2023 QA/QC

Published

October 23, 2024

Introduction

Prior to publishing analysis and interpretation of water quality data, we will ensure that all data that meets QA/QC standards outlined in the current project Quality Assurance Project Plan (QAPP) and is accessible in the appropriate public repository.

Water quality data from this project is ultimately destined for public archival in the Environmental Protection Agency’s Water Quality Exchange (EPA WQX).

The QAPP for this project describes data management details and responsible parties for each step of the data pipeline from observation to repository. The 2023 data preparation and review process is published here.

Year 2023 Water Quality Data

In this chapter we will collate 2023 laboratory data from several sources into a single spreadsheet document with a consistent format. The desired end format is a spreadsheet template provided by the EPA Water Quality Exchange. These template files are available to download from the EPA at https://www.epa.gov/waterdata/water-quality-exchange-web-template-files.

Once the data is collated, it will be evaluated according to a Quality Assurance Checklist (template example provided by the Alaska Department of Environmental Conservation Soldotna office). Field observations that do not meet the quality assurance standards described in the evaluation checklist will be flagged as “Rejected” before being uploaded to the EPA WQX.

Data that has been uploaded to the EPA WQX is evaluated biannually by the Alaska Department of Environmental Conservation (ADEC) in their Integrated Water Quality Monitoring and Assessment Report1. The integrated report evaluates available water quality data from the previous five years against Alaska water quality standards and regulations (adec2020?).

2023 Water Quality Data Formatting

The code scripts in this document assemble water quality data from the two analytical laboratories that partnered with Kenai Watershed Forum for this project in 2023:

  • SGS Laboratories (Anchorage, AK)

  • Soldotna Wastewater Treatment Plant (Soldotna, AK)



2023 Metals/Nutrients Lab Results (SGS Labs)


–> use EPA metals guidance in QA/QC rather than at this stage!


2023 Fecal Coliform Lab Results (Soldotna Wastewater Treatment Plant Lab)

Chain of custody documents available upon request.


2023 Total Suspended Solids Lab Results (Soldotna Wastewater Treatment Plant (SWWTP))

Chain of custody documents available upon request

Year 2023 Data QA/QC Evaluation

Prior to upload to the EPA WQX, all water quality data must be checked against a series of standard questions in order to evaluate how quality assurance / quality check (QA/QC) requirements are met. The draft Data Evaluation Checklist Template (available for download below) outlines these questions:

Pre-database

Overall project success

1.) Were the appropriate analytical methods used for all parameters?

Yes. Analytical methods from the approved 2023 QAPP were employed, with certain exceptions which are not anticipated to affect results (see below).

Yes. Analytical methods from the approved 2023 QAPP were employed, with exceptions (described below) that are not anticipated to affect results (see below).

Changes from the approved 2023 occurred, including:

  • For summer 2023, a laboratory method used to analyze total metals differed slightly from that specified on the QAPP. EPA method 200.8 was used for total metals rather than 200.7. The project manager at SGS Laboratories in Anchorage, AK describes that no differences are anticipated in how results can be interpreted. Both methods are appropriate for total metals in surface waters.


2.) Were there any deviations from the sampling plan?

In 2023 there were several small deviations from the sampling plan due to a late ice-out date and challenging spring field logistics. One site in spring 2023 could not be accessed for sampling due to low water conditions (Kenai River main stem, RM 10.1). As a result there are no samples from this site/date. Additionally, one fecal coliform sample result is missing from site RM 40 (Killey River) on 5/2/2023 due to an on-site loss from bottle spillage.


3.) Were field duplicates, blanks, and/or other field QC samples collected as planned?

Yes, all planned field blanks, trip blanks, and duplicate samples were collected as planned. See the two downloadable tables below for further details on sample types and analysis types for all 2023 samples:


4.) Do the laboratory reports provide results for all sites and parameters?

The laboratory reports from both labs provide results corresponding with the chain of custody documents provided, within the parameters of what is described in questions #1 - #3.


5.) Is a copy of the COC included with the laboratory reports?

Yes. Chain of custody documents from SGS laboratories are included in the results PDFs linked above. Chain of custody documents from the Soldotna Wastewater Treatment Plant are linked below:


6.) Do the laboratory reports match the COC and requested methods throughout?

Yes, with the exceptions discussed in question #1.


7.) Are the number of samples on the laboratory reports the same as on the COC?

Yes, no loss of samples occurred in the process of generating laboratory results.


8.) Was all supporting info provided in the laboratory report, such as reporting limits for all analyses and definitions?

SGS laboratory reports include reporting limits in both the electronic data deliverables as well as the PDF reports. Results from the Soldotna Wastewater Treatment Plant do not contain reporting limits. Reporting limits and other QA/QC data considerations are provided in the 2023 QAPP.


9.) Are site names, dates, and times correct and as expected?

Numerous corrections to site names and dates were necessary to prepare data into final form. Original documents (Electronic Data Deliverables) were not modified, and corrections are applied throughout the data read-in process using R coding script embedded in this document.


10.) Were there any issues with instrument calibration?

No issues are documented with calibration for KWF’s field or laboratory instruments. No calibration issues are described in the “Case Narrative” sections of the spring and summer SGS PDF laboratory reports.


11.) Did the instrument perform as expected?

TBD with KWF lab results. (Check ranges to decide if including conductivity & turbidity results)


12.) Was instrument calibration performed according to the QAPP and instrument recommendations?

Yes.


13.) Was instrument verification during the field season performed according to the QAPP and instrument recommendations?

For water temperature probes, instrument verification rather than calibration is performed. An ice-bath test was performed on all water temperature probes according to methods described in (Mauger et al. 2015) prior to field use, and all probes recorded values within 0.25 degrees Celsius of a NIST certified thermometer.


14.) Were instrument calibration verification logs or records kept?

Yes. Calibration and verification records are kept at Kenai Watershed Forum’s office at 44129 Sterling Hwy, Soldotna, AK and are available upon request.


15.) Do the instrument data files site IDs, time stamps and file names match?

Instrument data files from fieldwork are not generated as part of this project.


16.) Is any in-situ field data rejected and why?

No, no in-situ field data is rejected. Water temperature was the sole parameter measured in-situ in 2023. Other applicable intrinsic water quality parameters were measured in the KWF Office (pH, conductivity, turbidity).


17.) Were preservation, hold time, and temperature requirements met?

Joining with `by = join_by(result_analytical_method_id)`

We calculated time from sample field collection to lab receipt as documented in 2023 lab reports. All 2023 samples were within holding times specified in the QAPP.

In the field, all samples were stored in coolers with ice packs at 4 degrees C until arrival at the laboratory. In the results from SGS laboratories, two individual observations include the asterisk “*” in the “result_qualifier” column. This indicates that “the sample was warm when received.” These observations correspond not to sample handling in the field and delivery to the laboratories, but rather to internal laboratory procedures used for method blank measurements. The laboratory case narrative does not indicate that any individual sample results would be affected.

Hold time result calculations are available in the downloadable table below in the right-most columns.


18.) Are dissolved metal quantities less than total metals quantities?

Dissolved metals observations are not consistently lower that total metals observations in 2023 data. For 2023 results, a total of 52 instances exist where dissolved metals observations are paired with total metals observations. These consist exclusively of copper and zinc observations. Of the the 52 paired observations, in 32 instances dissolved metals values are greater than total metals values.

These results will have important implications for data-flagging decisions as final results are prepared for upload to the EPA Water Quality Exchange.


19.) Are the duplicate sample(s) RPD within range described in QAPP?

In 2023, field duplicate samples were collected at two sites on both 5/2/2023 and 7/18/2023:

  • 5/2/2023

    • Kenai City Docks (RM 1.5) (ID #10000002)

    • Moose River (RM 36.0) (ID #10000026)

  • 7/18/2023

    • No Name Creek (RM 00.0) (ID #10000008)

    • Moose River (RM 36.0) (ID #10000026)

Only results that are meaningfully representative of the physical sample may be used for RPD calculations. Following the example in the Alaska Department of Environmental Conservation 2021 Kenai River Metals Field Report (Apsens and Petitt 2022): “… a set of paired samples was evaluated for RPD only if:

  • a.) one or both of the samples were above the Limit of Quantitation (LOQ); AND if

  • b.) one or both of the samples were at least two times the LOQ.”

A csv file of Relative Percent Difference values organized by site, date, and parameter may be downloaded below:

Nomenclature note: “Limit of Quantitation (LOQ)”, as used by ADEC and SGS, is equivalent to another term used by EPA CDX, “Lower Quantitation Limit,” which is used in this assessment. A memo from SGS detailing nomenclature and interpretation of reporting limits can be downloaded at the link below:

Discussion on 2023 Relative Percent Difference (RPD) Values In 2023, we had a total of 23 pairs (out of 44 total pairs) of instances where parameter observations met the Limit of Quantitation (LOQ) criteria described above. In all other cases, the paired observations did not meet criteria for inclusion in RPD analyses.

Among the 23 value pairs included in RPD analyses, RPD values ranged from 0% to 45.6%. A total of five eligible value pairs exceeded 20% RPD, all of which were from the spring sampling event (5/2/2023). Each of the parameters that constitute the five RPD exceedences have another paired observation where RPD does not exceed 20%. This suggests that the variability among replicate samples is not systematic, and is likely associated with individual crew sampling techniques. Thus, at this stage we will not exclude any specific results based on RPD analyses.


20.) Were there any laboratory discrepancies, errors, data qualifiers, or QC failures (review laboratory duplicates, matrix spikes and blanks)?

Yes, there were. They are listed below:

Laboratory discrepancies, errors

  • Sample collection date

    • The SGS PDF report shows some samples as collected on 5/3/2022. All spring field samples were in fact collected on 5/2/2023, and none on 5/3/2023. An error of pre-printed dates on page 1 of the SGS chain of custody was responsible for this error. We applied the time/date correction as part of the data read-in script integrated into this document.
  • Sample receipt time/date to SGS laboratories

    • The SGS Electronic Data Deliverable (EDD; spreadsheet) of results shows 5/9/2023 as the receival date for all spring project samples (sample_type = “PS”), and time of day is not specified. However, the PDF report for these same results indicates all samples were in fact received on 5/04/23 08:51, which is consistent with the chain of custody docs. We applied the time/date correction as part of the intake script.
  • Field site names

    • Both of the laboratory’s results contained miscellaneous spellings and formats of site names that were inconsistent with of the needs of preparing data for the EPA CDX. These were corrected in the intake script by use of matching tables csv files, which can be viewed in the project GitHub repository under the directory”other/input/2023/misc”.

Data qualifiers, QC failures (review laboratory duplicates, matrix spikes and blanks)

  • Data qualifiers

    • Two instances of internal laboratory QC checks report, “sample was warm when received,” for one matrix spike duplicate (copper) and one method blank (zinc). While these data qualifiers do not affect the result of any individual field observations, it may be important to note this qualifier in the context of interpreting laboratory data for copper and zinc.
  • QC failures

    • No lab QC failures are reported from Soldotna Wastewater Treatment Plant for fecal coliform or total suspended solids

    • Lab QC failures are listed on Listed on page 2 of the spring and summer SGS PDF reports

      • Spring 2023

        • Zinc: Two dissolved zinc method blanks (200.8) (MB) are above the Limit of Quantitation of 10.0 ug/L. One method blank (MB) is at 11.3 ug/L, the other at 15.9 ug/L. As a result, dissolved zinc results from spring 2023 may need to be flagged for QC failure. PLAN: review 2021 ADEC report.

        • Total Nitrate/Nitrite: One matrix spike duplicate sample for total nitrate/nitrite is outside of QC criteria. The range of permissible recovery values includes the range from 90% - 110%, and the value is listed at 89%. This QC failure does not suggest a mechanism by which sample values are not still broadly representative of environmental conditions, and will not result in spring 2023 total nitrate/nitrate values being flagged for QC failure.

      • Summer 2023

        • One matrix spike sample for total nitrate/nitrite is outside of QC criteria. The range of permissible recovery values includes the range from 90% - 110%, and the value is listed at 112%. This QC failure does not suggest a mechanism by which sample values are not still broadly representative of environmental conditions, and will not result in spring 2023 total nitrate/nitrate values being flagged for QC failure.


21.) Is any laboratory data rejected (flagged) and why?

Based on the above discussion, as of 6/5/2024 we will be flagging 2023 dissolved copper and zinc results as not representative of in-situ environmental conditions. The primary QA/QC not of concern for these two parameters is that a) dissolved metals values were frequently greater than total metals values, which is not physically realistic. Detections of dissolved zinc in the pring 2023 method blanks also indicate that some dissolved zinc samples may not be representative of environmental conditions.

With this decision, a total of 60 observations are flagged (30 dissolved Cu and 30 dissolved Zn observations).

Diagnosis is in progress of this issue for future sampling events (2024 and beyond) and QAPP updates.


22.) During the field season, review raw data files (EDDs, instrument records) as they are received. Document changes and corrections to methods as needed.

Changes and corrections to EDDs are documented and described throughout this series of questions.


23.) Is the dataset complete and did you receive the expected number of results?

Yes, we received the anticipated number of results.


24.) Was the data collected representative of environmental conditions?

Data that is unlikely to represent environmental conditions is identified and flagged as part of this data QA/QC review process.


25.) Does project meet Completeness Measure A criteria?

From the QAPP, Completeness Measure A: “the primary number of samples collected divided by the usable number of samples submitted to ADEC, with a goal of 85% completeness.” (Note that as of 2023 results are now submitted directly to EPA rather than DEC, per request of DEC).

We calculated Completeness Measure A at the following project scales:

  • As a project whole

60 of 574 total observations are flagged, resulting in an overall Completeness Measure A value of 89.5%, satisfying Completeness Measure A requirements for overall project considerations.


26.) Does project meet Completeness Measure B criteria?

From the QAPP, Completeness Measure B: “the planned number of samples divided by the useable samples (submitted to ADEC) with a goal of 60%.”

(Note: The description for Completeness Measure B appears to be a typo and should instead read as, “… the number of usable samples divided by the number of planned samples …”; it is calculated here as such.)

For these calculations, we will consider “usable” as “unflagged,” and will calculate the value for the project whole:

60 of 616 total planned samples are flagged, resulting in an overal Completeness Measure B value of 90.2%, satisfying Completeness Measure B requirements for overall project considerations. As noted in question #2, one site (RM 10.1) was not visited in spring 2023, and in addition one fecal coliform sample was not collected in spring 2023.


27.) Was the QA Officer consulted for any data concerns?

Kenai Watershed Forum consulted with staff from the Alaska Department of Environmental Conservation and EPA Region 10 Office in order to prepare 2023 field data and confirm field methods and data QA/QC procedures.


Database Prep

28.) Are the correct monitoring locations associated with the project?

We used the leaflet package to generate a map of unique sites from the 2023 dataset:


29.) Are the QAPP and other supporting documents attached?

The 2023 QAPP is available to download at the link below, and will be attached in the upload to EPA CDX:


30.) Is all metadata correct?

TKA


31.) Is the organization ID correct?

Kenai Watershed Forum’s Organization ID in the EPA Water Quality Exchange is “Kenai_WQX.” This value is manually confirmed during the upload process.


32.) Are the time zones consistent and correct (AKDT in summer)?

Yes.


33.) Are all media types included? Media types appropriate to Characteristic?

“Water” is the only media type considered in this project. All “Characteristics” (parameters) are measured from water samples or in-situ water conditions.


34.) Check Sample Collection, Preparation and Preservation Methods, Thermal Preservative, Equipment ID, Activity Media. Is supporting information included and correct?


35.) Are all expected activity types present and are QC samples correctly identified?


36.) Is the Activity media subdivision filled in (if relevant)?

“Activity media subdivision” is solely “Surface water” in the 2023 dataset.


37.) For Water activity media, is the relative depth filled in?

Yes, all samples are listed at an approximate depth of 15 cm.


38.) Is the number of results for each Characteristic correct?

Questions #2 and #3 address this topic in detail. A summary table of the total number of observations for each characteristic is available in the downloadable table below.


39.) Do the range of result values make sense?

Prior to upload to the EPA WQX, the range of results will be evaluated visually and numerically in each characteristic-specific section of the comprehensive report, relative to past results. Likely outliers will be identified and recorded in a dedicated spreadsheet (download below). Each likely outlier will have accompanying notes discussing the choice, and a decisions as to whether a more detailed statistical investigation is warranted.


40.) Are units correct and consistent for each parameter?

  unique.z.result_unit.
1                  ug/l
2                  mg/L
3                     %
4             cfu/100ml


41.) Are detection limits and laboratory qualifiers included for analytical results?

Laboratory qualifiers including “J” (below limit of quantitation; is an estimate), “=”, (observed value), “U” (below detection limit), and “ND” (Not Detected) are included in the column titled “result_qualifier.”

Detection limits and their corresponding units are included in columns titled “result_detection_limit_type_1” and in “result_detection_limit_unit_1” corresponding to Limit of Quanititation, and in columns titled “result_detection_limit_type_2” and “result_detection_limit_unit_2” corresponding to Method Detection Level.


42.) Are results trip blanks and/or field blanks above detection limits, and is any related data flagged as a result?

In summer 2023, trip blanks were included with those field crews tasked with collection water samples for hydrocarbon analyses. Sites visited by these crews include RM 1.5 - Kenai City Dock, RM 6.5 - Cunningham Park, RM 40 - Bing’s Landing, and RM 43 - Upstream of Dow Island.

(any equivalent 2023 concerns?)

On the summer 2021 SGS chain of custody documents, BTEX trip blanks are specified for the above sites. However in the reported results, a single sample named “Trip Blank” is reported. This error resulted from a miscommunication with SGS Laboratories staff.

In this case, all hydrocarbon results in the Trip Blank are reported as below detection limit, suggesting there is not a need to flag summer 2021 hydrocarbon results.

(true for 2023?)


  1. https://dec.alaska.gov/water/water-quality/integrated-report/↩︎