3. - The EIA in the Pulp and Paper Industry (Contd.)

3.3 - Environmental Impact Assessment

3.3.1 - The steering committee

When possible, it is recommended to form a steering committee (ST), with the appropriate public authorities, specialized agencies when they exist (e.g.: energy, security, water supply), local elected representatives, borrowers, universities, associations (e.g.: residents, affected groups…), NGOs, and any expert able to help the committee in its role.

The role of the ST is to:

• Manage the whole EIA cycle,
• Write out the EIA terms of reference,
• Decide on the methodology to be implemented,
• Define scoping and screening EIA stages: limits of the EIA in time, space and the environmental impact to be studied,
• Validate each stage of the EIA and, particularly, the study of alternatives, the initial state, the prediction of repercussions and the likely efficacy of the proposed mitigating measures.

3.3.2 - Project description

Once the alternatives have been studied, a precise description of the project and site has to be carried out. The role of the investor's team at this stage is to describe the project in terms of land occupation, area of influence, type of raw material used, type of plant and linked infrastructures (roads, electricity grids, dumpsites, water supply and drainage networks…), technologies proposed, etc.

All inputs and outputs of the process must be perfectly defined: how to supply inputs and how to export, treat or eliminate outputs.

The description must be as precise as possible, while remaining easily understandable by non-specialists. The use of maps, collected photographic information, drawings, diagrams, graphs… is particularly relevant in helping people get a good picture of the project.

3.3.3 - Site description

Site description presents a description of the project area of influence and its linked infrastructures. It basically includes,

• the site where the plant has to be built,
• the logical areas of influence of each parameter (i.e., water catchment area, zone where raw material is produced and exploited, zones under windstream, view points from where the plant is visible, heavy load of traffic on affected roads and surroundings…)

Figure 9 shows the different classes of parameters likely to be addressed in a site description.

Figure 9 : Parameters likely to be addressed in the site description of an EIA.

3.3.4 - Environmental and social effects of the project

Chapter 2.6 shows several methods for predicting and evaluating the impact of a development project on man and the environment. In the present stage of the EIA it is important to give precision on some characteristics of each environmental consequence to establish a classification. Each consequence likely to occur must be defined by four parameters:

• The magnitude, on the basis of a scale decided at the beginning of the EIA; three degrees of magnitude for each repercussion will be assessed: major, minor, negligible.
• The period of occurrence, particularly for impact occurring only during the construction phase or those likely to occur after a long period.
• The reversibility. This notion can be absolute (e.g. disappearance of a threatened species), or economic (e.g. enormous cost of amending soils lost through erosion).
• The type: direct (primary) or indirect (secondary). A direct impact is a direct destruction of an element of the environment (e.g. a forest is cut down to build the plant), an indirect impact is a knock-on effect (e.g. an animal disappears because its habitat was lost during project implementation).

The worst kinds of impact are those of major magnitude, irreversible and direct. For such repercussions, mitigating measures have to be proposed.

Table 17 : Example of impact synthesis

3.3.4.1 - Impacts resulting from the production and exploitation of the raw material

Chapter 3.2.2 shows the various parameters which are to be addressed in raw material production and exploitation. It is recommended to refer to the FAO “Model code of forest harvesting practice” before writing the management plan of forests to be exploited. Check-list No. 5 shows what a management plan should include:

Check-list 5: Quality of forest management plan and forecasted works

A prediction of the impact arising from exploitation cannot be done before the redaction of the management plan is achieved. Nevertheless, it is advisable to bring in an environmentalist to work alongside the forester team in charge of the redaction of the management plan to help them include the idea of a sustainable development concept in their thinking.

If reforestation is planned, great emphasis must be given to the evaluation of the impact arising from this operation, because the natural or social impact of such plantations can be very severe (invasive plants, erosion, destruction of ecosystems, sensitivity to fire, soil depletion and its productivity…).

In the case of agricultural crops, the fibrous raw materials used in paper making are by-products of crops which represent the main income. The environmental impact of such products must be linked with the main crop and evaluated very early in the EIA.

3.3.4.2 - Impacts of the industrial activity

Processes have been carefully studied in the first stage of the EIA (Pre-environmental Impact Assessment) depending on the raw material, energy and water supply, type of paper to produce, etc. Only small variations can be implemented at this stage to improve the efficiency of a given equipment. The EIA will now study very precisely each potential consequence of the plant on man and the environment (refer to Table 17 and figure 9). The aim of this phase of this particular EIA is to predict environmental issues, to compare them to a standard and to define where improvement in the processes are necessary.

3.3.4.2.1 - Impact on water

In order to examine the impact of the pulp and paper industry on water it is first necessary to understand that, as a heavy industry, it stands as one of the main users of water in its field. Table 18 shows characteristics of combined untreated typical effluents of pulp and paper mill operations; Table 19 shows mill effluents from different processes from wood preparation to papermaking in old and new technologies; and Table 20 the toxicity of some effluents examined through the Median Survival Time (MST) of salmon exposed to 100% concentration of the various effluents of a bleached kraft mill (this method is commonly used in Canada to determine the toxicity of effluents).

Table 18 : Typical characteristics of pulp and paper mill untreated effluents

Source: Environment Canada

Table 19 : Mill effluents from different processes (before out-plant treatment)

Source: World Bank

Table 20 : Typical bleached kraft mill effluent characteristics

Source: Environment Canada

These data show that consumption of water and discharges of pollutants reach very high levels, that the data themselves give very scattered information and that bleaching is the operation of foremost importance as regards water pollution.

Water consumption is probably the easiest factor to assess. The mill consumption and the productivity of water catchment are usually well estimated before construction. The most difficult task is to find out about other users, competitors, consumption and to evaluate the probable evolution of their needs. Here, it is particularly important to determine whether the drinking water supply is threatened and to find out if the needs of the pulp and paper mill exceed the local capacities.

Water quality is much more difficult to assess. First, because the EIA is conducted before the construction of the plant and thus data are of course calculated or issued from characteristics of similar mills and second, because water quality does not mean exactly the same thing everywhere world-wide. The effluents of mills are usually discharged into waterbodies where various pollutants are intended to be, more or less, assimilated. The biological, physical and chemical quality of water where effluents are sent can be evaluated by means of standards. These standards are available both for effluent maximum loads for various pollutants and for natural water receiving effluents. Table 21 shows the guideline values of allowable suspended solids losses and BOD₅ from mills in some regions in 1980. Table 22 shows the same value for another group of regions. The difference actually shows how much water quality standards vary according to the country concerned and time periods. Something that remains constant is the regular increase in quality requirements.

Table 21: Typical guideline values of allowable suspended solids losses and typical value of allowable BOD₅ discharges from new pulp and paper mills (in kg/air dry ton of product)

Source: World Bank 1980

Table 22: Typical guideline values of allowable suspended solids losses and typical value of allowable BOD₅ discharges from new pulp and paper mills (in kg/air dry ton of product)

Source: US and French regulations

Beyond the compliance to standard requirements, it is important to note the different effects that each parameter can have on man and the environment.

Suspended solids (SS): Main components of SS are parts of the wood like fibres or bark particles or losses from the process additives, dirt, fillers and coating substances. Important quantities of SS are dangerous for fish, particularly if this supply is high and regular. In addition, if the waterbody self-clean capacity is not sufficient, the SS are deposited on the river bed and anaerobic decomposition is undertaken by micro-organisms. These fermentation give rise to products which increase both BOD and H₂S.

Biochemical Oxygen Demand (BOD): Aerobic organisms living in water need oxygen to develop. If large quantities of effluents with important BOD are discharged into insufficient quantities of natural water, the dissolved oxygen contained in the natural water can be rapidly used to degrade biodegradable substances. Aerobic organisms present in this water are thus starved of oxygen and can be affected and, in the worst cases, eventually die. If the waterbody regeneration capacity is overtaken, anaerobic conditions are permanent which lead to the emission of olfactory nuisances and the destruction of all the aerobic fauna, including fish.

Toxicity: This factor is very difficult to evaluate due to the evolution of knowledge on toxic substances. The example of dioxin gives a particularly good demonstration of this point of view. When some scientists, and later associations for the protection of the environment, discovered that pulp and paper mills effluents contained dioxin, at the same time as research workers at the John Hopkins University brought news of how it was the “most potent carcinogen known to man”, it could only result in a vast public outcry. Bleaching plants effluents effectively contain dioxin but it proved very difficult for the pulp and paper industry to make a convincing plea in order to show that the concentrations were so small that the probable effects were not significant. To prevent further legal proceedings, the pulp and paper industry spent great amounts of money on studying and implementing solutions for avoiding dioxin production. Other chlorinated organic compounds, like AOX, which are present in significant amounts in mills effluents, are currently under study to evaluate their toxicity.

As mills effluents are mixtures of known and unknown complexes and changing compounds, and because environmental conditions (like dissolved oxygen, pH, temperature…) can widely alter the sensitivity of organisms, chances are high that toxicity will remain a topical subject for a long time.

The chemical recovery procedures now implemented in all mills have significantly decreased the amount of toxic discharge, it is hoped that technical and economic progress is still in the making to even further decrease the toxicity of these effluents.

Toxicity can also appear several years after effluents have been discharged, when sediments release persistent organic (i.e., DDT or PCBs) or toxic minerals (i.e., Zn), compounds which can be stored for a long time in river beds and released when environmental conditions change (i.e., variation in temperature, salinity…).

Nevertheless, EIA authors have to take large safety margins when they try to estimate the ability of the receiving environment to assimilate the toxicity of the pollutant to be discharged. Moreover, standards of reference are scarce for tropical waterbodies.

Temperature: Increase in waterbody temperature can produce various effects on aquatic organisms. If the increases are too great (i.e., if the receiving waterbody is small), fish can be affected and in worst cases die. An indirect effect on the organisms is that an increase in temperature involves the depletion of dissolved oxygen rate which can also be a cause of death for aquatic organisms.

Taste, odour and colour: Some compounds can give water an undesirable taste, odour or colour. This is particularly the case with chemical pulping. In some cases the fish flesh can be coloured. If these problems do not constitute the major harmful effects caused by pulp and paper operations, it is nonetheless the role of an EIA to study how to eliminate or reduce these problems.

Check-list 6 : Impact of the plant on water

3.3.4.2.2 - Impact on air quality, noise and odours

Noise is only a concern for the immediate vicinity of the pulp mill (noise from transportation is seen in chapter 3.3.4.3). The main parameter to address in the EIA is the possible proximity of communities and the mitigating measures to be implemented to allow normal living conditions for these communities.

Impact on air quality is the best known concern of the pulp and paper industry, while it is not often the most dangerous for human health. Odours, smokes, vapours and dust are emissions that people recognize immediately as characteristic of a pulp mill. Table 23 shows the characteristics of different compounds, with their approximate odour threshold which is the main factor of this pollution because these thresholds are very low. This particularity means that any release will have great repercussions.

Table 23 : Characteristics of kraft mill reduced sulphur gas (Source Handbook of pulp and paper technology, TAPPI)

If odours are the easiest gaseous emissions to identify, some others are less visible or odorous but much more dangerous. Emissions from a pulp mill are generally characterized by particle emissions and potentially toxic gas emissions. Tables 24, 25 and 26 show some typical sources of emissions and the nature of the discharge. Table 24 shows data of particle matter emissions, Table 25 shows typical Total Reduced Sulphur (TRS) emissions and Table 26 SO_x and NO_x emissions.

Table 24: Typical emissions of particle matter from older and modern mills (Source World Bank)

Table 25: Typical Total Reduced Sulphur (TRS) emissions from older and modern mills

Source: World Bank

Table 26: Typical emissions rates for SO_x and NO_x from kraft pulp mill combustion sources (before control devices)

Source: World Bank
Note: * Where all electrical power is produced on site, the emissions would be higher.

Most modern mills control gaseous emissions so that pollution is very low and human health rarely threatened. The most significant dangers come from accidental releases which can affect both local population and workers. This particular point is addressed in chapter 3.3.4.2.5. For regular emissions, it is important to note that hydrogen sulphide, organic sulphides, chlorine and chlorine dioxide emissions from kraft mills are generally below levels dangerous to organisms and man. The terpenes and phenols at the levels usually released during mechanical pulping are also normally without significant toxicity. Conversely, potential emissions of sulphur dioxide, which can cause health problems at very low concentrations (less than 1 mg/m³), must be assessed very accurately in the EIA.

The role of the EIA author regarding gaseous emissions of a project is mainly to obtain information from engineers, to define the type of emissions likely to occur during the mill operations and to make a comparison between those levels and international guidelines, such as those shown in Table 27 where typical modern emissions limits are given. This comparison normally leads to making a good impact prediction. Check-list 7 has similar goals.

Table 27: Typical modern emissions limits (monthly average).

Source: Pulp and paper international 1991

Check-list 7 : Impact of the plant on air quality

3.3.4.2.3 - Impact on soil and topology

Impact on soil related to raw material production and exploitation are seen in chapter 3.2.2. Impact on soil can occur during the construction phase and can lead both to erosion of steep slopes and sedimentation in waterbodies. Normally this can be easily controlled if clear recommendations are given to the engineers in charge of building the project.

The worst impact on soil related to industrial operations stems mostly from solid waste landfills. Table 28 shows some averages of solid waste generation in pulp and paper mills.

Table 28: Solid wastes in pulp and paper mills

Source: UNIDO
(1) : Incinerated.
(2) : Included in sludge.
(3) : In waste water sludge.
(4) : data not available.
(5) : Sludge from biological treatment 15% concentration. Incinerated.

This table shows the amount of solid waste from various processes but it does not give a detailed composition, even though it is the main factor to be addressed in the EIA. Some components of the additives used in the process (i.e., acids or alkali), of the equipment (i.e., PCBs in electrical equipment), or of the raw materials used (i.e., fuel oil) can pollute the soil at the plant site and/or at the dumpsites. This soil pollution can contaminate the underground water.

The role of the EIA author is to assess with precision the solution(s) proposed by the investors team for protecting the soil. Check-list 8 is a guide for conducting this analysis.

Check-list 8: Solid wastes management impacts

All these factors have to be cross-referenced with environmental sensitivity (urban zones, natural habitats, threatened species…) in order to propose mitigating measures when negative impact can affect sensitive areas or communities.

3.3.4.2.4 - Impact on fauna, flora and biodiversity

Impacts on vegetal or animal organisms, or on their habitats are very difficult to evaluate because this implies knowing of their existence. While these are sometimes known in developed countries, it is seldom the case in developing countries; consequently the EIA author must be very watchful even if it means he has to advocate protection measures that appear too drastic. The protection of a species generally consists in the protection of its habitat. The reserves must be surrounded by buffer zones to ensure the transition between the developed areas and the natural zones.

The different steps leading from the initial state to the impact prediction are shown on check-list 9.

Check-list 9: Impacts on fauna, flora and ecosystems

A pulp and paper mill construction leads unavoidably to negative impact on nature. Thus it is very important to draw out a hierarchy of the various negative consequences likely to occur, in order to be able to highlight the most important and those for which it is necessary to implement protection or mitigating measures. Table 29 shows the danger for fish, of toxic compounds from paper mills. As these data go back to 1977, some toxic compounds like dioxins are not yet highlighted.

Table 29: Compounds toxic to fish in pulp mill effluents

K=Kraft,
P=Pulping,
D=Debarking,
M=Mechanical,
S=Sulphite pulping

Source: Walden and Howard in TAPPI

The impact on domestic animals or on crops and forests can be either mentioned in this chapter or in the chapter related to the impact on land uses. In the instance of forests this topic can be divided into two parts, in this chapter the notions related to natural resources (biotopes, biodiversity, primary rain forest, mangroves…) and in the next chapter, forest for production (timber, fuelwood…)

3.3.4.2.5 - Impact on land uses and activities

This chapter can be the most important of the EIA, because it can take into consideration all existing forms of land use that may be affected by the project. Land use can be extremely varied and it is not possible here to address all potential forms. The following list is only mentioned to highlight the most commonly encountered land uses or resources:

• Activities: Agriculture, animal husbandry, forestry, fishing, hunting, industry, accommodation, business, recreation, reserves.

• Heritage: Archaeological, historical, spiritual, natural, human health, landscape.

• Man-made facilities: Infrastructures, buildings, shops, plants, transport, communication, services, capital.

All of these parameters have to be addressed individually with the impact due to:

• raw material production,
• plant operation and
• transportation.

Table 30: Example of matrix to analyze the interference between pulp and paper operations and land uses and riches

If the prediction of impact shows that resettlements are unavoidable, the EIA must dedicate a special chapter to detail the real consequences of these resettlements.

3.3.4.2.6 - Hazards generated by the project

Industrial facilities include a wide variety of transportation, energy generation, manufacturing, and waste disposal operations with inherent hazards which require careful management. These risks need to be adequately managed to minimize adverse impact: conditions potentially leading to major release accidents, occupational health and safety, and conditions of well-being of workers and affected communities.

Hazardous material in the pulp and paper industries can fall into two different risk classes, such as, first: inflammable, corrosive, reactive, toxic, pathogenic, mutagenic, and second: general hazards associated with industrial facilities like: electrical, structural, mechanical, or general conditions like: ergonomy, temperature, noise, oxygen deficiency, which can lead to accidents.

The EIA has to address each type of hazard likely to occur precisely with equal attention to the plant and the outside, as well as ensuring that the project complies with national or international standards for safety of workers and population. The EIA must particularly emphasize the location of the different buildings where dangerous substances have to be stocked, which type of warehouse management is planned, the product separation and compartmentalization, fire and emergency procedures, the personnel conception of hygiene and safety, waste management, etc. With all this information, the EIA author must predict the major risks likely to occur and cross-reference them with the sensitivity of the area, particularly so in densely inhabited zones.

3.3.4.3 - Impacts of transportation

Transportation mainly takes place outside the plant. The impact on the local network can be very important. The EIA must focus on traffic disturbance, public safety. The particular case of transportation of hazardous products has to be detailed very precisely and the routes must be selected by cross-referencing the type of hazards with the sensitivity of the area. Raw material exploitation sometimes involves the creation of roads, this particular point is very important to assess, specially if the EIA is to predict the negative impact likely to occur with such developments.

3.3.4.4 - The actual phase of project construction

Some EIA authors sometimes forget to study the particular instance of the construction phase of the project. For some categories of impact like dust emissions, traffic or noise, the EIA author must pay particular attention and point out those which have an impact specific to the construction phase and their extent.

3.3.5 - Mitigating measures

The chapter usually called “mitigating measures” can be divided into three categories of measures leading to a global reduction of negative impact related to the project, which can in fact :

• suppress impact, like the classification as “reserve” of rare ecosystems of a forest normally to be exploited,
• reduce impact, such as covering a noise emitting point,
• or mitigate impact, like the reforestation of another site of similar surfaces to that of forest tracts cut down for the project.

It is not possible here to emphasize all the mitigating measures likely to be implemented to reduce the impact of a project because they are, most of the time, tailored to the project itself. The mitigating measures shown here are possibilities that generally exist to reduce some of the common repercussions of pulp and paper projects.

3.3.5.1 - Measures related to raw material production and exploitation

For forest harvesting, the EIA author can find precious information in the FAO Model code of forest harvesting practice.

Measures to protect the remaining stands

Avoid land clearing,
Collect information on ecology, regeneration and silviculture of similar forests,
Consider various regeneration and harvesting methods,
Choose silvicultural systems that will ensure regeneration, sustainable production and minimize damage,
Protect endemic species and avoid the plantation of pest species,
Establish large enough reserves of ecologically significant forest areas, or forest growing on particularly sensitive areas like coast lines, bodies of water, steep slopes…
Implement a monitoring plan.

Measures to protect water

Avoid land clearing,
Maintain vegetation along all bodies of water,
Provide waste disposal facilities,
Implement procedures for use and storage of chemicals, oil and fuel and to minimize potential pollution effects and implement a monitoring plan to verify the efficiency of the system regularly,
Implement a monitoring plan.

Measures to protect air

Reduce burning,
Limit operations when dust and fire are a problem and plan transportation routes to avoid population centres.

Measures to protect soil

Avoid land clearing,
Avoid logging in the rainy season and clearly mark areas that should not be harvested (i.e., steep slopes),
Use low impact harvesting equipment and methods and reduce skid trail distances,
Restore disturbed areas,
Implement a monitoring plan.

Measures to protect wildlife

Initiate an inventory of species present in the area with professionals,
Plan harvesting on the basis of such information,
Prohibit forest fires,
Implement a monitoring plan.

Measures to avoid accidents

Avoid leaving workers alone in the forest,
Establish rules for working in the forest,
Make the wearing of safety clothes for loggers mandatory (helmet, shoes…),
Ban the creation of forest tracks in low stability areas,
Implement a monitoring plan.

Socio-economic measures

Protect significant traditional land areas, historical or archaeological sites,
Establish clear rules about local involvement in decision making,
Monitor and control diseases,
Implement an economic system to link the local economy to the development planned.

3.3.5.2 - Measures related to plant operation

Technology is always making progress, it is thus very difficult to update brochures continuously. The measures proposed here, to protect the environment and man can, with time, become obsolete. The EIA redaction team thus have to keep informed of new technologies made available to avoid certain types of negative impact.

3.3.5.2.1 - Measures to avoid or limit water consumption and pollution

Consumption: A modern papermill uses 85% less water than it did 3 decades ago. This feature shows that great progress has already been accomplished in this field. Mitigating measures related to water consumption have, as principal aim, to propose actions leading to control water consumption efficiently and the relationship between the capacity of the bodies of water and the plant needs. All measures related to re-use of waste water have to be detailed precisely here.

Temperature, colour and pH control: The temperature of effluents must be controlled, and if possible kept below 30°C and/or with less than a 5°C difference between effluent and waterbody temperature. The elevation of water temperature in the waterbody must be less than 3°C (1.5°C if possible in salmon rivers). pH must remain between 5.5 and 8.5. The colour modification must, if possible, be lower than 100 mg Pt/l. If some of the effluent characteristics are not in compliance with these guidelines, mitigating measures have to be proposed in the EIA. These measures have to be emphasized precisely and the processes detailed with the expected pollution rate abatement.

Examples of measures allowing both pH and temperature control are the construction of storage basins where effluents can be cooled and neutralized before discharge.

Colour control is much more difficult to achieve. It can involve an end-of-pipe treatment, a sedimentation clarifier for primary clarification, an aerated lagoon, activated sludge, or anaerobic treatment for secondary treatment.

Process modifications can include:

• high percentage of chlorine dioxide instead of chlorine (which can lead to a 65% to 70% reduction of colour bleaching of the area), use of peroxide and ozone or the introduction of an oxygen stage in the course of bleaching;
• the installation of various systems like spill control devices to contain black liquor spills, evaporator condensates, increased evaporator capacity or improved pulp washing technologies.

Pollution control: Pollution can include a very wide range of problems like toxicity, turbidity, oxygen deficiency, which can generate environmental issues and thus must be studied to propose adapted mitigating measures. For toxicity, Table 31 shows an example of the classification of effects on aquatic organisms. For each type of problem technical responses exist that are adapted to each particular disturbance.

Table 31: Classification of effects in relation to ecological significance

Source: Swedish water and air pollution research institute

If the evaluation of BOD, TSS, toxic loads at the EIA stage is somewhat difficult, the process engineers can nevertheless provide for the EIA author levels likely to be reached for each parameter. With these levels known, impact prediction is normally possible and mitigating measures must be proposed for any negative impact.

There are numerous technologies available to limit effluent toxicity. They can be divided in two major classes : in-plant and out-plant operations.

- In-plant operations are special processes, equipment or procedures to lower noxious emissions directly at the source. They basically involve fibre, chemical and energy recovery. They can take place all along the pulping process.

If wet debarking is planned, in-plant equipment must allow the recycling of water and the suspended solids once screened can be burnt to produce energy.

In modern plants, the digester only produces condensates which can contain turpentine. Turpentine can now be sold as a by-product or burnt. Stripping of condensates after turpentine extraction allows for it to be recycled in the process.

Two decades ago pulp washing provided large quantities of polluting agents like toxic compounds, colour, BOD, chemicals. Now environmental consideration and cost efficiency have led to a same goal. Energy and chemical recoveries allow both important productivity gains and a significant pollution decrease. Modern mills are now increasingly equipped with closed washing plants.

Screening operations usually produce significant quantities of wood rejects and dirt. Wood wastes can be lower if the initial preparation of wood is correct and dirt quantities can represent less than 0.5% of production if properly concentrated. The final treatment of this solid waste must be included in the solid waste management plan.

Bleaching remains the major source of pollution in pulp mills. The pollution load can be significantly decreased if pulp does not contain black liquor and if chlorine use is minimized. The use of chlorine dioxide, or hydrogen peroxide, can decrease the load of the main polluting agents of effluents and particularly dioxins and AOX production.

Drying and papermaking, in new plants normally do not discharge effluents. They all can be recycled in preceding operations.

Chemical and energy recovery and spill control are major operations for decreasing pollutant loads to sewer. They are mainly based on evaporator efficiency, good recausticizing and self production of energy. Spill prevention and monitoring procedures must be implemented because in new mills, where discharges of polluting agents are increasingly reduced, spills now represent a major concern of pollution.

- Out-plant operations treat the end of pipe effluents produced by the mill. They generally consist of a pre-treatment, and primary and secondary treatments.

Pre-treatment before entering the sewer system is necessary to screen the effluents to remove pieces of wood or rocks that can still be present. After screening the neutralization of effluents is effected in order to raise the pH level which is very acidic for kraft pulp and mildly acidic for mechanical pulp. This operation ensures a protection of the system against corrosion and allows the bodies of water, towards which the discharge of effluents is eventually directed, to avoid acidic pollution.

Primary treatment is a sedimentation in a clarifier to remove suspended solids from effluents. This mechanical treatment removes about 50% to 90% of suspended solids and delivers an effluent with 20 to 200 mg/l. If chemicals are added, the efficiency is increased. Primary treatment can also lead to a reduction of BOD by 30% to 50%.

Secondary treatment is a biological treatment where organic pollution and oxygen demand are reduced. Several processes like ponds, aerated lagoons, activated sludge, trickling filters or anaerobic treatment, are available. The effluents need to stay 5 to 10 days to obtain a BOD₅ reduction by 70 to 95%. Toxicity is also significantly reduced while colour remains at a fairly high level. Effluents of secondary treatment are normally non toxic to fish at full concentration and can thus be discharged into waterbodies, with all due precaution to avoid water quality disturbance. These precautions must be adapted to the recipient environment (stream, river, lake, ocean…).

In the case of specific problems, a tertiary treatment can take place, such as activated carbon absorption, massive lime treatment and foam separation.

Sludge from out-plant treatments must be dewatered somewhere downstream depending on what further usage it is destined for, which can be burning, landfill, composting and even animal feeding…

3.3.5.2.2 - Measures to avoid air pollution

While air pollution was the major concern of people living in the vicinity of pulp mills two decades ago, it is now considered to be a minor problem. This is due to the ongoing progress in technology.

The Total Reduced Sulphur (TRS) that generates foul smelling emissions and sulphur dioxide are now incinerated after various operations to collect them.

Dust, ash, particles are usually scrubbed with an efficiency ranging from 95% to 99% except in the debarking area where dust is likely to be a concern for neighbours.

Odours from out-plant water treatment plants have become a source of concern in urban areas.

3.3.5.2.3 - Measures to avoid land pollution

One of the most important sources of concern for new technology is to be able to concentrate the pollutant; which, in the past, remained as a constituent of effluents. This waste is made up of a large array of components, as shown in Table 32.

Table 32: Solid wastes characterization

Source: World Bank

The mitigating measures implemented to avoid soil pollution must give the solid wastes management plan in detail and explain how different classes of wastes are segregated and treated. Toxic substances and all special industrial refuse must be treated separately like oil and domestic refuse.

The waste management plan must emphasize the measures to be undertaken to reduce waste production, the recycling systems and the disposal systems and operations.

3.3.5.2.4 - Other measures

Like any development project, pulp and paper industries can generate other negative impacts such as risks, competition in land uses, resettlements, changes in life style, deleterious effects on particular patrimonies. These repercussions are not specific to these sectors of industry. They must be clearly identified and adequate mitigating measures have to be proposed to reduce these effects on the environment, populations and man made facilities.

3.3.6 - Monitoring, management and training plans

To increase EIA's efficiency it is useful to see if, once the project is operating, major mistakes have occurred or not. The emphasis has to be put on the fact that management and training plans throughout the duration of the EIA have to remain in compliance with reality. Environmental auditing has to be carried out to detect the weakness of processes and procedures which need to be set-up to ensure the protection of both man and the environment, respectively.