The success of source protection in ensuring safe drinking water is centered around being able to understand the hazards present in the catchment then plan and implement control measures to manage water quality risk to levels which can be controlled through downstream barriers. The programs in place to manage source protection are complex sociotechnical systems involving policy, standards, regulators, technology, human factors and so on. This study uses System Theoretic Process Analysis (STPA) to analyze the operational hazards of a typical drinking water source protection (DWSP) program and identify countermeasures to ensure safe operations. To validate the STPA results a questionnaire was developed based on selective grouping of the initial countermeasures identified and distributed to specialists in DWSP in Taiwan, Australia and Greece. Through statistical analysis using Principle Components Analysis (PCA), the study identified four critical success factors (CSFs) for DWSP based on the questionnaire responses. The four CSFs identified were “Policy and Government Agency Support of Source Protection”, “Catchment Risk Monitoring and Information”, “Support of Operational Field Activities” and “Response to Water Quality Threats”. The results of this study provide insight into the approach of grouping of source protection measures to identify a series of targeted CSF for operational source protection programs. Using CSF can aid catchment management agencies in ensuring that the risk level in the catchment is managed effectively and that threats to public health from drinking water are managed appropriately.

The technology available to water quality management applications needs to be advanced due to greater use of automation to increase ease of operation, support remote operation and reduce risks due to operator error. In this case study, a comparison is made between System-Theoretic Process Analysis (STPA) and the Bow-tie methodology for identifying process hazards and countermeasures which can be used to guide the design and testing of an automated water quality management system (AWQMS). For this study, the application considered is a small hydroponics installation where water quality management has been automated. The STPA methodology uses a system theory-based approach to identify hazards, which include operational failures, human errors, and component interactions. The Bow-tie diagram focuses on individual barriers for a given threat which can prevent the realisation of a hazardous event and unwanted consequences. Thus, the 22 preventative barriers and seven recovery barriers identified through the Bow-tie diagram provide the design process with broad requirements for reducing the risks of user error as well as the ones associated with ongoing operations. The STPA method identified many Causal Factors (CF) generated from the Unsafe Control Actions after considering all the feasible scenarios. For design input, the STPA provided the design process with 204 specific CFs which were used to create 94 countermeasures to be included in software and hardware design as well as user information material. Both methods identified useful measures to control the hazards associated with human interaction with the AWQMS. However, the measures differed in the level of detail and the involvement in the evolution in the final system losses. In this study, the STPA process was able to identify several hazards which did not visibly relate to the Bow-tie barriers. However, the Bow-tie diagram illustrates a distinction between preventative and recovery hazard controls.

The success of source protection in ensuring safe drinking water is centered around being able to understand the hazards present in the catchment then plan and implement control measures to manage water quality risk to levels which can be controlled through downstream barriers. The programs in place to manage source protection are complex sociotechnical systems involving policy, standards, regulators, technology, human factors and so on. This study uses System Theoretic Process Analysis (STPA) to analyze the operational hazards of a typical drinking water source protection (DWSP) program and identify control measures to ensure safe operations. To validate the results a questionnaire was developed and distributed to specialists in DWSP in Taiwan, Australia and Greece. Using Principle Components Analysis (PCA) of the questionnaire responses, the study identified four critical success factors (CSFs) for DWSP. The four factors identified are ‘Policy and Government Agency Support of Source Protection’, ‘Catchment Risk Monitoring and Information’, ‘Support of Operational Field Activities’ and ‘Response to Water Quality Threats’. The results of this study provide insight into the approach of grouping of source protection measures to identify a series of targeted CSF for operational source protection programs. Using CSF can aide catchment management agencies in ensuring that the risk level in the catchment is managed effectively and that threats to public health from drinking water are managed appropriately.

The management structures put in place for the protection of drinking water sources are multifaceted and include a range of government agencies, landholders and regulatory agencies. While source protection is widely practiced in the water industry, there is limited research on underlying constructs that support successful outcomes in drinking water source protection (DWSP) programs. This study builds on current research by further investigating the following proposed critical success factors (CSFs) for source protection: CSF1: policy and government agency support of source protection; CSF2: catchment condition information and risk monitoring; CSF3: support of operational field activities; and CSF4: response to water quality threats. This study uses structural equation modeling (SEM) to confirm the associations amongst the four CSFs. The results show that policy and government agency support for DWSP has a significant influence over how water service providers (WSPs) plan operational activities for risk management. This emphasizes the importance of the role policy and government agencies have in supporting DWSP. The relationships between the CSFs, which typically fall under the responsibility of WSPs, show that information on catchment condition influences operational activities for risk management, and these mediate the influence over response to water quality threats. The response to threats also showed a strong relationship with the function of monitoring catchment risk. The resulting SEM framework provides new insights into the underlying structures that influence outcomes in catchment management and source protection.

Material modification of TiO2 photo-catalyst (NMTi) by doping urea and cobalt via sol-gel method was used to achieve high efficiency degradation of rhodamine B (RhB) under visible light (Vis). Although good removal (up to 42% of TOC removed) of RhB by Degussa P25 under ultra violet irradiation, P25 did not effectively degrade RhB (up to 14% TOC removed) under Vis. In the batch photo-catalytic experiment with Vis irradiation, the removal efficiencies of absorbance and TOC by NMTi were 28 and 30%. We used terephthalic acid as fluorescence probe to catch hydroxyl radical (OH) and calculated their quantum yields. The OH yields of NMTi with Vis irradiating was 8.91×10-6 while P25 of 2.65×10-6 (P25 of 1.44×10-5 and NMTi of 1.00×10-5 under UV). The OH yields of NMTi were higher than that of P25 under Vis, but otherwise under UV irradiation. Therefore, our new composited NMTi was more effective than P25 under Vis for both absorbance and TOC removal of RhB. It seemed possessed the application potential under Vis irradiation.