Climate Change Could Increase 'Saltwater Intrusion'

Guest Blog By Andy Reid, Sun Sentinel, September 12, 2011 Summer rains can't wash away a growing underground threat to South Florida's water supply. Saltwater seeping in from the ocean keeps spreading farther west, threatening to foul underground freshwater supplies that provide most of South Florida's drinking water. "Saltwater intrusion" in South Florida has worsened through the decades as providing water and flood control for a growing population siphons away freshwater and allows more saltwater to seep into aquifers and well fields. Ninety percent of South Florida gets its drinking water from underground supplies, most from the Biscayne aquifer. Pumping too much water from underground supplies can allow saltwater to push in from the coast. Droughts can make saltwater intrusion worse as pumping to provide drinking water continues while rains don't come to replenish underground freshwater supplies. Now South Florida officials are projecting that sea-level rise due to climate change could increase the reach of saltwater that can make water from community wells undrinkable. That has city and county utilities along the southeast Florida coast exploring expensive alternatives, with costs passed along to ratepayers, to avoid getting cut off from freshwater. "It is still progressing westward," Hector Castro, Hallandale Beach public works and utilities director, said. "Eventually all coastal communities will deal with this in some way, shape or form." Hallandale Beach, Pompano Beach, Dania Beach, Lantana and Lake Worth are among local cities that in recent years have been most at risk from saltwater intrusion. But the line of saltwater spreading inland comes close to or reaches cities from Jupiter to Florida City, including West Palm Beach, Delray Beach, Boca Raton, Fort Lauderdale, Hollywood and Miami, according to theU.S. Geological Survey. Reducing well-field pumping, moving well fields farther inland and requiring utilities to pursue alternative water supplies have helped hold the line of saltwater intrusion in some areas and even push it back east. "It's a serious threat," said Pete Kwiatkowski, South Florida Water Management District water-shortage incident commander. "That saltwater front is very dynamic (and) it does shift." Six of the eight wells that Hallandale Beach relies on have been closed through the years due to saltwater intrusion. That's because 85 percent of the city is within the area where saltwater has seeped in, Castro said. As a result, the city pays to get half of its water from Broward County's western well fields and is working on a deal for new western wells of its own. Hallandale Beach proposes building six new wells and new water lines in West Park for about $10 million. Operating them over 40 years would cost about $36 million, Castro said. "Any given day, if we were to pull too much water … we could lose another well," Castro said. Instead of building well fields farther inland, some utilities build new water plants capable of tapping into and treating deeper, saltier underground water supplies. Lake Worth recently completed a $24 million reverse osmosis water plant to keep 5 million to 7 million gallons of water a day flowing, without threats from saltwater. Lake Worth also has stricter once-a-week landscape-watering limits intended to cut water use and help avoid saltwater intrusion. Rising sea levels are expected to add to the spread of saltwater intrusion, said Jennifer Jurado, Broward County director of natural resources planning and management. Man-made pollution produces more carbon dioxide and other heat-trapping greenhouse gases that capture the sun's heat, leading to climate change. Increased temperatures mean melting ice sheets and swelling oceans, projected to bring rising sea levels. South Florida sea levels rose about 8 inches during the past 100, but are projected to increase between 9 and 27 inches over the next 60 years, according to Jurado. That would lead to more saltwater forcing its way into freshwater supplies, she said. "Potable water supply is obviously a major concern long-term," said Jurado. Building water plants capable of converting ocean water into drinking water is one alternative that so far South Florida utilities have deemed too expensive. Making better use of regional water supplies could help beat back saltwater intrusion, said Ron Nunes, chairman of the Southeast Florida Utility Council, which represents water providers serving nearly 5 million residents. Flood control for cities and farms built on what used to be the Everglades leads to draining nearly two billions of gallons of storm water out to sea each day after a typical South Florida summer rainstorm. More of that storm water should be redirected to beef up groundwater levels depleted by decades of draining and paving land that once held water and naturally replenished the aquifer, Nunes said. "The biggest issue is the water is there and it is all going out to sea," Nunes said. "Why can't it be re-engineered to help keep the saltwater back?"

Newest Golf Course Irrigation RO Near Completion

Water Treatment Systems,Inc, Boca Raton FL has delivered it's newest reverse osmosis water treatment system to Spirit Hollow GC in Burlington IA. The 500,000 GPD RO will provide a consistent supply of irrigation quality water for the golf course.

At times of low rainfall, which is an annual occurrence during the golf season in Iowa, the facilities back up source of water has been a brackish water well. At 2000 ppm TDS this water was detrimental to the fairways greens and tees.

The new RO system will provide a product water of approximately 100 ppm TDS which will then be stored in a natural pond. The blended pond water should reach approximately 400 ppm TDS before being pumped onto the golf course.

A new building was constructed over the winter to house the equipment. The Water Treatment Plant is expected to start-up around May 18th.

Desalinated Seawater for Haiti - A Missed Opportunity

Soon after Haiti was struck by an earthquake the world learned of the devastation and enormous extent of this disaster, It wasn’t very long after that that some charitable agencies envisioned plans to provide clean water for the stricken area where there was precious little to be had.
At that time, my company, Water Treatment Systems, Inc had two seawater desalination systems on hold for a customer who would not need them for another three months, time enough for us to build two more if needed. With our customers agreement we made the two SW RO systems available to the marketplace.
We had several serious inquiries from non-profit groups who wished to include them as part of temporary or mobile water treatment plants located on or near the sea to provide water to those that desperately needed it. Unfortunately, the organizations could not obtain financing and none of their plans were realized. Each of the seawater RO systems would have produced 60,000 gallons of potable water per day and would have been a great assistance especially in light of the current events.
An outbreak of cholera was confirmed in Haiti on October 21, 2010. Cholera had not been documented in Haiti for decades so cholera outbreaks were considered unlikely in Haiti immediately following the earthquake in January, 2010. For a cholera outbreak to occur, two conditions have to be met: (1) there must be significant breaches in the water, sanitation, and hygiene infrastructure used by groups of people, permitting large-scale exposure to food or water contaminated with Vibrio cholera organisms; and (2) cholera must be present in the population. While it is unclear how cholera was re-introduced to Haiti, both of these conditions now exist. (CDC Report)
One groups plans to supply clean water called for an off shore barge to serve as a platform for the desalination systems. Seawater would be drawn directly from the sea and piped a short distance to sanitary storage facilities onshore. Potable water would be distributed from there.
I am certain that such a plant would have supplied much needed drinking water to at least a portion of the population and alleviated some suffering in the aftermath of the earthquake. Sadly, it also would have been a great asset in the fight against cholera if it had come to pass.