Appendix 12. Assessment of Air Quality Effects. Appendix 12

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1 Appendix 12 Assessment of Air Quality Effects Appendix 12 OTAIKA QUARRY - PROPOSED OVERBURDEN DISPOSAL AREA Application for Land Use Consent and Assessment of Environmental Effects

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3 Memorandum AECOM New Zealand Limited 8 Mahuhu Crescent Auckland 1010 PO Box 4241 Auckland 1140 New Zealand tel fax To Ian Wallace Page 1 CC Subject From Catherine Clarke Whangarei District Council - Relevant District Plan Rules Jonathan Harland File/Ref No. Date 01-May GBC Winstone engaged AECOM New Zealand Limited (AECOM) to assess the air quality aspects associated with the disposal of overburden on land adjacent to the Otaika Quarry, to support a resource consent with the Northland Regional Council. However, as this assessment only covered the relevant rules of the Air Quality Plan, GBC Winstone has requested that AECOM addresses, through this memorandum, the relevant rules of the District Plan that is administered through the Whangarei District Council. The discharge of contaminants to air (dust) from quarrying operations are subject to conditions (i) and (x) of Rule of the District Plan, which states the following: Activity Matters of Discretion (i) (x) Effects of noise, dust and other nuisances, and; Effects of excavation, mineral extraction, transport and processing (including the effects of dust) on any water body or indigenous vegetation. The placement of overburden disposal has the potential to generate dust through a number of operations, such as; enabling works, overburden placement and wind erosion of fill areas. The type of effect that can occur from all of these activities is the generation of nuisance dust. This is dust that is generally greater than 50 microns in size, that once disturbed, rapidly falls to the ground again, coating surfaces. Typically, if left unmitigated the settling of nuisance dust would only be experienced within 100 metres of the source, however with very strong wind conditions nuisance dust could be experienced out to 200 metres. Given the relative closeness of the site boundary (~60m), waterbody (~120m to the southeast) and indigenous vegetation (~60m) from the overburden placement area, mitigation measures must be undertaken to minimise off-site effects. AECOM has assessed the various factors that affect the potential for off-site dust nuisance, namely; size and deposition of the overburden material, meteorological conditions at the Pegram Block, the location of the overburden disposal area in relation to the boundary and sensitive receptors, and the dust mitigation measures that will be employed by GBC Winstones. AECOM considers that providing the mitigation methods presented in our previous assessment are undertaken, there is limited potential for adverse off-site effects of nuisance dust. Jonathan Harland Senior Air Quality Scientist jonathan.harland@aecom.com Direct Dial: p:\605x\ \4. tech work area\4.4 environment\m001 winstone otaika - district plan memo.docx

4 GDC Winstone 17-Mar-2017 GBC Winstone Otaika Quarry Dust Management Assessment - Pegram Block

5 Dust Management Assessment - Pegram Block Client: GDC Winstone ABN: N/A Prepared by AECOM New Zealand Limited 8 Mahuhu Crescent, Auckland 1010, PO Box 4241, Auckland 1140, New Zealand T F Mar-2017 Job No.: AECOM in Australia and New Zealand is certified to ISO9001, ISO14001 AS/NZS4801 and OHSAS AECOM New Zealand Limited (AECOM). All rights reserved. AECOM has prepared this document for the sole use of the Client and for a specific purpose, each as expressly stated in the document. No other party should rely on this document without the prior written consent of AECOM. AECOM undertakes no duty, nor accepts any responsibility, to any third party who may rely upon or use this document. This document has been prepared based on the Client s description of its requirements and AECOM s experience, having regard to assumptions that AECOM can reasonably be expected to make in accordance with sound professional principles. AECOM may also have relied upon information provided by the Client and other third parties to prepare this document, some of which may not have been verified. Subject to the above conditions, this document may be transmitted, reproduced or disseminated only in its entirety.

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7 Table of Contents 1.0 Introduction Statutory Requirements Site Location Meteorological Particulate Matter Overburden Removal and Placement Emissions to Air Environment Performance Standards Sensitivity of the Receiving Environment Mitigation Measures Overburden placement Topsoil Storage Transport of Overburden Monitoring Measures Conclusion Limitations 14 List of Tables Table 1 Wind Speed Frequency Distribution from the Portland Cement site 4 Table 2 Summary of TSP Results 17 November 2016 to 8 March Table 3 MfE Trigger Levels for TSP 10 Table 4 Dust Monitoring Programme 12 List of Figures Figure 1 General Site Location 2 Figure 2 Area Surrounding the Pegram Block 2 Figure 3 Wind speed and wind direction distribution at Whangarei Airport for (1-hour average) 3 Figure 4 Wind speed and wind direction distribution at the Portland Cement site for (1-hour average) 4 Figure 5 E-BAM monitoring station 5 Figure 6 1-hour Average TSP Concentration at 11 Grove Lane 6 Figure 7 24-hour Average TSP Concentration at 11 Grove Lane 6 Figure 8 TSP Polar Plot 11 Grove Lane 6 Figure 9 Proposed Staged Overburden Placement 8 Figure 10 Particulate Settling Rates 9

8 1 1.0 Introduction GBC Winstone (a division of Fletcher Concrete and Infrastructure Limited) owns and operates Otaika Quarry in Whangarei, which has been operating since the 1950s. The Quarry currently produces a variety of coarse and fine aggregate for the production of asphalt and concrete products and for use in roading applications. A new overburden disposal area is required to allow the on-going development of Otaika Quarry (overburden is material overlaying the rock resource below). After assessing potential options, GBC Winstone has determined that the most appropriate location for overburden disposal is on what is called the Pegram Block, a piece of land adjoining the quarry site owned by GBC Winstone. AECOM New Zealand Limited (AECOM) has been engaged to assess the air quality aspects of this proposal, and provide appropriate recommendations as to management measures that should be implemented to minimise the potential for off-site effects from this activity. This assessment has been written to assess whether the proposed overburden disposal activity meets the permitted activity rule in Section of the Regional Air Quality Plan for Northland. 2.0 Statutory Requirements The discharge of contaminants to air (dust) from quarrying operations is a permitted activity subject to conditions (a) of Rule of the Regional Air Quality Plan for Northland which states that: The discharge of dust into the air arising from: 1) Quarrying operations, earthworks, clean fill operations; or 2) Road construction and maintenance, or the use of unsealed roads; or 3) Railway line construction and maintenance; or 4) The loading, unloading and on-site movement of materials having a dust producing capacity; is a Permitted Activity provided that: (a) The discharge shall not result in any offensive or objectionable dust deposition, or any noxious or dangerous levels of airborne particulate matter, beyond the boundary of the subject property. This document has been prepared to assess whether with the mitigation proposed, the overburden disposal activity will meet the permitted activity standard (a), above. 3.0 Site Location The Pegram Block is located at (Lot 2 DP and Lot 2 DP ) Quarry Road, Otaika and covers approximately 40 hectares of land. The site is located approximately 4 km south-southwest of Whangarei. The Pegram Block, which is the subject of this assessment, is immediately to the northeast of the current quarry. Residential properties border the Pegram Block from the northwest to the northeast, and the Otaika Sports Park is to the south. The location of the Pegram Block is highlighted in red in Figure 1, and Figure 2 shows the neighbouring area. The Pegram Block is currently used for grazing stock, the area is largely in pasture, with sporadic trees throughout the area.

9 2 Figure 1 General Site Location Figure 2 Area Surrounding the Pegram Block

10 3 3.1 Meteorological Wind can have a significant effect on dust generation and transportation. Meteorological monitoring has been conducted at Whangarei Airport by MetService which is approximately 5 km to the east of the overburden placement. Meteorological measurements from this location are indicative of conditions likely to be experienced in the area of Pegram Block (subject to variations in local topography), therefore AECOM has also obtained data from GBC Winstone s Portland Cement plant which is approximately 6 km to the south-southeast of the Pegram Block. The distribution of hourly average wind speeds and directions recorded at Whangarei Airport for the years 2008 to 2012 is shown in Figure 3, and the hourly average wind speeds and directions recorded at the Portland Cement site for the 2011 to 2015 is shown in Figure 4. Table 1 presents the distribution frequency of wind speed at the Portland Cement site. Wind speeds greater than 5 m/s, when there is higher potential for adverse dust effects on the residential property surrounding the Pegram Block (south to southwest), occur for approximately 4-6% of the time. Figure 3 Wind speed and wind direction distribution at Whangarei Airport for (1-hour average)

11 4 Figure 4 Wind speed and wind direction distribution at the Portland Cement site for (1-hour average) Table 1 Wind Speed Frequency Distribution from the Portland Cement site Direction Wind Speed (m/s) >10 Total (%) North North northeast Northeast East northeast East East southeast Southeast South southeast South South southwest South west West southwest West West northwest Northwest North northwest

12 5 3.2 Particulate Matter Total Suspended Particulate (TSP) monitoring has been undertaken at a monitoring station installed at 11 Grove Lane since 17 November 2016, which is approximately 40 meters north of the proposed overburden placement (Figure 5). The hourly and daily average TSP concentrations recorded at 11 Grove Lane for the period 17 November 2016 to 8 March 2017 are summarised in Table 2 and presented graphically in Figure 6 to Figure 8. The maximum 1-hour average was 235 µg/m³, and maximum 24-hour average was 34.6 µg/m³. As discussed further in Section 5.1, the values are all below the guideline values developed by the Ministry for Environment for moderately sensitive receiving environments. The polar plot in Figure 8 shows three variables in one representation, wind speed, wind direction and TSP concentration in micrograms per cubic meter (µg/m³). A coloured dot is placed over the grid for each possible wind direction and speed. The colour of the dot represents the maximum concentration of TSP measured at the monitoring station during the wind conditions at that spot i.e. for the plot below, the higher the TSP concentration, the darker the colour (from light yellow dark red). The Otaika Quarry appears to be the main source of TSP at the monitoring location at 11 Grove Lane. Table 2 Summary of TSP Results 17 November 2016 to 8 March hr Average Concentration (µg/m³) 24-hr Average Concentration (µg/m³) Maximum Median Minimum Average Figure 5 E-BAM monitoring station

13 Concentration µg/m³ Concentration µg/m³ AECOM 6 Figure hour Average TSP Concentration at 11 Grove Lane Figure 7 24-hour Average TSP Concentration at 11 Grove Lane Figure 8 TSP Polar Plot 11 Grove Lane

14 7 4.0 Overburden Removal and Placement Overburden placement involves the removal, transport and disposal of materials that have little to no commercial value but need to be removed to gain access to saleable aggregate resources. In the case of the Otaika Quarry, this is the removal of vegetation, topsoil, clay, limestone and green sand in order to reach the greywacke resource below. Overburden is excavated using an excavator, loaded into haul trucks for transport to the overburden disposal area. Overburden placement will generally occur during a 6-8 month period, typically over the summer months, and depending on market demand will take place every 3-5 years. There will be approximately 40 truck movements per hour between the Quarry and the Pegram Block. The proposed overburden placement is shown on Figure 9, the area in purple indicates the surrounding residential area. Enabling works will be undertaken initially, which will include granular material being placed to form a construction bund. Overburden placement will occur during the general works phase. The development will be progressive, commencing at the eastern end of the foot print progressing westwards.

15 8 Figure 9 Proposed Staged Overburden Placement Source: Boffa Miskell 5.0 Emissions to Air The potential for air quality effects associated with the operation of the Pegram Block relates almost exclusively to the potential for there to be dust emissions. While there will be a number of vehicles operating on the site, the emissions from these vehicles are considered insignificant and they are unlikely to result in any noticeable changes in air quality. The operation of the overburden disposal site on the Pegram Block will have the same degree and type of effects as any large earth moving project, that is there is the potential for dust to be generated by a number of the potential operations. These include: Initial enabling works, including construction of the haul roads, removal of topsoil, construction of erosion and sediment controls, and construction of the toe bund to the overburden disposal area. Placement and compaction of overburden. Operation of vehicles on the haul roads. Rehabilitation of the overburden disposal area. Wind erosion of fill areas. The actions undertaken by GBC Winstone will have a direct influence on all of the above activities. The type of effect that can occur from all of these activities is the generation of nuisance dust. This is dust that is generally greater than 50 microns in size (approximately half the thickness of a human hair) that once disturbed, rapidly falls to the ground again, coating surfaces. The actual distance that the dust travels before settling will depend on two factors, firstly how strong the wind is, and secondly how large the particle is. Figure 10 illustrates this. In general particles greater than 100 microns (the point at which material generally starts to feel gritty) will only travel

16 9 about 60 metres before resettling in 10 m/s winds, while material between 50 and 100 microns can travel approximately 250 metres under the same wind conditions. In stronger wind conditions the potential exists for dust to be carried further. Based on the meteorological data collected by the two meteorological station, winds stronger than 10 m/s only occur for about 0.6 percent of the time, however only 0.06 percent (~5 hours a year) of the wind is in the direction of the residential areas. Figure 10 Particulate Settling Rates 5.1 Environment Performance Standards Rule of the Regional Air Quality Plan for Northland allows the placement of overburden as permitted activity provided the discharge shall not result in any offensive or objectionable dust deposition, or any noxious or dangerous levels of airborne particulate matter, beyond the boundary of the subject property. Because offensive or objectionable dust cannot necessarily be identified until it has occurred, there are numerical guidelines that can be used in conjunction with Total Suspended Particulate monitoring to identify levels of dust that are likely to be considered a nuisance. These values, developed by the Ministry for the Environment (MfE) 1, are set out in Table 3. 1 Ministry for the Environment Good Practice Guide for Assessing and Managing Dust

17 10 Table 3 MfE Trigger Levels for TSP Trigger Averaging Period Sensitivity of receiving environment High Moderate Low Short Term 5 min 250 µg/m³ n/a n/a Short Term 1 hour 200 µg/m³ 250 µg/m³ n/a Daily 24 hour (rolling average) 60 µg/m³ 80 µg/m³ 100 µg/m³ Wind Warning 1 minute 10 m/s (during two consecutive 10-minute periods) Rain warning 12 hours There has been no rain in the previous 12 hours Visible dust Instantaneous Visible dust crossing the boundary 5.2 Sensitivity of the Receiving Environment The level of mitigation that may be required to control nuisance effects is dependent to a large degree on the sensitivity of the surrounding land uses in the vicinity of the Pegram Block. Those land uses that are most likely to be sensitive to airborne dust and other air contaminants include (but are not limited to): Residences; Recreational grounds; Rivers and creeks; and Agricultural land. The most sensitive areas to nuisance dust effects are those located to the north and northeast of the Pegram Block. In both areas a comparatively high number of sensitive receptors will be located near the overburden placement. The residences in Acacia Park are expected to be the most likely effected, due to the close proximity of the overburden placement (~60 m at the closest point) and lack of protection the largely open space provides between the two locations. Other sensitive receptors include residential housing located in and around Smeaton Drive to the northeast (~300 m) and the Otaika Sports Park to the southeast (~150 m). Due to the distance and meteorological conditions, there is little potential for effects of dust emissions from the overburden placement towards the residential properties in the northeast and the Otaika Sports Park. Based on the current environment and guidance from the MfE, AECOM considers the receiving environment to be of moderate sensitivity. 5.3 Mitigation Measures Based on the above, and in order to ensure that activities comply with the permitted activity rule, AECOM recommends that the following measures are included in the dust management plan Overburden placement The placement of overburden has the highest potential for dust emissions as it involves the movement of large amounts of dust generating material. This process uses large machinery such as dump trucks, and excavators to move and place overburden, and if left unmitigated can cause nuisance dust to the nearby residential areas. However nuisance dust can be controlled by placing and moving overburden during optimum meteorological conditions, not allowing material to dry out, and vegetating the overburden. AECOM recommends the following measures: Water and / or dust suppressants to be applied on all disturbed surfaces when required. Areas of exposed ground will be minimised during overburden placement. GBC Winstones propose that a maximum of 3 hectares of ground (excluding any haul roads, batter slopes and top soil piles) will be exposed at any time. Within 100 m of houses mulching, grassing and / or planting of bare areas shall be undertaken as soon as reasonably practicable.

18 11 Disturbed areas will be progressively stabilised. All vehicles operating within 200 m of dwellings will travel at less than 20 km/h. Overburden placement and soil disturbing activities will not take place within 300 m of a residential dwelling when the wind is blowing towards the dwelling at a speed exceeding 5 metres per second, during two consecutive 10-minute periods, based on the wind speed monitor located on the Otaika Quarry site, and there has been less than 5 mm of rainfall in the last 24 hours. This meteorological station needs to be capable of sending alarms (visual and/or via internet, and mobile phone). Overburden placement can resume once wind speeds are below 5 metres per second for two consecutive 10-minute periods or the wind direction is no longer coming towards the dwelling Topsoil Storage Top soil that is removed in construction of the overburden area and other works will be stockpiled on the northern side of the Haul Road for future rehabilitation of final surfaces. The fine material in these stockpiles can result in dust emission during periods of wind speeds exceeding 5 m/s. AECOM recommends the following measures: Stockpiles to be kept below 3 meters in height. Stockpiles will be stabilised and grassed when required. Any stockpiles that will not be used within an earthworks season will be sown with grass. During the construction of the stockpile, limit the drop height of the top soil from the excavators to no greater than 3 metres Transport of Overburden Haul roads have the potential to result in dust emission, if they are not appropriately mitigated. The two most common measures used to control dust emissions from haul roads are speed control and road watering. The other measure that can be used to control dust emissions from unsealed roads is regular road maintenance. As vehicles move over the road, they break down the surface material, which leads both to the potential for dust generation, and also increased road resistance on the vehicles. Therefore, it is recommended that the haul roads be maintained as and when necessary and practical to keep them in optimum condition. This will involve measures such as grading of the haul road. AECOM recommends the following measures: The main haul road will be regularly graded to maintain an even surface with potholes and bumps smoothed over as soon as is reasonably practical. The main haul road surfaces to the overburden placement on the Pegram Block will be a smooth compacted surface. Daily inspections of the haul roads will be undertaken to identify any surface deterioration that may result in increased dust generation. Site personnel will be encouraged to immediately report any deterioration of the haul road surface. Haul roads will be regularly watered using the water cart during dry periods. In the event the water cart breaks down a replacement will be sourced as soon as practicable. Haul routes will be generally restricted to the shortest possible travel distance along defined travel routes. When loading material onto trucks, drop heights from excavators shall be minimised as much as practicable to limit dust emissions. GBC Winstone ensures that all its vehicles do not have downward facing exhausts as these may act to raise dust in dry conditions. All vehicles are regularly maintained to ensure minimum emissions. All drivers will be advised to maintain a good following distance between vehicles using the site haul roads to minimise the potential for cumulative dust emissions arising from closely traveling vehicles.

19 Monitoring Measures While AECOM is confident that the above proposed dust mitigations will significantly reduce the potential for off-site dust nuisance, due to the close proximity of the neighbouring residential properties, AECOM considers that it is prudent that some monitoring be undertaken to assess the actual effects associated with the activity. AECOM recommends that Winstones carry out the following visual and instrumental monitoring. General visual monitoring of the overburden placement area should be undertaken on a daily basis or potentially more frequently, if conditions change. Table 4 describes the monitoring programme. Table 4 Dust Monitoring Programme Monitoring Activity Check weather forecasts for strong winds and rainfall to plan appropriate work schedule and dust management response. Inspect land adjacent to the works for the presence of dust deposition. Observe weather conditions including wind and rain via observations and data outputs from weather stations. Inspect all exposed surfaces for dampness and to ensure that the exposed un-stabilised area is minimised. Inspect stockpiles to ensure enclosure, covering, stabilisation or dampness. Ensure stockpile height is less than 3 m where possible or appropriate. Inspect dust generating activities to ensure dust emissions are effectively controlled. Inspect watering systems (water carts) to ensure equipment is maintained and functioning to effectively dampen exposed areas Monitor dust generating activities and water application rate. Frequency Daily Daily Daily and as conditions change Daily and as conditions change Daily and as conditions change Daily and as new activities are commenced Weekly In winds over 3.0 m/s AECOM recommended that a meteorological station measuring wind speed and wind direction, and capable of sending alarms base on the wind triggers mentioned in this assessment should be installed in the vicinity of the overburden placement. After consulting with AECOM, GBC Winstone has indicated that it will install a 5 metre meteorological station on the southern corner of the Pegram Block, which will be capable of monitoring these parameters. AECOM also recommends that a dust monitor, such as that currently being used by GBC Winstone at 11 Grove Lane, that is capable of continuously measuring Total Suspended Particulate (TSP) concentrations and capable of sending alarms (visual and/or via internet, and mobile phone) based upon 1-hour and 24-hour average concentrations, is installed to detect if any nuisance dust is generated from the Pegram Block. This monitor is to be installed at the border of Acacia Park and the Pegram Block, prior to, and the entire duration of an overburden placement campaign that take places within 100 m of residential dwellings. AECOM recommends the following trigger limits, based on the MfE guidance for moderate sensitive receiving environments: If concentrations exceed 250 µg/m³ over a 1-hour period or 80 µg/m³ over 24-hours (rolling average) period, overburden placement will cease until an investigation into to the cause of the exceedance will be undertaken and any issues addressed, until the concentration drops below the trigger limit.

20 Conclusion AECOM has assessed the potential effects associated with the use of the Pegram Block adjacent to the Otaika Quarry, for the disposal of overburden from the quarry. As discussed earlier, the purpose of this assessment is to assess if the proposed overburden disposal activity will meet the permitted activity performance standard (a) in Rule of the Regional Air Quality Plan for Northland Based on this assessment, the placement of overburden material on the Pegram Block will most likely result in an increase of ambient concentration of dust if left unmitigated. Considering the close proximity (~60 m at the closest point) of the residential properties to the proposed overburden placement, AECOM has recommended appropriate mitigation measures. Provided the proposed mitigation measures are strictly adhered to, AECOM considers that the potential effects of the proposed overburden disposal activity will be no more than minor, and not result in any adverse offsite effects. Accordingly the proposal will satisfy permitted standard (a) in Rule of the Regional Air Quality Plan for Northland.

21 Limitations AECOM New Zealand (AECOM) has prepared this Dust Assessment report in accordance with the usual care and thoroughness of the consulting profession for GBC Winstone for use in a statutory process from the Northland Regional Council under the Resource Management Act 1991 to support an application for resource consent for the placement of overburden at the Pegram Block at Otaika Quarry, Whangarei. Except as specifically stated in this section, AECOM does not authorise the use of this Report by any third party except as provided for by the Resource Management Act It is based on generally accepted practices and standards at the time it was prepared. No other warranty, expressed or implied, is made as to the professional advice included in this Report. It is prepared in accordance with the scope of work and for the purpose outlined in the contract dated 2 November Where this Report indicates that information has been provided to AECOM by third parties, AECOM has made no independent verification of this information except as expressly stated in this Report. AECOM assumes no liability for any inaccuracies in or omissions to that information. This Report was prepared during November 2016 to March 2017 and is based on the conditions encountered and information reviewed at the time of preparation. AECOM disclaims responsibility for any changes that may have occurred after this time. This Report should be read in full. No responsibility is accepted for use of any part of this Report in any other context or for any other purpose than that stated above. This Report does not purport to give legal advice. Legal advice can only be given by qualified legal practitioners. To the extent permitted by law, AECOM expressly disclaims and excludes liability for any loss, damage, cost or expenses suffered by any third party using this report for any purpose other than that stated above. AECOM does not admit that any action, liability or claim may exist or be available to any third party.