Application of Discrete Event Simulation to Design and Management of Waste Water Pit –A Case Study Esra E. Aleisa and Mohammad D. S. Al-Ahmed Department of Industrial and Management Systems Engineering, Kuwait University, 13060 Safat. Environment Public Authority, 13046 Safat Kuwait Abstract — This paper comprises a study to escort the design and management of a residential sewage holding pit near a local water treatment facility. The pit is designed to replace an existing waste dump area. The study consists of a discrete-event simulation for predicting performance, capacity, utilization and flow at pit and its support activities. The pit is designed receive residential sewage tank truck loads, hold it temporally, and then pipe daily accumulated loads to the nearby water treatment facility. Simulation turned out to be an excellent tool in the facility planning effort for the pit project, as it insured smooth flow lines of tank trucks load discharge and best utilization of facilities on site. Index Terms — Discrete event simulation, Discrete event systems, Waste materials, Water. I. INTRODUCTION As part of the national movement to protect the environment, a local environmental authority has planned to create a new sewage pit to replace an existing waste water dump site. The construction of the pit was of particular importance as it planed pump daily accumulated waste to be recycled at near by water treatment facility rather than polluting the desert and areas around. Over two hundred water tank trucks that accumulate to almost 6000m 3 of water waters will be saved and recycled by accomplishing this project. This paper explains the use discrete-event simulation that was used to model activities encountered in design and management of the residential sewage holding pit under consideration. The study aims to predict the total timing, efficiency, performance, capacity, operators’ headcounts, utilization and flow of tank truck at pit. The availability of this information facilitate the generation of educated decisions early in the design process, which prevents costly alterations to take place when construction starts. II. BACKGROUND In the broader literature of facilities planning and simulation, simulation has become an essential tool in complex facility layout projects because it can incorporate many of the constraints commonly found in large-scale systems. According to Grajo [1], layout optimization and simulation are two complementary tools indispensable to any plant layout or productivity task. Such that simulation is the only methodology that is robust enough to systematically examine the role and impact of process complexity and other key variables on factory performance [2]. This is mainly due to the inadequacy of analytical to consider many of the requirements of material flow, overall flow efficiency and many operational characteristics [3, 4]. Discrete-event simulation tools have been applied to analyze various projects that analyzes the management and performance of waste water facilities these repeatedly to investigate flow analysis and capacity in various waste water management projects [5-10]. Printemps et al. [11] have utilized simulation to develop simplified mathematical tool able to reproduce and anticipate the behavior of certain Wastewater Treatment Plant discussed in their study. In Glen et al. [12] a discrete-event simulation model was created using General-Purpose Simulation System (GPSS) to investigation of the batch operation of a poultry processing wastewater treatment plant. Huang et al. [13] have applied simulation on higher level to assess potential dynamic evolution of environmental systems caused by various strategies. In addition, Ferrer et al. [14] presents a software tool to design, simulate and optimize wastewater treatment plants. The program is called DESASS (DEsign and Simulation of Activated Sludge Systems). III. TESTING TANK TRUCK LOADS After consulting with the team of experts, water testing at the pit facility under study includes on-site and detailed water testing. The on-site water testing is performed by hand-held probes, which measures temperature, pH, and conductivity. Detailed tests are performed twice every week on the pit. The detailed tests are conducted in waster testing laboratory at a nearby wastewater treatment plant.