What is runoff pollution – and what can we do about it?

Pollution of our waterways is a growing global crisis, with an estimated 80% of ocean pollution coming from land-based sources, including runoff. While issues like sewage discharge often make headlines, runoff pollution – where rainwater washes contaminants from roads, farms and industries into rivers and lakes – tends to receive less attention. However, this less visible threat also harms ecosystems, public health and water quality.

Here, we explore the sources of runoff pollution, highlighting the innovative solutions being developed to tackle it. From advanced water monitoring to sustainable farming, new technologies are offering a path towards cleaner, healthier waterways.

Runoff pollution happens when pollutants from roads and agriculture are swept into the waterways by rain or snow melt that cannot drain into the ground. Oil, tyre wear particles, and brake dust left behind by vehicles on roads, farm fertilizers, pesticides and manure as well as debris from construction and industrial sites are just a few of the noxious substances rainwater can pick up.

And they all end up in rivers, lakes and other bodies of water. The effects are particularly strong with stormwater, due to the masses of water involved.

The chemicals and nutrients carried by rainwater are harmful to aquatic ecosystems, disrupting their balance and affecting aquatic life, according to Smart Water, a water management company. Nutrient run-off can cause algae to excessively grow and then decompose, depriving plants and animals of oxygen through a process termed eutrophication. In addition, eroded soil carried by runoff can cloud water and block sunlight, while sediment can build up to destroy spawning or feeding grounds for fish and other aquatic creatures. As a result, habitats are being degraded, leading to a decrease in fish populations and other aquatic life.

However, the runoff can also threaten humans and non-aquatic wildlife. Heavy metals like copper, zinc, and lead can accumulate in aquaculture, entering our food chain. Chemicals and bacteria can contaminate drinking water, while antimicrobial residues from agricultural use contribute to antimicrobial resistance (AMR), reducing the effectiveness of antibiotics in treating infections.

Preventing the impact of runoff starts with sustained monitoring. Fluidion, a Top Innovator of the World Economic Forum’s UpLink and HCL Group’s Aquapreneur Innovation Initiative, does just that. Its water quality analyzers use IoT-enabled platforms with cloud-based data integrations to provide rapid results directly in the field, eliminating the need for lab analysis and making monitoring possible in remote and previously inaccessible areas.

A key mechanism to prevent the impact of runoff pollution is responsible land management, Smart Water says. This includes erosion control measures such as avoiding overgrazing, using vegetation and ground cover along bodies of water, and building retaining walls.

Reducing the use of chemicals, including fertilizers and pesticides, can help minimize their contribution to runoff pollution. Unibaio, a winner of Uplink’s Smarter Climate Farmers Challenge, has developed a naturally derived microparticle that enhances the efficiency of pesticides and fertilizers, minimizing agricultural chemical use and the harmful runoff.

Improving urban planning by incorporating more green spaces and permeable surfaces that allow water to drain, as well as integrating rain gardens and green roofs, can further reduce the volume of surface runoff and mitigate its noxious effects.

Proper waste disposal and the creation of circular economies in industry will help reduce pollutants, heavy metals, and other contaminants in our waterways. Additionally, promoting responsible antibiotic use is essential to limit the spread of AMR.

Membrion, another UpLink Aquapreneur, specializes in treating heavily polluted industrial wastewater on-site. With the help of Its electro-ceramic membranes enable the recovery of up to 98% of water, which can then be recycled for reuse. The added benefit is that the technology can save over half a million dollars in costs per year and pay for itself within one to two years.

In addition to the measures mentioned, restoring and creating wetlands is essential for flood control and filtering out runoff pollutants. Wetlands act as natural buffers, improving water quality and supporting biodiversity. Countries like the UK are also leveraging fines imposed on water companies to fund efforts aimed at improving water quality and tackling pollution.

Implementing measures like these can make substantial strides towards fighting runoff pollution and protecting our water resources for future generations. These efforts not only protect ecosystems but also help ensure cleaner, healthier water for communities around the world. As the Forum’s Water Futures Community highlights, addressing water pollution is key to achieving sustainable development and building resilient communities globally.

UpLink is a World Economic Forum initiative, founded in collaboration with Deloitte and Salesforce, designed to unlock the power of entrepreneurship to tackle the world’s most urgent challenges. UpLink builds ecosystems that enable purpose-driven, early-stage entrepreneurs to scale their businesses for the markets and economies that are essential to a net-zero, nature-positive and equitable future.

Water supports nearly 60% of global economic activity, and with a projected 40% freshwater shortfall by 2030, the demand for sustainable solutions has never been greater. Through a five-year collaboration, UpLink and HCL’s Aquapreneur Innovation Initiative, with support from the Forum’s Food and Water Initiative, is unlocking this potential by creating an innovation ecosystem to empower "aquapreneurs" to scale breakthrough technologies that can transform water management.