Water quality pollution indices to assess the heavy metal contamination: A case study of the estuarine waters in Cirebon City (West Java, Indonesia) Pre- and post- CARE COVID-19

The outbreak of Covid-19 has hindered societal activities, leading the government to implement lockdown measures aimed at minimizing transmission. The reduction in human activities, particularly among communities residing in estuarine areas, has the potential to impact the water quality of estuaries based on physical, chemical, and biological parameters. The impact of the Covid-19 pandemic on the coastal and marine environment is also evident in Cirebon, a port city renowned for trade and industry situated on the northern coast of Java Island. This study aims to analyse the water quality of three river estuaries in Cirebon before, during, and after the Covid-19 lockdown, specifically during the implementation of Community Activities Restrictions Enforcement (CARE) in Indonesia. Water samples from the Kesenden, Sukalila, and Kalijaga estuaries were collected in 2019, 2020, 2022, and 2023. These three stations were chosen because they are the three major river estuaries in the city of Cirebon, and each station is located in close proximity to coastal communities. These estuaries are adjacent to residential areas and serve as parking areas for small fishing boats owned by coastal communities residing around the estuaries. The river estuaries were selected as they represent transitional areas and the final discharge point of community activities that ultimately flow into the sea. Each parameter will be compared against the water quality standards of Class II as per Indonesian Government Regulation No. 22 of 2021. The Heavy Metal Pollution Index (HPI) method will be employed to classify the heavy metal index. The assessment of the heavy metal pollution index in 2019 ranged between 34.138 and 34.140, in 2020 the range was from 34.137 to 34.139, in 2022 it ranged from 29.561 to 31.86, and in 2023, the values for the heavy metal index were approximately ±34.116. Consequently, the water quality at the three observation stations exhibited improvement during the pandemic but regressed after the conclusion of the lockdown period. [Display omitted] •The water quality of three river estuaries in Cirebon before and after the CARE Covid 19.•Water samples from Kesenden, Sukalila, and Kalijaga estuaries were collected in 2019, 2020, 2022 and 2023.•Parameters will be compared with the water quality standards of Class II according to Indonesian Government Regulation No. 22 of 2021.•HPI methods for heavy metal pollution index will be used to classify the heavy metal category.•