Alyssa M. Thornton, U.S. Geological Survey 20250311 Comma delimited (.csv) Richmond, VA U.S. Geological Survey- ScienceBase https://doi.org/10.5066/P144VS6G Alyssa M. Thornton 2025 publication n/a US Geological Survey https://doi.org/10.3133/ofr20251016 A series of blank samples were analyzed as part of a study to evaluate alternative coatings for USGS water-quality samplers. The open-file report to be published in association with this data is titled "Evaluation of Alternative Coatings for U.S. Geological Survey Water-Quality Samplers" (Thornton, 2025) and includes further details of the study. The five coating options evaluated were Duracoat, Plasti-Dip, Powder Coat, Raptor, and bare metal (no coating). Water-quality samples were processed to determine if any coating leached constituents that are commonly collected using these samplers. Samples were collected and processed in late 2020 at the USGS Virginia and West Virginia Water Science Center in Richmond, VA (USGS VA/WV-WSC), and analyzed for nutrients and trace elements by the USGS National Water-Quality Laboratory in Denver, CO. Analyte concentrations, measured in samples collected for each of the five sampler coating types, are reported in the file "Dataset_blank_sample_data.csv". A description of each parameter is provided in the file "Data Dictionary.csv". The purpose of this data release is to provide the results of the blank sample sets from the alternative sampler coating study. 20201124 20201202 ground condition Complete None planned -77.47526181 -77.47526181 37.63931167 37.63931167 none USGS Water-quality sampler Blank sample Water quality Coating USGS Metadata Identifier USGS:679b864ad34ea8c183773670 none United States Virginia none None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Alyssa M. Thornton USGS Virginia and West Virginia Water Science Center Supervisory Hydrologic Technician mailing and physical

1730 E. Parham Road

Richmond Virginia 23228 USA 804-404-9094 amthornton@usgs.gov No formal attribute accuracy tests were conducted No formal logical accuracy tests were conducted Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details. No formal positional accuracy tests were conducted No formal positional accuracy tests were conducted Blank sample sets were collected in two phases. The first sample set was processed following the initial coating application of the water-quality samplers. The second sample set was processed with worn samplers following the controlled wear test conducted at the USGS VA/WV Water Science Center. Each blank sample set contained five samples: churn equipment blank, wash basin equipment blank, sampler blank 1, sampler blank 2, and sampler blank 3. The presentation and content of the description of the data collection methods has been replicated from Thornton (2025). Equipment Blank Sample Collection A series of equipment blanks was collected and processed to quantify the potential for each coating type to contaminate the environmental sample. Equipment blanks were collected following standard USGS procedures (U.S. Geological Survey, variously dated). Equipment used for each blank included an 8-liter (L) polyethylene churn splitter, 20-L plastic wash basin, coated DH-95 sampler body, and 1-L polytetrafluoroethylene (PTFE) sampler bottle. The wash basins were newly purchased for this study; however, the churn splitters, samplers, and sampler bottles were used stock from Virginia and West Virginia Water Science Center. Inorganic blank water (IBW) was used for all blanks and was obtained from National Field Service Supply. Samples were submitted to the National Water Quality Laboratory (NWQL) to be analyzed for nutrients and trace elements (sample containers and parameters listed in table 1.1). Five blank sample sets were submitted for each of the five sampler coatings. The following process was completed for each sampler: 1. Initial equipment blank with 8-L churn.—An initial equipment blank was processed from the churn using a PTFE sampler bottle. The churn and sampler bottle were triple rinsed with deionized water from the in-house laboratory source, Millipore Integral Deionized Water (DIW) system. The churn and sampler bottle were then rinsed with the IBW following procedures in the NFM (U.S. Geological Survey, variously dated). The remaining volume of IBW was poured into the sampler bottle and then into the funnel assembly of the churn, filling the churn to just less than 4 L of water. Blank water was then processed into the sample containers (refer to appendix 1) following recommended guidance from NFM (U.S. Geological Survey, variously dated) and NWQL. Samples were labeled, bagged, and refrigerated immediately after processing. 2. Equipment blank with 20-L wash basin.—A basin was designated for each sampler to be used during both rounds of blank sample processing. The basin was triple rinsed with DIW from the Millipore Integral DIW system, then rinsed and filled with five 4-L containers of IBW. The sampler bottle was rinsed with water from the basin, then used to pour a native-water rinse into the churn, then used to fill the churn with 4 L of water. The blank samples were then processed from the churn following the steps previously listed for the initial blank. While this sample set was being processed, one additional 4-L container of IBW was poured into the basin to provide enough volume for the remaining three blank sample sets. The selected DH-95 sampler (with the tail removed) was lowered into the wash basin and submerged in blank water. 3. Set of three consecutive equipment blanks from wash basin with sampler body.—The next three blank sample sets were collected and processed from the wash basin with the DH-95 coated (one bare) sampler soaking (fig. 2). For the first blank sample, the sampler had been soaking for 10 minutes. The subsequent blank samples were processed after the sampler soaked for 20 minutes and then at 30 minutes. The 10-minute soaking interval was chosen to provide adequate soaking time for the samplers to yield sufficient leaching or contamination potential. Blank Sample Collection with Worn Samplers The previously described blank sample processing steps were repeated using the worn samplers. This stage of the study was designed to measure any release of chemical constituents from coating material following significant wear of the samplers. Details of the full alternative coating study and interpretation of results can be found in the open-file report. References Cited - U.S. Geological Survey, [variously dated], National field manual for the collection of water-quality data, section A of Handbooks for water-resource investigations: U.S. Geological Survey Techniques of Water-Resources Investigations, book 9, 10 chap. (A0–A8, A10), accessed November 2020 at https://pubs.water.usgs.gov/twri9A. Thornton, Alyssa M., 2025, Evaluation of Alternative Coatings for U.S. Geological Survey Water-Quality Samplers: U.S. Geological Survey Open-File Report TBD. 20250310 One Comma-delimited (.csv) data file with corresponding data dictionary file (.csv). U.S. Geological Survey GS ScienceBase U.S. Geological Survey - ScienceBase mailing and physical

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Denver CO 80225 United States 1-888-275-8747 sciencebase@usgs.gov Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data for other purposes, nor on all computer systems, nor shall the act of distribution constitute any such warranty. 20250417 Alyssa M. Thornton U.S. Geological Survey Supervisory Hydrologic Technician mailing and physical

1730 East Parham Road

Richmond VA 23228 USA 804-404-9094 amthornton@usgs.gov Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998