In the United States alone, billions of gallons of water are treated each day at water resource recovery facilities. Once the water is clean, a different challenge remains: determining what to do with the solids that are removed during the treatment process. The resulting mixture is often a unique semi-solid blend of organic and inorganic materials, trace elements, chemicals, and even pathogens, so there is no across the board solution for handling and processing the combinations of constituents that may be present.

Because these solids are often rich in nutrients, like nitrogen and phosphorus—which also happen to be the perfect ingredients for promoting healthy soil and plant growth—many facilities have turned to land application. Before these solids can be put to use for things like fertilizing farmland, however, they must undergo rigorous treatment to meet stringent regulations, at which point they become known as biosolids.

Climate change is altering our natural hydrologic cycle, creating uncertainty when it comes to the quality and quantity of water sources. WRF’s research on climate change covers the key areas of climate risk assessment, climate adaptation, and mitigation strategies.

Because the first step in preparing for climate change is understanding the potential and variable impacts these changes can have on water sources and treatment systems, WRF research tracks potential outcomes, considering a variety of possibilities, and provides resources and tools to help facilities identify and address risks and vulnerabilities in their operations and infrastructure.

Implementing climate change adaptation strategies will be critical as the water sector moves forward. WRF’s research in this area helps utilities create better long- and short-term adaptation plans, respond more effectively to severe weather, and improve infrastructure and operations to meet changing needs, including the production of onsite energy systems and reliable back-up power to protect critical services.

The water sector must also have a hand in mitigating the root causes of climate change. By pioneering approaches to improve energy efficiency, including process optimization, improved energy management, and the use of renewable energy, WRF is helping the water sector decrease activity that is driving these changes.

For more information, contact Harry Zhang.

Aquatic microscopic algae and cyanobacteria (formerly known as blue-green algae) occur naturally in most surface waters. However certain nutrient and temperature conditions can cause them to multiply rapidly, leading to “blooms.” Under certain conditions, some species of cyanobacteria can produce toxic secondary metabolites or cyanotoxins, which may pose health risks to humans and animals. Even when cyanobacteria are not toxic, they can produce unpleasant tastes and odors.

Cyanobacteria continue to be among the most problematic organisms in fresh water systems. Without clear guidance or consensus regulations in place, many utilities struggle with responding to cyanobacterial harmful algal bloom (cHAB) events. Since 1994, WRF has completed more than 40 research projects on these microscopic organisms and the cyanotoxins they produce, helping facilities detect, monitor, and manage these organisms—as well as communicate with the public.

For more information, contact Sydney Samples.

The use of strong oxidants to disinfect water has virtually eliminated waterborne diseases like typhoid, cholera, and dysentery in developed countries. However, research has shown that chlorine interacts with natural organic matter present in water supplies to form regulated and emerging disinfection byproducts (DBPs).

To minimize the formation of regulated DBPs and comply with existing regulations, water utilities have increasingly been moving away from chlorine to use alternative disinfectants like chloramine, or installing more advanced and costly treatment processes, such as ozone or granular activated carbon to remove DBP precursors. However, while reducing the formation of halogenated DBPs, alternative oxidants have been shown to favor the formation of other DBPs (e.g., ozone producing bromate and halonitromethanes, and chloramines producing N-nitrosodimethylamine and iodinated DBPs). 

For more information, contact Kenan Ozekin.

For most water facilities, energy is one of the highest costs in their operating budget. Stricter regulations are pushing facilities to use even more advanced—and energy-intensive—treatment technologies. Optimizing energy use can provide huge cost savings and numerous additional benefits, including improving air quality, protecting the environment, and bolstering energy security. WRF has published more than 100 projects that explore ways to not only optimize current energy use, but to generate power as well—setting the course for a self-sufficient water sector.

As with other industries, newly developed technologies drive water utilities to adapt their day-to-day operations. Water networks have been a special focus, with new instrumentation options for water production, transmission, distribution, wastewater collection, and consumer end-points coming to market. Implementing these technologies can improve the efficiency and reliability of water networks, but with myriad options, utilities need guidance on which technologies are most worthwhile and how they should be implemented. 

Control of microbes in water systems is critical to achieving water quality and public health goals. While most microbes are not considered human pathogens, certain microbes can pose health risks or contribute undesirable tastes and odors. 

Since the early 20th century, modern drinking water treatment has made great advancements in the detection, removal, and inactivation of bacteria, viruses, and protozoa. As technologies in the drinking water space continue to progress, new challenges have arisen in the form of opportunistic premise plumbing pathogens. 

Wastewater and stormwater utilities also play an essential role in reducing the pathogen load to receiving waters used for recreation.  Additionally, more recent advancements in water reuse, especially direct potable reuse, demand more understanding of pathogen detection, removal, and inactivation in wastewater. 

For more information, contact Grace Jang (drinking water & reuse) or Lola Olabode (wastewater).

In recent decades, the wastewater sector has moved away from the idea of wastewater treatment plants as waste disposal facilities, instead envisioning these plants as water resource recovery facilities (WRRFs). WRRFs can produce clean water, recover nutrients (such as phosphorus and nitrogen), and potentially reduce fossil fuel consumption through the production and use of renewable energy.

For more information, contact Jeff Moeller.