Camp Rilea WW Groundwater Monitoring Plan Final 30OCT2024~2.pdf

Groundwater Monitoring Plan Camp Rilea 30 October 2024

Contents

1. Introduction

1.1. Background

1.2. Objectives

1.3. Selection of Analytes

1.1.1 Water Quality Parameters

1.1.2 Organic and Inorganic Compounds

1.1.3 Metals

2. Site Description

2.1. Treated Effluent Characteristics

2.2. Rapid Infiltration Basins

2.3. Existing RIB Groundwater Monitoring Wells

2.4. New RIB Groundwater Monitoring Wells

2.4.1 PZ-1

2.4.2 RIBMW-6

2.4.3 RIBMW-7

2.4.4 PZ-2

3. Groundwater Monitoring Plan

3.1. Groundwater Quality Monitoring Requirements

3.2. Groundwater Quality Limits

3.3. Health and Safety

3.4. Field Records

3.5. Instrument Calibration

3.6. Depth to Groundwater Measurements

3.7. Groundwater Sampling

3.7.1 Alternative Groundwater Sampling

3.8. Equipment Decontamination

4. Quality Assurance Project Plan

4.1. Analytical Methods

4.2. Quality Control Procedures

4.3. Data Validation and Usability

4.4. Significant Water Quality Changes

4.4.1 Upper Tolerance Limit Calculation

30 October 2024

4.4.2 pH Tolerance Limit Calculation

5. Reporting Requirements

6. References

Figures

Appendix A - Rapid Infiltration Basin Area Monitoring Well Logs

1. Introduction The Oregon Military Department (OMD) has prepared this Groundwater Monitoring Plan (Plan) to routinely assess the network of groundwater monitoring wells installed around the Rapid Infiltration Basins (RIBs) at OMD’s Camp Rilea training site (Site) that is located south of Warrenton, Oregon.

Figure 1 is a site location map. OMD operates a wastewater treatment plant within the Site under a Department of Environmental Quality (DEQ) Water Pollution Control Facility (WPCF) Permit #101887.

The current WPCF permit became effective on 1 June 2024. In accordance with Schedule C, Section 1 of the permit, this Plan is an update to the previous groundwater monitoring plan dated 20 October 2011.

1.1. Background

Camp Rilea has operated the current facultative lagoons for approximately 50 years. Historically, effluent from the lagoons was irrigated on a spray field located south of the lagoons. Groundwater in the vicinity of the spray field was periodically monitored with a network of 11 groundwater monitoring wells.

Discharge to the spray field ceased with the construction of the RIBs in late 2011. Also in 2011, a Class A recycled water treatment system was constructed to allow Camp Rilea to irrigate fully treated wastewater on turf grass at specific locations on site. Five monitoring wells (RIBMW-1 through RIBMW-5) were installed to monitoring the groundwater in the vicinity of the RIBs. Major wastewater treatment system features are shown on Figure 2.

1.2. Objectives

The objectives of this Plan are to:

• Provide for the installation of new monitoring wells in accordance with Schedule C, Section 1 of the wastewater permit

• Provide a monitoring plan for the RIB monitoring wells

• Identify monitoring wells included in the program, frequency of observation, analytes, and reporting requirements

• Provide field methods and protocols for groundwater sampling

• Determine if there is likely to be any offsite migration of targeted analytes in groundwater within the uppermost water bearing zones at concentrations exceeding the Permit Specific Concentration Limit (PSCL)

1.3. Selection of Analytes

Analytes of interest for groundwater monitoring were selected based on typical constituents of potential concern from domestic wastewater treatment plants. Additional analytes have been included in the analysis due to DEQ’s concern that the treated wastewater may have a negative effect on the drinking water aquifer around and downgradient of the RIBs.

1.1.1 Water Quality Parameters

Water quality parameters will provide general information on groundwater conditions and can provide insight into biological and chemical processes in the subsurface. Permit required parameters include depth to groundwater, pH, temperature, and electrical conductivity.

1.1.2 Organic and Inorganic Compounds

Organic and inorganic compounds are typically found in domestic wastewater and will be analyzed to determine if they are present at levels that may impair the use of the drinking water aquifer. Analytes include total chloride, total nitrite (as N), total nitrate (as N), total sulfate, and total dissolved solids.

1.1.3 Metals

DEQ has expressed concern that the treated wastewater may be leaching metals from the soil into the drinking water aquifer. Arsenic in the vicinity of Camp Rilea naturally occurs in groundwater at concentrations exceeding drinking water standards. This will require careful comparison to an upgradient background well to ensure that the wastewater discharge is not impairing the quality of the shallow groundwater aquifer. Total arsenic, total iron, and total manganese are of concern and will be analyzed.

2. Site Description The Site is located along the northern coast of Clatsop County and is comprised of approximately 2,000 acres of rolling coastal dunes between the towns of Seaside and Warrenton, Oregon (Figure 1). The facility is bordered on the west by the Pacific Ocean and on the east by Highway 101, which provides access to the Site. A cattle/livestock operation and golf course are located immediately south of the Site.

Property to the north of the Site is currently either residential or undeveloped.

2.1. Treated Effluent Characteristics

Discharge to the RIBs between January 2018 and December 2023 totaled 43.9 million gallons with an average discharge event of approximately 90,000 gallons. The maximum single day discharge was 216,000 gallons. During 2019 through 2021 there was no discharge to the recycled water system.

Construction during 2019 and 2020 to reline the lagoons resulted in a lower quality (primary treatment) effluent.

Table 2.1 Average Effluent Analytical Results January 2018 Through December 2023 pH 7.61 standard units Dissolved Oxygen 7.95 mg/L Five-Day Biological Oxygen Demand 14.13 mg/L Total Suspended Solids 12.63 mg/L Nitrate 4.46 mg/L Total Kjeldahl Nitrogen 4.92 mg/L Nitrite 0.24 mg/L Total Phosphorous 5.52 mg/L

Table 2.1 averages include the 2019 and 2020 years when one lagoon was out of service due to liner replacements. Excluding those years the averages are lower except for pH and dissolved oxygen which remain about the same.

Future effluent is not expected to change significantly. Camp Rilea’s maximum population has not changed. The average population can fluctuate widely depending on the season and the number of groups training at the Site.

2.2. Rapid Infiltration Basins

The existing RIBs are located approximately one third mile north of Slusher Lake (completely within the bounds of Camp Rilea) and half a mile east of the Pacific Ocean. Camp Rilea’s drinking water production wells are located approximately one third mile and half a mile north of the RIBs. The RIBs are located on top of a sand dune ridge at an elevation of approximately 80 feet to maximize the distance to the top of the groundwater table. This area was formerly forested stabilized dune sands west of a firing range.

The RIBs are rectangular and oriented so that the longer dimension is perpendicular to the regional east-west groundwater flow. A total of four RIBs were installed to allow for designed cycling using three days for the loading/wetting cycle for summer and winter and a resting/drying time of five days for summer and eight days for winter. Camp Rilea generally operates on a schedule of three days of loading and nine days of resting. Each RIB consists of approximately 1,300 square feet (0.03 acres) of bottom surface area.

The interior side slopes provide additional infiltrating surface area that serves as a safety factor for basin overflow. Additionally, overflow piping is provided between the RIBs to allow a full RIB to overflow to the adjacent RIBs.

2.3. Existing RIB Groundwater Monitoring Wells

Five groundwater monitoring wells (RIBMW-1 through RIBMW-5) were installed in September 2011 in the RIB area to monitor groundwater conditions including groundwater quality, gradient, and flow directions. Figure 3 illustrates the monitoring well and RIB locations.

The lithology encountered during drilling consists of fine to medium sand in all the borings. Groundwater was encountered during drilling at depths ranging from 17 feet below ground surface (BGS) in monitoring well RIBMW-3 to 67 feet BGS in monitoring well RIBMW-5. Copies of the monitoring well logs are included as Appendix A. Table 2.3 summarizes the monitoring well construction. The top of polyvinyl chloride (PVC) casing and horizontal location of each monitoring well was surveyed by a licensed professional surveyor. The survey elevations are used to evaluate the groundwater flow direction and gradients.

Table 2.3 Rapid Infiltration Basin Network Monitoring Well Construction Details

Well Date Installed Total Depth (ft BGS)

Screened Interval (ft BGS)

Elevation of Top of Casing (ft AMSL)

RIBMW-1 9/12/2011 65 50-65 84.23

RIBMW-2 9/13/2011 50 35-50 62.64

RIBMW-3 9/13/2011 30 15-30 36.61

RIBMW-4 9/14/2011 75 60-75 88.69

RIBMW-5 9/15/2011 80 65-80 83.33

Notes:

ft BGS - Feet below ground surface ft AMSL - Feet above mean sea level

2.4. New RIB Groundwater Monitoring Wells

During the wastewater permit renewal process DEQ expressed concerns with the existing RIB monitoring well network’s ability to monitor the full extent of wastewater mixing. This has necessitated the installation of two additional monitoring wells and two piezometers as discussed below. Monitoring wells will be installed in accordance with Oregon Administrative Rules (OAR) 690-240. Prior to advancing borings, utility locates will be completed.

Once installed, the new monitoring wells will be developed to remove the highly turbid water generated during the drilling process. Purging will continue until turbidity levels, measured five minutes apart, have stabilized to within 10% of the prior reading for three consecutive measurements. When this is achieved, the well will be capped and allowed to sit overnight so remaining suspended particulates can settle to the bottom of the casing below the screened interval. Samples will be collected at least one day after wells are installed.

Reference elevations at new and existing wells will be established by an Oregon licensed surveyor and will have an error of less than 1/100th of a foot. Elevations will be tied to the National Geodetic Vertical Datum (NGVD) or a local datum. This will ensure that all groundwater measurements tie back to the same datum and are as accurate as possible for assessing groundwater mounding and flow.

Spoils generated from the installation of the monitoring wells and piezometers are not known or likely to be contaminated by regulated materials. As such the soil will be spread out in the area immediately surrounding the wells. Groundwater generated during development and sampling of the wells will be discharged to the ground surrounding the wells, taking care not to create erosion of the soil.

2.4.1 PZ-1

DEQ has expressed concerns over groundwater mounding resulting from use of the RIBs. There can be no doubt that there is some amount of mounding when infiltrating tens of thousands of gallons per day when discharging to the RIBs. The amount, duration, and significance of the mounding is currently unknown. Typical fluid dispersal due to gravity into cohesive soils results in an outward expansion of the saturated zone resulting in a frustum shape. However, the soils at Camp Rilea are excessively drained consisting of clean sands which may result in a more columnar saturated zone during discharge. When the RIBs are receiving treated water, water ponds to a depth of approximately 18 inches regardless of how long they are receiving flow. Within two hours of the discharge pump being turned off, all ponding has dissipated, and the bottoms of the RIBs are unsaturated.

OMD will install a piezometer in the middle of the RIB compound to assess the amount and duration of any groundwater mounding. The effects of this assessment are further discussed below in Section 3.4. The piezometer is expected to encounter groundwater about 55 feet below ground with the intent of keeping it submerged even during the summer when the RIBs receive little discharge. The piezometer will be made of one-inch PVC with five feet of screen at the bottom. The well will be a flush mount configuration to allow maintenance vehicles to drive around the RIBs as needed. The location of this piezometer is shown on Figure 3.

2.4.2 RIBMW-6

The new wastewater permit has groundwater permit limits for nutrients and may have additional limits added after new monitoring wells are sampled. Under the previous permit, OMD submitted a report indicating that any nutrient residuals would attenuate before reaching the property boundary, which is the public beach, approximately 0.4 miles west of the RIBs. At the time DEQ concurred with that assessment and the recommendation that no permit limits were needed. In response to new permit limits and in accordance with Schedule C, Section 1 of the permit a new downgradient monitoring well (RIBMW-6) will be installed to act as a point of compliance. DEQ rules allow the waste management boundary to extend up to the property boundary. Installation of a monitoring well at the rack line of the beach is not feasible and may have significant effects from the ocean and tidal changes. RIBMW-6 will instead be installed along the shoulder of Dune Road, south of the Demolition Range and directly downgradient (west) from the RIBs based on historic groundwater flow.

Groundwater at RIBMW-6 is expected to occur at about six feet below ground. The well will be installed to a depth of 20 feet below ground. It will be a ‘stick up’ configuration surrounded by bollards in accordance with Oregon Water Resources Department (OWRD) regulations. The casing will be two-inch PVC and almost entirely consist of a well screen. Due to the expected shallow depth of groundwater and the potential for shallower winter groundwater elevations, it may be necessary for the licensed well driller to request a waiver from OWRD due to a minimal well seal thickness. A shallower well seal will allow for as much well screen as possible which will minimize the chance of the well screen being completely submerged during winter months. The location of this monitoring well is shown on Figure 3.

2.4.3 RIBMW-7

Groundwater levels in existing wells indicated potential mounding which may also be a ridge correlating to the sand dune ridge where the RIBs are located. This mound or ridge indicates that groundwater is flowing primarily west toward the Pacific Ocean as expected, but also to the east toward RIBMW-5 which was originally intended to be an upgradient background monitoring point. The new wastewater permit requires the installation of a new background monitoring well at a location that is unaffected by the RIB system.

A new background well (RIBMW-7) will be installed around Building 7360. This well is expected to encounter groundwater around 35 feet BGS. It will be a two-inch PVC cased well with approximately 20 feet of well screen half submerged in the groundwater. It will be a ‘stick up’ configuration surrounded by bollards in accordance with OWRD regulations. The location of this monitoring well is shown on Figure 3.

2.4.4 PZ-2

The ground surface elevation at RIBMW-5 is approximately 87 feet above mean sea level (AMSL) and the elevation at RIBMW-7 is 55 feet AMSL. This means that observing just the groundwater elevations at those two points it may appear that RIBMW-7 is not upgradient even though it is an additional 800 feet east from RIBMW-5 and about halfway up the next inland dune. As an additional point of evidence, a piezometer (PZ-2), will be installed at the low point or trough between sand dunes. The intent is that the piezometer will show a lower groundwater elevation than at either RIBMW-5 or RIBMW-7. Shallow groundwater elevation is expected to generally follow surface topography with groundwater elevation decreasing to the east from RIBMW-5 to PZ-2 and increasing to the east from PZ-2 to RIBMW-7, which supports the conclusion the selected location for RIBMW-7 is upgradient from the RIBs and is a suitable location for a background well.

Groundwater is expected to occur at PZ-2 at approximately 25 feet BGS. The piezometer will be made of one-inch PVC with five feet of screen and a total depth of approximately 30 feet. The well will be a flush mount configuration located on the west side of a berm in the middle of the Know Distance Range. The berm and flush mount configuration will minimize the potential for damage from use of the target range as well as allowing the grass to be mowed without obstruction. The location of this piezometer is shown on Figure 3.

3. Groundwater Monitoring Plan The monitoring plan identifies the wells to be monitored and/or sampled, monitoring frequency, and analytical methodologies in accordance with the WPCF permit. Laboratory analysis of groundwater samples will be conducted using U.S. Environmental Protection Agency (EPA) or Standard methods by the analytical laboratory at Camp Rilea that is accredited by the Oregon Environmental Laboratory Accreditation Program (ORELAP) for the specific analysis being performed. Analysis of metals (arsenic, iron, and manganese) will be completed by a commercial laboratory that is also ORELAP certified for those analyses.

3.1. Groundwater Quality Monitoring Requirements

Table B7 of the wastewater permit specifies the minimum groundwater quality parameters and analytes to be monitored. These requirements are also shown below in Table 2.5. The initial monitoring frequency will be semi-annually as a continuation of the approved conditions in the previous permit. Following installation of the new monitoring wells and piezometers discussed above, the sampling frequency for all wells will be increased to quarterly. Piezometers will only have groundwater elevations gauged. Once the new wells have been sampled for three years (12 sampling events) all monitoring wells may return to semi-annual sampling as indicated in the WPCF Permit.

Table 3.1 Groundwater Quality Monitoring Requirements

Constituent/ Parameter Reporting Units Sample Type/ Required Action Depth to Groundwater Feet (nearest tenth) Measured Groundwater Elevation Feet (AMSL) Calculated pH Standard Units Grab (Field Measurement) Temperature °C Grab (Field Measurement) Electrical Conductivity mmhos/cm Grab (Field Measurement) Total Arsenic mg/L Grab Total Chloride mg/L Grab Total Iron mg/L Grab Total Manganese mg/L Grab Total Nitrite (as N) mg/L Grab Total Nitrate (as N) mg/L Grab Total Sulfate mg/L Grab Total Dissolved Solids mg/L Grab Definitions:

°C: Degrees Celsius mmhos/cm: Millimhos per centimeter, equivalent to milli-Siemens per centimeter mg/L: milligram per liter

Following three years of monitoring the new wells OMD will evaluate the monitoring results and may submit a request to DEQ for a reduction in the number of wells to be sampled, specifically monitoring wells RIBMW-3 and RIBMW-5. Following the installation of the new monitoring wells, RIBMW-3 and RIBMW-5 are expected to provide somewhat redundant groundwater analytical data. They would not be abandoned and would continue to be used to measure depth-to-groundwater to determine groundwater flow.

3.2. Groundwater Quality Limits

Initial groundwater concentration limits will only exist for nitrate and nitrite with a combined concentration of 10 mg/L. Table A4 in the wastewater permit also lists arsenic, chloride, iron, manganese, sulfate, and total dissolved solids, however no permit limits exist at this time. Groundwater quality concentration limits for these constituents will be established by DEQ following the analysis of 12 or more samples from all wells.

As discussed in Section 2.4.2 RIBMW-6 will be the point of compliance for the Camp Rilea Wastewater Treatment Plant. Oregon Administrative Rule 340-040-0010 (2) defines the compliance point (referred to here as point of compliance) as the point or points where groundwater quality parameters must be at or below the permit-specific concentration limits or the concentration limit variance. Groundwater concentrations at RIBMW-2 and RIBMW-3 may exceed any or multiple of the groundwater concentration limits, however they must be reduced to at or below the concentration limit by the time the groundwater reaches the point of compliance (RIBMW-6).

The increase in sampling following well installation will allow for analysis of groundwater across all seasons and include enough sample results to calculate statistically appropriate permit limits. New permit limits will largely be based on the background concentrations detected in the upgradient background well RIBMW-7 and at the down gradient point of compliance RIBMW-6. Future permit limits are expected to mirror primary and secondary drinking water quality standards if DEQ determines they are needed.

3.3. Health and Safety

The sampling team leader will function as the field safety officer and ensure safe practices and operating conditions are maintained during each sampling event. Sampling staff will exercise sound field judgment and practices to maintain safe working conditions. The sampling team leader will conduct a daily tailgate safety meeting before each sampling event. All personnel will have stop work authority during sampling.

At a minimum, field personnel will wear safety glasses and new disposable nitrile or latex gloves while sampling or handling sample containers with preservative. Gloves will be replaced between sample locations or when they become dirty.

3.4. Field Records

A combination of Standard Operating Procedures (SOPs) and field forms will be used during sampling events. The field forms will log all data collected in the field and note any deviations from the SOPs.

The following information will be recorded on the field forms:

• Date, general description of site conditions, and weather

• Documentation of sampling personnel on site, including subcontractors

• Time, location, medium, and sample ID of each sample collected

• Documentation of instrument calibration

• Documentation of field parameters collected

• Deviations from SOP or other problems in the field

• Visitors to the Site relating to the sampling event

• Communications made with outside parties relating to the sampling event

• Time of day that work began and stopped

3.5. Instrument Calibration

Daily, prior to each sampling event, the groundwater quality instruments will be calibrated following the instrument manufacturers calibration instructions. Sampling staff will complete the calibration log sheet as part of the field forms. Current instrumentation includes a YSI ProDSS (temperature, dissolved oxygen, pH, and electrical conductivity) and a Hach 2100Q portable turbidimeter.

3.6. Depth to Groundwater Measurements

In July 2024, Camp Rilea installed Solinst Levelogger data loggers in the existing monitoring wells. The level loggers are absolute pressure transducers that when placed in each well record the water pressure on the unit. Water pressure readings can then be converted to water level equivalent measurements when correlated to a manual gauging event. Each Levelogger is hung on a stainless-steel cable approximately three feet from the bottom of the well. This will ensure that the transducers always remain submerged but do not contact any sediment at the bottom of the wells.

A Solinst Barologger is also present at the RIBs which is used to compensate the Levelogger pressure readings for changes in barometric pressure. All well plugs will be vented to ensure that submerged well screens do not alter the groundwater readings by trapping air or creating a vacuum.

Initially the Leveloggers were set up to record readings every half hour. This should provide enough data resolution to see groundwater levels change over time including potential groundwater mounding from use of the RIBs. Data from the Leveloggers and Barologger will be downloaded at least during each sampling event. Following installation of the new monitoring wells and piezometers a Levelogger will be placed in each new well and piezometer. Data collected prior to installation of the new wells will be evaluated to determine if more frequent readings are required to analyze potential groundwater mounding effects.

Currently, OMD expects to increase transducer readings to every 15 minutes for at least three summer and three winter months. Based on drinking water well drawdown and recovery rates, more frequent water level readings will be necessary to observe the infiltrated water before it blends into the natural groundwater level. Observation during different seasons will also be important. During summer months, when most discharge is directed toward the recycled water system, prolonged observations between infiltration events will be allowed. Winter observations will show the effects of rainfall infiltration and more frequent infiltration of wastewater. If necessary, the transducers can be reprogrammed to an even more frequent reading schedule to observe the potential effects of groundwater mounding.

Prior to sampling each monitoring well, depth to groundwater measurements will be taken using an electronic water level indicator calibrated to hundredths of feet. Monitoring wells will be opened and allowed to equilibrate for 5-10 minutes prior to gauging. The depth to groundwater will be measured from the top of the PVC casing at the marked survey point and recorded in the field log. Measurements will be recorded before sampling and before the pressure transducer has been removed from the well or the sampling pump placed into the well.

3.7. Groundwater Sampling

Groundwater sampling will be conducted by using an electric submersible pump connected to a low flow controller. The pump will be placed in the middle of the water column but never above the top of the screened interval. If possible, the pump intake will be kept at least two feet from the bottom of the well, to minimize mobilization of particulates present in the bottom of the well. The pump will be connected to new disposable Low-Density Polyethylene (LDPE) tubing at each well. Initially the low flow controller will be used to keep the pump off and power gradually applied until water is discharged from the sample tubing. The discharge rate should be adjusted until the discharge stream is approximately the diameter of a pencil.

Purged water will be directed into a flow through cell for the field water quality meter (YSI). This will enable constant monitoring of the field parameters. Purge water that is discharged from the flow cell will be directed toward a graduated bucket to determine the total volume of water purged. Turbidity samples will be analyzed immediately.

At five-minute intervals during purging, water quality parameters (temperature, dissolved oxygen, electrical conductivity, pH, turbidity, and total purge volume) will be recorded on the field forms.

Stabilization is achieved when three consecutive readings are within the following limits:

Turbidity: 10% for values greater than 5 NTU; if three turbidity values are less than 5 NTU, consider the values as stabilized Dissolved Oxygen: 10% for values greater than 0.5 mg/L; if three dissolved oxygen values are less than

0.5 mg/L, consider the values as stabilized Conductivity: 3%

Temperature: 3% pH: ± 0.1 unit

Following stabilization of groundwater quality parameters, the pump tubing will be disconnected from the flow through cell without stopping the pump. Samples will be collected directly from the sample tubing into labeled laboratory supplied sample containers. Care will be taken to ensure the pump tubing does not enter the mouth of the sample container and that the pumping rate is not altered from the stabilized conditions. Once samples are collected, they will be recorded on a chain of custody sheet (one per laboratory) and hand delivered to the Camp Rilea Laboratory and the commercial laboratory.

3.7.1 Alternative Groundwater Sampling

If the submersible pump is inoperable or becomes damaged during the sampling event, the use of disposable bailers is allowed. Bailers will be gently lowered into the groundwater to prevent unnecessary agitation of the groundwater. Prior to collecting groundwater samples, a minimum of three well casing volumes will be purged from each monitoring well. Well purge volume will be determined using the following formula:

𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃𝑃 𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉𝑉 (𝑔𝑔𝑔𝑔𝑔𝑔)

= 3 × 0.1632( 𝑔𝑔𝑔𝑔𝑔𝑔 𝑓𝑓𝑓𝑓 𝑖𝑖𝑖𝑖 2" 𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤) × [𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷ℎ 𝑡𝑡𝑡𝑡 𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏𝑏 𝑜𝑜𝑜𝑜 𝑤𝑤𝑤𝑤𝑤𝑤𝑤𝑤 (𝑓𝑓𝑓𝑓)

− 𝐷𝐷𝐷𝐷𝐷𝐷𝐷𝐷ℎ 𝑡𝑡𝑡𝑡 𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔𝑔 (𝑓𝑓𝑓𝑓)]

If insufficient groundwater is produced from the well, the well will be purged until the well is dry and then allowed to recover prior to sampling. Disposable bailers will be discarded after use at one monitoring well. Parameters of temperature, dissolved oxygen, electrical conductivity, pH, turbidity, and total purge volume will be monitored and recorded in the field log during purging activities. Each bailer will be emptied into a container for measurement of water quality parameters and then emptied into a calibrated purge bucket. Groundwater samples will be collected when these parameters are stabilized after a minimum of three well volumes have been removed or, if insufficient groundwater is available for purging, upon recovery of the groundwater into the well. Samples will be collected directly from the bailer into labeled laboratory supplied sample containers. Once samples are collected, they will be recorded on a chain of custody sheet and hand delivered to the Camp Rilea Laboratory and the commercial laboratory.

3.8. Equipment Decontamination

The water level indicator and the sample pump will be decontaminated prior to sampling each monitoring well.

Any point of the water level indicator and sample pump that contacted groundwater plus approximately 10 feet of tape/wire will be decontaminated using a three-stage process. Items to be decontaminated will first be washed with a laboratory phosphate and nitrate free soap (e.g. Liquinox). The sample pump will be turned on in the soap wash for approximately 30 seconds to clean the internal parts of the pump that may contact a sample. The second step of the decontamination process is a potable water rinse that will remove any soap residues. The sample pump will also be operated during this stage for approximately 30 seconds to clean the internal pump components that may contact samples. The final stage of the decontamination process is a thorough distilled water rinse.

The field parameter instrument and flow cell will only receive a potable water and distilled water rinse.

This is due to the sensitive nature of the probes and precautionary so that the soap will not affect the calibration of the sensors. Any potential residual on the field meter or flow cell will be rinsed off during stabilization of the next well. The flow cell is removed before filling laboratory analytical samples therefore it is not possible for the field parameter instrument to introduce contamination to the sample containers.

Disposable equipment such as gloves, tubing, and bailers will not be decontaminated. Groundwater will be removed to the extent possible before carefully placing them in a trash bag to be disposed of as general garbage. Used disposable equipment will be kept separate from new disposable equipment to minimize the chance for cross contamination.

4. Quality Assurance Project Plan This QAPP describes the plan and procedures in place to ensure the data collected meets the objectives for this project. The overall data quality objective for this Plan is to collect representative groundwater data of known and acceptable quality that can be used to answer questions related to the occurrence of the analytes of interest that have the potential to negatively affect the uppermost groundwater aquifer at Camp Rilea which is also a drinking water aquifer.

4.1. Analytical Methods

Analytes of interest are outlines above in Table 2.5 and below in Table 4.2. The table below provides information on laboratory analytical methods, holding times, sample containers, and preservation requirements for each analyte of interest.

Table 4.2 Laboratory Analytical Methods, Hold Times, Sample Containers, and Preservation Methods

Constituent/ Parameter

Analytical Method

Hold Time Minimum Sample Container Size

Preservation

Total Arsenic EPA 200.8 180 Days 250 mL Poly 4°C & HNO3 Total Chloride SM 4500-Cl B 28 Days 250 mL Poly or Glass 4°C Total Iron EPA 200.7 180 Days 250 mL Poly 4°C & HNO3 Total Manganese EPA 200.7 180 Days 250 mL Poly 4°C & HNO3 Total Nitrite (as N) SM 4500-NO2 B 48 Hours 100 mL Poly 4°C Total Nitrate (as N) SM 4500-NO3 D 48 Hours 100 mL Poly 4°C Total Sulfate EPA 375.4 28 Days 100 mL Poly 4°C Total Dissolved Solids EPA 160.1 7 Days 250 mL Poly 4°C

4.2. Quality Control Procedures

The following steps and activities will ensure quality control to achieve data quality objectives during field activities, and will be overseen by the sampling team leader:

• Close adherence to this Plan, and documentation of any deviations from this Plan

• Maintain detailed field logs

• Use of appropriate, lab supplied sample containers and preservatives (see Table 4.2)

• Adherence to appropriate holding times (see Table 4.2)

• Daily calibration of field instruments, and documentation of standards used

For this Plan, field Quality Assurance and Quality Control (QA/QC) sampling will consist of one equipment blank and one field duplicate. Once the new monitoring wells are installed there will be seven monitoring well samples. The equipment blank and field duplicate each represent a 14 percent QC rate which exceeds the typical requirement of 10 percent. The sample containers listed in Table 4.2 above show volumes that are at least double the minimum sample volume required by the analytical method.

The Camp Rilea Laboratory generally supplies even larger containers which allow for laboratory duplicates and matrix spike (MS)/matrix spike duplicates (MSD) as needed. The laboratories will ensure that the appropriate number of duplicate and MS/MSD samples are analyzed.

The equipment blank sample will be used to ensure that decontamination procedures are adequate and are being followed. The field duplicate sample is used to assess field precision and variability through improper well purging and aquifer stabilization. Field QA/QC samples will be clearly identified on the sample collection logs.

4.3. Data Validation and Usability

Analytical data will be assessed to ensure that the specified QA/QC objectives for precision, accuracy, representativeness, completeness, and comparability have been met. This section describes routine procedures for assessing project data. The following QC data results (at a minimum) will be reviewed for all samples:

• Chain of custody documentation

• Holding times

• Equipment blanks

• Method blanks

• MS

Analytical data will be assessed for the data quality indicators: precision, accuracy, bias, sensitivity, representativeness, completeness, and comparability. These indicators will be assessed using methods consistent with EPA guidance. Data that do not meet acceptance criteria may be usable with specific limitations. Data indicated to be usable with limitations will be identified using data qualifiers, quantitative evaluations, and narrative statements regarding potential bias. Unusable data will be identified as such.

In accordance with Schedule B, Section 2(d)(ii) of the wastewater permit if QA/QC requirements are not met for any analysis the laboratory will reanalyze the sample. If the sample cannot be reanalyzed, then OMD will resample at the earliest opportunity. If OMD is unable to collect a sample that meets QA/QC requirement, the data will be reported with a qualifier and an explanation of how the data does not meet QA/QC requirements. Data that does not meet QA/QC requirements will not be used in any calculations unless authorized by DEQ.

A less than symbol (<) or other industry standard qualifier such as non-detect (ND) is not considered a failure of QA/QC requirements, but and indicator that the analytical result is below that method detection limits. An estimate qualifier (J or other industry standard) is also not considered a failure of QA/QC requirements but indicate that the analytical result is between the method detection limit and the reporting limit, so long as the reporting limit is at or below the Groundwater Quality Concentration Limits specified in the wastewater permit.

4.4. Significant Water Quality Changes

Schedule B, Section 4(e)(iii) specifies that if groundwater monitoring indicates a significant increase (or decrease of pH) in the value of a parameter monitored, then OMD must immediately resample the monitoring well(s) for the increased or decreased parameter and other parameters deemed necessary by

DEQ. If resampling confirms a change in water quality OMD must report results to DEQ within 10 days of receiving the lab report and within 30 days submit a plan for developing a preliminary assessment.

DEQ confirmed via email that depth to groundwater/groundwater elevation and temperature are excluded from this requirement.

In previous discussions with DEQ, the Department has stated that it interprets a ‘significant’ change to be a valid statistical change. DEQ recommended calculation of the Upper Tolerance Limit (UTL) of the data set for each well and if the UTL is exceeded will be considered a significant change. Calculation of the upper tolerance limit is further described in the next section.

Any UTL exceedances will be discussed with DEQ immediately to determine if resampling is required based on the analyte or parameter and the amount of the exceedance. If DEQ believes that the exceedance is a cause for concern, then OMD will coordinate resampling in accordance with the permit as soon as practicable considering existing use of the firing ranges at Camp Rilea and the relevant surface danger zones. Resampling within two weeks is generally acceptable and DEQ will be contacted if this is not feasible. Work during weekends may be necessary to meet this requirement.

4.4.1 Upper Tolerance Limit Calculation

The UTL of a data set can be calculated (except for pH) using the following formula:

𝑈𝑈𝑈𝑈𝑈𝑈 = 𝑥𝑥 + 𝑘𝑘𝑘𝑘

Where x is the mean and S is the standard deviation from the data set. k is a one-sided tolerance factor from Table 4.5.1 below.

Table 4.5.1 Tolerance Factors (k) for One-Sided Normal Tolerance Intervals with Probability level

Confidence Factor Y = 0.95 and Coverage P = 95% n k n k n k 3 7.655 12 2.736 21 2.371 4 5.145 13 2.67 22 2.35 5 4.202 14 2.614 23 2.329 6 3.707 15 2.566 24 2.309 7 3.399 16 2.523 25 2.292 8 3.188 17 2.486 30 2.22 9 3.031 18 2.543 35 2.166 10 2.911 19 2.423 40 2.126 11 2.815 20 2.396 45 2.092

50 2.065 n = number of samples in data set

4.4.2 pH Tolerance Limit Calculation A significant increase of decrease of pH may be in indication of water chemistry that could result in leaching of metals from the subsurface geology. Since a decrease in pH can also have a negative impact on the environment the UTL calculation is slightly different and shown below:

𝑈𝑈𝑈𝑈𝑈𝑈 = 𝑥𝑥 ± 𝑘𝑘𝑘𝑘

Where x is the mean and S is the standard deviation from the data set. k is a one-sided tolerance factor from Table 4.5.1 above. The UTL calculation must be performed twice for the plus and minus in the formula for comparison to the sample result.

5. Reporting Requirements Monthly discharge monitoring reports (DMRs) are required to be submitted to DEQ by the 15th day of the following month.

An annual groundwater monitoring report (one paper copy and one electronic copy) will be submitted to DEQ by February 15th each year. The annual report will contain the analytical results of the groundwater monitoring from the previous year, an analysis of these data, and reporting information identified in Section 3 of this plan. The annual report will also include a concentration versus time graph for nitrate for each monitoring well using all the available data.

Following installation of the new monitoring wells and piezometers a one-time letter report will be submitted to DEQ. The report will include information on well installation including copies of well logs submitted to the OWRD. The report will include results of the initial sampling event for all the monitoring wells in the network.

6. References Oregon Department of Environmental Quality. 2024. WPCF Permit Issuance, Permit No. 101887, File

No. 64802, Camp Rilea, Clatsop County. DEQ, 8 May 2024.

U.S. Environmental Protection Agency. 1996. Low Stress (low flow) Purging and Sampling Procedure for the Collection of Groundwater Samples from Monitoring Wells. Revision 4, 20 SEPT 2017.

Lieberman, Gerald F., 1958. “Tables for One-sided Statistical Tolerance Limits.” Industrial Quality Control. Vol. XIV, No. 10.

Figures

USGS The National Map: National Boundaries Dataset, 3DEP Elevation Program, Geographic Names Information System, National Hydrography Dataset, National Land Cover Database, National Structures Dataset, and National Transportation Dataset; USGS Global Ecosystems; U.S. Census Bureau TIGER/Line data; USFS Road data; Natural Earth Data; U.S.

Department of State HIU; NOAA National Centers for Environmental Information

Figure 1 Camp Rilea- Site Location Map

Oregon Counties No warranty is made by the Oregon Military Department as to the accuracy, reliability, or completeness of these data for individual use or aggregate use with other data. This map is a "living document" in that it is intended to change as new data become available and is incorporated into the Enterprise GIS database.

Projected Coordinate System: WGS 1984 UTM Zone 10N 0 1,000 2,000500

Meters

Map Author:C.Anderson, JFHQ OMD AGI-E Date: 22 August 2024 SME: Chris Richardson

Security:Category 4 - Products for Public Display and Distribution

Legend Rapid Infiltration Basins

Installation Boundary

0 3,900 7,8001,950 Feet

1:50,000

Rapid Infiltration Basins kj kj kj kj

07005 - Recycled Water Treatment Building

Figure 2 Camp Rilea- Wastewater Features

Oregon Counties No warranty is made by the Oregon Military Department as to the accuracy, reliability, or completeness of these data for individual use or aggregate use with other data. This map is a "living document" in that it is intended to change as new data become available and is incorporated into the Enterprise GIS database.

Projected Coordinate System: WGS 1984 UTM Zone 10N 0 200 400100

Meters

Map Author:C.Anderson, JFHQ OMD AGI-E Date: 4 September 2024 SME: Chris Richardson

Security:Category 4 - Products for Public Display and Distribution

. 0 800 1,600400 Feet

1:10,000

Rapid Infiltration Basins

Legend kj Existing Monitoring Well

Sanitary Sewer Lines

Recycled Water Irrigation Lines

Sanitary Sewer Line - Force Main to RIBs

Wastewater Lagoon

Rapid Infiltration Basins

Recycled Water Treatment Building

Installation Boundary kj kj kj kj kj kj kj

RIBMW-5

RIBMW-4

RIBMW-3

RIBMW-2

RIBMW-1

Figure 3 Camp Rilea- Rapid Infiltration Basin Network and Monitoring Well Locations Oregon Counties

No warranty is made by the Oregon Military Department as to the accuracy, reliability, or completeness of these data for individual use or aggregate use with other data. This map is a "living document" in that it is intended to change as new data become available and is incorporated into the Enterprise GIS database.

Projected Coordinate System: WGS 1984 UTM Zone 10N 0 100 20050

Meters

Map Author:C.Anderson, JFHQ OMD AGI-E Date: 4 September 2024 SME: Chris Richardson

Security:Category 4 - Products for Public Display and Distribution

. 0 400 800200 Feet

1:6,000

Legend kj Existing Monitoring Wells kj Proposed Monitoring Wells

Rapid Infiltration Basins

Installation Boundary

General Groundwater Flow Direction

Average Groundwater Flow Direction 2011-2022

RIBMW-7

(Background)

RIBMW-6

(Point of Compliance)

PZ-1

PZ-2

Appendix A - Rapid Infiltration Basin Area Monitoring Well Logs

WELL LABEL # L

START CARD #

Owner Well I.D.

First Name

Address Zip

(1) LAND OWNER

(2) TYPE OF WORK New Deepening Alteration (repair/recondition) Abandonment

Conversion

(3) DRILL METHOD

Rotary Air Rotary Mud Cable Hollow Stem Auger Cable Mud

OtherReverse Rotary

State City

STATE OF OREGON

MONITORING WELL REPORT

(as required by ORS 537.765 & OAR 690-240-0395)

(5) WELL TESTS

Yield gal/min Drawdown Drill stem/Pump depth Duration (hr)

(6) LOCATION OF WELL (legal description)

Tax Lot Lot

Twp Range E/W WM Sec 1/4 1/4

Lat ° ' " or DMS or DD Long ° ' " or DMS or DD

County N/S of the

(7) STATIC WATER LEVEL

(8) WELL LOG Ground Elevation Material To

CompletedDate Started

(unbonded) Monitor Well Constructor Certification I certify that the work I performed on the construction, deepening, alteration, or abandonment of this well is in compliance with Oregon monitoring well construction standards. Materials used and information reported above are true to the best of my knowledge and belief.

License Number Date

Signed

(bonded) Monitor Well Constructor Certification

Tax Map Number

I accept responsibility for the construction, deepening, alteration, or abandonment work performed on this well during the construction dates reported above. All work performed during this time is in compliance with Oregon monitoring well construction standards. This report is true to the best of my knowledge and belief.

License Number Date

Signed

From

Company Last Name

Electronically Submitted

Temperature °F Lab analysis

Water quality concerns?

Yes

From Yes (describe below)

To Description

By

Amount Units

Supervising Geologist/Engineer

ORIGINAL - WATER RESOURCES DEPARTMENT

THIS REPORT MUST BE SUBMITTED TO THE WATER RESOURCES DEPARTMENT WITHIN 30 DAYS OF COMPLETION OF WORK

Depth of Completed Well ft. Special Standard

SEAL

CASING

LINER

MONUMENT/VAULT

ToFrom

FILTER

BORE HOLE

SCREEN

(4) CONSTRUCTION

From To Material Size of pack

ToFromDiameter

From To Material Amount Grout weight

Gauge

From To

Wld Thrd

Dia.

Material

Gauge

From To

Wld Thrd

Dia.

Material

Casing/Liner Diameter From To Slot Size

Material

WATER BEARING ZONES

Completed Well Existing Well / Predeepening

Date SWL(psi)

SWL(ft)

SWL Date From To Est Flow SWL(psi)

SWL(ft) Depth water was first found

Piezometer Well

Electronically Submitted

Contact Info (optional)

107251

1014817

P11277-5027

OREGON MILITARY DEPARTMENT

RIBMW-1

P.O. BOX 14350

SALEM OR 973096

SONIC

09-12-2011 09-12-2011

10618 12-01-2011

1522 12-01-2011

53941CLAT

12-01-2011

MICHAEL BRUCE NIERMEYER (E-filed)

CHRISTOPHER BAKER (E-filed)

Above Ground

Flowing Artesian?

09-12-2011 56

6 0 65

3 48 Bentonite Grout

3.00 S 10.5

2 0 50

SCH 40

PlasticSteel

PlasticSteel

Casing 2 50 65 .010

SCH 40 PVC

3 0

SILICA SAND48 65 10/20

650FINE/MEDIUM SAND

Clatsop 7.00 N 10.00 W

4 NW SE 3100

91296 HWY 101, WARRENTON, OR 97146

Street address of well Nearest address

Pump Bailer Air Flowing Artesian

09-12-2011 56 65 56

Dry Hole?

Form Version: 0.95

Map of well

MONITORING WELL REPORT -

Map with location identified must be attached and shall include an approximate scale and north arrow

WELL I.D. # L

START CARD #

107251

1014817

53941CLAT

12-01-2011

START CARD #

Owner Well I.D.

First Name

Address Zip

(1) LAND OWNER

(2) TYPE OF WORK New Deepening Alteration (repair/recondition) Abandonment

Conversion

(3) DRILL METHOD

Rotary Air Rotary Mud Cable Hollow Stem Auger Cable Mud

OtherReverse Rotary

State City

STATE OF OREGON

MONITORING WELL REPORT

(as required by ORS 537.765 & OAR 690-240-0395)

(5) WELL TESTS

Yield gal/min Drawdown Drill stem/Pump depth Duration (hr)

(6) LOCATION OF WELL (legal description)

Tax Lot Lot

Twp Range E/W WM Sec 1/4 1/4

Lat ° ' " or DMS or DD Long ° ' " or DMS or DD

County N/S of the

(7) STATIC WATER LEVEL

(8) WELL LOG Ground Elevation Material To

CompletedDate Started

(unbonded) Monitor Well Constructor Certification I certify that the work I performed on the construction, deepening, alteration, or abandonment of this well is in compliance with Oregon monitoring well construction standards. Materials used and information reported above are true to the best of my knowledge and belief.

License Number Date

Signed

(bonded) Monitor Well Constructor Certification

Tax Map Number

I accept responsibility for the construction, deepening, alteration, or abandonment work performed on this well during the construction dates reported above. All work performed during this time is in compliance with Oregon monitoring well construction standards. This report is true to the best of my knowledge and belief.

License Number Date

Signed

From

Company Last Name

Electronically Submitted

Temperature °F Lab analysis

Water quality concerns?

Yes

From Yes (describe below)

To Description

By

Amount Units

Supervising Geologist/Engineer

ORIGINAL - WATER RESOURCES DEPARTMENT

THIS REPORT MUST BE SUBMITTED TO THE WATER RESOURCES DEPARTMENT WITHIN 30 DAYS OF COMPLETION OF WORK

Depth of Completed Well ft. Special Standard

SEAL

CASING

LINER

MONUMENT/VAULT

ToFrom

FILTER

BORE HOLE

SCREEN

(4) CONSTRUCTION

From To Material Size of pack

ToFromDiameter

From To Material Amount Grout weight

Gauge

From To

Wld Thrd

Dia.

Material

Gauge

From To

Wld Thrd

Dia.

Material

Casing/Liner Diameter From To Slot Size

Material

WATER BEARING ZONES

Completed Well Existing Well / Predeepening

Date SWL(psi)

SWL(ft)

SWL Date From To Est Flow SWL(psi)

SWL(ft) Depth water was first found

Piezometer Well

Electronically Submitted

Contact Info (optional)

107252

1014816

P11277-5027

OREGON MILITARY DEPARTMENT

RIBMW-2

P.O. BOX 14350

SALEM OR 973096

SONIC

09-13-2011 09-13-2011

10618 12-01-2011

1522 12-01-2011

53942CLAT

12-01-2011

MICHAEL BRUCE NIERMEYER (E-filed)

CHRISTOPHER BAKER (E-filed)

Above Ground

Flowing Artesian?

09-13-2011 37

6 0 50

3 33 Bentonite Grout

3.00 S 10.5

2 0 35

SCH 40

PlasticSteel

PlasticSteel

Casing 2 35 50 .010

SCH 40 PVC

3 0

SILICA SAND33 50 10/20

500FINE/MEDIUM SAND

Clatsop 7.00 N 10.00 W

4 NW SE 3100

91296 HWY 101, WARRENTON, OR 97146

Street address of well Nearest address

Pump Bailer Air Flowing Artesian

09-13-2011 37 50 37

MONITORING WELL REPORT -

Map with location identified must be attached and shall include an approximate scale and north arrow

WELL I.D. # L

START CARD #

107252

1014816

53942CLAT

START CARD #

Owner Well I.D.

First Name

Address Zip

(1) LAND OWNER

(2) TYPE OF WORK New Deepening Alteration…