Arab Press

بالشعب و للشعب
Wednesday, Oct 01, 2025

A wealthy California enclave has some of the purest tap water in the country, and it starts out as sewage

Orange County tap water, which is filtered sewage, is "as clean as water can be," Seth Siegel writes in his new book, "Troubled Water." Here's how.

Orange County tap water is "as clean as water can be," activist Seth Siegel writes in his new book, "Troubled Water."

Things weren't always that way: For decades, seawater was seeping into the community's fresh water supply, threatening to expose residents to excess sodium in their taps.

But in 2008, the county revealed a new system that filters sewage water through microscopic holes and disinfects it with UV light to zap contaminants.

Siegel said the system can be replicated all across the country, even in low-income communities.

Whenever I visit my hometown of Orange County, California, I get to sip some of the purest drinking water in the country.

The quality is sometimes hard to spot, since many drinking water contaminants are odorless, tasteless, and invisible to the human eye. Even in cities where the water is contaminated with lead, residents have reported that their taps are crystal clear.

But in Orange County, the water is actually as clean as it looks.

It wasn't always that way. In his new book, "Troubled Water," activist Seth Siegel explains how Orange County's taps went from having too much saltwater to spouting the purest drinking water in the US.


Saltwater was seeping into Orange County's freshwater supply

Orange County is just 35 miles away from Los Angeles, but it relies on a completely different water system to serve its nearly 3.2 million residents. About a decade ago, that system begin churning out the most pristine water the country has ever seen.

From about the 1930s to the 1970s, farmers over-pumped water through Orange County's underground aquifers, the bodies of porous rock that act as a natural filtration system. The process allowed seawater to seep into the county's freshwater supply — what's known as "saltwater intrusion" — and threatened to expose residents to excess sodium in their taps.

Though scientists are still studying the health effects of too much sodium in drinking water, early research suggests it could lead to hypertension and chronic kidney disease.

Orange County prevented this scenario by getting people to drink recycled water instead.


Now, Orange County tap water starts out as sewage

In 2008, the county unveiled a Groundwater Replenishment System that purifies wastewater from the local sewage system and turns it into clean drinking water.

Many cities have struggled to implement the system due to pushback from local residents who aren't keen on drinking water that originated in their toilets. But more than 4 million Americans — including residents of Dallas, Phoenix, and Atlanta — now get at least a portion of their drinking water from treated sewage.

But Orange County's process is unique because it filters for inorganic contaminants — things like pesticides and industrial chemicals that are hard to detect in water, and may still be allowed under federal law.

The US Environmental Protection Agency currently has drinking water regulations for more than 90 contaminants, but Siegel said more than 100,000 chemicals and pharmaceutical compounds escape regulation.

"What makes Orange County so special is they say, 'Okay, fine, the federal rules are X. We don't really care. We're going to go so far beyond those rules that we're going to make the purest water flow we can possibly have,'" he told Business Insider.


Water gets filtered through invisible holes and zapped with UV light


Orange County's filtration process begins like most "toilet to tap" systems in the US. Household sewage arrives at local wastewater treatment facilities, where it's filtered by screens. Then friendly bacteria is added to get rid of lingering organic material (aka human waste).

Most communities allow this treated water to be discharged into public waterways, but Orange County's process doesn't stop there.

Next, the water heads to the Groundwater Replenishment System, where it passes through another set of filters with holes so tiny that they're invisible to the human eye. Mike Wehner, the assistant general manager at the Orange County Water District, told Siegel that the holes are 150 times smaller than the width of a human hair.

From there, the water goes through reverse osmosis, a process that extracts salt, minerals, chemicals, and pharmaceutical compounds.

The water that emerges is free of minerals, so it's slightly acidic, which means it can corrode local pipes. So the county adds crushed limestone back into the water supply to neutralize the pH. From there, it disinfects the water by zapping it with ultraviolet light. This ensures that not a single molecule of waste can survive.

"It's not fair to say that a contaminant could never possibly be in Orange County's water," Siegel said. But the community's taps, he added, are "as pure as pure can be."


The process could be replicated all over the country


Orange County's "toilet to tap" system was expensive — around $480 million to get off the ground. But Siegel makes the argument in his book that almost any city can replicate the process for cheaper.

In many poor communities, he said, water fees aren't actually used to improve the local water system by investing in water infrastructure and technology. The majority of these fees, he said, go toward the municipal budget.

"Flint actually had the highest water fees in the United States when the crisis broke," Siegel said. "What they did wrong was they diverted money from water fees to the general budget."

Based on his conversation with Wehner, Siegel estimates that having water as pure as Orange County's would cost communities an extra $33 per person per year. (That's after replaying any loans used to build the system, and not including state and federal subsidies.)

As filtration technologies become more advanced, he said, that cost could drop even lower.

"Now that Orange County has led the way and spent fortunes of money to figure it out, everybody can adopt more or less the Orange County system at not a phenomenal expense," Siegel said. "Why isn't everyone doing it? The answer is: because nobody's pushing them to."

Newsletter

Related Articles

Arab Press
0:00
0:00
Close
Altman Says GPT-5 Already Outpaces Him, Warns AI Could Automate 40% of Work
Trump Organization Teams with Saudi Developer on $1 Billion Trump Plaza in Jeddah
Archaeologists Recover Statues and Temples from 2,000-Year-Old Sunken City off Alexandria
Colombian President Petro Vows to Mobilize Volunteers for Gaza and Joins List of Fighters
Nvidia and Abu Dhabi’s TII Launch First AI-&-Robotics Lab in the Middle East
UK, Canada, and Australia Officially Recognise Palestine in Historic Shift
Dubai Property Boom Shows Strain as Flippers Get Buyer’s Remorse
JWST Data Brings TRAPPIST-1e Closer to Earth-Like Habitability
UAE-US Stargate Project Poised to Make Abu Dhabi a Global AI Powerhouse
Saudi Arabia cracks down on music ‘lounges’ after conservative backlash
Saudi Arabia Signs ‘Strategic Mutual Defence’ Pact with Pakistan, Marking First Arab State to Gain Indirect Access to Nuclear Strike Capabilities in the Region
Turkish car manufacturer Togg Enters German Market with 5-Star Electric Sedan and SUV to Challenge European EV Brands
World’s Longest Direct Flight China Eastern to Launch 29-Hour Shanghai–Buenos Aires Direct Flight via Auckland in December
New OpenAI Study Finds Majority of ChatGPT Use Is Personal, Not Professional
Kuwait opens bidding for construction of three cities to ease housing crunch.
Indian Student Engineers Propose “Project REBIRTH” to Protect Aircraft from Crashes Using AI, Airbags and Smart Materials
Could AI Nursing Robots Help Healthcare Staffing Shortages?
Turkish authorities seize leading broadcaster amid fraud and tax investigation
Apple Introduces Ultra-Thin iPhone Air, Enhanced 17 Series and New Health-Focused Wearables
Big Oil Slashes Jobs and Investments Amid Prolonged Low Crude Prices
Social Media Access Curtailed in Turkey After CHP Calls for Rallies Following Police Blockade of Istanbul Headquarters
Gold Could Reach Nearly $5,000 if Fed Independence Is Undermined, Goldman Sachs Warns
Uruguay, Colombia and Paraguay Secure Places at 2026 World Cup
Trump Administration Advances Plans to Rebrand Pentagon as Department of War Instead of the Fake Term Department of Defense
Tether Expands into Gold Sector with Profit-Driven Diversification
Trump’s New War – and the ‘Drug Tyrant’ Fearing Invasion: ‘1,200 Missiles Aimed at Us’
At the Parade in China: Laser Weapons, 'Eagle Strike,' and a Missile Capable of 'Striking Anywhere in the World'
Information Warfare in the Age of AI: How Language Models Become Targets and Tools
Israeli Airstrike in Yemen Kills Houthi Prime Minister
After the Shock of Defeat, Iranians Yearn for Change
YouTube Altered Content by Artificial Intelligence – Without Permission
Iran Faces Escalating Water Crisis as Protests Spread
More Than Half a Million Evacuated as Typhoon Kajiki Heads for Vietnam
HSBC Switzerland Ends Relationships with Over 1,000 Clients from Saudi Arabia, Lebanon, Qatar, and Egypt
Sharia Law Made Legally Binding in Austria Despite Warnings Over 'Incompatible' Values
Dogfights in the Skies: Airbus on Track to Overtake Boeing and Claim Aviation Supremacy
Tim Cook Promises an AI Revolution at Apple: "One of the Most Significant Technologies of Our Generation"
Are AI Data Centres the Infrastructure of the Future or the Next Crisis?
Miles Worth Billions: How Airlines Generate Huge Profits
Zelenskyy Returns to White House Flanked by European Allies as Trump Pressures Land-Swap Deal with Putin
Beijing is moving into gold and other assets, diversifying away from the dollar
Trump Backs Putin’s Land-for-Peace Proposal Amid Kyiv’s Rejection
Zelenskyy to Visit Washington after Trump–Putin Summit Yields No Agreement
Iranian Protection Offers Chinese Vehicle Shipments a Cost Advantage over Japanese and Korean Makers
United States Sells Luxury Yacht Amadea, Valued at Approximately $325 Million, in First Sale of a Seized Russian Yacht Since the Invasion of Ukraine
Saudi Arabia accelerates renewables to curb domestic oil use
Cristiano Ronaldo and Georgina Rodríguez announce engagement
Asia-Pacific dominates world’s busiest flight routes, with South Korea’s Jeju–Seoul corridor leading global rankings
Private Welsh island with 19th-century fort listed for sale at over £3 million
Sam Altman challenges Elon Musk with plans for Neuralink rival
×