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How this leading utility is implementing water reuse - The example of SWIFT

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Water reuseLeading utilities

[originally posted on LinkedIn by AM-TEAM CEO Dr. Wim Audenaert]

The Sustainable Water Initiative For Tomorrow (SWIFT) is a leading edge water reuse project people should know about. There are two big reasons: 1) Let’s just face the future: water reuse is unavoidable and will become an integral part of our modern society. It’s extremely relevant. 2) It’s an example of a leading utility (HRSD) daring to create the future and not waiting for societal and regulatory barriers to disappear. It’s true leadership.

With this article I DO NOT just want to define problems such as water scarcity, land subsidence, saltwater intrusion, … Talking about problems is easy. Therapy is more challenging than diagnosis. I want show that solutions and proactive measures exist, and regulatory barriers can be overcome, if the vision and leadership are there.

Water reuse is unavoidable, whether you like it or not, whether regulation is there or not

I was just thinking about the water stress in Belgium, a country with an annual rain fall of around 800mm. Not supposed to be a water scarce region, right? Annual rainfall is even increasing (Figure 1). However, water can’t infiltrate sufficiently, we have a high population density, and periods of rain/drought are becoming more extreme due to climate change. Last week, temperature reached 40°C (104°F) in Belgium, for the first time ever. Additionally, we have a highly ‘inflexible water use’, meaning that it’s not easy to reduce consumption without high costs (Figure 2). This makes it extra relevant. Giving such micro-examples is valuable AND relevant. I learned this from reading Jared Diamond’s books such as 'Collapse'. I expect that water reuse initiatives will grow significantly during the coming decade. Let’s hence learn from SWIFT and other leading initiatives.

By failing to prepare, you are preparing to fail - Benjamin Franklin

Figure 1: average annual rainfall in ‘rainy’ Belgium has been increasing (milieurapport.be)

Figure 2: Belgium is currently one of the most 'water stressed' regions in Europe. There’s a high likelihood that we will be reactively forced towards reuse in the coming decade.(source: Qin et al., Flexibility and intensity of global water use. Nature Sustainability 2, pages 515–523 (2019))

The SWIFT project

SWIFT (swiftva.com) is an indirect potable reuse (IPR) project with big ambitions. In a matter of a decade, 1 billion USD will be invested to bring the IPR capacity to 100MGD (ca. 380.000 m³/day). It will then be among the largest reuse initiatives in the world. SWIFT provides a number of benefits, and some are (at least now) more pressing than others:

  1. Protecting the precious Chesapeake Bay
  2. Counteracting land subsidence (with measurable result)
  3. Preventing saltwater intrusion
  4. Safeguarding long-term groundwater availability

Don’t rely on the likelihood of the enemy not coming, but on your own readiness to receive him - Sun Tzu

Current status and planning of the project

HRSD operates 16 WRRFs, of which 9 are relatively large ones. A 1MGD demonstration facility is now up and running at its Nansemond Plant. In total, 7 of the plants will be equipped with advanced treatment, with the first to be built at the James River Treatment Plant.

Figure 3: The SWIFT Research Center at Nansemond

How the treatment train looks like

What makes it very special is that it is not following the ‘gold standard’ of membrane treatment. No RO. The SWIFT process includes flocculation/sedimentation (FlocSed),ozonation, biological activated carbon filtration (BAC),granual activated carbon (GAC) and final UV disinfection (UVD). The FlocSed step can contribute to disinfection credit (removing turbidity),decrease ozone demand and lower final TOC. AM-TEAM works with HRSD on ozonation modelling, to minimise bromate formation and pick the best mitigation strategy. A feature I liked very much was the ease of sampling each treatment step in the research laboratory (Figure 4). The dream of every researcher, I guess.

Figure 4: Sampling ports in the lab providing samples from each treatment step, continuously - the first time I've ever seen this

The drinking water quality SWIFT Water is then used to replenish the Potomac aquifer, at a depth of around 1.500 feet (ca 450 m)

Figure 5: The 1MGD demonstration facility: FlocSed, Ozonation, BGAC, GAC, UV and advanced control room

Figure 6: Potomac aquifer recharge well. The black pump is solely for backflushing

What about regulatory barriers?

I’ll keep this section limited. However, it’s important to talk about this. I have observed three (there can be more) ways of handling regulation when aiming for potable reuse:

  1. You don’t go for potable reuse and keep discharging (regular effluent limits apply)
  2. You go for direct or indirect potable reuse using RO-based trains, whereby you remove virtually ‘everything’ to omit difficult regulatory discussions (eg Arizona, California, Singapore, (even 1 site in Belgium, in 2002 one of the first worldwide!),… )
  3. You go for indirect potable reuse without RO-based trains, whereby you inject in a very deep aquifer and demonstrate an extremely long aquifer residence time (e.g. 50 years)

It’s 2 and 3 that ultimately put water reuse in practice and drive regulatory innovation. The experiences currently being gathered with projects like SWIFT are of relevance at the global scale.

The role of SWIFT in education and dissemination

In my opinion, you shouldn’t underestimate the long term impact of disseminating such initiatives globally, and to the wide audience, including kids. The SWIFT Research Center was smartly designed with this in mind. The whole facility can be viewed from behind a window, and educational movies are all over the place. Schools visit regularly.

Figure 7: The tasting and screens for educational purposes. Thumbs up.

Figure 8: Drinking the reused water at SWIFT. On the picture from left to right: Samantha Hogard (SWIFT researcher),Mack Pearce (SWIFT researcher),Wim Audenaert (AM-TEAM; raving SWIFT fan) and Germano Salazar-Benites (SWIFT project manager) (swiftva.com)

I thought it was worth sharing this inspirational story with you.

I want to acknowledge Germano Salazar-Benites (SWIFT project manager) and Leila Rice (HRSD director of communications) for taking the time to review this article

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