(9) Wrap the completed form around the sample bottle and secure it in
place with a string or rubber band. Deliver the sample to the laboratory as soon as
possible. The following guidelines are recommended:
(a) Process the sample within one hour after collection, whenever
possible. If this is not possible, refrigerate samples by means of ice coolers.
(b) Process refrigerated samples, normally, within 6 hours after
collection. It should be noted that various state regulatory agencies might allow a
modification to the above time guideline.
(c) Contact the appropriate state agency having regulatory power
and/or installation medical authority (generally the Preventive Medicine Activity) for
additional instructions when it is impossible to achieve the above-recommended time.
c. Sampling Swimming Pools and Natural Waters. The environmental health
specialist will be required to collect water samples periodically from swimming pools,
natural bathing areas, and natural raw water sources (lakes, ponds, and streams).
(1) Sample bottles, completion of DD Form 686, and forwarding of samples
are as described in a and b, above.
(2) Samples from swimming pools should be from both the deep and
shallow ends. In natural waters, samples usually should be collected about 25 feet from
shore in water at least 2 1/2 feet deep and representative of the bathing water.
Samples should be collected from wading pools and be representative of the wading
water. Collect samples in accordance with (IAW) Chapter 7, TB MED 575.
(3) When samples are being collected, the bottle top should be removed
and held so as to prevent contamination of the top or mouth of the bottle. The bottle is
then plunged, mouth down, at least 6 inches below the surface of the water and filled by
moving it forward through the water so that no water that has come in contact with the
hand or outside of the bottle enters it. Do not rinse the bottle. In a stream, the bottle is
moved against the current.
(4) Samples from raw water sources are collected in the same manner as
those from natural bathing areas. The sampling point should be near the intake into the
water supply system so that the sample is representative of the raw water entering the
Prior to the development of the membrane-filter technique, the multiple-tube
fermentation (MTF) technique was the standard method for determining the presence of
coliform bacteria in water samples. Today it is used primarily as an alternate or back up