Waste water generation and treated water

Our project has a big treatmet plant that is treating to tertiary standards not only blackwater but also graywater. The form automatically draws from the WEp1 the wastewater calculations considering only black water, but the treatment plan has a lot more capacity than the one required by WEc2. Can we include the amount of treated water that comes from gray water? This is water treated to tertiary standards and surpases a lot the credit requirements. If so, how do we include calculations on the "Table. wastewater treament", should we input two rows, one for gray water and another one for blackwater? Thank you so much in advance black