Arsenic concentrations (ppb) at three background wells and one compliance well
(six monthly samples for each well; first four missing at compliance well). Nondetects
A data frame with 24 observations on the following 6 variables.
a character vector of original arsenic concentrations (ppb)
a numeric vector of arsenic concentrations with
<5 coded as
a logical vector indicating which observations are censored
a factor indicating the month of collection
a factor indicating the well number
a factor indicating the well type (background vs. compliance)
USEPA. (1992c). Statistical Analysis of Ground-Water Monitoring Data at RCRA Facilities: Addendum to Interim Final Guidance. Office of Solid Waste, U.S. Environmental Protection Agency, Washington, D.C. p.60.