67. Each sampling station must have an automatic sampling device designed to perform one of the following sampling procedures:
(1) the taking of at least 6 equal and representative samples each hour containing at least 50 ml each, at a fixed frequency; or
(2) the taking of at least 144 equal and representative samples each day containing at least 50 ml each, at a frequency proportionate to the flow.
The components of the sampler that are in contact with the sample must be of materials compatible with the nature of the contaminants taken, and the sampler strainer must be situated at a place enabling a sample representative of the effluent to be taken.