I didn't get the job. The owner just couldn't bear to line it. She liked my proposal but she chickened out. I should say that her other landscaper told me that she was real wishywashy on this one.
But I did make some real progress finding large scale alternatives to rubber liners. The Akwaseal product looks real straight forward. There is a big time excavation contractor near hear that swears he will never use rubber again. His jobs are 100x100 up to acres. His company also maintains the ponds and says that there are no long term issues with proformance.
Does this link work...
http://www.akwaseal.com/Akwaseal%20Design%20Manual.pdf