A photograph of street art on a building in New Brighton. The artwork includes the phrases "No one is superior, everyone is special", "Occupy Equality Street", and "Love is the child of freedom".
Access to clean and safe drinking water is a fundamental human requirement. However, in many areas of the world natural water sources have been impacted by a variety of biological and chemical contaminants. The ingestion of these contaminants may cause acute or chronic health problems. To prevent such illnesses, many technologies have been developed to treat, disinfect and supply safe drinking water quality. However, despite these advancements, water supply distribution systems can adversely affect the drinking water quality before it is delivered to consumers. The primary aim of this research was to investigate the effect that water distribution systems may have on household drinking water quality in Christchurch, New Zealand and Addis Ababa, Ethiopia. Water samples were collected from the source water and household taps in both cities. The samples were then tested for various physical, chemical and biological water quality parameters. The data collected was also used to determine if water samples complied with national drinking water quality standards in both countries. Independent samples t-test statistical analyses were also performed to determine if water quality measured in the samples collected from the source and household taps was significantly different. Water quality did not vary considerably between the source and tap water samples collected in Christchurch City. No bacteria were detected in any sample. However, the pH and total iron concentrations measured in source and tap water samples were found to be significantly different. The lower pH values measured in tap water samples suggests that corrosion may be taking place in the distribution system. No water samples transgressed the Drinking Water Standards for New Zealand (DWSNZ) MAVs. Monitoring data collected by the Christchurch City Council (CCC) was also used for comparison. A number of pH, turbidity and total iron concentration measurements collected by the CCC in 2011 were found to exceed the guideline values. This is likely due to structural damage to the source wells and pump-stations that occurred during the 2011 earthquake events. Overall, it was concluded that the distribution system does not adversely affect the quality of Christchurch City’s household drinking water. The water quality measured in samples collected from the source (LTP) and household taps in Addis Ababa was found to vary considerably. The water collected from the source complied with the Ethiopian (WHO) drinking water quality standards. However, tap water samples were often found to have degraded water quality for the physical and chemical parameters tested. This was especially the case after supply interruption and reinstatement events. Bacteria were also often detected in household tap water samples. The results from this study indicate that water supply disruptions may result in degraded water quality. This may be due to a drop in pipeline pressure and the intrusion of contaminants through the leaky and cross-connected pipes in the distribution network. This adversely affects the drinking water quality in Addis Ababa.
1. PHIL TWYFORD to the Minister for State Owned Enterprises: What reports, if any, has he received about KiwiRail's plans to get rid of electric locomotives on the North Island Main Trunk Line and replace them with diesel locomotives? 2. JULIE ANNE GENTER to the Minister for State Owned Enterprises: Is he considering replacing the electric locomotives with diesel locomotives on the Main Trunk Line, and would this mean removing electrification on that line. 3. DAVID BENNETT to the Minister of Finance: What reports has he received on the New Zealand economy and business sentiment? 4. Rt Hon WINSTON PETERS to the Minister for Primary Industries: Does he believe the Dairy Industry Restructuring Amendment Act 2012 has achieved "a stable, permanent capital base for the Co-operative, secures our future and will support progress with our strategy to grow volumes and value"; if so, why? 5. MATT DOOCEY to the Minister for Social Development: What announcements has she made to improve statutory child protection in New Zealand? 6. Dr DAVID CLARK to the Minister for Economic Development: What lessons, if any, on regional economic development has he drawn from his recent ministerial visits to Northland? 7. CATHERINE DELAHUNTY to the Minister for State Owned Enterprises: Will he stop any further work on dairy conversions by Landcorp, in light of the drop in the dairy price yesterday and concerns about the impact that those conversions will have on water quality; if not, why not? 8. MARK MITCHELL to the Minister of Trade: What recent steps has the Government taken to promote and support New Zealand exporters? 9. Hon DAVID PARKER to the Minister of Trade: What monetary and other assistance was provided by the New Zealand Government in support of his bid for appointment as Director-General of the World Trade Organisation? 10. BARBARA KURIGER to the Minister for Small Business: How are small businesses benefiting from the Better for Business - Result 9 Programme? 11. POTO WILLIAMS to the Minister for Social Housing: Why are Christchurch's social housing organisations facing increased homelessness four years after the last major earthquake? 12. MAHESH BINDRA to the Minister of Corrections: Does he stand by all his answers given to the House on 1 April 2015?