Wastewater Woes

The unique chemical structure and bonding properties of two hydrogen atoms and one oxygen atom enables water to harbor its wondrous, life-sustaining properties. While some animals possess the ability to live without water for 30 years, most organisms on Earth cannot survive more than a few days without it. Humanity often overlooks its power and undervalues its plethora of uses. Water is commonplace on Earth, but that doesn’t justify careless management. All water, whether fresh, salty, or feces-infested has intrinsic value. In today’s dynamic climate, water management has become increasingly important. Recycling wastewater has become paramount to the future of the state’s water resources, especially in arid areas like Southern California.

The treatment of wastewater includes numerous complex processes which are vital in ensuring public health and safety. Through technological advancements in the water treatment industry, wastewater can be safely reused for a multitude of purposes. Wastewater contains a variety of microorganisms, heavy metals, and other chemicals that all pose public health risks. To address these concerns, the Clean Water Act was enacted in the United States to reduce water pollution in order to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters (CWA section 101(a)).” In California, “gray water” is defined as wastewater that comes from bathtubs, showers, and washing machines. “Black water” is defined as wastewater that comes from toilets, bathroom sinks, and kitchens, due to the presence of higher levels of pathogens and grease. However, it is worth noting that some states/other countries consider kitchen and bathroom sink water to be graywater. There are two types of potable water reuse: direct potable reuse and indirect potable reuse. Direct potable reuse means putting purified wastewater back into the drinking water system. Indirect potable reuse means that water is stored in an underground aquifer or reservoir and given time to settle. 

The LA City Sanitation and Environment (LASan) uses recycled water for “potable reuse, saltwater intrusion barriers to protect our groundwater aquifers, environmental uses, and urban irrigation.” According to the EPA, California uses 37% of its recycled water for agricultural irrigation, 17% for landscape irrigation, and 12% for groundwater recharge. All other uses of recycled water, including habitat restoration, industrial uses, etc. make up less than 10% of recycled water usage. In Los Angeles County, treated water that is not reused is emptied into the Los Angeles River or the Santa Monica Bay. As part of LA’s Green New Deal, the city of Los Angeles intends to recycle 100% of its water by 2035. The Hyperion Water Reclamation Plant, the city of Los Angeles’ oldest and largest wastewater treatment facility, currently only treats wastewater to the point where it is safe enough to be released into the ocean. The plant would have to be upgraded in order to treat wastewater that will be potable.

 

6 Pros and Cons of Recycled Water

 

Benefits of Recycled Water 

  • According to a new study, researchers found that wastewater treated by reverse osmosis was of similar or better quality to the groundwater, which is traditionally the most sought-after. 
  • Recycled water is a virtually drought-proof source of water. California is a relatively dry state and due to climate change, the state is projected to become even drier. If California reuses its water, there will be less of a demand for water restrictions for landscaping and domestic use.
  • Recycled water reduces dependence on imported water from other states. It doesn’t have to travel as far and it won’t take away resources from other nearby dry states.
  • By using recycled water, less freshwater is removed from waterways and aquifers. The removal of waterways can severely impact the water system and wildlife. Many years ago, the Colorado River used to empty into the Gulf of California. Since the overconsumption of the river water, the Colorado River no longer reaches the ocean. The lack of water has negatively affected wildlife, farming, and domestic use in Mexico. There are restoration efforts, but the future of the project is still unknown. The aridification of this area and many others like it exacerbate climate change and other ecological problems such as extinction.
  • The groundwater can be recharged more frequently and deeply through the use of recycled water. Many areas in the world have experienced land subsidence due to the lack of groundwater, which upholds the ground’s structural integrity. Generally, the aquifer is considered permanently collapsed if there is land subsidence. In the cases where the groundwater system has recovered, there is often a permanent reduction in the volume of water retained. In many coastal areas, the overuse of groundwater can lead to saltwater intrusion. Underground, there is a freshwater/saltwater barrier where the two waters mix. If there is not enough freshwater in the aquifer, saltwater will creep in and take its place. In some instances, the damage can be reversed. In other cases, the aquifer may be permanently compromised. In several cities in Los Angeles County, there are “seawater barrier projects,” where freshwater is injected into the aquifer in order to prevent saltwater intrusion.
  • Recycling water is a better alternative than desalination. Instead of recycling water, many dry regions of the world turn to desalination. The desalination of ocean water into potable water is very inefficient, expensive, energy-intensive, hazardous to wildlife, and creates hazardous waste. Desalination is 3-10 times more energy-intensive compared to recycled water. One of the biggest ecological concerns with desalination is the inadvertent killing of marine wildlife. Water intake pipes suck up fish and marine larvae. An estimated 70 billion fish larvae and other wildlife are killed, according to the California State Water Resources Control Board. Additionally, the byproduct of the production of freshwater is salt and minerals with dangerously high concentrations. These minerals are toxic to both people and marine life, yet are often still released into the water. 

Concerns with Recycled Water 

  • Recycled water is generally considered to be unappealing to the public. The phrase “toilet-to-tap” has been used as a catchphrase for those who oppose drinking recycled water. Although astronauts have been doing it for a long time, public acceptance has proven to be a challenge.
  • While wastewater treatment successfully removes many dangerous constituents, pharmaceutical drugs and other chemicals like soap can still be found in recycled water. Researchers are still in disagreement in terms of the dangers of exposing people to low levels of these chemicals. Triclosan, which is a chemical commonly found in many soaps (check out biodegradable soap), has been found to be toxic to algae and disrupts the hormones in fish. Triclosan is still found in treated wastewater. Crops have tested positive for a range of chemicals, generally in the range of nanograms (one nanogram = one billionth of a gram) per gram of dried food. In one study, 91% of crops tested contained levels of at least one or more of the chemicals found in treated wastewater. One study, which surveyed water in 25 states, found that 53 out of 74 waterways contained traces of one or more pharmaceutical chemicals. Some researchers claim the current levels of chemicals found in treated wastewater are harmless. As of 2013, there is no federal legislation regarding pharmaceutical waste in potable water.
  • The risk of food-borne illness increases when farmers choose to irrigate their crops with recycled water. The water quality for crop irrigation is important in preventing illnesses such as e. coli and other pathogens. The use of drip irrigation, which prevents contact with water on leaves, can reduce this risk. Foods that are generally uncooked such as lettuce pose more of a health risk when exposed to recycled water. Depending on the quality of the recycled water, the pH and salinity of the soil can also be adversely affected. This can negatively affect soil health which in turn can make it harder to grow healthy plants.
  • Retrofitting or creating new wastewater treatment systems will be expensive, a burden that can potentially yield new taxes. The Hyperion Water Reclamation Plant, for example, is projected to spend $3-3.5 billion dollars in order to capture all wastewater and convert it into potable water. The cost to maintain a more in-depth treatment system will likely increase which in turn will most likely raise the rates of water use. One study, conducted in Las Vegas, found significant differences in the costs of direct potable reuse and indirect potable reuse. The net present worth of direct potable reuse ranges from $1.0 billion to $4.0 billion. In comparison, indirect potable use (the status quo) costs $0.6 billion.
  • Intensive wastewater treatment systems used to create potable water require more energy than typical wastewater treatment plants. The advanced technologies are more energy intensive when wastewater treatment already uses a massive amount of energy. One study found that UV radiation, on average, required 100 times more energy than chlorination. According to the same study, membrane bioreactor treatment plants require 1.9 times more energy than conventional activated sludge treatment plants.
  • Using recycled water can be dangerous and spread illness if it’s not done correctly. Wastewater treatment plants require intensive maintenance and negligence can expose people to deadly diseases and chemicals. Wastewater treatment plants that treat water to a higher standard are even more intensive to maintain properly. Broken equipment or human error can pose serious risks to public health. One would hope that an established wastewater treatment plant would legally dispose of its waste, but there is always a chance that someone illegally dumps waste.

Water reclamation and purification can be attained in a number of ways, although it requires a lot of money, energy, and effort. Nonetheless, it is a feasible endeavor if the alternatives aren’t viable. California uses more renewable energy than most states. The energy spent to purify water is a lot greener than states that use fossil fuels to power their wastewater treatment and hazardous waste facilities. To counteract the potential increase in water rates with advanced water recycling treatments, taxes or government subsidization of water may be necessary. Nevertheless, we can ensure access to sustainable sources of clean water for posterity, even for places that experience water scarcity.

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