Different types of pollution can occur in many different places along the supply chain for wood and paper-based products (Figures 10 and 11). The amount and intensity of emissions depend on the type, condition and capacity of the equipment causing pollution and the location of the discharge points. The degree of deviation (i.e., lack of compliance) from legally established emission thresholds is also an important factor and the opportunity for continuous improvement exists.
Types of pollution include:
Emissions to air
Energy-related emissions resulting from the combustion of wood and fossil fuels to generate power
Processing emissions resulting from processes such as pulping, bleaching, pressing, evaporating, and the chemical recovery systems.
Sludge from wastewater treatment plants
Ash from boilers
Miscellaneous solid waste, including wood, bark, non-recyclable paper, and rejects from recycling processes.
Emissions to water - large amounts of water are needed to carry the fibers through each manufacturing step in making paper products.
Noise - is a concern in the immediate vicinity of a mill. Its impact depends on the proximity of human settlements and the mitigation measures taken.
More information on pollutants commonly associated with manufacturing of wood and paper-based products can be found in Box 11: Pollutants.
Bleaching can be a potentially major source of pollution (Box 12: Bleaching of wood pulp). Most of the global paper industry has phased out the use of Elemental Chlorine (EC) as a bleaching agent; however, some facilities still use it. The prevailing bleaching systems are Elemental Chlorine Free (ECF) and Enhanced Elemental Chlorine Free (EECF). Totally Chlorine Free (TCF) bleaching may be an option for certain products although it tends to use more fiber and produce a lower quality product.
The law is the formal reference for what constitutes an acceptable level of emissions in a country. No international agreement on acceptable levels of emissions exists, but some multilateral and bilateral lending institutions have established policies based on Environmental Impact Assessments (EIA).
Factors to consider regarding pollution
Engaging in dialogue with landowners, trade associations and NGOs can be useful as they are often familiar with specific issues and local circumstances.
The emission of pollutants is often specific to the country and the site. Some countries are more stringent in their regulation of emissions. Continuous improvement should be the goal; although compliance may not always be enough (e.g., in cases where requirements are not stringent) therefore holistic environmental impact reductions are also a goal. Adherence to the relevant and local regulations and/or international lending standards can be used as a proxy to assess a company's procurement policy requirements.
Best management practices in the forest industry to deal with pollution include:
Minimizing the generation of effluents, air emissions and solid waste through better technology
Increasing reuse and recycling of waste materials
Increasing rates of chemical recovery from pulping and bleaching processes
Use of high-efficiency washing and bleaching equipment
Elimination of uncontrolled discharges of wastewater and solid waste due to equipment lack or failure, human error, or maintenance procedures
Usage of ECF, TCF, and EECF bleaching systems
Time-bound plans and management systems to minimize impacts from specific toxic pollutants.