Just How Water-Intensive Are Power Plants?
Did you know that power plants are thirsty? As it turns out, they are big gulpers of water. Every kind of fossil fuel power generation requires water, and lots of it. Nuclear, coal, and natural gas each use many gallons of water in the process of generating every kilowatt of electricity. Natural gas is the lowest user, using around 3 gallons for each kWh. But, who cares? It’s New Orleans! We are quite literally surrounded by water! Just suck it out of the ol’ Mississippi or dig a well. But when thinking about water it is important to consider the differences between surface water (the water you can skip a pebble over like lakes and rivers) and groundwater (like water deep underground in water vaults called aquifers).
The majority of the water used at New Orleans’ own Michoud power facility in New Orleans East is withdrawn from surface water: the Intracoastal Waterway that runs alongside the plant. But since the 1960s, Michoud has also been withdrawing many millions of gallons of groundwater each day from the Gonzales-New Orleans Aquifer on which most of Orleans Parish rests. In fact, Michoud draws 84% of all of the groundwater withdrawn in the city every day while most power plants that are situated near surface water rely on these rivers, lakes, or waterways for their needs, instead of tapping aquifers.
So what is the problem with withdrawing groundwater instead of surface water? Well, there’s this thing called subsidence. It is one of the reasons New Orleans is sinking. the water in the soil is partly responsible for holding the ground up, so when it is removed, the soil compacts and sinks. It is the real culprit for those potholes and roller-coaster streets and it is a major issue for the safety, and relative dryness of our city. The withdrawal of groundwater is one of the man-made activities that leads to subsidence. How much? Well, In New Orleans East, the Paris Road Bridge, that runs alongside Michoud and its four wells, subsided 80 centimeters in the first 40 years of power production. That’s 2’7”, right along a levee in New Orleans East.
Michoud is scheduled for decommissioning in June 2016, so the 10.87 million gallons that are pumped from under the city every day will stay in the ground. The next question is, when we need to replace that power will water usage and subsidence be part of the conversation about how that energy is generated. The Alliance intends to make sure that it does.