Browse Forums Building Standards; Getting It Right! Re: Rainwater tank/Stormwater 2Aug 04, 2019 4:16 pm 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rainwater tank/Stormwater 4Aug 22, 2019 11:28 am First flush devices are not mandatory in Victoria but nearly all of the ones that you see in photos on Homeone are incorrectly installed in any case. When incorrectly installed, they are just a waste of money and collected water. It might surprise you to know that mosquito proof screening devices are also not mandatory as per the NCC and referenced Australian Standards although it could be argued that they are required as per a Performance Requirement in the Plumbing Code of Australia (PCA) under BP6.1. The PCA is Part 3 of the NCC. "BP6.1 Stored rainwater (1) A rainwater harvesting system must be designed, constructed and installed in such a manner as to reduce the likelihood of stored rainwater becoming contaminated or otherwise posing a hazard to public health." I rarely see a rainwater harvesting system on Homeone that isn't sub standard and many are also not compliant with the Victorian 6 Star Standard. If you want me to critique your system and offer solutions, posting some photos and information in this thread is a good place because of the thread's title. It could also help others. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rainwater tank/Stormwater 6Aug 22, 2019 7:31 pm Hi all (esp. @SaveH2O), here are the images I took today of the tank setup. A couple of things I thought were weird include the pump housing is not attached to the slab (literally just sitting there loose), and as mentioned already no first flush. I should have snapped the pump setup closer, might do that tomorrow and report back in. Thanks for any more info you can provide. Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ --------------------------------------------------------------------- Check our Homeone build blog here Re: Rainwater tank/Stormwater 7Aug 22, 2019 9:15 pm Hi darb74. First, some Qs. Did you have the tank installed as a requirement of the Victorian 6 Star Standard or do you also have either recycled water or a solar HWS installed? It looks like the pump cover might be hard to remove to take some photos unless the top can be removed. I really need to see a photo that shows the suction line between the tank and the pump where it connects to the pump. When plumbing rainwater to the house when you are already on mains water, you have the option of having either a manual or automatic mains water switching device fitted. Because I can't see an external automatic switching device, a photo of the top of the pump will show whether you have a manual or automatic system. You only have one downpipe draining to the tank. If the tank is fitted as a requirement of the Victorian 6 star standard, I need to know the gutter type and size so that I can calculate the compliant maximum roof catchment areas drained to each downpipe. The gutter looks like 115 mm slotted quad, is it? The minimum roof catchment area drained to the tank as a requirement of the 6 Star Standard is 50 sq m. What region are you in? I also need to know your area's 1:20 Average Recurrence Interval on which eaves gutter compliance is calculated to determine the maximum compliant roof catchment areas. I can look up the 1:20 ARI easy enough once I know the region. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rainwater tank/Stormwater 9Sep 15, 2019 10:51 am Hi again, Hopefully Harts doesn't mind me using this thread as it relates to the same topic I think? Water tank and stormwater setup on our new build (still under construction). So firstly I am curious about our water tank setup. Currently it is plumbed to both toilets, and also to the washing machine in the laundry (although our builder left out a town water connection also for the WM which they are sorting out, as we were only wanting to run the WM off rainwater if we ended up putting in a larger tank off a future shed). Anyhow here are some recent pics of the tank and pump setup: Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Is this strange that the tank enclosure is not anchored to the concrete?Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ --------------------------------------------------------------------- Check our Homeone build blog here Re: Rainwater tank/Stormwater 10Sep 15, 2019 11:00 am I thought I would put some stormwater/downpipe images in a separate post, with our house plans Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ This is a hand drawn plan with our approximate stormwater pipe locations.Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ --------------------------------------------------------------------- Check our Homeone build blog here Re: Rainwater tank/Stormwater 11Sep 15, 2019 7:08 pm darb74 So firstly I am curious about our water tank setup. Currently it is plumbed to both toilets, and also to the washing machine in the laundry (although our builder left out a town water connection also for the WM which they are sorting out, as we were only wanting to run the WM off rainwater if we ended up putting in a larger tank off a future shed). Like ⋅ Add a comment ⋅ Pin to Ideaboard ⋅ That could be tricky to do if the water coming from the pump is plumbed into the mains water line. The builder will/should be able to advise. The pipe that you see coming from the right hand side in the above photo incorporates a mains water switching device that switches over to mains water when the tank's water level is low but mains water will also flow when the pump is switched off. This gives you the option of only supplying mains water to the laundry when needed. I don't recognise this particular switching device but devices like these are generally bullet proof and a lot cheaper than the commonly used electronic devices. A good choice. Cisterns and washing machines are low flow end fixtures, there is no need to have a powerful 750W pump rated at 80 lpm when 6 lpm is the requirement. Pumps use about x3 the normal energy demand at start up and an oversized pump can also cause water hammer which isn't good, particularly for washing machine solenoids. Unfortunately, the tank water is plumbed to enter the pump via a 90 degree elbow fitted to the pump's suction side. The suction hose should respect a minimum of 5 to (preferably) 8 internal diameters of straight hose immediately before the pump. This would have been easily achieved if the pipe entered the cover a lot closer to the end of the cover. If the pump was to later supply an outdoors tap, the current plumbing would be highly undesirable and particularly so given that the high pressure Blue Stripe poly hose used appears to be 25mm which has an internal diameter of about 21mm. Using undersize suction hose voids most pump's terms and conditions of warranty and the amateurish combination of the 90 degree elbow, undersized suction hose and an oversized powerful pump is most likely to cause pump damaging inner wall flow separation at the elbow should you ever plumb the pump to an outdoors tap. The cover is also exposed to full sun, I would be drilling a few more ventilation holes higher up the cover in an area not on the weather side. I can see what appears to be a vertical seam at both ends of the tank but they could just be lines left by a two part mold that close to mold a one piece tank. It is not compulsory to manufacture tanks with AS/NZS 4776 certification but tanks with this certification must be rotationally molded in one-piece seamless construction. I would not recommend any tank that was not roto molded as one piece. If it was my tank, I would be checking to make sure that it is a one piece roto molded construction. Can you see any stamping on it that says that it has AS/NZS 4776 certification? For other reasons, I doubt that it has certification. I don't like to see tanks fitted with a low outlet valve that supplies the pump but from what I can see in this instance, it is a result of poor tank design rather than a mistake made when optioning the valve's position. The poly thickness is almost certainly greater where the valve is fitted but being so close to the bottom will ensure that the worst possible water and sediment is drawn from the anaerobic zone to the pump unless a floating inlet hose has also been installed. You need to regularly check the filter on the pump's suction side to make sure that the mesh is kept clean and not further restrict the flow. A flow restriction can easily cause cavitation and flow restricting filters on the pump's suction side are bad news. I would never recommend that set up. The focus should be on delivering the best quality water in the tank to the pump, not the worst quality water. You will also see in another photo that the tank's downpipe discharges water from a height above the tank's outlet valve.This is also sub standard because falling water will resuspend sediment which then gets dragged to the pump (but to the filter in this case). The downpipe should have discharged into the opposite end of the tank. No problem having the cover just sitting there. There is only one downpipe diverted to the tank. To be compliant with the Victorian 6 Star Standard and unless you have either a solar HWS or recycled water connected, the tank must harvest a minimum 50 sq m roof catchment area. You appear to have the standard 22.5 degree roof slope and 115mm slotted quad gutters which generally have a cross sectional area of about 5,250 sq mm. The roof catchment area is the roof space (plan area) multiplied by a figure determined by the roof slope to allow for wind driven rain. For example, the roof space draining to each downpipe on a 22.5 degree roof is multiplied by 1.21 to arrive at the roof catchment area. EXAMPLE: A 22.5 degree 30 sq m roof space would be 30 sq m x 1.21 = a 36.3 sq m roof catchment area. This calculation is used to determine compliance for the downpipe size and the gutter cross sectional area for eave gutter roof areas drained during a 1:20 year Average Recurrence Interval (ARI) in varying rain intensity areas. In Victoria, roof stormwater drainage must be installed in accordance with AS/NZS 3500.3 Plumbing and drainage Part 3. https://www.vba.vic.gov.au/__data/asset ... mwater.pdf Your house plan shows that the house, garage and portico area is 278 sq m. If we use this figure as also being the roof space area (the roof space is actually measured to the gutter's edge), 278 sq m x 1.21 = a 336.4 sq m roof catchment area. I can see 8 downpipes and your region's 1:20 year Average Recurrence Interval as per AS/NZS 3500.3 is 130 mm/hr, this is based on an average rain intensity of 2.166 mm/min over a 5 minute duration. AS/NZS Figure 3.5(A) shows that a 5,250 sq mm gutter in a 130 mm/hr ARI area requires a minimum 100mm x 50mm rectangular downpipe and can drain a maximum roof catchment area of about 37.5 sq m. If your gutters are 115mm slotted quad and roof drainage compliance aside, I seriously doubt that the single downpipe diverted to the tank meets the Victorian 6 Star Standard to drain a minimum 50 sq m roof catchment area to meet compliance. If the above is not compliant with the 6 Star Standard, it is the only non compliant issue with the rainwater harvesting system, the others are sub standard issues most often resulting from a lack of knowledge in rainwater harvesting basics. Are you able to post your gutter's make, style and cross sectional area? It should be listed in the manufacturer's gutter specifications. Can you also confirm the total roof plan area too thanks? Apart from these observations, your rainwater harvesting installation is better than most of the ones I see. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. Re: Rainwater tank/Stormwater 12Sep 16, 2019 8:09 pm Thanks for all that info, it’s very useful. Particularly with a thought I had re: laundry running on mains....am I right in thinking that if I want to a late night washing load I can simply switch off the pump and tank valve and then our system will happily run on mains instead of tank water? Also good to know there are no major issues, but I would like to know if that diverter system on your website link would be possibly on our tank setup as an easy retrofit? --------------------------------------------------------------------- Check our Homeone build blog here Re: Rainwater tank/Stormwater 13Sep 16, 2019 9:41 pm darb74 am I right in thinking that if I want to a late night washing load I can simply switch off the pump and tank valve and then our system will happily run on mains instead of tank water? Yes, you can do a trial run to test it. The pipe that feeds in the mains water is also a clever automatic mains water switching device that operates on hydraulic pressure. The link below shows a similar device with details of how it works. Whoever optioned your system has done the best they know how to give you a good system. Most people are given RainBanks! https://www.asctanks.com.au/product/asc ... k-2-mains/ darb74 I would like to know if that diverter system on your website link would be possibly on our tank setup as an easy retrofit? Yes, it's a very easy retrofit and I will mention a few advantages further below. Ordinarily, to divert from a second or third downpipe, downpipe(s) have to be changed to 90mm pvc stormwater pipe, disconnected from the subsurface stormwater system and trenched underground to the tank. The pipe would then divert vertically to the top of the tank and discharge into the tank through a meshed opening. The underground pipe and downpipe(s) will retain water to the level of the water at the top of the vertical riser and flushing a buried pipe to purge built up crud is let's say 'somewhat difficult' when it is a flat block! This diversion method is known as a wet system or charged system. An alternative is to divert pvc downpipes along a wall to the tank which can be aesthetically challenging. The Supadiverta is fitted to a downpipe by removing a small section of pipe and water is diverted to a small but stronger pvc pressure pipe that connects to an inlet valve plumbed about 100mm above the bottom of the tank. The downpipe remains intact and two or more Supadivertas can share a common horizontal pipe at ground level to supply the tank. PVC pressure pipe is AS/NZS 4020 certified as being compliant for use with potable water whereas pvc stormwater pipe is not. This low restriction flow path has an increased variable hydraulic head because of the lower height of water in the tank compared to the height of water in the vertical riser. The emptier the tank...the higher the potential flow rate during heavy rain. The smaller and shorter pipe also retains considerably less water in between rain events. Supadivertas can be fitted to the downpipe at a height that discharges water back to the stormwater system once the tank fills. This gives a huge benefit in that you could effectively divert water from every downpipe to the tank and if you didn't have the current downpipe discharging to the top of the tank, the tank wouldn't need the overflow pipe. Sealing off the overflow port can increase the capacity of most tanks by 8-15%. You also have the option of having a flashing made by a roll former to fit under the Supadiverta, I just haven't got around to putting the dimensions and a photo on the website yet. I think that your tank may possibly only be able to be fitted with a valve in a position near the bottom of the tank as I can see that the plastic where the existing valve is fitted is thicker there, you would need to check this. If so, then you will need to determine the largest valve that can be fitted. A 32mm valve would be good if it can be fitted because 32mm pvc pressure pipe has an internal diameter of (Class 12) 37.5mm and (Class 9) 38.5mm. If a valve can be fitted higher up, it would usually be fitted about 100mm high. Irrigation outlets are invariably cheaper for pressure pipe sales than the big green shed and the larger internal volume (+ 5.8%) Class 9 pipe should be about 25-30% cheaper than class 12 pipe. The tank would have to be emptied to fit the valve. There are many instructional You Tube videos that show how to fit a tank fitting through a new hole near the bottom of the tank. A hole saw with a centre bit is used to drill the hole and the hole size is measured by the fitting's outside thread, not the valve's nominal size. Cutting the wrong size hole is not unheard of unfortunately. 3in1 Supadiverta. Rainwater Harvesting Best Practice using syphonic drainage. Cleaner Neater Smarter Cheaper Supa Gutter Pumper. A low cost syphonic eaves gutter overflow solution. DIY, Home Maintenance & Repair But if it is a ground level open pit, then it is not a charged system. No surprises there. The pipes have obviously been altered and there would be a reason for this.… 3 31284 Grate, thank you! RexChan if thats the reason i could sleep well without thinking about additional cost. But 1st i'll need to read about NRV cleaning/replaing stuff. I… 7 31164 Once you know the basics, the rest is easy. Read my post in the thread linked below. viewtopic.php?p=1919271#p1919271 2 19520 |