Yes, it is possible for a facility to undertake the ZDHC ETP Assessment if they wish to upgrade themselves from level 1 to level 2 or level 3. 

In this scenario, the facility should work on the KPIs that are highlighted in the report by the ZDHC Approved Reviewer. Once the facility has worked on the KPI’s the facility can undergo the on-site assessment by the ZDHC Approved ETP Reviewer and based on the scoring of the re-assessment the scoring may change from level 1 to level 2 or level 3 and this will also impact the on-site assessment cadence.