Achieving positive social impact through One Water planning and water reuse
Increasing climate change impacts and rising infrastructure costs mean that planning how communities manage and meet their water needs is increasingly important. Because of this, One Water planning and water reuse projects are integral to meet future water management challenges. Vijay Sundaram PhD, PE, our Global One Water Director, looks deeper into the One Water approach, along with the future of water reuse and its benefits.
The time is right for a One Water approach
How do we source enough sustainable water? What do we do with wastewater? How do we distribute water equitably? These questions have focused water infrastructure experts on the One Water approach that manages water holistically, using a complete and collaborative methodology to improve our environment and society.
One Water looks at multiple water sources to deliver water to communities, whether from recent rainfall, impaired groundwater or treated wastewater, ensuring a supply that is diverse and sustainable. It’s essential to develop new water sources and combine water infrastructure. And while the cost of new water supplies may sometimes appear higher than existing supplies, additional water supplies make communities more resilient and provide social value benefits.
One of the most important aspects of the One Water approach is developing future drought-proof water supplies by incorporating water reuse into a regional water resource portfolio. The benefits of this are manifold, from environmental improvements to reducing wastage and providing a constant supply that’s not limited by the amount of snow or rainfall. Cost and public acceptance are challenges, but today’s solutions have been proven in practice.
Diversifying water supply is key
No community in the world should rely on a single water source to meet all its future needs. Changing weather patterns could mean that supplies run out, amplifying the risk of drought and social imbalance in that region. This risk was exemplified in Cape Town, South Africa, during the droughts of 2017 and 2018. At the time, Cape Town had just one groundwater source to supply the city. When severe drought took hold, the community was restricted from using water for everyday purposes such as flushing toilets, accessing running water and even sterilizing surgical equipment in hospitals.
Fortunately, today, with a full spectrum of water reuse solutions available from wetland restoration to potable reuse — those able to implement a One Water approach can diversify their water supply and build resilience in their communities.
Closing the disparity between coastal and inland water reuse
Making water reuse solutions accessible to all communities is a work in progress. The use of reverse osmosis, (to generate purified water from treated wastewater for drinking water augmentation) for example, is more suited to coastal locations. This is due to the constant stream of reject water it generates (between 5 percent and 20 percent) containing salt and other impurities. Disposing of this in costal locations is achievable but for inland regions it is far more challenging.
However, recent advances in technology accompanied by changing legislation are improving this situation. Innovative ways of using carbon-based advanced treatment (CBAT), including ozonation followed by biological activated carbon (BAC) filtration and additional polishing steps, are making inland groundwater recharge and drinking water augmentation feasible. The technology is eco-friendly and cost-effective.
The following projects illustrate how using the CBAT approach at scale can bring water reuse benefits to new communities:
- Hampton Roads Sanitation District Sustainable Water Initiative for Tomorrow (SWIFT) Program in the state of Virginia in the United States (U.S.) takes treated water that used to be discharged into the James River and processes it further using CBAT to meet drinking water quality standards. Up to 50 million gallons per day of this water will be used to recharge the Potomac Aquifer, the primary source of groundwater throughout eastern Virginia.
- OneWater Nevada Advanced Purified Water Facility at American Flat, will take highly treated effluent water from the Reno Stead Water Reclamation Facility and re-treat it through CBAT processes. The water will then be recharged into an outlying groundwater aquifer. Initially, it will be used to irrigate American Flat Farm, but in the future, it will provide homes and business with a drought-proof supply of extremely high-quality water. Facility construction is slated to begin in 2025.
Water reuse is not ‘one-size fits all’
By treating wastewater to a high level, in ways such as those mentioned above, communities of all sizes can unlock additional water sources in case one dries up. However, outcomes and impacts can vary depending on which methods are chosen, so these must be considered in ways that are appropriate for each specific community.
All options for recycled water use should be kept on the table. Beyond irrigation and drinking water, creating a wetland or augmenting a stream could provide significant community benefits. In Tucson, Arizona, in the U.S., the Santa Cruz River Heritage Project has released recycled water into a dry riverbed. Reflecting on the project’s impact, John Kmiec, Director of Tucson Water comments: “This has revitalized the water course and created recreational and economic opportunities along the river, while acquiring groundwater recharge credits for the infiltration.” The project has been credited with significant improvements to quality of life in the surrounding community The creation of an attractive recreational area with walking trails, where there was once just desert, is a welcome social asset. The environmental benefits are also striking, with an abundant increase in native vegetation and wildlife along the revitalized river.
Several large cities and communities worldwide are considering a combination of large-scale purification and desalination projects to create alternative sources of sustainable water supply. Also in the U.S., the Metropolitan Water District of Southern California, in partnership with the Los Angeles County Sanitation Districts, has embarked on a regional water recycling program. Pure Water Southern California would reuse cleaned wastewater currently flowing into the ocean to generate up to 150 million gallons per day of purified water.
These examples demonstrate the variety of ways that water, once effectively treated, can be reused. They offer practical benefits by creating a more resilient water infrastructure and social benefits — through enhancing the natural environment and providing the peace of mind that comes from a drought-resistant supply.
Fostering public acceptance
Ensuring the local community understands the social benefits of water reuse is essential and helps achieve local buy-in. Initially, public outreach and clear communication with community leaders can be effective ways to do this.
Visitor and learning centers with interactive exhibits and public education kiosks at reuse projects are helpful in explaining how systems work, as well as describing far-reaching and less obvious benefits. Tours for school children can be organized, which help water utilities be transparent about how and why water reuse is carried out.
Years of implementing reverse osmosis and carbon-based advanced water treatment processes around the world have demonstrated that water reuse can be made accessible to all communities. Working alongside utilities, non-profit organizations and economists, social value can be woven in, making it easier to explain the concept, holistic benefits and wider economic output of water reuse to both decision-makers and the community.
If you’re considering a One Water or water reuse project of any kind, please get in touch via our Global One Water Director, Vijay Sundaram, who’d be delighted to offer our experience in using it for social impact.