Beyond Dams/Sustainable Water Management Alternatives

Another tool that can reduce the need for dams and other traditional water supply infrastructure. Recycled water derives from residential and commercial wastewater that has been treated to produce a high-quality source of water.[1] Instead of this wastewater being dumped into rivers, it receives a high level of treatment and is put directly back to use in the system. The level of treatment it receives and where it goes depends on its intended use. An Environmental Protection Agency (EPA) chart, available at http://www.epa.gov/region9/water/recycling/index.html, outlines treatment requirements for various uses of recycled water.^[1]

Recycled water used in irrigation can be stored in a cistern or tank of some kind and can be reused only once, while industrial (e.g., power plants) water reuse pulls the water into a closed system and cycles the same water through the system continually. Recycled water can decrease the amount of water diverted from freshwater sources as well as the dependence on a water supply dam. Recycled water can be used for agricultural and landscape irrigation, toilet flushing and industrial processes. In fact, recycled water has the greatest potential when replacing freshwater in small-scale agriculture and landscape irrigation^[2] (e.g., public parks, golf courses, and small farms) and cooling water for power plants and oil refineries because so much water is used in these processes.^[3] Cycling through used water can significantly decrease water use in highly industrialized areas.^[4]

While individuals and industry can proactively implement water-recycling programs, participation increases significantly when a municipality develops a water-recycling program and offers incentives to the public. Many cities have undertaken large-scale water recycling programs in schools and government buildings to reduce waste and supplement current water supply systems during dry periods and droughts. Many municipalities not only offer incentives for voluntary water recycling using, but also use reclaimed water (see below) to recharge groundwater aquifers and supplement water supply reservoirs. This is known as indirect potable reuse and is practiced in several locations throughout the United States (see case study below for example). By injecting recycled water into an aquifer or a water supply reservoir, cities and regions can raise water tables and increase water availability.^[1]

'Reclaimed water' is often used interchangeably with 'recycled water.' However, many publications make the distinction between these two at point of use. 'Reclaimed' water usually undergoes more advanced treatment and is used for indirect potable use. Recycled water may not undergo as thorough a treatment and is generally used for non-potable use.

Use of recycled water as a direct potable^[5] supply is common in European cities, including London, and has also been safely used in Namibia (Africa).

Water recycling has become a high profile and controversial issue in Australia in 2006 and 2007, with the Queensland government declaring that due to the critical need for water, it would implement recycling in spite of a negative referendum result in the city of Toowoomba. See Wikipedia:Toowoomba#Water. Green groups and water professionals have advocated water recycling in Sydney,^{[verification needed]} but the New South Wales government favors desalination.

While it has been explored in the United States in places such as San Antonio, this is not yet considered acceptable practice in the United States.^[1]

Recycled water can meet a variety of water supply needs and can reduce the impacts of water supply development on sensitive watersheds. Depending on the magnitude of the project and the watershed it is in, this water "savings" could offset the need for a water supply dam and reduce the amount of water diverted from rivers. An additional benefit is the reduction of the amount of pollutants flowing into rivers and oceans due to the decrease in the amount of treated wastewater being discharged into the environment.^[6]

While the use of recycled water for non-potable^[7] purposes is generally accepted practice, public misperceptions and concerns still exist about its use (both in regard to non-potable and direct/indirect potable use). Certain municipalities, such as San Antonio and San Diego, are finding they have to undertake substantial public outreach campaigns to educate consumers and address their concerns about recycled water programs. Furthermore, when used in aquifer recharge, there could be a risk of contaminating groundwater and drinking water with inadequately treated wastewater. Other barriers to the use of recycled water include the initial costs (see below) associated with installing the wastewater reuse and distribution system, and also (depending on the type of system proposed) difficulty in obtaining permits from appropriate agencies.^[1]However, it can actually be a cheaper alternative when compared to the cost of building a new dam or stormwater treatment facility.

Costs of water recycling systems vary widely depending on the use and the level of treatment required, ranging from a few hundred dollars to as much as $8,000.^[8] However, many agencies sell recycled water at rates 60 to 85 percent of their potable supply in order to encourage industry and local communities to participate.^[9] The city of San Diego, for instance, offers rates of $0.80/HCF for recycled water and rates of $1.57/HCF for potable.^[10] States like California that are forced to be progressive in dealing with water issues often provide funding or direct interested parties to potential funding sources. For example, the San Diego County Water Authority has two sources of financial assistance available for setting up a recycled water system: the Financial Assistance Program and the Reclaimed Water Development Fund. Other sources of funding include the Metropolitan Water District of Southern California's Local Resource Program, the Bureau of Reclamation's Title XVI Grant Program, and the State Water Resources Control Board's low-interest revolving loan program.32 In San Jose, the city will provide the design and construction to retrofit a facility for recycled water at no cost to the owner.33

1. City of San Jose, Environmental Services, Retrofits for Recycled Water, (2 July 2003).

Around 1989, the cities of San Jose, Santa Clara, and Milpitas in California launched the South Bay Water Recycling (SBWR) program to bring a reliable and sustainable water supply to the South Bay area. Recycled water is now used to irrigate golf courses, parks, school grounds, and agricultural lands, and for industrial processes and cooling towers at over 360 locations in the three cities.^[11] Using recycled water is often significantly cheaper for both the city and the end-user. For example, as of December 2001, using recycled water for irrigation within the South Bay area costs 20 to 42 percent less than using potable water for irrigation.^[12]

For more information about the South Bay Water Recycling program, contact Jennifer Durkin at Jennifer.durkin@ci.sj.ca.us

The Hueco Bolson Aquifer supplies much of the water to the arid town of El Paso. For the past 15 years, this aquifer has been successfully recharged with up to 3.27 billion gallons per year of reclaimed water treated to "drinking water standards". The reclaimed water has been introduced to the aquifer through a series of injection wells and infiltration basins. Subsurface storage of water has proved beneficial to the long-term management of the aquifer by supplying additional recharge, which offsets water level declines from the operation of its production wells. Prior to implementing this project, water tables were dropping at a rate of two to six feet per year. By 1990, the project had raised water tables eight to ten feet above what they would have been without the project.^[13]

For more information about this project, contact Scott Reinerts, El Paso Water Utilities, at 915-594-5579.

• For more information, contact your state natural resources agency, such as Department of Natural Resources or Department of Environmental Protection.
• Environmental Protection Agency Water Program: http://www.epa.gov/region9/water/recycling.
• Richardson, Tom and Bob Gross. Use of Recycled Water to Augment Potable Supplies: An Economic Perspective. WateReuse Association: http://web.archive.org/web/20051023081741/http://www.watereuse.org:80/Pages/information.html.
• National Water Research Institute. Water from Water: Recycling (video) and Issues in Potable Reuse: http://www.nwri-usa.org.
• Legal Environmental Assistance Foundation (LEAF). Aquifer Storage and Recovery Wells: http://www.leaflaw.org/press/ASRposition2003.pdf.

A key component of reducing the reliance on water supply dams is making the process of providing water as efficient as possible. While the minimum amount of water required by the average person for drinking, cooking, bathing and sanitation is considered to be 13 gallons per day, the average person in the United States uses between 65 and 78 gallons of water for those same purposes.^[14] According to a study conducted by the Organization for Economic Cooperation and Development, the United States has the highest rate of per capita water consumption among its member countries.^[15] Municipalities and industry have the opportunity to reverse wasteful water practices and improve efficiencies by encouraging and/or mandating conservation, while individuals can become part of the solution by implementing conservation practices in their own homes. Techniques for reducing indoor water use include installing low-flow water fixtures such as toilets, shower heads, washing machines and dishwashers; detecting and repairing leaky pipes and fixtures; and implementing educational campaigns to reduce wasteful practices such as running water when washing dishes or brushing teeth. Outdoor conservation can include using water-conserving landscaping methods such as drought tolerant planting and watering in the early morning or evening. While outdoor water consumption is the largest area of residential water use, bathroom fixtures consume the majority of indoor water in most households. The Energy Policy Act of 1992 established a national manufacturing standard of 1.6 gallons per flush for most toilets. By replacing one old toilet with a newer 1.6-gpf model, toilet water use can be reduced by up to 46 percent. The EPA estimates that use of these high-efficiency toilets in new construction projects along with standard replacements will result in a savings of 7.6 billion gallons per day by 2020. Many municipalities are even offering incentives to replace old toilets with high-efficiency versions.^[16] The theory behind high-efficiency toilets can be applied to other areas. The average five-minute shower sends 40 gallons of water down the drain. By installing a low flow showerhead or flow restrictor, consumers can save up to 30 gallons per shower.^[17] Fixing leaks can also save several thousand gallons of water. A slow-dripping, leaky faucet wastes 5,475 gallons per year.

To curb outdoor water use, homeowners, businesses, and city planners must find a solution that is appropriate for the climate they live in. One solution is xeriscaping, which is a comprehensive landscaping method that employs drought-resistant and water-efficient gardening techniques in an effort to conserve water. It was developed in response to a severe drought that devastated Colorado in 1981. Instead of using turf and grass, xeriscaping encourages the use of mulch, which is functional for water retention, long-term fertilization and weed control. Drought-resistant plants are planted in groups, according to water needs, in order to utilize irrigation methods efficiently. In addition, placement is based on the optimal amount of sun exposure. Efforts are made to improve the soil, which subsequently allows for better absorption of water.^[18] Homeowners who use xeriscape can expect to save a considerable amount of money on both maintenance and water use. Contrary to popular belief, automated sprinkler systems do not save water or money because owners rarely adjust them for weather or humidity variations. Manually operating a sprinkler system or using a hose where watering is needed is much more cost and water efficient.^[19]

Many cities and states are undertaking intense conservation efforts to ensure water supplies for their growing populations.

• California has embarked on a major effort to retrofit toilets. Full implementation could save an additional 400,000 acre-feet per year—the size of a large California reservoir.
• With continued population growth in the city of San Antonio, Texas, officials have put an emergency aquifer management plan in place with a hotline for reporting incidences of water waste. The city also offers rebates for installing low-flow toilets and high efficiency washing machines.^[16]
• Officials in Mexico City instituted a program to replace 350,000 toilets with newer high efficiency versions that have already saved enough water to supply some 250,000 additional residents.^[20]

One of their space saving ideas could also save us water. Some WC's don't have room for a toilet and a wash basin, so some have the two combined. They have a toilet as per usual, however the lid or top of the cistern, instead of being convex with a button in the middle is concave and has a small tap above it. After flushing the toilet you then rinse your hands in the small sink on top of the cistern, and then this water fills the cistern. You thus end up saving the water that would otherwise have been used to wash your hands, and reuse greywater in a closed system that should be acceptable to the appropriate building/water regulations.^[21]

The alternatives offered above are not new ideas and, in fact, have become commonplace. However, while there are laws mandating the use of high efficiency appliances in new building projects, there are few examples of large-scale efforts or incentives available for upgrades. As evidenced by some of the city and state programs referenced in the sidebar, efforts to increase water efficiency do work and could help fill the demand typically met by a water supply dam, especially in some of the smaller scale water supply systems that can be found in the Northeast and Mid-Atlantic regions of the USA.

Depending on the scope of the project, cost can be a factor when installing new equipment (e.g., low-flow toilets) or replacing dilapidated pipes. There are also social considerations to take into account, such as resistance to low-flow toilets and showerheads because people feel like they are not getting adequate water. The biggest drawback of xeriscaping is the original cost of re-landscaping a yard. In addition, it takes an average of two to three years for the plants to reach full growth. Water conservation methods that rely on behavioral changes such as these may require ongoing educational efforts to maintain water-saving habits.

While the initial outlay for installing water-conserving fixtures can be substantial, these costs can be recovered - often rather quickly - through savings on water, energy and sewage. The Port Authority of New York and New Jersey at LaGuardia Airport implemented water conservation measures by renovating their restrooms. These measures included installing low-flow toilets, showerheads and faucets and implementing a leak detection and prevention program. Total cost for the equipment was $79,276, but they were able to recoup these costs within eight months through water and sewage savings.^[22] For an individual looking to take initial steps to make their home more water efficient, rebates and other incentives can make switching quite affordable. New low-flow toilets can start at $61-$80 and go as high as $700.^[23] Low-flow showerheads range from $8-$50 depending on the number of features. While xeriscaping can also save water and money in the long run, the initial landscaping costs are not insignificant. For example, the Southern Nevada Water Authority has estimated the cost of converting 1,275 sq. ft. to xeriscape at $2,130. However, they also estimate that costs can be recovered in the first five years, with a savings of $1,500 or more after ten years.^[24]

Thanks to concerted citizen action, the Massachusetts Water Resources Authority (MWRA) undertook a coordinated effort to reduce water consumption to below the safe yield of the Quabbin Reservoir – thereby making a plan to divert the Connecticut River into the Quabbin unnecessary. The key to their success was demonstrating the cost and water savings potential of demand control measures, including a domestic retrofit program and a new retail water and sewer charge system. They also identified system leaks and unaccounted for water that were targeted for repair. Because of the consensus work of MWRA and the committee, metropolitan Boston decreased its consumption by 35 percent and was able to avoid additional diversions from the Connecticut River.

For more information, contact Eileen Simonson with the Water Supply Citizens Advisory Committee at 413-586-8861.

As part of their global water stewardship initiative, Unilever Home and Personal Care – USA wanted to demonstrate that conservation measures could have positive economic repercussions. In 1995, Unilever began implementing an extensive water efficiency program at its Cartersville, Georgia plant to prove just that. The company had put all aspects of the plan into effect by 2000, including:

• Heightened employee awareness of environmental and economic benefits of water conservation;
• Water reuse in non-contact cooling water, wash water and water from scrubbers and parts washing;
• Collection and use of rainwater in manufacturing process; and
• Automatic control of cooling water.

Since implementing this program, Unilever has reduced its wastewater effluent volume by 77 percent at a savings of $20,000 per year for potable water. By downgrading their usage status, they are also saving an additional $85,000 per year in permitting fees. A portion of this savings from the water efficiency program is added to employee bonuses.^[25]

For additional information on the Unilever case study, please contact Ella Lott at 770-382-8660 or Judy Adler with the Georgia Department of Natural Resources Pollution Prevention Assistance Division at 404-651-5120.

• For more information, contact your state natural resources agency, such as Department of Natural Resources or Department of Environmental Protection.
• Vickers, A. Handbook of Water Use and Conservation. WaterPlow Press, 2001.
• WaterWiser: The Water Efficiency Clearinghouse, http://www.waterwiser.org.
• Water Conserve: A water conservation portal, http://www.WaterConserve.info/.
• EPA Office of Wastewater Management. Appendix A: Water Conservation Measures from Water Conservation Plan Guidelines: http://www.epa.gov/OWOWM.html/water-efficiency/wave0319/appendia.pdf.
• Niemeyer, Shirley. Making Decisions: Household Water-Saving Equipment and Practices. Cooperative Extension, University of Nebraska-Lincoln. NF 97- 338.
• EPA Office of Wastewater Management. Water Efficiency Measures for Residences, 1999: http://www.epa.gov/OW-OWM.html/water-efficiency/resitips.htm.
• H2Ouse Tour: Water Saver Home. California Urban Water Conservation Council: http://www.h2ouse.org.
• PortaPotty. The 25 Best Ways to Conserve Water. http://www.portapotty.net/water-conservation/.

The desalination of ocean water or brackish groundwater is an alternative to obtaining water from fresh water sources (surface water or groundwater), and could be used to replace the need for a water supply dam. Several different technologies exist to remove salt and other impurities from ocean water. Desalination is already used as a main source of potable water in the Caribbean, Mediterranean and Middle East.^[26]

The two most commonly used technologies are:

• Thermal distillation, which mimics the natural water cycle by using heat to create a vapor that is converted into freshwater, and
• Reverse osmosis, which involves pushing water through a porous membrane that filters out salts and other impurities.

Thermal distillation is possible using solar heat or even waste heat. For, solar heat can be directed unto the water using CSP-plants^W (see solar thermal)^[27] Some successes have been claimed for small scale solar distillation - however it has usually given weak results and/or has high capital costs, and so is not the best option in most situations.

Other technologies, like reverse osmosis can create unlimited amounts of pure water from polluted water, ocean water. On vehicles as yachts, seawater through reverse osmosis can also be used. Water makers are available herefore that convert seawater and electricity into potable water and brine.

For coastal states, desalination represents an opportunity to draw on oceanic water resources. If the appropriate conditions are present, a desalination plant has the potential to replace an existing or a planned dam.

• In order for a desalination plant to be a viable alternative to a water supply dam, the water users must be located fairly close to a coast.
• Adverse environmental impacts:
  • Desalination is potentially very energy intensive, depending on the energy recovery system used.
  • Disposal of a large amount of deoxygenated, highly concentrated saline byproduct into the ocean or estuarine ecosystem. This will naturally tend to flow along the ocean floor, and will potentially smother and kill any organism that requires oxygen. In a reverse osmosis plant, the volume of waste saline water is several times greater than the volume of fresh water produced.
• Desalination plants can be costly to construct and operate.
• The facilities require large amounts of land.^{[verification needed]}

Desalination shows a very distinct economy of scale. This means that larger plants can producer water at lower cost and lower energy consumption. As a consequence desalination plants tend to be large requiring high investments for the plants and energy supply facilities.^[28] In the case study below, the desalination plant built in Tampa, Florida cost $110 million, of which the Southwest Florida Water Management District paid $85 million. The water produced in this plant is expected to sell for about $2 per 1,000 gallons, far below the desalination industry standard. The cost of regular groundwater sources is about $1.00 per 1,000 gallons. As technology continues to progress, the cost of desalination is expected to decrease, particularly when compared to many of the alternatives.^[29]

A second more modern example is the Perth Seawater Desalination Plant, Kwinana, Australia.^[30] The total project cost was AUS$387m for an annual output of 45 GL, with expected water cost at AUS$1.2 for 1000 L (kL) and a specific energy demand of 4.0kWh/kL to 6.0kWh/kL. Small scale desalination plants are due to the economy of scale relatively expensive. This is even valid for plants that utilise solar energy. Typical water production prices for plants with less then 10'000 L/d capacity are between 4 - 12 US$ per 1000L (kL) and have energy requirements between 23 and 40 kWh/kL.^[31] Some recent work done on numerical simulations on optimized CPCs for solar stills offered some hope for decreasing costs considerably,^[32] but further experimental and field tests are needed to verify the life cycle costs of distilled water produced on the small scale. open access

Tampa, Florida is home to the largest desalination plant in the United States. It is projected to produce 25 million gallons per day in order to meet 10 percent of the region's water needs. The saltwater undergoes osmosis and is then treated with lime and chlorine to ensure proper alkalinity. Historically, this region has derived its drinking water supply from groundwater. However, their new water plan calls for production cutbacks at the 11 existing northern Tampa Bay well fields to allow environmentally stressed areas to recover. To accommodate these cutbacks and still produce enough water for the region, Tampa Bay Water is turning to alternative sources for water, like desalination. Unlike other desalination plants in the United States, the Florida plant is not an emergency water source, but an economically sound, major source of a consistent water supply.^[33][34]

For more information on the Florida desalination plant, visit Tampa Bay Water at http://web.archive.org/web/20120925030955/http://www.tampabaywater.org:80/facilities/desalination_plant/index.aspx.

A second large

• For more information, contact your state natural resources agency, such as Department of Natural Resources or Department of Environmental Protection.
• International Desalination Association: http://www.idadesal.org/
• European Desalination Society: http://www.edsoc.com/
• Middle East Desalination Research Center http://www.medrc.org/
• Water Treatment Engineering and Research Group, U.S. Bureau of Reclamation: http://web.archive.org/web/20061011214844/http://www.usbr.gov:80/pmts/water/desalnet.html.
• World Bank Desalination Study [2]