Site data

Includes Name, State, County, Longitude (Deg, Min, Sec), Latitude (Deg, Min, Sec), Township, Range, Section, Qtr section, Date collected, Map datum, and Sample collector. Location data are of variable quality. Sites with locations given to degrees, minutes, and seconds are considered most accurate, sites with locations given to degrees and minutes are less accurate, and sites with locations given only to decimal degrees are approximate.

Basic data

Includes T°C, pH_field, pH_lab, spec_cond_field (mS), spec_cond_lab (mS), dissolved solids (mg/L), discharge (gallons per minute)

Major dissolved constituents

Includes Ca, Mg, Na, K, Li, SiO₂, alkalinity_field, alkalinity_lab, Cl, F, SO₄, cation_total, anion_total, charge balance (in %). Concentrations in mg/L, alkalinity is reported as bicarbonate (HCO₃).

Minor dissolved constituents

Includes B, Br, Fe, H, H₂S _field, H₂S_lab, I, Mn, NH₄ (as N), NO_{3 field}, NO_{3 lab}, NO_{2 field}, NO_{2 lab} , OH, PO₄ (as P), Rb, Sr. Concentrations in mg/L.

Trace elements

Includes Ag, Al_monomeric, Al_total, As, Au, Ba, Be, Cd, Co, Cr, Cs, Cu, Hg, Mo, Ni, Pb, S, Sb, Se, U, Zn. Concentrations in mg/L.

Gas composition (free gas bubbles, gas seeps, fumaroles, and steam wells)

Includes Ar, O₂ + Ar, O₂, N₂, CO₂, CO, CH₄, C₂H₆, H₂S, He, H₂, NH₃, SO₂, Total free gas. Concentrations in volume percent.

Gas composition (dissolved gas) in micromoles gas per kilogram of water

Includes Ar, O₂, N₂, CH₄, CO₂, He, H₂. Concentrations in millimoles gas per kilogram of water.

Water Isotopes

Includes δD, δ¹⁸O, tritium. The isotope compositions of oxygen and hydrogen in a sample are expressed as per mil differences relative to standard mean ocean water (SMOW). Tritium concentrations are reported in tritium units (TU).

Isotopes (dissolved constituents, minerals, and rocks)

δ¹³C_{total dissolved}, δ¹⁸O _sulfate, δ¹³C_{mineral carbonate}, δ¹⁸O_{mineral sulfate}, ¹⁴C, ⁸⁷Sr/⁸⁶Sr, ²⁰⁸Pb/²⁰⁴Pb_diss., ²⁰⁸Pb/²⁰⁴Pb_rock, ²⁰⁷Pb/²⁰⁴Pb_diss., ²⁰⁷Pb/²⁰⁴Pb_rock, ²⁰⁶Pb/²⁰⁴Pb_diss., ²⁰⁶Pb/²⁰⁴Pb_rock. The isotope composition of carbon in the sample is expressed as per mil differences relative to PDB. The isotope composition of oxygen in the samples is reported in per differences relative to SMOW. Strontium and lead values are isotope ratios. The denominator in both the strontium and lead values is a stable isotope that is not produced by decay of any other naturally occurring isotope. 14C values are reported as % modern carbon.

Isotopes (free gas)

Includes δ¹³C of CO₂, δ¹⁸O of CO₂, δ¹⁵N of N₂, δ¹³C of CH₄, ³He/⁴He. Nitrogen isotope compositions are reported in per mil notation relative to the ¹⁵N/¹⁴N value of air. ³He/⁴He values are reported as R/Ra.