Final Report:
Technical Assistance for the
Gilson Road Superfund Site
Nashua, New Hampshire
EPA Region 1
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Solid Waste and EPA-542-R-09-012
Emergency Response September 2009
(5203P) www.epa.gov
Final Report:
Technical Assistance for the
Gilson Road Superfund Site
Nashua, New Hampshire
EPA Region 1
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Notice and Disclaimer
Work described herein was performed by GSI Environmental, Inc. for the U.S.
Environmental Protection Agency (U.S. EPA) and has undergone technical review by
EPA. Work conducted by GSI Environmental, Inc., including preparation of this report,
was performed under EPA contract EP-W-07-037 to Environmental Management
Support, Inc., Silver Spring. Maryland. Reference to any trade names, commercial
products, process, or service does not constitute or imply endorsement, recommendation
for use, or favoring by the U. S. EPA or any other agency of the United States
Government. The views and opinions of the authors expressed herein do not necessarily
state or reflect those of the United States Government or any agency thereof. For further
information, contact:
Kirby Biggs Kathy Yager
U. S. EPA/OSRTI U. S. EPA/OSRTI
703-299-3438 617-918-8362
biggs.kirby@epa.gov yager.kathleen@epa.gov
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TABLE OF CONTENTS
EXECUTIVE SUMMARY i
1.0 INTRODUCTION 1
1.1 Site Background 2
1.2 Remedial Activities 3
1.3 Geology and Hydrology 4
1.4 Current Regulatory Status and Site Monitoring Objectives 5
2.0 MAROS EVALUATION 6
2.1 Overburden Results 6
2.1.1 COC Choice 6
2.1.2 Plume Stability 7
2.1.3 Well Redundancy and Sufficiency 10
2.1.4 Sampling Frequency 11
2.2 Bedrock Aquifer 12
2.2.1 COC Choice 12
2.2.2 Plume Stability 12
2.2.3 Well Redundancy and Sufficiency 13
2.2.4 Sampling Frequency 14
2.3 Summary Results 14
3.0 CONCLUSIONS AND RECOMMENDATIONS 17
4.0 REFERENCES 20
TABLES 21
Table 1: Gilson Road Monitoring Well Network
Table 2: Priority Constituents, Screening Levels and Maximum Recent Concentrations
Table 3: Aquifer Input Parameters
Table 4: Trend Summary Results Overburden Aquifer
Table 5: Trend Summary Results Bedrock Aquifer
Table 6: Final Recommended Monitoring Network
FIGURES 36
Figure 1: Gilson Road Site Monitoring Network
Figure 2: Historic Conceptual Model
Figure 3: Overburden Groundwater Arsenic and Benzene Average Concentrations
and Trend Results
Figure 4: Combined Concentration Trends for Source and Tail
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Figure 5: Spatial Uncertainty in Overburden Network
Figure 6: Spatial Uncertainty in Final Recommended Overburden Network
Figure 7: Bedrock Groundwater Arsenic and Benzene Average Concentrations and
Trend Results
Figure 8: Final Recommended Monitoring Network
APPENDIX A: MAROS 2.2 METHODOLOGY A-l
APPENDIX B: MAROS REPORTS B-l
APPENDIX C: LIST OF ACRONYMS C-l
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EXECUTIVE SUMMARY
The following report reviews and provides recommendations for a long-term
groundwater monitoring network for the Gil son Road (Sylvester) Superfund Site (Gil son
Road). Extensive remedial actions have been successfully implemented at the site over
the past 30 years, and the site is currently in a long-term operation and maintenance phase
(O&M). The primary goal of developing an optimized groundwater monitoring strategy
at the Gilson Road site is to create a dataset that fully supports site management decisions
while minimizing expense and effort associated with long-term O&M.
The current groundwater monitoring network at the site has been evaluated using a
formal qualitative approach as well as statistical tools found in the Monitoring and
Remediation Optimization System software (MAROS). Recommendations are made for
groundwater sampling frequency and location based on current hydrogeologic conditions
as well as the long-term monitoring (LTM) goals for the site. The following report
evaluates the monitoring system using analytical data collected from the site after
cessation of the extraction remedy, including the time between 1999 and 2009. The report
outlines recommendations based on a formal evaluation, but final determination of
sampling locations and frequencies are to be decided by the overseeing regulatory
agencies.
Site Groundwater Monitoring Goals and Objectives
Groundwater data at the Gilson Road site will be collected to address the following
primary objectives:
Evaluate the risk to human health and the environment.
Establish long term trends in contaminant levels to support future site
management decisions.
Evaluate the effectiveness of the current remedial action (monitored natural
attenuation) in achieving risk reduction.
Document changes to the area groundwater quality and geochemistry after
cessation of the groundwater extraction and treatment system.
Ensure that contaminant concentrations above applicable screening levels are not
migrating horizontally and vertically to potential surface water receptors.
. Monitor groundwater concentrations at the boundaries of the groundwater
management zone (GMZ).
The goal of the long-term monitoring optimization (LTMO) analysis presented in this
report is to review the current groundwater monitoring program and provide
recommendations for improving the efficiency and accuracy of the network in supporting
the site monitoring objectives listed above. Specifically, the LTMO process provides
information on the site characterization, stability of the plume, sufficiency and
redundancy of monitoring locations, and the appropriate frequency of sampling. The end
product of the LTMO process at the Gilson Road site is a recommendation for specific
sampling locations and frequencies that best address monitoring goals and support future
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management and redevelopment decisions (see Figure 8 for the final network
recommendations).
Results
Statistical and qualitative evaluations of the Gilson Road site analytical data have been
conducted, and the following general conclusions have been developed based on the
results of these analyses:
. Historic remedial activities have diminished the size of the plume. The
containment wall and groundwater extraction remedies have removed the
majority of volatile organic contaminants (VOCs) from the overburden and
bedrock aquifers. Arsenic is currently the contaminant of concern (COC) that
exceeds cleanup standards at the most locations and by the highest amount.
. Site characterization and conceptual model development are comprehensive and
explain significant site details. No significant data gaps in site characterization
were found. The current network is sufficient to support most site management
decisions. However, due to the age of the site and the format and distribution of
historic documents, relevant site data can be time-consuming to access.
. Individual well trends and plume-wide trends indicate a stable to shrinking plume
for all COCs in both the overburden and bedrock aquifers. Arsenic concentrations
show strongly decreasing trends, particularly in the area downgradient of the
slurry wall. Concentration trends for benzene, lead, and chlorobenzene are largely
decreasing in both source (inside the slurry wall) and tail (outside the slurry wall)
regions of the plume.
. Chlorobenzene shows some variable trends in the overburden aquifer, outside of
the slurry wall. Concentrations results for 2009 indicate chlorobenzene at well T-
64-2 is just below the screening level; however, the concentrations show an
overall increasing trend at this location. Chlorobenzene concentrations at HA-5-A
have exceeded standards historically, but now show a decreasing trend. Nested
wells at T-48 have some historic exceedances of the standard but now show a
stable to decreasing concentration trend. Chlorobenzene concentrations at the
downgradient boundary of the GMZ are below regulatory screening levels and
show stable concentration trends.
. Monitoring Well Redundancy/Sufficiency: Spatial analysis indicates networks in
both aquifers can be reduced in the number of locations monitored. Overall, the
aquifers show low variability and low uncertainty in concentrations.
. Reduced Sampling Frequency: The statistical sampling frequency analysis along
with a qualitative review indicated that a reduced sampling frequency (biennial)
may be appropriate for many wells in the network.
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Recommendations
The following recommendations are made based on the results of the qualitative and
quantitative review of data received, with findings summarized above and in Sections 3
and 4.
. Plume Stability: Based on the results of the individual well trend and plume-wide
stability analysis, the plumes in both the overburden and bedrock aquifers are
stable to shrinking. Stable or shrinking plumes are candidates for reduction in
monitoring effort.
. Routine Monitoring Program: Several wells have been recommended for removal
from the routine monitoring program for both the overburden and bedrock
aquifers (see Table 6). For the overburden aquifer, 33 monitoring locations are
recommended for retention in a routine monitoring program; 12 of these locations
are recommended for biennial sampling with the remainder recommended for
annual sampling. For the bedrock aquifer, 16 monitoring locations are
recommended, with 3 at a biennial sampling frequency and the remainder
recommended for annual sampling. Going forward, a consistent set of wells
should be sampled at regular intervals to provide a dataset that supports plume-
wide statistical evaluation of trends and plume-wide progress toward cleanup
goals. A consistent dataset will provide a higher level of confidence in statistical
results.
. One additional bedrock monitoring well is recommended. While the spatial
analysis indicates very low concentration uncertainty within the current network,
there is currently no bedrock monitoring location at the northwestern boundary of
the GMZ near HA-10 and HA-11. This area is downgradient from locations that
exceed standards for arsenic and other COCs in the bedrock zone. A bedrock
monitoring location in this area would provide information on concentrations at
the edge of the institutional control (1C).
. GMZ monitoring. One objective of the monitoring network is to confirm that
groundwater outside of the GMZ meets quality standards. However, several wells
that monitor the boundary of the current GMZ show concentrations above the
background and some above the AGWS (e.g. HA-10-C for arsenic, T-54-3 for
benzene and arsenic, T-60-3 for lead and arsenic). Technically, the GMZ must
delineate the boundary between affected and unaffected groundwater. Based on
results from the 2009 sampling, either the size of the GMZ must be adjusted or
the requirements for groundwater attainment should be modified (e.g. calculating
regional background concentrations for arsenic and lead). Additional monitoring
locations may be required after expansion of the GMZ. Additional sampling
locations may include the overburden downgradient from HA-10-C, and cross-
gradient from HA-5-A and T-54-2. In addition to the bedrock well described
above, another well may be necessary cross gradient from T-54-3.
. Sampling Frequency: An annual sampling frequency is recommended for the
majority of the monitoring locations and is recommended for locations in the
source area and wells that monitor the downgradient area near Lyle Reed Brook.
No locations are recommended for quarterly or semi-annual sampling. Biennial
in
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sampling is recommended for wells that delineate the GMZ or serve as point of
compliance (POC) locations.
Data Management: Continue efforts to organize site data and transfer new and
significant historical information to an electronic format to improve access to site
data.
Chlorobenzene concentrations should be monitored and trends reviewed in the
area immediately downgradient from the slurry wall in the overburden aquifer.
Chlorobenzene concentrations at HA-5-A, T-64-2, and T-48-2, 3, and 4 should be
carefully monitored for any increasing trends. Surface water in Lyle Reed Brook
should be sampled downgradient from these locations in order to determine if
concentrations exceed surface water quality standards.
Surface water and sediment monitoring: While surface water and sediment
sampling locations were not evaluated in this report, the recommendation is to
continue sampling the locations identified in the database on an annual basis
along with groundwater locations.
Future reductions in monitoring effort may be possible if trends continue
downward. After collection of a consistent dataset over a period of approximately
4 years, the network can be re-evaluated and reductions, particularly in sampling
frequency may be appropriate.
IV
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1.0 INTRODUCTION
The Gilson Road (Sylvester) Superfund Site is a National Priorities Listed (NPL) site
near Nashua, New Hampshire in Region 1 of the U.S. Environmental Protection Agency
(USEPA). The site comprises about 28 acres historically affected by the operation of an
illegal waste disposal facility between the 1960s and 1979. Investigation and remediation
activities began in the early 1980s, making the Gilson Road site one of the oldest sites to
be managed under the Comprehensive Environmental Response and Liability Act
(CERCLA or Superfund). Management of the site predated the 1986 Superfund
Amendments and Reauthorization Act (SARA).
The Gilson Road site has undergone significant remedial activities over the past 30 years
including isolation of a 20 acre parcel with a subterranean containment wall (slurry wall)
and cap and installation of a groundwater pump and treat (P&T) system. Groundwater
testing and monitoring began in 1981. Groundwater within the slurry wall was
determined to have attained initial cleanup goals in 1995 and the active P&T remedy was
terminated in 1996 (USEPA 2004). Groundwater monitoring efforts are currently
underway to evaluate conditions after the cessation of the P&T remedy. Groundwater
monitoring data will be used to evaluate whether monitored natural attenuation (MNA) is
an appropriate long-term remedy for residual contamination. Therefore, current
monitoring goals for the site include: 1) confirming that concentrations of constituents of
concern (COCs) remain below relevant regulatory levels; 2) documenting changes to the
groundwater quality and geochemistry after cessation of the P&T system; and 3) ensuring
that COCs are not migrating horizontally and vertically to potential surface water
receptors or beyond the boundaries of the groundwater management zone (GMZ).
Groundwater data collected for the Gilson Road site may also be important in evaluating
regional groundwater quality.
EPA Region 1 has requested GSI Environmental (GSI) under contract to EMS to review
the Gilson Road site groundwater monitoring network and provide recommendations for
improving the efficiency and accuracy of the network for supporting site management
decisions. To this end, the following tasks have been performed:
Review monitoring objectives and current groundwater quality, and evaluate the
ability of the monitoring network to achieve goals and objectives.
Evaluate individual well concentration trends over time, both within and outside
of the slurry wall.
Evaluate overall plume stability through concentration trend and moment
analysis.
Develop sampling location recommendations based on an analysis of spatial
concentration uncertainty.
Develop sampling frequency recommendations based on both qualitative and
quantitative statistical analysis results.
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1.1 SITE BACKGROUND
The Gilson Road (Sylvester Site) is located near Nashua, New Hampshire about one-half
mile east of the Nashua River, a tributary of the Merrimack River (see Figure 1). The site
is bounded on the south by Gilson Road with low-density residential property to the south
and west. Higher density residential property lies to the east and north of the site. The
Four Hills Municipal Landfill is located to the northeast. Groundwater flow from the
municipal landfill is in the direction of Lyle Reed Brook and the landfill may affect
groundwater quality and geochemistry in this area. Lyle Reed Brook circles the site
flowing northward from the west and bounding the site to the north. Lyle Reed Brook
joins with Trout Brook northwest of the site, eventually discharging to the Nashua River
to the northwest. The Nashua River joins the Merrimack River seven miles to the east of
the site. The Merrimack is a water supply for the City of Lowell, Massachusetts.
The original source of contamination was a six-acre former sand and gravel borrow pit
that was converted into an illegal solid waste disposal facility sometime in the 1960s by
C & S Disposal Company. The disposal area was operated adjacent to the home of the
owner, William Sylvester. The borrow pit was originally used to dispose of residential
solid waste and demolition material; however, in the mid- 1970s the operator began
accepting significant quantities of industrial hazardous wastes. Waste liquids and sludges
containing VOCs, flammable solvents, heavy metal waste, and semivolatile organic
compounds (SVOCs) (H&A 1994) were delivered to the site by tanker trucks and piped
directly to the borrow pit or into subsurface leaching fields. Drums containing waste
liquids and solids also were buried in the pit and stored on site.
A court order was issued in 1979 prohibiting further disposal of hazardous wastes at the
site. In 1980, regulatory agencies acquired access to the property and removed 1,324
drums of primarily liquid BTEX (benzene, ethylbenzene, toluene, and xylenes) waste.
Remedial investigation activities and an emergency response occurred between 1981 and
1982. Groundwater monitoring wells were installed in 1981, and a groundwater
extraction system to contain affected groundwater was installed in 1982. A Record of
Decision (ROD) was issued in July 1982 (USEPA 1982) requiring the construction of a
slurry trench cutoff wall and surface cap isolating a 20-acre area. The slurry wall was
constructed in December 1982 and several groundwater monitoring wells were installed
during this time. (A list of current groundwater monitoring locations is provided in Table
1 and on Figure 1). A 1983 Supplemental ROD (SROD) (USEPA 1983) specified that a
300 gallon per minute (gpm) groundwater treatment plant be constructed to extract and
treat affected groundwater from within the slurry wall. The 1983 SROD established
cleanup goals, known as Alternative Concentration Limits (ACLs), for 16 constituents.
Because the remedial action was initiated before the widespread development of risk-
based cleanup goals, the ACLs for the site were established at 90% of the original
maximum concentrations of identified contaminants. ACLs were modified in a 2002
Explanation of Significant Differences (ESD) revising cleanup goals for 1,1-
dichloroethane and 1,1,2-trichloroethane. ACLs apply to groundwater within the
containment wall. No ACL for arsenic was specified in the SROD and analyses and state
standards for 1,4-dioxane have only recently been developed.
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In the intervening years, the state of New Hampshire has developed risk-based Ambient
Groundwater Quality Standards (AGQS) and Ambient Water Quality Standards (AWQS)
for surface water. The site currently has institutional controls (ICs) in place which
incorporate a GMZ. Compliance at the boundary of the GMZ is based on the AGQS
standards and AWQS apply to surface water in Lyle Reed Brook and the Nashua River.
ACLs are the applicable standard within the containment wall. ACLs and AGQS values
are shown in Table 2 for priority contaminants of concern (COCs) along with the most
recent maximum concentrations in the plume. For the purpose of this report, ACLs are
used to evaluate attainment of cleanup goals within the containment wall and to ensure an
active remedy is not required in this area. AGQS apply outside the wall and to all
compounds not specified in the SROD (e.g., arsenic, 1,4-dioxane).
1.2 REMEDIAL ACTIVITIES
At the time of the initial investigation, contaminated groundwater was estimated to be
moving through the upper aquifer at a rate of 2 ft/day (Backers and Beljin 1996). The
soil/bentonite slurry cutoff wall was constructed in September 1982 and consisted of a
three-foot thick wall extending between 90 and 110 feet below ground surface (bgs) fully
encompassing 20 acres (see Figure 1). A synthetic cover was installed over the site. The
300 gpm groundwater pump and treat (P&T) system was initiated in April 1986,
becoming the first P&T system installed in the nation (USEPA 2004). Inorganic
contaminants were removed from groundwater and disposed of in an onsite, lined landfill
while volatile organic compounds (VOCs) were incinerated onsite. Following treatment,
250 gpm of effluent was discharged to trenches inside the slurry wall with 50 gpm
discharged outside the slurry wall. Discharge within the slurry wall was intended to flush
contaminants while discharge upgradient of the slurry wall was intended to raise the
hydraulic head and facilitate groundwater migration from bedrock into the containment
area. The remedial conceptual model from a 1989 report by Weston Solutions (Weston
1989) is illustrated on Figure 2. The groundwater extraction system was originally
anticipated to run for three years.
The Gilson Road remedial system was reviewed in 1989 (Weston 1989), and an BSD was
issued in 1990 (USEPA 1990). The 1990 BSD identified additional remedial measures
including a soil vapor extraction system to address residual toluene and addition of six
groundwater recovery wells to extend the capture zones to areas where contaminants had
been redistributed by the trenching system. The BSD also stipulated than a Remedial
Action Evaluation Study was to be conducted to evaluate the progress toward attaining
ACLs. In 1994, the Remedial Action Evaluation Study (H&A 1994) concluded that the
additional remedial measures had been successful and that groundwater was close to
attaining ACLs within the containment wall. The groundwater P&T system was shut
down in 1996 when the EPA determined that the cleanup goals set forth in the SROD had
been attained. Between 1986 and 1996 the P&T system had pumped more than a billion
gallons of water and removed more than 430,000 pounds of contaminants (USEPA
1997).
While several studies of the remedial system (Weston 1989) (H&A 1994) indicated that
the slurry wall effectively prevented contaminant migration through the overburden, it
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was known that contaminated groundwater was escaping through the bedrock flow zone.
In a 1996 study, transport through the slurry wall was found to be minimal (Backers and
Beljin 1996). However, groundwater migrating through the bedrock fractures beneath the
cutoff wall was found to be substantial, with approximately 7,800 gal/day exiting the
containment area (H&A 1994). Currently, one objective of the groundwater monitoring
network is to document how leakage through and under the slurry wall affects
surrounding ground and surface water.
ICs have been established at the site. A chain-link fence currently surrounds the 20-acre
containment area and former treatment plant, and a GMZ has been established
encompassing the containment area and downgradient locations around Lyle Reed Brook
(see Figure 1). The current remedy at the site is monitored natural attenuation (MNA).
Groundwater at the site has been monitored since 1997 with the objective of confirming
that groundwater has attained standards within the slurry wall and that the plume is stable
to decreasing outside of the slurry wall during the period since cessation of the active
remedy.
While concentrations of VOCs were dramatically reduced as a result of the P&T system,
concentrations of arsenic in site groundwater have remained fairly high. It is unclear how
much of dissolved arsenic is a result of residual waste and how much may have been
mobilized from endogenous rock by changes in site geochemistry. Regionally,
groundwater from the Four Hills Landfill discharges to the Lyle Reed Brook area and
data indicate elevated arsenic in this area as well. The Gilson Road monitoring network
contributes to a regional network evaluating arsenic concentrations.
1.3 GEOLOGY AND HYDROLOGY
Regional geology consists of two principal subsurface zones: a stratified drift in the
overburden (overburden aquifer) and a fractured biotite schist bedrock layer (bedrock
aquifer). At the Gilson Road site, the overburden consists of anthropogenic fill, glacial
outwash, and a glacial till. The sand and gravel borrow pit in the eastern portion of the
site was filled with various types of refuse including construction/demolition debris
during the 1960s. Test borings indicate that the fill ranges from 3 to 25 feet in depth and
consists largely of coarse sand, gravel with bricks and wood fragments. The majority of
the native overburden consists of glacial outwash, a coarse to fine sand with varying
amounts of gravel and silt. The outwash ranges in thickness from 8 to 53 feet in depth,
with thicker deposits to the south. Groundwater in the overburden aquifer is largely
unconfined. A discontinuous layer of low-permeability glacial till separates the
overburden from the bedrock and can be confining in some areas.
The bedrock surface varies with highs to the northeast and northwest, with a depression
in the north central portion of the site. The bedrock elevation drops to the west of the site.
The bedrock unit is moderately weathered and highly to moderately fractured. Fractures
in the bedrock result in preferential groundwater flow paths. Groundwater in the bedrock
aquifer is semi-confined in the secondary fractures. Based on the 1989 Weston report
(Weston 1989), the two principal flow zones have similar transmissivity. A summary of
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aquifer input parameters used in the analysis of overburden and bedrock groundwater is
provided in Table 3.
The general groundwater flow direction is to the northwest toward the Nashua River.
Groundwater flow in the overburden and bedrock are largely parallel. While the slurry
wall contains overburden groundwater within the 20-acre enclosure, the hydraulic trend is
vertically downward on the upgradient side of the northern slurry wall and vertically
upward on the downgradient side (see Figure 2 for generalized conceptual model).
Groundwater flowing downward under the wall then flows upward partially discharging
to Lyle Reed Brook. Flow through the bedrock aquifer is toward the Nashua River where
it discharges to the surface. With the current ICs in place, primary risk to environmental
receptors focuses on human and ecological exposure pathways associated with discharge
to Lyle Reed Brook.
Due to the age of many of the groundwater monitoring wells, accurate potentiometric
surface measurements are difficult to obtain. Freezing and thawing of the ground can
cause well casings to change position, resulting in inaccuracies in calculated depth to
groundwater. Additionally, due to the age of the site, boring logs and as-built diagrams
are not available for all wells and records of well installation are not uniform nor are they
available in electronic format.
1.4 CURRENT REGULATORY STATUS AND SITE MONITORING
OBJECTIVES
Since shutdown of the P&T system in 1996, groundwater monitoring has been conducted
to confirm attainment of ACLs within the slurry wall and to monitor concentrations
outside of the wall and in adjacent surface water as part of the MNA remedy. The site is
currently in a verification stage to confirm that groundwater cleanup objectives will
continue to be met under the current passive treatment scenario. In addition to
groundwater monitoring, the slurry wall and surface cap and institutional controls are
maintained.
Groundwater monitoring since 1999 has not been conducted on a regular schedule or
with a regular group of wells. Additionally, results for 1,4-dioxane, used as an industrial
solvent stabilizer during the 1970s, are limited to samples taken in 2009.
Based on the 2008 Draft Sampling and Analysis Plan (SAP) (NHDES 2008) for Gilson
Road, the specific data quality objectives for the groundwater sampling program are to:
Evaluate the risk to human health and the environment.
Establish long term trends in contaminant levels to support future site
management decisions.
Evaluate the effectiveness of the remedial action in achieving risk reduction.
In order to address these objectives, the following monitoring location categories were
used to design the network. Each groundwater monitoring location in the network was
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evaluated qualitatively to determine how well it fulfilled one or more of the following
functions:
. Monitor possible exposure pathways such as discharge to surface water bodies
(near Lyle Reed Brook);
Evaluate plume stability and possible migration of contaminants;
. Monitor the boundaries of the GMZ to ensure that concentrations do not exceed
regulatory limits outside of the 1C;
. Monitor the historic source area inside of containment wall to confirm attenuation
of constituents and to anticipate future source strength;
Recommendations developed in the following report for the Gilson Road monitoring
network are designed to address the objectives listed above. Results from both the
qualitative evaluation and the statistical analyses contained in the MAROS software were
reviewed to recommend optimized sampling locations and frequencies. Each well
recommended for the final monitoring network (see Table 7) has been identified as
addressing one or more of the monitoring objectives above.
2.0 MAROS EVALUATION
The MAROS 2.2 software was used to evaluate the LTM network at the Gilson Road
site. MAROS is a collection of tools in one software package that is used to statistically
evaluate groundwater monitoring programs. The tool includes models, statistics, heuristic
rules, and empirical relationships to assist in optimizing a groundwater monitoring
network system. Results generated from the software tool can be used to develop lines of
evidence, which, in combination with professional judgment, can be used to inform
regulatory decisions for safe and economical long-term monitoring of affected
groundwater. A summary description of each tool and statistical method used in the
analysis is provided in Appendix A of this report. For a detailed description of the
structure of the software and further utilities, refer to the MAROS 2.2 Manual ((AFCEE
2004); http://www.gsi-net.com/software/MAROS V2 2Manual.pdf) and Aziz et al.,
2003 (Aziz, Newell, et al. 2003).
Groundwater data collected between 1999 and 2009, after total shutdown of the P&T
system, were used for the majority of statistical analyses. Data from the overburden and
bedrock aquifers were evaluated separately, despite the hydraulic connection and
variability in vertical gradients between the two units. A summary of wells evaluated is
presented in Table 1; regulatory screening levels are show in Table 2 and generalized
aquifer input parameters for the MAROS software are presented in Table 3.
2.1 OVERBURDEN RESULTS
2.1.1 COC Choice
MAROS includes a short module that provides recommendations for prioritizing COCs
plume-wide based on toxicity, prevalence, and mobility. A report showing results of the
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COC prioritization for the overburden aquifer is shown in Appendix B. Based on a
comparison with AGQS screening levels (which are largely below the ACLs) arsenic,
1,4-dioxane and benzene are the only constituents that exceed standards on a plume-wide
basis. Due to the low screening level (10 ug/L), arsenic is the priority COC both inside
and outside the containment wall. Benzene concentrations are well below ACLs within
the slurry wall and have exceeded AGQS in the recent past in a limited area outside the
wall at T-48-2/3/4, T64-2, and HA-5A/C.
The dataset for 1,4-dioxane is small, with results for only eight wells in the network from
2009. The AGQS for 1,4-dioxane is very low (3 ug/L), so even low concentration
detections can be problematic. Because of the limited dataset, trends for 1,4-dioxane as
well as sampling locations and frequency could not be evaluated statistically. 1,4-
Dioxane is highly mobile and detected at T-60-1, indicating that area impacts may
originate from other sources such as the Four Hills Landfill. Additional data on the
prevalence and distribution of 1,4-dioxane is needed.
Historically, chlorobenzene concentrations have exceeded AGQS standards in a limited
area in the overburden aquifer outside the slurry wall (HA-5-A/C, T-48-2/3/4, and T64-
2), but chlorobenzene does not exceed standards over a broad area, and recent (2009)
samples indicate concentrations may be attenuating.
2.1.2 Plume Stability
Plume stability is an important concept in long-term site maintenance. A stable plume is
one that is predictable under ambient conditions and requires less monitoring effort than
plumes that are expanding or changing rapidly. Within the MAROS software, time-series
concentration data and plume-wide trends are analyzed to develop a conclusion about
plume stability.
Individual Well Trends
Data from 51 wells monitoring the overburden aquifer were evaluated. Summary
statistics, including maximum detected concentrations (1999 - 2009), detection
frequencies and concentration trends for arsenic, benzene, and chlorobenzene are shown
in Table 4. Historic maximum concentrations for arsenic and benzene have been
normalized by the AGQS and plotted on Figure 3 in order to provide an idea of the
distribution of groundwater above the standards.
Individual well concentration trends were determined using the Mann-Kendall (MK) and
linear regression (LR) methods for data collected between 1999 and 2009. A summary of
trend results for the overburden aquifer is provided in the table below and in Table 4.
Roughly one quarter of wells (12) sampled in the 2009 event have not been sampled
more than three times in the previous ten years. A concentration trend cannot be
calculated for locations with less than 4 sampling results. Detailed reports for MK trends
are provided in Appendix B. Results of the individual well MK trends for arsenic and
benzene are illustrated on Figure 3.
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Overburden COC
Arsenic
Benzene
Chlorobenzene
Lead
Total
Wells
51
50
50
51
Number and Percentage of Wells for Each Trend Category
Non
Detect
1 (2%)
14(28%)
1 3 (26%)
7(14%)
Decreasing/
Probably
Decreasing
1 9 (37%)
8(16%)
6(12%)
14(27%)
Stable
13(25%)
1 3 (26%)
11 (22%)
10(19%)
Increasing/
Probably
Increasing
0
0
3 (6%)
0
No Trend
6(12%)
4 (8%)
6(12%)
8(16%)
N/A
12(24%)
11 (22%)
11 (22%)
12(24%)
Note: Number and percentage of total wells in each category shown. N/A = insufficient data to evaluate a trend.
For arsenic, the majority of well locations show decreasing to stable trends. This is true
for the other constituents as well, with non-detect, decreasing and stable trends
dominating results for wells with sufficient data to determine a trend. No locations show
increasing or probably increasing trends for arsenic. Trend results indicate a shrinking
arsenic plume, perhaps indicating that geochemical conditions conducive to arsenic
mobility have reversed. Six wells have no trend for arsenic, indicating higher variability
in the data.
While no increasing concentration trends were found for arsenic, benzene, lead, and vinyl
chloride, three locations show an increasing trend for chlorobenzene. The three locations
with increasing trends for chlorobenzene are T-13-3 and T-19-3 inside the slurry wall and
T-64-2 outside of the wall (MK trend reports are in Appendix B). While concentrations
are below AGQS at T-19-3, concentrations exceed AGQS at T-13-3 and are close to
exceeding at T-64-2. An area of elevated chlorobenzene exists outside of the slurry wall
around T-64-2, including HA-5-A and C, the T-48 nested wells and T-63-1.
Concentrations of chlorobenzene are decreasing at location T-64-3, co-located with T-64-
2 and screened approximately 30 feet deeper than T-64-2.
The MAROS software groups trend results from individual wells to determine a general
trend for a specific area. For the overburden aquifer, arsenic trends within the slurry wall
are generally stable while concentrations outside the wall show an overall decreasing
trend. Figure 4 shows the combined MAROS trend results for priority constituents inside
the slurry wall (Source Stability) and outside the wall (Tail Stability). For the five COCs
evaluated, all show decreasing or probably decreasing concentration trends outside of the
slurry wall and most show probably decreasing trends within the slurry wall. These
results support the conclusion of a stable to shrinking plume.
Moment Analysis
Moment analysis was used to estimate the total dissolved mass (zeroth moment) and
center of mass (first moment) for dissolved constituents for the full plume (both inside
and outside the slurry wall) and for a limited number of wells outside of the slurry wall.
Zeroth and first moments were found for annually consolidated data collected between
1999 and 2009, and an MK trend was determined for each. Due to variations in the
number and identity of wells sampled during each event, annual consolidation of data
-------
was necessary in order to calculate moments based on a more consistent set of wells.
Results of the moment analysis of priority COCs for the full plume area are summarized
in the table below.
Zeroth moments are rough estimates of total dissolved mass, assuming a constant
porosity and uniform plume thickness across the site. Because of heterogeneities in the
subsurface, the mass estimates are best used to calculate a trend of dissolved mass over
time within the network rather than accurate calculations of total mass. The total
dissolved mass estimate between 1999 and 2009 for arsenic is strongly decreasing. The
total dissolved mass of benzene, chlorobenzene and lead were found to be stable. These
results support the conclusion of a largely stable to decreasing plume.
Type of Moment
Zeroth Moment
First Moment
Second Moment X
Second Moment Y
Arsenic
D
NT
S
S
Benzene
S
1
NT
NT
Chlorobenzene
S
1
S
S
Lead
S
PI
S
S
Decreasing trend (D), Probably decreasing trend (PD), Stable (S), Probably Increasing trend (PI), and Increasing trend (I);
(NT) No trend; (N/A) insufficient data to evaluate a trend.
The plume center of mass (first moment) was estimated for each year, and the distance of
the center of mass from the source (assumed to be near T-33-1) was calculated. MK
trends were evaluated for the distance of the center of mass from the source over time.
No trend was seen in the center of mass for arsenic; however, benzene, chlorobenzene,
and lead showed an increasing center of mass indicating that concentrations may have
shifted downgradient over time. Because the total mass is stable, the results indicate that
concentrations in the upgradient area are decreasing leaving more relative mass in the
downgradient area of the plume. Centers of mass for all constituents evaluated are in the
vicinity of well T-13. Centers of mass for arsenic and benzene are shown on Figure 3.
Second moments indicate the spatial distribution of mass between the center and the edge
of the plume. Second moments in the X direction are metrics of the distribution of mass
in the direction of groundwater flow, while those in the Y direction indicate the spread of
mass orthogonal to groundwater flow. An increasing second moment would indicate an
increase in mass at the edge of the plume relative to the center. For the overburden
aquifer, most second moments are stable, with some variability seen in the second
moments for benzene.
Moments calculated only for the plume outside of the slurry wall support the conclusion
of stability. Annually consolidated data for 14 wells were evaluated for the priority
constituents between 1999 and 2009. For arsenic outside the slurry wall, total mass was
strongly decreasing and the center of mass was stable. For benzene, chlorobenzene and
lead, total dissolved mass was stable. The center of mass for chlorobenzene was stable,
and that for lead showed a probably decreasing trend. The center of mass for benzene
showed not trend. No increasing trends were found for any of the constituents evaluated.
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2.1.3 Well Redundancy and Sufficiency
Spatial analysis modules in MAROS recommend elimination of sampling locations that
have little impact on the characterization of contaminant concentrations. Algorithms also
identify areas within the monitoring network where additional wells may be needed. The
spatial redundancy and sufficiency analysis for Gilson Road included a statistical analysis
using data collected between 2006 and 2009 as well as a qualitative evaluation of well
locations relative to monitoring objectives. For details on the MAROS redundancy and
sufficiency analyses, see Appendix A or the MAROS Users Manual (AFCEE 2004).
Redundancy
A Delaunay mesh spatial analysis method was used to evaluate well redundancy for 54
wells in the overburden aquifer. The algorithm includes calculation of a slope factor (SF)
that mathematically evaluates how well the concentration at a particular location can be
estimated from the nearest neighbors. Because the analysis is for a two-dimensional slice
of the aquifer, for each well nest, data from the screened interval with the highest
concentration was used for the redundancy analysis. An average SF less than 0.30 was
the criteria to identify a well that may provide redundant information and may be eligible
for removal from the network. Average SFs for arsenic and the MAROS recommendation
for elimination from the network are shown in Table 6. Results of the qualitative analysis
were combined with the results of statistical analyses to make a final recommendation for
inclusion of the well in the network.
The general results of the spatial redundancy analysis indicate overall low SFs and a
moderate level of spatial redundancy. The results of the spatial redundancy analysis were
considered along with the qualitative review of the function of the well in the network
(also summarized in Table 6) in order to make the final recommendation. Some wells
were recommended by the software for removal because they are located close together
and have similar concentrations. However, for wells on opposite sides of the slurry wall
(e.g. T-12-1/3 and HA-5-A/C), the monitoring objective of assessing contaminant
passage through the slurry wall is served by close proximity of wells. For the most part, if
the software recommended including one well in a nested group, the entire group was
retained for vertical delineation. Of the 54 wells reviewed, 21 were recommended for
removal from the program. For the overburden, 33 monitoring locations are
recommended for inclusion in the program with varying sampling frequencies (see 2.1.4
Sampling Frequency).
Sufficiency
The well sufficiency module recommends potential locations for new wells in areas of
high concentration uncertainty. The graphical results of the well sufficiency analysis for
arsenic are shown on Figure 5. Like the redundancy analysis, well sufficiency is
evaluated using SF. Areas between wells with higher SF, corresponding to higher
concentration uncertainty, are candidates for new wells. For the Gilson Road overburden
network, no areas of excess concentration uncertainty were found for the priority COCs
within the current extent of the network. Overall, the plumes show very low spatial
uncertainty, so no new wells are recommended.
10
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In order to determine if removal of redundant wells causes excess spatial uncertainty, the
sufficiency analysis was re-run with the final recommended well network. The results of
the well sufficiency analysis of the final network for arsenic are shown on Figure 6. No
excess concentration uncertainty resulted from removal of sampling locations from the
program.
Because MAROS only evaluates well sufficiency within the current network, a
qualitative review of the delineation of affected groundwater at the Gilson Road site was
conducted. The boundary of the current GMZ is shown on Figure 1. Groundwater outside
of the GMZ should be unaffected by site contaminants. The extent of the current GMZ
presents some challenges for the plume outside of the slurry wall. Concentrations of
arsenic at several sampling locations on the boundary of the GMZ are above the AGQS,
such as HA-10-C, T-60-3, and T-54-2. Locations T-60-3 and T-62-2 exceed for lead.
Groundwater at HA-5-A/C, very close to the cross-gradient boundary of the GMZ,
exceeds standards for several constituents.
Currently, wells along the GMZ do not confirm that groundwater outside of the GMZ
meets AGQS. For the inorganic constituents, arsenic and lead, no background
concentrations are specified in the documents reviewed. If current lead and arsenic
concentrations are a result of indigenous geochemical processes, then screening
concentration levels may be adjusted and the GMZ does not need to be expanded.
However, if the boundary of the GMZ changes, additional wells may be required for
delineation. Specifically, additional wells below AGQS may be required downgradient
from HA-10-C and T-60-1/3 and cross-gradient from HA-5-A/C and T-54-2.
2.1.4 Sampling Frequency
The recent sampling frequency and identity of wells at Gilson Road has not been
consistent. Sampling has been roughly annual for the years between 2002 and 2006 with
varying numbers of wells sampled (30 in 2003, 24 in 2004, 37 in 2005, and 29 in 2006).
No samples were recorded in the years 2007 and 2008. A comprehensive sampling event
was conducted in February and March 2009 where 47 wells were sampled.
Because of the uneven sampling interval, several wells in the network could not be
evaluated for recent (2003 - 2009) rate of change and trends to determine an appropriate
sampling interval. Wells with insufficient data within the recent sampling interval are
assigned a default quarterly sampling frequency recommendation by the software in order
to collect a sufficient amount of data. For wells with sufficient recent data, the MAROS
results were considered along with other lines of evidence (see Table 6) to recommend a
final sampling frequency. For wells with smaller datasets, sampling frequency was
recommended based on the overall concentration trend and monitoring rationale for the
well. Final recommendations are shown on Table 6 and on Figure 8.
Of the 33 wells recommended for the final network, 13 are recommended for biennial
sampling (every two years). These can be sampled in alternate years (even and odd) or all
every two years, depending on which is easier for contracting purposes. Wells
recommended for biennial sampling function as point of compliance (POC) or GMZ
11
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monitoring locations. 20 wells in the overburden aquifer are recommended for annual
monitoring. These wells largely function as source monitoring locations (inside the slurry
wall) and sentry wells that may indicate when concentrations in excess of standards may
be migrating toward potential receptors. A summary of locations, frequencies, associated
monitoring objectives, and suggested data analysis strategies is located in section 2.3.
2.2 BEDROCK AQUIFER
2.2.1 COC Choice
The results of the COC prioritization for the bedrock aquifer indicate that arsenic
concentrations exceed the AGQC by the highest amount and at the largest number of
monitoring locations. Lead and benzene also exceed AGQCs on a plume-wide basis, but
exceedances are neither as high nor as widespread as those for arsenic. As in the
overburden aquifer, 1,4-dioxane exceeds the AGQC, but analytical results for this
constituent are so limited that it is difficult to determine if 1,4-dioxane is a long-term
issue.
While chlorobenzene has been detected above AGQCs in the bedrock aquifer at three
locations (T-12-4 inside the slurry wall and HA-5B and T-48-5), the distribution of
chlorobenzene is limited.
2.2.2 Plume Stability
Individual Well Trend Analyses
MK and linear regression trend results for select constituents are shown on Table 5 and
summarized below. Historic maximum concentrations for arsenic and benzene have been
normalized by the AGQS and plotted on Figure 7 in order to provide an idea of the
distribution of groundwater above the standards.
Overburden COC
Arsenic
Benzene
Chlorobenzene
Lead
Total
Wells
21
21
21
21
Number and Percentage of Wells for Each Trend Category
Non
Detect
0
7 (33%)
8 (38%)
3(14%)
Decreasing/
Probably
Decreasing
9 (43%)
8 (38%)
4(19%)
3(14%)
Stable
5 (24%)
5 (24%)
3(14%)
8 (38%)
Increasing/
Probably
Increasing
1 (5%)
0
0
0
No Trend
1 (5%)
0
5 (24%)
4(19%)
N/A
5 (24%)
1 (5%)
1 (5%)
3(14%)
N/A = insufficient data to evaluate a trend.
As in the overburden aquifer, the majority of bedrock monitoring locations showed
decreasing to stable trends for arsenic. In particular, wells located along and just outside
of the northern section of the slurry wall show strongly decreasing trends (HA-5B, T-12-
4, T-64-4, and T-48-5). The only location with an increasing trend for arsenic is the
12
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upgradient bedrock location T-33-4, with an average concentration roughly twice that of
the AGQC. T-33-4 is just inside the slurry wall. The adjacent location, T-32-4, is just
outside the slurry wall and shows a probably decreasing trend for arsenic. These results
may indicate some type of geochemical effect of the slurry wall on adsorption and
desorption behavior of arsenic.
No increasing trends were found for benzene, chlorobenzene, or lead. Individual well
trend results for bedrock indicate largely stable to decreasing concentrations for priority
constituents and are consistent with reduced monitoring effort.
Moment Analysis
The results of the moment trend analyses are summarized below for the priority COCs.
All bedrock wells were included in the analysis. As with the overburden, data were
consolidated annually. Zeroth moments (estimates of total dissolved mass) for arsenic,
benzene and chlorobenzene show decreasing to probably decreasing trends, indicating
continued attenuation of COC concentrations after shut-down of the active remedy. Lead
concentrations show no trend, due to higher variability in the data.
Type of Moment
Zeroth Moment
First Moment
Second Moment X
Second Moment Y
Arsenic
PD
S
NT
S
Benzene
D
PI
1
1
Chlorobenzene
D
S
NT
S
Lead
NT
NT
NT
S
Decreasing trend (D), Probably Decreasing trend (PD), Stable (S), Probably Increasing trend (PI), and Increasing trend
(I); (NT) No Trend; (N/A) insufficient data to evaluate a trend.
Centers of mass over time for arsenic and benzene are shown on Figure 7. The first
moment, or center of mass for arsenic is stable indicating that arsenic concentrations are
decreasing uniformly across the network. The center of mass for benzene is probably
increasing, however, the spatial variation in centers of mass over time is quite low
relative to the size of the plume. All centers of mass for the bedrock network are close to
well T-24-2/3.
2.2.3 Well Redundancy and Sufficiency
Redundancy
The well-redundancy analysis for the bedrock aquifer included a review of 22 wells. The
bedrock aquifer was analyzed as one 2-dimensional slice. Average SFs calculated for
arsenic and the MAROS recommendation for elimination from the network are shown in
Table 6. Results of the qualitative analysis were combined with the results of statistical
analyses to make a final recommendation for inclusion of each well in the network.
13
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As in the overburden aquifer, the spatial analysis for the bedrock network indicates low
variability and low uncertainty within the network. The general results of the spatial
redundancy analysis indicate overall low SFs, with only 4 locations with SF for arsenic
above 0.3 (T-62-3, T-33-4, T-99, and T-44-2). The results of the spatial redundancy
analysis were considered along with the qualitative review of the function of the well in
the network in order to make the final recommendation. Six locations were recommended
for elimination from the network either due to MAROS recommendation (T-19-4 and T-
100-2) or due to low SF and lack of sufficient monitoring rationale (T-38-2 and T-44-2)
or insufficient recent data (T-29-3 and T-25-3). Sixteen bedrock locations are
recommended for future monitoring. A summary of the recommended locations and
monitoring rationales is provided in section 3.3.
Sufficiency
The well sufficiency analysis for the bedrock aquifer resulted in no recommendations for
new monitoring locations. However, the algorithm is not designed to recommend
locations outside of the current network. The extent of affected groundwater in the
bedrock is not as well delineated as that in the overburden. Overburden locations HA-10
and HA-11 as well as T-63 are significantly downgradient of the 20-acre source and
define the plume to the northwest at the boundary of the GMZ. The bedrock well T-99
monitors bedrock in the vicinity of the Nashua River; however, there are very few
bedrock wells between locations HA-5-B, T-64-4, and T-48-5 and the Nashua River. In
particular, the concentration of arsenic at the extent of the GMZ in bedrock is not known.
A bedrock monitoring location in the area of HA-10 or HA-11 may provide important
data for evaluating the regional geochemistry of arsenic and the extent of exceedance in
the bedrock aquifer.
2.2.4 Sampling Frequency
The sampling history of the bedrock aquifer is similar to that of the overburden. The
MAROS sampling frequency analysis was performed for locations with sufficient data
(more than 4 recent sampling events). The final sampling frequency recommendation is
based on both the quantitative rate of change estimates and a qualitative review based on
the monitoring rationale of the location.
Of the 16 wells recommended for the final network, three are recommended for biennial
sampling (every two years): T-32-4, G-42-2, and T-99. Wells recommended for biennial
sampling function as POC or GMZ monitoring locations. Thirteen bedrock wells are
recommended for annual sampling. A summary of locations, frequencies, and associated
monitoring objectives as well as suggested data analysis strategies are located in section
3.3.
2.3 SUMMARY RESULTS
The final recommended monitoring network is summarized below and shown on Figure 8
and Table 6.
14
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Monitoring locations have been recommended to address the monitoring objectives for
delineating the plume, monitoring the GMZ boundary, assessing source attenuation and
for monitoring the plume outside of the slurry wall for possible expansion. The
recommended network contains 49 locations with an estimated average of 41 samples
annually.
Overall results for the site indicate continued decreasing concentrations trends for COCs
in most locations. In particular, arsenic concentrations appear to be strongly decreasing
downgradient from the original source area. Statistical and qualitative results indicate a
stable to shrinking plume in both bedrock and overburden aquifers during the time since
cessation of the P&T remedy. Results are supportive of a reduction in monitoring effort
for the site.
The table below summarizes the recommended monitoring network for the near future.
As concentrations decrease with time, further reduction in monitoring effort may be
appropriate.
15
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Final Recommended Monitoring Network
Monitoring Objective
Monitor GMZ
Boundary or Point of
Compliance or
Upgradient Location
Monitor GMZ
Boundary or Point of
Compliance
Sentry/Plume
Attenuation
Source Attenuation
Recommended Wells
Overburden
HA- 10- A
HA-10-B
HA-10-C
HA- 11 -A
HA-11-B
HA-11-C
HA-13-B
HA- 14
HA-9-A
T-32-3
T-42-1
1-62-2
T-98
HA-4-B
T-60-1
T-60-3
HA-5-A
HA-5-C
HA-7-B
1-48-2
1-48-3
T-64-2
T-64-3
T-12-1
T-13-1
T-13-2
T-13-3
T-19-1
T-24-1
T-27-1
T-33-1
T-8-1
T-8-2
Bedrock
T-32-4
T-42-2
T-99
(possible new
well)
HA-4-A
T-54-3
HA-5-B
HA-7-A
T-48-5
T-62-3
T-64-4
T-12-4
T-13-4
T-24-2
T-24-3
T-33-4
T-8-3
TOTAL Wells
TOTAL Samples Annually
Number of
Wells
16
(+1)
5
12
16
49
41
Recommended
Sampling
Frequency
Biennial
Annual
Annual
Annual
Recommended
Statistical Analysis
Detection Monitoring,
Comparison Compare
detections with
screening levels
Detection Monitoring,
Compare detections
with screening levels
Statistical Trends;
95% UCL
Statistical Trends;
Comparison with
cleanup goals
Note: The recommended statistical trend analysis is Mann-Kendall, 95% UCL= upper confidence limit.
16
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3.0 CONCLUSIONS AND RECOMMENDATIONS
Extensive remedial activities at the Gilson Road site have achieved groundwater cleanup
standards set forth in the 1982 and 1983 RODs for the area within the containment wall.
Extensive groundwater extraction and treatment has removed the overwhelming majority
of VOC contaminants in groundwater. However, some residual contamination remains
both within and outside of the slurry wall. While dissolved arsenic may not have been a
major concern during the initial site investigation phase, arsenic is currently the major
site COC in both the overburden and bedrock aquifers.
Arsenic concentrations have become more problematic both because regulatory screening
levels have dropped from 50 ug/L to 10 ug/L (USEPA MCLs) and because changes in
the geochemistry of the Gilson Road site may have enhanced desorption of arsenic from
native sediments. Dissolved arsenic concentrations appear to result from a combination of
historic waste disposal and geochemical conditions exacerbated by the installation and
operation of the waste disposal and remedial systems. Part of the objective of the Gilson
Road monitoring network is to evaluate regional arsenic geochemistry and the possible
impact of both the Gilson Road site and the Four Hills Municipal Landfill on area ground
and surface water.
Overall, arsenic concentrations are decreasing across the groundwater plume, both within
the slurry wall and particularly downgradient of the slurry wall. A decreasing plume
indicates that the monitoring effort may be reduced without loss of significant decision
support metrics. Concentrations are also decreasing for benzene, chlorobenzene, and lead.
Results for most other VOCs have dropped below detection limits. The center of mass of
most of the constituent plumes is near well T-13 at the northern end of the containment
area, where the majority of the monitoring effort is now centered.
Spatial redundancy and sufficiency analyses indicate very little spatial uncertainty in the
plume and that the site has been well characterized by the number and location of the
wells. Several locations are recommended for elimination from the routine monitoring
program. No new locations are recommended for the overburden aquifer within the
current network and only one possible downgradient POC/GMZ boundary well may be
necessary for the bedrock aquifer. If the GMZ is expanded to encompass all groundwater
currently above AGQC, additional overburden and bedrock wells may be required
downgradient from HA-10 and cross-gradient from HA-5 and T-54.
Overall, statistical and qualitative analyses indicate that the sampling frequency can be
reduced at most locations where concentrations are not changing rapidly. However,
monitoring a consistent set of wells at regular intervals would provide a dataset that is
easier to analyze and more robust to evaluate plume-wide trends and plume-wide
progress toward cleanup goals.
Results and Recommendations
Result: Site characterization and conceptual model development are
comprehensive and explain significant site details. No significant data gaps were
17
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found. The current network is largely sufficient to support site management
decisions. However, due to the age of the site and the format and distribution of
historic documents, site data can be time-consuming to access.
Recommendation: Continue efforts to organize site data and transfer new and
significant historical information to an electronic format. When possible, scan
pages from historic site reports with boring logs, geologic cross sections, and
remedial designs into electronic format.
Result: The sampling frequency and number and identity of wells sampled have
been variable over the last 5 to 10 years.
Recommendation: Choose a specific set of wells and a regular sampling interval
to institute over the next few years. A consistent set of wells sampled at regular
intervals can provide important data for comparing site-wide trends over time and
demonstrating site-wide compliance with cleanup goals. A consistent dataset will
provide a higher level of confidence in statistical results.
Result: Historic remedial activities have diminished the size of the plume and
removed the majority of VOCs. Arsenic is currently the contaminant of concern
(COC) that exceeds cleanup standards at the most locations and by the highest
amount in both the overburden and bedrock aquifers.
Recommendation: Optimize the groundwater monitoring network for arsenic and
to a lesser extent, lead contamination. Continue to develop a regional conceptual
model for arsenic fate and transport that includes possible contributions from
changes in area geochemistry and the Four Hills Municipal Landfill.
Result: Individual well trends and plume-wide trends indicate a stable to
shrinking plume for all COCs in both geologic formations.
Recommendation: Based on trend and stability analysis, reduction in monitoring
effort is appropriate. With continued decreasing concentration trends, further
reduction in monitoring effort, particularly in sampling frequency may be
appropriate.
Result: Concentration trends for chlorobenzene are increasing at a limited number
of locations in the overburden aquifer, including one location outside of the slurry
wall.
Recommendation: Monitor chlorobenzene concentrations in the overburden area
of HA-5, T-48 and T-64 nested locations outside of the slurry wall. Continue
monitoring surface water in Lyle Reed Brook for chlorobenzene on an annual
basis. If concentration trends continue to increase at T-64-2, consider monitoring
the surface water semi-annually and outline possible triggers for installation of a
contingent remedy for this location.
18
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Result: Well redundancy analysis indicates that networks in both aquifers can be
reduced in number. Overall, the aquifers show low variability in concentrations.
Recommendation: Several wells have been recommended for removal from the
routine monitoring program for both the overburden and bedrock aquifers (see
Table 6).
Result: Well sufficiency analysis indicates very low spatial uncertainty in the
plumes and that no new monitoring locations are required within the current
networks. However, there is currently no bedrock monitoring location at the
northwestern boundary of the GMZ, downgradient from locations that exceed
standards for arsenic. Also, not all overburden wells bounding the GMZ have
concentrations below AGQS.
Recommendation: Install a new bedrock monitoring location in the vicinity of
HA-10 or HA-11 to delineate arsenic impacts near the GMZ boundary. If the
GMZ is modified, additional overburden wells may be necessary to delineate
affected groundwater.
Result: Sampling frequency can be reduced at many locations due to the low rate
of concentration change, the limited likelihood of plume migration and the
reduced need for frequent management decisions.
Recommendation: Reduce the sampling frequency at many locations to biennial
(every two years) and maintain annual sampling frequency within and just
downgradient of the slurry wall for the next four years to confirm decreasing
trends.
Result: Concentrations of COCs are decreasing across the site. ACLs already have
been met within the containment area, and the site is progressing toward
attainment of all cleanup goals.
Recommendation: Re-evaluate data needs in four years, and reduce both the
number and frequency of sampling locations as appropriate for the designated
land re-use.
Additional
While surface water and sediment sampling locations were not evaluated for this report, it
is recommended that the locations indicated in the database be sampled annually, at
roughly the same time as groundwater is sampled. Compliance with AWQC for arsenic,
benzene and chlorobenzene should be confirmed along Lyle Reed Brook. Sampling for
chlorobenzene downgradient from T-64-2 is particularly important as concentrations in
this area are variable.
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No recommendations have been made for a reduction in the analyte list for groundwater
samples. The 2008 SAP indicates that some locations will only be sampled for arsenic
and lead, and others for an expanded list of geochemical indicators. There is nothing in
the analysis above that would counter-indicate this strategy and the approach appears
reasonable.
4.0 REFERENCES
AFCEE (2004). Monitoring and Remediation Optimization Software User's Guide, Air
Force Center for Environmental Excellence.
Aziz, J. A., C. J. Newell, et al. (2003). "MARDS: A Decision Support System for
Optimizing Monitoring Plans." Ground Water 41(3): 355-367.
Backers, M. and M. Beljin (1996). Ground-Water Models of the Gilson Road Hazardous
Waste Site. Ada, OK, US EPA RSKERL.
H&A (1994). Remedial Action Evaluation Study Gilson Road Superfund Site Nashua,
New Hampshire. Concord, NH, New Hampshire Department of Environmental Services.
NHDES (2008). Sampling and Analysis Plan Gilson Road Superfund Site. Concord, NH,
New Hampshire Department of Environmental Services.
USEPA (1982). Record of Decision: Sylvester. Washington D.C., US Environmental
Protection Agency.
USEPA (1983). Record of Decision: Sylvester. Washington D.C., US Environmental
Protection Agency.
USEPA (1990). Explanation of Significant Differences: Sylvester. Washington, D. C.,
US Environmental Protection Agency.
USEPA (1997). Sylvester/Gil son Road Superfund Site Verification of Attainment Phase.
Boston, MA, US Environmental Protection Agency Region 1.
USEPA (2004). Five-Year Review Report: Third Five-Year Review Report for the
Sylvester Superfund Site. Boston, US Environmental Protection Agency Region 1.
Weston (1989). Remedial Program Evaluation Gilson Road Site, Nashua, New
Hampshire. Concord, New Hampshire, Roy F. Weston.
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Groundwater Monitoring Network Optimization
Gilson Road Superfund Site
Nashua, New Hampshire
TABLES
Table 1 Gilson Road Monitoring Well Network
Table 2 Priority Constituents, Screening Levels and Maximum Recent Concentrations
Table 3 Aquifer Input Parameters
Table 4 Trend Summary Results Overburden Aquifer
Table 5 Trend Summary Results Bedrock Aquifer
Table 6 Final Recommended Monitoring Network
21
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Issued: 11-SEPT-2009
Page 1 of 2
TABLE 1
GILSON ROAD MONITORING WELL NETWORK
Long-Term Monitoring Optimization
Gilson Road Superfund Site, Nashua, New Hampshire
Well Name
Interior or
Exterior of
Slurry Wall
Screened
Interval
(FT below
TOC)
Total Depth
(FT below
TOC)
Minimum
Sample Date
Maximum
Sample Date
Number of
Samples
1999 - 2009
Priority Constituent
Above or Below
AGQS
Overburden Locations
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-18-1
T-18-2
T-18-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-97
T-98
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Exterior
Interior
Interior
Interior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Interior
Interior
Exterior
Exterior
24
50
20
5
96
19
15
10
5
28
17.5
25
17
15
1.2
32
62
3
36.5
28.5
13.3
33.8
64.8
10
11.5
29
55
25
15
112.2
29
55
25
39
55
20
40
65
15
50
0
38
48
65
27.5
45
35
27
25
6.2
37
67
85.5
43
8
38
30
18.3
38.8
69.8
20
38.2
14
12/1/1999
12/1/1999
11/29/1999
12/1/1999
12/1/1999
11/29/1999
6/2/2005
6/2/2005
6/2/2005
12/2/1999
12/2/1999
7/25/2003
12/3/1999
12/3/1999
12/3/1999
12/2/1999
12/1/2000
12/9/1999
12/9/1999
12/10/1999
12/10/1999
12/10/1999
12/10/1999
12/10/1999
12/10/1999
12/10/1999
12/10/1999
12/8/1999
12/8/1999
12/8/1999
12/7/1999
12/6/1999
12/7/1999
12/7/1999
12/6/1999
7/28/2003
7/16/2003
12/6/1999
12/6/1999
12/6/1999
12/6/1999
7/16/2003
12/2/1999
12/2/1999
12/2/1999
12/2/1999
10/18/2000
12/2/1999
12/2/1999
12/2/1999
12/9/1999
12/9/1999
7/23/2003
7/23/2003
2/27/2009
2/27/2009
2/27/2009
3/4/2009
3/4/2009
3/16/2009
3/10/2009
3/10/2009
3/10/2009
3/17/2009
3/16/2009
3/9/2009
3/5/2009
3/5/2009
3/10/2009
3/16/2009
3/17/2009
3/6/2009
4/25/2002
3/6/2009
3/12/2009
3/12/2009
3/6/2009
4/12/2000
4/12/2000
3/6/2009
3/12/2009
3/6/2009
3/6/2009
4/25/2002
3/10/2009
3/12/2009
3/9/2009
6/9/2005
3/9/2009
3/9/2009
3/6/2009
3/9/2009
3/10/2009
3/10/2009
3/12/2009
3/13/2009
3/16/2009
3/9/2009
3/17/2009
3/13/2009
3/13/2009
3/4/2009
3/4/2009
4/24/2002
3/6/2009
3/13/2009
6/9/2005
3/9/2009
10
11
11
11
11
11
3
3
3
12
10
6
14
13
9
11
11
14
7
16
14
15
4
2
2
11
8
16
9
7
8
11
15
10
12
6
6
8
15
16
8
6
7
13
13
13
9
10
8
7
7
7
4
6
ARSENIC
ARSENIC
ARSENIC
LEAD
ARSENIC
ARSENIC
ARSENIC
None
None
ARSENIC
ARSENIC
LEAD
ARSENIC
ARSENIC
ARSENIC
ARSENIC
LEAD
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
LEAD
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
METHYLENE
CHLORIDE
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
CHLOROFORM
1 ,4-DIOXANE
LEAD
LEAD
LEAD
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
None
CHLOROFORM
Below
Below
Above
Below
Below
Below
Below
Below
Below
Above
Above
Below
Above
Above
Above
Below
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Below
Above
Above
Above
Below
Above
Above
Above
Above
Above
Above
Below
Above
Above
Above
Above
Above
Above
Above
Above
Above
Below
Below
See notes end of table
22
-------
Issued: 11-SEPT-2009
Page 2 of 2
TABLE 1
GILSON ROAD MONITORING WELL NETWORK
Long-Term Monitoring Optimization
Gilson Road Superfund Site, Nashua, New Hampshire
Well Name
Interior or
Exterior of
Slurry Wall
Screened
Interval
(FT below
TOC)
Total Depth
(FT below
TOC)
Minimum
Sample Date
Maximum
Sample Date
Number of
Samples
1999 - 2009
Priority Constituent
Above or Below
AGQS
Bedrock Locations
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T-33-4
T-38-2
T-42-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
Exterior
Exterior
Exterior
Exterior
Interior
Interior
Interior
Interior
Interior
Interior
Interior
Exterior
Interior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Exterior
Interior
Exterior
49.3
77.2
44
26.5
70
66.7
64
60
95.2
62.6
79.75
89
81
47.9
40.33
38.4
97
60
45.5
97.5
60.9
29
7/25/2003
12/3/1999
12/3/1999
12/1/2000
12/9/1999
12/10/1999
12/10/1999
12/8/1999
12/8/1999
12/8/1999
12/7/1999
12/6/1999
12/7/1999
12/7/1999
7/28/2003
7/16/2003
12/6/1999
7/16/2003
10/18/2000
12/2/1999
12/9/1999
7/23/2003
3/16/2009
3/5/2009
3/10/2009
3/17/2009
3/12/2009
3/12/2009
3/12/2009
3/13/2009
3/13/2009
4/25/2002
3/13/2009
3/12/2009
7/18/2006
3/17/2009
6/9/2005
3/13/2009
5/5/2004
3/13/2009
3/13/2009
3/17/2009
3/13/2009
3/9/2009
6
18
14
11
17
9
13
8
8
7
9
13
13
9
4
6
10
6
9
10
16
6
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
LEAD
ARSENIC
ARSENIC
ARSENIC
LEAD
ARSENIC
ARSENIC
LEAD
ARSENIC
ARSENIC
ARSENIC
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Above
Below
Above
Above
Above
Above
Above
Above
Below
Wotes:
1. Well screened intervals, locations and sample history from the Weston database, 2009.
2. AGQS = Ambient Groundwater Quality Standard for New Hampshire (see Table 2).
3. Priority constituent determined by normalizing historic maximum concentrations by the AGQS.
The constituent with the highest concentration to screening level ratio is the priority COG for the well.
4. Above = Locations with maximum concentrations of any constituent over the AGQS data 1999 - 2009.
23
-------
O)
8
CL
LU
co ^
^ 'S
w
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LU
O
O
o
LU
O
LU
o:
LU
O
Z
LU
LU
CC
O
CO
CO
CO
o
o
a:
o
a:
a.
(0
7 a.
21
X S
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rv Q-
6 T?
b
Q.
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OLD LO LO O ^ LO 5 LO g LO CM
CM T- ^ LO 0
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cu
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cu
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T3
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03
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cu
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0
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CO
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-t-Ť
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CM
SI
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03
^
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Ll-
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c
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LO
24
-------
Issued 11-SEPT-2009
Page 1 of 1
TABLE 3
AQUIFER INPUT PARAMETERS
LONG-TERM MONITORING OPTIMIZATION
Gilson Road Superfund Site
Parameter
Porosity(n)
Seepage velocity
Plume Thickness
Plume Length
Plume Width
Distance to Receptors (Lyle Reed
Brook)
GWFIuctuations
SourceTreatment
Contaminant Type
NAPLPresent
Groundwater flow direction (N/NW)
Source Location near Well
Source X-Coordinate
Source Y-Coordinate
Coordinate System
Non-detect values
Value
0.3
365
20
1500
650
1500
Yes
Cap and slurry wall/historic pump
and treat
Chlorinated solvents/metals
No
N/NW
T-33-1
1023045
79861.84
NAD 83 SP New Hampshire
Set to lowest detection limit
Units
ft/yr
ft
ft
ft
ft
135
ft
ft
Notes:
1. Aquifer data from Weston, 1989 and Haley and Aldrich, 1994.
2. Data above were used for both overburden and bedrock aquifers.
25
-------
Issued: 11-SEPT-2009
Page 1 of 3
TABLE 4
TREND SUMMARY RESULTS OVERBURDEN AQUIFER
LONG-TERM MONITORING OPTIMIZATION
Gilson Road Superfund Site, Nashua, New Hampshire
WellName
Number of
Samples
Number of
Detects
Percent
Detection
Maximum
Result 1999-
2009
[ug/L]
Max Result
Above
Standard?
Average
Result 1999-
2009
[ug/L]
Average
Result Above
Standard?
Mann-
Kendall
Trend
Linear
Regression
Trend
ARSENIC
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-18-1
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
9
9
9
9
9
9
1
1
1
10
1
1
11
10
8
1
9
10
6
11
11
11
1
8
7
11
7
6
1
9
10
8
10
1
1
7
11
11
7
1
6
11
11
11
7
8
7
6
6
6
1
7
1
9
8
1
5
1
0
0
6
1
0
11
10
8
1
3
10
6
11
11
11
1
8
7
11
7
6
1
4
10
3
10
1
1
7
11
11
7
1
0
8
11
10
3
8
7
6
6
6
0
78%
11%
100%
89%
11%
56%
100%
0%
0%
60%
100%
0%
100%
100%
100%
100%
33%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
44%
100%
38%
100%
100%
100%
100%
100%
100%
100%
100%
0%
73%
100%
91%
43%
100%
100%
100%
100%
100%
0%
2.2
1.1
50.3
3.8
1.4
7.1
6.4
ND
ND
10.9
14
ND
796
580
198
2.2
18.3
496
889
399
633
1400
395
114
4.2
605.0
759.0
805.0
136.0
3.6
705
1.5
2120
1.2
28.9
627
693
703
685
18.1
ND
3.5
30.4
9.7
1.9
1870
1050
843
455
401
ND
No
No
Yes
No
No
No
No
ND
ND
Yes
Yes
ND
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
No
Yes
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
ND
No
Yes
No
No
Yes
Yes
Yes
Yes
Yes
ND
1.38
1.01
38.70
2.58
1.04
2.21
6.40
ND
ND
3.19
14
ND
675
542
66
2.15
4.29
378
786
218
572
965
395
52.7
2.66
524
604
682
136
1.66
149
1.11
347
1.20
29
342
550
517
566
18
ND
1.79
11
2.09
1.23
963
852
679
368
251
ND
No
No
Yes
No
No
No
No
ND
ND
No
Yes
ND
Yes
Yes
Yes
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
No
Yes
No
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
ND
No
Yes
No
No
Yes
Yes
Yes
Yes
Yes
ND
S
S
NT
S
S
D
N/A
N/A
N/A
S
N/A
N/A
D
D
NT
N/A
NT
D
NT
D
S
D
N/A
D
NT
D
S
NT
N/A
D
D
S
D
N/A
N/A
S
D
PD
PD
N/A
ND
D
D
D
S
D
S
D
S
S
N/A
S
D
NT
S
S
D
N/A
N/A
N/A
NT
N/A
N/A
D
D
NT
N/A
NT
D
NT
D
S
D
N/A
D
PI
D
S
PI
N/A
D
D
S
D
N/A
N/A
D
D
D
D
N/A
ND
D
S
NT
PD
D
S
D
S
S
N/A
See notes end of table
26
-------
Issued: 11-SEPT-2009
Page 2 of 3
TABLE 4
TREND SUMMARY RESULTS OVERBURDEN AQUIFER
LONG-TERM MONITORING OPTIMIZATION
Gilson Road Superfund Site, Nashua, New Hampshire
WellName
Number of
Samples
Number of
Detects
Percent
Detection
Maximum
Result 1999-
2009
[ug/L]
Max Result
Above
Standard?
Average
Result 1999-
2009
[ug/L]
Average
Result Above
Standard?
Mann-
Kendall
Trend
Linear
Regression
Trend
Benzene
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
7
7
7
7
7
7
1
1
1
9
1
1
11
11
4
1
9
11
6
11
11
11
4
6
11
7
6
1
9
11
4
9
1
1
5
11
11
7
1
5
9
9
9
7
8
7
5
7
7
1
0
0
0
0
0
0
0
0
0
0
0
0
11
11
0
0
0
9
6
4
11
11
0
2
11
7
6
1
0
6
1
1
0
0
0
10
11
7
0
0
2
1
2
0
7
7
1
6
7
0
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
100%
100%
0%
0%
0%
82%
100%
36%
100%
100%
0%
33%
100%
100%
100%
100%
0%
55%
25%
11%
0%
0%
0%
91%
100%
100%
0%
0%
22%
11%
22%
0%
88%
100%
20%
86%
100%
0%
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
11
7.3
ND
ND
ND
6.1
9.8
5.2
30
36
ND
7.4
26
51.0
23.0
5.7
ND
8.2
2.2
27
ND
ND
ND
7.8
8.9
8.4
ND
ND
2.2
2.2
2.9
ND
8.7
13
4.4
42
55
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Yes
Yes
ND
ND
ND
Yes
Yes
Yes
Yes
Yes
ND
Yes
Yes
Yes
Yes
Yes
ND
Yes
No
Yes
ND
ND
ND
Yes
Yes
Yes
ND
ND
No
No
No
ND
Yes
Yes
No
Yes
Yes
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
7
5
ND
ND
ND
3.42
6
3
15
21
ND
3.17
18.80
28
13
5.7
ND
3.49
2
4.78
ND
ND
ND
5
6
6
ND
ND
2.03
2.02
2
ND
4.76
6
2
25
28.1
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Yes
Yes
ND
ND
ND
No
Yes
No
Yes
Yes
ND
No
Yes
Yes
Yes
Yes
ND
No
No
No
ND
ND
ND
Yes
Yes
Yes
ND
ND
No
No
No
ND
No
Yes
No
Yes
Yes
ND
ND
ND
ND
ND
ND
ND
N/A
N/A
N/A
ND
N/A
N/A
D
S
ND
N/A
ND
S
PD
PD
D
D
ND
PD
S
S
S
N/A
ND
D
NT
NT
N/A
N/A
ND
S
S
NT
N/A
ND
S
S
S
ND
PD
NT
S
S
S
N/A
ND
ND
ND
ND
ND
ND
N/A
N/A
N/A
ND
N/A
N/A
D
D
ND
N/A
ND
S
D
D
D
D
ND
D
S
D
D
N/A
ND
D
NT
NT
N/A
N/A
ND
D
D
D
N/A
ND
S
D
S
ND
PD
S
PD
NT
S
N/A
See notes end of table
27
-------
Issued: 11-SEPT-2009
Page 3 of 3
TABLE 4
TREND SUMMARY RESULTS OVERBURDEN AQUIFER
LONG-TERM MONITORING OPTIMIZATION
Gilson Road Superfund Site, Nashua, New Hampshire
WellName
Number of
Samples
Number of
Detects
Percent
Detection
Maximum
Result 1999-
2009
[ug/L]
Max Result
Above
Standard?
Average
Result 1999-
2009
[ug/L]
Average
Result Above
Standard?
Mann-
Kendall
Trend
Linear
Regression
Trend
Chlorobenzene
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
7
7
7
7
7
7
1
1
1
9
1
1
11
11
4
1
9
11
6
11
11
11
5
6
11
7
6
1
9
11
4
9
1
1
5
11
11
7
1
5
11
11
11
7
8
7
6
7
7
1
0
0
0
0
0
0
0
0
0
0
0
0
11
11
2
0
0
11
6
11
11
11
5
6
11
7
6
1
0
11
0
0
0
0
3
11
11
7
0
0
11
11
11
0
8
7
6
7
7
0
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
0%
100%
100%
50%
0%
0%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
0%
100%
0%
0%
0%
0%
60%
100%
100%
100%
0%
0%
100%
100%
100%
0%
100%
100%
100%
100%
100%
0%
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
160
130
7
ND
ND
118
90
87
123
150
28
36
470
168.0
16.0
23.0
ND
26
ND
ND
ND
ND
20
110
142
110
ND
ND
54
59
60
ND
120
110
25
88
32
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Yes
Yes
No
ND
ND
Yes
No
No
Yes
Yes
No
No
Yes
Yes
No
No
ND
No
ND
ND
ND
ND
No
Yes
Yes
Yes
ND
ND
No
No
No
ND
Yes
Yes
No
No
No
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
130
104
4
ND
ND
72.8
77
49
68
67
14.6
13.1
219.00
75
10
23
ND
12.60
ND
ND
ND
ND
8
70
79
84
ND
ND
36.40
30.40
34
ND
82.10
72
16
26
21.4
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Yes
Yes
No
ND
ND
No
No
No
No
No
No
No
Yes
No
No
No
ND
No
ND
ND
ND
ND
No
No
No
No
ND
ND
No
No
No
ND
No
No
No
No
No
ND
ND
ND
ND
ND
ND
ND
N/A
N/A
N/A
ND
N/A
N/A
D
S
S
N/A
ND
D
NT
NT
NT
I
S
I
PD
S
S
N/A
ND
D
ND
ND
N/A
N/A
NT
S
S
NT
N/A
ND
S
S
S
ND
S
I
D
NT
PD
N/A
ND
ND
ND
ND
ND
ND
N/A
N/A
N/A
ND
N/A
N/A
S
S
S
N/A
ND
S
PI
I
NT
I
S
I
S
NT
S
N/A
ND
D
ND
ND
N/A
N/A
S
D
PD
S
N/A
ND
S
S
S
ND
S
NT
D
NT
NT
N/A
Notes
1. Trends were evaluated for data collected between 1999 and 2009.
2. Number of Samples is the number of samples for the compound at this location 1999-2009.
Number of Detects is the number of times the compound has been detected for data 1999 -2009.
3. Maximum Result is the maximum concentration for the COG analyzed between 1999 and 2009.
4. Screening level Arsenic = 10 ug/L; Benzene = 5 ug/L; Chlorobenzene = 100 ug/L.
5. D = Decreasing; PD = Probably Decreasing; S = Stable; PI = Probably Increasing; I = Increasing; N/A = Insufficient Data to determine trend;
NT = No Trend; ND = well has all non-detect results for COG; INT = Intermittent detections <30% detection frequency.
6. Mann-Kendall trend results for arsenic are illustrated on Figure 3.
28
-------
Issued: 11-SEPT-2009
Page 1 of 2
TABLE 5
TREND SUMMARY RESULTS BEDROCK AQUIFER
LONG-TERM MONITORING OPTIMIZATION
Gilson Road Superfund Site, Nashua, New Hampshire
WellName
Number of
Samples
Number of
Detects
Percent
Detection
Maximum
Result 1999-
2009
[ug/L]
Max Result
Above
Standard?
Average
Result 1999-
2009
[ug/L]
Average
Result Above
Standard?
Mann-Kendall
Trend
Linear
Regression
Trend
ARSENIC
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
1
11
11
9
11
7
11
7
7
6
6
10
9
1
1
8
1
7
8
10
1
1
11
11
9
11
7
11
7
7
6
6
10
9
1
1
8
1
3
8
10
1
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
100%
43%
100%
100%
100%
559
853
656
18.1
1030
1730
183
947
96.6
1150
429
14.9
20.2
10.6
1
1170
419
160
929
781
2.1
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
No
559
718
534
8.33
850
1470
158
834
84
888
347
8.31
16
11
1
854
419
39.2
574
688
2
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
No
N/A
D
D
D
D
S
S
PD
D
S
S
PD
I
N/A
N/A
D
N/A
NT
D
S
N/A
N/A
D
D
D
D
D
D
D
D
S
D
S
I
N/A
N/A
D
N/A
NT
D
S
N/A
Benzene
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
1
11
11
9
11
7
7
6
7
6
7
11
9
1
1
8
1
7
8
11
1
0
11
4
0
11
7
0
6
6
6
7
5
1
0
0
8
1
0
4
11
0
0%
100%
36%
0%
100%
100%
0%
100%
86%
100%
100%
45%
11%
0%
0%
100%
100%
0%
50%
100%
0%
ND
11
2.5
ND
22
37
ND
30
41
16
12
4.4
5.3
ND
ND
10
24
ND
6.5
25
ND
ND
Yes
No
ND
Yes
Yes
ND
Yes
Yes
Yes
Yes
No
Yes
ND
ND
Yes
Yes
ND
Yes
Yes
ND
ND
7.14
2.08
ND
9.53
27.70
ND
13.70
18.40
9.93
9
2.61
2
ND
ND
6.55
24
ND
4
12
ND
ND
Yes
No
ND
Yes
Yes
ND
Yes
Yes
Yes
Yes
No
No
ND
ND
Yes
Yes
ND
No
Yes
ND
ND
D
S
ND
D
D
ND
S
D
D
S
PD
S
ND
ND
PD
N/A
ND
S
D
ND
ND
D
S
ND
D
D
ND
S
D
D
S
PD
PD
ND
ND
S
N/A
ND
S
PD
ND
See notes end of table
29
-------
Issued: 11-SEPT-2009
Page 2 of 2
TABLE 5
TREND SUMMARY RESULTS BEDROCK AQUIFER
LONG-TERM MONITORING OPTIMIZATION
Gilson Road Superfund Site, Nashua, New Hampshire
WellName
Number of
Samples
Number of
Detects
Percent
Detection
Maximum
Result 1999-
2009
[ug/L]
Max Result
Above
Standard?
Average
Result 1999-
2009
[ug/L]
Average
Result Above
Standard?
Mann-Kendall
Trend
Linear
Regression
Trend
Chlorobenzene
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
1
11
11
9
11
6
7
6
5
6
6
9
8
1
1
8
1
7
8
11
1
0
11
11
0
11
6
1
6
1
6
6
0
0
0
0
8
1
0
8
11
0
0%
100%
100%
0%
100%
100%
14%
100%
20%
100%
100%
0%
0%
0%
0%
100%
100%
0%
100%
100%
0%
ND
140
49
ND
135
89
11
18
11
13
11
ND
ND
ND
ND
110
15
ND
63
34
ND
ND
Yes
No
ND
Yes
No
No
No
No
No
No
ND
ND
ND
ND
Yes
No
ND
No
No
ND
ND
119
29.1
ND
92.2
52.5
3.29
15.7
3.8
8.72
8
ND
ND
ND
ND
92.5
15
ND
49
17
ND
ND
Yes
No
ND
No
No
No
No
No
No
No
ND
ND
ND
ND
No
No
ND
No
No
ND
ND
PD
D
ND
PD
S
NT
S
NT
NT
S
ND
ND
ND
ND
NT
N/A
ND
NT
D
ND
ND
D
D
ND
PD
I
NT
S
NT
NT
PD
ND
ND
ND
ND
D
N/A
ND
I
PD
ND
Lead
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
1
10
10
9
11
7
10
7
7
6
6
10
9
1
1
8
1
8
8
10
1
0
1
0
1
2
6
4
5
6
5
5
10
7
1
1
5
1
8
5
5
0
0%
10%
0%
11%
18%
86%
40%
71%
86%
83%
83%
100%
78%
100%
100%
63%
100%
100%
63%
50%
0%
ND
1.7
ND
2
2.2
13.3
4.8
23.6
45.4
241
5.6
83.3
6.2
3.1
29.2
106
4.1
890
47.7
7.8
ND
ND
No
ND
No
No
No
No
Yes
Yes
Yes
No
Yes
No
No
Yes
Yes
No
Yes
Yes
No
ND
ND
1.07
ND
1.11
1.21
7.15
1.67
13.10
22.90
119
3
21.20
3
3
29
35.20
4.10
191
22
3
ND
ND
No
ND
No
No
No
No
No
Yes
Yes
No
Yes
No
No
Yes
Yes
No
Yes
Yes
No
ND
ND
S
ND
S
S
S
S
S
S
NT
NT
D
D
N/A
N/A
NT
N/A
NT
S
PD
ND
ND
S
ND
S
PD
S
S
S
S
S
S
D
D
N/A
N/A
D
N/A
NT
NT
S
ND
Notes
1. Trends were evaluated for data collected between 1999 and 2009.
2. Number of Samples is the number of samples for the compound at this location 1999 -2009.
Number of Detects is the number of times the compound has been detected for data 1999 -2009.
3. Maximum Result is the maximum concentration for the COG analyzed between 1999 and 2009.
4. Screening level Arsenic = 10 ug/L; Benzene = 5 ug/L; Chlorobenzene = 100 ug/L.
5. D = Decreasing; PD = Probably Decreasing; S = Stable; PI = Probably Increasing; I = Increasing; N/A = Insufficient Data to determine trend;
NT= No Trend; ND = well has all non-detect results for COG; INT = Intermittent detections <30% detection frequency.
6. Mann-Kendall trend results are illustrated on Figures 3 and 4.
7. Well locations are shown on Figure 7.
30
-------
Issued 11-SEPT-2009
Page 1 of 5
TABLE 6
FINAL RECOMMENDED MONITORING NETWORK
LONG-TERM MONITORING OPTIMIZATION
Gllson Road Superfund Site
Well Name
OVERBURDEN
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
Mann Kendall Trends
Arsenic
S
S
NT
S
S
D
N/A
N/A
N/A
S
N/A
N/A
D
D
NT
N/A
Average SF
Arsenic
N/A
N/A
0.17
N/A
N/A
0.50
0.00
N/A
N/A
0.42
0.53
0.64
0.06
N/A
0.10
0.08
Lines of Evidence
Monitoring Rationale
Monitors overburden west of Lyle Reed
Brook in neighborhood on the edge of the
GMZ. POC locations for area fartherst
west downgradient of Gilson Road Site.
HA-10C exceeds standards for arsenic,
but no other COCs are detected.
Monitors overburden northwest of Lyle
Reed Brook in neighborhood on the edge
of the G MZ. POC locations for area
fratherst northwest downgradient of
Gilson Road Site. HA-1 1C has detected
concentrations for arsenic and lead, but
does not exceed standards.
Monitors overburden near discharge of
Lyle Reed Brook to Nashua River - no
exceedances of site COCS
Monitors overburden east of site in
adjacent neighborhood. Detected
concentrations of lead and arsenic.
Functions as POC well and alternate
point of exposure for potential receptor in
the residential area.
Co-located with well T-58. Limited
sample data, arsenic detected.
Monitors overburden just southwest of
slurry wall. Limited recent sampling data
show no detections. Functions as POC
location to monitor GMZ and confirm
containment of plume within slurry wall.
Redundant with T-54-2
Monitors area just outside of slurry wall
on the northwest side. Near high
concentration areas within slurry wall.
Monitors passage of constituents through
slurry wall. Functions as a POC for the
GMZ and sentry well for possible
discharge to Lyle Reed Brook.
Monitors area just outside of slurry wall
on northern end of containment area.
Only monitored for metals. Like HA-5A/C,
functions as sentry well between slurry
wall and Lyle Reed Brook.
Monitors neighborhood downgradient
from Four Hills Landfill. Significant for
regional groundwater quality, does not
directly monitor Gilson Road Site.
MAROS Recommendation
Recommended for inclusion in
network.
Recommended for inclusion in
network.
arsenic and benzene network by
software. Redundant with
upgradient locations T-60-1, and T-
62-1/2/3.
Redommended for inclusion in the
network
Recommended for removal for lead
and inclusion for arsenic.
Recommended for inclusion in
network.
Recommended by software for
removal for arsenic, chlorobenzene
and lead network. Near wells T-1 2-
1/3 inslude slurry wall.
Recommended by software for
removal for arsenic and lead.
Adjacent to T-1 8-1 and T-19-1/3
inside of slurry wall.
Software recommends retention as
outer hull well.
Final
Recommended
Frequency
Biennial
Biennial
Biennial
Biennial
Biennial
Biennial
Eliminate
Eliminate
Eliminate
Biennial
Biennial
Annual
Annual
Annual
Annual
Biennial
See notes end of table
31
-------
Issued 11-SEPT-2009
Page 2 of 5
TABLE 6
FINAL RECOMMENDED MONITORING NETWORK
LONG-TERM MONITORING OPTIMIZATION
Gllson Road Superfund Site
Well Name
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-18-1
T-18-2
T-18-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
Lines of Evidence
Mann Kendall Trends
Arsenic
NT
D
NT
D
S
D
N/A
N/A
N/A
D
NT
D
S
NT
N/A
D
Average SF
Arsenic
0.18
0.06
N/A
N/A
N/A
0.14
0.26
N/A
N/A
0.56
N/A
0.13
0.08
N/A
0.30
0.61
Monitoring Rationale
Monitors area downgradient from Lyle
Reed Brook; a non-detect location for
VOC. Adjacent to T-62-2.
Monitors overburden inside slurry wall on
northwest. Functions as source
monitoring location. Exceedances for
arsenic and benzene. T-12-3 not
sampled in the recent time frame.
Monitors overburden inside slurry wall in
center. Located near center of mass of
the plumes. Monitors high concentration
source area. Exceeds standards for
arsenic, 1,4-dioxane, benzene, lead and
vinly chloride.
Monitors interior of slurry wall on northern
side, only monitored for lead and arsenic.
Exceeds for arsenic concentrations.
Limited recent sample results.
No recent data.
No recent data.
Monitors interior of slurry wall on northern
side, only monitored for lead and arsenic.
Exceeds for arsenic concentrations.
Low level detections for organic
compounds, lower concentrations for
metals than 19-1.
Monitors center of area contained within
slurry wall in closed landfill cell.
Monitors center of area contained within
slurry wall southeast of closed landfill
cell. Exceedances for arsenic, vinyl
chloride, lead, chlorobenzene and
benzene. Monitors residual source of
COCs
Monitors upgradient area of containment
area. Only one sample is available
between 1999 and 2009. Concentrations
exceed for benzene and arsenic.
Monitors area upgradient from slurry wall
to the south. Largely non-detect for site
COCs, background concentrations for
lead and arsenic. Does not characterize
affected groundwater.
MAROS Recommendation
Recommended by software for
removal for arsenic .
Recommended by software for
removal for arsenic, chlorobenzene
and lead network. Adjacent to HA-
5A/C, but separated by slurry wall.
No recent data for location.
Presumed removed from network.
Recommended by software for
removal for arsenic, chlorobenzene
and lead.
Recommended for removal for lead
and inclusion for arsenic.
No recent data for location.
Presumed removed from network.
No recent data for location.
Presumed removed from network.
Recommended for removal for lead
and inclusion for arsenic.
Recommended by software for
removal for arsenic and lead.
Recommended by software for
removal for arsenic, chlorobenzene
and lead. Not sampled between
2002 and 2009.
Not sampled since 2002; presumed
removed from network.
Recommended by software for
inclusion in the network.
Recommended by software for
inclusion in the network.
Final
Recommended
Frequency
Eliminate
Annual
Eliminate
Annual
Annual
Annual
Eliminate
Eliminate
Eliminate
Annual
Eliminate
Annual
Eliminate
Eliminate
Annual
Biennial
See notes end of table
32
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Issued 11-SEPT-2009
Page 3 of 5
TABLE 6
FINAL RECOMMENDED MONITORING NETWORK
LONG-TERM MONITORING OPTIMIZATION
Gllson Road Superfund Site
Well Name
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-64-2
T-64-3
T-8-1
T-8-2
T-97
T-98
Lines of Evidence
Mann Kendall Trends
Arsenic
D
S
D
N/A
N/A
S
D
PD
PD
N/A
ND
D
D
D
S
S
D
S
S
N/A
N/A
Average SF
Arsenic
0.34
N/A
0.19
0.61
0.01
0.20
0.11
N/A
N/A
0.23
0.53
N/A
0.32
0.36
0.47
0.13
N/A
0.34
N/A
N/A
0.38
Monitoring Rationale
Monitors most upgradient location within
slurry wall. Historic exceedances for
arsenic, benzene, PCE, TCE, 1,4-
dioxane, and vinyl chloride.
Monitors upgradient area of contaminant
area. Area of highest arsenic
concentration in plume, other COCs not
detected. Monitors historic source of
arsenic.
Monitors area just outside of the slurry
wall to the northeast. Limited recent
sampling, concentrations below detection
and below screening levels. Delineates
GMZtoeast.
Monitors area within slurry wall
downgradient to the northeast. Limited
recent samples, exceeds only for arsenic.
Monitors area outside of slurry wall to the
north at very shallow depth. Some
redundancy with T-48 wells.
Monitors area outside of slurry wall to the
north, monitors deeper locations in
overburden. Immediately upgradient of
Lyle Reed Brook. Arsenic concentrations
increase with depth.
Redundant with T-48-2 and T-48-3
Monitors area outside of slurry wall to
west. Limited recent samples. Functions
as POC well to monitor edge of GMZ.
Redundant with HA-4B.
Monitors area outside of slurry wall to
north, co-located with and redundant with
HA-1 4. Non-detect for site COCs.
Monitors downgradient of site along Lyle
Reed Brook in residential area. POC
Exceeds for arsenic. May be impacted by
Four Hills Landfill.
Monitors downgradient of site adjacent to
T-60 nest. Redundant with T-60.
Monitors downgradient area west of Lyle
Reed Brook. POC location that monitors
edge of GMZ. Exceedances for lead.
Monitors area north of Lyle Reed Brook,
near T-63-1 . Exceedances for arsenic,
benzene, chlorobenzene and vinyl
chloride. Functions as a sentry well for
spread of plume downgradient.
Increasing trend for chlorobenzene.
Monitors area msiae or siurry wan near
western portin of slurry wall.
Exceedances for arsenic, benzene, lead
and vinvl chloride
Monitors area far downgradient near
Nashua River. Functions as POC
location.
Monitors area far downgradient near
Nashua River. Functions as POC
location.
MAROS Recommendation
Recommended for by software for
inclusion in the network.
Largely non-detect values,
redundant with T-33-1.
Recommended by software for
removal for arsenic and lead.
Recommended by software for
inclusion in the network.
Recommended by software for
removal for arsenic.
Recommended by software for
removal for arsenic and lead.
Recommended by software for
removal for arsenic, chlorobenzene
and lead.
No samples between 2002 and
2009.
Recommended by software for
removal for arsenic.
Recommended by software for
removal for chlorobenzene and lead.
Recommended for removal for lead
and benzene.
Recommended by software for
removal for benzene, chlorobenzene
and lead.
Recommended by software for
inclusion in the network.
Recommended by software for
retention in the network.
Recommended by software for
inclusion in the network.
No data for this location
Recommended by software for
inclusion in the network.
Final
Recommended
Frequency
Annual
Eliminate
Eliminate
Biennial
Eliminate
Eliminate
Annual
Annual
Eliminate
Eliminate
Eliminate
Annual
Annual
Eliminate
Biennial
Annual
Annual
Annual
Annual
Eliminate
Biennial
See notes end of table
33
-------
Issued 11-SEPT-2009
Page 4 of 5
TABLE 6
FINAL RECOMMENDED MONITORING NETWORK
LONG-TERM MONITORING OPTIMIZATION
Gllson Road Superfund Site
Well Name
Lines of Evidence
Mann Kendall Trends
Arsenic
Average SF
Arsenic
Monitoring Rationale
MAROS Recommendation
Final
Recommended
Frequency
Bedrock
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
N/A
D
D
D
D
S
S
PD
D
S
S
0.08
0.03
0.15
0.19
0.03
0.17
0.05
0.26
0.26
0.14
N/A
Monitors overburden just southwest of
slurry wall. Limited recent sampling data
show arsenic exceedances. Functions as
POC location to monitor GMZ and
confirm containment of plume within
slurry wall. Redundant with T-54-3
Monitors area just outside of slurry wall
on the northwest side. Near high
concentration areas within slurry wall.
Monitors passage of constituents through
slurry wall. Functions as a POC for GMZ
and a sentry well for possible discharge
to Lyle Reed Brook. Part of nested
location.
Monitors area just outside of slurry wall
on northern end of containment area.
Only monitored for metals. Like HA-5,
functions as sentry well between slurry
wall and Lyle Reed Brook.
Monitors area downgradient from Lyle
Reed Brook; a non-detect location for
VOC. Adjacent to T-62.
Monitors overburden inside slurry wall on
northwest. Functions as source
monitoring location. Exceedances for
arsenic, 1,4-dioxane and benzene. Near
exterior well HA-5B.
Monitors overburden inside slurry wall in
center. Located near center of mass of
the plumes. Monitors high concentration
source area. Exceeds standards for
arsenic, and benzene.
Monitors interior of slurry wall on northern
side, only monitored for lead and arsenic.
Exceeds for arsenic concentrations.
Monitors center of area contained within
Monitors center of area contained within
slurry wall southeast of closed landfill
cell. Exceedances for arsenic, vinyl
chloride, lead, chlorobenzene and
benzene. Monitors residual source of
COCs
Monitors center of area enclosed by
slurry wall. Not sampled between 2001
and 2009. Exceeds for arsenic
concentrations.
Recommended by software for
inclusion in the network.
Recommended by software for
removal for arsenic, benzene,
chlorobenzene and lead.
Recommended by software for
removal for arsenic and lead.
Recommended by software for
removal for arsenic, benzene,
chlorobenzene and chloroform.
Recommended by software for
removal for arsenic, benzene,
chlorobenzene and lead.
Recommended by software for
removal for arsenic and lead.
Recommended by software for
removal for arsenic and lead
Recommended by software for
removal for lead and inclusion in the
network for arsenic.
Recommended by software for
removal for arsenic and lead
Not sampled since 2001 ; presumed
removed from network.
Insufficient data for spatial analysis.
Annual
Annual
Annual
Eliminate
Annual
Annual
Eliminate
Annual
Annual
Eliminate
Eliminate
See notes end of table
34
-------
Issued 11-SEPT-2009
Page 5 of 5
TABLE 6
FINAL RECOMMENDED MONITORING NETWORK
LONG-TERM MONITORING OPTIMIZATION
Gllson Road Superfund Site
Well Name
T-32-4
T-33-4
T-38-2
T-42-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
Lines of Evidence
Mann Kendall Trends
Arsenic
PD
I
N/A
N/A
N/A
D
N/A
NT
D
S
N/A
Average SF
Arsenic
0.28
0.36
0.15
N/A
0.69
N/A
0.04
0.32
0.02
0.13
0.44
Monitoring Rationale
Monitors area upgradient from slurry wall
to the south. Largely non-detect for site
COCs, background concentrations for
lead and arsenic. Does not characterize
affected groundwater.
Monitors most upgradient location within
slurry wall. Monitors depth below major
contamination, some exceedances for
arsenic.
Monitors area upgradient from slurry wall
to the southeast. Limited sample results.
Outside of plume, but exceeds for
arsenic.
Monitors area just outside of the slurry
wall to the northeast. Limited recent
sampling, concentrations below detection
and below screening levels. Delineates
GMZtoeast.
Limited recent sample results
Monitors area outside of slurry wall to the
north, immediately upgradient of Lyle
Reed Brook. Exceedances for arsenic,
and benzene. The overburden shows
increasing trends for chlorobenzene in the
area.
Monitors area outside of slurry wall to
west. Limited recent samples. Functions
as POC well to monitor edge of GMZ.
Evidence of benzene above screening
levels. Redundant with HA-4B.
Monitors downgradient area west of Lyle
Reed Brook. Exceedances for arsenic
and lead. Sentry point for spread of
metals.
Monitors area north of Lyle Reed Brook,
near T-63-1 . Functions as a sentry well
for spread of chlorobenzene and
benzene.
Monitors area inside of slurry wall near
western portin of slurry wall. Exceeds for
arsenic and benzene.
Monitors area far downgradient near
Nashua River. Functions as POC
location.
MAROS Recommendation
Recommended by software for
inclusion in the network.
Recommended by software for
inclusion in the network.
Recommended by software for
inclusion in the network.
Limited sample results. Insufficient
data for spatial analysis.
Recommended by software for
inclusion in the network.
Not sampled since 2004, insufficient
data for spatial analysis.
Recommended by software for
inclusion in the network.
Recommended by software for
inclusion in the network for arsenic
and lead.
Recommended by software for
removal for arsenic.
Recommended by software for
removal for arsenic, lead, and
benzene.
Recommended by software for
inclusion in the network.
Final
Recommended
Frequency
Biennial
Annual
Eliminate
Biennial
Eliminate
Annual
Annual
Annual
Annual
Annual
Biennial
Wotes:
1. Arsenic MK trend results detailed in Tables 4 and 5.
2. SF = Slope Factor. SF <0.3 indicates potentially redundant location.
3. Monitoring Rationale summarizes the results of the qualitative review of the well..
4. MAROS Recommendation is a summary of the well redundancy results.
5. Final Recommended Frequency is based on both qualitative and quantitative results.
35
-------
Groundwater Monitoring Network Optimization
Gilson Road Superfund Site
Nashua, New Hampshire
FIGURES
Figure 1 Gilson Road Site Monitoring Network
Figure 2 Historic Conceptual Model
Figure 3 Overburden Groundwater Arsenic and Benzene Average Concentrations
and Trend Results
Figure 4 Combined Concentration Trends for Source and Tail
Figure 5 Spatial Uncertainty in Overburden Network
Figure 6 Spatial Uncertainty in Final Recommended Overburden Network
Figure 7 Bedrock Groundwater Arsenic and Benzene Average Concentrations and
Trend Results
Figure 8 Final Recommended Monitoring Network
36
-------
Legend
Sampling Locations
^ Groundwater Monitoring Well
H Sediment Sample
<> Surface Water Samples
======= Slurry Wall
Lyle Reed Brook
- Approximate GMZ
5oale (ft)
0 200 400
GILSON ROAD SITE
MONITORING NETWORK
Gilson Road Superfund Site
Nashua, New Hampshire
NAD 83 SP NH
MV
~MV
11-SEPT-2009
Figure 1
-------
E
o
Figure 2: Historic Site Conceptual Model reproduced
from Roy F. Weston, 1989.
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GILSON ROAD SITE
NASHUA, NEW HAMPSHIRE
SCHEMATIC REPRESENTATION
GILSON ROAD SITE
WATER BALANCE
OF
DRAWN
R.E.C.
CHECKED
A,0
DATE
2/89
W.O,
1395-I9-IO
FIGURE 4-25
-------
b
Arsenic Average Concentrations
Benzene Mann-Kenda Trends
Average Concentrations
Arsenic Mann-Kendall Trends
Legend
Ratio of Average
Concentration toAGQS
A 0-0.05 A 10-50
A 0.05-1 A 50-100
A 1-10
Mann-Kendall Trend Results
Non-detect
Decreasing
Probably Decreasing
Stable
No Trend
Insufficient Data
o First Moments 1999 - 2009
======= Slurry Wall
- Lyle Reed Brook
Scale (ft)
^Eą
0 230 460
OVERBURDEN GROUNDWATER
ARSENIC AND BENZENE
AVERAGE CONCENTRATIONS
AND TREND RESULTS
Gilson Road Superfund Site
Nashua, New Hampshire
NAD 83 SP NH
MV
11-SEPT-2009
Figure 3
-------
Monitoring System Category
0>
0
t_
D
o
CO
PI
I
NT
S
PD
D
Tail
PI
- Graph Key: \-
Monitoring System Categories
E: Extensive
M: Moderate
L: Limited
Plume Status
(I) Increasing
(PI) Probably Increasing
(S) Stable
(PD) Probably Decreasing
(D) Decreasing
(NT) NoTrend
COG
ARSENIC
BENZENE
CHLOROBENZENE
LEAD
VINYL CHLORIDE
Tail Stability
D
D
PD
PD
D
Source Stability
S
PD
PD
PD
D
Category Result
L
L
L
L
L
Worst Case:
Figure 4: Combined concentration trends for wells inside (source stability) and outside (tail stability)
the containment wall for overburden aquifer.
-------
NORTH
82500.0 -
82000.0 -
81500.0-
81000.0-
80500.0 -
80000.0 -
79500.0
Figure 5: spatial Uncertainty in Overburden Network including all current well locations.
^ HA-9-A
/ S
/ \
T-61 / >J.
^v ^
2~~~ \x
;o-3^ -^c---. V"
/ \
X ^- \ -A-13-B
\\ >W"\ s /!\
\ \x ^'\ // \
\ ' ::/ -V \ / '" \
N HA-11-cP^^ \\ S1^ \HA/-B/ \M
\ / "-^ SNJ--63-1 V\/ ' \
\ / >e*vx-J^%:-4-t19-1 T-""-I ^
\ / s T-^9Ťf^%^-fi -Jt- N
/ ^-- T-\8/3\ ft S^ ~~ ^^ V
New Location
Analysis for
ARSENIC
Existing
Locations
Potential areas for
new locations are
indicated by triangles
with a high SF level.
Estimated SF Level:
S - Small
M- Moderate
L - Large
E- Extremely large
High SF-> high
estimation error ->
possible need for
new locations
Low SF-> low
estimation error ->
no need for new
locations
Back to
Access
1019500.0
EAST
1020000.0 1020500.0 1021000.0 1021500.0 1022000.0 1022500.0 1023000.0 1023500.0
-------
NORTH
82500.0 -
82000.0 -
81500.0-
81000.0
80500.0 -
80000.0
79500.0
Figures
Spatial Uncertainty in Final Recommended Overburden Network
T-98
*"- -^HA-9-A
\\ ^ / V
HA-14
HA-10-C
1019500.0
1020000.0
1020500.0
1021000.0
1021500.0
1022000.0
1022500.0
1023000.0
EAST
1023500.0
New Location
Analysis for
ARSENIC
Existing
Locations
Potential areas for
new locations are
indicated by triangles
with a high SF level.
Estimated SF Level:
S - Small
M- Moderate
L - Large
E- Extremely large
High SF-> high
estimation error ->
possible need for
new locations
Low SF-> low
estimation error ->
no need for new
locations
Back to
Access
-------
Arsenic Average Concentrations^
Arsenic Mann-Kendall Trends
mi *
O _ ,#'
Benzene Average
Concentrations
Benzene Mann-Kendall Trends
Legend
Ratio of Average
Concentration toAGQS
0-0.05
0.05 - 1
1 -10
10-50
50-150
Mann-Kendall Trend Results
Non-detect
Decreasing
Probably Decreasing
Stable
No Trend
Insufficient Data
===== Slurry Wall
Lyle Reed Brook
o First Moments 1999 - 2009
Scale (ft)
0 200 400
BEDROCK GROUNDWATER
ARSENIC AND BENZENE
AVERAGE CONCENTRATIONS
AND TREND RESULTS
Gilson Road Superfund Site
Nashua, New Hampshire
NAD 83 SP NH
MV
11-SEPT-2009
Figure 7
-------
Legend
Sampling Locations
and Frequencies
O Annual
O Biennial
J Sediment Sample
& Surface Water Samples
===== Slurry Wall
- Lyle Reed Brook
- Approximate GMZ
Scale (ft)
^m
0 200 400
FINAL RECOMMENDED
MONITORING NETWORK
Gilson Road Superfund Site
Nashua, New Hampshire
NAD 83 SP NH
MV
~MV
11-SEPT-2009
Figure 8
-------
APPENDIX A:
MAROS 2.2 METHODOLOGY
1.0 MAROS CONCEPTUAL MODEL A-l
2.0 DATA MANAGEMENT A-2
3.0 SITE DETAILS A-5
4.0 CONSTITUENT SELECTION A-5
5.0 DATA CONSOLIDATION A-5
6.0 OVERVIEW STATISTICS: PLUME TREND ANALYSIS A-6
6.1 Mann-Kendall Analysis A-6
6.2 Linear Regression Analysis A-8
6.3 Moment Analysis A-9
6.4 Overall Plume Analysis A-10
7.0 DETAILED STATISTICS: OPTIMIZATION ANALYSIS A-10
7.1 Well Redundancy Analysis- Delaunay Method A-ll
7.2 Well Sufficiency Analysis - Delaunay Method A-12
7.3 Sampling Frequency - Modified CES Method A-12
7.4 Data Sufficiency - Power Analysis A-13
8.0 CITED REFERENCES
TABLES
Table 1: Data Input for MAROS
Table 2: Mann-Kendall Analysis Decision Matrix
Table 3: Linear Regression Analysis Decision Matrix
A-1
-------
MAROS METHODOLOGY
MAROS is a collection of tools in one software package that is used in an explanatory,
non-linear but linked fashion to review and increase the efficiency of groundwater
monitoring networks. The tool includes models, statistics, heuristic rules, and empirical
relationships to assist the user in optimizing a groundwater monitoring network system.
The final optimized network maintains adequate delineation while providing information
on plume dynamics over time. Results generated from the software tool can be used to
develop lines of evidence, which, in combination with expert opinion, can be used to
inform regulatory decisions for safe and economical long-term monitoring of
groundwater plumes. For a more detailed description of the structure of the software and
further utilities, refer to the MAROS 2.2 Manual (AFCEE, 2003; http://www.gsi-
net.com/en/software/free-software/maros.html) and Aziz et al., 2003.
1.0 MAROS CONCEPTUAL MODEL
In MAROS 2.2, two levels of analysis are used for optimizing long-term monitoring
plans: 1) an overview statistical evaluation based on temporal trend analyses and plume
stability information; and 2) a more detailed statistical optimization based on spatial and
temporal redundancy and sufficiency identification methods (see Figures A.I and A.2 for
further details). In general, the MAROS method applies to 2-D aquifers that have
relatively simple site hydrogeology. However, for a multi-aquifer (3-D) system, the user
has the option to apply the statistical analysis layer-by-layer.
The overview statistics or interpretive trend analyses assess the general monitoring
system category by considering individual well concentration trends, overall plume
stability, and qualitative factors such as seepage velocity, remedial systems, and the
location of potential receptors. The method relies on temporal trend analysis to assess
plume stability, which is then used to determine the general monitoring system category.
The monitoring system category is evaluated separately for both source and tail regions.
Source zone monitoring wells could include areas with non-aqueous phase liquids
(NAPLs), contaminated vadose zone soils, and areas where aqueous-phase releases have
been introduced into ground water. Alternately, a source zone could be an area
upgradient of a remedy such as a pump and treat (P&T) system or barrier wall. The
source zone generally contains locations with historical high groundwater concentrations
of the COCs.
The tail zone is usually the area downgradient of the contaminant source zone or major
remedial system. Although this classification is a simplification of the plume conceptual
model, this broadness makes the user aware on an individual well basis that the
concentration trend results can have a different interpretation depending on the well
location in and around the plume. The location and type of the individual wells allows
further interpretation of the trend results, depending on what type of well is being
analyzed (e.g., remediation well, leading plume edge well, or source monitoring well).
A-2
-------
General recommendations for the monitoring network frequency and density are
suggested based on heuristic rules applied to the source and tail trend results.
Figure A.1. MAROS Decision Support Tool Flow Chart
MAROS: Decision Support Tool
MAROS is a collection of tools in one soft ware package that is used in an explanatory, non-linear fashion. The tool
includes models, geostatistics, heuristic rules, and empirical relationships to assist the user in optimizing a
groundwater monitoring network system while maintaining adequate delineation of the plume as well as knowledge
of the plume state over time. Different users utilize the tool in different ways and interpret the results from a different
viewpoint.
T
Overview Statistics
What it is: Simple, qualitative a nd quantitative plume informat ion can be gained through evaluatio n of monitoring
network historical data trends both spatially and temporally. The MAROS Overview Statistics are the foundation the
user needs to make informed optimization decisions at the site.
What it does: The Overview Statistics are designed to allow site personnel to develop a better understanding of the
plume behavior over time and understand how the individual well concentration trends are spatially distributed within
the plume. This step allows the user to gain information that will support a more informed decision to be made in the
next level of optimization analysis.
What are the tools: Overview Statistics includes two analytical tools:
1) Trend Analysis: includes Mann-Kendall and Linear Regressio n statistics for individual wells and results in
general heu ristically-derived mon itoring categorie s w ith a sug gested sampling de nsity a nd monit oring
frequency.
2) Moment Analysis: includes dissolved mass estimation (0 th Moment), center of m ass (1st Moment), and
plume spread (2nd Mom ent) overtime. Trends of these mo ments show the useranot her piece of
information about the plume stability over time.
What is the product: A first-c ut blueprint for a futur e long-t erm monitoring program t hat is in tended to be a
foundation for more detailed statistical analysis.
T
Detailed Statistics
What it is: The MAROS Detailed Statistics allows for a quantitative analysis for spatial and temporal optimization of
the well network on a well-by-well basis.
What it does: The results from the Overview Statistics should be considered alon g side the MAROS optimization
recommendations gained from the Detailed Statistical Analysis. The MAROS Detailed Statistics results should be
reassessed in view of site knowledge and regulatory requirements as well as the Overview Statistics.
What are the tools: Detailed Statistics includes four analytical tools:
1) Sampling Frequency Optimization: uses the Mo dified CES method to establish a recommended future
sampling frequency.
2) Well Redundancy Analysis: uses the Delauna y Method to evaluate if any wells within the moni taring
network are redundant and can be eliminated without any significant loss of plume information.
3) Well Sufficiency Analysis: us es the Delaun ay Meth od to e valuate areas where ne w wells are
recommended within the monitoring network due to high levels of concentration uncertainty.
4) Data Sufficiency Analysis: uses Power Analysis to assess if th e historical monitoring data record has
sufficient pow er to accuratel y r eflect the location of the plum e relative to the nearest recep tor or
compliance point.
What is the product: List of wells to remove fro m the monitoring program, locatio ns where monitoring wells may
need to be added, recommended frequency of sa mpling for each well, analysis if the overall system is statistically
powerful to monitor the plume.
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Figure A.2: MAROS Overview Statistics Trend Analysis Methodology
Select Representative Wells in "Source" and "Plume" Zone
Source Zone i Tail Zone
Identify Site Constituents of Concern (COCs).
(Assistance provided by software.)
Analyze Lines of Evidence (LOEs)
for Plume Stability (by well and by COC)
Categorize concentrations of COC in each well as:
Increasing (I)
Probably Increasing (PI)
No Trend (NT) '
Stable (S)
Probably Decreasing (PD)
Decreasing (D)
Determine General Trend
for Each Well Based On All
LOE's
SOURCE PLUME WEIGHT
"Lump Lines of Evidence"
Determine General Trend for Source and
Tail Zones
Increasing (I)
Probably Increasing (PI)
No Trend (NT)
Stable (S)
Probably Decreasing (PD)
Decreasing (D)
"Lump Wells" in Source and Tail Zone
Dele
LTMP
Monitoring
Category
for COC By
Source / Tail
(e.g., E)
Monitoring Categories
E: Extensive
M: Moderate
L: Limited
Specify Preliminary Monitoring
System Optimization Results based on
Monitoring category and site-specific
parameters.
Well Density
Sampling Frequency
Sampling Duration
Site Classification
Fuel
Big Small
win inr ann try
E
n
L
:::;
-- --
Solvent
Big Small
lan IW laŤ 117
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The detailed sampling optimization modules consist of well redundancy and well
sufficiency analyses using the Delaunay method, a sampling frequency analysis using the
Modified Cost Effective Sampling (MCES) method. For plumes very close to the cleanup
standards, a data sufficiency analysis including statistical power analysis can be used to
identify statistically 'clean' locations. The well redundancy analysis is designed to
eliminate monitoring locations that do not contribute unique data to the program. The
sampling frequency module is designed to suggest an optimal frequency of sampling
based on the rate of change of constituent concentrations. The data sufficiency analysis
uses simple statistical methods to assess the sampling record to determine if groundwater
concentrations are statistically below target levels and if the current monitoring network
and record is sufficient to evaluate concentrations at downgradient locations.
2.0 DATA MANAGEMENT
In MAROS, groundwater monitoring data can be imported from simple database-format
MicrosoftŽ Excel spreadsheets, Microsoft Access tables, previously created MAROS
database archive files, or entered manually. Monitoring data interpretation in MAROS is
based on historical analytical data from a consistent set of wells over a series of sampling
events. The analytical data is composed of the well name, coordinate location,
constituent, result, detection limit and associated data qualifiers. Statistical validity of the
concentration trend analysis requires constraints on the minimum data input of at least
four wells (ASTM 1998) in which COCs have been detected. Individual sampling
locations need to include data from at least six most-recent sampling events. To ensure a
meaningful comparison of COC concentrations over time and space, both data quality
and data quantity need to be considered. Prior to statistical analysis, the user can
consolidate irregularly sampled data or smooth data that might result from seasonal
fluctuations or a change in site conditions. Because MAROS is a later-stage analytical
tool designed for long-term planning after site investigation and remedial system
installation, impacts of seasonal variation in the water unit are treated on a broad scale, as
they relate to multi-year trends.
Imported ground water monitoring data and the site-specific information entered in the
Site Details input screens can be archived and exported as MAROS archive files. These
archive files can be appended as new monitoring data becomes available, resulting in a
dynamic long-term monitoring database that reflects the changing conditions at the site
(i.e. biodegradation, compliance attainment, completion of remediation phase, etc.). For
wells with a limited monitoring history, addition of information as it becomes available
can change the frequency or redundancy recommendations made by MAROS.
The type of data required to run MAROS is shown in Table 1 below.
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TABLE 1
Data Input for MAROS
Data Input
Sample Dates
Well Names
Analyte Name
Result
Detection Limit
Data Flag
X and Y Coordinates
Seepage velocity
Plume length and width
Distance to receptors
Groundwater flow
direction
Porosity
Source Coordinates
Saturated Thickness
Format
MM/DD/YYYY
Text format
Text format
Number format; null cell
for non-detect results
Number format
NDorTR
Geographical
coordinates in number
format; units are feet.
Number in units of feet
per year
Number in units of feet
Number >0
Number between 1 and
359
Number <1
Geographic coordinates
in number format; units
are feet
Number >1
Details
Sampling event dates can be consolidated
in the
Well names must be spelled consistently
Analyte names must conform to MAROS
input standards outlined shown in
MAROS_ConstituentList.xls
Detection limits must be included for all
samples. Missing detection limits can be
estimated.
Flag non-detect results with "ND".
Identification of trace values (J flag) data is
optional.
Coordinates can be in State Plane feet or
in a site specific coordinate system. Values
must be in units of feet.
Estimated value for formation
Estimated value from plume maps
Estimated distance from source/tail to
surface water, property boundaries or
drinking water wells that represent
potential points of exposure.
Predominant groundwater flow direction
with due east being 0 and moving counter-
clockwise, north 90, west 180 and south
270.
Total porosity estimate for soil type
An estimate of the coordinates of the most
likely source area
An estimate of plume thickness, either
plume-wide or at each well location.
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3.0 SITE DETAILS
Information needed for the MAROS analysis includes site-specific parameters such as
seepage velocity and current plume length and width. Information on the location of
potential receptors relative to the source and tail regions of the plume is entered at this
point. Part of the trend analysis methodology applied in MAROS focuses on where the
monitoring well is located, therefore the user needs to divide site wells into two different
zones: the source zone or the tail zone. Although this classification is a simplification of
the well function, this broadness makes the user aware on an individual well basis that the
concentration trend results can have a different interpretation depending on the well
location in and around the plume. It is up to the user to make further interpretation of the
trend results, depending on what type of well is being analyzed (e.g., remediation well,
leading plume edge well, or monitoring well). The Site Details section of MAROS
contains a preliminary map of well locations to confirm well coordinates.
4.0 CONSTITUENT SELECTION
A database with multiple COCs can be entered into the MAROS software. MAROS
allows the analysis of up to 5 COCs concurrently and users can pick COCs from a list of
compounds existing in the monitoring data. MAROS runs separate optimizations for each
compound. For sites with a single source, the suggested strategy is to choose one to three
priority COCs for the optimization. If, for example, the site contains multiple chlorinated
volatile organic compounds (VOCs), the standard sample chemical analysis will evaluate
all VOCs, so the sample locations and frequency should based on the concentration
trends of the most prevalent, toxic or mobile compounds. If different chemical classes are
present, such as metals and chlorinated VOCs, choose and evaluate the priority
constituent in each chemical class.
MAROS includes a short module that provides recommendations on prioritizing COCs
based on toxicity, prevalence, and mobility of the compound. The toxicity ranking is
determined by examining a representative concentration for each compound for the entire
site. The representative concentration is then compared to the screening level (PRO or
MCL) for that compound and the COCs are ranked according to the representative
concentrations' percent exceedance of the screening level. The evaluation of prevalence
is performed by determining a representative concentration for each well location and
evaluating the total number of wells with exceedances (values above screening levels)
compared to the total number of wells. Compounds found over screening levels are
ranked for mobility based on Kd (sorption partition coefficient). The MAROS COC
assessment provides the relative ranking of each COC, but the user must choose which
COCs are included in the analysis.
5.0 DATA CONSOLIDATION
Typically, raw data from long-term monitoring networks have been measured irregularly
in time or contain many non-detects, trace level results, and duplicate results. Therefore,
before the data can be further analyzed, raw data are filtered, consolidated, transformed,
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and possibly smoothed to allow for a consistent dataset meeting the minimum data
requirements for statistical analysis mentioned previously.
MAROS allows users to specify the period of interest in which data will be consolidated
(i.e., monthly, bi-monthly, quarterly, semi-annual, yearly, or a biennial basis). In
computing the representative value when consolidating, one of four statistics can be used:
median, geometric mean, mean, and maximum. Non-detects can be transformed to one
half the reporting or method detection limit (DL), the DL, or a fraction of the DL. Trace
level results can be represented by their actual values, one half of the DL, the DL, or a
fraction of their actual values. Duplicates are reduced in MAROS by one of three ways:
assigning the average, maximum, or first value. The reduced data for each COC and each
well can be viewed as a time series in a graphical form on a linear or semi-log plot
generated by the software.
6.0 OVERVIEW STATISTICS: PLUME TREND ANALYSIS
Within the MAROS software, analyses of historical data provide support for a conclusion
about plume stability (e.g., increasing plume, etc.). Plume stability results are assessed
from time-series concentration data with the application of three statistical tools: Mann-
Kendall Trend analysis, linear regression trend analysis and moment analysis. Mann-
Kendall and Linear Regression methods are used to estimate the concentration trend for
individual well and COC combinations based on the statistical trend analysis of
concentrations versus time. These trend analyses are then consolidated to give the user a
general stability estimate for source, tail and plume-wide areas as well as a preliminary
recommendation for monitoring frequency and well density (see Figures 1 through 3 for
further step-by-step details). The Overview Statistics are designed to allow site personnel
to develop a better understanding of the plume behavior over time and understand how
the individual well concentration trends are spatially distributed within the plume. The
Overview step allows the user to gain information that will support a more informed
decision in the next level of detailed statistical optimization analysis.
6.1 MANN-KENDALL ANALYSIS
The Mann-Kendall test is a statistical procedure that is well suited for analyzing trends in
groundwater data. The Mann-Kendall test is a non-parametric test for zero slope of the
first-order regression of time-ordered concentration data versus time. The advantage of
the Mann-Kendall test is that no assumptions as to the statistical distribution of the data
(e.g. normal, lognormal, etc.) are required, and it can be used with data sets that include
irregular sampling intervals and missing data. The Mann-Kendall test is designed for
analyzing a single groundwater constituent, multiple constituents are analyzed separately.
The Mann-Kendall test for trend relies on three statistical metrics. The first metric, the S
statistic, is based on the sum of the differences between data in sequential order. An S
with a positive value may indicate an increase in concentrations over time and negative
values indicate possible decreases. The strength of the trend is proportional to the
magnitude of the S statistic (i.e., a large value indicates a strong trend). The confidence in
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the trend is determined by performing a hypothesis test to determine the probability of
accepting the null hypothesis (no trend). The S statistic and the sample size, n, are found
in a Kendall probability table such as the one reported in Hollander and Wolfe (1973).
The Confidence in the Trend is found by subtracting the probability of no trend (p) from
1. For low values of p (<0.05), confidence in the trend is high (>90%) or (p < 0.01) very
high (>95%).
The concentration trend is determined for each well and each COC based on results of the
S statistic, the confidence in the trend, and the coefficient of variation (COV). The
coefficient of variation (COV) is calculated from the standard deviation divided by the
mean for the dataset. The decision matrix for the Mann-Kendall evaluation is shown in
Table 2 below. A Mann-Kendall statistic that is greater than 0 combined with a
confidence of greater than 95% is categorized as an Increasing trend while a Mann-
Kendall statistic of less than 0 with a confidence between 90% and 95% is defined as a
probably Increasing trend, and so on.
Depending on statistical indicators, the concentration trend is classified into six
categories:
. Decreasing (D)
Probably Decreasing (PD)
. Stable (S)
. No Trend (NT)
Probably Increasing (PI)
Increasing (I)
. Non-detect (ND)
Insufficient data (N/A)
Wells where the compound is not detected are labeled "ND" for the COC evaluated.
These trend estimates are then analyzed to identify the source and tail region overall
stability category (see Figure 2 for further details).
TABLE 2
Mann-Kendall Analysis Decision Matrix (Aziz, et. al., 2003)
Mann-Kendall
Statistic
S>0
S>0
S>0
S<0
S<0
S<0
S<0
s = o
Confidence in the Trend
> 95%
90 - 95%
< 90%
< 90% and COV > 1
< 90% and COV < 1
90 - 95%
> 95%
0
Concentration Trend
Increasing
Probably Increasing
No Trend
No Trend
Stable
Probably Decreasing
Decreasing
Non-detect
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6.2 LINEAR REGRESSION ANALYSIS
Linear Regression is a parametric statistical procedure that is typically used for analyzing
trends in data over time for datasets that have a normal or lognormal distribution. The
objective of linear regression analysis is to find the trend in the datA through the
estimation of the log-slope as well as placing confidence limits on the log-slope of the
trend. The Linear Regression analysis in MAROS is performed on Ln(concentration)
versus time. The regression model assumes that for a fixed value of x (sample date) the
expected value of y (In(concentration)) can be found by evaluating a linear function. The
method of least squares is used to obtain the estimate of the linear function.
In order to test the confidence in the regression trend, confidence limits are placed on the
slope of the regression line. A t-test is used to find the confidence interval for the slope
by dividing the slope by the standard error of the slope. The result of the t-test along with
the degrees of freedom (n-2) is used to find the confidence in the trend from a t-
distribution table. The coefficient of variation, defined as the standard deviation divided
by the average, is used as a secondary measure of scatter to distinguish between "Stable"
or "No Trend" conditions for negative slopes. The resulting confidence in the trend, slope
of the regression through the data and variance are used to determine a final trend based
on the decision matrix shown on Table 3.
Using this type of analysis, a higher degree of scatter simply corresponds to a wider
confidence interval about the average log-slope. Assuming the sign (i.e., positive or
negative) of the estimated log-slope is correct, a level of confidence that the slope is not
zero can be easily determined. Thus, despite a poor goodness of fit, the overall trend in
the data may still be ascertained, where low levels of confidence correspond to "Stable"
or "No Trend" conditions (depending on the degree of scatter) and higher levels of
confidence indicate the stronger likelihood of a trend. Depending on statistical indicators,
the concentration trend is classified into six categories:
. Decreasing (D)
Probably Decreasing (PD)
. Stable (S)
. No Trend (NT)
Probably Increasing (PI)
Increasing (I)
TABLE 3
Linear Regression Analysis Decision Matrix (Aziz, et. al., 2003)
Confidence in the
Trend
< 90%
90 - 95%
> 95%
Log-slope
Positive
No Trend
Probably Increasing
Increasing
Negative
COV < 1 Stable
COV > 1 No Trend
Probably Decreasing
Decreasing
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6.3 MOMENT ANALYSIS
The role of moment analysis in MAROS is to provide a relative estimate of plume
stability and condition within the context of results from other MAROS modules. The
moment analysis algorithms in MAROS are simple approximations of complex
calculations and are meant to estimate changes in total mass, center of mass and spread of
mass within the network over time. The Moment Analysis module is sensitive to the
number and arrangement of wells in each sampling event, so, changes in the number and
identity of wells during monitoring events, and the parameters chosen for data
consolidation can cause changes in the estimated moments.
The analysis of moments can be summarized as:
Zeroth Moment: An estimate of the total dissolved mass of the constituent within
the network for each sample event;
. First Moment: An estimate of the center of mass for each sample event;
Second Moment: An estimate of the spread of the plume around the center of
mass for each sample event.
Moments are calculated using the method of Delaunay Triangulation. The software
constructs triangles between all of the wells in the network and estimates the total mass
within each triangle using the Saturated Thickness value input as the depth of the plume.
To determine the zeroth moment, the mass within each of the triangles is summed to give
a plume-wide value. To find the center of mass, or first moment, the center of each
triangle is determined and multiplied by the mass within the triangle, which is then
normalized by the total mass in the plume. The second moment is an estimate of the
relative distribution of mass between the center of the plume and the edges of the plume.
Estimates are made of the relative distribution of mass in the direction of groundwater
flow (X) and orthogonal to groundwater flow (Y) for each sample event.
Once moments are calculated for each sample event, the Mann-Kendall trend test is
applied to determine if the results show increasing, stable or decreasing trends. When
considering the results of the zeroth moment trend, the following factors could effect the
calculation and interpretation of the plume mass over time: 1) change in the spatial
distribution of the wells sampled historically 2) different wells sampled within the well
network over time (addition and subtraction of wells within the network). 3) delineation
of the plume as mass outside of the network is not included in the estimate.
The first moment estimates the center of mass, coordinates (Xc and Yc) for each sample
event and COC and the distance of these coordinates from the source. If the center of
mass is farther from the source, then there is an increasing trend. The changing center of
mass indicates the relative distribution of mass between the source and tail over time and
an increasing trend does not necessarily signal and expanding plume. An increasing
center of mass is often found where significant source reduction has occurred. No
appreciable movement or a stable trend in the center of mass would indicate plume
stability. However, changes in the first moment over time do not necessarily completely
characterize the changes in the concentration distribution (and the mass) over time.
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Therefore, in order to fully characterize the plume the First Moment trend should be
compared to the zeroth moment trend (mass change over time).
The second moment indicates the spread of the contaminant about the center of mass
(Sxx and Syy), or the distance of contamination from the center of mass for a particular
COC and sample event. An increasing trend in the second moment indicates that there is
less mass in the center of the plume relative to the edge. This is often seen in cases where
diffusion is occurring or when a remedial system may be removing mass from the center
of the plume. A decreasing trend may indicate that mass destructive processes are active
on the edge of the plume.
6.4 OVERALL PLUME ANALYSIS
General recommendations for the monitoring network sampling frequency and density
are provided by MAROS after the trend and moment analysis modules. Monitoring
network improvements are suggested based on heuristic rules applied to the source and
tail trend results as well as qualitative factors such as seepage velocity and distance to
potential receptors.
Individual well trend results are consolidated and weighted by the MAROS software
according to user input, and the direction and strength of contaminant concentration
trends in the source zone and tail zone for each COC are determined. The software
suggests a general, preliminary optimization plan for the current monitoring. The flow
chart detailing how the trend analysis results and other site-specific parameters are used
to form a general sampling frequency and well density recommendation is shown in
Figure 2.
For example, a generic plan for a shrinking petroleum hydrocarbon plume (BTEX) in a
slow hydrogeologic environment (silt) with no nearby receptors would entail minimal,
low frequency sampling of just a few indicators. On the other hand, the generic plan for a
chlorinated solvent plume in a fast hydrogeologic environment that is expanding but has
very erratic concentrations over time would entail more extensive, higher frequency
sampling. The preliminary plan is based on a heuristically derived algorithm for assessing
future sampling duration, location and density that takes into consideration plume
stability. For a detailed description of the heuristic rules used in the MAROS software,
refer to the MAROS 2.2Manual (AFCEE, 2003).
7.0 DETAILED STATISTICS: OPTIMIZATION ANALYSIS
Although the overall plume analysis shows a general recommendation for sampling
frequency and sampling density, a more detailed analysis is also available with the
MAROS software in order to allow for further refinements on a well-by-well basis. The
MAROS Detailed Statistics allows for a quantitative analysis for spatial and temporal
optimization of the well network. The MAROS Detailed Statistics results should be
evaluated considering the results of the Overview Statistics as well as other qualitative
features such as site monitoring objectives and the frequency of site decision making.
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The Detailed Statistics sampling optimization in MAROS consists of four parts:
Well redundancy analysis using the Delaunay method
Well sufficiency analysis using the Delaunay method
Sampling frequency determination using the Modified Cost Effective Sampling
method
Data sufficiency analysis using statistical power analysis.
The well redundancy analysis using the Delaunay method identifies and eliminates
redundant locations from the monitoring network. The well sufficiency analysis can
determine the areas where new sampling locations might be needed. The Modified CES
method determines the optimal sampling frequency for a sampling location based on the
direction, magnitude, and uncertainty in its concentration trend. The data sufficiency
analysis examines the risk-based site cleanup status and power and expected sample size
associated with the cleanup status evaluation.
7.1 WELL REDUNDANCY ANALYSIS - DELAUNAY METHOD
The well redundancy analysis using the Delaunay method is designed to select the
minimum number of sampling locations based on the spatial analysis of the relative
importance of each sampling location in the monitoring network. The approach allows
elimination of sampling locations that have little impact on the historical characterization
of the contaminant plume. An extended method for evaluating well sufficiency based on
the Delaunay method is used for recommending new sampling locations in areas with
high concentration uncertainty. Details about the Delaunay method can be found in
Appendix A.2 of the MAROS Manual (AFCEE, 2003).
The sampling location modules use the Delaunay triangulation method employed during
the moment analysis. The method determines the significance of each sampling location
relative to the overall monitoring network with respect to characterizing concentration
within the plume. The Delaunay method calculates the area within the network and the
average concentration of the plume using data from multiple monitoring wells. A slope
factor (SF) is calculated for each well by assessing how accurately concentration at the
well can be estimated from concentrations at neighboring wells.
The sampling location optimization process is performed in a stepwise fashion. Step one
involves assessing the SF; if a well has a small SF (little significance to the network), the
well may be removed from the monitoring network. Locations with a SF = 0.3 or less are
candidates for removal. Step two involves evaluating the information loss of removing a
well from the network. Information loss is measured by evaluating and Area Ratio and a
Concentration Ratio, which is the plume-wide area or concentration after removal of the
well normalized by the original values. If one well has a small SF, it may or may not be
eliminated depending on whether the information loss in terms of area or average
concentration estimates is significant. If the information loss is not significant, the well
can be eliminated from the monitoring network and the process of optimization continues
with fewer wells. However if the well information loss is significant then the
optimization terminates. This sampling optimization process allows the user to assess
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"redundant" wells that will not incur significant information loss on a constituent-by-
constituent basis for individual sampling events.
7.2 WELL SUFFICIENCY ANALYSIS - DELAUNAY METHOD
The well sufficiency analysis, using the Delaunay method, is designed to recommend
new sampling locations in areas within the existing monitoring network where there is a
high level of uncertainty in contaminant concentration. Details about the well sufficiency
analysis can be found in Appendix A.2 of the MAROS Manual (AFCEE, 2003).
In many cases, new sampling locations need to be added to the existing network to
enhance the spatial characterization of the plume. If the MAROS algorithm calculates a
high level of uncertainty in predicting the constituent concentration at nodes for a
particular Delaunay triangle, a new sampling location is recommended for that area. The
SF values obtained from the redundancy evaluation described above are used to calculate
the concentration estimation error for each triangle. The estimated concentration
uncertainty value, based on the calculated SF for each area is then classified into four
levels: Small, Moderate, Large, or Extremely large (S, M, L, E). Therefore, the triangular
areas with the estimated SF value at the Extremely large or Large level can be candidate
regions for new sampling locations.
The results from the Delaunay method and the method for determining new sampling
locations are derived solely from the spatial configuration of the monitoring network and
the spatial pattern of the contaminant plume. No parameters such as the hydrogeologic
conditions or regulatory factors are considered in the analysis. Therefore, professional
judgment and regulatory considerations must be used to make final decisions.
7.3 SAMPLING FREQUENCY DETERMINATION - MODIFIED CES
METHOD
The Modified CES method optimizes sampling frequency for each sampling location
based on the magnitude, direction, and uncertainty of its concentration trend derived from
its recent and historical monitoring records. The Modified Cost Effective Sampling
(MCES) estimates a conservative lowest-frequency sampling schedule for a given
groundwater monitoring location that still provides needed information for regulatory and
remedial decision-making. The MCES method was developed on the basis of the Cost
Effective Sampling (CES) method developed by Ridley et al (1995). Details about the
MCES method can be found in Appendix A.9 of the MAROS Manual (AFCEE, 2003).
In order to estimate the least frequent sampling schedule for a monitoring location that
still provides enough information for regulatory and remedial decision-making, MCES
employs three steps to determine the sampling frequency. The first step involves
analyzing frequency based on recent trends. A preliminary location sampling frequency
(PLSF) is developed based on the rate of change of well concentrations calculated by
linear regression along with the Mann-Kendall trend analysis of the most recent
monitoring data (see Figure 3). The variability within the sequential sampling data is
accounted for by the Mann-Kendall analysis. The rate of change vs. trend result matrix
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categorizes wells as requiring annual, semi-annual or quarterly sampling. The PLSF is
then reevaluated and adjusted based on overall trends. If the long-term history of change
is significantly greater than the recent trend, the frequency may be reduced by one level.
The final step in the analysis involves reducing frequency based on risk, site-specific
conditions, regulatory requirements or other external issues. Since not all compounds in
the target being assessed are equally harmful, frequency is reduced by one level if recent
maximum concentration for a compound of high risk is less than 1/2 of the Maximum
Concentration Limit (MCL). The result of applying this method is a suggested sampling
frequency based on recent sampling data trends and overall sampling data trends and
expert judgment.
The final sampling frequency determined from the MCES method can be Quarterly,
Semiannual, Annual, or Biennial. Users can further reduce the sampling frequency to, for
example, once every three years, if the trend estimated from Biennial data (i.e., data
drawn once every two years from the original data) is the same as that estimated from the
original data.
7.4 DATA SUFFICIENCY ANALYSIS - POWER ANALYSIS
The MAROS Data Sufficiency module employs simple statistical methods to evaluate
whether the collected data are adequate both in quantity and in quality for revealing
changes in constituent concentrations. The first section of the module evaluates
individual well concentrations to determine if they are statistically below a target
screening level. The second section includes a simple calculation for estimating projected
groundwater concentrations at a specified point downgradient of the plume. A statistical
Power analysis is then applied to the projected concentrations to determine if the
downgradient concentrations are statistically below the cleanup standard. If the number
of projected concentrations is below the level to provide statistical significance, then the
number of sample events required to statistically confirm concentrations below standards
is estimated from the Power analysis.
Before testing the cleanup status for individual wells, the stability or trend of the
contaminant plume should be evaluated. Only after the plume has reached stability or is
reliably diminishing can we conduct a test to examine the cleanup status of wells.
Applying the analysis to wells in an expanding plume may cause incorrect conclusions
and is less meaningful.
Statistical power analysis is a technique for interpreting the results of statistical tests. The
Power of a statistical test is a measure of the ability of the test to detect an effect given
that the effect actually exists. The method provides additional information about a
statistical test: 1) the power of the statistical test, i.e., the probability of finding a
difference in the variable of interest when a difference truly exists; and 2) the expected
sample size of a future sampling plan given the minimum detectable difference it is
supposed to detect. For example, if the mean concentration is lower than the cleanup goal
but a statistical test cannot prove this, the power and expected sample size can tell the
reason and how many more samples are needed to result in a significant test. The
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additional samples can be obtained by a longer period of sampling or an increased
sampling frequency. Details about the data sufficiency analysis can be found in Appendix
A.6 of the MAROS Manual (AFCEE, 2003).
When applying the MAROS power analysis method, a hypothetical statistical compliance
boundary (HSCB) is assigned to be a line perpendicular to the groundwater flow
direction (see figure below). Monitoring well concentrations are projected onto the HSCB
using the distance from each well to the compliance boundary along with a decay
coefficient. The projected concentrations from each well and each sampling event are
then used in the risk-based power analysis. Since there may be more than one sampling
event selected by the user, the risk-based power analysis results are given on an event-by-
event basis. This power analysis can then indicate if target are statistically achieved at the
HSCB. For instance, at a site where the historical monitoring record is short with few
wells, the HSCB would be distant; whereas, at a site with longer duration of sampling
with many wells, the HSCB would be close. Ultimately, at a site the goal would be to
have the HSCB coincide with or be within the actual compliance boundary (typically the
site property line).
" HSCB"
Concentrations
projected to this
line
The nearest
downgradient
receptor
Groundwater flow direction
In order to perform a risk-based cleanup status evaluation for the whole site, a strategy
was developed as follows.
. Estimate concentration versus distance decay coefficient from plume centerline
wells.
. Extrapolate concentration versus distance for each well using this decay
coefficient.
Comparing the extrapolated concentrations with the compliance concentration
using power analysis.
Results from this analysis can be Attained or Not Attained, providing a
statistical interpretation of whether the cleanup goal has been met on the site-scale
from the risk-based point of view. The results as a function of time can be used to
evaluate if the monitoring system has enough power at each step in the sampling
A-16
-------
record to indicate certainty of compliance by the plume location and condition
relative to the compliance boundary. For example, if results are Not Attained at early
sampling events but are Attained'in recent sampling events, it indicates that the recent
sampling record provides a powerful enough result to indicate compliance of the
Sampling
Frequency
Q: Quarterly
S: SemiAnnual
A: Annual
Rate of Change (Linear Regression)
High MH Medium LM Low
0>
re
re
PI
D
plume relative to the location of the receptor or compliance boundary.
Figure A.3. Decision Matrix for Determining Provisional Frequency
(Figure A.3.1 of the MAROS Manual (AFCEE 2003)
8.0 CITED REFERENCES
AFCEE 2003. Monitoring and Remediation Optimization System (MAROS) 2.1
Software Users Guide. Air Force Center for Environmental Excellence, http://www.gsi-
net. com/software/MARO S_V2_1 Manual. pdf
AFCEE. 1997. Air Force Center for Environmental Excellence, AFCEE Long-Term
Monitoring Optimization Guide, http://www.afcee.brooks.af.mil.
Aziz, J. A., C. J. Newell, M. Ling, H. S. Rifai and J. R. Gonzales (2003). "MAROS: A
Decision Support System for Optimizing Monitoring Plans." Ground Water 41(3): 355-
367.
Gilbert, R. O., 1987, Statistical Methods for Environmental Pollution Monitoring, Van
Nostrand Reinhold, New York, NY, ISBN 0-442-23050-8.
Hollander, M. and Wolfe, D. A. (1973). Nonparametric Statistical Methods, Wiley, New
York, NY.
Ridley, M.N. etal., 1995. Cost-Effective Sampling of Groundwater Monitoring Wells,
the Regents of UC/LLNL, Lawrence Livermore National Laboratory.
A-17
-------
U.S. Environmental Protection Agency, 1992. Methods for Evaluating the Attainment of
Cleanup Standards Volume 2: Ground Water.
Weight, W. D. and J. L. Sonderegger (2001). Manual of Applied Field Hydrogeology.
New York, NY, McGraw-Hill.
A-18
-------
APPENDIX B
Groundwater Monitoring Network Optimization
Gilson Road Superfund Site
Nashua, New Hampshire
MAROS REPORTS
Overburden Aquifer Reports
COC Assessment
Mann-Kendall Summary Report
Linear Regression Summary Report
Individual Trend Summary Reports
Zeroth Moment Reports
Full Plume: Arsenic
Summary of Moment Analyses - Select Wells Exterior to Slurry Wall
Bedrock Aquifer Reports
COC Assessment
Trend Summary Report
Individual Trend Summary Reports
Zeroth Moment Reports
Full Plume: Arsenic
Overburden Aquifer Reports
COC Assessment
Mann-Kendall Summary Report
Linear Regression Summary Report
Individual Trend Summary Reports
Zeroth Moment Reports
Full Plume: Arsenic
Summary of Moment Analyses - Select Wells Exterior to Slurry Wall
B-1
-------
MAROS COC Assessment
Project: Overburden
Location: Nashua
Toxicitv:
User Name: MV
State: New Hampshire
Contaminant of Concern
ARSENIC
1 ,4-DIOXANE (P-DIOXANE)
BENZENE
Representative
Concentration
(mg/L)
2.4E-01
1.7E-02
5.3E-03
PRG
(mg/L)
1.0E-02
3.0E-03
5.0E-03
Percent
Above
PRG
2316.5%
480.8%
5.0%
Note: Top COCs by toxicity were determined by examining a representative concentration for each compound over the entire site. The
compound representative concentrations are then compared with the chosen PRG for that compound, with the percentage exceedance
from the PRG determining the compound's toxicity. All compounds above exceed the PRG.
Prevalence:
Contaminant of Concern
ARSENIC
1 ,4-DIOXANE (P-DIOXANE)
BENZENE
Class
MET
ORG
ORG
Total
Wells
51
8
50
Total
Exceedances
30
4
16
Percent
Exceedances
58.8%
50.0%
32.0%
Total
detects
46
4
26
Note: Top COCs by prevalence were determined by examining a representative concentration for each well location at the site. The
total exceedances (values above the chosen PRGs) are compared to the total number of wells to determine the prevalence of the
compound.
Mobility:
Contaminant of Concern
Kd
1,4-DIOXANE (P-DIOXANE)
BENZENE
ARSENIC
0.000479
0.0984
25
Note: Top COCs by mobility were determined by examining each detected compound in the dataset and comparing their
mobilities (Koc's for organics, assume foe = 0.001, and Kd's for metals).
Contaminants of Concern (COC's)
ARSENIC
BENZENE
CHLOROBENZENE
LEAD
VINYL CHLORIDE
MAROS Version 2.2, 2006, AFCEE
Saturday, August 01, 2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Project: Overburden
Location: Nashua
User Name: MV
State: New Hampshire
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Well
Source/ Number of
Tail Samples
Number of
Detects
Coefficient
of Variation
Mann-Kendall
Statistic
Confidence
in Trend
All
Samples Concentration
"ND" ? Trend
ARSENIC
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-18-1
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
S
S
S
S
S
S
S
S
S
T
S
S
S
T
T
T
T
T
9
9
9
9
9
9
1
1
1
10
1
1
11
10
8
1
9
10
6
11
11
11
1
8
7
11
7
6
1
9
10
8
10
1
1
7
11
11
7
1
9
8
1
5
1
0
0
6
1
0
11
10
8
1
3
10
6
11
11
11
1
8
7
11
7
6
1
4
10
3
10
1
1
7
11
11
0.30
0.03
0.13
0.45
0.13
0.88
0.00
0.00
0.00
0.97
0.00
0.00
0.11
0.04
1.08
0.00
1.39
0.15
0.08
0.53
0.08
0.22
0.00
0.86
0.35
0.07
0.20
0.14
0.00
0.56
1.38
0.19
1.81
0.00
0.00
0.51
0.17
0.12
-8
-4
12
-13
-4
-29
0
0
0
-5
0
0
-45
-33
-4
0
-5
-27
1
-31
-17
-45
0
-22
7
-26
-3
7
0
-18
-39
-9
-29
0
0
-5
-43
-21
76.2%
61 .9%
87.0%
89.0%
61 .9%
100.0%
0.0%
0.0%
0.0%
63.6%
0.0%
0.0%
100.0%
99.9%
64.0%
0.0%
65.7%
99.2%
50.0%
99.2%
89.1%
100.0%
0.0%
99.8%
80.9%
97.5%
61.4%
86.4%
0.0%
96.2%
100.0%
83.2%
99.5%
0.0%
0.0%
71 .9%
100.0%
94.0%
No
No
No
No
No
No
No
Yes
Yes
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
S
S
NT
S
S
D
N/A
ND
ND
S
N/A
ND
D
D
NT
N/A
NT
D
NT
D
S
D
N/A
D
NT
D
S
NT
N/A
D
D
S
D
N/A
N/A
S
D
PD
MAROS Version 2,.2 2006, AFCEE
Friday, August 07, 2009
Page 1 of 6
-------
Project: Overburden
Location: Nashua
User Name: MV
State: New Hampshire
Well
Source/
Tail
Number of
Samples
Number of
Detects
Coefficient
of Variation
Mann-Kendall
Statistic
Confidence
in Trend
All
Samples
"ND" ?
Concentration
Trend
ARSENIC
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
BENZENE
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T
T
T
T
T
T
T
T
T
T
S
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
S
S
S
S
S
S
S
S
T
S
S
S
T
T
T
7
1
6
11
11
11
7
8
7
6
6
6
1
7
7
7
7
7
7
1
1
1
9
1
1
11
11
4
1
9
11
6
11
11
11
4
6
11
7
6
1
9
11
4
9
1
1
5
7
1
0
8
11
10
3
8
7
6
6
6
0
0
0
0
0
0
0
0
0
0
0
0
0
11
11
0
0
0
9
6
4
11
11
0
2
11
7
6
1
0
6
1
1
0
0
0
0.18
0.00
0.00
0.56
0.86
1.21
0.28
0.48
0.15
0.15
0.16
0.30
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.31
0.22
0.00
0.00
0.00
0.39
0.43
0.45
0.48
0.30
0.00
0.69
0.24
0.50
0.59
0.00
0.00
0.56
0.05
1.74
0.00
0.00
0.00
-11
0
0
-31
-26
-26
-5
-18
-9
-11
-5
-3
0
0
0
0
0
0
0
0
0
0
0
0
0
-27
-6
0
0
0
-7
-9
-20
-36
-31
0
-9
-8
-3
-7
0
0
-33
1
2
0
0
0
93.2%
0.0%
42.3%
99.2%
97.5%
97.5%
71 .9%
98.4%
88.1%
97.2%
76.5%
64.0%
0.0%
43.7%
43.7%
43.7%
43.7%
43.7%
43.7%
0.0%
0.0%
0.0%
46.0%
0.0%
0.0%
98.0%
64.8%
37.5%
0.0%
46.0%
67.6%
93.2%
92.9%
99.8%
99.2%
37.5%
93.2%
70.3%
61 .4%
86.4%
0.0%
46.0%
99.5%
50.0%
54.0%
0.0%
0.0%
40.8%
No
No
Yes
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
No
No
No
No
No
Yes
No
No
No
No
No
Yes
No
No
No
Yes
Yes
Yes
PD
N/A
ND
D
D
D
S
D
S
D
S
S
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
D
S
ND
ND
ND
S
PD
PD
D
D
ND
PD
S
S
S
N/A
ND
D
NT
NT
ND
ND
ND
MAROS Version 2,.2 2006, AFCEE
Friday, August 07, 2009
Page 2 of 6
-------
Project: Overburden
Location: Nashua
User Name: MV
State: New Hampshire
Well
Source/
Tail
Number of
Samples
Number of
Detects
Coefficient
of Variation
Mann-Kendall
Statistic
Confidence
in Trend
All
Samples
"ND" ?
Concentration
Trend
BENZENE
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
CHLOROBENZENE
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T
T
T
T
T
T
T
T
T
T
T
T
S
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
S
S
S
S
S
S
S
S
T
S
S
S
T
11
11
7
1
5
9
9
9
7
8
7
5
7
7
1
7
7
7
7
7
7
1
1
1
9
1
1
11
11
4
1
9
11
6
11
11
11
5
6
11
7
6
1
9
11
4
9
1
10
11
7
0
0
2
1
2
0
7
7
1
6
7
0
0
0
0
0
0
0
0
0
0
0
0
0
11
11
2
0
0
11
6
11
11
11
5
6
11
7
6
1
0
11
0
0
0
0.30
0.36
0.28
0.00
0.00
0.03
0.03
0.15
0.00
0.54
0.58
0.26
0.70
0.50
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.13
0.16
0.62
0.00
0.00
0.40
0.18
0.36
0.45
0.63
0.58
0.94
0.56
0.63
0.41
0.00
0.00
0.67
0.00
0.00
0.00
-2
-16
7
0
0
-5
-4
-9
0
-12
1
-4
-4
-9
0
0
0
0
0
0
0
0
0
0
0
0
0
-23
-7
-1
0
0
-25
8
17
13
29
0
13
-20
-1
-3
0
0
-43
0
0
0
53.0%
87.5%
80.9%
0.0%
40.8%
65.7%
61 .9%
79.2%
43.7%
91.1%
50.0%
75.8%
66.7%
88.1%
0.0%
43.7%
43.7%
43.7%
43.7%
43.7%
43.7%
0.0%
0.0%
0.0%
46.0%
0.0%
0.0%
95.7%
67.6%
50.0%
0.0%
46.0%
97.0%
89.8%
89.1%
82.1%
98.7%
40.8%
99.2%
92.9%
50.0%
64.0%
0.0%
46.0%
100.0%
37.5%
46.0%
0.0%
No
No
No
Yes
Yes
No
No
No
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
Yes
No
Yes
Yes
Yes
S
s
NT
ND
ND
S
S
S
ND
PD
NT
S
S
S
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
D
S
S
ND
ND
D
NT
NT
NT
I
S
I
PD
S
S
N/A
ND
D
ND
ND
ND
MAROS Version 2,.2 2006, AFCEE
Friday, August 07, 2009
Page 3 of 6
-------
Project: Overburden
Location: Nashua
User Name: MV
State: New Hampshire
Well
Source/
Tail
Number of
Samples
Number of
Detects
Coefficient
of Variation
Mann-Kendall
Statistic
Confidence
in Trend
All
Samples
"ND" ?
Concentration
Trend
CHLOROBENZENE
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
LEAD
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-18-1
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
S
S
S
S
S
S
S
S
S
T
S
1
5
11
11
7
1
5
11
11
11
7
8
7
6
7
7
1
8
8
8
9
9
9
1
1
1
9
1
1
10
10
7
1
9
10
6
11
11
11
1
7
7
11
7
6
1
9
10
0
3
11
11
7
0
0
11
11
11
0
8
7
6
7
7
0
0
0
0
6
0
7
1
0
0
4
0
0
1
0
0
0
3
5
5
5
5
3
0
5
6
5
6
5
1
3
5
0.00
1.00
0.39
0.40
0.28
0.00
0.00
0.36
0.50
0.43
0.00
0.33
0.43
0.42
1.10
0.35
0.00
0.00
0.00
0.00
0.66
0.00
0.79
0.00
0.00
0.00
0.47
0.00
0.00
0.03
0.00
0.00
0.00
1.99
1.12
0.64
1.17
1.07
0.31
0.00
0.65
1.79
1.36
0.92
1.01
0.00
0.31
0.98
0
1
-11
-13
6
0
0
-14
-12
-13
0
-5
15
-15
-1
-10
0
0
0
0
-17
0
-29
0
0
0
2
0
0
-5
0
0
0
-5
-19
1
-36
-20
-1
0
-10
-4
-30
-11
3
0
-11
-29
0.0%
50.0%
77.7%
82.1%
76.4%
0.0%
40.8%
84.0%
79.9%
82.1%
43.7%
68.3%
98.5%
99.9%
50.0%
90.7%
0.0%
45.2%
45.2%
45.2%
95.1%
46.0%
100.0%
0.0%
0.0%
0.0%
54.0%
0.0%
0.0%
63.6%
46.4%
43.7%
0.0%
65.7%
94.6%
50.0%
99.8%
92.9%
50.0%
0.0%
90.7%
66.7%
99.0%
93.2%
64.0%
0.0%
84.6%
99.5%
Yes
No
No
No
No
Yes
Yes
No
No
No
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
ND
NT
S
S
NT
ND
ND
S
S
S
ND
S
I
D
NT
PD
ND
ND
ND
ND
D
ND
D
N/A
ND
ND
NT
ND
ND
S
ND
ND
ND
NT
PD
NT
D
PD
S
ND
PD
NT
D
PD
NT
N/A
S
D
MAROS Version 2,.2 2006, AFCEE
Friday, August 07, 2009
Page 4 of 6
-------
Project: Overburden
Location: Nashua
User Name: MV
State: New Hampshire
Well
Source/
Tail
Number of
Samples
Number of
Detects
Coefficient
of Variation
Mann-Kendall
Statistic
Confidence
in Trend
All
Samples
"ND" ?
Concentration
Trend
LEAD
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
VINYL CHLORIDE
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
s
s
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
s
s
s
s
s
s
s
s
8
10
1
1
7
11
11
7
1
6
11
11
11
8
7
7
6
6
6
1
7
7
7
7
7
7
1
1
1
9
1
1
11
10
4
1
9
11
4
11
9
11
4
4
10
5
4
1
8
6
0
1
4
5
3
5
1
0
6
6
7
8
2
2
1
5
1
0
0
0
0
0
0
0
0
0
0
0
0
0
5
1
0
0
0
2
0
4
2
6
0
0
3
2
0
0
0.61
2.14
0.00
0.00
0.70
0.73
0.24
0.42
0.00
0.00
0.68
1.17
1.59
0.52
1.27
0.39
0.54
1.22
0.12
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.23
0.00
0.00
0.00
0.00
0.11
0.00
0.29
0.13
0.33
0.00
0.00
0.89
1.19
0.00
0.00
-8
-21
0
0
-10
-12
-3
-3
0
0
-31
-29
-23
-8
-3
-2
-1
-1
5
0
0
0
0
0
0
0
0
0
0
0
0
0
-21
9
0
0
0
-17
0
-8
-5
3
0
0
-8
-3
0
0
80.1%
96.4%
0.0%
0.0%
90.7%
79.9%
56.0%
61 .4%
0.0%
42.3%
99.2%
98.7%
95.7%
80.1%
61 .4%
55.7%
50.0%
50.0%
76.5%
0.0%
43.7%
43.7%
43.7%
43.7%
43.7%
43.7%
0.0%
0.0%
0.0%
46.0%
0.0%
0.0%
94.0%
75.8%
37.5%
0.0%
46.0%
89.1%
37.5%
70.3%
65.7%
56.0%
37.5%
37.5%
72.9%
67.5%
37.5%
0.0%
No
No
Yes
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
No
Yes
No
No
No
Yes
Yes
No
No
Yes
Yes
s
D
ND
N/A
PD
S
S
S
N/A
ND
D
D
D
S
NT
S
S
NT
NT
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
PD
NT
ND
ND
ND
S
ND
S
S
NT
ND
ND
S
NT
ND
ND
MAROS Version 2,.2 2006, AFCEE
Friday, August 07, 2009
Page 5 of 6
-------
Project: Overburden
Location: Nashua
User Name: MV
State: New Hampshire
Well
Source/
Tail
Number of
Samples
Number of
Detects
Coefficient
of Variation
Mann-Kendall
Statistic
Confidence
in Trend
All
Samples
"ND" ?
Concentration
Trend
VINYL CHLORIDE
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
T
S
s
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
T
g
9
4
9
1
1
5
9
9
7
1
5
10
10
10
7
6
5
4
5
5
1
0
1
0
0
0
0
0
1
0
2
0
0
2
1
1
0
0
4
0
1
0
0
0.00
0.46
0.00
0.00
0.00
0.00
0.00
0.16
0.00
0.16
0.00
0.00
0.18
0.08
0.08
0.00
0.00
0.74
0.00
0.32
0.00
0.00
0
8
0
0
0
0
0
0
0
1
0
0
-17
-9
-9
0
0
-6
0
4
0
0
46.0%
76.2%
37.5%
46.0%
0.0%
0.0%
40.8%
46.0%
46.0%
50.0%
0.0%
40.8%
92.2%
75.8%
75.8%
43.7%
42.3%
88.3%
37.5%
75.8%
40.8%
0.0%
Yes
No
Yes
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
No
No
No
Yes
Yes
No
Yes
No
Yes
Yes
ND
NT
ND
ND
ND
ND
ND
S
ND
NT
ND
ND
PD
S
S
ND
ND
S
ND
NT
ND
ND
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A)-
Due to insufficient Data (< 4 sampling events); Source/Tail (S/T)
The Number of Samples and Number of Detects shown above are post-consolidation values.
MAROS Version 2,.2 2006, AFCEE
Friday, August 07, 2009
Page 6 of 6
-------
MAROS Linear Regression Statistics Summary
Project: Gilson Road
Location: Overburden
User Name: MV
State: New Hampshire
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Well
Average
Source/ Cone
Tail (mg/L)
Median
Cone
(mg/L)
Standard
Deviation
All
Samples
"ND" ?
Coefficient
Ln Slope of Variation
Confidence Concentration
in Trend Trend
ARSENIC
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-18-1
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
S
S
S
S
S
S
S
S
S
T
S
S
S
T
T
T
T
T
T
1 .4E-03
1 .OE-03
3.9E-02
2.6E-03
1 .OE-03
2.2E-03
6.4E-03
1 .OE-03
1 .OE-03
3.2E-03
1 .4E-02
1 .OE-03
6.8E-01
5.4E-01
6.5E-02
2.2E-03
4.3E-03
3.8E-01
7.9E-01
2.2E-01
5.7E-01
9.6E-01
3.9E-01
5.3E-02
2.7E-03
5.2E-01
6.0E-01
6.8E-01
1.4E-01
1 JE-03
1.5E-01
1.1E-03
3.5E-01
1 .2E-03
2.9E-02
3.4E-01
5.5E-01
5.2E-01
5.7E-01
1.4E-03
1 .OE-03
3.8E-02
3.0E-03
1 .OE-03
1 .9E-03
6.4E-03
1 .OE-03
1 .OE-03
2. OE-03
1 .4E-02
1 .OE-03
6.5E-01
5.5E-01
3.5E-02
2.2E-03
1 .OE-03
3.7E-01
7.8E-01
1.8E-01
5.8E-01
9.9E-01
3.9E-01
5.8E-02
2.9E-03
5.2E-01
6.0E-01
7.0E-01
1.4E-01
1 .OE-03
8.4E-02
1 .OE-03
1.4E-01
1 .2E-03
2.9E-02
3.3E-01
5.4E-01
5.1E-01
5.7E-01
4.1E-04
3.3E-05
5.1E-03
1.2E-03
1.3E-04
1.9E-03
O.OE+00
O.OE+00
O.OE+00
3.1E-03
O.OE+00
O.OE+00
7.2E-02
2.2E-02
7.1E-02
O.OE+00
6.0E-03
5.7E-02
6.1E-02
1.2E-01
4.4E-02
2.1E-01
O.OE+00
4.5E-02
9.2E-04
3.9E-02
1.2E-01
9.8E-02
O.OE+00
9.2E-04
2.1E-01
2.1E-04
6.3E-01
O.OE+00
O.OE+00
1.8E-01
9.2E-02
6.0E-02
1.0E-01
No
No
No
No
No
No
No
Yes
Yes
No
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
-2.0E-05
-7.1E-06
3.0E-05
-1.3E-04
-2.5E-05
-4.3E-04
O.OE+00
O.OE+00
O.OE+00
3.0E-05
O.OE+00
O.OE+00
-9.1E-05
-3.1E-05
-2.5E-04
O.OE+00
2.0E-04
-1.0E-04
1.3E-05
-3.4E-04
-3.0E-05
-1.9E-04
O.OE+00
-1.4E-03
1.6E-04
-4.2E-05
-5.6E-05
3.1E-04
O.OE+00
-2.7E-04
-8.4E-04
-1.2E-04
-6.3E-04
O.OE+00
O.OE+00
-5.4E-04
-1.3E-04
-7.7E-05
-1.6E-04
0.30
0.03
0.13
0.45
0.13
0.88
0.00
0.00
0.00
0.97
0.00
0.00
0.11
0.04
1.08
0.00
1.39
0.15
0.08
0.53
0.08
0.22
0.00
0.86
0.35
0.07
0.20
0.14
0.00
0.56
1.38
0.19
1.81
0.00
0.00
0.51
0.17
0.12
0.18
57.8%
100.0%
74.9%
74.3%
73.5%
98.2%
0.0%
0.0%
0.0%
54.2%
0.0%
0.0%
100.0%
99.8%
74.5%
0.0%
66.8%
99.3%
54.1%
95.1%
89.8%
100.0%
0.0%
100.0%
91 .9%
97.7%
75.0%
92.9%
0.0%
96.3%
99.9%
89.5%
97.6%
0.0%
0.0%
99.5%
99.9%
99.1%
99.7%
S
D
NT
S
S
D
N/A
ND
ND
NT
N/A
ND
D
D
NT
N/A
NT
D
NT
D
S
D
N/A
D
PI
D
S
PI
N/A
D
D
S
D
N/A
N/A
D
D
D
D
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 1 of 6
-------
Project: GNson Road
User Name: MV
Location: Overburden
State: New Hampshire
Average Median
All
Well
Source/
Tail
Cone
(mg/L)
Cone
(mg/L)
Standard
Deviation
Samples
"ND" ?
Ln Slope
Coefficient
of Variation
Confidence
in Trend
Concentration
Trend
ARSENIC
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
BENZENE
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T
T
T
T
T
T
T
T
T
S
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
S
S
S
S
S
S
S
S
T
S
S
S
T
T
T
T
1 .8E-02
1 .OE-03
1 .8E-03
1.1E-02
2.1E-03
1 .2E-03
9.6E-01
8.5E-01
6.8E-01
3.7E-01
2.5E-01
1 .OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
7.2E-03
5.3E-03
2. OE-03
2. OE-03
2. OE-03
3.4E-03
5.5E-03
2.9E-03
1 .5E-02
2.1E-02
2. OE-03
3.2E-03
1 .9E-02
2.8E-02
1 .3E-02
5.7E-03
2. OE-03
3.5E-03
2.1E-03
4.8E-03
2. OE-03
2. OE-03
2. OE-03
5.2E-03
1.8E-02
1. OE-03
1.2E-03
5.8E-03
1 .4E-03
1 .OE-03
8.8E-01
8.3E-01
6.9E-01
3.7E-01
2.2E-01
1 .OE-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
6.3E-03
5.5E-03
2. OE-03
2. OE-03
2. OE-03
3.5E-03
4.5E-03
2. OE-03
1 .5E-02
1 .9E-02
2. OE-03
2. OE-03
1 .8E-02
2.8E-02
1 .OE-02
5.7E-03
2. OE-03
3.4E-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
5.2E-03
O.OE+00
O.OE+00
1. OE-03
9.1E-03
2.5E-03
3.5E-04
4.6E-01
1.2E-01
1.0E-01
6.0E-02
7.5E-02
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
2.2E-03
1.2E-03
O.OE+00
O.OE+00
O.OE+00
1.3E-03
2.3E-03
1.3E-03
7.2E-03
6.2E-03
O.OE+00
2.2E-03
4.5E-03
1.4E-02
7.7E-03
O.OE+00
O.OE+00
2.0E-03
1.0E-04
8.3E-03
O.OE+00
O.OE+00
O.OE+00
1.6E-03
No
Yes
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
No
No
No
No
No
Yes
No
No
No
No
No
Yes
No
No
No
Yes
Yes
Yes
No
O.OE+00
O.OE+00
-3.8E-04
-3.6E-04
-2.5E-04
-1.4E-04
-2.7E-04
-3.4E-05
-3.7E-04
-3.3E-05
-5.1E-05
O.OE+00
8.7E-35
8.7E-35
8.7E-35
8.7E-35
8.7E-35
8.7E-35
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
-1.6E-04
-8.9E-06
O.OE+00
O.OE+00
O.OE+00
-3.5E-05
-8.9E-04
-2.3E-04
-3.4E-04
-1.7E-04
O.OE+00
-1.3E-03
-6.4E-05
-1.5E-06
-1.6E-03
O.OE+00
O.OE+00
-3.6E-04
5.3E-05
5.6E-05
O.OE+00
O.OE+00
O.OE+00
-2.3E-04
0.00
0.00
0.56
0.86
1.21
0.28
0.48
0.15
0.15
0.16
0.30
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.31
0.22
0.00
0.00
0.00
0.39
0.43
0.45
0.48
0.30
0.00
0.69
0.24
0.50
0.59
0.00
0.00
0.56
0.05
1.74
0.00
0.00
0.00
0.30
0.0%
100.0%
99.7%
89.9%
89.5%
91 .3%
96.4%
72.6%
96.8%
68.3%
68.6%
0.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
0.0%
0.0%
0.0%
100.0%
0.0%
0.0%
97.2%
100.0%
100.0%
0.0%
100.0%
61 .5%
96.1%
97.2%
99.7%
99.1%
100.0%
97.2%
77.9%
100.0%
98.3%
0.0%
100.0%
99.8%
62.8%
56.6%
0.0%
0.0%
100.0%
98.7%
N/A
ND
D
S
NT
PD
D
S
D
S
S
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
D
D
ND
ND
ND
S
D
D
D
D
ND
D
S
D
D
N/A
ND
D
NT
NT
ND
ND
ND
D
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 2 of 6
-------
Project: GNson Road
User Name: MV
Location: Overburden
State: New Hampshire
Average Median
All
Well
Source/ Cone
Tail (mg/L)
Cone
(mg/L)
Standard
Deviation
Samples
"ND" ?
Coefficient
Ln Slope of Variation
Confidence Concentration
in Trend Trend
BENZENE
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
CHLOROBENZENE
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T
T
T
T
T
T
T
T
T
T
T
S
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
S
S
S
S
S
S
S
S
T
S
S
S
T
T
5.8E-03
6.5E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.1E-03
2.0E-03
4.8E-03
6.4E-03
2.3E-03
2.5E-02
2.8E-02
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
1.3E-01
1.0E-01
4.3E-03
2.0E-03
2.0E-03
7.3E-02
7.7E-02
4.9E-02
6.8E-02
6.7E-02
1 .5E-02
1 .3E-02
2.2E-01
7.5E-02
9.6E-03
2.3E-02
2.0E-03
1 .3E-02
2.0E-03
2.0E-03
2.0E-03
2.0E-03
5.7E-03
6.4E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
4.7E-03
6.8E-03
2.0E-03
3.3E-02
2.5E-02
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
1.3E-01
1.0E-01
4.1E-03
2.0E-03
2.0E-03
6.7E-02
8.1E-02
4.8E-02
7.2E-02
5.2E-02
1 .4E-02
1.0E-02
1.8E-01
7.0E-02
8.9E-03
2.3E-02
2.0E-03
1.1E-02
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.1E-03
1.8E-03
O.OE+00
O.OE+00
7.1E-05
6.7E-05
3.1E-04
O.OE+00
2.6E-03
3.7E-03
5.8E-04
1.8E-02
1 .4E-02
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
1.7E-02
1.7E-02
2.7E-03
O.OE+00
O.OE+00
2.9E-02
1.4E-02
1.7E-02
3.1E-02
4.2E-02
8.5E-03
1 .2E-02
1.2E-01
4.7E-02
4.0E-03
O.OE+00
O.OE+00
8.4E-03
O.OE+00
O.OE+00
O.OE+00
O.OE+00
No
No
Yes
Yes
No
No
No
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
No
Yes
Yes
No
No
No
No
No
No
No
No
No
No
No
Yes
No
Yes
Yes
Yes
Yes
-3.2E-04
-2.7E-04
O.OE+00
O.OE+00
-1.2E-05
-9.1E-06
-5.7E-05
O.OE+00
-3.3E-04
-1.6E-04
-5.4E-04
1.7E-04
-9.4E-05
O.OE+00
8.7E-35
8.7E-35
8.7E-35
8.7E-35
8.7E-35
8.7E-35
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
-4.9E-05
-9.9E-06
-1.1E-04
O.OE+00
O.OE+00
-1.0E-04
4.0E-04
1.9E-04
2.1E-04
4.9E-04
-1.8E-04
2.5E-03
-1.4E-04
2.7E-04
-3.8E-04
O.OE+00
O.OE+00
-6.2E-04
O.OE+00
O.OE+00
O.OE+00
O.OE+00
0.36
0.28
0.00
0.00
0.03
0.03
0.15
0.00
0.54
0.58
0.26
0.70
0.50
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.13
0.16
0.62
0.00
0.00
0.40
0.18
0.36
0.45
0.63
0.58
0.94
0.56
0.63
0.41
0.00
0.00
0.67
0.00
0.00
0.00
0.00
99.6%
99.1%
0.0%
100.0%
81.8%
100.0%
88.0%
100.0%
94.3%
75.1%
94.5%
62.7%
69.4%
0.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
0.0%
0.0%
0.0%
100.0%
0.0%
0.0%
88.3%
100.0%
51 .8%
0.0%
100.0%
78.3%
91 .7%
96.6%
87.3%
99.0%
56.3%
99.0%
77.3%
85.1%
70.0%
0.0%
100.0%
100.0%
100.0%
100.0%
0.0%
0.0%
D
D
ND
ND
S
D
S
ND
PD
S
PD
NT
S
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
S
D
S
ND
ND
S
PI
I
NT
I
S
I
S
NT
S
N/A
ND
D
ND
ND
ND
ND
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 3 of 6
-------
Project: GNson Road
User Name: MV
Location: Overburden
State: New Hampshire
Average Median
All
Well
Source/
Tail
Cone
(mg/L)
Cone
(mg/L)
Standard
Deviation
Samples
"ND" ?
Ln Slope
Coefficient
of Variation
Confidence
in Trend
Concentration
Trend
CHLOROBENZENE
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
LEAD
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-18-1
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
T-33-1
T-33-2
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
S
S
S
S
S
S
S
S
S
T
S
S
7.8E-03
7.0E-02
7.9E-02
8.4E-02
2.0E-03
2.0E-03
3.6E-02
3.0E-02
3.4E-02
2.0E-03
8.2E-02
7.2E-02
1 .6E-02
2.6E-02
2.1E-02
2.0E-03
1 .OE-03
1 .OE-03
1 .OE-03
3.3E-03
1 .OE-03
2. OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .3E-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
5.6E-03
3.8E-03
1 .2E-02
2.6E-02
4.5E-03
1 .2E-03
1 .OE-03
2.8E-03
1 JE-02
4.0E-03
1 .OE-02
1 .OE-02
1 .9E-03
1 .2E-03
2.4E-03
1 .3E-02
3.9E-03
7.4E-02
8.5E-02
9.1E-02
2. OE-03
2. OE-03
3.3E-02
2.3E-02
2.9E-02
2. OE-03
6.9E-02
7.6E-02
1.7E-02
2. OE-02
1 .9E-02
2. OE-03
1. OE-03
1. OE-03
1. OE-03
3.2E-03
1 .OE-03
1 .6E-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1. OE-03
1.2E-03
1. OE-02
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
2.6E-03
4.2E-03
1 .OE-03
5.5E-03
5.9E-03
1 .9E-03
1 .OE-03
1.1E-03
1 .4E-02
7.8E-03
2.7E-02
3.2E-02
2.4E-02
O.OE+00
O.OE+00
1.3E-02
1.5E-02
1.5E-02
O.OE+00
2.7E-02
3.1E-02
6.6E-03
2.9E-02
7.5E-03
O.OE+00
O.OE+00
O.OE+00
O.OE+00
2.2E-03
O.OE+00
1.6E-03
O.OE+00
O.OE+00
O.OE+00
6.2E-04
O.OE+00
O.OE+00
3.2E-05
2.3E-19
O.OE+00
O.OE+00
1.1E-02
4.3E-03
7.3E-03
3.0E-02
4.8E-03
3.7E-04
O.OE+00
1.8E-03
3.0E-02
5.4E-03
9.2E-03
1.1E-02
O.OE+00
3.7E-04
2.3E-03
7.7E-03
No
No
No
No
Yes
Yes
No
No
No
Yes
No
No
No
No
No
Yes
Yes
Yes
Yes
No
Yes
No
No
Yes
Yes
No
Yes
Yes
No
Yes
Yes
Yes
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
-3.1E-04
-3.3E-04
-1.8E-04
-1.1E-04
O.OE+00
O.OE+00
-7.4E-05
-9.6E-05
-1.2E-04
O.OE+00
-9.7E-05
2.2E-04
-1.4E-03
5.1E-04
8.1E-05
O.OE+00
O.OE+00
O.OE+00
O.OE+00
-3.5E-04
O.OE+00
-3.8E-04
O.OE+00
O.OE+00
O.OE+00
1.6E-04
O.OE+00
O.OE+00
-7.8E-06
O.OE+00
O.OE+00
O.OE+00
4.6E-04
-6.3E-04
-1.5E-03
-1.6E-03
-4.6E-04
6.8E-06
O.OE+00
-4.4E-04
3.4E-04
-6.9E-04
-2.3E-04
-2.5E-04
O.OE+00
-9.4E-05
-4.9E-04
-9.5E-04
1.00
0.39
0.40
0.28
0.00
0.00
0.36
0.50
0.43
0.00
0.33
0.43
0.42
1.10
0.35
0.00
0.00
0.00
0.00
0.66
0.00
0.79
0.00
0.00
0.00
0.47
0.00
0.00
0.03
0.00
0.00
0.00
1.99
1.12
0.64
1.17
1.07
0.31
0.00
0.65
1.79
1.36
0.92
1.01
0.00
0.31
0.98
0.61
73.9%
98.3%
91 .9%
83.2%
0.0%
100.0%
73.5%
75.0%
81 .8%
100.0%
79.0%
87.4%
99.9%
89.7%
72.0%
0.0%
100.0%
100.0%
100.0%
90.9%
100.0%
97.9%
0.0%
0.0%
0.0%
93.6%
0.0%
0.0%
100.0%
100.0%
100.0%
0.0%
83.6%
98.3%
80.7%
99.8%
90.8%
100.0%
0.0%
98.3%
76.3%
98.7%
67.2%
55.1%
0.0%
87.0%
99.0%
99.8%
S
D
PD
S
ND
ND
S
S
S
ND
S
NT
D
NT
NT
ND
ND
ND
ND
PD
ND
D
N/A
ND
ND
PI
ND
ND
D
ND
ND
ND
NT
D
S
D
PD
I
ND
D
NT
D
S
NT
N/A
S
D
D
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 4 of 6
-------
Project: GNson Road
User Name: MV
Location: Overburden
State: New Hampshire
Average Median
All
Well
Source/
Tail
Cone
(mg/L)
Cone
(mg/L)
Standard
Deviation
Samples
"ND" ?
Ln Slope
Coefficient
of Variation
Confidence
in Trend
Concentration
Trend
LEAD
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
VINYL CHLORIDE
HA-10-A
HA-10-B
HA-10-C
HA-11-A
HA-11-B
HA-11-C
HA-12-A
HA-12-B
HA-12-C
HA-13-B
HA-14
HA-4-B
HA-5-A
HA-5-C
HA-7-B
HA-9-A
T-100-1
T-12-1
T-12-3
T-13-1
T-13-2
T-13-3
T-19-1
T-19-3
T-24-1
T-25-1
T-25-2
T-27-1
T-32-3
s
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
S
s
s
s
s
s
s
s
s
T
1.3E-01
1 .OE-03
8.6E-03
2.7E-03
1 JE-03
1 .2E-03
2.4E-03
3.1E-02
1 .OE-03
2.5E-03
3.0E-02
5.4E-03
3.4E-02
3.9E-03
1 .2E-03
1 .3E-03
1 .9E-02
1 .OE-03
1 .OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2.3E-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2.1E-03
2. OE-03
2.2E-03
2.1E-03
2.7E-03
2. OE-03
2. OE-03
3.2E-03
7.3E-03
2. OE-03
2. OE-03
2. OE-03
3.7E-02
1 .OE-03
8.6E-03
2.6E-03
1 .OE-03
1 .OE-03
2.7E-03
3.1E-02
1 .OE-03
1 .4E-03
1 JE-02
2.6E-03
2.9E-02
1 .OE-03
1 .OE-03
1 .OE-03
9.8E-03
1 .OE-03
1 .OE-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2.1E-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2. OE-03
2.7E-01
O.OE+00
O.OE+00
1.9E-03
1.3E-03
2.7E-04
1. OE-03
O.OE+00
O.OE+00
1.7E-03
3.5E-02
8.6E-03
1 .8E-02
5.0E-03
4.5E-04
6.9E-04
2.3E-02
1.2E-04
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
5.1E-04
8.4E-19
O.OE+00
O.OE+00
O.OE+00
2.2E-04
O.OE+00
6.6E-04
2.7E-04
8.8E-04
O.OE+00
O.OE+00
2.8E-03
8.7E-03
O.OE+00
O.OE+00
O.OE+00
No
Yes
No
No
No
No
No
No
Yes
No
No
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
Yes
Yes
No
Yes
No
No
No
Yes
Yes
No
No
Yes
Yes
Yes
-1.2E-03
O.OE+00
O.OE+00
-3.8E-04
5.9E-06
1.9E-05
4.9E-05
O.OE+00
O.OE+00
-5.4E-04
-1. OE-03
-3.4E-04
-1.8E-04
-2.9E-04
-5.1E-05
-1.8E-04
-8.5E-04
8.3E-05
O.OE+00
8.7E-35
8.7E-35
8.7E-35
8.7E-35
8.7E-35
8.7E-35
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
-9.4E-05
1.1E-19
O.OE+00
O.OE+00
O.OE+00
-4.9E-05
O.OE+00
-8.0E-05
-3.4E-05
1.1E-05
O.OE+00
O.OE+00
-2.2E-04
-3.6E-04
O.OE+00
O.OE+00
O.OE+00
2.14
0.00
0.00
0.70
0.73
0.24
0.42
0.00
0.00
0.68
1.17
1.59
0.52
1.27
0.39
0.54
1.22
0.12
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.00
0.23
0.00
0.00
0.00
0.00
0.11
0.00
0.29
0.13
0.33
0.00
0.00
0.89
1.19
0.00
0.00
0.00
93.5%
0.0%
0.0%
91 .6%
100.0%
60.7%
58.9%
0.0%
100.0%
99.8%
95.2%
84.6%
79.0%
73.6%
66.4%
60.6%
96.6%
100.0%
0.0%
100.0%
100.0%
100.0%
100.0%
100.0%
100.0%
0.0%
0.0%
0.0%
100.0%
0.0%
0.0%
94.8%
100.0%
100.0%
0.0%
100.0%
95.0%
100.0%
87.7%
78.3%
54.6%
100.0%
100.0%
87.1%
75.6%
100.0%
0.0%
100.0%
PD
ND
N/A
PD
I
NT
NT
N/A
ND
D
D
NT
S
NT
S
S
D
I
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
PD
I
ND
ND
ND
PD
ND
S
S
NT
ND
ND
S
NT
ND
ND
ND
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 5 of 6
-------
Project: GNson Road
User Name: MV
Location: Overburden
State: New Hampshire
Well
Average Median All
Source/ Cone Cone standard Samples
Tail (mg/L) (mg/L) Deviation "ND" ? Ln Slope
Coefficient
of Variation
Confidence Concentration
in Trend Trend
VINYL CHLORIDE
T-33-1
T-33-2
T-34-1
T-42-1
T-44-1
T-47
T-48-2
T-48-3
T-48-4
T-54-2
T-58
T-60-1
T-60-3
T-61
T-62-2
T-63-1
T-64-2
T-64-3
T-8-1
T-8-2
T-98
Note: Increasing
Applicable (N/A)
s
s
s
T
T
T
T
T
T
T
T
T
T
T
T
T
T
T
S
S
T
2.4E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.1E-03
2.0E-03
2.1E-03
2.0E-03
2.0E-03
2.2E-03
2.1E-03
2.1E-03
2.0E-03
2.0E-03
5.6E-03
2.0E-03
2.3E-03
2.0E-03
2.0E-03
(I); Probably Increasing (PI)
- Due to insufficient Data (<
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
5.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
1.1E-03
O.OE+00
O.OE+OO
O.OE+00
O.OE+00
O.OE+00
3.3E-04
O.OE+00
3.4E-04
O.OE+00
O.OE+00
3.9E-04
1.6E-04
1.6E-04
O.OE+00
O.OE+00
4.2E-03
O.OE+00
7.6E-04
O.OE+00
O.OE+00
No
Yes
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
No
No
No
Yes
Yes
No
Yes
No
Yes
Yes
2.3E-04
O.OE+00
O.OE+00
O.OE+00
O.OE+00
O.OE+00
-7.4E-06
O.OE+00
-3.2E-05
O.OE+00
O.OE+00
-7.6E-05
-2.7E-05
-2.7E-05
O.OE+00
O.OE+00
-4.1E-04
O.OE+00
2.1E-04
O.OE+00
O.OE+00
; Stable (S); Probably Decreasing (PD); Decreasing (D);
4 sampling events); COV = Coefficient of Variation
0.46
0.00
0.00
0.00
0.00
0.00
0.16
0.00
0.16
0.00
0.00
0.18
0.08
0.08
0.00
0.00
0.74
0.00
0.32
0.00
0.00
No Trend (NT);
98.6%
100.0%
100.0%
0.0%
0.0%
100.0%
100.0%
100.0%
71 .7%
0.0%
100.0%
93.6%
87.3%
87.3%
100.0%
100.0%
88.7%
100.0%
99.9%
100.0%
0.0%
Non-detect (ND); Not
I
ND
ND
ND
ND
ND
D
ND
S
ND
ND
PD
S
S
ND
ND
S
ND
I
ND
ND
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 6 of 6
-------
MAROS Mann-Kendall Statistics Summary
Well: HA-5-A
Well Type: T
COC: BENZENE
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
~
B)
o
1
c
o
o
1 op n9
1 .ŁC~UŁ
1.0E-02-
8.0E-03 -
6.0E-03
4.0E-03 -
2.0E-03 -
n np4-nn .
O° ^S o° ^ O° ^ V^ <$^ <$^ V^ ^
ť
* . *
Mann Kendall S Statistic:
Confidence in
Trend:
I 98.0%
Coefficient of Variation:
0.31
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
HA-5-A
HA-5-A
HA-5-A
HA-5-A
HA-5-A
HA-5-A
HA-5-A
HA-5-A
HA-5-A
HA-5-A
HA-5-A
Well Type
T
T
T
T
T
T
T
T
T
T
T
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/1/2009
Constituent
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
Result (mg/L) Flag
1.1E-02
1.1E-02
6.8E-03
6.1E-03
5.8E-03
6.9E-03
9.5E-03
6.1E-03
6.3E-03
4.2E-03
6.0E-03
Number of
Samples
1
1
1
1
1
1
2
1
1
1
2
Number of
Detects
1
1
1
1
1
1
2
1
1
1
2
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
7/30/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: HA-10-A
Well Type: T
COC: ARSENIC
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
-------
MAROS Mann-Kendall Statistics Summary
Well: HA-10-C
Well Type: T
COC: ARSENIC
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
B)
o
1
c
o
o
5.0E-02 -
4.0E-02 -
3.0E-02
2.0E-02
1.0E-02-
n np4-nn .
* * *
* *
Mann Kendall S Statistic:
I 12
Confidence in
Trend:
I 87.0%
Coefficient of Variation:
0.13
Mann Kendall
Concentration Trend:
(See Note)
[ NT
Data Table:
Well
HA-10-C
HA-10-C
HA-10-C
HA-10-C
HA-10-C
HA-10-C
HA-10-C
HA-10-C
HA-10-C
Well Type
T
T
T
T
T
T
T
T
T
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2005
3/1/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
3.6E-02
3.9E-02
3.4E-02
3.3E-02
3.8E-02
5.0E-02
4.1E-02
3.7E-02
4.1E-02
Number of
Samples
1
1
2
1
1
1
2
1
1
Number of
Detects
1
1
2
1
1
1
2
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
7/30/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-25-1
Well Type: s
COC: BENZENE
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
6.(
_ 5.0E-02
Ł 4.0E-02
o
Ť 3.0E-02
g 2.0E-02
o
0 1.0E-02-
0.
^
Mann Kendall S Statistic:
Confidence in
Trend:
I 61.4%
Coefficient of Variation:
0.50
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-25-1
T-25-1
T-25-1
T-25-1
T-25-1
T-25-1
T-25-1
Well Type
s
s
s
s
s
s
s
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
3/1/2009
Constituent
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
Result (mg/L) Flag
3.8E-02
1.7E-02
3.2E-02
2.2E-02
5.1E-02
8.1E-03
2.8E-02
Number of
Samples
1
2
1
1
1
1
1
Number of
Detects
1
2
1
1
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
7/30/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-34-1
Well Type: s
COC: ARSENIC
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
O* T? 0° *S
2.5E+00
2- 2.0E+00
E
c 1.5&-00
o
1
Ł 1.0&-00
S
c
O 5.0E-01
O.OE+00
Mann Kendall S Statistic:
I ~29
Confidence in
Trend:
I 99.5%
Coefficient of Variation:
1.81
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-34-1
T-34-1
T-34-1
T-34-1
T-34-1
T-34-1
T-34-1
T-34-1
T-34-1
T-34-1
Well Type
s
s
s
s
s
s
s
s
s
s
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/1/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
2.7E-01
3.1E-01
2.1E+00
2.3E-01
1.6E-01
6.6E-02
8.6E-02
6.5E-02
5.0E-02
1.2E-01
Number of
Samples
1
1
2
1
1
2
1
1
1
1
Number of
Detects
1
1
2
1
1
2
1
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/1/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: 1-48-2
Well Type: T
COC: CHLOROBENZENE
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
1.2E-01
1.0E-01
__ 8.0E-02
| 6.0E-02
g 4.0E-02
o
0 2.0E-02 -
O.OE+00
Date
^ o" ^ sť
ť ť
Mann Kendall S Statistic:
Confidence in
Trend:
I 77.7%
Coefficient of Variation:
0.39
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-48-2
T-48-2
T-48-2
T-48-2
T-48-2
T-48-2
T-48-2
T-48-2
T-48-2
T-48-2
T-48-2
Well Type
T
T
T
T
T
T
T
T
T
T
T
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/1/2009
Constituent
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
Result (mg/L) Flag
4.6E-02
5.9E-02
7.6E-02
9.3E-02
9.4E-02
1.1E-01
8.2E-02
7.4E-02
7.2E-02
4.6E-02
1.5E-02
Number of
Samples
1
1
1
1
1
1
2
1
1
2
1
Number of
Detects
1
1
1
1
1
1
2
1
1
2
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/7/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-13-3
Well Type: s
COC: CHLOROBENZENE
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
Mann Kendall S Statistic:
_j
E.
o
1
Concent
1.4E-01 -
1.2E-01 -
1.0E-01 -
8.0E-02
6.0E-02
4.0E-02
2.0E-02 -
n np4-nn .
*
*
*
I 29
Confidence in
Trend:
I 98.7%
Coefficient of Variation:
0.63
Mann Kendall
Concentration Trend:
(See Note)
[ I
Data Table:
Well
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
Well Type
s
s
s
s
s
s
s
s
s
s
s
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/1/2009
Constituent
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
Result (mg/L) Flag
1.0E-02
7.3E-02
3.0E-02
7.5E-02
3.2E-02
4.2E-02
5.2E-02
5.0E-02
1.5E-01
1.2E-01
1.1E-01
Number of
Samples
1
1
1
1
1
1
2
1
1
3
1
Number of
Detects
1
1
1
1
1
1
2
1
1
3
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/7/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-19-3
Well Type: s
COC: CHLOROBENZENE
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
o
I
o
o
A OF 09
t.UC~UŁ
3.5E-02 -
3.0E-02 -
2.5E-02 -
2.0E-02
1.5E-02-
1.0E-02-
5.0E-03 -
n np4-nn .
o ^T ,v js.' ,v xŤ.
ťcŤ o >^o o >^o o
o v^ o ^** o ^
*
4 *
, * *
Mann Kendall S Statistic:
I 13
Confidence in
Trend:
I 99.2%
Coefficient of Variation:
0.94
Mann Kendall
Concentration Trend:
(See Note)
[ I
Data Table:
Well
T-19-3
T-19-3
T-19-3
T-19-3
T-19-3
T-19-3
Well Type
s
s
s
s
s
s
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
Constituent
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
Result (mg/L) Flag
3.2E-03
4.3E-03
1.4E-02
5.9E-03
1.5E-02
3.6E-02
Number of
Samples
1
1
1
1
1
1
Number of
Detects
1
1
1
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/7/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: 1-64-2
Well Type: T
COC: CHLOROBENZENE
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
1.2E-01
1.0E-01
__ 8.0E-02
| 6.0E-02
g 4.0E-02
o
0 2.0E-02 -
O.OE+00
Mann Kendall S Statistic:
I 15
Confidence in
Trend:
I 98.5%
Coefficient of Variation:
0.43
Mann Kendall
Concentration Trend:
(See Note)
[ I
Data Table:
Well
T-64-2
T-64-2
T-64-2
T-64-2
T-64-2
T-64-2
T-64-2
Well Type
T
T
T
T
T
T
T
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
3/1/2009
Constituent
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
Result (mg/L) Flag
2.9E-02
3.6E-02
6.4E-02
9.8E-02
7.6E-02
1.1E-01
9.1E-02
Number of
Samples
2
1
1
1
1
1
1
Number of
Detects
2
1
1
1
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/7/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-64-3
Well Type: T
COC: CHLOROBENZENE
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
-
°
2.5E-02
2- 2.0E-02
E
o
1.5E-02
Ł 1.0E-02
8
O 5.0E-03 -
0.
Mann Kendall S Statistic:
Confidence in
Trend:
I 99.9%
Coefficient of Variation:
0.42
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-64-3
T-64-3
T-64-3
T-64-3
T-64-3
T-64-3
Well Type
T
T
T
T
T
T
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
Constituent
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
Result (mg/L) Flag
2.3E-02
2.2E-02
2.1E-02
1.2E-02
9.9E-03
8.0E-03
Number of
Samples
2
1
1
1
1
1
Number of
Detects
2
1
1
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/7/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: 1-25-2
Well Type: s
COC: ARSENIC
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
-
°
_j
1
o
1
Concen
9.UOU 1 '
8.0E-01 -
7.0E-01 -
6.0E-01 -
5.0E-01
4.0E-01
3.0E-01 -
2.0E-01 -
1.0E-01 -
n np4-nn .
,
ť *
*
*
Mann Kendall S Statistic:
Confidence in
Trend:
I 86.4%
Coefficient of Variation:
0.14
Mann Kendall
Concentration Trend:
(See Note)
[ NT
Data Table:
Well
T-25-2
T-25-2
T-25-2
T-25-2
T-25-2
T-25-2
Well Type
s
s
s
s
s
s
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
5.3E-01
6.2E-01
8.1E-01
6.8E-01
7.3E-01
7.3E-01
Number of
Samples
1
1
2
1
1
1
Number of
Detects
1
1
2
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/1/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-13-3
Well Type: s
COC: ARSENIC
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
Mann Kendall S Statistic:
_j
o
1
Concent
1.4E+00 -
1.2E+00 -
1.0E+00 -
8.0E-01
6.0E-01 -
4.0E-01
2.0E-01 -
n np4-nn .
Ť
Ť
ť * * *
'
Confidence in
Trend:
I 100.0%
Coefficient of Variation:
0.22
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
T-13-3
Well Type
s
s
s
s
s
s
s
s
s
s
s
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/1/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
1.4E+00
1.2E+00
1.0E+00
9.6E-01
1.0E+00
9.9E-01
9.0E-01
9.9E-01
8.5E-01
7.3E-01
6.1E-01
Number of
Samples
1
1
2
1
1
1
2
1
1
3
1
Number of
Detects
1
1
2
1
1
1
2
1
1
3
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/1/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-8-1
Well Type: s
COC: BENZENE
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
I 0.1
o
o
O
0.01 -
0.001
Date
VŤ
.#
Mann Kendall S Statistic:
Confidence in
Trend:
I 66.7%
Coefficient of Variation:
0.70
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-8-1
T-8-1
T-8-1
T-8-1
T-8-1
T-8-1
T-8-1
Well Type
s
s
s
s
s
s
s
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
3/1/2009
Constituent
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
Result (mg/L) Flag
4.2E-02
3.3E-02
3.8E-02
2.0E-03 ND
1.7E-02
3.0E-03
4.2E-02
Number of
Samples
1
1
1
1
1
1
1
Number of
Detects
1
1
1
0
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
7/30/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-60-3
Well Type: T
COC: LEAD
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
I 0.1
o
o
O
0.01 -
0.001
Date
Mann Kendall S Statistic:
I ~29
Confidence in
Trend:
I 98.7%
Coefficient of Variation:
1.17
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-60-3
T-60-3
T-60-3
T-60-3
T-60-3
T-60-3
T-60-3
T-60-3
T-60-3
T-60-3
T-60-3
Well Type
T
T
T
T
T
T
T
T
T
T
T
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/1/2009
Constituent
LEAD
LEAD
LEAD
LEAD
LEAD
LEAD
LEAD
LEAD
LEAD
LEAD
LEAD
Result (mg/L)
8.9E-02
3.8E-02
8.5E-02
3.0E-02
6.1E-02
1.0E-03
1.0E-03
1.0E-03
1.0E-03
1.0E-03
1.7E-02
Flag
ND
ND
ND
ND
ND
Number of
Samples
1
1
2
1
1
1
2
1
1
1
1
Number of
Detects
1
1
2
1
1
0
0
0
0
0
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/1/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-63-1
Well Type: T
COC: ARSENIC
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
^
_J
1
o
1
c
Concei
2.0E+00 -
1.8E+00 -
1.6E+00 -
1.4E+00 -
1.2E+00
1.0E+00
8.0E-01
6.0E-01
4.0E-01
2.0E-01 -
n np4-nn .
0* & 0° ^ 0° ^ S> ^
*
^
* *
^
* * *
Mann Kendall S Statistic:
Confidence in
Trend:
I 98.4%
Coefficient of Variation:
0.48
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-63-1
T-63-1
T-63-1
T-63-1
T-63-1
T-63-1
T-63-1
T-63-1
Well Type
T
T
T
T
T
T
T
T
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
3/1/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
1.3E+00
1.9E+00
9.7E-01
1.1E+00
7.8E-01
5.5E-01
5.6E-01
5.8E-01
Number of
Samples
1
1
2
1
1
1
2
1
Number of
Detects
1
1
2
1
1
1
2
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/1/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: 1-64-2
Well Type: T
COC: ARSENIC
Time Period: 12/1/1999 to 3/1/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
1.2E+00
_ 1.0E+00
Ł 8.0E-01
| 6.0E-01
§ 4.0E-01
o
0 2.0E-01 -
0.
^
Mann Kendall S Statistic:
Confidence in
Trend:
I 88.1%
Coefficient of Variation:
0.15
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-64-2
T-64-2
T-64-2
T-64-2
T-64-2
T-64-2
T-64-2
Well Type
T
T
T
T
T
T
T
Effective
Date
12/1/1999
4/15/2000
10/1/2000
4/1/2001
10/1/2001
4/1/2002
3/1/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
9.6E-01
8.8E-01
8.3E-01
7.6E-01
1.1E+00
6.9E-01
8.0E-01
Number of
Samples
1
1
2
1
1
1
1
Number of
Detects
1
1
2
1
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/1/2009
Page 1 of 1
-------
MAROS Zeroth Moment Analysis
Project: Overburden
Location: Nashua
User Name: MV
State: New Hampshire
COC: ARSENIC
Change in Dissolved Mass Over Time
Date
7.0&-01
6.0&-01 -
5.0&-01 -
* 4.0&-01 -
I 3.0&-01 -
S
2.0&-01 -
1.0&-01 -
0.0&-00
Porosity: 0.30
Saturated Thickness:
Uniform: 20 ft
Mann Kendall S Statistic:
Confidence in
Trend:
I 978%
Coefficient of Variation:
066
Zeroth Moment
Trend:
Data Table:
Effective Date
12/1/1999
4/15/2000
10/1/2000
12/1/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/1/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Estimated
Mass (Kg)
4.7E+01
4.5E+01
6.1E+01
O.OE+00
4.0E+01
4.1E+01
1.8E+01
1.7E+01
1.2E+01
1.7E+01
8.8E+00
2.9E+01
Number of Wells
21
21
22
1
23
22
15
16
13
14
15
33
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A)
Due to insufficient Data (< 4 sampling events); ND = Non-detect. Moments are not calculated for sample events with less than 6 wells.
MAROS Version 2.2, 2006, AFCEE
8/18/2009
Page 1 of 1
-------
MAROS Spatial Moment Analysis Summary
Project: Gilson Road
Location: Overburden
Effective Date
Select Wells Exterior of Slurry Wall
Oth Moment 1st Moment (Center of Mass)
Estimated Source
Mass (Kg) Xc (ft) Yc (ft) Distance (ft)
User Name: MV
State: New Hampshire
2nd Moment (Spread)
Sigma XX Sigma YY
(sq ft) (sq ft)
Number of
Wells
ARSENIC
7/1/1999
7/1/2000
7/1/2001
7/1/2002
7/1/2003
7/1/2004
7/1/2005
7/1/2006
7/1/2009
BENZENE
7/1/1999
7/1/2000
7/1/2001
7/1/2002
7/1/2003
7/1/2004
7/1/2005
7/1/2006
7/1/2009
CHLOROBENZENE
7/1/1999
7/1/2000
7/1/2001
7/1/2002
7/1/2003
7/1/2004
7/1/2005
7/1/2006
7/1/2009
LEAD
7/1/1999
7/1/2000
7/1/2001
7/1/2002
7/1/2003
1.1E+01
8.4E+00
9.4E+00
6.3E+00
6.1E+00
1.4E+00
4.0E+00
1.5E+00
6.2E+00
O.OE+00
3.2E-01
3.5E-01
3.4E-01
3.1E-01
2.4E-01
3.4E-01
1.9E-01
2.8E-01
3.9E-01
1.2E+00
1.5E+00
1.4E+00
1.4E+00
8.3E-01
1.1E+00
6.8E-01
1.3E+00
3.7E-01
5.6E-01
3.9E-01
1.2E-01
2.1E-01
1,021,724
1,021,749
1,021,768
1,021,704
1,021,748
1,021,933
1,021,732
1,021,877
1,021,721
1,021,763
1,021,746
1,021,757
1,021,809
1,021,912
1,021,791
1,021,905
1,021,782
1,021,772
1,021,776
1,021,791
1,021,756
1,021,827
1,021,920
1,021,809
1,021,915
1,021,764
1,021,694
1,021,725
1,021,747
1,021,630
1,021,803
80,808
80,737
80,759
80,680
80,732
80,916
80,724
80,854
80,714
80,966
80,955
80,966
80,991
81,092
80,991
81,121
81,002
80,981
80,917
80,926
80,853
80,908
81,019
80,920
81,042
80,896
81,070
81,098
81,072
81,054
81,094
1,625
1,564
1,561
1,571
1,562
1,532
1,570
1,532
1,574
1,692
1,698
1,696
1,674
1,672
1,688
1,699
1,702
1,695
1,650
1,645
1,626
1,605
1,613
1,628
1,634
1,646
1,813
1,808
1,775
1,851
1,750
22,811
24,195
25,533
16,381
30,337
16,479
28,482
10,904
21,389
40,684
41,647
40,258
38,200
8,820
36,318
8,431
37,775
3,953
30,861
31,305
29,161
36,485
12,598
36,601
12,347
29,060
33,289
24,418
29,592
6,687
29,159
39,911
26,596
35,735
8,358
21,252
18,536
27,045
36,330
23,450
63,066
63,456
61,672
59,866
36,086
57,069
37,510
63,050
43,416
77,509
73,216
61,130
59,764
40,778
62,146
46,335
72,217
27,225
30,063
33,508
13,562
47,720
12
14
14
12
11
8
10
9
14
4
14
14
13
11
8
10
8
13
7
14
14
13
11
8
10
8
13
12
14
14
9
11
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 1 of 3
-------
P roj ect: Gil son Road
Location: Overburden
User Name: MV
State: New Hampshire
Effective Date
Oth Moment 1st Moment (Center of Mass)
Estimated Source
Mass (kg) Xc (ft) Yc (ft) Distance (ft)
2nd Moment (Spread)
Sigma XX Sigma YY
(sq ft) (sq ft)
Number of
Wells
LEAD
7/1/2004
7/1/2005
7/1/2006
7/1/2009
VINYL CHLORIDE
7/1/1999
7/1/2000
7/1/2001
7/1/2002
7/1/2003
7/1/2004
7/1/2005
7/1/2006
7/1/2009
6.7E-02
2.8E-01
1.5E-01
4.8E-01
O.OE+00
3.1E-01
3.0E-01
2.5E-01
2.5E-01
1.7E-01
2.5E-01
1.7E-01
2.5E-01
1,021,693
1,021,814
1,021,836
1,021,788
1,021,763
1,021,750
1,021,787
1,021,787
1,021,902
1,021,787
1,021,902
1,021,787
81,038
81,100
81,091
81,147
81,003
80,991
81,037
81,035
81,140
81,037
81,141
81,037
1,792
1,746
1,724
1,797
1,716
1,718
1,722
1,720
1,715
1,722
1,716
1,722
3,167
26,871
17,404
35,893
44,131
44,543
43,139
35,995
7,797
34,440
7,710
37,014
26,836
41,055
33,268
30,366
61,074
59,756
56,670
59,405
35,875
58,123
35,560
59,337
7
10
9
14
1
14
14
13
11
8
10
8
13
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 2 of 3
-------
Project: Gilson Road
Location: Overburden
User Name: MV
State: New Hampshire
Moment Type Constituent
Zeroth Moment: Mass
ARSENIC
BENZENE
CHLOROBENZENE
LEAD
VINYL CHLORIDE
1st Moment: Distance to Source
ARSENIC
BENZENE
CHLOROBENZENE
LEAD
VINYL CHLORIDE
2nd Moment: Sigma XX
ARSENIC
BENZENE
CHLOROBENZENE
LEAD
VINYL CHLORIDE
2nd Moment: Sigma YY
ARSENIC
BENZENE
CHLOROBENZENE
LEAD
VINYL CHLORIDE
Coefficient
of Variation
0.55
0.43
0.35
0.58
0.43
0.02
0.01
0.02
0.02
0.00
0.29
0.45
0.48
0.50
0.48
0.38
0.21
0.23
0.30
0.20
Mann-Kendall
S Statistic
-22
-6
-4
-6
-12
-6
6
-8
-16
2
-4
-18
2
-4
-16
-4
-12
-4
6
-14
Confidence
in Trend
98.8%
69.4%
61 .9%
69.4%
87.0%
69.4%
72.6%
76.2%
94.0%
54.8%
61 .9%
98.4%
54.0%
61 .9%
96.9%
61 .9%
91.1%
61 .9%
69.4%
94.6%
Moment
Trend
D
S
S
S
S
S
NT
S
PD
NT
S
D
NT
S
D
S
PD
S
NT
PD
Note: The following assumptions were applied for the calculation of the Zeroth Moment:
Porosity: 0.30
Saturated Thickness: Uniform: 20 ft
Mann-Kendall Trend test performed on all sample events for each constituent. Increasing (I); Probably Increasing (PI); Stable (S);
Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A)-Due to insufficient Data (< 4 sampling events).
Note: The Sigma XX and Sigma YY components are estimated using the given field coordinate system and then rotated to align with the
estimated groundwater flow direction. Moments are not calculated for sample events with less than 6 wells.
MAROS Version 2.2, 2006, AFCEE
Friday, September 04, 2009
Page 3 of 3
-------
MAROS Zeroth Moment Analysis
Project: Gilson Road
Location: Overburden Select Wells Exterior of Slurry Wall
User Name: MV
State: New Hampshire
COC: ARSENIC
Change in Dissolved Mass Over Time
Date
1.0&-01 -
8.0&-00 -
O)
Ť 6.0E+00
ro
S 4.0&-00 -
2.0&-00 -
Porosity: 0.30
Saturated Thickness:
Uniform: 20 ft
Mann Kendall S Statistic:
Confidence in
Trend:
I 98.8%
Coefficient of Variation:
1 0.55
Zeroth Moment
Trend:
Data Table:
Effective Date
7/1/1999
7/1/2000
7/1/2001
7/1/2002
7/1/2003
7/1/2004
7/1/2005
7/1/2006
7/1/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Estimated
Mass (Kg)
1.1E+01
8.4E+00
9.4E+00
6.3E+00
6.1E+00
1 .4E+00
4.0E+00
1 .5E+00
6.2E+00
Number of Wells
12
14
14
12
11
8
10
9
14
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A)
Due to insufficient Data (< 4 sampling events); ND = Non-detect. Moments are not calculated for sample events with less than 6 wells.
MAROS Version 2.2, 2006, AFCEE
9/4/2009
Page 1 of 1
-------
MAROS Zeroth Moment Analysis
Project: Gilson Road
Location: Overburden Select Wells Exterior of Slurry Wall
User Name: MV
State: New Hampshire
COC: BENZENE
Change in Dissolved Mass Over Time
Date
vJ?
in
u>
ro
3.5E-01 -
3.0E-01 -
2.5E-01 -
2.0E-01 -
1.5E-01 -
1.0E-01 -
5.0E-02 -
n nR-nn .
* * *
^
*
Porosity: 0.30
Saturated Thickness:
Uniform: 20 ft
Mann Kendall S Statistic:
-6
Confidence in
Trend:
I 6974%
Coefficient of Variation:
I °'43
Zeroth Moment
Trend:
Data Table:
Effective Date
7/1/1999
7/1/2000
7/1/2001
7/1/2002
7/1/2003
7/1/2004
7/1/2005
7/1/2006
7/1/2009
Constituent
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
Estimated
Mass (Kg)
O.OE+OO
3.2E-01
3.5E-01
3.4E-01
3.1E-01
2.4E-01
3.4E-01
1.9E-01
2.8E-01
Number of Wells
4
14
14
13
11
8
10
8
13
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A)
Due to insufficient Data (< 4 sampling events); ND = Non-detect. Moments are not calculated for sample events with less than 6 wells.
MAROS Version 2.2, 2006, AFCEE
9/4/2009
Page 1 of 1
-------
MAROS Zeroth Moment Analysis
Project: Gilson Road
Location: Overburden Select Wells Exterior of Slurry Wall
User Name: MV
State: New Hampshire
COC:CHLOROBENZENE
Change in Dissolved Mass Over Time
O)
in
as
1.8E+00 -
1.6E+00 -
1.4E+00 -
1.2E+00
1.0E+00
8.0E-01 -
6.0E-01 -
4.0E-01 -
2.0E-01
n nR-nn .
Date
X^ X^ X^ X^ X^ X^ X^ X^ X^
^
- . '
J?
Porosity: 0.30
Saturated Thickness:
Uniform: 20 ft
Mann Kendall S Statistic:
-4
Confidence in
Trend:
I 6T9%
Coefficient of Variation:
I 0.35
Zeroth Moment
Trend:
Data Table:
Effective Date
7/1/1999
7/1/2000
7/1/2001
7/1/2002
7/1/2003
7/1/2004
7/1/2005
7/1/2006
7/1/2009
Constituent
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
Estimated
Mass (Kg)
3.9E-01
1.2E+00
1.5E+00
1.4E+00
1.4E+00
8.3E-01
1.1E+00
6.8E-01
1.3E+00
Number of Wells
7
14
14
13
11
8
10
8
13
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A)
Due to insufficient Data (< 4 sampling events); ND = Non-detect. Moments are not calculated for sample events with less than 6 wells.
MAROS Version 2.2, 2006, AFCEE
9/4/2009
Page 1 of 1
-------
September, 2009
GROUNDWATER MONITORING NETWORK OPTIMIZATION
GILSON ROAD SUPERFUND SITE
Nashua, New Hampshire
APPENDIX B:
Bedrock Aquifer Reports
COC Assessment
Trend Summary Report:
Selected Individual Trend Summary Reports
Zeroth Moment Report: Arsenic
-------
MAROS COC Assessment
Project: Gilson Road Site
Location: Bedrock
Toxicitv:
User Name: MV
State: New Hampshire
Contaminant of Concern
ARSENIC
1 ,4-DIOXANE (P-DIOXANE)
LEAD
BENZENE
Representative
Concentration
(mg/L)
4.3E-01
3.5E-02
2.3E-02
7.3E-03
PRG
(mg/L)
1.0E-02
3.0E-03
1 .5E-02
5.0E-03
Percent
Above
PRG
4216.0%
1058.3%
55.3%
46.3%
Note: Top COCs by toxicity were determined by examining a representative concentration for each compound over the entire site. The
compound representative concentrations are then compared with the chosen PRG for that compound, with the percentage exceedance
from the PRG determining the compound's toxicity. All compounds above exceed the PRG.
Prevalence:
Contaminant of Concern
1 ,4-DIOXANE (P-DIOXANE)
ARSENIC
BENZENE
LEAD
Class
ORG
MET
ORG
MET
Total
Wells
2
21
21
21
Total
Exceedances
2
17
10
7
Percent
Exceedances
100.0%
81 .0%
47.6%
33.3%
Total
detects
2
21
14
18
Note: Top COCs by prevalence were determined by examining a representative concentration for each well location at the site. The
total exceedances (values above the chosen PRGs) are compared to the total number of wells to determine the prevalence of the
compound.
Mobility:
Contaminant of Concern
Kd
1,4-DIOXANE (P-DIOXANE)
BENZENE
LEAD
ARSENIC
0.000479
0.0984
10
25
Note: Top COCs by mobility were determined by examining each detected compound in the dataset and comparing their
mobilities (Koc's for organics, assume foe = 0.001, and Kd's for metals).
Contaminants of Concern (COC's)
ARSENIC
BENZENE
CHLOROBENZENE
LEAD
CHLOROFORM
MAROS Version 2.2, 2006, AFCEE
Monday, August 10, 2009
Page 1 of 1
-------
MAROS Statistical Trend Analysis Summary
Project: Gilson Road Site
Location: Bedrock
User Name: MV
State: New Hampshire
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Well
Source/
Tail
Number Number
of of
Samples Detects
Average Median
Cone. Cone.
(mg/L) (mg/L)
All
Samples
"ND" ?
Mann-
Kendall
Trend
Linear
Regression
Trend
ARSENIC
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
BENZENE
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T
T
T
T
S
S
S
S
S
S
S
T
S
T
T
T
T
T
T
S
T
T
T
T
T
S
S
S
S
S
S
S
T
1
11
11
9
11
7
11
7
7
6
6
10
9
1
1
8
1
7
8
10
1
1
11
11
9
11
7
7
6
7
6
7
11
1
11
11
9
11
7
11
7
7
6
6
10
9
1
1
8
1
3
8
10
1
0
11
4
0
11
7
0
6
6
6
7
5
5.6E-01
7.2E-01
5.3E-01
8.3E-03
8.5E-01
1 .5E+00
1.6E-01
8.3E-01
8.4E-02
8.9E-01
3.5E-01
8.3E-03
1.6E-02
1.1E-02
1.0E-03
8.5E-01
4.2E-01
3.9E-02
5.7E-01
6.9E-01
2.1E-03
2.0E-03
7.1E-03
2.1E-03
2.0E-03
9.5E-03
2.8E-02
2.0E-03
1.4E-02
1.8E-02
9.9E-03
8.6E-03
2.6E-03
5.6E-01
6.9E-01
5.3E-01
6.6E-03
8.4E-01
1.5E+00
1 .6E-01
9.1E-01
8.9E-02
8.3E-01
3.4E-01
7.7E-03
1 .5E-02
1.1E-02
1 .OE-03
8.3E-01
4.2E-01
1 .OE-03
4.5E-01
6.7E-01
2.1E-03
2. OE-03
6.9E-03
2. OE-03
2. OE-03
8.8E-03
2.9E-02
2.0E-03
1 .2E-02
1.6E-02
8.2E-03
7.7E-03
2.0E-03
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
No
No
Yes
No
No
Yes
No
No
No
No
No
N/A
D
D
D
D
S
S
PD
D
S
S
PD
I
N/A
N/A
D
N/A
NT
D
S
N/A
ND
D
S
ND
D
D
ND
S
D
D
S
PD
N/A
D
D
D
D
D
D
D
D
S
D
S
I
N/A
N/A
D
N/A
NT
D
S
N/A
ND
D
S
ND
D
D
ND
S
D
D
S
PD
MAROS Version 2.2, 2006, AFCEE
Monday, August 10, 2009
Page 1 of 3
-------
MAROS Statistical Trend Analysis Summary
Well
Source/
Tail
Number Number
of of
Samples Detects
Average Median
Cone. Cone.
(mg/L) (mg/L)
All
Samples
"ND" ?
Mann-
Kendall
Trend
Linear
Regression
Trend
BENZENE
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
CHLOROBENZENE
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
CHLOROFORM
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
s
T
T
T
T
T
T
S
T
T
T
T
T
S
S
S
s
s
s
s
T
S
T
T
T
T
T
T
S
T
T
T
T
T
S
S
S
s
s
s
s
T
9
1
1
8
1
7
8
11
1
1
11
11
9
11
6
7
6
5
6
6
9
8
1
1
8
1
7
8
11
1
1
9
9
9
9
5
7
4
5
4
5
9
1
0
0
8
1
0
4
11
0
0
11
11
0
11
6
1
6
1
6
6
0
0
0
0
8
1
0
8
11
0
0
0
0
1
0
0
0
0
0
0
0
0
2.2E-03
2.0E-03
2.0E-03
6.6E-03
2.4E-02
2.0E-03
3.5E-03
1.2E-02
2.0E-03
2.0E-03
1.2E-01
2.9E-02
2.0E-03
9.2E-02
5.3E-02
3.3E-03
1.6E-02
3.8E-03
8.7E-03
8.1E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
9.3E-02
1.5E-02
2.0E-03
4.9E-02
1.7E-02
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.1E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
6.4E-03
2.4E-02
2.0E-03
2.9E-03
9.3E-03
2.0E-03
2.0E-03
1.2E-01
3.2E-02
2.0E-03
9.1E-02
4.5E-02
2.0E-03
1.7E-02
2.0E-03
9.0E-03
7.7E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
1.0E-01
1.5E-02
2.0E-03
4.9E-02
1.6E-02
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
No
Yes
Yes
No
No
Yes
No
No
Yes
Yes
No
No
Yes
No
No
No
No
No
No
No
Yes
Yes
Yes
Yes
No
No
Yes
No
No
Yes
Yes
Yes
Yes
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
s
ND
ND
PD
N/A
ND
S
D
ND
ND
PD
D
ND
PD
S
NT
S
NT
NT
S
ND
ND
ND
ND
NT
N/A
ND
NT
D
ND
ND
ND
ND
S
ND
ND
ND
ND
ND
ND
ND
ND
PD
ND
ND
S
N/A
ND
S
PD
ND
ND
D
D
ND
PD
I
NT
S
NT
NT
PD
ND
ND
ND
ND
D
N/A
ND
I
PD
ND
ND
ND
ND
S
ND
ND
ND
ND
ND
ND
ND
ND
MAROS Version 2.2, 2006, AFCEE
Monday, August 10, 2009
Page 2 of 3
-------
MAROS Statistical Trend Analysis Summary
Well
Source/
Tail
Number Number
of of
Samples Detects
Average Median
Cone. Cone.
(mg/L) (mg/L)
All
Samples
"ND" ?
Mann-
Kendall
Trend
Linear
Regression
Trend
CHLOROFORM
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
LEAD
HA-4-A
HA-5-B
HA-7-A
T-100-2
T-12-4
T-13-4
T-19-4
T-24-2
T-24-3
T-25-3
T-29-3
T-32-4
T-33-4
T-38-2
T-44-2
T-48-5
T-54-3
T-62-3
T-64-4
T-8-3
T-99
s
T
T
T
T
T
T
S
T
T
T
T
T
S
S
S
s
s
s
s
T
S
T
T
T
T
T
T
S
T
8
1
1
6
1
7
6
9
1
1
10
10
9
11
7
10
7
7
6
6
10
9
1
1
8
1
8
8
10
1
0
0
0
0
0
0
0
0
0
0
1
0
1
2
6
4
5
6
5
5
10
7
1
1
5
1
8
5
5
0
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
1.0E-03
1.1E-03
1.0E-03
1.1E-03
1.2E-03
7.2E-03
1.7E-03
1.3E-02
2.3E-02
1.2E-01
2.5E-03
2.1E-02
2.9E-03
3.1E-03
2.9E-02
3.5E-02
4.1E-03
1.9E-01
2.2E-02
3.3E-03
1.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
2.0E-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
1 .OE-03
7.2E-03
1 .OE-03
1 JE-02
2.4E-02
1.2E-01
1.8E-03
1.3E-02
1.5E-03
3.1E-03
2.9E-02
2.8E-02
4.1E-03
1 .OE-02
2.7E-02
2.8E-03
1 .OE-03
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Yes
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
S
ND
S
S
S
S
S
S
NT
NT
D
D
N/A
N/A
NT
N/A
NT
S
PD
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
S
ND
S
PD
S
S
S
S
S
S
D
D
N/A
N/A
D
N/A
NT
NT
S
ND
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable
(N/A); Not Applicable (N/A) - Due to insufficient Data (< 4 sampling events); No Detectable Concentration (NDC)
The Number of Samples and Number of Detects shown above are post-consolidation values.
MAROS Version 2.2, 2006, AFCEE
Monday, August 10, 2009
Page 3 of 3
-------
MAROS Mann-Kendall Statistics Summary
Well: HA-5-B
Well Type: T
COC: ARSENIC
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
_j
1
o
1
Concen
8.0E-01 -
7.0E-01 -
6.0E-01 -
5.0E-01
4.0E-01
3.0E-01 -
2.0E-01 -
1.0E-01 -
n np4-nn .
* ť ť
* * * *
. *
Mann Kendall S Statistic:
I ~39
Confidence in
Trend:
I 99.9%
Coefficient of Variation:
0.12
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
Well Type
T
T
T
T
T
T
T
T
T
T
T
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/5/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
8.5E-01
7.9E-01
6.9E-01
7.5E-01
7.9E-01
7.9E-01
6.9E-01
6.9E-01
6.6E-01
5.8E-01
6.1E-01
Number of
Samples
1
2
4
1
2
1
2
2
1
1
1
Number of
Detects
1
2
4
1
2
1
2
2
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: HA-5-B
Well Type: T
COC: BENZENE
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
^ o" ^ sť
__
B)
o
1
c
o
o
1.0E-02-
8.0E-03 -
6.0E-03
4.0E-03 -
2.0E-03 -
n np4-nn .
* ť
*
Mann Kendall S Statistic:
I "35
Confidence in
Trend:
I 99.7%
Coefficient of Variation:
0.30
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
HA-5-B
Well Type
T
T
T
T
T
T
T
T
T
T
T
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/5/2009
Constituent
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
Result (mg/L) Flag
1.1E-02
9.0E-03
7.3E-03
6.4E-03
6.9E-03
8.2E-03
8.9E-03
6.5E-03
6.2E-03
3.3E-03
4.8E-03
Number of
Samples
1
2
1
1
1
1
2
2
1
1
1
Number of
Detects
1
2
1
1
1
1
2
2
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-13-4
Well Type: s
COC: ARSENIC
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
_J
1
o
1
c
Concei
1.8E+00 -
1.6E+00 -
1.4E+00 -
1.2E+00
1.0E+00
8.0E-01
6.0E-01
4.0E-01
2.0E-01 -
n np4-nn .
.*.*
*
Mann Kendall S Statistic:
Confidence in
Trend:
I 80.9%
Coefficient of Variation:
0.15
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-13-4
T-13-4
T-13-4
T-13-4
T-13-4
T-13-4
T-13-4
Well Type
s
s
s
s
s
s
s
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
4/1/2002
3/5/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
1.5E+00
1.7E+00
1.6E+00
1.4E+00
1.6E+00
1.5E+00
1.0E+00
Number of
Samples
1
1
2
1
1
2
1
Number of
Detects
1
1
2
1
1
2
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-13-4
Well Type: s
COC: BENZENE
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
^
^)
E
c
o
1
1
o
o
3.5E-02 -
3.0E-02 -
2.5E-02 -
2.0E-02
1.5E-02-
1.0E-02-
5.0E-03 -
n np4-nn .
*
* 4 ť
A
~
ť
Mann Kendall S Statistic:
Confidence in
Trend:
I 99.9%
Coefficient of Variation:
0.25
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-13-4
T-13-4
T-13-4
T-13-4
T-13-4
T-13-4
T-13-4
Well Type
s
s
s
s
s
s
s
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
4/1/2002
3/5/2009
Constituent
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
Result (mg/L) Flag
3.7E-02
3.2E-02
3.0E-02
2.8E-02
2.9E-02
2.3E-02
1.5E-02
Number of
Samples
1
1
1
1
1
1
1
Number of
Detects
1
1
1
1
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-32-4
Well Type: T
COC: ARSENIC
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
o
I
o
o
1.4E-02-
1.2E-02-
1.0E-02-
8.0E-03
6.0E-03 -
4.0E-03
2.0E-03 -
n np4-nn .
0* / 0* / 0*' ^ ^ ^ ^ ^
* *
ť
4 *
* * *
,#
Mann Kendall S Statistic:
Confidence in
Trend:
I 92.2%
Coefficient of Variation:
0.44
Mann Kendall
Concentration Trend:
(See Note)
[ PD
Data Table:
Well
T-32-4
T-32-4
T-32-4
T-32-4
T-32-4
T-32-4
T-32-4
T-32-4
T-32-4
T-32-4
Well Type
T
T
T
T
T
T
T
T
T
T
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/5/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
9.9E-03
1.4E-02
1.5E-02
5.6E-03
5.2E-03
7.4E-03
7.9E-03
5.1E-03
4.1E-03
9.2E-03
Number of
Samples
1
1
2
1
1
2
1
2
1
1
Number of
Detects
1
1
2
1
1
2
1
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-33-4
Well Type: s
COC: ARSENIC
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
2.5E-02
2- 2.0E-02
B)
T 1.5E-02
o
Ł 1.0E-02
8
c
O 5.0E-03
O.I
Mann Kendall S Statistic:
I 22
Confidence in
Trend:
I 98.8%
Coefficient of Variation:
0.20
Mann Kendall
Concentration Trend:
(See Note)
[ I
Data Table:
Well
T-33-4
T-33-4
T-33-4
T-33-4
T-33-4
T-33-4
T-33-4
T-33-4
T-33-4
Well Type
s
s
s
s
s
s
s
s
s
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
6/15/2003
5/1/2004
5/1/2005
6/1/2006
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
1.7E-02
1.4E-02
1.2E-02
1.3E-02
1.4E-02
1.5E-02
2.0E-02
2.0E-02
2.0E-02
Number of
Samples
2
1
2
1
2
2
1
1
1
Number of
Detects
2
1
2
1
2
2
1
1
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-48-5
Well Type: T
COC: ARSENIC
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
&'
Mann Kendall S Statistic:
-
B)
c
o
Ť
>I
c
S
c
o
O
1.2E+00
1.0E+00
8.0E-01 -
6.0E-01 -
4.0E-01 -
2.0E-01
n np4-nn .
* *
*
A ^
^
*
^
Confidence in
Trend:
I 96.9%
Coefficient of Variation:
0.28
Mann Kendall
Concentration Trend:
(See Note)
Data Table:
Well
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
Well Type
T
T
T
T
T
T
T
T
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Result (mg/L) Flag
9.8E-01
1.1E+00
9.2E-01
7.4E-01
1.2E+00
7.2E-01
5.2E-01
6.5E-01
Number of
Samples
1
1
2
1
1
1
2
1
Number of
Detects
1
1
2
1
1
1
2
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-48-5
Well Type: T
COC: BENZENE
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
_J
1
c
o
1
c
S
c
o
O
1.0E-02-
8.0E-03 -
6.0E-03
4.0E-03 -
2.0E-03 -
n np4-nn .
ť
^
V
*
* *
Mann Kendall S Statistic:
Confidence in
Trend:
I 91.1%
Coefficient of Variation:
0.33
Mann Kendall
Concentration Trend:
(See Note)
[ PD
Data Table:
Well
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
Well Type
T
T
T
T
T
T
T
T
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
Constituent
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
BENZENE
Result (mg/L) Flag
1.0E-02
9.2E-03
3.9E-03
7.0E-03
4.7E-03
6.7E-03
6.1E-03
4.8E-03
Number of
Samples
1
1
1
1
1
1
2
1
Number of
Detects
1
1
1
1
1
1
2
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
MAROS Mann-Kendall Statistics Summary
Well: T-48-5
Well Type: T
COC: CHLOROBENZENE
Time Period: 12/15/1999 to 3/5/2009
Consolidation Period: No Time Consolidation
Consolidation Type: Median
Duplicate Consolidation: Average
ND Values: Specified Detection Limit
J Flag Values : Actual Value
Date
1.2E-01
_ 1.0E-01
_j
Ł 8.0E-02
| 6.0E-02
§ 4.0E-02
o
0 2.0E-02 -
O.OE+00
&
Mann Kendall S Statistic:
Confidence in
Trend:
1 59.4%
Coefficient of Variation:
°'16
Mann Kendall
Concentration Trend:
(See Note)
[ NT
Data Table:
Well
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
T-48-5
Well Type
T
T
T
T
T
T
T
T
Effective
Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
Constituent
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
CHLOROBENZENE
Result (mg/L) Flag
9.9E-02
1.0E-01
7.0E-02
1.1E-01
7.2E-02
1.0E-01
1.0E-01
8.5E-02
Number of
Samples
1
1
1
1
1
1
2
1
Number of
Detects
1
1
1
1
1
1
2
1
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A) -
Due to insufficient Data (< 4 sampling events); ND = Non-detect
MAROS Version 2.2, 2006, AFCEE
8/14/2009
Page 1 of 1
-------
MAROS Zeroth Moment Analysis
Project: Gilson Road Site
Location: Bedrock
User Name: MV
State: New Hampshire
COC: ARSENIC
Change in Dissolved Mass Over Time
Date
O)
in
as
4.5&-01 -
4.0&-01 -
3.5&-01 -
3.0&-01 -
2.5&-01 -
2.0&-01 -
1.5&-01 -
1.0&-01 -
5.0&-00
n nR-nn .
A * *
^
* * * *
*
Porosity: 0.30
Saturated Thickness:
Uniform: 20 ft
Mann Kendall S Statistic:
-27
Confidence in
Trend:
I 9870%
Coefficient of Variation:
I °'34
Zeroth Moment
Trend:
Data Table:
Effective Date
12/15/1999
4/15/2000
10/15/2000
4/1/2001
10/1/2001
4/1/2002
6/15/2003
5/1/2004
5/1/2005
6/1/2006
3/5/2009
Constituent
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
ARSENIC
Estimated
Mass (Kg)
3.9E+01
4.0E+01
4.3E+01
3.7E+01
4.0E+01
2.0E+01
2.1E+01
2.2E+01
1.9E+01
1.7E+01
3.3E+01
Number of Wells
14
14
16
16
15
11
11
10
9
9
18
Note: Increasing (I); Probably Increasing (PI); Stable (S); Probably Decreasing (PD); Decreasing (D); No Trend (NT); Not Applicable (N/A)
Due to insufficient Data (< 4 sampling events); ND = Non-detect. Moments are not calculated for sample events with less than 6 wells.
MAROS Version 2.2, 2006, AFCEE
8/10/2009
Page 1 of 1
-------
APPENDIX C:
LIST OF ACRONYMS
ACL alternative concentration limits
AFCEE Air Force Center for Engineering and the Environment
AGQS Ambient Groundwater Quality Standards
AR area ratio
AWQS Ambient Water Quality Standards
BGS below ground surface
BTEX benzene, toluene, ethylbenzene and xylenes
CES cost-effective sampling
CERCLA Comprehensive Environmental Response, Compensation and Liability Act
COC contaminant of concern
CR concentration ratio
ESD Explanation of Significant Difference
FS feasibility study
GIS geographic information system
GMZ groundwater management zone
1C institutional control
LTM long-term monitoring
LTMO long-term monitoring optimization
MAROS Monitoring and Remediation Optimization Software
MCES modified cost-effective sampling
MCL Maximum Contaminant Level
MNA monitored natural attenuation
NPL National Priorities List
O&M operation and maintenance
C-1
-------
PLSF preliminary location sampling frequency
P&T pump and treat
RA remedial action
RI remedial investigation
ROD Record of Decision
SF slope factor
SROD Supplemental Record of Decision
SVOC semivolatile organic compound
UCL upper confidence limit
USEPA United States Environmental Protection Agency
VOC volatile organic compound
C-2
------- |