Groundwater pumping effects on contaminant loading management in agricultural regions

• Published in: Journal of environmental management 2014-06, Vol.139, p.97-108
• Main Authors: Park, Dong Kyu, Bae, Gwang-Ok, Kim, Seong-Kyun, Lee, Kang-Kun
• Format: Article
• Language: English
• Subjects: Agriculture; Agriculture - methods; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Conservation, protection and management of environment and wildlife; Contaminant leaching; Contaminant loading management; Contamination; Environmental Monitoring; Fertilizers; Fundamental and applied biological sciences. Psychology; General agroecology; General agroecology. Agricultural and farming systems. Agricultural development. Rural area planning. Landscaping; General agronomy. Plant production; General aspects; Generalities. Agricultural and farming systems. Agricultural development; Groundwater - analysis; Groundwater pollution; Groundwater pumping; Leaching; Models, Theoretical; Nitrates - analysis; Pumping conditions; Pumps; Republic of Korea; Water Pollutants, Chemical - analysis; Water quality
• ISSN: 0301-4797; 1095-8630
• DOI: 10.1016/j.jenvman.2014.02.029

Groundwater pumping changes the behavior of subsurface water, including the location of the water table and characteristics of the flow system, and eventually affects the fate of contaminants, such as nitrate from agricultural fertilizers. The objectives of this study were to demonstrate the importance of considering the existing pumping conditions for contaminant loading management and to develop a management model to obtain a contaminant loading design more appropriate and practical for agricultural regions where groundwater pumping is common. Results from this study found that optimal designs for contaminant loading could be determined differently when the existing pumping conditions were considered. This study also showed that prediction of contamination and contaminant loading management without considering pumping activities might be unrealistic. Motivated by these results, a management model optimizing the permissible on-ground contaminant loading mass together with pumping rates was developed and applied to field investigation and monitoring data from Icheon, Korea. The analytical solution for 1-D unsaturated solute transport was integrated with the 3-D saturated solute transport model in order to approximate the fate of contaminants loaded periodically from on-ground sources. This model was further expanded to manage agricultural contaminant loading in regions where groundwater extraction tends to be concentrated in a specific period of time, such as during the rice-growing season, using a method that approximates contaminant leaching to a fluctuating water table. The results illustrated that the simultaneous management of groundwater quantity and quality was effective and appropriate to the agricultural contaminant loading management and the model developed in this study, which can consider time-variant pumping, could be used to accurately estimate and to reasonably manage contaminant loading in agricultural areas. •The importance of pumping condition in agricultural contaminant management was shown.•Optimal designs for contaminant loading were determined differently with the pumping conditions.•A model to manage contaminant loading together with pumping condition was developed.•It also was expanded for contaminant management under time-variant pumping condition.