2007 Ground Water Summit

Monday, April 30, 2007 : 10:10 a.m.

Assessing the Impact of Changes in Agricultural Land-Use Practices on Ground Water Quality

Claus P. Haslauer, M.S., David L. Rudolph, Ph.D., PE and Neil R. Thomson, Ph.D., PE, University of Waterloo

The primary groundwater supply for the City of Woodstock, Ontario is drawn from a well field situated in a rural setting outside the city limits. Nitrate concentrations in several of the wells have exceeded the Ontario Maximum Allowable Concentration (MAC) of 10 mg-N/L leading to significant concern regarding the long-term water quality of this key supply. The source of nitrate is likely  related to historical agricultural land-use practices. In an attempt to reduce nitrate levels in the municipal wells, nutrient loadings on the agricultural land within the immediate vicinity of the well field are being significantly reduced through monitored and reduced fertilizing practices.

To evaluate the success of these pro-active agricultural  beneficial management practices (BMPs), a multi-faceted investigative approach has been adopted. A key component of this approach involves a detailed hydrogeologic investigation to: (a) improve the conceptual model of the groundwater flow system, (b) estimate the nitrate mass present in the subsurface, and (c) quantify the spatial nitrate mass loading from the agricultural land under investigation. Building on these data, a three-dimensional flow and transport model was developed with  the objective of predicting the magnitude and timing of the influence of these land-use changes on the nitrate concentrations extracted by the municipal well field. The model is going to be used for (a) recommending the optimum magnitude of fertilizer reduction on the parcels of land, which are currently under BMPs and (b) suggesting additional parcels of land on which BMPs should be incorporated.

Claus P. Haslauer, M.S., University of Waterloo Claus Haslauer is a Research Associate at the Department of Earth Sciences and at the Department of Civil and Environmental Engineering at the University of Waterloo. He is an environmental engineer graduating from the University of Stuttgart, Germany, and received his M. Sc. at the University of Waterloo in Hydrogeology. Claus Haslauer’s hydrogeological experience includes detailed field-data collection, data analysis, and numerical modeling

David L. Rudolph, Ph.D., PE, University of Waterloo Dr. Rudolph is a Professor in the Department of Earth Sciences at the University of Waterloo specializing in regional hydrogeology and groundwater protection and management. He is a geological engineer graduating from the University of Manitoba and received his M.S. and Ph.D. at the University of Waterloo in Hydrogeology. Dr. Rudolph’s primary research interests relate to the regional management of groundwater resources and he has worked extensively with municipal authorities in the development of groundwater protection and management strategies. Research applications have included assessing the impacts on water quality from agricultural land-use practices on the local and regional scale.

Neil R. Thomson, Ph.D., PE, University of Waterloo Dr. Neil R. Thomson is a Professor in the Department of Civil and Environmental Engineering at the University of Waterloo. He has over twenty years of research experience and expertise in the use of field investigations, laboratory experiments and numerical models to explore subsurface contaminant fate and remediation issues.


The 2007 Ground Water Summit