Sealing liner to waterfall

[Osddvdjv]

I have a 1000 gallon pond with 2 waterfalls and recently had a leak at the waterfall. My liner was not sealed well to the waterfall and thus a leak. What is the best material and method to re-attach the liner and seal so I won't have any more leaks?

Thanks
Don

 

[addy1]

I have used pl roofing sealant (home depot lowes), clean the liner with acetone, make sure it is dry, goop it well, let it dry for a little...............done