Table 3

Comparison of nitrate and sulfate levels between groups (µg/L).

Groups	N	Mean	Std. Dev.	95% Confidence Interval for Mean		Min.	Max.	P-values
Groups	N	Mean	Std. Dev.	Lower Bound	Upper Bound	Min.	Max.	P-values
F
Well water	2	.16465	.006576	0.10557	0.22373	.160	.169	.070
Network water	2	.14360	.005091	0.09786	0.18934	.140	.147
Total	4	.15413	.013067	0.13333	0.17492	.140	.169
Cl
Well water	2	46.17500	.247487	43.95141	48.39859	46.000	46.350	.028
Network water	2	47.19185	.002616	47.16834	47.21536	47.190	47.194
Total	4	46.68343	.604219	45.72198	47.64487	46.000	47.194
Nitrate
Well water	2	7.03330	.004667	6.99137	7.07523	7.030	7.037	.001
Network water	2	6.60365	.005162	6.55727	6.65003	6.600	6.607
Total	4	6.81848	.248091	6.42371	7.21324	6.600	7.037
Sulfate
Well water	2	84.48475	.006718	84.42440	84.54510	84.480	84.490	.001
Network water	2	82.55360	.005091	82.50786	82.59934	82.550	82.557
Total	4	83.51917	1.114961	81.74502	85.29333	82.550	84.490
Phosphate
Well water	2	.00415	.000212	0.00224	0.00606	.004	.004	.028
Network water	2	.00310	.000141	0.00183	0.00437	.003	.003
Total	4	0.00363	0.000624	0.00263	0.00462	0.003	0.004