Infrastructure Strategy The smaller treatment plants at Havelock and Picton have limited capacity to deal with Treatment Pump Grinder Mains additional trade waste growth. This can be an issue for industries such as seafood and Area Plants Stations Pumps (kms) Connections meat processing. Processing can add value to exports and create jobs, but early Havelock 1 6 9.8 296 consideration needs to be given to the treatment of the associated liquid wastes. Seddon 1 2 7.9 177 The Marlborough Urban Growth Strategy has identified land for future growth pockets in each settlement. The land is often on the periphery of the existing settlements and The wastewater system collects and treats the sewage from both domestic requires new pipework and upgrades to the existing reticulation to accommodate the and industrial properties. The treatment plants at Blenheim and Havelock are additional flows. For example, development to the west and north of Blenheim and on low lying coastal plain that is vulnerable to liquefaction associated with further development in Waikawa will require careful design as these areas are a earthquake shaking and tsunami. The design of treatment plants need to be considerable distance from the treatment plants. Sequencing the order of development resilient to sea level rise and storm surges that may result from climate will assist in construction and ensure the system is installed in an efficient manner. The change. Council’s Development Contributions Policy has been updated to reflect these costs. As the wastewater reticulation ages, stormwater is able to seep into leaky 1.2 Renewals joints. The levels of service are challenged when the ingress of stormwater The age profile of the wastewater network indicates that $9 million worth of pipes will into the sewerage system causes sewage overflows during severe storms, reach the end of their useful life within the next ten years followed by a further $25 with subsequent insanitary conditions and pollution of waterways. Reduction million worth of pipes in the following 20 years. Work is being undertaken to assess of stormwater infiltration and improved resilience of the pipe network to the condition of pipes and verify the assumptions on life expectancy, as identified in earthquake damage are two major benefits from a well targeted renewals the Earthquakes discussion below. programme. The chart below shows the age profile and pipe materials of the wastewater reticulation. The large spike in PVC/Polyethylene during the 2000s coincides with new 1 Specific challenges sewers installed in Renwick, Spring Creek and Grovetown. Pipe replacement assumes most buried mains will be will serviceable for 80 to 100 years. However this can vary 1.1 Growth in demand related to trade waste and urban considerably for a variety of reasons and the assumption needs to be verified through development pipe condition assessment. There are a number of growth-related challenges for wastewater treatment. Certain industries create large volumes of liquid waste with high organic content. These require far more treatment than normal domestic sewage and can quickly overwhelm the treatment capacity of a plant designed for an urban population. Blenheim wastewater treatment plant has undergone several major upgrades in recent years to cope with the demand from the wine industry. The upgrades have been planned and funded by the wineries. As growth continues, further upgrades are likely. The Council is committed to ongoing communications with industry representatives and individual businesses to ensure infrastructure is provided to meet demand and to overcome uncertainties about the required timing of upgrades, given that the popularity of Marlborough wines in the world market has led to very rapid growth in volumes. The funding methodology will be agreed at this time. 2018-2028 Long Term Plan Page 195