Monday, February 1, 2010

Timber Products Sector A - Arizona Requirements

The Arizona Department of Environmental Quality (ADEQ) recently released an updated draft of its proposed multisector industrial stormwater discharge general permit, known officially as the AZPDES Multi-Sector General Permit, or MSGP 2010. This permit, once promulgated, will replace the existing industrial stormwater permit, which expired in 2005.

Review a summary of the ADEQ Industrial Stormwater Permit

The proposed permit details requirements for 29 different industrial sectors. The requirements described below are proposed for the Timber Products Sector (Sector A). Sector A covers a fairly broad range of facility types, including log storage or handling areas, mills, producing lumber and wood basic materials, wood preserving, manufacturing finished articles made entirely of wood or related materials, and manufacturing wood buildings or mobile homes. These requirements are in addition to permit requirements that apply to all sectors.

If the facility performs wood surface protection and preservation activities, monthly inspections must include processing areas and treated wood storage areas to assess the effectiveness of practices to eliminate the deposit of treatment chemicals on unprotected soils and eliminate all contact with stormwater discharges.

Industry-Specific Stormwater Controls:
The facility must have secondary containment for all significant materials stored indoor and outdoor, (e.g. arsenic, chromium, zinc, copper, and phenolic solution storage tanks and structures). Facility must also drain containment stormwater for outdoor storage tanks and structures only after inspection demonstrates that no stormwater contact with solutions has occurred.

Potential Pollutant Sources:
If the operation uses chlorophenolic, creosote, or chromium-copper-arsenic formulations for wood surface protection or preserving, the SWPPP must document 1) areas where contaminated soils, treatment equipment, and stored materials still remain, and 2) the management practices employed to minimize the contact of these materials with stormwater runoff.

Stormwater Monitoring Benchmarks:
All facilities are required to conduct visual and chemical (benchmark) monitoring. For benchmark monitoring, the benchmark concentrations or values depend on product type:

General Sawmills and Planing Mills (SIC 2421):
COD 120 mg/L
TSS 100 mg/L
Zinc 0.04 to 0.26 mg/L, depending on hardness

Wood Preserving (SIC 2491):
Total Arsenic 0.15 mg/L
Total Copper 0.004 to 0.033 mg/L, depending on hardness

Log Storage and Handling (SIC 2411):
TSS 100 mg/L

Hardwood Dimension and Flooring Mills and others:
TSS 100 mg/L
COD 120 mg/L

The permit also established EFFLUENT LIMITS for discharges from log spray-down areas

[What is the difference between a “bench mark” and a permit or effluent limit?]

[Read more about what a 100 mg/L benchmark for TSS relates to]

Looking for other sector information? Click here for information on proposed stormwater requirements for specific sector.

Caltha LLP provides expert consulting services to public and private sector clients nationwide to address Stormwater Permitting & Regulatory Support, Stormwater Pollution Prevention Plans (SWPPP), Stormwater Monitoring and Stormwater Training.

For further information contact Caltha LLP at
Caltha LLP Website

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