The vast holes left behind after mining are utilised for*1 pointwastewater storagewaste disposalwaste storagedomestic wastewater storage

The vast holes left behind after mining are often utilized for wastewater storage. Mining operations leave behind large voids which can be repurposed to manage the disposal of various wastes, particularly in mining-contaminated areas.

These voids can serve as spatial storage for water that has been used in mining processes or has been contaminated with minerals and chemicals used during extraction. This is crucial as it helps mitigate the environmental impact by containing hazardous substances in a controlled area rather than allowing them to seep into the surrounding ecosystem.

Additionally, using these holes for wastewater storage can prevent surface water pollution and manage excess water, which might pose risks if not handled properly. However, it's important to monitor these sites closely to prevent any leakage or contamination of ground or surface waters.

Thus, the correct choice in this context is wastewater storage.