Copper concentrations (ppb) at three background and two compliance wells
(eight monthly samples for each well; first four missing at compliance wells).
Nondetects reported as <5
.
EPA.92c.copper2.df
A data frame with 40 observations on the following 6 variables.
Copper.orig
a character vector of original copper concentrations (ppb)
Copper
a numeric vector of copper concentrations with <5
coded as 5
Censored
a logical vector indicating which observations are censored
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)