Desalination systems based on reverse osmosis technology are increasing the availability and quality of clean drinking water in Toas Island in Lake Maracaibo, Venezuela.

Until recently, the thought of drawing drinking water from the sea to serve the masses was considered largely out of reach due to high costs.   Ten years ago, pulling 1000 U.S. gallons of water from the sea and making it drinkable utilizing reverse osmosis (RO) would cost a municipality close to $5.00. Thanks to advances in technology, the cost has dropped dramatically to roughly $2.00. For the first time, coastal communities are able to draw and desalinate water from the sea for nearly the same price they may used to pay to have clean water piped in from inland freshwater sources. This spells hope for a thirsty world, especially the six billion people who reside in coastal areas.

Developments in RO membrane desalination technology are making the option increasingly attractive from a technical and financial viewpoint. In fact, current estimations of the membrane desalination market show that it will generate $3 billion per year in new business over the next decade, largely due to the falling cost of water produced by RO systems.  

Desalination Brings Water, and Hope, to Venezuelan Community

WET recently implemented a reverse osmosis solution to supply useable water to Toas Island in Venezuela. Toas Island was one of the country's poorest sections in this country. Today, the island enjoys enough fresh water to consider starting a tourist business.

Toas Island is located in the middle of Lake Maracaibo, once one of the world's largest fresh water lakes. For the last 60 years, the lake has been channeled to the sea for freight traffic that over time has allowed seawater intrusion – making it unsuitable for drinking, cooking or other everyday needs.

Island residents were dependent on a corroded water pipeline from the mainland that only ran twice a week for four hours, and a rusted, undependable barge that would make two trips a week for water. That is when it wasn't broken down.  

“To the people on the island, water was like gold,” says Mainor Vega, Business Manager, Latin America, for ITT Industries – Sanitaire Water Equipment Technologies (WET) unit.

This past year, ITT oversaw the complete installation of a reverse osmosis desalinization system that is pumping 1.5 million liters of water to Toas residents every day. One of the key design features is a system that is flexible in its operating parameters.   Depending on tide swings and seasonal shifts, the salt levels in this area of Lake Macacaibo change drastically – ranging from 8,000 parts-per-million (ppm) all the way up to sea water levels of 32,000 ppm. The higher the salinity level, the more pressure is needed to push water through the reverse osmosis membranes. In addition, ITT's system is designed so operators can take constant measurements and make the appropriate pressure adjustments.

The system is also durable enough to handle the mud, silt and suspended particles being pulled in from the lake. ITT Industries' pumps are used to transport the water from the lake to the clarification tanks, the multimedia filtration system and finally to the reverse osmosis systems.

After it was designed, the system had to be transported by boat and truck to the remote island.   The water from the desalination plant is sent through more than 10 kilometers of piping to a 1.5 million liter storage tank located at the highest point of the island. Gravity does the rest, supplying fresh water to the 2,500 households on the island.  

ITT's WET system changed the island on a very human level. “The first day with water, children were outside my window at 2 a.m., playing in the mud because they couldn't believe there was enough extra water to even create mud. The smiles were incredible and very real,” he remembers. The water is transforming the island on a larger scale, too. As a result, the island is thinking of building a tourist business - something that would never be possible without clean, potable water.

Municipalities and Commercial Entities See Promise in Desalination

ITT Industries designed a seawater reverse osmosis system capable of producing drinking water from the Red Sea. The Red Sea has an incredibly high salinity level, approximately 43,000 ppm.   The high salinity level made it imperative for the system designed to not only perform efficiently, but also to be capable of withstanding the harsh conditions of the application. The system is now producing 134,000 gallons per day of high-purity drinking water at the same or better cost than trucked in well water of much higher salinity. Today, almost all the resorts in this area rely on seawater desalting for their water needs.

In the United States, California, Florida and Virginia are among the many states using desalination. With a pending shortage of drinking water, a municipal water utility in Newport News, Virginia employed the technology of a reverse osmosis system to tap a brackish groundwater supply.   With design, technical support and operator training from ITT Industries' WET unit, the municipality was able to quickly augment its safe drinking water supply and enhance the quality of its overall water supply. The facility is capable of producing 5.7 million gallons per day.

Beyond these examples, approximately 9,500 desalination plants worldwide have an aggregate capacity of 8.5 billion gallons per day (32 billion liters). And forecasts from Global Water Intelligence suggest a greater than 100 percent increase in installed global capacity from 2005 to 2015, creating a total market worth $95 billion over the next decade.

Supporting these forecasts is the fact that an RO desalination system marketplace is justifiably anywhere that there is lack of adequate fresh water supplies and a good source of available seawater or brackish water. Essentially there is a candidate for desalination by RO anywhere that there is growth and development and a shortage of clean drinking water.  

In California, Florida, Mid-Atlantic and Gulf States, the Caribbean, Central and South America, the Mediterranean, Middle-East and Pacific Rim (i.e., anywhere there's an ocean and a need), RO desalination is a viable resource for the world's constantly increasing fresh water requirements.

Author:
Jorg Menningmann
General Manager
ITT Industries - Sanitaire Water Equipment Technologies