Turtle Farm filtration system eyed

A proposed new effluent discharge treatment system at the Cayman Turtle Farm could reduce the volume of water going into the ocean.

Managing Director of COO and Boatswain’s Beach, home of the Cayman Turtle Farm, Joseph Ebanks said the system would ultimately mean that the environmental impact of the farm could be reduced to zero per cent.

‘This means that what comes out at the end of the pipe is going to be so small that Mother Nature simply can deal with it,’ he said.

Once the environmental impact has been reduced Dr. Thomas Goreau, president of the Global Coral Reef Alliance will begin restoring the coral reefs that have been damaged from the Turtle Farm pumping untreated effluent into the ocean for the past 40 years.

Henning Gatz of Aquacare Environment designed the effluent-discharge treatment system.

‘We’re so confident in this system that we’re also looking at recycling the water, so it’s going to allow us to pull less water out of the ocean and of course our discharge numbers will drop aswell,’ said Mr. Ebanks.

The Turtle Farm received its discharge permit in October from the Water Authority, which is reviewing the proposed $1 million discharge system.

Turtle Farm Manager Walter Mustin described the system as an energy friendly, biologically friendly, environmentally friendly, sound profitable system that’s going to help the Turtle Farm and the island.

Mr. Ebanks explained how the system would work.

The water from the turtle tanks flows into the filtration system. It goes through UV lighting to help kill some of the bacteria. It also goes through a series of filters that take the solids out and treat the nutrients, algae and bacteria.

‘Some bacteria is good so we want to add some of the good bacteria to consume the nutrients and help us reduce them,’ explained Mr. Ebanks.

The farm uses 5,000 gallons of water per minute.

Mr. Mustin said, ‘When they specked the system it became obvious toward the end of it that the water quality was so good that it didn’t make sense discharging 5,000 gallons of good water, why not just re-use it: save the energy, re-use the water and discharge one tenth of it.’

He said that they will still use 5,000 gallons but only 500 gallons per minute will be added to replace the 500 gallons per minute discharged so one tenth of the volume is going to leave the system with probably 1/100th of the nutrients per gallon, bringing an enormous reduction in the volume of water leaving the farm, improving the quality of that water and reducing the cost.

He described the system as a combination of physical filters, biological filters, UV light, foam fractionators and filter bags.

‘The bags take the end product of filtration. The water leeches through these bags, returns to the system to be recycled and the solids are carried away,’ Mr. Mustin explained.

Mr. Ebanks said the water that stays in the system is clean.

‘It has to be as clean as what we’re putting in so it goes through our system of cleaning and goes back into the turtle tanks clean,’ he said.

There is no timeline for implementation of the system because Water Authority approval is needed.

Mr. Ebanks said he is excited about the project.

‘It all fits with who we are,’ he said. ‘We have this fantastic turtle research programme under way; we have some global human capital working with us . . . We’re now looking at it being more environmentally friendly and green to fit what we do and we’re going to be looking at the signature reef, which is going to be unique for Cayman.’

Mr. Ebanks said the Turtle Farm has set new standards for discharge, well above what The Water Authority requires.

Already there are some measures in place at the Turtle Farm to trap nutrients and solids and filter them from the water returning to the ocean.

The positive effects of these measures have already been seen by Mr. Goreau, he said.

‘In fact at his last visit he discovered that the coral reef out there has already begun to come back. It’s on its way but there’s only one species that’s recovering very rapidly since his initial dive and study. The discharge content is so low now that they’re beginning to come back,’ he said.

The signature reef will be a Biorock reef. This essentially is started using rebar with a low voltage applied. The rebar is wired together to a frame and it’s taken out into the water and it goes down to the ocean bed. Because of the low voltage charge it builds up a calcium covering and fuses itself to the floor and pieces of coral are collected and tied to it. The low energy that is applied helps the rapid growth.

Coral reefs built with the Biorock process are now growing in the Maldives, Seychelles, Thailand, Indonesia, Papua New Guinea, Mexico and Panama.

Mr. Ebanks said Mr. Goreau is confident he can restore the reef in Cayman. ‘I mean he’s doing it all the time,’ he said.

The design for the shape of the rebar is a huge female turtle with little turtles, but this will only be seen initially.

‘Once the coral grows it becomes a garden of flowers so you’ll never tell the shape,’ he said.

The reef will be used to help promote the Cayman Turtle Farm while it will be an addition to the tourism attraction in the West Bay area, said Mr. Ebanks. ‘Of course we’ll never get into dive operations but dive companies can use it and it will help them make money,’ he said.