Individual or global aspect register

As far as I understand your question, it is preferable to keep an aspect and impact register per individual site. ISO 14001:2015 definition of environmental aspect states, “element of an organization’s activities or products” and when organizations want to evaluate the significance of a particular aspect and impact it is important to be aware of the specific situation. Different individual sites may have the same environmental aspects, but their significance can be very different.

Please check this information below with more detailed answers:

• Article - Environmental aspect identification and classification - https://advisera.com/14001academy/blog/2019/08/27/key-iso-14001-benefits-to-customers/nowledgebase/environmental-aspect-identification-and-classification/
• Article - Catalogue of environmental aspects - https://advisera.com/14001academy/blog/2019/08/27/key-iso-14001-benefits-to-customers/nowledgebase/catalogue-of-environmental-aspects/
• Enroll for free in this course – ISO 14001:2015 Foundations Course - https://advisera.com/training/iso-14001-internal-auditor-course/
• Book – The ISO 14001:2015 Companion - https://advisera.com/books/the-iso-14001-2015-companion/