Columbia Test guidelines ordinance (§ 22-219.3)

(a) All measurements, tests and analyses of the characteristics of water and wastes shall be determined using analytical procedures approved in 40 CFR Part 136 and amendments thereto.

(b) Except as indicated in paragraph (c) below, the user must collect wastewater samples using flow proportional composite collection techniques. In the event flow proportional sampling is infeasible, the director 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.

(c) Samples for oil and grease, temperature, pH, cyanide, phenols, sulfides, and volatile organic compounds must be obtained using grab collection techniques.