International Journal of Advanced Research in Computer Engineering & Technology (IJARCET) Volume 7, Issue 4, April 2018, ISSN: 2278 – 1323 www.ijarcet.org 406 Abstract—Water quality due to its direct correlation with human health becomes an important issue in fulfilling the needs of domestic water. The feasibility of water quality for the domestic needs must be in accordance with the standard as defined by the Regulation of Health Minister Number 416/PER/IX/1990. Domestic water refers to the water used to fulfil the needs of daily activities such as cooking, drinking, plant watering, or sanitary. The water quality can be observed from physical, chemical and biological parameters. These parameters must, at least, include odor, solved residue (TDS), turbidity, flavor, temperature, pH, and total Coliform. In this research, Fuzzy logic has been used to determine the water quality based on the physical, chemical and biological parameters. Not all parameters were tested with fuzzy method; there were a number of parameter tests must be carried out in the laboratory such as total total coliform, pH and TDS. Based on the sample taken, the water was seen transparent, little bit turbid, odorless, flavorless and at the average temperature of℃. From the testing result using Fuzzy and the result of laboratory test, it can be concluded that the ground water in the region of Mungkid city on average is feasible to fulfil the domestic needs (daily needs of people nearby). Index Terms—waterquality, domestic water,fuzzy, turbidity, water colour. I. INTRODUCTION Water quality is related to the content characteristics of the living creatures, substances, energy or other components in water. It is stated with some parameters; namely physical parameters (temperature, turbidity, dissolved density, and so on), chemical parameters (pH, dissolved oxygen, BOD, metal content, and so on) and biological parameter (the existence of plankton, bacteria and so on) [1]. The purpose of monitoring the water quality is to assess the feasibility of water resource for certain need such as to fulfil the domestic needs. Domestic water must fulfil the standards of quality in accordance with its allocation as stated in the Government Regulation of Indonesia Republic Number 20 of 1990. Today, the volume of qualified water has been decreasingalong with the increase of the needs for domestic water and production activities in society [2]. In addition, the decline of water quality is related to the increase of population, topography, and land use [3]. The use of pipe for water distribution is one of factors determining the water quality for household needs. Water quality is something that must continually be concerned. As revealed by WHO, the unqualified water can be the cause of disease as well as the factor of mortality in children under 5 [4]. The quality of ground water is the measurement of feasibility for the needs of domestic or daily water. To keep the quality of water, the regular examination must be given in accordance with the provision of regulation. The parameter must be reviewed as stated in the Regulation of Health Minister No. 32 of 2017 on the Quality Standards of Environment Health and Water Health that cover turbidity, total dissolved solid substances, color, temperature, flavor and odor (Table 1). Meanwhile, the obligatory parameters for biology include Total Coliform and E-colli (Table 2). TABLE.1 Physical Parameters in Quality Standard of Environment Health for Water Media [5] No Obligatory Parameter Unit Quality Standards 1. Turbidity NTU 25 2. Color TCU 50 3. Dissolved Solid Substance mg/l 1000 4. Temperature ℃ Air temperature of ±3 5. Flavor Flavorless 6. Odor Odorless TABLE.2 Parameter Biologi [5] No Obligatory Parameter Unit Quality Standard 1. Parameter Coliform CFU/100ml 50 2. E.coli CFU/100 ml 0 The quality standard as shown in Table 1 and Table 2 furthermore was used as a base in determining the feasibility of the condition of well water in the area of Kotamungkid. When taking the sample, the condition of well water was so varied and the environment around the well was highly influential towards the water health. It can be proven from the result of the laboratory measurement towards the samples that have been taken as shown in Table 3. The result of the laboratory test showed the high rate of Total Dissolved Solids) was still in the allowed range but Total coliform in most of area of Kotamungkid exceeded the limit allowed. In addition to the laboratory test, Fuzzy method was used to measure the parameters of temperature, color, and turbidity; further to be used as one of the ways to determine the feasibility of fresh water. The Fuzzy method is a method related to the uncertainty that has been the human nature [6]. The natural language of human would be changed into mathematical compilation [7]. Fuzzy Method to Determine the Feasibility of Domestic Water Quality Retantyo Wardoyo 1) , Linda Nur Afifa 2) 1) Computer Science, Universitas Gadjah Mada Yogyakarta 2) Informatics Engineering, Universitas Darma Persada Jakarta