Xylene concentrations (ppb) at three background wells and one compliance well. Eight monthly measures at each complaince well; three monthly measures at the compliance well.

EPA.09.Ex.18.4.xylene.df

Format

A data frame with 32 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)

Xylene.ppb.orig

a character vector of original xylene concentrations (ppb)

Xylene.ppb

a numeric vector of xylene concentrations (ppb) with nondetects set to their detection limit

Censored

a logical vector indicating which observations are censored

Source

USEPA. (2009). Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities, Unified Guidance. EPA 530/R-09-007, March 2009. Office of Resource Conservation and Recovery Program Implementation and Information Division. U.S. Environmental Protection Agency, Washington, D.C. p.18-22.

USEPA. (2010). Errata Sheet - March 2009 Unified Guidance. EPA 530/R-09-007a, August 9, 2010. Office of Resource Conservation and Recovery, Program Information and Implementation Division. U.S. Environmental Protection Agency, Washington, D.C.