GB 50015-2019 第2.0.7条
| Greywater system: If a greywater system is provided in the hotel building, high-quality greywater (such as bath wastewater) should be given priority as the greywater source; the treated greywater supply should be used for toilet flushing, landscaping, etc., and its quality should meet the requirements of GB/T 18920 "Urban Sewage Recycling and Reuse – Water Quality Standard for Urban Miscellaneous Water Consumption".