Table 1.

Summary Statistics of Groundwater Arsenic from the greater Augusta, Maine area in 2006

			As in simplified bedrock unit
	As	Ln(As)	Ss	Sw	SOv	D	OZc
number of observations (n)	790	790	163	259	249	87	32
mean (μg/L)	12.2	0.9	16.3	14.4	10	7.7	3
standard deviation (μg/L)	25.9	2.2	27.5	22.7	31.1	15.6	8.6
median (μg/L)	3.8	1.3	6.8	6.1	2.0	2.5	0.2
Maximum (μg/L)	325	5.8	200	199	325	95	41
skewness	6.4	-0.5
observed probability of >10μg/L	31%		42%	39%	24%	15%	9%
kriged probability of >10μg/L			40(±3)%	38(±2)%	25(±2)%	21(±4)%	7(±3)%

^a Values in the parenthesis indicate 95% confidence interval.

^b The well depth analysis shows no significant difference in the 5 bedrock units (see Supporting Information Table S2)