In Bangladeshi rural areas, the groundwater may get contaminated with chemical contaminants. Aiming at removing chemical contaminants, piped water supply(PWS) systems were built. However, due to insufficient water quality tests, a lack of households' participation with the monitoring and maintenance of the PWS system, together with a lack of an efficient monitoring model and maintenance system, the PWS systems may fail to provide safe drinking water to the households, and households lose their trust with the water from the PWS system. To provide proper monitoring and maintenance to the PWS system, the DELTAP project and the TAPP-BDP project decided to use water quality field tests and a smartphone application to enable regular water quality tests to monitor the water quality of the PWS system. The TAPP could also engage the local households in the monitoring of their drinking water. The TAPP operator application has been designed based on the analysis of the current strip test and the AKVO technology, which could help to improve the accuracy of the strip test by reading strip test results. The TAPP operator application could help the local PWS system operators to do water quality strip tests and give a reliable indication of the water quality to monitor the PWS system. After researching the households' communication needs and smartphone usage, the TAPP customer application is designed to enable the households to participate in the monitoring and maintenance of the PWS system by requesting water quality tests and receiving water quality test results. After having the water quality test methods and TAPP application, a monitoring model and maintenance system are created to guide the stakeholders to monitor and maintain the PWS system. The design will contribute to monitoring and maintaining the PWS system in Bangladesh, restoring the households' trust in the PWS system, and assisting the PWS system to provide safe drinking water to the Bangladeshi households.