By Sriya Byrapuneni
What is wastewater runoff and how is bad for the Ocean? Waste water consists of water contaminated by human use including feces, urine, laundry and stormwater runoff. This water includes solids and liquid waste along with chemical and heavy metals from pesticides which mix into sewage by storm runoff.
The contaminants of water often include various contagious diseases causing pathogens, such as bacteria and viruses. As the human population continues to grow at high rates, the amount of wastewater produced continues to increase as well.
While treatment of wastewater eliminates many pathogens, improper treatment can contribute to public health crises with the outbreak of contagious diseases. Wastewater returns to the environment without being purified when regions do not have the proper sewage system in place or when the systems are overwhelmed with water. This also leaves individuals without access to clean water for drinking and cooking.
The World Health Organization (WHO) estimates that about 2.5 billion people do not have access to clean water, which contributes to about 6.3% of deaths across the world2.
These deaths are preventable by increasing access to clean water worldwide. Untreated wastewater contributes to outbreaks of disease including Typhoid, Cholera, Hepatitis A, Polio, Norwalk virus, Dysentery, Salmonella, and many stomach illnesses3. In areas that do not have proper systems for waterwaste management, people are encouraged to boil water and regularly wash hands in an effort to remove disease causing pathogens.
It is estimated that the United States processes about 34 million gallons of wastewater daily. Across the globe, the United Nations (UN) estimates that nearly 80% of wastewater returns to the environment without proper treatment, a total estimate of about 850 billion gallons per year5. Proper treatment of waste is done by first filtering the water with biological and chemical processes by sewage treatment facilities.
Next, wastewater is treated initially with bacteria and then with the use of chemicals, heat drying, or composting. The treatment is methodically done with the eventual goal of removing pathogens, chemicals, and heavy metals.
The final waste treatment process or product is often disposed of into bodies of water, eventually traveling into the ocean, or burned which produces smoke full of dangerous chemicals that may end up in the ocean. While treatment of water has been very effective, the rapidly increasing population and the lack of adequate structures for water waste management contributes to water pollution.
When sewage treatment facilities are not developed or overwhelmed, wastewater that is not processed can contaminate ground and surface water, eventually reaching oceans.
Contaminants and toxins can then be spread by ocean currents, harming marine life and contaminating seafood. The chemicals and heavy metal contaminants can be toxic to marine animals, reducing their lifespan and ability to reproduce.
Even when wastewater is properly treated, nutrients in the discharged water can destroy marine ecosystems through a process called eutrophication.
Eutrophication is when an increase in nutrients, such as nitrogen and phosphorus, causes an overgrowth of bacteria and plants.
The proliferation, or increase in organisms, decreases the oxygen levels in the ecosystem while also blocking sunlight, which kills natural marine life and creates “deadzones”, which do not have any life7.
While sewage treatment facilities generally work well to purify contaminated water, the increasing use of water can overwhelm the systems. With the increasing world population and an increase in people moving to urban cities, facilities have been passing their capacity.
Another problem is an increase in wastewater from heavy rains and snow melt. In addition, the water pipes in water systems break down over time with the average lifespan of systems being 15 to 95 years. As the systems break down or pass the capacity, contaminated water spills and overflows back into the environment. Read other blogs:
One of the major calls for action by environmental organizations is to increase funding for developing water pipelines and underwater sewage structures. It is estimated by the Environmental Protection Agency (EPA) that $660 billion needs to be invested to meet the current needs for water waste management9.
A new and promising topic currently being researched and developed is the use of fungi in treating water waste. Fungi are a specific kingdom of organisms which include yeasts, molds, and mushrooms.
The method of water treatment currently uses bacteria in the initial step of purification which makes a waste product called sludge. Sludge can be used to create energy, however, bacterial sludge has been shown to be expensive to produce with a low energy yield.
The use of fungi in water treatment converts organic, or carbon rich, matter into proteins and biochemicals which can be used in human diets or to feed animals. When compared to bacteria, fungi have been found to produce biochemical and proteins, called enzymes, which are more efficient at breaking down large sugar molecules such as starch.
Breaking down sugar molecules is important in wastewater treatment to break down the solid organic material in sewage. In doing so, fungi reabsorb toxic waste and break down pathogens to purify water. Fungal treatment also requires fewer additional resources than traditional treatment of wastewater which makes the final purification of water easier.
In addition, the large genetic make up of fungi makes the organisms more resistant to destruction by other organisms in the wastewater when compared to bacteria. While this new method of water treatment is promising, there still needs to be more work to understand the processes and functioning of fungi to build a complete understanding of the technique. In doing so, the fungi and conditions for water processing can be optimized to produce the most effective outcomes11.