Water Quality Concerns Continue For Groundwater Management Area



Nitrate levels in groundwater above the federally designated maximum continue to plague an area of concern in the Lower Loup Natural Resources District, resulting in new regulations from the NRD Board requiring mandatory flow meter use.  Designated as Groundwater Quality Area 28 by the NRD, officials say the 50,000 acre strip of land south of the Loup River in Merrick, Nance and Platte Counties is seeing a continual rise in nitrate levels despite management efforts.
 
            Lower Loup NRD General Manager Leon “Butch” Koehlmoos said that, to combat the high nitrate levels, the Lower Loup NRD Board of Directors, at their meeting on July 25th, gave initial approval to a recommendation from its Water Resources Committee to require mandatory use of groundwater flow meters.  The flow meters will provide groundwater pumping information to the landowners.  With that data, the producers will be able to better calculate how much nitrogen credit from the irrigation water they should allow when determining fertilizer application.  The new regulation, as a change in groundwater management regulations, will require a public hearing before it can be enacted.
 
            To assist with the implementation of the new program, the LLNRD will offer landowners cost-share on the flow meters.  The three year program will offer 100% cost-share in the first year, 75% in the second year, and 50% in the third year.  Flow meters must be in place at the end of the final year.  That cost-share program will begin later this year.
 
            LLNRD Assistant Manager Russell Callan said that nitrate levels in Area 28 are often four times higher than the Environmental Protection Agency’s maximum contaminant level of 10 parts per million.  To combat the high levels, the Lower Loup NRD created a Phase III groundwater quality management plan.  Callan said that Phase III, the highest level of groundwater quality management under NRD rules, is triggered when average nitrate levels reach 8.5 parts per million, requiring producers to complete a nitrogen application certification test and report nitrogen applications rates to the NRD. 
 
Phase III also requires split application of nitrogen fertilizer, pre-plant and post-emergence.  Callan said that, under NRD rules, fertilizer application can’t begin until after March 1st.  Each farmer must also do nitrate testing of soil and water samples for each field that they farm and supply the data to the NRD annually.  That data is used to calculate the field’s nitrogen fertilizer recommendation.
 
            Callan said that despite these management efforts, the average nitrate levels in groundwater in Area 28 are increasing.  Callan said that it appears that, despite the NRD recommendation that producers utilize the Nitrogen Needs Calculator developed by the University of Nebraska-Lincoln, some farmers are still over-applying fertilizer.
 
            To get more data on the status of Area 28, Koehlmoos said that the Lower Loup NRD contracted with Olsson Associates, an engineering firm in Lincoln, to conduct a groundwater management study to determine why nitrate levels continue to rise.  The study, completed in 2012, pointed to several factors affecting nitrate levels.  Those factors included a shallow water table, sandy soils, high groundwater recharge rates, and individual management practices regarding nitrogen fertilizer application.
 
            Callan said that, of those factors, only one can be managed to decrease the nitrate problem – fertilizer application practices.  He said that has been the focus that the NRD has applied to the problem, with limited or no success.  He said that the failure of some farmers to follow the recommended fertilizer application rates could lead to more drastic management requirements. 
 
Callan said that the LLNRD hopes to avoid direct regulation of nitrogen fertilizer application.  However, if producers continue to over-apply nitrogen fertilizer, the rising nitrate levels in groundwater and the resulting health concerns will require more stringent measures.
 
A color map highlighting the nitrate problem areas in Area 28 is available on the Lower Loup NRD web site, www.llnrd.org.

Filed Under :  
Topics : Environment
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Locations : LincolnMerrickNanceNebraskaPlatte
People : LeonRussell Callan




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