WATER RESOURCES RESEARCH GRANT PROPOSAL
Project ID: 2005KS45B
Title: Fate of Nitrate Beneath Fields Irrigated with Treated Wastewater in Ford County, Kansas Using Field Data and Preferential Flow Modeling
Project Type: Research
Focus Categories: Models
Keywords: preferential flow modeling, nitrogen cycling, leaching, dye tracing, wastewater irrigation
Start Date: 03/01/2005
End Date: 02/28/2006
Federal Funds: $28,812
Non-Federal Matching Funds: $60,483
Congressional District: 2nd
Kansas Geological Survey, The University of Kansas
Margaret A. Townsend
Kansas Geological Survey
With increasingly limited groundwater resources, reuse of treated wastewater
provides an alternative source of water for irrigation of crops and landscaping.
A long-term irrigation project with treated wastewater in Ford County, Kansas,
will be the focus of this study. The use of treated wastewater at this site
has resulted in high nitrate concentrations (10 – 50 mg/kg) throughout
the upper 50-ft profile but at varying concentrations, suggesting that preferential
flow processes have occurred at the proposed study area. Evaluation of the
environmental impact of such land use strategies needs to be made in order
to determine if and when this process may impact usable groundwater at depth.
We therefore are proposing to estimate the leaching rates and time of arrival
of N- (and Cl-) contaminants using preferential flow and N-cycling numerical
modeling in combination with field and laboratory measurements at the study
site. This approach also will help to identify key parameters and processes
that influence N losses in agricultural soils and can facilitate evaluation
of the environmental impact of different land use practices.
To achieve this goal we are proposing to collect deep cores for physical and chemical properties characterization, including using the Geoprobe capabilities for electrical conductivity profiling; perform dye tracer experiments; install neutron moisture probe access tubes and regularly collect soil moisture data; and obtain soil chemical data, crop and irrigation application rate information, climatic data, and other additional information from the ongoing study in the area, which is managed by the two consultant co-PIs in this proposal. All these data will be used in a comprehensive N cycling model such as DAISY or RZWQM (both of which also account for preferential flow and transport) to identify key parameters and processes that influence N losses in the study area.
Results from this study will assist in determining leaching rates and fate of nitrogen in the High Plains aquifer from wastewater irrigation, provide additional data for enhancing the detailed nitrogen budget the consultant co-PI’s have developed for the area in question, and assist in providing information for other areas where there is an interest in using reclaimed water for landscape irrigation as a means to conserve water or for disposal purposes.
Progress/Completion Report, PDF