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.