TABLE 3.

Analysis of assumed t-distributed RS and ES at the Nauholzbach gauge for independence from each other, using the one-sided t-test for two spot checks with different variances (1997 data)

Parameter	RS (n = 16)			ES (n = 7)			t test t (empirical)	df (empirical)	P(α) (one sided)a
	Arithmetic mean	Maximum	SD	Arithmetic mean	Maximum	SD
Turbidity (NTU)	1.30	3.80	0.92	47.38	93.80	37.22	3.275	6.004	0.008b
pH	7.18	7.50	0.19	6.98	7.30	0.25	1.819	10.311	0.049c
Runoff (liters/s)	49.29	190.00	56.25	139.06	317.00	113.84	1.983	7.748	0.044b
Nitrate (mg/liter)	6.84	10.90	2.70	11.43	13.90	2.34	4.128	15.217	0.000b
Nitrite (mg/liter)	0.00	0.02	0.01	0.00	0.00	0.00	1.000	15.000	0.167
Ammonia (mg/liter)	0.00	0.00	0.00	0.00	0.00	0.00
Total phosphorus (mg/liter)	0.01	0.05	0.02	0.09	0.40	0.16	1.325	6.068	0.117
Borate (mg/liter)	0.00	0.04	0.01	0.02	0.04	0.02	1.605	9.049	0.071
CC 20°C (CFU/ml)	673.06	1,730.00	534.50	5,509.86	10,629.00	3,746.37	3.401	6.143	0.007b
CC 37°C (CFU/ml)	100.94	339.00	93.64	439.43	849.00	205.85	4.166	7.477	0.002b
E. coli (CFU/100 ml)	33.81	148.00	36.87	235.71	650.00	190.69	2.779	6.263	0.016b
Coliforms (CFU/100 ml)	3,300.75	15,000.00	4,464.67	17,114.29	42,000.00	11,844.61	2.994	7.009	0.010b
Fecal streptococci (CFU/100 ml)	41.56	400.00	99.27	207.14	620.00	205.48	2.031	7.670	0.041b
C. perfringens (CFU/100 ml)	4.06	31.00	7.75	66.71	155.00	65.95	2.506	6.097	0.023b
Giardia (cysts/100 liters)	0.11	1.10	0.30	0.00	0.00	0.00	1.396	15.000	0.091
Cryptosporidium (oocysts/100 liters)	7.18	52.20	13.18	15.30	35.50	11.85	1.461	14.709	0.083

^aValues were considered significantly different if the P(α) value was <0.05.

^bThe ES values were significantly greater than the RS values.

^cThe ES values were significantly less than the RS values.