water-reuse
(6)
Hydraloop
Hydraloop is a Dutch water technology company that makes compact, in-home and in-building water recycling systems. Its certified, chemical-free devices collect and clean up to 85% of a household's water - from showers, baths, washing machines and air-conditioning condensation - and return it for toilet flushing, laundry, garden irrigation and pool top-up, cutting fresh water use and sewage output by up to 45%. Founded in 2015 by Arthur Valkieser and Sabine Stuiver, the company won CES 2020's 'Best of the Best' award and a 2022 UN WIPO Global Award, and sells decentralized greywater systems to homeowners, developers and the hospitality sector worldwide.
OptiRTC (Opti)
Opti (OptiRTC, Inc.) is a Boston-area software company that makes stormwater infrastructure smart. Its cloud platform - built around a technique it calls Continuous Monitoring and Adaptive Control (CMAC) - links sensors, valves, and weather forecasts to actively move water in ponds, tanks, and detention systems before, during, and after storms. Spun out of engineering consultancy Geosyntec in 2014 and acquired by global infrastructure firm Aliaxis in 2022, Opti helps cities, utilities, developers, and engineers cut flooding, reduce combined-sewer overflows, and improve water quality with existing infrastructure rather than costly new construction.
Epic Cleantec
Epic Cleantec is a San Francisco cleantech company that builds onsite water reuse systems for buildings, letting towers and campuses recycle up to 95% of their own wastewater into clean non-potable water, recovered heat energy, and organic soil products. Its OneWater platform installs treatment in the basement so showers, sinks, and laundry water get reused on site instead of flushed to a distant plant. The company got famous for turning recycled building water into commercial beer, and it counts high-rise developers as its core customers.
Porifera
Porifera builds forward osmosis membrane systems that concentrate beverages and treat wastewater without heat or pressure. Its proprietary PFO technology removes water from juices, coffee, beer and wine while preserving flavor, aroma and color - cutting energy use up to 80% versus conventional evaporators. In 2025 the company launched Draftfox, a beer concentration and Microkeg dispense system that shrinks a keg by 6x.
Gradiant
Gradiant is an MIT spinout turned global water-technology company that designs, builds, and operates advanced systems to treat, reuse, and recover industrial water and wastewater. Using a stack of proprietary technologies - from Carrier Gas Extraction to Counterflow Reverse Osmosis and an AI control layer called SmartOps - Gradiant helps semiconductor fabs, food and beverage giants, pharmaceutical makers, miners, and refiners cut freshwater use, recover lithium and other minerals, and destroy 'forever chemicals.' The first unicorn in the water industry, it reached a $2 billion valuation in 2026.
Woodard & Curran
Woodard & Curran is a 100% employee-owned environmental engineering and consulting firm founded in 1979 and headquartered in Portland, Maine. With roughly 1,300 employees across 30+ offices in 14 states, the firm integrates engineering, science, design-build, and operations to solve complex water and environmental challenges for municipal, industrial, and government clients. From treating 11.7 billion gallons of drinking water annually to cleaning up Superfund contamination sites, Woodard & Curran positions itself as the firm that takes on the hard problems in water infrastructure and environmental health — not as a contractor but as a long-term partner.