Environmental engineering is a professional engineering discipline related to environmental science. It encompasses broad scientific topics like chemistry, biology, ecology, geology, hydraulics, hydrology, microbiology, and mathematics to create solutions that will protect and also improve the health of living organisms and improve the quality of the environment. Environmental engineering is a sub-discipline of civil engineering and chemical engineering. While on the part of civil engineering, the Environmental Engineering is focused mainly on Sanitary Engineering.
Sanitation refers to public health conditions related to clean drinking water and treatment and disposal of human excreta and sewage. Preventing human contact with feces is part of sanitation, as is hand washing with soap. Sanitation systems aim to protect human health by providing a clean environment that will stop the transmission of disease, especially through the fecal–oral route. For example, diarrhea, a main cause of malnutrition and stunted growth in children, can be reduced through adequate sanitation. There are many other diseases which are easily transmitted in communities that have low levels of sanitation, such as ascariasis, cholera, hepatitis, polio, schistosomiasis, and trachoma, to name just a few.
A water supply network or water supply system is a system of engineered hydrologic and hydraulic components that provide water supply. A water supply system typically includes the following:
- A drainage basin
- A raw water collection point where the water accumulates, such as a lake, a river, or groundwater from an underground aquifer. Raw water may be transferred using uncovered ground-level aqueducts, covered tunnels, or underground water pipes to water purification facilities.
- Water purification facilities. Treated water is transferred using water pipes.
- Water storage facilities such as reservoirs, water tanks, or water towers. Smaller water systems may store the water in cisterns or pressure vessels. Tall buildings may also need to store water locally in pressure vessels in order for the water to reach the upper floors.
- Additional water pressurizing components such as pumping stations may need to be situated at the outlet of underground or aboveground reservoirs or cisterns.
- A pipe network for distribution of water to consumers and other usage points
- Connections to the sewers are generally found downstream of the water consumers, but the sewer system is considered to be a separate system, rather than part of the water supply system.
Sustainable urban infrastructure expands on the concept of urban infrastructure by adding the sustainability element with the expectation of improved and more resilient urban development. In the construction and physical and organizational structures that enable cities to function, sustainability also aims to meet the needs of the present generation without compromising the capabilities of the future generations.
The "Melbourne Principles" for Sustainable Cities are ten short statements on how cities can become more sustainable. They were developed in Melbourne (Australia) on 2 April 2002 during an international Charrette, sponsored by the United Nations Environment Programme (UNEP) and the International Council for Local Environmental Initiatives. Experts at the Charrette were drawn from developing and developed countries.
Water supply and sanitation in Indonesia is characterized by poor levels of access and service quality. More than 16 million people lack access to an at least basic water source and almost 33 million of the country's 275 million population has no access to at least basic sanitation. Only about 2% of people have access to sewerage in urban areas; this is one of the lowest in the world among middle-income countries. Water pollution is widespread on Bali and Java. Women in Jakarta report spending US$11 per month on boiling water, implying a significant burden for the poor.
Sustainable sanitation is a sanitation system designed to meet certain criteria and to work well over the long-term. Sustainable sanitation systems consider the entire "sanitation value chain", from the experience of the user, excreta and wastewater collection methods, transportation or conveyance of waste, treatment, and reuse or disposal. The Sustainable Sanitation Alliance (SuSanA) includes five features in its definition of "sustainable sanitation": Systems need to be economically and socially acceptable, technically and institutionally appropriate and protect the environment and natural resources.
Water supply and sanitation in Iran has witnessed some important improvements, especially in terms of increased access to urban water supply, while important challenges remain, particularly concerning sanitation and service provision in rural areas. Institutionally, the Ministry of Energy is in charge of policy and provincial companies are in charge of service provision.
Water resources are natural resources of water that are potentially useful for humans, for example as a source of drinking water supply or irrigation water. These resources can be either freshwater from natural sources, or water produced artificially from other sources, such as from reclaimed water (wastewater) or desalinated water (seawater). 97% of the water on Earth is salt water and only three percent is fresh water; slightly over two-thirds of this is frozen in glaciers and polar ice caps. The remaining unfrozen freshwater is found mainly as groundwater, with only a small fraction present above ground or in the air. Natural sources of fresh water include surface water, under river flow, groundwater and frozen water. People use water resources for agricultural, industrial and household activities.
Tunisia has achieved the highest access rates to water supply and sanitation services among the Middle East and North Africa. As of 2011, access to safe drinking water became close to universal approaching 100% in urban areas and 90% in rural areas. Tunisia provides good quality drinking water throughout the year.
Water supply and sanitation in Jordan is characterized by severe water scarcity, which has been exacerbated by forced immigration as a result of the 1948 Arab–Israeli War, the Six-Day War in 1967, the Gulf War of 1990, the Iraq War of 2003 and the Syrian Civil War since 2011. Jordan is considered one of the ten most water scarce countries in the world. High population growth, the depletion of groundwater reserves and the impacts of climate change are likely to aggravate the situation in the future.
Urban water management in Bogotá, a metropolitan area of more than 8 million inhabitants, faces three main challenges: improving the quality of the highly polluted Bogotá River, controlling floods and revitalizing riparian areas along the river. The main public entities in charge of water resources management in Bogotá are the district government, the regional environmental agency Corporación Autónoma Regional (CAR) of the department of Cundinamarca, and the water and sanitation utility Empresa de Acueducto y Alcantarillado de Bogotá (EAAB). A court mandated that these entities cooperate to improve the river's quality, a ruling that translated into an agreement signed in 2007 that defined the responsibilities of each entity and forced them to approach the water management challenges in an integrated way. The agreement prepared the ground for the expansion of the Salitre wastewater treatment plant, construction of a new one, widening and protecting of riparian zones, restoring the natural meander of the river, and hydraulically connecting the river to its flood plains. These measures are supported by the World Bank and the Inter-American Development Bank.
Integrated urban water management in Aracaju, the capital city of the Brazilian State of Sergipe (SSE) has been and still is a challenging prospect. Home to half a million people, Aracaju is located in a tropical coastal zone within a semi-arid state and receives below average rainfall of 1,200 mm/year where average rainfall in Latin America is higher at 1,556 mm/yr. Most of the residents do have access to the potable water supply and non-revenue water losses are nearly 50%.
Integrated urban water management in Medellín, Colombia is considered to be an overall success and a good example of how a large metropolitan area with moderate income disparity can adequately operate and maintain quality water supply to its many citizens. This is quite remarkable given the large urbanized population in the metropolitan area of the Aburrá Valley of 3.3 million, many of whom live on the slopes of the Aburrá Valley where Medellín is situated and highly prone to landslides and stormwater erosion. Sound urban water management within the metropolitan area of the Aburrá Valley is carried out by a set of technically strong institutions with financial independence—and lack of political interference such as Empresas Publicas de Medellin (EPM).
Water supply and sanitation in Tanzania is characterised by: decreasing access to at least basic water sources in the 2000s, steady access to some form of sanitation, intermittent water supply and generally low quality of service. Many utilities are barely able to cover their operation and maintenance costs through revenues due to low tariffs and poor efficiency. There are significant regional differences and the best performing utilities are Arusha and Tanga.
Water-sensitive urban design (WSUD) is a land planning and engineering design approach which integrates the urban water cycle, including stormwater, groundwater, and wastewater management and water supply, into urban design to minimise environmental degradation and improve aesthetic and recreational appeal. WSUD is a term used in the Middle East and Australia and is similar to low-impact development (LID), a term used in the United States; and Sustainable Drainage System (SuDS), a term used in the United Kingdom.
Water supply and sanitation in Vietnam is characterized by challenges and achievements. Among the achievements is a substantial increase in access to water supply and sanitation between 1990 and 2010, nearly universal metering, and increased investment in wastewater treatment since 2007. Among the challenges are continued widespread water pollution, poor service quality, low access to improved sanitation in rural areas, poor sustainability of rural water systems, insufficient cost recovery for urban sanitation, and the declining availability of foreign grant and soft loan funding as the Vietnamese economy grows and donors shift to loan financing. The government also promotes increased cost recovery through tariff revenues and has created autonomous water utilities at the provincial level, but the policy has had mixed success as tariff levels remain low and some utilities have engaged in activities outside their mandate.
Decentralized wastewater systems convey, treat and dispose or reuse wastewater from small and low-density communities, buildings and dwellings in remote areas, individual public or private properties. Wastewater flow is generated when appropriate water supply is available within the buildings or close to them.
Urban flooding is the inundation of land or property in cities or other built environment, caused by rainfall or coastal storm surges overwhelming the capacity of drainage systems, such as storm sewers. Urban flooding can occur regardless of whether or not affected communities are located within designated floodplains or near any body of water. It is triggered for example by an overflow of rivers and lakes, flash flooding or snowmelt. During the flood, stormwater or water released from damaged water mains may accumulate on property and in public rights-of-way. It can seep through building walls and floors, or backup into buildings through sewer pipes, cellars, toilets and sinks.
One Water is a term encompassing the management of all water sources in an integrated and sustainable way considering all water sources and uses. This idea stems from core principles of providing affordable water access for everyone.
