I have problem with leakage in Raw
I have problem with leakage in Raw
(OP)
I have problem with leakage in Raw water pond lining with 1mm.HDPE SHEETwith welding joint type. My pond was 90 m. by 45 m.water level is 3.5 m. The water level is lower 1.2 mm./hour which is 2.88 cm/day. My point is we cannt find the criteria that this is accepatble for such kind of this linning or not.
Does anyone out there has experience with acceptance criteria of this HDPE sheet. Is there any sources that I can reference to?.
My Site condition : avg.temp 32deg.c(dry bulb), Humidity 70% wind 3m/s dew point 20deg.c
Thanks
Does anyone out there has experience with acceptance criteria of this HDPE sheet. Is there any sources that I can reference to?.
My Site condition : avg.temp 32deg.c(dry bulb), Humidity 70% wind 3m/s dew point 20deg.c
Thanks





RE: I have problem with leakage in Raw
Notwithstanding the liner design (clays, soil cover on liner), I would think the liner may be a little thin based on the overall depth and area. Over the longterm, stretching (and tearing) of the HDPE will be a problem. For Liner information, I use NILEX at www.nilex.com They should be able to assist you.
KRS Services
www.krs-services.com
RE: I have problem with leakage in Raw
This pond is currently leaking, what I have no idea is Is this leaking quantity is normal acceptable for such kind of this linning. Also, I understand that there shall be some evaporation. how can I calculate this figure.
Thanks
RE: I have problem with leakage in Raw
KRS Services
www.krs-services.com
RE: I have problem with leakage in Raw
Typical permeability values for HDPE membrane liners is on the order of 1x10^-13 cm/sec. Evaporation can certainly be a factor, but if the pond has experienced a sustained "loss" rate of 2.88 cm/day, there is probably another reason. You probably have a punctured liner or a failure in one or more of the welded joints. If this is the case, the only way to locate and repair the leaks is to drain the pond and walk every square foot of the liner. You did not mention whether you have any intended inflow/outflow from the pond. If you do, a water balance will be required to determine if you do in fact have a leak. If you attempt to calculate a water balance, you will need accurate as-built geometry on the pond as earthen ponds are never built exactly to plan. In my experience, the as-built volume of an earthen pond the size you describe can easily be 5%-6% different from the design.
RE: I have problem with leakage in Raw
Thank you for your helpful hints.
We checked the pond by check depth of water in various points along the pond,as nealt said it is diificult to check exact volume of pond. The problem is the client may not accept this pond as they quote that have to pay for additional water to fill in this pond regarding to this loss.
Do you have any suggests.
RE: I have problem with leakage in Raw
Of course this would change in accordance with the pumping cost. How does that figure then compare to the total usage cost in the pond? How does that cost compare with the cost of having to drain, desludge (if required), locate tears and repair the liner in the pond?
I would wager that the pond loss is a fraction of the system losses in the distribution system, and those losses by comparison are much more costly (if dealing with treated or potable water). Unless the soils under the pond are highly porous, such as a native granular soil, a direct loss of 116 m3/day (as a single failure) should show up someplace. If the loss is cumulative from several small (stretch) rips and seam/joint tears in the liner then you will have to assume sectional repairs - and those are costly. This brings up another point though, how old is the pond? Is the liner due to be replaced soon and is the leakage currently being experienced a function of an aging liner?
I feel the approach to your client should deal with the issue of costs in this matter. Assuming no berm or structural failures, they should balance out the cost of examining and repairing the liner, postponing or leaving until evidence of leakage is present. It could very well be that you have several small leaks and evaporation. Finally, if the pond was leak proof how much loss to evaporation would be present on average? Does the different (your loss) actually merit further action being taken, or is it an achademic exercise? Let me know how it shakes out!
KRS Services
www.krs-services.com
RE: I have problem with leakage in Raw