Battling our Water Crisis: Issues and Potential Solutions
Today I’d like to talk water. We all know it’s necessary for life on earth and used by humans for nearly all our activities and products, and those of us who paid attention in 4th grade science also recall that it is a naturally renewable resource that requires nothing more than the sun’s energy and gravity to continue existing. Rain falls, it evaporates and then falls again, usually somewhere else. The amount of water on earth doesn’t change, but the location and quality of water has countless times as global conditions transform.
That brings me to our current water crisis on the west coast: Vast amounts of money have been invested in the construction of dams, reservoirs, canals and levees to capture and distribute water throughout the US. Major rivers have been bled dry and vast man-made lakes have appeared, often to the detriment of our ecosystems. Despite these investments, however, our nation’s water resources are buckling under the strains of a growing population, increased affluence and its subsequent material consumption, and changes in our climate.
Agriculture, which uses over 7% of all freshwater withdrawals globally, has the most to lose from limited water supply. California’s current 4-year drought, the worst on record, has left thousands of acres of land fallow, cost billions of dollars and thousands of jobs. The drought has prompted the state to enact new legislation aimed at protecting its valuable underground reserves before they become over exploited and set municipal reduction targets for each of its water districts.1 This is not only a case of California hurting, national supply chains are also affected, possibly increasing prices of specialty crops across the country.2 What is happening on (and under) the ground and what viable solutions exist?
Mind the Gap: Water Price & Availability
While the majority who live on the west coast are taking its current drought seriously, there still seems to be a general disconnect between water users and the geographic limits posed by the patterns of the hydrological cycle. In a survey of 30 metropolitan areas in the US, the areas with water scarcity were found to have the highest water use and the lowest prices.3 In fact, the overall US water footprint is nearly triple that of India or China and double the world average, at 2,842 cubic meters per person each year.4 The good news is that total water withdrawal on US soil has stabilized since 1985, even in the face of a growing population, and in 2010, total withdrawals declined to 1970 levels.5 Although a seemingly optimistic trend, water utilities are caught in the “conservation conundrum”. As users reduce their water consumption, utilities revenues fall, which jeopardizes investment in maintenance and infrastructure. Utilities are forced to either increase rates or, perversely, promote higher water consumption in their districts.
With most of the US’s growth over the next 30 years projected to be in the water scarce southwest6, the strain placed on water supplies will be greater than ever. According to one study, 1 in 10 watersheds in the US are already water stressed, mostly in the Southwest.7 Combined with the projected effects of climate change, predictions show that, between 2041 and 2060, most of the watersheds west of the Mississippi (especially in California, Arizona, New Mexico, Utah and Nevada) will be water stressed, even with the assumption that groundwater supplies are unlimited.4
Excess Groundwater Withdrawals
US groundwater reserves of freshwater are huge, probably greater than 100 times our reservoir capacity.9 Nearly 79.6 billion gallons are extracted daily to supplement demand from surface water, of which California is responsible for 8%.8 Half of US residents, including 97% of rural households, depend on groundwater for everyday use. Although they hold tremendous amounts of water, aquifers are not immune from over extraction, contamination and seawater intrusion. The nation’s largest groundwater reserve, the Ogallala aquifer, covers 174,000 square miles and would take 6,000 years to refill if it were ever fully withdrawn.9 The Ogallala supplies water to major cities and agriculture in the heart of the US farm belt and is a key resource to that $20 billion a year industry. Over extraction of Ogallala is not uniform and in some regions that has led to a drop of 150 feet forcing farmers to abandon their wells.10
Costly & Aging Infrastructure
The traditional route for increasing water supply has been the construction of dams and reservoirs. There are currently over 75,000 dams in the US with a total capacity of about 860 million acre feet (maf). Statewide sedimentation is reducing the capacity of U.S. reservoirs with about 200 that are likely to have lost more than half of their initial capacity.11 The cost of increasing capacity in old dams and construction of new dams is prohibitive. In 1992, a third of dams were already classified as hazardous and in need of costly repairs, while most new capacity potential is in areas already developed for urban expansion, making construction either impossible or very costly. In addition to the cost, public attention and greater understanding of ecological value makes altering current streams and rivers an almost impossible task. This means increasing capacity through traditional sourcing is no longer viable at the scale needed.
Did you think there would be just one? I wish. The solution to our water problems will not come as a silver bullet, but requires various solutions pieced together in a regionally-specific way.
#1: Quit Wasting Wastewater!
Don’t be fooled by the name: wastewater is a valuable resource that can increase the local water supply and our collective resilience to climate change. Often called grey or black water, the water collected by storm drains, from rain or any water that has been contaminated by a process can still be useful. Municipalities around the world are looking at innovative ways to use this water.
Direct potable reuse (DPR), is the process of treating wastewater using filtration, osmosis and U.V. processes to drinkable standards and returning it to the raw water supply, upstream of the drinking water treatment plant. The Colorado River Municipal Water District opened the first DPR plant in 2013, with another opened in Wichita Falls, Texas that has the capacity to treat up to 10 million gallons of wastewater each day.12 Californian cities, San Diego, Los Angeles and Sacramento are all considering developing their own DPR systems. There are several advantages, beyond supply, of using DPR; one is that the water source is far closer to the end consumer and hence large infrastructural support, such as aqueducts and large pumps, are not necessary, reducing the energy required for moving water.13 DPR appears to be a great alternative that hits the sweet spot of the increasingly important Water-Energy Nexus.
Another example comes from the City of Los Angeles. Starkly aware of their impending nightmare as they seek business investment and support a thriving population while getting dangerously close to their water resource limit, the Mayor has pledged to increase storage in above and below-ground reservoirs.14 Only 10% of LA’s water comes from the LA water catchment area. The other 2.35 billion gallons come from the city’s aqueducts, which could be easily crippled by a natural disaster. The City hopes to reduce freshwater use by investing in water recycling for industrial and irrigation uses and continue to try to convince residential customers, who consume more than 50% of region’s freshwater supply on landscaping,15 to replace their water thirsty lawns with more drought tolerant plants.
But could such technologies and techniques work at smaller scales, gaining even greater energetic efficiencies through proximity? Researchers at Stanford University in California are working on a building-scale wastewater recovery system at their Codiga Resource Recovery Center that could not only turn wastewater into clean non-potable water, but could also produce energy by utilizing the nitrous oxide and methane in wastewater.16 Such a system promises to increase individual and community water resilience to disasters much like distributed generation has done for energy.
#2: Seek Innovation through Collaboration
While technological innovation is important for the future of how we use and distribute water, in many cases innovation has and will come from collaboration. For example, the Empire Generating Power Plant, located in Rensselaer, New York, uses reclaimed water from the City of Albany’s wastewater treatment plant for cooling its turbines.17 Such re-purposing saves up to 4,800 gallons per minute of freshwater. A truly impressive feat.
The Dow Chemicals plant in Terneuzen, a water stressed region of The Netherlands, accepts household wastewater from the local utility, treated only for residual contaminants that would otherwise have been dumped into the North Sea. The wastewater is used twice, first to produce steam and then for the plant’s cooling towers. This effort uses 90% less energy than running a desalination plant and saves 2.6 million gallons of freshwater daily.18
In Los Angeles an experiment in the collaborative governance of water, developed by the non-profit organization TreePeople, has brought together the City of Los Angeles Bureau of Sanitation, City of Los Angeles Department of Water and Power and Los Angeles County of Public Works to form a powerful coalition to address the city’s water crisis through joint planning and coordination. Surprisingly, this is the first time these agencies have worked together at this level, which promises to find efficiencies of economy and implementation and generate innovation.
#3: Easy & Smart Conservation
Repurposing of wastewater for both residential and industrial customers has enormous potential, however, as populations increase, there will be added freshwater needs if our individual consumption continues at its current rate. This means another piece of the solution puzzle should come from a per capita consumption decrease. WaterSmart, a software company, is looking at this from a data analytics and behavioral science lens. By providing smart meters with apps that provide easy read outs and comparative statistics, consumers become much more aware of their and their neighborhood’s consumption patterns. WasterSmart has seen users’ water usage reduced by up to 5% in the first year of using the tools.19 Such monitoring devices could also incorporate predictive analytics, noting behaviors of users and suggesting alternatives that increase efficiency and predicting maintenance prior to leaks occurring. We’ve already seen these techniques catching on in the energy industry with the introduction of smart thermostats, such as Google’s Nest and Honeywell’s Lyric. Imagine if every household could see exactly how many gallons of water they were using during their 10-minute shower and it came paired with a quick reminder that replacing old showerheads with newer, low-flow models could save them 750 gallons of water a month. Pretty compelling stuff.
#4: Better Policy & Regulation
Though there is new research and investment in wastewater treatment and independent distribution systems, policy and pricing has become a barrier to scaling these innovations. We have already discussed the conservation conundrum, but as utility water prices remain relatively low, return on investment of new technology is long, hampering their adoption and integration. In these cases, legislation may hold the key. In some areas of San Francisco, for example, dual plumbing (a parallel system for potable and recycled gray water) has been required in new buildings for over 20 years. It is easier to justify investment in new technologies in these locations because building owners are required to install the initial dual plumbing system in the first place.
According to Paula Kehoe, Director of Water Resources for the City of San Francisco Public Utilities Commission, lack of public policies and regulation are creating barriers to mainstreaming innovative technologies for wastewater.20 Currently in the U.S., there are no national water quality standards for on-site re-use systems, leaving each state to establish its own interpretation of the laws, guidelines and codes. In 2012, San Francisco created the Non-Potable Water code by coordinating three city agencies to provide the permitting, review, and approval process. Two or more buildings are now permitted to aggregate their treatment and reuse of alternate water supplies in order to be able to maximize their water reuse.20
The Road Ahead…
So, what have we learned? Innovation and invention are alive and kicking in the water industry and have the potential to help us solve our water crises. The path forward, however, will require changes in business models, legislation and investment as well as collaboration amongst diverse stakeholders to truly realize a transformation in the way water is collected, distributed and used and reused again.
Michael S. Roy (PhD) is Milepost’s Chief Scientist.
8 Estimated Use of Water in the United States in 2005, U.S. Geological Survey Circular 1344, October 2009 from: http://www.ngwa.org/Fundamentals/use/Pages/Groundwater-facts.aspx
13 Drinking water Drinking Water Through Recycling. The benefits and costs of supplying direct to the distribution system. Report of a study by the Australian Academy of Technological Sciences and Engineering (ATSE) ISBN 978 1 921388 25