Each person discharging industrial wastes into the sanitary sewer system may, at his option, or shall, when directed by the WRD Manager, construct and maintain an approved control manhole, together with such flow measurement, flow sampling, and sample storage facilities for all waste entering the public sewer as may be required by the WRD Manager. These facilities may be used to obtain flow and wastewater characteristics for use as a basis for an industrial wastewater service charge. These facilities will be installed and maintained at the user’s expense.

In lieu of directing the construction of measurement, sampling and sample storage facilities, the WRD Manager may require each person discharging industrial wastes into the sanitary sewer system to procure and test at the user’s expense and in a manner approved by the WRD Manager, sufficient composite samples on which to base and compute the person’s industrial wastewater service charge.

The WRD Manager may, at his option, procure and test the wastewater discharge to determine the wastewater strength for use as a basis for an industrial wastewater service charge.

At least three consecutive or separate 24-hour composite waste samples shall be taken for the initial year. Additional composite waste samples shall be taken at least once during each subsequent 18-month period to determine changes in wastewater strengths.

A composite sample is a series of samples mixed together to approximate the average strength of discharge to the sewer. The sampling period may include any 24-consecutive-hour period, not necessarily midnight to midnight. All measurement methods shall be approved by the WRD Manager.

The WRD Manager shall determine which industrial waste discharges require sampling to determine waste strengths and shall, in accordance with this section, determine the wastewater strengths.