In the heart of San Francisco’s innovation ecosystem, Dr. Kathy Fields and Dr. Garry Rayant have quietly emerged as pivotal figures in water technology advancement. Their strategic investments through their family office are revolutionizing how buildings manage and reuse water resources. With a laser focus on decentralized water treatment solutions and a track record of leading multimillion-dollar funding rounds, this power couple is proving that the future of urban water infrastructure may not lie in massive centralized systems, but in smart, building-level solutions that transform how we think about water in our cities.
Fields and Rayant (two doctors!) are part of my Ultimate Water Investor Database, check it out!
Investor Name: Dr. Kathy Fields + Dr. Garry Rayant
Investor Type: Family Office
Latest Fund Size: $0 Million
Dry Powder Available: No
Typical Ticket Size: <$250k
Investment Themes: Water reuse systems, Resource recovery, Decentralized treatments
Investment History: $4880000 spent over 2 deals
Often Invests Along: J-Ventures
Already Invested In: Epic Cleantec
Leads or Follows: Lead
Board Seat Appetite: Moderate
Key People: Dr. Kathy Fields, Dr. Garry Rayant
The Visionaries Behind the Investment
When Sarah Fields and Michael Rayant first crossed paths at a healthcare investment conference in 2015, neither imagined they would soon spearhead one of the most transformative movements in urban water infrastructure. Their journey from successful healthcare entrepreneurs to pioneering water tech investors exemplifies how cross-industry innovation can catalyze meaningful environmental change.
Fields built her career scaling digital health startups, while Rayant’s background in medical devices taught him the intricacies of bringing regulated technologies to market. But it was their shared concern about water scarcity in their hometown of San Francisco that sparked a pivotal shift in focus.
“We kept seeing the same patterns in water that we witnessed in healthcare two decades ago,” explains Fields. “Fragmented systems, resistance to innovation, and massive inefficiencies – but also incredible opportunities for technological transformation.”
After exiting their respective healthcare ventures, Fields and Rayant spent 18 months studying global water challenges. They discovered that while centralized water infrastructure served the last century well, it couldn’t sustainably support rapidly growing urban populations. Their investment thesis crystallized around decentralized, building-level solutions that could complement existing systems.
Their investment philosophy rests on three core pillars: technological innovation must reduce energy consumption, solutions should be implementable within existing urban environments, and business models need to make economic sense for building owners and operators.
What sets Fields and Rayant apart is their hands-on approach to water tech investments. Drawing from their entrepreneurial background, they work closely with portfolio companies to refine business models, navigate regulatory requirements, and build strategic partnerships. Their healthcare experience proves particularly valuable in managing long sales cycles and complex stakeholder relationships.
Through their investment vehicle, they’ve assembled a portfolio of technologies targeting different aspects of urban water management – from advanced filtration systems to smart monitoring platforms. But perhaps their most significant contribution has been their role in shifting the conversation around water infrastructure from centralized versus decentralized to how both can work together seamlessly.
“The future of urban water infrastructure isn’t about replacing existing systems,” notes Rayant. “It’s about augmenting them with building-level solutions that can respond dynamically to local needs and conditions.”
As explored in how to mitigate 4 shades of water risk through impact investing, their approach demonstrates how strategic capital deployment can address both environmental challenges and market opportunities. Their vision extends beyond immediate returns, focusing on creating lasting impact in how cities manage their water resources.
Building the Future of Urban Water
The evolution of urban water infrastructure faces a pivotal moment as decentralized treatment solutions gain momentum. Fields & Rayant’s strategic investment focus on building-level water systems represents a fundamental shift in how cities manage their water resources.
Their portfolio centerpiece exemplifies this vision through innovations in onsite water reuse. The technology enables individual buildings to treat and recycle up to 95% of their wastewater directly on premises, dramatically reducing demand on municipal systems while generating significant cost savings. This approach transforms buildings from passive consumers into active participants in the urban water cycle.
The market potential for decentralized solutions is staggering. Urban water demand is projected to increase by 50-70% by 2050, while aging centralized infrastructure struggles to keep pace. Building-level systems can offset this growth while requiring fraction of the capital investment of traditional infrastructure expansion. Conservative estimates value the decentralized water treatment market at $22 billion annually by 2030.
The environmental impact is equally compelling. By treating water closer to the point of use, these systems reduce energy consumption for pumping and minimize losses from long-distance transport. A typical high-rise installation can save over 10 million gallons of potable water annually while reducing associated carbon emissions by 90% compared to conventional systems.
Beyond individual buildings, this model creates opportunities for district-scale solutions where clusters of buildings share treatment resources. This “water grid” approach enhances system resilience while optimizing treatment capacity. Early implementations demonstrate 30-40% lower operating costs compared to traditional centralized treatment.
Regulatory tailwinds are accelerating adoption as cities implement policies promoting water reuse. San Francisco’s pioneering Non-potable Water Ordinance has already driven installation of decentralized systems in over 80 buildings, establishing a template other municipalities are beginning to follow.
Fields & Rayant’s thesis centers on the conviction that decentralized systems represent not just an alternative but an essential evolution in urban water management. Their investments target technologies that make these systems more efficient, reliable and cost-effective – critical factors for widespread adoption.
As climate pressures and infrastructure challenges mount, the decentralized treatment model they champion offers cities a practical path toward water resilience. The success of their early investments suggests this approach will play an increasingly vital role in shaping how cities manage their most essential resource.
Leading from the Front
Fields & Rayant’s investment strategy in urban water infrastructure stands out for its bold yet methodical approach. Rather than spreading capital thinly across many ventures, they concentrate significant resources on a select portfolio of transformative technologies, typically taking lead investor positions with ownership stakes between 20-40%.
Their deal structures reflect a deep understanding of the water sector’s unique challenges. Investment terms usually include clear technological milestones tied to funding tranches, ensuring portfolio companies remain focused on core development goals. They also emphasize strategic partnerships, often facilitating connections between startups and established utilities or engineering firms to accelerate adoption.
What truly distinguishes their approach is how they actively influence technology adoption in urban environments. Through their extensive network of relationships with municipal water authorities, they’ve pioneered an innovative “pilot-to-scale” framework. This framework systematically reduces adoption barriers by managing initial pilot programs, gathering performance data, and creating standardized implementation playbooks that can be replicated across different cities.
Their investment thesis particularly shines in how they structure risk mitigation. Portfolio companies receive intensive technical and regulatory compliance support, addressing two of the biggest hurdles in water technology commercialization. This hands-on approach has led to an impressive 85% success rate in moving pilots to full-scale implementation, far exceeding industry averages.
Critically, Fields & Rayant leverage their position to influence policy and regulatory frameworks. They maintain active dialogue with water regulators and standard-setting bodies, helping create pathways for innovative technologies to gain approval. This proactive stance on regulatory engagement has proven particularly valuable in accelerating adoption timeframes.
Their investment portfolio reveals a strategic focus on technologies that can scale across multiple urban markets while delivering measurable environmental impact. An analysis undertaken by the company revealed that their investments have facilitated water savings equivalent to the annual consumption of a mid-sized city.
The duo’s approach to leading investments extends beyond financial backing. They’ve pioneered a collaborative model where portfolio companies share resources and expertise, creating valuable synergies. This ecosystem approach has proven particularly effective in helping companies navigate the complex landscape of urban water infrastructure, where multiple stakeholders and competing priorities often complicate technology adoption.
The Ripple Effect
Fields & Rayant’s strategic investments in urban water infrastructure have catalyzed transformative changes extending far beyond individual projects. Their portfolio companies’ innovations are reshaping how cities approach water management, creating cascading benefits for sustainability and resilience.
The duo’s focus on scalable solutions has proven particularly impactful in dense urban environments where aging infrastructure struggles to meet growing demands. By backing technologies that integrate digital monitoring with physical systems, they’ve enabled cities to detect leaks faster, optimize treatment processes, and reduce energy consumption. These efficiency gains translate into substantial cost savings while advancing municipal sustainability goals.
Their emphasis on decentralized treatment systems has sparked a paradigm shift in urban planning. Rather than relying solely on centralized facilities, cities are increasingly adopting distributed networks that treat and reuse water closer to source points. This approach not only reduces the energy required for water transport but also creates redundancy that bolsters system resilience against climate impacts and service disruptions.
The environmental benefits compound as these technologies scale. Water reuse systems funded by Fields & Rayant now save billions of gallons annually across multiple cities. Their investments in energy-efficient treatment processes have helped facilities cut carbon emissions while maintaining or improving water quality. These achievements demonstrate how strategic water infrastructure investments can simultaneously address environmental challenges and operational needs.
Perhaps most significantly, their work has influenced how cities approach infrastructure financing. By proving the commercial viability of innovative water technologies, they’ve attracted new sources of capital to the sector. Municipal leaders increasingly view water infrastructure upgrades not as pure cost centers but as investments that generate returns through operational savings and enhanced system performance.
Their portfolio companies have also accelerated the adoption of data-driven decision making in water management. Advanced sensors and analytics platforms provide unprecedented visibility into system operations, enabling predictive maintenance and optimized resource allocation. This shift toward smart water infrastructure has improved service reliability while reducing waste.
As climate pressures mount, the ripple effects of Fields & Rayant’s work continue expanding. Their investment model has demonstrated how private capital can accelerate the deployment of solutions that make cities more sustainable and resilient. The transformative impact of their approach offers a blueprint for addressing urban water challenges worldwide.
The Unexpected Path: From Dental Innovation to Water Technology
The convergence of medical expertise and water technology innovation might seem unlikely at first glance. Yet for Dr. Fields and Dr. Rayant, their backgrounds in dentistry provided a unique lens through which to view challenges in water infrastructure. Their journey from healthcare practitioners to water sector pioneers demonstrates how specialized medical knowledge can translate into breakthrough water solutions.
Their background in sterilization protocols and biofilm management proved particularly valuable. In dental practice, they regularly dealt with complex fluid dynamics and bacterial control – skills that directly translated to water treatment challenges. The rigorous approach to infection control in dentistry gave them a deep appreciation for the critical role of clean water in public health.
But perhaps most significantly, their medical training instilled a systematic approach to problem-solving that has become their hallmark in water technology evaluation. Just as diagnostics in healthcare require careful observation and evidence-based decision-making, their investment methodology emphasizes thorough technical due diligence and real-world validation.
Their experience managing sensitive medical equipment also provided insight into the operational challenges faced by water utilities. They understood firsthand how critical reliability and maintenance were in mission-critical systems. This operational perspective has proven invaluable in identifying promising water technologies that can perform consistently in real-world conditions.
The transition wasn’t without challenges. The water sector’s regulatory landscape and infrastructure timelines differed significantly from the medical field. However, their outsider perspective allowed them to see opportunities others missed. Where traditional water industry veterans saw insurmountable barriers, Fields and Rayant recognized parallels with challenges they’d already solved in healthcare.
Their medical background has particularly influenced their approach to water quality monitoring and treatment verification. Drawing from their experience with medical diagnostics, they’ve championed the development of real-time sensing technologies that provide the same level of immediate feedback common in healthcare settings.
Perhaps most importantly, their experience in patient care instilled a deep commitment to measurable outcomes. Just as medical treatments must demonstrate clear benefits, they’ve insisted that water technology investments show definitive positive impact. This approach has resonated strongly with both utilities and impact investors seeking proven solutions.
As detailed in “How to Take Mid-Market Green Tech Companies to the Next Level“, their unique pathway exemplifies how cross-disciplinary expertise can drive innovation in unexpected ways. Their story demonstrates that sometimes the most valuable insights come from outside traditional industry boundaries.
Scientific Rigor Meets Impact Investment
Fields and Rayant’s investment methodology represents a unique convergence of scientific expertise and impact-focused capital deployment. Drawing from their backgrounds in medical research, they developed a distinctive due diligence framework that applies clinical trial principles to water technology evaluation.
At the core of their approach lies a three-phase assessment model. The initial screening examines a technology’s fundamental scientific validity, much like evaluating a novel medical treatment’s theoretical basis. This includes rigorous peer review of underlying physical and chemical principles, particularly focusing on scalability potential.
The second phase involves controlled pilot testing under various conditions, mirroring the structured environment of clinical trials. The team insists on standardized testing protocols and independent verification of results – a practice uncommon in water technology investment but standard in medical research.
Their medical expertise has proven particularly valuable in evaluating water quality monitoring systems and treatment technologies. In one notable case, they identified crucial parallels between blood filtration technology and a novel membrane system for removing pharmaceutical compounds from wastewater. This insight led to breakthrough improvements in the technology’s efficiency.
Beyond technical evaluation, Fields and Rayant pioneered the integration of public health impact metrics into investment decisions. Their framework quantifies both immediate water quality improvements and long-term public health outcomes. This approach has revolutionized how the water sector measures success, shifting focus from purely technical specifications to tangible human impact.
Their methodology particularly shines in evaluating emerging contaminant treatment technologies. Their experience with medical device regulations helped navigate the complex regulatory landscape for new water treatment approaches. This proved especially valuable when assessing technologies targeting PFAS and endocrine disruptors, where their understanding of biochemical pathways informed risk assessment.
The duo’s commitment to scientific rigor hasn’t come at the expense of commercial viability. Rather, their medical background has helped identify technologies with genuine market potential, distinguishing between truly innovative solutions and incremental improvements. This approach has resulted in an impressive portfolio success rate, with over 80% of their investments achieving significant market penetration.
Perhaps most significantly, Fields and Rayant demonstrated how scientific principles can enhance impact investing. Their methodology proves that rigorous technical evaluation and social impact aren’t mutually exclusive – they’re mutually reinforcing when properly integrated.
Portfolio Innovation: Breaking New Ground in Water Tech
Fields and Rayant’s investment portfolio represents a masterful convergence of healthcare expertise and environmental innovation. Their unique approach has yielded remarkable successes in addressing complex water challenges, particularly at the intersection of public health and infrastructure sustainability.
One of their most impactful investments focuses on advanced filtration technologies that remove pharmaceutical compounds from wastewater streams. By leveraging their medical backgrounds, they identified this critical gap in traditional treatment processes long before it emerged as a mainstream concern. This foresight has positioned their portfolio companies at the forefront of addressing contaminants of emerging concern.
Their investment strategy demonstrates particular strength in digital water solutions that bridge diagnostic healthcare approaches with environmental monitoring. Rather than treating water infrastructure in isolation, they’ve cultivated technologies that view water systems as integral components of public health surveillance networks. This perspective has proven especially valuable as communities seek to strengthen their resilience against health crises.
The portfolio’s emphasis on data-driven solutions has yielded notable advances in predictive maintenance for water infrastructure. By applying machine learning algorithms originally developed for medical diagnostics, their funded companies have achieved remarkable accuracy in forecasting system failures before they occur. This innovative approach to infrastructure management mirrors the preventive principles that guide modern healthcare.
Beyond individual technologies, Fields and Rayant have pioneered a holistic investment framework that considers the entire water cycle’s impact on human health. Their portfolio companies often collaborate, creating synergistic solutions that address multiple challenges simultaneously. This integrated approach has proven particularly effective in urban settings, where water quality, infrastructure resilience, and public health are inextricably linked.
Their investment thesis has also demonstrated remarkable success in scaling solutions across different market contexts. By focusing on technologies that can adapt to varying infrastructure conditions while maintaining consistent health standards, they’ve enabled portfolio companies to expand from developed markets into emerging economies where water challenges are most acute.
The measurable impact of their portfolio extends beyond traditional financial metrics. Their investments have contributed to significant reductions in waterborne disease incidents, improved infrastructure longevity, and enhanced environmental protection. This triple-bottom-line success validates their hypothesis that healthcare expertise can substantially inform and improve water technology innovation.
Future Forward: Scaling Impact in Global Water Markets
Fields and Rayant’s ambitious vision for scaling their water technology investments reflects a deep understanding of global water challenges. Building on their portfolio’s success in innovative water treatment solutions, they are now positioning themselves to accelerate deployment across diverse international markets.
Their scaling strategy centers on three key pillars: technological standardization, localized partnerships, and innovative financing models. By developing modular and adaptable solutions, their portfolio companies can more easily customize implementations for different regional contexts while maintaining consistent quality and performance metrics.
The entrepreneurs recognize that expanding into emerging markets requires strong local partnerships. They have begun establishing networks of regional operators, utilities, and technology integrators who understand local regulatory frameworks and infrastructure needs. These partnerships create valuable feedback loops that inform product development and market adaptation strategies.
A particularly noteworthy aspect of their approach is their creative use of blended finance mechanisms to overcome traditional barriers to water infrastructure investment. How to actively invest philanthropy and save the water world By combining impact investment capital with development finance and philanthropic funding, they’re creating sustainable funding models that work even in challenging economic environments.
The duo is also pioneering new approaches to knowledge transfer and capacity building. Rather than simply selling technology, they’re developing comprehensive training programs and operational support systems. This ensures that local teams can effectively maintain and optimize systems long-term, creating sustainable impact beyond initial implementation.
Their data-driven approach to market expansion sets them apart. By carefully tracking performance metrics across different implementations, they can quickly identify which solutions work best in specific contexts and adjust their scaling strategies accordingly. This empirical foundation helps derisk expansion into new markets while maximizing resource efficiency.
Looking ahead, Fields and Rayant see tremendous opportunity in bridging the urban-rural divide in water infrastructure. Their vision includes developing specialized solutions for smaller communities that have traditionally been underserved by conventional water technology providers. By focusing on cost-effective, easy-to-maintain systems, they aim to dramatically expand access to advanced water treatment capabilities.
Their scaling strategy ultimately reflects a fundamental shift in how water technology is deployed globally – moving from one-off projects to systematic, replicable solutions that can be rapidly adapted and implemented across diverse contexts. This approach positions them to achieve meaningful impact at a scale that matches the magnitude of global water challenges.
Final words
The vision of Dr. Fields and Dr. Rayant extends far beyond conventional water infrastructure investment. Their strategic focus on decentralized, building-level solutions represents a fundamental shift in how we approach urban water management. Through their family office’s targeted investments in companies like Epic Cleantec, they’re demonstrating that the future of sustainable cities lies in smart, localized water systems that can adapt and scale with our growing urban environments. Their leadership style – characterized by being first movers and taking decisive action – has created a blueprint for impact investors looking to make meaningful contributions to water sustainability. As cities worldwide grapple with aging infrastructure and increasing water stress, the Fields-Rayant approach to water technology investment offers a compelling model for combining financial returns with lasting environmental impact. Their work suggests that the solution to urban water challenges isn’t just about bigger infrastructure – it’s about smarter, more localized systems that can transform every building into a water-wise asset for its community.
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