Diane and Michael Bumstead find their refuge from the stresses of civilization on the rocky shores of Lopez Island, 27 miles from Bellingham Bay. For years, the Bumsteads vacationed in a tiny lodge Michael’s father built in the 1940s. To accommodate a growing family, the couple recently decided to build a larger cabin on their property. Preparations were made and development was underway. Then disaster struck.
Salinity testing showed the Bumstead’s well water was too salty to drink. They had to find another freshwater source or give up their home. In need of clean H2O, the couple did what a rising number of communities facing water shortages around the world are doing: they turned their attention and their checkbooks to the sea.
This story is familiar for residents of the San Juans. Lopez Island’s population has grown roughly 20 percent since the year 2000, and so have pressures on the island’s freshwater resources. The decline in available drinking water means many of the island’s inhabitants–including the Bumsteads–may be forced to move.
At present, 6 percent of San Juan Islanders get their drinking water via desalination - the process of turning saltwater into freshwater. While some promoters hail the practice as the answer to freshwater woes, others are concerned. Desalination releases salty effluent into the sea, is initially more expensive than groundwater sources and may open up untapped coastline to developers. Considering all this, is desalination the answer?
Meet Andrew Evers: consulting engineer and environmentalist. For the last 10 years, his company, Watek LLC, has brought alternative freshwater sources to the San Juan Islands.
"I’ve been to Mexico, Australia and the Middle East – I’ve seen the problems they have over there," Evers said. "As far as Washington and Oregon, there’s so much water here that nobody really thinks about it. But since we [on Lopez] have an isolated case where we have no rivers, we have no reliable supply of water. We fit with the rest of the world and their water shortage–trying to meet population demand and growth."
As Evers said, many parts of the world are facing water supply problems. In the United States alone, large cities like Santa Barbara, Calif., and Tampa Bay, Fla., began large-scale desalination projects in the 1990s in response to droughts and shortages.
On Lopez, Watek specializes in what’s called seawater reverse osmosis–a type of desalination that pushes saltwater at high pressure through a series of membranes, separating the water molecules from everything else.
Evers pointed out that over 97 percent of the world’s water is found in the oceans. Only a very small fraction of the remaining 3 percent freshwater is accessible to humans. If Evers and other supporters can show that desalination is environmentally safe, coastal communities around the world will have a new, virtually unlimited source of clean, drinkable water.
So what’s happening to the freshwater supply on Lopez Island? Ronald Mayo, a former water consultant for San Juan County, is concerned about seawater intrusion. Freshwater is contained in the ground in what is known as an aquifer. When water in the aquifer has been pumped out faster than rainfall can replace it, the level of the aquifer drops and the connected well runs dry. If the well sits on a coastline, gravity eventually pulls the nearby seawater through the soil and into the aquifer.
"Lopez Islanders have over-exceeded the replacement rate of the aquifers, so the freshwater line is receding," Evers said. Humans may not be the only ones affected. Research still needs to be done to understand how seawater intrusion may affect soil quality and vegetation growth.
While Evers said reverse osmosis is a safe and sustainable way to meet freshwater demand, not everyone is convinced.
Doctor Richard Strathmann heads the University of Washington’s biology research laboratory at Friday Harbor on San Juan Island. Like other opponents of reverse osmosis, he is concerned about the negative impact desalination plants may have on marine ecosystems. According to Strathmann, the salty wastewater produced by the plants is usually sent back into the ocean, resulting in a measurable increase in salt concentration.
When the wastewater is mismanaged, as when it is released into a slow-moving current, it can pool on the seafloor and threaten marine life. In a letter response to Ronald Mayo, Strathmann wrote that dense pockets of high-salinity water decrease oxygen levels, making these areas uninhabitable for many marine animals. These dead-zones are unlikely to occur where effluent is released into a fast-moving current, Strathmann said.
Evers acknowledged the risk of waste management. Watek’s research shows that none of their facilities create dead-zones. No independent studies of Watek’s impact exist at this time.
Strathmann is also concerned about potential pollution caused by added chemicals. In Evers’ facilities, no chemicals are added to the wastewater. However, chlorine and calcium are added to the desalinated water. The Washington State Department of Health requires chlorine be added to any public water system to kill bacteria. Calcium is also added to prevent the rusting of pipes used to transport the water.
Watek also requires the cleaning of its desalination equipment to occur off-site. None of the chemicals involved in cleaning are at risk of finding their way into the ocean, according to Evers.
Still, Strathmann remains wary. More research needs to be done in order to understand how desalination effluent affects marine as well as near-shore ecosystems.
For now, the environmental cost of reverse osmosis is up for debate, but there is no question about desalination’s financial expenses.
According to Mayo’s report, a glass of desalinated water will cost the Bumsteads roughly twice as much as a glass of well water. To begin with, Watek charges an average of $300,000 to build a reverse osmosis plant capable of serving up to 40 households–typical for a plant in the San Juan Islands. Well installations serving a handful of homes cost roughly $30,000.
After initial construction costs, a customer’s monthly bill reflects the price of energy, maintenance and repair. Extra steps in the desalination process mean the plants can be expensive to fuel. While renewable energy sources like wind and solar power can provide electricity, the last 30 years saw desalination primarily in oil-rich countries like Saudi Arabia. Recent improvements in efficiency have made the practice more viable for the rest of the developed world.
Energy is initially used to draw seawater uphill, from the ocean to the plant. Once inside, seawater is forced through a large strainer to filter out any visible solids. Since groundwater aquifers do this naturally, this extra step means more energy for reverse osmosis. After the initial filtration, the water is forced against the membranes at high pressure.
According to Watek’s Web site, $1 spent on energy can yield 600 gallons of clean water. Evers also said newly designed energy recapture devices are being installed to recycle energy expended in desalination–resulting in even lower prices for consumers.
More technological improvement means the cost of equipment is falling as well. In 2000, one membrane cost over $5,000. Today’s membranes sell for less than $1,000.
While reverse osmosis desalination may seem more expensive, many Lopez Islanders have no other choice. Rainwater catchment–the process of collecting and purifying rainwater–has become more common, but it is not a reliable source of drinking water during the summer’s dry spells.
"It does cost more, there’s no way around it," Evers said. "Wells are much cheaper, but they’re not sustainable over the long run. Reverse osmosis is virtually limitless."
Mayo said the difficulty is in persuading people that the switch from wells to reverse osmosis is worth the expense. At $300,000 per plant, sharing the initial construction cost between 40 households would come out to $7,500 each–well below the price of installing an individual well capable of serving a fraction of the consumers.
Outside of small communities, where costs are diffused over a wider customer base, prices begin to drop. In Sydney, Australia, large-scale desalination systems only cost customers roughly 5 percent more per month than previously existing water sources. For now, a smaller desalination system spread over fewer customers means Lopez Islanders will pay more for freshwater.
Regardless of the cost, the need for desalination is growing. Evers believes reverse osmosis will replace well water sources in the future.
The Bumstead home was completed in late 2007. Without access to freshwater, their project would not have been possible. The couple’s success has left island conservationists worried. Many are concerned that virtually unlimited access to freshwater will open up the island’s coastline for development.
"By its very nature, desalination promotes development," said Mike Kaill, former professor at the University of the Pacific in Stockton, Calif., and marine aquarium manager for the Port of Friday Harbor. "It means we’ve gone beyond the natural water supply. With this technology, anyone with enough money can move in and start building."
Mayo anticipates Kaill’s apprehension, but thinks development and water issues should be addressed separately. In his view, water policies should not be manipulated to restrict development.
"I’m probably more interested than most in controlling development out here, but to arbitrarily pick out something like reverse osmosis–why not just keep people from drinking surface water?"
There is currently no county-determined protocol in place to ensure the responsible management of reverse osmosis facilities. Kaill anticipates the need for desalination, but wants to see the county hold facility operators responsible for any mismanagement that could adversely affect the island’s ecosystems, such as the irresponsible handling of effluent discharge.
Evers shares Kaill’s concern. To ensure Watek’s plants meet environmental standards, each facility is regulated by a number of federal, state and local permitting agencies. Among them are the U.S. Army Corps of Engineers, the U.S. Department of Fish and Wildlife and the Washington State Department of Ecology.
Although the debate continues, the water scarcity issue needs to be addressed soon.
"One of the biggest problems for the planet right now is that there are too many people," Evers said.
Overuse of traditional water sources has put unnatural strain on rivers and aquifers. Because of that overuse, rivers like the Colorado no longer meet their oceans.
If we do not stop over-pumping these sources, the natural environment will be affected much more than we are, Evers said. He believes desalination is a safe and sustainable way to reduce the pressure on natural sources and provide communities with access to clean water.
"The skeptics say reverse osmosis uses too much energy; we’re polluting our oceans, etc. No matter what we do, we’ll have an impact," Evers said. "Reverse osmosis will reduce our impact on the environment. Just because it’s not zero impact doesn’t mean it’s not a useful tool. It’s better than where we are today."
Alexander Kelly spends most of his time in the Liberal Studies Department. This is his first published piece.