DRAFT. Wastewater Asset Management Plan. Southland District Council

Transcription

1 DRAFT Wastewater Asset Management Plan Southland District Council Version November

2 Document Control: Version Notes Authors Reviewed Issued Approved by 1.0 Approved by APAC for input to LTP, 7 December Final Draft for LTP 1 July Ian Evans, Three Waters Manager Lisa Roberts, Infrastructure Decisions Limited Ian Marshall, Group Manager Services and Assets 275

3 Contents Executive Summary Introduction Purpose of this Plan Objectives of the Wastewater Activity An Overview of the Activity Urban Areas Serviced by Public Wastewater System Rural Areas and Isolated Towns Asset Management Responsibilities Plan Limitations Status of the AMP Limitations of the AMP Plan Framework The Levels of Service We Deliver Reason for Providing a Service Strategic and Corporate Goals Customer Expectations Planning Framework Levels of Service, Performance Measures and Targets Managing Future Demand Predicting Future Demand for the Service Asset and Service Implications Demand Management Strategies Asset Upgrades to meet Demand District-wide Asset Management Strategies Overview of the Wastewater Assets Asset Value and Depreciation Asset Condition and Performance Data Source and Confidence Operating and Maintaining the Assets Service Delivery Operations and Maintenance Forecasts Performance Monitoring Systems Unplanned (Reactive) Operations and Maintenance Strategy Planned (Scheduled) Operations and Maintenance Strategy Renewing the Assets Renewal Definition Renewal Strategy Renewals are sometimes deferred to do them in a combined contract with upcoming road works. Renewal Past Trends Renewal Forecasts Future Improvement Upgrading and Developing New Assets for Levels of Service Upgrading and Developing New Assets for Demand Risk Management Financial Summary Summary of Key Assumptions What-if Scenarios Funding Principles Financial Forecast Summary Valuation Approach Long Term Financial Sustainability Funding Review Draft Asset Management Plan - Wastewater Page i r/14/6/

4 6. Asset Management Improvement Plan Progress against Previous AM Improvement Programme Assessing Current and Desired AM Practices Understanding and Defining Requirements Developing Asset Lifecycle Strategies Asset Management Enablers AM Improvement Plan Scheme Plans Balfour Browns Edendale Wyndham Gorge Road Lumsden Manapouri Monowai Nightcaps Ohai Otautau Riversdale Riverton Stewart Island Te Anau Tokanui Tuatapere Wallacetown Winton Draft Asset Management Plan - Wastewater Page ii r/14/6/

5 Executive Summary The Services Provided Eighteen towns within the District are reticulated with Southland District Council (SDC) owned and maintained sewerage infrastructure. Based on current information the schemes have a current valuation in excess of $80M. While Council is the legal entity for the ownership of the asset, the day to day operations are delegated to separate governance groups which are Community Boards and Community Development Area (CDA) Subcommittees. A number of isolated rural townships have individual private schemes which are not included within the Wastewater Asset Management Plan. The Council owned and provided facilities are Balfour, Browns, Edendale/Wyndham, Gorge Road, Lumsden, Manapouri, Monowai, Nightcaps, Ohai, Riversdale, Riverton, Stewart Island (Oban), Te Anau, Tokanui, Tuatapere, Wallace (Otautau), Wallacetown and Winton. Council s schemes are operated and maintained by Downer with all capital work planned and programmed by Council s Water and Waste Services Department. What We Aim to Achieve Council s Levels of Service (LOS), performance measures and targets are illustrated in Table 1. Over the next 10 years, Council s intention is generally to maintain improve the level of performance by: reducing the number of overflow incidents; and improving the quality of wastewater effluent discharges and the level of compliance with consent conditions. Level of Service Performance Measure Performance Results Targets Sewerage is managed to reduce the risk to public health. Minimise effects on the environment. Prompt response to requests for service. Prompt resolution to requests for service. Provide a reliable wastewater service. Wastewater service is managed cost effectively Number of overflow incidents effecting private property caused by council networks Percentage of effluent tests which comply with relevant resource consent conditions. Less than 5 confirmed incidents per year about odour from sewerage reticulation and treatment systems throughout the District. Number of overflows effecting the environment. Respond to customer requests within time set for type of problem. Resolve customer requests within time set for type of problem.³ Issue decision on application for connection within 10 days of application. Percentage of customers satisfied with the service. All schemes are managed within 10% of annual budget 07/08 08/09 09/10 10/11 12/ Less Less than than % 93% 84% 85% 100% 100% New Measure Less than 5 Less than 5 New Measure Less than 5 Less than 5 42% 77% 80% 90% >90% >90% New Measure >90% >90% New Measure 100% 100% 93% 94% Not Meas ured 94% >90% >90% New Measure Draft Asset Management Plan - Wastewater Page 1 r/14/6/

6 Level of Service Performance Measure Performance Results Targets Maintenance of wastewater service is effective Number of periodic maintenance works New Measure 80% 80% that are ordered compared to completed work orders Table 1: Wastewater Performance Management Framework Note: Performance measures shown in bold are those that will be monitored and reported through the LTP and Annual Plan process. Managing Future Demand Demand for wastewater services due to population growth is not expected to change significantly over the plan period. Continued steady growth in townships such as Te Anau, Riverton and Winton is expected however at current rates it is anticipated that current infrastructure will be capable of dealing with this growth. As a result capital expenditure has been deferred to the final years of the Council Long Term Plan Demand projects included within previous Asset Management Plans and Long Term Council Community Plans have been deferred as a result of slower than previously anticipated growth in these catchments. Demand projects are funded via development contributions and do not impact on rates. A demand project has been identified for the Te Anau scheme but this has been deferred until the final years of the plan. Lifecycle Asset Management Table 2 presents an overview of the Council-owned wastewater schemes in the District. Scheme Installed (date) Number of Connection s Overall Condition Overall Performanc e Comments Balfour Ageing reticulation, renewal peak expected Browns Significant compliance issues relating to plant performance to be addressed 11/12. Edendale/ Wyndham New plant - no issues. Gorge Road Biofilter cleaning programme required to improve performance. Rising main needs renewal. Lumsden New plant - performing well. Ageing reticulation, renewal peak expected Manapouri Growth pressures are driving a review of treatment and disposal options. Monowai Possible replacement of disposal field. Nightcaps Increasing blockages indicate ageing reticulation. Consent renewal due Ohai Reticulation near end of asset life. Treatment plant and pump station not performing well. Otautau High levels of infiltration. Issues with irrigation field performance. Riversdale Significant infiltration issues. Resource consent renewal required May require alternative disposal route. Poor wetland performance. Riverton Infiltration issues, renewals required. Consent renewal Stewart Island/Oban Pump and electrical renewals required. Te Anau Consent renewal required 2014, major treatment and disposal work expected to be required. Some reticulation in poor condition. Electrical upgrades Draft Asset Management Plan - Wastewater Page 2 r/14/6/

7 Scheme Installed (date) Number of Connection s Overall Condition Overall Performanc e Comments required. Tokanui Consent renewal required 2014, upgrades to treatment and disposal may be required. Ageing reticulation. Tuatapere Performing well. Wallacetown Performing well. Winton Significant treatment plant performance issues to be addressed in staged project starting 11/12. Ageing renewals, reticulation peak expected Table 2: Wastewater Scheme Overview To achieve Council s intentions, the general asset management strategy is to: Maintain the assets to a level fit for purpose; Work with Council contractors and governance bodies to identify capital or maintenance requirements. Ensure that the asset management requirements (operational and capital) are appropriately funded, prioritised and scheduled. Develop and refine renewal strategies, based on age, condition and best available local knowledge. Ensure resource consent conditions are met. Longer term, consideration will need to be given the management of some schemes as they reach the end of their asset lives and begin to require significant capital expenditure. As a consequence Council is considering a move from local funding of these schemes to district wide funding by a single targeted rate for those connected or able to be connected. This proposal is in response to concerns over the long term sustainability of some schemes. Based on Hansen asset life data water renewals in the next 10 years average less than $0.5m per year, however a number of additional water renewals projects have been identified by Water and Waste Staff and contractors based on local knowledge of known problem area. All renewals will be subject to future condition assessments prior to any work being undertaken. Draft Asset Management Plan - Wastewater Page 3 r/14/6/

8 Figure 1: Long Term Renewal Forecasts Financial Summary Operations and maintenance expenditure (OPEX) on this activity has increased for this activity from $0.8M to $1.9M over the last five years, largely as a result of inflation and the introduction of a new O&M Contract in 2010, and new schemes becoming operational (including Tuatapere, Wallacetown and Stewart Island). Capital expenditure (CAPEX) over the same period has been around $22M - predominantly LOS expenditure driven by the availability of Ministry of Health Funding for new sewerage schemes and scheme improvements. Future operational costs are forecast to increase to $3.5M over the 10 year period principally as a result of inflation, but also due to additional operational and maintenance costs associated with scheme upgrades, and repayment of loans that have been taken out to fund capital projects.. Total capital cost across all schemes is forecast to be approximately $40M in total. Significant expenditure is planned in Te Anau as a requirement to upgrade the scheme by 2014 when the resource consent expires. Significant demand expenditure in a number of towns has been deferred to 2021/22 and will be further deferred if demand still does not exist at that time. Further information on planned capital work is included within the individual scheme AMPs in Appendix A. The timing of renewals and LoS projects but may change depending on the outcome of additional condition assessments or further investigation work. Previously schemes were funded via a local rate, however a proposal to fund community wastewater and water supplies via District rating was consulted on as part of the 2012 Long Term Plan, and was adopted by Council as part of the LTP. The proposal covers community supplies and includes clubbing all future operational and capital costs. Construction of new schemes however will continue to be funded locally, however once built all future costs will be included within the District-wide rate. It is believed that this move will help secure the longer term future of a number of these schemes. Draft Asset Management Plan - Wastewater Page 4 r/14/6/

9 In addition, Council will be reviewing its approach to funding new schemes, partly driven by a change to Government subsidies. This will be done following a review the Water and Sanitary Services Assessments to assess the public health impacts of areas without reticulation and potential options to address issues. This has been identified as a specific improvement in the improvement plan section of this document. Figure 2: 10 Year Financial Forecasts Figure 3: 10 Year CAPEX Forecasts Draft Asset Management Plan - Wastewater Page 5 r/14/6/

10 Table 3: 10 Year Financial Forecasts Draft Asset Management Plan - Wastewater Page 6 r/14/6/

11 1. Introduction 1.1 Purpose of this Plan The purpose of this plan is to document the SDC (Council) asset management practices and achieve an optimised lifecycle strategy for wastewater infrastructure for the next 20 years. This is a long term planning document. It represents the aspirations of SDC and will be reviewed every three years. The budgets and timeframes provided in this plan will be recommended to the Council for adoption through the Long Term Council Plan (LTP) and Annual Plan process. 1.2 Objectives of the Wastewater Activity The wastewater activity in Southland District (SDC) is focused on the achievement of the following objective: To provide an effective, environmentally friendly sewage disposal system with odour control. The standard to which this objective will be delivered is outlined by the LOS detailed in Section An Overview of the Activity Urban Areas Serviced by Public Wastewater System Eighteen towns within the District are reticulated with SDC owned and maintained sewerage infrastructure, see Figure 1 for localities. These public wastewater systems are intended to carry out two main functions: The collection, treatment and disposal of wastewater from residential properties, business properties and from public sanitary facilities in Southland District. The collection, treatment and disposal of industrial liquid wastes (often known as trade wastes) from industry in the District. The local wastewater reticulation to which each serviced property is connected consists of an extensive network of relatively small diameter pipes (mostly 150 mm) which discharge into a system of trunk sewers of larger sizes (ranging up to 525 mm in diameter). The trunk sewers convey wastewater to treatment plants, which use a range of processes including screening, sedimentation (settlement of suspended material), biological stabilisation of the organic material in the wastewater and disinfection using ultra violet light to deactivate micro-organisms (typically bacteria and viruses) in the effluent. Treated effluent is typically discharged into the environment as directed by individual resource consents administered by Environment Southland (ES) Rural Areas and Isolated Towns The Southland District is predominantly a rural area. Properties in rural areas and small isolated towns usually have private individual wastewater disposal systems which generally comprise conventional septic tanks with soak holes or on-site effluent disposal fields. It is not usually practical to provide a reticulated wastewater service in rural areas because of the lengths of the networks required and the inability to spread the cost of the infrastructure required (pipes, pumps, treatment facilities, operation and maintenance, management) across a sufficient number of consumers. Reticulated wastewater systems are provided when the land use in these areas change or they are developed for normal residential housing with sections too small to provide adequate on-site treatment, or where there is public health or environmental risks associated with current private sewage disposal facilities. This Activity Plan does not cover private wastewater systems. Draft Asset Management Plan - Wastewater Page 7 r/14/6/

12 Figure 1-1: Council Wastewater Schemes Draft Asset Management Plan - Wastewater Page 8 r/14/6/

13 1.4 Asset Management Responsibilities The assets covered in this plan are the responsibility of the Council s Water and Waste Services Department (WWS) under the strategic direction of Council, the Executive Team and Community Boards. Asset management responsibilities are covered in detail in Council s AM Policy Service delivery is provided as follows: Operation and maintenance (O&M) is delivered by Downers. Capital works design and procurement is provided by WWS and engineering consultants. 1.5 Plan Limitations Status of the AMP A status review of all AMPs for services provided by the Water and Waste Services Department was carried out in The review found that the plans were meeting the core status with some areas moving towards advanced. In updating this AMP the results of the 2007 review were taken into account. It is anticipated that over the course of implementing the projects and programmes in this AMP, significant progress will be made towards the advanced status in some of the larger townships in the District Limitations of the AMP This AMP attempts to address all wastewater asset management issues in the District. It is a living document which will undergo a formal review every three years to make amendments to reflect changes in LOS, demand projections, risk profile, lifecycle information, or financial information. This AMP has been developed with the following key limitations: Projects have been identified and scheduled based on the best information available at the time. Budgets for these projects have been assessed based on the best information available at the time. Projects towards the end of the 10 year period are flags that work are likely to be needed but it is very much at the concept phase. Options and detailed estimates will be carried out closer to the time. The completion of projects is limited to resourcing of both SDC staff and external engineering support. 1.6 Plan Framework AM Planning Framework, Council Policy and planning document Council Outcome and Objectives District forecasts population, economic, tourism, land-use AM Policy AM goals, responsibilities Risk Management Framework. Corporate Reference Information Introduction Plan Purpose, Activity objectives, Activity Overview The Levels of Service Delivered Future Demand Lifecycle Strategies (District- Wide) Financial Forecasts (Activity- Wide summaries) AM Improvement Plan Wastewater Activity Management Plan For each area, a summary of the: Assets/services (what we have) Asset condition/performance Issues and Risks Proposed strategies and works programmes Budget forecasts Appendix: Area- Specific Plans Figure 1-2: Plan Framework Draft Asset Management Plan - Wastewater Page 9 r/14/6/

14 2. The Levels of Service We Deliver Sections outline why the Council is involved in the activity and the key drivers for levels of service; including customer expectations, legislative/regulatory requirements and Council outcomes. Section 2.5 then details what level of service will be provided and the performance measures and targets which will be used to monitor performance. 2.1 Reason for Providing a Service Council provides wastewater networks to maintain public health by preventing spread of disease, to reduce the effects of wastewater discharges into the environment in a cost effective manner. 2.2 Strategic and Corporate Goals Council has adopted a set of community outcomes that it is working towards which aim to promote the social, economic, environmental, and cultural wellbeing of the District in the present and for the future. These community outcomes are detailed in the Council s Corporate Activity Plan. The table below details how the wastewater contributes to these outcomes. Council Outcomes Activity Contribution Level of service Supporting our Communities We want Southland s communities to be desirable places to live, grow up, work, run a business, raise a family and enjoy a safe and satisfying life. The health and safety of urban built areas is strongly influenced by the sanitary systems available and the reliability of those services - without which public health may be at risk. Sewerage is managed to reduce the risk to public health. Provide a reliable wastewater service. Making the most of our Resources We want to be good custodians of the environment to ensure that people living here now and in the future can sustain themselves and that the natural beauty of Southland is retained. Being an effective Council Council will be prudent, innovative and be an enabler for its communities. Wastewater collection, treatment and disposal helps to protect public health by providing a sanitary service which helps to prevent the spread of disease and odours. Through treatment, disposal and ongoing monitoring, the activity also works towards improving ground water quality as well as the quality of water in streams, rivers and coastal areas, which may be used for recreation gathering. Utilising culturally sensitive methods of disposal is also an important part of the activity. The potential for growth of an area is strongly linked to the availability of reticulated sewerage. Without such systems in place, there is a limit to the level of residential, industrial and commercial development which can be accommodated. By providing a wastewater service which meets the needs of businesses and industry at the lowest sustainable cost, the activity contributes towards building a strong economy in the district. Table 2-1: Activity Contribution to Council Outcomes Minimise the effects of wastewater treatment and disposal on the receiving environment. Prompt response to requests for service. Prompt resolution to requests for service. Wastewater service is managed cost effectively Maintenance of wastewater service is effective Draft Asset Management Plan - Wastewater Page 10 r/14/6/

15 2.3 Customer Expectations In providing services it is important to understand what the customer using the service expects and if those expectations may change. The table below details the key customer groups, their expectations and any issues that this raises for the activity. There is an increasing public awareness of environmental issues and intolerance of pollution. This is reflected in increasingly stringent discharge consents imposed for the quality effluent from the sewage treatment plants, including requirements for land disposal. Customer Stakeholder Group Residents/Trade Waste Users. Guardians of Lakes Manapouri, Monowai and Te Anau. Environment Southland. How we understand their requirements Resident survey. Monitoring complaints. Requests for services. Monthly meetings. Opportunities to comment on AMPs. Specific Interests Wastewater disposal away from properties in an efficient manner. Wastewater does not discharge into the lakes. Wastewater discharges do not cause environmental deterioration. Expectations and Key Issues For there to be no overflows, odours or contaminations. Wastewater systems are cost efficient. No overflows or discharges from nearby pipes. New discharge consent standards likely to be more stringent with respect to overflow standards, effluent quality meet consent requirements. Public Health South. Consultation over the content of Water Services Assessments. Public health. Overflows or discharges do not contaminate public water supplies. Iwi. Alliance Group Limited. Regular meetings with representatives from Te Ao Mārama Incorporated. Contract Agreement. Discharges of water go to land. Wallacetown discharge does not compromise the consent and payments are made on time. Table 2-2: Customer Expectations Wastewater is discharged to land to stop contamination of water. Wastewater discharges are kept to consent conditions. 2.4 Planning Framework Legislation, regulation and Council s existing strategies and policies mandate influence some of the LOS and performance targets we set, as illustrated in the table below for the Wastewater activity. A full description of the Council policy and planning framework impacting AMPs is included in the Corporate Activity Plan. Draft Asset Management Plan - Wastewater Page 11 r/14/6/

16 Below is a list of legislation and regulations that have an impact on the wastewater asset. Legislation / Regulation Local Government Act 2002 Regional Policy Statement 1997 Regional Water Plan for Southland 2008 Regional Coastal Plan for Southland 2007 Regional Effluent Land Application Plan for Southland District Plan 2001 Long Term Plan Annual Plans Utilities Access Amended Act 2010 Subdivision and Land Development Standards Bylaw 2005 Trade Waste Bylaw 2008 Wastewater Drainage Bylaw 2008 NZ Water Industry National Asset Grading Standards Pipe Inspection Manual Hazardous Substances and New How it affects levels of service and performance standards. Provisions for public ownership and control of public wastewater services. Requirement to make Wastewater Assessments Development contributions. This documents purpose in relation to wastewater is to ensure the quality of water and the environment is not contaminated by wastewater discharges. It aims to provide for current and future generations while aiming to improve the quality of the environment. The purpose of this plan is to promote the sustainable management of Southland s rivers, lakes, groundwater and wetland resources. The plan is aimed at enabling the use and development of fresh water where this can be undertaken in a sustainable way, providing a framework for activities such as discharges to water. Fundamental principles in the management of the CMA are set out and then sections of the plan deal with wastewater discharges that have a range of environmental, social and cultural effects. Document outlining the issues and associated policies to better manage the application of effluent and sludge onto land. Sets out the Council s resource management strategy, including how the Council will control the effects of wastewater discharges to ensure that the adverse effects on the environment are avoided. Summarises the key components of the Wastewater Activity Management Plan - rationale for delivery of the activity, any negative impacts of the activity on the well-being of the community, asset management information and information on intended levels of service provision, associated expenses and revenue sources. Sets out 10 Year forecasts of revenue and expenditure. Details amount of capital expenditure related to replacing existing assets, improving levels of service and meeting additional demand. Must also note and explain any significant variation from the latest assessment of water and sanitary services or waste management plan. Also sets the annual work programme for the first year and the amount of rates to be collected for the wastewater activity. Identifies the annual works and financial programmes for the years between the LTP cycle, including the amount of rates to be collected for the wastewater activity. Also identifies any changes from the LTP for the year. The purpose of the Code is to enable access by utility operators to transport corridors to be managed in a way that disruptions to roads by wastewater pipe installations are kept to a minimum while maintaining safety and maximising the benefits to the public. Specifies Council s minimum requirements for subdivision and land development while promoting sustainable development. Requires persons on trade premises to apply for a permit to discharge to the sewer network and allows conditions to be placed on the wastewater parameters before discharge. Requires all persons to make application before connecting to the wastewater network and outlines conditions for accepting wastewater. Provides guidelines on asset grading. Provides guidelines on pipe asset grading. The purpose of this Act is to protect the environment, and the health and safety of people and communities, by preventing or managing the adverse Draft Asset Management Plan - Wastewater Page 12 r/14/6/

17 Legislation / Regulation Organisms Act 1996 Health and Safety in Employment Act Resource Management Act 1991 How it affects levels of service and performance standards. effects of hazardous substances and new organisms. Sets requirements for managing health and safety in workplaces. Promotes the sustainable management of natural and physical resources. Regulates land use and subdivisional activity. Regulates discharges to land, air and water. Recognises the principles of the Treaty of Waitangi. Compliance with district and regional plans. Table 2-3: Regulatory and Planning Framework. 2.5 Levels of Service, Performance Measures and Targets LOS, performance measures and targets form the performance framework for the activity detailing what the Council will provide, and to what level or standard: LOS are the outputs that are expected to be generated by the activity. They demonstrate the value being provided to the community or reflect how the public use or experience the service. Performance measures are quantifiable means for determining whether a LOS has been delivered and are generally broken into customer measures (which focus on how the public uses or experiences the service) or technical measures (which tend to be used internally to track performance or measure what the organisation does). Performance targets are the desired levels of performance against the performance measures. The table below details the LOS, performance measures and performance targets for the activity. The ones shown in bold will be used in the LTP (generally customer measures). The LOS have been chosen to ensure that wastewater meets all obligations, whether legal or public. The measures will guarantee that if any problems do occur there is a minimum response time and that the action will be to a suitable standard. The main points covered in the LOS below are: Prevention of disease by good quality network management. Promote the environment by using sustainable services. Provide a reliable, efficient wastewater service. LOS improvements are sought in two key areas: Reduction in wastewater overflows from the system. Improvement in compliance with effluent discharge conditions. Council proposes to achieve these improvements by: Undertaking a programme of infiltration studies in areas where there are known issues. Liaison with key stakeholders during the development of operational and capital improvement plans to improve the quality of our effluent discharges. Draft Asset Management Plan - Wastewater Page 13 r/14/6/

18 Level of Service Sewerage is managed to reduce the risk to public health. Minimise effects on the environment. Prompt response to requests for service. Prompt resolution to requests for service. Provide a reliable wastewater Performance Measure Number of overflow incidents effecting private property caused by Council networks Percentage of effluent tests which comply with relevant resource consent conditions.¹ Less than five confirmed incidents per year about odour from sewerage reticulation and treatment systems throughout the District. Number of overflows effecting the environment. Respond to customer requests within time set for type of problem.² Resolve customer requests within time set for type of problem.³ Issue decision on application for connection within 10 days of application. Percentage of customers satisfied Performance Results Performance Targets Measurement Procedure 10/11 11/12 12/13 13/14 14/15 15/16 16/ Less than 20 Less than 20 Less than 20 Less than 20 Report from Hansen (work order) 85% 89% 89% 89% 100% 100% 100% 100% SCADA records and physical monitoring results. 94% Not Measured Less than 5 Less than 5 Less than 5 Less than 5 Less than 5 Less than 5 Less than 5 Less than 5 Report from Hansen (odour complaints). Report from Hansen (work order) >90% >90% >90% >90% Report from Hansen (work orders). 100% 100% >90% >90% >90% >90% Report from Hansen (work orders). Not Measured 100% 100% 100% 100% Report from in Pathway. 94% >90% >90% >90% >90% Survey - Resident Draft Asset Management Plan - Wastewater Page 14 r/14/6/

19 service. Wastewater service is managed cost effectively Maintenance of wastewater service is effective with the service. All schemes are managed within 10% of annual budget Number of periodic maintenance works that are ordered compared to completed work orders The target is an average for all sewerage schemes where the quality of effluent is monitored. Response time is one hour for all problems. Response means someone will contact customer either by phone or visit to the property. Resolve time is six hours for all problems which does not include the one hour response time. Table 2-4: Performance Management Framework Report from in TRIM (financial reports) 80% 80% 80% 80% Report from Hansen Draft Asset Management Plan - Wastewater Page 15 r/14/6/

20 3. Managing Future Demand This section describes how the demand for Wastewater is likely to change over the period of the plan, the impact any changes are likely to have and whether the Council is planning to make any changes to the activity as a result. 3.1 Predicting Future Demand for the Service Council has prepared corporate wide assumptions/projections for growth drivers (population, land use, dwellings, and tourism) which have been used as the basis for assessing future demand for the service. These projections are detailed in the Corporate LTP and AM Reference Document. Demand Driver Impact on Future Demand Population Expect wastewater volumes to increase in proportion to population and in areas of new sub development. Stock Trucks Expect stock truck effluent to increase due to increase in dump sites. Land Changes Expect wastewater volumes to increase in proportion to the amount of subdivisions created. Water consumption trends With the exception of water used for irrigation and unaccounted for water, most water supplied by the SDC water supply systems are subsequently discharged into the wastewater reticulation. Network condition Expect wastewater volumes to increase in areas where there is an ageing network, and/or high levels of groundwater which can have an effect on levels of infiltration. Stormwater cross Expect wastewater volumes to increase in areas where there connections are unknown stormwater cross connections during times of heavy rainfall. Table 3-1: Demand Drivers, Wastewater The information in the Corporate Activity Plan suggests that: Population will increase by 11% over 20 years The amount of land used for dairy farming is projected to rise from about 154,000 ha in 2010 to 302,000 ha in 2031 due to the ongoing conversion of sheep and beef (pastoral) farms to dairy. The number of tourism visits to Southland is expected to increase from around $2.2M in 2006, to $3M in 2021 and reach $3.5M by As a result of this, we expect demand for the service will remain mostly the same. Growth in Te Anau and Riverton, Winton, Oban and Manapouri may need extensions to the wastewater reticulation to service new subdivisions, although at present the rate of development across the District has slowed down in response to current economic conditions so the timing of this is uncertain and is likely to extend beyond the current 10 year window covered in the Long Term Plan Asset and Service Implications Urban growth and peak growth will require upgrades to the wastewater pumping and storage infrastructure to service new residential subdivisions and, in some cases, upgrading the capacity of existing pipes. However, with the exception of Te Anau, scheme capacities are expected to cater for 10 year demand. Where necessary there may to be some extensions to the wastewater reticulation to service new subdivisions, which would be funded by development/financial contributions Draft Asset Management Plan - Wastewater Page 16 r/14/6/

21 Stock truck effluent dump sites and motor home dump stations could cause issues with overloading in both nutrient/pathogen levels and flow for local pump stations and treatment plants. At present none of Council s schemes are significantly impacted on by either. Prior plans identified potential growth in Stewart Island (Oban), Riverton and Winton which could require investment. The expenditure is still included within 10 year plans but has been deferred to the latter years and will either continue to be deferred, or removed if the demand does not materialise. 3.3 Demand Management Strategies SDC uses the following strategies to manage demand: Property Inspections SDC have historically carried out inspections of properties where volume in the sewers increase dramatically during rain events. Owners of properties that are found to have downpipes connected to gully traps are sent letters instructing them to redirect stormwater out of the sewer. Tradewaste Septic Tank cleaning businesses have access to discharge into treatment plants located within the larger communities (i.e. Riverton, Te Anau, Winton). This is so that small treatment systems are not overwhelmed by the concentrated discharge. Council proposes to: Review and enforce (where appropriate) the Trade Waste Bylaw to control the discharge of industrial effluents to the wastewater networks. (Trade waste does not form a significant proportion of the waste stream in the majority of Council s schemes). Apply Trade Waste discharge charges. Public Education Although there is no formal education programme, W&WS publish articles on a regular basis in the Council s First Edition quarterly newsletter. The newsletter is steps they can consider to reduce water consumption. Important local issues are also advised through the respective Community Board, Water Supply Committee, or Community Development Area as appropriate. CCTV Inspections Close Circuit Television is used to help us identify the cause of blockages. CCTV inspections are crucial when there are problems in drains. Drains block for many reasons and it is essential to really see the problem before taking the next step. CCTV is carried out in areas where there are suspected high levels of infiltration, and also prior to upcoming renewals work to help target expenditure to those areas where it is required the most. Inflow/Infiltration It is estimated from variations in flows through the treatment plant and pump stations that stormwater inflow and groundwater infiltration makes up a significant amount of total wastewater volumes in the following sewerage systems: Balfour Otautau Lumsden Riversdale Manapouri Winton Ohai Schemes that also suffer from infiltration/inflow but not to the same extent are: Oban Te Anau Tokanui Draft Asset Management Plan - Wastewater Page 17 r/14/6/

22 Further CCTV work and infiltration studies and condition assessments will be carried out across a number of communities where it is known that infiltration forms a significant portion of the base flow. Identified renewals expenditure within the 10 year period will be targeted on areas where identified by studies and via information supplied by Council s Operations and Maintenance contractor. 3.4 Asset Upgrades to meet Demand Over the past four years SDC has taken advantage of the Ministry of Health s Sanitary Works Subsidy Scheme (SWSS) to gain maximum funding assistance (50%) for a scheme extension on Stewart Island and new schemes in Gorge Road, Wallacetown, and Tuatapere. Council is currently commissioning its final schemes under SWSS in Edendale and Wyndham. With the removal of the subsidy scheme it is not anticipated that any new schemes will be constructed within the upcoming 10 year period. Draft Asset Management Plan - Wastewater Page 18 r/14/6/

23 4. District-wide Asset Management Strategies 4.1 Overview of the Wastewater Assets Asset Value and Depreciation The scheme values and depreciation information below is from the 2013/14 valuation. The following assumptions have been made in the preparation of the 2010/11 valuation. 1. That all asset data has been reviewed and updated. 2. That all valuations are based on the Modern Equivalent Replacement Cost (MERC) basis. 3. Where new technology is available or where present assets do not require full replacement, adjustments have been made. 4. That sewer gravity main and rising main rates have been based on recent and extensive sewer contracts in the Southland District. 5. That sewer laterals have been included in the valuation. 6. The asset lives have been reviewed. Asset Component Replacement Cost Depreciated Asset Annual Value Depreciation Balfour 1,135, ,042 18,465 Browns 407, ,405 10,144 Edendale/Wyndham 9,707,874 9,152, ,987 Gorge Road 832, ,002 16,100 Lumsden 4,538,400 2,199,368 75,585 Manapouri 4,148,852 1,929,029 64,716 Monowai 214, ,466 2,836 Nightcaps/Wairio 2,873,068 1,903,160 37,723 Oban 14,298,922 11,210, ,782 Ohai 3,511, ,498 51,653 Otautau 6,449,493 4,799,115 99,736 Riversdale 2,991,197 1,377,488 46,265 Riverton 16,935,769 10,297, ,072 Te Anau 24,766,567 16,056, ,014 Tokanui 1,003, ,152 16,799 Tuatapere 5,826,992 5,252,723 92,925 Wallacetown 4,048,328 3,702,518 48,363 Winton 11,188,337 3,872, ,593 Total $114,877,041 $74,281,735 $1,756, Asset Condition and Performance Table 4-1: Wastewater Scheme Valuations The condition of the schemes have been rated using the condition and performance table presented in Appendix A. A summary of scheme condition is presented in Table 4-2. Condition monitoring of pipes is carried out on sewer pipes and rising mains prior to upcoming renewals to help target expenditure. Mechanical assets are serviced in accordance with the manufacturer s specifications checked for wear. Pumps also undergo an annual drawdown test to monitor efficiency. This is built into the Operations and Maintenance contractors work schedules in Hansen. Draft Asset Management Plan - Wastewater Page 19 r/14/6/

24 The condition grade of any asset on which work is carried out is expected to be provided by the contractor to the Council for recording in Hansen on completion. CCTV inspections are established as a project in Hansen with condition grades being recorded against the project group rather than the asset. Currently it is not possible to view the condition of a network based on CCTV footage. All work orders carried out are also recorded on GIS. Thermatic layers are used to identify areas with high levels of excessive reactive maintenance. This information will be used to plan and prioritise capital expenditure for renewals. Performance monitoring is carried out in association with AM Plan updates and not recorded in Hansen. Scheme Installed (date) Number of Connection s Overall Condition Overall Performanc e Comments Balfour Aging reticulation, renewal peak expected Browns Significant compliance issues relating to plant performance to be addressed 2011/12. Edendale/ New plant - no issues. Wyndham Gorge Road Biofilter cleaning programme required to improve performance. Rising main needs renewal. Lumsden New plant - performing well. Aging reticulation, renewal peak expected Manapouri Growth pressures are driving a review of treatment and disposal options. Monowai Possible replacement of disposal field. Nightcaps Increasing blockages indicate aging reticulation. Consent renewal due Ohai Reticulation near end of asset life. Treatment plant and pump station not performing well. Otautau High levels of infiltration. Issues with irrigation field performance. Riversdale Significant infiltration issues. Resource consent renewal required May require alternative disposal route. Poor wetland performance. Riverton Infiltration issues, renewals required. Consent renewal Stewart Pump and electrical renewals required. Island/Oban Te Anau Consent renewal required 2014, major treatment and disposal work expected to be required. Some reticulation in poor condition. Electrical upgrades required. Tokanui Consent renewal required 2014, upgrades to treatment and disposal may be required. Aging reticulation. Tuatapere Performing well. Wallacetown Performing well. Winton Significant treatment plant performance issues to be addressed in staged project starting 2011/12. Aging renewals, reticulation peak expected Table 4-2: Wastewater Scheme Overview Draft Asset Management Plan - Wastewater Page 20 r/14/6/

25 4.1.3 Data Source and Confidence Activity Asset Description Current Reliability Rating Reliable Comments Description data is available in Hansen and will be reviewed and updated as further information is received following the introduction of the O&M contract. Valuation Reliable Annual valuation now undertaken. As part of the review process we are considering what opportunities are available to refine the valuations process so that more scheme specific information could be utilised, rather than generic information. For example where it is known that the asset life of asbestos cement pipes is adversely affected by ground conditions the valuation process will be altered to reflect this. Condition and Performance Financial Forecasts Reliable Reliable Condition and performance is currently assessed through review of data in Hansen relating to planned and reactive maintenance activities. We also rely on local operator knowledge and experience. In addition water quality data is sampled in accordance with ES resource consent requirements and data is stored in TRIM and reported on in Council s quarterly report. Currently estimates have been made based on current market rates, annual asset valuations and direct enquiries. Projects within the first three years should be expected to have an uncertainty of up to +/- 20% with projects in the outer years up to +/- 50%. Currently no capital work will be carried out without the permission of the local CB/CDA/WSC. As part of the current plan review an assessment of funding options will be carried out to address issues of sustainability and affordability especially of a number of smaller schemes. Table 4-3: Data Source and Confidence 4.2 Operating and Maintaining the Assets The purpose of this section is to outline the broad operations and maintenance philosophies for the assets, understand any underlying issues and trends, and set the basis for the O&M financial forecasts. The operation of collection, treatment and disposal assets includes a limited amount of CCTV inspections, sewer flow monitoring activities, and day-to-day running of plant such as pump stations and treatment plants. Details of each facility are located in the Downer Operations and Maintenance Manuals which are developed for each site. These are maintained by Downer and located at its offices in Invercargill. Maintenance is the day to day work needed to keep assets operating at required service levels, and falls into two broad categories: Scheduled (Proactive) Maintenance: Proactive inspection and maintenance works planned to prevent asset failure. Unplanned (Reactive) Maintenance: Reactive action to correct asset malfunctions and failures on an as required basis (i.e. emergency repairs). There are also a number of services are delivered from other Council units: Information Management Department provides assistance with asset management information systems, plans and mapping. Rates Department provides assistance with rates collection and trade waste billing. Draft Asset Management Plan - Wastewater Page 21 r/14/6/

26 The contractors' procedures are accepted as the default best practice O&M practices (in the absence of other info). The purpose of the maintenance is to keep councils assets at the agreed condition. The agreed condition follows an audit of all above ground assets at the beginning of the O&M contract carried out jointly by Water and Waste and the Operations and Maintenance contractor Service Delivery SDC implement performance based contracts to achieve defined service standards for the operation and maintenance of the wastewater system, and undertake monthly audit procedures for monitoring contractor performance and controlling the quality of data (work activity, financial, attribute and spatial data) and physical works. Council has for the last 12 years contracted out the operation and maintenance requirements of the water and waste water utilities of the District. The objectives of this Contract are to ensure that: The Principal s drinking water, rural water and wastewater systems comprising the Contract Facilities are managed and operate in compliance with the requirements of Resource Consents and the New Zealand Drinking Water Standards as appropriate. The Levels of Service and Key Performance Indicator target levels contained in the Activity Management Plans and the Contract are achieved. The condition of the Principal s drinking water, rural water and wastewater assets comprising the Contract Facilities is maintained as specified in the Contract throughout the Contract term. The operation and maintenance of the Principal s drinking water, rural water and wastewater services comprising the Contract Facilities are delivered safely and in a cost effective manner. Drinking water, rural water and wastewater services are provided reliably in the District. Requests for Service and incidents are responded to and resolved promptly. In principle the district is considered as a whole. Levels of service and responsiveness have been established that are achievable across the district and the contract pricing is designed to smooth the small differences in costs that may occur from town to town Operations and Maintenance Forecasts Operations and maintenance costs have increased from $794K to $1853K principally for the following reasons. Operations and maintenance costs associated with the new schemes constructed with the aid of subsidy funding ie Wallacetown, Tuatapere Edendale Wyndham and the extension to the scheme on Stewart Island. (This also explains the increase in depreciation over the same period). Inflation. Introduction of new Operations and Maintenance contract in Draft Asset Management Plan - Wastewater Page 22 r/14/6/