Measurable levels and data characterization

Measurable levels for effluent and background data shall be less than or equal to the MQLs established in Appendix B of this Chapter. Where a pollutant has an established MQL, DEQ will include a provision in the permit requiring the measurable levels be less than or equal to the MQL. Data will be characterized as follows: (1) Where a background or effluent concentration data set reflects some measurable and some unmeasurable levels of a substance at or below the MQL, DEQ will use Robust ROS to estimate the unmeasurable quantities. When there are fewer than three (3) measurable data points, DEQ will use one-half (1/2) of the MQL to estimate the unmeasurable quantities and not Robust ROS. (2) If a substance is unmeasurable in all samples collected for a background or effluent concentration data set, DEQ will use a zero level. (3) If analytical data submitted does not meet the established MQL, DEQ will allow the permit applicant to provide additional data that meets the established MQL. If the applicant does not do so, DEQ will assume the substance is present at the reported measurable level.