Dispersion modelling is a key element of most odour assessments around the world. There are 2 or 3 well known dispersion models developed for regulatory assessments of which the most well-known are, AERMOD and CALPUFF. Because both models have been US EPA guideline models until CALPUFF was recently removed in 2017, they are routinely used in most air quality and odour assessments.

   This article highlights the history and background behind CALPUFF and, the reason for its removal as a US EPA guideline model. Concerns with AERMOD for odour assessments will be presented in a separate document, Part 2.

Jennifer Barclay

Atmospheric Science Global (ASG). Auckland, New Zealand

   The 17th of December, the final draft of the revision process of the Standard EN 13725 on Dynamic Olfactometry was sent to the CEN secretariat in order to prepare the Enquiry document. The Working Group 2 of the Technical Comittee 264 of the European Committee for Standardization (CEN) had the task of reviewing the existing Standard and it looks like the final draft is ready. 

   This reviewed European Standard has been developed taking into account 284 working documents and 14 meetings of a group of over 20 people. The first meeting took place in Barcelona in November 2012 and after 6 years of discussions, the draft is here. The process of enquiry is a lenghy process that will take a few months, but we expect that the reviewed EN 13725 will be available along next 2019.