Electronic Thesis and Dissertation Repository

Degree

Doctor of Philosophy

Program

Civil and Environmental Engineering

Supervisor

Professor Ernest Yanful

Abstract

Direct discharge of treated and untreated wastewater to natural surface water bodies, including rivers and lakes, is generally known to produce adverse environmental impacts that have been of concern for the past 10–15 years, particularly in the Great Lakes basin. Examples of these impacts include eutrophication and the emergence of pharmaceuticals and personal care products (PPCPs). Advancement in wastewater treatment plant operations alone may not be feasible to meet the 2016–2019 Federal Sustainable Development Strategy (FSDS), especially on phosphorus reduction targets. Diverting treated wastewater to land could present a multibarrier approach for integrated PPCPs management, and could also shift current phosphorus management from contamination to resource recovery.

Two case studies were considered: one from a developing country and the other from an industrialised country. City-level decision making in this paradigm was investigated in the context of developing countries, taking Ghana as a case study. In-depth, semi-structured interviews were conducted with senior officials of seven participating organizations from local governments, academia, and international non-governmental organizations in Ghana. The Analytical Hierarchy Process (AHP) was deployed to prioritize challenges as they were perceived by these institutions. Results show that social factors were the main barrier to wastewater reuse (31%), followed by financial (29%), institutional (24%), and technical challenges (16%). Strengths, weaknesses, opportunities, and threats (SWOT) analysis was also conducted. This was combined with a toxicological assessment of local waste stabilization ponds, whereby effluents were found to be suitable for reuse in agriculture as per the latest 2006 Food and Agriculture Organization guidelines.

Several On-site Sanitation Systems (OSSs), commonly known as septic tanks in Canada and the United States, pose a threat to groundwater and surface water, and have the potential to negatively impact human health over the long term. A new Biochar-Modified Soil Aquifer Treatment (BMSAT) system was investigated for its ability to resist or reduce toxicity and microbiological contamination as per the 2012 U.S. Environmental Protection Agency guidelines for water reuse in agriculture. The assessment included 18 chemical compounds, as well as E. coli. The BMSAT system showed promising results, and could be a possible alternative to existing OSSs in rural areas.

Keywords: Water reuse, Wastewater treatment, Eutrophication, Pharmaceuticals and Personal Care Products, Lakes, Impact, Socio-economic, Institutional challenges, Analytical Hierarchy Process, Decision Making, Interviews, Biochar, Soil Aquifer Treatment, Agriculture.

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