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SFWMD could cut Lake Okeechobee discharges by a third with deep injection wells

Tyler Treadway
Treasure Coast Newspapers
A deep injection well at the Okeechobee Utility Authority.

Is the best way to give the St. Lucie and Caloosahatchee rivers relief from Lake Okeechobee discharges to go deep?

The South Florida Water Management District is considering using deep injection wells to dispose of water that otherwise would pollute the estuaries and has even renamed them Emergency Estuary Protection Wells.

Opponents say the wells are a "bright, shiny object" that could divert attention from Everglades restoration projects, and could contaminate aquifers where Floridians get their drinking water.

How do they work?

There already are about 220 deep injection wells in Florida. Most of them pump treated wastewater or byproducts from drinking water plants about 3,000 feet into the ground, to what's known as "the boulder zone."

The Stuart Utility Department, for example, sends about 1.5 million gallons of treated wastewater into two deep injection wells.

There are about 220 deep injection wells in South Florida, most dispose of wastewater effluent and drinking water plant byproducts.

The water management district is considering drilling wells to send surface water in and around Lake Okeechobee that otherwise could be discharged to the St. Lucie or Caloosahatchee rivers to the boulder zone.

With each well pumping up to 15 million gallons a day, the proposed 30 to 60 wells could dispose of 450 million to 900 million gallons of water a day.

Lake O discharges are currently averaging about 2.7 billion gallons a day: 1.9 billion gallons a day to the Caloosahatchee and 756.2 million gallons a day to the St. Lucie.

That means:

  • 30 wells pumping at maximum capacity would cut the discharges by about 20 percent to slightly more than 2.1 billion gallons a day
  • 60 wells could cut them by a third to about 1.8 billion gallons a day
The view inside a deep injection well 2,777.7 feet underground.

'Bright, shiny object'

Opponents worry the wells could direct time and money away from efforts to bring about long-term solutions to the discharges — namely the reservoirs north, south, east and west of Lake O and projects designed to move water to the Everglades.

Daniel Andrews of Fort Myers, executive director of the Captains for Clean Water, called the wells the latest "bright, shiny, object" at a water forum Saturday sponsored by the Stuart-Sunrise Rotary Club.

Daniel Andrews is founder of Captains for Clean Water.

If the wells succeed in diverting water from the estuaries "people are going to argue that the problem is solved," said Shannon Estenoz, chief operating officer and vice president of policy and programs at the Everglades Foundation. "Well, it won't be. The problem won't be solved for the Everglades and Florida Bay."

Shannon Estenoz

The estuaries might not survive the wait for those projects, countered Brandon Tucker of Palm City, a South Florida Water Management District board member.

Tucker said completing all the Comprehensive Everglades Restoration Plan projects will cost $16 billion and, with current funding levels from the state and federal governments, take more than 50 years to complete.

In seven years, from 30 to 60 deep injection wells could be in the ground and providing relief to the estuaries, Tucker said.

But all the CERP projects don't have to be online for the estuaries to get relief. Those designed to store excess Lake O water and send it south are scheduled to be completed by 2030. 

Brandon Tucker

Where does water go once it's gone?

The wells' fans and critics agree not much is known about where water will go once it's sent 3,000 feet underground.

"The water you put down there is going to move around to where you don't want it," said Harold R. Wanless, geography professor at the University of Miami.

Some of the water, Wanless said, will "migrate" up into the aquifers where some Floridians get their drinking water.

"The problem is you're pumping freshwater into an area that's saltwater," Wanless said. "Freshwater is less dense than saltwater, so it's going to find a way back up into the limestone that separates the boulder zone and the upper aquifer."

The limestone has "plenty of cracks and fissures and holes to allow the water you pump down to come back up," Wanless said.

Deep injection well at the Delray Beach South Central Facility.

As a safeguard, the district plans to have monitors adjacent to each deep well "to allow us to see, in real time, what's happening down there," said Eva Velez, the district's head of Everglades Policy. "If there's a potential for water to migrate up into the upper aquifer, we can pump less water to ease the pressure."

The water also will move laterally, Wanless said, out to the ocean, where it can pollute coral reefs. That shouldn't be a problem, either, Velez said. At least not right away.

Water in the boulder zone, she said, "is like a very slowly moving ocean. It moves a lot more slowly underground than it does on the surface."

Tucker said the "geological issues" will have to be worked out before he'll vote to proceed with the project.

"We don't want to do something stupid, something that would have unintended environmental consequences," Tucker said. "But right now, I look at the possible benefits; and that's what sells me."

By the numbers

  • $5 million to $10 million: Cost of each well
  • $150 million to $600 million: Cost of the proposed 30 to 60 wells
  • 15 million: Maximum gallons of water each well could pump per day
  • 450 million to 900 million: Maximum gallons the proposed 30 to 60 wells could pump per day
  • 2.7 billion gallons: Current average daily Lake Okeechobee discharges into the St. Lucie and Caloosahatchee rivers 
  • 20 to 34: Percentage of daily discharged water 30 to 60 wells could remove