Text and Photos by Henrylito D. Tacio
What happened to the water you use after taking a bath? Or, where does the water go after you use it in washing your clothes? Or the water you use in cleaning the vegetables, fish, and meat?
The used water is called wastewater. It also includes food scraps, oils, soaps, chemicals and even human waste. In homes, this includes water from sinks, showers, bathtubs, toilets, and washing machines.
Economic activities (that is, agriculture, manufacturing, mining and institutions like offices, hospitals and schools) also produce wastewater which has to be collected and treated to avoid environmental pollution and risk to health.
In the Philippines, only 10% of wastewater is treated. “Metro Manila alone generates about 2 million cubic meters of wastewater every day,” said Jonathan Breton, general manager of Grundfos Philippines.
What’s in the wastewater is still water (99.9%). The 0.1%, of what is removed, contains organic matter, microorganisms and inorganic compounds. Wastewater effluents are released to a variety of environments, such as lakes, ponds, streams, rivers, estuaries, and oceans.
Wastewater is generally at risk to harmful effects of wastewater. Toxic compounds in the effluent disrupt aquatic ecosystems. When large amounts of biodegradable substances end up in the water, organisms will start to break them down, and they use a lot of dissolved oxygen.
Dissolved oxygen is critical for marine life to thrive, and as it becomes depleted, it can be life-threatening for marine species living in the waters.
Wastewater can cause pollution in the bodies of water where it is being released. For one, they do physical and biological damage to mangroves, seagrasses and coral reefs. For another, they are polluting the air and the surrounding areas.
If you happen to come in contact with wastewater or its products, you could end up being subjected to harmful microorganisms that can cause illnesses. Among those that you may end up having are gastroenteritis (diarrhea or vomiting), giardiasis and cryptosporidiosis (severe stomach cramps, diarrhea or vomiting).
Long seen as an environmental and health hazard, wastewater possesses untapped potential as an alternative energy and clean water source to offset fertilizer use, according to a report released by the United Nations Environment Program (UNEP).
UNEP, in its new report, Wastewater: Turning problem to solution, warned that only 11% of treated wastewater is reused while around half of the world’s untreated wastewater still enters rivers, lakes and seas.
In addition, carbon dioxide emissions from wastewater are substantial, hovering slightly below those from the global aviation industry.
With the right policies in place, wastewater could provide alternative energy to half a billion people, supply over 10 times the water obtained through desalination processes and reduce the demand for synthetic fertilizers.
“Globally, wastewater is full of potential, yet it is currently allowed instead to contaminate the ecosystems we rely on,” said Leticia Carvalho, Head of Marine and Freshwater Branch at UNEP.
“We must not let the opportunity simply disappear down the drain: it’s time to realize the promise of wastewater as an alternative source of clean water, energy, and important nutrients.”
The report highlights wastewater’s potential to morph from a climate concern to a solution.
By generating biogas, heat, and electricity, wastewater could produce five times more energy than is needed for its treatment.
Moreover, proper wastewater management could help countries adapt to climate change and reduce water insecurity. Reusing nitrogen, phosphorus, and potassium from wastewater could offset 13.4% of the global agricultural nutrient demand.
Proper management of wastewater also has the potential to irrigate around 40 million hectares – an area larger than Germany.
The report also features successful wastewater management examples from various countries, both high and low-income, including China, Colombia, Denmark, Egypt, Germany, India, Israel, Namibia, Senegal, Sweden, Singapore, the Solomon Islands, and Tunisia, as well as from the Caribbean region.
The initiatives demonstrate the potential for scalable solutions across multiple climate zones and economies.
The report also urges governments and businesses to look at wastewater as a “circular economy” opportunity, outlining the potential jobs and revenue the valuable resource can generate.
“We need to keep the pressure up to improve some critical underlying conditions if these actions are to succeed,” said Peter Harris, Director of GRID-Arendal, a Norwegian non-profit organization.
“For that to happen, we need more effective governance, investment, supporting innovation, strengthening data, improving capacity to implement and – critically shifting our behavior – all of us as individuals and institutions.” – ###