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DEPARTMENT OF PUBLIC WORKS
INCINERATOR INSTALLATION AT HELDERSTROOM
CORRECTIONAL FACILITY
PRELIMINARY DESIGN REPORT REV 2
18 JULY 2015
TEL : (021) 557 6099
FAX :086 758 0581
E-MAIL :[email protected]
PO Box 30
MILNERTON 7435
1A THE AVENUES
PARKLANDS MAIN ROAD
MEMBERS : TJ ESTERHUIZEN Pr Eng DT MANOEK Pr Tech EngPARKLANDS 7441
CK 199806948423
18 July 2015 Ref: 10M037/B Department of Public Works Private Bag X9027 Cape Town 8001 For Attention: Mr Patrick Phaswana Sir PORTERVILLE: VOORBERG CORRECTION FACILITY DPW FILE NO 6504/6000/6; WCS NO 047912 REPLACEMENT OF INCINERATOR: PRELIMINARY DESIGN REPORT REV 2
Attached please find our revised Preliminary Design Report for your consideration. It has become necessary to update our original Preliminary Design Report dated 26 August 2011, due to changes in legislation governing incinerator installations. When the original report was complied, the applicable Listed Activity was Category 8 in terms of the National Envoronmental Management: Air Quality Act (Act No 39 of 2004). The Listed Activity document of the Act has subsequently been updated (22 November 2013), and the facility will now be applying under subcategory 8.2. The report provides recommendations and updated cost estimates applicable to the proposed incinerator installation. We hold ourselves available to provide any further information that you may require. Yours faithfully
TOM ESTERHUIZEN
TOM ESTERHUIZEN AND ASSOCIATES
DPW Incinerators/150718/Helderstroom Report Rev 2
INCINERATOR INSTALLATION
AT HELDERSTROOM CORRECTIONAL FACILITY EXECUTIVE SUMMARY Tom Esterhuizen and Associates were appointed as the Mechanical Consulting Engineers to investigate the existing incinerator installation, and to propose a new incineration plant at Voorberg Correctional Facility. Primarily carcasses from pigs, sheep and cattle must be incinerated on a daily basis. The incineration capacity has increased since the existing incinerator was installed. The incinerator has reached the end of its useful economic life and thus the need for a bigger, more efficient incinerator has become necessary. On 31 March 2010 the Department Of Environmental Affairs published the National Environmental Management: Air Quality Act (39/2004), further referred to in this document as NEM: AQA. Part 3 of the NEM: AQA sets out the listed activities and minimum emission standards for facilities with a waste incineration capacity of 10 kg per hour or larger. When the original Preliminary Design Report was compiled in August 2011, the applicable Listed Activity was Category 8. The NEM: AQA Listed Activity document has subsequently been updated (22 November 2013) and the facility will now be applying under Subcategory 8.2. Emission limits set by Subcategory 8.2 cannot be reached without a proper filtration system and gas cooling system. An Incinerator operating licence will only be obtained when proper emission tests have been done and emission levels are within the required limits. There are currently no data on emissions for similar installations and a definite undertaking to confirm that the plant can be designed, installed and operated to comply with NEM: AQA cannot be provided unconditionally. It is therefore recommended that the plant installed at Voorberg be built as a pilot plant and that this plant be used to monitor emissions for compliance with the act. The results from this plant can then be used as a model for any alterations or additions required at Voorberg and also for further installations at Drakenstein and Helderstroom. At Helderstroom Correctional Facility, a calculated maximum incineration capacity of 233 kg per hour is required. The estimated cost for a fully compliant incinerator plant is R12 710 000 (excluding VAT). This excludes building work, electrical supplies, water supplies, waste water piping, running costs of plant and operator, filter replacement, emission monitoring reports and the consumption of diesel, water and electricity. In this report, the incineration rate and incinerator design for Helderstroom Correctional Facility is discussed. Different filtration and cooling systems and the necessity for a pollution monitoring system, are also considered. A preliminary concept plant and building layout is provided.
TOM ESTERHUIZEN AND ASSOCIATES
DPW Incinerators/150718/Helderstroom Report Rev 2
INCINERATOR INSTALLATION AT HELDERSTROOM CORRECTIONAL FACILITY
TABLE OF CONTENTS
1. TERMS OF REFERENCE .......................................................................................................... 1
1.1. LETTER OF APPOINTMENT ............................................................................................. 1
2. SCOPE OF REPORT ................................................................................................................. 1
3. EXISTING INCINERATOR INSTALLATION .............................................................................. 1
3.1. SLAUGHTERING RATE .................................................................................................... 1
3.2. EXISTING EQUIPMENT .................................................................................................... 1
3.3. WASTE REMOVAL ............................................................................................................ 2
4. REGULATORY REQUIREMENTS ............................................................................................. 2
4.1. MIMUMUM EMISSION STANDARDS ............................................................................... 2
4.2. POLLUTION MONITORING ............................................................................................... 3
4.3. WASTE MANAGEMENT .................................................................................................... 3
5. EMISSIONS ................................................................................................................................ 5
5.1. COMBUSTIBLE GAS EMISSIONS .................................................................................... 5
5.2. NON COMBUSTIBLE GAS EMISSIONS ........................................................................... 5
5.3. DIOXINS ............................................................................................................................. 6
6. DESIGN PARAMETERS ............................................................................................................ 6
7. PROPOSED NEW INSTALLATION ........................................................................................... 7
7.1. DESCRIPTION OF EQUIPMENT ...................................................................................... 8
7.1.1. INCINERATOR ........................................................................................................... 8
7.1.2. GAS COOLING .......................................................................................................... 8
7.1.3. FILTRATION ............................................................................................................... 9
7.1.3.1. ELECTROSTATIC PRECICPITATION .................................................................. 9
7.1.3.2. BAG HOUSE FILTRATION .................................................................................... 9
7.1.3.3. CERAMIC FILTRATION ......................................................................................... 9
7.2. SPECIFICATIONS............................................................................................................ 10
7.2.1. INCINERATOR ......................................................................................................... 10
7.2.2. POLLUTION MONITORING SYSTEM ..................................................................... 11
7.2.3. FILTERING SYSTEM ............................................................................................... 12
7.2.4. STACK ...................................................................................................................... 12
7.2.5. DUCTING ................................................................................................................. 12
7.2.6. PLANT ROOM .......................................................................................................... 12
7.2.7. HEAT EXCHANGER + COOLING TOWERS .......................................................... 13
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7.2.8. PUMPS ..................................................................................................................... 13
7.2.9. FAN........................................................................................................................... 13
7.2.10. DIESEL STORAGE .............................................................................................. 13
7.3. INCINERATOR OPERATOR ........................................................................................... 13
7.4. ALTERNATIVES ............................................................................................................... 14
8. ESTIMATED COST .................................................................................................................. 14
9. CONCLUSIONS ....................................................................................................................... 15
10. RECOMMENDATIONS ........................................................................................................ 15
APPENDICES APPENDIX A: DRAWING APPENDIX B: TYPICAL INCINERATOR DESIGN
LIST OF FIGURES FIGURE 1: EXISTING INCINERATOR INSTALLATION WITH DIESEL TANKS…………….......…..2
LIST OF TABLES
TABLE 1: MINIMUM EMISSION STANDARDS IDENTIFIED IN TERMS OF SECTION 21 OF THE
NATIONAL ENVIRONMENTAL MANAGEMENT: AIR QUALITY ACT (2004, ACT NO. 39).............3
TABLE 2: APPROXIMATELY INCINERATOR DIMENSIONS……………...................…….…….....11
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1. TERMS OF REFERENCE
1.1. LETTER OF APPOINTMENT
Tom Esterhuizen and Associates were appointed on 3 July 2007 as the Mechanical Consulting Engineers to investigate the existing incinerator installation and propose a new incineration plant at Helderstroom Correctional Facility.
2. SCOPE OF REPORT
This report is a preliminary design report and provides preliminary design information. Various alternatives are considered and discussed in this report. This report deals specifically with the following items:
− The existing incinerator installation
− Regulatory Requirements
− The proposed new incinerator installation
− Estimated Cost
− Recommendations
3. EXISTING INCINERATOR INSTALLATION
The slaughtering rate has increased since this incinerator was initially installed and thus a bigger, more efficient incinerator is required. There are no facilities available to store dead or sick animals and immediate incineration is a necessity to prevent the spreading of sickness. The existing incinerator must be replaced with a new incinerator that needs to burn waste at a calculated rate of 311 kg/hour. 3.1. SLAUGHTERING RATE
Only one breed of animal is slaughtered each day, either only sheep or only cattle.
• Sheep = 80/day (± 35 kg)
• Pigs = 75/day (± 75 kg)
• Cattle = 10/day (± 400 kg)
3.2. EXISTING EQUIPMENT
The existing incinerator is a 150LA model from S.A. Incinerator Company and has reached the end of its useful economic life. The installation comprises one 2000 litre Diesel storage tanks which are filled by Caltex when necessary. The incinerator is housed inside a bricked room and protected with a steel roof. Electricity is supplied from the abattoir building next to the incinerator. The figures below show the existing incinerator installation.
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FIGURE 1: EXISTING INCINERATOR INSTALLATION WITH DIESEL TANKS AT VOORBERG CORRECTIONAL FACILITY
3.3. WASTE REMOVAL Animal waste is currently being buried on the farm, but when it was incinerated, animal waste was transported from the abattoir to the incinerator in plastic bins and fed into the incinerator at no specific rate. When loading and burning the animal waste inside the incinerator, blood and fat is spilled onto the concrete floor and not properly drained or washed away. Ash produced by the incinerator is dumped on a piece of land.
4. REGULATORY REQUIREMENTS
4.1. MIMUMUM EMISSION STANDARDS
On 31 March 2010 the Department Of Environmental Affairs published the new National Environmental Management: Air Quality Act (39/2004), further referred to in this report as NEM: AQA. Section 21 of the Air Quality Act (39/2004) sets out the listed activities and minimum emission standards for facilities with a waste incineration capacity of 10 kg per hour or larger. When the original Preliminary Design Report was completed in August 2011, the applicable Listed Activity was Category 8. The NEM: AQA Listed Activity document has subsequently been updated (22 November 2013), and the facility will now be applying under Subcategory 8.2. The set of requirements under Subcategory 8.2 are not as stringent as the previous set of requirements. The new requirements are as listed in Table 1.
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TABLE 1: MINIMUM EMISSION STANDARDS IDENTIFIED IN TERMS OF PART 3 OF THE NATIONAL ENVIRONMENTAL MANAGEMENT: AIR QUALITY ACT (2004, ACT NO. 39), SUBCATEGORY 8.2: CREMATORIA AND VETERNIRY WASTE INCINERATION
SUBSTANCE OR MIXTURE OF SUBSTANCE mg/Nm3 UNDER NORMAL
CONDITIONS OF 11% O2, 273 KELVIN AND 101,3 kPa COMMON NAME CHEMICAL SYMBOL
Particulate matter N/A 40
Carbon monoxide CO 75
Oxides of nitrogen NOx expressed as NO2 500
Mercury Hg 0.05
4.2. POLLUTION MONITORING
Continuous on-line emissions monitoring is not required in terms of the new requirements of the act. The online monitoring equipment allowed for in the original Preliminary Design Report will therefore not be required. Regular sampling and testing will be required as prescribed by authorities and this must be outsourced to an approved specialist company
4.3. WASTE MANAGEMENT
All waste management activities on-site, specifically those relating to the transport, temporary storage and handling of waste, must take place in accordance with relevant provisions of the Department of Water Affairs, “Minimum Requirements for the Handling, Classification and Disposal of Hazardous Waste” (second edition, 1998) and applicable national standards for hazardous chemicals and wastes (as relevant), or with any future guidelines, standards or legislation pertaining to waste classification, handling, storage and/or disposal that may supersede the provisions of the current Minimum Requirements (1998) and/or standards.
Waste storage areas on-site must be designed and operated in such a way so as to prevent the unauthorised or accidental release of any polluting substances (gaseous, liquid or solid) into the air, soil, surface water and groundwater. The following must accordingly be taken into account:
− Possible incompatibility of waste material during handling, transport and storage. Liquids must be stored separately to solid wastes. Flammable liquids shall be stored separately to substances with a high oxidizing potential. Non-compatible wastes are to be stored separately.
− Storage vessels or containers shall be designed in accordance with regulations or adopted standards, and must be clearly marked as per relevant standards.
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− Procedures governing the loading, off-loading and transportation of hazardous waste, including the relevant national standards and codes.
− Any appointment of waste transport or contractor shall be subject to (1) the contractor complying with all requirements and relevant national standards for the transportation of dangerous goods / hazardous substances, (2) all emergency response equipment as stipulated in the national standards are carried out on vehicles, (3) all drivers carry a professional driver’s permit and are trained in HAZMAT response, (4) all documentation relevant to loads is accurate and complete, (5) adequate emergency response facilities has been contracted along the route from the waste generator to the plant, (6) all placarding and emergency information relevant to the load is correctly displayed.
− Establishing suitable and safe transfer systems from transportation to storage areas to avoid health, safety and environmental risks from spillage, such as fugitive emissions or vapour displacement. Suitable vapour filtration and capture equipment must be in place to minimise impact to the reception point and surrounding areas from unloading activities.
− Assuring that storage facilities are fit for purpose. Appropriate storage of liquids must meet relevant safety and design codes and standards for storage, pressures and temperatures, and adequate bunding is required to ensure the containments of spills.
− Adequate dust control systems for solid materials handling systems.
− Storage design must be appropriate to maintain the quality of the materials, e.g. for solids, preventing build-up of old, solid materials, and mixing or agitation for liquids to prevent settlement.
− Transfer and storage areas must be adequately designed to manage and contain accidental spills into rainwater or firewater, which may be contaminated by materials. This requires appropriate design for isolation, containment and treatment. Storage for liquids must have adequate secondary containment.
− Written procedures and instructions for the unloading, handling, and storage of solid and liquid waste treated or co-processed on site.
− Identification of designated routes for vehicles carrying specified waste or AFR materials within the site.
− Appropriate signs per relevant national standard indicating the nature of the material storage, stockpiling, and tank locations.
− Storage halls must be fitted with suitable fire fighting systems and be vented to control the accumulation of solvent vapours.
− Tanks containing low flashpoint material must be fitted with explosion safety device. Additional devices may be required such as atmosphere control (e.g. nitrogen blankets) and temperature control (e.g. shell cooling). The relevant national codes and standards for storage of hazardous liquids must be consulted.
− Equipment must be grounded and appropriate anti-static devices and adequate electrical devices selected (e.g. motors, instruments, etc.) where relevant.
− All material must be stored in fit for purpose facilities in accordance with their characteristics in such a way that environmental pollution or degradation is prevented. In particular, transfer of wastes from the transporter must occur within an enclosed or bunded area.
− Emergency response plans must cater for any accidents and incidents, and spill kits must be maintained on-site.
− Storage areas for hazardous waste must be as close to the point of application to the plant as possible, but far enough away to prevent being heated by the radiant heat of the treatment plant, and to allow truck delivery access.
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− Pumps and piping systems for liquid and sludge transfers must be able to tolerate varying viscosities and solid particles (or filters should be installed to remove such). Adequate maintenance of these pumping systems has to be performed to prevent pipe bursts.
− Transfer of dry materials (e.g. paper, sewage pellets and plastic) must be enclosed to prevent the wind from blowing waste material, dust / waste particles and litter.
5. EMISSIONS
5.1. COMBUSTIBLE GAS EMISSIONS
The burning process converts waste to gases and solids. The solids produced are either airborne, exiting the furnace in the flue gas (fly ash), or they leave as bottom ash. The gaseous discharge will exit the furnace in the flue gas. The majority of furnace emissions, on a volume basis, are gaseous. As with particulate, gaseous emissions can be classified as either combustible or non-combustible. Combustible gases include carbon monoxide, hydrocarbons and other products of incomplete combustion. The presence of these gases is undesirable. Some of them can be toxic at relatively low concentrations. When a furnace is operating properly with sufficient air injection and with high enough temperatures, almost all of the combustibles should be destroyed. Therefore, the quantity of combustibles present in the exhaust reflects the efficiency of the burning process. The more combustibles exiting the incinerator the less effective is the incineration process.
Likewise, with fewer combustibles in the exhaust the thermal treatment process is more effective. Carbon monoxide is the most significant of these combustible gases. The allowable amount of carbon monoxide is limited by regulatory standards. Hydrocarbon emissions include methane, hexane, and a myriad of other organics. With good combustion, the level of unburned carbonaceous materials, including hydrocarbons, will be low. If combustion efficiency drops, the discharge of unburned carbonaceous material will rise. Carbon monoxide concentration has been found to be related to hydrocarbon emissions. When the carbon monoxide concentration is low, hydrocarbon emissions will be low. When carbon monoxide emissions are high, it is likely that the emissions of all unburned gases (and particulate also) will be high. Other combustible emissions are products of incomplete combustion, referred to as PICs, or toxic organics. They are a category of hydrocarbons that may be toxic. They are by-products of combustion and, as with other hydrocarbon emissions, may be at such low concentrations as to be undetectable when good combustion is occurring. As the combustion process degrades with an increase in the measured carbon monoxide level, the PICs concentration will increase. When chlorine is present in the waste feed, such as with polyvinyl chloride (PVC) and other chlorinated
plastics, the organic emissions may include highly toxic chlorinated organic such as dioxins
(dibenzo-p-dioxins) and furans (dibenzofurans), which are unwanted by-products of the
combustion process.
5.2. NON COMBUSTIBLE GAS EMISSIONS
Non-combustible gases in the exhaust include water vapour, oxygen, nitrogen, nitrogen oxides, carbon dioxide, sulphur oxides, hydrogen chloride and metals in the gas phase (e.g., lead, mercury and cadmium). Water vapour, oxygen and nitrogen are non-polluting gases. Some of these other gases may be harmful if present in large enough quantities.
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When air is injected into an incinerator as waste combustion air, or for burner air for supplemental fuel firing, it introdeces nitrogen and oxygen (air is approximately 79% nitrogen and 21% oxygen by volume). This nitrogen source, as well as the nitrogen that is normally present as a component of the waste, will combine with oxygen into any of a number of nitrogen oxides. Nitrogen oxide generation is normally not significant unless the combustion chamber temperature exceeds 1,093°C. Sulphur oxides and hydrogen chloride are non-combustible emissions which generate acidic compounds. They condense as they leave the stack and are reduced in temperature below 149°C. Sulphur oxides form sulphuric acid and hydrogen chloride condenses to hydrochloric acid, both contributing to atmospheric pollution, damage to structures, and both having a potential health effect when emitted in sufficient quantities.
Hydrogen chloride will form regardless of conditions in the incinerator. In general, all of the chlorine in the chlorinated plastic component of the waste stream, as well as most of the other chlorine components of the waste, will exit the incinerator as hydrogen chloride in the exhaust gas. The control of hydrogen chloride emissions requires the use of scrubbing systems, as discussed hereinafter. Some metals such as lead, mercury and cadmium, are converted to the gas phase (vaporize) when exposed to the high temperatures of an incinerator. When exhaust gases are cooled these metals may either solidify or condense onto other particulate matter in the off-gas. An important consideration in air emissions control system selection and design is to insure that flue gases are cooled to a low enough temperature when exiting the incinerator to condense metals to particulate. Unwanted particulate matter can be removed much more effectively from flue gas than unwanted gases by an air emissions control system.
5.3. DIOXINS Dioxins (dibenzo-p-dioxins) are a family of chlorinated organic compounds (organic compounds containing chlorine). It has been found that the concentration of dioxins and furans is not related to the amount of chlorine present, but only to its presence. Most fuels or other burnable materials contain some chlorine or chlorinated compounds, although often very small amounts of them. Therefore, dioxins will be found just about any time burning occurs, whether burning charcoal, gasoline, cigarettes or plastics, etc. Dioxins and furans are however not applicable to Subcategory 8.2 of NEM: AQA.
5.4. EMISSIONS APPLICABLE TO THIS FACILITY
It should be noted that only the substances mentioned in item 4.1 ie carbon monoxide, oxides of nitrogen and mercury are applicable to subcategory 8.2 for Crematoria and Veterinary Waste Incineration, as in this case.
6. DESIGN PARAMETERS
− Exit stack gas temperatures must be maintained below 200 °C.
− The pollution control device (exhaust gas cooling and filtration system) must have a daily availability of 98% (downtime of 2%).
− Emissions must be kept under the specified limits set by NEM: AQA and reflected in Table 1. Refer to item 4.1
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− All waste management activities on-site, specifically those relating to the transport, temporary storage and handling of waste, must take place in accordance with relevant provisions of the Department of Water Affairs, “Minimum Requirements for the Handling, Classification and Disposal of Hazardous Waste” (second edition, 1998) and applicable national standards for hazardous chemicals and wastes (as relevant), or with any future guidelines, standards or legislation pertaining to waste classification, handling, storage and/or disposal that may supersede the provisions of the current Minimum Requirements (1998) and/or standards. See waste management above.
− All incinerator capacities are calculated for an incinerator operation of 8 hours per day.
− All incinerator capacities are calculated with a General Refuse Equivalent Factor (G.R.E Factor) of 1.66 for the incineration of animal carcasses.
− The heat input capacity of each burner in the primary and secondary chambers of the incinerator must be sufficient to raise the temperature in the primary and secondary chambers to 800±50°C and 1050±50°C respectively.
− Plant rooms must be built according to the National Building Regulations (SANS 10400) with proper mechanical cross ventilation.
7. PROPOSED NEW INSTALLATION
The proposed incinerator plant in this report is based on a dry air filtering system with a separate gas cooling system. A wet scrubber system was evaluated in the original Preliminary Design Report but found to be not feasible, due to high cost. It must be stressed that a proper emission test must be carried out on an existing incinerator with the required waste incineration capacity to establish what emission levels can be expected. There are currently no data available for emissions on existing similar installations and a definite undertaking to confirm that the plant can be comply with NEM: AQA can not be provided unconditionally. It is therefore recommended that the plant to be installed at Voorberg be built as a pilot plant and that this plant be used to monitor emissions for compliance with the act. The results from this plant can then be used as a model for any alterations or additions required at Voorberg and also for future installations at Drakenstein and Helderstroom. The detail design and selection of the filtering system is dependent on the efficiency of each different make of incinerator and will be carried out by the contractor that is appointed to carry out the installation, with proper guidance from the mechanical engineers to ensure that the system complies with the National Emission Standards.
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7.1. DESCRIPTION OF EQUIPMENT 7.1.1. INCINERATOR The existing incinerator must be replaced with a new incinerator that needs to burn waste at a maximum rate of 233 kg/hour. A general refuse equivalent factor (G.R.E Factor) of 1.66 was used to calculate the incinerator capacity required to burn animal carcasses. When put into operation, the incinerator should be strictly monitored to operate only inside the specified operating parameters. The incinerator capacity is calculated for a daily operation of 8 hours. The appropriate incinerator dimensions are as follows:
TABLE 2: APPROXIMATE INCINERATOR DIMENSIONS
Case Dimension
Length mm 2940 Width mm 3000 Height mm 3010 Loading Door mm 750 Chimney Dimension
Diameter mm 641 Height mm 13310 Max Height mm 18000 Capacity Data
Grate Hearth Area m2 2.71
Primary Volume m3
3.54 Secondary Volume m
3 4.37
Incinerator Weight kg 16500 Chimney Weight kg 1035
7.1.2. GAS COOLING The following alternatives can be considered for the gas cooling system:
7.1.2.1. Option1: The system comprises a heat exchanger interconnected with cooling towers adjacent to the incinerator plant. Water will be pumped through the cooling tower and heat exchanger to cool the gas blowing over the secondary side of the heat exchanger. By means of this application it is possible to lower the stack exit temperature to acceptable levels.
7.1.2.2. Option2: In lieu of the installation of a cooling tower with heat exchanger, a
very long section of ducting from the incinerator exhaust will give off heat by means of natural radiation. The disadvantage is that a steel duct of approximately 60-80 meters is required to achieve reasonable cooling. This option is not recommended.
7.1.2.3. Option 3: An air cooled chiller can be used instead of a cooling tower to
achieve the required cooling. A chiller will achieve the same amount of cooling as the cooling tower, but this option is expensive. This option is not recommended.
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7.1.2.4. Option 4: Should a wet filtration system be used (wet scrubber), the cooling is primarily done by rapid quenching techniques. Pollutants can be controlled by injecting a slurry of lime/sodium bicarbonate and activated carbon/ammonia into a wet scrubber after passing through a particle filter. The costs of wet scrubber systems are in the order of 3 times more expensive than dry filtering system. A wet scrubber system also has a very high operating cost, due to the need for a sewage water treatment plant. This option is not recommended.
7.1.3. FILTRATION As previously mentioned, the final filtering system can only be determined at a later stage and may consist of a number of stages of filtering, depending on the content of the off-gas. Three options of dry filtration are electrostatic precipitation, bag house filtration or ceramic filtration:
7.1.3.1. ELECTROSTATIC PRECICPITATION
An electrostatic precipitator (ESP) induces an electrical charge on particulate matter by passing the flue gas flow through a series of electrodes. These particles are then attracted to plates which have an opposite charge (the plates are grounded). They are collected on the plates and removed by the automatic rapping of the plates with an internal hammer. The key to successful operation of this system is the ability to remove accumulated particulate from the collector plates. Electrostatic precipitation is utilised for highly sophisticated systems and are too advanced and expensive for this application.
7.1.3.2. BAG HOUSE FILTRATION
A fabric filter (bag house) is a collection of bags constructed of a fabric (nylon, fiberglass, etc.) suspended inside a housing. Flue gas is drawn into the housing and passes through a series of permeable bags. When exhaust gas is drawn through a bag particulate matter is retained on the fabric, while the cleaned gas passes through it. The collected particles are removed from the filter by a cleaning mechanism, typically by using blasts of compressed air. They are stored in a collection hopper for eventual disposal. Bag house filtration systems are only suited for temperatures lower than 200°C. This could be a problem if reagents must be used to treat the off-gas, as reagents needs to be injected at higher temperatures.
7.1.3.3. CERAMIC FILTRATION
Ceramic filters are different from other hot gas filters because the filtration medium is made of a ceramic material. There are two types of ceramic filter elements: high density, which are based on alumina or silicon carbide granules; and low density, which are based on alumina-silicate or mineral wool fibres. The elements hang vertically in the filter vessel from the header plate, which separates the clean and dirty compartments.
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In use the hot gas is sucked through the filter medium from outside to inside, depositing the particles on the outer surface of the medium. At controllable intervals a sharp pulse of gas is blown back down the inside of the filter element causing a momentary reversal of flow. This reversal causes the accumulated solids to be detached from the outer surface of the filter elements. The solids fall into the hopper section of the vessel from where they may be discharged. A ceramic filtration system can operate at elevated temperatures up to 600°C, which makes it ideal for this application.
7.2. SPECIFICATIONS
7.2.1. INCINERATOR
− Burn animal waste at a maximum rate of 233 kg/hour
− General refuse equivalent factor (G.R.E Factor) = 1.66
− Waste gas + fuel gas = total gas flow rate = approx. 3.9 m3/s
− Minimum secondary chamber temperature = 1050°C
− In front of the incinerator a scale will be installed to measure the amount of waste in a stainless steel container prior to entering the incinerator.
− The sides and the top portion of the primary and secondary chambers shall preferably
have rounded corners from inside to avoid the possibility of formation of black pockets/dead zones.
− The size of the secondary chamber shall be properly designed so as to facilitate a minimum of one second of residence time to gas flow. For the estimation of residence time in the secondary chamber its volume shall be calculated starting from the secondary burner tip to the thermocouple. The refractory lining of the chamber shall be strong enough to sustain minimum temperature of 1000°C in the primary chamber and 1200°C in the secondary chamber. The refractory and insulation bricks shall have minimum 115 mm thickness.
− The Incinerator shell shall be made of mild steel plate of adequate thickness (minimum
5 mm thick) and painted externally with heat resistant aluminium paint suitable to withstand temperature of 250°C with proper surface preparation. Refractory lining of the hot duct shall be done with refractory castable (minimum 45 mm thick) & insulating castable (minimum 80 mm thick). Ceramic wool shall be used at hot duct flanges & expansion joints.
− The thermocouple location shall be as follows:
• In Primary chamber-Before admission of secondary air.
• In Secondary chamber-At the end of secondary chamber or before admission of dilution medium to cool the gas.
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− There shall be a separate burner each for the Primary & Secondary chamber. The
burners shall have automatic switching "off/on" control to avoid the fluctuations of temperatures beyond the required temperature range.
• Each burner shall be equipped with a spark igniter and main burner.
• Proper flame safeguard of the burner shall be installed.
• Provide view ports to observe flame of the burner.
• Flame of the primary burner: o Shall be pointing towards the centre of the hearth. o Shall be having a length such that it touches the waste but does not
impinge directly on the refractory floor or wall.
• The secondary burner shall be positioned in such a way that the flue gas
passes through the flame.
− A tamper-proof PLC (Programmable Logic Controller) based control system shall be installed to prevent:
• Wastes charging until the required temperature in the chambers are attained
during beginning of the operation of the incinerator.
• Waste charging unless primary and secondary chambers are maintained at the specified temperature range.
• Waste charging in case of any unsafe conditions such as very high temperature
in the primary and secondary chambers, failure of the combustion air fan, ID fan, recirculation pump and high temperature of the flue gas at the outlet of air pollution control device.
− The incineration system must have an emergency vent. The emergency vent shall remain closed (it shall not emit flue gases during normal operation of the incinerator).
− The double chamber incinerator shall preferably be designed on "controlled-air"
incineration principle, as particulate matter emission is low in such incinerator. Minimum 100% excess air shall be used for overall design. Air supply in the primary and secondary chamber shall be regulated between 30-80% and 170-120% of stoichiometric amount respectively. Primary air shall be admitted near / at the hearth for better contact. Flow meter / suitable flow measurement device shall be provided on the primary & secondary air ducting. The combustion air shall be supplied through a separate forced draft fan after accounting for the air supplied through burners.
− A minimum negative draft of 1.27 to 2.54 mm of WC (Water Column) shall be maintained in the primary chamber to avoid leakage of gaseous emissions from the chamber and for safety reasons. Provision shall be made in the primary chamber to measure the Water Column pressure.
7.2.2. POLLUTION MONITORING SYSTEM A continuous on-line monitoring system is not required in terms of the new requirements of the act and it is recommended that this not be provided. Regular sampling and testing will be required as prescribed by the authorities and this must be outsourced to an approved specialist company. Sampling points will be provided in the exhaust ducting and stack, in accordance with the prescriptions of the specialists.
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7.2.3. FILTERING SYSTEM As previously mentioned, the exact filtering system can only be determined at a later stage and may consist of a few stages of filtering, but will primarily comprise a ceramic filtration system with ceramic elements.
7.2.4. STACK
Structural design of the chimney/stack shall be as per National Regulations. The chimney/stack shall be lined from inside with minimum of 3 mm thick natural hard rubber suitable for the duty conditions and shall also conform to National Regulations to avoid corrosion due to oxygen and acids in the flue gas.
7.2.5. DUCTING
• Mild steel ducting will be used, which can withstand elevated temperature levels of around 1000°C
• Main duct = Ø600 mm diameter minimum 7.2.6. PLANT ROOM
− The complete incinerator installation shall be housed in a brick plant room with proper roofing and cross ventilation. The room must be mechanically ventilated with wall mounted extraction fans. There must be minimum of 1.5 m clear distance in all the directions from the incinerator structure to the wall of the incinerator room.
− The room must be equipped with a double door, big enough for the stainless steel trolley to fit through. The door must have louvres, big enough to let sufficient amount of fresh air through when closed. Suction from the extraction fans will draw air through the louvres and into the enclosed room.
− The floor and inner wall of the incinerator and storage rooms shall have outer covering of impervious and glazed material so as to avoid retention of moisture and for easy cleaning. The area shall be washed and chemically disinfected daily. The floor slab will be built to fall, to a concrete trench or gulley covered with a steel grille and connected to the nearest drain.
− The incineration ash must be stored in a closed sturdy container to avoid any pilferage. Finally, the ash must be disposed in a secured manner.
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7.2.7. HEAT EXCHANGER AND COOLING TOWERS
The approximate cooling capacity is calculated as follows: Q = m� C�∆T
= 3.9m s� x1.2 kg m � � x1 ��
��.� x[1273K-873K]
= 1872kW A suitable cooling tower configuration will be determined during the detail design stage. Two cooling towers can be installed, one serving as a standby to the other 7.2.8. PUMPS Pumps will be required to circulate the cooling liquid from the cooling towers to the heat exchanger. A backup pump will be installed to ensure 100% operation at all times. 7.2.9. FAN A bifurcated single inlet centrifugal fan must be installed, with a working flow rate of approximately 3.9 m
3/s and an operating temperature of 350°C.
7.2.10. DIESEL STORAGE
• Existing Diesel tanks (2000 l) does not have sufficient capacity for the new incinerator and two (2000 l) tanks must be added.
• Fuel will last approximately 6 weeks, when operated for 8 hours per day and 5 days a week.
7.3. INCINERATOR OPERATOR
Previously personnel of the correctional facility operated the incinerator without any training or knowledge of how to operate the incinerator. Animal waste was thrown into the incinerator without knowing the precise amount (kg) they put into it. This would block the flame and eventually cause the burner to malfunction. Automatic feed systems must be considered as a loading option, but because animal carcass size varies, a trained manual operator is required.
− A skilled person must be designated to operate and maintain the incinerator. The operator must have appropriate qualifications and shall be trained and certified by the incinerator supplier in operation and maintenance of the incinerator.
− At least one assistant must be designated at the incinerator plant to keep track of the wastes, records of incinerator operation, cleanliness of the surrounding area and incinerator and waste storage room. The assistant must also take care of waste charging and incineration ash disposal.
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− All staff at the incinerator plant must wear protective gear such as gumboots, gloves, eye glasses, etc. for safety reasons.
− All accidents must be reported immediately to the facility operator. The facility operator must have well defined strategies to deal with such an accident/emergency.
− The trained operator must be equipped with a hook and shuffle to move the waste into and around the incinerator, without touching the infected/dead animals or carcasses.
− Animal waste from the abattoir must be transported with a stainless steel trolley to the incinerator and manually fed by a trained operator.
7.4. ALTERNATIVES
The following alternatives are not recommended as a solution to the existing problem: 7.4.1. The least expensive system is to install a stack to a determined height to disperse
the pollutants to acceptable levels. This can be done in conjunction with air dispersion modelling to determine the required stack height. With the new emission limits, it is it is highly unlikely that the installation of a tall stack will comply with the emission requirements. The stack would just be too high. There is no guarantee that the emissions will be as predicted by the computer simulations. This alternative was considered in our original Preliminary Design Report and found to be not viable.
7.4.2. In lieu of the installation of on an incineration plant, companies such as Waste Man can be contracted to remove waste on a daily basis, or when necessary. This was addressed in our reports dated 9 November 2011 and 1 December 2011 and found to be not viable
7.4.3. As previously discussed there are further alternatives which can be considered. This
will be considered during the detail design stage.
8. ESTIMATED COST
8.1. The recommended option incorporates a filtration system, which consists of dry ceramic filter elements. The cooling system consists of a heat exchanger and open type cooling towers which dissipates the heat absorbed from the hot flue gas.
- Estimated cost for complete incinerator installation, filters,
cooling system and exhaust stack as described in this document ........R 12 710 000
8.2. The following are excluded from the estimated cost:
− VAT
− Plantroom and associated builderswork
− Electrical power supplies
− Sewer effluent system
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− Domestic water supplies
− Maintenance and replacement of the ceramic filters estimated at R400 000 per annum
− Water consumption of the cooling tower
− Plant operator
− Emission monitoring reports
− Annual emission tests by specialist
− Diesel Fuel
− Maintenance
− Electricity
− Contingency amount
− Cost escalation and currency exchange rate fluctuations from date of this report
− Professional fees
9. CONCLUSIONS
9.1. There are currently no data available on emissions for similar installations and a definite undertaking to confirm that the plant can be designed, installed and operated to comply with NEM: AQA can not be provided unconditionally.
9.2. In order to comply with the existing regulations on emissions, a filtration system is required to treat the exhaust gas of the incinerator.
9.3. The detail design and selection of the filtration system is dependent on the emissions
and the efficiency of each different make of incinerator and thus will be carried out by the successful contractor, following detailed emission tests under guidance from the mechanical engineers, to ensure that the system complies with the National Emission Standards.
9.4. The incinerator efficiency and emission control is directly proportional to the level of
training of the operator of the incinerator. Automatic feed systems should be considered as an option, but because carcass size varies, a trained manual operator is, in our opinion necessary.
9.5. A cooling system is required to limit the temperature of the exhaust gas at acceptable
levels, in order to comply with National Emission Standards.
9.6. An automated continuous pollution monitoring system is not required by the new requirements of the National Environmental Management: Air Quality Act. Regular sampling and testing will be required as prescribed by the authorities and this must be outsourced to a specialist company.
10. RECOMMENDATIONS
10.1. It is recommended that the plant to be installed at Voorberg be built as a pilot plant and that this plant be used to monitor emissions for compliance with the act. The results from this plant can be used as a model for any alterations or additions required at Voorberg and also for future installations at Drakenstein and Helderstroom.
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10.2. It is recommended that a filtering system comprising ceramic filters be installed.
10.3. It is recommended that further treatment of the exhaust gas be considered, after
tests have been conducted, as mentioned in item 10.1 above.
10.4. It is recommended that a gas cooling system comprising cooling towers, heat exchanger and circulating pumps be installed.
10.5. It is recommended that personnel be properly trained to operate all the elements of
the incinerator facility.
10.6. It is recommended that the regular sampling and testing of emissions be outsourced to a specialist company.
10.7. The estimated cost for the recommended solution is R 12 710,000 (excluding VAT).
The estimated cost excludes:
− Plantroom and associated builderswork
− Electrical power supplies
− Sewer effluent system
− Domestic water supplies
− Operating and maintenance costs
− Cost escalation and fluctuation in currency exchange rates
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APPENDICES
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APPENDIX A
CONCEPT LAYOUT
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APPENDIX B
TYPICAL INCINERATOR DESIGN
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Incinerator Emission Control System Carbonaceous Matter
This group includes hydrocarbons; many of which are malodorous and/or acidic, carbon monoxide and pure carbon. Very fine particles of carbon constitute black smoke. Requirements for complete combustion are:
i. Oxygen (air) must be available in sufficient quantities for complete oxidisation of
carbon and hydrogen (volatiles) released. An oxygen shortfall is usually the result of volatiles being released too rapidly. Control of the rate of combustion ensures that carbonaceous emissions due to a shortage of oxygen are eliminated.
ii. Time. Combustion is a chemical reaction (oxidisation). It requires time for completion. The time available is determined by the speed at which the volatiles pass through the incinerator and by the volume of the chambers. Large secondary chamber volumes and controlled rate of combustion ensure sufficient time.
iii. Turbulence. Thorough mixing of air and volatiles is essential for complete combustion. The flame port, mixing chamber and heated refractory screens are designed to produce turbulence. Optimum turbulence is dependent on gas velocities. Gas velocities are determined by the rate of combustion.
iv. Temperature. Elevated temperatures are required for complete oxidisation in secondary zones of the incinerator. Conversely, reduced temperatures are required on the hearth and in the primary chamber to control the rate of volatilisation. Temperatures have a direct effect on the rate of combustion and the rate of combustion has a direct effect on the temperatures. Control of the rate of combustion is essential.
Chemically Formed Compounds Obnoxious, incombustible vapours and gasses are sometimes liberated or formed during the combustion process. Many of these emissions are completely invisible. Others are in gaseous form at the temperatures in the incinerators and condense to a visible plume of liquid or solid particles on leaving the chimney. They cannot be eliminated by combustion. However in some cases ensuring combustion conditions that inhibit the process can reduce the formation or liberation of these compounds. Chemically compounds are so diverse that it is impossible to do any more than describe a few of the more common ones.
i. NOx is formed at very high temperatures. Such high temperatures are prevented by combustion control.
ii. Halogens include chlorine, fluorine, bromine and iodine. The most common sources are PVC and PTFE plastics. Ashes produced by wood, paper or animal tissue consist of basic oxides. They have a high affinity for halogens and combine readily to form chlorides, bromides, etc.
iii. Dioxins and furans, which are a cause for concern in incinerators, are not formed in the absence of halogens. In large doses it may cause cancer in human beings.
iv. Sulphur emissions rarely cause concern, because of the low sulphur content inside an incinerator.
v. Very small amounts of lead, silver, mercury, chrome and cadmium may occur in oxide form, but quantities are usually negligible.
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Entrained Ash
Fine particles of flakes of combustible material usually light in colour, are entrained in the stream of gasses. Visible flakes are called fly ash. Clouds of fine dust are described as white smoke. They cannot be eliminated by combustion. Removal of entrained fly ash becomes more difficult as the gas volume and temperature increase. The combustion process, secondary air, gasses from the secondary burner and increasing temperature, all add to the volume of gasses. Ash entrainment prevention is best controlled at source, on the hearth, before the volume and temperature increase. Entrainment from the hearth is minimised by control of rate of combustion. The Combustion System
Incinerators eliminate emissions at source by using advanced techniques of combustion control. Combustion takes place in two distinct phases:
Phase 1 When heat is applied to waste, volatiles are driven off. These can be oxidised (burnt) at source, in the fire-bed or later in the secondary combustion zone. Volatilisation does not require air or oxygen. The rate of volatilisation is temperature dependant. Volatiles, burnt in the fire-bed, raise the temperature of the bed and promote more rapid volatilisation. Inhibiting combustion of the volatiles in the bed-fire can slow volatilisation. Not all volatiles are combustible. Water vapour is a volatile. High percentage of incombustible or low heat volatiles, require additional heat from auxiliary burners. Phase 2 Once the volatiles have been driven off, a black carbon char remains. This char is completely unaffected by heat. It can only be burnt in the fire-bed and requires a steady supply of air or oxygen at high temperature for combustion. Primary VS Secondary The two phases of combustion outlined above, must not be confused with primary and secondary combustion. Primary combustion refers to combustion that takes place on or in the fire-bed itself. Thus all the combustion in phase 2 above is primary combustion. Secondary combustion refers to combustion that takes place at some point away from the fire-bed. Air or heat, added to the gas stream above the fire-bed in the primary chamber can have either a primary or secondary effect. If the gas stream moves down onto the fire-bed, it has a primary effect. If it moves away from the fire-bed, it is secondary air or heat, even though it was introduced in the primary chamber. It is possible to increase or decrease the rate of volatilisation (rate of combustion) by simply diverting heat and air either down onto the fire-bed or away from it. Elements of Combustion Control
i. The primary chamber of an incinerator is designed so that the heat, air and hot
gasses move in a vortex with horizontal axis. Temperatures differential and the release of volatiles from the fire-bed interrupt the vortex and deflect the heat and air into the second chamber. This ensures a constantly modulated supply of heat and air to the fire-bed and thus controls the rate of combustion.
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ii. Negative pressure resulting from the chimney draught induces some of the air into the primary chamber. When strong burning is in progress, a pressure build-up in the primary chamber reduces the negative pressure and the air available for primary combustion. The rate of combustion is reduced accordingly.
iii. Most of the air for secondary combustion is induced by negative pressure. It is introduced into the gas stream at a point where a constriction in the gas flow path causes an increase in the gas velocity. This creates a venture effect. As the volume and velocity of the gas stream increase, the venture effect is increased. Consequently the volume of secondary air induced will increase to compensate for the reduction in primary air mentioned in the previous paragraph.
iv. Natural draught chimneys automatically increase the draught as the chimney’s temperature increases.
v. Control is achieved without any moving parts. Burners mounted on the primary chamber perform both primary and secondary functions. Almost instantaneous diversion of heat and air from primary to secondary provides correspondingly rapid adjustment of the conditions required for optimal combustion.
vi. A portion of the fly ash entrained in the gas stream is not pure ash. It contains a high percentage of carbon. The carbon flakes have a large surface area, are readily entrained and difficult to trap. The carbon can be burnt away, but the time is much longer that required for combustion of volatiles. The heated refractory screen is designed to slow down the flakes in a zone of high temperature, turbulence and plenty of excess oxygen. Two sets of refractory slabs, located across the stream of gas in the mixing chamber, force the gas to zigzag between them. Fly ash impinges on the slabs and is stopped briefly. This is very effective in ensuring complete burnout of the carbon. The heated refractory screens add considerably to turbulence in the mixing chamber. This ensures better mixing of the volatiles and air and more complete combustion.
vii. The control elements outlined above are complimented by conventional controls such as pyrometers, to switch burners and fans on and off according to the heat demand.
Final Combustion Chamber The combustion of carbon and volatiles takes time. A large secondary or final combustion chamber is required to ensure sufficient time for complete burn out. Incinerators have exceptionally large final combustion chambers. The effective size is further increased by the fact that the secondary air and heat are added to the gas stream as far upstream as possible. The secondary burner (or after burner) is mounted on the side of the primary chamber. The upper levels of the primary chamber, the flame port and the mixing chamber are all effectively part of the secondary combustion zone. The large final combustion chamber also acts as a settling chamber. After burn out of the carbon on the heated refractory screens, the mechanical strength of the flake is reduced. Impingement and the subsequent turbulence break the flakes down into smaller particles. Although they are smaller, they have much reduced surface areas and they settle very effectively in the large final chamber.
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Retention Times
Chamber Incinerator Temperature Exposed (°C)
Primary 1.2 seconds 900-1100 Secondary 2.0 seconds 900-1100 Total 3.2 seconds
The temperatures are ranging from 900-1100°C, which is due to fluctuation caused by differing flash points of particular waste types and rate of feed. These temps are however an average. Generally these temperatures are maintained well above the 850°C minimum required.
Draught Limiter
The inrush of cold air when a cremator door is opened is a potential cause of fly ash entrainment, loss of combustion control, over-cooling of the fire and thermal shock on the refractories. The loading door is fitted with an automatic draught limiter that reduces the chimney draught, and the inrush of air as the door is opened. Some negative pressure must however be maintained to prevent hot gas and flames from escaping through the open door. A reduced amount of excess air is therefore drawn in through the open door. To compensate for the excess air, the normal secondary air supplies are automatically reduced as the door is opened. Liquids on the Hearth
The hearth is inclined upwards away from the inlet. Because refractory and firebrick cannot be made impervious to liquids, the underside of the inclined refractory hearth is lined with stainless steel. Fat and liquids, penetrating the refractory, run down the stainless steel sheet into a stainless steel pan, located beneath the refractory at the tunnel outlet. On either side of the tunnel, the pan is exposed to the heat and gasses chamber. Molten fats and liquids are burnt away in the pan.
Project done on behalf of
Sillito Environmental Consulting (Pty) Ltd
AIR QUALITY IMPACT ASSESSMENT FOR THE
HELDERSTROOM CORRECTIONAL FACILITY INCINERATOR
Report No.: APP/11/SEC-01c Rev 01
DATE: August 2012
L Burger
D Fletcher
REPORT DETAILS
Reference APP/11/SEC-01c Rev 01
Status Final
Report Title Air Quality Impact Assessment for the Helderstroom Correctional
Services Incinerator
Date Submitted August 2012
Client Sillito Environmental Consulting (Pty) Ltd
Prepared by Lucian Burger, PhD (Natal), MSc Eng (Chem), BSc Eng (Chem)
Derek Fletcher, BSc (Hons) Environmental Management (University of
Pretoria)
Notice Airshed Planning Professionals (Pty) Ltd is a consulting company
located in Midrand, South Africa, specialising in all aspects of air
quality, ranging from nearby neighborhood concerns to regional air
pollution impacts. The company originated in 1990 as Environmental
Management Services, which amalgamated with its sister company,
Matrix Environmental Consultants, in 2003.
Declaration Airshed is an independent consulting firm with no interest in the
project other than to fulfil the contract between the client and the
consultant for delivery of specialised services as stipulated in the
terms of reference.
Copyright Warning Unless otherwise noted the copyright in all text and other matter
(including the manner of presentation) is the exclusive property of
Airshed Planning Professionals (Pty) Ltd. It is a criminal offence to
reproduce and/or use, without written consent, any matter, technical
procedure and/or technique contained in this document
Acknowledgements The authors would like to express their sincere appreciation for the
invaluable discussions and technical input from Colleen McReadie at
Sillito Environmental Consulting (Pty) Ltd.
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 i
EXECUTIVE SUMMARY
Airshed Planning Professionals (Pty) Limited was appointed by Sillito Environmental
Consulting (Pty) Ltd to undertake an air quality impact assessment for the Helderstroom
Correctional Facility Incinerator (hereafter referred to as HCFI), located ~ 20 km north of the
small town of Caledon in the Western Cape.
The aim of the investigation was to quantify the possible impacts resulting from the
incinerator stack emissions on the surrounding environment and human health. To achieve
this, it was necessary to develop a good understanding of (a) the anticipated air pollution
emissions from the proposed incinerator, (b) the geographic location of the facility (c) the
atmospheric dispersion potential of the study area, (d) location and types of sensitive
receptors and (e) the existing air pollution and air quality in the study area.
The investigation followed the methodology required for a specialist report, comprising the
baseline characterisation and an impact assessment study.
Baseline Assessment
The main findings regarding the baseline assessment are as follows:
In the absence of any major industrial activities, it is expected that the current air
quality would be dominated by air emissions from agricultural activities. Emissions
from these activities include Particulate Matter (PM). PM of a diameter of equal to or
less than 10 micrometres (PM10), is legislated in the National Ambient Air Quality
Standards (NAAQS). It is also referred to as thoracic particulates as it is proven to
accumulate in the throat and lungs of humans over certain exposure periods. The
main sources likely to contribute to cumulative PM10 impact are surrounding
agricultural activities as well as vehicle entrainment on unpaved road surfaces.
Ambient monitoring data recorded for the Paarl region showed that of the criteria
pollutants, PM10 could exceed the NAAQS daily standard. SO2, NOx and CO were
well below their respective NAAQS standards.
It is expected that the most significant airborne particulate impacts would be during
the dry summer season.
Wind field data were obtained from the Department of Environmental Affairs and
Development Planning (D:EA&DP), which commissioned the simulation of wind fields
for selected parts of the Western Cape Province to serve as a common basis for the
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 ii
evaluation of Environmental Impact Assessments. The hourly average wind field
database covers a five-year period (2006 – 2010). The wind field in the study area is
bimodal with the dominant wind direction being from the northerly and south easterly
sectors. This indicates that receptors located north west and south of the incinerator
will be most likely to be impacted by emissions emanating from it.
The nearest sensitive receptors to the site are local farm houses. The closest farm house is
approximately 1.2 km south west of the HCF boundary. The Pearl Valley Golf estate is ~ 1.5
km north west of the HCFI.
Assumptions and Limitations
In interpreting the study findings it is important to note the limitation and assumptions on
which the assessment was based. The most important limitations of the air quality impact
assessment are summarised as follows:
The quantification of sources of emission was restricted to the HCFI activities,
including only the emissions associated with the single stack in operation at the HCFI.
Although other background sources were identified, such sources were not quantified
and are assumed not to contribute meaningfully to cumulative impacts.
Information required to calculate emissions from the stack as a point source for the
proposed operations was provided (Table A). The assumption was made that this
information was accurate and correct.
Routine emissions for the proposed operations were estimated and modelled.
Atmospheric releases occurring as a result of non-optimal incineration conditions
were not accounted for.
As a conservative approach, it was assumed that all PM2.5 emissions calculated using
Category 8.2 Emission Limits would be equal to the PM10 emissions calculated for
this same scenario.
When this report was compiled in 2012, the applicable Listed Activity was Category 8.
The NEM:AQA Listed Activity document has subsequently been updated (22
November 2013), and the facility will now be applying under Category 8.2.
Emission factors employed came from a variety of international sources. In each
instance, emission factors that resulted in the maximum emission rate for a given
pollutant, regardless of its source, was used to conservatively estimate expected
impacts from the HCFI.
Carcinogens were assessed for the “worst case” scenario i.e. where the maximum
emission factors and daily incineration rates of material were employed in the
calculation of emissions. In the absence of knowing the oxidative state of chromium,
it was conservatively assumed that all chromium would be hexavalent chromium.
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 iii
Nitrogen monoxide (NO) is rapidly converted in the atmosphere into the much more
toxic nitrogen dioxide (NO2). The rate of this conversion process is determined by the
rate of the physical processes of dispersion and mixing of the plume and the chemical
reaction rates as well as the local atmospheric ozone concentration. It was
conservatively assumed that all NO instantaneously undergo this conversion in the
atmosphere upon release from the HCFI stack.
The construction and closure phases were assessed qualitatively due to the
temporary nature of these operations.
Current operations were assumed to be twenty-four hours over a 365 day year in
order to model a “continuous” process as well as preserve the most conservative
modelling approach.
Emission Inventory
In the absence of actual stack emission measurements, the emissions inventory was
compiled for the activities at the HCFI using the technical specifications (i.e. stack parameter)
and design feed rates of the incinerator (Table A) provided by the client, with NEM:AQA
Listed Activity Category 8 emission limits. At the time of this assessment, Category 8
emission limits were applicable and included in the model simulations. Currently, Category
8.2 emission limits are applicable, which include less pollutants and have less stringent
values for PM, CO and NOx (increase of 4, 1.25 and 2.5 times more “allowed” to be emitted
from Category 8 to Category 8.2).
Table A: HCFI stack parameters
Stack Parameters Helderstroom Units
Waste 353 kg/hr
Stack Height 13.3 m
Stack Diameter 0.64 m
Exit Temperature 180 °C
Exit Velocity 4.8 m/s
Actual Volumetric Flow Rate 6.3 m³/s
Normal Volumetric Flow Rate 3.7 Nm³/s
Control Efficiency 0 %
Cattle Feed Rate 2 day
Pig Feed Rate 60 day
Chicken Feed Rate 4000 day
Design Rate 353 kg/hr
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 iv
Table B: Calculated emission rates
Pollutant Emission Factor (max) Emission
Rate (g/s)
Licence Emission Rate (g/s) (Cat. 8)
Min EF - times greater than
Licence Emission Rate
Max EF - times greater than
Licence Emission Rate
CO 0.25 0.186 0.3 1
NOx 1.35 0.745 0.4 2
SO2 0.73 0.186 3 4
HCl 0.16 0.037 2 4
HF 0.00 0.004 1 1
NH3 0.20 0.037 5 5
PM10 0.15 0.037 2 4
Cadmium 7.26E-06 1.86E-04 0 0
Mercury (b) 2.15E-03 1.86E-04 12 12
Dioxins/Furans 9.81E-10 3.73E-10 3 3
NMVOC 1.96E-10 3.73E-02 0 0
Heavy Metals 2.22E-03 3.73E-04 0.2 6
Note: (a) Bold letters indicate that the minimum Emission Factor employed will result in stack emission
concentrations greater than those stipulated in the NEM:AQA category 8.2 Listed Activity document –
indicating that further investigation through monitoring is necessary.
Note: (b) Mercury Emission Factors were only available for Human Crematoria. It is suspected that this value may be
too conservative for use in animal incineration.
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 v
In addition, and to test whether the Category 8.2 emission limits are achievable, emission
factors were also used to calculate empirical emission rates. These emission factors
originate from the European Environment Agency (EMEP/EEA) Air Pollutant Emission
Inventory Guidebook, and more specifically, emission factors associated with Human
Crematoriums, Sheep Incineration and Cow Incineration. The calculated emission rates are
summarised in Table B.
Impact Prediction Study
Due to the complex nature of the modelling domain (i.e. complex topography toward the east
and south), it was decided to employ the US EPA’s CALPUFF model, which forms part of the
US EPA’s CALMET/CALPUFF suite. CALPUFF is a regional Lagrangian Puff model suitable
for application in modelling domains of up to 200 km. Due to its puff-based formulation the
CALPUFF model is able to account for various effects, including land-sea/lake interactions,
spatial variability of meteorological conditions, dry deposition and dispersion over a variety of
spatially varying land surfaces. The simulation of plume fumigation and low wind speed
dispersion are also facilitated. It was decided to include a study domain 10 km by 10 km
while the modelling grid resolution was set to be 300m by 300m. Five years’ of
meteorological data (2006 – 2010) were used to simulate hourly, daily and annual average
ground level concentrations The tables that follow summarise the findings for each pollutant
investigated in this study.
Table C: Predicted NAAQS Criteria Pollutant average ground level concentrations
(GLCs)
Helderstroom Incinerator - Predicted average GLC's (µg/m³)
NAAQS Criteria Pollutant Cat. 8 Emis. Limits
Using EMEP/EEA Emission Factors
Hourly Daily Annual Hourly Daily Annual
PM10 - 0.7 0.2 - 3 1
CO 13 - 1 13 - 1
SO2 13 3 3 54 13 12
NOx 54 - 0.8 108 - 2
Percentage of the NAAQS Limit Value
PM10 - Immediate - 0.01 0.003 - 0.02 0.01
PM10 - 1 Jan 2015 - 0.01 0.02 - 0.04 0.02
CO 0.0004 - - 0.0004 - -
SO2 0.04 0.03 0.06 0.15 0.11 0.24
NOx 0.27 - 0.02 0.54 - 0.04
Note: a) Percentage values (bottom section of table) greater than 1 indicates non-compliance with the NAAQS
Limit.
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Table D: Non-carcinogenic pollutants and their reference exposure levels
Chronic (Long-term)
Non-carcinogenic Irritants
Predicted GLC (µg/m³)
Chronic Reference Concentration a
Chronic Hazard Ratio
HCl 5.25E-03 2.00E-02 0.26
HF 1.51E-04 1.40E-02 0.01
NH3 6.60E-03 1.00E-01 0.07
Acute (Short-term)
Non-carcinogenic Irritants
Predicted GLC (µg/m³)
Acute Reference Concentration a
Acute Hazard Ratio
HCl 4.14E-01 2.10E+00 0.2
HF 1.19E-02 1.64E-02 0.7
NH3 5.21E-01 1.18E+00 0.4
Note: (a) Hazard ratio values of greater than 1 indicate that the associated Reference concentration level
(Rfc) is exceeded
Table E: Carcinogenic exposure levels as a result of heavy metals
Heavy Metals (Carcinogens) - Increase in Lifetime Cancer Risk
Category 8 Listed Activities heavy
metals
Predicted Annual GLC (µg/m³)
Inhalation Unit Risk a Increased Lifetime
Cancer Risk fraction
arsenic 7.94E-05 4.30E-03 1 in 10 Million
cadmium 2.94E-05 1.80E-03 1 in 100 Million
chromium 7.92E-05 8.40E-02 1 in 1 Million
formaldehyde 5.74E-10 1.30E-05 1 in 10 Million x 1014
nickel 1.01E-04 2.40E-04 1 in 100 Million
Total - Heavy Metals 2.89E-04 9.04E-02 2 in 1 Million
Note: a) All Unit risk Factors obtained from the US EPA’s Integrated Risk Information System (IRIS) Programme
where the cancer unit risk for a range of pollutants is given
The main findings from the impact assessment due to proposed operations are as follows:
The predicted criteria pollutant concentrations are extremely low when compared to
the limit values stipulated by the NAAQS. There are no exceedances of the NAAQS
frequency of exceedance values over any time period for any criteria pollutant.
NOx was predicted to have the highest percentage value of its associated hourly
NAAQS limit value, being approximately 27% (Category 8 emission limit estimates)
and 54% (emission factor estimates), respectively. SO2 was predicted to be
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approximately 6% (Category 8 emission limit estimates) and 24% (emission factor
estimates) of the NAAQS annual limit value.
At the time of this study, Category 8 emission limits were applicable; currently Category 8.2 emission limits are applicable. This reflects an increase in CO, NOx and PM emissions of 1.25, 2.5 and 4 times. To investigate the effects of this, it is accurate to multiply long term (annual) concentrations by the same factor. This proves that even with Category 8.2 emission rates being used, the relative long term assessment criteria for NOx, CO and PM are not exceeded. In order for this to occur one would need an increase in Category 8 based emissions of 40 times for PM and NOx, and an increase in CO emissions of 2400 times. CO impacts are extremely low.
Other irritants, including HCl, HF and NH3 are predicted to be well below their
respective Rfc’s over chronic (annual) and acute (hourly) exposures.
The increased life-time cancer risk associated with the proposed incinerator was
estimated to be 1 in 2 million, which may be classified as a “Low” risk.1
Conclusions
The conclusions that can be drawn from air quality impact assessment are as follows;
The operation of the HCFI under the provided daily rates of incineration will not result
in any exceedances of the NAAQS criteria pollutants emission standards and limits.
The impact of non-criteria pollutants were also shown to be insignificant when
compared to health criteria recommended by the US EPA. The predicted incremental
cancer risk associated with the emissions from the proposed incinerator is low.
Using empirical emission factors, it was indicated that the Category 8 minimum
emission limits could be exceeded unless additional gas cleaning equipment is
1 Some authorities tend to avoid the specification of a single acceptable risk level. Instead a “risk-ranking system”
is preferred. For example, the New York Department of Health produced a qualitative ranking of cancer risk
estimates, from very low to very high:
Equal to or less than one in a million : Very low
Greater than one in a million to less than one in ten thousand : Low
One in ten thousand to less than one in a thousand : Moderate
One in a thousand to less than one in ten : High
Equal to or greater than one in ten : Very high
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installed. The same can be said for Category 8.2 emission limits. However, even with
the assumption of maximum emissions determined using emission factors (see
emissions in Table B), ambient air pollutant concentrations at ground level were
predicted to be low and within NAAQS limits, for both Category 8 and 8.2 emission
limits.
Recommendations
Given that the empirical emission rates calculated using emission factors result in
exceedance of Category 8 Emission Limits, it is recommended that;
The supplier of the incinerator be able to demonstrate that Category 8.2 Emission
Limits will not be exceeded. This may require the installation of gas cleaning
equipment such as a wet scrubber or baghouse (Caustic solution – emissions from
the incinerator will be acidic).
Implementation of regular stack monitoring to ensure that emissions are within the
minimum Emission Limits as contained in the Category 8.2 Listed Activity. Frequency
of this monitoring must be agreed with the appropriate authority (District Municipality).
For monitoring methods please refer to Schedule A – Methods for sampling as
Contained in the NEMAQA Listed Activities document (NEMAQA 39/2004).
Best Practice measures must be employed to minimise or avoid offensive odours
emanating from the incinerator feed material.
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TABLE OF CONTENTS
1 INTRODUCTION ........................................................................................................ 1-1
1.1 TERMS OF REFERENCE ......................................................................................... 1-2
1.2 METHODOLOGICAL APPROACH .............................................................................. 1-2
Atmospheric Dispersion Model Selection .................................................................... 1-2
Source Data Requirements ......................................................................................... 1-4
Modelling Domain ....................................................................................................... 1-5
1.3 ASSUMPTIONS AND LIMITATIONS ............................................................................ 1-5
1.4 OUTLINE OF REPORT ............................................................................................. 1-6
2 LEGAL REQUIREMENTS AND HUMAN HEALTH CRITERIA .................................. 2-1
2.1 AIR POLLUTION LEGISLATIVE CONTEXT .................................................................. 2-1
Emission Limits and National Ambient Air Quality Standards ...................................... 2-3
Listed Activities ........................................................................................................... 2-3
National Ambient Air Quality Standards ...................................................................... 2-6
2.2 HEALTH THRESHOLDS FOR NON-CARCINOGENIC AND CARCINOGENIC EXPOSURES .. 2-8
Non-Carcinogenic Exposures ..................................................................................... 2-8
Carcinogenic Exposures ........................................................................................... 2-10
3 BASELINE CHARACTERISATION ............................................................................ 3-1
3.1 SITE DESCRIPTION ................................................................................................ 3-1
3.2 SENSITIVE RECEPTORS ......................................................................................... 3-1
3.3 ATMOSPHERIC DISPERSION POTENTIAL ................................................................. 3-4
Meso-scale ventilation and site-specific dispersion potential ....................................... 3-4
3.4 EXISTING SOURCES OF EMISSIONS NEAR HCFI .................................................... 3-10
3.5 MEASURED BASELINE AMBIENT AIR QUALITY ....................................................... 3-12
4 IMPACT ASSESSMENT ............................................................................................ 4-1
4.1 CONSTRUCTION PHASE ......................................................................................... 4-1
4.2 OPERATIONAL PHASE - EMISSIONS INVENTORY ...................................................... 4-1
Dispersion Simulation Results and Time Series Data ................................................. 4-5
Compliance Assessment of Predicted Impacts ......................................................... 4-22
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4.3 CLOSURE PHASE ................................................................................................ 4-24
5 CONCLUSIONS AND RECOMMENDATIONS ........................................................... 5-1
5.1 FINDINGS AND CONCLUSIONS ................................................................................ 5-1
5.2 RECOMMENDATIONS ............................................................................................. 5-2
6 REFERENCES ........................................................................................................... 6-1
7 APPENDIX A: EMISSION FACTORS AND EQUATIONS .......................................... 7-1
7.1 EMISSION FACTORS FROM THE EMEP/EEA ........................................................... 7-1
7.2 HEALTH RISK CRITERIA FOR NON-CARCINOGENIC EXPOSURES ................................. 7-3
7.3 UNIT RISK FACTORS ............................................................................................ 7-12
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LIST OF TABLES
Table 2-1: National Ambient Air Quality Standards (NAAQS) ....................................... 2-7
Table 2-2: Excess Lifetime Cancer Risk (New York Department of Health) ................ 2-12
Table 3-1: Long-term Temperature for Paarl (Schulze, 1986) ...................................... 3-7
Table 3-2: Monthly Temperature statistics .................................................................... 3-7
Table 3-3: Long-term precipitation for Paarl (Schulze, 1986) ........................................ 3-9
Table 4-1: HCFI stack parameters ............................................................................... 4-2
Table 4-2: Calculated emission rates ........................................................................... 4-2
Table 4-3: Summary of Emission Factors investigated ................................................. 4-4
Table 4-4: Isopleth plots presented in the current section ............................................. 4-5
Table 4-5: Time Series Graphs showing Hourly PM10 GLC’s ........................................ 4-7
Table 4-6: Time Series Graphs showing Hourly CO GLC’s ........................................ 4-11
Table 4-7: Time Series Graphs showing Hourly SO2 GLC’s ...................................... 4-15
Table 4-8: Time Series Graphs showing Hourly NOx (As NO2) GLC’s ........................ 4-19
Table 4-9: Predicted NAAQS Criteria Pollutant average GLC’s .................................. 4-22
Table 4-10: Non-carcinogenic pollutants and their reference exposure levels .............. 4-23
Table 4-11: Carcinogenic exposure levels as a result of heavy metals ......................... 4-24
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LIST OF FIGURES
Figure 2-1: Listed Activities Cat. 2.2 - Storage and Handling of Petroleum Products ..... 2-4
Figure 2-2: Listed Activities Cat. 8 - Disposal of Hazardous and General Waste ........... 2-5
Figure 2-3: Section 21 of NEMAQA, Listed Activities Category 8.2 Cremation of human
remains, companion animals and veterinary waste. .................................................... 2-6
Figure 3-1: Location of the Helderstroom Correctional Facility ...................................... 3-2
Figure 3-2: Location of the sensitive receptors to HCFI ................................................. 3-3
Figure 3-3: Period, Day and Night time wind roses for Paarl - (Jan 07–Dec 09) ............ 3-5
Figure 3-4: Seasonal wind roses for Paarl – (Jan 07–Dec 09) ....................................... 3-6
Figure 3-5: Period, Day and Night time wind roses using WRF data (2008-2010) ..... Error!
Bookmark not defined.
Figure 3-6: Seasonal wind roses using WRF data (2008-2010)Error! Bookmark not
defined.
Figure 3-7: Diurnal temperature profile at HCFI (Jan 2009 – Dec 2011) ........................ 3-8
Figure 3-8: Rainfall recorded for Paarl (Jan 07 – Dec 09) ............................................ 3-10
Figure 3-9: Ambient PM10 Concentrations (Jul-Aug 2005) ........................................... 3-13
Figure 3-10: Ambient PM10 concentrations (Feb-Mar 2006) ........................................... 3-14
Figure 3-11: Ambient SO2, NO2 and Benzene concentrations (26 Jun – 3 Jul 2006) ..... 3-14
Figure 3-12: Ambient PM10 concentrations (Apr 2008 – May 2009) ............................... 3-15
Figure 3-13: Ambient SO2 concentrations (Apr 2008 – May 2009)................................. 3-16
Figure 3-14: Ambient NO2 concentrations (Apr 2008 – May 2009) ................................ 3-16
Figure 3-15: Ambient O3 concentrations (Apr 2008 – May 2009) ................................... 3-17
Figure 4-1: Predicted annual PM10 Ground Level Concentration ................................... 4-6
Figure 4-2: Predicted hourly CO Ground Level Concentration ..................................... 4-10
Figure 4-3: Predicted annual SO2 Ground Level Concentration .................................. 4-14
Figure 4-4: Predicted annual NOx Ground Level Concentration ................................... 4-18
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AIR QUALITY IMPACT ASSESSMENT FOR THE
HELDERSTROOM CORRECTIONAL FACILITY INCINERATOR
1 INTRODUCTION
Airshed Planning Professionals (Pty) Limited was appointed by Sillito Environmental
Consulting (Pty) Ltd to undertake an air quality impact assessment for the Helderstroom
Correctional Facility Incinerator (hereafter referred to as HCFI), located ~ 20 km north of the
small town of Caledon in the Western Cape.
The aim of the investigation was to quantify the possible impacts resulting from the
incinerator stack emissions on the surrounding environment and human health. To achieve
this, it was necessary to develop a good understanding of (a) the anticipated air pollution
emissions from the proposed incinerator, (b) the geographic location of the facility (c) the
atmospheric dispersion potential of the study area, (d) location and types of sensitive
receptors and (e) the existing air pollution and air quality in the study area.
Typical of specialist investigations conducted, the air quality investigation comprises both a
baseline study and an impact assessment. The baseline study includes the review of site-
specific atmospheric dispersion potentials, and existing ambient air quality in the region, in
addition to the identification of potentially sensitive receptors.
The pollutants associated with the National Environmental Management: Air Quality Act
(39/2004) Listed Activity Category 8 are of concern in the context of the current study. This is
as a result of the HCFI process being described as the incineration of general waste
(livestock is in this case deemed general waste). Some of these pollutants are classified as
criteria pollutants, with ambient air quality guidelines and standards having been established
by various countries to regulate ambient concentrations of this pollutant. Particulates in the
atmosphere may contribute to visibility reduction, pose a threat to human health, or simply be
a nuisance due to their soiling potential.
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1.1 Terms of Reference
The terms of reference for the baseline air quality characterisation component of the
assessment are as follows:
The site-specific atmospheric dispersion potential;
Identification of the potential sensitive receptors within the vicinity of the proposed
site;
Preparation of hourly average meteorological data for the model input;
Identification of existing sources of emission in the area;
Characterisation of ambient air quality in the region based on observational data and
recorded to date (if available);
The legislative and regulatory context.
The terms of reference for assessing the air quality impacts associated with the proposed
activities:
Compilation of an emissions inventory, comprising the identification and quantification
of all potential routine sources of emission from the incinerator;
Dispersion simulations of ambient concentrations for the HCFI activities;
Analysis of dispersion modelling results from the HCFI operations;
Evaluation of potential for human health and environmental impacts;
1.2 Methodological Approach
Atmospheric Dispersion Model Selection
Dispersion models compute ambient concentrations as a function of source configurations,
emission strengths and meteorological characteristics, thus providing a useful tool to
ascertain the spatial and temporal patterns in the ground level concentrations arising from
the emissions of various sources. Increasing reliance has been placed on concentration
estimates from models as the primary basis for environmental and health impact
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assessments, risk assessments and emission control requirements. It is therefore important
to carefully select a dispersion model for the purpose.
It was the initial intension to simulate a three-dimensional wind field using meteorological
data measurements at weather stations nearby the HCFI, and upper air data from the South
African Weather Services (SAWS). These wind field simulations would have been done by
the US Environmental Protection Agency’s (US EPAs) CALMET model.
Instead, the Department of Environmental Affairs and Development Planning (D:EA&DP)
commissioned the simulation of wind fields for selected parts of the Western Cape Province
to serve as a common basis for the evaluation of Environmental Impact Assessments.
Although not a prerequisite for this project, it was nevertheless decided to follow D:EA&DPs
recommendation, and to utilise their wind field database for the five-year period, 2006 to
2010. The wind field was developed using the CALMET model with initial wind input data
from the predictions of the large scale Weather Research and Forecasting (WRF) model.
CALMET simulates the meteorological field within the study area, including the spatial
variations – both in the horizontal and in the vertical - and temporal variations in the wind
field and atmospheric stability. Surface meteorological hourly average data include wind
speed, wind direction, temperature, relative humidity and rainfall. Upper air data required by
CALMET include pressure, geopotential height, temperature, wind direction and wind speed
for various levels.
Due to the complex nature of the modelling domain (i.e. complex topography toward the east
and south), it was decided to employ the US EPA’s CALPUFF model, which forms part of the
US EPA’s CALMET/CALPUFF suite. CALPUFF is a regional Lagrangian Puff model suitable
for application in modelling domains of up to 200 km. Due to its puff-based formulation the
CALPUFF model is able to account for various effects, including land-sea/lake interactions,
spatial variability of meteorological conditions, dry deposition and dispersion over a variety of
spatially varying land surfaces. The simulation of plume fumigation and low wind speed
dispersion are also facilitated.
It was decided to include a study domain 10 km by 10 km. Five years’ of meteorological data
(2006 – 2010) were used to simulate hourly average ground level concentrations for the
criteria pollutants included in the NAAQS Category 8 Listed Activities. The model grid
resolution was set to be 300 m by 300 m. The highest hourly, daily and annual average
concentrations were calculated and displayed in Tables with the Annual concentrations being
represented in isopleths plots on the modelling domain base map. Calculations were also
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made for discrete locations (receptors) and portrayed as time series graphs for every criteria
pollutant investigated in this study.
The predicted ground level concentrations for the various averaging times and pollutants
were compared to the DEAs NAAQS for compliance purposes. There will always be some
error in any geophysical model, but it is desirable to structure the model in such a way to
minimise the total error. A model represents the most likely outcome of an ensemble of
experimental results. The total uncertainty can be thought of as the sum of three
components: the uncertainty due to errors in the model physics; the uncertainty due to data
errors; and the uncertainty due to stochastic processes (turbulence) in the atmosphere.
The stochastic uncertainty includes all errors or uncertainties in data such as source
variability, observed concentrations, and meteorological data. Even if the field instrument
accuracy is excellent, there can still be large uncertainties due to unrepresentative placement
of the instrument (or taking of a sample for analysis). Model evaluation studies suggest that
the data input error term is often a major contributor to total uncertainty. Even in the best
tracer studies, the source emissions are known only with an accuracy of ±5%, which
translates directly into a minimum error of that magnitude in the model predictions. It is also
well known that wind direction errors are the major cause of poor agreement, especially for
relatively short-term predictions (minutes to hourly) and long downwind distances. All of the
above factors contribute to the inaccuracies not even associated with the mathematical
models themselves.
Source Data Requirements
The CALPUFF model is able to model point, area, volume and line sources. The emissions
due to the HCFI activities were modelled as point sources, including only a single point
source in the form of a stack. Two scenarios were modelled; viz. where emissions were
calculated using licence Emission Limits (based on NEM:AQA’s Category 8 Listed Activity)
coupled with design specification, and where Emission Factors for Human Crematoria,
Sheep and Cow incineration were employed. These scenarios broaden what the potential
impact the HCFI might have on the surrounding area’s air quality. It also represents the
potential characteristics of emissions from the HCFI stack without mitigation measures (i.e.
scrubbers) being put in place.
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Modelling Domain
The dispersion of pollutants was modelled for an area covering ~10 km (east-west) by
~10 km (north-south). This area was divided into a grid with a resolution of 300 m (east-
west) by 300 m (north-south). CALPUFF simulates ground-level concentrations (GLC’s) for
each of the receptor grid points.
1.3 Assumptions and Limitations
In interpreting the study findings it is important to note the limitation and assumptions on
which the assessment was based. The most important limitations of the air quality impact
assessment are summarised as follows:
The quantification of sources of emission was restricted to the HCFI activities,
including only the emissions associated with the single stack in operation at the HCFI.
Although other background sources were identified, such sources were not quantified
and are assumed not to contribute meaningfully to cumulative impacts.
Information required to calculate emissions from the stack as a point source for the
proposed operations was provided. The assumption was made that this information
was accurate and correct.
Routine emissions for the proposed operations were estimated and modelled.
Atmospheric releases occurring as a result of non-optimal incineration conditions
were not accounted for.
As a conservative approach, it was assumed that all PM2.5 emissions calculated using
Category 8 Emission Limits would be equal to the PM10 emissions calculated for this
same scenario.
Emission factors employed came from a variety of international sources. In each
instance, emission factors that resulted in the maximum emission rate for a given
pollutant, regardless of its source, was used to conservatively estimate expected
impacts from the HCFI.
Carcinogens were assessed for the “worst case” scenario i.e. where the maximum
emission factors and daily incineration rates of material were employed in the
calculation of emissions. In the absence of knowing the oxidative state of chromium,
it was conservatively assumed that all chromium would be hexavalent chromium.
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Nitrogen monoxide (NO) is rapidly converted in the atmosphere into the much more
toxic nitrogen dioxide (NO2). The rate of this conversion process is determined by the
rate of the physical processes of dispersion and mixing of the plume and the chemical
reaction rates as well as the local atmospheric ozone concentration. It was
conservatively assumed that all NO instantaneously undergo this conversion in the
atmosphere upon release from the HCFI stack.
The construction and closure phases were assessed qualitatively due to the
temporary nature of these operations.
Current operations were assumed to be twenty-four hours over a 365 day year in
order to model a “continuous” process as well as preserve the most conservative
modelling approach.
1.4 Outline of report
The applicable legal requirements and health criteria are described in Section 2. The
baseline characterisation comprising of atmospheric dispersion potential and existing
sources of air pollution are discussed in the subsequent section. The impact assessment for
the proposed operations is provided in Section 4. Section 5 provides the findings,
conclusions and recommendations.
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2 LEGAL REQUIREMENTS AND HUMAN HEALTH CRITERIA
Prior to assessing the impacts from the proposed operations, reference needs to be made to
the environmental regulations and guidelines governing the emissions and impact of such
operations.
Air quality guidelines and standards are fundamental to effective air quality management,
providing the link between the source of atmospheric emissions and the user of that air at the
downstream receptor site. The ambient air quality limits are intended to indicate safe daily
exposure levels for the majority of the population, including the very young and the elderly,
throughout an individual’s lifetime. Air quality guidelines and standards are normally given
for specific averaging periods. These averaging periods refer to the time-span over which
the air concentration of the pollutant was monitored at a location. Generally, five averaging
periods are applicable, namely an instantaneous peak, 1-hour average, 24-hour average, 1-
month average, and annual average. The application of these standards varies, with some
countries allowing a certain number of exceedances of each of the standards per year.
2.1 Air Pollution Legislative Context
Although the NEM:AQA already commenced on 11 September 2005, the Atmospheric
Pollution Prevention Act (APPA) of 1965 was only repealed completely, and the new Act only
brought into full force on the 1st of April 2010. The new Act has shifted the approach of air
quality management from source-based control to the control of the receiving environment.
The act has also placed the responsibility of air quality management on the shoulders of local
authorities that will be tasked with baseline characterisation, management and operation of
ambient monitoring networks, licensing of listed activities, and emissions reduction
strategies. The main objective of the act is to ensure the protection of the environment and
human health through reasonable measures of air pollution control within the sustainable
(economic, social and ecological) development framework.
Previously under the Air Pollution Prevention Act (Act No 45 of 1965) (APPA) the focus was
mainly on sourced based control with permits issued for Scheduled Processes. Scheduled
processes, referred to in the Act, are processes which emit more than a defined quantity of
pollutants per year, including combustion sources, smelting and inherently dusty industries.
Although emission limits and ambient concentration guidelines were published, no provision
was made under the APPA for ambient air quality standards or emission standards.
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The new AQA has shifted the approach of air quality management from source-based control
only to the control of the receiving environment. The act has also placed the responsibility of
air quality management on the shoulders of local authorities that will be tasked with baseline
characterisation, management and operation of ambient monitoring networks, licensing of
listed activities, and emissions reduction strategies. The main objective of the act is to
ensure the protection of the environment and human health through reasonable measures of
air pollution control within the sustainable (economic, social and ecological) development
framework.
The National Framework for achieving the Act was published in the Government Gazette on
the 11th of September 2007. The National Framework is a medium- to long term plan on how
to implement the Air Quality Act to ensure the objectives of the act are met. The National
Framework states that aside from the various spheres of government responsibility towards
good air quality, industry too has a responsibility not to impinge on everyone’s right to air that
is not harmful to health and well-being. Industries therefore should take reasonable
measures to prevent such pollution order degradation form occurring, continuing or recurring.
In terms of NEM:AQA, certain industries have further responsibilities, including:
• Compliance with any relevant national standards for emissions from point, non-point
or mobile sources in respect of substances or mixtures of substances identified by the
Minister, MEC or municipality.
• Compliance with the measurements requirements of identified emissions from point,
non-point or mobile sources and the form in which such measurements must be
reported and the organs of state to whom such measurements must be reported.
• Compliance with relevant emission standards in respect of controlled emitters if an
activity undertaken by the industry and/or an appliance used by the industry is
identified as a controlled emitter.
• Compliance with any usage, manufacture or sale and/or emissions standards or
prohibitions in respect of controlled fuels if such fuels are manufactured, sold or used
by the industry.
• Comply with the Minister’s requirement for the implementation of a pollution
prevention plan in respect of a substance declared as a priority air pollutant.
• Comply with an Air Quality Officer’s legal request to submit an atmospheric impact
report in a prescribed form.
• Taking reasonable steps to prevent the emission of any offensive odour caused by
any activity on their premises.
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• Furthermore, industries identified as Listed Activities (see Section 3.2) have further
responsibilities, including:
• Making application for an Atmospheric Emission Licence (AEL) and complying
with its provisions.
• Compliance with any minimum emission standards in respect of a substance or
mixture of substances identified as resulting from a listed activity.
• Designate an Emission Control Officer if required to do so.
Emission Limits and National Ambient Air Quality Standards
The AQA makes provision for the setting of ambient air quality standards and emission limits
on National level, which provides the objective for air quality management. More stringent
ambient standards may be implemented by provincial and metropolitan authorities. Listed
activities will be identified by the Minister and will include all activities regarded to have a
significant detrimental effect on the environment, including health. In addition, the Minister
may declare priority pollutants for which an industry emitting this substance will be required
to implement air pollution prevention plans.
Listed Activities
The AQA was developed to reform and update air quality legislation in South Africa with the
intention to reflect the overarching principles within the National Environmental Management
Act. It also aims to comply with general environmental policies and to bring legislation in line
with local and international good air quality management practices. Given the specific
requirements of the NEMAQA, various projects had to be initiated to ensure these
requirements are met. One of these included the development of the Listed Activities and
Minimum National Emission Standards. These standards were published on 31 March 2010
(Government Gazette No. 33064). The project aimed to establish minimum emission limits
for a number of activities identified through a consultative process at several forums.
According to the process description, the Listed Activities that could potentially apply include:
Category 2.2: Storage and handling of petroleum products - petroleum product storage tanks
and product transfer facilities, except those used for liquefied petroleum gas
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Figure 2-1: Listed Activities Cat. 2.2 - Storage and Handling of Petroleum Products
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Figure 2-2: Listed Activities Cat. 8 - Disposal of Hazardous and General Waste
Category 8.2: Crematoria and Veterinary Waste Incineration – where the cremation of human
remains, companion animals (pets) and veterinary waste is conducted.
The proposed plant will store diesel fuel in a number of storage tanks. However, these tanks
all fall below the 500 m³ capacity criteria given in Category 2.2. Therefore it is anticipated
that this category would not apply.
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After the initial application and assessment were undertaken in 2012, the relevant listed
activity changed from Category 8 to Category 8.2, and the AEL application was also updated
to include only those pollutants relevant to the Category 8.2. HCFI therefore only needs to
meet the Category 8.2 Listed Activity emission limits as shown in Figure 2-3 below.
Figure 2-3: Section 21 of NEMAQA, Listed Activities Category 8.2 Cremation of human
remains, companion animals and veterinary waste.
Listed Activity Category 8.2 also makes reference to Schedule 4, Section 11.4 of the National Policy
on Thermal Treatment of General and Hazardous Waste (Government Gazette No. 32439, Notice No.
777 of 24 July 2009. This Policy provides the framework for the incineration of general and hazardous
waste, which includes emission limits and conditions for environmental authorisation. The conditions
for environmental authorisation include
general requirements and prerequisites, which must be in place to prevent and reduce risks
prior to commencing with treatment of hazardous wastes on a routine basis;
operational management procedures, including the receipt, temporary storage, handling and
treatment of the waste;
minimum design and operating requirements to minimise air quality impacts; and
management plans and programmes which must be implemented during operation.
National Ambient Air Quality Standards
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Air quality limits and thresholds are fundamental to effective air quality management,
providing the link between the potential source of atmospheric emissions and the user of that
air at the downwind receptor site. Air quality standards are enforceable by law whilst
guidelines, as used in the current context, are used primarily as an indication of the level of
impact. Ambient air quality guideline values (and standards) generally indicate safe daily
exposure levels for the majority of the population, including the very young and the elderly,
throughout an individual’s lifetime. However, setting standards may also include other
factors such as economic implications.
Table 2-1: National Ambient Air Quality Standards (NAAQS)
Pollutant Averaging
Period
Limit
Value
(µg/m³)
Limit
Value
(ppb)
Frequency
of
Exceedance
Compliance Date
Carbon
Monoxide
(CO)
1 hour 30000 26000 88 Immediate
8 hour(a) 10000 8700 11 Immediate
Nitrogen
Dioxide
(NO2)
1 hour 200 106 88 Immediate
1 year 40 21 0 Immediate
PM10
24 hour 120 - 4
Immediate – 31 Dec
2014
75 - 4 1 Jan 2015
1 year
50 - 0 Immediate – 31 Dec
2014
40 - 0 1 Jan 2015
Sulphur
Dioxide
(SO2)
10 minutes 500 191 526 Immediate
1 hour 350 134 88 Immediate
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Pollutant Averaging
Period
Limit
Value
(µg/m³)
Limit
Value
(ppb)
Frequency
of
Exceedance
Compliance Date
24 hour 125 48 4 Immediate
1 year 50 19 0 Immediate
Benzene 1 year
10 3.2 0 Immediate – 31 Dec
2014
5 1.6 0 1 Jan 2015
2.2 Health Thresholds for Non-Carcinogenic and Carcinogenic Exposures
Non-Carcinogenic Exposures
The non-carcinogenic pollutants included in this study are taken from the NEM:AQA
Category 8 Listed Activities and include Hydrogen Chloride, Hydrogen Flouride and
Ammonia. The full list of non-carcinogenic exposure levels can be viewed in Appendix A,
section 7.2 Health risk criteria for non-carcinogenic exposures.
WHO guideline values are based on the number of observed adverse effect level (NOAEL)
and the lowest observed adverse effect level (LOAEL). Although most guideline values are
based on NOAELs and/or LOAELs related to human health endpoints, certain of the
guidelines given for 30 minute averaging periods are related to odour thresholds. The short
term environmental screening levels (ESLs) issued by TARA for certain odorous compounds
are similarly intended to be used for a screening for potential nuisance impacts related to
mal-odour.
Reference concentrations (Rfc’s) related to inhalation exposures are published in the US-
EPA’s Integrated Risk Information System (IRIS) database. Rfc’s are used to estimate non-
carcinogenic effects representing a level of environmental exposure at or below which no
adverse effect is expected to occur. The Rfc is defined as "an estimate (with uncertainty
spanning perhaps an order of magnitude) of a daily exposure to the human population
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(including sensitive subgroups) that is likely to be without appreciable risk of deleterious
effects during a lifetime" (IRIS, 1998). Non-carcinogenic effects are evaluated by calculating
the ratio, or hazard index, between a dose (in this case the dosage) and the pollutant-specific
inhalation Rfc. In the current study reference was made to the chronic inhalation toxicity
values published by US-EPA (IRIS, 1998) .
Rfc’s are based on an assumption of lifetime exposure and thus provide a very conservative
estimate when applied to less-than-lifetime exposure situations. The Rfc is also not a direct
or absolute estimator of risk, but rather a reference point to gauge potential effects. Doses at
or below the Rfc are not likely to be associated with any adverse health effects. However,
exceedance of the Rfc does not imply that an adverse health effect would necessarily occur.
As the amount and frequency of exposures exceeding the Rfc increase, the probability that
adverse effects may be observed in the human population also increases. The US-EPA has
therefore specified that although doses below the Rfc are acceptable, doses above the Rfc
are not necessarily unsafe.
The US Agency for Toxic Substances and Disease Registry (ATSDR) uses the
NOAEL/uncertainty factor (UF) approach to derive maximum risk levels (MRLs) for
hazardous substances. They are set below levels that, based on current information, might
cause adverse health effects in the people most sensitive to such substance-induced effects.
MRLs are derived for acute (1-14 days), intermediate (>14-364 days), and chronic (365 days
and longer) exposure durations, and for the oral and inhalation routes of exposure. MRLs are
generally based on the most sensitive substance-induced end point considered to be of
relevance to humans. ATSDR does not use serious health effects (such as irreparable
damage to the liver or kidneys, or birth defects) as a basis for establishing MRLs. Exposure
to a level above the MRL does not mean that adverse health effects will occur.
MRLs are intended to serve as a screening tool to help public health professionals decide
where to look more closely. They may also be viewed as a mechanism to identify those
hazardous waste sites that are not expected to cause adverse health effects. Most MRLs
contain some degree of uncertainty because of the lack of precise toxicological information
on the people who might be most sensitive (e.g., infants, elderly, and nutritionally or
immunologically compromised) to effects of hazardous substances. ATSDR uses a
conservative (i.e., protective) approach to address these uncertainties consistent with the
public health principle of prevention. Although human data are preferred, MRLs often must
be based on animal studies because relevant human studies are lacking. In the absence of
evidence to the contrary, ATSDR assumes that humans are more sensitive than animals to
the effects of hazardous substances that certain persons may be particularly sensitive. Thus
the resulting MRL may be as much as a hundredfold below levels shown to be non-toxic in
laboratory animals. When adequate information is available, physiologically based
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pharmacokinetic (PBPK) modelling and benchmark dose (BMD) modelling have also been
used as an adjunct to the NOAEL/UF approach in deriving MRLs.
Proposed MRLs undergo a rigorous review process. They are reviewed by the Health
Effects/MRL Workgroup within the Division of Toxicology; and expert panel of external peer
reviewers; the agency wide MRL Workgroup, with participation from other federal agencies,
including EPA; and are submitted for public comment through the toxicological profile public
comment period. Each MRL is subject to change as new information becomes available
concomitant with updating the toxicological profile of the substance. MRLs in the most recent
toxicological profiles supersede previously published levels.
TARA ESLs are based on data concerning health effects, odour nuisance potential,
vegetation effects, or corrosion effects. ESLs are not ambient air quality standards! If
predicted or measured airborne levels of a constituent do not exceed the screening level, it is
not expected that any adverse health or welfare effects would results. If ambient levels of
constituents in air exceed the screening levels it does not, however, necessarily indicate a
problem, but should be viewed as a trigger for a more in-depth review.
In the assessment of the potential for health risks use will generally be made of the lowest
threshold published for a particular pollutant and averaging period. TARA ESLs will however
only be used in the event that WHO guideline values, IRIS reference exposure
concentrations, ATSDR MRLs or Californian RELs are not available.
Carcinogenic Exposures
2.2.1.1 Unit Factors
Unit risk factors (URFs) are applied in the calculation of carcinogenic risks. These factors
are defined as the estimated probability of a person (60-70 kg) contracting cancer as a result
of constant exposure to an ambient concentration of 1 µg/m³ over a 70-year lifetime. In the
generic health risk assessment undertaken as part of the current study, maximum possible
exposures (24-hours a day over a 70-year lifetime) are assumed for all areas beyond the
boundary of the proposed development site. Unit risk factors were obtained from the WHO
(2000) and from the US-EPA IRIS database (accessed May 2005). URFs for compounds of
interest in the current study are given in Table 4-11, while the full list of pollutants as listed by
the US-EPA can be seen in Appendix A, Section 7.3- Unit risk factors.
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2.2.1.2 Acceptable Cancer risk
The Carcinogenic pollutants included in this study include those in the Heavy metals
category of the NAAQS, Listed Activities Category 8. Not all metals that are in this category
have a carcinogenic character, only those that do were included in the study (See Section
4.2.1.3).
The identification of an acceptable cancer risk level has been debated for many years and it
possibly will still continue as societal norms and values change. Some people would easily
accept higher risks than others, even if it were not within their own control; others prefer to
take very low risks. An acceptable risk is a question of societal acceptance and will therefore
vary from society to society.
In spite of the difficulty to provide a definitive “acceptable risk level”, the estimation of a risk
associated with an activity provides the means for a comparison of the activity to other
everyday hazards, and therefore allowing risk-management policy decisions. Technical risk
assessments seldom set the regulatory agenda because of the different ways in which the
non-technical public perceives risks. Consequently, science does not directly provide an
answer to the question.
Risk assessment as an organized activity of the US Food and Drug Administration (FDA) and
the EPA began in the 1970s. During the middle 1970s, the EPA and FDA issued guidance
for estimating risks associated with small exposures to potentially carcinogenic chemicals.
Their guidance made estimated risks of one extra cancer over the lifetime of 100 000 people
(EPA) or 1 million people (FDA) action levels for regulatory attention. Estimated risks below
those levels are considered negligible because they add individually so little to the
background rate of about 250 000 cancer deaths out of every 1 million people who die every
year in the United States, i.e. 25%. Accepting 1 in 100 000 or 1 in a million risk translates to
0.004% or 0.0004% increase in the existing cancer risk level, respectively.
The European Parliament and the European Council, when considering the proposal for a
Directive on Drinking Water, agreed that an excess lifetime risk of 1 in a million should be
taken as the starting point for developing limit values. In South Africa, DEAT has only been
noted to give an indication of cancer risk acceptability in the case of dioxin and furan
exposures. According to the DEAT, emissions of dioxins and furans from a hazardous waste
incinerator may not result in an excess lifetime cancer risk of greater than 1: 100 000 on the
basis of annual average exposure (DEAT, 1994). In general, excess cancer risks of less
than 1:100 000 appear therefore to be viewed as acceptable to the DEAT.
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The SANS for Benzene (SANS 1929:2004) adopted a limit value of 5µg/m³ that is based on
the value developed for the European Community (EC) Standard. This value is to be met by
2010. Depending on which unit risk factor is used, the equivalent incremental cancer risk for
this standard varies from a minimum of 1.5:100 000 (California Air Resources Board (CARB))
to 3.5:100 000 (WHO) and 3.9:100 000 (US EPA), respectively. (The geometric mean of the
range of WHO estimates of the excess lifetime risk of leukaemia at an air concentration of
1µg/m³ is 6x10-6. The concentrations of airborne benzene associated with an excess
lifetime risk of 1:10 000, 1:100 000 and 1:1 000 000 are 17, 1.7 and 0.17µg/m³ respectively.
Whilst it is perhaps inappropriate to make a judgment about how much risk should be
acceptable, through reviewing acceptable risk levels selected by other well-known
organizations, it would appear that the US EPA’s application is the most suitable, i.e.
“If the risk to the maximally exposed individual (MEI) is no more than 1x10-6, then no further
action is required. If not, the MEI risk must be reduced to no more than 1x10-4, regardless of
feasibility and cost, while protecting as many individuals as possible in the general population
against risks exceeding 1x10-6”
Some authorities tend to avoid the specification of a single acceptable risk level. Instead a
“risk-ranking system” is preferred. For example, the New York Department of Health
produced a qualitative ranking of cancer risk estimates, from very low to very high (Table
2-2). Therefore if the qualitative descriptor was "low", then the excess lifetime cancer risk
from that exposure is in the range of greater than one per million to less than one per ten
thousand.
Table 2-2: Excess Lifetime Cancer Risk (New York Department of Health)
Risk Ratio Qualitative Descriptor
Equal to or less than one in a million Very low
Greater than one in a million to less than one in ten thousand Low
One in ten thousand to less than one in a thousand Moderate
One in a thousand to less than one in ten High
Equal to or greater than one in ten Very high
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3 BASELINE CHARACTERISATION
3.1 Site Description
The existing incinerator located at the Helderstroom Correctional Facility is approximately 15
to 20 years old and has reached the end of its useful economic life. The slaughtering rate
has increased since this incinerator was first installed and thus a bigger, more efficient
incinerator is required. There are no facilities available to store dead or sick animals and
immediate incineration is a necessity to prevent the spreading of sickness. The type of
materials intended to be incinerated are as follows:
• Cattle = 2/day (+- 400 kg per unit)
• Pigs = 60/day (+- 75 kg per unit)
• Chicken = 4000/day (+- 1 kg per unit)
The existing incinerator must be replaced with a new incinerator that needs to burn waste at
a maximum rate of 233 kg/hour. Only one type of material will be incinerated per day.
The Helderstroom Correctional Facility is located approximately 19km north-north-west of
Caledon and 11km south-east of Villiersdorp (Figure 3-1) in the Overberg Local Municipality.
The facility is situated in the Helderstroom Valley, through which the Riviersonderend runs
and is surrounded by the Donkerhoek Mountain Range.
3.2 Sensitive Receptors
The closest sensitive receptors and site description for the HCFI are as follows;
North: Approximately 100m north of the incinerator are the incineration out-buildings, where
an abattoir etc. is located. The foot of the Donkerhoek mountain range is approximately 1.2
km north. The Riviersonderend Mountain Catchment area Reserve boundary is
approximately 11 km north of the incinerator. The small town of Villiersdorp is situated
approximately 11 km north west of the incinerator. There is undeveloped land situated
between these areas and the incinerator. Undeveloped land (some of which has been
transformed in the past, probably by agricultural activities) lies from approximately 0.5km to
11 km north of the incinerators. This land includes farm dams, farm houses and agricultural
buildings.
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Figure 3-1: Location of the Helderstroom Correctional Facility
East: Prison land under cultivation extends to approximately 500m east of the incinerator.
Agri-industrial buildings, agricultural and residential smallholdings are situated from
approximately 1km – 10km north-east and east of the incinerator. Beyond this is the start of
the Donkerhoek Mountains. The Riviersonderend valley also runs away from the incinerator
in a north easterly direction, thus creating a north east to south west “channel” valley within
which the incinerator is located.
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South: Approximately 0.1-1.5 km south and south east of the incinerator is cultivated land.
Beyond this at approximately 2-2.5 km are 2 farm houses situated down valley from the
incinerator. 7km south west of the incinerator lies the R43 public road which runs in a general
north-south direction.
West: The foot of Donkerhoek Mountain range is located approximately 1.1 km west of the
incinerator, with cultivated land between them. Approximately 700m west of the incinerator
are buildings belonging to the Helderstroom correctional facility. Beyond this, at
approximately 7 km west north west of the incinerator is the Threewaterskloof residential
estate. Sensitive receptors are shown below (Figure 3-2);
Figure 3-2: Location of the sensitive receptors to HCFI
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Sensitive receptors are characterised by farm buildings and farm residential areas. The
nearest of these is approximately 1km east of the incinerator. On site there are two sensitive
receptors where the guards and staff of the HCF will reside, these are found approximately
500m east south east and 900m south south east of the incinerator.
3.3 Atmospheric Dispersion Potential
Meteorological mechanisms govern the dispersion, transformation and eventual removal of
pollutants from the atmosphere. The extent to which pollution will accumulate or disperse in
the atmosphere is dependent on the degree of thermal and mechanical turbulence within the
earth’s boundary layer. Dispersion comprises vertical and horizontal components of motion.
The stability of the atmosphere and the depth of the surface-mixing layer define the vertical
component. The horizontal dispersion of pollution in the boundary layer is primarily a
function of the wind field. The wind speed determines both the distance of downwind
transport and the rate of dilution as a result of plume ‘stretching’. The generation of
mechanical turbulence is similarly a function of the wind speed, in combination with the
surface roughness. The wind direction, and the variability in wind direction, determines the
general path pollutants will follow, and the extent of crosswind spreading. Pollution
concentration levels therefore fluctuate in response to changes in atmospheric stability, to
concurrent variations in the mixing depth, and to shifts in the wind field.
Spatial variations, and diurnal and seasonal changes, in the wind field and stability regime
are functions of atmospheric processes operating at various temporal and spatial scales
(Goldreich and Tyson, 1988). Atmospheric processes at macro- and meso-scales need
therefore be taken into account in order to accurately parameterise the atmospheric
dispersion potential of a particular area. A qualitative description of the synoptic systems
determining the macro-ventilation potential of the region may be provided based on the
review of pertinent literature. Meso-scale systems may be investigated through the analysis
of meteorological data observed for the region.
Meso-scale ventilation and site-specific dispersion potential
3.3.1.1 Local wind field
The vertical dispersion of pollution is largely a function of the wind field. The wind speed
determines both the distance of downward transport and the rate of dilution of pollutants. The
generation of mechanical turbulence is similarly a function of the wind speed, in combination
with the surface roughness.
Wind roses for HCFI are shown in Figure 3-3 and Figure 3-4 between the periods January
2006 to December 2010. They depict recorded data obtained from purchased MM5 data.
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These wind roses comprise 16 spokes, which represent the directions from which winds blew
during the period. The colours reflected the different categories of wind speeds with the
dotted circles indicating the frequency of occurrence, and each circle representing a 3%
frequency of occurrence. The predominant wind field for the period is from the east. During
the day-time, dominant southerly and northerly winds occur and during night-time conditions
the dominant winds are from the east and strong winds are evident from the west-north-west.
Calm conditions (wind speeds less than 1m/s) during the day-time (6%) and increase to 14%
at night.
Figure 3-3: Period, Day and Night time wind roses MM5 date – Jan 2006- Dec 2010
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Figure 3-4: Seasonal wind roses MM5 date – Jan 2006- Dec 2010
A distinct shift in the prevailing wind field between seasons is evident. The seasonal wind
roses in above reflect the same trends during autumn, spring and summer, with the wind
coming mostly from the east and east-north-east. Winter shows the prevailing winds from the
north which range between 1 and >6 m/s. .
3.3.1.2 Ambient Temperature
Air temperature is important, both for determining the effect of plume buoyancy (the larger
the temperature difference between the plume and the ambient air, the higher the plume is
able to rise), and determining the development of the mixing and inversion layers.
Temperature provides an indication of the extent of insulation, and therefore of the rate of
development and dissipation of the mixing layer. Long term temperature recorded at Paarl is
used as an indication of temperature conditions experienced at the HCFI.
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The long term monthly minimum, maximum and average temperatures for Paarl (1951 -
1984) are given in Table 3-1 (Schulze, 1986).
Table 3-1: Long-term Temperature for Paarl (Schulze, 1986)
Temp
(°C) Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Ave
Min 21.3 21.6 19.6 16.1 13.7 11.6 11.7 11.8 13.5 14.7 18.3 19.6 16.1
Max 38.0 37.8 36.8 33.6 28.9 25.7 24.9 27.1 30.4 33.2 35.0 36.4 32.3
Mean 22.3 23.0 21.6 18.2 14.7 12.5 11.9 12.4 14.6 17.0 19.9 21.5 17.5
The monthly distribution of average daily maximum temperatures shows that the average
midday temperatures for Paarl range from 24°C in July to 37°C in February. The region is the
coldest during July when the mercury drops to 16°C on average during the night.
Monthly temperature statistics for the area are presented in Table 3-2. Diurnal temperature
trends for the area, based on MM5 data for Jan 2006 to Dec 2010, are presented in Figure
3-5. Typical diurnal trends are observed. Temperatures decrease during night-time and
reach a minimum just before sunrise at between 06h00 and 07h00. Temperatures increase
during daylight hours, peaking at around 13h00. Very little monthly variation in ambient
temperatures is noted.
Table 3-2: Monthly Temperature statistics
Monthly Temperature Statistics [°C]
Month
MM5 Data (Jan. 2008 to Dec. 2010)
Average Minimum Maximum
January 19.2 7.0 35.2
February 19.4 9.9 36.0
March 19.7 9.4 36.8
April 16.0 7.2 33.8
May 14.7 3.6 27.0
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Monthly Temperature Statistics [°C]
Month
MM5 Data (Jan. 2008 to Dec. 2010)
Average Minimum Maximum
June 13.6 4.8 26.9
July 13.2 2.9 25.3
August 14.3 4.9 27.5
September 14.0 5.5 28.6
October 14.3 6.1 30.8
November 15.6 8.2 29.8
December 17.6 7.8 31.0
Figure 3-5: Diurnal temperature profile at HCFI (MM5 data for Jan 2006 to Dec 2010)
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3.3.1.3 Rainfall
Rainfall for the region is assumed similar to the values recorded at Paarl, approximately 40
km to the north-west. Paarl normally receives about 900mm of rain per year and because it
receives most of its rainfall during winter it has a Mediterranean climate. March to July and
September to November are wet season months while the dry season lasts from July to
August and November to the end of February. Paarl receives the lowest rainfall (0mm) in
January and the highest (486mm) in June (
Table 3-3).
Rainfall data collected at Paarl from 2007 to 2009 indicates annual rainfall of between 625
mm and 785 mm. On average, the area receives 58 mm of rain per month. A summary of
monthly rainfall recorded at Paarl is provided in Figure 3-6.
Table 3-3: Long-term precipitation for Paarl (Schulze, 1986)
Temp
(°C) Jan Feb Mar Apr May Jun Jul Aug Sept Oct Nov Dec Ave
Min 0 1 0 4 8 12 16 40 3 3 0 0 594
Max 98 103 129 253 391 486 374 381 184 161 129 127 1389
Mean 22 26 32 73 148 162 137 141 69 57 36 30 933
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Figure 3-6: Rainfall recorded for Paarl (Jan 07 – Dec 09)
3.4 Existing Sources of Emissions near HCFI
A comprehensive emissions inventory for the study area was not available for the current
assessment and the establishment of such an inventory was not within the scope of the
current study. Instead source types present in the area and the pollutants associated with
such source types are noted with the aim of identifying pollutants which may be of
importance in terms of cumulative impact potentials. The main types of sources include:
Vehicle tailpipe emissions (R301 ~ 1.3 km east of the HCFI and the R45, ~3 km south
west of the HCFI),
Household fuel combustion (particularly coal and wood used by lower income
communities)
Biomass burning (veld fires in agricultural areas within the region), and
Various miscellaneous fugitive dust sources (agricultural activities, wind erosion of
open areas, vehicle-entrainment of dust along paved and unpaved roads).
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It is likely that certain households within local communities are using wood for space heating
and/or cooking purposes. Pollutants arising due to the combustion of wood include
respirable particulates, carbon monoxide and sulphur dioxide with trace amounts of
polycyclic aromatic hydrocarbons (PAHs), in particular benzo(a)pyrene and formaldehyde.
Particulate emissions from wood burning have been found to contain about 50% elemental
carbon and about 50% condensed hydrocarbons.
Crop-residue burning and general wild fires (veld fires) represent significant sources of
combustion-related emissions associated with agricultural areas. The quantity of dry,
combustible matter per unit area is on approximately 6 tons per hectare for African
Grasslands receiving 750 mm precipitation/ year; grass biomass is largely controlled by the
precipitation. Biomass burning is an incomplete combustion process with carbon monoxide,
methane and nitrogen dioxide being emitted during the process. About 40% of the nitrogen
in biomass is emitted as nitrogen, 10% remains in the ashes and it is assumed that 20% of
the nitrogen is emitted as higher molecular weight nitrogen compounds. The visibility of
smoke plumes from vegetation fires is due to their aerosol content.
Fugitive dust emissions may occur as a result of vehicle entrained dust from local paved and
unpaved roads, wind erosion from open areas and dust generated by agricultural activities
(e.g. tilling) and mining. The extent of particulate emissions from the main roads will depend
on the number of vehicles using the roads and on the silt loading on the roadways. The
extent, nature and duration of agricultural activities and the moisture and silt content of soils
is required to be known in order to quantify fugitive emissions from this source. The quantity
of windblown dust is similarly a function of the wind speed, the extent of exposed areas and
the moisture and silt content of such areas.
The pollutants listed above are released directly by sources and are therefore termed
'primary pollutants'. 'Secondary pollutants' which form in the atmosphere as a result of
chemical transformations and reactions between various compounds include: NO2, various
photochemical oxidants (e.g. ozone), hydrocarbon compounds, sulfuric acid, sulfates, nitric
acid and nitrate aerosols.
The sources of SO2 and NOx that occur in the region include veld burning, vehicle exhaust
emissions and household fuel burning.
Various local and remote sources are expected to contribute to the suspended fine
particulate concentrations in the region. Local sources include wind erosion from exposed
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areas, fugitive dust from agricultural operations, vehicle entrainment from roadways and veld
burning.
3.5 Measured Baseline Ambient Air Quality
Ambient monitoring campaigns within the Helderstroom Local Municipality include a
continuous monitoring station located in Paarl for the period March 2008 to June 2009.
Ambient concentrations of sulphur dioxide (SO2), nitrogen oxide (NO), nitrogen dioxide
(NO2), and oxides of nitrogen (NOx) were measured. In addition PM10 concentrations, ozone
and meteorological parameters were also included.
A two-week screening campaign was conducted during the winter months July-August 2005
and again in the summer months of February-March 2006 to sample PM10, SO2, NO2, ozone
and H2S. Passive diffusive samplers1 were setup in areas around Paarl, Wellington and
Mbekweni. The Cape Winelands District Municipality (CWDM) undertook another passive
sampling campaign between 26 June and 3 July 2006 whereby PM10, SO2, NO2 and VOCs
levels were sampled.
The monitoring undertaken as part of the screening campaigns for PM10, SO2, NO2, ozone
and H2S at Paarl, Wellington and Mbekweni indicated that:
• Paarl had relatively high PM10 concentrations for the period July–August 2005 (Figure
3-7), and Wellington had high concentrations for the period February-March 2006 as
reflected in Figure 3-8 and Figure 3-9, respectively. One explanation could be the
contribution to windblown dust originating from agricultural activities and tilling. An interesting
observation was the generally higher concentrations occurring during the winter rainfall
period, when concentrations are expected to be lower. A possible explanation for this
uncharacteristic occurrence was that these higher concentrations were due to a localised
source (e.g. construction activities, waste burning, etc).
• SO2, NO2 and ozone concentrations were not found to be problematic for the broader
municipal area with all concentrations well below the national standards. The towns of
Wellington and Paarl did, however have the highest NO2 and benzene concentrations in
relation to the other areas. This was expected due to the higher vehicle numbers in the two
towns with resultant vehicle tailpipe emissions. Compared to Paarl and Mbekweni,
Wellington displayed the highest SO2 concentrations possibly due to nearby boilers, but need
to be confirmed by further investigation.
1 Passive monitoring is a cost effective monitoring method that can be applied over a wide area sampling a range of pollutants
(i.e. SO2, NO2, ozone, hydrogen sulphide, hydrochloric acid, Volatile Organic Compounds etc.). The samples are exposed for a
period of time from where an average concentration is calculated. This provides a useful method to identify areas with potential
high air pollution.
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• During the sampling campaign, hydrogen sulphide (H2S) odour exceedances were
recorded in Mbekweni. This could possibly be due to the sewage system vents but need to
be confirmed by further investigations.
Figure 3-7: Ambient PM10 Concentrations (Jul-Aug 2005)
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Figure 3-8: Ambient PM10 concentrations (Feb-Mar 2006)
Figure 3-9: Ambient SO2, NO2 and Benzene concentrations (26 Jun – 3 Jul 2006)
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Due to the findings from the monthly monitoring campaigns undertaken, it was decided that
continuous monitoring was necessary over a longer period. This occurred over the year of
2009. The main findings of the one year ambient monitoring campaign (Figure 3-10 to Figure
3-13) in Paarl indicated:
• Non-compliance with the South African PM10 daily standard, with 5 daily exceedances
of 120 µg/m³ and 25 exceedances of 75 µg/m³, mainly during the March/April and June/July
months.
• The SO2 and NO2 concentrations were low and well within the standards.
• Ozone concentrations increased during 2009, exceeding the 8-hourly mean standard
of 120 µg/m³ three times
Figure 3-10: Ambient PM10 concentrations (Apr 2008 – May 2009)
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Figure 3-11: Ambient SO2 concentrations (Apr 2008 – May 2009)
Figure 3-12: Ambient NO2 concentrations (Apr 2008 – May 2009)
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Figure 3-13: Ambient O3 concentrations (Apr 2008 – May 2009)
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4 IMPACT ASSESSMENT
The proposed operations at the HCFI include the incineration of approximately 353 kg/hr of
meat in the form of slaughtered cattle, pigs or chickens. There are no storage facilities on-
site and therefore immediate incineration is required in order prevent the spreading of
disease and sickness from the animals that have been slaughtered.
The following section covers the emissions quantification, dispersion modelling, results and
impact assessment for the current and proposed operations.
4.1 Construction Phase
It is not anticipated that the various construction activities will result in higher off-site impacts
than the operational phase activities. The temporary nature of the construction activities, and
the likelihood that these activities will be localised and for small areas at a time, will reduce
the potential for significant off-site impacts.
Since construction will primarily include the updating of an existing incinerator and the
associated equipment with newer, larger equipment, these operations were seen to coincide
with the current operations and not assessed separately.
4.2 Operational Phase - Emissions Inventory
In the absence of actual stack emission measurements, the emissions inventory was
compiled for the activities at the HCFI using the technical specifications (i.e. stack parameter)
and design feed rates of the incinerator (Table 4-1) provided by the client, with NEM:AQA
Listed Activity Category 8 emission limits.
In addition, and to test whether the Category 8 emission limits are achievable, emission
factors were also used to calculate empirical emission rates. These emission factors
originate from the European Environment Agency (EMEP/EEA) Air Pollutant Emission
Inventory Guidebook, and more specifically, emission factors associated with Human
Crematoriums, Sheep Incineration and Cow Incineration. The calculated emission rates are
summarised in Table 4-2.
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Table 4-1: HCFI stack parameters
Stack Parameters Helderstroom Units
Waste 353 kg/hr
Stack Height 13.3 m
Stack Diameter 0.64 m
Exit Temperature 180 °C
Exit Velocity 4.8 m/s
Actual Volumetric Flow Rate 6.3 m³/s
Normal Volumetric Flow Rate 3.7 Nm³/s
Control Efficiency 0 %
Cattle Feed Rate 2 day
Pig Feed Rate 60 day
Chicken Feed Rate 4000 day
Design Rate 353 kg/hr
Table 4-2: Calculated emission rates
Pollutant Emission Factor (max) Emission
Rate (g/s)
Licence Emission Rate (g/s) (Cat. 8)
Min EF - times greater than
Licence Emission Rate
Max EF - times greater than
Licence Emission Rate
CO 0.25 0.186 0.3 1
NOx 1.35 0.745 0.4 2
SO2 0.73 0.186 3 4
HCl 0.16 0.037 2 4
HF 0.00 0.004 1 1
NH3 0.20 0.037 5 5
PM10 0.15 0.037 2 4
Cadmium 7.26E-06 1.86E-04 0 0
Mercury (b) 2.15E-03 1.86E-04 12 12
Dioxins/Furans 9.81E-10 3.73E-10 3 3
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Pollutant Emission Factor (max) Emission
Rate (g/s)
Licence Emission Rate (g/s) (Cat. 8)
Min EF - times greater than
Licence Emission Rate
Max EF - times greater than
Licence Emission Rate
NMVOC 1.96E-10 3.73E-02 0 0
Heavy Metals 2.22E-03 3.73E-04 0.2 6
Note: (a) Bold letters indicate that the minimum Emission Factor employed will result in stack emission
concentrations greater than those stipulated in the NEM:AQA category 8 Listed Activity
document – indicating that further investigation through monitoring is necessary.
Note: (b) Mercury Emission Factors were only available for Human Crematoria. It is suspected that this
value may be too conservative for use in animal incineration.
A detailed description of the emission factors used in the calculation of the pollutant
emissions is provided in Appendix A. Table 4-3 on the following page depicts the summary of
the emission factors investigated for the purpose of this study.
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Table 4-3: Summary of Emission Factors investigated
Incineration Process Type of Fuel
Min Max Unit EMEP/EEA - Sheep
EMEP/EEA - Cow
EMEP/EEA - Human
No Fuel Heavy Fuel Oil Fat
CO - - - 2.52 0.59 0.52 0.52 2.52 kg/tonne
NOx - - - 2.73 13.82 10.40 2.73 13.82 kg/tonne
SO2 - - - 7.19 19.54 6.46 6.46 19.54 kg/tonne
HCl - - - 0.75 1.31 1.59 0.75 1.59 kg/tonne
HF - - - 0.03 0.04 0.05 0.03 0.05 kg/tonne
NH3 2.00 2.00 - - - - 2.00 2.00 kg/tonne
TSP 2.18 0.90 - - - - 0.90 2.18 kg/tonne
PM10 1.53 0.63 - - - - 0.63 1.53 kg/tonne
PM2.5 1.31 0.54 - - - - 0.54 1.31 kg/tonne
Arsenic - - 2.00E-04 - - - 2.00E-04 2.00E-04 kg/tonne
Beryllium - - 9.20E-06 - - - 9.20E-06 9.20E-06 kg/tonne
Cadmium - - 7.40E-05 - - - 7.40E-05 7.40E-05 kg/tonne
Chromium - - 2.00E-04 - - - 2.00E-04 2.00E-04 kg/tonne
Formaldehyde - - 1.45E-09 - - - 1.45E-09 1.45E-09 kg/tonne
Mercury - - 2.20E-02 - - - 2.20E-02 2.20E-02 kg/tonne
Nickel - - 2.55E-04 - - - 2.55E-04 2.55E-04 kg/tonne
PAH 0.10 0.10 - - - 1.00E-01 1.00E-01 kg/tonne
Dioxins/Furans 10.00 10.00 - - - 10.00 10.00 µg I-TEQ/tonne
NMVOC 2.00 2.00 - - - 2.00 2.00 kg/tonne
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Dispersion Simulation Results and Time Series Data
The plots provided for the relevant pollutants of concern are given in Table 4-4. Only plots
applicable to the requirements of the NAAQS criteria pollutants were included. These also
only include the Ground Level Concentration (GLC) for each in accordance with the NAAQS
standard averaging time (Annual or Hourly GLC). The predicted impacts are due only to
operations at the HCFI. Time series graphs follow after every pollutant’s isopleth plot
depicting the calculated hourly GLC for each sensitive receptor over the space of a year.
There are 5 time series plots, one for every year from 2006 – 2010 (Table 4-5 to Table 4-8).
Table 4-4: Isopleth plots presented in the current section
Pollutant Averaging Period Figure
PM10 Annual Concentration Figure 4-1
CO Hourly Concentration Figure 4-2
SO2 Annual Concentration Figure 4-3
NOx Annual Concentration Figure 4-4
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Figure 4-1: Predicted annual PM10 Ground Level Concentration
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Table 4-5: Time Series Graphs showing Hourly PM10 GLC’s
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Figure 4-2: Predicted hourly CO Ground Level Concentration
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Table 4-6: Time Series Graphs showing Hourly CO GLC’s
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Figure 4-3: Predicted annual SO2 Ground Level Concentration
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Table 4-7: Time Series Graphs showing Hourly SO2 GLC’s
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Figure 4-4: Predicted annual NOx Ground Level Concentration
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Table 4-8: Time Series Graphs showing Hourly NOx (As NO2) GLC’s
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Compliance Assessment of Predicted Impacts
4.2.1.1 Criteria Pollutants PM10, CO, SO2 and NOx
Predicted GLC’s at sensitive receptors included in the study area are presented in and
illustrated in Figure 4-1, Figure 4-2, Figure 4-3 and Figure 4-4. The predicted Criteria
Pollutants impacts and GLC’s at all of the sensitive receptors (due to current operations at
HCFI) are predicted to be well within their respective NAAQS Limit Values. There are no
predicted Frequency of Exceedances at any discrete sensitive receptor or within the study
area.
Table 4-9: Predicted NAAQS Criteria Pollutant average GLC’s
Helderstroom Incinerator - Predicted average GLC's (µg/m³)
NAAQS Criteria Pollutant Cat. 8 Emis. Limits
Using EMEP/EEA Emission Factors
Hourly Daily Annual Hourly Daily Annual
PM10 - 0.7 0.2 - 3 1
CO 13 - 1 13 - 1
SO2 13 3 3 54 13 12
NOx 54 - 0.8 108 - 2
Percentage of the NAAQS Limit Value
PM10 - Immediate - 0.01 0.003 - 0.02 0.01
PM10 - 1 Jan 2015 - 0.01 0.02 - 0.04 0.02
CO 0.0004 - - 0.0004 - -
SO2 0.04 0.03 0.06 0.15 0.11 0.24
NOx 0.27 - 0.02 0.54 - 0.04
Note: a) Percentage values (bottom section of Table 4-4) greater than 1 indicates non-compliance with
the NAAQS Limit.
4.2.1.2 Non-Carcinogenic Exposure levels
Certain pollutants included in this study carry an inherent “irritant” risk, whereby they are not
necessarily detrimental to human health, but at a certain concentration can irritate human
respiratory tracts and sinuses. In Table 4-10 on the following page, a Chronic Hazard ratio of
1 or less indicates no “flagging” of that pollutant i.e. that it will not be greater than the
reference concentration due to the HCFI operations.
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Table 4-10: Non-carcinogenic pollutants and their reference exposure levels
Chronic (Long-term)
Non-carcinogenic Irritants
Predicted GLC (µg/m³)
Chronic Reference Concentration a
Chronic Hazard Ratio
HCl 5.25E-03 2.00E-02 0.26
HF 1.51E-04 1.40E-02 0.01
NH3 6.60E-03 1.00E-01 0.07
Acute (Short-term)
Non-carcinogenic Irritants
Predicted GLC (µg/m³)
Acute Reference Concentration a
Acute Hazard Ratio
HCl 4.14E-01 2.10E+00 0.2
HF 1.19E-02 1.64E-02 0.7
NH3 5.21E-01 1.18E+00 0.4
Note a: Hazard ratio values of greater than 1 indicate that the associated Reference concentration level
(Rfc) is exceeded
4.2.1.3 Carcinogenic Exposure levels
Heavy metals as listed in Category 8 of the NEM:AQA Listed Activities are known to carry
inherent cancer risk to humans subjected to them over a period of time. These metals will be
present in the emissions emanating from the incineration process based on the diet of the
animal being incinerated. Incorporating the Integrated Risk Information System (IRIS)
programme employed by the US-EPA, an increase in lifetime cancer risk through the
operation of the HCFI was investigated. The metals shown in Table 4-11 on the following
page have their annual concentrations calculated using emission factors related to Human
Crematoriums.
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Table 4-11: Carcinogenic exposure levels as a result of heavy metals
Heavy Metals (Carcinogens) - Increase in Lifetime Cancer Risk
Category 8 Listed Activities heavy
metals
Predicted Annual GLC (µg/m³)
Inhalation Unit Risk a Increased Lifetime
Cancer Risk fraction
arsenic 7.94E-05 4.30E-03 1 in 10 Million
cadmium 2.94E-05 1.80E-03 1 in 100 Million
chromium 7.92E-05 8.40E-02 1 in 1 Million
formaldehyde 5.74E-10 1.30E-05 1 in 10 Million x 1014
nickel 1.01E-04 2.40E-04 1 in 100 Million
Total - Heavy Metals 2.89E-04 9.04E-02 2 in 1 Million
Note: a) All Unit risk Factors obtained from the US EPA’s Integrated Risk Information System (IRIS) Programme
where the cancer unit risk for a range of pollutants is given
4.3 Closure Phase
It is assumed that all incineration activities will have ceased when the Incinerator shuts down.
The potential for impacts during the closure phase will depend on the extent of rehabilitation
efforts on the cleared and exposed areas around the incinerator building/s. The closure
phase will include wind erosion and to a lesser extent vehicle and equipment movement on
access roads.
The significance of the closure phase is likely to be linked to impacts from windblown dust.
Windblown dust is likely to only impact off-site under conditions of high wind speed. Due to
the nature of the incinerator, it is expected that these impacts will be extremely small and
localised and will not affect any off-site receptors.
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5 CONCLUSIONS AND RECOMMENDATIONS
5.1 Findings and Conclusions
The main findings regarding the baseline assessment are as follows:
In the absence of any major industrial activities, it is expected that the current air
quality would be dominated by air emissions from agricultural activities. Emissions
from these activities include Particulate Matter (PM). PM of a diameter of equal to or
less than 10 micrometres (PM10) is legislated in the National Ambient Air Quality
Standards. It is also referred to as thoracic particulates as it is proven to accumulate
in the throat and lungs of humans over certain exposure periods. The main sources
likely to contribute to cumulative PM10 impact are surrounding agricultural activities as
well as vehicle entrainment on unpaved road surfaces.
Ambient monitoring data recorded for the Paarl region showed that of the criteria
pollutants, PM10 could exceed the NAAQS daily standard. SO2, NOx and CO were
well below their respective NAAQS standards.
It is expected that the most significant airborne particulate impacts would be during
the dry summer season.
Wind field data were obtained from MM5 data. The hourly average wind field
database covers a five-year period (2006 – 2010). The wind field in the study area
has the wind direction being from the east and east-north-east. This indicates that
receptors located west and west-south-west of the incinerator will be most likely to be
impacted by emissions emanating from it.
The nearest sensitive receptors to the site are local farm houses. The closest farm
house is approximately 3.2 km west-south-west of the HCF boundary.
The main findings from the impact assessment due to proposed operations are as follows:
The predicted criteria pollutant concentrations are extremely low when compared to
the limit values stipulated by the NAAQS. There are no exceedances of the NAAQS
frequency of exceedance values over any time period for any criteria pollutant.
NOx was predicted to have the highest percentage value of its associated hourly
NAAQS limit value, being approximately 27% (Category 8 emission limit estimates)
and 54% (emission factor estimates), respectively. SO2 was predicted to be
approximately 6% (Category 8 emission limit estimates) and 24% (emission factor
estimates) of the NAAQS annual limit value.
At the time of this study, Category 8 emission limits were applicable; currently Category 8.2 emission limits are applicable. This reflects an increase in CO, NOx and
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PM emissions of 1.25, 2.5 and 4 times. To investigate the effects of this, it is accurate to multiply long term (annual) concentrations by the same factor. This proves that even with Category 8.2 emission rates being used, the relative long term assessment criteria for NOx, CO and PM are not exceeded. In order for this to occur one would need an increase in Category 8 based emissions of 40 times for PM and NOx, and an increase in CO emissions of 2400 times. CO impacts are extremely low.
Other irritants, including HCl, HF and NH3 are predicted to be well below their
respective Rfc’s over chronic (annual) and acute (hourly) exposures..
The increased life-time cancer risk associated with the proposed incinerator was
estimated to be 1 in 2 million, which may be classified as a “Low” risk.
The conclusions that can be drawn from air quality impact assessment are as follows;
The operation of the HCFI under the provided daily rates of incineration will not result
in any exceedances of the NAAQS criteria pollutants emission standards and limits.
The impact of non-criteria pollutants were also shown to be insignificant when
compared to health criteria recommended by the US EPA. The predicted incremental
cancer risk associated with the emissions from the proposed incinerator is low.
Using empirical emission factors, it was indicated that the Category 8 minimum
emission limits could be exceeded unless additional gas cleaning equipment is
installed. The same can be said for Category 8.2 emission limits. However, even with
the assumption of maximum emissions determined using emission factors (see
emissions in Table 4-2), ambient air pollutant concentrations at ground level were
predicted to be low and within NAAQS limits, for both Category 8 and 8.2 emission
limits.
5.2 Recommendations
Given that the empirical emission rates calculated using emission factors result in
exceedance of Category 8 Emission Limits, it is recommended that;
The supplier of the incinerator be able to demonstrate that Category 8.2 Emission
Limits will not be exceeded. This may require the installation of gas cleaning
equipment such as a wet scrubber or baghouse (Caustic solution – emissions from
the incinerator will be acidic).
Implementation of regular stack monitoring to ensure that emissions are within the
minimum Emission Limits as contained in the Category 8.2 Listed Activity. Frequency
of this monitoring must be agreed with the appropriate authority (District Municipality).
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For monitoring methods please refer to Schedule A – Methods for sampling as
Contained in the NEMAQA Listed Activities document (NEMAQA 39/2004).
Best Practice measures must be employed to minimise or avoid offensive odours
emanating from the incinerator feed material.
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6 REFERENCES
Andreae, M., Atlas, E., Cachier, H., Cofer, W., Harris, G., Helas, G., et al. (1996). Trace gas
and aerosol emissions from savanna fires. In J. Levine, Biomass Burning and Global
Change. Cambridge: MIT Press.
CEPA/FPAC Working Group. (1998). National Ambient Air Quality Objectives for Particulate
Matter. Part 1: Science Assessment Document. A Report by the Canadian
Environmental Protection Agency (CEPA) Federal-Provincial Advisory Committee
(FPAC)on Air Quality Objectives and Guidelines.
Dockery, D., & Pope, C. (1994). Acute Respiratory Effects of Particulate Air Pollution. 15.
EMEP/EEA air pollution emission inventory guidebook (2009), NFR-Cremation, Snap-
090901 Incineration of Corpses and Snap-090902 Incineration of carcasses.
EPA. (1996). Compilation of Air Pollution Emission Factors (AP-42). US Environmental
Protection Agency.
Ernst, W. (1981). Monitoring of particulate pollutants. In L. Steubing, & H.-J. Jager,
Monitoring of Air Pollutants by Plants: Methods and Problems. The Hague: Dr W Junk
Publishers.
Garstang, M., Tyson, P., Swap, R., & Edwards, M. (1996). Horizontal and vertical transport of
air over southern Africa.
Goldreich, Y., & Tyson, P. (1988). Diurnal and Inter-Diurnal Variations in Large-Scale
Atmospheric Turbulence over Southern Africa. South African Geographical Journal,
48-56.
National Environmental Management: Air Quality Act, 2004, act number 39 of 2004.
(NEM:AQA 39/2004), Government Gazette number 33064.
Pope, C. (2000). Epidemiology of fine particulate air pollution and human health: biologic
mechanisms and who’s at risk? Environmental Health Perspectives, 713-723.
Pope, C., Burnett, R., Thun, M., Calle, E., Krewski, D., Ito, K., et al. (2002). Lung cancer,
cardiopulmonary mortality, and long term exposure to fine particulate air pollution. .
Journal of the American Medical Association, 1132-1141.
Preston-Whyte, R. A., & Tyson, P. D. (1988). The Atmosphere and Weather over South
Africa. Cape Town: Oxford University Press.
Schulze B R (1986). Climate of South Africa. Part 8. General Survey, WB 28, Weather
Bureau, Department of Transport, Pretoria, 330 pp.
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 6-2
Tiwary, A., & Colls, J. (2010). Air Pollution: Measurement, Modelling and Mitigation.
Weather Bureau. (1986). Climate of South Africa. Part 8: General Survey, WB 28. Pretoria:
Weather Bureau.
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7 APPENDIX A: EMISSION FACTORS AND EQUATIONS
7.1 Emission Factors from the EMEP/EEA
As written in the EMEP/EEA;
“The contribution of emissions from the incineration of carcasses to the total national emissions is
thought to be relatively insignificant (i.e. less than 1 % of the national emissions of any pollutant).
The contribution of crematoria to national emissions is comparatively small for all pollutants
except for heavy metals (HM), especially mercury, in certain countries. Hydrogen chloride (HCl)
emissions can be significant, although the emissions of HCl from individual crematorium can vary
considerably. The contribution of this source category to the total emissions of dioxins and furans
is reported to be 0.2 % (Oslo and Paris Commission – Environmental Regulations for the
European Community (Osparcom)-Helsinki Commission – Baltic Marine Environment Protection
Commission (Helcom)-United Nations Economic Commission for Europe (UNECE) Emission
Inventory). Crematoria also have the potential to emit polycclic aromatic hydrocarbons (PAHs),
but are unlikely to release significant emissions of other persistent organic pollutants (POPs)
(European Topic Centre on Air Emissions (ETC/AEM)-CITEPA-RISOE 1997).”
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7.2 Health risk criteria for non-carcinogenic exposures
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
1,1,1 – Trichloroethane 10912 3819 10800 1080
1,1,2-Trichloroethane 550 55
1,1,2,2-Tetrachloroethane 2746 70 7
1,1-Dichloroethane 4000 400
1,1-Dichloroethene 200 70 79 40 4
1,2-Dichloroethane 160 4
1,2 – Dichloroethylene 7930 793
1,2 – Dichloropropane 4 231 32 1150 (a) 115
1,2,3 - Trimethylbenzene 1250 125
1,2,4 - Trimethylbenzene 1250 125
1,3,5 - Trimethylbenzene 1250 125
1,3-Butadiene 2 20 110 11
1,4-Butanediamine
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-4
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
1,5-Ddiaminopentane
1-Pentane 90 (a) 9
2-Propanol
2-Butoxyethanol 240 24
2-Methylpentane 289 (a) 28.9
3-Methylpentane 3500 350
Acetaldehyde 2000 (TC) 24-
hrs 50 (TC) 9 9 90 (a) 9
Acetone 61762 30881 30881 5900 590
Acrylonitrile 2 5 217 43 4.3
Aldehydes
Aluminium 50 5
Ammonia 100 3200 (1 hr) 200 1184 70 170 17
Arsenic 0.19 (4 hrs) 0.03 0.1 0.01
Benzene 30 1300 (6 hrs) 60 160 13 75
12 (24-
1
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-5
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
hrs)
Benzo(a)pyrene 0.03 0.003
Boron 100 10
Bromodichloromethane
Butane 19000 1900
Butyl mercaptan 1.8 (a) 0.18
Butylcellosolve 240 24
Butyric acid 18 (a) 1.8
Cadmium 0.005 (GV) 0.02 0.1 0.01
Caproic acid 48 (a) 4.8
Carbon disulphide 100 (GV) 24-
hrs 700 6200 (6 hrs) 800 934 30 3
Carbon Tetrachloride 6.1 (TC) 1900 (7 hrs) 40 189 189 126 13
Carbonyl sulphide 8 0.8
Chlorinated dibenzo-p-
dioxins & chlorinated 0.00004
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-6
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
dibenzo-furans(h)
Chlorine 210 (1 hr) 0.2 15 1.5
Chlorobenzene 1000 460 46
Chloroethane 500 50
Chlorodifluoromethane 50000 18000 1800
Chloroform 150 (7 hrs) 300 488 244 98 98 9.8
chromium (II) and (III)
compounds 1 0.1
Chromium
(VI) compounds 0.1 0.2 0.1 0.01
Cobalt 0.1 0.2 0.02
Copper 100 (1 hr) 10 1
Cresol (all isomers) 600 5 (a) 0.5
Cumene 400 500 (a) 50
Cyclohexane 1435 (a) 143.5
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-7
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
Cyclohexanone 481 (a) 48.1
Decane 10000 1000
Dichlorobenzene 1000 (GV) 200 (a)
800 (b) 800 (d)
12025
(d) 601 (d) 120 (d)
2500 (e)
1500( f)
600 (g)
250 (e)
150 (f)
60 (g)
Dichlorodifluoromethane 49500 4950
Dichlorofluoromethane 420 42
Dimethyl disulphide
Dimethyl sulphide 3 (a) 0.3
Dodecane
Ethane (simple
asphyxiant)
Ethanol
Ethyl Acetate 14400 1440
Ethyl Benzene 22000 (GV) 1000 2000 4342 2000 (a) 200
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-8
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
Ethyl chloride
(chloroethene) 10000 30000 39583 500 50
Ethyl mercaptan 0.8 (a) 0.08
Ethylbutyrate 39 (a) 3.9
Ethylene dibromide 0.8 3.8 0.38
Fluorotrichloromethane 28000 (a) 2800
Formaldehyde 100 (GV) 30
min 94 (1 hr) 3 49 37 10 15 1.5
Heptane 3500 350
Hexane 200 7000 2115 1760 176
Hydrogen chloride 2100 (1hr) 9
Hydrogen cyanide 3 340 (1 hr) 9 50 5
Hydrogen Fluoride 240 (1hr) 14
Hydrogen Sulphide 7 (GV) 30-min
(a)
150 (GV) 24
hrs
2 42 (1 hr) 10 533 53
Iso-octane 3500 350
Ketones
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-9
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
Limonene
Manganese 0.15 (GV) 0.05 0.2 0.04 2 0.2
Mercaptans (total)
Mercury 1 (GV) 0.3 1.8 (1 hr) 0.09 0.2 0.25 0.025
Methyl chloride
(chloromethane) 1043 417 104 1030 103
Methyl ethyl disulphide
Methyl ethyl ketone 5000 13000 (1 hr) 3900 (a) 390
Methyl isobutyl ketone 3000 2050 205
Methylene Chloride 14000 (1 hr) 400 2084 1042 1042 260 26
Methyl methacrylate 200 (TC) 700 340(a) 34
Methyl mercaptan 2 (a) 0.2
Molybdenum 100 10
n-Butyl Acetate 1850 (a) 185
n-heptane 3500 350
n-hexane 200 7000 1760 176
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-10
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
n-propyl mercaptan 6475 (a) 648
n-cymene 2745 275
Napthalene 3 9 3.7 440 (a) 44
Nickel 0.05 0.2 0.09 0.15 0.015
Nonane 10500 1050
Pentane 3500 350
Phenol 5800 (1 hr) 200 154 (a) 15.4
Propane 18000 1800
Propionic Acid 103 10.3
Propyl Benzene
Styrene 1000 21000 (1hr) 900 110 11
Tetrachloroethylene
(perchloroethylene)
8000 (GV) 30-
min
250 (GV) 24-
hrs
20000 (1 hr) 35 1373 275 340 34
Toluene 1000 (GV) 30- 400 37000 (1 hr) 300 3768 301 1880 188
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-11
Constituent
WHO Guidelines
(2000) (µg/m³)
US-EPA IRIS Inhalation
Reference Concentrations
(May 2005) (µg/m³)
Californian OEHHA
(adopted as of
August 2003) (µg/m³)
US ATSDR Maximum
Risk Levels (MRLs)
(May 2005) (µg/m³)
TARA ESLs
(1997) (µg/m³)
Acute & Sub-
acute
Guidelines
(ave period
given)
Chronic
Guidelines
(year +)
Sub-chronic
Inhalation
Rfc’s
Chronic
Inhalation
Rfc’s
Acute RELs
(ave period
given)
Chronic
RELs
Acute
(1-14
days)
Intermediate
(>14-365 days)
Chronic
(365+
days)
Short-
term ESL
(1hr)
Long-
term ESL
(year+)
min (a)
260 (GV) 1-
week
Trichloroethylene 600 10748 537 1350 135
Trimethylbenzene 1250 125
Undecane
Valeric acid 3 (a) 0.3
Vinyl acetate 200 200 150 15
Vinyl chloride 100 180000 (1 hr) 1278 77 130 13
Xylene 4800 (GV) 24-
hrs 870 (GV) 100 22000 (1 hr) 700 4342 3040 434 3700 (a) 370
Zinc 50 5
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-12
7.3 Unit risk factors
Compound
Californian
EPA Unit Risk
Factor (µg/m³)
WHO Inhalation
Unit Risk (µg/m³)
US-EPA IRIS
Unit Risk
Factor (µg/m³)
IARC
Cancer
Class
US-EPA
Cancer
Class (a)
1,1,2,2-
Tetrachloroethane (0.6–3.0) x 10
-6 5.8 x 10
-5 3 C
1,1,2-Trichloroehane 1.6 x 10-5
3 C
1,1-Dichloroethane 1.6 x 10-6
C
1,2-Dichloroethane 2.1 x 10-5
(0.5-2.8) x 10-6
2B C
1,3-Butadiene 1.7 x 10-4
3 x 10-5
2A B2
Acetaldehyde 2.7 x 10-6
(1.5-9) x 10-7
2.2 x 10-5
2B B2
Acrylonitrile 2.9 x 10-4
2.0 x 10-5
6.8 x 10-5
2A B1
Arsenic, Inorganic(a) 3.3 x 10-3
1.5 x 10-3
4.3 x 10-3
1 A
Benzene 2.9 x 10-5
4.4 x 10
-6 to 7.5 x
10-6
2.2 x 10-6
to 7.8
x10-6
1 A
Benzo(a)pyrene 8.7x10-2
8.8x10-4
(b) B2
Bromodichloromethane 3.7 x 10-5
B2
Cadmium 4.2 x 10-3
1.8 x 10-3
B1 2A
Carbon tetrachloride 4.2 x 10-5
1.5 x 10-5
2B B2
Chloroform 5.3 x 10-6
4.2 x 10-7
2.3 x 10-5
2B B2
Chromium VI
(particulates) 1.5 x 10
-1
1.1 x 10-2
to 13 x
10-2
1.2 x 10
-2 1 A
Dioxins 33 A
Formaldehyde 6.0 x 10-6
1.3 x 10-5
2A B1
Lead 1.2 x 10-5
B2 2B
Methylene chloride 1.0 x 10-6
4.7 x 10-7
2B B2
Nickel 2.6 x 10-4
3.8 x 10-4
2.4 x 10-4
A 1
Tetrachloroethylene 5.9 x 10-6
2B
Trichloroethylene 2.0 x 10-6
4.3 x 10-7
2A
Air Quality Impact Assessment for the Helderstroom Correctional Facility Incinerator
Report No.: APP/11/SEC-01c Rev 01 7-13
Compound
Californian
EPA Unit Risk
Factor (µg/m³)
WHO Inhalation
Unit Risk (µg/m³)
US-EPA IRIS
Unit Risk
Factor (µg/m³)
IARC
Cancer
Class
US-EPA
Cancer
Class (a)
Vinyl chloride 7.8 x 10-5
1 x 10-6
(4.4-8.8) x 10-5
1 A
1
PO Box 30134, Tokai, 7966 Tel: 021 712 5060 Fax: 021 712 506
Email: [email protected] CC Number 2001/072542/23
Members: Adrian Sillito & Diane Sillito Associate: David Spencer
Department of Public Works
Tom Esterhuizen & Associates
Helderstroom Correctional Facility, Western Cape: Environmental Summary Report
February 2013 SEC Reference Number: 0100814
2
DPW Helderstroom Groundwater Quality Assessment Summary Report
1. BACKGROUND & SCOPE OF WORK
Sillito Environmental Consulting was appointed by Tom Esterhuizen and Associates for the
Department of Public Works (DPW) to conduct a groundwater quality assessment in the vicinity of
an area used for disposal of animal carcasses and associated waste products.
Previous discussions with the national Department of Environmental Affairs had indicated that a
baseline assessment of the groundwater quality in the vicinity of this area was required to check for
environmental impacts.
This report represents a summary of the fieldwork and subsequent laboratory results pertaining to
the groundwater samples recovered from the site on the 21st January 2013 as well as any
recommendations that may be applicable to the outcomes of the assessment.
The Helderstroom Correctional Facility is located to the south of the R361 near Caledon, Western
Cape Province. The GPS co-ordinates of the area assessed are 34°03’55.98” South and
19°21’14.60” East and the elevation is approximately 320m amsl.
The site location information, groundwater flow direction and sampling locations are presented in
Figure 1 below.
The primary objective for the assessment was to determine the groundwater quality in the vicinity of
the burial area.
The scope of the fieldwork, which was carried out on the 21st January 2013, is summarised below.
1. Two groundwater monitoring wells were to be installed, during week 41 in 2012, up and
down-gradient of the disposal area by a specialist drilling contractor, Environmental Site
Investigation (ESI).
2. After the monitoring wells were drilled SEC returned to site once the wells has stabilised
(21/01/13) to purge the wells and to recover groundwater samples from the wells.
3. The selected groundwater samples were placed in laboratory supplied vials, packaged in
a cooler box and delivered to a SANAS accredited laboratory for specific analysis.
4. The analysis of the groundwater samples was carried out for the following parameters:
Dissolved Oxygen, Total Organic Carbon, Biochemical Oxygen Demand, Total
Chlorine, Chemical Oxygen Demand, pH, Total Suspended Solids, Electrical
3
DPW Helderstroom Groundwater Quality Assessment Summary Report
Conductivity, Ammonia, Nitrates and Nitrites, Orthophosphate, Sulphates,
Dissolved Cations, Total Coliforms and Escherichia Coli.
5. The assessment of potential source and receptor pathways and the assessment of the
laboratory results using:
South African Water Quality Guidelines
Table 1 below summarizes the monitoring well depths and static water levels recorded during the
sample recovery phase.
The laboratory results have been presented in Table 2.1 to Table 2.2 inclusive. Where any of the
screening levels have been exceeded, the value is highlighted in bold red in the table itself.
General site photographs are presented in Appendix A. The Chain of Custody documentation is presented in Appendix B, with the actual laboratory test certificates presented in Appendix C.
4
Helderstroom Environmental Assessment Summary Report
Figure 1: Site Location Map
Location of
Incinerator
5
DPW Helderstroom Groundwater Quality Assessment Summary Report
Table 1: Monitoring Well Details
Monitoring Well ID
Sampling Event date: 21/01/2013
Depth of Monitoring Well
Depth to Groundwater
HSMW1
8.60 4.31
HSMW2
9.76 2.37
N
6
DPW Helderstroom Groundwater Quality Assessment Summary Report
Table 2.1: Groundwater analytical results (mg/L)
Sa
mp
le N
um
be
r
De
pth
(m b
gl)
Sa
mp
ling
Da
te
To
tal C
hlo
rine
Am
mo
nia
as
N
Nitra
te a
s N
Nitrite
as
N
Orth
op
ho
sp
ha
te a
s
P
Su
lph
ate
as
SO
4
So
diu
m
Ca
lciu
m
Ma
gn
esiu
m
Iron
Po
tass
ium
HSMW
1 8.60 21/01/201
3 <0.05 2.2 1.0 <0.08 <0.2 9.0 127 1.7 4.6 600 0.88
HSMW
2 9.76 21/01/201
3 <0.05 13.4 1.7 <0.08 <0.2 19.0 268 3.2 25.9 1700 7.3
South African Water
Quality Guidelines Volume
4 – Agriculture use
(Irrigation)
100
NV
D
NV
D
NV
D
NV
D
NV
D
70
NV
D
NV
D
0 –
5
NV
D
South African Water
Quality Guidelines Volume
5 – Agriculture use
(Livestock Watering)
0 –
1 5
00
NV
D
0 –
10
0
0 –
10
NV
D
0 –
1 0
00
0 –
2 0
00
0 –
1 0
00
0 - 5
00
0 - 1
0
NV
D
7
DPW Helderstroom Groundwater Quality Assessment Summary Report
Table 2.2: Groundwater analytical results (mg/L)
Sa
mp
le N
um
be
r
De
pth
(m b
gl)
Sa
mp
ling
da
te
To
tal O
rga
nic
Ca
rbo
n
Ch
em
ica
l Oxy
ge
n
De
ma
nd
pH
To
tal S
us
pe
nd
ed
So
lids
Ele
ctric
Co
nd
uc
tivity
To
tal C
olifo
rms
Es
ch
eric
hia
Co
li
HSMW1 8.60 21/01/2013 8.6 25.3 5.60 138 67.3 140 <1
HSMW2 9.76 21/01/201
3 6.4 49.7 4.34 217 152 146 <1
South African Water Quality
Guidelines Volume 4 –
Agriculture use (Irrigation) NVD NVD 6.5 – 8.4 50 40 <1 1
South African Water Quality
Guidelines Volume 5 –
Agriculture use (Livestock
Watering)
NVD NVD NVD NVD NVD 0 – 1 000 0 - 200
8
DPW Helderstroom Groundwater Quality Assessment Summary Report
Notes:
mg/L: milligrams per litre. NVD: No value defined South African Water Quality Guidelines Volume 4 (Irrigation): South African Water Quality Guidelines Volume 5 (Livestock Watering):
(a) - Nitrate (b) - Nitrite
9
DPW Helderstroom Groundwater Quality Assessment Summary Report
2. FINDINGS AND COMMENTS
1. The laboratory results for both wells indicated high iron levels which are above
the allowable levels in the South African Water Quality Guidelines for irrigation
and livestock watering. As such the groundwater quality is poor and as a result
could not be used, regardless of the impact that the animal waste burial had had
on the groundwater.
2. When comparing the water quality from the up and down gradient wells, it is clear
that there is an impact on the water quality, with the Chemical Oxygen demand,
Total Suspended Solids, Electrical Conductivity and Total Coliform results all
considerably higher in the down gradient wells. This indicates that the water
quality has been impacted by the burial activities,
3. CONCLUSIONS AND RECOMMENDATIONS
1. Water quality generally in the area is poor and is unsuitable for either irrigation or
livestock watering due to the iron content which exceeds the guideline levels
considered. As such regardless of the impact of the animal waste burial activities
it would not be useable.
2. The practice of burying animal waste on site should not be carried out in future. It
is understood that this activity has ceased some time ago.
We trust that this brief summary is sufficient for your requirements at this stage. Please
contact the writer should you require any further information.
Yours faithfully,
Adrian Sillito
SEC
10
Helderstroom Environmental Assessment Summary Report
APPENDIX A
11
Helderstroom Environmental Assessment Summary Report
Photograph 1 and 2: Photo 1 shows a south-westerly view of the up gradient monitoring well (HSMW1). Photo 2 shows a south-westerly view
of the down gradient monitoring well (HSMW2).
CLIENT :
Department of Public
Works
PROJECT:
DPW Helderstroom
TITLE:
Site Photographs
JOB NUMBER:
0100814
12
Helderstroom Environmental Assessment Summary Report
APPENDIX B
13
Helderstroom Environmental Assessment Summary Report
SEC SAMPLE CHAIN OF CUSTODY SHEET SEC JOB No 0100814……
SILLITO ENVIRONMENTAL CONSULTING SEC CONTACT: David Spencer SEC SITE DETAILS:
P O BOX 30134 PHONE No.: 021 712 5060 HS
TOKAI 7966 FAX No.: (021)712 5061
Laboratory Laboratory Address Phone No.
AL Abbott and Associate Woodstock
Sampled By (Please print name & sign) Shipped By Shipment Date
Razzaaq Mahomed Razzaaq Mahomed
Analytical Time Scale
Standard Other (Specify) COMMENTS
SAMPLE IDENTIFICATION SEC SAMPLE DATE TIME MATRIX
NUMBER DAY MONTH YEAR 24 HRS
1 21 1 2013 Water x x x x x x x x x x x x x
1 21 1 2013 Water x x x
1 21 1 2013 Water x x x x x x x x x x x x x
1 21 1 2013 Water x x x
RELINQUISHED BY / AFFILIATION DATE TIME ADDITIONAL COMMENTS
SEC
RECEIVED AT LABORATORY DATE TIME
COC No. NB: PLEASE FAX SIGNED FORM TO SEC (021)712 5061 TO
CONFIRM RECEIPT OF SAMPLES AND SAMPLE CONDITIONB
OD
2013/01/21
HSMW1 (200ml)
HSMW2 (200ml)
ANALYSIS REQUIRED
Lab
Fil
trati
on
Esch
eri
ch
ia C
oli
DO
HSMW2 (500ml)
HSMW1 (500ml)
To
tal
Co
lifo
rms
Su
lph
ate
s a
s
SO
4
Dis
so
lved
Cati
on
s (
Na;
K;
Ca;
Mg
; F
e)
TO
C
2013/01/21
Nit
rate
& N
itri
te a
s N
Ort
ho
ph
osp
ate
as P
To
tal
Clo
rin
e
CO
D
Ph
To
tal
& S
usp
en
ded
So
lid
s
Ele
ctr
ic C
on
du
cti
vit
y
Am
on
ia a
s N
14
Helderstroom Environmental Assessment Summary Report
APPENDIX C
15
Helderstroom Environmental Assessment Summary Report
16
Helderstroom Environmental Assessment Summary Report
17
Helderstroom Environmental Assessment Summary Report