The imminent global water crisis is looming particularly large in developing countries, but experts note that this is a crisis of water quality, not quantity. The solution, they explain, lies in restoring natural ecosystem processes.
Solving the global water crisis
Usable freshwater supplies are coming under increasing pressure worldwide, in large part due to eutrophication, or the overabundance of in-water nutrients. These conditions can lead to periodic cyanobacteria harmful algae blooms (cyanoHABs) which poison water supplies and cause water shortages, hospitalisations, and animal and human casualties.
According to the UN Environment Programme, by 2025 two-thirds of the world’s population are likely to face water stress exacerbated by climate change, rapidly growing urban populations, pollution, land development, and other factors.
Dave Shackleton, CEO of integrated water resource management company, SIS.BIO believes that by combining the power of natural processes with innovative biotechnology in an integrated approach, a solution to this crisis is available if governments and water corporations are willing to listen.
Bioremediation of water resources presents a golden opportunity for developing countries to ensure maximum access to freshwater supplies in the future. It is based in part on the use of enzymes to digest the excess nutrients in the sediment of water bodies. The benefits of this require an understanding of the cycle of eutrophication and the HABs that are currently choking water bodies globally.
Remedying the collapse of aquatic ecosystems
Freshwater ecosystems are naturally self-sustaining – the aquatic food web processes nutrients to produce biomass, which passes through the food web in the form of plants and animals until it is cleared from the system by external predators.
“Human impacts cause increased nutrient inflows and oxygen depletion, overwhelming these natural processes and driving a cycle of weed, algae, and cyanobacteria growth, until water becomes untreatable and unusable,” Shackleton explains.
Cycles of blooming and dying algae and cyanobacteria create a rich nutrient stockpile in the sediment and the water itself, destabilising the ecosystem and altering the nutrient cycle. By increasingly eutrophic conditions, things go from bad to worse as cyanobacteria come to dominate in a new stable but imbalanced ecosystem that is characterised by low levels of the dissolved oxygen that aquatic animals need to survive.
The importance of ecological restoration
The logic behind bioremediation mirrors the main tenet of the international standards for ecological restoration: ensuring the return of a self-sustaining and functioning ecosystem. However, this concept is being overlooked when it comes to remediating freshwater areas.
Toxic cyanoHABs kill aquatic animal life and cannot be removed by water purification plants. This, argues Shackleton, is the death of renewable water; the only way to return to a balanced, healthy system is to reverse the eutrophication process that causes this imbalance.
An integrated water resource management approach that focuses on ecosystem restoration has the potential to be a game-changer in the developing world, managing water throughout the natural water cycle, including water bodies (outside the pipes), instead of only treating water within the engineered infrastructure (in the pipes).
The paradox of wastewater treatment infrastructure
Reports from countries including South Africa regularly cite a shortage of or poorly maintained water treatment infrastructure as one major aspect of water shortages. While many developing nations lack access to treated water, wastewater treatment facilities may, in fact, be part of the problem.
“There is a paradox of infrastructure in traditional water management: as we build more wastewater treatment plants – even if they are compliant with regulated standards – we actually increase the total nutrient overload in treated wastewater being discharged into our water bodies,” says Shackleton.
“Solutions ‘in the pipes’ reduce but do not remove nutrient inflow to water bodies. On the other hand, using biotechnology to boost nutrient processing and clearance from these water bodies can transform water ‘outside the pipes’ into natural wastewater treatment infrastructure. This can scale up water treatment so water purification plants don’t need to do all the heavy lifting. Bioremediation is also highly effective at optimising operations within these existing water treatment facilities,” he elaborates.
“In many places lacking waterborne sewerage infrastructure, installing piping and big wastewater treatment plants is prohibitively expensive. Many countries run simple lagoon or sewage pond systems, which are just not up to the task without biological support,” he continues.
Pond systems fill up with sludge over time, become mosquito breeding hotspots, and present various health risks to human populations.
“A parallel second system is usually built when the first fills up, so one system runs for two years while the other is dried out and excavated for reuse, but this is extremely costly,” explains Shackleton, adding that bioremediation can make these systems fully sustainable:
“The ability to run pond systems with simple automated or manual bioremediation treatments, running alongside oxygenation, represents an ideal opportunity for the developing world to remediate this water so that it can be used for market gardening and other applications.”
The potential for savings is clear considering that in the United States, as of 2019, US$18.6 billion was invested in building new or improved infrastructure via USDA Rural Development water and wastewater loans and grants, and US$272 million was provided in technical assistance to rural communities. A further US$7 billion in annual funding for water infrastructure (loans and grants) came from the US EPA Clean Water State Revolving Fund and the Water Infrastructure Finance and Innovation Act.
Reducing the proportion of harmful cyanobacteria
In the US, there are several projects from which a wealth of data has already been collected. Highlighting an intervention at a 320-acre lake in Missouri, Shackleton says that success hinges not just on reducing the total amount of algae in the water, but also on the proportion of cyanobacteria within the phytoplankton community.
“In May 2022 at the start of the intervention, the total algal community was measured at 140 million cubic micrometres (µm3)/ml, which is through the roof. This was almost exclusively harmful cyanobacteria. By June 2022 this was down to just under 25 million µm3/ml, still over 95% dominated by cyanobacteria,” he reports. “We now have three years of data, taken during the summer peak months for HABs. By June 2023 the total was down to under five million µm3/ml (over 95% beneficial algae), and by June 2024 samples showed under a million µm3/ml, (all beneficial algae).”
The importance of dissolved oxygen
A pilot project in 2022 aimed to demonstrate the effectiveness of biotechnology in treating a heavily polluted waterway in Delhi, India.
“The project was challenging, not least because the specifications provided were for a two-metre-wide canal. It was actually seven metres wide, so the intervention was massively underdesigned. Despite this, oxygenating the water and adding enzyme treatments significantly and immediately improved water quality at the source and up to 150m downstream. We were able to achieve a roughly 90% reduction in both chemical (non-organic) and biochemical (organic) oxygen demand – essentially a measure of the contamination level,” relates Shackleton.
Improving lake water storage capacity
Shackleton also highlights a project at the 30-acre Roland Lake in Virginia, which produced five years of data up to 2022.
“Lake remediation was progressing well up to 2020, but then Covid prevented travel and we were unable to apply biological treatments. Conditions leveled off and there was no further improvement. After dosing resumed and the enzymes were digesting the accumulated muck and sediment again, there is now more than 50% more water in that reservoir than when we started. So, for reservoirs losing storage capacity, this is a highly effective intervention,” he says.
Altering the status quo
Scientific insight and technological innovation are critical to understanding and overcoming the flaws inherent in current HAB treatment strategies such as dosing with copper sulfate, which clears up water in the short term but promotes nutrient recycling and eutrophic conditions and drives long-term cyanobacterial dominance.
“We need a solution to cyanotoxins, but we are restricting activities with standards that cannot be met without severe financial losses,” continues Shackleton. “Biotechnology can lower water treatment costs, while reducing both the sediment nutrient stockpile and disinfection by-products to achieve stricter, but more affordable, water quality standards.”
By optimising wastewater treatment, minimising nutrient inflows, and processing more nutrients, biotechnology can open a new path to renewable water without further restricting farming, economic growth, and competitiveness. As part of a holistic integrated water resource management program, bioremediation of freshwater bodies helps to restore and support their self-sustaining functions to maintain water quality, dealing with the causes of eutrophication rather than desperately trying to treat its symptoms.
