What is the ruling on someone who sees black spots, potentially repulsive, on a school wall bearing Quranic verses, and is he obligated to inform the school?

If the Quranic writing is on a filthy place on the wall, it is not permissible to leave it there, due to the obligation of glorifying and safeguarding the Book of Allah, and because leaving it would constitute degradation. The فقهاء (jurists) have explicitly stated the impermissibility of engraving the Quran and the names of Allah on walls if it leads to degradation. Therefore, this objectionable situation must be rectified by removing the Quranic words from the dirty wall, or by informing the school administration about it. However, if the writing is far from places of filth, the matter is different.