The issues of freshwater pollutions and the high demand of clean freshwater for daily human activities have forced developing countries such as Malaysia to continuously monitor the quality of the freshwater. The present study objective is to present the trend of water quality status in the Kelantan River downstream, Peninsular Malaysia from 2005 to 2018. Water samples were collected during dry and monsoon seasons from a sampling station located at downstream of the Kelantan River. Water quality parameters such as temperature, pH and dissolved oxygen (DO) were measured in situ while other parameters were analysed in the laboratory based on retrieved water samples. Water quality status was determined based on National Water Quality Standard (NWQS) for River in Malaysia by calculating the water quality index (WQI) according to the concentration of six water quality parameters involving pH, dissolved oxygen (DO), biochemical oxygen demand (BOD), chemical oxygen demand (COD), suspended solids (TSS) and Ammonia Nitrogen (AN). The results showed that Kelantan River had good water quality during the dry season classified in Class II at 2005. The water quality was found to be slightly lower during the monsoon season in year 2006. In addition, increasing the number of construction, human activities in the land use areas, land use changes and the sewage water from domestic, industrial, wet market and food outlets in the Kelantan State have declined the water quality in Kelantan River from Class II (in 2005) to Class III (in 2010 and 2011) and to become Class IV in 2017 to 2018. The results of the present study are expected to give valuable information for the water managers in order to deal with better strategies in controlling the quality of freshwater at the Kelantan River and minimize the incidence of pollution-oriented problems, thus the water can be utilized for various water uses with appropriate quality.

Tempat pemrosesan akhir (TPA) Bakung merupakan salah satu tempat pemrosesan akhir sampah yang dikelola oleh Pemerintah Kota Bandar Lampung. Peningkatan jumlah timbulan sampah di Kota Bandar Lampung sendiri setiap harinya mencapai 750-800 ton/hari atau sekitar 292.000 ton/tahun. Dalam mengevaluasi sistem pengelolaan sampah di TPA Bakung dilakukan dengan menggunakan metode ARRPET, yang dilanjutkan dengan perencanan skenario pengembangan sistem pengelolaan sampah di TPA melalui pendekatan Cost Benefit Analysis (CBA) sehingga efisiensi dari segi biaya ekonomi serta daerah pelayanan untuk Kota Bandar Lampung dan perkembangannya di masa mendatang dapat dijadikan perhatian yang lebih baik pada perencanaan dalam bidang persampahan. Hasil analisis TPA menggunakan metode ARRPET didapatkan nilai indeks risiko sebesar 476,962 dimana tindakan yang direkomendasikan adalah segera merehabilitasi TPA menjadi TPA berkelanjutan. Rehabilitasi TPA yang direncanakan menjadi controlled landfill, dengan perbaikkan secara bertahap. TPA yang sudah direhabilitasi nantinya akan dilakukan perencanaan skenario pengelolaan sampah kota. Hasil analisis biaya manfaat untuk skenario A (business-as-usual) diperoleh nilai BCR 0,67 dan NPV Rp.-4.858.570.081, skenario B (pengelolaan sampah dengan pola 3R) diperoleh nilai BCR tahun 2037 sebesar 0,28 dan NPV Rp.-153.823.436.569, dan skenario C (pola 3R dan pengembangan fasilitas TPA) diperoleh nilai BCR tahun 2037 sebesar 0,30 dan NPV Rp.-125.147.291.399. Hal ini menunjukkan bahwa nilai NPV yang dihasilkan negatif, dimana biaya operasional yang dikeluarkan untuk pengelolaan sampah di TPA Bakung akan lebih besar dibandingkan dengan pemasukannya. Oleh karenanya, nilai tersebut dapat dijadikan informasi untuk pengelola khususnya di TPA, dimana pemerintah bisa mensubsidi biaya baik dalam investasi maupun operasional.

The large population and the diversity of activities in big cities in Indonesia have resulted in the emergence of common problems in urban infrastructure services, such as solid waste problems. One of them is the city of Bandung which has the highest landfill load, which is 3.55 m3 (BPLHD, 2008). According to data from PD Kebersihan Bandung City, that waste services only cover 62.73% of the total waste generation. Currently, waste in the city of Bandung is disposed of at the Sarimukti TPA, which is located in Cipatat District, West Bandung Regency. This location and the city of Bandung is relatively far, which is about 45 km from the center of Bandung. The results of the evaluation transport trucks from TPS to TPA Sarimukti at 1 ritation obtained a total time of 10 hours, in the waste collection system only exist one driver who works day and night. The potential gas from CO2 and CH4 landfills to cause a greenhouse effect, it is necessary to capture gas. The IPL configuration, TPA sarimukti consists of an Anaerobic Pond, Aerobic Pool, Sedimentation Pond and Sanitation Pool. However, the parameters for COD, BOD, TDS, free ammonia, and H2S have not met the quality standard. The treatment efficiency is low for COD of only 20% due to the design depth that does not meet the design criteria, the number of aerators is insufficient or the aerators are not started according to the requirements so that the oxygen supply in the aerobic pond is reduced.

In the urban area, flooding becomes the most common disaster that has not been resolved until today. The utilization of river border area into housing and lack of absorption area becomes the trigger factor of urban flooding, as what is happening around Way Halim River on Seroja street. In this area, floods often happen during the rainy season, with the latest events recorded on January 21st, 2021. Analysis of flood intensities and discharges can be parameters for the decision-making of flood mitigation strategies. This study aims to analyze the flood discharges along Way Halim River, Seroja street by comparing the flood discharges resulting from three analysis methods of Synthetic Unit Hydrograph (SUH) including Gama I SUH, Nakayasu SUH, and Snyder SUH. Finally, suitable flood mitigation strategies were also proposed in this study based on the flood discharges and rain intensities. The results showed that Nakayasu SUH had the highest peak flood discharge than Snyder SUH and Gama I SUH. Based on the results of the investigation of land suitability; and analysis of rainfall intensities and flood discharges, the proposed flood mitigation in Seroja street is by installing biopore infiltration holes along Seroja street for storing water and reducing the risk of flooding in the area.

Bandar Lampung City is part of the major city of Lampung province. The problem that arises in Bandar Lampung City is solid waste management. The amount of solid waste in Bandar Lampung City reaches 1000 tons/day. One of the district  of Bandar Lampung named Kedamaian district still uses the old method (collecting-transport-throw) in solid waste management, which  causes the load of waste to accumulate in the landfill. The constraints encountered  this time are the absence of sorting locations  and limited land. Kedamaian district needs to develop waste  treatment facilities, an approach based on  Cost Benefit Analysis (CBA). The results show  from the analysis that BCR in the scenario A <1 is 0.85 with NPV - Rp. 72.968.828. the  activity in the existing conditions can still be carried out, but the waste reduction has not been maximized to the TPS (Container). Scenario B, NPV is Rp. 95.319.338 and BCR is 1.13, which value of BCR is >1. This indicates that a waste processing facility  in the Kedamaian District is suitable to  operate  with TPS-3R. The results of scenario B are  obtained by increasing the effectiveness of processing facilities to 100% by  2025. In 2025, with the implementation of the TPS-3R obtained, BCR is 1.20 with NPV is Rp. 218.447.621.