Bringing the Ocean to Your Table

If it were easy, we’d all be drinking seawater. Texas would be fertilizing fields with the ocean, and the deserts in the Middle East would be growing vegetables.

Of the 2% of the earth's water that is fresh, the largest majority is in the polar icecaps.  21% of our .036% of the global fresh water supply is in the Great Lakes in the US. 

What makes getting fresh water from the ocean hard is the energy demands of the technology. But energy has been a major factor in supplying fresh water to citizens for millennia. In China, for thousands of years aqueducts have been used to pump water from the wet south to the dry north, at the cost of untold billions. Recently, China looked at the costs in transport­ing water and began investing heavily in desalination, as a less energy-intensive effort than pumping.

In California, the single largest user of electric energy is the SWP (), which transports water from the Sacramento-San Joaquin Delta to 20 million residents in Southern California. Along that journey, the water trav­els nearly 400 miles and is lifted more than 2,000 feet over the Tehachapi Mountains, at the cost of millions of dollars to ratepayers.

As demands on energy and clean water mount, many around the globe are looking thirstily at the oceans that surround them, realizing that the costs of desalination may pale before expanding, improving and maintaining hundreds — or thou­sands — of miles of water infrastructure.

Thomas Rooney Jr., President and CEO of Energy Recovery, Inc. [NASDAQ: ERII] spends much of his time traveling. Most recently, he was in the Middle East, where desalination has been in use for some time. Some facilities are very old, using highly inefficient technologies such as steam condensation. In other cases, the salts extracted were pumped into stagnant ponds where they became an environmental li­ability. This practice, and others no longer in use, are still rais­ing concerns with environmentalists.

However, installing newer technologies and building more fa­cilities has become a priority for Mideast countries. Many now strive to reduce the high percentage of exportable oil that is used domestically — as much as 30% — by a population with rising incomes and demands on all resources — water and energy among them.


Salt Water Reverse Osmosis Clean Water Desalination today has dramatically evolved over the last ten to fifteen years. The most prevalent technology for desalinating seawater is reverse osmosis: forcing water through a semi-per­meable membrane that extracts salts and other minerals. The process has improved through nano-membranes, along with other advances. However, the pressure needed to push water through the membrane is considerable.

ERII has a proprietary technology that captures water pressure, recycling 98% back into the process, dramatically reducing costs. A simple concept, it is much like heat recovery, whereby utilities use the heat generated in creating electricity to heat buildings or water. However simple the concept, until ERI’s recovery devices, that pressure has been largely lost. As Mr. Rooney said:

“Industry knows how to recycle heat — they do a lot of that. Industry doesn’t know how to recycle pressure. That’s what we do.”

As the simplified diagram at the right shows, the process keeps pres­surized water within a loop, so that it can be used to force more water through the system.

ERI’s most ubiquitous product is three feet long by 12 inches in di­ameter, much the same size as a large fire extinguisher. With 14,000 installed, the company has a 90% market share, with product on all seven continents and all oceans. The latter is partly because luxury ocean liners must have an onboard desalination solution that is energy efficient.

One of their largest installations is in Barcelona, where one plant installed 560 units at one time. For the Chinese and Asian market, ERI is looking at installations that could be calibrated at a million cubic meters per day. On the other end, smaller installations, such as hotels, may treat as little as 300 gallons of water per minute.

You are 60% water. If you weigh 150 pounds, then you are carrying 90 pounds of water.


There are political barriers to desalination, many stemming from poor practices of the past.

  • Re-injection of salts from membrane: Current technologies ensure that salts are distributed into moving currents a half mile from the installation. The salinity is normalized within two feet of the nozzle. While this concern is intuitive, the reality is that were we to desalinate as much as in all our rivers and lakes, we would inject .036% into the 98% of water that is in our oceans.
  • The influx of seawater into a pipe will harm ocean life: The concern is that fish and small mammals may be harmed. However, the installation in Carlsbad, California, estimates the cost to wild life to be similar to introducing 2-3 Pelicans to the ecosystem.
  • Energy consumption: Energy consumption is high, but for many critical situations, not as expensive as long distance water transportation. In the last 15 years, newer technologies have brought energy use down by 60%. With pressure recy­cling, that will drop even more.

These concerns have been heard in other environmentally-conscious countries like Australia and Spain. In Australia, a de­salination plant in Perth took 3 years to get approved. Within a year of operations, the environmental concerns did not ma­terialize. The result is five new plants approved. In California, Mr. Rooney believes that with the completion of the plant in Carlsbad will have the same positive effect in the United States.

The future for ERII goes beyond desalination. The company is expanding into oil and natural gas extraction, as well as other industrial applications. Mr. Rooney sees capturing and reusing pressure as a break-through technology in a world that is in­creasingly concerned about energy.