TABLE 4.

Summary of phase 2 Dunnett's test results for time 0 comparisons (alpha = 0.05)

Site	Method	Spiked	Coolant	Mean no. of E. coli/ 100 ml at time 0	No. of E. coli/100 ml (significant change in density) at indicated time (h) after sample collectiona
					8	24	30	48
Williamstown, Ky.	Colilert	Yes	Wet ice	66	NS	NS	NS	NS
	Colilert	Yes	Utek	66	NS	NS	NS	NS
	mFC/NA-MUG	Yes	Wet ice	57	NS	NS	NS	NS
	mFC/NA-MUG	Yes	Utek	57	NS	NS	NS	NS
Northern, Newport, Ky.	Colilert	No	Wet ice	3,057	NS	NS	NS	NS
	Colilert	No	Utek	3,057	NS	NS	NS	NS
	mFC/NA-MUG	No	Wet ice	2,523	NS	NS	NS	NS
	mFC/NA-MUG	No	Utek	2,523	NS	NS	NS	NS
Bethel, Ohio	Colilert	Yes	Wet ice	102	NS	NS	NS	NS
	Colilert	Yes	Utek	102	NS	NS	NS	NS
	mFC/NA-MUG	Yes	Wet ice	92	NS	NS	NS	69 (D)
	mFC/NA-MUG	Yes	Utek	92	NS	NS	NS	NS
Cincinnati Water Works,	Colilert	Yes	Wet ice	89	NS	NS	NS	NS
Cincinnati, Ohio	Colilert	Yes	Utek	89	NS	NS	NS	NS
	mFC/NA-MUG	Yes	Wet ice	63	NS	NS	NS	NS
	mFC/NA-MUG	Yes	Utek	63	NS	NS	NS	41 (D)
Clermont County, Ohio	Colilert	Yes	Wet ice	78	NS	NS	NS	NS
	Colilert	Yes	Utek	78	NS	NS	NS	NS
	mFC/NA-MUG	Yes	Wet ice	83	NS	NS	INVD	NS
	mFC/NA-MUG	Yes	Utek	83	NS	NS	INVD	55 (D)
Falmouth, Ky.	Colilert	No	Wet ice	9,840	NS	NS	6,087 (D)	4,240 (D)
	Colilert	No	Utek	9,840	6,827 (D)	NS	6,073 (D)	5,700 (D)
	mFC/NA-MUG	No	Wet ice	8,200	NS	5,400 (D)	4,533 (D)	3,600 (D)
	mFC/NA-MUG	No	Utek	8,200	NS	5,200 (D)	NS	4,400 (D)
Williamsburg, Ohio	Colilert	Yes	Wet ice	1,597	2,051 (I)	NS	1,089 (D)	893 (D)
	Colilert	Yes	Utek	1,597	NS	NS	NS	NS
	mFC/NA-MUG	Yes	Wet ice	1,477	NS	1,083 (D)	906 (D)	1,067 (D)
	mFC/NA-MUG	Yes	Utek	1,477	1,117 (D)	1,097 (D)	992 (D)	1,066 (D)

^aD, significant decrease in E. coli density compared to the time 0 results; I, significant increase in E. coli density compared to the time 0 results; NS, no significant difference in E. coli density compared to the time 0 results; INVD, invalid data.