Groundwater Sampling and Analysis Plan by cityofindepmo

Blue Valley Coal Combustion Residuals Impoundment Groundwater Monitoring Sampling and Analysis Plan Blue Valley Power Plant, Independence Power & Light Prepared for Independence Power and Light March 2021

1001 Diamond Ridge, Suite 1100 Jefferson City, MO 65109 573.638.5000 www.barr.com

Blue Valley Coal Combustion Residuals Impoundment Groundwater Monitoring Sampling and Analysis Plan March 2021

Contents 1

Introduction ........................................................................................................................................................................... 1 1.1

Project Organization ...................................................................................................................................................... 2 Sampling Objectives ........................................................................................................................................................... 3

2.1

Data Quality Objectives ................................................................................................................................................ 3

2.2

Selection of Analytical Parameters .......................................................................................................................... 3

2.3

Selection of Monitoring Locations ........................................................................................................................... 3

Pre-Sampling Activities ..................................................................................................................................................... 5 3.1

Sampling Frequency ...................................................................................................................................................... 5

3.2

Measurement of Static Water Level Elevation..................................................................................................... 5

3.2.1

3.2.1.1

Review Site Map and Well Data................................................................................................................. 6

3.2.1.2

Inspect and Open Well .................................................................................................................................. 6

3.2.1.3

Establish a Measuring Point ........................................................................................................................ 6

3.2.1.4

Measure and Record ...................................................................................................................................... 6

3.2.1.5

Decontamination ............................................................................................................................................. 6

3.2.1.6

Documentation ................................................................................................................................................ 7

3.3

Well Purging ..................................................................................................................................................................... 7

3.3.1

Standard Operating Procedure ............................................................................................................................ 5

Standard Operating Procedure ............................................................................................................................ 7

3.3.1.1

Low Flow ............................................................................................................................................................. 8

3.3.1.2

Bailer ..................................................................................................................................................................... 8

Well Sampling .....................................................................................................................................................................10 4.1

Required Materials .......................................................................................................................................................10

4.1.1

Equipment ..................................................................................................................................................................10

4.1.2

Documentation ........................................................................................................................................................10

4.1.3

Sample Containers and Preservation...............................................................................................................11

4.2

Collecting Groundwater Samples ...........................................................................................................................11

4.2.1

Standard Operating Procedure ..........................................................................................................................11

4.2.1.1

Sample Event Planning ................................................................................................................................11

P:\Jeff City\25 MO\49\25491019 Groundwater Monitoring Program\WorkFiles\GMSAP\3 - Final Version\FINAL IPL GMSAP.docx

4.2.1.2

Measure Static Water Levels .....................................................................................................................12

4.2.1.3

Purge Well ........................................................................................................................................................12

4.2.1.4

Sample Collection .........................................................................................................................................12

4.2.1.5

Filling Containers ...........................................................................................................................................13

4.2.1.6

Sample Labels .................................................................................................................................................14

4.2.1.7

Documentation ..............................................................................................................................................14

4.2.1.8

Transportation to Laboratory ...................................................................................................................14

4.3

In-Situ or Field Analyses.............................................................................................................................................15

4.4

Decontamination ..........................................................................................................................................................15

4.5

Quality Control Samples ............................................................................................................................................16

4.5.1

Field Duplicate Samples ........................................................................................................................................16

4.5.2

MS/MSD Samples....................................................................................................................................................16

4.5.3

Equipment (Rinsate) Blanks .................................................................................................................................16

4.5.4

Temperature Blanks ................................................................................................................................................16

4.6

Training .............................................................................................................................................................................17

4.7

Reports ..............................................................................................................................................................................17

Reporting ..............................................................................................................................................................................18 5.1

Annual Report Components .....................................................................................................................................18

5.2

Annual Report Submittal ...........................................................................................................................................18

5.3

Baseline Report ..............................................................................................................................................................18

5.4

Baseline Report Submittal .........................................................................................................................................19

Statistical Analysis Plan....................................................................................................................................................20 6.1

Statistical Approach .....................................................................................................................................................20

6.2

Groundwater Monitoring Network ........................................................................................................................20

6.3

Monitoring Parameters and Statistical Analysis Reporting..........................................................................21

6.4

Statistical Procedures ..................................................................................................................................................21

6.5

Determination of Statistically Significant Increases ........................................................................................22

6.5.1

Nonparametric Prediction Limits ......................................................................................................................22

6.5.2

Control Charts ...........................................................................................................................................................22

6.6

Response to a Statistically Significant Increase ................................................................................................23

6.7

Groundwater Protection Standards .......................................................................................................................23

Health and Safety ..............................................................................................................................................................25

Well and Sampling Equipment Repair.......................................................................................................................26

References ............................................................................................................................................................................27

List of Tables Table 1

Constituents of Concern - Groundwater Sampling

Table 2

Monitoring Well Construction Summary

Table 3

Well Sampling Order

Table 4

Sampling Containers, Preservatives, and Holding Times

Table 5

Decision Criteria for Monitoring Well and Sampling Equipment Repair

List of Figures Figure 1

Regional Site Location Map

Figure 2

Site Property Boundary

Figure 3

Groundwater Monitoring Well Network

List of Appendices Appendix A

Independence Power and Light Missouri State Operating Permit

Appendix B

Missouri Geological Survey Geological Survey Program

Appendix C

Standard Operating Procedures

Appendix D

Monitoring Well Design and Construction Requirements

Appendix E

Compendium of Field Documentation

Appendix F

Statistical Procedures Documentation

iii

Abbreviations CFR

Code of Federal Regulations

COC

Constituents of Concern

DQO

Data Quality Objective

EPA

U.S. Environmental Protection Agency

gpm

gallons per minute

GMSAP

Groundwater Monitoring Sampling and Analysis Plan

L/min

liters per minute

LTM

long-term monitoring

MDNR

Missouri Department of Natural Resources

Milliliters

MS/MSD

Matrix Spike/Matrix Spike Duplicate

MSOP

Missouri State Operating Permit

NTU

Nephelometric Turbidity Units

Quality Assurance

Quality Control

SOP

Standard Operating Procedure

WPP

Water Protection Program

1 Introduction This Groundwater Monitoring Sampling and Analysis Plan (GMSAP) presents a groundwater monitoring program that has been developed for the coal combustion residuals (CCR) impoundments located at the Independence Power & Light (IPL) Blue Valley Power Plant facility in Independence, Missouri (Site). A regional site location map is included as Figure 1 and the boundary of the Site is illustrated on Figure 2. This GMSAP contains information concerning the sampling protocols, techniques, data quality objectives (DQOs), procedures, and equipment to conduct groundwater sampling associated with the long-term monitoring (LTM) program for the Site. The facility’s Missouri State Operating Permit (MSOP), MO-0115924, Part C. Special Condition 16. (Appendix A), outlines a list of requirements that lead up to full implementation of a GMSAP for the site. Special Condition 16(c) requires the GMSAP be developed and submitted to the Missouri Department of Natural Resources (MDNR) Water Protection Program (WPP), by March 17, 2021. This work plan was developed in accordance with the requirements of the MSOP. In addition, this GMSAP aligns with the requirements of the Federal CCR rule, in 40 CFR Part 257, Subpart D. In accordance with 40 CFR 257.90, all facilities with CCR impoundments must design and operate a groundwater monitoring system. The groundwater monitoring system must include both the installation of a groundwater monitoring well network and the implementation of a GMSAP. As the Site has been previously investigated to properly design the groundwater monitoring well network, the information collected during the Site characterization investigation will be utilized to develop the GMSAP. IPL acknowledges that compliance with the MSOP and the Federal CCR rule are separate paths; however, IPL intends to use the same groundwater monitoring well network and GMSAP to achieve compliance with both the MSOP and 40 CFR Part 257, Subpart D. This GMSAP was developed in accordance with the Guidance for Conducting a Detailed Hydrogeologic Site Characterization and Designing a Groundwater Monitoring Program (2010, Missouri Department of Natural Resources, Missouri Geological Survey) which is included as Appendix B. This GMSAP is based on our understanding of the current site conditions, as well as an evaluation of the data obtained from work completed during the site characterization process. The purpose of this GMSAP is to present methodology for the collection of data of sufficient quantity and quality to monitor the extent and rate of migration of groundwater compounds of concern on the Site. Items discussed include sampling locations and analytical parameters, sampling frequency, the field and laboratory methods, and quality assurance and quality control (QA/QC) measures. The groundwater monitoring well network was installed in accordance with the Missouri Well Construction Code (10 CSR 23-4).

1.1 Project Organization The project organization is designed to identify the parties involved in the project and establish the chain of authority for decision making. The project organization is as follows: Project Manager – Independence Power and Light

Project Manager – MDNR WPP

Eric Holder

Pam Hackler

Project Manager – Barr Engineering Andrea Collier The laboratories utilized at the Site are: Project Manager – Pace Analytical Services, Inc.

Pace Analytical Services, Inc.

Angela Brown

9608 Loiret Boulevard Lenexa, KS 66219

Quality Control Director – Pace Analytical National

Pace Analytical National Center for Testing and

Center for Testing and Innovation

Innovation

Steve Miller

12065 Lebanon Road Mt. Juliet, Tennessee 37122

2 Sampling Objectives This GMSAP has been developed to ensure that all environmental data collected meet the objectives for the monitoring program and satisfy the requirements for groundwater monitoring as set forth in the MSOP and the 40 CFR 257.91. The collection and analysis of any data require that procedures be implemented to assure that the precision, accuracy, completeness, and representativeness of the data are known and documented. This GMSAP presents the data collection objectives, the sampling analysis procedures, and the QA/QC activities.

2.1 Data Quality Objectives The overall objective of the GMSAP is to obtain data of sufficient and representative quality to adequately monitor the rate of migration of potential Constituents of Concern (COCs) in the groundwater at the IPL Blue Valley CCR Impoundments. To achieve this objective, standard operating procedures (SOPs) have been developed to be used during field sampling activities and are detailed in the sections below and in Appendix C. To provide quality data collection at the Site, this plan will focus on the DQOs outlined below and the LTM represented by the groundwater sampling and monitoring program. The groundwater monitoring program for the Site consists of groundwater sample collection from eight (8) monitoring wells. DQOs are discussed in more detail in Section 7.

2.2 Selection of Analytical Parameters Groundwater monitoring for the Site is being performed as assessment monitoring in compliance with Missouri State Operating Permit (MSOP), MO-0115924, Part C Special Condition 16. Selection of analytical parameters was determined by constituents of concern detected in groundwater samples collected at the Site. Radionuclides were not selected as a constituents of concern to be sampled and analyzed due to the results of the 2017 and 2019 sampling efforts (SCS, 2017 and Barr, 2019) which indicated concentrations of Radium 226 and 228 were not present in the ash or groundwater above background concentrations. Selected constituents of concern will be analyzed as part of the monitoring program, which is consistent with the Federal CCR rule, in 40 CFR Part 257, Subpart D, in accordance with 40 CFR 257.90. The parameters selected for analysis are presented in Table 1.

2.3 Selection of Monitoring Locations As of February 2020, a total of eight (8) permanent monitoring wells are located at the Site (Figure 3). Three (3) monitoring wells are located along the western Site boundary (upgradient) and five (5) are located along the eastern Site Boundary (downgradient). Downgradient wells, MW-1, MW-2, MW-3, and MW-4 are along the toe of the impoundment toe slope of the former CCR impoundments. MW – 05 is furthest downgradient well, located southeast of the former CCR impoundments. The upgradient wells, MW-6, MW-7, and MW-8, are located along the parallel and upgradient perimeters of the former impoundments. The permanent wells were installed in compliance with the Missouri Well Construction Code (10 CSR 23-4). Wells in the monitoring network are located at the Site upgradient and downgradient

of the former CCR impoundment to best identify migration of any detected COCs. The Site’s monitoring wells were positioned to satisfy the following 40 CFR 265.91(b) requirements: •

Installed hydraulically upgradient from the former waste management area and to yield groundwater samples that are: o

representative of background groundwater quality in the uppermost aquifer near the facility, and

o •

not affected by the facility.

Installed hydraulically downgradient at the limit of the CCR impoundment area.

The results of past investigations (Site Characterization Report, Barr, 2020) determined the locations for the groundwater monitoring network. Table 2 provides a summary of the monitoring well network and well construction details. Figure 3 illustrates the locations of the existing wells. All existing wells and any potential future wells will be designed and constructed per the requirements provided in Appendix D.

3 Pre-Sampling Activities 3.1 Sampling Frequency Groundwater samples will be collected and analyzed quarterly for the first two (2) years, subsequent to GMSAP implementation to establish a baseline of COC concentrations at the Site. Upon completion of the two years of baseline sampling, the sampling frequency will be modified to a semi-annual basis (two times per year). The groundwater monitoring results will be used to assess the rate and extent of potential contaminant migration. Table 1 provides a summary of monitoring well sampling parameters, analytical methods, and sampling frequency. Upgradient monitoring wells will be sampled utilizing passive sampling methodology. The Snap Sampler system is proposed to be used at the Site; use of this sampling technology negates the need to collect equipment blanks to document potential cross contamination between wells, and is better suited for areas of low groundwater recharge which is a characteristic of the upgradient wells. The Snap Sampler will be utilized to collect samples from monitoring wells MW-6, MW7, and MW-8. Downgradient monitoring wells will be sampled using low-flow purge methodology in accordance with the U.S. Environmental Protection Agency (EPA) guidance (EPA 1996). Equipment blanks will be collected if dedicated or disposable equipment cannot be used. Wells will be sampled in the order shown on Table 3 to reduce potential cross-contamination between wells. Groundwater monitoring schedules for upcoming years will be included in semi-annual groundwater monitoring reports. Groundwater quality data collected at the Site during other activities will be reported in semi-annual groundwater monitoring reports submitted to the MDNR subsequent to the data collection. A set of water level measurements will be collected from the entire monitoring well network semi-annually, coincident with water quality sampling intervals. The results of the semi-annual, and any additional, water level measurements will be reported as elevation data and plotted on the contour maps included in the semiannual groundwater monitoring reports.

3.2 Measurement of Static Water Level Elevation Groundwater level measurements are collected from monitoring wells to assist in defining Site hydrogeologic conditions. These data are critical for the evaluation of groundwater flow direction, velocity estimates, hydraulic gradient, and determination of key aquifer parameters. Accurate groundwater elevation measurements are an important element of any groundwater monitoring program and will be obtained from all monitoring wells within an approximate 24-hour period that occurs prior to each sampling event (or as close as possible depending on the sampling schedule) in order to develop a representative potentiometric surface.

3.2.1 Standard Operating Procedure The procedure for obtaining a water level measurement in a monitoring well are described in Sections 3.2.1.1 through 3.2.1.6.

3.2.1.1 Review Site Map and Well Data A review of historical COC concentrations and expected static water levels in wells should be performed prior to mobilizing to the Site. Wells in the Site groundwater monitoring network will be sampled from suspected least to the most impacted based on the most recent groundwater analytical results. Table 3 provides a suggested sampling order based on historic groundwater data. Equipment should be inspected, calibrated if needed, and tested prior to leaving for the Site. The water level indicator cable should be periodically checked for stretch.

3.2.1.2 Inspect and Open Well Inspect the condition of the surface seal and wellhead. Record any damage or change in the field log data sheet. Clear the area around the wellhead of weeds or other material prior to opening the well. Open the monitoring well and bail out standing water to below the riser. If applicable, note on the field form the level of water in the annular space and if it appears impacted.

3.2.1.3 Establish a Measuring Point The measuring point is typically measured on the north side of the riser or from a consistent point marked with an indelible marker or a notch in the casing. A mark should be made if one is not present. The top of a protective casing or manhole should never be used as a reference point due to the potential for settling and frost heave. Note the groundwater elevation on the Field Log Data Sheet if any other reference points are used in the measurement. A copy of the Field Log Data Sheet is included in Appendix E.

3.2.1.4 Measure and Record The static water level will be measured with an electronic water level indicator, capable of measuring to 200 feet with an accuracy of +/- 0.01 foot. The decontaminated water level indicator will be lowered into the well until an audible sound or red light is detected from the indicator. Repeatedly raise and lower the probe to obtain an exact measurement and confirm the water level is stable. The measurement should be recorded on the Field Log Data Sheet (Appendix E) to the nearest 0.01 foot. Once per year (annually), the total well depth at each well should be measured using the probe, a weighted tape measure, or marked cable constructed of materials that are chemically inert. The same instrument should be used in all Site wells. The sensitivity control setting of the water level indicator should be consistent for each well at the Site (typically a mid-range setting is appropriate for units with variable settings). Care must be taken to assure that the probe hangs freely and straight in the well, especially in cold weather where the cord may kink.

3.2.1.5 Decontamination The measuring device shall be decontaminated immediately after each use. Decontaminate the probe as follows: •

Rinse with clean water

•

Wipe probe and exposed line with clean paper towel

•

Rinse or spray with Alconox® (or equivalent non-phosphate solution) or alcohol wash

•

Rinse with clean water (de-ionized water if possible)

•

Dry with clean paper towel

Additional decontamination procedures may be required based on the level of contamination and specific project requirements. Appropriate health and safety protection should be applied as specified in the Site health and safety plan or by the project manager, and decontamination materials should be properly disposed.

3.2.1.6 Documentation Complete the Field Log Data Sheet (Appendix E) and include weather conditions or other observed phenomenon believed to be influencing ground water levels. An original and copy of the Field forms should be placed in the project file and contain the following information: •

Identity of well/location

•

Date and time of measurement

•

Location and elevation of reference point – is it referenced to arbitrary Site datum or an established benchmark

•

Groundwater depth, or bottom of well

•

Calculate/record groundwater elevation

•

Enter data onto project hydrograph, project database, or both (if applicable)

3.3 Well Purging Snap Samplers are the preferred method of sample collection in upgradient wells, therefore well purging is not required. However, downgradient wells will need to be evacuated prior to sampling, because recharge rates are higher. The preferred method of sample collection for the downgradient wells is lowflow purging, but bailing the well is a suitable secondary method for purging the downgradient well. The stagnant water will be purged from the well and filter pack prior to sampling to ensure that samples collected from the well are representative of the groundwater formation to be monitored.

3.3.1 Standard Operating Procedure The SOP for well purging at the Site’s downgradient wells will be performed using dedicated bailers or by low-flow purge with a submersible pump. Wells utilizing passive sampling methodology will not be purged, as it is not necessary. Prior to purging a monitoring well, the volume of water in the well will be calculated from the static water level and the total depth measurements. To determine the level of potential siltation, the construction well depth as noted on the well log will be compared to the bottom of the well at the time of sampling. The volume of water removed will be measured by collecting it in graduated five-gallon plastic containers. If the well is purged to the point it is dry or purged such that full recovery exceeds two hours, the well should be sampled as soon as a sufficient volume of groundwater has re-entered the well to enable

collection of the necessary groundwater samples. Purged monitoring well water will be disposed of in accordance with appropriate MDNR disposal guidance.

3.3.1.1 Low Flow Setup at the well with a pump (2-inch centrifugal pump, or other equivalent pump which does not produce turbulent flow in the well), bucket, field notebook, field forms, sample bottle(s) and labels, knife, and new sampling gloves.to perform low-flow sampling. Insert the pump into the well and lower it to near the top of the screened interval to ensure that fresh water from the aquifer moves through the well screen to the pump intake. In low-yield wells, the pump will be lowered in increments of one to three feet until the required volume is removed or until the well is pumped dry. Pumping rates should be between 0.05 to 0.08 gallons per minute (gpm) (0.2 to 0.3 liters per minute [L/min]), as described above, or below the recharge capability of the aquifer. Extracted groundwater will be contained in a five-gallon plastic bucket until measurements of temperature, pH, oxidation-reduction potential (ORP), dissolved oxygen (DO), and specific conductivity have stabilized within approximately ten percent of the previous two measurements, and turbidity is below 100 nephelometric turbidity units (NTU). If turbidity stabilizes within ten percent over two measurements above 100 NTU, or begins to increase, the turbidity reading will be considered satisfactory. These water quality parameters will be collected at the beginning of purging and every five to ten minutes during purging, with a minimum of four sets of measurements collected during purging. Record purged water level, stabilization parameters, and time of sample collection on the Field Log Data Sheet. An example of a Field Log Data Sheet is included in Appendix E. Pumps will be decontaminated between wells at a central decontamination area using Alconox® solution, followed by a tap water rinse, and then a final de-ionized water rinse. The power cord for the pump will be decontaminated by washing with Alconox® and rinsing with tap water. Decontaminated equipment will then be permitted to air dry or be wiped dry with paper towels. Waste decontamination fluids will be containerized and disposed of per applicable requirements. Decontamination procedures are further detailed in Section 4.5.

3.3.1.2 Bailer Setup at the well with one bailer (laboratory cleaned, dedicated, or disposable), bailing rope, bucket, field notebook, sample bottle(s) and labels, cutting tool, and new sampling gloves. The sampling personnel should wear nitrile sampling gloves and expose the bailer from its packaging. Tie the bailing rope to the top of the bailer securely and lower the bailer very slowly down the well casing. The end of the bailer cord should be secured so that it cannot accidently be pulled down the well with the bailer. Pull off one to two more feet of rope, cut rope from spool, and tie rope to your wrist, the protective well casing, or bumper post. It is very important not to let the bailer “free fall” into the well/water. Lower the bailer into the water at least two bailer lengths if possible, or if the well recharges slowly, to the bottom of the well. To extract water from the well, lift the rope slowly with a “windmill” or hand-over-hand

motion. Avoid removing the bailer using a jerking motion or allowing the bailer to bang or scrape against the well casing. When the bailer reaches the surface, empty the contents into the bucket by inverting or using the supplied discharge apparatus. Repeat purging until at least three well volumes are extracted, and measurements of temperature, pH, ORP, DO, and specific conductivity have stabilized within ten percent of the previous two measurements, and turbidity is below 100 Nephelometric Turbidity Units (NTU). If turbidity stabilizes within ten percent over two measurements above 100 NTU or begins to increase, the turbidity reading will be considered satisfactory. These water quality parameters will be collected at the beginning of purging and following each well volume removed, with a minimum of four sets of measurements collected during purging. If a well normally recovers slowly or bails dry, collect water quality parameters more than once per well volume to confirm a minimum of four sets of water quality parameters are collected during purging. Record purged water level, stabilization parameters, and time of sample collection on the Field Log Data Sheet (Appendix E).

4 Well Sampling The primary objective of sampling is to obtain a groundwater sample representative of the aquifer or groundwater unit being monitored. Results of the sampling event and the subsequent chemical analysis are used to evaluate groundwater chemistry and extent of groundwater impacts. Sampling methodologies are based on “RCRA Ground-Water Monitoring Technical Enforcement Guidance Document” (USEPA, 1986) and updated per “Groundwater Sampling Guidelines for Superfund and RCRA Project Managers” (USEPA, 2002a). The groundwater sampling will be conducted as described in Section 4.2.

4.1 Required Materials The equipment needed for collecting the groundwater samples may include the following:

4.1.1 Equipment •

Centrifugal Pump, or similar – low-flow pump sampling only, OR Disposable Bailers

•

Snap Sampler with sampler bottles and attachment/trigger line

•

Water Quality Multi-Parameter Meter with operator’s manual

•

Electronic water level tape of appropriate length to measure depth to water and total well depth

•

Nitrile gloves, or similar, to be worn during field sampling

•

Buckets

•

Clean barrel or drums for pump decontamination

•

De-ionized or distilled water

•

Alconox® solution spray bottle and brushes

•

Paper towels

•

Sample bottles and labels

•

Shipping container/cooler

•

Storage bags

•

Ice

4.1.2 Documentation •

Field notebook

•

Sampling Information Sheets

•

Chain of Custody Record

•

Sample custody seal

•

Indelible marker

•

GWSAP with QA/QC procedures

Field equipment, such as a water quality meter, will be calibrated and operated in accordance with the manufacturer’s instructions and calibrations will be documented in field notes. Copies of all instruction manuals for calibration and operation will be available for sampling personnel at the Site. All field instruments will be calibrated at the beginning of the day during each sampling event. Instrumentation drift, if any, is determined by the calibration logs from one day to the next. The field instrument data will

be used to determine well stabilization and field parameters and does not correct or validate analytical data based on field instrumentation.

4.1.3 Sample Containers and Preservation Table 4 specifies the appropriate sample container, volume of sample required, preservative needed, and maximum holding times for samples based on the parameters to be analyzed. The cleanliness of sample containers shipped from the laboratory will be verified in the laboratory. The containers will remain sealed and stored in a clean environment until they are needed for sampling.

4.2 Collecting Groundwater Samples Monitoring wells will be sampled on a semi-annual basis for COC analysis (subsequent to the completion of the two year quarterly baseline sampling period). Table 1 provides a summary of analytical parameters and methods.

4.2.1 Standard Operating Procedure The procedure for collecting groundwater samples from monitoring wells is described in Sections 4.2.1.1 through 4.2.1.8.

4.2.1.1 Sample Event Planning To plan the sampling event, determine sampling dates, wells to be sampled, parameters to be tested, quality control samples needed, and any other necessary arrangements for sampling at least one week in advance of the proposed sampling event. The arrangements will be communicated to Pace Analytical or others impacted by the sampling. Identify the location of all wells and keys required for access. Check laboratory bottles for number, condition, proper type, and verify if there are any special sampling, filtering, or preservation procedures. Plan to ship the samples as soon as possible following the sampling event. If sampling using a pump, evaluate well and previous sampling data (from the previous year’s annual report) to determine sampling order from least to most impacted. Table 4 provides a suggested sampling order based on historic Site data. If sampling using a Snap Sampler, the unit will need to be deployed ahead of time to allow for sufficient equilibration. Preferably, replacement Snap Samplers should be deployed immediately after sampling so that they are present for the next monitoring event. If Snap Samplers are not deployed immediately after the previous sampling event, evaluate the well and previous sampling data to determine the amount of equilibration time required. Verify proper operation and decontamination equipment to be used during sampling. Verify that copies of all required forms will be taken into the field and review the sampling plan with the project manager, including any special health and safety considerations.

4.2.1.2 Measure Static Water Levels Follow procedures outlined in Section 3.2 of this plan.

4.2.1.3 Purge Well Follow procedures outlined in Section 3.4 of this plan. If a passive sampling method will be used to collect samples, purging is not necessary.

4.2.1.4 Sample Collection Due to the low hydraulic conductivities calculated for the former impoundments and the observed low recharge rates during the Site characterization field work, it is recommended that passive sampling methods be considered for the long-term monitoring in upgradient wells. Collecting groundwater samples from the upgradient wells is likely to be a time-consuming process and it may be difficult to provide a representative, unbiased sample utilizing standard low-flow sampling techniques. Therefore, upgradient wells will be sampled passively using a Snap Sampler. If sampling passively using a Snap Sampler, the following procedure, which adheres to ASTM Standard D7929-14 and is included in the SOP in Appendix C, will be used for deploying the sampler and collecting samples: 1.

Calculate the distance from a reference point at the top of the well to the point where the Snap Sampler is to be placed.

Turn the translucent “Snap Cap” on each end of the bottle slightly to release any sticking on the o-ring.

Insert the bottle into the upper end of the sampler.

Place the sampler connector onto each end of the sampler; turn clockwise to align the set

Pivot the Snap Cap into its seat with the Snap driver. Push the retainer pin up through the lower

pins/screw; then gently tighten the set screw with the Snap Driver Tool. hole in the vial cap. Repeat for all Snap Caps. If an o-ring should dislodge from its seat during setting, remove the sample bottle and carefully replace it in the o-ring groove; repeat the setting procedure. 6.

For the manual trigger, feed ball-fitting end of trigger cable through lower release pin groove; click tub fitting into connector.

Press the ball fitting in to attach to lower release pin.

For the pneumatic trigger system, attach the wireline from the plunger.

Deploy to desired depth with trigger cable/tubing and attach to well head.

10. Additional Snap Samplers can be deployed with separate trigger lines or in series with a single trigger. If separate triggers are used, the ID tags should be marked at the surface for later reference. 11. Recommended minimum deployment period is one to two weeks. There may be hydrogeologic conditions where a shorter deployment is possible, but one to two weeks assures that the well returns to steady-state condition. There is no upper bound for time of sampler deployment and can be deployed for extended periods.

12. Upon completion of the deployment period, the sampler should be triggered at the well head without disturbing the sampler position. For the manual trigger, the cable end should be pulled with sufficient force to move cable up the tubing. Closure should be felt through the trigger line. If more than one triggering line is present, closure should proceed from the deepest to the shallowest sampler position to limit capture of sediment potentially resuspended by closure of the first sampler. 13. Once retrieved, sample bottles should be removed from the sampler by loosening the blue retainer screw and turning the white cover piece. It is important not to agitate the samples until the all screw caps are tightened. There should be no headspace in the bottles unless the air was entrained while deployed. If sampling for multiple parameters, the first sample will be collected, preserved, and containerized in the order of the parameter’s volatilization sensitivity. Sample bottle type, sample volume, preservatives, and holding times are shown on Table 4. Extra bottles should be carried to the Site in case the bottle caps are defective. The time and date of sample collection and sample field measurements will be recorded in the Field Log Data Sheet (Appendix E). As every attempt should be made to minimize changes in the chemistry of a sample, groundwater samples collected for organic constituents or parameters should not be filtered in the field.

4.2.1.5 Filling Containers Table 4 summarizes the sample container type, preservation method, and holding time for each potential analytical parameter. For completeness, all typical analytical groups are discussed, regardless of their current applicability to the parameter list for the Facility. To clarify and supplement the summary in Table 4, the manner and order in which containers will be filled is described below. Individually prepared bottles will not be opened until they are to be filled with water samples. Special care will be taken to ensure that the procedures listed below are followed: 1.

The area surrounding the wellhead will be kept as clean as practical to minimize the potential for sample contamination. A clean sheet of polyethylene will be placed on the ground underneath sampling equipment to minimize potential sample and sampling equipment contamination from the ground surface materials.

Care will be exercised to minimize the potential for airborne contamination of sample water during collection. If vehicles or generators are left running during sample collection, containers will be filled at least 30 feet upwind (or crosswind if upwind location is not accessible) from engine exhaust sources. If conditions are dusty, an effort will be made to shield the sample collection area from windborne contamination.

A clean pair of latex or nitrile™ gloves will be put on at the onset of sampling activities at each new sampling point. Sampling personnel will keep their hands as clean as practicable and replace gloves if they become soiled while performing sampling activities.

Sampling personnel will not touch the inside of sampling containers, inside of bottle caps, or rim of sample containers. If contact occurs, sample containers will be replaced.

Laboratory-provided sample containers will be checked prior to filling to make sure that they are the correct containers for the analyses and contain any necessary preservatives required for the appropriate sample analyses.

Care will be taken to avoid overfilling sample containers with preservatives. If overfilling occurs, a

All sample containers will be placed directly in a cooler with ice immediately after sample

new sample container will be used to replace the overfilled container. collection. Samples will be kept on ice (or in a refrigerator at a similar temperature) until they are received by the laboratory. The bottles will be filled with water in the order to be analyzed, as follows: •

Total metals

•

Dissolved metals

•

Hexavalent chromium

•

General parameters

Field duplicate samples will be collected sequentially as described in Section 4.5. Methods for filling sample containers for individual analyses are described below. All water samples will be collected from a sampling point before the water has passed through the flowthrough cell. The sample water discharge point at the end of the tube will be held as close as possible to the sample container without allowing the sample tubing to contact the container. The sample tubing should remain filled with water to minimize potential changes in water chemistry. At a minimum, sampling personnel will use their body to shield the sampling container from wind and airborne dust while filling. When strong winds, heavy rain, or dusty conditions are present, additional measures will be implemented to mitigate background interference to the extent possible.

4.2.1.6 Sample Labels Labels will be attached to each sample bottle. The sample label must be sufficiently durable to remain legible even when wet. Each sample label should contain, at a minimum, a sample identification number, name of the sampling personnel, Site name, date and time of collection, well number (location of collection), and analyses to be performed.

4.2.1.7 Documentation To document sample collection, the Field Log Data Sheet (Appendix E) will be filled out with the sampling point, project, location, well order number, well depth, water level, depth to water, casing diameter, wellbore volume purged, sampling method, bailer type, sample appearance, and samples collected. Fill in the identical applicable information on the field chain of custody record. Refer to Section 5 of this plan for a complete detail of chain of custody and documentation procedures.

4.2.1.8 Transportation to Laboratory Samples will be placed in insulated containers with ice and transported to Pace Analytical via overnight service or courier under chain of custody protocols. Sample bottles and ice should be placed in separate

overpack bags (freezer bags) to prevent melt water from reaching the sample bottles or leaking from the cooler. Samples sent to collaborating laboratories by common carrier will be sealed with custody tape and a chain of custody record.

4.3 In-Situ or Field Analyses If using bailers, samples for temperature, turbidity, pH, and specific conductance will be collected by separate bailer pulls. One sample will be collected immediately after sampling for COCs and one more will be collected as the last sample from the well as a check on stability. Field water quality parameters will be measured using a YSI Pro DSS meter or equivalent. The meter will be calibrated with the manufacturersupplied standard before each day’s use. Data obtained will be recorded in the field notes.

4.4 Decontamination The intent of the decontamination procedure is to prevent cross-contamination between wells. Procedures or equipment that minimize or eliminate the risk of cross-contamination will be used in favor of, or in conjunction with, decontamination. These include: •

Sample wells in an order from least to most impacted (based on historical analytical results)

•

Sampling personnel will wear nitrile gloves or equivalent while handling equipment or samples

•

Sample containers will be purchased new, used once, and discarded

•

Use disposable or dedicated sampling equipment, such as bailers or use a single sampler for each well

•

Use disposable or dedicated tubing for each well if wells are to be sampled with pumps

•

Use of dedicated submersible pump(s)

When disposable sampling equipment is not available, sampling and/or purging pump decontamination is required between wells. To decontaminate a submersible pump, use the following procedure. Materials needed for decontamination of a submersible pump include: •

Clean barrel or drums for pump decontamination

•

De-ionized water

•

Tap water

•

Spray bottle with Alconox® (or equivalent non-phosphate solution) or alcohol wash

•

Spray bottle

•

Paper towels

Rinse the outside of the pump and its accessories with Alconox® solution, followed by a tap water rinse, and then a final de-ionized water rinse. Accessories may include, but are not limited to cords, cables, screens, or weights. Decontaminated equipment will be air dried or wiped dry with paper towels. Waste decontamination fluids should be containerized and disposed of properly. Once sampling equipment has been decontaminated it should not be allowed to contact the ground or other contaminated surfaces prior to insertion into the well. To demonstrate the effectiveness of the

decontamination process, a field blank may be obtained by pumping a volume of de-ionized water through the pump and collecting the pump water into appropriate sample containers.

4.5 Quality Control Samples Quality control of data will involve collecting field duplicates matrix spike/matrix spike duplicate (MS/MSD) samples and using equipment blanks. The role of these samples, along with the preparation and analysis, are identified and discussed in Sections 4.5.1 through 4.5.4. Duplicate and MS/MSD samples will be collected after the actual sample vials for a specific analyte group are collected.

4.5.1 Field Duplicate Samples Field duplicate samples are used to assess field sampling procedures and the laboratory’s precision. The location where duplicate samples are collected shall be noted on the Field Log Data Sheet (Appendix E). A duplicate sample will follow all the same collection procedures as the primary sample and will be analyzed for all the same parameters. At least 10 percent of the total number of locations sampled (or 1 for every 8 sample locations) will be duplicated each sampling event. The wells duplicated may change during each sampling event.

4.5.2 MS/MSD Samples MS/MSD samples are required by Pace Analytical to assess laboratory quality. A MS/MSD will be collected and analyzed using the same procedures as a primary sample. The location(s) where MS/MSD samples are collected shall be noted on the Field Log Data Sheet (Appendix E). At least five percent of the total number of locations sampled (or 1 for every 8 sample locations) will be sampled for a MS/MSD sample each sampling event. The wells sampled for MS/MSD samples may change during each sampling event.

4.5.3 Equipment (Rinsate) Blanks For non-dedicated sampling equipment, equipment blanks will be prepared by rinsing the sampling equipment (after decontamination) and collecting a sample of the rinsate water. To evaluate decontamination procedures, these samples will be analyzed for the same parameters as field samples. One equipment blank will be collected during each sampling event for which non-dedicated or nondisposable sampling equipment is used. The equipment and the sampling location will be noted on the Field Log Data Sheet (Appendix E). Equipment blank samples are not required when Snap Samplers are used to collect groundwater samples or when dedicated equipment is used.

4.5.4 Temperature Blanks The laboratory will measure sample temperature when samples are received and logged in for analysis by the sample custodian. The measurement will be taken from a temperature blank included with each sample container shipped to the laboratory. Temperature blanks are laboratory-supplied water-filled containers, typically 125 milliliters (mL) high-density polyethylene (HDPE), used to allow for thermal sample preservation monitoring during shipment.

4.6 Training The individuals collecting samples will have appropriate training in sampling techniques, wellhead protection, first aid/CPR, and the 40-hour hazardous waste site operations training course.

4.7 Reports Groundwater monitoring reports will be forwarded to IPL for their review and approval prior to submitting them to state and federal agencies.

5 Reporting 5.1 Annual Report Components Data collected during the groundwater monitoring sampling events and any additional groundwater quality or water level data collected will be included in the semi-annual groundwater monitoring reports and used in the associated evaluation of the Site. The results of the sampling and analysis program will be documented in the annual groundwater monitoring report submitted in accordance with the MSOP. The report will include the following: •

Status and integrity of the monitoring well network

•

Discussion of any variations in sampling protocol

•

Water level data summary tables

•

Preparation of potentiometric maps

•

Analytical data summary tables

•

Statistical data summary tables

•

Preparation of isoconcentration contour maps, as needed

•

Discussion of data validation results

•

Evaluation of variations in upgradient and/or downgradient groundwater quality.

Contouring and evaluation of potentiometric maps will be performed under the direction of a qualified geologist. Data tables will be used to summarize the constituents analyzed, concentrations detected, units of concentration, detection limits, sample location, and data of sampling. A separate table may be prepared for the QA/QC samples and will include similar information. The groundwater program QA information will be presented as required and will include the following: •

Field and laboratory quality assurance activities

•

Data validation results

•

Precision and accuracy of data

•

Completeness of data

•

Usability of data

5.2 Annual Report Submittal Groundwater monitoring reports will be forwarded to IPL for their review and approval prior to submitting them to state and federal agencies.

5.3 Baseline Report Prior to performing statistical analysis for data collected during routine groundwater monitoring sampling events, quarterly sampling for a period of two years (baseline sampling) will be performed to gather baseline concentration information. During the two-year baseline sampling event period, two reports will be developed discussing the sampling procedures and results. The first of the two reports will be developed at the completion of the first four baseline monitoring events. The report will include a

description of sampling procedures, figures, and analytical results. The second report will be the evaluate baseline data, and will be developed at the completion of all eight baseline sampling events. In addition to the report information detailed in Section 5, the baseline data evaluation report will include: •

Detailed description of the statistical analysis of the baseline results

•

Discussion of any statistically derived limits

•

Baseline concentration evaluation

5.4 Baseline Report Submittal The baseline report will be forwarded to IPL for review and approval prior to submitting it to MDNR.

6 Statistical Analysis Plan This section describes the statistical methods required pursuant to 40 CFR 257.93(f)(1) and the MSOP. The methods are used to determine background concentrations, select appropriate statistical tests, and documenting procedures to be followed in the event that reported constituent concentrations in groundwater samples indicate a statistically significant increase (SSI) from the background concentration. A detailed description of statistical analysis methodologies are presented in Appendix F. For the purposes of describing the proposed statistical analysis, the term “background” will refer to a distribution or set of intrawell sample measurements of representative and appropriate historical data to be used for comparison with current intrawell sample data.

6.1 Statistical Approach The statistical analysis plan addresses the methodologies that will be followed pursuant to 40 CFR 264.93 detection monitoring requirements to determine if detected compounds in groundwater may indicate SSIs over the background water quality, and potentially indicate a release to groundwater from the impoundments. An SSI may be caused by several factors including, but not limited to, a release of contaminants to groundwater. The detailed approach described in this plan is intended to minimize false positives (false indication of an SSI), while providing a means of determining whether the impoundments are potentially adversely influencing groundwater quality. The statistical procedures presented herein adhere to 40 CFR 264.93 and MSOP requirements and were developed based on the principals and procedures of Statistical Analysis of Groundwater Monitoring at RCRA Facilities Addendum to Interim Final Guidance (EPA, 1992), ASTM Standard D6312 entitled Standard Guide for Developing Appropriate Statistical Approaches for Groundwater Detection Monitoring Programs, and Statistical Methods for Groundwater Monitoring (ASTM, 1994). With the release of the EPA publication, “Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities” (EPA 530/R-09-007) in 2009, the document, also referred to as Unified Guidance, will be used as guidance for principles and procedures for the statistical analysis of the groundwater data. The routine detection monitoring procedure can be summarized as follows: After the groundwater data are collected and data quality has been verified, the constituent values will be compared to statistically derived control limits. If the constituent value exceeds the control limit, a potential SSI has been indicated, and confirmation sample collection and further actions need to be taken (as detailed in Sections 10.5 and 10.6 of the Unified Guidance).

6.2 Groundwater Monitoring Network The groundwater monitoring program is designed to evaluate the effectiveness of groundwater protection at the Site. All wells identified in Table 2 constitute the point of compliance for the Site. Based on 40 CFR 264.93, all wells listed in Table 2 require sampling, analysis, and statistical evaluation. Monitoring well locations are shown on Figure 3.

6.3 Monitoring Parameters and Statistical Analysis Reporting Monitoring wells will be analyzed for the parameters listed in Table 1. Per the permit, statistical analysis will be conducted for the hazardous constituent and indicator parameters listed in Table 1. The statistical analysis will determine if a SSI (or decrease for pH) has been detected. Time verses concentration graphs will also be compiled for all the hazardous constituent and indicator parameters listed in Table 1. The field measurements of static groundwater elevation, temperature, DO, physical appearance, ORP, turbidity, and total well depth will not be statistically analyzed. The results of the statistical analysis will be reported in the annual and semi-annual reports.

6.4 Statistical Procedures There are several factors that are considered in determining the appropriate statistical method to use for detection monitoring including, but not limited to, hydrogeology, monitoring history, constituent detection frequency, site setting, and data distributions. Spatial variability is typically the largest component of statistical differences between wells in any groundwater monitoring network; therefore, intrawell analysis is generally preferred to interwell analysis for detecting releases (Section 1.8 of ASTM D6312 – 96). Intrawell analysis uses each well’s historical data record to establish background concentrations for each constituent. Statistical testing is used to determine if there is a, SSI (or decrease in pH) over background levels. As documented in Section 3.1, low-flow sampling procedures will be used on all downgradient monitoring wells. Low-flow sampling methods are designed to minimize sample agitation and disturbance. Low-flow sampling is designed to prevent particulates that are not transported by ambient groundwater flow from being entrained in the sample resulting in a biased sample. Low-flow sampling has the potential to influence the measured constituent concentrations as compared to samples collected via non-low-flow sampling procedures, especially for total metals and specific conductance. The historical data for establishing background constituent concentrations is minimal; therefore, sampling will be conducted quarterly to establish baseline concentrations. The results from the low-flow sampling events will be used to determine background concentrations in groundwater at each monitoring well. These data will be compared to future Site groundwater monitoring data to determine appropriate statistical procedures and if additional monitoring is necessary. In general, two types of intrawell statistical tests will be used depending on the number of samples, detection frequency, and data distribution of the parameters from each well’s background data. These are: •

Nonparametric Prediction Limits (NPPLs) – Used when a sample parameter has less than 25 percent detection frequency or when the data distribution is neither normal nor lognormal. The NPPLs are set at either the highest background detected value, the ‘typical’ practical quantification limit (PQL), or a calculated Poisson prediction limit. Poisson prediction limits are especially useful when there are less than eight samples per well and constituent.

•

Control Charts – An intrawell test used for selected constituents where detection frequencies are greater than 25 percent, there is no increasing trend in the historical data record, and the data are either normally or lognormally distributed.

A third type of intrawell statistical test, parametric prediction limits, may be suitable for some well and parameter combinations – for example, if the control chart limits are excessively high, a parametric prediction limit may be appropriate. In general, because the data distribution and detection frequency requirements are the same for parametric prediction limits and control charts, it is not anticipated that parametric prediction limits will be utilized in the statistical analysis. Background concentrations for all wells/parameters will be assessed at yearly intervals until at least eight (8) acceptable background samples are available. Although not used directly as part of the statistical analyses, time versus concentration graphs for all wells at the Site will be compiled for additional data interpretation.

6.5 Determination of Statistically Significant Increases This section describes the procedures to determine an SSI using NPPLs, parametric prediction limits, and Control Charts. Evidence of an SSI will be evaluated for all COCs listed in Table 1. Confirmation sampling is an integral part of all the statistical testing and; therefore, as described in Sections 6.5.1 and 6.5.2, the first sample to exceed a compliance limit will be identified as a potential SSI awaiting confirmation. Confirmation sampling required by initially determining a potential SSI will occur during the next scheduled routine semi-annual event to ensure a statistically independent sample for confirmation of the potential SSI. The confirmation sampling event shall occur within 180 days of the sampling event that identified a potential SSI. The confirmation samples will be analyzed for all the parameters in Table 1.

6.5.1 Nonparametric Prediction Limits The actions to be taken in response to an exceedance of the prediction limits are as follows: •

If a constituent exceeds the prediction limit, the well will be resampled to confirm the potential SSI.

•

If the result from confirmation sampling is also above the prediction limit and the background sample size (n) > 8, an SSI will have been confirmed.

•

If (n) < 8, the constituent would have to exceed the prediction limit in two consecutive sampling events to confirm the SSI (if only one of the confirmation sample concentrations exceeds the prediction limit then an SSI would not be confirmed).

•

If the confirmation sampling is below the prediction limit, the potential SSI will not be confirmed and detection monitoring will continue.

6.5.2 Control Charts For parameters statistically monitored using control charts, the Shewhart Control Limit (SCL) is used to identify significant short-term increases while the cumulative sum control (CUSUM) control parameter h monitors long-term increases. If either the SCL or the CUSUM control parameter h is exceeded, a potential SSI will be identified, and the well will be resampled to confirm. If the confirmation sample concentration exceeds the SCL, the SSI will be confirmed. The confirmation sample will replace the original sample in the

calculation of the CUSUM. If the confirmation sample concentration still exceeds the CUSUM control parameter h, the SSI will be confirmed. If the confirmation sample concentration is below the CUSUM control parameter h, this value will permanently replace the original sample value in the statistical database and in the calculation of the CUSUM.

6.6 Response to a Statistically Significant Increase If one of the COCs in Table 1 exhibits a confirmed SSI in one of the downgradient wells and there is no evidence of COCs impacting upgradient wells it will be assumed that the SSI(s) is likely due to the CCR impoundments impacting the groundwater. The following procedure will be followed: 1.

If a potentially adverse impact is indicated, the MDNR will be notified of the SSI within seven days of the Facility's knowledge of such a determination. The notification will indicate the constituent(s) that has (have) shown such an increase and in which well(s) the increase(s) has (have) occurred.

Within 60 days of the notification, a report detailing an assessment of the potential causes(s) of the SSI(s) will be submitted to the MDNR. Typically, the assessment will be submitted as part of the semi-annual groundwater monitoring report.

If, based on the submittal, the MDNR determines that the SSIs are due to releases from the CCR

If IPL disagrees that the SSIs are not likely due to a release from the CCR impoundments, an

impoundments, a compliance monitoring program will be submitted by the Facility. alternative source demonstration (ASD) can be performed to investigate the potential sources for the SSI. 5.

Confirmed increases for indicator parameters (pH, sulfate concentration (SO4) and specific conductivity), will not results in an SSI. As indicator parameters, an increase in pH, specific conductance, or sulfate is not necessarily an indicator of a release from the impoundments. The pH, specific conductance, and sulfate results may be due to upgradient subsurface materials and not related to an impoundment release. As indicator parameters, the only action that will be taken is continued monitoring.

If one of the COCs listed in Table 1 exhibits a confirmed SSI in one of the downgradient wells and there is evidence of COCs impacting upgradient wells, it will be assumed that the SSI(s) is likely due to the natural presence of COCs in the soil and the following procedure will be followed: 1.

The MDNR will be notified of the SSI within seven days of the Facility’s knowledge of such a determination. The notification will indicate the constituent(s) that has (have) shown such an increase and in which well(s) the increase(s) has (have) occurred.

The MDNR, in consultation with the Facility, will then determine what additional action(s) may be necessary. The MDNR will notify the Facility in writing of follow-up requirements, if any.

6.7 Groundwater Protection Standards If a constituent is consistently identified as SSI for the Site, but concentrations for the constituent are far below any regulatory action level, a risk-based Groundwater Protection Standard (GWPS) may be selected

or derived. The GWPS would represent “the maximum concentration limits for a hazardous constituent in the groundwater at the point of compliance during the compliance period.” To date, GWPS values have not been established at the Site for any constituents. If a confirmed SSI in the groundwater detection parameters is determined in the future, GWPS values may be considered for development for the Site.

7 Health and Safety The Blue Valley Groundwater Monitoring Project Health and Safety Plan (Barr, 2019) has been prepared for the Site. All work will be performed in accordance with the health and safety requirements described in the Project Health and Safety Plan, which is maintained at the Site. Based on the results of previous investigations it is anticipated that Level D safety procedures are sufficient to protect workers at the Site, which includes the following protective equipment: •

Hard hat

•

High visibility vest

•

Safety boots/shoes

•

Safety glasses

•

Gloves

The primary COCs that impact the Site are the metals listed on page 11 of the MSOP Fact Sheet in Appendix A: All sampling personnel involved in groundwater monitoring activities will be trained on the contents of the Project Health and Safety Plan. Training sessions will be conducted on site by the Site Health and Safety Officer or his/her designated representative. Personnel training will include a review of the project, contaminant types and specific hazards, safety zones, training levels and level of protection, explanation of air monitoring, decontamination procedures, emergency procedures, and location of the Project Health and Safety Plan.

8 Well and Sampling Equipment Repair During each sampling event, components of the monitoring network will be inspected, and the need for repair or replacement will be determined. Table 5 provides a checklist of components and decision criteria for their repair or replacement. Protective well casing and posts, concrete well pads, well locks, well risers and screens, dedicated bailers, water quality parameter meter, and the water level indicator will be inspected for proper operation or condition. Consistently high turbidity readings, turbidity readings which do not stabilize, and a total depth of well reading that decreases over time can indicate a well may need to be redeveloped. Development techniques, described in Section 3.3, to remove silt from the well and clear fines from the well screen and sand pack, will be utilized as necessary to maintain operational wells.

9 References ASTM, 1995. Standard Guide For Developing Appropriate Statistical Approaches for Groundwater Detection Monitoring Programs at Waste Disposal Facilities, ASTM D6312-17. Barr, 2019. Blue Valley Coal Combustion Residuals Impoundment Project Health and Safety Plan, Independence Power and Light Blue Valley Power Plant, Independence, Missouri. January 2019. Barr, 2020. Blue Valley Coal Combustion Residuals Impoundment Site Characterization Report, Independence Power and Light Blue Valley Power Plant, Independence, Missouri. May 2020. SCS Engineers, 2017. Summary Report Blue Valley Power Station Coal Combustion Residual Material Characterization Project, August 2017. USEPA. 1986. RCRA Ground Water Monitoring Technical Enforcement Guidance Document (TEGD) U. S. Environmental Protection Agency Office of Waste Programs Enforcement, Office of Solid Waste and Emergency Response (OSWER) 9950.1. EPA/530/SW- 86/055. USEPA. 2002a. Ground-Water Sampling Guidelines for Superfund and RCRA Project Managers. U.S. Environmental Protection Agency Office of Solid Waste and Emergency Response (OSWER). EPA/542/S-02/001. USEPA. 2002b. Guidance on Environmental Data Verification and Data Validation, U.S. Environmental Protection Agency Office of Environmental Information. Washington, DC: Agency. EPA/240/R02/004. USEPA, 2009. Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities, U.S. Environmental Protection Agency Office of Resource Conservation and Recovery. Washington, DC: Agency EPA 530/R-09-007. USEPA. 2017. National Functional Guidelines for Organic Data Review, U. S. Environmental Protection Agency Office of Superfund Remediation and Technology Innovation. EPA-540-R-2017-002.

Tables

Table 1 Constituents of Concern - Groundwater Sampling Blue Valley Power Plant Location

MW-01 Independence, MW-02 MW-03 MO

Sampling Method Parameter

General Parameters Carbon, total organic Chemical Oxygen Demand Chloride Fluoride Hardness, as CaCO3 Nitrogen, nitrate + nitrite, as N Nitrogen, nitrate, as N Nitrogen, nitrite, as N Solids, total dissolved Sulfate, as SO4 Metals Aluminum Antimony Arsenic Barium Beryllium Boron Cadmium Chromium Chromium, hexavalent Chromium, trivalent Cobalt Copper Iron Lead Lithium Magnesium Manganese Mercury Molybdenum Nickel Selenium Silver Sodium Thallium Zinc Aluminum Antimony Arsenic Barium Beryllium Boron Cadmium Calcium Chromium Chromium, hexavalent Chromium, trivalent Cobalt Copper Iron Lead Lithium Magnesium Manganese Mercury Molybdenum Nickel Selenium Silver Sodium Thallium Zinc 1

Total or Dissolved

MW-04

MW-05

MW-06

MW-07

MW-08

Low-Flow

Passive

Units

N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A

mg/l mg/l mg/l mg/l ug/l mg/l mg/l mg/l mg/l mg/l

x x x x x x x x x x

Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Dissolved Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total Total

ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l mg/l mg/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l mg/l mg/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l ug/l

x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x x

Analysis frequency is semi-annual. If after two consecutive years a metals parameter(s) has had no concentration in any well exceed the EPA Maximum

Contaminant Level (MCL) or the MRBCA Lowest Default Target Level for that parameter(s) at anytime within those two consecutive years, it will be dropped from the semi-annual sampling list and sampled for in five years. If the criteria are exceeded in the future sampling event, the parameter(s) will be added back to the semiannual sampling list, and the process will start over. This evaluation will start after completion of the eight quarters of baseline sampling.

Page 1 of 1 3/15/2021 P:\Jeff City\25 MO\49\25491019 Groundwater Monitoring Program\WorkFiles\GMSAP\Tables\Table 1- IPL Sampling Parameters- Version 2.xlsx

TABLE 2 MONITORING WELL CONSTRUCTION SUMMARY Well ID

Installation Date

Well Type

Surface

Riser

Total

Borehole

Riser Pipe

Elevation

Depth

Diameter

(Inches)

(Feet)

MW-1

6/26/2019

Permanent

756.09

758.54

35.00

8.25

MW-2

6/25/2019

Permanent

752.94

755.45

35.00

8.25

MW-3

6/25/2019

Permanent

749.09

751.63

35.00

8.25

MW-4

6/25/2019

Permanent

749.49

751.17

42.00

8.25

MW-5

8/5/2019

Permanent

756.63

758.81

56.00

MW-6

8/2/2019

Permanent

774.29

776.01

71.00

MW-7

8/4/2019

Permanent

776.5

778.29

90.00

MW-8

8/2/2019

Permanent

770.69

772.61

76.00

Notes: (1) Elevations are based on survey data collected 5/5/20. (2) From Surface Elevation

Riser Pipe

Screened Interval (Feet) 1

Material Schedule 40 PVC Schedule 40 PVC Schedule 40 PVC Schedule 40 PVC Schedule 40 PVC Schedule 40 PVC Schedule 40 PVC Schedule 40 PVC

Top

Bottom

741.09

721.09

737.94

717.94

734.09

714.09

737.49

707.49

710.63

700.63

708.29

703.29

696.5

686.5

704.69

694.69

Table 3 Well Sampling Order Blue Valley Power Plant Independence, MO

Sampling Order

Well ID

MW-05

MW-07

MW-01

MW-02

MW-03

MW-04

MW-08

MW-06

Table 4 Sampling Containers, Preservatives, and Holding Times Independence Power and Light Independence, MO

Analyte

Container

Total Metals Total Organic Carbon

P G

Chemical Oxygen Demand

Volume

Preservative

Holding Time

500 mL 125 mL

Ice, HNO3 Ice, H2SO 4

180 days 28 days

125 mL

Ice, H2SO 4

28 days

Chloride

125 mL

Ice

28 days

Required

Fluoride

100 mL

Ice

28 days

Hardness, as CaCO 3

250 mL

HNO3

180 days

Nitrogen, nitrate + nitrite, as N

250 mL

Ice, H2SO 4

28 days

Nitrogen, nitrate, as N Nitrogen, nitrite, as N Solids, total dissolved Sulfate, as SO4 pH Conductivity Temperature Turbidity Dissolved Oxygen

P P P P P P P P P

250 mL 250 mL 250 mL 125 mL 125 mL 125 mL 125 mL 125 mL 125 mL

Ice Ice Ice Ice None Required None Required None Required None Required None Required

48 hours 48 hours 7 days 28 days Field Analysis Field Analysis Field Analysis Field Analysis Field Analysis

Notes: P = Polyethylene G = Glass

Notes: (1)

Bottom of borehole, top of screen, and bottom of screen elevation estimated; surface elevation missing.

Table 5 Decision Criteria for Monitoring Well and Sampling Equipment Repair Independence Power and Light Independence, MO

Item Well identification Protective casing and posts (above ground)

Flush mount

Concrete well pad

Well locks

Riser and screen

Symptom Faded or unreadable well ID.

Water quality parameter meter Water level meter

Verify well ID with site maps and re-mark.

Paint chipped or rusted.

Repaint if more than 50% of surface is exposed.

Hinges rusted/misaligned.

Lubricate with graphite and physically realign; or replace hinge.

Insect infestation.

Apply spray insecticide to insects (do not spray directly into well).

Cover is cracked/broken.

Replace cover.

Gasket is missing or damaged.

Replace gasket.

Water/ice in manhole.

Remove water/ice before removing riser cap.

Bolts are missing.

Replace bolts.

Pad is cracked (riser is exposed).

Replace pad; or abandon well; replace well if needed.

Pad is cracked (riser is not exposed).

Repair with crack sealer; or replace pad.

Soil erosion around or under pad.

Backfill and revegetate as appropriate.

Overgrown with vegetation.

Clear vegetation using hand tools.

Lock mechanism is corroded.

Lubricate with graphite.

Lock is broken.

Replace with appropriate lock.

Missing or damaged cap.

Replace cap.

Filterpack sand in well/screen is cracked or dislocated.

Bail sand; if problem remains, replace well if needed.

Silt in well.

Redevelop if estimated silt thickness is > 25% of screened interval.

Screen plugged/abnormally slow recharge.

Redevelop well.

Missing measuring point mark on top of casing.

Add mark to northern lip of top of casing with permanent marker.

Apparent well casing elevation change.

Dedicated bailers

Repair Step

Water leaks out of bailer through check valve. Bailer is cracked or bent. Bailer string is frayed or spliced. Bailer is lost down well. Error message. Water inside controls. No indicator sound or light is observed (probe is wet). No indicator sound or light is observed (probe is dry).

Resurvey top of casing; if needed, cut to appropriate height. Check internally for cracking. Replace bailer. Replace bailer. Replace string. Place fishing hooks on bottom of new bailer and use to retrieve. See equipment manual/check battery. Use compressed air to blow out. Turn meter on/up; or check battery. Check for obstruction in well; or well is dry.

Figures

Ja c k s o n C o u n t y

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Closed Railroad Property Boundary

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SITE PROPERTY BOUNDARY Independence Power & Light Independence, Missouri

FIGURE 2

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Imagery: Nearmap, July 2020

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Downgradient Monitoring Well Upgradient Monitoring Well Property Boundary Closed Railroad

; ! N

175

350

Feet

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GROUNDWATER MONITORING WELL NETWORK Independence Power & Light Independence, Missouri FIGURE 3

Appendices

Appendix A Independence Power and Light Missouri State Operating Permit

Appendix B Missouri Geological Survey Geological Survey Program

Missouri Department of Natural Resources Missouri Geological Survey Geological Survey Program

Guidance for Conducting a Detailed Hydrogeologic Site Characterization and Designing a Groundwater Monitoring Program

December 10, 2010 – revised March 2016

Table of Contents 1.0 - Introduction ............................................................................................ 1 2.0 - Definitions .............................................................................................. 1 3.0 - Elements of a Detailed Site Characterization Work Plan ........................ 2 4.0 - Elements of a Detailed Site Characterization ......................................... 2 4.1 - General Procedures ......................................................................... 3 4.2 - Oversight Requirements ................................................................... 3 4.3 - Field Investigation ............................................................................ 3 4.3.1 - Surficial Materials Investigation................................................... 3 4.3.2 - Bedrock and Hydrogeologic Characterization of Aquifer ............. 4 4.4 - Records............................................................................................ 5 4.5 - Water Level Data Collection ............................................................. 6 4.6 - Monitoring Wells ............................................................................... 6 5.0 - Presentation of Data and Interpretations ................................................ 7 5.1 - Table of Contents ............................................................................. 7 5.2 - Introduction ...................................................................................... 7 5.3 - Method of Study ............................................................................... 7 5.4 - Results of Investigation .................................................................... 7 5.5 - Conclusion ....................................................................................... 7 5.6 - References ....................................................................................... 8 5.7 - Appendices ...................................................................................... 8 5.8 - Tables .............................................................................................. 8 5.9 - Maps ................................................................................................ 8 5.10 - Cross-Sections ............................................................................... 9 5.11 - Aerial Photographs ......................................................................... 9 Appendix A – General Cost Estimate for Site Characterization .................... 10 List of Tables Table 1 - Factors Influencing the Density of Boreholes….…………………..4 References ................................................................................................... 12

1.0 - Introduction This guidance is intended to shed light on the elements required to design an adequate groundwater monitoring program. The adequacy of a groundwater monitoring program depends greatly on the quality of the detailed hydrogeologic site characterization used to design the program. Regardless of regulatory agency oversight, the basic requirements to characterize the hydrology and geology underlying a specific site are the same. Only after an adequate understanding of the underlying geology and hydrology has been achieved can the implementation of a groundwater monitoring program begin. 2.0 - Definitions Aquifer – A hydrostratigraphic unit or group of units which are capable of providing sufficient amounts of water to meet intended purposes. Detailed site characterization – A scientific examination of a facility that allows the identification and characterization of the hydrostratigraphic units underlying a facility, including the uppermost continuous zone of saturation. Typically, this includes a threedimensional assessment of the underlying geologic materials and the movement of groundwater within the materials. Facility – An area and/or locations that may be impacted by contaminates. This includes liquid and solid waste treatment facilities as well as associated land application areas. Groundwater monitoring program – A program utilizing the site specific data collected during a detailed site characterization to establish a system of monitoring wells that will best detect any release of contaminates into the environment. Groundwater monitoring plan – A plan (typically a document) that describes not only the groundwater monitoring program, but also the strategy for effectively monitoring groundwater at the facility. The plan typically details the standard operation procedures related to field sampling, laboratory analysis, data presentation and analysis of data trends. Hydrostratigraphic unit – A geologic stratum or group of strata that exhibit similar characteristics with the respect to transmission or fluids or gasses. Lysimeter – An apparatus that collects water moving through the soil column and used to determine the water soluble constituents or contaminates transported vertically within the unconsolidated materials. Monitoring well – A well that is ten feet (10’) or greater in depth, screened or open to a saturated interval for the specific purpose of obtaining site-specific water quality,

contaminant movement or hydrogeologic data. Soil borings, piezometers, and some lysimeters are considered types of monitoring wells or monitoring devices. Piezometer – A type of monitoring well that is ten feet (10’) or greater in depth and used to measure the hydraulic head of groundwater in a subsurface water bearing zone and/or conduct hydrologic testing of a hydrostratigraphic unit. Uppermost continuous zone of saturation – The hydrostratigraphic zone nearest the natural ground surface which is capable of yielding sufficient amounts of water to allow sampling

3.0 - Elements of a Detailed Site Characterization Work Plan 

Topographic map at a scale of 1:24,000



Site map at suitable scale to display pits, borings and piezometers



General description of proposed facility



Total acreage of facility including individual land application areas



Description of proposed methods for site exploration to include: o Drilling methods o Sampling procedures o Piezometer and monitoring well construction methods o Approximate screen depths o Specific grout mixtures and emplacement methods o Aquifer test methods (if required) o Record keeping procedures for: o Well logs, boring logs, drilling logs, and pit logs o On-site precipitation data (If required)

4.0 - Elements of a Detailed Site Characterization Almost all groundwater investigations will include an intrusive field program that involves drilling, hydrological monitoring, and groundwater sampling. The extents of such investigations are a function of the size and complexity of the facility. Depending on the geologic environment, several drilling techniques may be available. The U.S. E.P A. documents 625/R-93/003a and 625/R-93/003b provide an overview of subsurface characterization and monitoring techniques which can be utilized.

4.1 - General Procedures 

As per the State of Missouri’s RSMo 256.450 through 256.483, all geologic and hydrogeologic work must be completed by a registered geologist.



A consultant who subcontracts the drilling of monitoring wells and/or piezometers must hold a restricted or non-restricted monitoring well installation contractors permit as required by Missouri Well Construction Rules, 10 CSR 23 chapters 1, 2 and 4.



Drilling must be done by a driller holding a non-restricted monitoring well installation contractor permit. As required by Missouri Well Construction Rules, 10 CSR 23 chapters 1, 2 and 4.

4.2 - Oversight Requirements 

A qualified groundwater scientist should direct: o Excavation of all pits o Drilling of all borings o Performance of any geophysical surveys o Installation, development, and abandonment of all exploratory wells or piezometers



A qualified groundwater scientist should supervise: o All field testing used to determine geologic or hydrologic characteristics of materials encountered o All field testing of materials intended for use at a proposed site



A qualified groundwater scientist should maintain accurate and complete field notes of investigation activities.



A land surveyor registered with the State of Missouri must determine the location and elevation of all wells and piezometers. o Borings, excavation pits, and transects as part of a geophysical exploration must be surveyed to within one-tenth (0.1) foot. o Monitoring well and piezometer measuring-point elevations must be accurate to the nearest one-hundredth (0.01) foot.

4.3 - Field Investigation

4.3.1 - Surficial Materials Investigation 

A qualified groundwater scientist should determine: 3

o The thickness of significant geologic units above competent bedrock o The geotechnical characteristics of significant geologic units above competent bedrock 

All borings should be continuously sampled (exploration pits may be substituted for borings if the surficial materials thickness can be adequately and completely evaluated by the pits).

4.3.2 - Bedrock and Hydrogeologic Characterization of Aquifer 

A qualified groundwater scientist must determine: o Depth of the uppermost aquifer(s) beneath the proposed site o Thickness of the uppermost aquifer(s) beneath the proposed site o Lateral extent of the uppermost aquifer(s) beneath the proposed site o Additional aquifers which are potentially at risk (as determined by GSP)



Piezometer construction and development must be done in accordance with Missouri Well Construction Rules 10 CSR 23-4.



Piezometers should be distributed in a grid pattern across the site or located in a manner that will optimize characterization of the site.



An adequate number of piezometers must be located across the facility or anticipated facility to sufficiently characterize each aquifer o The location and spacing of necessary borings depends on subsurface complexity to the project. The density of boreholes should be greater when characterizing geology that is more complex. Table No. 1, located below, discusses the factors most commonly influencing borehole spacing. Table No. 1 - Factor Influencing the Density of Boreholes (Modified from U.S. EPA, 1992) Factors that may substantiate reduced density of boreholes  Simple Geology (e.g., horizontal, thick homogeneous geologic strata that are continuous across a site and unfractured) substantiated by site specific geologic information  Use of electric cone penetrometer surveys with additional tools  Use of geophysical data to correlate hydrological data between boreholes  Use of surface to borehole and cross borehole geophysical methods to interpret complex subsurface geologic structures

Factors that may substantiate increased density of boreholes  Fractured zones, conduits in karst terranes  Suspected pinch-out zones  Tilted or folded geologic formations  Suspected zones of high hydraulic conductivity that would not be defined by drilling at large horizontal intervals  Laterally transitional geologic units with irregular hydraulic conductivities



In the event that the original series of piezometers fail to adequately characterize the hydrogeology of a site, especially in the case of complex geological settings, additional piezometers and site characterization may be warranted. o An example of complex geologic setting is karst terrane. The carbonate bedrock which produces this terrane underlies a large portion of Missouri. Groundwater flow is typically through discrete conduits with velocities varying by orders of magnitude.



It is recommended that water level data be collected for a minimum of one year to allow for the assessment of seasonal variation within the uppermost continuous zone of saturation.



The measuring point elevation of the piezometers must be determined by survey.



If geophysical methods are used, piezometers must be installed to verify the results of the geophysical survey.



Injected tracers are an additional and viable field method used to help characterize the hydrogeology of a facility, especially in karst terranes. A tracer typically consists of a dye carried by groundwater that will indicate the direction and movement of groundwater and/or potential contaminates across a site.



It is recommended that a continuously recording precipitation gauge, capable of measuring precipitation events greater than one-tenth (0.1) inch, be installed at the site concurrent with or prior to installation of piezometers.



It is recommended that the hydraulic conductivity be determined in one out of every four borings (25% of borings on site) for each geologic unit evaluated.



The hydraulic conductivity should be determined in the field.



Acceptable field tests are in-situ slug, pump, or packer tests which isolate the geologic unit of interest.

4.4 - Records  Field logs and notes pertaining to the field investigation should be retained.  At a minimum, a qualified groundwater scientist should, in the field, note the following on a descriptive log: o Texture of bedrock or surficial materials o Color (Qualitative description - including mottling) of bedrock or surficial materials 5

o o o o o o o o o o o o o o

Relative degree of saturation (description) Voids Geologic origin Secondary permeability features Zones of incomplete sample recovery Depth at which water was encountered Depth and rate of drilling fluid gain or loss Type and size of drilling/excavation equipment Drilling rate or blow counts Packer test (including interval tested and results) Start and Stop time for drilling/excavation Names of field personnel Date, time, weather conditions Depth to water upon completion

 All boring or pits should be observed until water levels have stabilized or for at least 24 hours following completion.  Observations should determine if groundwater has entered the borehole, the depth to water, and if possible, the water bearing zones.  All borings and pits should be protected from rainfall and runoff during observation. 4.5 - Water Level Data Collection 

Measurements of water level should be made every month for one year for all piezometers.



Water level measurements should be made to the nearest tenth (0.1) of a foot



Water level measurements should be made within a time period of 48 hours if possible.

4.6 - Monitoring Wells  Monitoring wells are not required as part of the detailed hydrogeologic site characterization, however water quality data will be required as part of the regulatory process. Typically, for small 1 to 5 acre sites, a minimum of one monitoring well must be located hydrologically up gradient and three monitoring wells located hydrologically down gradient. Larger facilities and land application areas will likely require additional monitoring wells and sampling locations.

5.0 - Presentation of Data and Interpretations A hydrogeologic site investigation report should provide a detailed description of the geology and hydrology underlying the facility. The description should be based on data collected from boreholes, piezometers and test pits. The report must be prepared under the direction of a qualified groundwater scientist who is a geologist registered in the State of Missouri per RSMo 256.450 through 256.483 and the rules promulgated pursuant thereto. This person must sign and seal the report. The following information should be provided within the report. 5.1 - Table of Contents

5.2 - Introduction (general information about study area)  Location: A written narrative of the geographic setting with legal description (Section, Township, and Range).  Regional Geology: A written narrative describing the regional lithologic, stratigraphic, and hydrologic settings of the area.  Historic Land Use: A written narrative describing previous land use such as mining or mineral exploration. 5.3 - Method of Study - A written narrative must be provided which describes field and laboratory procedures used to characterize geologic and hydrologic conditions of the site. Standardized laboratory and field procedures may be referenced. All other procedures must be described in detail. 5.4 - Results of Investigation - A written detailed narrative must be provided that describes the site-specific geology and hydrology based on data collected. The narrative must include explanations of any anomalous data. Interpretations of results must be presented in a clear and concise manner. 5.5 - Conclusion - A written narrative must be provided that details how the site-specific geology and hydrology will impact the facility and design of the groundwater monitoring program. The narrative must assess any inadequacies of the investigation and propose future investigations if needed. The narrative must describe the proposed groundwater monitoring program design.

5.6 - References - All published information sources used in the compilation or research of the hydrogeologic investigation must be listed. 5.7 - Appendices - The appendices of the site characterization report must include: 

Compiled logs of all borings, excavations, wells and piezometers.



The raw data for any and all tests (e.g., pumping tests).



All additional information that may facilitate the assessment of the acceptability of the proposed site.



Logs - Lithologic logs of all borings and excavations, including well construction diagrams, should be provided. Each log should include borehole identification, borehole grid location, soil and rock description, sample depths, methods of sampling, sampling date, land surface elevation, borehole total depth.

5.8 - Tables - Presentation of tabular data that should be supplied include the following: 

All borehole, well and piezometer construction data. Such data should include the borehole, well or piezometer identification, grid location, total depth, surface elevation and, if applicable, screened interval and hydrogeologic unit monitored.



Monthly groundwater elevation measurements for each piezometer or well. The table(s) should indicate the well or piezometer identification, depth to water from measuring-point, groundwater elevation and date of measurement.



Results of all unconsolidated material testing. The table(s) should include the sample location, depth, sampling date, and test results.



Results of all hydrologic testing. The table(s) should include the well or piezometer identification, method and date of test, depths of interval tested, hydrologic unit tested and results.



Daily precipitation data collected at the site.

5.9 - Maps All detailed site maps for the report should be drawn on a scale where one inch equals 400 feet or less. As appropriate, maps should be drawn on a consistent scale. All maps must include a scale, north arrow, and a clear and concise legend describing all of the symbols used on the map. More than one map will be required to include the following information:  A base map showing initial topography of the facility or proposed facility

 Maps(s) showing land use, ownership, residences, septic systems, lateral lines, buildings, wells, cisterns, mined or quarried areas, mine shafts, spoil piles, and all other man-made features within 1/4 mile of the facility or proposed facility.  Map(s) showing springs, water courses, streams, lakes, caves, sinkholes, rock outcrops, and other significant geologic features within 1/4 mile of the facility or proposed facility.  Map(s) showing locations of all borings, excavations, piezometers, and wells constructed for the study.  Monthly piezometric maps per aquifer to be monitored. The maps must include labels showing water elevations next to each well or piezometer and must indicate the date when the water elevation was measured.  Map(s) showing inferred results of geophysical explorations with survey tracks (if applicable).  Map(s) locating cross-sections, and borings used in cross-section representation.  Map(s) locating floodplains, wetlands and fault(s).  Map delineating seismic impact zones.  Bedrock contour maps (where applicable). 5.10 - Cross-Sections 

Geologic cross-sections should be constructed through all appropriate borings both perpendicular and parallel to the facility baseline as well as along and across all transects which include major geologic features such as faults, sinkholes, and buried valleys. At least one cross-section should be constructed parallel to groundwater flow. The subsurface conditions of the site should be illustrated in these cross-sections. Where more than one interpretation may be reasonably made, conservative assumptions should be used.

5.11 - Aerial Photographs 

One or more vertical aerial images, representing the entire area of the proposed site plus the area within 1/4 mile of the site should be included in the report.

Appendix A – General Cost Estimate for Site Characterization

Generalized Cost Estimate for Site Characterization The following cost estimates are for the completion of drilling activities related to a detailed site characterization. The costs provided are approximate and obtained in August 2010. They may not reflect cost everywhere. The cost estimates do not include additional services, site visits or the installation of groundwater monitoring wells. Piezometer installation in soil – $46/ft includes boring, PVC and completion Piezometer installation in bedrock – $92/ft includes rock coring, PVC and completion Geologist time – $75/hour Site Characterization Report – $3,000 Monitoring well registration fees – $100/well Water level sampling fee – $300/round

Borings 3 required

Table No. 1 - Simple (1 to 5 acre) Site Cost Estimates Borehole – Soil Borehole – Soil Borehole – 20 foot boring with water boring with water soil and 40 foot level @ 10 feet level @ 30 feet bedrock, water level @ 50 feet 3 @ $46.00 X 20 3 @ $46.00 X 40 3 @ $46.00 X 20 foot = $2,760 foot = $5,520 foot = $2,760

Borehole – 20 foot soil and 80 foot bedrock, water level @ 90 feet 3 @ $46.00 X 20 foot = $2,760 3 @ $92.00 X 80 Feet = $22,080 Five 10-hour days = $3,750

Geologist Time

Two 10-hour days = $1,500

three 10-hour days = $2,250

3 @ $92.00 X 40 Feet = $11,040 Four 10-hour days = $3,000

Report

Report = $2,000

Report = $4,000

Well Registration

Well registration 3 @ $100 = $300

Water level Sampling Total Cost

12 months = $3,600 $10,160

12 months = $3,600 $13,670

12 months = $3,600 $24,700

12 months = $3,600 $31,495

Borings

Table No. 2 - Larger or Hydrologically Complex Site Cost Estimates Borehole – Soil Borehole – Soil Borehole – 20 foot Borehole – 20 foot boring with water boring with water soil and 40 foot soil and 80 foot level @ 10 feet level @ 30 feet bedrock, water bedrock, water level @ 50 feet level @ 90 feet 10 @ $46.00 X 20 10 @ $46.00 X 40 10 @ $46.00 X 20 10 @ $46.00 X 20 foot = $9,200 foot = $18,400 foot = $9,200 foot = $9,200

Report

four 10-hour days = $3,000 Report = $3,000

five 10-hour days = $3,750 Report = $3,000

10 @ $92.00 X 40 Feet = $36,800 six 10-hour days = $4,500 Report = $5,000

Well Registration

Well registration 10 @ $100 = $1,000

Water level Sampling

12 months = $3,600

Total Cost

$16,800

$29,750

$60,100

$98,400

Geologist Time

10 @ $92.00 X 80 Feet = $73,600 eight 10-hour days = $6,000 Report = $5,000

REFERENCES Missouri Department of Natural Resources (MDNR), January 2007, Missouri Environmental Geology Atlas (MEGA) Missouri Department of Natural Resources (MDNR), January 2007, 10 CSR 80-2 (Appendix 1), Guidance for Conducting and Reporting Detailed Geologic and Hydrologic Investigations at a Proposed Solid-Waste Disposal Area. Available online: http://www.dnr.mo.gov/geology/geosrv/envgeo/swmpapp1.htm Missouri Department of Natural Resources (MDNR), June, 1996, Missouri Well Construction Rules, 10 CSR 23-1.00 through 10 CSR 23-6.060, (Miscellaneous Publication No. 50) United States Environmental Protection Agency (USEPA), 1993. Subsurface Characterization and Monitoring Techniques, A Desk Reference Guide, EPA/625/R93/003a and EPA/625/R-93/003b. United States Environmental Protection Agency (USEPA), 1992b. RCRA GroundWater Monitoring: Draft Technical Guidance. Office of Solid Waste, EPA 530R-93001.

Appendix C Standard Operating Procedures

Standard Operating Procedure Collection of Groundwater Samples from a Temporary or Permanent Monitoring Well (Includes Well Purging and Stabilization) Revision 1 April 5, 2016 Approved By:

Kim Johannessen Print Technical Reviewer

Terri Olson Print

QA Manager

Signature

04/05/16 Date

Signature

04/05/16 Date

Review of the SOP has been performed and the SOP still reflects current practice. Initials:

Date:

Initials:

Date:

Initials:

Date:

Initials:

Date:

Minneapolis, MN ● Hibbing, MN ● Duluth, MN ● Ann Arbor, MI ● Jefferson City, MO ● Bismarck, ND ● Calgary, AB, Canada ●Grand Rapids, MI ●Salt Lake City, UT

1.0

Scope and Applicability

The purpose of this Standard Operating Procedure (SOP) is to describe the methods used for monitoring well purging, stabilization, and sampling (excluding residential/water supply systems). The SOP also provides details regarding the calculation of purge volumes and measurement of groundwater stabilization criteria and identifies the common container, preservative, and holding times for typical groundwater sample analyses. The recommended procedures in this SOP should be followed unless conditions make it impractical or inappropriate to do so. Modifications should be noted in the applicable documentation and communicated to appropriate personnel. Significant changes may result in a revision or newly created SOP.

2.0

3.0

Limitations •

Sample collection methods can vary by project. If not specified in the project scope of work and/or documentation (e.g., Work Plan, Sampling Analysis Plan (SAP), or Quality Assurance Project Plan (QAPP)), consult with the appropriate regulatory agency for guidance.

•

Collection of groundwater samples from residential/water supply systems are not discussed within this SOP.

•

Dedicated sampling equipment and/or decontamination of sampling equipment is required to prevent cross-contamination.

•

Low-flow sampling methods are not discussed within this SOP.

•

Sample collection using ‘clean hands/dirty hands’ methods is not discussed within this SOP.

Responsibilities

Equipment Technicians are responsible to maintain equipment in working order and aid in troubleshooting equipment issues. The role of the Project Health and Safety Team Leader is to oversee all aspects of on-site safety activities. The Project Manager, in conjunction with the client, develops the site specific scope of work (e.g., Work Plan, SAP, etc.). Experienced Field Technician(s) are responsible for the measurement of well pumping rates, calculation of well purge volume, field screening procedures, field equipment and calibration, proper sample identification, collection of samples, quality control procedures, and documentation. Project staff are responsible for ordering sample containers prior to the sampling event.

4.0

Safety

Groundwater Sampling from a Temporary or Permanent MW

Page 2 of 12

Revision Date: 04/05/16

Printed Copy is Uncontrolled. Controlled copy is maintained on the internal Barr network. Print a new copy each time a hard copy is required.

Collection of Groundwater Samples from a Monitoring Well (Includes Well Purging and Stabilization)

contamination, symptoms of exposure, methods to minimize exposure, personal protection equipment (PPE), and personal air monitoring required when using this SOP. Minimum protection of two pair of sample contact with the skin and eyes. When sampling waters contaminated with corrosive materials, emergency eye flushing facilities should be available.

5.0

6.0

Equipment, Reagents, and Supplies •

Water quality meter (e.g., YSI, or equivalent)

•

Pump (peristaltic or submersible), power source, and appropriate drive tubing

•

Polyethylene bailer and rope

•

Cord reel (optional)

•

Sample tubing and fittings

•

Graduated measuring container

•

Turbidimeter (optional)

•

Plastic bags

•

Coolers

•

Waterproof ink pen or pencil

•

Ice

•

Clock or stopwatch

•

Chemical resistant gloves (e.g., nitrile)

•

Sample containers (method specific)

•

Custody seal, if applicable

•

Sample labels

•

Calculator

•

Chain-of-custody (COC)

•

Locks/keys

Procedure

This section describes the procedure(s) for calibrating field equipment, measuring pumping rates, calculating purge volumes, well purging, measuring well stabilization, and the sampling, handling, and delivery of groundwater samples. Best practices include setting up the purging, stabilization, and sampling equipment in an upwind direction from any potential source of contamination. This SOP describes the groundwater collection from a bore hole, temporary well, or permanent monitoring well. Typically, a direct-push (Geoprobe® or equivalent) will be used to create the bore hole or temporary well by advancing the direct-push sampler to the desired sampling interval (sampling depth). When the sampling depth is reached, small diameter extension rods are inserted through the steel probe rods to hold the groundwater sampler screen in place while the rods and screen sheath are retracted, exposing the screen. The groundwater sampler screen can typically be exposed up to 41 inches, but can be exposed a shorter length depending on project requirements. Alternately, a small diameter PVC well screen and riser pipe may be installed in the bore hole for use as a temporary well. Polyethylene (or project specified) tubing is placed into the bore hole or temporary well, and a peristaltic pump (or equivalent) or project specified pump is used to draw water samples to the surface for collection. Well stabilization is not always necessary for temporary well s but if required by the project, see Section 6.2.6 of this SOP. After each borehole or temporary well is constructed, the probe rods are decontaminated by the drilling contractor in accordance with project requirements. The polyethylene (or project specified) tubing is discarded after each sample is collected and new tubing is used for the collection of the next sample. The

Groundwater Sampling from a Temporary or Permanent MW

Page 3 of 12

Revision Date: 04/05/16

Printed Copy is Uncontrolled. Controlled copy is maintained on the internal Barr network. Print a new copy each time a hard copy is required.

chemical resistant gloves (e.g., nitrile) and safety glasses with side shields should be worn to prevent

borehole and temporary well locations will be permanently sealed following applicable state and local regulations.

The water quality meter and turbidimeter will be calibrated as per the applicable Barr SOP. The meters will undergo calibration checks, at a minimum, before and after sampling. The calibration check will be documented on a calibration form (as appropriate) and/or in the field notebook. Any significant issues found during the calibration check will be noted in the field notebook and the Equipment Technicians will be notified.

Purging/Well Stabilization/Sampling Prior to sampling, purging of the monitoring well is performed to remove stagnant water from within the well and to stabilize the well to allow for representative groundwater sample collection. The term ‘purge volume’ refers to the amount of water removed from a well before groundwater sample collection occurs. Purging well volumes and stabilizing to remove stagnant water from a temporary well may not be necessary due to the short time frame between well installation and sampling. Purging and well stabilization procedure for temporary wells may vary by project or by well. Recommended practice is to purge a temporary well until the water clears, if possible, prior to sampling; however, purging prior to sampling may not be possible at all if water is limited (as it might be in a perched water zone), or water recharge is slow (as it would be in a clayey or silty water bearing zone). 6.2.1

Purge Volume

The volume of standing water in the well is calculated to determine the purge volume that needs to be removed from the well. The water level must be measured in order to determine the volume (see applicable Barr SOP). Calculation of the purge volume is addressed in Section 6.3, Data Reduction/Calculation of this SOP and Table 1. If a well is pumped dry, this constitutes an adequate purge and the well can be sampled following recovery. Refer to project documentation for volumes required to be purged. 6.2.2

Bailer Purging

A bailer can be used for slowly recovering wells with minimal water volume and a depth to groundwater greater than 25 feet. A new disposable polyethylene bailer with a check valve can be attached to a cord reel or a downrigger and support assembly. Polyethylene bailers can be hauled using stainless steel wire or new nylon line (rope). •

Put on gloves for skin protection and to prevent sample contamination.

•

Secure the bailer and lower slowly into the water column until the bailer is submerged. Avoid rapid movements of the bailer to minimize turbidity. A cord reel can be used to aid in the lowering of the bailer.

•

Raise the bailer and empty the water collected from the bailer into a graduated measuring container.

•

Sampling may begin once desired volume is purged and the well has stabilized (see Section 6.2.6, Well Stabilization of this SOP).

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Calibration

6.2.3

Peristaltic Pump Purging

A peristaltic pump is used when the water level is within suction lift (e.g., within about 25 feet of the

•

Put on gloves for skin protection and to prevent sample contamination.

•

Lower tubing into the well water (1 to 2 feet below surface) and cut to the desired length.

•

Connect the well tubing to the drive tubing entering the pump.

•

Connect the drive tubing exiting the pump to the short section of tubing entering the flowthrough cell or graduated measuring container.

•

Turn on pump and set the speed at the desired rate of flow.

•

Sampling may begin once desired volume is purged and the well has stabilized (see Section 6.2.6, Well Stabilization of this SOP).

6.2.4

Submersible Pump Purging

A submersible pump is used when the water level is greater than the suction lift associated with a peristaltic pump. It is commonly used in conjunction with a control box to achieve the desired pumping rate (low to high). Variable rate submersible pumps are available to fit inside 2 inch or larger wells. 6.2.4.1 1.5-inch Submersible Pump This is a type of submersible pump that can be used in 2-inch or larger diameter wells. It can purge water from depths down to 200 feet or greater, depending on pump model and manufacturer. •

Put on gloves for skin protection and to prevent sample contamination.

•

Attach appropriate diameter tubing to pump intake, lower pump, and secure at desired depth.

•

Cut off tubing, allowing additional tubing length for discharge.

•

Plug the pump into the controller. Pump will begin pumping using the variable speed controller. There are a variety of speed controllers available, typically designed for a specific pump.

•

Attach the controller to the power supply.

•

Turn on the controller and dial the speed control to the desired flow rate. The controller can slow the purge rate down to the optimum rate. Note: If the submersible pump is not running, turn off the pump and then disconnect from the power supply. Check connections and try again.

•

Attach the flow-through cell for the water quality meter. Note: If water is considerably turbid after initial pump start-up, the flow-through cell may be connected after purge water has cleared visually.

•

Sampling may begin once desired volume is purged and the well has stabilized (see Section 6.2.6, Well Stabilization of this SOP).

6.2.4.2 3 or 4-inch Submersible Pump This pump may be used to purge water samples from any depth. •

Put on gloves for skin protection and to prevent sample contamination.

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ground surface but may be less at higher altitudes). It usually is a low-volume suction pump with low pumping rates suitable for sampling shallow, small-diameter wells.

Attach purging hose to the pipe connected on the top of the submersible pump.

•

Lower the submersible pump slowly into the well until it is completely submersed into the water and secure at desired depth.

•

Connect the pump to the generator with an extension cord.

•

Turn switch to start the generator, put choke on, pull recoil rope, and let generator idle until it is running smoothly

•

Turn on power (which is located on the front of the generator). Note: Submersible pump should be running; if not, turn off the generator and check connections.

•

Adjust flow rate to desired rate with the valve and measure the flow rate with the graduated measuring container.

•

• 6.2.5

Sampling may begin once desired volume is purged and the well has stabilized (see Section 6.2.6, Well Stabilization of this SOP). Well Purging with In-place Plumbing

In-place plumbing consists of dedicated, submersible pumps that are permanently installed in a well. •

Put on gloves for skin protection and to prevent sample contamination.

•

Turn switch to start the generator, put choke on, pull recoil rope, and let generator idle until it is running smooth.

•

Connect the pump to the generator with an extension cord.

•

Connect the pipe, elbow, and valve to the discharge pipe of the submersible pump (located at the top of the well) and turn on the generator. Note: If the pump does not start, check the connection from the generator to the pump.

•

When water flows from discharge of the pump, adjust the flow according to desired flow rate and measure the flow rate with the graduated measuring container.

•

Sampling may begin once desired volume is purged and the well has stabilized (see Section 6.2.6, Well Stabilization of this SOP). Note: Each dedicated pump has its own pipe, elbow, and valve. These pieces are left at each well.

6.2.6

Well Stabilization

Well stabilization is typically conducted to help verify that the groundwater sample is representative of aquifer conditions. A well is considered ‘stabilized’ after the well purge volume has been met and the groundwater (or well) stabilization parameter measurements are within acceptable limits for three consecutive readings. Well stabilization parameters may vary by project or regulatory agency but at a minimum typically include pH, temperature, and specific conductance (temperature corrected electrical conductivity). Dissolved oxygen (DO) and oxidation-reduction potential (ORP) may also be used as stabilization parameters. Groundwater Sampling from a Temporary or Permanent MW

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•

The procedure to stabilize a well includes recording well stabilization parameter measurements collected with the water quality meter at the beginning of the well purging process and after subsequently purged casing (i.e., from the base of the well to the water level measurement) and is defined in the footnotes of Table 1. Groundwater aliquots used for stabilization parameter measurements are typically collected by either directing the purge water discharge line through a flow-through cell or by pouring groundwater from a bailer into a container holding the water quality meter probe (depending on the purging method used). Documentation of the well stabilization process typically includes recording pertinent information such as the pump type, pumping rate, volume pumped, and well stabilization measurements on the field log data sheets or field notebook. If only the minimum parameters are used for stabilization, the DO and ORP should still be measured and recorded as they may be needed to interpret other chemical parameter results. Turbidity is measured with a standalone turbidimeter but is typically not used as a stabilization parameter. A qualitative determination of turbidity may also be noted (e.g. clear, cloudy, very cloudy, etc.). The well may be sampled after three consecutive measurements (typically one well volume per measurement), collected at the intervals described above, are within specific project criteria or the criteria presented in Section 7.2, Measurement Criteria of this SOP. If field parameters do not stabilize after five well volumes have been purged, then the field technician will verify that the probes and related equipment are functioning properly and that operator error is not an issue. They will also re-evaluate whether or not water is being withdrawn from the appropriate depth to effectively evacuate the well. If all the checks produce no new insight, a decision will need to be made by the project team on whether to collect samples for laboratory analysis. When samples are collected, it will be clearly documented that stabilization was not achieved; at a minimum, this fact will be reported on the field log data sheets and in the Field Sampling Report. If the well was purged dry, it shall be allowed to recharge and the samples should then be collected. If there is insufficient sample volume for the analyses being sampled, the project team will need to decide if sampling should be carried out or if a reduced prioritized list of analyses should be collected. 6.2.7

Sampling

The project team will determine the order for sampling the wells but general guidelines are below: •

Where water quality data are available, the least contaminated wells would be sampled first, proceeding to increasingly contaminated wells.

•

Where the distribution of contaminants is not known, wells considered to be up gradient from likely sources of contamination would be sampled first and downgradient wells closest to the suspected contamination would be last.

•

Make certain to keep records of the order in which wells were sampled.

Similar to purging, sampling requires the use of pumps or bailers. It may be appropriate to use a different device to sample than that which was used to purge. The most common example of this is the use of a pump to purge and a bailer to sample. There are several factors to take into consideration when choosing

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well volumes. A well volume is measured as the volume of water present inside a well screen and/or

a sampling device. The experience of the project team will be used to determine which is appropriate and care should be taken when reviewing the advantages or disadvantages of any one device. should be collected first with as little agitation and disturbance as possible, then proceed in order towards the least volatile parameter as listed in Barr’s ‘Water Sampling Guidelines’ form. The 40 mL vials used to collect the VOC samples should be checked for air bubbles. Air bubbles may be caused by insufficient meniscus when sealing the vial, degassing after sample collection or during sample shipment, or reaction between the sample and preservative (HCl). If air bubbles > 6 mm (pea-sized) are observed during sampling, discard the vial and recollect the sample using a new vial. If air bubbles are believed to be due to the sample reacting with the preservative, the sample should be collected in an unpreserved vial if possible. Put on new sampling gloves at each sampling site to reduce the risk of sample cross-contamination and exposure to skin. Never reuse old gloves. Prepare sampling containers by filling out the label, using an indelible permanent pen, with the following information at a minimum: •

Sample ID

•

Date and time of sample collection

•

Preservative

•

Sample analysis (if required by the lab)

When filling the containers, do not insert the tubing into the containers and do not overfill preserved containers. When all samples are containerized, place the filled sample containers in a sampling cooler with ice, turn off any equipment, disassemble the sampling apparatus, dispose of all one-time use (disposable) equipment, and decontaminate reusable equipment per Barr’s SOP ‘Decontamination of Sampling Equipment’. 6.2.7.1 Bailer Sampling After the well has been purged and stabilized, secure the bailer and slowly lower into the top of the water column making certain not to stir up the water with the bailer, which could result in volatizing the samples. Keep the bailer in the top portion of the water column when collecting the sample. When the bailer is filled, slowly raise the bailer out of the well. A clean tarp may be used to cover the ground to minimize the contact of the rope with the ground. Fill containers in the order listed in Barr’s ‘Water Sampling Guidelines’ form. 6.2.7.2 Peristaltic / Submersible Pump Sampling After the well has been purged and stabilized, disconnect the tubing exiting the pump from the flowthrough cell, if used and fill containers as listed in Barr’s ‘Water Sampling Guidelines’ form. 6.2.7.3 Check Valve Sampling Sampling temporary wells through tubing with a check valve may be conducted following a drilling subcontractor’s procedure.

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To prevent the possible loss of some volatile organic compounds (VOCs), samples for volatile parameters

6.2.8

Preservation

Container volume, type, and preservative are important considerations in sample collection. Container analyses. The container type varies with the analysis required. Typically, the analytical laboratory will preserve the container before shipment. Preservation and shelf life vary; contact the laboratory to determine if an on-hand container is still useful. Barr’s ‘Water Sampling Guidelines’ form lists the parameter, container type, container volume, and preservative for many of the most common parameters collected. 6.2.9

Handling

The samples will be bubble wrapped or bagged after collection, stored in a sample cooler, and packed on double bagged wet ice. Samples will be kept cold (≤ 6 °C, but not frozen), until receipt at the laboratory (where applicable). Note: Samples may need to be stored indoors in winter to prevent freezing. 6.2.10 Shipment/Delivery Once the cooler is packed to prevent breaking of bottles, the proper chain-of-custody (COC) documentation is signed and placed inside a plastic bag then added to the cooler. All samples will be kept secured to prevent tampering. If sample coolers are left in a vehicle or field office for temporary storage, the area will be locked and secured. Custody seals may be present, but at a minimum, the coolers must be taped shut to prevent the lid from opening during shipment. The coolers must be delivered to the laboratory via hand or overnight delivery courier, if possible, in accordance with all Federal, State and Local transportation regulations and Barr’s SOP ‘Domestic Transport of Samples to the Laboratory’.

Data Reduction/Calculations Table 1 provides the volume of water (per foot or meter of depth) based on the diameter of the casing or hole. The following are two examples of calculations used in Table 1: Volume of Standing Water (V), cubic feet

Where: π

𝑉𝑉 = (𝜋𝜋)(𝑟𝑟 2 )(ℎ) =

3.1416

Well radius (ft)

Total well depth (ft) – depth to static water (ft) = Water column height (ft)

Note: For the table calculations, ‘h’ is equal to one foot.

Well Volume (WV), gallons 𝑊𝑊𝑊𝑊 = (𝑉𝑉)(7.48)

Where:

𝑉𝑉 =

7.48

Groundwater Sampling from a Temporary or Permanent MW

Volume of standing water, cubic feet Cubic foot to US Gallons conversion factor

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volume must be adequate to meet laboratory requirements for quality control, split samples, or repeat

Calculate the volume of water to be purged using the equation below:

Where: VP

Volume of water to be purged

Well volume in gallons

NMV =

Number of well volumes to be purged per project requirements

Disposal Waste generated by this process will be disposed of in accordance with Federal, State and Local regulations and Barr’s SOP ‘Investigative Derived Waste’. Where reasonably feasible, technological changes have been implemented to minimize the potential for environmental pollution.

7.0

Quality Control and Quality Assurance (QA/QC)

The QC activities described below allow the self-verification of the quality and consistency of the work.

QA/QC Samples QA/QC samples are defined in Barr’s SOP ‘Collection of Quality Control Samples’. The sampling frequency should be performed at the frequency noted in the project scope of work and/or documentation (e.g., Work Plan, SAP, or QAPP).

Well Stabilization Criteria Well stabilization criteria to be used if there are no project specific criteria: •

pH ± 0.1 standard units

•

Temperature ± 0.5 °C

•

Specific conductance ± 5%

•

Optional Criteria: o

ORP ± 10 mV

Dissolved oxygen ± 10% (> 0.5 mg/L) Note: Three consecutive readings ≤ 0.5 mg/L can be considered stabilized.

Turbidity ± 10% (> 5 Nephelometric Turbidity Units (NTU)) Note: Three consecutive readings ≤ 5 NTU can be considered stabilized.

8.0

Records

The field technician will document the pumping flow rate, well volume, time purged, volume purged, water level, total well depth and stabilization test measurements on the field log data sheet and/or field notebook. They will also document the type and number of bottles on the chain-of-custody record, as appropriate. The analysis for each container and the laboratory used will be documented on the chain-ofcustody record. Refer to Barr’s SOP ‘Documentation on a Chain-of-Custody (COC)’ for further information. Examples of common field documentation are available in Barr’s “Compendium of Field Documentation”. Field documentation specific to this SOP are listed below: •

Chain-of-custody (COC)

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𝑉𝑉𝑉𝑉 = (𝑊𝑊𝑊𝑊)(𝑁𝑁𝑁𝑁𝑁𝑁)

Sample label

•

Custody seal (if applicable)

•

Water Level Data Sheet

•

Field Log Data Sheet

•

Field Log Cover Sheet

•

Field Sampling Report

•

Water Sampling Guidelines (includes sampling order, container, preservation, and holding time)

The field documents and COCs are provided to a Barr Data Management Administrator for storage on the internal Barr network. Additional records information can be found in Barr’s “Records Management System Manual”. Other Barr SOP subjects referenced within this SOP: water level measurement, water quality meter, turbidimeter, collection of QC samples, decontamination of sampling equipment, and documentation on a COC.

9.0

References

Environmental Protection Agency. Title 40 of the Code of Federal Regulations, Part 136.3. Environmental Protection Agency, EPA/540/P-91/007. 1999. Compendium of ERT Groundwater Sampling Procedures. Minnesota Pollution Control Agency, Water Quality Division. 2006. Sampling Procedures for Groundwater Monitoring Wells.

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•

Table 1

Diameter of Casing or Hole (In) 1 1½ 2 2½ 3 3½ 4 4½ 5 5½ 6 7 8 9 10 11 12 14 16 18 20 22 24 26 28 30 32 34 36

Gallons per Foot of Depth (WV) 0.041 0.092 0.163 0.255 0.367 0.500 0.653 0.826 1.020 1.234 1.469 2.000 2.611 3.305 4.080 4.937 5.875 8.000 10.44 13.22 16.32 19.75 23.50 27.58 32.00 36.72 41.78 47.16 52.88

Cubic Feet per Foot of Depth (V) 0.0055 0.0123 0.0218 0.0341 0.0491 0.0668 0.0873 0.1104 0.1364 0.1650 0.1963 0.2673 0.3491 0.4418 0.5454 0.6600 0.7854 1.069 1.396 1.767 2.182 2.640 3.142 3.687 4.276 4.909 5.585 6.305 7.069

Liters per Meter of Depth

Cubic Meters per Meter of Depth

0.509 1.142 2.024 3.167 4.558 6.209 8.110 10.26 12.67 15.33 18.24 24.84 32.43 41.04 50.67 61.31 72.96 99.35 129.65 164.18 202.68 245.28 291.85 342.52 397.41 456.02 518.87 585.68 656.72

0.509 x 10-3 1.142 x 10-3 2.024 x 10-3 3.167 x 10-3 4.558 x 10-3 6.209 x 10-3 8.110 x 10-3 10.26 x 10-3 12.67 x 10-3 15.33 x 10-3 18.24 x 10-3 24.84 x 10-3 32.43 x 10-3 42.04 x 10-3 50.67 x 10-3 61.31 x 10-3 72.96 x 10-3 99.35 x 10-3 129.65 x 10-3 164.18 x 10-3 202.68 x 10-3 245.28 x 10-3 291.85 x 10-3 342.52 x 10-3 397.41 x 10-3 456.02 x 10-3 518.87 x 10-3 585.68 x 10-3 656.72 x 10-3

1 gallon = 3.7854 liters 1 liter = 0.26417 gallons 1 meter = 3.281 feet 1 gallon water weighs 8.33 lbs. = 3.785 kilograms 1 liter water weighs 1 kilogram = 2.205 lbs. 1 gallon per foot of depth = 12.419 liters per foot of depth 1 gallon per meter of depth = 12.419 x 10-3 cubic meters per meter of depth

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Volume of Water in Casing or Hole

Standard Operating Procedure Collection of Quality Control Samples

Revision 6 October 22, 2015

Approved By:

Terri Olson Print

QA Manager

Signature

10/22/15 Date

Review of the SOP has been performed and the SOP still reflects current practice. Initials:

Date:

Initials:

Date:

Initials:

Date:

Initials:

Date:

Minneapolis, MN ● Hibbing, MN ● Duluth, MN ● Ann Arbor, MI ● Jefferson City, MO ● Bismarck, ND ● Calgary, AB, Canada ● Grand Rapids, MI

Collection of Quality Control Samples Scope and Applicability

The purpose of this Standard Operating Procedure (SOP) is to describe the procedures used in the collection and handling of field quality control (QC) samples: field blanks, equipment blanks, trip blanks, field (masked) duplicate samples, matrix spikes and matrix spike duplicate samples. The recommended procedures in this SOP should be followed unless conditions make it impractical or inappropriate to do so. Modifications should be noted in the applicable documentation and communicated to appropriate personnel. Significant changes may result in a revision or newly created SOP.

2.0

Limitations •

3.0

Laboratory specific QC samples (e.g., method blanks, laboratory control samples) are not discussed within this SOP.

Responsibilities

Experienced Field Technicians are responsible for the accurate collection of QC samples and the laboratory is responsible for the accurate set-up and analysis of QC samples. Project staff are responsible for ordering sample containers prior to the sampling event. The role of the Project Health and Safety Team Leader is to oversee all aspects of on-site safety activities. The Project Manager, in conjunction with the client, develops the site specific scope of work (e.g., Work Plan, Sampling Analysis Plan (SAP), etc.).

4.0

Safety

Barr staff is responsible for conducting all aspects of the job safely. When applicable, refer to the appropriate Project Health and Safety Plan (PHASP) to understand the hazards associated with suspected contamination, symptoms of exposure, methods to minimize exposure, personal protection equipment (PPE), and personal air monitoring required when using this SOP. Minimum protection of two pair of chemical resistant gloves (e.g., nitrile) and safety glasses with side shields should be worn to prevent sample contact with the skin and eyes. When sampling soils contaminated with corrosive materials, emergency eye flushing facilities should be available. Some of the sample containers may require the use of preservatives. Consult the applicable Safety Data Sheet to review hazards and appropriate PPE to minimize exposure.

5.0

Equipment, Reagents, and Supplies •

Laboratory-certified containers appropriate for the required analysis

•

Matrix specific sampling devices and equipment

•

Chemical resistant gloves (e.g., nitrile)

•

Sample containers/media

•

Sample labels

•

Analyte-free water

Collection of Quality Control Samples

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1.0

6.0

Procedure

This section provides the definitions and sampling procedure(s) for QC samples.

Calibration is not applicable to this SOP.

Sampling General considerations to be taken into account when planning and conducting sampling operations are the required sample amount, sample holding times, sample handling, and special precautions for trace contaminant sampling. Matrix specific sampling SOPs should be followed for the collection and preservation of samples. The QC samples will be handled in the same manner as the sample group for which they are intended (i.e. stored and transported with the sample group). 6.2.1

Field Blank

Field blank samples are prepared on-site and are a sample of analyte-free water exposed to environmental conditions at the sampling site by transfer from one vessel to another. It measures field and laboratory sources of contamination. Generally, blanks are collected for each parameter of interest. 6.2.2

Equipment Blank (Rinsate Blank)

Equipment blank (or rinsate blank) samples are prepared on-site by pouring analyte-free water through decontaminated sample collection equipment (e.g., bailer or pump, hand-trowel, etc.) and collecting the “rinsate” in the appropriate sample container. If collecting a blank for dissolved metals or dissolved organic carbon, the rinsate will be filtered before adding to the sample container. In addition to the field sources of contamination that may be introduced in the transferring of samples to one vessel to another, an equipment blank also tests the potential cross contamination from incomplete decontamination. Generally, blanks are collected for each parameter of interest. 6.2.3

Trip Blank

Trip blank samples are used when sampling volatile organic compounds (VOC) only. Analyte-free water is used for water samples and methanol (or other applicable sample preservative) is used for soil samples. They are prepared or provided by the laboratory along with the VOC sampling containers prior to a sampling event. Trip blank sample containers are not to be opened in the field and accompany the VOC samples during collection, storage, and transport to the analytical laboratory. There must be one set of trip blank samples per sample cooler containing VOC samples from the Site. The trip blanks should be listed on the chain-of-custody (COC) along with the samples and the analysis required. The purpose of the trip blank sample is to determine the extent of potential contamination introduced during sample transport and handling. 6.2.4

Field (Masked) Duplicate

Field (masked) duplicate samples are two aliquots of a sample collected at the same time using the same procedures, equipment, and types of containers as the required samples. The samples are collected by rotating sampling containers from the original/source sample to the field duplicate sample (using the same exact methods for both). The field duplicate sample is identified with an alias (e.g., M-1 or FD) on

Collection of Quality Control Samples

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Calibration

the sample container label and on the COC to avoid alerting laboratories to the source of the sample duplicated. The time collected should be omitted on this sample also. Analyses of field duplicate samples collection, preservation, and storage, as well as laboratory procedures. Field duplicate samples are submitted to the laboratory for the same analyses as the original/source sample. 6.2.5

Matrix Spike (MS) and Matrix Spike Duplicate (MSD)

Matrix Spikes (MS) and Matrix Spike Duplicate (MSD) samples are two aliquots of a sample to which known quantities of analytes are added (spiked) in the laboratory. The MS and MSD are prepared and analyzed exactly like their native/source sample aliquot. For some analyses, it is required that three separate sample aliquots are collected in the field for each analysis. One aliquot is analyzed to determine the concentrations in the native/source sample, a second sample aliquot serves as the MS and the third sample aliquot serves as the MSD. The purpose of the MS and MSD is to quantify the bias and precision caused by the sample matrix.

Data Reduction/Calculations 6.3.1

Field Duplicate

Field duplicate sample results are evaluated by calculating the Relative Percent Difference (RPD) value. The RPD formula is as follows:

Where:

𝑅𝑅𝑅𝑅𝑅𝑅 =

RPD = S = D =

|𝑆𝑆 − 𝐷𝐷| 𝑥𝑥 100 (𝑆𝑆 + 𝐷𝐷)/2

relative percent difference native sample result duplicate sample result

Note: The RPD equation may also be used to calculate the precision between the MS and MSD 6.3.2

MS/MSD

MS/MSD recoveries are calculated using the following equation:

Where:

%𝑅𝑅 =

%R SSR SR SA

= = = =

𝑆𝑆𝑆𝑆𝑆𝑆 − 𝑆𝑆𝑆𝑆 𝑥𝑥 100 𝑆𝑆𝑆𝑆

% recovery spiked sample result native/source sample result spike added to native/source sample

Disposal Waste generated by this process will be disposed of in accordance with Federal, State and Local regulations and Barr’s ‘Investigative Derived Waste’ SOP. Where reasonably feasible, technological changes have been implemented to minimize the potential for environmental pollution.

Collection of Quality Control Samples

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are the same as the required samples and give a measure of the precision associated with sample

7.0

Quality Control and Quality Assurance (QA/QC)

The QC activities described below allow the self-verification of the quality and consistency of the work.

The frequency of QC samples is generally one field blank/equipment blank/field duplicate/MS/MSD per twenty samples; however, specific project requirements may require alternative sampling frequencies.

Measurement Criteria Criteria are defined in project specific documentation or in Barr’s data evaluation SOPs.

8.0

Records

The field technician will document the type and number of QC samples collected during each sampling event on a COC and in a project dedicated field logbook or on field log data sheets. Examples of common field documentation are available in Barr’s “Compendium of Field Documentation”. Field documentation specific to this SOP are listed below: •

Field Log Data Sheet

•

COC

•

Sample label

•

Custody seal (if applicable)

Field documentation and COC are provided to a Barr Data Management Administrator for storage on the internal Barr network. Additional records information can be found in Barr’s “Records Management System Manual”. Other Barr SOP subjects referenced within this SOP: sample collection, investigative derived waste, decontamination of sampling equipment, and documentation on a COC.

9.0

References

EPA QA/G-5. 2002. Guidance for Quality Assurance Project Plans.

Collection of Quality Control Samples

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QA/QC Samples

Standard Operating Procedure Decontamination of Sampling Equipment Revision 1 March 15, 2018 Approved By:

John W. Juntilla Print Technical Reviewer

Terri Olson Print

QA Manager

Signature

03/15/18 Date

Signature

03/15/18 Date

Review of the SOP has been performed and the SOP still reflects current practice. Initials:

Date:

Initials:

Date:

Initials:

Date:

Initials:

Date:

Minneapolis, MN ● Hibbing, MN ● Duluth, MN ● Ann Arbor, MI ● Jefferson City, MO ● Bismarck, ND ● Calgary, AB, Canada ● Grand Rapids, MI ● Salt Lake City, UT

Decontamination of Sampling Equipment Scope and Applicability

The purpose of this Standard Operating Procedure (SOP) is to define the process used for

decontaminating environmental sampling-related equipment including pumps, meters, and materials

coming into contact with actual sampling equipment or with sampling personnel. This procedure is

applicable to all personnel who are collecting samples and/or decontaminating sampling and field equipment.

The recommended procedures in this SOP should be followed unless conditions make it impractical or inappropriate to do so. Modifications should be noted in the applicable documentation and

communicated to appropriate personnel. Significant changes may result in a revision or newly created SOP.

2.0

Limitations •

3.0

Equipment used once and discarded such as bailers, protective gear, and filtration devices are not part of this SOP.

Responsibilities

The equipment technician is responsible for ensuring field equipment has been thoroughly

decontaminated and prepared for use out in the field. The field technician(s) are responsible for

decontamination in the field at each individual sampling point and for ensuring adherence to any

investigative derived waste (IDW) project-specific requirements set forth in a QAPP or SAP (if applicable). The role of the Field Safety Representative is to oversee on-site safety activities.

4.0

Safety

Barr staff is responsible for implementing aspects of the job safely. Where available, refer to the

appropriate Project Health and Safety Plan (PHASP) to determine the proper personal protection

equipment (PPE) required when using this SOP. Barr staff is responsible for conducting all aspects of the

job safely. When applicable, refer to the appropriate Project Health and Safety Plan (PHASP) to

understand the hazards associated with suspected contamination, symptoms of exposure, methods to

minimize exposure, personal protection equipment (PPE), and personal air monitoring required when using this SOP. Minimum protection of one pair of chemical resistant gloves (e.g., nitrile) and safety

glasses with side shields should be worn to prevent sample contact with the skin and eyes. When

sampling soils contaminated with corrosive materials, emergency eye flushing facilities should be available.

Some of the sample containers may require the use of preservatives. Consult the applicable Safety Data Sheet to review hazards and appropriate PPE to minimize exposure.

Decontamination of Sampling Equipment

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1.0

5.0

Equipment, Reagents, and Supplies •

• • •

6.0

Scrub brush made of inert materials Oven

Bucket

Tap water

• • • • •

Analyte-free water (e.g., distilled or deionized (DI) water, or equivalent) Kimwipes®, or equivalent

Chemical resistant gloves (e.g., nitrile) Spray bottle

Organic solvent (e.g. methanol)

Procedure

This section describes the procedure(s) for the decontamination of equipment used to sample water, soil, or air.

Calibration Calibration is not applicable to this SOP.

Operation Decontamination of sampling equipment will be performed before sampling and after working at each sampling point, if applicable. 6.2.1

Water Sampling Equipment

Equipment that does not contact sample water or the inside of the well should be rinsed with analyte-free

water and inspected for remaining particles or surface film. If these are noted, repeat cleaning and rinse procedures.

Equipment that contacts sample water or the inside of the well should be cleaned (inside and outside

where possible) with a non-phosphorus detergent solution applied with a spray bottle and/or scrub brush (if needed). Rinse with analyte-free water and containerize with other IDW if required by the SAP or QAPP and inspect for remaining particles or surface film. If these are noted, repeat cleaning and rinse procedures. Shake off remaining water and allow to air dry.

The internal surfaces of pumps and tubing that cannot be adequately cleaned by the above methods

alone will also be cleaned by first circulating a non-phosphorus detergent solution through them followed by circulating analyte-free water. Special care will be exercised to ensure that the “rinse” fluids will be circulated in sufficient quantities to completely flush out contaminants and detergents.

When transporting or storing equipment after cleaning, the equipment will be stored in a manner that minimizes the potential for contamination. 6.2.2

Soil/Sediment Sampling Equipment

A variety of samplers (split-barrel, split-barrel with brass liners, piston sampler, backhoe, hand-auger, or

shovel) may be used to retrieve soil from sampling locations. The soil sample will either be sealed within

the sampler (e.g., collecting volatile samples) or the soil sample will be transferred to laboratory-supplied

containers depending on the analysis to be conducted on the soil sample. The equipment required to

transfer the soil from the sampler to the laboratory-supplied sample containers includes: stainless-steel

Decontamination of Sampling Equipment

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•

Non-phosphorus detergent (e.g., LiquinoxTM)

spoons or scoops and the appropriate personal protective equipment necessary for collection and handling of soil samples as described in the PHASP.

cleaned before and during sampling with a tap water and non-phosphorus detergent solution, using a

brush if necessary to remove particulate matter and films. The equipment is then rinsed three times with tap water and/or three times with analyte-free water. Inspect equipment and repeat procedure if any

residual soil or visible contaminants are present. Dry sampler with a Kimwipes®. Organic solvents (e.g., methanol) may be used to aid with desorbing organic material but should be kept to a minimum and must be collected and containerized if used.

At the completion of the work day, the samplers should be decontaminated following the procedure above and stored in a manner that minimizes the potential for contamination. 6.2.3

Air Sampling Equipment

For non-laboratory manifold equipment, methanol soak manifold components for a minimum of two

hours. Remove from the methanol bath and place in an oven pre-heated to 90 °C and continue to heat

manifold components for at least 3 hours or until interior and exterior surface inspections of the manifold components indicate that they are free of liquid methanol. 6.2.4

Handling

All equipment will be handled in a manner that minimizes cross-contamination between points. After

cleaning, the equipment will be visibly inspected to detect any residues or other substances that may exist after normal cleaning. If inspection reveals that decontamination was insufficient, the decontamination procedures will be repeated.

Data Reduction/Calculations No data reduction or calculations are associated with this procedure.

Disposal IDW generated by this process will be disposed of in accordance with Federal, State and Local regulations and/or as required by project-specific SAP or Work Plan. Where reasonably feasible, technological changes have been implemented to minimize the potential for environmental pollution.

7.0

Quality Control and Quality Assurance (QA/QC)

The QC activities described below allow the self-verification of the quality and consistency of the work.

QA/QC Samples Decontamination procedures may be monitored through the use of an equipment blank which consists of analyte-free water processed through non-disposable or non-dedicated aqueous or solid sampling

equipment after equipment decontamination and before field sample collection. The equipment blank is

analyzed for the same parameters as the samples at a project specific frequency (e.g., one per twenty samples).

Decontamination of Sampling Equipment

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All soil sampling equipment, including split-barrels, stainless-steel spoons and scoops, will be carefully

Measurement Criteria Equipment blank results should be below the laboratory’s method detection limit or reporting limit

8.0

Records

When required, the field technician(s) will document the field equipment decontamination procedures in a project dedicated field logbook or on field log data sheets.

Examples of common field documentation are available in Barr’s “Compendium of Field Documentation”. Field documentation is listed in the applicable sample collection SOP.

Field documentation and COC are provided to a Barr Data Management Administrator for storage on the internal Barr network.

Additional records information can be found in Barr’s “Records Management System Manual.” Other Barr SOP subjects referenced within this SOP: collection of samples and investigative derived waste.

9.0

References

ASTM. 2015. Standard Practice for Decontamination of Field Equipment Used at Waste Sites.

Decontamination of Sampling Equipment

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(depending on the data quality objectives).

Standard Operating Procedure Collection and Disposal of Investigative Derived Waste Revision 6 March 15, 2018

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Scope and Applicability

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Standard Operating Procedure Documentation on a Chain-of-Custody Form Revision 5 March 14, 2018 Approved By:

Andrea Nord Print Technical Reviewer

Signature

03/14/18 Date

Terri Olson Print

Signature

03/14/18 Date

QA Manager

Review of the SOP has been performed and the SOP still reflects current practice. Initials:

Date:

Initials:

Date:

Initials:

Date:

Initials:

Date:

Minneapolis, MN ● Hibbing, MN ● Duluth, MN ● Ann Arbor, MI ● Jefferson City, MO ● Bismarck, ND ● Calgary, AB, Canada ● Grand Rapids, MI ● Salt Lake City, UT

Documentation on a Chain-of-Custody Form

The purpose of this procedure is to describe how to properly document information on a Chain-of-

Custody (COC) form. A COC is a legally binding document that identifies sample identification, analyses required, and shows traceable possession of samples from the time they are obtained until they are

introduced as evidence in legal proceedings. A Field Technician completes the information on the COC at the time he/she collects samples and the COC accompanies the samples during transport to a storage facility or to the laboratory for analysis.

The recommended procedures in this SOP should be followed unless conditions make it impractical or inappropriate to do so. Modifications should be noted in the applicable documentation and

communicated to appropriate personnel. Significant changes may result in a revision or newly created SOP.

2.0 Limitations • •

The SOP does not apply to sample aliquots that are only collected for field screening purposes.

The SOP does not apply to samples remaining on-site.

3.0 Responsibilities Experienced Field Technicians are responsible for the proper sample identification and for accurate and

complete documentation on the COC.

4.0 Procedure The COC is the most important sampling document; it must be filled out accurately and completely every time a sample is collected. The instructions below are specific to Barr’s COC for air canisters and Barr’s

COC typically used for solid and liquid samples. The COC for air canisters is typically used when collecting

soil gas, soil vapor, or air samples in an evacuated canister. The COC for solid and liquid samples is

typically used when collecting matrices such as groundwater, surface water, drinking water, waste water, storm water, soil, sediment, oil, paint chips, bulk materials, etc. Information common to both chains-of-

custody and specific to each COC are detailed below. Some of the information on a COC may be filled out ahead of time (e.g., report and invoice recipient details, project number, project name, project manager,

purchase order number, etc.) while other information should be completed when sampling. Complete one

COC or more as needed for each set of project samples. The COC should be completed prior to leaving the sampling location.

Laboratory supplied COCs may be used but may differ in the information captured. The use of a Barr COC is recommended as it allows for more efficient data processing within Barr’s systems. If there are any questions, please contact a member of Barr’s Data Quality team.

Documentation on a COC Form

Page 2 of 4

Revision Date: 03/14/18

Printed Copy is Uncontrolled. Controlled copy is maintained on the internal Barr network. Print a new copy each time a hard copy is required.

1.0 Scope and Applicability

The laboratory receiving the samples will sign the COC, record the date and time of sample receipt, assign a laboratory work order number, document sample condition, and document whether custody seals were

Common Chain-of-Custody Information • • • • • • • • • • • • • • • • • • •

Barr office location managing the work.

Two digit identification for the state or province the samples originated from/sampled in.

COC numbered pages (e.g., 1 of 1).

Report and invoice recipient information. Purchase order number (if applicable).

Barr project name and number. Sample location.

Sample collection date and time.

Sample matrix abbreviation (see “Matrix Code” on COC).

Analysis requested.

Field Technician (i.e. sampler) name.

Barr Project Manager and project Data Quality (DQ) Manager names.

Laboratory name and location in which samples are to be relinquished. Requested due date.

Signature of Field Technician (i.e. sampler) under the first ‘relinquished by’.

Signature of sample transferee.

Date and time of sample transfers.

Method of transport (UPS, FedEx, local courier, sampler, etc.). Air Bill number (if applicable).

Completing a Chain-of-Custody for Air Canisters Lab deliverable contents (based on project needs). • • • • • • •

Canister serial # and size.

Flow controller serial #.

Initial and final vacuum measurement (record unit).

Record both the start and stop time and calculate the total time. Matrix Code.

PID reading (indicate if ppm or ppb). Sample comments (if any).

Completing a Chain-of Custody for Solid and Liquid Samples • • •

Sample start and stop depth (if applicable) and unit of measurement (meter, feet, inches, etc.).

Information regarding whether to perform sample Matrix Spike (MS) and MS duplicate (MSD). Container preservative type (see “Preservative Code” on COC).

Documentation on a COC Form

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Revision Date: 03/14/18

Printed Copy is Uncontrolled. Controlled copy is maintained on the internal Barr network. Print a new copy each time a hard copy is required.

used and if they were intact.

• •

Number of each container type and the total number of containers for the sample.

Presence or absence of ice.

Distribution of the COC Pages Page one (white copy) accompanies the sample shipment to the laboratory; page two (yellow copy) is the Field Technician’s copy; and page three (pink copy) is submitted to a Barr Data Management

Administrator for filing.

5.0 Quality Control and Quality Assurance (QA/QC) The Field Technician should review the COC for accurate and complete documentation.

6.0 Records Examples of common field documentation are available in Barr’s “Compendium of Field Documentation”. Field documentation specific to this SOP are listed below: • •

Chain-of-Custody for Air Canisters Form Chain-of-Custody Form

A copy of the COC is provided to a Barr Data Management Administrator for storage on the internal Barr

network files.

Additional records information can be found in Barr’s “Records Management System Manual”.

7.0 References United States Environmental Protection Agency. 2002. Guidance for Quality Assurance Project Plans. EPA QA/G-5.

Documentation on a COC Form

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•

Information regarding whether the sample was field filtered.

Appendix D Monitoring Well Design and Construction Requirements

Monitoring Well Design and Construction

If needed, future groundwater monitoring wells will be installed to meet general groundwater monitoring requirements outlined in 40 CFR 264.97 and Missouri 10 CSR 23-4. Below describes the requirements for the design and construction of any monitoring wells to be installed on Site.

D1.1 Drilling Methodology The selected drilling method should minimize the potential of “smeared” boreholes and their potential to reduce well yield. The geology of the Site consists of clayey and silty materials near the surface. Potential methods for boring and well installation include hollow stem auger, sonic rotary, and casing hammer techniques.

D1.1.1 Hollow Stem Auger Hollow Stem Auger drilling uses a rotary motion to advance an auger bit into the surface while cuttings are rotated to the surface as the borehole is advanced. Soil samples can be collected in 2 to 5 foot increments ahead of the auger using split-spoon or thin-walled samplers to preserve lithology, or samples can be collected from composited surface cuttings. Generally, the introduction of fluids is not needed and the rigs are smaller and lighter than their Sonic and Air Rotary counterparts. Wells are constructed inside of the auger stem once it has been advanced to the target depth.

D1.1.2 Sonic Rotary Drilling Sonic rotary drilling uses high frequency mechanical oscillations developed in the drill head to transmit resonant vibrations and rotary power to the drill stem. Sonic vibrating action “fluidizes” soil particles pushing them away from the tip of the drill bit and along the sides of the drill pipe. The method allows for clean, continuous core samples to be collected without the use of drilling fluids. The sonic method utilizes a dual line drill pipe to collect soil samples and to prevent caving of the borehole wall. The inner line is the core barrel that is advanced ahead of the outer pipe without any fluids or air. Once the soil core is collected in the pipe, the outer casing is advanced to the same depth as the core barrel to prevent caving. Soil cores are collected in 5-foot sections. Once sampling is completed, the wells are constructed inside of the outer casing. This method allows for quick, continuous soil sampling. The outer drill pipe may be used to seal off potentially contaminated zones and soil sampling may be continued to the required depth.

D1.1.3 Air Rotary Casing Hammer Drilling Air Rotary Casing Hammer drilling is performed by using a pneumatically-operated hammer mounted in the drill rig mast, which drives temporary steel. The casing hammer allows casing to be advanced during the drilling operation, thus setting a temporary seal to facilitate hole integrity and prevent lost circulation. Each operation (drilling and driving) is controlled independently, allowing the operator to advance the casing ahead of the drill bit in highly unconsolidated formations. In certain formations, a down-hole air

hammer can be used while driving the casing, resulting in faster penetration rates. Soil samples retrieved at the surface more accurately represent the borehole lithology due to the fact that the sample material is transported through the annulus, between the drill pipe and the temporary steel casing.

D1.2 Containment of Cuttings and Formation Water The drilling contractor should provide equipment for containment, removal, and transportation of drill cuttings, drilling fluids (if needed), and purge water. All cuttings and water generated by drilling will be contained at the wellhead. Cuttings will be transported to a location designated by Independence Power and Light and temporarily stored on and covered with plastic. Any water generated during well installation will be contained in a drilling contractor supplied tank or drum. The fluids will be disposed of per applicable regulations.

D1.3 Well Installation Procedures All monitoring wells will be drilled and installed under the supervision of an experienced field geologist and a well driller licensed in the State of Missouri. Prior to drilling activities, an inventory of drilling supplies, well completion materials, and monitoring well supplies will be completed by the driller and the on-site geologist. A containment area should be constructed around the drilling rig and immediate working area of the rig to contain water, drill cuttings, and other drilling derived wastes from the borehole. Wells will be installed according to the Missouri Well Construction Rules (10 CSR 23-4). The well will be constructed by placing the filter pack and sealant in the annular space between the well screen, casing, and borehole wall. In wells where the top of the screen is submerged, the filter pack will be placed via tremie pipe between the well screen and the borehole wall to prevent bridging of the filter pack between the borehole wall and well casing. If the screen is not submerged, the filter pack will be placed by carefully placing pack material via gravity drop to the proper depths. The filter pack material will be chemically inert washed silica sand that is 90 percent by weight larger than the screen size, with a uniformity coefficient of 2.5 or less. The volume of filter material required will be calculated and depth of the filter pack will be periodically checked with a stainless steel tape to assure no bridging has occurred. The filter pack will extend at least 2 feet above the top of the screen. Up to 2 feet of fine silica sand will be layered on top of the filter pack material to minimize the potential for intrusion of bentonite or grout material into the filter pack and well screen. A 2-foot to 3-foot bentonite seal will be placed above the fine sand. The sealant used may consist of bentonite pellets, chips, or bentonite slurry. Pellets or chips will be used in shallow wells only and will be poured in slowly and measured with a tape to assure no bridging has occurred. Once in place, the pellets or chips will be hydrated using potable water from a known supply. The slurry will be tremied by gravity or pressure. The seal will sit for approximately one hour prior to grouting the remaining annular space.

The annular seal will consist of a grout material tremied into place by gravity or pressure. The grout will consist of a neat cement mixture that includes approximately 96 percent Portland cement with 4 percent bentonite. The tremie pipe will be placed at least 2 feet above the top of the bentonite slurry seal that overlies the filter pack. The grout will be pumped into the annular space until it comes to within 2 feet of the surface. Additional grout may be added to compensate for settling. After the grout has settled for several hours, the final 2 feet of annular space will be sealed with concrete and a 6-inch diameter protective steel casing will be placed in the hole. The casing will extend 3 feet into the ground and will have a locking cap. Well construction diagrams will be completed after the well is installed. Any modifications to these requirements must be approved in advance by Independence Power and Light and shall be in accordance with Missouri Well Construction Rules.

D1.3 Soil Sampling Soil samples will be collected for lithological classification and screening for total organic vapor (TOV) characteristics by use of a PID. Information regarding these characteristics will be incorporated with data from previous investigations. Soil samples will be collected from each boring using a continuous core from rotary sonic drilling method or by split spoon methodology for casing hammer and hollow stem auger drilling. Following retrieval of the sampler from the borehole, the undisturbed soil will be immediately screened with a PID to measure the TOVs. The maximum reading will be recorded on the soil-boring log, and this location will be screened for a headspace reading using the PID by collecting soil into a standard, clear, soil sample jar or ziplock type plastic bag. The container will be one-half to three-quarters filled with soil taken from the area with the highest vapor reading from the split-barrel sampler. The headspace will be allowed to develop at least 10 minutes at room temperature (but not more than one-half day) prior opening the container. The measurement will be collected by placing the PID nozzle into the soil container. The highest headspace PID reading will be noted on the boring log. Following the PID measurements, visual physical characterization will be completed that will include a grain-size (sand, silt, etc.) determination, grain-size shape and gradation, sample color, moisture content, and any other descriptive characteristics (fractures, laminations, oxidation, etc.). The Unified Soil Classification should be used in conjunction with this description. The visual description will be recorded on the boring log to accurately reconstruct the subsurface. A portion of the sample may be saved in a soil sample jar for the potential of additional physical tests.

D1.4 Decontamination To reduce the possibility of cross contamination, all sampling equipment and surfaces of measuring instruments will be thoroughly decontaminated between each use. This will include a trisodium phosphate (e.g., Alconox®) wash followed by a potable water rinse followed by a distilled or de-ionized water rinse. Prior to arriving at the site, the drilling contractor will certify that the drill rig, tools, and any down-hole components or materials have been steamed cleaned since their last use. An on-site controlled

decontamination area will be selected for cleaning equipment between well locations. The back and lower portion of the drilling rig and all equipment associated with drilling and well installation will be decontaminated with a steam cleaner before drilling is started and between boreholes. The contractor will provide a temporary, portable decontamination area. The drilling contractor will be responsible for setting up and maintaining the decontamination area. All fluids collected from decontamination procedures will be containerized and disposed of per applicable standards.

D1.5 Well Development The objective of well development is to provide a monitoring location that yields formation water as closely as it exists within the formation. Properly developed wells will produce water that is not turbid, does not contain fines, and represents the water quality conditions in the formation. After a well is completed, development will be accomplished through alternating cycles of over- pumping and/or surging. Over-pumping will be accomplished using a portable impeller pump capable of pumping fluids containing suspended solids (i.e., submersible pump). Surging will be completed using a surge block with a diameter slightly less than the inside diameter of the well. Surging will be completed by carefully placing the block into the well, ensuring that the block does not strike the bottom of the well, and then quickly pulling the block above the water level within the well. Well development will involve several alternating cycles of pumping and surging. Well development will be considered complete when three times the volume of water added during drilling has been removed, field parameters of temperature, specific conductivity, and pH have stabilized (+/- 10 %). All fluids removed during development will be containerized and disposed of per applicable requirements. A temporary storage container will be provided by the drill contractor.

D1.6 Waste Management During drilling, the cuttings and air space around the rig will be screened with a PID. Representative samples will also be collected from the cuttings pile and sealed in a clean container for headspace measurements. If the PID measures 10 parts per million (ppm) or greater, the soil will be containerized and segregated with soils having similar magnitudes of PID values. The selected contractor will provide Department of Transportation approved drums, transport containers, or a soil staging area, which has been lined and bermed with visqueen plastic for drilling derived waste (DDW) storage. A composite soil sample will be collected from containers having PID measurement greater than 10 ppm by the on-site geologist and will be submitted to the laboratory for analysis of VOCs (USEPA Method 8260B) to determine the proper disposal of cuttings. DDW will be retained on site for future treatment and/or disposal pending the results from the soil analysis. DDW determined to be “clean”, less than 10 ppm as measured with the PID will be thin-spread on site. Vickers will properly dispose of DDW determined to be “hazardous” by laboratory analysis.

All wash and rinse water from the decontamination activities and groundwater generated from the development activities will be contained on site and disposed of per applicable standards.

Appendix E Compendium of Field Documentation

Compendium Of Field Documentation

Minneapolis, MN ● Hibbing, MN ● Duluth, MN ● Ann Arbor, MI ● Jefferson City, MO ● Bismarck, ND ● Calgary, AB, Canada ● Grand Rapids, MI ● Salt Lake City, UT

Chain of Custody Form

Meter Calibration Summary Form

Troll Checklist / Data Sheet

Water Level Data Sheet

WATER LEVEL DATA SHEET Project: Project Number: Environmental Staff: Monitoring Location

Date: Measuring Point Elevation

Water Level Depth

Total Well Depth

Static Water Elevation

Comments

Field Log Data Sheet

Client:

Monitoring Point:

Location:

Date:

Project #:

Sample time: GENERAL DATA

STABILIZATION TEST

Barr lock: Casing diameter:

Time/ Volume

Total well depth:*

Temp. ºC

Cond. @ 25

Turbidity

ORP PH

D.O.

NTU (not appearance)

Static well level:* Water depth:* Well volume: (gal) Purge method: Sample method: Start time:

Odor:

Stop time:

Purge Appearance:

Duration: (minutes)

Sample Appearance:

Rate, gpm:

Comments:

Volume purged: Duplicate collected: Sample collection by: Others present:

Well condition:

MW: groundwater monitoring well

WS: water supply well

VOC

General

Oil, grease

Semi-volatile Bacteria

Total Metal

Nutrient

SW: surface water Cyanide

Filtered Metal

SE: sediment

Other: sump

DRO

Sulfide

Methane

Filter

Others: * Measurements are referenced from the top of riser pipe, unless otherwise indicated.

Recovery Rate Test Form

Recovery Rate Test Project:

Sampled by:

Date: Well Number: Water Level Before Evacuation (0.01 Ft.):

Time Well Was Evacuated:

Time from Evacuation (min.) :00 :30 1:00 1:30 2:00 2:30 3:00 3:30 4:00 4:30 5:00 6:00 7:00 8:00 9:00 10:00 11:00 12:00 13:00 14:00 15:00

Water Level (0.01 ft.)

Sample Time:

Time from Evacuation

Water Level (0.01 ft.)

Field Sampling Report

Water Sampling Guidelines Safety Considerations: Acids and bases are used for some of the preservatives - use appropriate PPE when sampling, Minimum protection of gloves and safety glasses should be worn to prevent sample contact with the skin and eyes. Sampling Order

Parameter Group

Container Type, Size, and Number

Preservation

Sampling Instructions

Holding Time

Allow slow stream of water to fill vial at an angle to minimize agitation. Near top, return vial to vertical and add water until meniscus forms, avoid overfilling. Cap tightly, invert and tap lightly; should be no headspace, if bubbles appear (> 6mm), recollect sample.

14 Days, 7 Days if pH > 2

VOCs, WI GRO, TPH as Gasoline

3-40 mL VOA glass vials, Teflon septum cap

HCl, pH < 2, Zero Headspace; Cool, ≤ 6 °C

SVOCs, Pesticides, Herbicides, Dioxin/Furans

1 L amber glass, Teflon septum cap

Cool, ≤ 6 °C

Fill slowly to minimize sample agitation. Fill bottle with enough water to minimize headspace.

7 Days

WI DRO

1 L amber glass, Teflon septum cap

HCl, pH < 2; Cool, ≤ 6 °C

Fill slowly to minimize sample agitation. Fill bottle with enough water to minimize headspace.

7 Days

TPH as Jet Fuel, Fuel Oil, Motor Oil (etc.)

1 L amber glass, Teflon septum cap

Cool, ≤ 6 °C

Fill slowly to minimize sample agitation. Fill bottle with enough water to minimize headspace.

7 Days

PCBs

1 L amber glass, Teflon septum cap

Cool, ≤ 6 °C

Fill slowly to minimize sample agitation. Fill bottle with enough water to minimize headspace.

None

Metals, Mercury

500 mL polyethylene; LL Hg – fluoropolymer or glass

HNO3, pH < 2; Cool, ≤ 6 °C (not required, best practice)

Dissolved Metals, Mercury

500 mL polyethylene ; LL Hg – fluoropolymer or glass

Cyanide

1 L polyethylene

Sulfide

500 mL polyethylene

HNO3, pH < 2; Cool, ≤ 6 °C (not required, best practice) NaOH, pH > 12; Cool, ≤ 6 °C NaOH, pH >9 and zinc acetate; Cool, ≤ 6 °C

General Chemistry

Cool, ≤ 6 °C

Fill slowly to minimize sample agitation.

180 days; Hg 28 days; LL Hg preserve w/in 48 hrs. or if oxidized, 28 days

Filter sample through a 0.45 µm filter. Fill slowly to minimize sample agitation.

180 days; Hg 28 days; LL Hg lab filter w/in 24 hrs., if field filtered see above

Fill slowly to minimize sample agitation.

14 days

Fill slowly to minimize sample agitation.

7 days

Fill slowly to minimize sample agitation.

14-28 days (except below)

TDS, TSS

1 L polyethylene

Cool, ≤ 6 °C

Fill slowly to minimize sample agitation.

7 days

BOD, CBOD

1 L polyethylene

Cool, ≤ 6 °C

Fill slowly to minimize sample agitation.

48 hrs.

Nitrate or Nitrite Only

Cool, ≤ 6 °C

Fill slowly to minimize sample agitation.

48 hrs.

Chromium VI

250 mL polyethylene 250 mL polyethylene

Cool, ≤ 6 °C

Fill slowly to minimize sample agitation.

24 hrs.

Phenolics, Ammonia, Nitrate+nitrite, TKN, COD

Varies by parameter

H2SO4, pH < 2; Cool, ≤ 6 °C

Fill slowly to minimize sample agitation.

28 days

HEM (Oil and Grease)

1 L amber glass

Fill slowly to minimize sample agitation.

28 days

Total / Fecal Coliforms

125 mL sterile

Fill slowly to minimize sample agitation.

≤ 30 / ≤24 hrs

HCl or H2SO4, pH < 2; Cool, ≤ 6 °C Na2S2O3; Cool, ≤ 6 °C

Note: Hold times are from initial sampling event to first analytical process. The times stated above do not reflect hold times extended due to extraction or other preparatory methods. Note: Container types and sizes listed are for guidance only. Refer to your specific regulatory agency sampling protocols. Laboratories may use different containers or combine analyses into larger volume containers.

Water Sampling Guidelines

Revision Date: 03/11/16

Appendix F Statistical Procedures Documentation

Appendix F Statistical Procedures Documentation Blue Valley Coal Combustion Residuals Impoundment Groundwater Monitoring Program This appendix provides additional details on the statistical procedures described in Section 6 of the SAP. A statistical analysis of baseline data will be used to develop representative background concentrations for comparison to future monitoring data to determine if there has been a statistically significant increase (SSI) in the contaminants of concern (COCs) in groundwater resulting from storage activities at the CCR impoundments. The IPL Blue Valley Facility has conducted an initial sampling event at the CCR Impoundment Area in the summer of 2019 using low-flow sampling procedures. The IPL Blue Valley Facility will collect and analyze groundwater samples quarterly for the first two (2) years to establish a baseline of concentrations of the COCs at the Site. Once all of the laboratory analytical data have been received and a QA/QC review has been performed, background concentrations will be established for each well and COC, as described in Section F.1. The statistical methods used in this plan will be consistent with 40 CFR 257.93 and U.S. EPA guidance (USEPA, 2009). The recommended statistical procedures for the CCR Impoundment Area groundwater monitoring program are based on intrawell statistical tests (comparing each well to its historical data record) and include both parametric and nonparametric statistical tests. In general, parametric tests (e.g., control charts) are used when the detection frequency is high and the data are normally or lognormally distributed, and nonparametric tests (e.g., nonparametric prediction limits) are used when the detection frequency is low and/or the data are not normally or lognormally distributed. Specific conditions may warrant the use of other methods included in guidance and regulation. The consideration of which statistical tests to used will be based on evaluation of the distributional characteristics of the baseline data, the number of non-detects, trends, and outliers, as discussed below. Statistical methods may include more than one type of analysis depending on the data distribution for each well/COC combination.

F.1

Background Concentrations and Historical Data

As described in Section 6 of the SAP, statistical analysis during the detection monitoring program will be conducted for the COCs listed in Table 1. The selection of an appropriate statistical test is based on the background groundwater concentrations and distribution for each constituent from each CCR Impoundment Area Program well. As discussed previously, the ability to establish a background data set will be evaluated once all data from the low-flow/passive background sampling events are available for review. Determination of the initial background data set for each well and constituent will involve a statistical assessment of the low-flow/passive sampling data.

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Dissolved metals, although not required by the Permit, are included in the monitoring program for comparison to concurrent total metals concentrations collected during each event. The statistical analysis results and procedures for determining the background data set for each well and constituent will be provided to the MDNR. As detailed in this appendix and Section 6 of the SAP, the initial background data set, once established for each well and constituent, will be updated at regular intervals (e.g., every two years) provided that the constituent concentrations remain “in-control” and do not show increasing trends or SSIs.

F.2

Intrawell Statistical Tests

Intrawell testing is generally the preferred method for detecting a release to groundwater because intrawell tests remove the spatial variability component present in upgradient versus downgradient (interwell) comparisons (USEPA, 2009, Ch.6). Intrawell testing is recommended for this groundwater monitoring program. Selection of the appropriate intrawell test depends on the detection frequency and data distribution for each well and parameter. The CCR Rule requires a minimum of 8 background samples to establish background water quality.

F.2.1

Determination of Statistical Test

Selection of the appropriate statistical test generally follows a decision-tree approach that is based on the detection frequency and the data distribution for each well and parameter. The appropriate statistical test can change over time as more data are collected. The following paragraph summarizes the general approach for selecting the appropriate intrawell statistical test. If the detection frequency is greater than 85%, apply appropriate data substitution for non-detected values (discussed below), determine if trends exist, and test whether the data are normally or lognormally distributed. If there are no upward trends and the data are either normally or lognormally distributed, create control charts based on the mean and standard deviation of the background samples (USEPA, 2009, Ch.20). If data are trending, a detrending method can be used before creating control charts (USEPA, 2009, Ch.14). For parameters with a detection frequency of less than 85% and greater than 50%, determine if trends exist and test whether the data are normally or lognormally distributed. If there are no upward trends and the data are either normally or lognormally distributed, create control charts or parametric prediction limits (USEPA, 2009, Ch.18-19) based on the mean and standard deviation of the background samples calculated using a Kaplan-Meier estimation (USEPA, 2009, Ch.15). For data with a detection frequency of less than 50%, a distribution that is neither normal nor lognormal, and/or a significant trend that cannot be detrended, use a nonparametric prediction limit (NPPL) of the highest detected background value (USEPA, 2009, Ch.18). If the parameter has not been detected, use the highest typical PQL.

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F.2.2

Statistical Pretests

Before selecting the appropriate statistical test, the data need to be evaluated to determine which statistical tests may be appropriate to use for a given well and constituent. Normality Testing An underlying assumption for parametric tests, including control charts, is that the data used to construct the control or prediction limits are normally distributed or can be normalized through transformation – e.g., lognormal. Data distributions will be determined using the Shapiro-Wilk statistic as being normal, lognormal, or non-normal (USEPA, 2009, Ch.10). Trend Testing For parameters with a detection frequency of greater than 50%, the Mann-Kendall trend test will be conducted to determine if any statistically significant increasing trends (at a 99% confidence level) are present (USEPA, 2009, Ch.17). The trend test requires at least 8 samples to determine a statistically significant increase with 99% confidence, although trends can be identified with a lower confidence level (e.g., 90 or 95%) with fewer samples. An increasing trend in constituent concentrations is one indicator that the existing operations (and not the CCR Impoundment Area) may be affecting the groundwater. Outlier Testing Formal outlier testing will be conducted for values that are unusually higher or lower than the background data. Unless laboratory or quality control errors have been documented, no outliers will be excluded from compliance well analysis until the background data include at least 12 values. Outliers may then be removed from the background based on professional judgement combined with the following tests. For data that are normally or lognormally distributed, Dixon’s or Rosner’s tests will be used to identify outliers (USEPA, 2009, Ch.12). Dixon’s test will be used for sample sizes of 20 or fewer measurements, and Rosner’s will be used for larger datasets. For non-normal data with at least four detected measurements, outliers will be identified using the Tukey box plot method with a multiplier of three (USEPA, 2009, Ch.12). Values will be considered outliers if they fall outside the range of the 25th percentile minus three times the interquartile range to the 75th percentile plus three times the interquartile range. For data with fewer than four measurements above detection, no outlier analysis will be conducted. Non-detects Treatment of non-detects (measurements below analytical detection) will vary depending on the statistical methods being used. When parametric tests (e.g., control charts or PPLs) are being used, for constituents which have been detected in 85 percent or more samples and whose detection limits are lower than the detected values, the non-detect values use half the method detection limit or reporting limit for statistical tests. For constituents which have been detected in greater than 50 percent but less than 85 percent of samples and whose detection limits are lower than the detected values, the mean and standard deviation of the data will be calculated using the Kaplan-Meier method for non-detects (USEPA, 2009, Ch.15). For nonparametric prediction limits, data adjustment for non-detects is not necessary.

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Several constituents, especially trace metals, may have variable detection limits with detected values in the range of the detection limits. If there are sufficient data above all detection limits, these values can be evaluated using the Kaplan-Meier method. Non-detects with detection limits exceeding all quantified data should be removed from the analysis, provided the background data contain at least eight measurements after removal (USEPA, 2009, Ch.15).

F.2.3

Parametric Tests

In general, the preferred intrawell parametric test is the control chart; however, in some instances a parametric prediction limit may be desirable. Control Charts Control charts (USEPA, 2009, Ch.20) will be developed for those constituents that meet the requirements for detection frequency, sample number, normality determination, and existing trends. For parameters with existing trends, it is possible to remove the trend and recalculate the control chart; however, the suitability of this method for the CCR Impoundment Area detection monitoring program remains to be evaluated. The combined Shewhart-CUSUM control chart is the preferred statistical procedure for intrawell analysis. The Shewhart control limit (SCL) detects single point deviations from background and gradual increases through the cumulative sum component of the control chart. The mean and standard deviation of the background data, along with user-specified values for control chart sensitivity are used to establish the “in-control” condition. To user-specified values required to construct a control chart are: •

h – the CUSUM value which is used to determine if a statistically significant increase is declared

•

k – a reference value related to the standard deviation representing the displacement that the control chart should detect.

•

SCL – Shewhart control limit represents the allowable number of standard deviations that any single measurement should be within.

For parameters that will use control charts and have greater than 12 samples to calculate the mean and standard deviation, the selected values for h, k, and SCL are 4, 0.75, and 4, respectively. If fewer than 12 samples are used to calculate the mean and standard deviation, the selected values for h, k, and SCL should be are 5, 1, and 5, respectively. Control charts can be constructed for normally or lognormally distributed data. For the lognormal case, it is important to verify that the control limits are appropriate for the expected range of the constituent concentrations. The control chart background will be updated every two years provided that the parameters remain within control limits and normally distributed. As part of the update, the cumulative sum will be reset.

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Parametric Prediction Limits Parametric prediction limits (PPLs; USEPA, 2009, Ch.18-19) are calculated values which, if exceeded, indicate a statistically significant increase over background. A PPL is constructed based on the mean and standard deviation of the background data and a given level of confidence that the measured value would be considered to come from the same population as the background data. PPLs only indicate single sample deviations from the background data set, whereas control charts can indicate both trends and single point excursions. However, PPLs are less sensitive to the requirement of normality than control charts. Intrawell PPLs may be useful for data that have too many non-detects to be appropriate for simple substitution. The basic parametric prediction interval is calculated with the mean and standard deviation of the data and can account for resampling and site-wide false positive rates from multiple comparisons. For those parameters with an existing increasing trend, there is no intrawell statistical test which is directly applicable (USEPA, 2009, Ch.17). For these well and parameter combinations, the increasing constituent concentrations will be put in context of the site setting. Detrending procedures may be employed (USEPA, 2009, Ch.14).

F.2.4

Nonparametric Testing

Nonparametric statistical tests do not make any assumptions regarding the underlying data distribution and are referred to as “distribution-free” tests. Nonparametric tests are used most frequently for rarely or non-detected parameters, but nonparametric tests can be used for any well and parameter combination. The nonparametric prediction limit (NPPL; USEPA, 2009, Ch.18-19) is the highest measured value in the background data set. For the case of all non-detects, the NPPL is set at the typical detection limit. For those parameters that are neither normally nor lognormally distributed or where non-detects constitute greater than 50% of the data, a nonparametric prediction limit (NPPL) equal to the highest detected value will be the statistical test.

F.3

Other Statistical Considerations

There are several potential issues in the statistical analysis that do not allow for easy classification of the appropriate statistical test. These issues include varying detection limits, detected values within the range of detection limits, existing trends in the background data, and outliers. There are other concerns that affect the data interpretation, including groundwater flow, sampling methodology, and QA/QC results, as these issues affect data comparability and possibly the statistical test as well. Some of these complicating statistical issues for the monitoring network are discussed below. Blank Contamination There are several ways to address field blank contamination in the statistical analysis. If the concentration in the field blank is on the same order or greater than the concentrations in the samples, the samples are generally disregarded (i.e., one cannot say if the constituent is present or not in the groundwater) and not included in the statistical analysis. If the concentration in the field blank is much less than the sample concentrations, the samples generally are considered valid.

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Temporal Correlation In some instances, constituent concentrations seem to be related by sampling event. For many of the metals, concentrations were higher or more frequently detected during the beginning of the monitoring program. This pattern of detection could be the result of many factors such as actual groundwater changes over time, the groundwater needing a “stabilization” period, or different sampling and analytical methods and procedures. Regardless of the source of the apparent correlation, temporal correlation contributes to the variance structure and distribution of the data and more importantly may indicate changes in groundwater quality which are not actually occurring or fail to identify changes which are actually occurring (USEPA, 2009, Ch.14). If the trends are due to natural processes (e.g., occurring in all wells in the network, including upgradient) rather than a release, detrending procedures can be employed. Duplicate Data Duplicate samples are separate laboratory analyses conducted on the same sample or on two samples collected at the same time from the same location. Duplicate samples give information on the reproducibility of the result. In some instances, the duplicate and the original sample have shown pronounced differences. Duplicate samples are not statistically independent and should not both be used in statistical tests (USEPA, 2009, Ch.6). The original sample value should be used for the statistical analysis, and the duplicate value should be retained only for QA/QC purposes. Visual inspection of the data provides a key step in the data analysis process. Potential outliers and trends are readily identified, and investigation of the tabular data can show potential correlations between parameters. It is possible that when the CCR Impoundment Area is completed, the water balance and flow could change, thereby affecting the constituent concentrations in the groundwater monitoring wells. Therefore, trends in the time concentration graphs will be more indicative of a potential new equilibrium status after a few years of operation of the CCR Impoundment Area unit.

References: U.S. Environmental Protection Agency, 2009. Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities – Unified Guidance. EPA 530-R-09-007. March 2009.

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