Copper concentrations (ppb) at two background and one compliance wells (six monthly samples for each well).
EPA.92c.copper1.df
A data frame with 18 observations on the following 4 variables.
Copper
a numeric vector of copper concentrations (ppb)
Month
a factor indicating the month of collection
Well
a factor indicating the well number
Well.type
a factor indicating the well type (background vs. compliance)