Water is precious for many reasons. It is an essential resource for sustaining human, animal, and vegetable life. Agriculture is absolutely dependent on water to produce food crops and livestock. Water is crucial to tourism, navigation, and industry. Enormous amounts are used to generate power, mine materials, and produce goods. Water is an ingredient, a medium, and a means of conveyance or cooling in most industrial processes. Water supplies a vital habitat for many of Earth's creatures, from the whale to the tadpole. There are entire ecosystems that are water-based.
All these competing uses put an enormous strain on Earth's water supply. Overall, the amount of water on Earth remains constant, simply passing from one stage to another in a circular pattern known as the hydrologic cycle. Water in the atmosphere condenses and falls to Earth as precipitation, such as rain, sleet, or snow. Precipitation seeps into the ground, saturating the soil and refilling underground aquifers; it is drawn from the soil by vegetation for growth and returned into the air by plant leaves through the process of transpiration; and some precipitation flows into surface waters such as rivers, streams, lakes, wetlands, and oceans. Moisture evaporates from surface water back into the atmosphere to repeat the cycle. (See Figure 9.1.)
Humans have interrupted the cycle to accommodate the many water demands of modern life. Flowing rivers and streams are dammed up. Groundwater and surface water are pumped from their sources to other places. Water is either consumed or discharged back to the environment, usually not in the same condition. Water quality becomes increasingly important. There are two primary issues when it comes to water: availability and suitability.
Even though water covers nearly three-fourths of the planet, the vast majority of it is too salty to drink or nourish crops and too corrosive for many industrial processes. In general, saline water is defined as water that contains at least one thousand milligrams of salt per liter of water. No cheap and effective method for desalinating large amounts of ocean water has been discovered. This makes freshwater an extremely valuable commodity. Even though the overall water supply on Earth is enormous, freshwater is not often in the right place at the right time in the right amount to serve all the competing needs.
Overall Water Use in 2000
For reporting purposes, water use in the United States is classified as in-stream or off-stream. In-stream use means the water is used at its source, usually a river or stream, for example, for the production of hydroelectric power at a dam. Off-stream use means the water is conveyed away from its source, although it may be returned later.
water users. Susan S. Hutson et al., in Estimated Use of Water in the United States in 2000 (April 2004, http://pubs.usgs.gov/circ/2004/circ1268/pdf/circular1268.pdf), find that in 2000 an estimated 408 billion gallons of water per day (Bgal/d) were withdrawn from surface and groundwater sources for off-stream use in 2000. (See Table 9.1.) Of this total, 195 Bgal/d was withdrawn for generation of thermoelectric power, 137 Bgal/d was used for irrigation, and 43.3 Bgal/d went to public water supply. Together, these three uses accounted for 375.3 Bgal/d, or about 92% of the total water used.
Minor uses included miscellaneous industrial (including commercial and mining), livestock and aquaculture, and self-supplied domestic (from private wells). Complete data were not available for all minor uses in 2000.
Together, only three states—California, Texas, and Florida—accounted for 25% of all off-stream water withdrawals in 2000. Irrigation and thermoelectric power generation were the primary uses in these states.
In-stream water use for the generation of hydroelectric power at dams was not reported by Hutson and her collaborators for 2000, but according to Wayne B. Solley, Robert R. Pierce, and Howard A. Perlman, in Estimated Use of Water in the United States in 1995 (1998, http://water.usgs.gov/watuse/pdf1995/pdf/circular1200.pdf), it totaled 3.2 million gallons of water per day in 1995. In-stream water usage was highest at dams along the Columbia River in the Pacific Northwest and along the Niagara and St. Lawrence River systems in New York. The U.S. Department of Energy (DOE) notes in "Types of Hydropower Plants" (September 8, 2005, http://www1.eere.energy.gov/windandhydro/hydro_plant_types.html) that in 2005 there were approximately twenty-four hundred dams with hydro-electric-generating capacity in the United States.
freshwater and saline
freshwater and saline. Hutson and her colleagues note that freshwater accounted for 345 Bgal/d, or 85% of total off-stream water withdrawals in 2000. Freshwater is used exclusively for public water supply, domestic self-supply (private wells), irrigation, livestock watering, and aquaculture. It is also an important source
|Trends in estimated water use, selected years 1950–2000|
|[Billion gallons per day]|
|1950 a||1955 b||1960 c||1965 d||1970 d||1975 c||1980 c||1985 c||1990 c||1995 c||2000 c||1995–2000|
|a48 states and District of Columbia, and Hawaii.|
|b48 states and District of Columbia.|
|c50 states and District of Columbia, Puerto Rico, and U.S. Virgin Islands.|
|d50 states and District of Columbia, and Puerto Rico.|
|eFrom 1985 to present this category includes water use for fish farms.|
|fData not available for all states; partial total was 5.46.|
|gCommercial use not available; industrial and mining use totaled 23.2.|
|hData not available.|
|SOURCE: Susan S. Hutson et al., "Table 14. Trends in Estimated Water Use in the United States, 1950–2000," in Estimated Use of Water in the United States in 2000 (Circular 1268), U.S. Department of the Interior, U.S. Geological Survey, April 2004, http://water.usgs.gov/pubs/circ/2004/circ1268/ (accessed July 20, 2007)|
|Population, in millions||150.7||164.0||179.3||193.8||205.9||216.4||229.6||242.4||252.3||267.1||285.3||17|
|Rural domestic and livestock:|
|Livestock and aquaculture||1.5||1.5||1.6||1.7||1.9||2.1||2.2||4.47e||4.50||5.49||f||—|
|Thermo electric power use||40||72||100||130||170||200||210||187||195||190||195||13|
|Other industrial use||37||39||38||46||47||45||45||30.5||29.9||29.1||g||—|
|Source of water:|
for thermoelectric power plants, industry, and mining. Most freshwater is obtained from surface water sources (rivers and lakes), as shown in Figure 9.2.
According to Hutson et al., in 2000 irrigation and thermoelectric power plants were the largest users of off-stream water, using 137 Bgal/d (34%) and 195 Bgal/d (48%) of total freshwater and salt water withdrawals. However, the vast majority (around 91%) of the water withdrawn for thermoelectric power generation was used for cooling purposes and then discharged, meaning the actual amount of water consumed was only approximately 18 Bgal/d. Thus, irrigation was actually the largest consumer of off-stream freshwater in 2000.
Far less saline water than freshwater was used in 2000. Only 15% of all water used was saline. Hutson and her coauthors indicate that 98% of the saline water used in 2000 came from surface water sources. Thermo-electric power plants are the largest user of saline water. They accounted for 96% of all saline water use in 2000. Again, most of this water was used and returned to the environment. Industry and mining each accounted for 2% of saline water use. Saline water is unsuitable for drinking and other domestic purposes, irrigation, aquaculture, or livestock watering.
Water Use Trends (1950–2000)
According to Hutson and the other researchers, total off-stream water withdrawals in the United States climbed steadily from 1950 to 1980, declined through 1985, and have remained relatively stable since then.
Table 9.1 shows trends in U.S. population and off-stream water withdrawals between 1950 and 2000. The population rose from 150.7 million in 1950 to 285.3 million in 2000, an increase of 89%, whereas water withdrawals went from 180 Bgal/d in 1950 to 408 Bgal/d in 2000, an increase of 127%. In 1950 the per capita (per person) off-stream water withdrawal was around twelve hundred gallons per day. This value climbed steadily over the years, reaching a peak in 1975 of 1,940 gallons per day per person. Per capita use has since declined and was at 1,430 gallons per day per person in 2000.
Historically, freshwater has accounted for 85% to 95% of all water used. (See Table 9.1.) The percentage was at the high end during the 1950s and has gradually decreased, leveling off around 85% from 1980 through 2000. The nation's saline water withdrawals have consistently been 98% to 99% from surface water sources.
Even though in-stream water use for hydroelectric power is not covered by Hutson et al., Solley, Pierce, and Perlman note that in-stream withdrawals declined 4% between 1990 and 1995, from 3,290 Bgal/d to 3,160 Bgal/d.
Groundwater is water that fills pores or cracks in subsurface rocks. When rain falls or snow melts on the Earth's surface, water may run off into lower land areas or lakes and streams. Some is caught and diverted for human use. What is left absorbs into the soil where it can be used by vegetation, seeps into deeper layers of soil and rock, or evaporates back into the atmosphere. (See Figure 9.3.)
An aquifer is an underground formation that contains enough water to yield significant amounts when a well is sunk. Aquifers vary from a few feet thick to tens or hundreds of feet thick. They can be located just below the Earth's surface or thousands of feet beneath it, and one aquifer may be only a part of a large system of aquifers that feed into one another. They can cover a few acres of
land or many thousands of square miles. Because runoff water can easily seep down to the water table, aquifers are susceptible to contamination.
Modern technological developments allow massive quantities of water to be pumped out of the ground. When large amounts of water are removed from the ground, underground aquifers can become depleted much more quickly than they can naturally be replenished. Removal of groundwater also disturbs the natural filtering process that occurs as water travels through rocks and sand.
Focus on Irrigation
In 2000 irrigation accounted for 137 Bgal/d (34%) of all the water withdrawn that year. (See Table 9.1.) It was by far the largest single user of groundwater and the second-highest user of surface water (behind thermoelectric power plants). Because irrigation consumes more withdrawn water than do thermoelectric power plants, irrigation is actually the largest consumer of both surface water and groundwater.
Large-scale irrigation is concentrated in the Midwestern farm belt, southern Florida, the fertile valleys of California, and along the Mississippi River.
Water is a fundamental need in every society. Families use water for drinking, cooking, and cleaning. Industry needs it to make chemicals, prepare paper, and clean factories and equipment. Cities use water to fight fires, clean streets, and fill public swimming pools. Farmers water their livestock, clean barns, and irrigate crops. Hydroelectric power stations use water to drive generators, whereas thermonuclear power stations need it for cooling. Water quality is important to all users, as differing levels of quality are required for different uses. Even though some industrial users can tolerate water containing high levels of contaminants, drinking water requirements are extremely strict.
Clean Water Act
On June 22, 1969, the Cuyahoga River in Cleveland, Ohio, burst into flames, the result of oil and debris that had accumulated on the river's surface. This episode thrust the problem of water pollution into the public consciousness. Many people became aware—and wary—of the nation's polluted waters, and in 1972 Congress passed the Federal Water Pollution Control Act, commonly known as the Clean Water Act.
The objective of the Clean Water Act was to "restore and maintain the chemical, physical, and biological integrity of the nation's waters." It called for ending the discharge of all pollutants into the navigable waters of the United States to achieve "wherever attainable, an interim goal of water quality which provides for the protection and propagation of fish, shellfish, and wildlife and provides for recreation in and on the water."
Section 305(b) of the Clean Water Act requires states to assess the condition of their waters and report the extent to which the waters support the basic goals of the Clean Water Act and state water quality standards. Water quality standards are designed to protect designated uses (such as recreation, protection and propagation of aquatic life, fish consumption, and drinking water supply) by setting criteria (e.g., chemical-specific limits on discharges) and preventing any waters that do meet standards from deteriorating from their current condition.
Each state reports to the U.S. Environmental Protection Agency (EPA) data indicating:
- The water quality of all navigable waters in the state
- The extent to which the waters provide for the protection and propagation of marine animals and allow recreation in and on the water
- The extent to which pollution has been eliminated or is under control
- The sources and causes of the pollution
The act stipulates that the states must submit this information to the EPA on a biennial basis (every two years). Under Section 303(d) of the Clean Water Act, states are required to submit to the EPA a separate list of waters considered impaired and requiring pollution controls.
National Water Quality Databases
Before 2002 the EPA issued a biennial report called the National Water Quality Inventory that summarized the state reports required under Section 305(b) of the Clean Water Act. In 2002 the EPA began electronic collection of state water quality data and urged states to combine data required under Sections 305(b) and 303(d). This information is incorporated into the EPA's Watershed Assessment, Tracking, and Environmental Results information system as shown in Table 9.2. The EPA, in "Overview of WATERS" (May 17, 2006, http://www.epa.gov/waters/about/overview.html), provides a list of interactive databases that allow users to access water quality data for individual states. As of September 2007 not all data were included for all states. In "Status of Water Program Features (Linked to the NHD) by State, Tribe, and Territory" (September 17, 2007, http://iaspub.epa.gov/waters/eventstatus), the EPA indicates which data types were available in 2007.
The EPA also cautions against using state data to form conclusions about national trends in water quality. This is because the states use differing monitoring and assessment methods.
In general, the states assess surface water quality in rivers and streams, lakes, ocean shoreline, and estuaries. Estuaries are areas where ocean and freshwater come
|Overview of EPA's Office of Water Programs databases|
|How is water quality determined under the Clean Water Act?||Scope||Database||Description of database|
|SOURCE: Adapted from "Office of Water Programs," in Office of Water Programs, U.S. Environmental Protection Agency, August 21, 2006, http://www.epa.gov/waters/data/prog.html (accessed June 19, 2007) and "Overview of WATERS," in Overview of WATERS, U.S. Environmental Protection Agency, May 17, 2006, http://www.epa.gov/waters/about/overview.html (accessed June 30, 2007)|
|Step 1 1-Every state adopts goals or standards that need to be met for its waters, based on the intended uses of the waterbodies. Different goals are set for different waterbody uses.||Goals and uses||Water quality standards database (WQSDB)||Information on the uses that have been designated for waterbodies. Examples of such uses are: drinking water supply, recreation, and fish protection. As part of a state's water quality standards, these designated uses provide a regulatory goal for the waterbody and define the level of protection assigned to it.|
|Step 2 -Scientists monitor the waters and …||Monitoring results||Storage and retrieval database (STORET)||Repository for water quality, biological, and physical data dating back to the early part of the 20th century.|
|Step 3 -give them one of the following scores:
GOOD-The waterbody fully supports its intended uses.
IMPAIRED-The waterbody does not support one or more of its intended uses.
|Assessment scores||National assessment database (NAD)||Contains information on the attainment of water quality standards. Assessed waters are classified as either fully supporting, threatened, or not supporting their designated uses. This information is under section 305(b) of the Clean Water Act.|
|Step 4 -The impaired waters are then targeted by pollution control programs to reduce the discharge of pollutants into those waters.||Impaired waters||Total maximum daily load (TMDL) tracking system||Contains information on waters that are not supporting their designated uses. These waters are listed by the state as impaired under section 303(d) of the Clean Water Act. The status of TMDLs are also tracked. TMDLs are pollution control measures that reduce the discharge of pollutants into impaired waters.|
together. Because of the tremendous resources required to assess all water bodies, only a small portion of each water body type is actually assessed for each reporting period.
Water bodies meeting applicable water quality standards for criteria and designated uses are rated "good." Those water bodies meeting water quality standards but expected to degrade in the near future are rated "good, but threatened." Water bodies that do not meet water quality standards are rated "impaired."
National Water Quality Reports
For a better picture of the nation's overall water quality, the EPA recommends probability-based studies conducted at various sites using nationally consistent methods and designs. This approach was used in the EPA's 2007 Report on the Environment: Science Report (http://cfpub.epa.gov/ncea/cfm/recordisplay.cfm?deid=140917), which was released in draft form in May ¼ 2007 for public comment. The report presents "indicators" to gauge important aspects of water quality and track trends over time. The EPA acknowledges that data do not exist, or have shortcomings, for some indicators and should be addressed in future research and monitoring efforts.
In the draft report the EPA relies on many sources of water quality data and information, including the following reports:
- The H. John Heinz III Center for Science, Economics, and the Environment's The State of the Nation's Ecosystems: Measuring the Lands, Waters, and Living Resources of the United States (2002, http://www.heinzctr.org/ecosystems/pdf_files/sotne_complete.pdf)
- The EPA's Wadeable Streams Assessment: A Collaborative Survey of the Nation's Streams (December 2006, http://www.epa.gov/owow/streamsurvey/pdf/WSA_Assessment_May2007.pdf)
- The U.S. Geological Survey's (USGS) The Quality of Our Nation's Waters: National Water-Quality Assessment Program Pesticides in the Nation's Streams and Ground Water, 1992–2001 (Robert J. Gilliom et al., February 15, 2007, http://pubs.usgs.gov/circ/2005/1291/pdf/circ1291.pdf)
- The EPA's National Coastal Condition: Report II (2005) (December 2004, http://www.epa.gov/owow/oceans/nccr/2005/downloads.html)
The latter report was supplemented by the EPA in June 2007 with publication of National Estuary Program Coastal Condition Report (http://www.epa.gov/owow/oceans/nepccr/index.html).
the state of the nation's ecosystems
the state of the nation's ecosystems. The H. John Heinz III Center for Science, Economics, and the Environment is a nonprofit organization based in Pennsylvania that researches environmental issues of importance to national policy makers. In 2002 the center published The State of the Nation's Ecosystems, which presented and assessed various indicators that gauge the condition of natural ecosystems, including water resources. Some portions of the report were updated in 2005.
At the national level the report examines two core indicators related to water quality—nitrogen load/movement and chemical contamination—for which sufficient data exist for analysis. Nitrogen load and movement are important, because excess nitrogen can stimulate algae growth in water bodies, which can reduce oxygen concentrations to dangerous levels for aquatic creatures, such as fish and shellfish. The center found that the Mississippi River carried approximately twice as much nitrate (a form of nitrogen) in the 1990s as it did in the 1950s. Significant nitrogen sources include wastewater treatment plants, runoff from agricultural land and fertilized lawns, and certain industrial discharges. Nitrogen also makes its way into water systems through atmospheric deposition of air pollutants.
In regards to chemical contamination, the report notes that data collected between 1992 and 1998 indicate that multiple contaminants (such as pesticides and other complex organic compounds) were found in high percentages of tested water sources as follows:
- Streams—more than 80% of sites sampled had five or more contaminants detected.
- Streambed sediments—more than 90% of sites sampled had five or more contaminants detected.
- Groundwater—more than 80% of sites sampled had five or more contaminants detected.
wadeable streams assessment
wadeable streams assessment. The EPA describes Wadeable Streams Assessment: A Collaborative Survey of the Nation's Streams as "the first nationally consistent baseline of the condition of the nation's streams." It resulted from a sampling effort conducted between 2000 to 2004, in which 1,392 wadeable streams and small rivers in the lower 48 states were sampled. According to the report, wadeable streams and rivers make up 90% of all stream and river miles in the United States.
The assessment examined various physical, chemical, and biological indicators of stream health, including acidification, sedimentation (i.e., the presence of excess particles of soil in the water because of erosion), fish habitat, riparian (streambank) vegetative cover, and biological condition (as indicated by populations of benthic macro-invertebrates, such as dragonflies, mayflies, midges, and beetles). As shown in Figure 9.4, nearly all the stream length examined was in "good" condition in regards to acidification. Approximately half of the stream length was rated "good" with respect to sedimentation levels, fish habitat, and riparian vegetative cover. However, less than 30% of stream length showed a "good" biological condition. A greater percentage of stream length (42%) was rated in "poor" biological condition.
Figure 9.5 shows the most widespread or common stressors of wadeable streams determined from the assessment. These include high concentrations of nitrogen and phosphorus in the streams, high levels of riparian disturbance (e.g., from human modifications), and poor streambed sediment characteristics.
the quality of our nation's waters
the quality of our nation's waters. Since 1991 the USGS has operated the National Water-Quality Assessment (NAWQA) program to assess the condition of the nation's water resources and help policy makers make water management decisions. Data and findings have been disseminated through a series of publications known as The Quality of Our Nation's Waters. The latest report, The Quality of Our Nation's Waters: National Water-Quality Assessment Program Pesticides in the Nation's Streams and Ground Water, 1992–2001, is described by Gilliom et al. as "the most comprehensive analysis to date of pesticides in streams and ground water at the national scale."
Gilliom and his associates include data for water samples collected from 186 streams and 5,047 wells. In addition, 700 stream sites were sampled for fish and 1,052 streams were sampled for streambed sediments. Sampling was conducted in various land-use areas, such as agricultural, urban, undeveloped, and mixed use.
As shown in the left hand side of Figure 9.6, pesticides or their degradation products were detected in water samples more than 90% of the time from streams in agricultural, urban, and mixed land use areas. They were detected 65% of the time in streams in undeveloped areas. With regard to groundwater, pesticides were detected in more than half of the samples taken in agricultural and urban areas, and in one-third or less of the samples from mixed land use and undeveloped area. The right hand side of Figure 9.6 shows the surprisingly high occurrence of organochlorine compounds in fish and sediment samples taken from streams. Most organochlorine pesticides, such as dichloro-diphenyl-trichloroethane (DDT) and chlordane, have not been used in the United States for decades, yet they continue to linger in the environment.
Even though Gilliom and his collaborators find pesticides to be widespread in streams and groundwater, the detected levels were seldom greater than human-health benchmarks set by the EPA. (See Figure 9.7.) A troublesome result from a human-health standpoint is that nearly 10% of the stream water samples in agricultural areas contained one or more pesticides that exceeded the benchmarks. However, none of the stream sites sampled were sources of public drinking water. Gilliom et al. express concern regarding benchmark exceedances in ground-water because many of the wells sampled do supply domestic or public water supplies.
coastal condition reports
coastal condition reports. The National Coastal Condition: Report II presents data from assessments of 100% of the estuaries in the contiguous United States (the lower forty-eight states) and Puerto Rico. The estuary
waters were assessed for five parameters: water quality, sediment quality, benthic community quality, coastal habitat loss, and fish tissue contamination. The data were collected between 1997 and 2000. Overall, the nation's coastal waters were rated as fair, the same as in the first report issued in 2001.
Section 320 of the Clean Water Act concerns the National Estuary Program (NEP), in which threatened "nationally significant" estuaries receive special protection and restoration efforts. In 2007 the EPA issued a report on the condition of the nation's twenty-eight NEPs in the National Estuary Program Coastal Condition Report. The estuaries were rated based on four of the five parameters used in the 2004 report. The results are shown in Table 9.3 using a scale of one to five, where higher scores indicate better quality. Overall, the EPA rates the quality of the nation's NEPs as 2.7, which is considered "fair" condition.
In 2000 Congress passed the Beaches Environmental Assessment and Coastal Health Act. It requires the EPA to collect information from coastal states regarding beach closings because of environmental problems. In 2004 the states began electronic submission of the data, which were compiled into a database called the Beach Advisory and Closing On-line Notification (BEACON; http://oaspub.epa.gov/beacon/beacon_national_page.main). For the 2006 swimming season, the EPA (June 5, 2007, http://www.epa.gov/waterscience/beaches/seasons/2006/national.html) indicates that data were collected on 3,771 beaches. The EPA reports that 1,201 of these beaches (32% of the total) were
closed or issued warnings to swimmers because of high bacteria levels.
focus on water pollution sources
focus on water pollution sources. The main reason that a body of water cannot support its designated uses is that it has become polluted. There are a vast number of pollutants that can make water "impaired," but to control a specific pollutant, it is necessary to find out where it is coming from. Even though there are many ways in which contaminants can enter waterways, sources of pollution are generally categorized as point sources and nonpoint sources.
Point sources are those that disperse pollutants from a specific source or area, such as a sewage drain or an industrial discharge pipe. (See Figure 9.8.) Pollutants commonly discharged from point sources include bacteria (from wastewater treatment plants and sewer overflow), toxic chemicals, and heavy metals from industrial plants. Point sources are regulated under the National Pollutant Discharge Elimination System (NPDES). Any facility using point sources to discharge to receiving waters must obtain an NPDES permit for them.
Nonpoint sources are those that are spread out over a large area and have no specific outlet or discharge point. These include agricultural and urban runoff, runoff from mining and construction sites, and accidental or deliberate spills. Agricultural runoff is primarily associated with nutrients from fertilizers, pathogens from animal waste operations, and pesticides. Urban runoff can contain a variety of contaminants, including pesticides, fertilizers, chemicals and metals, oil and grease, sediment, salts, and atmospheric deposits. Nonpoint sources are much more difficult to regulate than point sources and may require a new approach to water protection.
The Future of Water Management
In June 2001 the EPA issued Protecting and Restoring America's Watersheds: Status, Trends, and Initiatives in Watershed Management (http://www.epa.gov/owow/protecting/restore725.pdf). A watershed is defined as a "land area that drains to a body of water such as a stream, lake, wetland, or estuary." In other words, a watershed is determined geologically and hydrologically, rather than
|Regional and national rating scores for condition of National Estuary Program estuaries, 2007|
|Index||Northeast Southeast coast||Southeast coast||Gulf coast a||West coast||Puerto Rico b||United States c|
|Note: Rating scores are based on a 5-point system, where a score of less than 2.0 is rated poor; 2.0 to less than 2.3 is rated fair to poor; 2.3 to 3.7 is rated fair; greater than 3.7 to 4.0 is rated good to fair; and greater than 4.0 is rated good.|
|aThis rating score does not include the impact of the hypoxic zone in offshore Gulf Coast waters.|
|bThis rating score includes only San Juan Bay Estuary, Puerto Rico.|
|cThe U.S.score is based on an a really weighted mean of the regional index scores.|
|SOURCE: "Table ES-2. Regional and National Rating Scores for Indices of Estuarine Condition and Overall Condition for the Nation's National Estuary Program estuaries," in National Estuary Program Coastal Condition Report, U.S. Environmental Protection Agency, June 2007, http://www.epa.gov/owow/oceans/nepccr/pdf/nepccr_exec_summ.pdf (accessed June 30, 2007)|
|Water quality index||3||5||3||3||3||3.6|
|Sediment quality index||1||4||2||1||1||2.1|
|Fish tissue contaminants index||1||4||4||1||1||2.6|
politically. Figure 9.9 shows a watershed example and the many issues and processes that affect it.
Watersheds are delineated by the USGS and identified with unique eight-digit numbers. There are more than two thousand individual watersheds around the country that are recognized by the USGS and the EPA.
The EPA believes that the nation's water quality problems cannot be solved by further regulating point-source discharges. Instead, the agency advocates a comprehensive approach that crosses jurisdictional boundaries and addresses all the air, water, land, social, and economic issues that affect a particular watershed. The watershed approach would balance competing needs for drinking water, recreation, navigation and flood control, agriculture and forestry, aquatic ecosystems, hydropower, and other uses. Currently, these uses are managed by a variety of agencies at the federal, state, and local levels. The EPA actively encourages the participation of private environmental and conservation groups in the watershed approach.
The EPA operates the program Adopt Your Watershed (http://www.epa.gov/adopt/). This program provides a database that provides information about each of the nation's watersheds. The database identifies thousands of local and regional groups that engage in activities to further water-shed protection and improvement.
Throughout history humans have used the oceans virtually as they pleased. Ocean waters have long served as highways and harvest grounds. Now, however, humankind
is at a threshold. Marine debris (garbage created by humans) is a problem of global proportions and is extremely evident in countries such as the United States, where there is extensive recreational and commercial use of coastal waterways.
International Convention for the Prevention of Pollution from Ships
Established in 1973, the International Convention for the Prevention of Pollution from Ships regulates many materials that are dumped at sea. The international treaty has been in effect in the United States only since its ratification in 1998. Even though eighty-three countries have ratified the treaty, they have not necessarily complied, as evidenced by the current level of marine debris.
Ocean Dumping Act
Congress enacted the Marine Protection, Research, and Sanctuaries Act in 1972 to regulate intentional ocean disposal of materials and to authorize research. Title 1 of the act, known as the Ocean Dumping Act, contains permit and enforcement provisions for ocean dumping. Four federal agencies have authority under the act: the EPA, the U.S. Army Corps of Engineers, the National Oceanic and Atmospheric Administration, and the U.S. Coast Guard. Title 1 prohibits all ocean dumping, except that allowed by permits, in any ocean waters under U.S. jurisdiction by any U.S. vessel or by any vessel sailing from a U.S. port. The act bans dumping of radiological, chemical, and biological warfare agents, high-level radioactive waste, and medical wastes. In 1997 Congress amended the act to ban dumping of municipal sewage sludge and industrial waste.
Oil Pollution Act
In 1989 the oil freighter Exxon Valdez ran into a reef in Prince William Sound, Alaska, spilling more than eleven million gallons of oil into one of the richest and most ecologically pristine areas in North America. An oil slick the size of Rhode Island killed wildlife and marine species. A $5 billion damage penalty was levied against Exxon, whose ship captain was found to be at fault in the wreck.
In response to the Valdez oil spill, Congress passed the Oil Pollution Act of 1990, which went into effect in 1993. The law requires companies involved in storing and transporting petroleum to have standby plans for cleaning up oil spills on land or in water. Under the act a company that does not adequately take care of a spill is vulnerable to almost unlimited litigation and expense. The law makes the Coast Guard responsible for approving clean-up plans and procedures for coastal and seaport oil spills, whereas the EPA oversees clean-ups on land and in inland waterways. The law also requires that oil tankers be built with double hulls to better secure the oil in the event of a hull breach.
Drinking Water Legislation
Almost any legislation concerning water affects drinking water, either directly or indirectly. The following pieces of legislation are aimed specifically at providing safe drinking water for the nation's residents.
safe drinking water act of 1974
safe drinking water act of 1974. The Safe Drinking Water Act (SDWA) of 1974 mandated that the EPA establish and enforce minimum national drinking water standards for all public water systems—community and noncommunity—in the United States. The law also required the EPA to develop guidelines for water treatment and to set testing, monitoring, and reporting requirements.
To address pollution of surface water supplies to public systems, the EPA established a permit system requiring any facility that discharges contaminants directly into surface waters (lakes and rivers) to apply for a permit to discharge a set amount of materials—and that amount only. It also created groundwater regulations to govern underground injection of wastes.
Congress intended that, after the EPA had set regulatory standards, each state or U.S. territory would run its own drinking water program. The EPA established the Primary Drinking Water Standards by setting maximum contaminant levels (MCLs) for contaminants known to be detrimental to human health. All public water systems in the United States are required to meet primary standards. Secondary standards cover nonhealth-threatening aspects of drinking water, such as odor, taste, staining properties, and color. Secondary standards are recommended but not required.
1986 amendments to the sdwa
1986 amendments to the sdwa. The 1986 amendments to the SDWA required that the EPA set maximum containment levels for an additional fifty-three contaminants by June 1989, twenty-five more by 1991, and twenty-five every three years thereafter. The amendments also required the EPA to issue a maximum contaminant level goal (MCLG) along with each MCL. An MCLG is a health goal equal to the maximum level of a pollutant not expected to cause any health problems over a lifetime of exposure. The EPA is mandated by law to set MCLs as close to MCLGs as technology and economics will permit.
The 1986 amendments banned the use of lead pipe and lead solder in new public drinking water systems and in the repair of existing systems. In addition, the EPA had to specify criteria for the filtration of surface water supplies and to set standards for the disinfection of all surface and groundwater supplies. The EPA was required to take enforcement action, including filing civil suits against violators of drinking water standards, even in states granted primacy if those states did not adequately enforce regulations. Violators became subject to fines up to $25,000 daily until violations were corrected.
water quality control act of 1987
water quality control act of 1987. Section 304 (1) of the revised Clean Water Act of 1987 determines the state of the nation's water quality and reviews the effectiveness of the EPA's regulatory programs designed to protect and improve that water quality. Section 308—known as the Water Quality Control Act—requires that the administrator of the EPA report annually to Congress on the effectiveness of the water quality improvement program.
The main purpose of the Water Quality Control Act is to identify water sources that need to be brought up to minimum standards and to establish more stringent controls where needed. States are now required to develop lists of contaminated waters as well as lists of the sources and amounts of pollutants causing toxic problems. In addition, each state is required to develop "individual control strategies" for dealing with these pollutants.
lead contamination control act of 1988
lead contamination control act of 1988. The Lead Contamination Control Act of 1988 strengthened the controls on lead contamination set out in the 1986 amendments to the SDWA. It requires the EPA to provide guidance to states and localities in testing for and remedying lead contamination in drinking water in schools and day care centers. The act also contains requirements for the testing, recall, repair, and/or replacement of water coolers that have lead-lined storage tanks or parts containing lead. It attaches civil and criminal penalties to the manufacture and sale of water coolers containing lead.
The ban on lead states that plumbing must be lead-free. In addition, each public water system must identify and notify anyone whose drinking water may be contaminated with lead, and the states must enforce the lead ban through plumbing codes and the public-notice requirement. The federal government gave the EPA the power to enforce the lead ban law by authorizing the agency to withhold up to 5% of federal grant funds to any state that does not comply with the new rulings.
reinventing drinking water law—1996 amendments to the sdwa
reinventing drinking water law—1996 amendments to the sdwa. In 1996 Congress passed a number of significant amendments to the SDWA. The law changed the relationship between the federal government and the states in administering drinking water programs, giving states greater flexibility and more responsibility.
The centerpiece of the law is the State Revolving Fund (SRF), a mechanism for providing low-cost financial aid to local water systems to build the treatment plants necessary to meet state and federal drinking water standards. The law also requires states to train and certify operators of drinking water systems. If they do not, states risk losing up to 20% of their federal grants. The law requires states to approve the operation of any new water supply system, making sure it complies with the technical, managerial, and financial requirements. The 1996 SDWA gives the EPA discretion in regulating only those contaminants that may be harmful to health, and it requires the EPA to select at least five contaminants every five years for consideration for new standards. A further change is that the EPA, when proposing a regulation, must now determine—and publish—whether or not the benefits of a new standard justify the costs.
Furthermore, the law affirms Americans' right to know the quality of their drinking water and mandates notification. Water suppliers must promptly (within twenty-four hours) alert consumers if water becomes contaminated by something that can cause illness and must advise as to what precautions can be taken. In 1998 states began to compile information about individual systems, which the EPA now summarizes in an annual compliance report. As of October 1999 water systems have been required to make that data available to the public. Large suppliers have to mail their annual safety reports to customers, whereas smaller systems can post the reports in a central location or publish them in local newspapers.
Sources of Drinking Water—Public and Private Supply
According to the EPA, there were 156,675 public water supply systems in operation in fiscal year 2006, serving 301.7 million people. (See Table 9.4.) These included systems that served homes, businesses, schools, hospitals, and recreational parks. Those who did not get their water from a public system were for the most part in rural areas and got their water from private wells. Even though most systems obtain their water from ground-water, most people receive drinking water from surface water sources. This is because a relatively small number of public systems using surface water sources serve large metropolitan areas.
|Public drinking water sources and violations, 2006|
|aCommunity water system: A public water system that supplies water to the same population year round.|
|bNon-transient non-community water system: A public water system regularly supplies water to at least 25 of the same people at least six months per year, but not year-round. Some examples are schools, factories, office buildings, and hospitals which have their own water systems.|
|cTransient non-community water system: A public water system that provides water in a place such as a gas station or campground where people do not remain for long periods of time.|
|SOURCE: Adapted from "EPA's Drinking Water Data," in Summary Inventory, Violations, and GPRA MS Excel PivotTables, U.S. Environmental Protection Agency, May 29, 2007, http://www.epa.gov/safewater/data/zips/annualtrends.zip (accessed June 30, 2007)|
|Community water systema||No. of systems 52,349
|Non-transient non-community water systemb||No. of systems
|Transient non-community water systemc||No. of systems
|Total no. of systems||156,675|
|Total population served||301,698,586|
|No. of systems reporting violations||50,102|
|Population served by systems reporting violations||89,375,580|
The EPA and state health or environmental departments regulate public water supplies. Public supplies are required to ensure that the water meets certain government-defined health standards. The SDWA governs this regulation. The law mandates that all public suppliers test their water regularly to check for the existence of contaminants and treat their water supplies constantly to take out or reduce certain pollutants to levels that will not harm human health.
Private water supplies, usually wells, are not regulated under the SDWA. System owners are solely responsible for the quality of the water provided from private sources. However, many states have programs designed to help well owners protect their water supplies. Usually, these state-run programs are not regulatory but provide safety information. This type of information is vital because private wells are often shallower than those used by public suppliers. The shallower the well the greater the potential for contamination.
How Clean Is Our Drinking Water?
Safe drinking water is a cornerstone of public health. In accordance with the 1996 SDWA amendments, public water systems are mandated to submit compliance reports to the EPA (March 29, 2007, http://www.epa.gov/safewater/data/pivottables.html) regarding the quality of their drinking water. The EPA indicates that 89% of the nation's community water systems achieved health-related water quality levels or treatment standards in fiscal year 2006.
According to the EPA, in "Public Drinking Water Systems: Facts and Figures" (February 28, 2006, http://www.epa.gov/safewater/pws/factoids.html), community water systems are defined as those that provide drinking water on a year-round basis. Two other classifications are non-transient noncommunity water systems—public water systems that regularly supply water to at least twenty-five of the same people at least six months per year, but not year-round (e.g., schools and hospitals with their own water systems)—and transient noncommunity water systems—public water systems that provide water to places where people remain for only short periods of time (e.g., campgrounds). The number of water systems and the population served during fiscal year 2006 are shown in Table 9.4.
Incidence of Disease Caused by Tainted Water—CDC Surveillance Report
It is difficult to know how many illnesses are caused by contaminated water. People may not know the source of many illnesses and may attribute them to food (which may also have been in contact with polluted water), chronic illness, or other infectious agents. Since 1971 the Centers for Disease Control and Prevention (CDC) and the EPA have collected and reported data that relate to water-borne-disease outbreaks. These historical data are presented and analyzed by Michael F. Craun et al. in "Water-borne Outbreaks Reported in the United States" (Journal of Water and Health, vol. 4, supp. 2, 2006). Craun and his associates define an outbreak as an incident in which at least two people develop a similar illness that evidence indicates was probably caused by ingestion of drinking water or exposure to water in recreational or occupational settings.
Figure 9.10 shows the average annual number of water-borne outbreaks by decade from 1920 through 2002. According to Craun and his coauthors, there were 207 outbreaks (averaging 17 per year) that caused 433,947 illnesses between 1991 and 2002.
Milwaukee—"The Nation's Worst Drinking Water Disaster"
In April 1993 more than four hundred thousand residents of Milwaukee, Wisconsin, became victims of what is considered the worst drinking water disaster the nation has experienced. Microscopic parasites called Cryptosporidium flourished in the city water supply, causing an outbreak of cryptosporidiosis, a diarrheal disease. At least forty deaths resulted. City and state public health officials conducted an extensive review of the outbreak's effects and causes, and their results were published by William R. Mac Kenzie et al. in "A Massive Outbreak in Milwaukee of Cryptosporidium Infection Transmitted through the Public Water Supply" (New England Journal of Medicine, July 21, 1994).
According to the article, the city was served by two water treatment plants in 1993, both of which accessed water from Lake Michigan. Both plants used a multi-step treatment process including chlorination, other chemical treatments, and filtration. Cryptosporidium are resistant to chlorine and other typical chemical treatments, because the parasites have a very hard outer shell. They also require very fine filtration for removal. Thus, they were able to move unimpeded through the system and into the public drinking water supply. Although one of the plants did notice unusually high levels of turbidity (cloudiness) in the raw water before the outbreak, biological organisms were not suspected as the cause until later. This oversight and mechanical problems at the plant were later blamed for allowing the outbreak to occur. Although the original source of the parasites could not be determined, suspected sources included cattle ranches, slaughterhouses, and sewage treatment plants that discharged to waters draining into Lake Michigan.
PUBLIC OPINION ABOUT WATER ISSUES
Each year the Gallup Organization conducts an annual poll on environmental topics. The last poll was Environment poll (2007, http://www.galluppoll.com/content/?ci=1615&pg=1). As described in Chapter 1, pollsters found that water issues dominate the list of Americans' environmental concerns. The percentage of people expressing a great deal of worry about a particular environmental problem was highest for pollution of drinking water (58%), followed by pollution of rivers, lakes, and reservoirs (53%). Maintenance of the nation's freshwater supply for household needs ranked fourth (51%). Concern over polluted drinking water has diminished since peaking in 2000. (See Table 9.5.) As shown in Table 9.6, concern about polluted surface waters has decreased dramatically since the question was first asked in 1989. By contrast, concern about the nation's freshwater supply for household needs was slightly elevated in 2007 when compared with historical levels. (See Table 9.7.)
|Public concern about pollution of drinking water, selected years 1990–2007|
|Great deal||Fair amount||Only a little||Not at all||No opinion|
|*Less than 0.5%.|
|SOURCE: "I'm going to read you a list of environmental problems. As I read each one, please tell me if you personally worry about this problem a great deal, a fair amount, only a little, or not at all. First, how much do you personally worry about—Pollution of drinking water?" in Environment, The Gallup Organization, 2007, http://www.galluppoll.com/content/?ci=1615&pg=1 (accessed June 19,2007). Copyright © 2007 by The Gallup Organization. Reproduced by permission of The Gallup Organization.|
|2007 Mar 11–14||58||24||12||5||*|
|2006 Mar 13–16||54||27||12||7||*|
|2004 Mar 8–11||53||24||17||6||*|
|2003 Mar 3–5||54||25||15||6||—|
|2002 Mar 4–7||57||25||13||5||*|
|2001 Mar 5–7||64||24||9||3||*|
|2000 Apr 3–9||72||20||6||2||*|
|1999 Apr 13–14||68||22||7||3||*|
|1991 Apr 11–4||67||19||10||3||1|
|1990 Apr 5–8||65||22||9||4||*|
|Public concern about pollution of rivers, lakes, and reservoirs, selected years 1989–2007|
|Great deal||Fair amount||Only a little||Not at all||No opinion|
|*Less than 0.5%.|
|SOURCE: "I'm going to read you a list of environmental problems. As I read each one, please tell me if you personally worry about this problem a great deal, a fair amount, only a little, or not at all. First, how much do you personally worry about—Pollution of rivers, lakes, and reservoirs," in Environment, The Gallup Organization, 2007, http://www.galluppoll.com/content/?ci=1615&pg=1 (accessed June 19,2007). Copyright © 2007 by The Gallup Organization. Reproduced by permission of The Gallup Organization.|
|2007 Mar 11–14||53||31||13||3||—|
|2006 Mar 13–16||51||33||11||5||*|
|2004 Mar 8–11||48||31||16||5||*|
|2003 Mar 3–5||51||31||13||5||—|
|2002 Mar 4–7||53||32||12||3||*|
|2001 Mar 5–7||58||29||10||3||*|
|2000 Apr 3–9||66||24||8||2||*|
|1999 Apr 13–14||61||30||7||2||*|
|1999 Mar 12–14||55||30||12||3||*|
|1991 Apr 11–14||67||21||8||3||1|
|1990 Apr 5–8||64||23||9||4||—|
|1989 May 4–7||72||19||5||3||1|
|Public concern about the nation's supply of fresh water, selected years 2000–07|
|Great deal||Fair amount||Only a little||Not at all||No opinion|
|*Less than 0.5%.|
|SOURCE: "I'm going to read you a list of environmental problems. As I read each one, please tell me if you personally worry about this problem a great deal, a fair amount, only a little, or not at all. First, how much do you personally worry about—Maintenance of the nation's supply of fresh water for household needs?" in Environment, The Gallup Organization, 2007, http://www.galluppoll.com/content/?ci=1615&pg=1 (accessed June 19, 2007). Copyright © 2007 by The Gallup Organization. Reproduced by permission of The Gallup Organization.|
|2007 Mar 11–14||51||27||16||5||*|
|2006 Mar 13–16||49||27||14||9||1|
|2004 Mar 8–11||47||25||20||8||*|
|2003 Mar 3–5||49||28||15||8||*|
|2002 Mar 4–7||50||28||17||5||*|
|2001 Mar 5–7||35||34||19||10||2|
|2000 Apr 3–9||42||31||14||12||1|
COPYRIGHT 2008 Gale
Demand and supply conditions are more complex for water than for most goods, partly because of the variety of ways in which water is useful. Residential and recreational demands for water are for such diverse uses as drinking, washing, filling swimming pools, carrying away waste, fishing, water skiing, and viewing. Comparing values in these uses is exceedingly difficult.
For most industrial processes water is a minor consideration. However, for steam generation of power, oil refining, foundries, and other coolant uses, there is demand to take in water of relatively low temperature and return it at a higher temperature. In a few processes, such as paper and textile production, there is demand to take in a large quantity of water of high quality and return it in low-quality condition, in that it then contains inorganic compounds. This is also true of irrigation, which has more effect on quantity of river flows than any other demand category, both in the United States and in the world as a whole. Irrigation affects quality because of the leaching of salts from the soil through which the water seeps during its return flow. Hydroelectric generation requires a special quantity condition (an amount at a place of fall), but it makes fewer demands on quality.
Water is essential to earthly life. At times water may be so plentiful that it is free. (At other times there may be such an oversupply that its value is negative, as in a flood.) Or the water may be nearly free, in the sense of being plentiful at a natural source but requiring effort to bring it through a spigot. Or it may be so scarce at the source that, at a zero price, more would be demanded than is available.
In addition to scarcity of quantity, scarcity of desired quality characteristics is common. Because water taken in may be discharged in a changed quality condition, one use of water can affect the quality of the water supply available to other users.
A continued decline can be expected in the fraction of demand for water met from free sources. The growth of population, the growth in per capita demand for water, and the increasing concentration of population in urban centers imply gradually rising supply prices for water of a given quality at the place of demand.
Development of a water facility serving many users is frequently less costly than for each user to attempt to satisfy his own needs individually. For instance, while individual wells and septic tanks are still used for residences in the open country, one reservoir and one sewage treatment plant will serve many thousands in a dense area. The frequently extreme economies of scale in constructing water facilities lead to water’s being supplied under local monopoly conditions, as in the cases of municipal water and outputs from a large dam. The economies of scale lead sometimes to the fulfilling of various demands for water under conditions of joint supply, for example, by a multipurpose dam, which supplies water for irrigation, power, recreation, and flood control.
Markets provide only one of the institutional means through which the uses of water supplies are determined and through which investments affecting supplies are made. Laws and administrative mechanisms also regulate water use; and in addition to private companies, governments at all levels make investments to obtain water and alter its quality.
Irrigation. In some cases, water can be analyzed in the traditional manner for a purchased input. For example, if the water withdrawn from a river for irrigation is of naturally good quality and if there is no downstream use affected by return flows, attention can be centered on the backward-sloping schedule showing how a change in the price paid for water would affect the amount of water a farmer chooses to take. At a sufficiently low price, a maximum amount would be chosen. If the charge is gradually raised above this point, the number of acre-feet of water demanded will decrease because a farmer will find it increasingly in his interest to bear the costs associated with using less water at higher charges per acre-foot. Possibilities for economizing on water include reducing ditch losses, varying the number of crops per year from a given field, shifting toward less water-intensive crops, and varying the proportion of his land which he irrigates. If the charge for water should become sufficiently high, no water would be used—landowners would resort to non-irrigated farming or would not farm at all on that particular land.
The schedule that has been described depicts a situation in which all the water chosen can be obtained at a given price. One could use the farmer-demand schedules to set a charge per acre-foot at which all demands added up to the total quantity diverted. In practice, predetermined quantities may be delivered to farms on an irrigation project. Yet, estimating the demand schedule can be helpful in indicating how value obtained from using the water depends on amounts delivered. The schedule could be used to make direct allotments of water to farmers, and thus achieve the same allocation as if purchases at a charge per acre-foot were allowed. There is a presumption that allotting water on this basis helps to obtain a maximum value from use of the water because the value to each farmer of having an extra acre-foot is then near the price per acre-foot and so tends to be the same for all farmers. Under these conditions, few if any reallocations of water from lower-value to higher-value uses might be possible.
The demand schedule for irrigation water is seldom estimated explicitly. Through judgment and informal comparing of possible levels of water application, a fair approximation to allocation for maximum value may nonetheless be achieved within many irrigation projects. In the allocation of water among different irrigation projects within a river system and among irrigation and other uses, failure to consider the demand schedule for water probably results in greater shortfalls from maximum value. Transfers between withdrawal sites are impeded by laws against selling water rights, by legally established use priorities, and by interstate compacts. As a result, the value of an extra acre-foot may be grossly different among uses, even though the water could be easily transferred by changing the point of withdrawal.
In the eastern United States, the riparian doctrine, attaching use of water to adjacent lands, tends to restrict water usage that would affect persons downstream. The effect on value obtained from water use is not, however, as great as one might at first suppose, since water is not generally scarce in quantity terms in the East. In the western United States the appropriative doctrine gives right to use of the water on land where it was first used, even though this may preclude downstream use. If the first use were always the most valuable use, this system would give allocation for maximum value, but current demands can become appreciably different from historical demands.
Some of the grosser geographical and temporal disparities between the values of extra water have been eliminated by the construction of interbasin canals and facilities to even out supplies through storing above and below ground. The costs may have exceeded the addition to value made possible by these investments; however, one use of supplies made available has been to meet higher-value demands.
The fact that there are large differences in the prices people would be willing to pay for additional water does not necessarily mean that additions to total value would be great if water were reallocated. For demands that are price inelastic, only limited quantities need to be reallocated to equalize marginal values, with a correspondingly limited increase in total value obtained from using water.
Some of the greatest losses connected with legal procedures may be due to delay. Streamlining court procedures could avoid the years now required to settle a case when water use is disputed.
Making water rights salable. How great the gains would be from following the frequently made suggestion that water rights be made salable is unknown. Some costs of new investments in water supplies might be avoided because growing demands could be partially met by buying out old uses instead of building new facilities. Yet, harmful effects on third parties (persons not directly involved in a water transaction but affected by it) may be particularly great in such cases. One challenging problem in making water rights salable is the avoidance of deleterious consequences for goals other than maximum value from water use, including prevention of the rapid decline of whole communities. Further problems are involved in devising procedures for complex situations. Because water flows, persons affected by transfers of water rights are often farther removed than those affected by ordinary property right transfers. If water rights are sold, it becomes necessary to devise means of reflecting the interests of these affected persons— interests similar to those protected by zoning in the case of ordinary property rights. Variation in quantity and quality of flows makes the rights transferred more difficult to specify than when selling a piece of land. Interrelations between users give rise to situations in which the operation of market incentives does not result in obtaining maximum value from use of water. In pump irrigation, for instance, where a number of individual farmers are utilizing a common underground supply, it is likely to be drawn down more quickly than is consistent with obtaining maximum value. [See Conservation, article onECONOMIC ASPECTS, for a discussion of the common-pool problem.]
Flood control. The demand schedule for flood protection shows the benefits achieved when various quantities of water are withheld. Each point on the schedule indicates the income that would be derived with that amount of flood protection minus the income that would have been derived if the last increment of flood protection were not provided. Planners contemplating the benefits of various sizes for a particular flood protection dam are roughly approximating this schedule. Greater attention to alternative sizes in the planning process could lead to designs that more nearly maximize the excess of benefits from flood protection over its costs.
It is difficult to sell increments of flood protection to those who benefit, since flood protection to one piece of property is likely to imply flood protection to many others. It is even unusual for a number of persons who would be affected by the same flooding to join together as a group to provide themselves with protection, although in many cases the group gains would exceed the costs. In the United States the federal government pays the cost of flood control. This creates a local incentive to press for flood control measures, since a flood control project represents an income transfer into the community. The incentive exists as long as there are any flood control benefits. A community might gain more if given a lump sum equal to the cost of constructing the dam, but this is not a choice available legislatively.
A much discussed alternative to building dams is zoning to restrict use of flood plains (see White et al. 1958). One might suppose that zoning would be inefficient because people would then be forced to find higher-cost locations; that is, one might suppose that unencumbered free choice would lead to the optimum location of activity, with people taking account of the risks of flooding. It has been contended, however, that adequate account is not taken of this particular risk. Underdiscounting is certainly encouraged if people expect that flood protection will be provided. Zoning might lead to a net gain by helping to avoid the costs of over-protecting against floods.
Residential intake. In some towns water charges to residential users do not vary with the amount of water taken, and people give little thought to how much they use. Hirshleifer, DeHaven, and Milli-man (1960) have reviewed evidence showing that among cities per capita water use tends to vary inversely with the amount charged per gallon of water. At charges severalfold higher than ordinarily observed, water intake would begin to be reduced toward necessity levels and would become highly inelastic. For a particular location, the amount demanded would finally be reduced to zero as people chose other places of residence. But because this would occur only at high prices for water, charges for water have a negligible influence on where most people live.
Demand schedules can be conceived for quality characteristics of water in residential use. The demand is undoubtedly inelastic with respect to characteristics affecting health, but there would be considerable response to charges connected with quality characteristics affecting only taste. Quality characteristics must almost necessarily be the same for all users served by a facility, and the characteristics are therefore not sold individually to each user. A nonprice method of determining quality prevails; reliance is on administrative standards. These standards have been described by the National Research Council Committee on Water:
The components of standards include technical analyses of requirements, estimation of social norms and acceptability, codification of previously acceptable practice, and professional regard for “better” practice. In the case of municipal water supply, for example, standards are set partly on grounds of health protection (scientific analysis of tolerance of human beings for coliform count and of effectiveness of treatment in reducing organic content), partly on estimation of the acceptability of given levels of color and taste, partly on confidence in traditional treatment (filtration and chlorination), and partly out of a desire to continuously upgrade the product. (1966, p. 38)
But standards may be set, in part at least, with a view to costs of different levels of quality, indicating some response of standards to market demand.
Disposal. In some cases the demand for water involves the economics of a waste product. This is exemplified by a town’s discharge of sewage into a river. Through biological action and dilution, the water will begin to purify as it moves downstream. But users in the stretch where purification is incomplete will be adversely affected. To the town discharging the sewage, the water pollution may be costless, but it is not costless if one takes account of users downstream who must treat water taken in or turn to alternative sources. One might, therefore, consider instituting a gradually rising charge to the town per unit of effluents discharged. The schedule of the amount of pollutants emitted as the charge is varied is the demand to use water as a medium of waste disposal. Kneese (1964) has examined the feasibility of such a system of charges, which would give users incentives to take account of the effects of their pollutants on downstream users. A user would then have to find that quantity on his demand schedule for emitting pollutants where the price he is prepared to pay just equals the cost that an extra unit of pollutant imposes on others.
The optimum degree of pollution—that which maximizes the value of the water resources to man—can at best be approximated. Lack of measuring devices to identify pollution impedes decisions affecting water quality. Knowledge about biological and chemical reactions is imperfect. Insofar as sewage and industrial pollution have been controlled, direct regulation has been the method most often used. There are barriers to altering standard-of-purity requirements, particularly in response to changing conditions. Waste disposal has generally been added gradually as activities have developed along rivers. Early polluters tend to establish “squatter’s rights” to their actions. Even when given the authority, regulating agencies have hesitated to require drastic changes in practices of polluters of long standing.
Group effort to control pollution may be less costly than individual efforts: a plant can treat several pollution sources; certain rivers can be maintained at high quality while others nearby are used as open sewers (a purpose of some multipurpose dams is to provide water in periods of low flow, to keep quality at acceptable levels). There is as yet no generally prevalent means for organizing to undertake group measures affecting water quality.
Values difficult to quantify. If a project affects the production of goods and services which are sold, then benefits can be estimated as the increase in real market value of national income resulting from the project. This is the approach implied for most of the water uses discussed above.
Market valuations can sometimes be used even when the outputs made possible by the water are difficult to value—by estimating benefits as the saving in costs over the cheapest alternative way of providing the outputs. This method has been used to estimate benefits from pollution abatement, municipal water supply, and navigation. A proviso, sometimes violated, is that the alternative way of providing the outputs should be justifiable. One should not falsely claim large benefits by assuming an alternative way which is more expensive than the benefit that would be obtained.
If something must be purchased in order to enjoy a recreation or aesthetic benefit, such as the land around a reservoir which gives access to use and sight of the water, the increase in sale value due to the water gives a clue to the magnitude of benefit. Because there are generally areas of public access to beaches and lakes, most water resource projects have some benefits whose enjoyment is not associated with anything salable. An approach to estimating public access benefits is to observe the efforts that people make to obtain the benefits. If a certain proportion of a distant population bears the expense of travel and time to visit a park, then it may be conjectured that, ceteris paribus, there is a saving in travel and time cost for a like proportion living nearby, who would be willing to travel far but do not have to. The Hotelling-Claw-son approach to estimation of park recreation benefits is based on this idea (see Clawson 1959).
But with regard to some of the most important benefits, it is difficult to think of any behavior permitting inferences about value. Thousands of commuters and tourists per day cross a river full of black water with detergent foam on it, and each person is revolted for a minute or two by the sight and the sickly smell. Irreplaceable assets are particularly difficult to evaluate. A dam may flood a famous, unique wild area or a sacred site that is the mecca for a Southwest Indian tribe.
Even if objective ways can be found to measure the value beneficiaries put on outputs, there remains the question of whether to accept people’s tastes. For instance, it may be desirable to encourage people to engage in outdoor recreation as a way of improving the quality of their lives— regardless of whether they originally feel this need.
Lacking objective guides to valuation, the public tends to split into two groups, one feeling that benefits which lack good market indicators have near zero value and the other feeling that they are almost infinitely valuable. To provide better guides remains a challenge to social science research.
General formulation. The present discussion has hinted at the variety of demands for water. More comprehensively, the demand for water is concerned with four magnitudes: quantity taken, quantity returned, quality taken, quality returned. Each user takes a quantity of water of some quality and may return a different quantity of changed quality. The ratio of quantity taken to quantity returned can sometimes be considered as fixed, but not always, so there may be significant variation in all four magnitudes. There may be costs associated with all the magnitudes. The demand for water is a set of simultaneous relations indicating how the magnitudes vary with each cost. These relations are
T = fT(p) ,
D = fD(p) ,
LT1 = ft1(p) ,. .. .. .
LTK = fT(p) ,
LD1 = fD1(p) ,. .. .. .
where T is the quantity of water taken in, D is the quantity discharged, and the L’s refer to quality-characteristic magnitudes taken in and discharged, e.g., pounds of compound or heat content—all magnitudes measured in rates per unit time. The demand for each quantity and quality magnitude can depend on all other costs and revenues. The vector p stands for (PT, Pn, PTi,…, PTx, PD1,…, PDx,R1,…,RN), where the P’s are the incremental values associated with the water quantity and quality magnitudes and the H’s are the prices of non-water inputs and outputs. Because of variation over time, especially seasonal variation, and because water may return from a use, with a lag, to a significantly different location from that at which it was taken in, place and time subscripts not shown here may be needed in some cases.
The above discussion of the difficulty of quantifying values concerned the estimation of the P’s in the absence of good market indicators. Most of the examples discussed earlier were simplified by assuming that every P except one in a particular situation was zero. As rivers become more crowded, this becomes less and less likely.
Demands are more elastic with respect to the P’s in the long run than in the short run, especially for industries whose location decisions are influenced by water availability. Development of new technologies in response to scarcity of water quantity and quality characteristics makes long-run demand more elastic. An example is the development of devices for extensive recycling of coolant water where river temperatures have become a problem. Much other engineering research on water treatment is affecting the demand for water by reducing costs, partly in response to incentives to economize with respect to particular quality characteristics.
Traditional benefit-cost analysis. Estimates of benefits and costs are made to help in deciding whether to undertake many particular federal water projects. Guidelines for agencies making the estimates have been prepared by a group of government economists known as the Subcommittee on Evaluation Standards (see U.S. Inter-agency Committee …1950). Benefit-cost analysis seeks to estimate, on the basis of investment theory and welfare economics, the contribution of projects to real national income. It has been intensively studied by Eckstein (1958), Krutilla and Eckstein (1958), and others. [See related discussions in Investment, article onthe investment decision; economics of defense.] The remainder of the present article will emphasize the unsettled questions important for water resource development.
Further valuation difficulties. Irreversibilities in decisions about water abound, and systematic procedures for making such decisions are needed. Ciriacy-Wantrup (1952) points out that resources may be used to the point where replenishing them becomes very expensive. An example is drawing down ground water levels until sea water intrudes. Uncertainty considerations are paramount, since unforeseeable future demand for resources may ex post facto make it desirable to have conserved the resource, even if this is not indicated by a present value calculation based only on expected demands. Therefore, even if agreement were to be reached on the appropriate discount rate, the problem would remain of making choices affecting benefits in different time periods. [See Conservation, article oneconomic aspects.]
Another problem of irreversibility is the phasing of related projects. Here again, uncertainty must be considered, and therefore the need for maintaining flexibility.
As a third type of irreversibility, consider the decision whether to reserve land for recreation around a reservoir. Costs are likely to be lower, in relation to the benefits, if the land is reserved before other urban uses come in. As congestion increases, recreation demands rise; but costs may rise more rapidly, due to the increasing acquisition price of the land, reflecting the value of alternative uses at the time of acquisition. The present value of net benefits for alternative starting years declines and in time may become negative as the starting year becomes more distant. Thus, the gains possible from early initiation of the project are lost forever as time passes.
A standard assumption is that costs reflect the alternative values that would be obtained in the absence of a project. Yet, if a project results in more productive employment, the wage rate overstates costs to society. Suppose a flood control project results in employment of geographically immobile workers who would otherwise be unemployed. As a result of increased production of tomatoes, say, on the protected land, workers in other regions who would be satisfying this demand in the absence of the project will be forced out of tomato production. But if the displaced workers are mobile and have skills suited to growing industries elsewhere, they will probably find alternative employment. In this case the project has a net employment-creating effect. Identifying these chains of events and estimating their importance is a challenge.
Another problem concerns the effect of a water resource project on local government services. In declining regions, past outmigration of productive persons has left concentrations of children and older persons, coupled with a relatively low local tax base. As a result, government services, particularly education, tend to be inferior. From the national point of view, more optimum expenditures on the services would be a benefit, as indicated by the high rates of return that have been found for investments in education. Thus, there is a need to quantify the indirect effects a project may have through changing local tax bases.
The importance of such geographical impacts is recognized in calculations of “secondary” benefits of increased income to local areas. But these calculations fail to indicate where activities in the rest of the economy are displaced. Moreover, guides are lacking as to what is a desirable distribution of economic activity spatially. Further analyses could yield regional development objectives, that recognize interrelations of regions, as part of a more consistent approach to the income-distributional effects of projects.
Policy. Income-distribution goals, broadly interpreted, greatly complicate the task of choosing projects. An example of how they have entered planning is the cost allocation procedures used as a basis for levying repayment charges. The separa-ble-costs-remaining-benefits method, which has been accepted in principle by government agencies, allocates proportionally to the gains received by beneficiaries costs not associable with any purposes. Yet, the method is seldom followed in a straightforward manner. For instance, interest is waived on costs of irrigation on federal projects, which amounts to a subsidy of about half the cost. Similarly, pricing of project outputs often reflects income-distributional objectives rather than attempting to give incentives to achieve maximum value from use of the water.
Besides favorable influence on the size distribution of income, distributional desiderata include protecting against sudden economic loss, protecting identity of cultural and social groups, providing equality of opportunities for children without extreme interference with the tastes of parents, to name only a few. Some persons feel that distributional goals should be overriding, while, at the other extreme, some persons still view distributional considerations as undesired interferences with the water value goal, resulting from an imperfect political process. There is surprisingly little serious discussion about the goals of policies (other than the water value goal), the weights to be assigned to the goals, or the alternative means of reaching the goals. This results in inability to distinguish between policy pressures that accurately reflect social welfare and those that run counter to it.
Even though we are hindered by lack of understanding of goals, it would be useful to attempt to develop criteria for evaluating the variety of institutional variables that influence water use, including those related to water contracts, water districts, laws, and governmental organization. Explanations of policy formation are needed to predict the effectiveness of possible reforms. These include analytical studies of how water laws and other institutions have responded previously to changing conditions. It would also be helpful to have theoretical models of legislative behavior predicting outcomes of water decisions on the basis of constituency interests, party positions, coalition formation, and the views of particular influential men. Ideologies and abstract ideas (the conservation movement, the appeal of dams as monuments) affect voting, particularly that of groups with a minor economic stake.
External pressures on legislatures and agencies are related to the value of water in alternative uses. If pressures from primary beneficiaries and secondary beneficiaries are proportional, the secondary beneficiaries do not change the pressure pattern. Pressures from those who might suffer sharp losses reflect distributional considerations that seem desirable. Pressures for secondary capital gains, e.g., a rise in local retail land values, are often strong and in the direction of a more unequal income distribution.
Analysis of pressures could yield quantitative estimates of gains and losses from legislative behavior under alternative arrangements. Estimates are needed of the true alternative (opportunity) costs of water projects, namely, the other activities legislatures would authorize if water project budgets were lower.
G. S. Tolley
Ackerman, Edward A.; and Löf, George 1959 Technology in American Water Development. Published for Resources for the Future. Baltimore: Johns Hopkins Press.
Brewer, Michael 1962 Public Pricing of Natural Resources. Journal of Farm Economics 44:35-49.
Ciriacy-Wantrup, Siegfried Von (1952) 1963 Resource Conservation: Economics and Policies. Rev. ed. Berkeley: Univ. of California, Division of Agricultural Sciences, Agricultural Experimental Station.
Ciriacy-Wantrup, Siegfried Von 1956 Concepts Used as Economic Criteria for a System of Water Rights. Land Economics 32:295-312.
Clawson, Marion 1959 Methods of Measuring the Demand for and Value of Outdoor Recreation. Washington: Resources for the Future.
Eckstein, Otto 1958 Water-resource Development: The Economics of Project Evaluation. Harvard Economic Studies, Vol. 104. Cambridge, Mass.: Harvard Univ. Press.
Hirshleifer, Jack; Dehaven, James C; and Milliman, Jerome W. 1960 Water Supply: Economics, Technology and Policy. Univ. of Chicago Press.
Kneese, Allen V. 1964 The Economics of Regional Water Quality Management. Published for Resources for the Future. Baltimore: Johns Hopkins Press.
Krutilla, John V.; and Eckstein, Otto 1958 Multiple Purpose River Development. Published for Resources for the Future. Baltimore: Johns Hopkins Press.
Maass, Arthur et al. 1962 Design of Water-resource Systems: New Techniques for Relating Economic Objectives, Engineering Analysis, and Governmental Planning. Cambridge, Mass.: Harvard Univ. Press.
National Research Council, Committee On Water 1966 Alternatives in Water Management: A Report. Publication 1408. Washington: National Academy of Sciences-National Research Council.
Smith, Stephen C. 1961 The Rural-Urban Transfer of Water in California. Natural Resources Journal 1: 64-75.
Symposium on the Economics Of Watershed Planning, Knoxville, 1959 1961 Economics of Watershed Planning. Edited by G. S. Tolley and Fletcher E. Riggs. Ames: Iowa State Univ. Press.
U.S. Congress, Senate, Select Committee On National Water Resources 1961 Report. 87th Congress, 1st Session, Senate Report No. 29. Washington: Government Printing Office.
U.S. Geological Survey 1960 A Primer on Water, by Luna B. Leopold and Walter B. Langebein. Washington: Government Printing Office.
U.S. Inter-Agency Committee On Water Resources (1950) 1959 Proposed Practices for Economic Analysis of River Basin Projects: Report. Subcommittee on Evaluation Standards. Rev. ed. Washington: Government Printing Office.
White, Gilbert F. et al. 1958 Changes in Urban Occu-pance of Flood Plains in the United States. University of Chicago, Department of Geography, Research Paper No. 57. The Department.
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The planet Earth is inherently short of freshwater, the proportion of which is as little as 3 percent of all available water. The remaining 97 percent of water is saline and is stored in the oceans. Of the 3 percent of water that is freshwater, only 0.3 percent flows through surface water systems such as rivers and lakes; the remaining 2.97 percent is frozen in glaciers and ice caps or held in the ground.
This inherent scarcity has been worsened by the accelerated diversion of water for agricultural, commercial, industrial, and residential uses, which has increased greatly in response to a growing world population that reached 6.5 billion people in 2006. As much as 95 percent of that growth has taken place in the water-deficit developing world, predominantly in Asia and Africa. Among all human uses, agriculture tends to use 70 percent of the available freshwater. According to experts, 1 ton of grain requires 1,000 tons of water. As agriculture increasingly is becoming dependent on irrigation, especially in Asia, the most populous continent, the availability of water for industrial, commercial, and municipal uses has been shrinking.
The impact of dwindling water supplies on humankind is evident worldwide. According to a 2006 report by the United Nations Development Program, over 1 billion people are without clean drinking water and over 2.4 billion lack basic sanitation. Access to clean drinking water is lowest in Africa, and Asia has the largest number of people without basic sanitation. The human toll of the inaccessibility of water and sanitation runs as high as 2 million child deaths a year (United Nationals Development Program 2006). In all, in the early years of the twenty-first century 12 million people died each year from drinking contaminated water.
In 2003 the United Nations World Water Development Report estimated that $110 billion to $180 billion would be needed each year to provide safe drinking water to the poor in developing countries. Although an annual outlay of that size for water resource development seems prohibitive for low-income nations, the economic benefits of such an outlay would be two to three times as large. Recognizing those benefits, the United Nations Millennium Development Project planned to widen the access of the poor to safe drinking water by 50 percent by 2015. The economic benefits of increased access to safe drinking water in terms of health, longevity, and time saved in fetching water range from $300 billion to $400 billion a year.
International development agencies such as the World Bank and the Asian Development Bank (ADB) plan to broaden the access of the poor to safe water by pricing water use and privatizing water resources. Water pricing means consumers will pay the fees, taxes, or charges for water supplies they use. It has been argued that water privatization can meet the water needs of the poor effectively. In 2005 Segerfeldt pointed out that public water systems in developing countries tend to serve wealthy and middleclass households, whereas the poor are left to draw from municipal water mains. However, 80 percent of the poorest parts of the population in fifteen developing countries are not served by municipal water supplies (Segerfeldt 2005). Although privatization is intended to bring the entire water supplies and treatment systems of developing countries into the private market, in the first decade of the twenty-first century only 3 percent of the poor worldwide were served by private-sector water supplies.
Critics see water privatization as a “global water grab” with disastrous outcomes in places such as Cochabamba, Bolivia. Between 1989 and 1999 the proportion of Bolivian households connected to the public water system fell from 70 percent to 60 percent. Water was available only sporadically; 99 percent of the wealthier households were receiving the subsidized water, whereas in some poorer suburbs less than 4 percent were receiving water.
In 2002 Vandana Shiva blamed the World Bank and the ADB for creating water markets to benefit multinational corporations (MNCs). Privatization, she argued, is preceded by a hike in water tariffs to “secure private sector investment in risky countries” (Shiva 2005). The tariff increase, Shiva asserted, exceeds by ten times the “full cost recovery,” although this is rationalized by privatization supporters. Using the case of her native India, Shiva stated that private operators will harvest public investment of 1 trillion rupees for private gains through water privatization in India (Shiva 2005).
Pricing and privatization of water are intended to rationalize water use. In light of worldwide extreme income inequalities, however, it is feared that privatization will save water by diverting it from the poor to the rich and from rural areas to urban centers. In 2005 Shiva argued that the best way to conserve water is to make a radical shift from water-intensive chemical farming to organic farming, along with a reversal in export-led agricultural production, which amounts to exporting “virtual water” to the rich consumers of the North at the expense of the poor in the South.
Like India, China is poor in freshwater supplies, the per capita availability of which is one-fourth of the world average (Yu and Danqing 2006). The pollution of rivers and groundwater from industrialization and urbanization has exacerbated the water shortage. In the first decade of the twenty-first century, two-thirds of Chinese cities had an insufficient supply of freshwater and 110 of them had critically inadequate access to freshwater.
Beijing’s plan to meet the water needs of urban centers angered Chinese rural residents. On July 6, 2000, thousands of farmers in the Yellow River Basin in eastern China clashed with police over a government plan to recapture runoff from a local reservoir for cities, industries, and other uses (Postel and Wolf 2001). The incident took place in Shandong, the last province through which the Yellow River runs before reaching the sea. Worldwide water disputes have been occurring in the downstream regions of overtapped river basins (Postel and Wolf 2001). The Yellow River has been running dry in its lower reaches on and off since 1972, and its dry spell grew to a record 226 days in 1997. As a result, per person use of water in China, which already was severely low, fell by 1.7 percent in seven years (Yu and Danqing 2006).
The Indus Basin Intrastate water shortages have spilled over into interstate water conflicts. In the first decade of the twenty-first century India and Bangladesh were worrying about alleged Chinese attempts to divert the waters of Yarlung Zangbo River (which in India is called Brahmaputra, and in Bangladesh Jamuna) into the Yellow River. The Yarlung Zangbo passes through the Tibet Autonomous Region into the Indian states of Arunachal Pradesh and Assam and into Bangladesh. Even starker conflicts have been simmering between India and Bangladesh over the Ganges River and between India and Pakistan over the Jhelum River. In the 1960s and early 1970s India unilaterally constructed a barrage (dam) on the Ganges River at Farakka, near the border with Bangladesh, to divert more river water to the port of Calcutta (Postel and Wolf 2001). That diversion left Bangladesh with significantly less water for irrigation during the dry season, causing increased migration of its population across the border into the Indian states of West Bengal (Postel and Wolf 2001) and Assam. Although the Indus River Basin Treaty between India and Pakistan of the 1960s has held, the growing water and power needs of each nation are fueling the conflicts as never before. The major conflict between Islamabad and New Delhi has erupted over the controversial construction of Bhagliar Dam over the Jhelum River in the disputed territory of Jammu and Kashmir; that conflict was being arbitrated by the World Bank.
Euphrates and Jordan River Basins Euphrates and Jordan River Basin nations have long argued over their shared surface water systems. Syria and Iraq experienced a reduction of almost 50 percent in the average flow of the Euphrates after the 1970s (Allan 1998). Both countries have been anticipating additional reductions in the flow of Tigris as well. The Euphrates and Tigris rivers originate in Turkey, which has diverted their water by building dams. In the case of the Jordan basin, the river system rises in four tributaries (Lowi 1995): the Yarmouk in Syria, the Banias in Israeli-occupied Syria, the Hasbani in Lebanon, and the Dan in Israel. The Banias, Hasbani, and Dan meet in northern Israel to form the Upper Jordan River, which flows into Lake Tiberias, and then the Lower Jordan. Israel has become the upstream riparian basin on the Upper Jordan system, and Syria is upstream on the Yarmouk. Jordan and the Palestinians, as downstream riparian basins vis-à-vis both Israel and Syria, have remained in the worst positions in the basin (Lowi 1995).
About one-half of Israel’s annual supply of groundwater and one-quarter of its total renewable supply of freshwater originate in two subterranean basins in the West Bank (Lowi 1995). By virtue of its occupation of the West Bank, Israel has been controlling water in the territory. The result has been that approximately 80 percent of West Bank water is exploited in Israel and by Israeli settlers in the territory, leaving only 20 percent for the Palestinian population (Lowi 1995). Although Lowi does not think that water disputes alone could cause active conflict between Israel and the countries of the Jordan River Basin, Adel Darwish (2003) and John Bulloch and Darwish (1993) believe that water disputes underlie the political conflict in the region. King Hussein of Jordan and the late Egyptian President Anwar Sadat, each of whom signed peace treaties with Israel, vowed never to go to war with Israel except to protect water resources (Darwish 2003). Bulloch and Darwish (1993) claim that water was the hidden agenda for past conflicts and has been a major obstacle to a lasting peace in the region. The Six Day War, they argue, started because Syrian engineers were working to divert part of the water flow from Israel. The Israeli leader Ariel Sharon backed up their argument by saying: “People generally regard 5 June 1967 as the day the Six-day war began. That is the official date. But, in reality, it started two and a half years earlier, on the day Israel decided to act against the diversion of the Jordan” (quoted in Darwish 2003).
It is feared that global warming will cause further stress in the already water-short nations of Asia, Africa, and the Middle East. Although bilateral and multilateral watersharing mechanisms are important to ensure critical water supplies, the significance of conservation and further development of water resources cannot be overemphasized. There are a number of technological means to augment water resources, including but not limited to cloud seeding, desalination, wastewater reuse, rain harvesting, and importing water from relatively wet zones (Postel and Wolf 2001). Of equal importance are a shift from water-intensive chemical farming to less water-intensive farming methods and a reversal in export-led agricultural production, which amounts to the export of virtual water from the water-short South to the water-surplus North (Shiva 2005).
SEE ALSO Agricultural Industry; Arab-Israeli War of 1967; Gender; Global Warming; Inequality, Political; Irrigation; Needs; Nutrition; Poverty; Poverty, Indices of; Privatization; Public Health; Sharon, Ariel; Women and Politics
Allan, Tony. 1998. Avoiding War over Natural Resources. Global Policy Forum. http://www.globalpolicy.org/security/docs/resource2.htm.
Bulloch, John, and Adel Darwish. 1993. Water Wars: Coming Conflicts in the Middle East. London: Victor Gollancz.
Darwish, Adel. 2003. Analysis: Middle East Water Wars. BBC News, May 30. http://news.bbc.co.uk/2/hi/middle_east/2949768.stm.
Lowi, Miriam R. 1995. Water and Power: The Politics of a Scarce Resource in the Jordan River Basin. Cambridge, U.K., and New York: Cambridge University Press.
Postel, Sandra L., and Aaron T. Wolf. 2001. Dehydrating Conflict. Foreign Policy 126: 60–67. http://www.edcnews/Reviews/Postel_Wolf2001.pdf.
Segerfeldt, Fredrik. 2005. Water for Sale: How Business and the Market Can Resolve the World’s Water Crisis. Washington, DC: Cato Institute.
Shiva,Vandana. 2002. Water Wars: Privatization, Pollution and Profit. Cambridge, MA: South End Press.
Shiva, Vandana. 2005. Water Privatization and Water Wars. ZNet Daily Communications. http://www.Zmag.org/Sustainers/Content/2005-07/12Shiva.cfm..
United Nations. 2003. First UN World Water Development Report, 2003: Water for People, Water for Life. United Nations: World Water Assessment Program. Paris: UNESCO Publishing.
United Nations Development Program. 2006. Human Development Report 2006: Beyond Scarcity: Power, Poverty, and the Global Water Crisis. Washington, DC: UNDP.
Yu, Au Loong, and Liu Danqing. 2006. The Privatization of Water Supply in China. Amsterdam, Netherlands: Transnational Institute. http://www.tni.org/books/waterchina.pdf.
COPYRIGHT 2008 Thomson Gale
Water Supply and Conservation
WATER SUPPLY AND CONSERVATION
WATER SUPPLY AND CONSERVATION. Water covers about three-quarters of the earth and makes up more than two-thirds of the human body. Without water (which supports animal habitats, the food chain, and human life) life as we understand it would be impossible. An abundant and invaluable resource, water can be poisoned and poorly used.
Each of us lives in a watershed, a landmass that drains into a body of water. Natural forces, such as gravity and condensation, distribute rainwater throughout the watershed, giving life to the plants and animals within.
When Europeans first began settling the New World, natural resources were considered basically inexhaustible. Over the centuries, however, trees were clear cut, animals over-hunted, and water used without concern for conservation or for maintaining it in an unpolluted state. As settlers pushed westward, they continued earlier practices—using (sometimes abusing) natural resources without thought for the future.
The largest damage human beings caused to the environment came with the Industrial Revolution. Factories dumped toxic materials freely into waterways and filled the air with particulate pollutants. Expansionists cut down trees to build railroads and settle new lands without regard to watersheds or the disruption of ecosystems. Forests, which are important to watersheds because of their ability to absorb water and prevent flooding, were completely cut down for timber throughout the country. The business of men was deemed more important than the business of nature, and those few voices that spoke out against expansion were labeled antiprogress.
Although Yellowstone, Sequoia, and Yosemite National Parks were created in the late nineteenth century, it was not until Theodore Roosevelt assumed the presidency in 1901 that a widespread program of conservation began. The word "conservation" probably originates with Gifford Pinchot, head of the United States Forest Service during the administration of Theodore Roosevelt. Roosevelt, greatly influenced by environmentalists such as John Muir, took advantage of the Forest Reserve Act of 1891 that permitted the president to set aside lands as national forests. Presidents William Henry Harrison, Grover Cleveland, and William McKinley had transferred some 50 million acres of timberland into the federal reserve system prior to Roosevelt; the conservation movement fully supported Roosevelt as he expanded these efforts, eventually adding another 150 million acres. Congress would complement Roosevelt's measures in 1911 with the Weeks Act, which allowed for multiple uses of public lands. Conservation in this era was not done for the benefit of nature itself, but for the benefit of people. A broad-based deep respect for nature, or even a firmly preservationist ethic, was in the future.
The Dust Bowl
The Dust Bowl of the 1930s would show Americans how nature could inflict more harm to man than man could to nature. Already in the midst of the Great Depression, the West and Southwest experienced lengthy droughts. Drought is actually the most deadly natural phenomenon in the world; agriculture eventually collapses as crops will not grow without water, the parched topsoil blows away, and animals and humans starve. The years of drought in the 1930s hurt not just the farmer, but all those who depended on him. Crop yields reached all-time lows, and migrant workers, without crops to help harvest, quickly became vagrants.
Franklin Delano Roosevelt, elected president in 1932, did not hesitate to apply his New Deal to nature. With the help of Congress, he created the Tennessee Valley Authority (TVA) and the Civilian Conservation Corps (CCC). The TVA built dams, at once helping to preserve the natural resources of the Tennessee Valley, but also inadvertently destroying some of them. The CCC enlisted able-bodied young men to dig ditches, plant trees, and beautify parks.
World War II and the Cold War put the issue of conservation on the backburner for some time, but a new movement would emerge in the 1960s, initiated by the writings and efforts of one woman. By far the most influential piece of literature written on the subject, Rachel Carson's Silent Spring (1962) forecast the terrible consequences of the damage being done to the environment by field chemicals such as DDT (dichloro-diphenyl-trichloro-ethane). Carson, a marine biologist, had studied the effects of chemicals and pesticides on plants, animals, and water. She found that these chemicals disturbed the natural balance of the ecosystem, poisoning birds and fish, and endangering the humans who eat them. "The most alarming of all man's assault's upon the environment is the contamination of air, earth, rivers, and sea with dangerous and even lethal materials." Carson wrote, "This pollution is for the most part irrecoverable; the chain of evil it initiates not only in the world that must support life but in living tissues is for the most part irreversible. In this now universal contamination of the environment, chemicals are the sinister and little recognized partners of radiation in changing the very nature of the world—the very nature of its life" (p. 6).
Silent Spring sent a shock wave throughout the nation. Many people had assumed that the government protected them from harmful substances such as DDT. They were outraged to learn that industry might be poisoning them. The outcry was tremendous, the environmentalist movement grew, and Congress was forced to act.
Legislation and Other Government Initiatives
In 1969 Congress passed the National Environment Policy Act. This Act established a general policy for protecting the environment; it required that all government agencies give proper consideration to the environment before initiating or approving projects. In 1970 Congress passed the Clean Air Act and the Occupational Safety and Health Act. The Clean Air Act regulates air emissions from area, stationary, and mobile sources. The Occupational Safety and Health Act provides for worker safety, protecting workers from toxic chemicals, excessive noise, mechanical dangers, poor climate conditions, and unsanitary settings. The Occupational Safety and Health Administration was created to enforce these standards nationwide.
In 1970, under President Richard Nixon, the Environmental Protection Agency (EPA) was formed. The EPA was established to enforce environmental standards, conduct research, help other organizations in reducing pollution through grants and technical assistance, and make recommendations to the president and the Council of Environmental Quality on ways to protect the environment. William D. Ruckelshaus was appointed the EPA's first administrator; he promised that the agency would "be as forceful as the laws that Congress has provided." Since its formation, the EPA has taken an active role in reducing hazardous emissions, restricting toxic wastes, and cleaning up oil spills and other environmental disasters.
In 1972, Congress passed the Federal Water Pollution Control Act Amendments, which would come to be known as the Clean Water Act (CWA). This Act established standards for regulating water pollution and gave the EPA the power to develop pollution control programs. The CWA also set water quality standards and limited contaminants in surface water. Industries were required to obtain a permit to discharge pollutants into water and were fined if they were found to be dumping waste into bodies of water.
The Act proved to be very effective. According to the EPA, in 1972 only a third of the nation's waters were safe for fishing and swimming; that had increased to twothirds by the early twenty-first century. Wetland losses were estimated to be about 460,000 acres a year, whereas today they are estimated to be between 70,000 and 90,000 acres a year. Agricultural runoff in 1972 was estimated to cause 2.25 billion tons of soil to erode and phosphorus and nitrogen to be deposited in many waters; runoff has been cut by about one billion tons annually, and phosphorus and nitrogen deposits have decreased.
Congress also passed the Federal Insecticide, Fungicide, and Rodenticide Act in 1972. This Act authorized the EPA to study the effects of pesticides and to regulate their distribution. Users, from the small-time farmer to large utility companies, were required to register with the EPA if purchasing pesticides. Later amendments to the Act forced pesticide users to take certification exams. In addition, all pesticides used must be registered with the EPA.
The Endangered Species Act of 1973 was the first law passed specifically to protect plants, animals, and their habitats. The Act created two lists: one for endangered species and one for threatened species; anyone can petition for a plant or animal to appear on the list. Currently, 632 species are listed as "endangered"; 190 are listed as "threatened." Killing, trading, or transporting any of these species is expressly prohibited. The Act also allows the EPA to issue emergency suspensions of certain pesticides that may adversely affect endangered species.
The Safe Drinking Water Act of 1974 authorized the EPA to establish standards for owners or operators of public water systems. In 1976, Congress passed the Toxic Substances Control Act, which gave the EPA the power to track the 75,000 industrial chemicals being produced by or imported into the United States. This Act was accompanied by the Resource Conservation and Recovery Act, which granted the EPA the authority to regulate hazardous waste from "cradle to grave." Later amendments provided for the regulation of underground tanks storing hazardous materials such as petroleum and for the phasing out of waste disposal on land.
The 1980 Comprehensive Environmental Response, Compensation, and Liability Act provided a "Superfund" for the EPA. The Act allows the EPA to respond quickly to oil spills and other disasters when those responsible cannot be found, or when the situation has become uncontrollable. The EPA can later recover costs from parties deemed responsible. This Act was strengthened by the Oil Pollution Act of 1990—a response to the Exxon Valdez disaster off of Prince William Sound in Alaska.
Conservation has also been advanced through management techniques. The Pollution Prevention Act of 1990 incorporated the efforts of government and industry to find cost-effective ways to reduce pollution. The Act made it easier for industries to comply with government regulations by opening the door for innovative operating strategies.
The Kyoto Protocol, which opened for signature before the United Nations in 1998, called for thirty-eight industrial countries to reduce their greenhouse gas emissions (which are thought to destroy earth's ozone layer, thus leading to global warming) by an average of 5.2 percent below 1990 levels by 2008–2012, including a 7 percent reduction by the United States. President George W. Bush has refused to sign the treaty. In May 2001, seventeen national science academies urged acceptance of Kyoto, declaring that "it is now evident that human activities are already contributing adversely to global climate change. Business as usual is no longer a viable option." In an address to the National Oceanic and Atmospheric Administration in February 2002, Bush called for voluntary action to slow the rising use of greenhouse gases.
Initially, the Bush administration had also expressed doubts as to how much of global warming was actually caused by humans. But in a dramatic turnaround in May 2002, the administration blamed human action for global warming for the very first time. Although Bush still declined to sign the treaty, a report was sent to the United Nations outlining the effects that global warming may have on the American environment.
Terrorism has brought a grim new face to conservation and preservation of resources. Fears have been expressed by both the government and the public that terrorists may, for example, try to contaminate drinking water. In June 2002, EPA administrator Christie Todd Whitman announced the first round of water security grants, part of a $53-million package designed to help water utilities across the nation address susceptibilities. Whitman noted that there are "168,000 public drinking water facilities," alerting the nation to possible wide scale contamination. The grants will be divided among approximately 400 different areas. "These grants," Whitman declared, "will help ensure that the water people rely on is safe and secure."
Brands, H. W. TR: The Last Romantic. New York: Basic Books, 1997.
Budiansky, Stephen. Nature's Keepers: The New Science of Nature Management. New York: Free Press, 1995.
Carson, Rachel. Silent Spring. Boston: Houghton Mifflin, 1962.
Findley, Roger W., and Farber, Daniel A. Environmental Law in a Nutshell. St. Paul, Minn.: West Publishing, 1983.
Gore, Albert. Earth in the Balance: Ecology and the Human Spirit. Boston: Houghton Mifflin, 1992.
Richardson, Joy. The Water Cycle. New York: Franklin Watts, 1992.
Snow, Donald, ed. Voices from the Environmental Movement: Perspectives for a New Era. Washington, D.C.: Island Press, 1992.
Stanley, Phyllis M. Collective Biographies: American Environmental Heroes. Springfield, N.J.: Enslow, 1996.
Weber, Michael L., and Judith A. Gradwohl. The Wealth of Oceans. New York: Norton, 1995.
COPYRIGHT 2003 The Gale Group Inc.
Water-supply infrastructure consists of what is built to pump, divert, transport, store, treat, and deliver safe drinking water. In the United States, this infrastructure consists of vast numbers of groundwater wells, surface-water intakes, dams, reservoirs, storage tanks, drinking-water facilities, pipes, and aqueducts .
As the figure on page 214 shows, a groundwater or surface-water source (or both) must be available and accessible. Groundwater naturally is stored in underground geologic formations, and is pumped from its subterranean source via a single well or multiple wells. Surface water can be accessed via an intake pipe in a river, canal, large lake, or artificial reservoir. In some rivers, low-head dams may be used to pool the water for more efficient withdrawal. In other cases, large dams have been constructed to impound water on a large scale, thereby ensuring a reliable water supply throughout the year, and from year to year.
In areas without adequate supply sources (e.g., some western U.S. states), water must be diverted from its basin of origin to the basin of use. This may involve transporting the water over great distances, and/or across geographic impediments such as hills and mountains.
Regardless of the water source, pipes and pumps must be designed to meet the anticipated demand from customers. Municipal water-supply systems use high-capacity wells and intakes, powerful pumps, and large pipes, as well as a power source (e.g., electricity) to drive the pumps.
After the raw (untreated) water is obtained, it is treated, if necessary, so that it meets federal drinking-water standards. In the United States, standards are established by the U.S. Environmental Protection Agency (EPA). Treatment plants are designed by engineers to meet site-specific needs of water consumption and water quality.
Water may be stored in underground or above-ground tanks. Storage most commonly is used for two reasons: (1) to provide adequate contact time for disinfection; and (2) to provide for peak demand, when customer demand may exceed what the pumping system can supply (e.g., in the morning when most people are showering and preparing breakfast).
The last component is the distribution system that moves the treated water throughout the community. The finished water often is stored in treated water reservoirs until it is needed for residential, industrial, municipal, or agricultural uses.
Maintenance and Safety
Many cities have aging water infrastructures, some as old as 100 years. The structures and materials used in piping systems are reaching the end of, or are exceeding, their life expectancy. Incredibly, some water systems still use asbestos-cement (AC) pipes and wooden storage tanks. These facilities are no longer allowed on newer systems; however, it is common to allow older water systems time to upgrade because of the expense. With these older systems, additional monitoring requirements may be imposed; for example, water systems that still have AC pipe in the ground are required to periodically test for asbestos in the water.
Because maintaining and operating aging infrastructure is getting more costly, municipalities have been deferring maintenance while spending money on more pressing needs, and some replace pipes only when they break. Direct infrastructure costs continue to escalate for building, replacing, or improving treatment plants; laying or replacing pipe; maintaining aging dams; and accessing new water sources. Indirect costs also are increasing for expenses such as electricity used to pump the water, and by new equipment made necessary by governmental mandates to treat for additional contaminants . Public utilities also are spending money to protect their water supplies from accidental pollution , changing land uses, and deliberate tampering by vandals or terrorists. The EPA estimates that the expense to repair and replace the water and wastewater infrastructure will be between $745 billion and $1 trillion over the first 20 years of the twenty-first century, excluding the cost of homeland security.
The Water Infrastructure Network (WIN) is a group of wastewater and drinking-water service providers, elected governmental officials, state health and environmental administrators, environmentalists, and engineers dedicated to protecting and preserving the drinking-water infrastructure and wastewater infrastructure within the United States.
The WIN has identified three core infrastructure needs for the country.
1. The drinking-water supply system, which includes water treatment facilities; treated-water storage and distribution systems; source-water development and protection; water-supply management and interconnection; demand management; and rehabilitation of untreated water conveyance and water storage infrastructure.
2. Domestic wastewater management systems, which includes wastewater infrastructure for collection, pumping, and discharge; wastewater treatment plants; wastewater reclamation and reuse facilities; and biosolids (sludge) management.
3. Stormwater runoff control systems and management practices, which include pollution prevention and reduction practices, as well as runoff collection, conveyance, and treatment facilities.
The EPA has been given the important responsibility under presidential directive for working with the water-supply sector (including water and waste-water utilities) to provide for the protection of the country's water infrastructure, particularly the systems used to collect, treat, and distribute drinkable water.
These critical infrastructures are fundamental to the public health and welfare. Infrastructures are subject to natural disasters, such as earthquakes and floods, and human-made hazards, such as vandalism and terrorist attacks. Such natural and human hazards could place populations at great risk.
In October 2001, as a direct reaction to the previous month's terrorist attacks on New York City and Washington, D.C., the EPA established an internal task force to ensure that activities are completely and efficiently carried out in order to secure and protect water-supply infrastructure. Under the authority of these task force directives, water utilities serving more than 100,000 customers are required to evaluate their risk to a terrorist attack and submit that evaluation to the EPA. Grants have been provided by the EPA to assist with these vulnerability assessments.
In December 2001, the U.S. Congress approved $345 million in funds for security at water infrastructure facilities. In 2002, the EPA began providing grants to support counterterrorism activities in the states and at drinking-water and wastewater utilities.
Security enhancements will continue to evolve in the water industry as more becomes known about detection and prevention of chemical, biological, and radiological attacks. The infrastructure of the country's water system should be a top security priority, not solely due to possible terrorist attacks, but also because of the critical nature of water itself in all facets of life in the United States.
see also Drinking-Water Treatment; Economic Development; Security and Water; Supplies, Protecting Public Drinking-Water; Supplies, Public and Domestic; Utility Management; Wastewater Treatment and Management; Water works, Ancient.
Laurel E. Phoenix
and William Arthur Atkins
American Society of Engineers. Renewing America's Infrastructure: A Citizen's Guide. Washington, D.C.: American Society of Engineers, 2001.
Cech, Thomas V. Principles of Water Resources: History, Development, Management, and Policy. New York: John Wiley & Sons, 2003.
Drinking Water Security and Protecting Small Water Systems. National Drinking Water Clearinghouse, National Environmental Services Center. <http://www.nesc.wvu.edu/ndwc/ndwc_protect.htm>.
Security and Preparedness Resources. American Water Works Association. <http://www.awwa.org/communications/offer/secureresources.cfm>.
Water Infrastructure Network. <http://www.win-water.org/>.
Water Infrastructure Security. <http://www.epa.gov/safewater/security/>.
SMALL LEAKS AND BIG BREAKS
Pipe leakage is inevitable as pipes age, soils shift or freeze, pipes are broken during construction projects, or new land uses put increased pressure on buried pipes. Public water systems compare water amounts leaving the plant with metered water usage and water used for flushing mains. Greater than 10 percent of unaccounted-for water loss will trigger a search for the leaks. Broken or leaking pipes may allow bacteria to enter the distribution system.
Not all water systems are metered and therefore are not able to accurately evaluate the extent of water loss. Many small water systems that do not have individual meters on households charge a flat rate, independent of use. Not only may this lead to undetected leaks, but the flat rates do nothing to encourage conservation of water.
Older cities sometimes have spectacular waterline breaks. For example, in January 1998, a 48-inch, 128-year-old water main burst on Fifth Avenue in New York City, flooding several streets with a foot of water, creating a 35-foot-wide crater, and rupturing gas lines, which then ignited and shot flames two stories high.
COPYRIGHT 2003 The Gale Group Inc.
Water Supply: Counter-Terrorism
Water Supply: Counter-Terrorism
█ BRIAN HOYLE
The water supply in many communities in the developed world comes from a surface water source such as a lake. Water can also be pumped from aquifer located underground. Typically, the water is routed to a treatment plant, where a variety of physical and chemical processes render the water safe to drink. The "finished" water is then pumped through pipes (i.e., the distribution system) to the consumer's taps.
For over a century this process has been geared toward providing high quality water, without consideration of the security of the acquisition, treatment, and distribution of water. However, particularly since the 1990s, the threat of a deliberate contamination of water supplies has become more probable.
In the wake of the September 11, 2001 terrorist attacks on the World Trade Center and the Pentagon in the United States, surface water supplies, water treatment plants, and distribution systems were quickly recognized as potential targets of a terrorist attack. While water facilities are often equipped to discourage mischief (i.e., a chain link fence surrounding a reservoir), virtually no water facilities are designed to prevent a deliberate and coordinated attack.
Many compounds dissolve in water and microorganisms are so small that, for example, up to 6 million bacteria need to be present in each milliliter of water before the water will appear less than crystal clear. Thus, the addition of a lethal quantity of a potent poison or disease-causing microorganism to a water supply could be done without attracting undue notice.
During the 1990s, and especially since the events of September 11, 2001, efforts to develop effective strategies to counter a terrorist attack on water supplies have been widely debated.
The fact that major urban systems need to supply huge quantities of drinking water every day could already be a counter-terrorist strategy. Even given the ease by which a reservoir could be contaminated, the large volume of the water reservoirs of major urban centers would dilute the added poison to very low levels. A lethal dose of a poison at the consumer's tap would require the addition of a huge amount of the contaminant. For example, it has been estimated over 400,000 metric tons of hydrogen cyanide would have to be added to the Crystal Springs Reservoir—a major reservoir for the city of San Francisco—to supply enough poison to kill or debilitate someone drinking one glass of water from the reservoir.
However, smaller reservoirs are at risk, as are smaller water tanks. Increased security at treatment plants would be an effective deterrent to sabotage. However, such security would be expensive and the cost would be passed to the consumer.
In most municipalities, water treatment involves the addition of chlorine or chlorine products to kill microorganisms. The deliberate disabling of the chlorination system of a treatment plant would make contamination of the drinking water a certainty. For example, a breakdown in the chlorination of the drinking water of Walkerton, Ontario, coincident with the run-off from a cattle field that contaminated the water supply with Escherichia coli O157:H7, sickened over 2,000 people and killed at seven people in the summer of 2000.
Even a secure treatment facility supplying chlorinated water is no guarantee of safe water. Recent history has shown that chlorinated water is susceptible to contamination by microorganisms that are resistant to the chemical. Specifically, the protozoa called Giardia and Cryptosporidium have a spore-like stage in their life cycles that survives exposure to chlorine. A Cryptosporidium contamination of the water supply of Milwaukee, Wisconsin, sickened over 200,000 people and killed almost 100 people.
While illness outbreaks with the protozoa have so far been accidental, the use of the microorganisms as a weapon is conceivable. In the United States, municipalities have been legislated to provide alternate means of dealing with drinking water to counter the threat posed by Giardia and Cryptosporidium. This legislation has been prompted by health concerns. Nonetheless, it will prove to be a counterterrorism measure.
The distribution system that carries water from the treatment plant to the consumer's taps is another potential target of terrorism. The high pressure inside the pipes would make the introduction of a contaminant difficult. However, the lack of security along the distribution system could enable a dedicated group to commission the digging equipment needed to uncover a pipe and stop water flow long enough to contaminate the water.
Patrolling a distribution system is impossible. For now, the most effective counter-terrorism strategy is to make manholes and storage tanks inaccessible.
Another microbial terrorist threat to drinking water is Bacillus anthracis. This bacterium, which is the cause of anthrax, can form a very hardy structure known as a spore. Studies have determined that the spore form can survive in chlorinated water for at least two years. If ingested in a glass of drinking water, or inhaled in the humid environment of a shower or bath, the spores can revive, and the growing bacteria can cause the disease.
Other chlorine-resistant microorganisms that have been identified as bioterrorism agents include Clostridium perfringens, Yersinia pestis (the cause of plague), and biotoxins (e.g., aflatoxin and ricin).
Countering the deliberate use of such microorganisms will necessitate the rapid detection of even tiny quantities of the microorganisms or their toxic products. Use of rapid detection devices in an early warning system would be an effective counter-terrorism strategy, albeit one that would require dedicated personnel or hardware to monitor the water system.
One promising technology is the use of an electronic sensor ("the electronic nose") to detect chemicals. This method has been successful in detecting spoilage and disease causing bacteria present on fruit by virtue of the unique chemical compounds given off by the bacteria. However, the electronic nose would have to be adapted for use with water.
A detection method that already successfully detects and identifies bacteria such as Escherichia coli in fresh water relies on the binding of fluorescent antibodies to the surface of the bacteria and the detection of the bound antibodies by the resulting fluorescence. A prototype of the device is portable and so can be taken to hydrants for the testing of water throughout a distribution system. When in production within the next several years, the device will offer a means of rapidly monitoring water for contaminants.
Another promising technology relies on the recovery of genetic material (deoxyribonucleic acid; DNA) from the sample, and the detection of sequences of the DNA that are unique to the target bacteria by the use of a mirror image piece of DNA that will selectively bind to the target sequence. DNA microchips utilize this technique to detect bacteria from samples as complex as soil and ocean water.
Thus, there is potential for the development of rapid tests to detect bacterial contamination of drinking water. Whether the benefits of implementing an early warning system of chemical and microorganism detection will justify the costs remain to be determined.
In the short term, the best counter-terrorism strategy for many water systems will continue to involve a survey of the system in order to identify points where the system is vulnerable (i.e., unlocked hydrants) and taking action to secure those points (i.e., locking hydrants). As well, public notification of water contamination, and response of authorities (e.g., police, fire department, and medical personnel) to a contamination should be an integral part of a community's emergency response plan.
Despite the vulnerability of water to deliberate contamination, the reality continues to be that the probability of such action is very low. A terrorist can deliver a lethal payload by air or through routes like the postal system more easily and using less microorganisms than would be required for the contamination of a water supply.
█ FURTHER READING:
Lesser, Ian O., and Bruce Hoffman. Countering the New Terrorism. Santa Monica: Rand Publications, 1999.
Betts, K. S. "DNA chip technology could Revolutionize Water Testing." Environmental Science and Technology no. 33 (1999): 300A–301A.
Burrows, W. D., and S. E. Renner. "Biological Warfare Agents as Threats to Potable Water." Environmental Health Perspectives no. 107 (1999): 975–84.
Foran, J. A., and T. M. Brosnan. "Early Warning Systems for Hazardous Biological Agents in Potable Water." Environmental Health Perspectives no. 108 (2000): 993–96.
Weckerle, J. F. "Domestic preparedness for events involving weapons of mass destruction." Journal of the American Medical Association no. 283 (1997): 435–38.
United States, Counter-terrorism Policy
COPYRIGHT 2004 The Gale Group
Water law is a system of enforceable rules that controls the human use of water resources. In the United States, these rules are created by statutes, court decisions, and administrative regulations. Much of U.S. water law is rooted in the common law system inherited from England. Under this system, courts resolved disputes by setting legal precedents that were followed by subsequent courts. Today, U.S. water law is a complex mix of federal and state regulations superimposed on a system of public and private water rights.
Resolving Water-Use Conflicts
Because water is a mobile (moving) resource, many management problems are created that require legal resolution. As water moves through the hydrologic cycle , many people in succession can use it. For example, a hydropower plant can nonconsumptively use river water to generate electricity. Far downstream from the powerplant, and at a later date, a golf-course owner may use the same water to irrigate the fairways.
Consumptive uses alter the hydrologic cycle and may modify the environment. Because the same drop (or even the same molecule) of water can be reused many times by humans and also is needed to maintain environmental integrity, conflicts between different uses are frequent. Water law attempts to resolve these conflicts by encouraging desirable uses and discouraging undesirable ones. Uses are encouraged or discouraged through the complex interlinkings of water rights systems and the exercise of government power.
From Private Rights to Public Values.
The exercise of government power and creation of water rights is based on societal values that have changed over time and vary from state to state. Although the U.S. common law system recognized public rights to navigate and to fish, most water rights historically were defined in terms of private rights . These private rights allocated water to individuals for their use. When conflicts occurred, they were resolved in court.
This water rights system oriented toward private rights often ignored public values such as recreation and environmental protection. But as societal values changed, the exercise of government power at times restricted traditional water rights.
In past decades, for example, many cities felt they had a right to use rivers for the routine disposal of raw sewage. But today, federal statutes prohibit such disposal and require sewage first be treated before the processed wastewater is discharged to waterways. In the American West, the right to remove all the water from a stream for use in irrigation was traditionally accepted. But today, federal statutes may require a minimum instream flow to protect endangered species or to maintain other designated instream uses. Public values have greater recognition today than in past decades, and are widely recognized by courts, legislation, and administrative regulations.
Relationship Between Rights.
Either state or federal laws can create public and private water rights. These water rights are relational and take on meaning when the exercise of one right conflicts with the exercise of other rights.
In addition, water rights are rarely exclusive. This need to share water results in conflicts between individuals who have private rights, between individuals with private rights and people with public rights, and between those who have federal rights and those who have state rights. Water law is used to resolve conflicts between different claimants by determining the rights and obligations of each party in a dispute.
Water Rights and the Hydrologic Cycle
Private water rights evolved as a pragmatic system to allocate water use in different parts of the hydrologic cycle. In a simplified hydrologic cycle, water can be classified as groundwater , surface water, atmospheric water, or soil moisture.*
Each part of the hydrologic cycle is treated by the legal system as if it were disconnected. For example, the law establishing rights to surface water is often different from the law for groundwater. In some parts of the hydrologic cycle, private water rights are difficult to establish. For example, soil moisture cannot be easily extracted from the soil in which it is found. This type of water is treated as land, and no water rights are created. Although this practice ignores the reality of the hydrologic cycle, it does reduce potential conflicts with those who own land.
Until recently, capturing atmospheric waters was difficult. Property rights generally did not exist until the water reached the land surface. Although increasing precipitation through cloud-seeding is possible, assigning a water right to the "newly created water" is still problematic. Proving the amount of precipitation increase and determining where this amount actually fell makes the basis for a claim difficult to establish.
Groundwater and Surface-Water Rights.
Groundwater science developed after early policymakers had already established a system of groundwater rights. Although these common-law approaches still exist, statutory regulations have been superimposed, modifying groundwater rights substantially.
One initial approach was to treat groundwater like part of the land, and give the owner of the land surface absolute ownership of the water below it. Another pragmatic approach, the so-called "rule of capture," was used on a limited basis. This right gave ownership to the person who pumped the water from the ground. Although these two approaches ignored the mobile nature of groundwater, the rights were easy to determine.
Today, the mobility of groundwater is accounted for in the dominant systems of water rights. In the eastern states, the doctrine of reasonable use allows water to be shared between surface owners. In the western states, the doctrine of prior appropriation establishes priorities between users.
Surface-water rights have the most developed set of water allocation laws. In the eastern states, the ownership of land adjacent to a river gives rise to a riparian water right. Initially, the right was attached to the riparian land and only that land. But over time, two kinds of riparian water rights evolved: natural flow and reasonable use.
Today, statutory permit systems often are imposed on private riparian rights. In the West, the prior appropriation doctrine evolved under different conditions. The need to move water long distances led to a system of temporal (time-based) preferences designed to protect investments. The right to water did not automatically come with ownership of land. Moreover, western states claimed they either owned all the water within the state, or they held it in trust for the people of the state. Thus, a private water right could be established only by following the requirements of state law.
This complex system of water laws controls almost all aspects of water use, including environmental protection. The system has never been static and will continue to evolve.
see also Conflict and Water; Law, International Water; Prior Appropriation; Reisner, Marc; Rights, Public Water; Rights, Riparian.
Olen Paul Matthews
Balleau, W. P. "Water Appropriation and Transfer in a General Hydrogeologic System." Natural Resources Journal 28 (1988):269–291.
Beck, Robert E., ed. Water and Water Rights. Charlottesville, VA: The Michie Company, 1991.
Matthews, Olen Paul. Water Resources, Geography and Law. Washington, D.C.: Association of American Geographers, 1984.
Reisner, Marc. Cadillac Desert. New York: Penguin Books, 1987.
Trelease, Frank J. "Government Ownership and Trusteeship of Water." California Law Review 45 (1957):638.
Worster, Donald. Rivers of Empire. New York: Pantheon Books, 1985.
* See "Hydrologic Cycle" for a schematic of the water cycle.
COPYRIGHT 2003 The Gale Group Inc.
An acquaintance once said that "every water faucet in New York City leaks." She was exaggerating, of course, but her point was that New Yorkers do not take the time or spend the money to repair leaks. Why? Most residents of the city pay a flat fee for their water. For a fixed monthly charge, residents can use as much water as they want. Marginal cost is zero. Hence, the wasted water costs them nothing, aside from the annoyance of listening to the drip.
But why should anyone worry about the cost of water? The figure shows recent prices of an additional 1,000 gallons per month in several U.S. cities in 2001, ranging from $1.25 to nearly $3.00. (Water rates in other countries often are considerably higher.) For most Americans, this is a very small part of their budgets. Even so, study after study has shown that most water users will indeed respond to a higher price by fixing leaks, using a broom instead of a hose to clean the driveway, and otherwise conserving water. Imposing a quantity charge, or raising it, forces users to rethink, even if only informally, their marginal benefit/marginal cost computations and adjust consumption accordingly.
What is Water's True Cost?
Even when water utilities use a quantity charge instead of a fixed fee, they often set the quantity charge too low. Typical public water utilities design their rates to cover out-of-pocket costs, but such costs often fall short of the true economic value of extracting and distributing water.
First, governments often subsidize water infrastructure . Developers often must contribute ready-to-use water systems to the utility. These subsidies do not come directly from the utility company and hence do not show up in their accounting records.
Second, capital equipment—pumps, water mains, buildings, and so on—is a major element of total water cost and tends to last for several decades. Replacing a water main built, for example, 40 years ago would cost almost six times the original cost because of inflation alone. Yet few if any utilities update the value of aging capital equipment when they add up costs.
Third, water in the ground or in a stream is valuable because it is scarce. The right to divert water from a stream or to pump it from an aquifer is an asset of growing value to utility companies but again is often ignored in standard accounting practice. One study estimated scarcity value to be at least as large as all other conventionally reckoned costs together. Similarly, any environmental costs incurred in providing public water supplies should be added to water rates.
Pricing as a Conservation Incentive
For the reasons outlined above, water rate schedules based on the utility's out-of-pocket costs leave consumers paying less than they should. And since consumers pay too little, they use too much.
However, an increasing number of water utilities have recognized the potential of pricing to provide an incentive for their customers to conserve water. Some (Seattle, Washington and southern California, for example) have refined the notion, charging higher rates during droughts or in dry seasons or for unexpectedly large quantities.
But if water is priced at its full economic cost, what about the poor? Several major cities have taken at least tentative steps toward establishing what is called an "inclined-block" water rate schedule, as shown here: Ideally, customers under this system would pay a low rate for the first few thousand gallons used, but the rate would rise until they pay the full marginal cost for the last thousand gallons. The criterion of marginal benefits equals marginal costs would be met, and yet even the poorest could afford at least a basic amount.
Trending Toward Demand Management.
On average, Americans use more than 1,000 gallons of water per day. The amount necessary to sustain life processes is quite small, perhaps a few gallons per day. Of the difference, how much is really needed for bathing, laundry, housecleaning, car washing, lawn and garden care, filling the swimming pool, and so on? Clearly, if consumers are presented with the right incentive, they can conserve on water use.
This article has considered mainly residential water users, but similar considerations apply to businesses and farms that use water. Farmers, for example, have developed highly sophisticated means of conservation by determining exactly how much water each plant needs and applying just that amount, but adjusting for water costs. Hotels install low-flow showerheads and toilets. Car washes and many other businesses reuse water.
Most public utilities and other water-supply agencies try to accommodate growth in water demand by looking for additional water sources to develop; this is supply-side management. But growth can often be met by conservation in the use of existing sources; this is demand management. Some utilities go so far as to charge a premium during the dry season, for unanticipated high water demands, or during periods of drought. Pricing is a powerful tool of growing importance in the toolkits of water managers and environmentalists.
see also Conservation, Water; Demand Management; Markets, Water; Utility Management.
James E. T. Moncur
Gardner, B. Delworth. "Water Pricing and Rent Seeking in California Agriculture." In Water Rights: Scarce Resource Allocation, Bureaucracy, and the Environment. Terry L. Anderson, ed. San Francisco, CA: Pacific Institute for Public Policy Research, 1983.
Howe, Charles W., and F. P. Linaweaver. "The Impact of Price on Residential Water Demand and Its Relation to System Design and Price Structure." Water Resources Research 3 (1967):12–32.
Moncur, James E. T., and Richard L. Pollock. "Accounting Induced Distortions in Public Enterprise Pricing." Water Resources Research 32, no. 11 (November 1996): 3355–3360.
——. "Scarcity Value for Water: A Valuation and Pricing Model." Land Economics 64, no.1 (February 1988):62–72.
"Estimated Use of Water in the United States in 1995." U.S. Geological Survey. <http://water.usgs.gov/watuse/pdf1995/html>.
EFFECTS OF SUBSIDIES
As anyone who has seen the 1939 film Gone with the Wind knows, cotton was once the staple crop of the southern United States. No more. Cotton, a very waterintensive crop, was well suited to the southern climate with its heavy rainfall. The center of cotton production has since shifted, however, to bone-dry parts of California. Why?
Several reasons exist for cotton's western migration, but clearly this shift could not have happened without federally funded irrigation projects. Generally, farmers who use water from these projects pay far less than its full economic value; they are thus subsidized. Subsidies are common among government-financed water resource projects. However, they are not free: taxpayers bear the cost in proportion to their tax payments.
COPYRIGHT 2003 The Gale Group Inc.
Some people think of water as a gift of nature, with profound cultural, spiritual, and aesthetic significance, concluding that such a natural resource should not be bought and sold like fast-food hamburgers, t-shirts, or diamond rings. But water has many uses and immense total value, and if people want to use it to maximum benefit, they must have some mechanism to decide who gets it, when, for what purposes, and at what levels of quality.
At one extreme, a government might allocate water. Government officials would decide who gets how much, for what uses, at what times, and how to invest in the search for additional sources. At the other extreme, individuals who want to use water might be allowed to make these decisions, diverting water from streams or pumping it from wells, using it entirely as they wish and buying and selling it at will. Problems exist with both approaches, and probably no complex society has ever used either allocation procedure in its pure form.
Balancing Cost and Benefit
How much water should be used? In the figure below, each point on the marginal benefits (MB) curve indicates the amount consumers are willing to pay for the last unit of water purchased. Generally, the more one has, the less intensely one wants additional amounts. Hence, this curve slopes downward from left to right.
The marginal costs (MC) line shows the value of resources necessary to produce an additional unit of water. Generally, higher rates of flow can be had only at higher cost, so this line slopes upward.
Consider the flow rate q1. Here, MB > MC, indicating that consumers value an additional unit of water more than the resources necessary to produce it. This calls for increasing the quantity produced and consumed. At q2, the opposite holds true. Only at qe does MB = MC. No incentive exists to either increase or decrease the amount produced; buyers and sellers have achieved the optimum quantity. This conclusion rests on the assumption that the MB and MC curves include all costs and benefits, whether they accrue to the buyer or the seller or to some third party.
Consider a problem sometimes created when a farmer sells irrigation water to a distant city. Much of the water applied to fields would have seeped through the ground and eventually back into the stream, thus becoming available for reuse by people living downstream. If the city diverts the water into a canal or aqueduct , however, the irrigation return flows are cut off, and the downstream users, who have not been a party to the transaction, are deprived of a resource without compensation. The private marginal benefit and cost calculations that led to the optimum qe may ignore "external" or third-party effects.
These effects have led many to conclude that governments must regulate water use tightly despite the high costs, delays, and controversy engendered by public decision processes. Economist Terry L. Anderson and others argue that properly defined water use rights would prevent much of the problem, in both quantity and quality dimensions—just as property rights in real estate, for example, prevent neighbors from encroaching or dumping trash into one another's yards. Indeed, the lack of well-defined water rights is the basis of much inefficiency and public controversy.
Market Institutions and Efficiency
Historically, the eastern United States generally enjoyed abundant water supplies, so the efficiency offered by market institutions was unnecessary (although this rosy picture darkened somewhat in the late twentieth century). Eastern states have mostly adopted variations of the riparian doctrine of water rights: owners of riparian land abutting streams have the right to withdraw water.
Market institutions have a longer history in the arid western states, where early settlers established efficient market systems on a type of firstcome, first-serve basis known as the prior appropriation doctrine. In New Mexico, Colorado, and Utah, for example, it is possible to buy and sell rights to the use of stream flows or groundwater and divert such purchases away from any riparian (streamside) land. Transactions crossing state lines pose further difficulties, even for these states, and have been handled by rather rigid interstate compacts .
Market institutions require a clear definition of what it means to own the right to use water as well as the right to sell or buy such rights. Even the most efficient market entails some transactions costs, of course, to cover fees of brokers, agents, lawyers, and so on. But market transfers generally involve fewer people and clearer rules and so minimize such costs. In sum, market institutions offer an underused path to increased efficiency in water use.
see also Demand Management; Law, Water; Pricing, Water; Prior Appropriation; Rights, Public Water; Rights, Riparian.
James E. T. Moncur
Anderson, Terry L. Water Rights: Scarce Resource Allocation, Bureaucracy, and the Environment. San Francisco, CA: Pacific Institute for Public Policy Research, 1983.
Howe, Charles W., Dennis R. Schurmeier, and W. Douglas Shaw Jr. "Innovative Approaches to Water Allocation: The Potential for Water Markets." Water Resources Research 22 (1986):439–445.
Roumasset, James, Rodney Smith, and James Moncur. "Optimal Allocation of Ground and Surface Water on Oahu: Water Wars in Paradise." In Conflict and Cooperation on Trans-Boundary Water Resources, eds. Richard E. Just and Sinaia Netanyahu. Boston, MA: Kluwer Academic Publishers, 1998.
Saliba, Bonnie Colby, and David B. Bush. Water Markets in Theory and Practice: Market Transfers, Water Values and Public Policy. Boulder, CO: Westview Press, 1987.
WATER MARKETS: THE PERVERSE CASE OF HAWAII
Relying mainly on water rights granted by the nineteenth-century monarchs, Hawaiian sugar planters developed extensive irrigation systems, according to their estimations of benefits and costs. They frequently bought or sold water rights, usually small amounts, as their needs changed, in transactions that were not much more involved or controversial than, say, buying a car. Titles were recorded officially by the government.
In 1972, however, the Supreme Court of Hawaii invalidated private water rights. Today, water transfers require elaborate and costly state approvals. No water sales have been recorded since 1972 despite vast changes in the state's water-using economy. Water allocation has been a continual major subject of public controversy, with costs for one single court case reaching millions of dollars.
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WATER LAW. Central issues in the history of U.S. water law are: (1) the development and evolution of state systems—both legal doctrines and institutions—for determining ownership and for allocating use of water and (2) the impact of those systems upon industrial, agricultural, and urban development. Colonists who settled along the Atlantic coast encountered in the "new world" a landscape crisscrossed with rivers. To create order upon this landscape, they applied the English common-law riparian doctrine, which recognized the right of riverbank owners to use the water in a river in ways that would not diminish or alter the river for downstream users—a right to the "natural flow" of the stream. A riparian owner could, for example, use the river for fishing, watering stock, cleaning, or travel, but could not alter the course of the river, reduce its volume, or pollute it so that downstream owners could not reuse the water. This riparian right could not be sold independently of the land adjoining the waterway, and all riparian owners along a river had an equal right to use the water.
The common law natural-flow regime was suited for places where demand for water was low, as was the situation in the East during much of the colonial period. In the eighteenth century, colonies, and then states, began to chip away at the common law by passing mill acts that allowed mill owners to build dams by making them pay damages when the dams overflowed on the lands of upstream neighbors. By the beginning of the nineteenth century, the natural-flow doctrine had become an impediment to industrial development, which required the use and diversion of large amounts of water to power manufacturing plants and mills. To accommodate changing economic circumstances, courts modified riparian law further by fashioning a reasonable use doctrine that allowed riparian owners to use up, alter, or divert a portion of the stream for reasonable purposes, typically defined as the usual practices or best interests of a community. These legal changes were both the product and cause of conflicts over water use in a rapidly changing world.
While courts in the eastern states were modifying the common law in light of changing economic circumstances, miners in the western states were developing an informal water-rights regime based not on riparianism, but on first use. The doctrine of prior appropriation recognizes that the person who diverts the water first and puts it to a recognized beneficial use has the best, most senior right to the water. Subsequent users can claim rights to any water still remaining in the stream. This right is not limited to riparian landowners, and it is a vested property interest that one can sell, trade, or give away. Reservation of federal land for a particular purpose (for instance, a national park) includes an implicit reservation of the amount of yet unappropriated, appurtenant water necessary to meet the purposes of the reservation.
Courts, and then state legislatures, ratified the miners' system. Today, almost all western states, the major exception being California, have adopted prior appropriation by statute. Some states also recognize, through case law, riparian rights. Many historians explain the widespread use of prior appropriation in western states by pointing to the relative scarcity of water in the West and the need to divert water to places where it did not exist. Others point to different local economic conditions or to the difference in the nature of nineteenth-century water use in the West (consumptive) and in the East (for power generation).
The legal rules for groundwater diversion evolved independent of these surface water doctrines because little was known about the relationship between groundwater and surface water in the nineteenth century. Courts developed several distinct approaches to groundwater law including variations of the riparian reasonable use rules and prior appropriation. Today, several states, particularly in the west, use sophisticated state or local management systems that authorize and supervise the pumping levels of groundwater users.
Because bodies of water do not recognize the political boundaries humans have created, states have developed administrative structures—such as levee, irrigation, and swamp drainage districts—that allow people within a region to jointly make decisions affecting shared water resources. States have also entered into agreements with each other to determine the allocation and use of water that moves across state boundaries. The Colorado River Compact is an example of one such interstate agreement. States, however, do not have absolute power to determine water rights or use. The Federal Government has rights to water through reservation and has the responsibility under the U.S. Constitution to protect and regulate navigable and coastal waters. To fulfill these responsibilities, Congress has passed far-reaching legislation such as the Clean Water Act and the Coastal Zone Management Act. Finally, Indian tribes have rights to water under their treaties with the federal government.
Baxter, John O. Dividing New Mexico's Waters, 1700–1912. Albuquerque: University of New Mexico Press, 1997.
Goldfarb, William. Water Law. 2ded. Chelsea, Mich.: Lewis Publishers, 1988.
Miller, Char, ed. Fluid Arguments: Five Centuries of Western Water Conflict. Tucson: University of Arizona Press, 2001.
Pisani, Donald J. To Reclaim A Divided West: Water, Law, and Public Policy, 1848–1902. Albuquerque: University of New Mexico Press, 1992.
Rose, Carol. "Energy and Efficiency in the Realignment of Common-Law Water Rights." Journal of Legal Studies 19 (June 1990): 261–296.
Shurts, John. Indian Reserved Water Rights: The Winters Doctrine in Its Social and Legal Context, 1880s–1930s. Norman: University of Oklahoma Press, 2000.
Steinberg, Theodore. Nature Incorporated: Industrialization and the Waters of New England. New York: Cambridge University Press, 1991.
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water supply, process or activity by which water is provided for some use, e.g., to a home, factory, or business. The term may also refer to the supply of water provided in this way.
In the United States, the average residential daily water supply demand is 100 gal (380 liters) per person, although it can go as high as 500 gal (1900 liters) per person. The stringency of the requirements that a supply of water must meet depends on the use to be made of it. For example, water used to wash semiconductor material from which transistors are made must be extraordinarily pure. The more usual requirements, however, are that water be free enough of harmful bacteria, chemicals, and other contamination to be drinkable; free of substances that make its taste or appearance unpleasant; and if the water is to be used for washing, free of salts of calcium and magnesium that will interfere with the action of soap.
The basic source of water is rainfall, which collects in rivers and lakes, under the ground, and in artificial reservoirs. Water from under the ground is called groundwater and is tapped by means of wells. Most often water must be raised from a well by pumping. In some cases a well will draw water from a permeable rock layer called an aquifer in which the water is under pressure; such a well needs little or no pumping (see artesian well). Water that collects in rivers, lakes, or reservoirs is called surface water. Most large water supply systems draw surface water through special intake pipes or tunnels and transport it to the area of use through canals, tunnels, or pipelines, which are known as mains or aqueducts. These feed a system of smaller conduits or pipes that take the water to its place of use. The California Water Plan, initiated in 1957, eventually entailed twenty dams, seven power plants, and more than 700 mi (1100 km) of canals, tunnels, and pipelines to meet the needs of southern California residents—a total of more than five billion cubic meters of water per year.
A complete water supply system is often known as a waterworks. Sometimes the term is specifically applied to pumping stations, treatment stations, or storage facilities. Storage facilities are provided to reserve extra water for use when demand is high and, when necessary, to help maintain water pressure. Treatment stations are places in which water may be filtered to remove suspended impurities, aerated to remove dissolved gases, or disinfected with chlorine, ozone, ultraviolet light, or some other agent that kills harmful bacteria and microorganisms. Sometimes hard water is softened through ion exchange, by which dissolved calcium and magnesium salts are replaced by sodium salts, which do not interfere with soap. Salts of iodine and fluorine, which are considered helpful in preventing goiter and tooth decay, are sometimes added to water in which they are lacking.
Not all water supply systems are used to deliver drinking water. Systems used for purposes such as irrigation and fire fighting operate in much the same way as systems for drinking water, but the water need not meet such high standards of purity. In most municipal systems hydrants are connected to the drinking water system except during periods of extreme water shortage. Because many cities draw water from the same body into which they discharge sewage, proper sewage treatment has become increasingly essential to the preservation of supplies of useful water (see sewerage; water pollution).
Copyright The Columbia University Press
"Water reuse" is the use of wastewater or water reclaimed from one application, such as municipal wastewater treatment, for another application, such as landscape watering. It is important that the reused water comply with all federal, state, and local laws and regulations. Some of the possible applications for the reuse of wastewater include industrial applications; landscape irrigation; agricultural irrigation; aesthetic uses, such as fountains in parks or cities; and fire suppression.
Several factors must be considered in any wastewater reuse program, including the quality of the water needed for the application, the identification of the wastewater source that meets this quality level, and the very practical needs of transporting this water to its new use.
The practical benefit of wastewater reuse (or reclaimed water) is that it reduces the need for surface water or groundwater. The reuse of water provides for conservation of new potable water sources as well as elimination of the need to expand treatment and processing facilities.
Water recycling is a part of water reuse. Recycling of water is the reuse of water for the same application for which it was originally used. In some cases, the recycled water requires treatment before it can be used again. The factors to be considered in a water recycling program are similar to the ones listed above for wastewater reuse. A very common example of water recycling is the circulation of cooling water. This represents a very large use of water in the United States. Water is passed through a system to lower the temperature of a heat source, then the water is discharged. Recycling the water, via a recirculating cooling system, can greatly reduce water use and still perform the cooling operation required.
Mark G. Robson
(see also: Drinking Water; Wastewater Treatment; Water Quality; Water Treatment )
Environmental Protection Agency (2000). Cleaner Water Through Conservation. Available at http://www.epa.gov/OWOW/NPS/chap3.html.
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