It is a globally accepted fact that billions of people live without proper sanitation facilities. World Toilet Day was declared by the UN in 2013 as an annual observation day celebrated on 19 November every year. By 2030, the Sustainable Development Goals (SDGs) aim to reach everyone with sanitation, and halve the proportion of untreated wastewater and increase recycling and safe reuse. The objectives of the world toilet day are:
Provide an opportunity to raise awareness of the importance of sanitation, and stimulate momentum towards reaching everyone, everywhere with equitable and improved sanitation.
Raise awareness about all the people who do not have access to a toilet, and the urgent need to end the sanitation crisis.
Theme of the world water day in 2017 is “Wastewater”. The World Toilet Summit 2017 runs parallel to the world toilet day with an attractive slogan “Improving Sanitation through Partnership” in Australia from 10-21 November 2017.
What is Wastewater?
A simple and more convincing interpretation for wastewater is given in the recently published book “Wastewater Management and Kandy City Wastewater Management Project”.
Accordingly “WASTEWATER” is the term used to denote water polluted by human activities such as bathing, washing, laundry, agriculture, and industrial activities. As such the term “wastewater” would typically indicate water which has been used, is no longer wanted as no further benefits can be derived out of it, and so needs to be disposed of. Wastewater can therefore include components such as spent industrial chemicals and various processing wastes, and human wastes collected where there are concentrations of human population. Water is an important part in many activities and hence generation of wastewater is a common occurrence.
Types of Wastewater
Majority of people do not have clear idea on wastewater, where they are generated and the impact of improper disposal of wastewater. Simply the waste water could be categorized as follows:
Domestic sewage and Municipal sewage: wastewater arising from typical living processes such bathing, toilet flushing, laundry, dishwashing, and cooking. Generally they are generated form houses, commercial units, public and private institutions and any other places where people do use water in their regular day to day activities. Wastewater generated from commercial activities such as food and entertainment outlets also included into this category, they are generally referred to as municipal wastewater.
This domestic wastewater is divided into two categories, grey-water and black-water. All wastewater generated from the shower stalls, baths, washing machines, dishwashers and sinks are called gray water. They are typically low in particulates and organic strength. Black water generally identifies as fecal contaminated water from toilets. It consists of fecal matter, urine, and paper used for cleaning. Such wastewater is high in particulates and organic strength.
Industrial or process wastewater: Wastewater released following industrial activities such as heating, cooling, cleaning and conveyance. Industrial wastewaters may include organic chemicals (pesticides, pharmaceuticals, paints and dyes, petrochemicals, detergents, oils and plastics) and inorganic chemicals (lead, mercury, cadmium, chromium, arsenic, selenium, and nitrogen compounds).
Storm Water: This is the surface runoff collected following rainfall. It generally contains fuel, oil, heavy metals, trash and other pollutants. Also it picksup leaking septic tank contents, and fertilizers and pesticides from cultivated areas.
Do We Need to Manage Wastewater?
Wastewater should be treated into a different degree before it is discharged into soil or into water bodies such as rivers, streams and seas. Discharge of wastewater into septic tanks is the common practice in wastewater disposal in almost all developing countries.
The majority of these septic tanks is of substandard quality and not built following any technical standards. Often septic tanks are unlined pits excavated within premises and tend to pollute both ground and surface water sources. Many studies revealed that the raw sewage go directly into water bodies due to absence of proper onsite or centralized wastewater disposal facilities.
Non-existence of proper wastewater management and prevalence of water pollution, and water borne diseases are going hand in hand. Absence of proper wastewater management facilities caused poor environmental conditions and pose significant threat to human health.
In many parts of the world including Sri Lanka, continuous and increase in pollution of fresh water resources, ground and surface, aggravate the present water scarcity. Hence, proper wastewater management has become essential for many reasons viz: ensure the better public health and the well-being of the people protect water resources and the environment from pollution; and
Reduce the pressure on potable resources making opportunities for reuse of water in water-scarce regions. According to the Census in year 2012 only 88% of households in Sri Lanka have access to proper toilet facilities. Around 1.7% households do not use toilets and the balance of 1.1% of households either use direct pit toilets or share neighbor’s toilets. The household survey in 2016 indicates that percentage of households who have proper toilets are 94.6% with 3.8% of pipe sewer system connections. The significant development in this period was to reduce the number of household who do not have toilets to 1%. Still 3.5% of households use pit toilets, which cannot be considered as proper toilets.
Although Sri Lanka has the highest coverage of sanitation facilities in south Asia, the widespread water pollution is evident in many parts of the country due to leakage of improperly constructed septic tanks. Special attention to the methods of onsite disposal and technical quality of septic tanks is needed to ensure the zero pollution of water sources from sewage.
Discharging of industrial wastewater, oil from service stations and petrol stations, fertilizer used for the agriculture into water bodies contributed to this situation further. Ground water sources in Jaffna peninsula and Kalpitiya have been contaminated with faecal matters and fertilizer substance beyond use.
Often houses and businesses, which are located close to water sources, make provisions to discharge their sewage into water sources covertly during rain. Sewage water from homes, restaurants and other public places are just discharged into nearby public drains, which ultimately ends up in water sources, which are used for drinking purpose. It is a fact that pollution of water bodies such as rivers, lakes, irrigation tanks in Sri Lanka is taking place at an alarming rate.