Mondi Richards Bay: Fugitive Dust Management Plan

Transcription

1 8 October 2012 Mondi Richards Bay: Fugitive Dust Management Plan 1. Introduction and scope of report Mondi Richards Bay (Mondi) is a pulp and paper making mill based in Richards Bay. The Mill was commissioned in 1984 and currently produces two key products. These products are Baycel, a high quality bleached hardwood pulp made from eucalyptus fibre, and Baywhite, a white board, which is used in the production of corrugated cardboard. The intention of this Fugitive Dust Management Plan (DMP) is to ensure compliance with Mondi s Atmospheric Pollution Prevention Act (APPA) Registration Certificate (issued on 3 March 2010), and identify all significant sources of fugitive dust and measures that will be implemented to address these fugitive sources. 2. Methodology The method of monitoring windblown, settle able dust fall-out monitoring used by Mondi is based on the American Society of Testing and Materials standard for collection and analysis of dustfall. This method employs a simple device consisting of a cylindrical 5l container half filled with de-ionised water exposed for one calendar month (30 days). The water is treated with an inorganic biocide to prevent algal growth in the bucket. The bucket stand comprises a ring that is raised above the rim of the bucket to prevent contamination from perching birds. The bucket holder in connected to a 2.1m galvanised steel pole, which is either directly attached to a fence post, which is buried to a depth of 500mm. this allows for a variety of placement options for the samplers. Exposed buckets, when returned to the independent laboratories, are rinsed with deionised water to remove residue from the sides of the bucket, and the bucket contents filtered through a coarse (>1mm) filter to remove insects and other coarse organic detritus. The sample is then filtered through a pre-weighed paper filter to remove the insoluble fraction, or dust fallout. This residue and filter are dried, and gravimetrically analysed to determine the insoluble fraction (dust fallout). Refer to Annexure A for Mondi Richards Bay Dust Management Areas. 3. Roles and Responsibility The Operations Manager (Richards Bay) has ultimate responsibility and authority for the minimization and management of fugitive dust on site. However, the authority has been delegated to the Environmental Manager for the administration of this plan. The operational role of dust bucket placement, monitoring and analysis is outsourced to independent consultants who specialise in Air Quality. 4. Reporting Criteria Monthly reports on dust deposition results are compiled by the independent consultants and submitted to Mondi on a monthly basis.

2 2 The Standards South Africa has published a set of dustfall standards (SANS 1929:2005). These standards have been used to evaluate the level of dust deposition and are stated in table 4.1 and 4.2 below. Dust deposition rates shall be expressed in units of mg/m 2 /day over a 30 day averaging period. Based on measurements to date, Mondi has not exceeded these standards. Table 5.1: Four-band scale evaluation criteria for dust deposition (SANS 1929:2005). Band Number Band Description Dustfall rate (D) Comment 9mg/m 2 /day, 30-day average) 1 Residential D < 600 Permissible for residential and light commercial. 2 Industrial 600 < D < Permissible for heavy commercial and industrial. 3 Action < D < Requires investigation and remediation if two sequential months lie in this band, or more than three occur in a year. 4 Alert < D Immediate action and remediation required following the first incidence of dustfall rate being exceeded. Incident report to be submitted to relevant authority. Table 5.2: Dustfall standards, target, action and alert thresholds for dust deposition (SANS 1929:2005. Level Dustfall Rate Permitted Frequency of Exceedances (mg/m 2 /day) Target 300 Action 600 Three within any year, no two sequential months. residential Action industrial Three within any year not sequential months Alert None. First exceedance requires remediation and compulsory report to authorities. 5. Dust Management Plan The DMP tabled below details the identification of all significant sources of fugitive dust at Mondi, mitigation measures, and delegates timeframes for implementation of mitigation activities. 2

3 6.1 SilvaCel and Woodyard Business Unit Woodchip Stock Piles (Richards Bay) Existing Mitigation Measures Proposed Mitigation Timeframe There are two woodchip piles at the woodyard storage area. One pile for Hardwood and the other for Softwood. Each pile has a storage capacity of tons. Screws underneath the Both Hardwood and Softwood logs are washed with water prior to entering the chipping process to remove any mud, grit or dirt. piles reclaim the chips and feed them onto an enclosed conveyor, which leads to the next stage in the process The chips are then screened to remove the fine particles before being stored on either the Hardwood or Softwood chip piles Woodchip Stock Piles (SilvaCel) Existing Mitigation Measures Proposed Mitigation Timeframe There are two woodchip piles at the woodyard storage area. Screws underneath the piles reclaim the chips and feed them onto an Logs are washed with water prior to entering the chipping process to remove any mud, grit or dirt. enclosed conveyor, which leads to the next stage in the process The chips are then screened to remove the fine particles before being stored on either the chip piles. 6.2 Power and Recovery Business Unit Coal Tippler Existing Mitigation Measures Proposed Mitigation Timeframe Coal is transported via Transnet Freight Rail from mines in northern KwaZulu-Natal to Mondi. At Mondi it is off loaded via a tippler and transferred onto a conveyor for transport to the coal storage yard. A dust suppression measure in the form of water sprayers are in operation at the coal tippler, whenever a load of coal has been received and is being tippled onto the conveyor.

4 Coal Storage Area Existing Mitigation Measures Proposed Mitigation Timeframe Coal is dropped from the coal conveyor onto the hard surface of the coal storage area which has the capacity to store approximately tons of coal. The coal storage area has an A shaped roof in order to minimize the surface area of the coal stockpiles exposed to the elements Coal Conveyor Existing Mitigation Measures Proposed Mitigation Timeframe A screw underneath the stockpile claims the coal and feeds it onto a conveyor, which takes the coal to the Power Boiler. The conveyor is semi enclosed to minimise the dispersion of coal dust from the conveyor by the wind. Wet quench system is effective on ash conveyors i.e. water sprays are used during operation of ash transfer conveyors to suppress dust Ash Collection Point Existing Mitigation Measures Proposed Mitigation Timeframe Ash from the Power Boilers is collected directly onto a waste removal truck and transported to the The ash collection point is completely enclosed to prevent dust dispersion. Mondi Landfill site for safe disposal. Once loaded onto the removal trucks the ash is sprayed with water to prevent dispersion during the sort distance from site to the landfill. 6.3 Chemical & Effluent Plan Business Unit Lime Storage Area Existing Mitigation Measures Proposed Mitigation Timeframe Lime (Calcium Carbonate) Wetting of lime stockpiles with water during days of high wind speed in order to minimize dust. No additional mitigation methods are 4

5 Lime Kiln Existing Mitigation Measures Proposed Mitigation Timeframe Lime (Calcium Carbonate) No existing mitigation measures are in place. 6.4 Technical Business Unit Mondi Landfill Site Existing Mitigation Measures Proposed Mitigation Timeframe Disposal of Power Boiler Ash. Wetting of stockpiles with water during days of high wind speed in order to minimize dust. ISO Environmental Management Procedure for Dust control on landfill Ref. No. R-WIEV.003. Monthly dust monitoring by Independent Consultants. 6.5 Projects Department Construction and Demolition Existing Mitigation Measures Proposed Mitigation Timeframe During construction and/or demolition, fugitive dust emissions may potentially occur as a result of During construction and/or Demolition dust shall be controlled as follows: disturbance of dusty materials by construction plant and wind action on soil surfaces. Effective barriers shall be provided around dusty activities or site boundaries Dusty surfaces shall be dampened down during dry/windy conditions Hard surfacing shall be swept regularly Size and duration of stockpiles shall be minimized 5

6 6 6.6 Central Maintenance Business Unit Mechanical Workshops Existing Mitigation Measures Proposed Mitigation Timeframe Fugitive dust may occur as a result of disturbance Dust shall be controlled as follows: of dust materials, wind action and the use of mechanical equipment. Vacuum sanders shall have dustcontainment bags to remove and collect dust Sandblasting Workshops Existing Mitigation Measures Proposed Mitigation Timeframe Fugitive dust may occur from the use of Dust shall be controlled as follows: mechanical equipment. All sandblasting shall be performed over hard surfaces to prevent sand or residue from falling into open water or onto the bare ground. Screens or tarps shall be installed around the area to be sandblasted to contain the maximum amount of residue possible. Appropriate dust protection personal equipment shall be used at all times when sandblasting takes place. On windy days sandblasting shall be either stopped or closely monitored to prevent residue from escaping the containment area. Spent abrasives shall be collected monthly and stored in sealed containers to await proper disposal at an authorised landfill site. 6

7 Mondi Landfill Mondi Sports Center Mondi Richards Bay Key Description Coal Storage and transfer area Lime Kiln and storage area Sandblasting area Mondi site boundaries Existing dust monitoring points Annexure A: Mondi Richards Bay Dust Management Areas