the past few years.: x in many societies, the task of cleaning toilets falls to women or children, which can increase their exposure to disease.: 19 woman collecting water in kenya. many women's rights and water advocacy organizations have identified water privatization as an area of concern, sometimes alleging negative effects that specifically affect women. violence against women women and girls usually bear the responsibility for collecting water, which is often very time-consuming and arduous, and can also be dangerous for them. women and girls who collect water may also face physical assault and sexual assault along the way (violence against women). this includes vulnerability to rape when collecting water from distant areas, domestic violence over the amount of water collected, and fights over scarce water supply. a study in india, for example, found that women felt intense fear of sexual violence when accessing water and sanitation services. a similar study in uganda also found that women reported to feel a danger for their security whilst journeying to toilets particularly at night. challenges urban low income areas part of the reason for slow progress in sanitation may be due to the "urbanization of poverty", as poverty is increasingly concentrated in urban areas. migration to urban areas, resulting in denser clusters of poverty, poses a challenge for sanitation infrastructures that were not originally designed to serve so many households, if they existed at all. there are three main barriers to improvement of urban services in slum areas: firstly, insufficient supply, especially of networked services. secondly, there are usually demand constraints that limit people's access to these services (for example due to low willingness to pay). thirdly, there are institutional constraints that prevent the poor from accessing adequate urban services. water pollution women at a village pond in matlab, bangladesh: the woman on the right is putting a sari filter onto a water-collecting pot (or kalash) to filter water for drinking. water supply sources include surface water and groundwater. these important water resources are often at risk of being polluted or overused. this section is an excerpt from water pollution. water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses.: 6 water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. water pollution results when contaminants mix with these water bodies. contaminants can come from one of four main sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. water pollution is either surface water pollution or groundwater pollution. this form of pollution can lead to many problems, such as the degradation of aquatic ecosystems or spreading water-borne diseases when people use polluted water for drinking or irrigation. another problem is that water pollution reduces the ecosystem services (such as providing drinking water) that the water resource would otherwise provide. this section is an excerpt from groundwater pollution. groundwater pollution (also called groundwater contamination) occurs when pollutants are released to the ground and make their way into groundwater. this type of water pollution can also occur naturally due to the presence of a minor and unwanted constituent, contaminant, or impurity in the groundwater, in which case it is more likely referred to as contamination rather than pollution. groundwater pollution can occur from on-site sanitation systems, landfill leachate, effluent from wastewater treatment plants, leaking sewers, petrol filling stations, hydraulic fracturing (fracking) or from over application of fertilizers in agriculture. pollution (or contamination) can also occur from naturally occurring contaminants, such as arsenic or fluoride. using polluted groundwater causes hazards to public health through poisoning or the spread of disease (water-borne diseases). failures of wash systems further information: failures of wash systems poorly maintained pit latrine at a school in nyanza province, kenya the failures of water supply systems (including water points, wells and boreholes) and sanitation systems have been well documented. many water and sanitation systems are unsustainable, failing to provide extended health benefits to communities in the long-term. this has been attributed to financial costs, inadequate technical training for operations and maintenance, poor use of new facilities and taught behaviors, and a lack of community participation and ownership. the poorest populations often cannot afford fees required for operation and maintenance of wash infrastructure, preventing them from benefitting even when systems do exist. leaks in water distribution systems improper management of water distribution systems in developing nations can exacerbate the spread of water-borne diseases. about 25%-45% of water in distribution lines is lost through leaks in developing countries. these leaks can allow for contaminated water and pathogens to enter the distribution pipes, especially when power outages result in a loss of pressure in the water supply pipes. cross-contamination of wastewater into potable water lines has resulted in major disease outbreaks, such as a typhoid fever outbreak in dushanbe, tajikistan in 1997. working conditions of sanitation workers this section is an excerpt from sanitation worker. sanitation workers carrying out manual pit emptying (in durban, south africa) with personal protective equipment a sanitation worker (or sanitary worker) is a person responsible for cleaning, maintaining, operating, or emptying the equipment or technology at any step of the sanitation chain.: 2 this is the definition used in the narrower sense within the wash sector. more broadly speaking, sanitation workers may also be involved in cleaning streets, parks, public spaces, sewers, stormwater drains, and public toilets. another definition is: "the moment an individual’s waste is outsourced to another, it becomes sanitation work.": 4 some organizations use the term specifically for municipal solid waste collectors, whereas others exclude the workers involved in management of solid waste (rubbish, trash) sector from its definition. climate change aspects further information: effects of climate change on the water cycle and water security § climate change greenhouse gas emissions water and sanitation services contribute to greenhouse gas emissions. these emissions are grouped into three scopes in the international greenhouse gas protocol: direct emissions, as well as two types of indirect emissions (see below). : 9 direct emissions (scope 1) scope 1 includes "direct emissions resulting directly from the activity". in the wash sector, this is methane and nitrous oxide emissions during wastewater and sewage sludge treatment. sanitation services produce about 2–6% of global human-caused methane emissions. septic tanks, pit latrines, anaerobic lagoons, anaerobic digesters are all anaerobic treatment processes that emit methane which may or may not be captured (in the case of septic tanks it is usually not captured). it has been estimated, using data from 2012 and 2013, that "wastewater treatment in centralized facilities contributes alone some 3% of global nitrous oxide emissions and 7% of anthropogenic methane emissions".: 11 data from 2023 from centralized sewage treatment plants in the united states indicate that methane emissions are about twice the estimates provided by ipcc in 2019, i.e. 10.9 ± 7.0 compared to 4.3-6.1 mmt (million metric tons) co2-eq/yr. current methods for estimating sanitation emissions underestimate the significance of methane emissions from non-sewered sanitation systems (nsss). this is despite the fact that such sanitation systems are prevalent in many countries. nsss play a vital role in the safe management of fecal sludge and account for approximately half of all existing sanitation provisions. the global methane emissions from nsss in 2020 was estimated to be 377 mt co2e/year or 4.7% of global anthropogenic methane emissions. this is comparable to the greenhouse gas emissions from conventional wastewater treatment plants. therefore, the ghg emissions from the non-sewered sanitation systems are a non-negligible source. india and china contribute extensively to methane emissions of nsss because of their large populations and nsss utilization. indirect emissions associated with the energy required (scope 2) scope 2 includes "indirect emissions associated with the energy required by the activity". companies that deal with water and wastewater services need energy for various processes. they use the energy mix that is available in the country. the higher the proportion of fossil fuels in the energy mix is, the higher the ghg emissions under scope 2 will be high too.: 12 the processes that need energy include: water abstraction (e.g. groundwater pumping), drinking water storage, water conveyance, water treatment, water distribution, treatment of wastewater, water end use (e.g. water heating), desalination and wastewater reuse.: 20–24 for example, electrical energy is needed for pumping of sewage and for mechanical aeration in activated sludge treatment plants. when looking at the emissions from the sanitation and wastewater sector most people focus on treatment systems, particularly treatment plants. this is because treatment plants require considerable energy input and are estimated to account for 3% of global electricity consumption. this makes sense for high-income countries, where wastewater treatment is the biggest energy consumer compared to other activities of the water sector.: 23 the aeration processes that are used in many secondary treatment processes are particularly energy intensive (using about 50 % of the total energy required for treatment).: 24 the amount of energy needed to treat wastewater depends on several factors: wastewater quantity and quality (i.e. how much and how polluted is it), treatment level required which in turn influences the type of treatment process that gets selected.: 23 the energy efficiency of the treatment process is another factor.: 23 energy and electricity usage by water and wastewater services under scope 2 of the carbon accounting method (indirect emissions associated with energy) parameter value additional comments source year of estimate total energy used by water sector worldwide 1400 twh : 20 2014 proportion of total energy used as electricity 60% mostly for pumping up groundwater for irrigation. : 20 2014 proportion of total energy used as thermal energy 40% : 20 2014 percentage of global electricity consumption used by the water sector 4% the energy for the use of water by end users (e.g. heating up water) is not included. : 20 2014 usage breakdown for electricity consumed for water supply water extraction: 40% wastewater treatment: 25% water distribution: 20% seawater desalination: 5% : 20 2014 percentage of global electricity consumption used for wastewater treatment plants 3% 2020 indirect emissions related to the activity but caused by other organizations (scope 3) scope 3 includes "indirect emissions related to the activity but caused by other organizations". the indirect emissions under scope 3 are difficult to assess in a standardized way. they include for example emissions from constructing infrastructure, from the manufacture of chemicals that are needed in the treatment process and from the management of the by-product sewage sludge.: 12 reducing greenhouse gas emissions solutions exist to reduce the greenhouse gas emissions of water and sanitation services. these solutions into three categories which partly overlap: firstly "reducing water and energy consumption through lean and efficient approaches"; secondly "embracing circular economy to produce energy and valuable products"; and thirdly by "planning to reduce ghg emissions through strategic decisions".: 28 the mentioned lean and efficient approaches include for example finding ways to reduce water loss from water networks and to reduce infiltration of rainwater or groundwater into sewers.: 29 also, incentives can to encourage households and industries to reduce their water consumption and their energy requirements for water heating.: 31 there is another method to reduce the energy requirements for the treatment of raw water to make drinking water out of it: protecting the quality of the source water better.: 32 methods that fall into the category of circular economy include: reusing water, nutrients and materials; low-carbon energy production (e.g. solar power on roofs of utility buildings, recovery of waste heat from wastewater, producing hydro-electricity by installing micro-turbines, producing energy from biosolids and sewage sludge.: 33–37 strategic decisions around reducing ghg emissions include: awareness raising and education, governance that supports changing practices, providing economic incentive to conserve water and reduce consumption, and finally choosing low-carbon energy and supplies.: 38–39 negative impacts from climate change further information: effects of climate change the effects of climate change can have negative impacts on existing sanitation services in several way, for example by damage and loss of services from floods and reduced carrying capacity of waters receiving wastewater. the sanitation sector is already affected in many different ways by "weather and climate-related phenomena such as variability, seasonality and extreme weather events".: 3 extreme weather events, such as floods and droughts, are generally increasing in frequency and intensity due to climate change in many regions.: 1157 they affect the