Effect of lockdown during Covid-19 pandemic on the water quality of Citarum River, Indonesia

The Covid-19 pandemic has impacted several business activities due to restrictions on community mobilization. During the pandemic, the Indonesian government implemented a lockdown with the term PSBB (Large-Scale Social Restrictions). Affected activities include industrial operations and other business activities in the Citarum watershed, West Java, Indonesia. This lockdown condition can potentially affect the water quality of the Citarum River. This study aims to determine the quality of the Citarum River due to the lockdown during the Covid-19 pandemic. The research was conducted using qualitative methods. The data obtained in this study is monitoring data obtained from the West Java Environmental Service. The data being compared is water quality in July 2020 and August 2019. The monitoring locations chosen were Wangisagara, Koyod, Nanjung and Walahar. Comparisons of data show that there has been an increase in water quality for several parameters. TSS concentrations decreased at all locations, while BOD and COD concentrations decreased at the Koyod and Nanjung locations. However, these 2 locations showed an increase in the MBAS value. Based on these results, it can be concluded that the lockdown imposed for residents’ mobility reduced the entry of waste from business activities, thereby improving the quality of the Citarum River.


Introduction
The river is a form of ecosystem that plays an important role in the hydrological cycle and functions to meet the living needs of organisms or populations in the surrounding area.The condition of a river is closely related to the characteristics of the surrounding environment [1].The river as an ecosystem is composed of biotic and abiotic components and each of these components forms a functional relationship that influences one another [2].
The Citarum River is the longest and largest river in West Java province with a length of about 269 km [3].The use of the Citarum river varies greatly from upstream to downstream from fulfilling household needs, irrigation, agriculture, to industry [4].The water that flows from its upstream on Mount Wayang south of the city of Bandung flows north and empties into the Java Sea.Citarum drains 12 district administrative areas and supplies water for the livelihood needs of 28 million people [5], [6].The river is a source of drinking water for people in Jakarta, Bekasi, Karawang, Purwakarta and Bandung [7], [8].Covid-19 spread and entered Indonesia in March 2020.It has an impact on various sectors, one of which is likely the river water quality.The Covid-19 pandemic has had an impact on several activities that have stopped due to the lockdown imposed by the government [9].These activities cover several domestic and industrial sectors in the Citarum watershed and several other activities.
Various activities take place in the Citarum watershed, be it domestic activities, industry, agriculture, animal husbandry, and others, which will certainly have an impact on the water quality of the Citarum River if these activities are not managed properly.This will cause a decrease in the carrying capacity and capacity of the Citarum River to be able to continue to support various activities along the Citarum watershed.The lockdown status may affect the condition of the Citarum River water.Investigation on this lockdown condition impact to the water quality of Citarum River has not been conducted.Therefore the purpose of this study was to determine the impact of activity restrictions due to the Covid-19 pandemic on the water quality of the Citarum River.

Methods
The scope of this research is to examine the water quality of the Citarum River from upstream to downstream, with details of the Citarum watershed monitoring as many as 4 (four) locations, i.e.Wangisagara, Koyod, Nanjung and Walahar.The investigation was conducted by comparing the results of secondary data in 2018-2020 before and during lockdown due to the Covid-19 pandemic.
Water quality data was obtained from the Bureau of Environmental Management of West Java Province.The data was visualized to provide clear illustration of differences between average yearly concentrations.Parameters considered in this research were TDS, TSS, BOD, COD, DO, total phosphate, MBAS surfactant, faecal Coliform, and total Coliform.Visualization of data was displayed using parameter of TSS, BOD and COD for 3 years period.To analyse the water quality, simple calculations were conducted to determine concentration changes of all monitored parameters.This process is carried out by comparing data of year 2019 and 2020.The year of 2019 is considered as before lockdown, whereas the year of 2020 is considered as during lockdown.

Land use conditions of the Upstream Citarum Watershed
Problems in the Upper Citarum area are caused by the reduced function of protected areas (forest and non-forest), unplanned development of residential areas, uncontrolled number of farms that do not follow existing management practices, logging and encroachment, land use which tends to change every year as well as agricultural cropping patterns that are not suitable for degraded lands.It may cause high levels of erosion and sedimentation that enter river bodies and water infrastructure networks [10].
Degradation of the conservation function of water resources, such as the critical land area which reached 26,022.47ha with surface runoff of 3,632.50 million m 3 /year and caused sedimentation of 7,898.59tons/ha.As a result of the large volume of sedimentation, it causes a decrease in the river water level so that the quantity of river water decreases.Waste pollution is more dominated by residential, industrial, hospital and agricultural and livestock activities such as plastic bag waste and agricultural fertilizer residue as a result of the use of agricultural land that has exceeded the threshold.In addition, exploitation of groundwater extraction for industrial and household activities results in land subsidence and increases the potential for areas prone to flooding and landslides.Forest destruction in catchment areas will threaten the availability of river water [11] [12].An increase in population accompanied by an increase in the need to make ends meet is one of the causes of changes in land use in the Citarum Upper Watershed.

Economical activities during lockdown of Covid-19
An outbreak of Covid-19 was detected in Indonesia, namely on March 2 2020, the transmission of the Covid-19 outbreak continued and spread to almost all parts of Indonesia.As a result of the Covid-19 pandemic, this has caused a decrease in activity activities.The Indonesian government implemented the PSBB (Large-Scale Social Restrictions) policy which aims to break the chain of transmission of the very dangerous Covid-19 virus, which of course also has an impact on limiting industrial activities in the Citarum watershed area.This greatly affects the social and economic conditions of the community due to the obstruction of various activities, including the limitation of activities or the cessation of operations of some industries in the Citarum watershed.It affected nationally [13].
Figure 1 shows a decrease in the production and operating activities of textile factories in West Java.Apart from having a great impact on the social and economic conditions of the community, it turns out that this pandemic has also indirectly improved the quality of the environment, due to a decrease in various activities because people have to stay at home.This water quality improvement includes reducing the load of waste water pollution from industries that reduce their activities or temporarily stop their operational activities.According to the records of the Indonesian Textile Association (API), textile production volume has dropped dramatically from 2019, reaching 85%.In 2019, the textile industry was able to produce as much as 6.7 million tons.While in 2020, until the second week of April, it was only able to produce 1 million tons [14].Textile export volume was also decrease by 11.04% [15].

Comparison results of Citarum River water quality
The following is a graph of the results of a comparison of Citarum river water quality in the year of 2018, 2019 and 2020.Some parameters of the analysis results still exceed the quality standard determined by the Republic of Indonesia government.The BOD and COD parameters, which are the main indicators of contaminants from industrial activities, appear to almost meet water quality standard, except in Nanjung.It can be caused by the reduced pollution load from industrial wastewater due to the fact that some industries reduced or stopped operating during the pandemic.Various types of industry, both large-scale and SMEs have experienced a decline in production and activities [16].
The surfactant parameter at 4 sampling locations exceeds the quality standard, this indicates that pollution in the waters originates mainly from domestic waste.The faecal coliform parameters in 4 locations showed values that exceeded the water quality standard.This indicated that pollution of residents' waste was still ongoing, especially during the lockdown period where many activities were carried out at home.Houses that do not have waste management facilities have the potential to drain their waste directly into the river.Faecal coliform as an indicator organism is an indicator of the presence of pathogenic bacteria.Its presence indicates contamination by feces of humans and other warm-blooded animals [17].It is necessary to identify residents' houses and farms that do not yet have wastewater management facilities as materials for handling such as individual, communal septic tanks or the construction of a centralized domestic wastewater treatment plant.Total coliform parameters at 4 locations showed values that exceeded the water quality standard.Total coliform is present in water sourced from the environment and is not contaminated with faecal coliform, but the presence of faecal coliform including Escherichia coli is considered as faecal contamination, which leads to various disease conditions [18].The presence of total coliform in water must still be watched out for, especially if the water source will be used for drinking water.Monitoring results during the Covid-19 pandemic showed the total coliform number exceeded the water quality standards in all locations.Besides being influenced by lockdown conditions, the high level of total coliform is also likely affected by rainwater which carries it into the river.

Comparison of Citarum River water quality
Tabel 1 -4 show the data on comparison of water quality parameters in 4 Citarum river locations to see how the impact of activity restrictions due to the Covid-19 pandemic has affected Citarum river water quality.Based on the comparison tables, the results show uneven results.For example in Koyod the BOD and COD parameters, which are the main pollutant indicators from industrial activities, show an increase in quality from the previous data in August 2019 for the parameters BOD 86.81% and COD 68.60% but the results still do not meet the quality standards.BOD concentrations were found worsen in residential area, i.e.Wangisagara and Walahar locations due to shifting activities from industrialcommercial areas to houses.Similar condition was found in Ganga River where BOD concentration increase during lockdown [19].In Nanjung, the MBAS-detergent parameters show a 1500% decrease in quality.This is because during the pandemic, many people were doing activities from home.The faecal coliform parameters in Nanjung experienced a significant increase in quality from the previous data, which was 99.28%, but the results still did not meet the quality standards.In general, improvement on water quality is dominantly shown, especially in the location of Nanjung and Koyod.
Positive impact of lockdown restriction to the river water quality was also found in River Damodar, India [20].In general some positives and negatives impact appear in water quality during Covid-19 [21].

Conclusion
Based on Citarum River water quality data for the 2018-2020 period, it was found that the TSS parameter decreased in 2020, but for the BOD, COD and MBAS-surfactant parameters, there was an increase in the Wangisagara and Walahar locations.Citarum river water quality conditions in the Koyod and Nanjung locations show improvement in almost all parameters.This shows that the movement of human activities has an impact on river water quality.Areas with industrial-dominated land use have shown improvement in river water quality due to the activities of domestic personnel working in the area.

Table 1 .
Comparison of Citarum River Water Quality in the Wangisagara Location

Table 2 .
Comparison of Citarum River Water Quality in the Koyod Location

Table 3 .
Comparison of Citarum River Water Quality in the Nanjung Location

Table 4 .
Comparison of Citarum River Water Quality in the Walahar Location