IN the MATTER of the Resource Management Act 1991 and the Local Government (Auckland Transitional Provisions) Act 2010 and in T
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BEFORE THE AUCKLAND UNITARY PLAN INDEPENDENT HEARINGS PANEL IN THE MATTER of the Resource Management Act 1991 and the Local Government (Auckland Transitional Provisions) Act 2010 AND IN THE MATTER of Topic 017 RUB South _______________________________________________________________________________________________________________ STATEMENT OF EVIDENCE OF RAY McNAMARA HEDGLAND ON BEHALF OF SARAH CHILMAN SUB 9423 WATER & WASTEWATER INFRASTRUCURE TO THE RUB TOPIC 017 – PAUP 13 November, 2015 _________________________________________________ Counsel Acting: Russell Bartlett QC Auckland 1010 Ph: 307 1769 1 Summary: My name is Ray Hedgland and I appear to give evidence on water and wastewater infrastructure in support of the submission by Sarah Chilman (Sub 9423). Ms Chilman wishes to have the whole area south of Beachlands through to the bottom of the Whitford landfill included in the Beachlands-Maraetai Rural and Coastal Towns RUB area. Existing water supply infrastructure in the Beachlands-Maraetai urban area relies on rainwater harvesting with tanker top-up as required. In my opinion It is technically feasible to continue this method of water supply for the entire area within the proposed Beachlands-Maraetai Rural and Coastal Towns RUB area. Many future subdivisions within this area could also be provided with a reticulated bore water supply for household tank top- up. This reticulation could beneficially include provision of fire hydrants. Significant water supply bores within this extended area would minimise the need for tanker truck activity for new developments and could be used to provide a local source of tanker water for the existing community thereby reducing tanker activity on Whitford-Maraetai Road. Therefore In my opinion there is no constraint with respect to water infrastructure on extending the Beachlands-Maraetai Rural and Coastal Towns RUB as requested by Ms Chilman. The existing design capacity and consent limit of the Beachlands-Maraetai Sewage Treatment Plant, which expires in 2025, is based upon 10,000 persons connected occupancy. The current consented development areas in the existing Beachlands- Maraetai urban areas together with those approved in Plan Changes 30, 30A and 34 exceed 10,000 person occupancy. Current population projections show that this limit is expected to be exceeded before 2025. Hence Watercare needs to urgently address an increase in plant capacity and undertake investigations for and secure an increase in the Discharge Consent limit irrespective of the current application to extend the Beachlands-Maraetai Rural and Coastal Towns RUB south of Beachlands. In my opinion It is technically feasible to increase the treatment plant capacity within the existing site. Investigations need to be undertaken to confirm the capacity of the existing receiving environment to accept more treated effluent. Whilst this may have limited capacity it is In my opinion technically feasible to augment this via irrigation to the adjacent forested hillsides. Effluent disposal and the ability to secure an increased Discharge Consent limit is not considered to be a constraint to future development by extending the Beachlands-Maraetai Rural and Coastal Towns RUB south of Beachlands. The existing conveyance pipeline to the treatment plant only has capacity for the existing consented developments. A new conveyance pipeline will be required to serve new development areas within an extended RUB, but in my opinion this is technically simple and would not be a constraint. 2 New development areas within an extended RUB can be required to provide their own local sewerage reticulation and contribute economically to new conveyance pipelines to the treatment plant, and to the treatment and effluent disposal extensions. It is my understanding that developers in the area are willing to contribute to the cost of such investigations, consent applications and the capital cost of the increased plant and conveyance capacity. In this way there would be no technical, consent nor economic constraint with respect to wastewater infrastructure to extend the Beachlands-Maraetai Rural and Coastal Towns RUB as requested by Ms Chilman. Consequently, in my opinion, there is no water or wastewater infrastructural constraint to including the requested area south of Beachlands within the Beachlands-Maraetai Rural and Coastal Towns RUB. It only remains to decide on the future population to be catered for and to include this within the required extension of the wastewater treatment plant and discharge consent. ___________________________________________________________________ 3 EVIDENCE IN FULL INTRODUCTION: 1. My name is Ray McNamara Hedgland I am a Principal with Fraser Thomas Ltd having retired on 31 March 2013 as a Director responsible for the Environmental Engineering Division with Fraser Thomas Ltd, a role I held for the previous 25 years. 2. My qualifications and experience are set out in Attachment A to this evidence and summarised briefly below. 3. My qualifications are: BE(Civil) Auckland 1970, Dip Sanitary Engineering (IHE Delft) 1978 and Making Good Decisions 2012 ( a prerequisite qualification to be a Commissioner at Council and Environment Court Hearings). I am a Chartered Professional Engineer. I am an Environmental Engineer with more than 40 years experience specialising in Water and Wastewater Engineering, particularly water and sewage treatment, including land disposal of effluent, investigations, design, supervision and commissioning of projects ranging from small on-site household projects, schools and small commercial centres through subdivisions to numerous small towns, especially in environmentally sensitive areas. 4. I am familiar with the Beachlands-Maraetai sewerage scheme, treatment plant and its receiving environment having been involved at a senior level in the original sewerage investigations, consent and design of the initial treatment plant and effluent disposal area in the early 1990's. 5. I am familiar with the proposed urban expansion area having until recently being a resident of Beachlands for some 10 years. 6. I am familiar with the Ahuareka site at 650-680 Whitford-Maraetai Road having investigated water and wastewater issues and developed options for a proposed 186 house development on the site for Ahuareka Trustees No2 Ltd. Wastewater options considered included discharge to either the Beachlands-Maraetai Sewage Treatment Plant or to a local cluster treatment plant followed by land disposal. Both were considered technically feasible, but at that time the latter was selected as the preferred option. CODE OF CONDUCT 7. I have read and agree to comply with the Environment Court’s Code of Conduct for Expert Witnesses contained in the Environment Court Consolidated Practice Note 2011. The evidence is within my scope of expertise except where I state otherwise. I have prepared this statement to meet my obligations under section 5 of the Practice Note and have considered and referred to all material facts that I am aware of that might alter or detract from the opinions expressed here. 4 WATER SUPPLY 8. Existing water supply infrastructure in the Beachlands-Maraetai urban area relies on rainwater harvesting with tanker top-up as required. This water supply methodology has been approved for continuing development in the Plan Change 30 and 34 extensions and in my opinion could be accepted as a prime water supply methodology for all future development in an extension of the Beachlands-Maraetai Rural and Coastal Towns RUB south of Beachlands as proposed by Ms Chilman. 9. As part of my commission by Ahuareka Trustees No2 Ltd for consideration of a 186 house subdivision development on 650-680 Whitford-Maraetai Road, which is within the extension area requested by Ms Chilman, I arranged for and supervised a bore water supply drilling and testing contract using Kiwi Welldrillers NZ Ltd on the site. Investigations determined good groundwater quality in this area, not requiring further treatment, and sufficient available water to provide all 186 houses with bore water. 10. Whilst a permanent bore water supply could have been provided to all houses, the option selected was for all houses to have rainwater tanks but with a reticulated water supply from the bore based upon a tank top-up supply such that the houses would only use bore water when their household tank ran out, typically only during extended dry periods, thereby conserving the groundwater resource. In addition the reticulation system was to be designed with fire hydrants to conventional standards. 11. In my opinion, based upon the results of my testing and a Tonkin and Taylor report on groundwater availability in the area (Attachment B), similar large bores could be located in the centre of major subdivisions south of Beachlands Road thereby providing household tank top-up as well as bulk water reticulation with fire fighting capacity to these developments. 12. I consider that there is no constraint on water supply for a proposed extension of the Beachlands-Maraetai Rural and Coastal Towns RUB south of Beachlands as requested by Ms Chilman. It could be provided by way of rain water harvesting to individual household water supply tanks with these sized for either tanker top-up as required or for a reticulated tank top-up from large bores within the development area. WASTEWATER 13. In the joint statement of evidence provided by David Blow, Chris Allen and Andre Stuart on behalf of Watercare they state in para 20.2 In terms of wastewater, the treatment