Understanding the impact of aravalli hills mining on groundwater contamination of Delhi, India.

Groundwater contamination poses a significant threat to public health and environmental sustainability, particularly in regions impacted by anthropogenic activities such as mining. The purpose of this study was examining the degree of groundwater contamination in Delhi, India, particularly regarding the effects of mining operations in the Aravalli Hills. This study uses an integrated approach that includes the water quality index (WQI), modified heavy metal pollution index, human health risk assessment (HHRA), and geospatial techniques to evaluate the effects of mining on groundwater quality. Data of various physiochemical parameters and heavy metals were collected from the Central Groundwater Board for the year 2023-24. The WQI was calculated by using a hybrid aggregation technique and human health risk was assessed due to the ingestion and dermal contact by using the United States Environmental Protection Agency model. The WQI of the Delhi varies from 2.15 to 94.03. Results of WQI concluded that the groundwater quality of Delhi state was mostly lie in the category of poor to very poor quality, indicating serious deterioration. According to the results of HHRA, the value of total hazard index (THI) was varying from 0.86 to 49.25 for infants, 0.39 to 33.62 for children, 0.18 to 15.71 for teens and 0.16 to 13.72 for adults. The spatial distribution of WQI, THI and cancer risk were further mapped using geospatial mapping techniques, which also connected them to certain mining zones and geological vulnerabilities. In order to reduce contamination and safeguard public health, finding of the study highlights the urgent need for groundwater management plans, sustainable mining methods, and regulatory actions. In order to encourage water conservation measures and lower the release of pollutants into the environment, public awareness campaigns and community involvement should also be crucial. SDG 6 goals may be further supported by funding groundwater recharge projects and cutting-edge treatment technology, which will restore damaged aquifers and guarantee that everyone has access to safe water.