(Tiny Tips) – Wastewater Treatment Plants – Other materials may be more expensive than clean water, but no resource is more precious than the fresh water we flush straight down the drain. Most Americans can turn on their faucets and expect clean drinking water to flow. Our dirty water disappears down the drain and we don’t really think about where it goes. But we should know about wastewater treatment systems because our lives actually depend on clean water.
The Earth is called the “Blue Planet” because 70% of its surface is covered with water. But most of it is the Aral Sea. Only 3% of the world’s water resources are freshwater, and only 1% is easily accessible. Globally, approximately 80% of the water we use flows back into the environment without treatment. Still, Americans take fresh, clean water for granted, even using it to fill our toilets, while more than 500 million people worldwide lack sanitation. In 2017, nearly 1.6 million people died from waterborne diarrheal diseases globally.
Even with extensive wastewater treatment systems, U.S. wastewater treatment plants discharge 3 to 10 billion gallons of untreated waste annually. Industrial plants often discharge wastewater directly into bodies of water. Nutrients in untreated water can cause eutrophication. Sewage pollution can also cause desalination, sedimentation and shading of marine ecosystems. Even treated water can carry an alphabet soup of pharmaceuticals and chemicals from personal care products into waterways.
Most Americans are connected to municipal sewer systems. In a sewer system, sewer pipes carry wastewater from homes and businesses to wastewater treatment plants. Combined sewers are designed to collect wastewater and stormwater in a single pipe system. When the wastewater reaches the treatment plant, the solids (what is flushed away) are separated from the liquids. These solids are physically and chemically treated to produce a semi-solid, nutrient-rich product called biosolids. Biosolids can be used as fertilizer or disposed of as waste.
Secondary treatment of liquids involves using bacteria in wastewater treatment plants to break down remaining organic matter and other contaminants in the water during filtration and aeration. These facilities often include circulating pools and fountain-like facilities to expose water to the air. The water is then allowed to settle in a settling tank and disinfected with chlorine to kill any remaining pathogens. Newer, modern systems can also use specialized treatment techniques to remove additional contaminants produced in lawn and garden fertilizers, such as nitrogen and phosphorus.
Wastewater Treatment Plants Can Fail
Unfortunately, wastewater treatment systems don’t always achieve the desired results. Wet weather can overload sewer systems and release untreated water into the environment. Sewage overflows are very common. New York Harbor alone receives more than 27 billion gallons of raw sewage and contaminated stormwater each year due to 460 combined sewer overflows. The EPA estimates that there are 23,000 to 75,000 sewage spills in the United States each year.
The American Society of Civil Engineers gives U.S. wastewater infrastructure a “D+” rating. (Find your state’s values here.) ASCE reports that the nation’s wastewater treatment plants are operating at an average of 81 percent capacity, barely able to handle the increased flows during wet weather. For example, during Hurricane Harvey in 2017, 18 of Houston’s 39 wastewater treatment plants flooded, leaving 30 percent of the city’s wastewater collection system under water for a week.
About 15% of wastewater treatment plants are at or above capacity. Many of them are also nearing their expected lifespan. Not only are these older systems more prone to pipe and equipment failures, they also lack the advanced treatment technology to remove all but the most essential contaminants.
Septic System
Nearly a quarter of Americans rely on septic systems to treat wastewater. These systems typically consist of a septic tank that stores water and a drainage field. Wastewater collects in a tank and solids settle to the bottom. This sludge must eventually be pumped out and can be spread on land as fertilizer, sent to wastewater treatment plants or buried in landfills. After the sludge settles, the remaining water and waste (called wastewater) enters the drainage field, seeps into the soil and enters groundwater.
Wastewater treatment plants can be just as effective as sewage treatment plants even though the wastewater is discharged into the ground. However, wastewater treatment plants can develop backlogs when groundwater rises due to climate change, when systems are overloaded by heavy use or extreme moisture, or when systems are poorly maintained or worn out. The result can contaminate groundwater and cause other environmental problems.
Better Water
You can do your part to protect fresh water from wastewater contamination by conserving water and reducing unnecessary waste going down the drain. Upgrade your toilet, don’t treat it like a trash can. Even “flushable” items like wipes and contact lenses pose a challenge to wastewater treatment plants because they don’t break down in water.
Save water by using high-efficiency, aerated faucets and shower heads, and turning faucets off instead of letting the water run out while washing dishes or brushing teeth.
In the kitchen, choose a powerful dishwasher and fill it before using the eco cycle. Scrape the panels down for compost instead of using a garbage disposal, which wastes up to five gallons of water per use. Keep the pipes clear of grease to avoid the formation of fat patches.
In the laundry room, choose a high-efficiency washing machine and run it at full load on a standard or eco cycle. Use less detergent. If your machine doesn’t have one, buy a microfiber filter.