Water Main Renewals
For many years we constructed water main renewals for Australian Water Technologies, Sydney Water, Hunter Water, Dept. of Public Works and Services, other public bodies and developers. Please find following a sample of varying sizes of pipe, materials and length of pipe work.
Water Main Renewal Lidcombe
The work involved partial design, community liaison, supply and construction of 100mm to 450mm water mains in residential streets.
We commenced the work with the engagement of a certified designer who completed the design and verified size and type of material for the works and submitted all the paperwork and backup material for the clients’ approval.
When we got approval to go ahead with the works, we submitted our community plan, QA documentation, OHS&R plan as well as our environmental plan for approval. We then notified residents of the impending works. Before we commenced we had our traffic management plans approved by the local council and applied for council permits to commence the works. We then notified the Police, Emergency Services and council of possible traffic delays in the streets where we would be working so as not to cause delays if there was an emergency.
When all of these procedures were approved and signed off we then completed our “Dial Before You Dig”, set up our compound, had our materials delivered and commenced excavation.
Pipe was laid at the rate of 35m per day on most streets with driveways being bored so as there were no arguments about matching concrete or paving and also residents could come and go with vehicles whenever they wanted.
When all pipework was completed, we would then complete our hydrostatic tests for leaks, chlorinated and disinfected the mains (this would be a “HOLD” point set by the client)
After all of these tests including compaction tests had passed we would hold a meeting with all stake holders to discuss the connections of the new mains. Where ever possible we would keep a dual system running. When both systems were up and running we would check with our community officer if there were any dialysis patients, dentists, medical surgeries or any other type of businesses who required water on a constant basis. If there were we would arrange a temporary supply. If everything was ok we would commence connections, after again notifying the residents that their water would be off for a short period of time. We would use multiple crews at this in order to complete the works in the shortest possible time. After we had completed a property we would do an audit for sign off with the residents to make sure they had full water pressure and that all taps, both inside and outside, were working.
We would continue this work street by street until all the house services had been transferred. When all of this was complete we would then disconnect the old main and remove all surface fittings and restore, at the same time install new marker posts to clearly identify where the new stop valves and hydrants were located. After all of the civil works were complete we would submit our complete package to Sydney Water for their records.
The following works are a sample of what was completed in water mains renewal.
WaterMain Renewal Lidcombe
Client Sydney Water
Water Main Renewal Bankstown
Client Sydney Water Corporation
Water Main Renewal Blacktown
Client Sydney Water Corporation
Water Main Renewal Woronora
Water Main Homebush
Changed out valves on 1200mm main and also replaced sections of pipe. This work was completed under very fine time constraints and also was carried out in a very busy street location.
MSCL water mains (mild steel cement lined Sintakote)
We completed numerous works in MSCL pipe in all sizes from 308mm to 1200mm. Some of these works were of a very critical nature where time was of the essence in highly populated areas at times with only 12 hours capacity in the reservoir, get this type of job wrong and all hell breaks loose as there is no plan B. We have also changed numerous faulty valves from these mains, valves which have been leaking or have failed completely.
The approach that has to be taken with a large steel trunk main that needs work to be done on it is to carefully plan the works. You can only put the most dedicated and qualified personnel on projects such as these and you have to involve the complete team from the start. You also have to work very closely with the asset holder.
We usually start with receiving what the client requires us to do and commence as soon as possible after a full review of the design, with a detailed take off of materials as there is usually a long lead time for pipe of this type and sometimes valves have to be manufactured overseas. You then prepare your site specific plans for approval. Then the major planning commences as you have to arrange welders, heavy lifting equipment and quite a lot of other equipment that you may not use on other types of projects. Also you must have good back up plans for equipment making sure they are freshly serviced and in good working order. Cutting equipment and pumps you have to have duplicates in case of breakdown.
During this period traffic management plans and permits must be put in place as most of the times these types of mains are in very busy urban areas All authorities have to be notified of impending closures especially Police, local hospitals, Council, Residents, Fire dept. so they can plan around the works. There can be a long lead time on approvals for major road shutdowns.
Where the works call for bores we would probably complete these with an outside casing as part of the early works as in most cases these can be completed without causing much disruption to residents or traffic as they are often completed from the road reserves or easements. You would only commence these works once you had proved the entry and exits of the bore for several meters to make sure that the new pipe can be pushed through the bore with spacers so as to centre the new pipe. Afterwards this would be grout filled so as it would probably be maintenance free conduit once it is in place.
When all of the materials have arrived and a full stock take taken to make sure all materials are in place for the works we would plan our crews. Sometimes we may have to work double shifts at critical stages of the works such as valve change out. For the safety of our staff there would have to be a double isolation on the main otherwise a valve could fail while our people are working on it. Safety is a non-negotiable issue where Firedam Civil P/L is concerned. This would mainly happen where connections to the mains are required or on the changing out of valves.
Before we commence the main works and after completing the “Dial Before You Dig”, a full meeting is organised with all the stake holders. This would include management from the authority who is the client together with the superintendent and maintenance staff as well as our team. All issues would be discussed. After this is completed we would commence our works. We would establish our compound together with equipment and materials. If there were long runs of pipe work we would string them out and commence welding straight lengths. After locating existing services with a non destructive vacuum system taking care not to damage them, we would commence laying pipe on a suitable bed in the trench, excavating bell holes for the welders to operate in. As much work as possible would be done above ground for ease and excavators would be used to lift in the pipes. Smaller pipes would be fillet welded with a continuous weld. Larger pipes would have a weld band/ring (sometimes grout filled).
All welds would be reinstated with Denzo wrap and shrink sleeve after welding so as not to allow corrosion to set in. Larger pipes would be repaired on the inside with grout for a smooth finish as per manufacturers’ requirements. Most bends would be pre-made at the foundry but there would also be a provision to manufacturer onsite. Progress for a steel pipe in urban areas should be at the rate of 24 – 36 metres per day, depending on the amount of bends and whether you are in the roadway or in a grassed easement. The pipe would be back filled with sand, warning tape (detectable) is placed 300m above the pipe and either grass put back or road base and hot mix completed at 50m intervals with pits finished level with the surface. All excess material to be tested and disposed of at a licensed facility.
While the main body of works are proceeding all the pipe work and existing pipe work in ground would be recorded for the “As-Constructed” drawings. Compaction tests would be completed as per standards. Planning for connections would be taking place as these always require a large shut down and sometimes have to take place in the winter months when requirements are at lower levels. When the main is laid it is tested and chlorinated to the requirements of the contract. All documentation is presented to the client and the connections can commence. This may require several crews and generally when you start you cannot stop until the main is connected. After all connections are completed, the works are restored. All remaining documentation is handed over to a very happy client.