Determining Groundwater Pollution: A proposed approach for the Development and Application of Guideline Values for Groundwater

Consultation Document, January 2017

Summary: This consultation document proposes an approach for the development of guideline values for groundwater and how these standards would be applied when determining if groundwater 'pollution' has occurred.

Published: 2017


Pages: 22

Filesize: 1,386KB

Format: pdf

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The EPA welcomes input from all stakeholders.  Those wishing to comment are encouraged to do so by emailing your comments to

The closing date for comments is 5pm, 28th February 2017.


Currently, a number of different values are being used to assess groundwater quality and ultimately pollution.  A clear understanding of what is 'pollution' is required for a number of reasons:

  • To provide a common framework across all regulatory regimes for determining pollution of groundwater and to determine the extend of groundwater contamination at licensed sites.
  • To determine concentrations in groundwater below which the danger of deterioration is the quality of the receiving groundwater is avoided.
  • To assess compliance with the Environmental Objective (Groundwater) Regulations.
    • To determine if the 'prevent or limit' objective is being met; and
    • To demonstrate that significant upward trends in concentration have been reversed and/or that any associated contaminant plumes are not expanding.

In order to assess compliance with the WFD, there is firstly a need to determine if the inputs of hazardous/non-hazardous pollutants have been prevented/limited and if they have not then to determine if the pollution has occurred as a result of the associated activities.  It is important to note that for pollution to occur there needs to be some actual or likely impact on drinking water sources, surface water or wetlands, or an impact that would impair future use of groundwater e.g. as a source of potable water.  Secondly, the extent and significance of the pollution (plume) needs to be determined as it influences the intervention that is required.