Figure 10	
"Trends in the Occurrence of MTBE in Drinking Water Derived from Ground Water in 6 Northeast States, 1993-2006"	

Title:	Detection frequency of MTBE in drinking water derived from ground water for all public water systems in six Northeast States by year from 1993-2006.
	
	
Description:	This is a graph of detection frequency of MTBE for systems in all States by year.
	
	
Origin of data:	The data were obtained from the full data set on MTBE in drinking water:  frozen_data_set_for_both_original_and_new_reports.rdb
	
	
Manipulation of data set:	"Initially, data was made unique by PWSID and SampleYear retaining any quantified concentrations of MTBE.  Then, detection frequencies were computed for all systems in all States by year.  No assessment level was used."
	
	
	
Other:	
