To ensure that industry models adhere to country or region-specific standards, a country kit can be applied. Country kits are typically defined as country, region, or market specific content and configurations that are added to a product for users within the target area. 

This app has Wastewater Calculation for Wastewater Country kits (Germany wastewater, Switzerland German Wastewater, Switzerland Italian Wastewater, Switzerland French Wastewater). This Wastewater Calculation need to be used together with any of those Wastewater Country kits which could be downloaded from the Autodesk App Store