CAPE MAY — Carl Behrens elevates his voice over the din of high-pressure pumps that squeeze salty water though tiny polymer membranes and create fresh water.
Behrens, plant operator at the city’s $5 million desalination plant, is like a high school science teacher as he draws charts and graphics to explain how the plant works. The simple version is that well water with high levels of chlorides and sodium —salts — are pushed through membranes that are wound tightly into cylinders.
The openings in the membranes are just .22 microns. A micron, Behrens explains, is about one-thousandth of 1 millimeter.
End result? Water that is 99.83 percent water — the highest percentage most people will ever drink. It’s so clean it has no taste at all. It’s so clean the city has entered it in water competitions and won.
“In my opinion, we have the best water in New Jersey,” Behrens yells above the noise.
Each minute Behrens talks, the city produces another 650 gallons. The plant has two skids full of the cylindrical membranes. Each skid is about the size of a tractor-trailer and capable of processing 968,000 gallons per day.
For a city that needs an average of 1.4 million gallons per day, with peaks of 2.8 million gallons on a summer day, the desalination plant that opened 14 years ago, in September 1998, has turned out to be the answer. It was the first to open in New Jersey, and there are still only two of them.
But at the time, the plant was considered a huge gamble.
Fred Sickels, who directs the state Department of Environmental Protection’s Division of Water Supply and Geoscience, credited the city for doing a thorough analysis of the situation and making a reasonable decision at the time.
“We’re happy with the plant. They’re doing a good job and they showed that desalination can work under the proper conditions and in certain circumstances,” Sickels said.
While the city was the first in the northeast to construct such a plant, Pierre Lacombe, a hydrologist with the U.S. Geological Survey, said others are considering them in sandy coastal regions, including towns on Cape Cod and Martha’s Vineyard.
Cape May’s big decision
During much of the last century, salt chased the city’s Water Department farther inland and deeper into the ground as one well after another went bad from pumping too close to the ocean. When pumping is done near salt water, it draws that water in.
The city once had artesian water that bubbled out of the ground, but by 1910 it had to abandon surface water wells. In 1940, it had to dig even deeper to avoid salts. Those deep wells were abandoned in 1962. In 1950, the city moved inland and dug wells on Canning House Lane — which is in Lower Township south of the Cape May Canal — but several of these wells have gone salty.
By 1998, salt levels were rising in the city’s last fully functioning well, Well No. 5, in the 560-foot deep Cohansey Aquifer. The city responded by digging two new deeper wells in the Atlantic City 800-Foot Sands Aquifer and building a plant that would use pumps to force this salty water through a series of membranes whose openings are so small that salts and other dissolved solids are prevented from going through.
Mayor Ed Mahaney said planning for the plant began when he took office in 1995, and he remembers doctors telling their patients not to drink the city’s water because it was high in chlorides and sodium. Potable water must be below 250 parts per million of chlorides and 50 parts per million of sodium.
The city at that point was purchasing some water from neighboring Lower Township. It also blended water from different wells to keep salt levels below the thresholds for potable water.
Back then, the city worried about a future where it had to buy all its water.
“In the 1980s and 1990s we got ongoing complaints about the quality of our water. Now, we don’t get those complaints at all and we now have a supply. The desalination plant has moved us into a position of water supply leadership. We do have control of our own destiny,” said Mahaney.
Salt-lite water is key
Energy is the big drawback: When officials got the first electric bills after the plant started operating they were in shock.
“At $250,000 a year, it’s the single largest energy component in our budget,” Mahaney said.
The city initially had a deal to run off peak times to reduce energy costs, but Mahaney said this was eliminated during some electric company mergers.
But it could have been worse if the city had not drilled several deep wells 860 feet down in the Atlantic City 800-Foot Sands Aquifer, which had only slightly salty water.
Behrens said pure seawater has chloride levels of 22,000 parts per million. Behrens said pure seawater would require pumps to run at 1,200 to 2,000 pounds per square inch. This would add greatly to energy costs.
The city uses pumps that operate at about 200 pounds per square inch. For every 100 gallons the city processes, it gets about 68 gallons of clean water with the salty discharge going to Cape Island Creek.
Desalinated water is not cheap.
When the desalination plant went online the cost to produce water rose from 70 cents to $1.80 per 1,000 gallons, but Behrens noted at $101.25 per quarter for the average user, it is only about $20 more per quarterly bill than nearby water utilities.
Cape May is now exploring wind turbines and solar panels to defray the costs.
The future
As the salt content in the last conventional well, Well No. 5, continues to rise, officials are also considering the future.
Currently, the water from this well is blended with the desalination output, accounting for up to 1 million gallons per day, Behrens said. Without this well, the city would not have enough water at peak times.
Mahaney said one option is to direct Well 5 water to the desalination plant, but that would require DEP approval.
“The DEP is cautious with the Cohansey. We could affect neighboring communities’ wells. They don’t want anybody hastening their demise,” Mahaney said.
Mahaney said another option is to drill another deep well in the Atlantic City 800-Foot Sands Aquifer. Behrens said desalination capacity could easily be added.
The city has even experimented with producing extra desalination water and recharging one of its old Cohansey Aquifer wells, Well No. 4, but ran into problems as the water was pulling too much iron out of underground clay layers.
Behrens wants to the revisit recharging Well No. 4, something Wildwood has done since the 1950s when it became the first in the nation to use this approach. Water can be pumped in the off season and used to recharge wells — a process known as Aquifer Storage and Recovery — that are tapped in the summer.
Lacombe said he has no doubt solutions will be found.
“They ran into problems for 100 years, and for 100 years they found solutions,” Lacombe said.
Contact Richard Degener:
609-463-6711
