Sosialisasi Pentingnya Air Bersih, dimana air bersih merupakan salah satu kebutuhan masyarakat yang menunjang kehidupan suatu komunitas. penyediaan air bersih berkaitan erat dengan status kebersihan dan kesehatan setiap individu dalam masyarakat. Kegiatan sosialisasi ini ditujukan pada masyarakat Desa Mbinanga untuk memberikan edukasi tentang pentingnya penggunaan air yang bersih dalam kehidupan sehari-hari. Maksud dari kegiatan ini adalah untuk memberikan pengetahuan pada masyarakat setempat tentang pentingnya penggunaan air bersih dalam kegaitan sehari-hari. Metode yang digunakan dalam kegiatan ini adalah sosialisasi.Masyarakat Desa Mbinanga sangat membutuhkan sentuhan nyata untuk dapat menerima manfaat secara langsung dari adanya sarana air bersih di lokasi mereka bertempat tinggal. Selama ini masyarakat harus berjalan jauh dari atas bukit ke lembah atau desa tetangga mereka yang berjarak sekitar 1-1,5 Kilometer dari desa mereka. Sehingga hal ini sangat memberatkan dan tidak efektif serta efisien baik dalam waktu, tenaga dan biaya. Sosialisasi Sehingga dengan adanya sosialisasi ini diharapkan ada tindakan secara langsung kepada masyarakat. Pengabdian ini dapat meningkatkan pengetahuan masyarakat tentang pentingnya air bersih. Masyarakat mampu menyediakan air bersihnya dengan bergotong royong dan bekerjasama dengan pihak luar sebagai penyokong dana untuk keperluan material pembangunan. Perlunya kerjasama lintas sektoral baik masyarakat, swasta, keagamaan dengan pemerintah agar terjadi sinergi yang positif secara terintegrasi sehingga manfaatnya lebih luas ke seluruh desa. Mengingat air bersih merupakan hak dan kebutuhan seluruh warga desa.

Aquatic plants are float on the surface of the water and easy to continue to grow and can even be detrimental to the environment and other aquatic organisms it they have expanded, so it is necessary to use them to reduce losses. One way to use aquatic plants is to know the phytochemical compounds of these aquatic plants, so that they can be used as medicinal plants. The purpose of this study was to determine the phytochemical compounds found in aquatic plants such as water eceng gondok (Eichhornia crassipes), genjer (Limnocharis flava) dan kiambang (Salvinia molesta). This research was conducted at the water resources management laboratory University of HKBP Nommensen Pematangsiantar with the extraction method from the leaves. Phytochemical test carried out consisted of alkaloids, flavonoids, saponins, phenolics, tannins, and vitamin c. phytochemical test results of alkaloids, flavonoids, phenolics and vitamin c were found in the three types of leaves the aquatic plants, while saponins were not found in genjer and eceng gondok, then tannins were not found in genjer. The highest phytochemical content is found in kiambang, and the lowest phtochemical content is found in genjer plants. Furthermore, it is necessary to test the antibacterial activity of aquatic plants originating from the water of Pematangsiantar city.

Batak fish (Neolissochilus sumatranus) is an endemic fish to North Sumatra Province, especially in Lake Toba. Currently, Batak fish are categorized as endangered due to overfishing and their habitat is starting to be damaged, so conservation efforts need to be made, one of which is from microbiological analysis of water found in the aquatic environment in Batak fish farming. This study aims to determine the quality of water in Batak fish farming in terms of aquatic microbiology. This descriptive research was conducted in Lake Toba waters, using random purposive sampling at 4 stations, namely: Parapat, Ajibata, Gorat, and Haranggaol Lake Toba, North Sumatra Province. Microbiological analysis was carried out at the Water Resources Management Laboratory, Faculty of Mathematics and Natural Sciences, University of HKBP Nommensen Pematangsiantar. The results showed that the bacteria found in Batak fish farming in Lake Toba waters were fecal coliform bacteria with numbers at station 1 (360/100 ml), station 2 (830/100 ml), station 3 (1310/100 ml), and station 4 (1110/100 ml). In general, the quality of Batak fish aquaculture water does not meet water quality standards, because the content of fecal coliform bacteria is above the 1000/100 ml quality standard.

Research on SST and chlorophyll-a content using GEE Cloud technology in Sibolga Waters has been carried out since February-December 2019. The analysis was carried out using the MODIS AQUA-L3SMI satellite. The SST results showed that it spread evenly from the coast of Sibolga to the sea, which was 28-33 0C and did not fluctuate, while the content of chlorophyll-a spread evenly, from February-April with a value of 0,1-1 mg/m3 varied, namely from June-August, and fluctuations namely in October-December 2019 with an amount of 0,5-2 mg/m3. SST spreads evenly, varies, and fluctuates around the outskirts of Sibolga coastal waters to the middle of Sibolga Waters, which is unsuitable for demersal fish species. Meanwhile, the chlorophyll-a content spreads evenly, varies, and fluctuates. The high content of chlorophyll-a in all waters and the high SST will make a certain type of fish that can live, namely carnivorous fish species. Image data can be used to map SST distribution patterns and chlorophyll-a content in Sibolga Waters.

Based on geological conditions, Indonesia is located between the Indo-Australian plate, the Eurasian plate, and the Pacific plate, making Indonesia prone to tectonic earthquakes. However, since the big earthquake that occurred in Aceh on December 26, 2004, the geological conditions in Sumatra have undergone significant changes marked by stressful situations in the western to southern regions of Sumatra, especially on Sibayak Volcano. This study used data from BMKG and Global CMT, which included magnitude (Mw), depth, earthquake coordinates (longitude and latitude), type of earthquake, strike, dip, and rake. From the analysis using Coulomb 3.3, the highest coulomb stress value of Sibayak Volcano was obtained in 2015 with an average change in coulomb stress of 0.235 bar, shear 0.1909 bar, normal 0.1106 bar. However, the lowest coulomb stress value occurs in 2021 with a moderate shift in coulomb stress of 0.0593 bar, shear 0.0251, normal 0.0849 bar.