March - April 2004: Volume 59, Number 2

Table of Contents

Features

• Eastern Europe: Where does conservation fit in?
  By: W.J. Busscher and J. Lipiec
• Kazakhstan
  By: T.D. Djalankkuzov, M.I. Rubinshtejn, B.U. Sulejmenov, Z.O. Oshakbaeva, and W.J. Busscher
• Ukraine
  By: V. Medvedev
• Poland
  By: J. Lipiec, S. Krasowicz, and R. D_bicki
• Romania
  By: A. Canarache

Research

• An application of water scarcity pricing with varying threshold, elasticity, and deficit
  J.M. Duke and R. Ehemann
• Stream nitrogen changes in an eastern Coastal Plain watershed
  K.C. Stone, P.G. Hunt, J.M. Novak, M.H. Johnson, D.W. Watts, and F.J. Humenik
• Fate of nitrogen from agriculture in the southeastern Coastal Plain
  R.K. Hubbard, J.M. Sheridan, R. Lowrance, D.D. Bosch, and G. Vellidis
• Concentration-discharge regression parameters in watersheds of varying lithology subjected to surface coal mining and reclamation
  J.V. Bonta

Departments

• Home Front
• Viewpoint
• Raise Your Voice
• Notebook
• Conservogram

An application of water scarcity pricing with varying threshold, elasticity, and deficit
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 2)

J.M. Duke and R. Ehemann
ABSTRACT: This paper modifies a general model of water demand to account for varying thresholds and deficits. Price elasticity of demand is also varied. Actual data on water consumption, demographics, water pricing, and weather are collected from northern New Castle County, Delaware. Under reasonable assumptions, the model predicts the effect of these three variables on price. The relationships between price increase and thresholds, elasticities, and deficits are examined in detail. The results suggest that increases in price will induce meaningful levels of conservation, even in the presence of a threshold.

Keywords: Delaware, residential water use, water conservation, water demand

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Stream nitrogen changes in an eastern Coastal Plain watershed
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 2)

K.C. Stone, P.G. Hunt, J.M. Novak, M.H. Johnson, D.W. Watts, and F.J. Humenik
ABSTRACT: Agricultural nonpoint source pollution (NPS) is a major water quality concern throughout the United States and the world. Concerns over agricultural nonpoint source pollution are heightened where intensive agricultural operations exist near environmentally sensitive waters. To address these environmental concerns, a water quality demonstration project involving federal, state, and local agencies, private industry, and local landowners was initiated in 1990 on the Herrings Marsh Run watershed in the Cape Fear River Basin in Duplin County, North Carolina. Best management practices (BMPs) to reduce nutrient losses to the environment included nutrient and animal waste management plans, soil conservation practices, and an in-stream wetland (ISW). Stream nitrate-N and ammonia-N were measured at the watershed outlet and at three subwatershed outlets from 1990-1998 to evaluate the effectiveness of the best management practices. The project was divided into pre-in-stream wetland (September 1990-May 1993) and post-in-stream wetland (June 1993-December 1998) time periods because the majority of the best management practices were implemented at the time of the in-stream wetland establishment. Post- in-stream wetland stream nitrate-N concentrations were significantly reduced on the watershed (56%) and on each of the three subwatersheds (4% to 56%). The watershed nitrate-N concentrations were reduced from 2.01 to 0.88 mg/L (ppm). One subwatershed had stream nitrate-N concentrations reduced from 5.63 to 2.74 mg/L (ppm). Nitrate-N mass export from the watershed was significantly reduced on an annual basis from 7.14 to 3.88 kg/ha (6.37 to 3.46 lb/ac). Ammonia-N concentrations and mass export from the watershed were unchanged from the pre- to post-in-stream wetland periods. The results of this study indicate that the implemented best management practices were effective in reducing nitrogen loss from the Herrings Marsh Run watershed.

Keywords: In-stream wetland, nitrogen, nonpoint source pollution, water quality

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Fate of nitrogen from agriculture in the southeastern Coastal Plain
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 2)

R.K. Hubbard, J.M. Sheridan, R. Lowrance, D.D. Bosch, and G. Vellidis
ABSTRACT: Nitrogen (N) contamination of surface and groundwater is a health concern for both humans and animals. Excess nitrogen in surface water bodies may contribute to eutrophication. Elevated nitrate (NO3-N) concentrations in drinking water have caused infant death from the disease methemoglobinemia. Formation of potentially carcinogenic nitrosamines in the soil from nitrite (NO2-N) and secondary amines is also a health concern. Both NO3-N and NO2-N have been shown to negatively affect the metabolism of domestic animals. Movement of NO3-N and NO2-N to groundwater is of particular concern in the southeastern Coastal Plain because of the unique climatic, soil morphology, and geohydrologic regimes of the region. Climatically, the southeastern Coastal Plain is characterized by warm temperatures and relatively high rainfall. Because of the extended growing season, multicropping, which requires multiple applications of nitrogen, is commonly practiced. Annual rainfall distribution often also requires use of supplemental irrigation. The combination of relatively high nitrogen inputs, high rainfall, and use of irrigation for crop production coupled with areas of permeable sandy-textured soils and geologic materials means that large portions of the coastal plain may have high potential for nitrogen contamination of surface and ground waters. Research at the Southeast Watershed Research Laboratory (SEWRL), USDA-ARS, in cooperation with the University of Georgia over the past 20 years has focused on determining factors affecting nitrogen transport and transport rates over a range of coastal plain soils and management scenarios. This paper examines the findings from these extensive studies, reports new findings from a long term study, and synthesizes all information to examine the long-term implications for nitrogen contamination of soil and water from agriculture in the southeastern Coastal Plain.

Keywords: Agriculture, coastal plain, leaching, nitrogen, riparian zones, solute transport, water quality

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Concentration-discharge regression parameters in watersheds of varying lithology subjected to surface coal mining and reclamation
(Full text appears in the Journal of Soil and Water Conservation, Vol.59, No. 2)

J.V. Bonta
ABSTRACT: Evaluations of the impacts of mining and reclamation require knowledge of changing hydrologic conditions and of changing sources and rates of release of chemicals into stream waters. Not much is known regarding the watershed-scale effects of mining and reclaiming watersheds on relations between surface-water chemical concentrations (C) and instantaneous discharge (Q) for different geological settings. These impacts were evaluated on three geologically dissimilar, small experimental watersheds subjected to surface mining for coal (C06, M09, and J11). Comparisons were made across watersheds during similar types of land disturbances during natural/undisturbed conditions (Phase 1), land disturbances caused by mining and reclamation activities (subphases of Phase 2), incomplete reclamation (subphases of Phase 3), and the final condition of the watersheds (Phase 3F). Regression analysis used a total of 5,047 laboratory analyses of 36 constituents. Of 429 regressions, 153 (36%) were statistically significant. More statistically significant regressions using a power equation were found during Phases 1 and 3F at the three sites - relatively stable watershed periods. The stability in log concentration versus log instantaneous discharge relations is quickly achieved for some constituents, mostly for major ions. Constituents for which significant regressions were found across all three watersheds during different phases of watershed disturbance were identified. Sign of the chemical concentrations - instantaneous discharge (C-Q) regression slope parameter (exponent of the power equation) was similar across the three geologically dissimilar watersheds for different phases. This study contains tables that document expected chemical concentrations - instantaneous discharge (C-Q) relations and changes in parameters due to mining coal seams and reclamation activities for 36 chemical constituents, using two mining methods, three reclamation practices, and three distinct geologic settings. The tables also provide guidance for simplified field sampling of streams for correlated and uncorrelated constituents.

Keywords: BMP, duration curves, mine spoil, overburden, strip mining, TMDL, water quality