Working together to improve beach water quality. Fixing our. public and private. sewers

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1 Working together to improve beach water quality Fixing our public and private sewers May 2004

2 FIND FIX DECIDE Narrow Neck Beach on a summer day As part of Project CARE, our long-term project to improve beach water quality, we are inspecting both public and private sewers in various areas throughout North Shore City. We will work on fixing the public sewers, but as the property owner you're responsible for fixing any problems with your private sewers. We need to work in partnership to fix our sewers, improve beach water quality and protect our environment. We will do everything possible to minimise disruptions. We start work first in areas where stormwater leaking into the sewer pipes and sewage leaking out is greatest. This means we are getting the maximum benefit for our investment in the sewer network. This brochure outlines the problems with our sewers and the repairing and replacing work we're doing (and you may need to do) as part of our major upgrading project and includes some helpful information.

3 What s the problem FIND The sewer system is made up FIX of pipes, pumping stations, DECIDE storage tanks and a treatment plant. In many parts of our city the sewer pipe network is old and leaky and has had little or no renewal over the years. When the pipes are cracked or faulty, water can leak into the network and sewage can leak out. When stormwater leaks into the pipes, called infiltration, following heavy rain, this increases the volume of sewage to be transported and treated by the sewage treatment plant. Where this volume exceeds the sewer network capacity this can cause sewage overflows that contaminate our streams and beaches. When sewage leaks out of the pipes, called exfiltration, it can contaminate stormwater and again cause pollution on our beaches. Wet weather overflows are the most common cause of pollution on our beaches. Stormwater also has a significant impact on our beach water quality. Road runoff comprising harmful chemicals, vehicle pollution and animal waste are prime causes of stormwater pollution. 1

4 Deciding how to fix the problem There is no perfect wastewater pipe network - pipes do leak! We have no choice but to fix pipes. We're using the best expertise available, spending money wisely and using a variety of methods to fix the problem. Repairing and replacing old pipes reduces leakage into and out of the pipes. It also reduces the total amount of sewage to be treated and prevents pumping stations overflowing into our streams and beaches. This is the work we will be doing in your area (see page 4 & 5 for more information) Increasing the capacity of the sewer network is achieved by increasing the pipe size, laying new sewer pipes and increasing the flow capacity of the pumping stations; for example, a larger pump and rising main allows a pumping station to cater for increased flows. Pumping station reliability is improved by installing new electric switchgear and duplicating rising mains. This provides a backup to keep the system working if there are mechanical problems or power failures. Storage tanks and tunnels reduce the load on the sewer network by storing increased flows, especially following wet weather when rain can leak into the pipes and increase the amount of sewage to be treated. Inspecting a public sewer with closed circuit television (CCTV) 2

5 FIND Public sewers are only part of the problem We're committed to fixing public sewers, but this is only part of what we do - the other part involves fixing private sewers. As the property owner you are responsible for fixing any problems we find with your private sewers. We will only be able to improve beach water quality if we work together in partnership and address problems with both public and private sewers. Following investigation we find many private sewers require no work, others require relatively minor work and a few properties need more substantial work. If there are any problems with your private sewers we will issue a Notice to Remedy Defective Drainage (NRDD) which will detail any work to be carried out by a registered plumber or drainlayer. As part of this process we will be asking you to advise us when the work is done. If there are no problems found when we test your private sewer pipes we will send you a letter to let you know. We will also place a copy of this letter on your property file here at the council, for future reference. We need to work together to improve beach water quality in North Shore City and protect our environment. (See over the page) FIX DECIDE Inspecting a private sewer in Stanley Point with closed circuit television (CCTV) 3

6 How to fix the problem We are responsible for fixing public sewers and private property owners are responsible for fixing private sewers. In some instances public sewers are located on private property. In these cases, we are responsible for fixing any problems and may need to visit the property several times. It is sometimes necessary to install an inspection shaft to give us access to the sewerage network. Obtaining adequate and reliable information is essential for us to determine the best way of fixing a sewer. Different contractors and subcontractors may need to visit your property several times. We aim to finish any works as soon as we can. Getting started We let you know what general work we have planned. The contractor will meet you and explain what needs to be done. We will physically inspect the private and public sewers and carry out water testing on any obvious leaks. We may check for additional leaks in sewers using environmentally friendly smoke and dye tests and sometimes closed circuit television (CCTV) if other results are of concern. We let you know what we have found. Many of the techniques we use are new to New Zealand and we take special care during decision making. We use the best advice and expertise available and continually review and assess our practices. 4

7 No problems with your private sewers No further action is required. We ll record this on your property file. Problems with your private sewers We send you a letter to let you know that we have found a defect and are rechecking the test results. We will be in contact again within a few months. If the defect is confirmed, we issue a Notice to Remedy Defective Drainage (NRDD) which will detail any work to be carried out by a registered plumber or drainlayer. You are responsible for ensuring any problems are fixed and as part of the process we ask you to advise us when the work is complete. Problems with public sewers on your private property We decide on the best technique available to fix the problem. We explain the problem and solution and seek consent to access your property. We take photographs of your property before we start any work. We arrange a convenient time for the work and get on with the job. When we finish the job we return your property to its prior or better condition and ask you to acknowledge this has been completed to your satisfaction. Problems with public sewers in your area or street We let you know when repairs will take place and how they are likely to affect you. We carry out repairs with as little disruption as possible and return your area or street to its prior or better condition. 5

8 Repairing and replacing old pipes Frequently asked questions Are the repairs necessary? Repairing the sewer network in your area is an essential part of the Project CARE works programme aimed at reducing wet weather overflows in North Shore City. Wet weather wastewater (sewage) overflows caused by heavy rain are the most common cause of pollution on our beaches. This is the greatest risk to public health. To improve beach water quality we must reduce the number of wet weather overflows. What do the repairs involve? The work we do to replace and repair old sewers involves a variety of mainly 'trenchless' methods. This means that many repairs are completed with less inconvenience than previous methods and only a minimum disruption to roads and property. For brief descriptions on various methods. (see the sewer repair methods over the page) Who pays for the work? We will test the public and private sewers at no direct cost to property owners. If leaks are found in the public sewer, the council is responsible for the cost. If leaks are found in a private sewer the property owner is responsible for the cost. How will the repairs affect me? We aim to minimise disruption to your neighbourhood and property. Our trenchless methods of repairing sewers, are quieter and less disruptive than many traditional methods for roadside works and where public sewers cross private property. Certain sewer problems do sometimes require us to use diesel powered equipment and this process can be noisy and smelly. During these instances we regret any inconvenience, but the equipment is necessary to carry out these essential repairs. We will do our best to ensure that our contractors comply with all noise and air emission requirements. 6

9 FIND Sewer repairs may also require us to close the public sewer for a period of time and during this time we may ask you to reduce any sewer waste you discharge from your property. This affects all discharges from toilets, baths, basins, sinks, dishwashers and washing machines. If the repairs on your property are going to affect your everyday activities we will let you know in plenty of time. What about alternative technology? The priority for Project CARE is to reduce sewage overflows and pollution on our beaches as soon as possible. Whether we choose to stay with established methods or to incorporate alternative technologies, the sewer network must be fixed. We are convinced that to achieve an improvement in beach water in the shortest time, the existing network must be upgraded first. Our longer-term planning can take a more holistic approach. This can include new environmentally friendly techniques such as water conservation, rainwater harvesting, on-site and satellite sewage treatment plants and composting toilets. How will I know that sewer repairs in my area are actually working? Everyone needs to know that the project and 'fix' is working. We are using a range of measures to check on progress. We will regularly report on the following things: the number of sewer overflows (monitored by Environmental Services) water quality monitoring (latest results are available by calling 0800 SAFESWIM) progress on the overall Project CARE programme (visit our website FIX DECIDE 7

10 Sewer repair methods Choosing a plumber or drainlayer We recommend you get advice and quotes for the work to be done from a number of professional trades people. You may like to refer to your local telephone directory or contact the Auckland Master Plumbers, Gasfitters and Drainlayers Association which may be able to refer you to suitably qualified tradesmen in your area who are members. They also offer advice and a range of other services that may be useful in getting the work done. All this is outlined in their information pack. Auckland Master Plumbers, Gasfitters and Drainlayers Association ph (09) or visit its website: Public sewer repair methods A number of factors influence how we fix sewer pipes such as the complexity and extent of the problem and surrounding landscape. Wherever possible we use trenchless technology, which means we can carry out repairs without an 'open cut' or excavation. The following list gives a brief overview of some of the methods we use to repair sewers. Partial or full replacement of drains We use an open excavation to lay new drainage pipes either in a new location, along the existing alignment, or along a different alignment from existing pipes. Birkley tunnel boring machine being lowered into the launch pit, Bayswater Nov

11 FIND Cured in place pipe (CIPP) lining We insert a fabric-reinforced tube that is woven with special heatsensitive resin into a pipe and inflate or invert this against the pipe wall. We then activate the resin by heating the tube, usually with hot water, steam or ultra violet light. The fabric tube becomes a new 'pipe within a pipe'. A variation to this process is inserting a flexible liner that is heated and pressurised to take the shape of the original pipe. Pipebursting We break up the existing pipe with tools and pull or jack a new pipeline in behind. The new pipeline can be either longer pipe lengths or a string of shorter pipes, which we add as work progresses. Sliplining This is a relatively simple process where we push or pull a new pipeline into the old pipe. Spiral lining We form a pipe with a hydraulically driven winding machine, which is normally located in a manhole or small excavation. A new pipe travels down the host pipe as the winding machine is driven. Packer grouting We position a 'packer' with inflatable end elements across a joint, crack, fracture or hole in a pipe and use air or water to pressurise it. We measure the pressure loss and inject a sealing gel into the pipe joint if the loss exceeds our set limit. FIX DECIDE We recommend you use partial or full replacement or CIPP lining to fix your private sewer drains 9

12 The quality of beach and stream water in North Shore City is important to the community and to this council. We know our city's beaches are a key reason that many of us live here. Looking after sewers - how you can help Make sure stormwater doesn't flow into sewer drains (gully traps) Conserve water where possible Keep sewers clear of tree roots, fat and other substances that can cause blockages Use a registered drainlayer or plumber for repairs to your private sewers. For more information on sewer repairs contact: North Shore City's Actionline on and ask for a wastewater engineer a member of your local community board visit the Water Info pages on our website at for general information on beach water improvement programmes look for regular updates in community newspapers. Printed on recycled paper c