Pollution Control System

Fire Water Cistern

If you look down and to your right, you will see our fire water cistern. The cistern is a large tank containing an emergency supply of water used to put out fires should they occur. Surrounding the cistern is a living wall of sky vine, which helps dampen noise and improve aesthetics.


The stack is 320 feet tall including the underground base - which is more than 28 stories high - and 25 feet across. To keep our emissions low, we invested more than $50 million in the most advanced emission control technology at the time.

Controlling Emissions

As you walk further down the bridge, you will see a window that looks into the Pollution Control System. REF 2 benefits from the best pollution control technology available. Carbon powder is used to remove mercury and volatile organic compounds from the ash after combustion. Then, lime slurry neutralizes acid gasses, which are the main components of acid rain. Next, the baghouse filters collect the fly ash, lime and carbon powder and prevents the release of particulates into the air. Finally, aqueous ammonia is used to turn harmful nitrogen oxide into inert nitrogen gas and water vapor using the Selective Catalytic Reduction system. REF 2 is the first waste-to-energy facility in the United States to reduce NOx emissions using the selective catalytic reduction system.

Collecting Rainwater

REF 2 features a unique rooftop rainwater collection system that includes a 2 million gallon cistern. This system provides a portion of the water necessary to operate the facility, and helps to reduce the use of groundwater or treated water at REF 2.

Recycling Water

On the other side of the bridge, you will see an Air Cooled Condenser. Giant fans are used to cool the steam down after it runs through the turbine and condenses it back into water. This water is recycled back into the system.

  1. 1
  2. 2
  3. 3
  4. 4