Nitrate concentrations (mg/L) at a well used for drinking water.
EPA.09.Ex.21.6.nitrate.dfA data frame with 12 observations on the following 5 variables.
Sampling.Datea character vector indicating the sampling date
Datea Date object indicating the sampling date
Nitrate.mg.per.l.origa character vector of original nitrate concentrations (mg/L)
Nitrate.mg.per.la numeric vector of nitrate concentrations (mg/L) with nondetects set to their detection limit
Censoreda logical vector indicating which observations are censored