Paying tax on the discharge of domestic and industrial waste water and on environmental loads generated by farming endeavours


Attention, this step is being updated. Please refer to the French version for the updated version !

The taxation system that has been implemented has two objectives. On one hand, it aims to give Wallonia the financial resources it needs to implement its water policy, specifically the programme to treat urban waste water (inspired by the “polluter-payer” principle); on the other hand, it aims to encourage the industrial and agricultural sectors to reduce the pollutant load contained in their discharged waste water. The tax revenue is allocated to a water-protection fund.

It also satisfies a requirement of the Water Framework Directive, which obligates Member States to recover costs related to the use of water, including the costs of its degradation.

The water tax covers various aspects:

  • Tax on the discharge of industrial water: this tax affects companies that discharge waste water as part of their industrial activity.
  • Tax on the discharge of domestic waste water generated by individuals and groups when the water does not come from the public network. When the water comes from the public network, consumption for domestic use is subject to the true sanitation cost, which forms an integral part of the cost of water.
  • Tax on pollutant loads generated by farming endeavours: this tax covers waste water generated by the livestock owned by the farmer and the pollutant loads generated by farming, based on the type of crop.

In detail

Target audience – details

Any individual or company affected by one of the three aforementioned tax regimes in Wallonia.


In the event that waste water comes from the public network, the true sanitation cost is not applied in the following cases:

1) volumes of water that are distributed to users who are subject to tax on the discharge of industrial waste water;

2) volumes of water consumed by farming endeavours that are subject to tax on environmental loads, excluding a volume equal to presumed household consumption, that is, 90 cubic metres.


Since 1 January 2005, domestic waste water from the public network has been subject to the true sanitation cost and not tax on the discharge of domestic waste water. However, all domestic waste water from alternative sources is subject to this tax.

Starting with the 2017 discharge year, when the user is liable for tax on the discharge of industrial waste water, the true sanitation cost has been replaced by a tax on the discharge of domestic waste water, with a view to streamlining administration.


In terms of tax on the discharge of waste water, the required form and annexes (water bills, etc.) must be sent to the Department of Financial Tools at SPW by 31 March of the year following the discharge. Several annexes must be attached to the declaration, including bills issued by the water supplier for the year the tax is collected, if the water is provided by the public network.

In terms of tax on environmental loads, no specific declaration is required from the taxpayer.  Data included in the SIGEC, in the context of the Walloon Agricultural Code, is used to establish this tax.

Legal references



Contact the Directorate of Economic Instruments and Financial Tools of the SPW ARNE for any question concerning these taxes and charges
For any question concerning the collection or recovery of these taxes, please contact SPW Taxation
081 33 00 01
Updated on
Process n° : 141972
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