Advanced Sanitation Planning Tool with Health Risk Assessment: Case Study of a Peri-Urban Community in Thailand

ABSTRACT

This article presents an application of Material Flow Analysis (MFA) and Quantitative Microbial Risk Assessment (QMRA) as means for advanced sanitation planning in order to quantify domestic waste flows and to estimate microbial infectious risks. The main domestic waste flows include sewerage, greywater from households, effluent of on-site sanitation systems, and illegal dumping of fecal sludge. These flows could cause the contamination of E. coli in canals at the concentration range of 9.0E+01 to 9.2E+04 MPN/100 ml. This study analyzed three scenarios of domestic waste managements: (1) household greywater treatment, (2) fecal sludge treatment, and (3) sewerage treatment, resulting in substantial reduction of E. coli concentrations in those treated effluents. Subsequently, QMRA results could confirm whether the yearly infectious risks due to the uses of treated effluents were lower than the acceptable risk of 1.0E-04 (USEPA 1994). With the aforementioned conditions, this research could demonstrate the potential as an advanced sanitation planning tool by integrating MFA and QMRA methods.

Key Words:

• E. coli
• MFA
• microbial infectious risk
• QMRA
• sanitation planning

ACKNOWLEDGMENT

This study was conducted within the National Centre of Competence in Research (NCCR) North-South program, which is financially supported by the Swiss National Science Foundation (SNSF) and the Swiss Agency for Development and Cooperation (SDC).

Notes

*Concentrations were calculated from the dilution equation:

^a Mara and Johnson (2007);

^b WHO (2006).

^a Steyn et al. (2004).