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Apr 05

Go with the low-flow

Posted on April 5, 2017 at 11:15 AM by Becky Robinson

April is Water Conservation Month, and you'd have to be a total drip to miss the value in conserving water resources.

y u no save water

According to the South Florida Water Management District, South Florida is one of the wettest areas of the country. Not surprisingly, most of our rain falls during Florida’s Wet Season (usually May through October). It trickles into the ground, replenishing the aquifers and surface waters that supply us with drinking water.

However, the District warns that “Even with our typical abundant annual rainfall, South Florida’s weather can quickly change from deluge to drought." Hence, the current county water restrictions that kick in during Florida’s Dry Season (usually November through April) that limit when lawns can be watered.  

We at the SWA take water conservation pretty seriously, too. The SWA's Renewable Energy Facility 2 (REF 2) and its sister facility, Renewable Energy Facility 1 (REF 1), work together to both generate electricity from trash and provide better than net zero water discharge. This means that both plants are designed to meet their water needs without wasting a drop of agua.

REF 1 and REF 2 at Sunset
REF 1 (left) and REF 2 (right) at dusk

REF 2 was constructed with a 2 million gallon cistern - basically, a ginormous rain barrel. This cistern collects rainfall from the extensive roofing systems throughout the facility. (To put that in some perspective, REF 2 collected an estimated 360,000 gallons of water during Hurricane Matthew in 2016.) About 5% to 15% of water needed to make electricity from trash at REF 2 is harvested rain water and 60% is recycled water leftover from REF 1's electricity generation process. (About 25% to 35% is off-site industrial water.)

REF 2 Cistern Collage_SM
Not to get too technical, but this 2 million gallon cistern is ginormous.

REF 2 also has a crazy-looking air cooled condensing system (ACC), which conserves more than a million gallons of water each day.

air cooled condenser
Under the ACC, in the foreground, you can see the round compartments where giant fans spin

REF 2 burns garbage to make steam, then uses that steam to turn a turbine generator, which produces electricity. Once the steam has done its job, it is piped into the ACC where a series of 15 humongous fans cools the steam back into water. The water is then recycled back through the process all over again. Without the ACC, an estimated 540 million gallons of water a year would go up in steam.

air cooled condenser close-up
A close-up of one ACC fan with an employee in the doorway for scale

Part of the REF 2 footprint, the SWA’s LEED Platinum Education Center has its own 12,000 gallon cistern to capture the rain that runs off its roof. This captured runoff is used to water the rooftop garden, an environmental addition to the building that reduces cooling costs. Not only that, but efficient fixtures inside reduce water consumption by 41%. 

Education Center
The Education Center at REF 2, with its cistern on the far right

So this April, while each of us does our part to conserve water with efficient toilets and home rain barrels, please know that the Solid Waste Authority of Palm Beach County is doing its part, too.


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