Drinking water is tested for the presence of two groups of bacteria, total coliform bacteria and E.Coli bacteria. Your results are the number of bacteria of each group in 100 millilitres of your water sample. Total coliform bacteria are always present in animal waste and sewage but are also found in soil and vegetation. E.Coli bacteria are only found in intestinal contents of warm-blooded animals. E.Coli bacteria tend to die more rapidly outside the body; consequently their presence in water indicates relatively recent contamination. The presence of total coliform and the absences of E.Coli bacteria may indicate a surface water contamination or a more remote sewage contamination.

Only water that comes from a protected source such as a properly constructed well or a source which has been subjected to some kind of treatment i.e. chlorination, ultraviolet light, is considered suitable for drinking. Cisterns that are connected to the eaves troughs are not considered to be a safe water source unless the water is adequately treated.

Possible Source of Contamination

Well  Construction

If there is a problem or suspected problem with your well construction, contact a licensed well driller for advice.

1. Top not sealed properly and surface water can enter the well. Most prevalent in dug or bored wells but can occur in drilled wells too.
2. Joints of bored or dug wells not sealed to depth of 10 feet (2.5 metres), below surface. This is the major source of contamination in old brick or stone wells.
3. Improper seal on steel casing and top of casing is below ground level and surface water drains into the well.
4. Earth should be mounded around well and graded away from well to prevent surface water accumulation around the well.

Well Location

1. Well located to close to a septic tank, weeping tile bed, stable, manure pile or other source of contamination.
2. Dug or bored wells located to close to a ditch, stream, pond or lake.

Cisterns

1. Cisterns attached to the eaves troughs are not considered safe for drinking unless adequately treated. Only sealed cisterns supplied with water from an approved source are considered safe, without further treatment.
   

Total Coliform  & E.Coli Explanation

Total Coliform 80 >
E.coli 60 >
UNSAFE FOR DRINKING.
This water is contaminated and should not be used for drinking. 

Total Coliform 5 TO 80
E.coli 1 to 60
UNSAFE FOR DRINKING.
Pollution source may be some distance from water source or diluted with large volumes of water.

Total Coliform 5 TO 80
E.coli 0
UNSAFE FOR DRINKING.
Contamination is usually from surface water. Not likely to be of sewage origin, but could be a remote sewage source. 

Total Coliform 1 TO 5
E.coli 0
DOUBTFUL.
Water should be resampled and if conditions remain the same and the supply is properly protected, it can be considered safe. 

Total Coliform 0
E.coli 0
SAFE FOR DRINKING.
Repeat samples may not show exactly the same results because bacteria are not distributed uniformly in water and water contamination can be intermittent particularly in dug or bored wells. Wells should be sampled routinely i.e. once every 3 to 4 months. 

Est. #
UNSAFE FOR DRINKING.
The number of bacteria has been estimated due to interference with the test, and is likely higher than number shown. 

O/G
UNSAFE FOR DRINKING.
Not recommended for drinking. No coliform bacteria could be detected because of “overgrowth” of other bacteria. This condition frequently occurs in new wells, dug wells receiving soil drainage, or wells that have been idle for some time. Collect another sample and identify clearly “REPEAT SAMPLE”. 

If you have any questions regarding your water analysis report, contact the Health Unit.