Hallandale Beach has abandoned six of its eight drinking water wells because saltwater has advanced underground across two-thirds of the city.

“The saltwater line is moving west and there’s very little that can be done about it,” said Keith London, a city commissioner for Hallandale Beach, who has worked on water conservation and reuse for the last decade.

A wall of saltwater is inching inland into the Biscayne Aquifer — the primary source of drinking water for 4.5 million people in South Florida.

A hundred years ago, saltwater intrusion was not a problem in the area. The Everglades seemed to hold more freshwater than residents could ever use.

But then swaths of the “River of Grass” were drained through canals to clear farmland and build single family homes. Utilities have been trying to keep saltwater at bay since the 1930′s. But saltwater has crept in to replace freshwater that drained out to sea.

Now, commissioner London and Hallandale Beach city staff need to secure a new source of . They are working on a deal to dig wells in West Park, another South Broward city about three miles inland. Hallandale would then pipe the fresh water back east.

The project will cost an estimated $10 million, says Earl King, Deputy Director of Hallandale Beach Utilities and Engineering. Residents will eventually pay those capital costs.

New drinking water wells are likely the cheapest alternative, London said. The city could build a reverse osmosis plant to filter out the salt, but the construction and maintenance costs would be astronomical.

“The energy needed to remove the salt would have made water cost 10 times, 100 times more than what we are paying now,” London said.

As the salt front crept inland, municipalities and agencies have restricted water use.

Gulfstream Park racetrack in Hallandale Beach, for example, was prohibited from pulling water from the Biscayne Aquifer in 2005. Gulfstream needs roughly 300,000 gallons every day for their 23-acres of pristine Celebration Bermuda turf.

Gulfstream managers opted to spend $1.5 million on a reverse osmosis filtration system. They pull water from 1,200 feet underground from the Floridan aquifer, a deep, highly-saline section of the aquifer.

The wall of seawater snakes up South Florida’s coast.

In one area in Broward County, the saltwater front is as far as five miles inland. In Miami-Dade, the saltwater reaches the eastern edge of the airport.

“The saltwater is slowly creeping west in cities like Dania Beach, Lake Worth and portions of Fort Lauderdale,” said Scott Prinos a hydrologist with the U.S. Geological Survey in Fort Lauderdale.

Prinos has tracked saltwater intrusion in South Florida for decades and he regularly tests the saltiness of a well dug in the heart of Hallandale Beach in 2005.

“This well, when it was first installed was fairly fresh and it’s become saltier as we’ve been monitoring it,” Prinos said.

He lowers a long hose into a narrow well, pumps water to the surface and sends it back to his lab.

The salt content of this well is thirty times saltier than normal.

The South Florida Water Management District and the U.S. Army Corps of Engineers monitor water control structures along drainage canals to prevent, and in some cases reverse, saltwater intrusion.

“In estuaries, you can see the salinity move inland,” said Susan Sylvester, Director of Operations Control for the SFWMD.

These control structures, like the one along the Miami River, act like a dam. They impound fresh water on one side, and that builds up pressure and pushes away the saltwater.

Commissioner London says saltwater intrusion will eventually touch everyone in South Florida.

It is likely saltwater will continue its westward creep. The USGS reports that sea level in southern Florida is currently rising by three quarters of a foot every century. As ocean levels splashes higher along beaches and canals, saltwater may keep inching inland.

London, 50, became a commissioner in 2006. On a recent Friday morning, he tended his lush garden and watched bees and butterflies suck nectar from white flowers. Despite thick greenery, there isn’t a single sprinkler.

“I have four, 55-gallon rain barrels that I capture rain coming off the roof,” London said.

London waters his garden with rain he has captured in his giant white plastic barrels. He curated his garden over the past 20 years so he does not need to use tap water.

“If everybody had one or two rain barrels, we could save millions, literally millions gallons of water a day,” London said.

Our water use in the past, said London — namely the drainage canals — led to the salty drinking water we have today.

“We’re all on this one little planet,” London said, “and what I do today is going to impact someone else down the road.”

Michael Waalkes, Ph.D., and his team at the National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, part of NIH, had shown previously that normal cells become cancerous when they are treated with inorganic arsenic. This new study shows that when these cancer cells are placed near, but not in contact with normal stem cells, the normal stem cells very rapidly acquire the characteristics of cancer stem cells. It demonstrates that malignant cells are able to send molecular signals through a semi-permeable membrane, where cells can’t normally pass, and turn the normal stem cells into cancer stem cells.

“This paper shows a different and unique way that cancers can expand by recruiting nearby normal stem cells and creating an overabundance of cancer stem cells,” said Waalkes. “The recruitment of normal stem cells into cancer stem cells could have broad implications for the carcinogenic process in general, including tumor growth and metastases.”

This reveals a potentially important aspect of arsenic carcinogenesis and may help explain observances by researchers working with arsenic that arsenic often causes multiple tumors of many types to form on the skin or inside the body. The paper is online in Environmental Health Perspectives.

Waalkes’ lab started working with stem cells about five years ago. The researchers used a prostate stem cell line, not embryonic stem cells.

“Using stem cells to answer questions about disease is an important new growing area of research. Stem cells help to explain a lot about carcinogenesis, and it is highly likely that stem cells are contributing factors to other chronic diseases,” Waalkes said.

Stem cells are unique in the body. They stay around for a long time and are capable of dividing and renewing themselves. “Most cancers take 30 or 40 years to develop,” said Linda Birnbaum, Ph.D., director of NIEHS and NTP. “It makes sense that stem cells may play a role in the developmental basis of adult disease. We know that exposures to toxicants during development and growth can lead to diseases later in life.”

Next, the laboratory team will look to see if this finding is unique to arsenic or if it is applicable to other organic and inorganic carcinogens.