[Mark Oomkes]

I'm not sure if this is the correct forum, so if not please move it Jeff.

I have a bunch of questions about installing a large pond liner. We are developing a partnership with the irrigation company that we sub our work to. We have been working them for many years and they have provided us with excellent service, we have given them referrals and they have given us referrals. They are getting into the pond business in a bigger way but they do not have the equipment to dig, grade, haul pond liners, install, etc.

Sooo, I could use some advice. The first project that they want us to price the install on is a small detention pond. Approximately 150' X 270' and 10' deep. Yeah, it's a nice small one to start out with, but I figure if we can handle this, anything else will be a piece of cake. We will probably have to do some of the finish grading, but most of it will be handled by the excavator, so that isn't too much of a problem, the problems are:
1) How thick of a liner am I going to need? Does it need to be double lined?
2) Am I going to need any sort of underlayment? It is all sand in this area, hence the need for a liner.
3) Any suppliers that you work with on something this large?
4) Approximate weight? In other words, how in the world do you move something like this around?
5) Any approximate installation production rates? (I know, it's different for every company) but I still need someplace to start.
6) Any other pitfalls or craters that I am not thinking of?

The irrigation company is going to handle the pumps and electrical for the fountain and stream from the upper pond, there is going to be a recirculating pump from the lower pond to the upper pond. I figure I'd try to get help on the big pond and the smaller upper pond and stream should be a piece of cake.

Thanks in advance for any advice.

[Dale Wiley]

You are going to need a big liner. Well over 55,000 square feet.

Probably a custom cut and order. 45 mil, single layer should do it depending on your soil profile. Probably going to involve at least one seam.

Probably come in on a semi, going to need some HD forks etc to get it off and place. A small army of men, probably about 20 or so to roll the thing out.

Careful initial placement is VERY important, as you got one shot to place it correctly.

Check the repose angle on the sides of the pond, that will affect how you roll it out.

[GLAN]

I am not sure if liners come in extra width sizes.........They can be gotten on a roll and I belive some of the rolls are 50 feet.

What you would have to do is glue liners together to reach the size you need.

If we're talking that big.......I would definitely put an underlayment of a felt type landscape fabric...at the least.

Moving liners of abundent size takes man power to move and position in place.

Installation rate?.........how fast can 1 man dig, or 2 men, even 3?

Pitfalls........I don't see large ponds any different than small ones.....only difference is for large ones I want more hands with me.

[Stonehenge]

Mark, I crossed this bridge last fall.

A liner in the sense you're thinking of may not be necessary.

What is the makeup of the soils where this pond will be going?

[Mark Oomkes]

Sand, sand, sand, sand and gravel. Less than a mile away, downhill, there was a gravel pit for 30+ years or so. Did I mention the soil is rather porous?

So I'm pretty sure a liner will be required. Maybe until they see the price that is.

GLAN, not sure I would want to take a chance on glueing liners together, but that might be the only option. I'm checking some local suppliers to see if this is even a reasonable request. I think Dale's on the right track, once it's rolled out, it's rolled out. I know I'm shuddering at the thought of rerolling and reunrolling.

[Dale Wiley]

Another option would be to shotcrete it with benonite. I don't know what the cost is, and you can get leaks. I have not seen a liner that size with any underlayment. Any leaks you get are going to be minor in the overall size of the project.

I would have about 20 guys, a way to hold down the liner until you get it all out and ready to fill. If the wind gets under you are royally screwed. It will start knocking it around like a kite. You need to be ready to fill ASAP, because if you have any ground water coming in underneath, it will lift that liner like a balloon.

Also, I am sure your looking at at least 10K for the liner or more ..

[Stonehenge]

Hmmm... Bentonite clay liner can be done with sandy soils, but it'll probably not be cost effective. When I searched for liners for our project (which was smaller than yours) I couldn't find a supplier that could make a single piece for this project. Doesn't mean one isn't out there, just that I couldn't find one.

So you'll have to consider how and where you'll attach one liner to the next - not where on the liner, but where geographically - a parking lot would be ideal, so hopefully there is one near where the pond will be going in. Trying to attach one to the next once inside the pond would seem nearly impossible without having leaks.

[Mark Oomkes]

Just got the first quote in, Dale you were off by about 50%. This will be a little low, they misunderstood and sent us the quote for the liner to be that size, not the pond.

Weight isn't too bad only 3400#'s.

I'm really going to show my ignorance here (shut up Dale, Stan, Rick and whoever else might want to jump in) but is 20 mil thicker or thinner than 45 mil?

PS That is for a one piece liner.

[HardDaysKnight]

This company claims to have a 1 piece 45mil up to
60,000 sq.ft. http://www.pondsolutions.com/pondliners.htm

[Paul]

What about welding one? there are a number of different ways to weld plastic and rubber liners ( heat and glue). Having worked on a few landfills (talk about restrictions and testing of liners!) a crew of to or three could roll out and weld one in a day. Check with http://www.geo-synthetics.com/

[dan deutekom]

My calculations put that size of pond liner 45 mil, at a weight of about 15000 pounds. And I would be looking at about a price in $20,000 range. I would definitely look into using bentonite clay for a project like this. I would be very surprised if you could find a one piece liner for this and you will have to join them.

You might want to browse Firestone's website to check out their liners
http://www.firestonebpe.com/lining/a...rrigation/_en/

PS: 20 mil is a lot thinner than 45 mil. (If I did my conversion right there are 245 Mil in 1 inch)

[TrickyDick]

I worked on a superfund cleanup in California where we had about a 40 or 50k sq ft liner for a containment area that was laid out in a few pieces and then welded in place. Worked great but it was a different material...I think 80mil PE. Don't know if that can be done with softer stuff but it probably can.

[Stonehenge]

TrickyDick -

Was that stuff sonic welded? What was the process?

[TrickyDick]

It was a while ago but I guess it would be called an extrusion welder. Looks kind of like a jackhammer. I know there are types of welders that work above the ground to keep the liner out of puddles and such while being welded.

[Dale Wiley]

This is what is so great here.... what a trove of information.

20 mil is less than 1/2 the thickness. I would be very hesitant to use a 20 mil liner. The 3400# thing is cool, but 20 mil is just to thin in my humble worthless opinion.

I have done several of these, and we always did them in summer, and rolled them out in the excavated area, and seamed them together right in the pond, (no water). We used a glue process on one, and the other I subed out to a dirt company that has some kind of heat glue gun from Martha Stewart or something.

That one was put in in Las Vegas area, in calichie soils, crumbly but fairly smooth after you took an excavator to the walls and bottom.

You only want to roll that bad boy out once and once only.

I would almost think about getting a soil engineer involved here and have some specs developed that you can install to. CYA.