Read through this thread for lots of good information about building a pond.
http://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=92487#Post92487Remember you dig a hole, however you build a pond. Dug holes leak, well built ponds are well sealed with a constructed clay liner and if built correctly those ponds have very few if any leaks. Emphasize your pond building reading education on proper soil compaction. A leaky pond can cost more to fix than the it cost originally to dig the pond. There are a large number of threads on this forum of members who have leaky problematic ponds. Choose your pond builder who has a good reputation and interview his references of previously built ponds. Don't be shy, check out his previous work. All pond owners enjoy talking about their pond/s.
Try for at least 0.2 ac. A roundish pond has the least amount of shore line and is the easiest to maintain due to weeds grow in shallower water along shorelines. I would not truck any dirt off site. Use the dirt to sculpt some higher ground that gently slopes into the pond to create a water shed that is well grassed/vegetated to deliver good 'clear' water quality. Make sure the contractor saves the topsoil to replace it as a thin layer on the final project so you have good overlying soil to plant and grow grass.
Good luck and we are here to provide 2nd opinions for your building and pond management.
