Desalination Plants Produce More Brine Than Fresh Water

The plants provide much-needed fresh water, but the environmental costs are immense.

1 minute read

January 22, 2019, 2:00 PM PST

By Camille Fink


Desalination

Andrea Izzotti / Shutterstock

Tik Root reports on a new study in the journal Science of the Total Environment about the outputs of desalination plants:

The literature had long assumed a one-to-one ratio. But [Manzoor] Qadir’s study found that the average desalination plant actually produced 1.5 times more brine than desalinated water—fifty percent more than previously thought. That translates to 51.8 billion cubic meters of brine each year, which Qadir says is enough to cover all of Florida, a foot deep.

Root notes that 16,000 plants are currently in operation or under construction around the world. The facilities are costly to operate, require large amounts of energy, and produce significant emissions. But the brine especially concerns scientists because of the effects of the salinity and temperature of the water and because copper and chlorine used during desalination ends up in the discharge. 

Some observers believe that the brine is not a huge problem because it can be disposed of safely, but others say the problem runs deeper. "[John] Burt adds that while regulation can help mitigate these risks, enforcement varies widely from place to place. And, in the Arabian Gulf, where nearly half of the world’s desalination occurs, he says oversight tends to be relatively weak," writes Root.

Monday, January 14, 2019 in National Geographic

portrait of professional woman

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching. Mary G., Urban Planner

I love the variety of courses, many practical, and all richly illustrated. They have inspired many ideas that I've applied in practice, and in my own teaching.

Mary G., Urban Planner

Cover CM Credits, Earn Certificates, Push Your Career Forward

Aerial view of town of Wailuku in Maui, Hawaii with mountains in background against cloudy sunset sky.

Maui's Vacation Rental Debate Turns Ugly

Verbal attacks, misinformation campaigns and fistfights plague a high-stakes debate to convert thousands of vacation rentals into long-term housing.

July 1, 2025 - Honolulu Civil Beat

Logo for Planetizen Federal Action Tracker with black and white image of U.S. Capitol with water ripple overlay.

Planetizen Federal Action Tracker

A weekly monitor of how Trump’s orders and actions are impacting planners and planning in America.

July 2, 2025 - Diana Ionescu

White and purple sign for Slow Street in San Francisco, California with people crossing crosswalk.

San Francisco Suspends Traffic Calming Amidst Record Deaths

Citing “a challenging fiscal landscape,” the city will cease the program on the heels of 42 traffic deaths, including 24 pedestrians.

July 1, 2025 - KQED

Google street view of red brick multi-story power plant building in Pittsburgh, PA.

Defunct Pittsburgh Power Plant to Become Residential Tower

A decommissioned steam heat plant will be redeveloped into almost 100 affordable housing units.

July 4 - Pittsburgh Post-Gazette

Cyclist on protected bike lane in middle of street in Washington D.C. with Washington Monument obelisk visible in background.

Trump Prompts Restructuring of Transportation Research Board in “Unprecedented Overreach”

The TRB has eliminated more than half of its committees including those focused on climate, equity, and cities.

July 4 - Streetsblog USA

Blue and silver Amtrak train at small station.

Amtrak Rolls Out New Orleans to Alabama “Mardi Gras” Train

The new service will operate morning and evening departures between Mobile and New Orleans.

July 3 - New Orleans City Business