Activity Group: Sewerage Including Treatment and Disposal Sampling routines have been imposed to check the quality of the outfall discharge of Sustainable Service — Routine maintenance is important for wastewater systems to each of the plants and on the shellfish ecology in the vicinity of two of the coastal ensure assets are clean and functioning correctly, and plant is serviced to prevent plants. premature failure. Responsible stewardship of major infrastructure requires the Council to repair, renew and upgrade the assets in a timely fashion and to avoid accumulating Treatment plants can become overloaded by highly concentrated wastewater from a legacy of decrepit assets. Decisions have to be made on when it is cost-effective to intensive trade effluent. Vigilance is required to monitor trade wastes discharging into replace failing assets rather than continue to repair them. the networks, particularly to the smaller treatment plants which have less capacity to treat concentrated contaminant loads. Asset Description Excessive wastewater volumes can lead to inadequate treatment at the plants, and The following table provides an overview of the extent of Council’s sewerage overflows from the reticulation. Most surcharging in the system occurs when rainwater reticulation network. enters the reticulation through inflow and infiltration during storms. An ongoing Pipeline Length Number of programme is in place to identify and remedy sources of leakage into the system. In Area Sub Area (km) Connections the event of a sewer overflow the Assets & Services Department advises Council’s Regulatory Department, Public Health and major stakeholders. A response plan is Blenheim 187.7 14,133 immediately implemented and environmental monitoring is undertaken to identify the Renwick 15.0 Included in Blenheim extent of the contamination and to progress the clean-up. Blenheim Spring Creek 3.9 Included in Blenheim Reliability and capacity — Blockages and pump breakdowns can cause occasional Riverlands 21.3 Included in Blenheim problems. They need rapid detection and response to prevent wastewater build-up and Grovetown overflow into the environment. Repeated breakdowns in the system may be of 17.0 Included in Blenheim considerable inconvenience to customers who are unable to drain wastewater from Picton 50.1 1,668 their property and may also be an indication to Council of a deteriorating asset or inadequate operational maintenance. Havelock 9.9 341 Timely and responsive service — A constant and reliable wastewater service is Seddon 7.9 182 often taken for granted, however all systems are likely to break down or fail from time to time. The Council operates a 24/7 emergency breakdown response service to Total 312.8 16,324 remedy blockages and breakdowns as a matter of urgency. There are four treatment plants, which are in Blenheim (Hardings Road), Havelock, Sewers may become partially blocked, causing considerable inconvenience and Picton and Seddon. (The Spring Creek treatment plant has been decommissioned.) restricting the service as the wastewater slowly drains away. More severely blocked There are 64 sewer pump stations and 197 sewer grinder pumps. The asset base has sewers can quickly backup and be at risk of sewage overflows. Many blockages occur grown considerably over the last 10 years to meet the growth in wastewater (domestic on the laterals (the smaller pipes connecting the property to the mains in the road). and industrial) and the higher standards expected by an increasingly environmentally Customer Services staff are trained to question customers reporting blockages, to try conscious population. to establish whether the problem is on the customer’s pipe within the property or is the Council’s responsibility. Service requests are prioritised based on the severity and the The total asset value for the Sewerage Activity as at 30 June 2017 was $157.6 million, number of customers affected, so that repair crews can be effectively dispatched to the and it depreciates at around $3M per annum. Detailed information on these assets is most urgent work. provided in the Wastewater Asset Management Plan. If the Council cannot restore toilet facilities within six hours of notification of a blockage, a temporary toilet or alternative facilities will be arranged. 2018-2028 Long Term Plan Page 81