Timber treatment plants use a lot of hazardous chemicals when treating timber so it is important that the waste is managed and disposed of correctly to avoid contaminating the environment.

The South African Wood Preservers Association (SAWPA) offers some helpful information to assist treatment plant owners, management and staff to managing and disposing of contaminated hazardous waste generated at treatment plants.

The association also creates awareness about compliance with NEMA – Waste Act (Act No59 of 2008) and the associated regulations and norms and standards.

Purpose of waste management

To prevent and minimise the generation of hazardous waste to prevent any contamination or pollution of the environment. Minimising hazardous waste will also reduce the costs associated with its disposal.

Hazardous waste at a treatment plant

Any material, other than timber, that comes into contact with a wood preservative solution or concentrate is regarded as hazardous, such as CCA. This includes contaminated personal protection equipment (PPE), sweepings collected from the bund and drip pad areas, sludge formed in the vessel or tanks like contaminated soil, sawdust and any other foreign materials such as strapping and string.

Proactive controls and measures

Management should enable prevention and reduction of waste and reuse of chemical. Where relevant, such measures should include the following:

  • Ensure timber destined for treatment is free of loose soil, mud, loose bark and sawdust.
  • In the case of water-borne preservatives, rinse plant waste using a rinsing filter to recover as much of the chemical as possible for re-use.
  • Allow wet waste to dry out to reduce volume and mass of the waste.
  • React promptly and correctly to any chemical spills and don’t use excessive absorbent material.
  • Contain and recover chemical drippings and spills for re-use.
  • Minimise the flow of rainwater that may carry soil into the plant area by proper design and construction.
  • Contaminated rainwater must be contained, recovered and re-used as process water.
  • Implement directives that prohibit eating, drinking and smoking in the treatment plant area.

For more information, click here to read the full advisory note.