Do you need to put 5,000 more cars to the road to get clean drinking water?
I find the trade-offs that arise in energy development, environmental protection and human health fascinating. Over the years I’ve written on this topic a few times:
Today I want to talk about a 160,000 square-foot new water treatment facility in New York that will be going online this year, and how it’s giving us safer water at the cost of a hefty increase in greenhouse gas emissions. I’m referring to the Catskill/Delaware Ultraviolet Light Disinfection Facility, which is in the final stages of construction just north of New York City. The facility will use ultraviolet light to disinfect an average of 1.3 billion gallons of water per day. It’s also going to use a lot of electricity and, as a result, increase greenhouse gas emissions.
The consequences of this project are neither unintended nor unforeseen. The project was required by Federal and State regulations to maintain the safety of New York City’s water supply, which is one of only a handful of major water supplies in the U.S. that remain unfiltered, according to civil engineer Robert Osborne, who is very into water. Having an unfiltered water supply is a kind of badge of honor. It means your water is exceptionally pure. But Federal and state regulations require water supplies to be protected by other means if filtration is not used. (The New York Times reported that a filtration system for this water supply would have cost up to $8 billion to build millions of dollars a year to operate.)
A project of this magnitude, whose costs are estimated at $1.6 billion, undergoes detailed analysis and planning, including an the creation of an environmental impact statement. The environmental impact statement says that the plant will draw an average of 4.45 megawatts of electric power. By my calculations (4.45MW X 24 hours X 365.25 days X 1000), that will equal about 39 million KWh of electricity annually.
You can calculate the amount of greenhouse gases emitted to provide 39M KWh of electricity in New York using EPA’s eGRID methodology (available via a cool tool on amee.com). Using my assumption, it comes to over 25,000 metric tons of CO2 equivalent. Taking the EPA’s estimate of the average annual greenhouse gas emissions of an average automobile (5.1 metric tons of CO2E per year) you find that these emissions are the equivalent of putting about 5,000 more cars on the road.
I have no doubt that this particular trade-off (cleaner water for dirtier air) is worth it. The project protects over 8 million people who depend on this water supply from the risk of water-borne contaminants that could cause a significant public health crisis. I point it out not to criticize this project but rather to illustrate the kinds of trade-offs policy makers face all the time.
I’d love to hear your thoughts.