Sector-Specific Benchmark Values and Effluent Limitations: Sector A - Timber products. Discharges may be subject to requirements for more than one sector or subsector.
Link to this table

Subsector Parameter Benchmark Values Effluent limits
A1 General Sawmills/Planing Mills COD (Chemical Oxygen Demand) 20 mg/L Effluent Monitoring Not Required
Solids, Total Suspended (TSS) 100 mg/L 2 Effluent Monitoring Not Required
Zinc, Total (as Zn) 0.234 mg/L 1 Effluent Monitoring Not Required
A2 Wood Preserving Arsenic, Total (as As) 0.680 mg/L Effluent Monitoring Not Required
Copper, Total (as Cu) 0.028 mg/L 1 Effluent Monitoring Not Required
Chromium, Total (as Cr) 3.5 mg/L 1 Effluent Monitoring Not Required
Pentachlorophenol (PCP) 0.011 mg/L Effluent Monitoring Not Required
Solids, Total Suspended (TSS) 100 mg/L 2 Effluent Monitoring Not Required
A3 Log Storage and Handling Solids, Total Suspended (TSS) 100 mg/L 2 Effluent Monitoring Not Required
A4 Discharges From Wet Decking Storage Areas pH 4 Benchmark Monitoring Not Required 6.0-9.0 SU
Debris Benchmark Monitoring Not Required No discharge of debris that will not pass through a 2.54cm (1 inch) round opening, instantaneous maximum (visual assessment) 3
A5 Hardwood Dimension and Flooring Mills COD (Chemical Oxygen Demand) 120 mg/L Effluent Monitoring Not Required
Solids, Total Suspended (TSS) 100 mg/L 2 Effluent Monitoring Not Required

1The benchmark values of some metals are influenced by water hardness. For these parameters, the Permittee may determine the hardness of the stormwater discharges to identify the applicable ‘hardness range’ for determining their benchmark value. See Table 4 of Appendix B for hardness dependent benchmark values in accordance with Minn. R. 7050.0222 and Minn. R. 7052.0100.
2If the Permittee is required to comply with Appendix A, part F.1, the benchmark value for Solids, Total Suspended (TSS) is 65 mg/L, instead of 100 mg/L.
3he Permittee is authorized under this permit to conduct a visual observation sufficient to determine the presence of debris that will not pass through a 2.54 cm (1inch) round opening and is not required to use a laboratory certified by the Minnesota Department of Health for this analysis.