Ammonia Modelling Report for the Existing Permit in 2013

Modelling ammonia emissions at Tolehurst poultry farm

(Permit Number KP3333US)

Report prepared for:

Fridays Limited Chequer Tree Farm Cranbrook Kent TN17 3PN

Report prepared by:

M J Sharp Senior Environmental Consultant November 2018

SAC Environment & Design 2 Technopole Centre Bush Estate Penicuik Midlothian EH26 0PJ

Tel: 0131 603 7511

Email: [email protected]

Modelling ammonia emissions at Tolehurst Poultry Farm Prepared for: Fridays Limited ______

CONTENTS

1. INTRODUCTION...... 3 1.1 Background ...... 3 2. MODELLING AT TOLEHURST FARM ...... 3 2.1 Emission factors ...... 3 2.2 Modelling methodology ...... 3 2.3 Sensitive receptors ...... 5 3. DISPERSION MODELLING RESULTS ...... 5 3.1 General ...... 5 3.2 Process contributions – concentrations and deposition ...... 5 4. CONCLUSIONS ...... 8 5. APPENDIX 1 ...... 9 6. FIGURE 1. Wind rose from Met data used in modelling (2010)...... 12 7. FIGURE 2 (below) Tolehurst 2018 Isopleths show predicted average ground level concentrations of ammonia in µg m-3 (2010 weather data)...... 12

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1. INTRODUCTION 1.1 Background Tolehurst poultry farm is located near Staplehurst in Kent. Tolehurst farm lies to the south of Knox Bridge village and contains free range and rearing housing. The site is currently permitted (KP3333US) for 96,000 places for layers and 84,000 places for pullets - a total of 180,000 birds. Fridays Limited are proposing to increase the capacity for pullet rearing on the site raising this to a total of 322,560 pullets that will be reared in two sheds each containing 161,280 birds. The number of free range laying hens will remain the same at 96,000.

The variation to the permit will therefore be for an additional 238,560 pullet rearing places. It is important to note that although the increase in bird numbers appears large the increase in ammonia emissions is not proportional as a different husbandry system is to be used. The pullets will be reared in belt clean caged systems. Ammonia emissions will increase by 28%. To mitigate this increase advanced ventilation techniques will be employed to aid with dilution and dispersion of emissions.

To quantify the environmental impacts of the proposed changes the company has requested SAC Consulting to undertake modelling of ammonia emissions.

2. MODELLING AT TOLEHURST FARM 2.1 Emission factors Fridays Limited has in the past been in discussion with the Environment Agency regarding emission factors for the belt clean aviary system used in the two free range sheds at Tolehurst, as they felt that a factor of 0.08 kg NH3 per bird per year was too high for modern systems of the type proposed.

The EA subsequently approved a change to allow the use of an emissions factor of 0.06 kg NH3 per bird place per year, and this emission factor was used in the ammonia modelling report for the existing permit in 2013. Consequently, this factor has also been used for the proposed variation at Tolehurst Farm.

For pullet rearing an emission factor of 0.025 kg NH3 per bird place per year has been used. This was also the factor used in 2012 modelling for pullet rearing in belt cleaned cage systems at the company. The factor takes into consideration the much smaller birds (day old to 17 weeks with an end weight of approximately 1.3 kg at 17 weeks) and is an appropriate yet precautionary factor for pullet rearing in caged systems where birds are much smaller, manure is removed twice weekly, and annual occupancy is generally lower.

2.2 Modelling methodology Modelling has been undertaken using Cambridge Environmental Research Consultants’ latest version of their model ADMS V5.2. ADMS V5.2 is widely used in the UK as one of the current industry standard advanced models for dispersion from point, line, area and volume sources. Depending on the type of modelling to be undertaken, the model takes as a starting point information on emissions from each source, in this case each poultry shed, that includes: • release rate of the substances being considered; • release temperature; • release velocity or volumetric flow; ______

• release point location; • release point height; • release point diameter, line length, volume or area; • location and dimensions of any buildings nearby; • local terrain between source and receptor; and • location of sensitive receptors nearby.

Modelling emissions from agricultural buildings can present challenges due to the diversity of ventilation systems in use. In general terms buildings with open roof- mounted fans can be modelled as a number of point sources and the task is relatively straight forward. The poultry houses at Tolehurst incorporate high efflux velocity roof mounted ventilation systems and these are summarised in Table 1 below along with a brief description of the methods used for this modelling assessment.

Table 1 Ventilation systems in use at Tolehurst Farms

House Bird Nos System Manure Ventilation Modelling Fan Building dimensions removal method efflux L x W x H velocity, m s-1 Tol 1 161,280 Cage Twice per Side Point 13.3* 120 x 26.7 x 9.5 rearing, week inlet/roof sources belt clean ridge exhaust Tol 2 161,280 Cage Twice per Side Point 13.3* 120 x 26.7 x 9.5 rearing, week inlet/roof sources belt clean ridge exhaust Tol 3 32,000 Free range Twice per Side Point 11.5 136.2 x 20.5 x 7.5 aviary, belt week inlet/roof sources clean ridge exhaust Tol 4 64,000 Free range Twice per Side Point 11.5 136.2 x 20.5 x 7.5 aviary, belt week inlet/roof sources clean ridge exhaust *Fan speed of 13.3. m s-1 achieved by fitment of guide vanes1.

Terrain data The complex terrain module was used to take account of complex terrain as there are slopes in excess of 1:10 to the south of Tolehurst Farm.

Buildings effects Because there were ancient woodland sites close to the poultry houses the buildings module was applied to the dispersion model to take account of building downwash effects from those sources at roof height.

All inputs used in the modelling runs described in this report are collated in reports generated by the ADMS software. For transparency the report for the worst year (2010) is appended to this report. The weather station used for the installation was Herstmonceau using data from 2007 - 2011.

The background concentration for the area, obtained from the APIS database2, was -3 1.4 µg NH3 m .

1 Ziehl-Abegg SE Guide vane for agricultural applications. DLG Plume Rise test report 5642F www.dlg-test.de ______

2.3 Sensitive receptors Sites of concern were identified in the Environment Agency’s screening exercise (undertaken in 2012). They consisted of one SSSI site, Sissinghurst Park Wood, and over 50 ancient woodland sites within 2 km of the farm. The closest of these are marked on Figure 1. Tolehurst Wood is located close to the rearing houses and Reeves Wood is approximately 80 metres to the east of the large free range house (Tol 4). Saunders and Brewers woods are also relatively close to the free range sheds being approximately 100 and 200 metres distant.

Because there are a large number of receptors within two kilometres of the poultry farm calculating specific values at all sites whilst applying other modelling features such as complex terrain and buildings effects would result in long model run-times. To reduce run-times specific values for only those sites likely to be affected by the farm as demonstrated during test model runs have been calculated. At distances greater than this it is considered that receptors are far enough away to be relatively unaffected.

Marden meadows SSSI and the River Beult SSSI were not included in the EA screening exercise. The closest edge of Marden Meadows is 5 km from the approximate centre point of the site and the closest point of the River Beult is approximately 4.63 km away. As these sites are unlikely to be affected and have screened out, they have not been included in this assessment.

Specific values for a number of ancient woodland locations and Sissinghurst Park Wood SSSI are listed below. Values are shown for both the higher and lower critical levels although the Environment Agency has confirmed that the ancient woodland -3 sites have been assigned a critical level of 3 µg m . A critical load (CLo) range of 10 - 20 kg N ha-1 y-1 has been applied to all sites listed in this assessment.

3. DISPERSION MODELLING RESULTS 3.1 General Results from the dispersion model for year 2010, which on balance is the worst year for the closest woodland sites, have been plotted as a contour plot on to Ordnance Survey maps shown in Figure 2 and are tabulated in Table 3.1 below. The isopleths on the map show the annual average ground level concentrations of ammonia in µg m-3 for 2010 weather data. The local wildlife sites are marked with the letters AW for ancient woodland or the name of the local site. Details of the modelling inputs are provided in Appendix 1, and a wind rose is shown in Figure 1.

3.2 Process contributions – concentrations and deposition Ammonia concentrations and the process contribution as a percentage of critical -3 levels of 1 and 3 µg NH3 m are provided in Table 3.1. In addition to concentrations an assessment of critical loads is also provided. Ammonia dry deposition has been calculated by the ADMS model after by applying a deposition velocity of 0.02 m s-1 across the modelled domain. This is an appropriate value for short semi-natural vegetation which is predominant around the poultry houses although there are woodlands to the south of the area. For specific locations, values for nitrogen deposition in kg N ha-1 y-1 have been provided. Some caution is advised when

2 UK Air Pollution Information System. www.apis.ac.uk ______

interpreting deposition data due to the inherent uncertainties in assumptions used in calculating deposition. The process contribution of nutrient nitrogen as a percentage of the critical load in Table 3.1 below is based on the lower value of a critical load -1 -1 -3 range of 10 - 20 kg NH3 ha y . However, when applying a critical level of 3 µg m it is reasonable to assume the higher of the critical load range for nutrient nitrogen, in this case 20 kg N ha-1 y-1, otherwise nutrient nitrogen would be the limiting factor thus negating the effects of applying the higher critical level.

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Table 3.1. Modelling results

Site – closest Year PC, PC as % of PC as % of PC, N PC as % of point affected NH3, µg CLe of 1 µg CLe of 3 µg deposition, CLo of 10 -1 -1 -1 -1 m-3 m-3 m-3 kg N ha y kg N ha y Sissinghurst 2011 0.092 9 3 0.5 5 Park Wood SSSI 2010 0.148 15 5 0.8 8 2009 0.110 11 4 1.0 10 GR 2008 0.115 12 4 0.6 6 580064,139281 2007 0.117 12 4 0.6 6 Tolehurst Wood 2011 1.582 158 53 8.2 82 AW 2010 2.371 237 79 12.3 123 2009 1.614 161 54 8.0 80 GR 2008 1.830 183 61 9.5 95 578545,140309 2007 2.142 214 71 11.1 111 Grandshore 2011 0.269 27 9 1.4 14 Wood AW 2010 0.216 22 7 1.1 11 2009 0.275 28 9 1.0 10 GR 2008 0.287 29 10 1.5 15 579762,140597 2007 0.251 25 8 1.3 13 Duck Pit Wood 2011 0.198 20 7 1.0 10 AW 2010 0.149 15 5 0.8 8 2009 0.191 19 6 1.0 10 GR 2008 0.194 19 6 1.0 10 580021,140886 2007 0.164 16 5 0.8 8 Grand Shore 2011 0.472 47 16 2.4 24 Wood 2 AW 2010 0.433 43 14 2.2 22 2009 0.505 51 17 3.0 30 GR 2008 0.493 49 16 2.5 25 579271,140302 2007 0.487 49 15 2.5 25 Mapelhurst Farm 2011 0.105 11 4 0.5 5 Wood AW 2010 0.084 8 3 0.4 4 2009 0.100 10 3 1.0 10 GR 2008 0.088 9 3 0.5 5 579316,141621 2007 0.072 7 2 0.4 4 Reeves Wood 2011 1.980 198 66 10.2 102 AW 2010 1.443 144 48 7.5 75 2009 1.838 183 61 10 10 GR 2008 2.063 206 69 10.7 107 578928,139906 2007 1.912 191 64 9.9 99 Saunders Wood 2011 1.063 106 34 5.5 55 AW 2010 1.188 119 40 6.1 61 2009 1.058 106 35 5.0 50 GR 2008 1.098 110 37 5.7 57 578624,139728 2007 1.167 117 39 6.0 60 Brewers Wood 2011 0.744 74 25 3.8 38 AW 2010 0.837 84 28 4.3 43 2009 0.741 74 25 4.0 40 GR 2008 0.769 77 26 4.0 40 578038,139786 2007 0.888 89 30 4.6 46

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4. CONCLUSIONS 4.1 The worst years in terms of the highest ammonia concentrations at Sissinghurst Wood SSSI was 2010. There was some variation as to which was the ‘worst year at the Ancient Woodland sites but at three of the closest (Tolehurst, Saunders and Brewers Woods it was also 2010. -3 4.2 The process contribution of NH3 did not exceed 100% of a critical level of 3 µg m at any of the ancient woodland receptors, and did not exceed 50% of a critical load of either 1 or 3 µg m-3 at Sissinghurst Park Wood SSSI. 4.3 The process contribution of nutrient nitrogen exceeded 100% of the lower range of a critical load of 10 – 20 kg N ha-1 y-1 at two of the ancient woodland sites – Tolehurst Wood and Reeves Wood. 4.4 The process contributions of nutrient nitrogen were all within a critical load range of 10 – 20 kg N ha-1 y-1. When applying a critical level of 3 µg m-3 it is reasonable to apply the higher of the critical load range for nutrient nitrogen, in this case 20 kg N ha-1 y-1, otherwise nutrient nitrogen would be the limiting factor thus negating the effects of applying the higher critical level. 4.5 There are greater uncertainties in the calculation of nitrogen deposition and concentrations are likely to be more reliable for assessment purposes. 4.6 Due to the change in husbandry system and ventilation systems used for pullet rearing, the conclusions of this assessment are not materially different to the current permitted situation.

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5. APPENDIX 1

______ADMS 5.2 (5.2) ______Atmospheric Dispersion Modelling System ______Copyright (C) 2017 Cambridge Environmental Research Consultants Ltd. ______This run was made at 14:19 on the 14/11/2018 ______Report File ______

1. SETUP INFORMATION:

Site name : Tolehurst Project name: Tolehurst R1 2018 10 met dep

Input file pathname : C:\MJS project folders\ADMS 5\Runs\Fridays Tolehurst 2018\Tolehurst R1 2018 10 met dep.APL Command-line options : /E1 /ADMS

Model information: - Pathname C:\Program Files (x86)\CERC\ADMS 5\ADMSModel.exe - Version 5.2.2.0 - Build number 3080 - Release date February 2017

2. MODEL OPTIONS:

Dry deposition Buildings - 3 buildings defined: > 'Tol 1&2', centre (578434.0, 140383.0), height 9.0m, length 120.0m, width 26.0m, angle 93.0 degrees > 'Tol 3', centre (578203.0, 139947.0), height 6.2m, length 136.0m, width 21.0m, angle 93.0 degrees > 'Tol 4', centre (578800.0, 139855.0), height 6.2m, length 240.0m, width 21.0m, angle 70.0 degrees - 'Tol 1&2' is the 'Main building' for this run Complex terrain - Modelling hills - Pathname of hills data C:\MJS project folders\ADMS 5\Terrain data\Fridays\Knoxbridge.ter - Calculation grid resolution = 32x32

3. SOURCE OPTIONS:

Your run includes the following sources:

15 point sources - 'Tol1 P1' - 'Tol1 P2' - 'Tol1 P3' - 'Tol2 P1' - 'Tol2 P2' - 'Tol2 P3' - 'Tol3 P1' - 'Tol3 P2' - 'Tol3 P3' - 'Tol3 P4' - 'Tol4 P1' - 'Tol4 P2' - 'Tol4 P3' - 'Tol4 P4' - 'Tol4 P5'

POINT SOURCE GEOMETRY:

Source name, Height(m), Location, Diameter(m), Main building, Tol1 P1, 9.50, (578395.0, 140403.0), 0.66, (Main), Tol1 P2, 9.50, (578435.0, 140398.0), 0.66, (Main), ______

Tol1 P3, 9.50, (578470.0, 140394.0), 0.66, (Main), Tol2 P1, 9.50, (578393.0, 140368.0), 0.66, (Main), Tol2 P2, 9.50, (578427.0, 140364.0), 0.66, (Main), Tol2 P3, 9.50, (578469.0, 140358.0), 0.66, (Main), Tol3 P1, 7.50, (578144.0, 139895.0), 0.66, (Main), Tol3 P2, 7.50, (578176.0, 139888.0), 0.66, (Main), Tol3 P3, 7.50, (578221.0, 139879.0), 0.66, (Main), Tol3 P4, 7.50, (578256.0, 139870.0), 0.66, (Main), Tol4 P1, 7.50, (578710.0, 139820.0), 0.66, (Main), Tol4 P2, 7.50, (578745.0, 139835.0), 0.66, (Main), Tol4 P3, 7.50, (578795.0, 139855.0), 0.66, (Main), Tol4 P4, 7.50, (578835.0, 139870.0), 0.66, (Main), Tol4 P5, 7.50, (578879.0, 139888.0), 0.66, (Main),

SOURCE CHARACTERISTICS:

Source name, Exit velocity(m/s), Temp(degC), Actual/NTP, Mol. mass(g), Cp(J/degC/Kg), Tol1 P1, 13.300, 20.000, Actual, 28.966, 1012.00, Tol1 P2, 13.300, 20.000, Actual, 28.966, 1012.00, Tol1 P3, 13.300, 20.000, Actual, 28.966, 1012.00, Tol2 P1, 13.300, 20.000, Actual, 28.966, 1012.00, Tol2 P2, 13.300, 20.000, Actual, 28.966, 1012.00, Tol2 P3, 13.300, 20.000, Actual, 28.966, 1012.00, Tol3 P1, 11.500, 20.000, Actual, 28.966, 1012.00, Tol3 P2, 11.500, 20.000, Actual, 28.966, 1012.00, Tol3 P3, 11.500, 20.000, Actual, 28.966, 1012.00, Tol3 P4, 11.500, 20.000, Actual, 28.966, 1012.00, Tol4 P1, 11.500, 20.000, Actual, 28.966, 1012.00, Tol4 P2, 11.500, 20.000, Actual, 28.966, 1012.00, Tol4 P3, 11.500, 20.000, Actual, 28.966, 1012.00, Tol4 P4, 11.500, 20.000, Actual, 28.966, 1012.00, Tol4 P5, 11.500, 20.000, Actual, 28.966, 1012.00,

EMISSION DATA:

Source name, Units, NH3, Tol1 P1, g/s, 0.043, Tol1 P2, g/s, 0.043, Tol1 P3, g/s, 0.043, Tol2 P1, g/s, 0.043, Tol2 P2, g/s, 0.043, Tol2 P3, g/s, 0.043, Tol3 P1, g/s, 0.015, Tol3 P2, g/s, 0.015, Tol3 P3, g/s, 0.015, Tol3 P4, g/s, 0.015, Tol4 P1, g/s, 0.024, Tol4 P2, g/s, 0.024, Tol4 P3, g/s, 0.024, Tol4 P4, g/s, 0.024, Tol4 P5, g/s, 0.024,

SUMMARY OF OUTPUT GROUP CONTENTS:

Group name, Source name, , Tol1 P1, , Tol1 P2, , Tol1 P3, , Tol2 P1, , Tol2 P2, , Tol2 P3, , Tol3 P1, , Tol3 P2, , Tol3 P3, , Tol3 P4, , Tol4 P1, , Tol4 P2, , Tol4 P3, , Tol4 P4, , Tol4 P5,

4. METEOROLOGY:

Site data: ______

- Latitude (degrees) = 51.00 - Dispersion site: > Surface roughness (m) = .300 ~ Using model default Minimum Monin-Obukhov length (m) ~ Surface albedo = .230 (Model default) ~ Priestley-Taylor parameter = 1.000 (Model default) ~ Precipitation at dispersion site same as at met site - Meteorological measurement site: > Surface roughness same as dispersion site ~ Minimum Monin-Obukhov length same as at dispersion site ~ Surface albedo same as at dispersion site ~ Priestley-Taylor parameter same as at dispersion site

Meteorological data: - From file C:\MJS project folders\ADMS 5\Met data\Herstmonceux\herstadms10.met - Sequential met data - Height of recorded wind (m) = 10.0 - Met lines with wind speed at 10m less than .75m/s are not modelled - Met data in sectors, size (degrees) = 10.0

5. BACKGROUND DATA:

6. GRID OPTIONS:

Cartesian co-ordinate system Gridded output - Regular spacing - 31x31 - South-West corner at (576000.0, 138000.0) - North-East corner at (581000.0, 143000.0) - Number of heights = 1 - Minimum height(m) = .0 - Maximum height(m) = .0 Specified points output - 'Sissinghurst Wood' at (580073.0, 139282.0, .0) - 'Tolehurst Wood' at (578462.0, 140333.0, .0) - 'Grandshore Wood' at (579776.0, 140600.0, .0) - 'Duck Pit Wood' at (580024.0, 140882.0, .0) - 'Grand Shore Wood 2' at (579271.0, 140300.0, .0) - 'Maplehurst Farm Wood' at (579314.0, 141619.0, .0) - 'Reeves Wood' at (578985.0, 139911.0, .0) - 'Saunders Wood' at (578622.0, 139730.0, .0) - 'Brewers Wood' at (578038.0, 139787.0, .0)

7. OUTPUT OPTIONS:

Groups modelled - ''

POLLUTANT OUTPUT DATA:

Pollutant, Statistic, Condition, Percentiles, Exceedences, NH3, Long-term 1-hourly non-rolling (ug/m3), None, None, None,

______End of Report File ______

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6. FIGURE 1. WIND ROSE FROM MET DATA USED IN MODELLING (2010).

I:\MSOffice\ADMS\Met data\Herstmonceux\herstadms10.met

350° 0° 10° 340° 500 20° 330° 30° 320° 40° 400 310° 50° 300 300° 60°

290° 200 70°

280° 100 80°

270° 90°

260° 100°

250° 110°

240° 120°

230° 130°

220° 140° 210° 150° 200° 160° 190° 180° 170° 0 3 6 10 16 (knot s) Wind speed 0 1.5 3.1 5.1 8.2 (m/ s)

7. FIGURE 2 (below) Tolehurst 2018 Isopleths show predicted average ground level concentrations of ammonia in µg m-3 (2010 weather data).

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This product includes mapping data licensed from Ordnance Survey Crown Copyright and or database right 2018. License number 100027745

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