9 CFR § 3.106 - Water quality.
(a) General. The primary enclosure shall not contain water which would be detrimental to the health of the marine mammal contained therein.
(b) Bacterial standards.
(1) The coliform bacteria count of the primary enclosure pool shall not exceed 1,000 MPN (most probable number) per 100 ml. of water. Should a coliform bacterial count exceed 1,000 MPN, two subsequent samples may be taken at 48-hour intervals and averaged with the first sample. If such average count does not fall below 1,000 MPN, then the water in the pool shall be deemed unsatisfactory, and the condition must be corrected immediately.
(2) When the water is chemically treated, the chemicals shall be added so as not to cause harm or discomfort to the marine mammals.
(3) Water samples shall be taken and tested at least weekly for coliform count and at least daily for pH and any chemical additives (e.g. chlorine and copper) that are added to the water to maintain water quality standards. Facilities using natural seawater shall be exempt from pH and chemical testing unless chemicals are added to maintain water quality. However, they are required to test for coliforms. Records must be kept documenting the time when all such samples were taken and the results of the sampling. Records of all such test results shall be maintained by management for a 1-year period and must be made available for inspection purposes on request.
(c) Salinity. Primary enclosure pools of water shall be salinized for marine cetaceans as well as for those other marine mammals which require salinized water for their good health and well-being. The salinity of the water in such pools shall be maintained within a range of 15-36 parts per thousand.
(d) Filtration and water flow. Water quality must be maintained by filtration, chemical treatment, or other means so as to comply with the water quality standards specified in this section.