Water Purveyors Research Articles

The Minus Approach Can Redefine the Standard of Practice of Drinking Water Treatment

Chlorine-based disinfection for drinking water treatment (DWT) was one of the 20th century's great public health achievements, as it substantially reduced the risk of acute microbial waterborne disease. However, today's chlorinated drinking water is not unambiguously safe; trace levels of regulated and unregulated disinfection byproducts (DBPs), and other known, unknown, and emerging contaminants (KUECs), present chronic risks that make them essential removal targets. Because conventional chemical-based DWT processes do little to remove DBPs or KUECs, alternative approaches are needed to minimize risks by removing DBP precursors and KUECs that are ubiquitous in water supplies. We present the "Minus Approach" as a toolbox of practices and technologies to mitigate KUECs and DBPs without compromising microbiological safety. The Minus Approach reduces problem-causing chemical addition treatment (i.e., the conventional "Plus Approach") by producing biologically stable water containing pathogens at levels having negligible human health risk and substantially lower concentrations of KUECs and DBPs. Aside from ozonation, the Minus Approach avoids primary chemical-based coagulants, disinfectants, and advanced oxidation processes. The Minus Approach focuses on bank filtration, biofiltration, adsorption, and membranes to biologically and physically remove DBP precursors, KUECs, and pathogens; consequently, water purveyors can use ultraviolet light at key locations in conjunction with smaller dosages of secondary chemical disinfectants to minimize microbial regrowth in distribution systems. We describe how the Minus Approach contrasts with the conventional Plus Approach, integrates with artificial intelligence, and can ultimately improve the sustainability performance of water treatment. Finally, we consider barriers to adoption of the Minus Approach.

Long-term Performance of Warm-season Turfgrass Species under Municipal Irrigation Frequency Restrictions

Landscape irrigation frequency restrictions are commonly imposed by water purveyors and municipalities to curtail domestic water use and to ensure adequate water supplies for growing populations during times of drought. Currently, published data are lacking concerning irrigation frequency requirements necessary for sustaining acceptable levels of turfgrass quality of commonly used warm-season turfgrass species. The objective of this 3-year field study was to determine comparative turfgrass quality of drought-resistant cultivars of four warm-season lawn species in the south–central United States under irrigation frequency regimes of 0, 1, 2, 4, and 8× monthly. Turfgrasses used in the study were based on previously reported drought resistance and included ‘Riley’s Super Sport’ (Celebration®) bermudagrass [Cynodon dactylon (L.) Pers.], ‘Palisades’ zoysiagrass (Zoysia japonica Steud.), ‘Floratam’ st. augustinegrass [Stenotaphrum secundatum (Walt.) Kuntze], and ‘SeaStar’ seashore paspalum (Paspalum vaginatum Swartz). During each growing season, slightly reduced irrigation volumes and bypassed events resulted from the 8× monthly treatment (34.95 cm, 38.13 cm, and 27.33 cm) compared with the 4× monthly treatment (35.36 cm, 40.84 cm, and 28.70 cm) in years 1, 2, and 3, respectively. For the once weekly treatment, the average fraction of reference evapotranspiration (ETo) supplied by effective rainfall and irrigation during the summer months was 1.22, 0.67, and 0.83 in years 1, 2, and 3, respectively, and was generally adequate to support acceptable turfgrass quality of all warm-season turfgrasses evaluated. Under the less than weekly irrigation frequency, st. augustinegrass and seashore paspalum generally fell to below acceptable quality levels because the average fraction of ETo supplied by effective rainfall and irrigation during the summer months of years 2 and 3 was 0.51, 0.39, and 0.26 for the 2× monthly, 1× monthly, and unirrigated treatments, respectively. Bermudagrass generally outperformed all other species under the most restrictive irrigation frequencies and also did not differ statistically from zoysiagrass. These results show that as irrigation frequency is restricted to less than once per week, species selection becomes an important consideration.

Effects of urban residential landscape composition on surface runoff generation

Lawns have long been a primary feature of residential landscapes in the United States. However, as population growth in urban areas continues to rise, water conservation is becoming a key priority for many municipalities. In recent years, some municipalities have begun to offer rebate programs which incentivize removal of turfgrass areas and conversion to alternative ‘water-efficient’ landscapes, with the goal of reducing outdoor water use. The environmental impacts and changes to ecosystem services associated with such landscape alterations are not well understood. Therefore, a 2-year continuous research project was conducted at the Urban Landscape Runoff Research Facility at Texas A&M University to evaluate rainfall capture and runoff volumes associated with several commonly used residential landscape types (including, St. Augustine grass Lawn, Xeriscaping, Mulch, Artificial Turf, and Sand-capped Lawn) and to characterize the flow dynamics of surface runoff in relation to rainfall intensity for each landscape. The results demonstrate that runoff dynamics differ between landscapes, but also change over time as the newly converted landscapes become established. Following the initial months of establishment, the effects of landscape type on runoff volumes were significant, with Artificial Turf and Xeriscaping generating greater runoff volumes than Mulch and St. Augustine grass Lawns for most runoff events, which is partially due to the low infiltration rate of such landscapes. Overall, Artificial Turf and Xeriscaping showed the greatest cumulative runoff volumes (>400 L m−2), whereas Water Efficient- Mulch, Sand-capped Lawn and St. Augustine grass Lawn had a significantly lower cumulative runoff volumes, ranging from 180 to 290 L m−2. Information from this research should be useful to municipalities, water purveyors, and homeowner associations as they weigh the long-term hydrological impacts of lawn removal and landscape conversion programs.

Public and private tapwater: Comparative analysis of contaminant exposure and potential risk, Cape Cod, Massachusetts, USA

BackgroundHumans are primary drivers of environmental contamination worldwide, including in drinking-water resources. In the United States (US), federal and state agencies regulate and monitor public-supply drinking water while private-supply monitoring is rare; the current lack of directly comparable information on contaminant-mixture exposures and risks between private- and public-supplies undermines tapwater (TW) consumer decision-making. MethodsWe compared private- and public-supply residential point-of-use TW at Cape Cod, Massachusetts, where both supplies share the same groundwater source. TW from 10 private- and 10 public-supply homes was analyzed for 487 organic, 38 inorganic, 8 microbial indicators, and 3 in vitro bioactivities. Concentrations were compared to existing protective health-based benchmarks, and aggregated Hazard Indices (HI) of regulated and unregulated TW contaminants were calculated along with ratios of in vitro exposure-activity cutoffs. ResultsSeventy organic and 28 inorganic constituents were detected in TW. Median detections were comparable, but median cumulative concentrations were substantially higher in public supply due to 6 chlorine–disinfected samples characterized by disinfection byproducts and corresponding lower heterotrophic plate counts. Public-supply applicable maximum contaminant (nitrate) and treatment action (lead and copper) levels were exceeded in private-supply TW samples only. Exceedances of health-based HI screening levels of concern were common to both TW supplies. DiscussionThese Cape Cod results indicate comparable cumulative human-health concerns from contaminant exposures in private- and public-supply TW in a shared source-water setting. Importantly, although this study’s analytical coverage exceeds that currently feasible for water purveyors or homeowners, it nevertheless is a substantial underestimation of the full breadth of contaminant mixtures documented in the environment and potentially present in drinking water. ConclusionRegardless of the supply, increased public engagement in source-water protection and drinking-water treatment, including consumer point-of-use treatment, is warranted to reduce risks associated with long-term TW contaminant exposures, especially in vulnerable populations.

A Systematic Review of Water and Gender Interlinkages: Assessing the Intersection With Health

Background: Significant developmental challenges in low-resource settings limit access to sustainable water, sanitation, and hygiene (WASH). However, in addition to reducing human agency and dignity, gendered WASH inequities can also increase disease burden among women and girls. In this systematic review, a range of challenges experienced by women relating to inadequate WASH resources are described and their intersection with health are explored. We further assess the effectiveness of interventions in alleviating inequalities related to the Sustainable Development Goals (SDGs) three (health), five (gender), and six (water). Methods: We searched the MEDLINE database to identify research articles related to water (i.e., WASH), gender, and sustainability. An analysis of both observational and interventional studies was undertaken. For each study, content analysis was performed to identify the relevant WASH, gender, and health related outcomes, and the main conclusions of the study. Results: Key themes from our search included that women and girls face barriers toward accessing basic sanitation and hygiene resources, including a lack of secure and private sanitation and of Menstrual Hygiene Management (MHM) resources. In total, 71% of identified studies reported a health outcome, suggesting an intersection of water and gender with health. Half of the research studies that included a health component reflected on the relationship between WASH, gender, and infantile diseases, including under-5 mortality, waterborne parasites, and stunting. In addition, we found that women and girls, as a result of their role as water purveyors, were at risk of exposure to contaminated water and of sustaining musculoskeletal trauma. A limited number of studies directly compared gender differences in accessing WASH resources, and an even smaller fraction (N = 5, 8.5%) reported sex-disaggregated outcomes. Educational, infrastructural, and programmatic interventions showed promise in reducing WASH and health outcomes. Indeed, infrastructural WASH interventions can be successful if long-term maintenance is ensured. Conclusions: Significant WASH inequities in women and girls further manifest as health burdens, providing strong evidence that the water-gender-nexus intersects with health. Thus, addressing gender and water inequities holds the potential to alleviate disease burden and have a significant impact on achieving the SDGs, including SDG three, five, and six.

Impact of local climate change on drinking water quality in a distribution system

Abstract In this study, air temperatures were collected between 1985 and 2016 and compared with water temperatures in four locations in the distribution system of Pasadena Water and Power (PWP), which received surface water imported into Pasadena between 2001 and 2016 from the Metropolitan Water District. The concentrations of chloramine residual and nitrite concentrations were collected between 2001 and 2016 from these five locations. The results indicate that the median nighttime temperature of the period 2009–2016 was 1.6 °C warmer than the period 1985–2000 and 0.5 °C warmer than the period 2001–2008. The median water temperature in the four distribution system samples increased by 0.8–1.4 °C depending on the location over the study period (p < 0.001). The median chloramine concentration fell significantly (p < 0.001) at three distribution system locations, and the nitrite concentrations increased significantly at all four distribution system locations (p < 0.001). As air temperature in the study area increased, water temperatures also increased resulting in the loss of disinfectant residual and the increase in the activity of ammonia-oxidizing bacteria. As this represented an increased risk to public health, PWP took additional steps to increase disinfectant residuals by adding chlorine and flushing stale water. In localities where climate change is most measurable, local water purveyors must adapt to warmer water to ensure stable concentrations of disinfectants. This article has been made Open Access thanks to the kind support of CAWQ/ACQE (https://www.cawq.ca).

Increasing chloride in rivers of the conterminous U.S. and linkages to potential corrosivity and lead action level exceedances in drinking water

Corrosion in water-distribution systems is a costly problem and controlling corrosion is a primary focus of efforts to reduce lead (Pb) and copper (Cu) in tap water. High chloride concentrations can increase the tendency of water to cause corrosion in distribution systems. The effects of chloride are also expressed in several indices commonly used to describe the potential corrosivity of water, the chloride-sulfate mass ratio (CSMR) and the Larson Ratio (LR). Elevated CSMR has been linked to the galvanic corrosion of Pb whereas LR is indicative of the corrosivity of water to iron and steel. Despite the known importance of chloride, CSMR, and LR to the potential corrosivity of water, monitoring of seasonal and interannual changes in these parameters is not common among water purveyors. We analyzed long-term trends (1992–2012) and the current status (2010–2015) of chloride, CSMR, and LR in order to investigate the short and long-term temporal variability in potential corrosivity of US streams and rivers. Among all sites in the trend analyses, chloride, CSMR, and LR increased slightly, with median changes of 0.9mgL−1, 0.08, and 0.01, respectively. However, urban-dominated sites had much larger increases, 46.9mgL−1, 2.50, and 0.53, respectively. Median CSMR and LR in urban streams (4.01 and 1.34, respectively) greatly exceeded thresholds found to cause corrosion in water distribution systems (0.5 and 0.3, respectively). Urbanization was strongly correlated with elevated chloride, CSMR, and LR, especially in the most snow-affected areas in the study, which are most likely to use road salt. The probability of Pb action-level exceedances (ALEs) in drinking water facilities increased along with raw surface water CSMR, indicating a statistical connection between surface water chemistry and corrosion in drinking water facilities. Optimal corrosion control will require monitoring of critical constituents reflecting the potential corrosivity in surface waters.

Total Water Solutions—Capturing Alternative Water Sources to Supplement Drinking Water Supply

Climate change and urbanization pressures in parts of the world characterized by water scarcity have strained resources to the point that many water purveyors must operate within more of a closed urban water cycle by using alternative sources while continuing to protect public health.

Effects of Mowing and Trinexapac-Ethyl on St. Augustinegrass Sod Establishment during a Simulated Water Variance Period

During water conservation periods, municipal water purveyors often limit irrigation for established lawns to once every 7 to 14 days, although a 4- to 6-week variance to these restrictions is often permitted for turfgrass establishment. Therefore, establishment practices promoting rapid development of a deep and expansive root system during this time may support long-term success of the turf once irrigation is scaled back. Sod producers and turf managers could benefit from information on the influence of mowing practices and plant growth regulator (PGR) applications on turf root development during this initial establishment period. The objectives of this greenhouse study were to 1) evaluate the effects of mowing and trinexapac-ethyl (TE) application on final turf quality and root development characteristics (weight, total length, and extension rate) of st. augustinegrass (Stenotaphrum secundatum) sod during a 35-day establishment period, and 2) compare the quality and rooting potential of ‘TamStar’, a newly released, embryo-rescue-derived cultivar possessing good drought resistance, with ‘Floratam’, the current industry standard for drought resistance. Weekly mowing reduced both total (2.5 to 90 cm) and deep (45 to 90 cm) root weight and root length in both cultivars. TE had no effect on visual quality of ‘TamStar’, but decreased turf quality in ‘Floratam’. TE reduced clipping yields of both cultivars but did not improve root development for either cultivar. Depth of maximal root extension during establishment was unaffected by cultivar, mowing, or TE treatment. At the conclusion of the 35-day establishment period, ‘TamStar’ exhibited superior turf quality and root weight relative to ‘Floratam’, but also produced higher rates of shoot growth. Results emphasize the importance of withholding mowing during st. augustinegrass establishment, particularly for improving total root length and deep root production, and also show that TE does not improve root development of st. augustinegrass during establishment.

Hydrologic framework of the Santa Clara Valley, California

The hydrologic framework of the Santa Clara Valley in northern California was redefined on the basis of new data and a new hydrologic model. The regional groundwater flow systems can be subdivided into upper-aquifer and lower-aquifer systems that form a convergent flow system within a basin bounded by mountains and hills on three sides and discharge to pumping wells and the southern San Francisco Bay. Faults also control the flow of groundwater within the Santa Clara Valley and subdivide the aquifer system into three subregions. After decades of development and groundwater depletion that resulted in substantial land subsidence, Santa Clara Valley Water District (SCVWD) and the local water purveyors have refilled the basin through conservation and importation of water for direct use and artificial recharge. The natural flow system has been altered by extensive development with flow paths toward major well fields. Climate has not only affected the cycles of sedimentation during the glacial periods over the past million years, but interannual to interdecadal climate cycles also have affected the supply and demand components of the natural and anthropogenic inflows and outflows of water in the valley. Streamflow has been affected by development of the aquifer system and regulated flow from reservoirs, as well as conjunctive use of groundwater and surface water. Interaquifer flow through water-supply wells screened across multiple aquifers is an important component to the flow of groundwater and recapture of artificial recharge in the Santa Clara Valley. Wellbore flow and depth-dependent chemical and isotopic data indicate that flow into wells from multiple aquifers, as well as capture of artificial recharge by pumping of water-supply wells, predominantly is occurring in the upper 500 ft (152 m) of the aquifer system. Artificial recharge represents about one-half of the inflow of water into the valley for the period 1970–1999. Most subsidence is occurring below 250 ft (76 m), and most pumpage occurs within the upper-aquifer system between 300 and 650 ft (between 91 and 198 m) below land surface. Overall, the natural quality of most groundwater in the Santa Clara Valley is good. Isotopic data indicate that artificial recharge is occurring throughout the shallower parts of the upper-aquifer system and that recent recharge (less than 50 yr old) occurs throughout most of the basin in the upper-aquifer system, but many of the wells in the center of the basin with deeper well screens do not contain tritium and recent recharge. Age dates indicate that the groundwater in the upper-aquifer system generally is less than 2000 yr old, and groundwater in the lower-aquifer system generally ranges from 16,700 to 39,900 yr old. Depth-dependent sampling indicates that wellbores are the main path for vertical flow between aquifer layers. Isotopic data indicate as much as 60% of water pumped from production wells originated as artificial recharge. Shallow aquifers not only contain more recent recharge but may be more susceptible to anthropogenic and natural contamination, as evidenced by trace occurrences of iron, nitrate, and volatile organic compounds (VOCs) in selected water-supply wells. Water-resource management issues are centered on sustaining a reliable and good-quality source of water to the residents and industries of the valley. While the basin has been refilled, increased demand owing to growth and droughts could result in renewed storage depletion and the related potential adverse effects of land subsidence and seawater intrusion. The new hydrologic model demonstrates the importance of the aquifer layering, faults, and stream channels in relation to groundwater flow and infiltration of recharge. This model provides a means to analyze water resource issues because it separates the supply and demand components of the inflows and outflows.

Consumptive water use and crop coefficients for warm-season turfgrass species in the Southeastern United States

Increased urban demand for landscape irrigation, as well as interest in promoting water-use efficient species by municipalities, water purveyors, and homeowners associations emphasize the need for comparative data on consumptive water use by warm-season lawn grasses. The objective of this study was to quantify actual evapotranspiration (ETa) and to develop crop coefficients (Kc) for four warm-season turfgrass species, namely ‘Tifway’ bermudagrass (Cynodon dactylon (L.) Pers. x Cynodon transvaalensis Burtt-Davy), ‘Empire’ zoysiagrass (Zoysia japonica Steud.), ‘Floratam’ St. Augustinegrass [Stenotaphrum secundatum (Walter) Kuntze], and ‘Argentine’ bahiagrass (Paspalum notatum Flugge). Crop coefficients were derived by dividing ETa (measured directly from lysimeter weight change over 24 to 72-h periods) by reference evapotranspiration (ETo) calculated from the ASCE–EWRI Standardized Method using onsite weather station data. Data were collected over three seasons from non-stressed, well-watered turf. For 17 of the 30 measurement periods, Kc did not differ among the 4 species, and on 24 of 30 periods zoysiagrass, bermudagrass, and St. Augustinegrass Kc did not differ from one another. A trend toward elevated Kc was observed in bahiagrass in years 2 and 3, particularly during early spring measurement periods. Kc values for all species fluctuated across seasons and years, peaking to ∼0.8 during active growth periods when vapor pressure deficit and solar radiation were greatest, and declining to ∼0.3 in late fall and winter. Root growth differences among the species appeared to have a stronger relationship to ET rates than did shoot growth rate. Results demonstrated that the commonly recommended warm-season turf coefficient of 0.6, while approximating overall average annual ETa, under-predicted ETa during active growth periods and over-predicted ETa during late fall and winter periods, when turf was slowly growing or quiescent. The results indicate seasonal refinement of Kc values may be needed to more effectively meet consumptive water use requirements of warm-season turfgrasses.

Seawater desalination as an option to alleviate water scarcity in South Africa: the need for a strategic approach to planning and environmental decision-making

In the last decade, seawater reverse osmosis (SWRO) has come to be seen by policy-makers as a novel technology that will significantly advance water security in South African coastal regions. Water purveyors, from the private sector, local/district municipalities and provincial authorities, are undertaking studies to explore the feasibility of SWRO to meet growing demand and relieve mounting pressure on current bulk water supply infrastructure. With this in mind, it is suggested that national strategic planning should be introduced to present the opportunities and constraints of the desalination option within the national water and energy policy. In absence of this, piece-meal decisions will be made at local authority levels and the construction of SWRO plants will be determined by regional circumstances (e.g. drought) as opposed to national water policy agenda. This paper explores the value of such a strategy by considering the drivers of SWRO in South Africa, the risk of unplanned large-scale SWRO implementation (with a focus on environmental impacts) and the initial steps that could be taken toward a Strategic Environmental Assessment for SWRO in South Africa.

Residential landscape water use in 13 North Carolina communities

In 2009, North Carolina State University researchers conducted a survey of residents from 13 North Carolina communities to gather information on attitudes and behaviors related to landscape water use. The survey gathered information on landscape type, water use, and the effectiveness of watering restrictions. Actual water‐use data for a two‐year period was anonymously matched with participating households. The survey achieved a 49% response rate. Most respondents indicated that more than 75% of their landscape consisted of lawn, with 60% using warm‐season turfgrass species. Those whose lawns were planted with cool‐season grass used more water than those whose lawns were planted with warm‐season species. A total of 42% of respondents restricted their landscape water use to new plantings or stressed plants. More than 88% of respondents watered by hand. In most communities, no watering restrictions were in place during this survey. Water purveyors can use the results of this survey to better understand their customers' outdoor water use and thus develop effective education programs on water conservation techniques related to landscape irrigation.

It isn't real, until it's on TV: Media and the water industry

Using entertainment media ‐ movies, video games, TV, and online apps ‐ water purveyors may be able to better communicate the value of water and engage the public in taking action.

Fire sprinklers: Protecting lives, property and assisting water conservation efforts

All model safety and building codes require fire sprinklers in newly constructed single‐family homes, duplexes, and townhomes. Requirements contained in model codes are then adopted by state and local jurisdictions. Mandates to include fire sprinklers in homes often spark debate, including among water purveyors. When faced with the possibility of communitywide adoption of a requirement to include fire sprinklers in all new home construction, water purveyors face many issues and decisions. By understanding the fine points of home fire sprinkler water use and hydraulic requirements, water purveyors will gain a more complete understanding of issues such as metering and infrastructure requirements. This article provides information specific to home fire sprinkler standards and presents the methods, procedures, and findings of several national studies that describe evidence of the benefits that home fire sprinklers offer in protecting life and property.

Emergency Do Not Consume/Do Not Use concentrations for potassium permanganate in drinking water

Over the past decade, regulatory authorities and water purveyors have become increasingly concerned with accidental or intentional adulteration of municipal drinking water. Emergency response guidelines, such as the 'Do Not Consume' or use concentration limits derived herein, can be used to notify the public in such cases. Potassium permanganate (KMnO(4)) is used to control iron concentrations and to reduce the levels of nuisance materials that affect odor or taste of finished drinking water. Manganese (Mn) is recognized an essential nutrient, permanganate (MnO4 (-)) and manganous (Mn(+2)) ions are caustic, and the acute toxicity of KMnO(4) is defined by its oxidant/irritant properties and by the toxicity of Mn. Ingestion of small amounts (4-20 mg/kg) of aqueous KMnO(4) solutions that are above 200 mg/L causes gastrointestinal distress, while bolus ingestion has caused respiratory arrest following coagulative necrosis and hemorrhage in the esophagus, stomach, or liver. Dilute KMnO(4) solutions (1-100 mg/L) are used as a topical antiseptics and astringents, but >1:5000 (200 mg/L) dilutions can irritate or discolor sensitive mucous membranes and direct skin or ocular contact with concentrated KMnO(4) can perforate tissues. Based on clinical experience with 200 mg/L KMnO(4), a Do Not Consume concentration of 7 mg/L KMnO(4) (equivalent to 2 mg Mn/L) is recommended. Recognizing limited empirical data from which to calculate an ocular reference value, a skin contact 'Do Not Use' concentration of 30 mg Mn/L is recommended based on the skin irritation in some patients after a 10-min contact with 100 mg KMnO4/L.

Water Conservation Potential of Landscape Irrigation Smart Controllers

In the past ten years, smart irrigation controllers have been developed by a number of manufacturers and have been promoted by water purveyors in an attempt to reduce excessive irrigation. Legislation has been introduced in California and Texas and passed in Florida mandating or incentivizing the use of these controllers. As a result of the interest in smart controllers, their use is increasing in new installations and retrofits of residential and light commercial irrigation systems. A number of controlled research studies using formal experimental design and statistical analyses indicate substantial water savings of anywhere from 40% to more than 70% when using these devices; however, real-world savings in larger pilot-scale projects indicate savings of typically less than 10%. Reasons for the divergence between the apparent potential savings and the realized savings in pilot projects are related to the lack of: targeting of high irrigation users (on either a relative or absolute scale), education for contractors and end users, and timely follow-up to assess water savings. In addition, much of the scientific research on smart controllers has been conducted in humid regions where higher potential savings are likely due to irrigation needed only to supplement rainfall. Future pilot projects should include comprehensive educational components aimed at irrigation sites with potential irrigation savings based on estimated landscape irrigation demand from climatic variables (i.e., high irrigation users).

Progress in US water conservation planning and implementation—1990–2009

Water conservation can be seen as a supplemental or even an alternative strategy for meeting safe drinking water needs. Because of their many benefits, conservation programs are being developed and implemented by municipal districts, regional governments and water purveyors in the United States. In recognition of the potential value of water conservation in infrastructure funding programs, many states now require, recommend, or encourage water system planners to prepare a conservation plan. This study investigates the history and progress of state‐level water conservation across the United States for the past two decades (1990 to 2009). On the basis of reviews of state legislation and relevant literature, this study finds that 23 states currently have mandates requiring conservation as opposed to nine states in 1990, indicating that progress (approximately one state added per year) has been made in conservation. Factors affecting the rate of progress are analyzed in the article.

Policy Analysis of Water Availability and Use Issues for Domestic Oil Shale and Oil Sands Development

Oil shale and oil sands resources located within the intermountain west represent a vast, and as of yet, commercially untapped source of energy. Development will require water, and demand for scarce water resources stands at the front of a long list of barriers to commercialization. Water requirements and the consequences of commercial development will depend on the number, size, and location of facilities, as well as the technologies employed to develop these unconventional fuels. While the details remain unclear, the implication is not – unconventional fuel development will increase demand for water in an arid region where demand for water often exceeds supply. Water demands in excess of supplies have long been the norm in the west, and for more than a century water has been apportioned on a first-come, first-served basis. Unconventional fuel developers who have not already secured water rights stand at the back of a long line and will need to obtain water from willing water purveyors. However, uncertainty regarding the nature and extent of some senior water claims combine with indeterminate interstate river management to cast a cloud over water resource allocation and management. Quantitative and qualitative water requirements associated with Endangered Species protection also stand as barriers to significant water development, and complex water quality regulations will apply to unconventional fuel development. Legal and political decisions can give shape to an indeterminate landscape. Settlement of Northern Ute reserved rights claims would help clarify the worth of existing water rights and viability of alternative sources of supply. Interstate apportionment of the White River would go a long way towards resolving water availability in downstream Utah. And energy policy clarification will help determine the role oil shale and oil sands will play in our nation’s future.

The Big Gulp: The Future of Groundwater Storage in the Los Angeles Coastal Plain

This article discusses an agreement referred to as the “Big Gulp” that was recently developed by California's state and local water agencies, public and private water purveyors, and local cities to create a framework for underground water storage and recapture in the previously unused empty aquifer space of the Central and West Coast groundwater aquifer basins. To meet the challenges posed by the current drought in California, the California Department of Water Resources (DWR) recommends that local groundwater agencies engage in conjunctive‐use projects, including the management and use of available aquifer space for artificial recharge. The Big Gulp would establish 450,000 acre‐ft of available dewatered space for active conjunctive use, and would create a governance structure to promote use of the basins’ storage space dedicated to the principles of local control, stakeholder participation, and transparent administration.