13.06.380  Sample Collection
   A.   Except as indicated in Section B, below, the user must collect industrial wastewater samples using flow proportional composite collection techniques. In the event flow proportional sampling is infeasible, the Director of Public Works may authorize the use of time proportional sampling or a minimum of four (4) grab samples where the user demonstrates that this will provide a representative sample of the effluent being discharged. In addition, grab samples may be required to show compliance with instantaneous discharge limits.
   B.   Samples for oil and grease, temperature, pH, cyanide, phenols, sulfides, and volatile organic compounds must be obtained using grab collection techniques.