(b) Reason: Before the standards are violated, up to 15 percent of the
samples can show 1.0 coliform organisms per 50 ml. In this situation, 15 percent would
be 3 samples (20 X .15 = 3). Three samples could have shown 1.0 per 50 ml. As only
2 samples had this count, the pool water is within the acceptable limits.
c. Reasons for Bacterial Limit Violations.
Pool area and equipment.
(a) Structure of pool. The lack of a smooth inner pool surface
contributes to the accumulation of foreign matter and microorganism growth.
(b) Disinfection. Inadequate disinfection devices, poor pool algae
control, and entrance into the pool of foreign matter such as leaves and other organic
matter will soon result in poor bacteriological reports.
(c) Water treatment equipment. Filtration equipment of inadequate
design or size is a prime cause of poor water condition.
(2) Swimmer control. Failure to adequately clean showers for swimmers
can result in poor bacteriological reports.
(3) Makeup water. Poor quality makeup water added to the pool will
obviously result in the contamination of otherwise satisfactory water.
(4) Sampling procedures. Deviation from recommended sampling
procedures could yield false results.
1-20. pH TESTING
a. Test Materials. Testing for pH is based on the ability of an indicator solution
to change color in varying hydrogen ion concentrations. Adding a small amount of the
indicator to a sample of pool water and then comparing the resulting watercolor with
color standards allows you to quickly determine pH. Your determination should be
accurate to within 0.5 pH units of the actual pH.
b. Testing Technique. You use this technique with the Army's standard test kit
Rinse the tubes with the water to be tested.
Fill the tubes to the etched mark with the water to be tested.