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Groundwater Visibility: The Missing Link published within Column Theme: Groundwater Management Directions—Stewardship to Sustain Our Water Resources, edited by Vicki Kretsinger Grabert and Dawn Samara Kaback.

Water rights for environmental flows are not universal, and oftentimes, legal tools used to incorporate the environment into water management only require new users to consider their impact. It can be difficult to include the needs of riparian and aquatic ecosystems in new plans when relevant information is not always available, especially when other existing uses already outstrip available supplies. There is a need for easily accessible and understandable science on the water requirements for riparian and aquatic species, so managers can make informed decisions about whether or not to include riparian and aquatic species in their community's water management future. In this paper, we describe the current understanding of the link between hydrology and Arizona's riparian and aquatic ecosystems through the creation of a geospatial Environmental Water Demands database that can be used to determine the water needs to maintain habitat. Analysis of 121 studies reveals that there are very few analyses of the surface water and groundwater requirements for intermittent or ephemeral river systems, and there are only limited generalizable data for aquatic species. Except for a few species, such as Cottonwood (Populous fremontii) and Willow (Salix gooddingii), few data are available on the flow requirements for vegetation. The Environmental Water Demands database can be used to identify critical geographic and topical knowledge gaps where further research is needed, as well as serve as a single place for water and land managers to assess and use the most currently available information to make more informed management decisions and recommendations. Copyright © 2014 John Wiley & Sons, Ltd.

Groundwater is a critical component of the water supply for agriculture, urban areas, industry, and ecosystems, but managing it is a challenge because groundwater is difficult to map, quantify, and evaluate. Until recently, study and assessment of governance of this water resource has been largely neglected. A survey was developed to query state agency officials about the extent and scope of groundwater use, groundwater laws and regulations, and groundwater tools and strategies. Survey responses revealed key findings: states' legal frameworks for groundwater differ widely in recognizing the hydrologic connection between surface water and groundwater, the needs of groundwater-dependent ecosystems, and the protection of groundwater quality; states reported a range in capacity to enforce groundwater responsibilities; and states have also experienced substantial changes in groundwater governance in the past few decades. Overall, groundwater governance across the United States is fragmented. States nevertheless identified three common priorities for groundwater governance: water quality and contamination, conflicts between users, and declining groundwater levels. This survey represents an initial step in a broader, continuing effort to characterize groundwater governance practices in the United States.

A pilot grey water treatment system and collection network were designed, installed, and operated in Jordan Valley using natural filtration materials. Grey water from showers and washing sinks was collected from four houses. In order to evaluate the performance of multi-layer filter (MLF) ability to remove the pollutants from the collected grey water, the quality of treated and untreated grey water was examined and the suitability of treated grey water for irrigation was assessed. The results revealed that the efficiency removal of organic material before UV disinfection stage for BOD5, COD, and TSS was about 88.6, 83, and 92.2%, respectively. The efficiency removal rates for nutrients by MLF were a bit low as 32.5% of total phosphorous and 19.8% of total nitrogen were removed, whereas the removal efficiency of heavy metals Zn, Fe, and Ba were 94.8, 81.2, and 15.7%, respectively. The results showed that the pilot plant has efficiently reduced the coliform organisms, thermo-tolerance coli count, and Escherichia coli by more than 99.9% removal efficiency by the double-filter stage and 100% after disinfection stage. The current MLF system has the transferability potential to other locations of the developing world.

High-volume semiconductor manufacturing (HVSM), with its associated high demands for freshwater, is often located in regions with limited water resources. This nexus of water demand and scarcity has generated concerns among municipal governments, prompting several to consider water supply restrictions as they plan for economic growth and development. By assessing water use data and economic valuations of land use from Chandler, Ariz., this study compared the economic benefit of HVSM with three alternative water uses: office, retail, and general manufacturing. Normalizing the economic benefit to net water use (after reclamation) had a marked effect on the fiscal consequences of water uses. The effects generated by mostly nonconsumptive water uses (such as HVSM and general manufacturing) increased significantly relative to less waterintensive, but more consumptive, water uses. Results showed that water-intensive land uses need not be avoided in communities where water is scarce, provided the community has the facilities necessary to reclaim the wastewater.

I. INTRODUCTION Water pollution is a serious public health risk. It is estimated that each year between 7 and 30 million people in the United States are affected by gastrointestinal illnesses from consumption of contaminated drinking water (Gelt, 1998). Also excessive nitrate concentrations in water supplies are the cause of "blue-baby" syndrome and can cause stillbirth in both humans and livestock. (1) Thus, water quality is an issue of state as well as federal attention and involvement. The Safe Drinking Water Act (SDWA), passed in 1974, authorized the U.S. Environmental Protection Agency (EPA) to set standards for drinking water quality. These standards, known as MCL, are maximum permissible levels of naturally occurring and human-made contaminants that can be present in drinking water without being harmful to health (Safe Drinking Water Act, U.S. Environmental Protection Agency, 1974). (2) The EPA defines a public water system (PWS) as "[a] system for the provision to the public of water for human consumption through pipes or other constructed conveyances, if such system has at least fifteen service connections or regularly serves at least twenty-five individuals" (United States Environmental Protection Agency, 2005). In Arizona, more than 5 million people receive drinking water from a regulated PWS (Arizona Department of Environmental Quality, 2004a). The remaining residents, amounting to about 10% of the state's entire population, get their supply of drinking water from private wells. There is growing concern about the operations of PWS responsible for providing safe drinking water to people. Drinking water can get contaminated through perforation of chemicals and bacteria in the soil or as a result of exposure to pollutants in the air. Regardless of the manner of pollution, if consumed, contaminated water can be perilous to human health. In Arizona, the Arizona Department of Environmental Quality (ADEQ) monitors water systems in accordance with the provisions of the SDWA of 1974 and amendments made to the act in 1986 and 1996. It is the state agency responsible for ensuring that the level of contaminants present in the water is lower than the maximum permissible limits specified by the EPA. (3) However, the mere presence of laws and regulations does not necessarily guarantee compliance. An effective monitoring and enforcement strategy is essential to ensure the success of any regulatory mechanism. Hence, there arises the need for a monitoring mechanism by ADEQ that is preemptive, effective, and ensures the delivery of safe drinking water. For ADEQ to be able to accomplish these objectives, it would require a clear identification of PWS that are more likely to violate MCL regulations. Having this knowledge will enable ADEQ to monitor identified PWS at regular intervals in a timely fashion. It will also allow ADEQ to devote its limited resources to the inspection of those systems that have a higher probability of violating MCL regulations instead of randomly inspecting each of the hundreds of water systems operating in the state. Whereas a large number of empirical studies have been devoted to analyzing determinants of environmental compliance (EC) by firms, less attention has been paid to EC by PWS. In this article, using data on MCL compliance of 971 PWS in Arizona, we identify the PWS and their associated characteristics that are more likely to violate MCL regulation. Our dependent variable of interest is the occurrence of an MCL violation by a PWS. Since this variable is binary (dichotomous) in nature, we estimate a probit model that allows the estimation of probability of MCL violation by an individual PWS. The remainder of the article is organized as follows. Section II describes the monitoring mechanisms of the ADEQ. Section III briefly discusses relevant previous studies addressing the determinants of EC. Section IV provides a description of the data used and the empirical methodology. …

The comparable worth approach is a radical departure from market determination of wages. This paper considers some economic issues pertinent to the comparable worth dialogue and focuses on implications of comparable worth legislation at the state and local levels. We show that current sex differentials in wages could reflect voluntary labor supply choices and/or discrimination. We also discuss the reverberations of comparable worth and note that some women in an occupation targeted with a wage increase could be made worse off as a result of employer cutbacks. We discuss why state or local officials may be hesitant to adopt comparable worth and also offer possible explanations for their being receptive to it. The intent throughout is to provide a balanced discussion that will aid individuals in taking an educated stand on the issue.