The goal of this project is to design a low-tech portable filter to reduce the arsenic concentration in portable water. Arsenic is a naturally occurring heavy metal known to cause adverse health effects with prolonged exposure. In some areas of the world, surface water is unsafe to drink due to biological contaminants, and so the population must use groundwater as their primary source of water for drinking, cooking, and bathing. There are areas around the world, especially in southern Asia, such as Bangladesh and eastern India. In these areas, the concentration of arsenic in groundwater exceeds 0.2 mg/L, which is well above the US EPA’s maximum contaminant level (MCL) of 0.010 mg/L and their own national standards of 0.050 mg/L. The MCL represents a safe concentration of a specific chemical for chronic exposure over an average lifetime. The performance goal of the filter would be to lower the concentration of arsenic below national standards. Our design requirements recognize that a treatment device must be inexpensive, not require the use of electricity, be effective over an acceptable period of time, and not require high technology support or parts, while reducing the arsenic concentration in the water to an acceptable level. The device will use ferric oxyhydroxide, a known sorbent for arsenic, which comes from the rust of steel. The media will be tested in our own prototype to ensure effectiveness. The poster will discuss the alternatives, design requirements, the design process and data regarding the effectiveness of the prototype.