Copper concentrations (ppb) at three background and two compliance wells (eight monthly measures at the background wells, four monthly measures at the compliance wells).
EPA.09.Ex.17.4.copper.df
A data frame with 40 observations on the following 6 variables.
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)
Copper.ppb.orig
a character vector of original copper concentrations (ppb)
Copper.ppb
a numeric vector of copper concentrations with nondetects set to their detection limit
Censored
a logical vector indicating which observations are censored