Risks of industrial emissions to air for drinking water production

Drinking water companies need to know how atmospheric emissions from industry may affect supplies of drinking water. Despite monitoring from source to tap, the existing monitoring activities hardly address, if at all, the possible impact of atmospheric deposition on groundwater quality. By analysing national databases and working up specific cases, this project aims to establish a picture of the scope of the problem.

Concerns about loads from persistent substances

Industrial activities, traffic and agriculture contribute to a range of airborne contamination. These emissions can represent a threat to drinking water quality, either directly via aeration filters or indirectly after atmospheric deposition. The vulnerability of drinking water supplies was confirmed in 2011 when, as a result of the fire at ChemiePack, the air filters of the drinking water treatment plant were filled with soot.

At present, the threat comes from the emission of PFAS from industrial activities. It has led to, among other things, the large-scale pollution of soils. Drinking water companies are concerned about whether their business models can cope with the burden on the environment caused by persistent substances of this nature.

Remedying the knowledge gap

To date, the risks of atmospheric emissions for ground and surface water quality and drinking water production have not been determined systematically. These risks are not covered in the ‘area dossiers’, they are not included in groundwater protection policies and, at least in the case of Brabant Water, they are not in the picture for the purposes of location management.

Drinking water companies and provincial authorities have been monitoring water quality from source to tap for decades and they are now working on the establishment of an early-warning monitoring network in groundwater protection areas around vulnerable groundwater extraction locations. However, these monitoring activities hardly address, if at all, the possible impact of atmospheric deposition on groundwater quality. So it is not known whether the analyses are adequate to monitor the associated risks. In addition, it is not known to what extent the contaminants found come from atmospheric deposition.

To address this gap in our knowledge, this project focuses on the risks of atmospheric emissions from industry for drinking water supplies.

Analysis of national databases, zooming in on cases

The risks of atmospheric emissions for drinking water supplies are described qualitatively using a source-path effect analysis. A distinction is made here between different types of emissions (the sources), examples being incidental emissions and those from normal activities, and diffuse, linear or point pollution. In addition, the project is looking at how emissions can affect drinking water supplies:

  1. through atmospheric deposition, and
  2. through the aeration of untreated water.

Recording emissions in this way establishes a picture of the annual total atmospheric emissions of all substances and substance groups that are relevant for environmental policy. To select these substances and substance groups, an assessment is being made of their relevance for drinking water supplies. We will confine ourselves to substances and groups that are emitted in large quantities or on a large scale according to the emission records.

The next step will be to elaborate the relationship between emissions and groundwater quality, and relevance for drinking water production, in a number of cases that have yet to be determined.

Understanding the scope of the problem

The intended products of the project are:

  • a conceptual elaboration of the possible emission routes to drinking water of atmospheric emissions;
  • an overview of industrial emissions to the atmosphere and an assessment of their potential relevance for drinking water supplies;
  • a description of three cases to further substantiate how industrial emissions can affect the quality of groundwater, surface water or drinking water;
  • recommendations for possible approaches to risk management.