Stamford Well Water - the stats

Compiled from 1977 by the number of tests

BACTERIA in colonies/ 100 mL
		above 30	not potable	1 colony	Okay	% Okay
total coliform	6.38	140	724	113	5671	85.30%
		above 30	E coli present	No E Coli
Escherichia coli	5.85	7	115	477
	tested not present	Present
cp-Crenothrix polyspora, Iron bacteria	0	4
gf-Gallionella ferruginea, Iron bacteria	8	115
sn-Sphaerotilus natans, Iron bacteria	0	23
st-Siderocapsa treubii, Iron bacteria	0	12
tmu-Thiodendron mucosum, Sulfur bacteria	0	1
tto-Thiobacillus thiooxid, Sulfur bacteria	0	3
		158
NUTRIENTS in mg/L
		above 1	0.1 to 1	0.01 to 0.1
nitrite nitrogen	0.02	6	1	276	1995	87.58%
		above 15	10 to 15	5 to 10
nitrate nitrogen	2.32	13	0	251	2776	91.32%

First set is of bacteria and nutrients. Basically over 30 years 15% of the wells have a problem, That really is not bad.
The nutrients show both the influx of fertilizer (almost non-existent) and microbial activity (also not really an issue).