Research Paper Public health risk assessment tool: strategy to improve public policy framework for onsite wastewater treatment systems (OWTS) Peter Emmanuel Cookey, Thammarat Koottatep, Peter van der Steen and Piet N. L. Lens ABSTRACT Public health risk assessment of onsite wastewater treatment systems (OWTS) in the city of Port Harcourt, Nigeria and its environs was carried out between the period of August 2012 and April 2013. The objective of the study was to show how the public health risk assessment tool can be used to improve public policies on OWTS. The study involved desk study reviews of the related literature on OWTS, an audit survey of 245 OWTS in the residential area of the city, a public policy survey of OWTS in Port Harcourt city, a public health risk assessment, eld observations and investigations. The results revealed that there were no specic policies, legislative and regulatory standards for sustainability of OWTS practice and no risk assessment considerations in the current policy instruments. In general terms, the public policy instruments of OWTS were found to be inadequate for improved and standard system construction, installation, operations and maintenance, compliance, enforcement and inspection. The outcome of the risk map showed widespread and dispersed risk in the use of OWTS. Peter Emmanuel Cookey (corresponding author) Thammarat Koottatep Asian Institute of Technology, Bangkok, Thailand E-mail: peter@earthwatchnigeria.org Peter Emmanuel Cookey Peter van der Steen Piet N. L. Lens UNESCO-IHE, Institute for Water Education, PO Box 3015, 2601 DA, Delft, The Netherlands Peter Emmanuel Cookey Rivers State College of Health Science and Technology, Port Harcourt, Nigeria Key words | legislation, onsite wastewater treatment system, public health, public policy, risk assessment, standards INTRODUCTION Sanitation is an important indicator of development, and poor coverage, such as in Nigeria, poses serious challenges (Adelegan & Ojo ), especially in developing countries like Nigeria where access to adequate sanitation facilities is a serious challenge. The WHO/UNICEF (); WHO () sanitation coverage for Nigeria records a total of 39% and 35% for urban and rural populations, respectively. According to Shako (), gures such as these were obtained from relaxed denitions and low standards, adopted by national governments and the international com- munity (UN-Habitat ), probably because anything above, for instance those of Kvarnstrom et al. (), could gravely affect the sanitation statistics of many developing countries. Considering that most developing countries design public policies and intervention programmes based on such gures as those mentioned above, it is safe to assume that there will be lax standards and requirements. Public policies and standards for onsite wastewater treat- ment systems (OWTS) are to ensure the adequate management of domestic wastewater by introduction of cost-effective and long-term options to meet public health and water quality goals. Therefore, the difference between failed and successful OWTS practice is in the adequacy and level of implementation of the relevant and related sani- tation policies and legal framework (USEPA ). OWTS such as septic tank systems are the major sani- tation infrastructure in Nigeria (Nigeria Demographic and Health Survey (NDHS) ; NISER ), as is the case 74 Research Paper © IWA Publishing 2016 Journal of Water, Sanitation and Hygiene for Development | 06.1 | 2016 doi: 10.2166/washdev.2016.081 Downloaded from https://iwaponline.com/washdev/article-pdf/6/1/74/595188/washdev0060074.pdf by guest on 11 July 2020