Reservoir Leak Test
Reservoir Leak Test
(OP)
We will be performing a leak test on a 55 million gallon concrete reservoir and are interested how others have measured the water loss. We are specified to follow ACI 350.1-01/350.1R-01 Tightness Testing of Environmental Structures with the HST-050 criteria. This criteria allows for a loss of 27,500 gallons per 24 hours. This computes to 0.017 inches per 24 hours due to our very large footprint. At this time we are considering pressure transmitters, ultrasonic transmitters, a simple ruler within a still on the reservoir wall or some combination of all three. Our biggest concern is the wave action of the water affecting results.





RE: Reservoir Leak Test
RE: Reservoir Leak Test
RE: Reservoir Leak Test
RE: Reservoir Leak Test
I did a fire water tank liner once and that took a day to notice we were loosing water, fixed it then took a week to confirm that the fix had worked. Wasn't 55 million gallons though!
My motto: Learn something new every day
Also: There's usually a good reason why everyone does it that way
RE: Reservoir Leak Test
As I said, it's tricky. The water is moving up and down, so you have to use some judgment. Maybe double the test time to get a more noticeable difference. But no matter what you do, it's never going to be exact. If it's less than a 1/4 inch per day, you're probably going to have to pass it and if it's an inch, it's going to fail.
RE: Reservoir Leak Test
RE: Reservoir Leak Test
RE: Reservoir Leak Test
Richard A. Cornelius, P.E.
WWW.amlinereast.com
RE: Reservoir Leak Test
Scott
RE: Reservoir Leak Test
If just the upper surface (6 inches or so) heats/cools from the original temeprature, you probably can't detect it in a level gage if the beginning and ending thermometers read the same.
Try placing four thermometers at your evaporation pan. One right under the surface (less than 1 inch from the surface). One 12 inches down. The next halfway between surface and bottom. The last right near the bottom. Hopefully, in a still open pond, your heat will be absorbed right near the surface, your evaporation will happen in the top few centimmeters, the daytime surface heating (and night time cooling) won't mix too much lower down.
RE: Reservoir Leak Test
"They pretend to build leak tight reservoirs and we pretend to measure it."
RE: Reservoir Leak Test
This is not my area of expertise, but I have a suggestion anyway.
Fill a clear vinyl tube with water. Drop one end into the reservoir well below the water surface. Run the other end to a shaded vertical surface at the same elevation as the water. Fix the tube to this surface with a scale behind it. Set your benchmark elevation.
0.174 inches should be discernible in a small diameter tube. I would run the entire length of tubing so that it is below the water level of the reservoir. By locating the reservoir end of the tubing well below (12" or so) the reservoir water level it should mitigate the wave action. Shading or burying the tubing should eliminate thermal effects. Perhaps a few drops of ordinary motor oil added to the observation end of the tube would help define the water level and make it easier to see.
Sometimes the best test or measurement technique is simple and far from sophisticated.
Ralph
Structures Consulting
Northeast USA
RE: Reservoir Leak Test