The Cicatih River in the Cikembar sub-watershed, located in Sukabumi Regency, flows along the upstream of the Cikembar sub-watershed and Palabuhan Ratu Bay. For decades, the river has served as a vital water resource, catering to various needs such as domestic use, agriculture, livestock, fisheries, industry, mining, tourism, and hydroelectric power. Recently, the Sukabumi Regency Government made the pollution of coastal and river areas one of the priority issues on sustainable development initiatives for the Sukabumi Regency. This highlights the importance of managing the Cicatih River, one of the main rivers in the regency. This research aims to analyze the potential pollution loads in the Cikembar sub-watershed to the Cicatih River by assessing its water quality status and potential pollution loads from four main sectors: domestic, agricultural, livestock, and industrial. The water quality was calculated based on the Pollution Index method. The potential pollution load from different sources was analyzed using various emission factor calculations. For each pollutant source, the following parameters were analyzed: total suspended solids (TSS), biochemical oxygen demand (BOD), chemical oxygen demand (COD), Total-N (nitrogen), and Total-P (phosphorus). Results showed that the condition of the Cicatih River is slightly polluted. The parameter exceeding its maximum threshold is BOD. The largest contributor to the potential pollution load of BOD is the domestic sector (53%), while the agricultural sector is the least (2%). In the domestic sector, Bojongkembar Village is the largest contributor to the potential pollution load. The results of this analysis can be used to develop strategies for managing the overall Cikembar sub-watershed.

Cisangkan River, a tributary in the Upper Citarum Watershed, West Java, stretches 8.91 km across 1,800 ha. Flowing through West Bandung Regency and three districts in Cimahi City, it discharges into the Saguling Reservoir. Over the past five years, the river’s water quality has been classified as heavily polluted. This study aims to estimate potential pollution loads from domestic, industrial, and agricultural sectors and evaluate the impact of pollution load reduction on water quality improvement. Pollution loads were estimated using emission factors, urban equivalent ratios, and pollutant transfer coefficients. Water quality simulation was conducted using the QUAL2Kw model, while spatial distribution analysis employed the Inverse Distance Weighted (IDW) interpolation for BOD, COD, and TSS parameters. Results show that the domestic sector contributes the highest BOD load at 441.1 kg/day (54%), while the industrial sector dominates COD pollution with 738.67 kg/day (53%). The highest TSS load also originates from the domestic sector, contributing 421.9 kg/day (52%). The QUAL2Kw model achieved satisfactory accuracy, with RMSPE values of 1.4% for BOD, 2.73% for COD, and 5.06% for TSS. Scenario V, simulating a 90% reduction in pollution loads, demonstrates significant improvement in pollution load capacity, allowing the river to meet national water quality standards. Spatial analysis using IDW indicates the highest BOD pollution load from the domestic sector in Leuwigajah Sub-district, from the agricultural sector in Citeureup Sub-district, and from the industrial sector in Padasuka Sub-district.

District Aerocity X in Kabupaten Majalengka is a commercial and industrial area that enhances economic growth in Provinsi Jawa Barat. The district with an area of 3,480 ha is integrated into the domestic sector. However, this area also has the potential to cause harm if the waste is not treated. Following PP No 142 Tahun 2015, each industrial area must provide an effective and efficient wastewater treatment plant (WWTP). This design plan begins with the analysis of issues on the study site . The data were obtained using the Aerocity X District Pre-Development Office study method . The method of designing effective alternatives for WWTP used the weighted ranking technique (WRT), each alternative was compared with two fundamental, technical and non-technical aspects. The purpose of this design plan is to analyze the index of land and cost requirements for WWTP. The yield of wastewater was 3.99 m³/s. The most effective land and the cost is complete mix-activated sludge. The result of installing the design plan requires an area of 9,446.5 m²/m³ of wastewater and a cost of Rp5,619.53x10⁶/m³ of wastewater.