Brent T. Aulenbach Joshua C. Henley Kristina G. Hopkins 20230404 tabular digital data Reston, VA U.S. Geological Survey https://doi.org/10.5066/P9G8HZTY Brent T. Aulenbach Joshua C. Henley Kristina G. Hopkins 2023 publication USGS Scientific Investigations Report 2023-5035 Reston, Virginia U.S. Geological Survey This dataset contains quality assurance sample concentrations for 19 constituents for the 15 monitored watersheds in Gwinnett County, Georgia, from 2000 to 2020. Samples include 431 replicate pairs and 335 field blanks. Replicate sampling allows for comparison of water quality to assess the combined variability in sample representativeness and laboratory precision and can also be used to identify possible sample contamination. Field blanks, samples of deionized “blank” water collected using the same sampling equipment and similar methodology as routine samples, were used to identify any possible contamination from field collection equipment and methodology. The purpose of this dataset is to document the quality assurance samples collected to assess sample representativeness, laboratory precision, and possible sample contamination. The quality assessment summary from these samples are contained in Appendix 1, “Quality assurance, quality control, and quality assessment summary” of the USGS Scientific Investigations Report "Hydrology, water-quality, and watershed characteristics in 15 watersheds in Gwinnett County, Georgia, 2002-20". This study is part of a long-term program to monitor and analyze the hydrologic and water-quality conditions of 15 watersheds in Gwinnett County, Georgia by the U.S. Geological Survey (USGS) in cooperation with Gwinnett County Department of Water Resources. 20000110 20200124 publication date Complete None planned -84.2721 -83.8468 34.1514 33.7676 ISO 19115 Topic Category inlandWaters USGS Thesaurus surface water quality water quality Other water quality assurance USGS Metadata Identifier USGS:63503ed9d34e47431c15c5ae Geographic Names Information System Gwinnett County State of Georgia None. Please see 'Distribution Info' for details. None. Users are advised to read the dataset's metadata thoroughly to understand appropriate use and data limitations. Brent T Aulenbach U.S. Geological Survey, Southeast Region Research Hydrologist mailing address

1770 Corporate Drive Suite 500

Norcross GA 30093 US 678-924-6626 678-924-6710 btaulenb@usgs.gov Funded through a cooperative agreement between Gwinnett County Department of Water Resources and the U.S. Geological Survey MacOS Big Sur, version 11.7.1; Microsoft Excel for Mac, version 16.67, 09_GwinnettCoGa_QualityAssuranceSamples.csv 687 KB The replicate and blank quality assurance data reported herein can be used to assess sample representativeness, laboratory precision, and possible sample contamination. The precision in sample concentrations can be assessed from the median absolute relative percent differences (RPDs) in concentrations between replicate sample pairs. Possible contamination in field collection methods can be assessed from the occurrence of, average, and mean detectable contaminant concentrations in blank samples. A summary of the quality assurance is provided in “Appendix 1. Quality assurance, quality control, and quality assessment summary” in Aulenbach and others (2023). Aulenbach, B.T., Henley, J.C., and Hopkins, K.G., 2023, Hydrology, water-quality, and watershed characteristics in 15 watersheds in Gwinnett County, Georgia, water years 2002-20: U.S. Geological Survey Scientific Investigations Report 2023-5035. No formal logical accuracy tests were conducted. Dataset 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. U.S. Geological Survey 20220405 application/service https://doi.org/10.5066/F7P55KJN Digital and/or Hardcopy 20000110 20200124 publication date NWIS Streamwater quality assurance data for 15 watersheds in Gwinnett County, Georgia. Replicate samples were periodically collected by collecting an extra sample at the location and nearly the same time as the routine sample. Sample pairs using the same sampling method were typically split replicates where samples were collected from the same carboy and were used to assess possible contamination during sample processing and laboratory precision. Sample pairs from mixed sampling approaches were collected sequentially and were used to assess representativeness of the sampling approaches. Blank samples were collected by running deionized “blank” water through manual samplers or by collecting a sample from the ISCO automatic sampler with the intake placed in blank water. Replicate and blank samples were handled and analyzed using the same sample and laboratory analytical procedures as the routine environmental samples. Sample data for 19 constituents from the 15 study watersheds was exported from the local U.S. Geological Survey (USGS) South Atlantic Water Science Center qwdata database number 06, where quality-assurance sample data are stored, using the USGS National Water Information System (NWIS) qwflatout routine. Samples were exported for the period January 2000 through January 2020. Water-quality assurance sample data was exported from the qwdata database on April 5, 2022. Nineteen water-quality constituents were assessed: sonde specific conductance (Sonde_SC), biochemical oxygen demand (BOD), chemical oxygen demand (COD), laboratory pH (Lab_pH; replicates only), laboratory turbidity (Lab_Turb), total suspended solids (TSS), suspended sediment concentration (SSC), total nitrate plus nitrite (NO3NO2), total ammonia plus organic nitrogen (TKN), dissolved ammonia (NH3), total phosphorus (TP), dissolved phosphorus (DP), total organic carbon (TOC), total calcium (Ca), total magnesium (Mg), total copper (TCu), total lead (TPb), total zinc (TZn), and total dissolved solids (TDS). NWIS 20220405 09_GwinnettCoGa_QualityAssuranceSamples.csv Comma Separated Value (CSV) file containing quality assurance sample concentrations for 19 constituents Producer Defined QA_Type Quality assurance type - replicate or blank Producer Defined replicate Replicate sample Producer defined blank Deionized water blank Producer defined Samp_Type Sample type - grab, integrated, composite, or field blank Producer Defined Grab Manually collected discrete sample (grab or point sample) Producer defined EWI Depth-integrated, equal-width-increment (EWI; stream velocities >1.5 ft per second} or multiple vertical (stream velocities ≤1.5 ft per second). Producer defined Comp Composite sample Producer defined Field blank Field blank Producer defined Site_nu U.S. Geological Survey site number Producer Defined "02205000" Wildcat Creek near Lawrenceville, Ga. Producer defined "02205865" Sweetwater Creek at Club Drive near Lilburn, Ga. Producer defined "02206500" Yellow River near Snellville, Ga. Producer defined "02207120" Yellow River at Ga 124, near Lithonia, Ga. Producer defined "02207185" No Business Creek at Lee Road, below Snellville, Ga. Producer defined "02207385" Big Haynes Creek at Lenora Road, near Snellville, Ga. Producer defined "02207400" Brushy Fork Creek at Beaver Road, nr Loganville, Ga. Producer defined "02208150" Alcovy River at New Hope Road, near Grayson, Ga. Producer defined "02217274" Wheeler Creek at Bill Cheek Road, near Auburn, Ga. Producer defined "02218565" Apalachee River at Fence Road, near Dacula, Ga. Producer defined "02334480" Richland Creek at Suwanee Dam Road, near Buford, Ga. Producer defined "02334578" Level Creek at Suwanee Dam Road, near Suwanee, Ga. Producer defined "02334885" Suwanee Creek at Suwanee, Ga. Producer defined "02335350" Crooked Creek near Norcross, Ga. Producer defined "02336030" North Fork Peachtree Creek at Graves Rd, near Doraville, Ga. Producer defined Watershed Watershed names used in the associated U.S. Geological Survey Scientific Investigations Report. Watershed drainage area defined by site specified in value definition shown in parentheses Producer Defined Wildcat Creek Wildcat Creek near Lawrenceville, Ga. (USGS site number 02205000) Producer defined Sweetwater Creek Sweetwater Creek at Club Drive near Lilburn, Ga. (USGS site number 02205865) Producer defined Yellow River near Snellville Yellow River near Snellville, Ga. (USGS site number 02206500) Producer defined Yellow River near Lithonia Yellow River at Ga 124, near Lithonia, Ga. (USGS site number 02207120) Producer defined No Business Creek No Business Creek at Lee Road, below Snellville, Ga. (USGS site number 02207185) Producer defined Big Haynes Creek Big Haynes Creek at Lenora Road, near Snellville, Ga. (USGS site number 02207385) Producer defined Brushy Fork Creek Brushy Fork Creek at Beaver Road, nr Loganville, Ga. (USGS site number 02207400) Producer defined Alcovy River Alcovy River at New Hope Road, near Grayson, Ga. (USGS site number 02208150) Producer defined Wheeler Creek Wheeler Creek at Bill Cheek Road, near Auburn, Ga. (USGS site number 02217274) Producer defined Apalachee River Apalachee River at Fence Road, near Dacula, Ga. (USGS site number 02218565) Producer defined Richland Creek Richland Creek at Suwanee Dam Road, near Buford, Ga. (USGS site number 02334480) Producer defined Level Creek Level Creek at Suwanee Dam Road, near Suwanee, Ga. (USGS site number 02334578) Producer defined Suwanee Creek Suwanee Creek at Suwanee, Ga. (USGS site number 02334885) Producer defined Crooked Creek Crooked Creek near Norcross, Ga. (USGS site number 02335350) Producer defined North Fork Peachtree Creek North Fork Peachtree Creek at Graves Rd, near Doraville, Ga. (USGS site number 02336030) Producer defined Strt_SDate Sample collection start date - this is the collection date of discrete samples and the start date of composite samples Producer Defined 1/10/2000 14:15 1/24/2020 14:25 m/d/yyyy h:mm End_SDate Sample collection end date and time Producer Defined NA Not applicable. No end date for discrete samples Producer defined 1/10/2000 14:24 10/20/2019 10:01 m/d/yyyy h:mm Constit Chemical constituent abbreviated name Producer Defined Sonde_SC Sonde specific conductance (USGS parameter code 00095) Producer defined BOD Biochemical oxygen demand (USGS parameter code 00310) Producer defined COD Chemical oxygen demand (USGS parameter code 00340) Producer defined Lab_pH Laboratory pH (USGS parameter code 00403) Producer defined Lab_Turb Laboratory turbidity (USGS parameter code 63675) Producer defined TSS Total suspended solids (USGS parameter code 00530) Producer defined SSC Suspended sediment concentration (USGS parameter code 80154) Producer defined NO3NO2 Total nitrate plus nitrite (USGS parameter code 00630) Producer defined TKN Total ammonia plus organic nitrogen (USGS parameter code 00625) Producer defined NH3 Dissolved ammonia (USGS parameter code 00608) Producer defined TP Total phosphorus (USGS parameter code 00665) Producer defined DP Dissolved phosphorus (USGS parameter code 00666) Producer defined TOC Total organic carbon (USGS parameter code 00680) Producer defined Ca Total calcium (USGS parameter code 00916) Producer defined Mg Total magnesium (USGS parameter code 00927) Producer defined TCu Total copper (USGS parameter code 01042) Producer defined TPb Total lead (USGS parameter code 01051) Producer defined TZn Total zinc (USGS parameter code 01092) Producer defined TDS Total dissolved solids (USGS parameter code 70300) Producer defined Conc Chemical concentration - E indicates estimated value; < indicates concentration is less that the laboratory reporting limit Producer Defined 0 11200 milligrams per liter except for TCu, TPb, and TZn which are in micrograms per liter This dataset contains quality assurance samples and their constituent concentrations for the 15 monitored watersheds in Gwinnett County, Georgia for January 2000 through January 2020. Samples include 431 replicate pairs including 276 storm-composite pairs collected from automatic samplers, 91 pairs of grab/point samples, 46 integrated samples and 18 pairs with mixed sampling approaches (grab/point and integrated). Sample pairs were collected during storm conditions in 366 cases and during base-flow conditions in 65 cases. A total of 355 field blanks were collected to assess possible contamination during field collection and processing. Blank water was run through manual samplers, and a sample was collected from the ISCO automatic sampler with the intake placed in blank water. Replicate and blank samples were processed, shipped, and analyzed the same way as routine samples. A summary of the analysis of the quality assurance samples is provided in “Appendix 1. Quality assurance, quality control, and quality assessment summary” in Aulenbach and others (2023). Aulenbach, B.T., Henley, J.C., and Hopkins, K.G., 2023, Hydrology, water-quality, and watershed characteristics in 15 watersheds in Gwinnett County, Georgia, water years 2002-20: U.S. Geological Survey Scientific Investigations Report 2023-5035. U.S. Geological Survey GS ScienceBase mailing address

Denver Federal Center, Building 810, Mail Stop 302

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 on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Digital Data https://doi.org/10.5066/P9G8HZTY None 20230404 Brent T Aulenbach U.S. Geological Survey, Southeast Region Research Hydrologist mailing address

1770 Corporate Drive Suite 500

Norcross GA 30093 US 678-924-6626 678-924-6710 btaulenb@usgs.gov FGDC Content Standard for Digital Geospatial Metadata FGDC-STD-001-1998