[TXnMA]

"... the warm water from the evaporative cooling tower is being discharged into the bay producing ideal conditions for algae growth."

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ThanQ!! I didn't see an evaporative cooling tower -- but, I'll look again...

TXnMA
  

[Aquamarine]

Source says underground tunnel temperatures should remain constant at around 48 to 54 degrees although the tunnels would need to be ventilated due to build up of gases. They could be using hot water transfer to heat through a transfer coil (hydronic’s). Hydronics is the use of water or another liquid heat transfer medium such as glycol as the heat-transfer medium in heating and cooling systems. Some of the oldest and most common examples are steam and hot-water radiators.