Myths vs. realities: Water reuse & recycled water systems — what the evidence actually supports

Recycled water is often dismissed as an inferior, unsafe, or prohibitively expensive alternative to conventional supplies. Yet across the United States, more than 3.4 billion gallons of treated wastewater are reused daily, serving agriculture, industrial cooling, landscape irrigation, and increasingly, direct potable applications. Despite this operational track record spanning decades, persistent myths continue to slow adoption at a time when water scarcity is intensifying across every major US watershed. This article examines the most common misconceptions about water reuse, weighs them against peer-reviewed evidence and operational data, and provides investors and practitioners with the clarity needed to evaluate recycled water projects on their merits.

Why It Matters

The US faces a widening gap between water demand and available supply. The Bureau of Reclamation estimates that by 2030, demand in the western states alone will exceed supply by approximately 3.2 million acre-feet annually. Groundwater aquifers that supply drinking water to more than 140 million Americans are declining at accelerating rates, with the Ogallala Aquifer losing water 10 times faster than natural recharge. Meanwhile, population growth in arid regions continues: Arizona, Nevada, and Texas collectively added over 3 million residents between 2020 and 2025.

Water reuse offers a drought-proof, locally controlled supply that reduces dependence on imported water and overtaxed aquifers. The WateReuse Association estimates that the US currently reuses less than 12% of its treated municipal wastewater, compared to Israel's 87% reuse rate. Closing even half of that gap would yield approximately 6 billion additional gallons per day, enough to supply 20 million households.

Regulatory momentum is accelerating. California's State Water Resources Control Board adopted direct potable reuse regulations in December 2023, establishing a framework for utilities to blend highly treated recycled water directly into drinking water systems. EPA released the National Water Reuse Action Plan in 2020, with updated milestones through 2026 emphasizing potable reuse pathways. The Bipartisan Infrastructure Law allocated $11.7 billion for water infrastructure, with significant portions eligible for reuse projects. For investors evaluating water infrastructure, understanding what the evidence actually supports about recycled water quality, cost, and public acceptance is essential for sound capital allocation.

Key Concepts

Direct Potable Reuse (DPR) involves treating wastewater to drinking water standards and introducing it directly into a potable water distribution system or into a raw water supply immediately upstream of a drinking water treatment plant. DPR eliminates the need for environmental buffers (reservoirs or aquifers) used in indirect potable reuse. Advanced treatment trains for DPR typically include microfiltration, reverse osmosis, and UV/advanced oxidation, producing water that exceeds federal drinking water standards across all regulated contaminants.

Indirect Potable Reuse (IPR) treats wastewater to high standards and then introduces it into an environmental buffer, such as a groundwater aquifer or surface reservoir, before it enters the drinking water supply. IPR has been practiced in the US for over 60 years. Orange County Water District's Groundwater Replenishment System, operational since 2008, is the world's largest IPR facility, producing 130 million gallons per day.

Non-Potable Reuse applies treated wastewater to applications that do not require drinking water quality, including agricultural irrigation, landscape watering, industrial cooling, toilet flushing, and environmental restoration. Non-potable reuse accounts for approximately 65% of all US water reuse by volume and faces fewer regulatory barriers than potable applications.

Advanced Treatment Trains combine multiple barrier technologies in sequence to remove contaminants. A typical advanced water purification facility uses three to five treatment steps: membrane bioreactor or secondary treatment, microfiltration, reverse osmosis, UV disinfection with advanced oxidation (hydrogen peroxide), and post-treatment stabilization. Each barrier independently reduces contaminant concentrations by 99% or more, providing redundancy that ensures safety even if one process underperforms.

Water Reuse Performance Benchmarks

Metric	Non-Potable Reuse	Indirect Potable Reuse	Direct Potable Reuse	Desalination
Treatment Cost ($/acre-foot)	$400-800	$800-1,500	$1,200-2,000	$1,800-3,200
Energy Use (kWh/acre-foot)	500-1,200	1,200-2,500	1,500-2,800	3,500-5,500
Total Dissolved Solids Removal	30-50%	95-99%	95-99%	99%+
Pharmaceutical Removal	Variable	>99%	>99%	>99%
Capital Cost ($/gpd capacity)	$3-8	$8-15	$10-18	$12-22
Drought Reliability	High	High	High	High
Carbon Footprint (kg CO2/acre-foot)	150-400	400-900	500-1,000	1,200-2,500

What's Working

Orange County Water District Groundwater Replenishment System

The world's largest water recycling facility for indirect potable reuse produces 130 million gallons per day, enough to supply water for 1 million people in Orange County, California. Since its launch in 2008 and expansion in 2015 and 2023, the system has recharged more than 400 billion gallons into the local groundwater basin. Operating costs run approximately $1,100 per acre-foot, roughly 40% less than the cost of imported water from the Metropolitan Water District of Southern California. Independent water quality monitoring by the California Division of Drinking Water has consistently shown that the purified water exceeds all state and federal drinking water standards. The facility's energy consumption of approximately 1,500 kWh per acre-foot is less than half that of seawater desalination.

City of El Paso Advanced Water Purification Facility

El Paso, Texas, opened the US's first direct-to-distribution potable reuse demonstration facility in 2016 and began planning its full-scale Advanced Water Purification Facility in 2022. The city blends advanced purified water into its drinking water system after treatment through microfiltration, reverse osmosis, UV/advanced oxidation, and granular activated carbon. Monitoring data published by El Paso Water showed that contaminant levels for 300+ tested parameters were below detection limits or far below regulatory thresholds. The facility addresses El Paso's declining Hueco Bolson aquifer, which has lost more than 30% of its capacity since 1950.

Hampton Roads Sanitation District SWIFT Program

Virginia's Hampton Roads Sanitation District launched the Sustainable Water Initiative for Tomorrow (SWIFT) in 2018 to address aquifer depletion and land subsidence in the Hampton Roads region. The program treats wastewater through advanced processes and injects it into the Potomac Aquifer, simultaneously replenishing groundwater and reducing nutrient pollution discharged to the Chesapeake Bay. The SWIFT Research Center demonstrated that injected water meets or exceeds all drinking water standards. The full-scale program, under construction with completion planned for 2030, will treat up to 100 million gallons per day. This project illustrates how water reuse can simultaneously address multiple environmental challenges: water supply, aquifer recovery, and nutrient pollution reduction.

What's Not Working

Fragmented State-Level Regulation

Water reuse regulation varies dramatically across US states, creating uncertainty for project developers and investors. As of 2025, only 10 states have established comprehensive potable reuse frameworks. Many states lack any regulatory pathway for direct potable reuse, not because of safety concerns but because regulators have not yet developed rules. This patchwork creates project delays of 2-5 years while utilities work with state agencies to establish permitting frameworks. Federal guidance from EPA has been voluntary rather than prescriptive, leaving gaps that slow nationwide adoption.

Public Perception Barriers

Despite strong safety records, public resistance (commonly labeled the "toilet-to-tap" concern) remains a significant barrier. A 2024 survey by the Water Research Foundation found that while 60% of Americans accept indirect potable reuse, only 38% initially accept direct potable reuse. However, the same survey found that acceptance increases to 72% after respondents receive factual information about treatment processes and water quality data. Utilities that invest in sustained community engagement and transparent monitoring programs consistently achieve higher public support. San Diego's Pure Water program overcame initial resistance through a decade-long outreach campaign, ultimately winning 73% public approval.

Capital Funding Gaps

Advanced water purification facilities require significant capital investment, typically $10-18 per gallon per day of capacity. A 50 million gallon per day DPR facility can cost $500 million to $900 million. While the Bipartisan Infrastructure Law and EPA's Water Infrastructure Finance and Innovation Act (WIFIA) program provide low-interest financing, many smaller utilities lack the technical capacity to navigate federal funding applications or the ratepayer base to support large capital programs. The result is that reuse adoption concentrates among large, well-resourced utilities while smaller communities facing water stress are left behind.

Myths vs. Reality

Myth 1: Recycled water is unsafe to drink

Reality: Advanced purified water consistently meets or exceeds all EPA Safe Drinking Water Act standards. Multiple independent studies, including a comprehensive 2024 review by the National Water Research Institute, found that advanced treated recycled water contains lower concentrations of regulated contaminants, pharmaceuticals, and microplastics than most conventional drinking water sources. The multi-barrier treatment approach (microfiltration, reverse osmosis, UV/AOP) removes contaminants more thoroughly than conventional surface water treatment. Orange County's system has produced over 400 billion gallons without a single regulatory violation.

Myth 2: Water reuse is more expensive than traditional supply

Reality: In water-scarce regions, recycled water is increasingly the lowest-cost new supply option. Orange County produces purified water at approximately $1,100 per acre-foot, compared to $1,600-2,000 per acre-foot for imported water and $2,200-3,200 per acre-foot for seawater desalination. Even where recycled water costs more than existing supplies, it provides drought-proof reliability that imported water cannot match. When factored against the economic damage of water curtailments (estimated at $50-150 per acre-foot in lost agricultural output), reuse economics become even more favorable.

Myth 3: Only arid regions benefit from water reuse

Reality: Water reuse provides value across diverse climates. Hampton Roads, Virginia (average annual rainfall of 46 inches) is investing over $1 billion in its SWIFT reuse program to address aquifer depletion and reduce nutrient pollution in the Chesapeake Bay. Florida, with abundant rainfall, reuses more water than any state except California, primarily for landscape irrigation and aquifer recharge. Water reuse addresses infrastructure capacity constraints, environmental discharge requirements, and supply resilience regardless of regional precipitation levels.

Myth 4: Recycled water requires enormous energy consumption

Reality: Advanced water purification for potable reuse typically requires 1,200-2,800 kWh per acre-foot, which is 40-60% less energy-intensive than seawater desalination (3,500-5,500 kWh per acre-foot). Non-potable reuse applications require 500-1,200 kWh per acre-foot, comparable to or less than the energy cost of pumping water from distant surface supplies. Several facilities, including Orange County's GWRS, have integrated on-site renewable energy and biogas cogeneration from the adjacent wastewater treatment plant, further reducing net energy consumption and carbon intensity.

Myth 5: The public will never accept drinking recycled water

Reality: Public acceptance of potable reuse has increased steadily over the past decade. Communities with operational reuse programs, including Orange County, El Paso, and Windhoek, Namibia (which has practiced direct potable reuse since 1968), consistently report high satisfaction and trust levels. San Diego's Pure Water program overcame fierce initial opposition through transparent engagement, ultimately achieving 73% public approval. Research published by the Water Research Foundation shows that hands-on experience, clear communication about treatment processes, and third-party water quality verification are the most effective strategies for building acceptance.

Key Players

Leading Utilities

Orange County Water District operates the world's largest advanced water purification facility for indirect potable reuse, with 130 million gallons per day capacity and plans for further expansion.

El Paso Water is pioneering full-scale direct potable reuse in the US, with decades of experience managing arid-region water supplies and a strong public engagement track record.

San Diego Pure Water is constructing North America's largest potable reuse program, targeting 83 million gallons per day by 2035 to supply one-third of the city's water needs from local recycled sources.

Technology Providers

Xylem provides advanced treatment technologies including membrane filtration, UV disinfection, and ozone systems used in major reuse installations globally.

Suez/Veolia operates water reuse facilities across the US and globally, with integrated engineering, construction, and operations capabilities for advanced treatment trains.

Trojan Technologies (now part of Xylem) supplies UV/AOP systems that serve as critical barriers in potable reuse treatment trains, installed in more than 200 water reuse facilities worldwide.

Investors and Funders

US EPA WIFIA Program provides low-interest federal loans for water infrastructure, with recycled water projects among the largest funded categories.

California State Revolving Fund offers low-interest financing specifically prioritizing water reuse and recycling projects.

XPV Water Partners is a dedicated water-sector private equity fund investing in treatment technology companies and water infrastructure across North America.

Action Checklist

• Evaluate current water supply portfolio vulnerability to drought, regulatory curtailments, and cost escalation for imported water
• Assess local and state regulatory frameworks for non-potable and potable reuse permitting pathways
• Review available wastewater effluent volumes and quality from local treatment facilities as potential reuse feedstock
• Conduct lifecycle cost analysis comparing reuse against desalination, imported water, and aquifer storage and recovery
• Engage early with public health regulators and community stakeholders to build understanding and support
• Investigate federal and state financing options including WIFIA, State Revolving Funds, and Bipartisan Infrastructure Law allocations
• Require independent third-party water quality monitoring and transparent public reporting for any potable reuse project
• Plan for 3-5 year project development timelines including permitting, environmental review, and community engagement

FAQ

Q: Is recycled water truly safe for drinking? A: Yes. Advanced treatment trains used in potable reuse (microfiltration, reverse osmosis, UV/advanced oxidation) remove contaminants more completely than conventional drinking water treatment. Independent monitoring at facilities like Orange County's GWRS has confirmed compliance with all Safe Drinking Water Act standards across more than 400 billion gallons produced. The National Water Research Institute's 2024 review concluded that advanced purified water poses lower health risk than most conventional surface water supplies.

Q: How does the cost of recycled water compare to other new supply options? A: Recycled water for potable reuse typically costs $1,200-2,000 per acre-foot, which is significantly less than seawater desalination ($2,200-3,200 per acre-foot) and increasingly competitive with imported water in regions facing supply constraints. Non-potable reuse costs $400-800 per acre-foot. When drought reliability and avoided curtailment costs are factored in, reuse is frequently the most cost-effective new supply option for water-scarce regions.

Q: What are the biggest barriers to scaling water reuse in the US? A: Three primary barriers persist. First, fragmented state regulation creates uncertainty and delays permitting; a unified federal framework would accelerate adoption. Second, capital costs for advanced treatment facilities are substantial ($500 million or more for large systems), requiring access to low-interest financing. Third, public perception remains a challenge, though evidence shows that sustained education and transparent monitoring programs effectively increase acceptance rates.

Q: How does water reuse fit into a climate adaptation strategy? A: Recycled water provides drought-proof, locally controlled supply that reduces dependence on climate-vulnerable imported water and declining aquifers. It enables communities to close the water cycle, turning wastewater from a disposal challenge into a resource. Water reuse also reduces nutrient pollution discharged to waterways, supports aquifer recovery, and can be paired with renewable energy to minimize carbon intensity. For investors, reuse represents infrastructure resilience with predictable demand and regulatory tailwinds.

Q: What regulatory changes should investors monitor? A: Key developments include California's direct potable reuse regulations (effective 2023, with implementation guidance through 2026), EPA's ongoing update of the Water Reuse Action Plan, state-level adoption of potable reuse frameworks (Texas, Florida, Arizona, Virginia, and Colorado are all advancing regulations), and potential federal standards for direct potable reuse. The Bipartisan Infrastructure Law funding timelines and WIFIA program allocations also affect project financing availability through 2030.

Sources

• National Water Research Institute. (2024). Independent Advisory Panel Review: Potable Reuse Water Quality and Public Health. Fountain Valley, CA: NWRI.
• Water Research Foundation. (2024). Public Perception of Potable Water Reuse: National Survey Results. Alexandria, VA: WRF.
• Orange County Water District. (2025). Groundwater Replenishment System Annual Report: Water Quality and Operational Performance. Fountain Valley, CA: OCWD.
• US Environmental Protection Agency. (2024). National Water Reuse Action Plan: 2024 Progress Report. Washington, DC: EPA.
• Bureau of Reclamation. (2023). SECURE Water Act Report to Congress: Water Supply and Demand Analysis. Washington, DC: US Department of the Interior.
• Hampton Roads Sanitation District. (2024). SWIFT Research Center: Water Quality Monitoring and Aquifer Recharge Results. Virginia Beach, VA: HRSD.
• WateReuse Association. (2025). State of Water Reuse in the United States: 2025 Annual Report. Alexandria, VA: WateReuse.