Water – Another View
by Doug Pushard
In a recent article I reviewed our growing population and the declining precipitation rates that the northern New Mexico (see related link) area has experienced over the past several decades. This paints a very arid picture indeed for this part of the country. Pumping more water or increasing water transfer from other areas is not going to solve this problem. Increased pumping and transferring water from further locations increases the need for more power generation and this directly translates into more power plants. For those of us who love our amazing vistas and crystal clear blue skies, the solution to our water needs can’t involve polluting our skies. Clearly, we must look to other solutions to solve our water needs.
No matter how much pollution control equipment is installed, traditional power plants still pollute. Another less realized fact is that power plants consume vast quantities of water. An average coal plant will consume 390 gallons of water for every MWh (megawatt hour) generated. The proposed Desert Rock Power Plant built on a 580-acre site on the Navajo Nation, San Juan County, New Mexico is a 1,500-megawatt (MW) coal-fired plant and is projected to produce 211,000 to 375,000 megawatt-hours of electricity per year. This hotly contested plant is projected to emit 12-13 million tons of CO2 and consume over 1.6 billion gallons annually or 438,000 gallons a day!
There is no free lunch when it comes to power generation. All types will require water, either during operations or during the manufacturing process. Wind and small distributed photovoltaic solar systems use virtually use none to operate, while nuclear and coal use prodigious amounts of water. However, manufacturing solar panels or wind turbines do require water, but recent studies show it is not extensive amounts.
Traditional power generation and distribution literally use tons of water each and every day. Water and energy usage are inextricably linked. Conserve one and it conserves the other, consume one and it consumes the other. The most direct way to prevent a kWh from needing to be generated or a gallon of water from being pumped is not to use either in the first place – conserve, don’t consume.
A National Resource Defense Council (www.nrdc.org) study concluded that there are more than 60,000 water systems and 15,000 wastewater systems in the United States and are among the country’s largest energy consumers, using about 75 billion kWh/yr nationally—3 percent of annual U.S. electricity consumption to treat and deliver water. This demand alone is equivalent to the entire residential demand for the state of California. If San Diego relied on water conservation instead of additional water from Northern California to provide the next 100,000 acre-feet of water, it would save water and enough energy to provide electricity for 25 percent of all of the households in San Diego.
Although buying and installing large cisterns and/or a photovoltaic tracking array may be sexy – they both consume resources. It is far better for the environment and your pocket book to start with conservation. To get the biggest bang, be extremely aggressive on water conservation. It saves water but it also saves energy, which in turn saves water.
Albuquerque and Santa Fe both have good water conservation programs; Albuquerque since 1995 and Santa Fe since 2002. Both cities have significantly reduced per capita water consumption with the introduction of these programs. These cities and others realize conserving water is the way of the future.
These programs have saved massive quantities of water, and consequently tons of CO2 emissions. Other cities in the US have come to realize that these normally small, isolated, “liberal environmental programs” can be part of the solution to other, much larger problems.
A great example is James City County (JCC), Virginia. The county knew that as the area grows, so does the demand for water. Between 1990 and 1999, JCC's population grew 33.5 percent, from 36,309 to 48,475. To meet that growth, JCSA's groundwater withdrawal had increased from 600 million gallons per year to over 1 billion — a 50 percent increase. In the first year of its aggressive water conservation program the county replaced just 0.15% of high-water use appliances owned by customers and saved 6 million gallons of water.
The program involved installing rain sensors, rain barrels and cisterns, high efficiency toilets, high efficiency washing machines, on-demand hot water recirculators and high efficiency dishwashers. For this program, the EPA recognized JCC as a WaterSense Water Efficiency Partner of the Year.
The county quickly determined that by increasing the replacement of low water use appliances from 0.15% to 25%, the county could meet over 50% of future water demands while at the same time reducing by 2,590 tons per year of CO2e (i.e. carbon dioxide equivalent) that would have been produced if the water was not saved.
Chicago is another city with a similar, yet even more aggressive and integrated water/energy management program. Chicago’s goal is to reduce CO2e by 98,000 MT by 2020 through a Green Infrastructure Program. Components of this program include aggressive replacement of aging, leaking infrastructure as well as programs to promote disconnecting downspouts from city stormwater system and directing this “waste water” to rain barrels, cisterns, rain gardens. Other programs include promotion of green roofs and replacing normal asphalt with green paving to reduce storm runoff. Permeable alleys and rain gardens reduce flooding, and use rainwater as a resource to beautify neighborhoods. These programs have been promoted through community meetings, instructional video tapes, brochures and discounts on materials to homeowners. The city already requires all public buildings be constructed to meet LEED criteria, and this has been in place for a number of years and is actively working to require specific water conservation approaches be mandatory on all other future buildings
The United States is no alone in the drive to conserve. Even more dramatic is the program implemented in Queensland, Australia. Australia’s fastest-growing state, with 2.7 million residents, Queensland Water Commission asked that residents use just 35 to 40 gallons of water per person per day -- a savings that could be more easily attained if residents reduced their seven-minute showers to four minutes. The message was widely advertised on television and in outdoor advertising. Queensland also implemented a major rebate program that provided its residents with over 500,000 water-saving devices, including rainwater tanks, low-flush toilets and water-efficient shower heads. The result was it didn’t just meet the stated goal - but exceeded it.
Rebates and education were substantial parts of the program in order to meet this objective. High efficiency showerhead were given away and rebates for cisterns could nearly pay for the tank (i.e. close to $1 a gallon) if the tank was plumbed to supply both water for outdoor irrigation and indoor toilets.
Cities around the country and world are discovering water conservation, but also the direct link between water, energy, and CO2 emissions. Aggressive water conservation programs (i.e., larger incentives, increased awareness programs, etc.) can be part of the solution to help us address even larger issues (i.e. future water supply needs, ease growth constraints, decreasing air pollution, etc.). It is not just the water - it is our clear blue skies we should also care about. Please help conserve our most precious resource. The solution starts with each of us doing what we can.