Building water confidence in a changing climate

Leading the way to safe water – Trojan UV’s water treatment solutions help municipalities address water scarcity.

Innovation, inspired ideas and cutting edge technology have all helped businesses thrive and attain reputable status. Yet truly great ideas not only change the way we work, but the best innovative thinking also changes the way we live. In most cases, ideas that change our world are initially responses to the biggest problems of the era. Today, the pressing issues of environmental protection and sustainability are considered two key driving forces behind innovation in many major industries.

Water scarcity is set to dominate the sustainability agenda in the 21st century. Population growth, climate change and increasing demand for water means we have to do more with less. Urban areas are especially vulnerable and recent trends in rainwater harvesting and water reuse will become mainstream. As we face the pressing issue of water scarcity, Trojan Technologies has led the way providing solutions using environmentally responsible, cost-effective ultraviolet (UV) light for water recycling and disinfection applications. 

Safely Destroying Contaminants

Unlike chemical approaches to water disinfection, UV disinfection provides rapid inactivation of potentially harmful microbes through a physical transformation process. When bacteria, viruses, and protozoa are exposed to germicidal UV wavelengths, their DNA is destroyed, rendering the microbes incapable of replicating. UV disinfection is extremely effective against harmful chlorine-resistant protozoa such as Cryptosporidium and Giardia.

Water sources we rely upon every day are becoming increasingly impacted by natural and man-made contaminants such as pesticides, fuel additives, volatile organic compounds and nitrosamines. UV light alone, or in conjunction with hydrogen peroxide, can safely destroy these chemical contaminants in water, helping to restore its natural condition.

A Clean Alternative

Wastewater treatment plants have traditionally used chlorine gas or liquid bleach (sodium hypochlorite) to disinfect treated sewage before discharge into rivers and streams. Chlorine, while an effective disinfectant, is a toxic, hazardous chemical that can be deadly in the event of a leak or spill. The chlorination process can also create carcinogenic byproducts harmful to the environment and aquatic life. Today, large cities including Hong Kong, Madrid, Milan, Doha, Madinah, Honolulu, and Las Vegas have adopted environmentally-friendly Trojan UV disinfection for their wastewater treatment plants.

Project Profile

The Orange County Groundwater Replenishment System in California is the world's largest Indirect Potable Reuse (IPR) system – capable of recycling 378, 500 cubic meter/day. The finished water, treated with a TrojanUVPhox™ system, is used to recharge underground aquifers and prevent seawater intrusion.

Responding To Water Scarcity

Climate change, growing population and the resulting water stress are driving forces for wastewater reuse in arid regions such as Qatar, UAE, Saudi Arabia, Australia, Mediterranean countries and many states in the southern US. Desalination (removing salt from seawater) may be an option to augment shrinking water supplies but downsides include extremely high energy consumption and disposal of the brine waste generated. Conversely, reuse practices that augment fresh water supplies, either directly or indirectly, use less energy, are locally-controlled and are "drought proof," making reuse an attractive option in water-scarce regions. The Orange County Water District's Groundwater Replenishment System in California and the Western Corridor Water Recycling Project in Brisbane, Australia, Kuwait, are examples of reuse projects that use advanced treatment to convert wastewater back to drinking water quality. Both sites use microfiltration, reverse osmosis, and UV-oxidation to ensure all chemical and microbiological contaminants are removed before treated water is returned to the potable water source.

Project Profile

In Roseville, California, the Dry Creek and Pleasant Grove Wastewater Treatment Plants have 265,000 m3 per day of reuse water capacity that is treated by a TrojanUV3000Plus™. The City's objectives to minimize chemical use, reduce energy consumption and reuse their wastewater all contribute to improving their environmental footprint for water treatment. The plants' effluent meets strict California state-regulated criteria for water recycling. Recycled water from both plants is used to irrigate golf courses, landscapes and commercial properties. Water from the Pleasant Grove facility supplies cooling water for the neighboring energy park, augments firewater, and other service and process water supplies.

A typical TrojanUV3000Plus™ reuse system

Reducing Environmental Impact

Several studies have been conducted that show UV disinfection has a smaller environmental impact than alternative chlorine disinfection processes. The City of Palo Alto, California conducted a detailed carbon footprint analysis and concluded that chlorination has a larger carbon footprint due to transportation of chemicals to the treatment plant by diesel trucks.

Trojan Technologies performed a Life Cycle Assessment on various disinfection processes to determine the overall environmental impact of UV and chlorine. It was shown that UV had the least environmental impact in all impact categories (e.g. global warming potential, human health effects, ozone depletion, etc.). Furthermore, as sources of electricity become more renewable, UV's overall impact on the environment continues to decrease.

This Life Cycle Assessment is based on a 50,000-resident city in the State of Washington, USA. The environmental impact of installing and operating UV is significantly lower than chlorine-based disinfection.

It's Easy To Be "Green"

Reuse of wastewater, now recognized as an ecological and economic necessity, is increasingly practiced not only in the United States, but globally in water scarce regions such as Australia, Middle East and Mediterranean countries. For the past two decades UV light has been successfully used to disinfect reuse water in a cost-effective manner. UV is a non-chemical disinfection technology for wastewater that protects the public against pathogenic microorganisms including protozoa, bacteria and viruses. In comparison to chemical disinfection, UV does not produce harmful by-products, is non-toxic to the environment and perhaps most importantly – has the lowest environmental impact making it truly a "green" solution.