Understanding The Ground Drainage Systems And The Methods To Treat Domestic Sewage: Hong Kong

pages Pages: 4word Words: 890

Question :

Hong Kong College of Engineering

Code: B3C30

Task 1

Discussing the below ground drainage systems are used to dispose of foul water from buildings (P1)

Calculations to determine quantity, velocity and depth of flow, pipe size and gradient of below ground drainage from given data (M1)

Evaluating the standard methods used to test, inspect and maintain below ground drainage (D1)

Task 2

Explaining the below ground drainage systems are used to dispose of surface water (P2)

Task 3

Explaining the ways to treat domestic sewage (P3)

Evaluation of methods used to dispose of sludge (M2)

Task 4

Description of  the methods used to dispose of solid domestic waste (P4)

Task 5

Describing the different stages used for purification and storage of drinking water (P5)

The technique to access purified drinking water as per the environment efficiency and cost effective term.

Methods of using  the domestic sewage  and drinking water in financial, legal, environmental and health and safety perspective

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Answer :


In Hong Kong, the government has received many queries regarding waste water treatment, waste disposal, quality of drinking water. A committee has been set up to solve those queries with civil engineers by the government. In this assignment, the ground drainage system, treatment of domestic sewage, disposal of solid domestic waste, purification and storage of drinking water are going to be discussed. 

Task 1

Discussing the below ground drainage systems are used to dispose of foul water from buildings (P1) 

Drainage systems of the underground drains or sewers from the buildings or wastewater treatments have been discussed in the particular segment. The different procedures under which the foul water would need to be used in Hong Kong would be illustrated in the project. The particular project would show the different ways from which the remedial systems would be provided.

  1. Outlets: The particular sections provides the guidelines on the different ways to construct the underground drains and sewers form the buildings to the exact point of the existing sewer or a wastewater treatment system and also includes drains which may be outside the exact sewage point (Astuti et al. 2017). A fitting routine about a legitimate availability between foul drainage and the fundamental channels is found in the waste arrangement of Hong Kong islands. The association for little improvements is made to an open sewer that is 30m profound and is the development of the waste is allowed by the owning establishment. Under a few basins and showers, uncommon traps are  put which don't have these shapes however their inward workings are intended to satisfy a similar goal. This goal is to prevent foul gasses from the deplete runs and sewer vents, going into the room. Under the following points, the different ways to dispose the wastewaters would be mentioned below in an effective way (Valipour, 2014). Different kinds of outlets contains different ways to evaluate the drainage systems under which it needs to be possible that the ways under which the drains are made the same way of disposing the waste in the drains would need to be used.
  2. Surcharging of drains: Some combined rainwater sewers have been designed to surcharge during heavy rainfall. There are foul sewers that also receive rainwater and therefore surcharge it. In some low-lying sites, some special decisions are being taken to provide it with some effective remedies to decrease the rate of flood during rainfall. The sewerage that has been taken into consideration would need to be surcharged effectively. In case of risk, some valves have been installed effectively to prevent it from the risk of flooding. Necessary care would need to be taken to ensure the sewage has not increased in the risk of flooding. The favored hostile to flooding valves are twofold valve sort, and reasonable for foul water having a manual conclusion gadget. The valves are as per the determinations of prEN 13564. A single valve cannot take the pressure of working effectively and it may not be kept for more than one building (Christensen et al. 2016). This may be because a single valve would not be able to take up the pressure if load is given to it. So, in that case a notice would need to be given in order to make the residents realize about the capacity of the drains and the ways in which it needs to be used effectively.   

Surcharging of drains

Figure 1: Surcharging of drains

(SourceJadhav, 2016)

  1. Layouts: Layout drainage system would need to be kept simple. If the place of the drains are being kept at the same position year after year then it may be necessary to overflow sometime or the other. Changes would need to be done slowly or would need to be minimised. Connections of private to public drains or public to private drains would need to be made accordingly. Some through points may be provided if blockage can not be cleared effectively. Connections would need to be made with fabricated pipes which may be beneficial for the building as these pipes may be useful at the time of flow of waters and guiding it effectively to its place (Jadhav, 2016). These access points would need to be provided at every point of the sewage point. The frameworks are ventilated by a stream of air. A ventilating channel is given close or, on the other hand at the leader of the fundamental channels. The open ventilating funnels that are set up without an air permission valve is given on any deplete fitted with a blocking trap and on any deplete, which is subjected to additional charge. The sewage drains that connect with the kitchens or commercial foods are being connected with separate drains that comply with BS EN 1825-1:2004 and the design would need to be BS EN 1825-2:2002. 
  2. Rodent Control: Necessary needs would need to be taken that may be beneficial to control the attack of rodents. This may be regarded as the main problem that rises a lot of questions in the minds of the people. Special sites to be taken for controlling the rodents. Special needs to be taken effectively that may be beneficial to take up steps and developing the previous sites effectively. The following points may help in finding the special needs:
  3. Protection of the Drainage: Drains would need to be sealed effectively to make the supply of the flooded water pass away in a nice way. This may be helpful in continuing the flow of the water effectively. A drain would need to be made almost 100mm from the building and flexible in filling up the provided pipes (Li et al. 2017). Drains would need to be inspected regularly and checked effectively and see whether the drains are in a good condition or not. 
  4. Effectively made pipes system: The pipes that would may be made would need to be done effectively and the construction of the pipes would need to be checked effectively. The pipes would need to have the effective drainage systems and have the surcharging of the drains effectively made.
  5. Rodent Barrier: The things are being used for trapping of the rodents would need to be maintained and made effectively. This may be beneficial for the building to to have a specific trapping system. Metal cages and trapping systems may be helpful in using it against the rodents. 

Calculations to determine quantity, velocity and depth of flow, pipe size and gradient of below ground drainage from given data (M1) 

  1. Calculations determining the quantity, depth of flow, size of the pipe, velocity and gradient would be formulated below:

Q=(A * R * P) 3600=(100000 mm * 30000mm * 150mm/hr * 0.875)/ 3600 + 109375000mm3/hr

      b.   Gradient ofpipe = u* du/dy

0.01 * (1.5m/s/ 100m * 30m)

0.01 * 0.0015 = 0.000015 m3/s

  The following above calculations had been done to determine the gradient of the pipe through which the water would flow. 

      c.   The following calculations would determine the size of the pipes, which may determine the following calculations:

Q= (V x A) = (1.5m 2 x 100m x 30m) = 4500 m 3

Cheezy formulae

F = (16/Re) x μ

Re = ↻ x v x D

Re = 1000 kg/m 3 * 0.8 m/s* 300mm= 240000 mm3/s

Through the following calculations, the size of the pipes can be determined. 

Evaluating the standard methods used to test, inspect and maintain below ground drainage (D1) 

The development of an appropriate waste framework for sewage transfer is not adequate. As per this the office has adjusted to a few strategies to test, examine and keep up the subterranean waste framework in Hong Kong Island. The measures are delineated as underneath:

  1. Water Tightness: The strategy for water tightness is executed subsequent to laying, and counting the essential concrete or other haunching encompassing or inlaying, gravity channels and private sewers (Sharma et al. 2017). It is done to obtain a thought regarding the weight of water that the whole seepage framework may bear. 

Strengths and sizes of the pipes

Figure 2: Pipes assumed to be the class M to BS 5911; other strengths and sizes of the pipes

(Source: Self developed)

      b. Air Test: The channels that have a distance across up to 300mm are pressurized with a weight of 110mm water gage and held for 5 minutes before testing. The pipe holding an underlying weight of 100 mm with a most extreme misfortune head on a manometer of 25mm out of a time of 7 minutes takes after this.

     c.Water Test: The channels that has measurement of 300mm are filled in with water upto a profundity of 5m over the most minimal alter in the test segment with a base profundity of 1m that is measured at a most astounding alter in the test segment. The pipe is then left for a cooling time of 60 minutes. The test weight is kept up for a time of 30 minutes, by garnish up the water at important levels so it is found inside 100mm of the required levels all through the tests. The losses that brought about per square meter of the surface range does not surpass 1.15liters for test lengths with the main pipelines or 0.20 liters for test lengths including the pipelines and sewer vents, or 0.40 liters for tests with just sewer vents and examination chambers alone. 

    d.Connectivity: Connecting the uses of the pipes in a effective manner the different ways under which the works that are being done would need to be done in an effective way (Billington et al. 2017). The connections would need to be appropriate, this is because if the connections are not upto the point then it may be harmful for the society who would be using it. 

Recommend support of pipeworks

Figure 3: Recommend support of pipeworks

(Source: Self Developed)

Task 2

Explaining the below ground drainage systems are used to dispose of surface water (P2)  

Transfer of surface water in the city has been a noteworthy concern making the waste framework to be troublesome now and again. In any case, there are sure methods utilized by the administration with the goal that the underground seepage frameworks could be successfully used to clean up the surface water. Nonetheless, there are sure territories that should be centered on while considering transfer of surface water. A noteworthy segment of the surface water is started as water from the yearly or occasional precipitation. Consequently, it can be seen clearly from a discourse these surface water must be depleted underneath the ground to liberated the surface from dormancy. Henceforth, the current arrangement of transfer of the surface water comprises of certain sub-parts (Skousen et al. 2017). The main technique connected for the same is to structure outlets to give the water a chance to deplete to the underground aquifers. However, because of interruption of this framework, there is the utilization of the consolidated framework that may attract the water to the underground arrangement of sewerage. From there on, there are kept couple of reinforcement frameworks that are exceedingly proficient to evacuate the dormant water and penetrate it in the underground sewer framework. In any case, such sort of framework is well relevant to the seepage securing little catchments comprising of impenetrable zones of around two hectares. This sort of framework is additionally pertinent to territories bigger than this. 

  1. Outlets: The outlets are composed in a way that is at risk to send or deplete the water in an underground soakaway. This is the principal type of outlet that has been wanted to evacuate the surface water. On the off chance that there is the inaccessibility of soakaway the water must be sent to some other invasion framework according to practicability. Nonetheless, there are few concerns while completing such an arrangement of ground water release. There is a prerequisite of assent from the Environment Agency that chooses or puts a farthest point to the rate at which the release must be finished. Most extreme stream of water can be allowed as per the arrangement of detainment basins (Whittle et al. 2017). Be that as it may, on account of inaccessibility of this sort of release framework, the water must be released into the underground sewer framework. 
  2. Combined: On the note of the consolidated framework, it is to be portrayed that it comprises of sewers that conveys both the surface water and the foul water from the household waste. These waters are sent in a similar pipe basically to the underground sewerage framework. There is another limitation of the framework as far as natural ramifications. Consolidated framework must be utilized when there is sufficient limit of the sewerage channels to convey the two waters all the while (Meegoda et al. 2017). With regards to sewerage funeral director, if the sewerage does not contain that much ability to convey the aggregate stream of both foul and crisp water, the surface water is go through a different waste framework.

Combined Sewer

Figure 4: Combined Sewer

(Source: Meegoda et al. 2017 )

Task 3

Explaining the ways to treat domestic sewage (P3) 

Domestic sewage is a type of sewage, which comes from houses and apartments. It includes wastewater with foul from houses and apartments. Treating domestic sewage is important because it can carry harmful diseases if not cleared on time. Therefore, in order to maintain hygiene, government needs to implement some procedures by which they can treat domestic sewage. There are two methods mostly used for treating domestic sewage onsite,

  1. Septic tanks,
  2. Sewage treatment plants.


  1. Septic tank: Septic tanks are generally constructed underground and used to collect sewage. That sewage will be decomposed by bacterial activity before draining. The primary treated effluent has been produced by septic tanks. Primary treated effluent consists own foul smell and it is toxic to aquatic worms and life. Primary treated effluent can only be discharged to a drainage field (Withers, Jordan, May, Jarvie & Deal, 2014). 

Location: The septic tanks need to be situated beyond 18 meter of any stream of water, spring or well. That is because, water from those sources can be used for drinking, preparation of foods or drinks, cleaning of vessels for manufacturing purpose etc. Apart from this, every septic tanks needs to be situated in way so that removal of sludge and periodic inspection are easy.

Design: The design of septic tank needs to be in a way so that it enables to collect all the sewage from household or apartment and easy to treat. The depth of the tank needs to be minimum 1.2 meter to 1.8 meter from the invert of the inlet to the floor. The length of the septic tank needs to be more than three times but less than four times of its width. A tank must contain two chambers those needs to access easily for inspection and cleansing purpose. The floor of every septic tank needs to be constructed by concrete. The thickness of that concrete made floor needs to be more than 150 mm. The sides of every septic tank need to be more than 215 mm thick and constructed by brickwork in cement mortar. The thickness of concrete has to more than 125 mm thick. Apart from this, a septic tank needs to be constructed with approved material to avoid any dispute (Richards, Withers, Paterson, McRoberts & Stutter, 2017). All the internal faces that include floor of any septic tanks need to be rendered in cement mortar or faced with other approved material. This helps to deliver impervious and smooth surface. 

Method of operation: The sewage in septic tanks generally treated by break its organic contents. In a septic tank, there are generally three layers of sewage. The Scum layer exists on top, liquid effluent layer exists in middle and sludge layer exists at the bottom. In order to reduce odour and sludge quantity, anaerobic bacteria needs to be added to a septic tank. This type of bacteria needs no oxygen to grow and break down organic materials in the septic tank. The whole process can run upto two months or more (Almomani, & Khraisheh, 2016). Methane gas can be produced from large plants that used for power generation or heating purpose. 

Sizing based on population: The size of septic tank generally produced by the number of population use it regularly. The capacity of septic tank for small population includes 16-48 hours flow and 3.5 cubic meter. The content in a septic tank should not disturbed by any entering flows. 0.8 liters per person per day should be the accumulated sludge volume. 

Disposal of sludge: The sludge can be used for various purpose such as agricultural, producing energy, landfilling etc. The content from the septic tank generally pumped out and put it into the soakaway pit of a tanker lorry. A specialist contractor needs to complete this procedure. 

Disposal of water after treatment: the remaining water, which has been treated in the septic tank, disposed in septic drainfield for further treatment. A building owner who is going to install a septic tank needs to submit methods of disposal of sewage to the building authority to get approved. 

Vehicle access: A septic tank needs to be constructed in a place where vehicles can access it easily. The vehicles include lorry to pump out sewage from the septic tank. The inlet level needs to be more than 3 meters of septic tank and within the 30 meters of vehicle access point (Sun, Liu, Tan, Tang & Kida, 2017). 

2. Sewage treatment plant (STP): A sewage treatment plant generally works as the same way of septic tank. However, its mechanical components help to break solids to produce more cleaner and environmentally friendly effluent. The secondary treated effluent can be produced by sewage treatment plant. This type of effluent is cleaner than primary treated effluent. The secondary treated effluent needs to be colourless and odourless. Apart from this, it can be discharged to the surface water such as rivers, streams and to the ground such as drainage field. 

Location: Sewage treatment plant generally used to treat a huge amount of sewage water from household and apartments. Therefore, in order to make a STP, outskirt of city or a less populated area of a city is preferred (Xu et al. 2015). The procedures of STP are open to view for all to better maintenance and operational purpose.

Design: The components of STP include submersible pump, general headroom, access walkways, artificial ventilation, staircases, open mesh flooring etc. 

The submersible pump allows flexibility to operate the STP. The pump used to recycle effluent of the plant while the incoming flow is less. It helps to maintain the working condition of whole STP. General headroom of 3 meters needs to be constructed for underground or closed STP, which consists artificial ventilation. The measurement of general headroom can be reduced to 2.5 meters at localized point such as under any beam. Minimum air volume of enclosed STP needs to be 14 cubic meter. 10 air changes per hour should be provided to the artificial ventilation. The exhaust pipes of ventilation need to be constructed more than 1 meter above the roof of STP. The width of access walkways needs to be minimum 0.75 meter in order to access all areas of STP to operation and maintenance purpose. 

The walkways should contain toe boards and safety rails made with stainless steel preferably. To restrict ponding, the walkways need to be laid to a 1:25 crossfall. The staircases need to be provided to go up and down whenever required. The tanks should contain step irons or ladders of stainless steel in order to access those. Mild steel needs to be restricted. The space maintained in step iron have to be 250 mm c/c vertically and 300 mm c/c horizontally. A tank needs to be covered with open mesh flooring if required (Schaubroeck et al. 2015). The mesh flooring should be constructed with aluminum alloy or stainless steel. It has to be designed for 5kPA uniformly distributed load. The fresh water taps need to be provided to any  suitable place for hand washing. The control panel and distribution board of electricity need to be placed in a position, which can not be flooded with water. Dehumidifying heater needs to be added with control panels. The diagrams and instructions need to be place with the control panels in Chinese and English. The valves, pumps and penstocks need to be labelled accurately. 

Method of operation: Sedimentation tanks can be two types such as circular/square upward flow tank and rectangular horizontal flow tank. The length to width ratio of sedimentation tank could not be less than 2. The length to width ratio between 1 and 2 needs to be avoided. In order to collect and remove sledges easily, minimum 60-degree hopper wall slops needs to be provided to upward flow sedimentation. A mechanical scraper system can be provided with horizontal sedimentation tanks on a nominal floor slope, which helps to discharge sludge hopper. Twin tanks are preferable to use but single tank can be allowed with proper scraper that allows maintaining underwater parts. 

The fine leveling can be done by using adjustable weirs in sedimentation tanks. V-notch weirs preferably use for the variation of wide flow. To prevent the sludge overflow, the sidewalls need to be minimum of 1 meter of height (Yang, Li, Zou, Fang & Zhang, 2014). A chamber needs to be included with the final sedimentation tank outlet after installation of recirculation pump’s weir. The actual flow is always lesser than designed flow. 

Sizing based on population: The basic design parameters are following:

  • 55g BOD/h/d
  • 55g SS/h/d
  • 0.30 to 0.46 cubic meter/h/d

The design for peak flow can be :

  • 6 DWF for under 1000 population
  • 4 DWF for over 1000 population

The feed pump needs to there to prevent flow more than 3 DWF.

Disposal of sludge: the sludge in sedimentation tanks need to be removed frequently by using airlifts, submersible sludge pumps or valves. A scum removal device also needs to be there. Both devices need to be controlled independently. A sludge-dewatering machine can be attaining 30% w/w dry solids materials for landfill disposal. An emergency storage of 14 days sludge volume needs to be added with sludge tanks. A STP constructed for less than 100 people needs to be include

  • A tank with 60 days sludge volume storage. 
  • Vehicle access for cleansing purpose. 

Disposal of water after treatment: a solution of sodium hypochlorite needs to be added to the effluent after final sedimentation in order to discharge it (van Loosdrecht & Brdjanovic, 2014). 

Vehicle access: vehicles should access the whole STP easily. 

Evaluation of methods used to dispose of sludge (M2)

The treatment of sewage water can be done by two methods. 

  1. Septic tank: Effluent produced by septic tank is primarily treated and contains foul odor. The effluent is toxic for aquatic life and worms. Therefore, the treatment of effluent needs to be good so that it can not affect environment. In a gravel field, a network of pipeline called drain field needs to be produced. The wastewater with solid waste gravitates towards a absorption field. However, other types of gravity based wastewater equally distributed in the drain field. At the final stage, the liquid wastewater runs through gravel layer after leak out of pipes. Then it moves through soil layer and filtered by soil. The microbes of soil help to treat the wastewater. After that the water moves to groundwater. The dry soil is more effective for the whole process. 


Regular inspection and cleaning is needed to maintain the septic tank. Water needs to be used efficiently and extra usage of water can be caused of system failure (Siegrist, 2017). Dumping of non-decomposable wastes needs to be avoided. The pesticides, acids, paints and other chemicals need to be avoided to dump in septic tank. Those can create harmful environment for microbes in the septic tank. 

  1. Sewage treatment plant: Without any discharge, high amount of impoundments are involved in treatment plants. If the precipitation exceeds, the evaporation of impoundments have to be high. In order to treat liquid wastewater, the storage requirements, groundwater pollution and other things need to be considered. The effluents can be discharged in natural water bodies. Those effluents can be used to cool industrial machines. That water also can be used for public usage. The wastewater can also be used for irrigation and agricultural purpose and for watering golf course, parks etc (Mahapatra, Chanakya, & Ramachandra, 2013). 

The harmful mixtures and toxins need to be separated from the water before releasing it. The technology needs to be improved in order to remove chemical materials from the wastewater. Composite and landfills are the other alternative method for safety. 

Task 4

Description ofthe methods used to dispose of solid domestic waste (P4)

Solid domestic wares in general terms are the everyday trash that gets discarded on a an everyday basis. The waste consists of various kinds of material that could be simply categorised into different forms. In this section, a brief overview of the complete process of the solid waste disposal that especially originates from the domestic sources is discussed in detail. The variou types of solid wastes are as follows:

  • Organic Waste - It includes wastes accumulated from food, and garden waste
  • Combustible Waste- Includes paper, cardboard, cartons, rags, bedding etc
  • Non combustible waste - Metals, tin, can bottles etc are included
  • Ashes- they are t6he burnt remains of fuel example: Municipal solid waste ash
  • Dust- They come from stone fines, sand debris, cement etc
  • Hazardous material- Oils, batteries, sticking plasters, bandages etc are included in this section (Sanlisoy & Carpinlioglu, 2017)

Hence, in order to carry out the process of disposal of household solid wastes the government has taken special initiatives. 

Hazardous of solid Wastes

Figure 5 : Hazardous of solid Wastes

(Source : Sanlisoy & Carpinlioglu, 2017)

  • Methods that are used for disposal of solid wastes are as follows :
  • Landfill- Tonnes of trash from the business, industry and residences are disposed of f at key sites of Hong Kong. THe major advantage of these landfills is that they provide the maximum space or capacity requires for the disposal of the solid wastes. The major landfill sites of Hong Kong are West New Territories (WENT) Landfills, South East New Territories (SENT) Landfills and lastly the North East New Territories (NENT) Landfill. 
  • Refuse Chutes- In order to pass the refuse from the each floor to the central ground floor of a building an inclined channel called as refuse chute is used. Before the year 2000 the refuse chute was named as a Refuse Storage. However those built after that year were named as Material Recovery Chamber (Garcia-Lodeiro, Carcelen-Taboada, Fernández-Jiménez & Palomo, 2016).

 Refuse Chutes

Figure 6 : Refuse Chutes

(Source : Garcia-Lodeiro, Carcelen-Taboada, Fernández-Jiménez & Palomo, 2016)

  • Compaction-  The collected wastes fromdiverse regions ar3e transported to refuse transfer stations majorly for compaction. After that, they are supplied strategically to the landfills by the help of well built containers. This bulk transportation reduces three major entities that are 



3.Environmental Nuisances caused due to large number of small supply vehicles. Compaction is a five step process. The process is as follows :

Normal Q-Q plot

Figure 7.1: Step 1 Refuse Supplied to compaction by Live Floor System

(Source: Garcia-Lodeiro, Carcelen-Taboada, Fernández-Jiménez & Palomo, 2016)

Refuse in sealed containers

Figure 7.2: Step 2 Refuse is compacted in sealed containers

(Source: Garcia-Lodeiro, Carcelen-Taboada, Fernández-Jiménez & Palomo, 2016)

washing of container before leaving Source

Figure 7.3: Step 3 Closure of the container wall and washing of it before leaving Source

(Source: Garcia-Lodeiro, Carcelen-Taboada, Fernández-Jiménez & Palomo, 2016)

Containers replaced by empty ones

Figure 7.4: Step 4 Containers replaced by empty ones

(Source: Garcia-Lodeiro, Carcelen-Taboada, Fernández-Jiménez & Palomo, 2016)

formula for mean

Figure 7.5: Step 5 Compacted refuse inside the containers

(Source: Garcia-Lodeiro, Carcelen-Taboada, Fernández-Jiménez & Palomo, 2016)

  • Incineration- The thermal technology that is used to dispose of the wastes that are generated from the domestic department is called as incinerators. The major beneficial factor associated with the usage of such thermal technology is the reduction in the large volumes of the solid wastes. It has estimated that an incinerator reduces 90% volume of the original volume of the solid wastes. The modern techniques used in the incineration plants are incorporate with power generation facilities as well as heat recovery facilities. Such a system further helps in recovery of heat and energy from the wastes.Figure 8 : Incinerator

(Source : Garcia-Lodeiro, Carcelen-Taboada, Fernández-Jiménez & Palomo, 2016)

  • Sorting- Based on the nature of source material a process of sorting is followed. The process involves wide range of labour intensive hand picking activities that carries on over to a very technical complex processes. The accumulation of wastes is essentially being done in separate containers initiating the process of sorting. Another method used in this kind is to sort the solid wastes after collection in the recycling centre (Chen et al. 2015). However, this process is quite complicated when compared to the process of segregation at the centre of generation.

 source separation of wastes

Figure 9 : Programme on source separation of wastes

(Source : Chen et al. 2015)

  • Composting- Nature’s own way of recycling waste materials is called as composting. Biodegradable form of wastes that is organic wastes (manures, food wastes, leaves, paper, wood, grass trimmings, feathers, residues of crops, etc.) are decomposed using this method. The government utilizes many kinds of decomposing processes like natural biological processes that are carried out in controlled aerobic conditions.Figure 10 : Composting

(Source : Chen et al. 2015)

Requirements and constraints 

Requirements and constraints of solid waste management is an important agenda of government.  In order to deal with the above-mentioned criteria, some internal and external factor needs to keep in concern to run the system in smooth manner.

Legal Requirements: According to the act of the Waste Disposal Ordinance (1980), all the soil wastage is managed to the final disposal of that material, this procedure is going through a systematic framework. The internal process is going through environment friendly procedures. Disposal of that wastage, in one part utilize the wastage materials and in another part, it creates some benefits for large quantity of people by managing different kind of disposal technique.

This initiative was done by many times in various times to improve all its strategy structure the solid waste management technique. Different things like Livestock string, wasting chemical, dumping illegal waste things and the process of import and export technique is important matter. In order to enlist those thing for the amendment procedure, aiming to improve the condition of waste management procedure. In 2006, all the rules and regulation are amended again to set up some rules according to the International Basel Ban to control the clinical waste also after use those materials.

US real GDP growth rate

Internet for small business

Waste management procedure

Real GDP and Price level

Source 11 : (www.epd.gov.hk) 

Health, safety and welfare:

Solid waste is necessary for the overall benefit of creature community; due to different reason like quality of solid, and concentration level and physical and chemical reaction of solid waste  it creates some side effects on human health safety and harmful for the environment also. Waste Disposal Regulation is already gives some threatening alarm for managing the solid waste in a particular framework.

Damage to the environment

Climate change is the result of the improper solid waste management in details any manufacturing product from its production to waste is such a phase that produce harmful gases. Product manufacturing going through some specific procedure that may creates a large amount of greenhouse gas. These gases are the leading reason for the global warming situation facing by the human civilization in today's world. The green house gas are, majorly impact the earth climate. 

Population increasing is the prime factor for the solid waste management. Different countries like Asia, Africa and Latin America are the most Victim country of climate change in negative perspective.

Cost implication

Landfills by government or the public is a systematic procedure for burning those materials or underground the solid waste. The simple thing is that by collecting those materials government can collect a huge number of money approximately $435 annually. The problem is lying in the psychology of the people that they produce wastage rather than recycle those products. Hong-Kong government set up a plan for mange all the waste materials in a modern technique about 400 hectares of land  till 2030.

Task 5

Describing the different stages used for purification and storage of drinking water (P5)

Purification of Water is a key part in guaranteeing access to safe drinking water. Safe drinking water emphatically affects the strength of the whole group. Frameworks are set up to guarantee to progress water quality, including water quality testing. The testing guarantees the water treatment prepare brings about an item that meets government’s water quality rules. Water examination includes searching for a few sorts of contaminants, including perilous levels of natural, microbial, inorganic and additionally radioactive contaminants. Precipitation is one of the wellsprings of water in the earth (Ruiz-Aguirre, Polo-López, Fernández-Ibáñez & Zaragoza,  2017). 

It takes after the hydrological cycle that includes a concurrent event of vanishing, builds up, and precipitation. The complex pathways incorporate the entry of water from vaporous envelope around the planet called the climate, through the water bodies on the surface of the earth. A hydrological cycle does not have any closures and it a principal quality of the cycle. The investigation of hydrological cycle can begin from any of the procedures among vanishing, build up, precipitation, capture attempt, invasion, permeation, transpiration, overflow, and capacity. In Hong Kong there are various sources of drinking water are as follows: 

  • The availability of fresh water in river was very limited till 1960s. The government of Hong Kong took steps regarding importing raw water from Guangdong province to improve the condition. Now they have 70-80 percent of fresh water imported from Dongjiang.
  • Small streams flow throughout the country that adds a major part of the country’s water. 
  •  Shallow wells are regularly the methods for getting to groundwater of shallow profundities (Pramanik, Thangavadivel, Shu & Jegatheesan,  2016). The water supply framework, talented individuals dive into the delicate ground developments until the point when they have to strike the water table.
  • The idea of profound wells is like the shallow wells just contrast lies in the profundity of water gathering.
  • Specific penetrating of soil and shake is completed for making bore wells. The gap is of 100-150 mm breadth in the event of drill gaps.
  • A supply that is appropriate to utilized for the capacity of water from stream or waterways stream actually and the water volume that is put away administers the store estimate. This can influence by the fluctuation of the inflow accessible for the store.

The steps included in the process of purification of water are as follows:

Screening: Screening removes many big obstacles from water. This water can come from lakes, streams or the ground goes through a screen as it enters the water treatment plant (Kravchenko, Chernova, Panchenko, Kosygina & Yakupova  2016). At the point when the water source is a lake or stream, the screen serves an essential capacity, keeping out substantial common contaminants, for example, plants and wood, or fish. In the event that groundwater is utilized, screening may not be important since the water has gone through layers of the earth in what is a characteristic screening capacity.

Coagulation: It is a process of removing nutrients and other remaining solids present in the water by adding chemicals to it. The chemicals create which is called floc, a type of sticky particles that attracts dirt making it heavier to sink down to the bottom of the storage tank. 

Sedimentation: As the dirt, sits in the bottom of the water tank thereby forming a sedimentation basin. The dirt-free water flows at the top. It takes lot of time in settling down of the sedimentation.

Filtration: In this stage, water passes through different layers of sand, gravel and other substances. All these layers act as a filtration process to filter any remaining substances. These layers are made deep to get the filtration process as best as possible. In filtration stage, anything swimming in the water will be removed.

Disinfection: This is the final stage where disinfection process is applied to get the purest form of water. By adding chlorine, this water is made truly drinkable by discarding all the toxins, killing all the bacteria, viruses and parasites. Finally the chlorine is counteracted by adding sodium bisulphate (ghigh, Alizadeh, Wong, Islam,  Amin, et al. 2015). 

Water further can be classified into parts: hard water and soft water. The portability of water is determined by the hardness of water. Hard water is made up of many dissolved minerals such as magnesium and calcium. Soft water contains only one ion, which is sodium. Soft water is basically a water. As the rainfall happens, the water falls on the ground in form of soft water. As it start settling in the ground, it gets mixed with different components such as calcium, magnesium and chalk and turns the water into hard water. The percentage of mineral content is found high in hard water, which is sometimes considered as potable water suited for drinking. Sometimes temporary hardness is found in the water, which cannot be removed after boiling also. Any liquid substance has two types of nature: acidic in nature and alkaline in nature. This nature can be measured by dipping a pH strip into the substance. If the pH strip is divided into parts 1-6 that shows acidic meter and 8-12 shows alkaline meter. 7 is the neutral value of the substance. If the pH strip turns red then it is acidic in nature and if pH strip turns blue then it is alkaline in nature. 

A reservoir is a water-stockpiling compartment that holds clean water after it has been dealt with in a water plant and before it is channeled to the end clients. These compartments are secured and are intended to guard the water against contamination. Their primary intention is to give a cradle inside the water supply framework with the goal that water supplies can be kept up crosswise over times of changing interest (Peng, Jin, Li, Li, Srinivasan, et al.2016).

 The technique to access purified drinking water as per the environment efficiency and cost effective term.

Drinking water is mainly serves the healthy life of human. Consumption drinking water is good and beneficial in one side but in another part, it can create major problems in public health. Most of the disease is speeded through the water in human body (Jembeck, 2015). Various kind of serious germ is injected in human body by drinking water. Drinking water can be used in various methods from different kind of water source. Different kind of sources of water is mentioned below:

River: The government mainly collects the water source from its neigjhbpoiuringf copunteries like Dogging that is situated in the east part of the country.


Small streams, which are not flow every time during a year is mainly, contribute the most part of the water Hong Kong city.  Government annually collects 70 to 80% of water in the small streams. 

Shallow water Shallow wells are one of the major sources of water in Hong Kong. Shallow wells water supply is the source of water in Hong Kong city. The small part of river or any kind of water reservation is the providing the drinking water in Hong Kong. Purified water is managing through applying a basic method of water purification. 

Deep wells holes: Not only the small part but also the deep well provide the large amount of drinking water in Hong Kong. In order to collect the drinking water a specific procedure is made to collect a drinking water from deep wells. 

Desalination impounding reservoirs: different reservoir also supplies the crisis of water. The basic process is same as the deep well technique. This procedure is cost effective and environmentally friendly.

Environment efficiency and cost effective procedure of water purification is a basic thing for storing the natural water resource. Rainfall storing is a huge matter for the water storing there has some specific procedure that can produce a clear and healthy water. That procedure is called the hydrological cycle. Evaporation cycling means evaporation, condensation and precipitation. These steps are associated with the different kind of human made technique.  The main thing is that evaporation occurs when the level of water of is transforming in evaporation from the liquid state. The main function is the storing of rainfall.

Condensation of rainfall is a procedure of changing the state of liquid form due to the climate procedure. Fresh water is sufficient in Hong-Kong that is faced from 1960. This procedure is made from accumulate the water from neighboring state. Streams from different region are the main source of water. 

The main function is dependent on the efficiency skills by the staff that are responsible to the job they have to take proper prevention to supply fresh and safe drinking water to the people of Hong Kong. The basic procedure was made through proper application of the standard procedure. Drinking water should be safe in order to not spreading germ via consumption of water, the water is the main source which operate the human body but the main thing is that the water supply is basically done through the government in specific time period.

The basic purpose to do this activity is to provide a fresh water trough to the public of Hong Kong ( Hering et al. 2015). All the procedure which are adopted is that they first accumulate there the water from different sources then after they use the technique of specified technique of water purify from those collected water. Then supply the purified water to the Hong Kong resides people. All the process is very cost and environmental free to deliver the cost free water to the citizen. All necessary part is done in a systematic procedure under basic surveillance. The water reservation technique should be done through a specific measurement, which is not harmful for the human health. The main thing is that the people who were responding to that thing take some measurement to provide safe water. 

Water pollution is causing through the wastage of solids and factory wastage so the place where the water pollution is done must have to reside from the distant place of those place. All the necessary part is some within a specific time. Main thing is that they have to deal with that product in very systematic way by how no other inevitable process is going through a proper surveillance. All the process is systemic in order to supply fresh and harmless water to the public of Hong Kong government. The procedure is very critical f but it has to be done by the Hong -Kong government supply the water to the public mainly they have to think about that specially for the children., they are very sensitive in order to tolerate the germ negative effect. They have less immunization power to tackle all those unpleasant factors of polluted water. 

 Methods of using  the domestic sewage  and drinking water in financial, legal, environmental and health and safety perspective

Domestic sewage and drinking water is mainly the one of the major problem faced by the Hong Kong government. They can be victim of that polluted water and face daily life problem in the rainy season due to the un proper system of domestic sewage. The people of Hong Kong  government is mainly served its country people a safe healthy water and also a systematic procedure of domestic sewage by how they can access a smooth formal system in the domestic sewage context(Anon, 2017).It has some specific process and have some factors lies in the domestic wage and drinking water facility. The above factor is mentioned below 


Financial context in the domestic sewage and availability of fresh water is mainly high concerning matter of the Hong-Kong government. They sometimes have to make MOU with other countries to get the sufficient amount of water (Salimi et al. 2017). Domestic Sewage system of Hong-Kong government is, mainly concerned for providing safe and healthy water, they can not violate rules by cross the boundary of any country or break the MOU on bilateral treaty (Rozin,Haddad, Nemeroff, & Slovic, 2015). Some financial activity done by the government is to provide in this particular context. The main purpose of the doing this term is to satisfy the public of Hong Kong. Some perspective is attached through the financial terms. Some implication also associates in the financial aspect. They have to take some definite procedure to collect the water and run the system accurately in domestic sewage process. 


Environmental factor is one of the major factor for controlling the drainage and water supply to the people of Hong Kong public. The Main perspective is to provide drinking water in a sustainable process manse the processto adopt by the practitioner by how people can gain the profit simultaneously store for the fort the future generation(Guerrero, Maas,Hogland, 2013). Environmental factor is a major factor, which are associated with the environmental system is the major part for the government of Hong-Kong.

Ecological factors have to concern is the basic thing means the accumulator has to store the water and provide that to the citizen o f the people in healthy state. In order to do that they can't violate the rule or destroy the ecological rule by how the creature of water will harm and the lifesystem of water is destroyed.

Not only that the sewage system, some time loosen the basic element of soil, which leads improper farming in the countries who are dependent on the farming.

Health and safety terms 

Health and safety matter is mainly concern of both the government and the public of Hong Kong. Water should be in that situation by how people will not became seriously ill due to consumption of those water supplied in their or use for drinking purpose. The main agenda in this sector is that process is to take the necessary elements to reduce the harmful ingredient from the water. All the process, which is associated, this procedure is highly concerned about the health and safety matter of people health. People should also gather some information about how they can get the sufficient amount of water and sewage system of domestic purpose has to take consideration about the safety and healthy manner. 

Proper knowledge of healthy water and its pros concert will enlighten the people about their health. They did not realise that how much they are effective in order to consume the healthy water supplied by the government but the main perspective is to deliver a germless water buy how they  are able to understand the positive impact over the health. In order to makeimproper system of drainagesystem is causing the germ production which leads several diseases in all aged people. Not only has that it created a trouble in the daily life of the people of Hong Kong. In order to remove the obstacle government have to take necessary action (Terzi,Gedik,Verep, & Yandi, 2015). In overall, the perspective is to maintain a good and healthy lifestyle by the citizen of people. In international forum there are mainly countries who are serving for the best procedure for the citizen of their own country, In that perspective they are also have to concern about their health by the citizen also. It is a two way process. The citizen also has to take care and gather proper knowledge about the safety measurement. A country which have standard rate of healthy people, and reduce their mortality rate by providing the proper infrastructure facility they are ranked in the  higher position after assessing by  the international territory (Maxwell,2014).The Hong Kong government always try to focus their activity and continuously make improvement of that. Now that country is in better situation; if they follow all the measurement for providing healthy water and property drainage system they will also can be achieved the best tagline in perspective of proper health condition and the domestic sewage system. 

The main thing is that they have to take care about the technique which is more cost effective simultaneously environment friendly ( Pronk, 2015).efficiency in this particular stage is very important because it's directly related with the health condition of the people resides on the countries . Therefore, it is the basic concept of every people of any country to support the government in order to achieve the excellence in that particular domain. All the necessary topic which are discussed a systematic way has to concern by the government 


The following assignment has focused on the portraying an appropriate comprehension about the ground seepage framework. The seepage state of Hong Kong Island is considered in this examination. The topic of this task depends on reviewing the questions that are raised by a portion of the nationals living in the Hong Kong Island. The representing bodies expected to answer the questions raised and it has been managed in this task. The task has endeavored to portray a reasonable outline of the strategies that are utilized for treating household sewage and the procedure of subterranean waste framework.