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The article reports on the importance of ground water replenishment in the U.S. It explores the significance of ground water replenishment using recycled water to increase drinking water supply. It mentions several processes including soil-aquifer treatment and direct injection into a potable aquifer to manage aquifer recharge (MAR). It highlights MAR as the important source of ground water replenishment and provide a viable treatment process that meets multiple treatment objectives.

The article focuses on the impact of pharmaceuticals and endocrine disrupting compounds (EDCs) to the ground water replenishment with recycled water in the U.S. It states that its use helps mitigate ground water depletion and it can provide a significant cost savings over alternative water sources. It highlights the significance of reverse osmosis, membrane bioreactors and advanced oxidation processes as the effective at reducing pharmaceutical and EDC concentrations in waste water effluent.

A two-year pilot study, involving the recharge of a groundwater basin with reclaimed water was completed in the city of Los Angeles. The city's Department of Water and Power is planning to initiate several ground water recharge projects using reclaimed water in the near future. One such project is the Headworks Recharge Project, the focus of this paper. Approximately 1 cfs of the Los Angeles (LA) River water comprised of 70% tertiary treated reclaimed water was recharged on a two-day wet and five-day dry cycle. The recharge water was then extracted from the basin approximately 1000 feed downgradient. Results showed greater than 4-log removal of coliform bacteria, up to 87% reduction in TOC, and compliance of the product water with federal and statedrinking water standards. Model simulation showed after 15 years of recharging 3000 acre-feet per year of the LA River water and extracting about 10,000 acre-feet from the basin, the product water would contain from 5% to 15% reclaimed water. This is well below the maximum allowable limit of 20% stipulated by the California regulation. [ABSTRACT FROM AUTHOR]

Sustainable landscaping programs are voluntary initiatives that recommend a set of practices to improve the environmental quality of urban ecosystems by providing landscaping materials, guidelines, and educational resources. Our goal was to examine the recommendations and outcomes of these programs in the United States and their value for encouraging conservation practices in residential ecosystems. We conducted a comprehensive web search and identified 193 sustainable landscaping programs in the United States. Programs aim to increase native species richness, affordably manage stormwater runoff, and offer residents meaningful experiences with nature. Sustainable landscaping programs present many opportunities to engage people with local ecological knowledge and conservation practices, provide accessible spaces for environmental education, cultivate interdisciplinary research collaborations, and advance inclusion in conservation. However, assessments of their ecological value are rare, leaving many questions surrounding the benefits to biodiversity and water quality afforded by participation. Many programs also require investments in landscaping materials and certification fees that might limit participation by some households. Future work should examine how recommended practices influence urban biodiversity, identify and address barriers to participation, and generate social-ecological knowledge that can inform future programs. [ABSTRACT FROM AUTHOR]

Midwestern cities require forecasts of surface nitrate loads to bring additional treatment processes online or activate alternative water supplies. Concurrently, networks of nitrate monitoring stations are being deployed in river basins, co‐locating water quality observations with established stream gauges. However, tools to evaluate the future value of expanded networks to improve water quality forecasts remains challenging. Here, we construct a synthetic data set of stream discharge and nitrate for the Wabash River Basin—one of the United States' most nutrient polluted basins—using the established Agro‐IBIS and THMB models. Synthetic data enables rapid, unbiased and low‐cost assessment of potential sensor placements to support management objectives, such as near‐term forecasting. Using the synthetic data, we established baseline 1‐day forecasts for surface water nitrate at 12 cities in the basin using support vector machine regression (SVMR; RMSE 0.48–3.3 ppm). Next, we used the SVMRs to evaluate the improvement in forecast performance associated with deployment of additional nitrate sensors. We identified the optimal sensor placement to improve forecasts at each city, and the relative value of sensors at each candidate location. Finally, we assessed the co‐benefit realized by other cities when a sensor is deployed to optimize a forecast at one city, finding significant positive externalities in all cases. Ultimately, our study explores the potential for machine learning to make near‐term predictions and critically evaluate the improvement realized by expanding a monitoring network. While we use nitrate pollution in the Wabash River Basin as a case study, this approach could be readily applied to any problem where the future value of sensors and network design are being evaluated. [ABSTRACT FROM AUTHOR]

This study explores the impacts of groundwater processes on the simulated land‐surface water balance and hydrometeorology. Observations are compared to multiscale Weather Research and Forecasting (WRF) simulations of three summer seasons: 2012, 2013, and 2014. Results show that a grid spacing of 3 km or smaller is necessary to capture small‐scale river and stream networks and associated shallow water tables, which supplies additional root‐zone water double that of simulations with 9‐km and 27‐km grid spacing and is critical to replenishing the depleted vegetation root zones and leads to 150 mm more evapotranspiration. Including groundwater processes in convection‐permitting models is effective to reduce: (1) 2‐m temperature warm biases from 5–6 to 2–3 °C and (2) the low precipitation bias by half. The additional groundwater supply to active soil flux in convection‐permitting simulations with groundwater for June‐August is nearly translated into the same amount of increased precipitation in the domain investigated. Plain Language Summary: Groundwater plays an important role in land‐atmosphere interactions. This study explores the impacts of groundwater processes on the model simulated land‐surface water balance and hydrometeorology. Observations are compared to multiscale Weather Research and Forecasting model simulations of summer seasons for three years: 2012, 2013, and 2014. Results show that high‐resolution modeling (with a grid spacing of 3 km or smaller) is necessary to capture small‐scale river and stream networks and associated shallow water tables, and supply crop and plant root‐zone water double that of low‐resolution simulations, which is critical to replenishing the depleted vegetation root zones and leads to 150 mm more evapotranspiration. Including groundwater processes in high‐resolution models is effective to reduce: (1) 2‐m temperature warm biases from 5–6 to 2–3 °C and (2) the low precipitation bias by half. The additional groundwater supply to active soil flux in high‐resolution simulations with groundwater for June‐August is nearly translated into the same amount of increased precipitation in the domain investigated. Key Points: Groundwater‐atmosphere nexus heavily depends on model resolution and is accelerated at convection‐permitting scalesConvection‐permitting simulations with groundwater effectively mitigates summer warm and dry biases in central United StatesThe amount of water transported from shallow water tables to plant root zones is nearly identical to the increased amount of precipitation [ABSTRACT FROM AUTHOR]

Both groundwater lateral flow (GLF) and human water regulation (HWR) significantly impact hydrological processes, climate, and even socioeconomic sustainable development. Reasonably representing these processes in climate system models is vital for improving hydrological predication and climate modeling. In this study, schemes including GLF and HWR were implemented into the Flexible Global Ocean‐Atmosphere‐Land System model grid‐point version 3 (CAS‐FGOALS‐g3) to investigate the hydroclimatic effects of GLF and HWR. Three groups of simulations using CAS‐FGOALS‐g3 were conducted for the period from 1976 to 2010. Comparisons between the simulations and the observations show their good performance in reproducing the hydrological processes. Results show that soil moisture and latent heat flux increased when GLF was included in the western United States, northern Australia, and northern South America, along with a shallower water table depth. The largest increases in latent flux are located in regions without water and energy limitations. Increased summer precipitation occurred in the western United States due to the wetting and cooling effects of GLF. Latent heat flux significantly increases in three key regions of the world (central United States, north China plain, and northern India), caused by wetting surface soil due to irrigation. The atmosphere also responded to HWR, with cooling at the 850 hPa level over northern India and Pakistan. Decreased precipitation occurred in India because the upward movement was weaker as a result of HWR. GLF can replenish the groundwater depression cone caused by overexploitation, especially in thick aquifers. Plain Language Summary: Groundwater lateral flow and human water regulation significantly impact hydrological processes and climate. In this study, we implemented the schemes including groundwater lateral flow and human water regulation into the Flexible Global Ocean‐Atmosphere‐Land System model to investigate the hydroclimatic effects of groundwater lateral flow and human water regulation. Comparisons between the simulations and the observations show their good performance in reproducing the hydrological processes. Groundwater lateral flow can replenish the groundwater depression cone caused by overexploitation, especially in thick aquifers. Human water regulation weakens the upward movement in India and reduces the summer precipitation. Both groundwater lateral flow and human water regulation affect soil moisture and energy fluxes at the land surface. These results suggest that groundwater lateral flow and human water regulation, which are generally simplified or excluded in climate system models, may provide missing parts for modeling water and energy fluxes and improving water management. Key Points: Schemes including groundwater lateral flow and human water regulation were coupled with CAS‐FGOALS‐g3 to study the hydroclimate effectsBoth groundwater lateral flow and human water use affect land energy fluxes by changing soil moistureHuman water use weakens the upward movement in India and reduces the summer precipitation [ABSTRACT FROM AUTHOR]

The article offers information on the ground water replenishment in the U.S. It states that ground water replenishment with recycled water is not a new approach but drought, population growth and effective use of all water resources have escalated worldwide interest in the benefits of augmenting ground water supplies. It mentions several perspectives on recycled water use including advanced waste water treatment technologies and the overall benefits of recycled water recharge.

Mountain‐block recharge (MBR) is the subsurface inflow of groundwater to lowland aquifers from adjacent mountains. MBR can be a major component of recharge but remains difficult to characterize and quantify due to limited hydrogeologic, climatic, and other data in the mountain block and at the mountain front. The number of MBR‐related studies has increased dramatically in the 15 years since the last review of the topic was conducted by Wilson and Guan (2004), generating important advancements. We review this recent body of literature, summarize current understanding of factors controlling MBR, and provide recommendations for future research priorities. Prior to 2004, most MBR studies were performed in the southwestern United States. Since then, numerous studies have detected and quantified MBR in basins around the world, typically estimating MBR to be 5–50% of basin‐fill aquifer recharge. Theoretical studies using generic numerical modeling domains have revealed fundamental hydrogeologic and topographic controls on the amount of MBR and where it originates within the mountain block. Several mountain‐focused hydrogeologic studies have confirmed the widespread existence of mountain bedrock aquifers hosting considerable groundwater flow and, in some cases, identified the occurrence of interbasin flow leaving headwater catchments in the subsurface—both of which are required for MBR to occur. Future MBR research should focus on the collection of high‐priority data (e.g., subsurface data near the mountain front and within the mountain block) and the development of sophisticated coupled models calibrated to multiple data types to best constrain MBR and predict how it may change in response to climate warming. Key Points: Mountain‐block recharge confirmed as important source of recharge to basin aquifers in a variety of climatic and geologic settings globallyRecent work advanced understanding of fundamental controls on mountain‐block recharge and somewhat improved methods for characterizationFuture research should aim to acquire subsurface data in mountain block and at the mountain front [ABSTRACT FROM AUTHOR]

Most tickborne disease studies in the United States are conducted in low-intensity residential development and forested areas, leaving much unknown about urban infection risks. To understand Lyme disease risk in New York, New York, USA, we conducted tick surveys in 24 parks throughout all 5 boroughs and assessed how park connectivity and landscape composition contribute to Ixodes scapularis tick nymphal densities and Borrelia burgdorferi infection. We used circuit theory models to determine how parks differentially maintain landscape connectivity for white-tailed deer, the reproductive host for I. scapularis ticks. We found forested parks with vegetated buffers and increased connectivity had higher nymph densities, and the degree of park connectivity strongly determined B. burgdorferi nymphal infection prevalence. Our study challenges the perspective that tickborne disease risk is restricted to suburban and natural settings and emphasizes the need to understand how green space design affects vector and host communities in areas of emerging urban tickborne disease. [ABSTRACT FROM AUTHOR]

The article discusses perpetual drought and persistent land development in California. Topics include evolution of water rights, the state Water Resources Control Board, land use planning laws, water use regulations, and proposed legislative and policy changes to conform water management and distribution with land development.

Perennial grasses are promising feedstocks for bioenergy production in the Midwestern USA. Few experiments have addressed how drought influences their carbon fluxes and storage. This study provides a direct comparison of ecosystem-scale measurements of carbon fluxes associated with miscanthus ( Miscanthus × giganteus), switchgrass ( Panicum virgatum), restored native prairie and maize ( Zea mays)/soybean ( Glycine max) ecosystems. The main objective of this study was to assess the influence of a naturally occurring drought during 2012 on key components of the carbon cycle and plant development relative to non-extreme years. The perennials reached full maturity 3-5 years after establishment. Miscanthus had the highest gross primary production (GPP) and lowest net ecosystem exchange (NEE) in 2012 followed by similar values for switchgrass and prairie, and the row crops had the lowest GPP and highest NEE. A post-drought effect was observed for miscanthus. Over the duration of the experiment, perennial ecosystems were carbon sinks, as indicated by negative net ecosystem carbon balance (NECB), while maize/soybean was a net carbon source. Our observations suggest that perennial ecosystems, and in particular miscanthus, can provide a high yield and a large potential for CO2 fixation even during drought, although drought may negatively influence carbon uptake in the following year, questioning the long-term consequence of its maintained productivity. [ABSTRACT FROM AUTHOR]

The concentrated ownership of farmland has influenced rural life in the state of California for more than a century. Reformers have introduced measures to counteract that concentration, such as acreage limits on farms receiving water from federally funded projects. Large landowners have fought back with policies that have protected their ability to amass and maintain their empires. In the first part of this article, Mason Gaffney presents this historical background in broad outlines. In the second part, Merrill Goodall explains an important policy that preserves the power of entrenched interests: water districts that are governed by a board elected by a voting system that allots one vote to each dollar of land value. In these districts, a tiny handful of landowners is able to control a public agency without opposition and without the need to persuade other voters. [ABSTRACT FROM AUTHOR]

Fresh groundwater resources of some medium and large cities (with population over 500000) are analyzed. The use of fresh groundwater for public water supply in individual regions (federal districts of the Russian Federation) and cities is demonstrated. A relationship was found to exist between the size of urban population and the use of fresh groundwater resources. It has been shown that the larger the city (in terms of its population), the lesser the contribution of groundwater to the public water supply. The use of fresh groundwater in Russia and the United States is compared. The effect of considerable groundwater withdrawal on the hazard of land subsidence is briefly characterized. Present notions of excessive groundwater exploitation are considered. Available statistical methods are used to forecast the population of medium and large cities in Russia. Current and expected drinking water demand in the population of federal districts as a whole and individual cities during emergency periods are considered. The values of the current and expected demand in the population are correlated with the explored and approved usable groundwater resources, making it possible to assess the availability of drinking groundwater resources in emergency periods for federal districts of the Russian Federation and the chosen cities. [ABSTRACT FROM AUTHOR]

The article discusses tribal strategies for protecting and preserving groundwater as of 2015, and it mentions U.S. federal and state water rights, litigation and legal settlement planning, and a correlative groundwater rights system in California. Tribal sovereignty and power are mentioned, along with U.S. jurisdiction, drought conditions in California, and Native American water rights. California's environmental conditions, Native American reservations, and water scarcity are examined.

The article presents information on several waste-water treatment plants in the U.S. One such plant was started in Wichita Falls, Texas, on July 9, 2014, for which Wichita Falls spent 13 million dollars to build a 12-mile pipeline that connects the treatment plant to the drinking water treatment facility. In 2007, California's Orange County Water District (OCWD) started an indirect potable reuse (IPR) operation, known as the Groundwater Replenishment System, for treating wastewater.

The article discusses access to safe drinking water. The author notes the use of water to clean sidewalks near residential and commercial properties in the U.S., arguing that the public considers water to be a throwaway commodity and doesn't understand the expense associated with the complex water treatment processes that makes it safe to drink. Topics include a comparison between the public's view of water in developed nations with parts of the developing world, diminishing public concern of the threats to continued availability of safe water in developed nations, and how safe water is regulated in the U.S., which includes determining a maximum contaminant level goal (MCLG) for each contaminant and enforcing the maximum contaminant level (MCL).

The article presents the volume 65, issue three of the journal. It outlines the different topics featured in the journal which include the challenged faced by the U.S. Environmental Protection Agency's Total Maximum Daily Load for Chesapeake Bay watershed pollutants, and the compensation sought by the Arkansas Game & Fish commission from the U.S. Army Corps of Engineers. It also mentions several zoning cases in the country and environmental impact statement.

The Ogallala Formation of Miocene/Pliocene age is present over a large area of the Great Plains in the central US. The formation is composed of mostly clastic material eroded and transported eastward from the Rocky Mountains by eastward flowing rivers and streams. It contains the life-giving water that supports the population and farming activities of this vast area. However, this precious water resource is fast being depleted. The geology and geologic history, groundwater recharge, irrigation development, and water law and management of the region are outlined so as to highlight the nature and extent of the water problems facing that region and point to a more sustainable path. Further strengthening local water management and coordination with state government as well as better interstate coordination of the High Plains states will help sustain this critical water resource for generations to come. [ABSTRACT FROM AUTHOR]

The article offers news briefs on topics related to groundwater remediation. Daniel B. Stephens & Associates Inc. has been selected for the Outstanding Ground Water Project Award from The U.S. National Ground Water Association (NGWA). Amendments to the NGWA Code of Regulations would be proposed by NGWA board at the 2011 annual meeting. U.S. Geological Survey hydrologist Paul Hsieh has been selected for the U.S. 2011 Federal Employee of the Year Award.

Riverbank filtration (RBF) has been used for many decades in Europe and the United States to provide drinking water to communities located on riverbanks. In India, the development of RBF has the potential to provide drinking water to many cities located on the Ganga Plains currently using surface water as a source for their public water supply. Water diversion for irrigation and discharge of wastewater to rivers with extremely low flows has aggravated the water supply situation for many Indian cities using surface water. A number of Indian cities, with source waters of significantly varying quality, are already using RBF. In most of these cities no significant additional treatment is provided to the filtrate for their water supply. The objective of this article is to examine selected operating bank filtration sites in India (that have been investigated since 2005) and to elucidate additional potential RBF sites based on water problems and hydrogeologic suitability. A summary of selected operational RBF systems in Ahmedabad, Delhi, Haridwar, Mathura, Medinipur and Kharagpur, Nainital, Patna and Srinagar and their ability to produce potable water is provided. Analysis of the suitability of RBF for Allahabad, Bhubaneswar, Guwahati, and Vijayawada, based on hydrogeology and land use, is also provided. [ABSTRACT FROM AUTHOR]

The article offers U.S. news briefs related to water quality management. The National Ground Water Association support the key provisions of the Science and Engineering to Comprehensively Understand and Responsibility Enhance Water Act. Massey Energy Co. has agreed to pay a $20 million civil penalty in a corporate-wide settlement to resolve its Clean Water Act violations in West Virginia and Kentucky. The water purification project in California will produce near-distilled quality water.

The fate of estrogenic activity in waste water effluent was examined during surface transport and incidental recharge along the Santa Cruz River in Pima County, Arizona. Based on measurement of boron isotopes, the fractional contribution of reclaimed water in surface waters and ground water wells proximate to the river was determined for a contemporary sample set. Estrogenic activity decreased by ∼60% over the 25 mi length of the river below effluent discharge points in Tucson. In ground water samples obtained from monitoring wells that are proximate to the Santa Cruz River, both dissolved organic carbon (p = 0.0003) and estrogenic activity (p = 3 X 10-6) were highly correlated to fractional waste water content. Results indicate that proximate ground water quality is sensitive to incidental recharge of reclaimed water in the Santa Cruz River bed. In a few locations, little attenuation of estrogenic activity was apparent during percolation of effluent in the river channel to well withdrawal points. [ABSTRACT FROM AUTHOR]

Substantial progress has been made within central Arizona in moving towards a more sustainable water future, particularly in transitioning the urban demand from a primarily nonrenewable groundwater-based supply Groundwater use in many areas of Arizona greatly exceeds the natural replenishment of the aquifer, so although a portion of the groundwater use is renewable, the majority is not. to increasing dependence on the Colorado River, Salt River and effluent. Management efforts include a wide range of regulatory and voluntary programs which have had mixed success. The Department of Water Resources has learned a number of key lessons throughout the years, and this paper attempts to establish the water management context and identify those lessons for the benefit of others who may want to evaluate alternative approaches to groundwater management. Themes to be discussed include evaluating water management approaches in a public policy context, the effectiveness of alternative management approaches and the relative merits of regulatory vs. nonregulatory efforts, and the importance of high-quality data in making management decisions. [ABSTRACT FROM AUTHOR]

1. The growth of riparian trees in semi-arid regions is influenced by stream flow regime, but the relative importance of base flow and seasonal floods on growth has not been explored. I examined abiotic influences on the growth of Platanus wrightii in four stream reaches in Arizona. All reaches had a bimodal pattern of discharge, but only two had continuous flow throughout the growing season. 2. In two reaches of Sycamore Creek without perennial flow, a large percentage of the annual variation in radial growth rate of P. wrightii was explained by annual and growing season flow rate. Growth was related to these same variables in a perennial reach of Sycamore Creek, but trees maintained higher growth during drought years than they did in the temporary reaches. At Oak Creek, a larger perennial stream, P. wrightii growth showed a bell-shaped relationship with flow. These data suggest that growth rate is frequently limited by water availability at Sycamore Creek, but not at Oak Creek. 3. At both rivers, much of the annual surface flow occurs as winter floods. Oak Creek, however, maintains a high summer base flow even during years with no floods. Platanus wrightii growth was significantly related to winter flood frequency only at Sycamore Creek. The positive relationship of growth with stream flow and winter flood frequency at Sycamore Creek presumably occurs because the P. wrightii trees are dependent on the winter flows to recharge the shallow alluvial aquifer and to raise the level of ground water within the root zone. 4. Frequent summer floods increased the growth of trees in perennial and non-perennial reaches alike. At perennial Oak Creek, summer flood frequency was the only variable linearly related to growth of P. wrightii. Summer flood frequency was a significant, but secondary, component of multiple-regression growth models for trees in the perennial and non-perennial reaches of Sycamore Creek. Summer floods may stimulate growth, in part, by replenishing... [ABSTRACT FROM AUTHOR]

Focuses on the water recycling project in California. Barriers to recycled water projects; Importance of the involvement of stakeholders in the project; Use of reclaimed municipal water supply and composted waste by the Left Field Farm to grow vegetables; Benefits of planned recycling projects.

Features a study which compared the effect of low energy precision application and spray sprinkler methods and irrigation amount on grain yields and water use efficiency of corn, grain sorghum and winter wheat in the Southern High Plains. Procedure; Results; Conclusions.

Problems of water resource development have been the focus of substantial interest to a growing number of economists and political scientists in the U.S. In both cases this interest unquestionably arises from the multiplicity of uses that can be derived from a water system. Political scientists have either been concerned with describing the game of politics associated with conflicts among the interests involved in water resource development or with the design of administrative arrangements which would assure comprehensive, multiple-purpose planning of water resource programs. The biases of many political scientists have led them to urge an integrated, regional approach to water resource planning. By contrast, economists have been concerned with the appropriateness of market mechanisms for allocating water resources among competing users and with the development of modes of analysis which would assure more explicit consideration of economic criteria in reaching decisions bearing upon water resource developments.

Focuses on the development of the Platte River Bottomland in South Central Nebraska. Investigations made byt he Nebraska Geological Survey and the Nebraska Water Survey; Views of the environing features of the Platte.

The article offers information on the Community Water System Survey (CWSS) conducted in 2006 by the U.S. Environmental Protection Agency's (EPA) to analyze characteristics of groundwater-supplied community water systems in the U.S. It presents findings of the survey on several aspects of water systems, including ownership, revenues, and expenses. A charts on the service population sizes of groundwater-supplied community water systems in the U.S. is included.

We identified intra-annual climatic drivers of stem water relationships and growth in foundation conifers at a subalpine site in the Great Basin Desert and at a montane site in the Mojave Desert (Nevada, USA). Sites were instrumented to represent naturally different levels of heat and drought stress as part of NevCAN (the Nevada Climate and ecohydrological Assessment Network). We analyzed three years (2013–2015) of sub-hourly dendrometer records for limber (Pinus flexilis) and bristlecone pine (Pinus longaeva) at the subalpine site, and for ponderosa (Pinus ponderosa) and pinyon pine (Pinus monophylla) at the montane site. Multiple logistic regression was used to identify relationships with environmental variables measured in-situ. At both sites, stem expansion occurred during the early morning and late afternoon, and irreversible stem increment was concentrated in the early morning hours. In subalpine species, stem growth started in late spring and continued until August, while at the montane site stem growth was episodic, peaking during summer monsoonal rainstorms. Circadian maximum and minimum stem size during the growing season were reversed during the dormant season at the colder/wetter subalpine site but not at the warmer/drier montane one. Knowledge of intra-annual tree-water relationships and stem growth helps understand how sky island forests grow under highly diverse climatic conditions, including severe drought and heat stress. [ABSTRACT FROM AUTHOR]

In this paper, we develop a theoretically consistent framework to incorporate the environmental effects of agricultural production and the depletion of natural capital caused by agricultural production intothe existing income accounts. We apply the framework and adjust the income attributed to the agricultural sector and economy-wide net national product (NNP) for the United States. Estimated adjustments to the income attributed to agriculture are in the range of $4 billion and have declined as a percentage of net farm income since 1982. [ABSTRACT FROM AUTHOR]