Author
 |
Replogle, John |
|
Submitted to: Hydrological Science and Technology
Publication Type: Other Publication Acceptance Date: 4/1/1997 Publication Date: N/A Citation: N/A Interpretive Summary: The two million acrefeet per year of renewable water supplies from the Salt and Colorado Rivers used in south-central Arizona also bring in about 1.5 million tons of salt per year. This salt accumulates wherever the water is used for irrigation, urban as well as agricultural, and is leached out with deep-percolation water that moves to underlying groundwater. The results are degradation of the water quality and rising groundwater levels where groundwater is no longer pumped. Before these rising water levels damage buildings, pipelines, and surface soils and plants, groundwater levels should be stabilized by pumping from wells and disposing of the water in designated salt lakes, or treating it for effective use. Remediation of groundwater pollution plumes from industrial and other point sources may not be feasible if the groundwater is going to be contaminated by irrigation deep-percolation water. Plume management to prevent further spreading, treatment of the water at the point of use, and providing alternate water supplies may then be more cost effective and benefitical to water managers, regulators, and the public. Technical Abstract: General principles of salt and water management for inland areas with water and salt imports but no export are applied to south central Arizona where two million acrefeet per year of Salt River and Colorado River water also bring in about 1.5 million tons of salt per year. Rises of groundwater levels and degradation of groundwater quality are predicted for irrigation areas, urban as well as agricultural. Groundwater pumping must be maintained, resumed, or initiated to prevent rises that can damage buildings, pipelines, and soils and plants. The well discharges must be treated for effective use, or they must be disposed of in designated salt lakes. Remediation of groundwater contaminated by point sources may not be feasible if it is going to be contaminated by non-point sources anyway. Plume management, treatment at the point of use, and introducion of alternate water supplies may then be more cost effective solutions. |