upland Black Birch Creek through infiltration galleries and the Essons Valley impounding dam that supports the bore supply to Picton. Since the enactment of the Health (Amendment) Act 2007 major upgrades have been undertaken to two treatment plants at Blenheim and Essons Valley at Picton to meet the Drinking Water Standards New Zealand. Major capital works have been planned for Speeds Road WTP. Planning is ongoing to bring the other systems into compliance but affordability for the smaller communities is an issue. For a summary of the water supply infrastructure refer to Table 1 Summary of Water Infrastructure. 4.1.1 Treatment Historically, water treatment in Marlborough provided either disinfection through chlorine and/or mitigated problems of corrosive groundwater resulting from low alkalinity and high levels of dissolved carbon dioxide. Prior to 2009 there was no disinfection of the Blenheim water supply and the micro-biological quality of the water relied upon a contaminant-free aquifer. Following the enactment of the Health (Amendment) Act in October 2007 two of the existing Blenheim treatment plants underwent comprehensive upgrades to meet the requirements of the DWSNZ. Further plants and upgrades are planned for the other supply areas but the costs are very high for smaller communities(see Figure 13) The time frame for compliance stipulated in the act will not be met whilst further consultation with the community is ongoing. Water Treatment Caustic Ultra- Schemes Plant Soda Lime Filtration Chlorine violet Future Blenheim Central WTP/Bomford Road 2000 2011 Middle Renwick Road 2000 2009 De- commissioned Andrew Street 2003 2012 Picton Speeds Road 1977 1975 2015/16 Essons Valley 1995 1995 1975 2012 Renwick Boyce Street 1975 Delayed Havelock Kaituna Valley 1993 Delayed MIOX Proposed Awatere 2012 2016/18 Hardings Road Malthouse Manganese Riverlands Lane Wairau Valley Morse Street 1991 Delayed Figure 13. Water Treatment Plant Summary Reticulation Analysis of the reticulation network shows some of the broad attributes of pipelines. Materials - The material type of the water network tends to reflect the era in which the pipes were laid. The common materials available for water pipes during the early years of urban development in Marlborough were steel and cast iron. The pipes were often protected from corrosion with zinc galvanisation or bitumen coating. The 1950s to early 1970s saw the ascendency of asbestos cement as the preferred material. During the late 60s AC began to be Page 53