SimpleTreat is an assessment tool for the fate of substances in waste water treatment plants. The tool considers the most important processes like volatilization, mixing, adsorption and degradation.


SimpleTreat 4.0 screenshot


SimpleTreat 4.0 is an exposure and emission model developed to estimate chemical emission from sewage treatment plants and exposure in surface water within the framework of risk assessment of chemicals. It is a revision of SimpleTreat 3.1 which supported the chemical act 25 years ago in the Netherlands and later in the European Union (EU). The revision was necessary to account for recent scientific insights with respect to behavior of the chemical in domestic sewage and activated sludge.


Beside the use as a research tool, SimpleTreat 4.0 is used to assess substances in accordance to REACH (Registration, Evaluation, Authorization and restriction of Chemicals) and other regulations of substances in the EU, such as biocides, medicines and plant protection products.

Model and documentation

SimpleTreat 4.0 is offered as a Windows application compatible with versions of Microsoft Windows 7 and higher. The technical background of the model is described in an RIVM Report. The application of the model in EU substance regulations is described in an UBA report.


The SimpleTreat Windows application is freely available for non-commercial use. The application can be downloaded after filling out a short form.

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Please note that if you are installing SimpleTreat on a PC without MS Office 2007 or higher, you will need to install Microsoft Access Database Engine first.