Application of building drainage solid transport modelling to village level: A case study of Marikuppam, India

Sanitation provision is a fundamental human need for survival. The use of engineering design to optimize sanitation provision appropriate to the means and resources available forms the basis of this work. Up-scaling is also an issue, with 2.6 billion people in the world without access to adequate sanitation and nearly 1 billion practicing open defecation, solutions need to provide appropriate means to remove waste at low cost and in a dignified and safe manner. Invariably this refers to sanitation provision in developing countries where poor infrastructure and inadequate social capital makes provision challenging.

The research presented in this paper seeks to use recognized methods associated traditionally with building drainage to expand its reach to a village level. A case study of a real village, Marikuppam in India, is used to illustrate and test the overall hypothesis.

Mixed methodologies were used to design, optimize and assess failure risk for the proposed installation. A steady state simplified sewerage model was used to do the initial design which was further modelling in DRAINET, a method of characteristics based numerical model traditionally used for above-ground building drainage systems. The input data for DRAINET was obtained from a detailed survey carried out on site, which included usage pattern and focus group data. A total of 106 properties were included in the design and the survey. Test runs were carried out for the whole site over a 12 hour period. All main pipe runs were 100mm and set to a gradient of 1:100.

Results from DRAINET modelling confirmed that the design operated during the day with little difficulty, however, there were areas of concern at the extremities of the site, confirming the importance of adjoining flows and the accumulation of water flow required to maintain drain self-cleansing velocity.