The Community and the Concept of Water Reclamation - Essay Example

? Wastewater Recycling: Gambling with Environmental Health? An Assessment of the Environmental Health Implications of Long?Term Exposure of Ecosystems to Recycled Wastewater Name Course title Instructor’s name Date Executive Summary Wastewater recycling can be termed as the treatment of used water; sent directly from homes or commercial enterprises, in order to remove solids and impurities. This treated water can then be reused in irrigation, as supplement for drinking water or in recharging the groundwater aquifers or generally released to the environment. This process of reclaiming wastewater has been in place since historical times but just gained attention recently when demand for water grew as a result of advancements in technology, growth in population and rapid urbanization which has greatly stressed the natural water cycle. Wastewater reuse for activities that demand huge amounts of water; which has so far consumed nearly all the available freshwater resources, has in effect engineered processes that imitate the natural water cycle. In brief, this paper will analyze factors leading to recycling of wastewater, the treatment process, wastewater effluent issues and wastewater quality impacts on the environment and on health. Introduction The supply of fresh water in the world today has become so limited that it has exceeded its demand. This, together with increased climate change leading to drought and water scarcity, has called for alternative ways of resorting to the problem of water shortage in which wastewater recycling is part of it (Rofe, 2004, p. 13). According to Robson (2011 p.1), wastewater is made up of 99.9% of water and 0.1% of waste; hence water is the main component. Wastewater reclamation serves as a valuable and efficient way for coping with water resources scarcity and water pollution severity, and this has been heightened by the fact that, there are strict regulations concerning wastewater effluent discharge thus better water quality (Mara & Horan, 2003, p. 24). There are problems associated with wastewater management though, mainly because of extensive industrialization, rapid population growth and urbanization (Alberto & Maksimovic, 2001, p. 4). The effluents generated from industrial and domestic activities constitute the major sources of pollution to natural waterways has proved to be a great burden in that waste water management can lead to point source pollution which not only raises costs of treatment but also introduces a diverse range of microbial contaminants and chemical pollutants to water (Davidson, Samad, & M, 2008, p. 8). The principle objectives for wastewater treatment are to prevent pollution of water sources and protect the public health through safeguarding of water supplies against disease spread (Singh & Yavada, 2003, p. 17). Reuse of wastewater is increasingly becoming important as a supplement to domestic and industrial uses around the world though a lot of care must be taken to minimize adverse environmental and health consequences (Henze, 2008, p. 3). The aim of this paper is to assess the long term impacts of wastewater recycling on ecosystems and will mostly concentrate on agriculture, environmental discharge, groundwater recharging and municipal uses. Reuse of Wastewater in Agriculture This purpose is by so far the oldest and largest reuse of wastewater that has been reported. Wastewater recycling acts as a supplement to scarce primary water sources, more especially in arid and semi-arid areas (Crites, Sherwood, & Middlebrooks, 2006, p. 5). This is mostly seen in South Africa, Israel and some parts of United States where wastewater recycling is practiced in large scale as an alternative to scarce availability of fresh water resources. In Mexico, for example, large portions of agricultural land outside the city are irrigated with reclaimed water (Wastewater Treatment and Use in Agriculture, 2011). Irrigation has the advantage of decreasing the purification level thus reducing the treatment costs due to the role played by soil and crops as biological treatment facilities. In addition to providing low cost source of water, other benefits are that it increases crop yields, acts as a good alternative to using chemical fertilizers and also increases protection against frost damage (National Academy of Sciences, 1992). These benefits coupled with the reduction scopes in headwork costs and systems for distribution, has been some of the motivations behind reuse schemes in some countries such as Japan, china, Tunisia among other countries (Wastewater Treatment and Use in Agriculture, 2011). Though wastewater for irrigation purposes has advantages, it also has its flaws. The National Academy of Sciences has failed to put into account the fact that irrigation with wastewater without the application of risk management measures may result in contamination of groundwater beneath the irrigation fields particularly when the water contains untreated industrial effluent. Moreover, some crops such as vegetables may transmit contaminants and pathogens to consumers if untreated waste is used to irrigate them. Groundwater Recharge Another use of reclaimed wastewater is artificial groundwater recharge and is mainly done as a way of managing water resources. For instance, if an aquifer is depleted, it can be recharged by injecting water that is highly treated, thereby restoring aquifer yields and preventing intrusion of salt water especially in coastal zones (Mara & Horan, 2003, p. 14). This method of ground water recharge is increasingly being used as a way of treating and storing effluent underground for subsequent recovery and unrestricted use. Such example of groundwater recharge using recycled water is seen in Sidney where scientists have proposed the use of recycled water as a means of maintaining sustainable levels of groundwater resource in the naturally occurring Botany sand aquifer. The advantage of sand aquifers is that contaminants are filtered naturally as water flows down through the sediments’ fine particles (Gregory, 1993). A drawback to this method of recharging groundwater aquifers not mentioned by Gregory is that contamination may occur from injected surface run off especially from road surfaces and agricultural fields thus degrading the aquifer and posing great health effects to users. Another issue that is worth mentioning is the high costs involved in artificially recharging groundwater aquifers. Non-portable wastewater uses This is the most common use of wastewater in many parts of the world and these uses may vary from toilet flushing, construction activities, dust control, artificial lakes, and cooling water for power plants among other uses. Non potable reuse has resulted in both water consumption reduction in other sources and wastewater flow rate reduction. It can therefore be said that non portable reuse schemes avoids adverse environmental consequences associated with wastewater disposal systems (Alberto & Maksimovic, 2001). Non-portable reuse requires a separate water supply network; therefore households must have two water supply lines, one for portable uses and the other for non portable functions. Alberto and Maksimovic have not considered the costs involved in having dual reticulation systems. Environmental Discharge By recycling wastewater, many environmental problems that may arise as a result of discharge of untreated or treated wastewater to the environment are avoided (Gregory, 1993, p. 15). Wastewaters have high levels of toxic pollutants and their disposal may have detrimental effects to the ecosystem of the receiving environment (Barcelo & Petrovic, 2011, p. 2). Additionally, disposal of wastewater to sensitive environments may trigger community concerns which in turn may result in political pressures to the water industries to treat water to a higher level before discharging to the environment (Ditz & Safir, 1980, p. 56). We cannot therefore allow wastewater to be disposed off in a manner that is dangerous to human health and other life forms or damaging to the natural environment, hence wastewater must undergo the treatment process as shown below; The process of Treatment The treatment of wastewaters can be biological or conventional (more preferable and thus will be explored here). The conventional process involves seven degrees of processing which include preliminary, primary, secondary, tertiary, disinfection, effluent storage and lastly, assessment of the reliability of the treatment conventions. The process involves removal of solids, nutrients as well as organic matters through biological, physical and chemical processes. The diagram below show a general wastewater treatment (Natural Resources Management and Environment Department, 2011 p. 3) http://www.fao.org/docrep/T0551E/t0551e0j.gif The purpose of the preliminary step is to eliminate coarse solids as well as other large particles commonly present in raw wastewater in preparation for the following treatment steps. The next step is primary treatment, which I aimed at eliminating the organic and inorganic solids that can be settled by sedimentation. Additional, materials that can float by skimming are also eliminated. The process is able to eliminate about 25-50% of the incoming biochemical oxygen demand, 65% of the grease and oil and 50-70% of suspended solids (FAO, 2011 p. 3). The secondary step treats the effluents from primary degree to eliminate the suspended solids and residual organics. The tertiary step is done when there are wastes that cannot be removed at the secondary treatment step. Lastly, the recycling process should have the required design and operation to ensure the treatment is reliable (Natural Resources Management and Environment Department, 2011 p. 3). Environmental Benefits of Wastewater Reclamation Wastewater reclamation provide tremendous benefits to the environment and one of them is that as an additional source of water, it will free fresh water of other needs such as agricultural and industrial uses thus allowing it to be diverted to sensitive ecosystems. Wildlife, plants and fish are dependent upon the supply of fresh water to their habitat for their reproduction and survival (Frumkin, 2010, p. 39). Another benefit is that, wastewater discharge to water bodies such as oceans and seas will be curtailed thus pollutant loadings to these water bodies will also decrease as a result of recycling. This practice therefore, minimizes water pollution in one way and protects the habitat for endangered species in another (Yudelson & Megdal, 2010, p. 11). Additionally, according to Vinson (2006, p. 5) reclaimed water may be used to enhance or create wetlands and also riparian habitats. Wetlands have many benefits and some of them include wildfowl and wildlife habitat, improvement of water quality, flood diminishment and breeding grounds for fish. Water flow in impaired or dried streams as a result of water diversion can be augmented with reclaimed water to improve and sustain the wildlife and aquatic habitat (Yudelson & Megdal, 2010, p. 25). Lastly, reuse water helps save energy in many ways (Rome, 2002). One is that the growing demand of water may require more water extraction, treatment and transportation over great distances which may need a lot of energy (Metropolitan North Georgia Water Planning District, 2003, p. 4). If the source of water in a particular place is ground water, then the level of water goes down with more extraction and this may require increase in energy in order to pump water to the surface. Recycling water on the other hand, reduces the energy required to transport water over great distances or pump water from deep within the aquifer (Jordan & Goulding 2003, p. 5). Furthermore, tailoring the quality of water to fit the specific need of use may help save energy in that, the quality of water required for drinking is more stringent than the quality of water required for flushing toilets (McCool, 2005). Therefore, using water that is of low quality for uses that do not require high quality water helps save energy and money by cutting down other treatment requirements (Henze, 2008, p. 38). Issues surrounding the Recycled Wastewater Practices Despite the fact that wastewater reuse has been taking place for a long time in many places around the globe, questions concerning the safety of reclaimed water still arise and this is because of the quality of recycled water (Safir & Carpenter, 1978, p. 32). Controversies have always arisen among the researchers and proponents of wastewater recycling about the quality that wastewater should meet. Generally, all the issues are concerned with impacts; and especially long term impacts of recycled water practices on public health (Davidson, Samad, & M, 2008, p. 23). The quality issues raised include; Pathogen survival The concerns of public health center on the great variety of pathogenic organisms that could be present in wastewater. Pathogen survival in wastewater and environmental conditions other than their host organisms is highly variable (Vymazal & Kropfelova, 2008, p. 9). While more emphasis is placed on the need to assess health hazards of wastewater recycling and routes of transmission, there is need to also recognize the existence of various successive barriers that may lead to pathogen die away (Pavey, 2002). Another aspect of pathogen contamination due to recycling wastewater is entry of pathogen into ground water through soil contamination (Davidson, Samad, & M, 2008, p. 17). Quality standards of effluent It has been difficult to set the quality standards for all types of wastewater reuses considering its wide range of potential uses (Stein, 2002). There is lack of detailed guidelines or standards of recycled wastewater in many countries around the world and many European countries either use the World Health Organization guidelines or the United States Environmental Protection Agency standards to form the decision of any kind of reuse. Other countries like Israel, Tunisia and old USSR, have developed their own standards for reuse (United States, 1993, p. 6). Other issues not related to quality are hydro-geologic conditions and socioeconomic considerations. The socioeconomic considerations include the cost of recycle systems and community perceptions. Generally, the community is not averse on the concept of water reclamation (Wiesmann & Dombrowski, 2007, p. 42). The economic considerations on the other hand are necessary since if there is availability of primary source of water at a cheaper price, then it may not be worthwhile to recycle water. Hydro geologic conditions are considered as it helps to build a comparison between quality of reuse water and that of alternative sources intended for the same kind of use (Barcelo & Petrovic, 2011, p. 51). Conclusion Water is an essential component for all living things on earth yet this valuable resource is being threatened by industrial, agricultural and municipal developments. Recycling of wastewater has proved to be very effective in creating an alternative source of water supply without compromising the environmental and public health. 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