The volumetric water consumption of British milk

Transcription

1 The volumetric water consumption of British milk Supplementary study on a sample of 11 dairy farms Report prepared for DairyCo by The E-CO 2 Project August 2013

2 Contents Executive summary Introduction Objective Method Farm data collection Estimating water consumption Consumption by animals Parlour use Industrial feed processing Results Farm characteristics Total water consumption Discussion and Conclusions Key messages for the dairy industry Glossary Bibliography Appendix A. WFT summary: total water usage per farm... 15

3 Executive summary In a previous study, Cranfield University modelled the volumetric water consumption of British milk. This estimated the quantity of water consumed per kg of fat and protein corrected milk (FMCP) for five different milk production systems, distinguishing between direct (ie blue ) water consumption, predominately resulting from drinking and cleaning routines, and virtual (ie green ) water used to grow forage and concentrate feedstuffs This supplementary study collected water use data on 11 commercial farms, making comparisons of metered water use with that estimated using a) a commercial water foot printing tool (Water Footprint Tool, E-CO2 Project) and b) the original Cranfield methodology. Metered water consumption varied considerably from farm to farm, reflecting individual circumstances and production system. Calculated water consumption was consistently higher than metered water usage, at least in part, due to the potential for animals to access other sources of water while at grass. Average consumption of blue water, derived from a sample of real farm data using WFT (5.3 per L FPCM) and Cranfield models (6.7 per L Fat and Protein Corrected Milk), were broadly comparable to the theoretical estimates for British milk production, given in the previous Cranfield report (7.4L to 8.1L per kg FPCM). In 10 herds following a grazing system, average metered water (per litre FPCM) was 4.3 L. This compared with estimated total consumption of 5.3 L and 6.7 L for the WFT and Cranfield models respectively. Average figures for water consumed in drinking were calculated to be 4.65 L and 4.17 L, for the WFT and Cranfield models respectively. For the fully housed herd, metered water consumption was 5.3 L, compared with estimated figures of 5.4 L and 5.4 L, for WFT and Cranfield models respectively. The greatest sources of variation are outside that consumed directly by the animal, indicating that these are the priority areas to target in order to increase water use efficiency. Efficient milk production will reduce the quantity of water used per litre of milk. Improvements in water use efficiency will reduce cost, as well as improve the environmental credentials of the dairy industry. Avoiding leaks, and regular checking of pipework, should be a given for efficient management of water supply. All eleven participating farms reported a 100% recycling of plate cooler water. However, only one reported use of a water-efficient pressure washer. 1

4 1. Introduction In a previous study for DairyCo, Cranfield University modelled the volumetric water consumption of British milk. This estimated the quantity of water consumed per kg of fat and protein corrected milk (FMCP) for five different production systems. The study distinguished between direct (ie blue ) water consumption, used for drinking, washing, cleaning and cooling, and virtual (ie green ) water used to grow forage and concentrate feedstuffs. E-CO 2 Project were commissioned to undertake this supplementary study to cross reference the modelled consumption of blue water (taken from the mains supply, rivers or ground water), with actual farm recorded data. 2. Objective Specific objectives of this supplementary study were to: Calculate the blue water consumption on 11 dairy farms, making comparisons with recorded metered usage over a 12-month period; Apply the methods used by Cranfield in calculating the volumetric consumption of blue water, to real farm data, comparing and contrasting with calculations made using a commercially-available water foot print tool; Gain further insight into how water use is apportioned on dairy farms, practically and in the wider context of water foot printing methodology; and Make relevant recommendations for improving water use efficiency 3. Method 3.1. Farm data collection Eleven dairy farms participated in the study. Ten herds followed a grazing management system; one was fully housed. Metered water use, defined as the volume of water provided to the farm by a utility company, was farmer-reported. None of the farms used borehole water. Metered water was reported for the dairy only; no other agricultural enterprises shared water from the same meter. A commercially available water foot printing tool (WFT, E-CO 2 Project) was used to collect farm data. A gap analysis was conducted between the WFT and Cranfield models, to ensure that information for all parameters required was collected. A proforma was then produced covering:- Metered and non-metered water use; Milk production and milk characteristics; Stock and feed information; Plate cooler requirements and water use; and Wash water usage. Water use assessments were completed by E-CO 2 assessors at the same time as the annual farm carbon assessment. 2

5 The categorical differences between both models are given in Table 1 below. Table 1: Components of the WFT and Cranfield methodologies Water Footprint Tool (WFT) A. 1 A1. Lactating cows Yes Yes A2. Female calves Yes No A3. Heifers Yes Yes A4. Male calves 2 Yes No A5. Bulls Yes No B. Feeds 3 B1. Industrial feed processing No Yes C. Parlour C1. Plate cooler Yes Yes C2. Milking system wash water Yes No 4 C3. Bulk tank Yes Yes C4. Udder washing Yes No C5. General washing Yes Yes 1 not inclusive of embedded water for replacements brought on-farm Cranfield 2 up to 12-months old 3 water for grazing and grass production is considered green water and is not included in either methodology 4 washing assumed in plate cooler use 3.2. Estimating water consumption For the purposes of this study, water consumption was categorized under three main headings:- consumed by animals in-parlour cleaning and washing consumed in feed processing Consumption by animals The WFT estimates consumption using the Kertz Equation developed by A.F. Kertz, Ralston Purina Company (Adams & Sharpe). This formula is based on milk production, milk fat content, ration moisture content, and dry matter intake. In the absence of recorded data, the WFT provides default averages for each of these inputs. Kertz equation used in the WFT: Total water intake (lbs./day) = (4 x dry matter intake) + lbs. 4% FCM Drinking water intake (lbs./day) = total water intake - ration water intake 4% FCM (fat corrected milk) = (0.4 x lbs. milk) + 15 x (lbs. milk x % fat as decimal) The Cranfield method derived water consumption for lactating animals from fat and protein corrected milk (FPCM) and dry matter intake (Thompson, King, Smith, & Tiffin, 2006). Equation used by Cranfield: I w = 2.15I d M+12.3 I w = water intake, kg/day l d = dry matter intake, kg/day M = milk yield, kg/day 3

6 The Agriculture Research Council (ARC) estimated drinking water requirement for replacement heifers l/kg DM ingested (Thompson, King, Smith, & Tiffin, 2006), was used in the Cranfield report Parlour use For this report, water consumed in the parlour consisted of water used in plate cooling, milking system washing, udder washing, and general washing. The WFT assumes a general volume of 2.5 L of water per litre of milk produced (2.5:1), for milk cooling. Milking system wash water was calculated based on litres used per wash cycle (ie Sink Fill Volume), wash cycles per milking, and milking frequency, with a default of 4 cycles per milking (Payer & Holmes, n.d.). On five of the ten farms studied, washing routine data were provided by the farmer. Where recorded data were not available, milk line/milking system wash water is estimated on a per cow basis L wash water per cow per day (Brugger, 2008). Bulk tank wash water was calculated by the WFT on the basis of tank size, volume of tank used per wash, and washes per week. Where this information was not available, the WFT automatically calculates an average bulk tank size based on milk production and a need for 2-days storage with 10% spare capacity. Water consumption is then calculated based on automatic (5% volume) daily washing (Payer & Holmes, n.d.); although there is the capacity to change this value for manual washing (ice bank tanks) or if the actual volume of wash water is known. Udder wash water is determined from washing method ( hand sprayed/auto or buckets/towels ). The WFT defaults to hand sprayed/automatic washing, at 0.9 L per animal per milking minimum (Payer & Holmes, n.d.). The WFT estimates general wash water based on flow rate and time, where both are known. However, if only the time of washing is known, a default rate was applied; 20 L per minute for mains water, 12 L per minute for pressure wash water, and 80 L per minute for volume wash water (Milk Development Council, 2007); and 2.5 L per minute for sink use (Swistock & Sharpe, 2005). WFT has the capacity to include water used for other purposes including, shed wash water, sinks, toilets, leaks, and irrigation. Several farms reported shed wash water, and the estimated volume of water was added to the general parlour wash water. No irrigation or water leaks were reported. The Cranfield method assumed plate cooler use at a ratio of 2:1 water to milk, and a total use of 3 L of water per litre of milk produced (3:1) to include washing functions (Hess, Chatterton, & Williams, 2012). Bulk tank and milking machine wash water is separately reported at 0.31 L per kg milk produced. An additional 25 L per lactating animal per day is allowed in the Cranfield report, for washing and cleaning, based on Thompson et al, Industrial feed processing Water consumption for processing of feed is not included by the WFT, as it is assumed to be negligible (<1% of total water consumption). The Cranfield report includes an estimate of 3.9 L of blue water used per tonne of purchased feed. 4. Results 4.1. Farm characteristics Farm characteristics for ten grazing herds and one housed herd are summarised in Table 2. On the ten grazing farms, herd size ranged from 65 to 319 milking cows (Table 2a). Daily milk production (litres FPCM) averaged 20.8 L per cow (range 15.9 L to 26.2 L). Heifer 4

7 numbers ranged from 10 to 107 (average 29). Nine of the ten farms, home-reared replacement animals. The housed herd contained 185 milking cows, yielding 26.1 L FPCM per day (or 9,500 L per annum), at 3.74% fat and 3.30% protein. Heifers were both home and contract reared. Table 2: General characteristics of farms assessed 20.8 Farm number Ave General management Replacement system 1 HR HR HR HR HR HR HR HR CR HR N/A Management 2 system FGS FGS NZ FGS PD FGS FGS FGS FGS FGS N/A Months on pasture PD N/A Months housed PD N/A Washer type pressure volume mains volume mains mains mains volume volume mains N/A Herd characteristics Lactating cows Heifers Female calves Bulls N/A Milk characteristics Daily production 22.2 (litres/cow) Yearly production (litres/cow) 3 Fat (%) Protein (%) Cow feed characteristics Ration moisture N/A content (%) Dry matter 4 intake N/A Additional enterprises Associated 5 with the dairy n.d. arable none none n.d. n.d. n.d. n.d. none None N/A 1 HR = Home reared, CR = Contract reared 2 FGS = full grazing summer, NZ = New Zealand system, PD = partial day/housed at night 3 FPCM 4 n.d. = not detailed 5 additional enterprises do not share metered water Four farms were able to provide ration moisture content. Two provided dry matter intake (18 kg and 17 kg per head per day, respectively). Where ration moisture content was not available, an average value of 55% was assumed. For the farm following a New Zealand grazing management system (Farm 3), ration moisture content was estimated at 70.5% based on a weighted average of the moisture content of fresh grass and concentrates fed to the cows. Where actual dry matter intake was not available, an average of 19.5 kg per animal per day was assumed (Reinemann, 2004). 5

8 4.3. Total water consumption Individual farm data are compared with outputs from the WFT and Cranfield models in Tables 3a and 3b. Comparison of total metered water consumption with modelled water consumption, is expressed both in terms of percent change or percent difference between the two values. Using metered water as the reference point, percent change describes calculated water consumption as a function of the metered value ie the difference between the metered water and calculated consumption as a percentage of the metered value, using the formula: Percent change = (V 2 -V 1 )/V 1 V 1 = the reference value (metered water use) V 2 = the changed value (calculated water use) Percent difference can be used to compare two values when neither is considered to be the definitive reference point. Therefore, it is used below to show the difference between metered water use and the calculated water footprint, as a percentage of the average of those two values. All values are expressed as a positive difference, according to the formula: Percent difference = (V 1 -V 2 )/[(V 1 +V 2 )/2] V 1 = the initial value (metered water use) V 2 = the changed value (calculated water use) For the purposes of this study, percent difference is the more appropriate comparator. On grazing farms, the average percent difference between metered and calculated water consumption was 27.4% (range 12.2% to 85.9%) and 47.5% (range 5.3% to 113.3%) for WFT and Cranfield models respectively. On nine out of the ten grazing farms, metered water consumption was less than that estimated by both models, indicating that water is also being obtained from other sources, for example, in grazing fields. Table 3a: Calculated water footprints relative to metered use: 10 grazed farms Metered Water Footprint Tool Cranfield methodology Water % % Litres/yr Litres/yr % change Litres/yr use difference difference % change Farm 1 2,300,000 2,598, % 13.0% 3,306, % 43.7% Farm 2 5,242,000 6,027, % 14.9% 7,482, % 42.7% Farm 3 1,528,000 3,829, % 150.6% 5,521, % 261.3% Farm 4 16,500,000 14,385, % -12.8% 15,644, % -5.2% Farm 5 5,800,000 7,842, % 35.2% 9,509, % 64.0% Farm 6 2,886,000 3,407, % 18.1% 4,027, % 39.5% Farm 7 4,802,000 6,555, % 36.5% 9,001, % 87.4% Farm 8 4,804,000 6,211, % 29.3% 7,110, % 48.0% Farm 9 6,176,000 8,301, % 34.4% 14,899, % 141.2% Farm 10 5,986,000 7,035, % 17.5% 7,402, % 23.7% Average 5,602,4000 6,619, % 33.7% 8,390, % 74.6% Data for metered versus calculated water consumption were much closer for the housed herd (Table 3b), with percent differences of 2.5% and 0.67% for WFT and Cranfield models, respectively. Table 3b: Calculated water footprints relative to metered use: Farm 11 Water use Housed system Metered Water Footprint Tool Cranfield methodology % % % Litres/yr Litres/yr % change Litres/yr difference difference change 9.369,000 9,606, % 2.5% 9,306, % -0.7% 6

9 4.4 Water use per litre of FPCM In terms of water used per litre of Fat and Protein Corrected Milk, average metered water use for herds following a grazing system was reported as 4.3 L, compared with estimated average consumption of 5.3 L and 6.7 L for the WFT and Cranfield models respectively (Table 4). The contained herd (Farm 11) reported a metered water use of 5.3 L. Table 4: Water use per litre of FPCM Lactating cows FPCM 1 Water Metered Water WFT Water Cranfield 2 Farm Number of cows Litres/cow/day Litres/litre FPCM Litres/litre FPCM Average Fat and protein corected milk 2 Cranfield methodology Litres/litre FPCM 7

10 4.5. Overall apportionment of water consumed The apportionment of water used is given, in Tables 5 and 6, by farm for WFT and Cranfield models respectively. Table 5: Apportionment of water consumed (grazed systems) WFT model Farm 1 Farm 2 Farm 3 Farm 4 Farm 5 Litres water/litre FPCM A1. Lactating cows A2. Female calves A3. Heifers A4. Male calves A5. Bulls Consumption sub total Feeds 1 B1. Industrial feed n/a n/a n/a n/a n/a processing Parlour C1. Plate cooler C2. Milking system wash water 3 C3. Bulk tank C4. Udder washing a C5. General washing Wash water subtotal Total estimated usage Farm 6 Farm 7 Farm 8 Farm 9 Farm 10 Litres water/litre FPCM A1. Lactating cows A2. Female calves A3. Heifers A4. Male calves A5. Bulls Consumption sub total Feeds 1 B1. Industrial feed processing n/a n/a n/a n/a n/a Parlour C1. Plate cooler C2. Milking system wash water C3. Bulk tank C4. Udder washing a C5. General washing Wash water subtotal Total estimated usage water for grazing and grass production is considered green water and is not included in either methodology 2 100% recycled if in italics not added in total 3 washing assumed in plate cooler use 4 zero if recycled water used for washing a zero if dry wipe recorded 8

11 Table 5: Apportionment of water consumed (grazing systems) Cranfield Farm 1 Farm 2 Farm 3 Farm 4 Farm 5 Litres water/litre FPCM A1. Lactating cows A2. Female calves n/a n/a n/a n/a n/a A3. Heifers A4. Male calves 2 n/a n/a n/a n/a n/a A5. Bulls n/a n/a n/a n/a n/a Consumption sub total Feeds 1 B1. Industrial feed processing Parlour C1. Plate cooler C2. Milking system wash n/a n/a n/a n/a n/a water 3 C3. Bulk tank C4. Udder washing n/a n/a n/a n/a n/a C5. General washing Wash water subtotal Total estimated usage Farm 6 Farm 7 Farm 8 Farm 9 Farm 10 Litres water/litre FPCM A1. Lactating cows A2. Female calves n/a n/a n/a n/a n/a A3. Heifers A4. Male calves 2 n/a n/a n/a n/a n/a A5. Bulls n/a n/a n/a n/a n/a Consumption sub total Feeds 1 B1. Industrial feed processing Parlour C1. Plate cooler C2. Milking system wash n/a n/a n/a n/a n/a water C3. Bulk tank C4. Udder washing n/a n/a n/a n/a n/a C5. General washing Wash water subtotal Total estimated usage water for grazing and grass production is considered 'green' water and is not included in either methodology 2 1/3 rd of estimated volume presented (used for wash water) 2/3 rds recycled 3 washing assumed in plate cooler use 4 based on lactating cows only Plate cooler water use, as presented, is only the proportion for cleaning (1 L per litre milk produced); water used for cooling has not been included as all ten farms reported 100% recycling of this water. A separate estimate of water consumption by male dairy 9

12 animals/bulls and female calves, is not included in the Cranfield methodology. Similarly, separate estimates are not made for udder wash water, or milking system wash water. For the housed system (Farm 11), metered water consumption was 5.3 L, compared with estimated figures of 5.4 L and 5.4 L, for WFT and Cranfield models respectively (Table 7). Table 7: Apportionment of water consumed (housed system) Farm 11 Water use - WFT Water use Cranfield Litres/litre FPCM Litres/litre FPCM A1. Lactating cows A2. Female calves 0.03 n/a A3. Heifers A4. Male calves n/a A5. Bulls 0.02 n/a Consumption sub total Feeds 1 B1. Industrial feed processing n/a 0.00 Parlour C1. Plate cooler C2. Milking system wash water n/a C3. Bulk tank C4. Udder washing a 0.99 n/a C5. General washing Wash water subtotal Total estimated usage water for grazing and grass production is considered 'green' water and is not included in either methodology 2 100% recycled if in italics - not added in total 3 washing assumed in plate cooler use 4 zero if recycled water used for washing 5 1/3rd of estimated volume presented (used for wash water) - 2/3rds recycled (for cooling) 6 washing assumed in plate cooler use 7 based on lactating cows only a zero if dry wipe reported 10

13 4.5 Proportion of total water consumed for drinking The proportion of water consumed for drinking is compared with that for washing and cooling in Tables 8 and 9. Table 8: WFT water consumption vs. washing and cooling % of total Washing and cooling % of total % of total Washing and cooling % of total Farm 1 Farm 2 Farm 3 Farm 4 Farm Farm 6 Farm 7 Farm 8 Farm 9 Farm Table 9: Cranfield water consumption vs. washing and cooling % of total Washing and cooling % of total % of total Washing and cooling % of total Farm 1 Farm 2 Farm 3 Farm 4 Farm Farm 6 Farm 7 Farm 8 Farm 9 Farm Estimates of the proportion of water used for drinking averaged 87.1% and 61.8 %, for the WFT and Cranfield models respectively. 5. Discussion and Conclusions Without accurate measurements of water consumption at the various points of use, this report can only give an overview of the relativity between total modelled and actual water consumption. Nevertheless, average consumption figures for blue water, derived from a sample of real farm data using WFT (5.3 per L FPCM) and Cranfield models (6.7 per L FPCM), were broadly comparable to the theoretical estimates for British milk production, given in the previous Cranfield report (7.4L to 8.1L per kg FPCM). Metered water consumption varied considerably from farm to farm, reflecting individual circumstances and production system. Calculated water consumption was consistently higher than metered water usage, at least in part, due to the potential for animals to access other sources of water while at grass. Modelled versus metered consumption was much closer for the fully housed herd in the farm sample, although this could be more the effect of the individual components of consumption contributing to overall net figure, rather than the inherent detailed accuracy of the models. 11

14 On the ten grazing farms, calculated water consumption was consistently higher using the Cranfield model, on average 26% higher than the WFT. Higher allowances for cooling and washing (0.68 L vs L), accounted for most of the difference in estimated water consumption. Average figures for water consumed in drinking were 4.65 L and 4.17 L, for the WFT and Cranfield models respectively. The vagaries of farm management, including the availability of accurate dry matter intakes, are likely to make absolute accuracy in water consumption difficult to obtain. In particular, accurately determining consumption is a challenge for pasture based systems. The greatest sources of variation are outside that consumed directly by the animal, indicating that these are the priority areas to target in order to increase water use efficiency. Better information on specific points of usage would allow more accurate estimates of water consumption as well as stimulate improvement in water use efficiency. All eleven participating farms reported a 100% recycling of plate cooler water; the results of which are supported by lower metered water consumption. However, only one farm reported use of a water-efficient pressure washer (12 L per minute). Five of the eleven farms reported use of a volume washer (80 L per minute). The remaining farms reported use of mains water for washing, which is estimated at 20 L per minute on average. All participating farms had a good knowledge of water use; eight of the eleven farmers knew the exact volume of bulk tank wash water required and six knew milking system wash water requirements. 6. Key messages for the dairy industry 1. Improvements in water use efficiency will reduce cost, as well as improve the environmental credentials of the dairy industry. 2. A cow producing an average of 20 L FPCM per day, at a charged-for water consumption rate averaging 6 L per litre milk produced, would cost approximately 68 annually, or 0.9p per litre of milk at 1.54 per m 3 water purchased. 3. Efficient milk production will also reduce the quantity of water used per litre of milk. 4. Water usage can be reduced significantly by using pressure washing systems and recycling water used for milk cooling. 5. Avoiding leaks, and regular checking of pipework, should be a given for efficient management of water supply. 6. A 0.5 litre reduction in water used per litre of milk produced, would add over 700 to the bottom line in a 130-cow herd. 12

15 Glossary Water colour (Water Footprint Network): Blue water fresh surface and groundwater; fresh water that can be extracted from lakes, rivers, and aquifers. This includes water extracted from a bore hole or well Green water precipitation that is directly used in plant growth, evapotranspiration, or evaporates before becoming blue water; it does not include the water that falls on crops and runs off into surface water or that recharges ground water Grey water an estimate of the amount of clean water needed to dilute any water contaminated by pollutants from the process being analysed, until it is of acceptable quality Further reading The Environment Agency publishes a range of literature relating to water conservation and demand management. These are available to download at: The Code of Good Agricultural Practice for the Protection of Water produced by Defra offers interpretation of legislation and provides best practice advice on minimising the risk of causing pollution, while protecting natural resources is available to download at or in hard copy from Defra publications quoting reference PB13558). Efficient use of water on a dairy farm produced by DairyCo increases awareness about water use on dairy farms and highlights some opportunities where water and money may be able to be saved. 13

16 Bibliography Adams, R. S., & Sharpe, W. E. (n.d.). Water Intake and Quality for Dairy Cattle. Penn State, Department of Dairy and Animal Science. University Park: Penn State. Adams, R., & Sharpe, W. (n.d.). Water Intake and Quality for Dairy Cattle. University Park: Penn State: Penn State, Department of Dairy and Animal Science. Brugger, M. (2008). Water Use and Savings on Large Dairy Farms. North Canton: Ohio State University. DairyCo. (2011, May 9). Average Milk Yield. Retrieved August 17, 2011, from DEFRA. (n.d.). Retrieved from DEFRA Department for Environment Food and Rural Affairs: DeLaval. (n.d.). DeLaval Plate Heat Exchanger. Retrieved August 2011, from Environment Agency. (2002). Waterwise on the Farm. Bristol: Environment Agency. Greenlands. (n.d.). Water Quality and Requirements for Your Cattle. Retrieved July 8, 2011, from Hess, T., Chatterton, J., & Williams, A. (2012). The Volumetric Water Consumption of British Milk Production. Bedford: Cranfield University. Met Office. (n.d.) Averages. Retrieved August 2011, from Met Office: Milk Development Council. (2007). Effective Use of Water on Dairy Farms. Cirencester. Payer, D. C., & Holmes, B. J. (n.d.). Estimating the Volume of Wastewater. Madison: Extension Publications. Reinemann, D. J. (2004, February). Water Supply and Distribution. Retrieved August 21, 2011, from South Staffs Water. (n.d.). Water Use in Your Business. Walsall: South Staffordshire Water Plc. Swistock, B. R., & Sharpe, W. E. (2005). Water Facts #2. Water System Planning - Estimating Water Needs. University Park: Penn State. Thompson, A. J., King, J. A., Smith, K. A., & Tiffin, D. H. (2006). Opportunities for Reducing Water use in Agriculture. Defra Project Wu0101. Water Footprint Network. (n.d.). Glossary. Retrieved April 17, 2013, from Water Footprint: 14

17 Appendix A. WFT summary: total water usage per farm Farm 1 Farm 2 Farm 3 Farm 4 Farm 5 Litres/year A1. Lactating cows 2,091,877 4,458,210 2,637,612 11,478,437 6,264,790 A2. Female calves 16,073 90,007 57, ,581 64,291 A3. Heifers 264, , , , ,439 A4. Male calves A5. Bulls ,625 97,539 0 Feeds 1 B1. Industrial feed processing n/a n/a n/a n/a n/a Parlour C1. Plate cooler 2 1,506,350 3,287,399 1,973,097 8,095,688 5,215,374 C2. Milking system wash water 3 142, , , , ,436 C3. Bulk tank 20, ,835 54, ,718 91,311 C4. Udder washing a 7,305 96, ,581 C5. General washing 4 54,786 51, , ,484 0 Total estimated usage 5 2,598,000 6,027,000 3,829,000 14,385,000 7,842,000 Farm 6 Farm 7 Farm 8 Farm 9 Farm 10 Litres/year A1. Lactating cows 2,632,934 5,344,816 4,088,447 5,315,424 4,540,060 A2. Female calves 16,073 35,360 70, , ,307 A3. Heifers 363, , , ,218 1,795,065 A4. Male calves A5. Bulls 24, Feeds 1 B1. Industrial feed processing n/a n/a n/a n/a n/a Parlour C1. Plate cooler 2 1,993,762 4,068,214 2,951,449 5,243,052 3,068,034 C2. Milking system wash water 328, , , , ,536 C3. Bulk tank 41, ,573 59, ,621 29,200 C4. Udder washing a , ,523 0 C5. General washing ,168, ,025 Total estimated usage 5 3,407,000 6,555,000 6,211,000 8,301,000 7,035,000 1 water for grazing and grass production is considered 'green' water and is not included in either methodology 2 100% recycled if in italics - not added in total 3 washing assumed in plate cooler use 4 zero if recycled water used for washing a zero if dry wipe reported 15

18 Appendix B. Cranfield summary: total water usage per farm Farm 1 Farm 2 Farm 3 Farm 4 Farm 5 Litres/year A1. Lactating cows 1,672,295 3,575,577 2,947,544 8,162,971 4,982,416 A2. Female calves n/a n/a n/a n/a n/a A3. Heifers 374,010 1,189, ,868 1,083, ,640 A4. Male calves n/a n/a n/a n/a n/a A5. Bulls n/a n/a n/a n/a n/a Feeds 1 B1. Industrial feed processing 501 1, ,495 1,326 Parlour C1. Plate cooler 2 502,116 1,095, ,699 2,698,561 1,738,457 C2. Milking system wash water 3 n/a n/a n/a n/a n/a C3. Bulk tank 164, , , , ,256 C4. Udder washing n/a n/a n/a n/a n/a C5. General washing 4 593,518 1,278,347 1,113,988 2,867,150 1,698,375 Total estimated usage 5 3,306,000 7,482,000 5,521,000 15,644,000 9,509,000 Farm 6 Farm 7 Farm 8 Farm 9 Farm 10 Litres/year A1. Lactating cows 2,103,571 4,626,936 3,275,996 8,035,927 3,519,779 A2. Female calves n/a n/a n/a n/a n/a A3. Heifers 304, ,953 1,363,929 1,002,589 1,261,400 A4. Male calves n/a n/a n/a n/a n/a A5. Bulls n/a n/a n/a n/a n/a Feeds 1 B1. Industrial feed processing 848 1, ,607 1,907 Parlour C1. Plate cooler 2 664,587 1,356, ,816 2,213,732 1,022,678 C2. Milking system wash water 3 n/a n/a n/a n/a n/a C3. Bulk tank 204, , , , ,261 C4. Udder washing n/a n/a n/a n/a n/a C5. General washing 4 748,746 1,661,851 1,187,037 2,912,805 1,278,347 Total estimated usage 5 4,027,000 9,001,000 7,110,000 14,899,000 7,402,000 1 water for grazing and grass production is considered 'green' water and is not included in either methodology 2 1/3 rd of estimated volume presented (used for wash water) 2/3 rds recycled 3 washing assumed in plate cooler use 4 based on lactating cows only 16

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