MONITORING WELL INSTALLATION  AND POTENTIAL CAPTURE WELL CONVERSION NEAR WELL 6M   PPL MONTANA’S COLSTRIP STEAM ELECTRIC STATION – PLANT SITE 

  MONITORING WELL INSTALLATION  AND POTENTIAL CAPTURE WELL CONVERSION NEAR WELL 6M   PPL MONTANA’S COLSTRIP STEAM ELECTRIC STATION – PLANT SITE 

 MONITORING WELL INSTALLATION AND POTENTIAL CAPTURE WELL CONVERSION NEAR WELL 6M PPL MONTANA’S COLSTRIP STEAM ELECTRIC STATION – PLANT SITE INTERIM RESPONSE ACTION WORK PLAN OUTLINE AREA: Plant Site LAND USE AND OWNERSHIP: Industrial. PPL Montana, LLC MEDIA: Soil Surface Water (identify water body):___________________ Groundwater Alluvial McKay/Rosebud Sub‐McKay Other LEVEL OF IMPACTS: Well 6M (4/4/2013) Parameter Bromide (mg/L) Specific Conductance (mhos/cm) Boron (mg/L) Chloride (mg/L) Sulfate (mg/L) Ca:Mg Result 2 4,530 1.1 93 2840 0.95 PROJECT SCOPE & OBJECTIVE: Investigation Capture SITE ASSESSMENT HISTORY (List reports/summary of work done in area in chronological order): DATE INVESTIGATION/REPORT SCOPE FINDINGS/RESULTS June 1978 Characteristics and Potential Impact of Wastewaters from a Coal‐Fired Power Plant at Colstrip, Montana, Westech Evaluation of potential impacts from process water associated with the Colstrip SES January 9, 1995 Investigation of the Quality of Groundwater and Surface Water in the Colstrip Plant Site and 1&2 Evaporation Pond Areas, Hydrometrics, Inc. Investigation of Plant Site Groundwater conditions Well completion details, aquifer testing results, and early water quality analysis for wells in the project area. Water quality at well 6M (9/20/1977): SC = 3,040 mhos/cm; chloride = 18 mg/L; sulfate = 1,590 mg/L; boron < 1 mg/L. A groundwater divide was present near the center of the plant in both the McKay and shallower units. Several cross sections and potentiometric maps were constructed H:\PROJECTS\PPLMT\130606MAreaInvestigation\IRA_6M_WorkPlanoutline.docx
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DATE INVESTIGATION/REPORT SCOPE FINDINGS/RESULTS April 1999 MPC Capture System Installation Report, Hydrometrics, Inc. The Wash Tray Pond, Units 3&4 Bottom Ash Pond, and the Sediment Retention Pond Areas were studied. Well 6M was converted for capture and started. A hydrologic divide trending northeast‐
southwest was identified near the Wash Tray pond and Units 3&4 Bottom Ash Ponds. Water quality at well 9M improved. Water in 6M was interpreted to be affected by pond water and was converted to a capture well. NEAREST DOMESTIC OR STOCK WELL(S)*: (indicate direction, distance, and completion zone) Well ID/GWIC ID NPRR /11992 NPRR /11993 NPRR /11994 Snider, J./269 Distance from 6M 2500 feet
1900 feet 2600 feet 3400 feet
Direction west
south
south
east
Formation of Completion / (Depth) Coal/Ft. Union Bedrock (55feet) Coal/Ft. Union Bedrock (120 feet)
Fort Union Bedrock (518.5 feet)
Alluvium (20 feet) DISTANCE FROM PROPERTY BOUNDARY: Project area is at south end of PPL Plant Site property. Closest proposed new well is Less than 100 feet from property boundary. PROPOSED ACTION: This Interim Response Action is intended to further investigate groundwater quality and flow patterns in spoils, Rosebud coal, and the McKay coal surrounding Pond C and the Wash Tray Pond. Investigative measures include: 
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
Installation of three groundwater monitoring wells; Groundwater quality sample collection and analysis at each new well; and Aquifer testing. Recommendations for additional evaluation and/or groundwater capture, if necessary, will be made following completion of the Interim Response Actions. MAPS/FIGURES: 
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Figure 1: Project Location Map Figure 2: Existing Well Network. Figure 3: Geologic Cross Section of Project Area Figure 4. Potentiometric Surface Map of Shallow Interval Figure 5. Potentiometric Surface Map of McKay Coal Figure 6. SC Iso‐contour Map in Shallow Interval Figure 7. SC Iso‐contour Map of McKay Coal Interval Figure 8. Proposed New Well Locations Figure 9. Typical Capture System Construction Details Figure 10. Schedule H:\PROJECTS\PPLMT\130606MAreaInvestigation\IRA_6M_WorkPlanoutline.docx
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SCHEDULE The proposed timeline to complete the scope of work outlined above is included in Figure 10. Work described in this plan will begin within 60 days. Monitoring well installation and groundwater quality sampling is expected to be completed within 90 days. As noted above, an interim report will be submitted within 60 days of well completion; but the final evaluation report may not be submitted until all sampling and testing results are compiled. REFERENCES Hydrometrics, Inc. (April, 1999). 1999. The Montana Power Company Groundwater Capture System Installation Summary Report. . Hydrometrics, Inc. (January 1995). Investigation of the Quality of Groundwater and Surface Water in the Colstrip Plant Site and 1&2 Evaporation Pond Areas. Westech Environmental Services. (June, 1978). Characteristics and Potential Impact of Wastewaters from a Coal‐Fired Power Plant at Colstrip, MT. H:\PROJECTS\PPLMT\130606MAreaInvestigation\IRA_6M_WorkPlanoutline.docx
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INTERIM RESPONSE ACTION
MONITORING WELL INSTALLATION
AND POTENTIAL CAPTURE WELL CONVERSION NEAR WELL 6M
PPL MONTANA’S COLSTRIP STEAM ELECTRIC STATION – PLANT SITE
Executive Summary
This Work Plan was prepared as an Interim Response Action in accordance with the
Administrative Order on Consent (AOC) Regarding Impacts Related to Wastewater Facilities
Comprising the Closed-Loop System at Colstrip Steam Electric Station, Colstrip, Montana
between PPL Montana as Operator of the Colstrip Steam Electric Station and the Montana
Department of Environmental Quality. This Work Plan addresses groundwater at the southern
extent of the Colstrip-SES Plant Site. Process or wastewater facilities in closest proximity to the
area addressed in this Work Plan include the Units 1&2 Cooling Tower Blowdown Pond C
(North Pond & South Pond) and the Units 3&4 Wash Tray Pond (WTP). Iso-contour maps of
typical process water indicator parameters and potentiometric surface maps of the area are
presented in this report and are suggestive of various locations surrounding Pond C and the WTP
where flow paths of groundwater potentially impacted by process pond water may exist. Further,
results of groundwater capture analyses derived from a transient, three-dimensional, numerical
groundwater flow model (AMEC, 2012) also suggested the possibility of a groundwater
flowpath to the south and east of the WTP. Ten new well installations are proposed for this
Interim Response Action to investigate groundwater quality around Pond C and the WTP.
Paired monitoring wells, installed in first groundwater and the McKay coal, will be installed at
four drilling locations. Single shallow wells will be installed at two other locations. Proposed
well locations and the justification for each are included in the Work Plan. A Scope of Work for
well installation, sampling, testing, and possible conversion to capture wells is included in this
Work Plan.
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Introduction
This Work Plan was prepared as an Interim Response Action in accordance with the
Administrative Order on Consent (AOC) Regarding Impacts Related to Wastewater Facilities
Comprising the Closed-Loop System at Colstrip Steam Electric Station, Colstrip, Montana
between PPL Montana as Operator of the Colstrip Steam Electric Station and Montana
Department of Environmental Quality. While the AOC provides for work to be done as an
Interim Response Action, the examples provided in the AOC are not exhaustive, and the prompt
action described in the following Work Plan is to respond to the circumstances identified
hereafter and not because of an acute threat to human health or a recent spill.
PPL Montana, LLC (PPL) monitors groundwater at the Colstrip Steam Electric Station
(Colstrip–SES) to detect inconsistencies in water quality that may be attributable to impacts from
process water.
As monitoring data become indicative of potential impacts, PPL installs
groundwater capture systems or converts monitoring wells to recovery wells to mitigate the
influence of process water on local groundwater. PPL has also aggressively implemented Best
Management Practices (BMP’s) and operational changes to reduce potential future losses of
process water, and/or to assist in groundwater mitigation. These have included worker training
and education, construction and operation of paste plants for fly ash processing, and lining of
process water ponds or cells.
This work plan addresses groundwater at the southern extent of the Colstrip-SES Plant Site.
Process or wastewater facilities in closest proximity to the area addressed in this work plan
include the Units 1&2 Cooling Tower Blowdown Pond C (Pond C) and the Units 3&4 Wash
Tray Pond (WTP). Pond C originally received cooling tower blowdown. In 1987, the pond was
split into two sections (North Pond and South Pond); and a portion of the South Pond that had
been damaged by waves was relined with clay and geotextile material overlain by scoria. In
1999, monitoring well 6M was converted to a groundwater capture system well at the south end
of this pond. Well 6M is actually completed in the shallower Rosebud Coal and not the McKay
Coal, as its “M” designation suggests. With approval from MDEQ, the north pond began
receiving groundwater collection water (Brine Pond and 10S/10M collection systems) to be used
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for a highway construction project in 2004. Currently, the north and south ponds are used to
store stormwater runoff.
The Units 3&4 WTP was constructed in 1983 and served as a scrubber wash tray loop until
1995. In 1988, geotextile with a clinker cover was placed on the bank on the southern half of the
pond as a repair for wind erosion. Use of the clay-lined pond was discontinued in 1995 but the
pond was not backfilled. At present, the pond contains residual fly ash and occasional water
from precipitation runoff.
The general project area is presented in Figure 1 and the
capture/monitoring well network is presented in Figure 2.
The lithology beneath Pond C and the WTP consists primarily of mine spoils, overburden, and/or
clinker, overlaying remnants of Rosebud Coal, interburden, and deeper McKay Coal. Rosebud
Coal was mined from the area east of the Units 1&2 Cooling Tower Blowdown Pond C. The
area directly east of the pond was mined initially by Northern Pacific to provide coal for railroad
engines in the period between 1924 and the mid-1950’s. Further eastward, the area was mined
by Western Energy. A geologic cross section of the area, oriented approximately perpendicular
to the groundwater flow direction, is included in Figure 3. First groundwater is encountered in
the spoils or Rosebud Coal, if present. Deeper hydrostratigraphic intervals coincide with McKay
Coal and sub-McKay sandstones. Based on measured water levels of paired wells, a weak
downward gradient exists from the shallow intervals to the sub-McKay.
Historically, the WTP and Pond C were situated atop a groundwater divide in both the shallow
and the McKay potentiometric surfaces. The divide is mapped in the report Investigation of the
Quality of Groundwater and Surface Water in the Colstrip Plant Site and 1&2 Evaporation Pond
Areas (Hydrometrics, Inc., January 1995).
The groundwater divide in the shallow
hydrostratigraphic interval (i.e. spoils and Rosebud) appears to have been largely attributable to
mounding from ponds at the plant site which were adjacent to spoil that were not fully recharged
following mining. However, based on a more recent map of the potentiometric surface (Figure
4), the shallow groundwater divide has since shifted southward—resulting in the majority of
groundwater flow to the northwest. The shift in the shallow groundwater divide is likely the
result of decreased pond operation in the area, increased groundwater capture efforts in the area,
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and higher water levels in the adjacent spoil reflecting the longer recharge period.
The
groundwater divide in the McKay Coal does not appear to be present in the updated
potentiometric surface map of the plant site. The prevailing direction of groundwater flow in the
current map is to the northwest; however, it is possible that the divide is still present and has
shifted even further south of the plant site. A more recent McKay coal potentiometric surface
map is presented in Figure 5.
Based on long-term monitoring results at several wells south of the plant site process ponds,
groundwater quality in the spoils is both highly temporally and spatially variable. For example,
no process water impacts and very little change in water quality have been observed at well 17S,
located on the east side of the WTP, from 1983 to present. In contrast, water quality has varied
at well 9S, located on the west side of the WTP. TDS concentrations as high as 7500 mg/L and
as low as 2500 mg/L have been observed.
approximately 6000 mg/L.
At present, the TDS concentration in 9S is
Variability of shallow groundwater quality is attributed to
heterogeneous distribution of spoils mineralogy, specifically the unpredictable dispersal of
soluble salts in reworked mine spoils. Groundwater quality in the Rosebud Coal at well 6M
(capture well) exhibits some of the abrupt variability observed in the spoils; and a long-term
trend of declining water quality has also been observed at this well since it was completed in
1975.
Iso-contour maps of specific conductance (SC) for the shallow and McKay hydrostratigraphic
intervals are included as Figures 6 and 7. The iso-contour maps, coupled with potentiometric
surface maps, are suggestive of various locations surrounding Pond C and the WTP where flow
paths of groundwater potentially impacted by process pond water may exist. Results of capture
analyses derived from a transient, three-dimensional, numerical groundwater flow model also
suggested the possibility of an impacted groundwater flowpath to the south and east of the WTP.
A complete discussion of the groundwater flow model is included in the report Plant Site
Groundwater Model Redesign and Calibration, Colstrip Steam Electric Station (AMEC, 2012).
The purpose of this Interim Response Action is to investigate groundwater conditions at the
southern extent of the plant site to further define local flow patterns and water quality. Methods
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selected for this evaluation and justification for specific areas of targeted by this Interim
Response Action are presented in the following Scope of Work.
Scope of Work
The Scope of Work proposed for this Interim Response Action includes the following five tasks:

Task 1 –Well Installation;
o Ten monitoring wells will be installed in the project area.
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Task 2 – Groundwater Quality Sampling;
o Water quality samples will be collected from each of the new wells and analyzed
for PPL’s typical parameter list.
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Task 3 – Pumping and/or Slug Testing;
o A pumping test or slug test will be performed at each of the new wells.
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Task 4 – Capture Well Conversion; and
o If necessary, some or all of the new monitoring wells will be converted to
groundwater collection wells. Conversion will take place pending review of
groundwater quality analytical results and well yields.

Task 5 – Data Analysis and Reporting.
o Results of well installation and groundwater quality analyses will be summarized
in an Interim Report. If results are indicative of process water impacts at a given
well or wells, recommendations for capture well conversion will be included in
the Interim Report.
o Further evaluation will be conducted and a Final Report of results will be
submitted. If necessary, the Final Report will include capture well construction
details, an evaluation of capture well startup, and a preliminary review of capture
system effectiveness.
Methodology of each of the five tasks listed above is detailed herein.
Task 1 -- Monitoring Well Installation
Proposed well locations are presented in Figure 8. A pair of wells is proposed for each of
drilling locations one through four. Paired wells at each of these locations will target first
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groundwater in spoils or the Rosebud coal and deeper groundwater in the McKay coal interval.
Single wells at drilling locations five and six will target first groundwater. The justification for
each well location is as follows:
1. Two wells are proposed at drilling location #1, which is about 150 feet from the southeast
corner of Pond C and approximately 500 feet east of capture well 6M. This location was
chosen to further define the extent of impacts that are apparent in the shallow subsurface
at neighboring wells 6M, 9S (9M), 16SP, and 33S. The shallow well may also provide a
location to augment capture south of Pond C. The well completed in the McKay coal at
this target will fill a gap in the deeper monitoring well network that exists between wells
38M and 16M.
Concentrations of dissolved constituents have increased above
background and remained elevated at well 16M. Conversely, process water impacts are
not evident at well 38M, which may have historically been on the opposite side of a
groundwater divide from the ponds and/or upgradient of the ponds. All new drilling
targets south and southeast of Pond C will help refine the location of the groundwater
divide, if a divide is still present.
2. Wells proposed at drilling location #2 in shallow groundwater and in the McKay coal will
specifically address particle tracking analyses performed via the numerical flow model
(AMEC, December 2012) that were suggestive of a flow path to the south and east of the
WTP. The proposed drilling site is situated in the gap between existing wells already
south and east of the WTP.
3. Drilling location #3 was chosen because it is downgradient of impacted well 6M, based
on the current understanding of the potentiometric surface in the area south of the Plant
Site. Also, this location is on or near the mapped areal extent of groundwater exceeding
baseline screening levels (BSLs) for boron, chloride, sulfate, or specific conductance that
were developed from numerical model simulations (AMEC, December 2012). Wells
completed in shallow and McKay groundwater at this location will provide data to refine
the existing groundwater model. If necessary, the wells will be converted to capture
points to help mitigate groundwater quality impacts.
4. Drilling location #4 is farther downgradient of known impacts at the south end of Pond C
but is also located within the areal extent of simulated BSL exceedances (AMEC,
December 2012). Location #4 will bridge a gap in the monitoring well network that
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exists downgradient of Pond C, yet upgradient of the capture well network southwest of
the Units 1&2 A/B Flyash Pond. This capture well network includes shallow wells
SRP-8, 10S, 68A, 114S, and McKay capture wells 10M, 59M, 98M, and 113M (See
Figure 2).
5. Drilling location #5 is proposed southeast of monitoring well 38SP. Monitoring well
38SP had high levels of process water indicator parameters (except boron); however, the
groundwater level elevation in this well is higher than wells to the north (e.g. 6S and
6M), suggesting that it is upgradient of the source of process water impacts.
Groundwater potential measured at the new well at location #5 will help delineate the
groundwater divide south of the Plant Site.
6. Drilling location #6 is proposed southwest of monitoring well 38SP. This proposed
drilling location is expected to be upgradient of known process water impacts and will be
used to help refine the location of the groundwater divide.
The monitoring well boreholes will be advanced using air-rotary methods. If necessary, 8-inch
diameter steel casing will be advanced through incompetent surface intervals (clinker, spoils, fill,
sloughing alluvium/ colluvium, etc.) using drill and drive methods. In such an instance, 4.5-inch
PVC casing will be installed through the steel casing. The hydrostratigraphic interval of interest
will be screened with 0.020-inch or 0.025-inch slot, four-and-one–half-inch diameter PVC
screen. A filter pack, consisting of 10-20 silica sand, will be placed across the entire length of
the screened interval. Bentonite chips will be used to create an annular seal from the top of the
silica sand to ground surface. Steel casing will be pulled back to expose the slotted section of
PVC. A minimum of five feet of eight-inch steel surface casing will be left in the completed
boreholes (approximately two feet of steel will extend above ground).
In addition to the
bentonite seal, a concrete pad will be poured around the eight-inch steel surface casing. A
locking steel lid will be installed at the wellhead.
Cuttings from each boring will be logged for lithology, including texture, color, relative
moisture, and origin (alluvium, colluvium, bedrock, etc.) by a geologist, hydrogeologist, or
engineer. A log of borehole lithology and well completion will be prepared for each well and
will be submitted to PPL and the Montana Board of Water Well contractors.
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Monitoring wells will be developed using air-lift methods or bailing. Air-lift development
involves forcing compressed air into the completed well to purge water, cuttings, fines, and
debris from the casing. Providing the well makes sufficient water, development will continue
until sufficient fines have been removed from the well to allow pumping using a submersible
pump. Bailing involves repeatedly removing water from the well with a steel bailer (with check
valve) until the well has been adequately purged. Field parameters (specific conductance, pH,
temperature) will be measured and recorded during development.
Task 2 – Groundwater Quality Sampling
Groundwater quality will be evaluated at each of the three monitoring wells installed as part of
this work plan. Groundwater samples will be collected using methods commonly used by PPL
for operational monitoring.
The samples will be collected using either a submersible sampling pump or a bailer. Field
parameters (specific conductance, pH, temperature) will be measured and recorded during
sampling. Samples will be submitted to Energy Laboratories in Billings, Montana for analysis of
the parameters listed in Table 1.
Task 3 – Aquifer Testing
A pumping test and/or slug test will be conducted on each well installed as part of this work
plan. A pumping test will be conducted if preliminary observations made during development
indicate sustainable yield from the well in excess of two gallons per minute. If applicable, the
pumping test will consist of 100 minutes of pumping followed by a recovery period. Water
levels will be measured during the pumping and recovery phases of the test using pressure
transducers with data loggers and/or electronic water level probes.
Slug tests will be conducted at wells with insufficient groundwater for pump testing. The slug
test will be conducted by displacing water from the well casing using a “slug” and measuring
groundwater recovery following slug injection and withdrawal. Water levels will be measured in
the well using submersible electronic pressure transducers and/or electronic water level probes.
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TABLE 1.
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New Monitoring Well Analytical Parameters
Physical properties
o pH
o Specific Conductance
o Total Dissolved Solids
Common Ions
o Alkalinity, Total as CaCO3
o Bicarbonate as HCO3
o Carbonate as CO3
o Chloride
o Sulfate
o Magnesium
o Calcium
o Potassium
o Sodium
o Bromide
Nutrients
o Nitrate plus nitrite
Dissolved Metals
o Boron
o Selenium
o Mercury
Pump test and/or slug test data will be entered into Aqtesolv® computer program for analysis. At
a minimum, test results will be used to estimate hydraulic conductivity and transmissivity of
targeted formations. Where appropriate observation wells exist, storativity values will also be
calculated.
Task 4 – Capture Well Conversion
The new monitoring wells will only be converted if they have apparent process water impacts.
Process water impacts will be evaluated upon receipt of water quality results. Conversion of any
new impacted wells, if necessary, will be completed according to PPL’s commonly used and
accepted procedure, as follows.

The existing monument and concrete pad will be removed and the area around the wells
will be excavated to an approximate depth of five feet below ground surface with a
backhoe or track excavator.
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
The excavations will be of sufficient width to place a six-foot diameter Corrugated Metal
Pipe (CMP) over the existing wellheads.

Excavated materials will be backfilled around the CMPs and mounded at the surface to
promote drainage from the capture wells.
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Washed gravel will be placed in the bottom of the CMPs at an approximate thickness of
one-foot.
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Existing PVC well casing will be cut off so that it extends just above the washed gravel
in the bottom of the CMP vaults.
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Hinged metal lids will be installed at the top of the CMPs.
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Aluminum ladders will be secured to the inside of the CMPs for access/egress into and
out of the culverts.
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A submersible pump, sized for the well, will be installed in each well at total depth.
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Submersible pumps will be hung in the wells by schedule 80 PVC threaded drop pipe
with brass couplings.
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Drop pipe will extend from the pump to fittings that will be located on the floor of each
vault.

Necessary pipe fittings (i.e. unions, tees, valves, and sample port) will be plumbed into
the discharge pipeline in each vault; and connected to existing or new HDPE pipelines
that will convey water to either the Plant Site ponds or the VSEP treatment plant.

Redundant check valves will be installed both immediately above the pump and inside
the vault to prevent backflow to the wells.

Electrical controls, an hour meter, and automated pump protection (i.e. pumptec) will be
installed in a secure electrical enclosure adjacent to each wellhead.
Captured groundwater from the new wells will be routed to the nearest practicable existing
HDPE collection system pipeline in the project Area. A typical capture well construction
diagram is presented in Figure 9. Note that pump and pipeline sizing may vary from those
shown on Figure 9 depending on the hydrologic conditions encountered.
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Task 5 – Data Analysis and Reporting
An interim report, including a narrative of monitoring well installation and construction, will be
written for submittal to the Montana Department of Environmental Quality (MT-DEQ). Per
requirements of the Administrative Order On Consent Regarding Impacts Related to Wastewater
Facilities Comprising the Closed-Loop System and Colstrip Steam Electric Station, Colstrip,
Montana, the interim report will be submitted within 60 days of completing the new wells. The
interim report will include well completion details, and if available, water quality sample results,
aquifer test results, and a detailed evaluation of said results. However, the final evaluation report
will not be submitted until results of the groundwater quality samples and aquifer tests are
complete. This may require submittal of a second final report, which will be submitted within
120 days of well completion.
Schedule
The proposed timeline to complete the scope of work outlined above is included in Figure 10.
Work described in this plan will begin within 60 days.
Monitoring well installation and
groundwater quality sampling is expected to be completed within 90 days. As noted above, an
interim report will be submitted within 60 days of well completion; but the final evaluation
report may not be submitted until all sampling and testing results are compiled. The expected
deadline of the final report is not more than 120 days after the new wells are completed or not
more than 180 days after submittal of this work plan.
Reference
AMEC . (December 2012). Plant Site Groundwater Model Redesign and Calibration, Colstrip
Steam Electric Station. AMEC Environment & Infrastructure, Inc.
Hydrometrics, Inc. (April 2013). Evaluation of 2012 Hydrologic Monitoring Data from Colstrip
Units 1 through 4 Process Pond System Colstrip Steam Electric Station .
Hydrometrics, Inc. (January 1995). Investigation of the Quality of Groundwater and Surface
Water in the Colstrip Plant Site and 1&2 Evaporation Pond Areas.
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Figures
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
General Project Location
Project Area Monitoring and Capture Well Network
Geologic Cross Section of Project Area
Potentiometric Surface Map of Shallow Groundwater
Potentiometric Surface Map of McKay Coal
Iso-contour Map of Specific Conductance (SC) for the Shallow Groundwater Interval
Iso-contour Map of Specific Conductance (SC) for the McKay Coal Groundwater
Interval
Figure 8. Proposed New Well Locations
Figure 9. Typical Capture Well Conversion Diagram
Figure 10. Schedule
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A
Elevation (feet MSL)
3,290
M
17
6S
6D
6M
3,280
3,300
3,280
3,270
3,270
3,260
3,260
MCKAY WATER LEVEL
3,250
3,250
ROSEBUD
3,240
3,240
3,230
3,230
3,220
3,220
3,210
3,210
MCKAY
3,200
3,200
MCKAY
3,190
3,190
3,180
3,180
3,170
3,170
3,160
0
200
400
600
800
1,000
1,200
Elevation (feet MSL)
Vertical Scale: 1"=30'
9S
9M
3,290
34
D
3,300
39
S
39
M
36
M
A'
1,400
1,600
1,800
2,000
2,200
2,400
2,600
2,800
3,160
3,000
Distance Along Profile (feet)
Horizontal Scale: 1" = 300' (10x Vertical Exaggeration)
NORTH
COOLING
TOWER
BLOWDOWN
POND C
68A
UNITS 3 & 4
WASH TRAY
POND
7R
A'
LEGEND
36M
17D
17M
17M-2
17S 17SP
SCALE
SOUTH
COOLING
TOWER
BLOWDOWN
9M
POND C 9S
300
0
300
SANDSTONE
MONITOR WELL
COAL
OCTOBER 2012
MCKAY WATER LEVEL
SILTSTONE
34D
SHALE
16SP
16M
37SP
A
A'
69R
MONITORING WELL
OCTOBER 2012
SHALLOW WATER LEVEL
OCTOBER 2012
MCKAY WATER LEVEL
CAPTURE WELL
OCTOBER 2012
DEEP WATER LEVEL
CROSS SECTION LINE
37M
6M
6S
6D
6D
A
WELL DESIGNATION
CLINKER
(Approximate Only)
33S
6M
SPOIL
6M
WECO
SEDIMENT
PONDS
67M
28SP
WECO
SEDIMENT
POND
NORTH
29SP
112R
SCREENED INTERVAL
TOTAL DEPTH OF HOLE
39M
39S
38M
38SP
Billings, Montana 59106
5602 Hesper Road
(406) 656-1172
INTERIM RESPONSE ACTION MONITORING
WELL INSTALLATION AND POTENTIAL
CAPTURE WELL CONVERSION NEAR WELL
6M PPL MONTANA'S COLSTRIP STEAM
ELECTRIC STATION - PLANT SITE
DRAWING FILE NUMBER
1306013B006
GEOLOGIC CROSS SECTION A-A'
AUTOCAD 2000 DRAWING (DWG)
FIGURE
3
10
32
15
32
32
64A
3215.8
75A
3213.8
79A
3212.8
74A
3214.8
SCALE
400
30S-2
3222.6
73A
3218.1
SRP-2
3221.9
86SP
3249.7
30
102A
3228.9
97A
3231.9
94A
3231.4
5
92A
3234.2
63S
3234.5
3223
91S
3230.2
5S
3229.9
SRP-7
3223.7
108A
3228.3
93A
3232.7
32
3
SRP-6
3222.6
107A
3231.0
106A
3233.6
SRP-8
3225.0
105A
3234.7
32
40
25SP
3251.2
B-4
27SP
3252.0
3255.8
B-5
3252.4
18SP
3252.5
18S
87SP
3252.5
3257.4
B-3
3251.8
71SP
3249.7
GROUNDWATER CAPTURE WELL
67M
GROUNDWATER MONITORING WELL
3239.0
GROUNDWATER ELEVATION (Feet)
B-7
3252.2
40SP
3257.5
35SP
3252.3
28SP
3257.2
17SP
3256.3
17S
3248.8
3245
16SP
3256.2
9S
3256.6
P-02(A)
3249.4
10M
52SP
3244.6
29SP
3238.6
P-03
3249.6
LEGEND
B-6
3250.8
EAST FORK
ARMELLS
CREEK
P-04
3251.2
51SP
3243.5
50
B-2
3251.7
B-1
3250.0
68A
3229.3
20SP
3267.2
20S
3267.6
WS116
3256.5
32
70SP
3251.4
26SP
3245.6
62S
3237.6
53SP
3265.3
4S
3242.6
10S
3228.2
104A
3238.1
54SP
3256.0
19SP
3251.3
3230
100A
3236.2
21SP-2
3260.1
PS-2
3250.4
41SP
3250.4
UNITS 1 & 2
POND B UNDERDRAIN
96A
3231.8
84SP
3249.4
111SP
3234.9
109A
3228.0
101A
3230.6
21S
3241.8
85SP
3250.3
13S
3237.6
15S
3227.6
32
22SP
3249.6
50
89SP
3249.1
32
SRP-1
3226.4
46S
3225.8
47S
3224.0
42S
3222.8
48S
3221.9
49S
3222.3
SRP-4
3221.6
50S
3222.4
SRP-5
3222.9
(Approximate Only)
32
55
25
U31
3238.3
76A
3223.2
43S
3214.1
44S
3219.3
78A
3219.0 SRP-3
3210.0
45S
1S
3221.8
3221.9
32
400
55
20
0
32
83A
3215.7
5
5
32
50
32
23S
3235.7
32
4
321
40
65A
3216.0
NORTH
32
35
32
32
25
32
2
81A
3213.4
30
0
10
32
82A
3210.1
33S
3256.2
P-01
3249.4
37SP
3255.2
6S
3254.4
0
325
39S
3251.5
32
55
3260
38SP
3260.9
POTENTIOMETRIC DEPRESSION
POTENTIOMETRIC LINE
(5 FOOT CONTOUR INTERVALS,
DASHED WHERE INFERRED)
Billings, Montana 59106
5602 Hesper Road
(406) 656-1172
INTERIM RESPONSE ACTION MONITORING WELL
INSTALLATION AND POTENTIAL CAPTURE WELL
CONVERSION NEAR WELL 6M
PPL MONTANA'S COLSTRIP STEAM ELECTRIC
STATION - PLANT SITE
DRAWING FILE NUMBER
OCTOBER 2012
SHALLOW UNITS
POTENTIOMETRIC SURFACE
1306013B003
AUTOCAD 2000 DRAWING (DWG)
FIGURE
4
NORTH
32
35
323
0
32
25
23M
3235.3
0
4
32
32
20
SCALE
400
0
400
32
15
(Approximate Only)
5
4
2
3
31M
3213.1
50
2
3
22M
3245.3
5
5
2
3
21M
3254.4
13M
3236.6
56M-P
3226.1
3225
3230
57M-P
3230.0
5M
3222.6
58M
3217.0
59M-P
3233.6
98M
3228.8
60M-P
3235.3
10M
3228.8
67M
3237.6
12M
3241.4
3
5
22
19M
3245.0
72M
3240.1
88M
3241.5
26M
3244.6
18M
3249.2
35M
3244.0
0
3
2
3
5
4
32
5
36M
3247.4
0
324
EAST FORK
ARMELLS
CREEK
WM135
3256.6
4M
3245.3
58M-P
3234.1
59M
3220.2
3
2
3
61M
3237.7
20M
3246.5
17M
3247.8
14M
3239.4
16M
3249.1
3245
37M
3250.6
LEGEND
10M
67M
3239.0
GROUNDWATER CAPTURE WELL
GROUNDWATER MONITORING WELL
39M
3248.0
38M
3248.5
GROUNDWATER ELEVATION (Feet)
POTENTIOMETRIC DEPRESSION
POTENTIOMETRIC LINE
(5 FOOT CONTOUR INTERVALS,
DASHED WHERE INFERRED)
Billings, Montana 59106
5602 Hesper Road
(406) 656-1172
INTERIM RESPONSE ACTION MONITORING WELL
INSTALLATION AND POTENTIAL CAPTURE WELL
CONVERSION NEAR WELL 6M
PPL MONTANA'S COLSTRIP STEAM ELECTRIC
STATION - PLANT SITE
DRAWING FILE NUMBER
OCTOBER 2012
MCKAY COAL
POTENTIOMETRIC SURFACE
1306013B003
AUTOCAD 2000 DRAWING (DWG)
FIGURE
5
00
4 ,0
81A
4420
82A
4700
U31
7960
49S
4180
00
4,0
SRP-4
4630
50S
7360
48S
4440
SRP-5
8170
15S
4260
107A
4540
106A
5050
105A
6550
89SP
4960
86SP
5360
400
21SP-2
4120
21S
3390
20S
3780
111SP
13000
AB14S
5250
AB16S
6900
AB27S
13300
AB17S
8330
AB28S
17400
4,0
20SP
4220
41SP
11900
52SP
3500
54SP
3220
53SP
3150
51SP
3460
19SP
11800
25SP
4080
5,000
70SP
21100
AB29S
6260
5,0
4S
5460
AB19SM
7560
0
,00
10
1
0
00
5,
B2
5330
B-1
14600
100A
3600
PS2
5710
00
85SP
4570
6,000
AB26S
6610
22SP
4480
84SP
5220
13S
4450
92A
6340
71SP
5630
B6
4920
10S
7420
104A
4680
0
811
5770
AB2S
8870
63S
4450
400
(Approximate Only)
46S
6960
47S
6930
AB10S
42S
9290
11400
SRP-3
5,000
6290
AB22S
5200
AB20S
AB23S
15300
4840
AB25S
5840
AB7S
10000
5S
15,000
8910
91S
6510
SRP-7
11600
AB4S
AB3S 9300
7540
SRP-8
7500
108A
4680
93A
5470
SRP-1
12400
0
10,00
96A
4240
AB8S
8270
SRP-6
12100
109A
4320
812
2650
00
1S
4180
U3-3
2120
,0
SRP-2
7060
76A
5550
SCALE
10
44S
7560
43S
5200
45S
4740
101A
4150
94A
4660
U3-2R
5140
30S-2
6000
74A
4500
78A
4890
97A
3930
NORTH
822
2320
73A
4190
102A
3520
23S
5140
4,0
00
79A
4710
75A
4220
3,000
00
83A
5070
OT7
12400
4,0
64A
4640
3,0
00
65A
3810
5,000
B-4
3860
B-5
3870
B3
18SP
5210
3580
18S
3440
B7
4040
29SP
4410
00
40SP
4140
27SP
4440
87SP
3820
35SP
3820
28SP
5610
68A
5510
00
00
7,0
4,0
62S
3390
4,00
0
17S
1970
17SP
5130
5,0
00
16SP
6520
9S
5480
33S
5950
4,000
37SP
4710
6S
6750
3,000
LEGEND
67M
GROUNDWATER MONITORING WELL
4000
4,000
GROUNDWATER CAPTURE WELL
38SP
5720
3,000
10M
39S
2160
GROUNDWATER SC CONCENTRATION ( mhos/cm)
SC CONCENTRATION DEPRESSION
DRAWING FILE NUMBER
SC CONCENTRATION CONTOUR
(1000 FOOT CONTOUR INTERVALS,
DASHED WHERE INFERRED)
Billings, Montana 59106
5602 Hesper Road
(406) 656-1172
INTERIM RESPONSE ACTION MONITORING WELL
INSTALLATION AND POTENTIAL CAPTURE WELL
CONVERSION NEAR WELL 6M PPL MONTANA'S
COLSTRIP STEAM ELECTRIC STATION - PLANT SITE
MAY 2012
SHALLOW UNITS SPECIFIC
CONDUCTANCE ISOCONTOUR MAP
1306013B004
AUTOCAD 2000 DRAWING (DWG)
FIGURE
6
0
NORTH
3,
00
0
4,
00
0
5,0
0
23M
5020
31M
5470
SCALE
0
0
2,0
400
400
(Approximate Only)
22M
1560
5,0
00
0
21M
1250
13M
4840
56M-P
5460
AB9SM
10300
20M
1250
57M-P
7550
5M
6690
12M
1750
19M
1510
72M
2920
58M
6920
4M
3080
58M-P
5920
59M-P
6260
6,0
00
10M
5890
4,0
0
0
26M
1620
59M
6260
98M
5340
60M-P
6550
18M
3670
88M
3650
35M
1860
67M
2500
3,000
61M
3760
3,000
4,000
36M
4040
4,000
17M
4170
14M
3560
3,0
00
16M
5060
37M
2090
39M
2010
38M
2410
LEGEND
10M
GROUNDWATER CAPTURE WELL
67M
GROUNDWATER MONITORING WELL
4000
GROUNDWATER SC CONCENTRATION ( mhos/cm)
SC CONCENTRATION DEPRESSION
DRAWING FILE NUMBER
SC CONCENTRATION DEPRESSION
(1000 FOOT CONTOUR INTERVALS,
DASHED WHERE INFERRED)
Billings, Montana 59106
5602 Hesper Road
(406) 656-1172
INTERIM RESPONSE ACTION MONITORING WELL
INSTALLATION AND POTENTIAL CAPTURE WELL
CONVERSION NEAR WELL 6M PPL MONTANA'S
COLSTRIP STEAM ELECTRIC STATION - PLANT SITE
MAY 2012
MCKAY COAL SPECIFIC
CONDUCTANCE ISOCONTOUR MAP
1306013B004
AUTOCAD 2000 DRAWING (DWG)
FIGURE
7
29SP
4
112R
NORTH
COOLING
TOWER
BLOWDOWN
POND C
M
S
UNITS 3 & 4
WASH TRAY
POND
17D
17M
17M-2
17S 17SP
7R
SOUTH
COOLING
TOWER
BLOWDOWN
POND C
36M
2
34D
16SP
9M
16M
9S
33S
37SP
M
S
3
M
S
37M
6S
6M
6D
1
M
S
39M
39S
38M
38SP
6
S
7
S
M PROPOSED MCKAY MONITORING WELL
S PROPOSED SHALLOW MONITORING WELL
1
SITE NUMBER
INTERIM RESPONSE ACTION MONITORING WELL
INSTALLATION AND POTENTIAL CAPTURE WELL
CONVERSION NEAR WELL 6M PPL MONTANA'S
COLSTRIP STEAM ELECTRIC STATION - PLANT SITE
NORTH
LEGEND
33S EXISTING
MONITORING WELL
6M
EXISTING
CAPTURE WELL
SCALE
0
400
FIGURE
PROPOSED NEW MONITORING WELL
LOCATIONS
8
Figure 10. Schedule ‐‐ 6M Area Investigation Task 1 ‐ Monitoring Well Installation
Task 2 ‐ Groundwater Quality Sampling
Task 3 ‐ Capture Well Conversion (if
necessary)
Task 4 ‐‐ Capture System Startup Evaluation
Interim Report
Task 5 ‐‐ Analysis and Reporting
0
10
20
30
40
50
60
70
80
90
Final Report 100 110 120 130 140 150 160 170 180
Elapsed Days Following Work Plan Submittal H:\PROJECTS\PPLMT\13060 6M Area Investigation\Gantt_6M Area_actual.xlsx
11/7/2013