Shaver’s Creek Watershed Raw Chemistry Data (2017 – 2021)

The below data is used to analyze dual nitrogen isotopes to document nitrate transport and reduction in hilly agricultural terrain. Data is from both surface water and groundwater.

* Analytes in “SCW Raw Chem” and “Cole Farm Raw Chem” tables:

** All samples were collected in 250 mL polyethylene bottles. Filtrates (0.45 µm) were split and i) acidified with 10% nitric acid immediately after filtration for cation analysis within one week, or ii) analyzed without acidification for anions within two days. Samples were analyzed for NO3-, SO42-, F-, Cl-, and Br- (Thermo Scientific Dionex ICS-2100 Ion Chromatograph (IC)), as well as Al, Ba, Ca, Fe, K, Mg, Mn, Na, P, Si, Sr, and Ti (Thermo iCAP 7400 inductively coupled plasma atomic emission spectrometry (ICP-AES)) at the Penn State University Laboratory for Isotopes and Metals in the Environment.

* Discharge in “SCW Raw Chem” table:
** ‘Q (m3/s)’ discharge values were measured using SonTek FlowTrackers
** ‘Qr (m3/s)’ discharge values are estimates calculated using regressions of measured discharge data as a function of drainage area

* Temp C, Press (mmHg), DO (%), DO (mg/L), SPC, C, pH, pH (mV), and ORP (mV) data in “Cole Farm Raw Chem” table were collected using a YSI Professional Plus Multiparameter Instrument.

* Nitrate and isotope data in “Raw Iso Data” spreadsheet:
** Samples were collected in 60 mL polyethylene bottles and frozen within six hours of collection for isotope analysis. Frozen samples were sent for d15N-NO3- and d18O-NO3- analysis using an Elemental IsoPrime Isotope Ration Mass Spectrometer (IRMS) in line with a Trace Gas at the University of Pittsburgh Stable Isotope Laboratory. Nitrate isotopes were measured using the denitrifier method (Sigman et al., 2001). Values for d15N and d18O were obtained by analyzing the product N2O on an IRMS. The IAEA-N3 nitrate standard, run with the samples, yielded a standard deviation of 0.2‰.