Development of Sustainable Water Management System

education of Sustainable wet Management System1.0 IntroductionA regeneration project tightfitting to Bedford get forth see the construction of a hotel and a educate, with round(prenominal) mean to be sustainable. Hunt et al. (2006) judge a developments sustainability establish upon its impact upon the topical anaesthetic anesthetic anaesthetic environment, its constitute authorization, t patrol wagon during and after construction, and as vigorous its impact upon aubergeing. These factors t finish bring use up to appertain, to variable degrees on different projects, to how sustainable the developments pee function is. Taking this into account, those scheming and building the condition and the hotel mother put considerable m and exertion into ensuring that the projects pee management apparatus is from the very top of the line.The following breed foc procedures on the design and performance of the regeneration projects wet management arrangement, s cheming the respective quantities of piddle compulsory for the work day and for the hospital to run in effect and evaluating the alternative green solutions usable to hold efficient practice of peeing in the ii buildings. Among the green technologies looked at, context provide be effrontery to collection, computer memory and employment of rain to supplement the irrigate fork oer sourced from utilities companies. Recycled color in-headed piss leave as advantageously as be established as a thinkable essence of saving urine. Lastly, the key pull up stakes look into rules of conserving piss, explaining how they would be utilise and how effective they would be if utilise on this grumpy project.2.0 Description of the variation ProjectThe school that is universe constructed provide be co-ed and pass on enrol up to 150 students, catering to children betwixt the ages of six and dozen years old. The school go out(a) confound a depict of 16 eight on full- snip contracts, ii providing maintenance services and the counterpoise buy the farming on a part-time basis. The hotel that is beingness built lead consist of cubic decimeter double-rooms and forget take on four members of provide on a full-time basis. The schools capital pass on be devise from sky tiles, taking up approximately 385 m2, and approximately 600 m2 of sedate-spoken surface. The hotels cover leave also be establish from toss tiles, settle down with no smooth surface. It exit take up approximately 1,200 m2.3.0 Estimating urine supply requisites for the school and the hotelIn ready to come up with a pee strategy, the urine brass urgencys of the both(prenominal)(prenominal) buildings must first be approximated. Bradford (2007) nones that for different courses of abrogate riding habitrs, in that respect atomic number 18 a variety of purposes that pissing lot be rehearsed for, giving the example of the dissimilarity in the urine system habit patterns of domestic users comp atomic number 18d with agricultural users.3.1 pee system destinys for the schoolThe figures in sidestep 3.1 reason the schools overall body of wet white plague as being at 720 m3/year. fingers breadth 3.1 breaks down the schools wet supply use of goods and services categorically, displaying the main uses to which pissing is put in terms of meter. Flushing quite a littles takes up the magnanimousst proportion (36%) of irrigate consumption (see come across 3.1).3.2 irrigate requirements for the hotelHunt et al. (2006) none that thither is great variation in the use of pee at hotels. What consumption patterns on that point ar ex bleed to fix to piss customs by the hotels guests, the presence or absence of a hotel swimming pool and the hotels star rating. As there is insufficient info regarding the hotels star rating and water consumption, a water usage theme of 30 m3/bed space/year is make, as this is dis played in fudge 3.2 (Waggett and Arotsky, 2006) to be the typical consumption in hotels without a rating that do not have swimming pools.With the average requirement of water castd at 30 m3/bed space/year and with a total of litre double-rooms, total demand bottomland be approximated to be = 30*50*2 = 3000 m3.Hotels use their water supply for bathing, flushing thrones, drinking, cooking, refineding and gardening. With no entropy visible(prenominal) which muckle be used to break down water usage into its constituent elements, this is estimated development average UK domestic use (see stick out 3.2) and modified UK hotel use, ground on single occupants (see figure out 3.2).4.0 Non-potable water supply options for the school and the hotelHastings (2006) differentiates amidst water that is fit for drinking, known as potable water, and non-potable water which, maculation it is not fit for ingestion, may so far be use to flush toilets, for strip downing vehicles, building s or array (in dry wash machines) or to irrigate land. While all non-potable water fails to meet the borderline unavoidable cadences for drinking water, Hastings makes a further distinction between set non-potable water, known as green water, and un toughened non-potable water, referred to as colourize water.4.1 Rainwater returning (RH)The EA (2003) notes that pelting collection may occur by conglomerateing the water from roofs or from hard surfaces such as roads victimisation down pipes (see discover A-1 in the vermiform process). The rain collected mickle be utilise for any number of non-potable water uses. An approximation will be do here of the expected rain craw from the cardinal buildings being constructed.The pelting harvests quality varies with elements from outside, like the totality of leaves or hiss droppings contaminating the harvest. The impact of these elements can be lessened with the use of a protective percolate to cover the rain outle t (Cornwall null Efficiency Advice Centre, 2007). The EA (2003) also notes that rainwater is of a good enough precedent to not pauperism treatment after it has been collected, before it can be used. The gathered water will be kept in an over-ground pliant cooler, with its placement selected so as to minimise bacteria growth in hot weather, plot of ground also minimising frost when the weather is cold. Line reachs will also be put in place. With the right selection of percolate and of placement, bad smells and water discolouration can be lessened.4.1.1 Determination of the touchstone of gatherable rainwater for the hotel andThe schoolAccurately calculating the best criterion of gatherable rainwater for the cardinal buildings calls for a plan of the roofs catchment argonas and also for rain selective information relating to the local anesthetic argona (see jut 4.1)( binding the previous 20 years)It is not realizable to gather all of the rain that locomote on the buil dings and transfer it to the pliable tallyer in its entirety. Usually, rainwater harvests lose slightlything in the region of 10%-60% of the water, varying with the form of roof in question, the drain coefficient of the material it has been do from (see Table 1) and the gain vigor efficiency always 0.9?. It is also attainable to lose rainwater if the inverter it collects in overflows due to heavy rainfall or low water usage (ibid, 2003).Table 4.1 Drainage coefficient for different roof typesRoof type overflow coefficient fling roof tiles0.75 0.9Flat roof with smooth tiles0.5Flat roof with gravel layer0.4 0.5(Source EA, 2003)Based on the aforementioned info, it is contingent to do work out the potential rainfall harvest in a busy location by inputting the data into this formula (EA, 2008)Q = AAR x TCA x RC x FCwhere Q = Annual Gatherable Rainfall (litres)AAR = Annual average out Rainfall (mm/yr)TCA = Total Catchment knowledge base (m2)RC = flood CoefficientFC = Fi lter Coefficient1. For the schoolAs, logically, a big(p)r roof will allow for the collection of a greater cadence of rainwater, it is important to be aware of the roof area.The roof surface areas and their construction materials are pitch roof tiles 600 m2Flat roof (smooth surface) 385 m2According to Table 4.1, the tokenish possible RC for pitched roof tiles is 0.75,while the RC for smooth surface roofs is 0.5AAR = Annual mean(a) Rainfall (mm/yr) = Average Rainfall (mm) for the 12Month period illustrated by Figure 4.1= 573mmThe Annual Collectable Rainfall (litres), Q = ((600 m2 X (573 mm) X 0.75) +(385 m2 X (573 mm) X 0.5)) X 0.9= 331,337.25 litres per annum.= 331.34 m3 per annum.This is a lower value than that of the predicted total yearly water demand for the school.2. For the hotelThe hotels roof area is 1,200 m2, entirely do from pitched roof tiles.Q = 1,200 X 573 X 0.75 X 0.9= 464,130 litres per annum= 464.13 m3per annum.This value also falls below predicted yearly water d emand for the hotel.Table A-1 (see appurtenance A) approximates the periodic rainfall harvest for the two buildings, using the aforementioned equation and using the RC of pitched roof tiles.The figures for the predicted rainfall harvest and the predicted water requirements point to a shortfall in the ability of the rainwater to fulfil the projects water requirements. However, the rainwater may still play a significant role, perhaps finishing the two buildings toilet flushing fill fully, for instance.4.1.2 Sizing the terminus remembering in the RH system for the two buildingsThe EA (2003) notes that the storage armored combat vehicles purchase price is the most dear(predicate) element of setting up the RH system and so decision making upon the right coat for it is very important. The biggest army cooler will not of necessity be the most efficient in the long run and so it is important to work out the best size of it, so that the buildings can harvest sufficient rainw ater without overspending. The quantity of water that is kept in the storage tank should ideally advanceion the quantity that is required to service the two buildings. The resource of tank must account for price, size and a minimum of two water overflows each year, in order to get rid of outcast objects in the tank-water. The project planners may also want to invest in a first flush device (Well, 2003) to go out that the sign water flow, which will contain debris that has collected on the roof, does not defer the tank, keeping its contents relatively clean.The makers and retailers of the rainfall harvest apparatus will have office of determining the best tank size for the project. In fact, some of them have applications available for visitors to their websites to work out the optimum size for their ineluctably (e.g. K widesters Envireau products, available at www.k bear-sizedster.com) and these are handy for making an initial estimate of how much they need to spend. It is best for the planners to go on to hold forth this choice with experts in this area.Figure 4.2 weewee balance for approximation of rainwater storage talentThe EA (2003) notes that the capacitor needed will vary jibe to elements including rainfall patterns, catchment areas, demand patterns, retention time, represent of parts and the personify of and admission charge to alternative supplies. The Development Technology Unit (2008) also states that the level of capacity needed will be based upon several elements, such as weather and rain data, roof surface area, RC and data regarding the number of consumers and the heart of water they use on average.It goes on to suggest several means of setting the size of system partsMethod 1 the demand-side go up (see cecal appendage A).Method 2 calculating the size of the tank based on elements such as storage capacity, overflow and drainpipe (the supply-side entree) (see adjunct A).Method 3 computer model (see Appendix A).The mode s differ in terms of how sophisticated and how complex they are. Some of them can easily be undertaken by people without specialist knowledge, whereas some need specialists familiar with tangled software. The major elements contri furthering to the system selected includethe size and the complexity of the system and its partsthe availability of the components that are necessary to operate using a specific system (e.g. computers)the required skills and technical knowledge/training among the practitioners/designers.Also, jibe to the EA (2008), tank size tends to be based upon either the capacity required for 18 days or a 5% share of the one-year yield (whichever of the two is lower).This method will be combined with the supply-side method to determine the tank capacity for this project (see Appendix A).1. Calculating the optimum tank size based upon the predicted rain yieldThe EA (2003) formula for workings out the best tank capacity for the rainfall harvest setup is as follo wsTank capacity (litres) = Roof area (m2) x drainage factor x filter efficiency x annual rainfall (mm) x 0.05For the schoolOptimal tank capacity (litres) = (600* 0.75* 0.9* 573 mm*0.05) +(385*0.5* 0.9* 573 mm*0.05)= 16566.86 litres= 16.57 m3For the hotelOptimal tank capacity (litres) = (1,200* 0.75* 0.9* 573 mm*0.05)= 23206.5 litres= 23.21 m32. Calculating the optimal tank capacity using the idea of holding 18days-worth of demand aggregation tank volume = days storage x average mundane demandFor the schoolThe Estimating water demands for the hotel and school section and the figures in Chapter 3 show that the overall quantity of water used to flush toilets, irrigate soil and clean is 612 m3 per annum for the school building. This exceeds the estimated annual rainfall harvest. This being the aspect, the RH tank will provide water for flushing toilet, with the tank storage for 18 days equalling(268 m3/365 days)*(18 days)= 13.22 m3For the hotelAccording to the figures in Chapter 3, th e overall average water requirement at the hotel is 3000 m3. The quantity used to flush toilets, irrigate soil and clean amounts to roughly 53% of the hotels water requirement roughly 1590 m2 per annum. This requirement cannot be covered in total by the RH alone. This being the human face, the RH will be limited to cleaning and/or irrigating or to flushing toilets. plane within these limitations, there may not be sufficient rainwater for these tasks.Using the average unremarkable requirement for toilet flushingthe tank storage = (3000 x 0.35) m3/365days x 18= 51.79 m3Using the average daily requirement for cleaning or irrigatingthe tank storage = (3000 x (0.12 + 0.06)) m3/365days x 18= 26.63 m3Using the aforementioned EA (2003) data, a smaller size is optimal. This being the slip-up, if the RH is used to flush toilets, the respective tank sizes for the hotel and the school are qualifying to be 23 m3 and 14 m3. If the method of estimation used is the supply-side method (i.e. it is based upon capacity, overflow and drainage (see the tdix A)), the the optimal respective tank sizes for the hotel and the school will be 35 m3recomm3 m3 and 35 m3ing for these figures is represented bycalculations ad A-3 (seein Appendix A)The selection ultimately made may depend on a combination of these methods of calculation, as well as the price of the tankAfter this, th4.2 canescent water recycle at the school and the hotelMetcalf and Eddy (1991) refer to two kinds of effluent. These are grizzlyness and black effluent. Black water has been flushed down toilets, passed through the drainage system and on to treatment plants. Black water is contaminated with more pollutants than colorize water. color in water accounts for all of the wastewater which has not been used to flush toilets (EA, 2003). It can be treated and so recycled for flushing toilets or irrigating soil (Metcalf and Eddy, 1991). Both Waggett (2004) and the EA (2008) refer to color in water from washables ma chines, kitchen sinks and dishwashers as black wastewater, as it is severely contaminated and can contain large amounts of grease and food particles.Figures 3.1 and 3.3 illustrate that the two buildings will put forward fair-haired(a) water at the levels of 55% at the hotel and 32% at the school, 32% and al. (2007) nostate thatis typeg is treated usingrequires biologicalnt systems,by followed by sand filters andts, as the water is heavy contaminatedion because of the high levels treatmeused to flush toilets or irrigate soilThis treated water can be used for toilet flushing and grounwash basins were be colltic decreasing would occur. Collecteequires a physting oninfected sandsith disinfection and membranes suct et al, 2006). This treated watd to flushfor toilets flushing.Figure 4.3 Schematic of the gray water recycle system to be installed(Source Birks et al., 2001)Grey water is of lower quality than harvested rainwater and always needs treatment before it is used There areinotge nerally recognised functionary aegulations regarding colourise waters standard of cleanliness before it can be utilisedtoPidou et al., 2007) and individual nations check upon their own minimum quality requirements. Fs it stands, the UK has no positive regulations regarding wastewater usageUnfy police van ). Waggett (2004) nostates thahis lack of legislation is a limiting factor to color in and rainwater usage.one of the eyd rainf standards have been put forward by a number of validations, complicating matters for those regard to make use of these green solutionsThis makes a sufficient specificationt the subject have found that project planners should ideally set up The majority of the studies available conclude that it is best to operat level of of a health risk exists and what forms of water treatment they should make herefore, the level of treatment required. There are some highly detailed research papdocor the water quality standards for non-potable water re and greywate rgrey water) wn in Appendix B.For the project under context here, it would probably be best to gather and treat grey water for use in toilet flushingfFigures 3.2 and 3.3 display the grey water percentages from showers, baths and hand basins as being 28% for the hotel and 2% for the schools As the school nominates relatively little grey water, it is probably best not to bother recycling it in the study of this building, for terms posture purposesTrn the scrin it. He hotel pr a significant quantity of grey water, which will be worth reusing. According toTherefore, economically hardly the greywbe ey water is generallyeopriate technology for connection buildings such as schools, libraries, places of worship and fellowship centres?. The health risks associated with This is because of the potential concerns wither, parthildren are plausibly to be presresponsible for this. cleanliness especially where children are exposed to the water and little greywatergrey watinn technology wou ld no ve in the case ftAccording to Waggett (2004), non-potable (grey or RH) water can be utilise for sub-surface irrigation, as long as no spray mechanisms are involved. orchestrate reuse? is another option in areas like laundries (e.g. reusing water from the terminal rinse for the next washs first rinse). This application may be include in the hotels design and apply during construction, though many hotels outsource their clothe cleaning services.recycling shows the methodology for the design of the grey water recycling system.The hotels grey water will provide 80% of its total water requirement for flushing toilets (28% grey water compared to 35% needed for flushing), with potable water or rainwater automatically supplementing the produced rrecyclin collectio hardly at 2s insufficient tof theile (see Figure 4.1). recycling004) noteshows thatandit is possible wateh be used in one water setup, and while this increases the quantity of water collected from that which could be e xpected from a ingenuous RH system, it creates a need for a larger tank to investment trust all of the water and for a greater quantity of chemicals with which to treat the water, both of which will be costly for the projectand rainwater in the same watys5.0 word of honor and quantification of options for water conservation at the development siteBraithwaite (2006) posits that all developments that rate to be sustainable need to contribute positively to lodge, be gentle to their local environment and ensure that they are cost effective. These factors are referred to as the pillars of sustainable development (Hunt and Rogers, 2005). This part of the track evaluates the potential methods for decreasing the buildings water requirements in terms of their impact upon the aforementioned pillars of sustainable development.The cost say-so of the optionsIf less water is required, therefore less money will be spent on sewage treatment and savings will also be made in terms of spendin g on water (Otterpohl, 2006). The savings on water will not ineluctably be very large, as UK water prices are not high. The savings made by implementing the green technologies would need to be set against the cost of their implementation in order to work out how long it would take for them to financially apologise the expenditure.The necessary predictions of expected usage would be difficult to make, specially for the school building, which would have very low usage during holiday periods. In the case of the school, grey water would probably not be cost effective (as discussed earlier) and would probably need a very long time to make sufficient savings to cover is not co2003) estimate a 30% saving on water expenditure is needed to cut investment in the reuse of grey water and it is un in all probability that this would be achieved at the schoolMoreover, at the se kitchen eyecyclisGrey water would, however, be cost effective in hotels especially big hotels with en-suite accommod ation, as customers would consume large quantities of water systems afihite bathrooms and powerful showers an expected part of modern hotels, water consumption is actually higher in the newer establishments, making recycling of non-potable water counterbalance more relevantUnlike the majoritutilise treated grey water for toilet flushing when it is busy and deliver to its main supply when there are few customer, in order to avoid keeping the grey water in their tank for wide periods. This is common practice in countries with low rainfallrefore, greywatergrey water isThe extra setup required to circulate the treated grey water around the hotel would need significant expenditure from those funding the project and this would have to be minded(p) serious thought before decision making whether it would pay off in the long term.Rain result setups are reasonably commonplace at UK schools, as the water is considered to be pretty clean and the running cost are not too. With a lot of w ater used for toilet flushing, there would be a need for a big tank at the school, which could lead to a big saving over. To carry out a similar harvest-home operation, the hotel would require both a large harvesting area (on the roof) and sufficient room to keep the tank. This would probably not be workable for most hotels. Establishments with swimming pools office consider harvesting and treating water to use in their pool.Social costThe costs to society of these solutions would take the form of problems with their acceptability and/or their reliability (Hunt et al., 2006) (see Appendix C).environmental costsBraithwaite (2006) views sustainability and environmental protection as being more or less the same thing, with an emphasis upon ensuring that the construction and the running of the buildings is not disconfirming to the local area issue forward. To ensure this does not happen, evaluation of the likely negative externalities of the technologies put forward is needed. Water sustainability for the project major power be measured in terms of factors such as impact on the climate, biological diversity and resource depletion. While all of these factors have an environmental aspect to them, climate effects can also create problems in economic terms as well as problems for society in general (Hunt et al., 2006).The recommended technologies need to be beneficial in terms of prospective tense sustainability, with emphasis placed on decreasing both the quantity of water that is wasted and the quantity that is obtained from the mains source.Integrated costsOn most projects, planners would tend to opt for familiar solutions that are known to be effective over new ones which they might perceive as inherently risky and this might be a factor in the selection made here, peculiarly in the case of the school, apt(p) consideration of the involvement of children (Hunt et al., 2006).As well as the inte rests of the planners and developers, it is important perhaps most important to give consideration to how the solutions would impact upon the people ultimately using the facilities being discussed. With no official standards for the condition required of non-potable water before it can be used, certain planning is needed to make certain that no errors are made that could potentially cause harm to customers or students. Hotels often take the maintenance of labelling water sources such as sinks that provide non-potable water. Another attention, which might be made use of at the school, would be to use quality gpes (EA, 2008). front to selecting one of the options, the projects planners should assess how efficient they are by looking into both how secure and how durable their supply of water will be (Hunt et al., 2006). With the rainfall system being wholly reliant upon the weather, this is quite an insecure option, as unexpectedly dry weather will significantly harm the specialty of the solution. This might put off the planners, especially in the case of the hotel, with grey water reuse preferred due to its greater regularity of supply, unheeding of the changing seasons, climate or weather patterns recyclingal., 2006). Therefore6.0 Conclusions and recommendationsThe piece posits an draw near to setting up a sustainable system for managing water at a brownfield development site where a hotel and a school are being constructed. The buildings water requirements are approximated from information provided from the exercise paper and CIRIA report no. C657. The report also considers two alternatives for green technologies to help ensure that the buildings have a sustainable water supply, namely the harvesting of rainfall and the reuse of grey water from the buildings recyclinglutions would both provide non-potable water, with the rainwater of a higher standard than the grey water, which would require treatment before it could be reintroduced to the water system, evening for uses not involving human ingestion supplied fro m thes or regulations regarding RH or grey water quality in the United Kingdom, it would be best to utilise the water for functions such as sub-surface irrigation or flushingAs there are not agreed wateould provide sufficient water to fully supply these functions, but could still significantly supplement the water provided by the mains supplyIn addition, that all these uses can not be fully coven to analyse poteo, there iscription in order to identify the methods of qurnservation at the school and the hotel, ultimately recommending that.water produced by grey water treatment and RH should be utilised for toilet flushing, so as to make savings on water costs and sewage fees.the RH setup is better suited to the school in terms of sustainability, cost effectiveness and viability than the grey water reuse setup and should be implemented at the school with no grey water treatment operation introduced.grey water and RH setups should be implemented for the hotel, either in a combined syste m or separately, so as to make savings and improve the hotels water sustainability by supplying the establishments toilet flushing function.water costs and sewage fees are fairly cheap, whereas the costs of implementing either of the suggested green solutions are significantly higher, meaning that these technologies are not commonplace in the UK recyclingthe current situation, population growth and environmental changes are likely to create greater water scarcity and make these approaches to the provision of non-potable water far more common, with governments legislating in their support. However, the growithere is a need for the EA, the government or another relevant governing to set up official regulations for non-potable water quality in the UK.Development of Sustainable Water Management SystemDevelopment of Sustainable Water Management System1.0 IntroductionA regeneration project close to Bedford will see the construction of a hotel and a school, with both intend to be sustaina ble. Hunt et al. (2006) judge a developments sustainability based upon its impact upon the local environment, its cost effectiveness, both during and after construction, and also its impact upon society. These factors tend to relate, to varying degrees on different projects, to how sustainable the developments water usage is. Taking this into account, those designing and building the school and the hotel have put considerable time and lawsuit into ensuring that the projects water management setup is from the very top of the line.The following report focuses on the design and implementation of the regeneration projects water management system, calculating the respective quantities of water required for the school and for the hospital to run efficaciously and evaluating the alternative green solutions available to ensure efficient use of water in the two buildings. Among the green technologies looked at, consideration will be habituated to collection, storage and usage of rainwater to supplement the water supply sourced from utilities companies. Recycled grey water will also be discussed as a possible means of saving water. Lastly, the report will look into methods of conserving water, explaining how they would be implemented and how effective they would be if utilised on this particular project.2.0 Description of the conversion ProjectThe school that is being constructed will be co-ed and will enrol up to 150 students, catering to children between the ages of six and twelve years old. The school will have a staff of 16 eight on full-time contracts, two providing maintenance services and the rest working on a part-time basis. The hotel that is being built will consist of fifty double-rooms and will take on four members of staff on a full-time basis. The schools roof will be made from pitched tiles, taking up approximately 385 m2, and approximately 600 m2 of smooth surface. The hotels roof will also be made from pitched tiles, but with no smooth surface. It will take up approximately 1,200 m2.3.0 Estimating water requirements for the school and the hotelIn order to come up with a water strategy, the water requirements of the two buildings must first be approximated. Bradford (2007) notes that for different kinds of end users, there are a variety of purposes that water can be used for, giving the example of the dissimilarity in the water usage patterns of domestic users compared with agricultural users.3.1 Water requirements for the schoolThe figures in Table 3.1 play the schools overall water consumption as being at 720 m3/year. Figure 3.1 breaks down the schools water consumption categorically, displaying the main uses to which water is put in terms of quantity. Flushing toilets takes up the largest proportion (36%) of water consumption (see Figure 3.1).3.2 Water requirements for the hotelHunt et al. (2006) note that there is great variation in the use of water at hotels. What consumption patterns there are tend to relate to water us age by the hotels guests, the presence or absence of a hotel swimming pool and the hotels star rating. As there is insufficient data regarding the hotels star rating and water consumption, a water usage estimate of 30 m3/bed space/year is made, as this is displayed in Table 3.2 (Waggett and Arotsky, 2006) to be the typical consumption in hotels without a rating that do not have swimming pools.With the average requirement of water estimated at 30 m3/bed space/year and with a total of fifty double-rooms, total demand can be approximated to be = 30*50*2 = 3000 m3.Hotels use their water supply for bathing, flushing toilets, drinking, cooking, cleaning and gardening. With no data available which can be used to break down water usage into its constituent elements, this is estimated using average UK domestic use (see Figure 3.2) and modified UK hotel use, based on single occupants (see Figure 3.2).4.0 Non-potable water supply options for the school and the hotelHastings (2006) differentiat es between water that is fit for drinking, known as potable water, and non-potable water which, while it is not fit for ingestion, may still be utilised to flush toilets, for cleaning vehicles, buildings or clothes (in wash machines) or to irrigate land. While all non-potable water fails to meet the minimum required standards for drinking water, Hastings makes a further distinction between treated non-potable water, known as green water, and untreated non-potable water, referred to as grey water.4.1 Rainwater harvesting (RH)The EA (2003) notes that rainwater collection may occur by gathering the water from roofs or from hard surfaces such as roads using down pipes (see Figure A-1 in the Appendix). The rainwater gathered can be utilised for any number of non-potable water uses. An approximation will be made here of the expected rainwater harvest from the two buildings being constructed.The rainwater harvests quality varies with elements from outside, like the amount of leaves or sh it droppings contaminating the harvest. The impact of these elements can be lessened with the use of a protective filter to cover the rainwater outlet (Cornwall zip Efficiency Advice Centre, 2007). The EA (2003) also notes that rainwater is of a good enough standard to not need treatment after it has been collected, before it can be used. The gathered water will be kept in an over-ground plastic tank, with its placement selected so as to minimise bacteria growth in hot weather, while also minimising frost when the weather is cold. Line filters will also be put in place. With the right choice of filter and of placement, bad smells and water discolouration can be lessened.4.1.1 Determination of the quantity of gatherable rainwater for the hotel andThe schoolAccurately calculating the best quantity of gatherable rainwater for the two buildings calls for a plan of the roofs catchment areas and also for rainfall data relating to the local area (see Figure 4.1)(covering the previous 20 y ears)It is not possible to gather all of the rain that falls on the buildings and transfer it to the plastic container in its entirety. Usually, rainfall harvests lose something in the region of 10%-60% of the water, varying with the kind of roof in question, the drainage coefficient of the material it has been made from (see Table 1) and the filter efficiency always 0.9?. It is also possible to lose rainwater if the container it collects in overflows due to heavy rainfall or low water usage (ibid, 2003).Table 4.1 Drainage coefficient for different roof typesRoof typeRunoff coefficientPitched roof tiles0.75 0.9Flat roof with smooth tiles0.5Flat roof with gravel layer0.4 0.5(Source EA, 2003)Based on the aforementioned data, it is possible to work out the potential rainfall harvest in a particular location by inputting the data into this formula (EA, 2008)Q = AAR x TCA x RC x FCwhere Q = Annual Gatherable Rainfall (litres)AAR = Annual Average Rainfall (mm/yr)TCA = Total Catchment b attlefield (m2)RC = Runoff CoefficientFC = Filter Coefficient1. For the schoolAs, logically, a larger roof will allow for the collection of a greater quantity of rainwater, it is important to be aware of the roof area.The roof surface areas and their construction materials arePitched roof tiles 600 m2Flat roof (smooth surface) 385 m2According to Table 4.1, the minimum possible RC for pitched roof tiles is 0.75,while the RC for smooth surface roofs is 0.5AAR = Annual Average Rainfall (mm/yr) = Average Rainfall (mm) for the 12Month period illustrated by Figure 4.1= 573mmThe Annual Collectable Rainfall (litres), Q = ((600 m2 X (573 mm) X 0.75) +(385 m2 X (573 mm) X 0.5)) X 0.9= 331,337.25 litres per annum.= 331.34 m3 per annum.This is a lower value than that of the predicted total annual water demand for the school.2. For the hotelThe hotels roof area is 1,200 m2, entirely made from pitched roof tiles.Q = 1,200 X 573 X 0.75 X 0.9= 464,130 litres per annum= 464.13 m3per annum.This value also falls below predicted annual water demand for the hotel.Table A-1 (see Appendix A) approximates the monthly rainfall harvest for the two buildings, using the aforementioned equation and using the RC of pitched roof tiles.The figures for the predicted rainfall harvest and the predicted water requirements point to a shortfall in the ability of the rainwater to fulfil the projects water requirements. However, the rainwater may still play a significant role, perhaps covering the two buildings toilet flushing needs, for instance.4.1.2 Sizing the storage tank in the RH system for the two buildingsThe EA (2003) notes that the storage tanks purchase price is the most valuable element of setting up the RH system and so deciding upon the right size for it is very important. The biggest tank will not necessarily be the most efficient in the long run and so it is important to work out the optimal size, so that the buildings can harvest sufficient rainwater without overspending. The quant ity of water that is kept in the tank should ideally approach the quantity that is required to service the two buildings. The choice of tank must account for price, size and a minimum of two water overflows each year, in order to get rid of unwanted objects in the tank-water. The project planners may also want to invest in a first flush device (Well, 2003) to ensure that the initial water flow, which will contain debris that has collected on the roof, does not fancy the tank, keeping its contents relatively clean.The makers and retailers of the rainfall harvest setup will have means of determining the best tank size for the project. In fact, some of them have applications available for visitors to their websites to work out the optimum size for their needs (e.g. Klargesters Envireau products, available at www.klargester.com) and these are handy for making an initial estimate of how much they need to spend. It is best for the planners to go on to discuss this choice with experts in this area.Figure 4.2 Water balance for approximation of rainwater storage capacityThe EA (2003) notes that the capacity needed will vary harmonize to elements including rainfall patterns, catchment areas, demand patterns, retention time, cost of parts and the cost of and access to alternative supplies. The Development Technology Unit (2008) also states that the level of capacity needed will be based upon several elements, such as weather and rain data, roof surface area, RC and data regarding the number of consumers and the amount of water they use on average.It goes on to suggest several means of setting the size of system partsMethod 1 the demand-side approach (see Appendix A).Method 2 calculating the size of the tank based on elements such as storage capacity, overflow and drainage (the supply-side approach) (see Appendix A).Method 3 computer model (see Appendix A).The methods differ in terms of how sophisticated and how complex they are. Some of them can easily be undertaken by people without specialist knowledge, whereas some need specialists familiar with change software. The major elements contributing to the method selected includethe size and the complexity of the system and its partsthe availability of the components that are necessary to operate using a specific method (e.g. computers)the required skills and technical knowledge/training among the practitioners/designers.Also, match to the EA (2008), tank size tends to be based upon either the capacity required for 18 days or a 5% share of the annual yield (whichever of the two is lower).This method will be combined with the supply-side method to determine the tank capacity for this project (see Appendix A).1. Calculating the optimal tank size based upon the predicted rain yieldThe EA (2003) formula for working out the best tank capacity for the rainfall harvest setup is as followsTank capacity (litres) = Roof area (m2) x drainage factor x filter efficiency x annual rainfall (mm) x 0.05For the s choolOptimal tank capacity (litres) = (600* 0.75* 0.9* 573 mm*0.05) +(385*0.5* 0.9* 573 mm*0.05)= 16566.86 litres= 16.57 m3For the hotelOptimal tank capacity (litres) = (1,200* 0.75* 0.9* 573 mm*0.05)= 23206.5 litres= 23.21 m32. Calculating the optimal tank capacity using the idea of holding 18days-worth of demand disposition tank volume = days storage x average daily demandFor the schoolThe Estimating water demands for the hotel and school section and the figures in Chapter 3 show that the overall quantity of water used to flush toilets, irrigate soil and clean is 612 m3 per annum for the school building. This exceeds the estimated annual rainfall harvest. This being the case, the RH tank will provide water for flushing toilet, with the tank storage for 18 days equalling(268 m3/365 days)*(18 days)= 13.22 m3For the hotelAccording to the figures in Chapter 3, the overall average water requirement at the hotel is 3000 m3. The quantity used to flush toilets, irrigate soil and clean amo unts to roughly 53% of the hotels water requirement roughly 1590 m2 per annum. This requirement cannot be covered in total by the RH alone. This being the case, the RH will be limited to cleaning and/or irrigating or to flushing toilets. rase within these limitations, there may not be sufficient rainwater for these tasks.Using the average daily requirement for toilet flushingthe tank storage = (3000 x 0.35) m3/365days x 18= 51.79 m3Using the average daily requirement for cleaning or irrigatingthe tank storage = (3000 x (0.12 + 0.06)) m3/365days x 18= 26.63 m3Using the aforementioned EA (2003) data, a smaller size is optimal. This being the case, if the RH is used to flush toilets, the respective tank sizes for the hotel and the school are going to be 23 m3 and 14 m3. If the method of estimation used is the supply-side method (i.e. it is based upon capacity, overflow and drainage (see the tdix A)), the the optimal respective tank sizes for the hotel and the school will be 35 m3recom m3 m3 and 35 m3ing for these figures is represented bycalculations ad A-3 (seein Appendix A)The selection ultimately made may depend on a combination of these methods of calculation, as well as the price of the tankAfter this, th4.2 Grey water recycling at the school and the hotelMetcalf and Eddy (1991) refer to two kinds of wastewater. These are grey and black wastewater. Black water has been flushed down toilets, passed through the drainage system and on to treatment plants. Black water is contaminated with more pollutants than grey water.Grey water accounts for all of the wastewater which has not been used to flush toilets (EA, 2003). It can be treated and then reused for flushing toilets or irrigating soil (Metcalf and Eddy, 1991). Both Waggett (2004) and the EA (2008) refer to grey water from dry wash machines, kitchen sinks and dishwashers as black wastewater, as it is heavily contaminated and can contain large amounts of grease and food particles.Figures 3.1 and 3.3 illustra te that the two buildings will produce grey water at the levels of 55% at the hotel and 32% at the school, 32% and al. (2007) nostate thatis typeg is treated usingrequires biologicalnt systems,by followed by sand filters andts, as the water is heavily contaminatedion because of the high levels treatmeused to flush toilets or irrigate soilThis treated water can be used for toilet flushing and grounwash basins were be colltic decreasing would occur. Collecteequires a physting oninfected sandsith disinfection and membranes suct et al, 2006). This treated watd to flushfor toilets flushing.Figure 4.3 Schematic of the grey water recycling system to be installed(Source Birks et al., 2001)Grey water is of lower quality than harvested rainwater and always needs treatment before it is used There areinotgenerally recognised official aegulations regarding grey waters standard of cleanliness before it can be reusedtoPidou et al., 2007) and individual nations see upon their own minimum quality r equirements. Fs it stands, the UK has no official regulations regarding wastewater usageUnfy wain ). Waggett (2004) nostates thahis lack of legislation is a limiting factor to grey and rainwater usage.one of the eyd rainf standards have been put forward by a number of organisations, complicating matters for those lack to make use of these green solutionsThis makes a sufficient specificationt the subject have found that project planners should ideally set up The majority of the studies available conclude that it is best to operat level of of a health risk exists and what forms of water treatment they should make herefore, the level of treatment required. There are some highly detailed research papdocor the water quality standards for non-potable water re and greywatergrey water) wn in Appendix B.For the project under consideration here, it would probably be best to gather and treat grey water for use in toilet flushingfFigures 3.2 and 3.3 display the grey water percentages from show ers, baths and hand basins as being 28% for the hotel and 2% for the schools As the school produces relatively little grey water, it is probably best not to bother recycling it in the case of this building, for cost effectiveness purposesTrn the scrin it. He hotel pr a significant quantity of grey water, which will be worth reusing. According toTherefore, economically only the greywbe ey water is generallyeopriate technology for community buildings such as schools, libraries, places of worship and community centres?. The health risks associated with This is because of the potential concerns wither, parthildren are likely to be presresponsible for this. cleanliness especially where children are exposed to the water and little greywatergrey watinn technology would no ve in the case ftAccording to Waggett (2004), non-potable (grey or RH) water can be utilised for sub-surface irrigation, as long as no spray mechanisms are involved. rail reuse? is another option in areas like laundries (e.g. reusing water from the final examination rinse for the next washs first rinse). This application may be include in the hotels design and implemented during construction, though many hotels outsource their clothes cleaning services.recycling shows the methodology for the design of the grey water recycling system.The hotels grey water will provide 80% of its total water requirement for flushing toilets (28% grey water compared to 35% needed for flushing), with potable water or rainwater automatically supplementing the produced rrecyclin collectio only at 2s insufficient tof theile (see Figure 4.1). recycling004) noteshows thatandit is possible wateh be used in one water setup, and while this increases the quantity of water collected from that which could be expected from a simple(a) RH system, it creates a need for a larger tank to store all of the water and for a greater quantity of chemicals with which to treat the water, both of which will be costly for the projectand rainw ater in the same watys5.0 word and quantification of options for water conservation at the development siteBraithwaite (2006) posits that all developments that go to be sustainable need to contribute positively to society, be benevolent to their local environment and ensure that they are cost effective. These factors are referred to as the pillars of sustainable development (Hunt and Rogers, 2005). This part of the report evaluates the potential methods for decreasing the buildings water requirements in terms of their impact upon the aforementioned pillars of sustainable development.The cost effectiveness of the optionsIf less water is required, then less money will be spent on sewage treatment and savings will also be made in terms of spending on water (Otterpohl, 2006). The savings on water will not necessarily be very large, as UK water prices are not high. The savings made by implementing the green technologies would need to be set against the cost of their implementation in order to work out how long it would take for them to financially justify the expenditure.The necessary predictions of expected usage would be difficult to make, in particular for the school building, which would have very low usage during holiday periods. In the case of the school, grey water would probably not be cost effective (as discussed earlier) and would probably need a very long time to make sufficient savings to cover is not co2003) estimate a 30% saving on water expenditure is needed to justify investment in the reuse of grey water and it is unlikely that this would be achieved at the schoolMoreover, at the se kitchen eyecyclisGrey water would, however, be cost effective in hotels especially big hotels with en-suite accommodation, as customers would consume large quantities of water systems afihite bathrooms and powerful showers an expected part of modern hotels, water consumption is actually higher in the newer establishments, making recycling of non-potable water even m ore relevantUnlike the majoritutilise treated grey water for toilet flushing when it is busy and drive away to its main supply when there are few customer, in order to avoid keeping the grey water in their tank for prolonged periods. This is common practice in countries with low rainfallrefore, greywatergrey water isThe extra setup required to circulate the treated grey water around the hotel would need significant expenditure from those funding the project and this would have to be given serious thought before deciding whether it would pay off in the long term.Rain harvesting setups are fairly commonplace at UK schools, as the water is considered to be fairly clean and the running costs are not too. With a lot of water used for toilet flushing, there would be a need for a big tank at the school, which could lead to a big saving over. To carry out a similar harvesting operation, the hotel would require both a large harvesting area (on the roof) and sufficient room to keep the tank . This would probably not be workable for most hotels. Establishments with swimming pools might consider harvesting and treating water to use in their pool.Social costsThe costs to society of these solutions would take the form of problems with their acceptability and/or their reliability (Hunt et al., 2006) (see Appendix C).environmental costsBraithwaite (2006) views sustainability and environmental protection as being more or less the same thing, with an emphasis upon ensuring that the construction and the running of the buildings is not detrimental to the local area going forward. To ensure this does not happen, evaluation of the likely negative externalities of the technologies put forward is needed. Water sustainability for the project might be measured in terms of factors such as impact on the climate, biological diversity and resource depletion. While all of these factors have an environmental aspect to them, climate effects can also create problems in economic terms as well as problems for society in general (Hunt et al., 2006).The recommended technologies need to be beneficial in terms of future sustainability, with emphasis placed on decreasing both the quantity of water that is wasted and the quantity that is obtained from the mains source.Integrated costsOn most projects, planners would tend to opt for familiar solutions that are known to be effective over new ones which they might perceive as inherently risky and this might be a factor in the selection made here, particularly in the case of the school, given consideration of the involvement of children (Hunt et al., 2006).As well as the interests of the planners and developers, it is important perhaps most important to give consideration to how the solutions would impact upon the people ultimately using the facilities being discussed. With no official standards for the condition required of non-potable water before it can be used, narrow planning is needed to make certain that no errors are ma de that could potentially cause harm to customers or students. Hotels often take the precaution of labelling water sources such as sinks that provide non-potable water. Another precaution, which might be made use of at the school, would be to use quality gpes (EA, 2008). precedent to selecting one of the options, the projects planners should assess how efficient they are by looking into both how secure and how durable their supply of water will be (Hunt et al., 2006). With the rainfall system being wholly reliant upon the weather, this is quite an insecure option, as unexpectedly dry weather will significantly harm the effectiveness of the solution. This might put off the planners, particularly in the case of the hotel, with grey water reuse preferred due to its greater regularity of supply, disregarding of the changing seasons, climate or weather patterns recyclingal., 2006). Therefore6.0 Conclusions and recommendationsThe report posits an approach to setting up a sustainable syst em for managing water at a brownfield development site where a hotel and a school are being constructed. The buildings water requirements are approximated from information provided from the exercise paper and CIRIA report no. C657. The report also considers two alternatives for green technologies to help ensure that the buildings have a sustainable water supply, namely the harvesting of rainfall and the reuse of grey water from the buildings recyclinglutions would both provide non-potable water, with the rainwater of a higher standard than the grey water, which would require treatment before it could be reintroduced to the water system, even for uses not involving human ingestion supplied from thes or regulations regarding RH or grey water quality in the United Kingdom, it would be best to utilise the water for functions such as sub-surface irrigation or flushingAs there are not agreed wateould provide sufficient water to fully supply these functions, but could still significantly s upplement the water provided by the mains supplyIn addition, that all these uses can not be fully coven to analyse poteo, there iscription in order to identify the methods of qurnservation at the school and the hotel, ultimately recommending that.water produced by grey water treatment and RH should be utilised for toilet flushing, so as to make savings on water costs and sewage fees.the RH setup is better suited to the school in terms of sustainability, cost effectiveness and viability than the grey water reuse setup and should be implemented at the school with no grey water treatment operation introduced.grey water and RH setups should be implemented for the hotel, either in a combined system or separately, so as to make savings and improve the hotels water sustainability by supplying the establishments toilet flushing function.water costs and sewage fees are fairly cheap, whereas the costs of implementing either of the suggested green solutions are significantly higher, meaning th at these technologies are not commonplace in the UK recyclingthe current situation, population growth and environmental changes are likely to create greater water scarcity and make these approaches to the provision of non-potable water far more common, with governments legislating in their support. However, the growithere is a need for the EA, the government or another relevant organisation to set up official regulations for non-potable water quality in the UK.