.79 0.2 2.7 J MW-3D
SuUato 0.01-0.12 2' 7 0.02 0." MW-4D
Orthophoaphato 1 6' 1 . 45 9.5 If' MW-4D
Blclrbonato a 7' 7 47 26 100 MW-7D
NOTHS:
J - QuantitlUon II Ipprollmato due to IImlQUonl1n the quality control review.
.- The mulmum detected val. II uacci a, the Avera. bcc:aulC the calculated IVellae II arcater than the m8llimum value due to elevlted "Dlple detection IImltl.
.. I. lu1arlthmetlc averale wal calculated ualnl 1/2 tho 18mple detection limit If.. uaI"e WII not detected.
. 2. PrClCDtl tho minimum and maalmum valuce for paeltlve detectlODl.
-------
Table 9
.,~~""
'.""'.\,:' 'Ir'"''''
. ""'''':~ ...,~,~. ~ ..:.1........- .
SUMMARY OP CHEMICALS DETECTED IN BEDROCK GROUNDWATER IN THB TOWN GARAGB ARBA ANb EAST oP ntB WBTI.ANDS, HOLTON ClRCLB RI
NUMBER OF
RANGE OF POSITIVE lilTS RAtfGB 0' LOCATION OP
DETECTION LIMITS PER 'AVERAGB (I) CONCE~RATIONI (2) MAXIMUM
MINIMUM MAXIMUM NUMBER OF. SAMPLES tONcENTRATION MINIMUM MAXIMUM CONCENTRATION
VOLATILE ORGANICS (ul/L) - December 1990
Tehac:hlorodhene 10 I I 7 1.0 . II MW-2D
Ttlc:hlorodheno 10 I I 7 1.0 . II MW-ID
1,1,1- Trlc:hlorocdt... 10 4 I 7 16 J 66 MW-5D
1,I-Dlc:hlOfUdhen8 10 5 I 7 16 1 41 MW-2D
1,I-DJc:hloroethane 10 5 I 7 21 ' 41 MW-ID
1,2-DIc:hlorueth8118 10 1 I 7 5.0 51 MW-3D
Carbon Tet'lc:hlortde 10 I I 7, 2.0 . 21 MW-ID
CWorometh8be 10 I I 7 2.0 . 2' MW-5D
Taluene 10 I , 3 I 7 4.0 . I .. , MW-4D
2-8utanoa8 '.' 10 I I 7 6.4 15 MW-3D
Carbon O"1II11de 10 2 I 7 4.0 . I 4 MW-ID
VoLATILB ORGANICS (uJIL) -Iwao 1991 (3) ,
Tetr.c:hloroethcne 5- 25 I I 7 2.1 . 2.1, MW-5D (LEVEL 4)
I; 1,1- Trlc:hIorocdtlD8 5 4 I 7 21 10 145 MW-2D (LEVEL 6)
I',I-Dlc:hloroethcne 5 5 I 7 1 J.I 19 MW-2D (LEVEL 4)
1,I-DIc:hIOfOelJwa8 5-9 5 I 7 14 .... 39 MW-2D (LEVEL 6)
Chlorofo'. 5 - 25 2 I 7 6.1 2." JS MW-ID (LEVEL 6)
CWorobeftuoe 5 -25 I I 7 2.6 . 2.61 MW-4D (LEVEL 2)
Benzene' 5 - 25 I I 7 2.1 .. 2.11 MW-5D (LEVEL 3)
Toluene 5 - 25 4 I 7 3.0 I.' ".5 MW-6D (LEVEL I)
Cltbon OJ"tyle . I, 5-25 2 I 7 3.3 4 7.1 MW-2D (LEVEL 2)
SEMI VOLATILE ORGANICS (uJIL) - December 1990 "
~ .' j
Phenol 10 I I 7 4.0 . 4' . MW-5D
Bi8(2-e1h)'lheayl)phtlW8Ie 10 - 47 I I 7 II 44 , MW;-:!D,.. , ,
TOTAL MEtALS (u&1l) - December 1990 . ~".:~.. . .
Altm1nudl 19-20 7 I 7 140 124 2,420 MW-3D
IrCIII . 7 - 17 7 I 7 1,000 .... U,700 MW-7D '
Celc:lum 10-19 7 I 7 370,000 35,500 692,000 MW-2D
MalRc.lulD 17 -27 7 I 7 110,000 1,900 52S,OOO MW-4D \
Sodium 39 - SO 7 I 7 1,270,000 24,500 6,140,000 MW-4D ~
Potalliunt 61 - 101 7 I 7 41,000 5,930 134,000 MW-4D 1
Barium 1-2 7 I 7 900 . 29.1 ",910 I MW-<4D .
-------
Table
10
ANAlYTICAl DATA FROM OFf -&lTE N:8IPENfIM. WEllS IN THE LONDONDEItR'Y NEW HAMPSHIRE AREA (1). HOLTON Cmcu: AI
" .. SPECIFIC'" ' ,.. . .". ." ' ..
", APPRoXIMATE ,", ' '" ....
WEll DEPffl' GEOLOGIC CONDUCTANoE CttlOAIDE MANGANESE CAlCIUM MAQNE_&JM. soDIUM PoTA8eIu,. ~~N"T~ SULfATE tflTt'ATE
LOCATIO" " DI8T~E,f~ 8IT~ ~F~"~ UNIT pH (UM~M:"" "t"0'4 (UQ14 (UQ14 (uoI4 '. (UQ14 '. (UQI4. :.c,~." ::'~' (~'.,
.. ... .., " " (2) (2) (2) .. (2) ' i: (2)" .
,.. .. " '
. NO. 712350 I MILES II BEOfK)CK '.1 112 186 120 37000 800 138000 6300 40 II ...
EA. 4248158
. NO. 712145 1.5 MILES 11.4 TI.l '.7 182 1. NR NR NR .100 11000 NR NR ""
fA. 421010
. NO. 712258 UMILES 1U 'I.L 7.2 221 2. NR NR NR 17000 3800 NR HR "A
EA. 42530t ."
. NO. 712348 :UMILES 10.. OUTWASH 7.4 ... 133 NR NR NR NR NR NR "R teR
EA. 424447
. NO. 711134 UMILES 11 TIU 7.' 148 8.2 NR NR NR NR NR NR "R "R
EA. 425117
~
I
'.J
SOURCE: New H.mplhl,. B.llo - D... Repolt No. t. OIoundw8l" 88,1.. L-, M."lmack ,.,. Vall.,.
Jam.. M. W.1g1e and Rlch.,d Kran... 1888.
, NOTES:
1. Datal, "poItad lor untllt.rad -pia..
2. D... pr...ntad ., mgIL In "f".nc.. Unit. chanoad 10 ugIL _1111. rapor1.
-------
Table
11
SUMMARY OP CHEMICALS Pln'ECTEi> IN RBSIDEHTIAL WELLs DURlNo 1990, HOLTON CIRCI.8 RI
NUMBER OF
RANOE OF POSITIVE HITS RANOE OF LOCATION OF
PETECTION LIMITS PER AVERAOe (I) CONCENTRATIONS (2) MAXIMUM
fdINIMU_at MAXIMUM NUMBER OF SAMPLES CONCENTRATION MINIMUM MAXIMUM ' CONC~NTRATION (])
VOLATILE OROANICS - (-&II.) APRIL 1990 (a¥E)
TelrachlOrocd!ene I 0.5 I' I 0.]4 1.0 TOMf OARAOE (DEEP)
I,I-Dlchloroedleno 0.5 ], I 5.2 11.0 17.0 TOMf OARAOE (DEEP)
truu-I,2-Dlchloroetheae 0.5 ., I 0.21 0.5 I-OT '4-'
C18-I,2-Dlchloroecheno 0.5 I' I 0.21 0.5 I-0T 14-'
1,l-DlchiorOdhano 0.5 - 2.0 5' I 9.9 1.0 27.0 TOMf OARAOE (DEEP)
1,2-DlchiorOdhane 0.5 2' I 0."" 1.0 1.0 TOMf OAlAOIi (DEEP)
Bromochloromethane I 0.5 I' I 0.21 0.5 LOT 14-'
ClllorOlDelhane 0.5 2' I 1.1 1.0 12.0 f.OT '4-24 (OLp)
Acetone 1.0 - 9.0 I' 6 ].1 ].0 I-OT 84-24 (OLp)
2-Butanoae I I' I 2.0 2.0 LOT 84-24 (NEW)
VOLATILE OROANICS - (.aIL) APRIL 8990 (HIIDES)
" Telrochloroethcne I 0.5 2' 7 2.0 1.15 11';3 LOT 14-'
~: 1,1 -DlchioroetJJane 0.5 5' 7 12 0.50 ]2.' TOWN OARAQi! (DEEP)
s:-
' I,I-Dlchlorocd!ene 0.5 2' 7 ].7 1.24 16.40 , TOWN OARAOE (DEEP)
N
N
V0J.ATILE OROANICS - (ualL) 1"'" '''~ (N"DES)
1.1, "-Trichloroethane I 0.50 I , 20 0.30 1.24 LOT 14-12
1.I-DlchiorOClthene 0.50 10' 20 2.] 0.80 11.02 LOT 14-1
I,I-Dlchloroethano 0.50 I], 20 5.6 0.79 24.21 LOT 84-27
Mctllyl-t-butyl ctIIer 0.98 2 , 20 0.45 0.66 0.98 LOT 14-19
VOLATILE OROANICS - (uaIL) SEPTIOCT 1990 (NHDES)
I,I-Dlchlorocthane I 0.50 12 , 20 5.1 I.] 25.5 LOT 84-26
I,I-Dlchloroethcno 0.50 12 , 20 2.7 0.5 II.] LOT 84-26
Chlorororm 0.50 ] , 20 0.46 0.9 2.2 LOT 14-2
Toluene 0.50 1 , 20 0.21 0.9 LOT 14-24 (NIW)
VOLATILE OROANICS - (ualL) DECEMBER 8190 (NHDES)
1,l,;,Dlchioroeth8ne 0..5 - 4.9 12' 18 ].1 0.94 16.00 LOT 84-27
I,I-Dlchloroethcno 0..5 - 5.0 7' 18 1.8 0.50 6.00 LOT 14-27
Chloroform' 0..5 - 1.0 2' 18 0.45 0.67 1.00, LOT 84-12
Toluene 0.50 1 , 18 0.29 0.96 TOWtf OARAaE (DEEP)
m-Xylcne 0.50 1 , 18 0.34 1.80 TOWtf OARAaE (DEEP)
-------
Table
11
(cont.. )
SUMMARY OJ ClIEMICAU DBTIICTED IN RElIDI!HTIAI. WIILU DURING 1990. HOLTON CIRCL8 ..
NUMBER OF
POSITIVE lilTS
rER
NUMBEIOF SAMPLES
aANQB OF
PETECTION UMrr!
MINIMUM MAXIMUM
TOTAL METAL! - (..IL) APIIL 1990 (Mal)
Iron I..' - .'.7
CalcI... I ,ClIO
. Me...". I ,ClIO
. Sodl.. I ,ClIO
Potea". I ,ClIO
.rl.. 40
N_~ I
Copper U .. 22.5
Lead I
M8JI'- 10.2
Nkkd .
NOTES:
I - Qu8lll1t..1on II ....-ahMt. "'10 ......... .. ... cpaI", allltrul reYlew.
I. An erlthmdlc e"uie - ....... ..... 1/2 ... .1IIpI. tldeetlon limit II.. ....,.. - - deled".
2. Prelellll the mhlllll....end -al... ,,""'or paeltl". tldedlon..
3. De'e'or dI. '_II.ere.. ..... (deep .... 1IIeIIow) ere praentecl here beee... ..... well, were -1IIpI" 810111 with die reekfentW welle.
~
,
N
W
AVERAOE (I)
CONCENTRATION
1 ,
7 ,
7 ,
7 ,
7 ,
7 ,
4 ,
I ,
, ,
, ,
4 ,
7
7
7
7
7
7
7
7
7
7
7
26
200,000
5.400
74.000
11,000
4.
2.9
II
U
35
6.7
. ;. ':
IANOE OF LOCATION OP
CONCENTIATIONS (2) MAXIMUM
MINIMUM MAXIMUM COHCENTIATION (3)
99.2 IDT 14-27
16.300 442,000 IDT 14-27
1.310 10,100 . IDT 14-27
17.350 158.000. LOT 14" .
2.400 20.900 LOT 14-1
12.1 " LOT 14-1
2.1 6.7 LOT 14-22
21.4 LOT 14-27
1.2 11.4 LOT 14-24 (OLD)
II 99.6 LOT 14-1
-------
Table
12
. SUMMAity op CHBMlCAU DB"I'8C11!D IN U!Sml!Hl1AL WI!lLI DURINO 1991, HOLTON ClltCLB ..
HUNBER OF
'ANO' OF POSITIVE HITS ItANOEOF LOCATION OF
DI!TECTIOII LIMITS PER AVERAOE(I) CONCENTRAnONS (2) ~AXIMUM
MINIMUM MAXIMUM NUMUIt OF SAMPLES CONCENTRATION MINIMUM MAXIMUM CONCENTRAnoH
-J
VOLATILE OROANICS (.&fL) -....." 1991 (MHD'S)
I,I-~ 0.' 1 I 4 0.90 2.84 LOT 14-15
1,1-DlcWoraedIe88 0.' 1 I 4 0.44 1.0 a.ar 14-15
Trlllllo8ctMM. 0.' I I 4 0.44 1.0 loOT 14-12
CHLORIDB (.aIL) 2.0 . I 4 56 21 75 loOT If-IS
,
VOLATILB OROANICS (.aIL) -I.., 1991 (MHDEIt
.J,I-DIcW""'" 0.. 12 I 17 6.J 0.5 21.0 .~. a.ar 1f-,6
1,l-Dlchloroedle88 G.I II I 17 2.2 0.' I.' LOT 14-26
CHLORIDE -(.aIL) -2" I I 2.500 2,471 LOT 14-26
NOTES:
....
,- QillatIt8tla8 II 8pprO&I8II8"" I.......... .... q8ll'" COIIIroi NYIcw.
. TrlW08IdII888 II the.. ofko8of'or8, ~8, dlbrGlDOCWOI08MIdIu8, .. ~lchiorollldhue.
I. Ita .rllh8et1c nere88 ... aIc8I8IecI ... In ... .mplo deloell..l... 11- lII8Iyte ... not detected.
2. Praentl the ........ and ....... ....... for ""'Ivo delectlOlll.
-------
Table
13
NUMBER OF
RANGE OF POSITIVE lilTS RANGE OF "OCATION OF
DETECTION LIMITS PER AVERAGE (I) CONCENTRATIONS (2) MAXIt.tUM
MINIMUM MAXIMUM NUMBER OF SAMPLES CONCENTRATION MINIMUM MAXIMU" CONCENTRATION
VOLATILE ORGANICS (wIlL)
1,I,I-Trlc:hJoroedlano 10 I , 2 4.0 . 4J SW-2
Cuban Dllulnde 10 2 , 2 4.0 2 , , SW-I
SEMIVOLATILE ORGANICS (uaIL)
DlcthylphthaJlte 10 I , 2 2.0 . 2J SW-I
TOT AL METALS (UIIL) -
'.
Aluminum 20 2 , 2 3,000 500 5,490 SW-2."
Iron 17 2 , 2 1,200 1,036 1,330 SW-2 .:
Cllclum 10 2 , 2 55,000 24,500 1S,400 SW-J
MI.nellum 27 2 , 2 5,100 3,155 ',480 . SW-J
Sodium 39 2 , 2 9SO,OOO 621,000 1,280,000 SW-J
Potlsslum 101 2 , 2 12,000 7,965 17,000' SW-J
Blrlum I 2 I 2 1)0 47.2 201 SW-J
Beryllium I I I 2 \\ 2.0 3.5 SW-J
Arsenic 2 I I 2 *.~ 3.4 SW-J
Cobalt 2 I I 2 30 51 SW-J
Leed 3 2 I 2 8.0 6.05 9.9 , SW-J
Mlnllnele 6 2 I 2 2,300 137 4,390 SW-J
Nickel 4 I I 2 12 21.2 SW-J
Zinc 17.5 - 20.5 I I 2 62 115 SW-J
WATER QUALITY PARAMETERS (milL)
Chloride , 2 2 I 2 1,600 1,160 2,010 ' SW-2
Orthopho.phate I 2 I 2 42 40.5 oM SW-2
SUMMARY OF ClIEMICALI DETECTED IN SURP~ WATER,IIOLTON CIRCLE RI
NOTES:
J - Qulntlt8110n I. Ipprollmete due to IImltltlonaln the qll8Jlty conirol revp.
. - The m"lmum detClCled "elue I. I8Ied I' th. lVerl.e bec:8UIC the cilcuilled Ivcrl.e Illreater then the m..lmum vllue due to elevlted umple detClClIon limit..
I. An Irllh", ~lIc lverlle Wit calculated u.In, In the umple detection IImlllr 811 Inalyte .11 not detected.
-------
Table 14
,
SUMMARY OF CHEMICALS D8TIICI1!D IN SI!DIMEHTS, HOLTON CIRCLE RI
NUMBER OF
IANOI OF POSrrlVE HrrS RANGE OF IJ)CATION OP
. DETECTION LIMITS PER AVERAGE(I) CONCE~ATIONS (2) MAXIN"'M
MINIMUM MAXIMUM NUMJU OF SAMPLES CONCENTRATION MINIMUM MAXIMUM CONcENTRAnoN
VOLATILE ORGANICS (8aJka) - Decem"" 1990
TetncWoroedIeM 5-10 I I I 13 131 SD-t
1,I,I-TrIc~ 5- '0 2 I 2 48 II 77 SD-I
I,t-Dlchlorodhae 12 2 I 3 22 6 54 1 SD-I
- Acet- 24 - '20 4 I 7 14,000 22 100,000 1 - SIH
2-BIIIMoIIe H " 4 110 ]9 220 1 SD-I
- .
ToI... 5-10 3' 3 10 4 17 1 SD-5
MdllJIeM aIorkIe 16 - S200 3' 7 64 . 44 641 SIH
Cuboa DIMfIcIe 5-'0 4' 4 21 6 291 SD-I
. -
VOLAnLE ORGANICS (8&1'8)-'- 1911
...
TetnclllorocdleM II - '10 2' 10 15 . 4 15 1 ID-2
1,I,I-TrIcWOfodhue II - '10 . I II 69 13 270 1 10-6
1,1-DIcIllorollhMe II - JlO ,., II 99 6 JIG 1 SD-II
Acet- )4-260 4 I II 530 1.200 1,600 1 10-6
2-1...... 11.10 2' 10 7) 220 )to 1 .'
MedIJI- ChlorIde II - 61 7' II 240 90 1.100 1 ""'.,
Cuboa DllulfIcIe 11-40 I' II 2,900 II 27,000 1 ID-I)
SEMIVOLAnLE ORGANICS (.&1'1) - Dece8ber '990
4-MeIh"pheaoI lJO.. 1600 I I I 410 . 4101 10-4
BI8(2-ethJIhcI,I)phdllllate I... I 100 4' 6 840 110 1,900 1 ID-I
BcnmIc AcIcJ 4000 - 4400 2' ) 1,900 JOO 3,400 1 - 10-4
Benzo(I)pJrene IJO - 1600 I' 4 1,000 2,400 1 ID-S
- PESTICIDES AND PCII (.&1'8) - Dm"" 1990
-------
Table
14
(cont..)
SUMMARY OP ClIEMICALI DBTIICTED IN SEDIMENTS, IIOLTON ClRCLB RI
.:...,;:..:"
. . ');' i~. I'. ',':\ ' "
.. .. ..
..~",.'.1.,"'.. '.'
'.; ,...~
RANOE OP LOCATION OF
AVERAOE(I) CONCENTRATIONS (2) "AXlMUM.
CONCENTRATION MINIMUM MAXIMUM CONC&NTaAnON
6,400 2.610 14,900 SIH
4.900 1.670 IS,MII) SIH
12.000 491.0 2A,ooo 81).5
1.300 563 . 5,CIeO SIH
4.100 62.9 14,500 11).'
181.5 . 103.1 181.5 SI).I
73 11.2 130 'IH
13 28.9 30.6 '1).1
9.9 1.9 26 IIH
10 5.' 43.1 IIH
U '.7 SIH
29 2.6 69.4 SI).J
120 35.0 370 SIH .
I.
13 5.1 23,2 SI).J . :
3.7 4.' 11.5 . ID-I
1.2 2.4 1D-7" .
14 4.4 ".1 IIH
17 '.5 46 SIH
210 21.7 669.0 . SO-So
NUMBER OF
RANOI OF POSITIVE HITS
DETECTION UMITS PER
MINIMUM MAXIMUM NUM8E8 OF SAMPLES
METALS(ml~I)-D~m~l~
Aluminum II " 9
Iron 7 , I 9
C"clum 18 . I 9
Malnellum I' t 1 9
Sodium 11.1 - 8020 6 I 9
PoIalllum 127 - 1910 J I 9
Barium 3 t I 9
AntI_Y ;' ..1 - 37.4 2 1 9
Areenlc . 9 1 9
Chromium 6.1 - ... 6 I 9
Cob"t U -:.88.5 I I 9
t.:e.d I 9 I 9
MUlueR 8 " 9
Nkltd 4 . I 9
Selenium 1.2 - '.2 J 1 9
Th..Uum 0.6 - J.5 I I 9
V_dlum a 9 1 9
Zinc '.7 - 12.3 2 1 9
PETROLEUM HYDROCARBON' (.&'kI) 10 9 1 9
(I*ember 1990)
TOT AL COMBUSTIBLE OROANICS (mallt~
(June 1991) I 100
NOTES:
J - Quantlt.tlon II appro.hute the to IImll8l1on1 In ... qll8l1ty control review.
. - The m..lmum nlue detect" II Died .1 tile .ver'r beenae tile c81culated nenle II II'.er thu the m..lmam ."ue due to deviled umple detect- 11mIta.
I. An .rlthmdlc IYCrllC W'I c81cuI.ted alln, 112 the umple detection limit If.. "",.e w.. not ddectcct.
2. Prcsenll the minimum ud ,,"mum ."uca ~OI' poeltl.c detectlonl.
"'"
630,000
13.800
892.000
-------
"Table
15
SU8CAlY 0' POTENTIAL IIUS 10 waalCEIS
MIENT LAJIO-UU CONDITICIIS
Carclnaglftic lilkl
.........................
~ MIdi..
laute of bpa8ure awwnte WoI'IC ease
Direcc CanClet (I) 41-06
Incld8nul l,...riC8t . (b) 31-06
D.,...l AbHl"pCiC8t (b) 1E-06
Df,..t CantlCt fl) 11-09 21-09
Incid8ntll l,...tiC8t 7!-tt 3E-10
D.,...l AbHl"pCiC8t 1E-09 21-09
IngestiC8t 1E-05 71-05
IIon-Carcfnagenic lisks
.....................-...
laute of bposuN Avenge Worse ease
Direct Contact (I) ct
Incid8nuL Ingestion (b) 9£-05
De,...l AbHr,lciC8t (b) 1E-04
Dll'ICt CanCICC (I) c1 ct
Incld8ntll l,...tlC8t 71-01 31-06
D..u. MIIoI'pCi C8t 11-05 1E-05
1...-1- a-a Z!-ot
T- GInIe Iurf- Sell
(0-2 tllC)
1"0 ..- IUrf- IoH
(0-2 flit)
TOWI III,.... Gl'OI.IIdIIIter
bposure lied I ..
TOWI Gel'''' Surface Sol l
(0-2 flit)
I.io 18ICaft SUrlIC8 SOil
(0-2 tilt)
T- ...... ........
(I) Direct Cantlet riata ~ Ute ... of Ute rfata for incl_tel
. i,...clC8t ... ....l ....",CiC8t.
(b) only... 8111Ple ... 8¥IIillble, Uter.fore 1ft 8Wf'8I8 cae could not be
C8LcuLlted-
-------
Table
16
.'
SUMICAIT OF POTENTIAL RISKS TO TRESPASSERS
aIIIEIfT ...-uu c:x.mClS
Ca~lnogenic Risks
...---..........-.....-.-
~ _118 Raut. of EJIPCISU" AwrlV8 Worst Case
II U SI~ Area SUrfac. soil DI rect Contact (a) l,C-07 71:-07
(0-2 feet) Incidental Ingestion l,C-07 71:-07
D.,..l AbsorJ:Ition 5E-10 9£-10
E..t of die Wetlll'ds Area Direct Contact (a) 2E-06 2£-06
surface Soil (0-2 teet) Incidental Ingestion 2£-06 2£-06
Denael AbsorJ:Ition 1E-10 3E- 10
.Ill Slope .,... SeGi.m: Direct Cont~t (a) 1E-09 ZE-G9
Incidental Ingestfon 1E-09 ZE-09
Dennal AbsorJ:Ition 6(-11 IoE-10
Wetland SedlMnt Oirect Contlct (I) l,C-09 1E-06
Incidental Ingestion 2£-09 1E-06
D....l Absorption 2£-09 3E-07
Mill Slope Area Ponded Del'lll8l Absorpt i on (c) 3E-08
Drai".,. Wltar
Wetland SUrfac. Water De...l Absorption (b) (b)
EJqxI8ure Medll8
at L L SLope ... SIIrf8c8 So, l
(II-Z fwtJ
East of the Wetlands Ar.1
SUrfac. Soil (0-2 feet)
"i II Sl~ Ar.a Sedl.."t
W&l88 -""'1
1
1M t l Sl~..... ,...
Drai,... WM8r
Wetland SUrface wat..
lion-Carcinogenic Risk.
.-.-.-..-....--.-.-.-----
Raut. of E.oIposure Awrqe Worst Case
Dtr~ tantlCt (I) <1 <1
(n&idIMel 1"185:1- S-ID I,f-CB
D8f'I8l Abs~Oft .-oe 2E~
Direct Contact (a) <1 <1
Incidental Ingestion 1E-02 , ZE-02
O.".l Absorpt i on 1E-06 3E-06
Direct Contlct (I) <1 <1
Incidental Ingestion 71:-06 2E-05
D8f'I8l Absorption 2£-06 1E-05
Di~ tanUCt 'I) c1 <1
In&iQanQL tn!I8d- .-8 ~
o.r..t ~iOft )I-CIS 6E-0lt
....... .- ~... (c) a-eM.
D8f'I8L AIiI8orption 1E-05 1E-05
(,8) Dfr'8ft C8I'tIC:C rim ...... -.IE the ...., tile rf- ,... tlll:fdafDt ffII8ri..
and dar88t ~iaft.
(b) DrIly ch.icals exhibfting non-carcinogenic eHecu I18r. detected In W8tl8nd
surfaca 118ter. '
(cl DrIly - s...,ll 118. IVlilable"ot Ponded Drlinqe water, therefora no average
-------
. ---------..- --- --- - - - . --
Table
17
~.
STHWl% OF POTmIAL RISKS ASSCX:IAnD WITB
~u.... (SF IICt1aIIf c:ma.z U:S~ .... """"''''''''''''I'WD
4.
c:tIRR!1rt" LAID-US! anmmca
Aver..e Case Wont Cue
!xce.. LJ.!et1m8 !xc... Ll!et1m8 Aver..e Ca.e Worst Ca.e
Lot lIumber Cancer !U.sJc Cancer !U.sJc Hazard IDdex Hazard IDdex
14-Z (a) 2E-7 (a) <1
110-8 6E-5 8E-5 <1 <1
14-10 1£-5 3E-5 <1 <1
14-12 1£-8 2E-6 <1 <1
14-110. D- 1!-6 U;-S <1 <1
l/o-14. old 1£-5 3E-5 <1 <1
110-15 8E-6 1£-5 <1 <1
l/o-18 . (b) (b) <1 <1
14-19 4E-5 6E-8 <1 <1
14-21 9£-6 U;-5 <1 <1
14-U 1£-5 U;-5 <1 <1
lIt-Z3 1£-5 3!-5 <1 <1
\ 14-Z4. Dew 2£-5 2£-7 <1 <1
14-Z4. ald (a) 5£-5 (a) <1
t4-%5 3-5 2E-5 <1 <1
14-%6 sr-5 5E-' <1 c1
14-Z7 5E-5 7E-5 <1 <1
(a)
(b)
.
110 aver..e cue w.. calculated siDce there was aDJ.,. ODe .8Iple.
-------
Table
18
SUlCAl' OF POTEllTtAL. RI5a DUE TO SOIL/SEDIMENT IIIG£STrCII TO RESrtJ!IIft
~ I.AIII~ QI81,TIQ111
CarCinogenic lisu
----....--........-.-.-.
!JpI8UMI Path.,.., Receptor Ayerage Worst CU.
Ircid8ntaL Ingestion 1-6 y.ar oLd 1oE-05 1E-0l0
of T~ Garage Ar.. Soil AGILt 2£-05 5E-05
Ircid8ntal Ingestion 1 -6 y.ar old 3E-10 2£-09
of 181110 a.Kon Ar.a Soil AGIlt 1E-10 BE- 10
lnel_tal Ingest I on 1-6 .,..r old 4E-09 SE-09
ot:HiLl SLape Ar.a SoiL AGIL t 2£-09 3E-09
trcid8MaL l"lfttion of 1 -6 yur old ze-Q8 5E-08
ponded Dralnag./HILL SLope Adult 1E-08 2£-08
SedI8n1:
Non-carcinogenic Iisks
..-------.-.---------.-.
~ur. Pathway lec~tor Aveng. ' Worst Cas.
IrcidentaL Ingestion 1-6 y.ar oLd 5E-01 2£+00
of T~ Garag. Am Sol L AduLt 5E-OZ 3E-01
IrcidintaL Ingestion 1 -6 year oLd 2£-05 9£-05
of 18dio Beacon Ara SoH AO.iLt 21-06 9£-06
Ircldental Ingestion 1 -6 .,..r oLd 2£-010 5E-0l0
of Hill Slape Ar.. Soil AGIL t 2£-05 61-05
lncid8MaL .",.tian of t-6 yur otd 61-1)4 2£-Q3
PcnW ;rainaplatlL Sl.- AcIut t 6I-Q5 ~-GIo
Sedi--
-------
~
".-
-
"
.~
~':-\~.
--.- +- ------'-.--'- - --_.---
rable
19
SUMMARY OF POTENTIAL OE~L ABSORPTIOI RISKS TO RESIDENTS
FUTUI8 LAID-4ISE..t:181TtG11
c.rc I noteni c R I sics
......-----.....-.-------
Expoaure NedIUl Ave"lIe WOnt cae
TOW'! ~"age A,... SOl l ]E-Q6 31-06
18dlo a8econ A,... Soil 5e-10 9£-09
Hill Slope A,.~. Soil 7E-Q9 1e-08
Hill Slope Itr iedl.m 9£-10 61-09
Hltl Sl~ Ar .a0flllect (I) 21-07
o,..inage '4tc
Non-c.,.c I nogenl c II sits
-.-....---..........--...
EJIJIOSUr'e Ned I UI Ave,.... Wor-st cae
T 0lIl' ~,.age Aru So I l 7E-04 3e-03
R8dlo a88Con Aru Sol l Se-06 ]E-Q5
Hill Slope Are. soil 61-05 2£-04
Hill Slope Aru Sedi8Mt 21-05 1e-04
Hi II Slope It,... Pond8d (I) 1E-03
aralNl8 wacer
(~ OM~""""''''' ...tl8Dl... .ltlll 51.- --......
OMilnage wacer, therefor. only 1ft It!! case could be
detemined- .
-------
Table
20
SllllMY Qf IIOTaTlAL II sa DUE TO GIn IIIMTB rllGESTtClf
IT USIDEIfTS
FUTUR£ LAJII)-USI CCNDITIOIIS
ea"cinog8ftic Rfsks
----.-----...--------....
LCIC8cfon Aquf fer Aw".ge Wol"St eas.
T 0Wt ;.".,. A".. OWr"burden 2£-05 6E-05
Bed"ock 5e-05 2£-04
Rd 0 Bacon Area OWr"burden (8) R-04
Bedrock (a) 3E-06
Hf U Slope Are. OWrtalrdert 7!-04 1&-03
Bed"ock ZE-04 6E-04
Nol ton Cf rcl. OVertall'den 7E-04 9£-04
Bed"ock 1E-04 2£-04
Non-Carcinogenic Risks
---....-.................
LCIC8tfon A~ife" Awrage Wo"st ease
TOWI ;'rage Ar.. OWI'buI'dln <1 <1
Bedrock <1 <1
hdfo Iacan Area OWrtlur'den (a) >1
Bedrock (a) <1
Hill Slope Ar.. 0WrburdIn >1 >1
I8dr'OCIr 1
lilt U8t CtI"Cle ~""1J ~ ~
Bedrock <1 <1
(a) only - Ulllpl. .... available, ttte"efo". an aw".ge ca.. could not
be dete,..i nect-
-------
Table 21
AL TERNA 1E WA TEA SUPPLY CONTINGENCY COSTS
<~~~u~ ~~:~.".<:.. "
Assumptions:
The costs presented below are calculated on a per residencQ basis.
Inflation rate III 5%
Discount rate.. 10'"
Time Period = 30years.
Option 1. Hook up 10 SNHWC suPPlY
Capital cost: (one lime hook up charge) $4,000
.
Annual cost (1): (water usage & service charge) $684
Net Present Worth: (30 year time period) I $15,490 I
".,.
. Option 2. Point 01 Use Residential Treatment System
Capital cost: $6,749
Annual cost (2): $11,408
Net Present Worth: (30 year time period) I $198,387 I
Notes:
(1) See calculation In Appendix C
(2) See Alternative 2 cost detail In Appendix C for Limited
Action with one residence utilizing point 01 use filters.
-------
APPENDIX C
M'PL1:om.E OR ~ Mm ~1'PIt01'RnD 1tEQul~~ (:P.DRS'
-------
AlAR
FEDEIAl . clean Water Act
(CWA), Allbl..,t Water Quality
Criteria (AWIIC)
(CWA , 304(.))
FEDERAL' Safe Drinking Water
Act, M.xi- ContBlllinant Levels
(HClI) and Maxi- ContBIIIlnsnt
Level Goals (MCLGs)
(40 CFR , 141.11-141.16;
40 CFR , 1'1.50-141.51)
FEDERAl. RCRA Groundwater
Protection Standards, Haxlmum
Concentration Limits (HCLs)
('0 CFR , 264.94)
Appendix C -- Chemical-SDeoific ARARs
Status
Relevant
and
Appropriate
(for alt five
alternatives)
Relevant
and
Appropriate
(for alt five
alternstlves)
Relevant
and
Approprl.te
(for al I five
al ternstl.,.s)
Remll re8ent Svnoos I.
AWQC are health-based criteria for t5
carcinogenic compounds from which States develop
water quality standards. CERCLA' '21(d)(2)
requires coq>l iance with AWQC when they are
relevant and appropriate, e.g., when protection
of aquatic organisms is being considered at a
site, a more stringent AWQC may be used rather
than an MCL (see below).
MCLs are enforceable standards fot contaminants
in public drinking water supplies. U~er CERCLA,
MCLs are relevant and appropriate for groundwater
aquifers used for private drinking water.
MCLGs are non-enforceable health-based criteria
for public drinking water supplies. MCLGs are
set at levels that would result In no known or
anticipated adverse health effects, with an
adequate margin of safety.
MCLs have' been adopted as part of the RCRA
groundwater protection standards for fourteen
toxic c~. These standards ate equal to
MCLs established under the Nationat Primary
Drinking Water Standards, based upon regulations
under the Safe Drinking Water Act.
Appendix C -1
Attlon To Ie Taken To Attain A~
_.
The AWQC for compounds detected on-site
were c~red to obserftd concentrations
in surface and groundwater. The AWQC were
considered In developing cleanup tevels.
Inter the selected r~. wetlr,.
water8 .t the site wit I .ttain :
thrOUJ(h natur.I atterAJ8tlon in L.
Deriod. IlDeClfled in the IlOO.
, :o,rfece
-
MCLs Ind non-zero MCLGI for compounds
detected on-site were c~red to observed
concentrations In groundwater. MCLs and
non-zlro MCLGs were considered in
devetoplng cleanup levels.
Inter the selected re8ldy. grOU'ldwater
thrOUlhout the ptu.e witt attain MCLs and
non-Z8l'O Ntlal through netural attenuation
in the tt- periods spftlfied in the IlOO.
MCLs for cCJq)Ounds detected on-site were
coq>ared to observed coricentrations In
groundWater. McLs werl considered in
developing cleanup levels.
tk1der the selected r-'Y. grCU1dwater
thrOUlhout the ptu.e witt attain MCLs
thr~ net..-.I atter&J8tionin the tl-
-------
Appendix C -- Chemical-SD8cific ARARs
AltAR Status Reaui re8!l'lt s-It action TO Be Taken To Attain AllAR
FEbEIAl - ttean Air Act, Retevant NMQS define primary and secondary levels for six Undet the setected re8edy there wi I I be no
Natlonat Anblent Air Quality and common air contaminants (sulfur dioxide, actl.'ties which will result in air
Standerds(NAAQS) Appropriate particulate matter, car~ monoxide, ozone, reteMes eaceeding 1IAAGs.
nitrogen dioxide and lead. t
(40 tFR Part 50) (for altt. Unde~ atts. 3'5, the tevels for these six
3 - 5 onl y) contaMinants would be used as target
level. which could not be exceeded by air.
releases from site treatment activities.
STAft . N~ Primary Drinking Retevant This statute provides the authority to establish NH MtLs for compounds detected on-site
"eter Standards end primary and secondary drinking water standards. were c~red to observed concentrations
Appropriate NH MCLs established under this statute shalt be in gl'OU'IdNeter. NH MCLs more stringent
(NH .SA Ch. 485: NH Admin. Code no less stringent than the most recent National than federat MCLs wer. considered In
Env-Ws Parts 315-319)
-------
Appendix C -- Location-SDecific ARARs
-.
AlAI Status Reaui re8!f'lt 5vnoIJ81a Action To Be T&ten to Attain AlAR
FEDEtAL- CI.en Water Act (OWA), Applicable Regulates the discharge of dredge or fill thteI' the selected re8edy, no dredge or
Discharge of Dredge or Fill material into wetlands. No activity that fiU activities will OCCUr in wetlands.
Material Into Wetlands (for alt.. adversely affects a wetland shall be permitted
3 - 5 only) if a practlca! alternative with lesser effects Under alts. 3 - 5, should the creation of
(CYA , 404(b)(1»; 40 CFR Part Is available. collection/discharge trenches resu'. in
2301 33 CFR Parts 320-330) actlyltles In or near wetlands, these
requirements wit I be c~lied with.
FEDEtAL - Floodplain Management Appl icable Federal agencies are required to reduce the risk The lite is not within 8 100 or 500 yr
and Yetlands Protection of flood loss, to minimize the Impact of floods, ft~lain. the selected r~ wi I I have
(for alt.. and to restore and preserve the natural and no llipact on ft~lalns or wetlands.
(Executl.,. Orders 11988 & 11990 3' 5 onl y) beneficial values of floodplains.
40 CFR Part 6, Appendix A) Under alts. 3 - 5, should the creation of
Federal agencies are required to avoid adversely collection/discharge trenches result in
impacting wetlands, to minimize wetlands impacts to the wetlands, measures would be
destruct ion, and to preserve and enhance the taken to miniMize haMl and to restore the
natural and beneficial values of ~etlands. wetl~..,h to its original state and utitity.
FEDERAL - Fish and Wildlife Applicable Federal agencies are required to tonsider the Undet the selected re8edy, no activities
Coordination Act effect of water-related project. (including wilt l.pact the wetlands or its resources.
(for alts. those in wetlands) upon fish and ~ildlife, and
(16 USC , 661 £!..!!g.) 3 - 5 only) to take action to prevent or minl~ize loss or Under alts. 3-5, Fish and Wildlife Service
damage to these resources. would be consulted to analyze impacts to
fish and wildlife. Remedial actions would
be ct..igned to prevent, mitigate, and/or
comoensate for loss of fish and wildlife.
STATE - NH Rules re Prevention Appllceble Establishes criteria for conductlhg any activity Undet the selected re8edy. no activities
of Pollution from Dredging, in or near a State surface water body which will occur In or Mer 8 surface water body.
Fftltng . , , and Construction (for alts. alters terrain or may otherwise adversely affect
(MH RSA ch, 485-A:17; NH Admin. 3 - 5 only) water qual it, Activities within the scope of Unde~ alts. 3 - 5, shOUld the creation of
these provisions include excavation, filling, collection/discharge trenches result in
code Env-Ws Part 415) and grading topsoi I in or nellr wetland areas. actl~lties In or near wetlands, these
requirements ~ill be c~lied with.
STATE - NH Criteria/Conditions Applicable Regulates filling and other activities in or Undet the selected re8edy. no activities
For Dredge and Fill in Wetlands adjacent to wetlands; establishes criteria for will Occur In or adjacent to wetlands.
(for alts. protection of wetlands from adverse impacts on
(MH RSA Ch, 482 A; NH Admin. 3 - 5 only) fish, wildlife, commerce and public recreation. Under lilts. 3 - 5, should the creation of
Code Env-Ws Parts 300-400, 600) collection/discharge trenches result in
activities In or adjacent to wetlands,
these requlr~nts will be c~lied with.
-------
MAR
FEDEIAL . Federal Noise Act
(40 CFR Plrt. 204, 205, 211)
FEDEIIAl . RCRA Requl rements
(40 CFR Plrt. 262 . 264)
FEDERAL. Clean Water Act (CWA),
Nltlonal Pollutant Discharge
EliMination System (NPDES)
(40 CFR P8rt. 122, 124, 125,
13"
FEDERAl - FI.h and Wildlife
Coordination Act
(t6USC' 661 £l.!!!9.)
StatUs
Applicable
(for alts.
3 . 5 only)
Applicable
(for alts.
3 . 5 onl y)
Relevant
and
Appropriate
(for alt..
3 . 5 only)
Applicable
(for alts.
3 . 5 only)
Appendix C -- Action-SDecific ARARs
Requl re8ef'lt Synop8 I.
Regulates noise level of construction, process,
and transportation equipment, and noise levels
at property boundaries of a site.
Regulations govern generators and transporters
of hazardous waste, Including requirements
regarding manifesting, recordkeeplng, storage
and packaging, and pretransport standards.
Regulations for hazardous waste facilities,
Including requirements regarding operation and
maintenance, contingency plamlng and emergency
procedures, preparedness and prevention,
recordkeeplng, temporary storage end containers,
air emissions from treatment system, and
groundwater monitoring.
Regulates direct discharges Into "waters of the
United States." Requirements Include: 1) use of
the best available technology or use of the best
conventional pollutant control technology; 2)
discharge must be monitored to IS sure
cGq)llance;' and 3) Federal I y Ipproved state
water quality standards must be compIled with.
Federal agencies are required to consider the
effect of water-related projects (Including
those In wetlands) upon fish and wildlife, and
to take action to prevent or minimize loss or
damage to these resources.
Appendix C -. 4
Action To Be Talt.... To Attain AIWI
The selected rt8edy ..I" not resul t In any
on-site activities other than periodic
s~l'ng 0' 8Onitorlng Mells.
Under Ilts. 3 . 5, remedial activities would
be carried out to maintain site noise levels
at or below these levels.
The sel ected rt8edy ..i II not resul tin any
generation, transportation, treat-.nt, or
disposal 0' hatardous I18Stes.
under Ilts. 3-5, EPA lIQUId determine whether
the groundwater to be treated Is a RCRA
hazardous waste, and whether the treatment
syst~ will result In the generation of any
hazardous wastes. If 10, the substantive
RCRA requirements for on-site activities
would be complied with, as well as all
apptleable off.slte requirements.
The .lected re.edy ..Ill not resut t in any
direct dlscharve Into I18ters of the United
Stat.. (Including wetlands).
Under Ilts. 3 . 5, no direct discharges of
treated groundwater to the wetlands would be
expected. If such discharges were to occur,
all s~tantlve NPDES requirements would be
met, Including effluent standards,
monitoring. end testing.
Under the selected rellledy, no activities
..Ill I~t the wetlands or its resources.
Under alts. 3 . 5, Fish and Wildlife Service
would be consulted to 8ssess Impacts to fish
and wildlife. Remedial activities would be
designed to prevent, mitigate, and/or
-------
Appendix c -- Action-soecific ARARs
AlAR Stat.. R~.Ii r-.t 5YnoII81s Actfcn to Be Talcen To Attain AlAR
FEDERAL- Ciean Vater Act (CVA), Apptfcabie Reg~lates discharge of dredge or fill material Under tile elected re8edy, no dredge or fill
blsch8rge of bredge or Fill into wettands. No activity that adversely activities lIft I occur in Mettands.
Materlai Into Wetlands (for aits. affects a wettand shatt be permitted if a
3 - 5 oniy) practical alternative with lesser effects is Under eits. 3 . 5, no dredging or filling of
(CVA I 404Cb)C1»; 40 CFR Part avai lable. wetlands would be anticipated during
230, 33 CFR P8rts 320-330) groundwater treatment. However, should the
creation of collection/discharge trenches
result In actiVities In or near wetlands,
these reQUirements wit I be cOllOI ied with.
FEDERAL. Floodpialn Management Apptfceble Federal agencies are required to reduce the risk The Site II not within. 100 or a 500 yr
and Wetlands Protection of flood loss, to minimize the IMpact of floods, fI~18In. thier the selected rMedy, no
(for alts. and to restore and preserve the natural and activities ",ll i8p8Ct floodplains or
(executive Orders 11988 & 11990 3. 5 only) beneficial values of floodplains. MeU artfs.
40 eFt Part 6, Appendix A)
Federal agencies are required to avoid adversely Under alts. J - 5, should the creation of
impacting wetlands, to minimize wetlands collection/discharge trenches result in
destruction, and to preserve and enhance .the activities impacting wetlands, measures
natural and beneficial values of wetlands. would be taken to mini-ire harm and ..)
restore the wetlands to Its original state
and utfl It".
FEDEtAL - Clean Air Act, Appll cabl e NAAQS define primary and secondary levels for Under the selected re8!Cfy there wi II be no
National Ambient Air Quality six common air contaminants (sulfur dioxide, activities "'ich will result in air releases
Stand8rds CNAAQS) (for alts. part iculate matter, carbon monolll~, ozone, exceeding IIAAOS.
3 - 5 only) nitrogen dioxide and lead.
(40 eFR Part 50) Under 'Its. 3 '5, the NAAQS for the six air
contaMinants would be used as target levels
which could not be exceeded by air releases
from on-site activities.
FEDEtAL - tlean Air Act NESHAPS Relevant Sets national emission standards for hazardous Under the selected re8!Cfy, there will be no
and air pollutants, including vinyl chloride rele.... of ..., hazardllus air pollutant.
(40 eFR Plrt 61) Appropriate
Under 'Its. J . 5, any on-site treatment
(for alts. systeft8 such al air strippers would be
3 - 5 onl y) designed to meet these standards.
-------
Appendix C -- Action-specific ARARs
AltAR Status Requi re8l!l'lt SynopII8 Actfbn To Be Taken To Attain ARAR
STATE. NH Hazardous Yaste Applicable Specifies recordkeeping, man,ifestlng, packaging The selected I'8edy wHI mt result in 8I'I'f
Managellent Act l .' and labeling, transportation and other generatIon. tranlpOrtation. treat8ent, or
(for alts. requirements for the generation, trahsportation, disposal of hazardous MIIIItes-
(He.P Chs. 1904, 1905) 3 - 5 only) treatment and/or disposal of hazardoUs wastes.
Under alts. 3-', EPA would determine whether
. , the groundwater to be treated is a RCRA
~ .,'1 hazardous waste, and whether the treatment
I system .111 result in the generation of any
hazardous wastes. If so, the substantive NH
" RCRA requirementl for on-site activities
would be c~lIed with.
STATE - Fugitive Dust Emission Relevant Requires precautions to prevent, abate, and The selected N!8edy wi I' hOt procb:e
Control and control fugitive dust during specified fugiti'" ciJst .. it does mt require 8I'I'f of
Appropriate activities, including construction, excavation, the specIfied ectivities.
(NH Achln. Code Env-A Part and bulk hauling.
1002) (for alts. Under alts. 3 - S. precautions would be
3 - 5 only) taken during conltruction of the collection
and discharge trenches, such as wetting,
covering, and shielding.
STATE - Control of VOC Relevant Specifies voc emission control methods and The selected r8lll!dy wi I I not procb:e VOC
Emisstons and establishes limitations on VOC emissions for _issi... for ~ specific process category-
Appropriate various process categories. Under a'ts. 3 - S, the groundwater treatment
(NH Adlin. Code Env-A Part . ,J/.
1305) (for alts. systems would be designed and operat~'
3 - 5 only) consistent with these VOC control me~nods.
STATE. Anti-Degradation Policy; Applicable Protects all surface waters from degradation The selected r8lll!dy wi I I mt resul t in I!IIlY'f
Surface Yater Classification caused by a new or increased point or nonpoint dischal'tes into the MeUInds-
(for al ts. source and all other activities which discharge Under a'ts. 3 - 5, discharges of' treated
NH Acilln. Code Env-Ys Parts 430 3 - 5 only) pollutants. Establishes water quality standards
- 431) for each surface water classification. groundw8ter to the wetlands (if they are
necessary) would meet these criteria.
STATE - Abandonment of Yells Applicable Requires that abandoned wells be sealed to Under the selected relledy (and each
prevent entry of contaminants into the altemllUve), 8Ohitorir1!8 Mells will be
(NH Adain. Code Env-Ys Part for illl five groundwater. sealed .fter c~letion Of the 8Dnitoring
604) alternatives) progr8lll.
-------
Appendix C -- CRITERIA. ADVISORIES. AND WIDAIICt TO BE aJlSIDERED
-------
TIC
ReGJire8!Ot Synopsis Action to Be Taken legarding TBC
STAtt - NH Groundwater Protection Proposed rule establishes allowable limits for NH groundwater standards and MCls for compounds
contaminants in groundwater, based upon Nil detected on.site Mere cOft1)8red to observed
(NH Admin. Code ENV-Ws 410.05; '10.05(e) health.based standards, federal HCls and MClGs, concentrations in groundwater. State standards
(proposed) and other relevant standards. Provides that no were considered in developing cleanup levels.
substance found to present a potential threat to
human health or the environment may be discharged under the s~lected remedy, groundwater throughout
to groundwater. the plume-wlll attain state standards through
! natural attenuation In the time periods specified
in the ROO.
Appendix C -- CRITERIA. ADVISORIES. AJIO WIDAilCE TO BE CONSIDERED (TBC)
. I
-------
-
-
-
CHE !cAlS DaEcrED
HIll9LOPE AREA
OVERbuRDEN WELLS
VOLA lE OhGANICS (ugII)
BenzeiMt. . . .: Dec;'90
Jun-91
. "'DeC~~
Jun-91
~.~.p~'~~i:!)\:;;i;.:.b8C':~
Jun-91
Caib6n tntr~"'Orid; .:oec~90
Jun-91
. . .P8c,:,90
Jun-91
Phl~~m. .. . , ,:,.;[)~~90
Jun-91
:: DeCf9Q
Jun-91
i~t7Qtc~I«:!~~!a.n..:: ,,<.~~90
Jun-91
l.~~f?lc.ft!qr~~h!~!.,".i, ,..}D~+90
Jun-91
1!j~~hi~~t~~n!" ,.\beC~90
Jun-91
"..
-------
.-11 II . .
. CHEMICAL-SPECIFIC ARARs FOR GROdW8~ 6v~~RDEN AQUIFER,
Hill SLOPE AREA
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detection
01 Detection limit
.... ..'> 515:,\,:,::';".. ':10
5/5 5
2i$. : ;0 '.
015 5
. Oi$i p ... p ':.'. ;10 )
015 5
.015,
015
CHEMICALS DETECTED
Hill SLOPE AREA
. OVERBURDEN wellS
1.1. ~~;r'lchlor~h~~ '-i', QeC::-90
Jun-91
M,J.; r,ICh.I~~~~n~:. : oeC~fK)
Jun-91
Tr~~lc)rOet~".:;" ::,peC;~90.
Jun-91
. x.Y.!~~ ~Otlil):{::):".~:g()
Jun-91
5
~r~~;~";;;T6t.i:.},(515» P. p
Dissolved (215)
:::):totaf.' (215)<
Dissolved (015)
::"Tot8(;:... ',.:., (415),
~.mi.~:'U. ......),:::\t;%~ :\\:: ~~t.>,
Dissolved (~) ...
.\,\rOtii::..:"\ (515» p
Dissolved (015) .
!Oiaf: .;,.. . (1/3) ...
Dissolved (0/5)
::;'-0181....:.."" .: . (515)'.
... ...'
Dissolved (5/5)
cf!~'!J~ ...\;.:;i:::tOia.t::'.;:,.. ::(5/5)..
~.~I~::r:.p.p PP.P .p:\:,t;r~;.;;,,:}1~:l::i:';t.p ....
Dissolved (215)
~htlffiqr,v :
ArSlnIt:... .
::.,...200)
200
...,60
60
10
10
;:::i:~OQ)
200
. ... <:.5,,).
5
.s
5
. 5000 p
5000
. 10.:
10
:'..:so.l
50
~~!i~fff.p
c8dmiu;n .
~It'u",:
i t~Hoo f830(0) ...;.:
(145:- 1470)
(1~~1~.5):.
NO
.'. (11- 41) p.
NO
. ppJ20~+~1n:p. ..-
J~. :: ~86) ..
... '\r.:(t~tr+ '~~2)~i"\r
NO
.. 4~ 1 .'
NO
. (274oo.~797000)..
(~82OO -.891000)
. d (~
-------
---.. 81 II
APPENDIX C - 3
CHEMICAL-SPECIFIC ARARs FOR GROUNDWATER: OVERBURDEN Aat,JIFER.
Hill SLOPE AREA
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detection
0' Detection limit
(515)}:'". . . 25
.:~::l:H::(;; . .1:
(315) 100
(515)%tf:i;(:;}> ;.;.;;;3 ;.
. ':/\ ~=~:m\/:::.,.:',;:500: .
(515) 5000
(515) .
... (515) ... . 15
: (2I5)}i: ,0.2 ;...
(215) 0.2
:«515)\./::, :,:~O,.
. .,/.\~(:}:;},;;;:::::.~:i
(515) 5000
....: (5Js)/:;::;;:m/:.::\.,~OOO .,..'; ......
. .(~~~.. ......... 5000
.. (11S)t{:::'('..' 10
(015) 1 0
(515) : 50
. (0I!i) 50
(4~4t:;... ...- ..20 ....
(015) 20
CHEMICALS bETECTED
Hill SLOPE AREA
OVERBURDEN WEllS
Total.. ..
Dissotved
. Totai ....,..
DIssotved
'Toial.';::':::;:..: ,
. bissolv8d
M~g;,~':I!;t: . . .: Total::,'
Dissolved
M~.n~)< .::..:" .:; 'TOtar::'?
Dlssotved
"... ToUt".' .:::.
Dissolved
foflc:~~( ... . .. .. .. TotaL=;-'
Dissolved
P. Ot... W..U.In.;."...:' . '.' .... :.:.:....:.:.T. .oi8.1...:':. .:.'.:.,.'.:;..i.;
,'.:':'.::':'::-:':':':':':'..
Dissolved
~iri..::'):>;:::U:: ...,.:,::T.oiltl',;" "
Dissolved
. ... .....' ...
-------
8
-
APPmDIX C - 4
II
.
--
.
.
.
CHEMICAL-SPECIFIC ARARs FOR GROUNDWATER: OVERBURbEN AQUIFER.
Hill SLOPE AREA
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detection
of Detection limit
CH ICAlS DETECTED
Hill SlOPI: AhEA
OVERBURDEN WEllS
WA"JER QUAUtY (mgtL) .
Chloride. ..::.. :: ::. Qe(:C:so.
NltrlteINltrale Dee-go
Suliitt.: . 084:'90
OrthoPhosphate .. .... DeC~90
BlCiit)Onat.: oec~90
Range 01
Detects
(515) .
(315)
...: (015) :.
...(~
.:(
:.....5..
0.01
L.:C),ot...
t
(530 - 3550)
(0.3 - 4.2)
:. NQ ......
(1.5 - 75)
... (6.8 -110 .
ARARa
Federal MCls
(a) (ug/l)
250 mwt.. S~'
10 moll .
~ ." ':
~ .::
To 8e Considered (T1JC)
NH Stds more RISK ..
stringent than . 10 -6
Fed. MCls (ug/l)"'
HAZARD
INDEX - 1
(ug/l). . .
. .-
. .
. .
Note: the Hili Slope Area Overburden Wells group contains the following sample locations: MW2S. MW4S. MW5S, MW8S and MW9S.
(a) Flderal 8afe Drinking Water Act Maximum Contaminant level
(b) PnIposed New Hampshire Ambient Oroundwaler Standards
MCl - Maxtmum COntaminant level Promulgated by EPA
HA - lIfellme Health AdvIsory established by EPA
8HM - NH Department of Health and Human Services. Division 01 Public Health Services. Bureau 01 Jiealth Risk
Assessment Health Advisory level .
AML - Analytical Method limitation. fn those cases where the EPA 10E-6 Risk level concentration was
less than the Practical Ouantllatlon limit (POl) 01 all analytical methods approved by Department
01 ErMronmenlal Services. the POl with the lowest concentration was established as the ambient
groundwater qualily standard
(1) - lotal trlhalomethanes
ND - not dettcted
. - exceeds standard
"" - A water concentration associated with 10-6 excess lifetime cancer risk. based on exposure assumptions presented In thl Baseline Risk AsSessment.
" "" - A water concentration associated with a hazard Index 01 1 lor noncarcinogenic ellects. based on exposure assumptions Jlresenled In the
baseline Risk Assessment.
P - ~roposed
A - Action level
S - Secondary MCl
- - No criteria available
-
-------
'... 8
II
III
.-
-
.
.
.
-
-
APPENDIX C - 5
. CHEMICA~-SPECIFIC ARARs FOR GROUNDWATER: BEDROCK AQUIFER,
HilL SLOPE AND TOWN GARAGE AREA
CHEMICAL9 DETECTED
HIU AND
TOWN GARAGE WEllS
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detection
of Detection limit
ARARs
o Be Considered (TBC)
NH Standards more
stringent than
Fed. MClI
(b) (ug/l)
RISK - HAZARD
10 -6 INDEX - 1
(ug/I)" (ug/l)" .
Range 0
DetectS
Federal MCls
(a) (ug/l)
VOlATILE ORGANICS (ugll)
BIn~e~~\:'> :HH: . ':'..::.:Apro:.9d . (0i1) ,
.. . .. jun~90 (011)
. . ... ..
'H:,:::.,:~..~(Qln .::.
Dee-go (015)
'...':i\?\~lJn~91:. HH '. (itS) ..H
Dee-go (015)
. ::H:: .'. .:.':::.: .,. ...::.':L::\(...J.~~;.:~t .:;(~)
C8fbonDiauiRdeH Dee-go (115)
..'~. . .," ,',',', .,', . J . .
. . :.H.H::::. :.. . H""""":' /\U~~91:(2I5) ,...
Apr-go (011)
jun..90' .: (011)
Sap-go (011)
. HH':::,).:::.:.::'~f~ :::oC()IS)::
Jun-91 (015)
'~~~Iij,..::..i:::::\:::.rr::::m.:.)::~r'7~' ,.\j(0I1).I:::::......
Jun-go (011)
:::::':::i '.'.' .'.. ..H . H... .'.'::: .:.::.:.<.::n::~t90' : :! (011);;:: :.'H"
Dee-go (015)
};'un..91 '."(1/5). ::;
Apr-go (0/1)
. . .Jun~90H(0I1)
Sap-90 H(oi1)
H. . "HH' ..: :'H 'H"HH ',:.::.:.:;::.::.: ",:,:,:",'.:H:..:..J)8C,:,SQ. .. .'..,(0/5).
Jun-91 (215)
(;ti!orom~~~~~ ...' .. ... .. .:.':':'..::.,:.::::'.::i~~+!jo .}:(0I1);i
Jun-SO (011)
. ..:'::.::}'\:>:H."H H:::..:'..;:...:~..9<) ::::(011)
Dee-9Q (011)
::)un-91 (015)
. ...
.:.: 2,9
NP .
ND
ND
ND
.: 1.
ND
HHHNQ
2
j~ ~ 2()):'
NO
NO.
NO
NO
5 NO
...' .().S.::.::.::':::::?.:::.::::::::?.::.:: ~~::':::.::,:::j
0.5 NO
:;'::.9.5: .: '::..:' ..:::':.}:;:~D:::.
10 NO
.5'. .'..3 ..',
0.5 NO
.:.0.5 .:,NO ..
0.5 NO
::,:....',:ND'"
(2 - 35)
:"':':'...'."..'r.t.D.''''H'
......
NO
...::ND:
2
ND';"::::
b.5
0.5
:..~.5 ':
10
10
.. ....
::i/ s.x')'.....
10
:.:5..",.::..:
nr;
2-Butanone
Carbon Tetr8Chlorlde
0.5
Chloroform
.....
-------
a. .-.--.-.--. II . a 81
CHEMICALS DETECTED
HILL SLOPE AND
TOWN GARAGE WEllS
1,1-DlchlOfoethane
1.2.,.bich'dtCJtthari~.i
1.1-DlchIOfoethene
. .. . . "
EthYthentCih't
Tetrachloroethene
TOIut!ne ..
......
Apr-90
. . Jun-90
Sap-90
Dee-OO
Jun-91
.~JJr-OO.
Jun-90
iSeP~90
Dee-90
Jun~91
Apr-go
. , jJJn-90
Sap-90
. i?8C~90
Jun-91
.:::::~F~.
Jun-90
.sep~90
Dee-90
. Jun-91
Apr-go
, :JLin.,.90
Sep-90
Dec790 .
Jun-91
... .
:A.pr':'90 /.
Jun-90
Sep~90
Dee-90
.... Jun-91
II
III
.II
-
II
.
.
.
.
APPENDIX C - 6
. CHEMICAL-SPECIFIC ARARs FOR Gf:fOUNDWATER: BEDAOCK AQUIFER,
Hill SLOPE AND TOWN GARAGE AREA
ARARs
To Be Considered (TBC)
N Standards more
strtngent than
Fed. MClt
HAZARD
INDEX - 1
(ug/l)' ..
3650
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detection
o' Deteetlon Limit
(1/1) 0.5
(1/1) .,... 0.5.
(1/1) 0.5
(415) . . 10
(415) . 5
... (di1) ..: ..0.5 ..
(0/1) 0.5
(011) .,.. . 0.5...
(Qffi) 10
«015) . 5
(1/1) 0.5
.. ,(1;1) . 0.5
(1/1) 0.5
~.i:::C5l5) :':. ",.,',' .... :.::::J~:;'
(415) 5
ii,:.::W1t: ..... ...\().S:
J~1) . 0.5. .
.: (011) ...0.5
(0/5) 1 0
.(Qffi) 5
(1/1) 0.5
(011) 0.5 :.
(0/1) 0.5
::'.(115) .:... ..10..
(015) 5
.... . . . .
: (011 >/: ':': 0.5
(0/1) 0.5
. .
:... (011): :0.5
(415) 10
...(315) . .5...
RISK-
10 -6
(ugll)"
Range of
Deteet!
32.5
/: 13.92:
10.9
.(~ d8~ :
(3 - 47)
:..'ND.
ND
.....ND.
ND
....' 1110:(
16.4
6.81
5.4
.. .. ... .
J~; 42)/
,).,(:.i~:~6t~;,::i::;,::.:
ND
ND ..;)\
ND
....ND
1.15
:/\ . ~D ); .(.\::::/ ::
ND
Federal MCls
(a)(ug/l)
(b)(Ug/I)
81 HA
ND
ND/
ND
ND
(1 - 4)
'''''u'. .-... .
-------
-..
-
-
-
CHEMICALS DETECTED
HILL SLOPE AND
TOWN GARAGE WEllS
1.1,1- trichloroethane
1 j ; i2~ trlchibroethane
Trichloroethane
. xv'sn. (toti!)
-
, ..
Apr-~
" Jun-OO
S.ap~90
Dee-oo
Jun-91
, .' Apt-90
Jun-90
, Sej)..90
Dec-90
Jon..91
Apr-90
: Juri-oo
s.!p~9()
,',,',D~"9Q
Jun-91
. .. ..
>Apr~90
Jun-90
Sap-90
Dec-90
Jun-91
-
..
-
..
-
..
-
-
.. ..
-
-
-
-
APPENDIX C - 7
CHEMICAL-SPECIFIC ARARs FOR GROUNDWATER: BEDROCK AQUIFER,
HILL SLOPE AND TOWN GARAGE AREA
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detecllon
01 Detecllon limit
(W1) , ~.5
, ,(OJ1)0~S '.
(011) 0.5
....(415) :,0
(315) ..5,
'.",:NA.., ,NA' '
NA NA
NA , NA, "
, (00i) 10 ,
, (015) 5 ',:,
(011) 0.5
(011) . " 0~5
"i::Jf~; , 0.5
, (015) ,', 5
,::(0/1)} , O.S
(0/1) 0.5
, (0/1) 0.5
(115) 10
(115) 5
Range 0'
Detects
NO
"NO,
NO
.':(3;,;66)',
, (~-:4oo)
NA
NA
,.NA "
NO
NO>
NO
"NO,
NO
NO
,',".".'.". ',"'.',..
',"..N"o".';'.,.':,..
.y)) .;:rt:"d';:\;::::=,
NO
, NO.'
2.54
3,
ARARs
to 88 eonlldered
NH andard. more
stringent thin
Fed. "'Cl8
C)
RISK-
, 10-6
(ug/l). .
HAZARO
INDEX - 1
(ug/l). ..
3285
Federal MCLs
(a) (ug/l)
200 .
(b) (uOlf>
.7~
.. ...
-------
811
II
.
-
APPEmIX C - 8
CHEMICAL-SPECIFIC ARARs FOR GROUNDWATER: BEDROCK AQlJIFE~,
HILL SLOPE AND TOWN GARAGE AREA
Range 01
DetectS
ARARs
C)
RISK. HAZARD
10 -6 INDEX. 1
(ug/l)" (ug/l)".
CHEMICALS DETECTED
HILL SLOPt: AND
TOWN GARAGE WELLS
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detection
01 Detection Limit
(b)(ug/l)
METALS (ug/\): Dee 90
AIUrTllnurn' '," "'",
(4/4) "
(0/4)
(114) ,
(0/4)
(014) . '
(114)
.,(4;4) ,," ,,'
(314)
" (014) ,
(0/4)
(0/0), ','
(0/0)
:(4/4) .',.' "..,'
(4/4)
("4).
(0/0)
.' (114)
(0/4)
, (111)
(214)
j: (4/4)
(214)
. ..,
\'t,:(~/4)
(0/4)
(4/4) ',.,,'
(4/4)
,(4/4) ,
(4/4)
Ahtlmony ..
AritniC
BariuM.. '
Beryllium
. eadmhirri,,'
Ci1Cliiro
Ctttorni,-m ' ,.
Cobalt
copper
Iron
" ,
Lead
Magnesium
Mangtnese
200
200
50,
60
10 '
10
200
200
"
5
5
5
'.,,: 5000:>
5000
10 "
10
50
50
25
25
100
100
""~
3
,5000 :
5000
, 15 ,
15
Federal MCLs
(a) (ug/\)
. '
(~65 ~ 24~'
ND
;4
ND
ND,
15.5
:(75 '~, 4!nO) ,
, (~7~ - 35~.,
,'" ,,' ND:,'".,~,"
ND
"ND~:
NO
(262000 ~~~) ,
(20600 - 5610(0)
'/'i 4.~:': ,,'
ND
5.5
NO
, '2.4 "
,.. (2. ~ ~ ~.5)
':i.\(4ae ~2m),.
,', ",(285 ~ 938) "
':,:tt(5. ~:~:1 ~.8»
NO
..., . . . . .
(34600:~ 625000)
(36200 - 0060(0)
: ,(61.8.~ 1960)
(57.7 - 2190)
..
\~5
.:- .
,,50..:"'"
"j1;;f.,.":
" , 2ooo,\r
t,Pi
<)83
,"
,18
\183
:"~ .
.- "
..'
" '
..... ..' ,..' p.""" .
,i5OQ,bH,:W.,j~
.;) ~:3650
-------
CHEMICALS DETECTED
HILL SLOPE AND
tOWN GARAGE WEllS
M"ctJry .
Nltkel
Potasssium .
Sddlum
thallium
Vanadium
, Zinc
Total...
Dissolved
. total
Dissolved
. ....o.. ...
.Total. ....
Dissolved
rotal. .
Dissolved
Total. .
Dissolved
: total ... ...
Dissolved
Total....
Dissolved
811
II
11&
III
II..
APPENDIX C - 9
. CHEMICAL-SPECIFIC ARARs FOA GROUNDWATER: BED hOCK AQUIFER,
Hill SLOPE AND TOWN GARAGE AAEA
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detection
0' Detection limit
.. . (314) ..... . .. 0.2<
(214) 0.2
(0/1)40
(~4~ . .. .~()
(4/4) . .. ..5000 ...
(4/4) 5000
. .
(4/4) . . 5000 :
(4/4) 5000
(0/2) .. 10.
(0/2) . 1() .
(0/4) . ..50..
(0/4) 50
(1/1) p 20/
(0/3) 20
ARARs
To Ue COnsidered (TBC)
H Standards mort
stringent '''an
Fed. MCls
.
-
.
Range of
Detee'S
.:...(0.31. ~.. 0.(4)
(0.2~ - O.fi3)
..Nb : :..
ND
. . (18oooji#0c)0)
(19900 -.155000)
(89000 . 67400(0)
(92900 - 8190(00)
ND.. ......
NO
ND( p.
NO
.20..
NO
.jooi:f~/
...:..t600Q:J!ij~:
HAZARD
INDEX - 1
(~gII). ..
11
<130
:.3
-------
.--.- 8
_II
-
.
.
-
-
APPEmIX C - 10
CHEMICAL-SPECIFIC ARARs FOR G~OUNDWATER: BEDF'OCK AQUIFEFt,
HIll SLOPE AND TOWN GARAGE AREA
WAtER QUALITY PARAMETEf.\8. (mg/l)
I ChI«ld4j)...>.. . . .:: beC~OO
NltrlteJNltrale Dee-go
Sulfa'. ..... ...... .... ...: Dee-OO
OrthophOllPhate Dec-go
OlClrb6ntltd ,.~~9(j
? t:it'4):. .:'
(1/4)
:(1/4) ..
(314)
:(4/4) <.
. ~,
0.01
9.01
1
...2::
,'"
.t1110.7:23!»~ .
0.23
jj.1~. .
(22 - 160)
..' . . . . .
:. (26 ~~);
Federal MCLs
(a) (ugf1)
(b)(ugfl)
CHEMICALS DETECTED
HILL SLOPE AND
TOWN GAf:tAGE WEllS
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER .
Frequency Detection Range 01
01 Detection limit DetectS
ARARs
RISK - HAZARD
10 -6 tNDEX - 1
(ugfl).. (ugf1). ..
Note: TM Hili Slope Area and Town Garage bedrock Wells group contains the lollowlng sarftple locations: MW2D. MW4D. MWsD.
MW8D and the Town Garage Well
(a) Federal 8ale Drinking Water Act MaxImum Contaminant Level
(b) "roposed New Hampshire Ambient Groundwater Standards
MCl - Maximum Contaminant Level Promulgated by EPA
HA - lifetime Health Advisory established by EPA
bHRA - NH Department 01 Health and Human Services, Division 01 Public Health Services, Bureau 01 Health Risk
Assessment Health Advisory level .
AMl - Analytical Method limitation. In those cases where the EPA 10E-6 Risk level concentration was
less Ihan the Practical Quantllatlon limit (Pal) 01 all analytical methods approved by Department
01 I:rwlronmental Services. the pal with the lowest concentration was established 81 the ambient
grOUndwater quality standard
(1) - total trlhalomethanes
Nb - not detected
NA - not analyzed
" - dati was relected during validation process. this data was not considered
NOR - no detects. at least one sample was rejected
. - cCJl11aminant concentration exceeds slandard
.. - A water concentration associated with 10-6 excess lIIetime cancer risk, based on eKposure assumptions prtsented In the Baseline Risk Assessment.
. .. - A water concentration associated with a hazard Index 01 1 lor noncarcinogenic elleets. based on exposure .ssu~puons presented In the
Basetlne Risk Assessment.
P - Proposed
A - Action Level
S - Secondary MCl
-------
1 i2-l)lchldt~~i"~,:\
1 ,t~t>Ic~k1t~h~~~
1.2-DjCh'O;o8t~~n~ ?
" ,
--. . IA
.
APPmDIX C - 11
-" CHEMICAL-SPECIFIC ARARs FOR GROUNDWATER: BEDROCK AQUIFER.
RESIDENTIAL AREA AND AREA EAST OF THE WETLANDS
S (ug/l):
.., APf'-OO,
Jun-90
,SeP;.90
DeC-90
Jan~91
Jun-91
':Jul~~~
'. Apt~90
Jun~90
.Sej)-!JO
, Dee-90
"jan~91
, Jun~91
. JiJi...91 ,
",.,.,.",:;APfb9().,
Jun~90
i~,":90
Dec-SO
Jan;:'91
Jun-91
Jul~91
, "
":,ApHid
... .. .. Ju'n~'90
:::''''':..:,sep~g()
..". Dee-90
LJaij...tu,
Jun-91
, Jlii"-91,
SUMM RY OF CHEMICALS DETECTED IN
GROUNDWATER
'Frequency Detection
01 Detection limit
Range 0
Detect.
(8111) ',.
, (7/12)
, ,'(7/15)
(9/17)
',. (1/4) ",..:
(2i3) ..
i ~8Itir.
:,,: (1/11)
(0112)
....(0115).
(0117)" ,
.... ,':':,' «()I4)
...):(~3~).:) ,'"
;::(:1111); ,,' ,"
, (8112)
(9I1~.i
(6117)"""
(1/4»
(213)
,(9111) "
,,""j";1);
.... . "(0;12)' .
..:) (0115):/
, (Oi17) ..
,.:....:.,.", '(0/4r'..
"..':::"\;::::' (013).::'
(0/11ft
......
ARARs
Federal MCLs
(a) (ug/l)
,)'(Ci.S'4'2It9) i:'
(1.74 - 28.9)
, (2.6~2S.5) :
'(0.94-16.0) ,
" ,';,',:" '.', (2.8),:)
. . (23.0 '-29.0) .
, .::(~;.t~~~9f
:~tt;\:\t\tt: f~\::::~(?:',J~\\("~;~:~:~..
0.5
'Q.S '.
5
:O.~
5
cUi
..5",:
"0.5 "
,O.S(
.. 5
::0.5:'
'5 '
(0.5,
......
"M'
i(1~u'
'ND
N"<,..::;:..
"0" "
NO..
NO"
~£t
......
.. '
..
.. ..
"..,.{,5.<::
0.5
ItS:}""
5
"C).S: '"
5
,0.5
/:(a.2~£'Ii(j).:
(0:80 ':'1t(2)
;::)(1;2;;:1'~~) .::::
"(0.56': 8.5) ,
/\:'.',.; (1;0)<::.
(10.5~ 1$.1)
" (O~~~.8.8)/
,"'-
,".",".'.',',
... .
....
...,...
P'" .
-
BC)
RISK-
10-6
) (ug/l). .
HAZARD
INDEX - 1
(ug/l).. .
$60
"::::~;9tC
.:::::::.:q;~.t,
:;::::~~,
-------
C ICA ETECTED
RESIDENtIAL AREA AND
A"EA EASt OF WETLANDS
APPENDIX C - 12
CHEMICAL-SPECIFIC ARARs FOR GROUNDWATER: BEDROCK AQUIFER.
RESIDENTIAL AREA AND AREA EAST OF THE WETLANDS
SUMMARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency D~tectlon
01 Detection LImit
1 i 1 ~ 1 ~ ttlC"'«'08tt\~ne.'. 0; ~pt 190.
. Jun-OO
, . :/.sep:'gQ
. Dee:..gO
'.}Jan:"91
Jun-91
Jul;:'9;
rtbitchlbtoMh&ni ..
ApHM> .
Jun-OO
,..,.Sep,:90
.. Dee-go
...,.Jan:"91::
..... Jun:"91
. ../t.,JuI7~.;
{~pi9~
... jun-go
.:. ..,.,sep~go
.. oee-90
'.'.,janl91
Juj,:"91
.jul'-91
;':..«01; 1) ,..
.. (1;12)
. . (0I16f'
(0;17) .
. (0/4)../
(;;3)
.... (0111)
'..,. (011 1»
. (0/12)"
(0/15)
(1117)
i.(0/4).i
. (113) .
'.\~0I1;):
. ..,'''(0111»
:.<\l%~~.;i
(2117) .
'.;'.. (014))
.. (013)
.. :. (0111)
..
II
-.
.j,
-
.",",.
<5
0.5
....:O.!t.:.".... . .
... 5 .,.
, 0.5.":
5
0.5 .
.: S{
0.5
0.5
5
0.5\
5
ARARs
HAZARD
INDEX - 1
(ug1\). ..
.3285
ND
(1.24). ..
:.NQi.'
NO
. NO
(10. .)
..',..,..,.0,.:":'
,.,....
.... .
..NO:
NO'" .
" N[).'...,
(2.0) .
.... i.ftb..\
..,:.}~~;.:\
. :i:~\
?{(o.g+I~2)'.:,
. . (0.61 :'1.0) ..
"".:". .'. .. H.Nt".}."::": .....
. "0'"
,NIL
;\\t~,.' .0'.
::)\\':?rHi':<~~
...., .
,,:,')S.::
0.5
....0.5...>".":':
.. .'.5 ..
.().S ....
... .5
-------
APPENDIX C - 13
.
II
II,
. CHEMICAL-SPECIFIC ARARs FOR GROUNDWATER: BEDROCK AaUIFER.
RESIDENTIAL AREA AND AREA EAST OF tHE WETLANDS
C MI DETECTED
RESIDENTIAL AREA AND
AREA EAst OF WETLANDS
METALS (ugll):
Aluminum
Antimony
APR 1990
, .. ..' .
,. "'. bEC 90 . Totai:
DEC 90 Dissolved:
APR1990
. . DEC 90. Toiai:
DEC 90 Dissolved:
APR199
. .. . . .
,.. DeC 9Ot()~ai: .
DEC 90 Dissolved:
APR1
. DEC 90 Totai:
DEC 90 Dissolved:
APR1990
.... . ,....., . . ..
, DEe 90 ". Totai:
DEC 90 Dissolved:
APR 1990
." .. P'"'''''' .
DeC 96/,.Jotai:
DEC 90 Dissolved:
APR 1990
.' .. ..
'. .' DeC 9010t;ll:
DEC 90 Dissolved:
APR 1990
.." ... .
.OECOO1otai:'
DEC 90 Dissolved:
APR 1990
. DEC 9(l, Total: .,
DEC 90 Dissolved:
ArsenIC
Barium
, .
Beryllium
Cadmium
Calcium
Chromium
Coba"
SU ARY OF CHEMICALS DETECTED IN
GROUNDWATER
Frequency Detection
01 Detection limit
(015)
. .'., (313) ,..',
(0/3)
(015)
,(013) '.
(0/3)
(315)
. (115)
(0/3)
(5/5)
(313)
(1/3) .
(0/5)
(013)
(0/3)
(015)
«011)
(0/3)
(515)
(313) .
(313)
(015)
(213)
(0/3)
(015)
, (0/3»)
(0/3)
.. .
200
..~.'"
200
60
60.
60
10
10
10
200
200
200
5
.:!), :
5
5
5
5
5000
5000.<
5000
10
'..'10,>
10
50
..50;
50
Range 01
DetectS
ND
.(~~,f2~20) .
NO
NO
. NO,
MO
(2.1 ~ 8.7)
"(!U»
NtJ
(12.8.. 96)
.. ..' . .... ....."
'. ... (29.t~,1t.6)'
(2".9)
NO
. ..
Nb
Nb
..'~b~)
MD
(100500" ..200
(3s5OG ~ 330()()() '..:
(36400 .. 394500
ND
.'...:'(~:fl~'!>i
t4D
~D
ARAAs
HAZARD
INDEX - 1
(ugll)8 8 8
Federal MCls
(a) (ugll)
183
18
-------
~-. II
II
II
-
...
.
APPnIDIX C .. 14
CHEMICAL-SPECIFIC ARARs FOR GROUK[)WATER: BEDROCK AQUIFEh.
RESIDENTIAL AREA AND AREA EAST OF Tt-IE WETLANDS
SUMMARY OF CHE ICAlS DETECTED IN
GROUNDWATER
Frequency Detection
01 Detection lImll
(115) 25
. (011) : 25:
(113) 25
(115) 100
. . . . ."
.(313) . ."oQ,'
(213) 1 00
(515) 3
.(PJ3) ',3
(0/3) 3
(515) 5000
..... (3i3) . .\ 5000>
(313) 5000
(415) 15
. ..
(3i3) , 15
(313) 15
(015) 0.2
......., ..' '"
/\t(oi3):\.) ."""
(113)
(415)
(112)
(0/3)
(515)
(313) i H H
(313)
(515)
.. (3i3)
(313)
MIC DETECTED
t:tESIDENTlAl AREA AND
AREA EAST OF WETlANDS
Copper
Iron
lead
Magnesium
.
Manganese
tJtercurr
Nickel
Polasssium
Sodium
. .
APR 1
..,. .'/OEC9(j> Tc)tal: ..
DEC 90 Dissolved:
APR 1990
H):'DI:~ OO\T6titl:
DEC 90 Dissolved:
APR 1990
)oecoo/TdUii:
DEC 90 Dissolved:
APR 1990
. .. .. ..., .,.. .
,.", .. ,... .".. ....
"".,...,'.'.D~C: 9(f'i.~tai:" .{:., ..
DEC 90 Dissolved:
APR 199
. .., . . . . .. . .
.', DEC 90:,:1.°131:
DEC 90 Dissolved:
APR 199
.. . . . .. . .. .
".' DEC 9O}Tolal:
DEC 90 Dissolved:
APR 1990
p' ...., .'
., . .DEC 00 > TOlai: .
DEC 90 Dissolved:
0.2
"'0
>40...
40
5000
.:,t:,', 5000 iH
5000
5000
.. ...'i'5000~T'."'"
5000
ARAAs
HAZARD
INDEX - 1
(ugfl)" .
Federal MCls
(a) (ugfl)
1300 A
Range
Delee"
28.4
,NDJ1'
(2.1)
89.2
..:'(2860'9:1!oo> .
(390.5 .. 1890)
(1.3 - 11.4)
(J.1 +t;~
MD
(3310 .10100)
..'..(1gQd}9400)
(1850" 10250)
(11.0 .. "9.6)
"..,..(68.6F196.0)
(25.4.. 67.2)
NO
. .
(O.~
(8.9 - 12.1)
.... ..-' . .
:: ~~:::'.::"«~ .a.6f:..~ .:.
Nb
(8495 - 20900)
'.'.,.. (5930~,)3000)
(6150. 14550)
(17350" 158000
..)::);;:'. ,.;(2!$OOO.~,S91 00)
-------
. MIl
81
II'.
.
-
APPENDIX C - lS
. CHEMICAL-SPECIFIC ARARs FOR GROUNDWATER: BEDROCK AQUIf=E~"
RESIDENTIAL AREA AND AREA EAST OF THE WETLANDS
ThaRium
ARARs
(TOG)
RISK-
10 -6
(ugll) ..
HAZARD
INDEX - 1
(ugll). . .
3
SUMM RY OF CHEMICALS DETECTED IN
GROUNDWATER
requency Detecllon
. 01 Detection LImit
APR 1 (015) 10
DEe 90 Totai: (013) .10
DEC 90 Dissolved: (013) 10
, APR 1 (015) 50
. ...' . ".
... . bee 96 . Toiai: ...«oi3) 50.
DEC 90 Dissolved: (013) 50
APR 1 (015) 20
. ..oee 00 ...iotai:...::..(Oi2):20 ...
DEC 90 Dissolved: (012) 20 ND
NoIe: The residential area bedrock Wen group contains the loIlowing sample loeallons: RW-10D, RW-11D, RW-120 (old) ,
~-12 (new) and RW-13D. Bedroek wells east 01 the wetland Include MW-3D, MW-6D and MW-7D were sampled In ~O 90.
(a) ted8f'al Sale Drinking Water Act Maximum Contaminant level
(b) "roposed New Hampshire Ambient Groundwater Standards
MCl - Maxh!un Contaminant lev'" ". ".,.,\,Igated by EPA
HA - lifetime Health Advisory asIa' I by EPA
IntRA - t4H Department 01 Health and Human Services, DMslon 01 Public Health SefVIc... Bureau 01 Health Risk
Assessment Health Advisory level
AML - Analytical Method limitation. fn those cases where the EPA 10E-6 Risk level eOl1Centration was
lest than the Practical Quantltatlon limit (POl) 01 all analytical methods approved br Department
01 I:nvlronmental Services, the POL with the lowest concentration was established 81 the ambient
groundwater quality standard
(1) - totll trlhalomethanes
Nb - not detected
NbR - no detects, and at least one sample was rejected
. . - contaminant concentration exceeds standard
.. - A water concentration associated wllh 10-6 excess IIletlme cancer risk, based on etposure assumptions pr8ented In the Baseline Risk Assessment.
. .. - A .ller concentration associated with a hazard Index 01 1 lor noncarcinogenic effetts, based on exposure assumptions presented In the
Baseline Risk Assessment.
It. - proposed
A - Action level
- - No Criteria Available
CH ICA ETECTED
RESfDEN11AL AREA AND
AREA EASt OF WETlANDS
Range or
. Detects
NO
..Nq
Nb
NO
.,\NtJ..\
ND
ND
Federal MCLs
(a) (ugll)
-------
II
II
-
...
-
APPaIDIX C - 16
Concentretlon. expre.88d In ugll
Federal SOWA CWA Amblenl Water ~PA brlnklng Federal sD'IIA Gtoundwatet Groundwater
Chlmlcal Federal SOWA Maximum Quality Criteria Wattr Health Secondar1 ConCentration Concentration
01 Concern Maximum Contaminant Protection 01 Adflsory lor Maximum at wttlch at which
Contaminant level Aquatic lIle lifetime Contaminant Risk III Hazard Index -
levels Goals (acute/chronic) Ekposure levels (10-6) (1)
(a) (a) (b) (c) (d) (e) (I)
Anllmony 10; 5 (P,g) 3 (P) 9,00011,600 -- -- -- 15
barium 1,000 (h) 2,000 -- 1,500 -.. -- 2555
2,000 (h)
Berylllu'" 1(P) 0 (P) 13O(J)I5.3() -- -- 0.02 183
Chromium 100 100 1,700(k,1)I210(k,1) 120 -. 183
1.1-Dlchloroethene 7 7 -- 7 -. 0.1 328
Lead 50 (I) 0 (g) 83(k)l3.2(k) 70 -. .- --
15 (Al)
thallium " 2(P) 0.5 (P) 140O(J)l40(J) -- I ... .- 3
I
1.1,1- Trichloroethane 200 200 -- 200 -. .- 3285
. FEDERAL ARARS AND OTHER GUIDANCE FOR CHRMICALS OF
CONCERN IN GROUNDWATER. HOLTON CIRCLE
- .. Stendard n04 dlMlloped lor thla chemical.
tPt .. PropollKl.
tAL) .. Action level
(I) 40 CFR. Pert 141-Natlonal Primary Drinking Water Regulatlona. 6511-683.820-821. .
lb. Federal Clean Water Act. Ambient Water QuaAIy Crherl. .tandarda are poIentially relevant and app'cltnlate under CERClA .. 1 :UtdI(2)(8)(11,
It' Environmental Pr04ectlon Agency (EPA). 1887, "'ahh AdvIaorle.. omce 01 DrinkinG Water. Wa8hlntton, D.C.
March St. 1987.
Cd) 40 CI'A, Part 143-Natlonal Secondary DrinkinG Water Reoulatloo,.
(el A waler concentration anoelated with 10-8 exce..llletlme cancer rlak, beaed on exposure a..umptlona pra..n1ed In the be..Unll rtak aa...alnent.
(I) A water concentration aalOClated with a hezard Index 011 tor noncartnogenlc e"eet., baaed on eJlPOellre ..aumptlona pre..nted 1ft the llaMhne rlak a_nment.
1111 EPA "ropo'" MCla of 10 ugll and 6 ullillor anllmony baaed on propoeed practical quantitatlon ..".,Ia (POL.).
(hI The MCl lor barium 011,000 ulIlI ahall remain e"ectlw until January 1, 1893 when the MCL 012,000 IIgll will take Ita place.
1'1 The MCllor lead lain e"act until December " 1892, when the action lewl win take Ita place. 58 rn No. 110,28480-28564.
ID In.uMclent deta to develop criteria. Value pre..nted I. the lowetlt obaerwd e"eet level (LOEl'.
Ckl Hardne.. dependent criteria (100 mllll Caco3 uaedJ
(IJ Value "eaented lor trivalent chromium.
-------
I -: . ~aIDIX C -17
I PROPOSED NEW HAMPSHIRE AMBIENT GROUNDWATER
QUALITY STANDARDS
I Source of Standard
Regulated Lifetime EP~ AML
Contaminant Concentr'ation MCL HA 1Q BHRA (Method)
. Acetone 700 ug/L X
Acryloni trile 5 ug/L X(8030)
I Alachor 2 ug/L X
. Aldicarb 3 ug/L X
I Aldicarb sulfoxide 4 ug/L X
Aldicarb sulfone 2 ug/L X
. Aldrin 0.04 ug/L X(8080)
Allyl Chloride 7.4 ug/L X
Antimony 3 ug/L X
. Arsenic 50 ug/L X
, A trazine 3 ug/L X
. Barium 2,000 ug/L X
Benzene 5 ug/L X
. Benzidene 0.8 ug/L X(605)
Benzo(a)pyrene 0.2 ug/L X(8310)
r
t. ~
. Benzoic Acid 2&,000 ug/L X
Beryllium 1 ug/L X(210.2),
(200.7 p 200.&>
Boron 620 ug/L X
Bromodichloromethane 90 ug/L X
. Bromomethane 10 ug/L X
1 ,3-Butadiene 0.019 ug/L X
Cadmium , ug/l. X
Camphor 200 ug/L X
Carbon Disulfide 7ug/I. X
Carbofuran 40 ug/L X
Carbon tetrachloride 5 ugl L X
-------
I
APPENDIX C - 18
~. (~ PROPOSED NEW HAMPSHIRE AMBIENT GROUNDWATER
QUALITY STANDAlU)S
I Source of Standard ~-
Regulated Lifetlme EP~ P.\M1.
Contaminant concentration MCL. HA 10- BHRA (MethOd)
. bis-(Chloroethyl)ether. 10 ug/L. X(8270)
bis-(chloro isopropy l)ether 300 ug/L. X X(&270)3
I- bis-( Chloromethy l)ether 10 ug/L.
Chloromethane 3 ug/L X
Chlorotoluene (o,p) 100 ug/L X
Chromium 100 ug/L X
cyanide 200 ug/L Xl
2,4-D 70 ug/L X
Dalapon 200 ug/L X
DDT O.l ug/L X
. Dibromochloropropane 0.2 ug/L X X2
Dibutylphthalate &00 ug/L
o-Dichlorobenzene 600 ug/L X
para-Dichlorobenzene 75 ug/L X
3 ,3-Dichlorobenzidene 1.3 ug/L X(605)
Dich1orodif1uoromethane 1,000 ug/L X
1 pl-Dich1or~thane &1 ug/L X
1 ,2-D ichloroetham! 5 ug/L. X
1, 1-Dichloroethy 1ene 7 ug/L. X
cis-l,2 -0 ichlorothey lene 70 ug/L X
trans-1 ,2-Dichloroethylene 100 ug/L X
Oichloromethane' 5 ug/L X
1,2-Di~e 5 ugJL. X
DieLdren O.0a2 ug/L X
DHethylexyI)adipate 500 ug/L. Xl
Di(ethy lexyl)phthala te 4 ug/L X(525)
~lp-Qini trotQluene 10 ug/L X(&270)
Dinoseb 7 ug/L X
1,2-DiphenyLhydrazine 10 ug/L Xl X(&270)
-------
J APPE2IDIX C - 19
I . (Continued). PROPOSED NEW HAMPSHIRE AMBIENT GROUNDWATER
QUALIIY STANDARDS
. Source of Standard AMi..
Regulated Lifetime EP~
eontarninant Concentration MCL HA 10 BHRA (Method)
. Endothall 100 ug/L X
Endrin 0.2 ug/L X
E thylbenzene 700 ug/L X
Ethylene dibromide 0.05 ug/L X
Ethylene glycol 7,000 ug/L X
Fluoride 4,000 ug/L X
Glyphosate 700 ug/L X
Gross alpha radionuclides 15 pel/I. X
Heptachlor 0.4 ug/L X
Heptachlor epoxide 0.2 ug/L X
Hexachlorob"- zene 0.02 ug/L X
Hexachlorot ~diene 0.5 u~!L X
Hexachlorocyclohexanes (HCCH)
alpha 0.006 ug/L X X2
beta 0.02 ug/L
technical 0.02 ug/L X
Hexachlorocyclopentadiene .50 ug/I. Xl
Hexachlorodibenzaciioxin 0.0221 ugJI. X(828Q>
Hexachloroethane 1 ug/L X
lsophorone 100 ug/L X
Lead 15 ug/ L X
Lindane 0.2 ug/L X
Mang~e 1,500 ug/L X
Mercury 2 ug/I. X
Methoxychlor 40 ug/L X
Methyl ethyl ketone 170 ug/L X
Methyl isobutyl ketone 350 ug/L X
-------
v
I APPmDIX C - 20
, . (contira.-{\- PROPOSED NEW HAMPSHIRE AMBIENT GROUNDWATER.
QUALITY STANDARDS
. Source of Standard ~ .
Regulated . Lifetime EP!6 AM!.
Contaminant Concentration MCL. HA 10- BHRA (MethOd)
. 4-Methyl phenol 350 ug/L X
Methyl-t-butyl ether 100 ug/L X
. Monochlorobenzene 100 ug/L X
Naphthalene 20 ug/L X
Nickel 100 ug/L X
Nitrate 10,000 ug/L X
Nitrite 1,000 ug/L X
Oxamyl 200 ug/L X
Pentachlorophenol 1 ug/L X
Phenol 4,000 ug/L X
picloram 500 ug/L X
Polychlorinated biphenyls 0.5 ug/L X
Potassium 35,000 ug/L X
Radium 226 and 228 5 pci/L X
Selenium 50 ug/L X
Silver 50 ug/L .X
SimcWne 1 ug/L X
Strontium 90 & pci/L X
Styrene lOO ug/L X Xl
Sulfate 400,000 ug/L
2,3,7,8- TeDD 0.00005 ug/L X(8280)
1 ~1 ,2,2- Tetrachloroethane 0.17 ug/L Xl
1, 1 ~1,7- Tettadtloeoemane 10 ug/L. X
T etrachloroethy lene , ug/L X
T etrahydrofuran 1;'" ug/L. X
Thallium 2 ug/L X(20Q.9;
(200.&)
Toluene l~OOO ugJL X
--
-------
I
"
I
I
I
I
I
I
8
8
-
-
I
.
8
I
I
I
I
APPENDIX C - 21
. (Corrtinuecf). PROPOSED NEW HAMPSHIRE AMBIENT GROUNDWATER. .
. QUALITY STANDARDS '.
Source of Standard
Regulated Lifetime EP~ AML
Contaminant Concentration MCL HA 10- BHRA (Method)
Total Colifom 0 ug/L X
Toxaphene 3 ug/L X
2,4,.5- TP (silvex) 50 ug/L X
1,3,5- Trichlorobenzene 40 ug/L X
1,2,4- Trichlorobenzene 9 ug/L X
1,1,1- Tr ichloroethane 200 ug/L X
1,1 ,2-Trichloroethane 3 ug/L X
Trichloroethylene 5 ug/L X
Tr ichlorofluoromethane 2,000 ug/L X
Trichloromethane 6 ug/L X
I ,2,3- ~richloropropane 40 ug/L X
2,4,6 : ichlorophenol 10 ug/L X(8270)
Trihalomehtanes (total) 6 ug/L 4 X
Tritium 20,000 pci/L X
Vinyl Chloride 2 ug/L X
Xylene (total) 10,000 ug/L X
'>, r'
Key:
MCL = Maximum Contaminant Level promulgated by EP A
Lifetime HA = Lifetime Health Advisory established by EP ~
EPA 10-6 = Environmental Protection Agency (EPA) 10- Risk Level -
BHRA = NH Department of Health and Human Services, Division of Public Health
Services, Bureau of Health Risk Assessment Health Advisory Levgl
= Analytical Method Limitation. In those cases where the EPA 10- Risk
Level concentration was less than the Practical Quantitation Limit (PQL)
of all analytical methods iij)FQveci by Department of Environmental
Services, the PQL with the lowest concentration was established as ~
ambient groundwater quality standard.
Based on U.S. EPA proposed Maximum Corrntminant level Goal
Based on U.S. EPA established ambient water quality criteria
Modification of Method
If groundwater is affected by chlorinated water supplies, then the Ambient
Groundwater Quality Standard shall be 100 ug/L.
Units of Measurement:
AML
1.
2.
3.
4-.
ug/l = micrograms per 'i !er
pci/L = picocuries per ,.:er
-------
-.
APPENDIX D
-------
~
~ES
.:..
State of New Hampshire
DEPARTMENT OF E~ONMENTAL SERVICES
6 H8zm~, P.O. Box 95. CGdcanL ~"'H Q33Q1.QQ9,
603-211-3503 F.~ 603.271.2867
me kc8sr: -I'nf ~;~
September 28, 1992
Mr. Merrill S. Hohman
Director, Waste Management Division
U5 Environmental Protection Agency
JFK Federal Building.
8o~tcn. MA Q2203
,
Re:
Record of Decision
Holton Circle Site
Londonderry,NH
Dear Mr. Hohman:
The New Hampshire Department of Environmemal Serviceo (DES), acting as agent
for the State of New Hampshire, has reviewed the recommended remedy presented in
the above referenced Record 01 Decision (ROD). DES concurs with USEPA that the
recommended remedy Is consistent with the rules and regulations 01 applicable or
relevant and appropriate State requirements. 'fthe Trust Fund is used and state funds are
available, the State agrees to provide it's matching shere.
DES shares the sentiments expressed at the public meetings and hearing by the
local residents and sincerely hopes that USEP A will pursue the delisting 01 this site at the
earliest possible time.
Sincerely,
O-~ ()
'( '-.~ --l. Or ~
Philip J. O'8rie~.D.
Director
Waste Management Dtvision
PJO/CWB/mjc/AodHoltn.Doc
cc: Danl@1 Coughlin, P.E., USEPA
James M. Dflc.'r!n%O, OSEPA
Carl W. Baxter, P.E., NHD!S-wMEB
Steven Hoursn. Esq.. NHDOJ
AIR RESOURCES Dl\'.
1W:o."(I JI1&:1131m::
Call.r Ben 2033
C:Oncurd. ~.H. OJ3O':!.20::
Tel. 6(1~,=":.1~7Q
F.. riI'~~71.11~1
Wo\STE MASAG£ME~" DI".
C.lto-tcQ Dri...
Coo..."rd. N.H. 03~\
Tt! (I03.:7\.mo
Fu -"3.21l-.456
~~TER RESOURCES DIY
64 ~'., y.," ~I""
POBox :008
Cor.cord. .'i.~. 0:30;:.20Q$
Tel. 603.~71.:~
FSl60~.:11.1:;31
~~TER S\;PPLY &. POLLt;TlO;o.; CONTROL DIY.
p.O. !'" 9' .
Coatord. N H. 033(1:~S
Tel. 603-:11.3'03
fs" SOH; t.: IS!
------- |