Axius Water: On the Frontlines of a Global Battle Against Harmful Algae Blooms

Nutrient pollution is one of the world’s most widespread, costly, and challenging environmental problems[1] – and, as the climate warms, its impacts are worsening. Axius Water is on a mission to help municipalities and industrial customers better manage nutrients in wastewater, meet increasingly stringent discharge limits, and offer cost-effective, innovative solutions that achieve each client’s unique needs. But what is nutrient pollution, exactly?

Nutrient pollution 101

Nutrients such as phosphorus and nitrogen are part of healthy ecosystems, but when high volumes enter waterways, they can pollute the water, upset natural cycles, and have other harmful impacts. Along with agricultural runoff, untreated (or poorly treated) wastewater is one of the top global contributors of nutrients to waterways, causing them to become “impaired.”

“When these nutrients get into water sources, they become food for algae,” says Chris McIntire, CEO, Axius Water. “If the conditions are right for algae to grow quickly – and in this warming climate, they more frequently are – the algae can create large blooms that consume oxygen and block sunlight. This creates problems for the ecosystem. Fish and plants can’t live without oxygen.”

These blooms are not only decimating ecosystems, they’re also causing problems for municipalities. Large masses of algae can obstruct drinking water intakes and filtration equipment, leading to major mechanical cleaning requirements. Depending on the type of bloom and the toxins it releases, there can also be direct health impacts for humans. For example, in 2014, a summer bloom in Lake Erie caused a three-day drinking water crisis for residents of Toledo, Ohio. “If toxins leach into the drinking water, there is a lot of extra work involved to ensure that contamination doesn’t reach the public,” McIntire adds.

Furthermore, nutrient pollution is linked to the release of harmful greenhouse gases (GHGs). Researchers estimate that methane emissions from impaired bodies of water will increase by 30-90% over the next century.[2] The same study reports that these emissions could have a global warming impact equivalent to 18-33% of current fossil fuel CO₂ emissions.

“It’s a vicious cycle,” McIntire says. “In warming ecosystems, the impacts of nutrient pollution become worse. In turn, these impacts contribute to climate change.”

Stricter regulations for managing nutrients

Nutrient management is the next level of removal in wastewater treatment, says McIntire. “With global warming, growing populations, and further demand on natural waters, the need to treat for nutrients is greater, and discharge limits – that is, what we’re permitted to put back into receiving waters – are becoming much lower, and more stringently regulated.”

In most cases, these new limits mean that municipal and industrial utilities need to upgrade and redesign equipment. “Utilities are being asked to implement higher levels of treatment – and for good reason,” he says. “However, at the same time, they are also under constant pressure to reduce costs at the facilities they manage. This puts them in a tight spot.”

Axius Water has the technical and design expertise to fill these gaps, McIntire says. Across its platform of experienced companies, the XPV Water Partners and KKR-developed initiative is focused on removing nutrients and contributing to the goals of improving overall water quality through better wastewater management.

“Our goals are to help our clients meet ever-tightening regulations, support them as they optimize their systems, and empower them to make processes more cost-effective and efficient,” he says. “Ultimately, we bring value by helping our customers make the right choices to have the greatest impact on nutrient pollution.”

Axius in action: Citronelle, Alabama

As concerns about algae blooms rise, wastewater treatment plants face greater regulatory pressure to reduce their contributions to nutrient pollution. When the small wastewater utility in Citronelle, Alabama was required to meet a new, exceptionally low phosphorus limit of <0.02 mg/L, among the lowest in North America, the town needed access to experts who could properly assess the utility’s needs and provide a cost-effective, passive, and sustainable solution with a small footprint.

Ultimately, the city selected Nexom’s Blue PRO® Reactive Filtration System – a simple yet powerful tool for meeting ultra-low phosphorus limits. Part of the Axius Water platform of companies, Nexom has installations at more than 700 sites across North America. The Blue PRO uses a patented reactive filtration process within Nexom’s Centra-flo® continuous-backwash media filter to achieve the industry’s lowest phosphorus levels.

Following project completion in March 2016, Citronelle’s utility met its limits and achieved its goals for its first compliance season (April-October). Furthermore, the surrounding area has seen a significant drop in the occurrence of algal blooms.

The promise of nutrient management

McIntire estimates that Nexom’s solutions will help wastewater treatment utilities remove more than 60 million kilograms of nutrients over the next five years, preventing excess loads from impairing ecosystems and contributing to climate change. Furthermore, EDI, another Axius Water company, will remove 500 million kg in the same span, and EOSi, a third company, has removed more than 45 million kg since the company’s start in 2003.

As the platform grows, so does the impact. “At Axius Water, our sole purpose and passion is helping the planet and our customers. By thriving as a platform, we’re contributing to better wastewater management, which, in turn, helps keep waterbodies and ecosystems healthy, and mitigates GHG emissions,” McIntire says. “It’s rewarding work.”

[1] US EPA

[2] Beaulieu, J. J., DelSontro, T., and Downing, J. A. (2019)