Sulfate concentrations (ppm) at two background wells (five quarterly measures at each well).
EPA.09.Ex.6.3.sulfate.df
A data frame with 10 observations on the following 4 variables.
Month
a numeric vector indicating the month the observations was taken
Year
a numeric vector indicating the year the observation was taken
Well
a factor indicating the well number
Sulfate.ppm
a numeric vector of sulfate concentrations (ppm)