Water Stewardship- Nitrate vulnerability study

Zenith Global is an active member of the Alliance for Water Stewardship (AWS). We were approached by a European bottled water producer who was concerned about the risk to their groundwater supply from agricultural practises in the catchment. Diffuse nitrate was considered a potential threat to water quality.

The project comprised multiple investigation phases culminating in a catchment-scale numerical model. This combined regional scale hydrogeological and land use data with local scale abstraction data. Water stewardship encourages the understanding of a site within its catchment context and this project was an opportunity to develop a holistic framework that looked at the impact of stakeholders beyond the site boundary. With a varied data set, we were able to forecast the timeframe for peak nitrate loading to the system and predict breakthrough concentrations at the supply wells. The model indicated how the current pumping regime across multiple wells might be altered to mitigate nitrate impacts.

The project identified several areas of concern using remotely sensed data, which could potentially be managed through a stakeholder engagement process. With the construction of a numerical model, we were able to simulate different pumping scenarios across the well-field quickly and economically without having to do costly field trials. We were able to recommend a course of risk reduction actions to improve the situation and identify where further efforts should be directed.