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More Wastewater Treatment Plants Turning to Energy Efficiency

Wastewater treatment is a massive industry, handling the greywater and sewage from every commercial, industrial and residential water grid in the country. In addition, it ensures that our planet’s limited potable water supplies are protected from contamination. While essential, it is also one of the most energy-intensive industries in the world, which is why many wastewater treatment plants are turning to energy efficiency. How are these plants becoming more energy-efficient and what technology is already in the works?

Wastewater treatment plants
Wastewater treatment plants, Image credit:

Securing Potable Water Worldwide

Securing safe and potable drinking water is one of the most important parts of life on this planet — and also one of the most challenging. There are massive amounts of water on this planet — but only three percent of it is drinkable. Of that, only one percent is easily accessible — the rest is frozen in the planet’s ice caps. We subsist on a single percentage of the water available on the planet, and that means we need to take care of what we have.

We’re already seeing cities around the world coming close to running out of water. Cape Town, South Africa, for example, nearly reached that tipping point in 2018, only averting the crisis by implementing strict water rations and getting lucky enough to get some rain during the next rainy season.

In many parts of the world, maintaining potable water supplies and keeping them separate from wastewater is difficult. Water scarcity is such a problem globally that, according to the World Wildlife Fund, more than 1.1 billion people don’t have access to clean water. Experts estimate that by 2025, we could be seeing water shortages in two-thirds of the world.

Wastewater treatment can help to offset some of these shortages, but not if it functions inefficiently or refuses to change with the times and make the switch to renewable energy.

Industries Requiring Wastewater Treatment

When most people think of wastewater treatment, they probably picture the greywater and sewage generated by residential households. While this is part of the equation, it is far from the largest piece of the puzzle. Many industries require their own type of wastewater treatment because of the waste they generate.

You can find nearly anything in wastewater, depending on the industry, from acids and ammonia to automotive fluids, bleach and prescription drug residue. Each type of contaminant needs to be treated differently, and may even need to be routed to a different type of holding tank. Each new industry and each new contaminant in the wastewater is another level that needs to be addressed and another drain on an already power-hungry sector.

Wastewater Treatment and Energy Efficiency

According to the Department of Energy, in the United States alone, the wastewater industry uses more than 30 terawatt-hours of energy every year, costing upwards of $2 billion. This might not seem like a huge expenditure in the developed world. However, in the developing world, it can make maintaining potable water supplies difficult or even impossible, contributing to water scarcity around the globe.

Wastewater treatment hasn’t changed much in decades, making the entire industry ripe for upgrades, especially when companies around the world are trying to make their businesses more sustainable and eco-friendly in response to consumer and commercial pressure.

The Benefits of Green Energy in Wastewater Treatment

What are the benefits of utilizing renewable energy in wastewater treatment plants? Right now, wastewater treatment uses roughly 4% of all the energy generated in the United States. If you look at the operational costs of a typical treatment plant, 40% of it is usually dedicated to power alone. Switching to renewable energy doesn’t necessarily reduce the amount of electricity needed to power one of these plants, but the addition of renewable energy can reduce the overall operating costs as well as the carbon footprint of the facility.

These renewable energy programs can also help wastewater treatment facilities become more self-sustaining. Without power, water doesn’t flow. Without purification, wastewater can become dangerous. Some facilities, such as those in New Jersey and Georgia, can keep themselves running for up to 10 days without the support of the primary power grid.

Adding solar energy and other renewable options doesn’t just keep these plants running. It’s also a useful tool to reduce overall operating costs. In most cases, experts estimate that adding solar alone can reduce operating costs by upwards of 57%, making the entire industry more cost-effective in the long run.

Generating Electricity With Wastewater

One of the best ways to make wastewater plants more energy-efficient is to equip them with the means to generate their own electricity. You might be picturing solar panels on the roof or wind turbines lining the exterior of the plant. While these are options, wastewater plants actually already possess the capability to generate electricity. They simply need the means to harness it.

Wastewater treatment plants use microorganisms to break down waste. This process produces methane gas as a natural byproduct. This accounts for roughly 16% of the entire planet’s greenhouse gasses. This is traditionally released into the atmosphere or captured for use in other industries. Instead of shipping it off to other facilities, these new systems allow the plant to capture and utilize the methane to generate both heat and electricity. This energy, in turn, gets fed back into the plant to help meet its power needs.

While they aren’t as common as they should be — at least not yet — these waste-to-energy systems are popping up in the United States as well as countries like Brazil, China, Norway and Argentina. Each system is small-scale, usually offering support for a single plant, but it could potentially become a viable source of energy for surrounding homes and businesses.

Green Programs Already in Place

What sort of green programs are already in place at wastewater treatment plants around the country? They’re not limited to renewable energy, but these green programs are shaping the wastewater treatment industry and will continue to do so for many years to come.

Wastewater treatment plant energy efficiency and renewability are crucial, especially when you consider the sheer amount of sludge produced by the industry every year. It’s often a challenge to find safe and eco-friendly ways to dispose of this sludge. Dumping it out into the world creates massively toxic environments, contaminating both water and land. In other countries, according to Washington, D.C.’s Wilson Center, upwards of 80% of wastewater sludge gets dumped in landfills or is illegally dumped somewhere else, creating hazardous situations.

Sludge-to-energy programs like the ones detailed above can help to reduce the amount of wastewater sludge that gets dumped in landfills while transforming it into something eco-friendly and reducing global reliance on fossil fuels.

Why Is Renewable Energy Crucial?

Renewable energy is crucial, not just for wastewater treatment but also for industries across the country and around the globe. Renewable energy:

  • Reduces our reliance on fossil fuels, which are a finite and non-renewable resource. Burning fossil fuels also releases greenhouse gasses like carbon monoxide, which contribute to global warming.
  • Improves energy security by diversifying fuel supplies and conserving natural resources.
  • Protects the environment by reducing the need for imported fuels, which in turn helps reduce the need for transportation and the risk of spills.
  • Helps improve local economies. The renewable energy market is set to grow exponentially in the coming years, creating new jobs and supporting local commerce. Currently, US oil production is up to 9.7 million barrels per day, the highest it’s been since the 1970s.
  • Offers price stability in energy production. With renewable energy, there is little to no variation in the cost of fuel or energy generation, so utility bills in areas serviced by renewable energy won’t climb or drop unexpectedly.

Creating environmentally friendly and renewable energy is swiftly becoming an essential part of all industrial activities. Consumers are looking for ways to reduce their environmental impact and carbon footprints and are, on average, willing to pay slightly more or change the companies they purchase from in order to achieve these goals. Companies that refuse to make the necessary changes to reduce their environmental impact are finding their customers disappearing as they “vote with their wallets.”

The Future of Energy Efficiency in Wastewater Treatment

Wastewater treatment is a necessary industry throughout the developed world. People are constantly generating waste, and to keep it from overwhelming the surface of the planet, that waste needs to be treated. Instead of relying on fossil fuels, making the shift to renewable energy is the perfect step toward sustainability in an industry that isn’t going away any time soon.

This is a sector of the industry that is in its infancy. While every developed country that has centralized waste processing will eventually need to start making the switch to more renewable and sustainable options, it isn’t common in most parts of the world.

Energy efficiency will become an essential part of the wastewater treatment industry as we move through the 2020s and beyond. Between the solar and wind energy industries that are currently booming and the push toward sludge-to-energy systems, renewable energy isn’t just possible in the wastewater treatment industry. It’s also becoming an essential tool to make this critical sector more environmentally friendly.


Emily Folk is a freelance writer and blogger on conservation and sustainability. To see her latest posts, check out her blog, Conservation Folks, or follow her on Twitter, @emilysfolk!

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