HSK 5
Wūshuǐ bùnéng zhíjiē pái rù héliú.
Sewage cannot be discharged directly into rivers.
HSK 5
Zhège chéngshì xīnjiàn le yī zuò wūshuǐ chǔlǐchǎng.
This city built a new sewage treatment plant.
HSK 5
Gōngyè wūshuǐ xūyào jīngguò chǔlǐ.
Industrial wastewater needs to be treated.