Waste water management is a global challenge that affects nearly every region of the world. When existing sanitation, industrial and municipal water treatment infrastructure is overloaded, both waste water and waste seep directly into the environment and contaminate groundwater sources. Each day, two million tons of sewage is discharged into the planet’s oceans, lakes and streams. Current systems are often unable to support the world’s growing population and urbanization, and water quality deteriorates as a result.
In many places around the world, industry is the largest source of water pollution, and nearly all sources of water have some level of contamination from industrial waste and chemicals. In the United States, over 34 billion liters of hazardous liquid waste is injected directly into groundwater by industries every year. The waste includes heavy metals, solvents and radioactive materials that eventually enter underground supplies of water. In the developing world, 70 percent of industrial waste is disposed of directly into water.
Industrial mining exposes sulfur compounds and heavy metals that are leached out of the earth by rainwater, leading to acid mine drainage that continues even after mining operations have ended. Rainwater also carries mining waste to freshwater sources, and some mining companies in the developing world dump the waste directly into bodies of water.
Climate change has led to a rise in global average temperatures and changes in worldwide patterns of precipitation. The resulting increase in floods and droughts exacerbates the amount of water pollution from pathogens, carbon, sediments, pesticides and nutrients. Sea levels rise along with temperatures, leading to the salinisation of estuaries and groundwater. When these sources are compromised, ecosystems and humans in coastal areas lose an important source of freshwater.
The world’s water is also contaminated with plastic waste, chemicals from disposed cleaning products, pharmaceuticals and personal care products, pesticides and fertilizers.