Wood preservation facilities, inorganic boron (borate): chapter I-9
9. Waste, Process Emissions and Disposal
For general information on process emissions and disposal, consult Section 9 of Part I, Chapter A - General Recommendations for All Wood Preservatives.
9.1 Control, Treatment and Disposal
Potential process emission sources from borate wood preservation facilities are described in Figure 1 and in Section 5.2. Recommended practices for handling liquid and solid wastes and sludge are presented in Chapter A, Table 23.
Federal and provincial regimes address hazardous waste and hazardous recyclable material in different manners. Provincial requirements may also differ from province to province. Consult your provincial authority for more information. Borates are generally considered nonhazardous waste when spilled or disposed of. When borate is spilled into water, advise local water authorities that none of the affected water should be used for irrigation or for potable water until natural dilution returns to its normal environmental background level.
9.2 Liquids Containing Boron
Liquid Process Wastes
Liquid process wastes are not normally discharged from borate plants. Liquid solutions containing boron, such as drips and washwaters, are routinely collected and reused in preparing new treatment solutions. If unusual circumstances (such as prolonged plant shutdown) prevent on-site reuse, transport to another borate facility (for reuse) should be arranged. Disposal should be considered only as a last alternative.
9.3 Solids with High Boron Concentrations
Consult Section 9 of Part I, Chapter A - General Recommendations for All Wood Preservatives.
9.4 Miscellaneous Solid Wastes
Miscellaneous solid wastes (e.g. plastic wrappers, chemical bags, cuttings from boron-treated lumber) from borate wood preservation plants may be disposed of at designated sanitary landfills as approved by the provincial regulatory agency.
- Do not use boron-treated wood as a compost or mulch.
- Incineration of materials contaminated with boron is not permitted except in facilities authorized for disposal of such products because of the formation of toxic combustion by-products.
9.5 Air Emissions
Air emissions at borate facilities are normally localized; effects, if any, would be restricted to workers at the facilities. Air emissions from borate facilities include the following:
- exhaust from tank vents
- mists from vacuum pump discharge
- mists from opening of retort cylinder doors