Pond Boss Forums AQUATIC VEGETATION Controlling unwanted plants Severe Eurasian Watermilfoil Problem

Hello folks, I'm a newbie to the board and a semi-newbie in the world of pond management. I have a 6 acre irregularly shaped pond. The north end (shallow end) is 3'-6', the south end (deeper) is 6' to 15' deep. I have owned the property for 2 years now.
My problem is a very nasty Eurasian Watermilfoil infestation that went from around 25% of the pond last year to virtually 100% this year. There is also a population of Coontail, but not nearly as bad as the milfoil. From lurking for a while and reading incessantly, I surmise that it originated from a bass boat a friend of mine brought in to make me a depth profile of the pond shortly after we bought the property. It seems that that was a major mistake on my part. We treated with granular CuSO4 and Reward last year and this year also. NOT EFFECTIVE. It knocked it down somewhat and it returned with a vengeance both years. The water in the pond is crystal clear and we have very good circulation in this pond with prevailing winds. Algae gets to be a minor problem in late July and August when the water warms > 75-80 degrees but is easily alleviated with granular copper sulfate. The milfoil has reached monster proportions late this summer and there is a mat over around 25% of the pond and the growth makes it virtually impossible to navigate the pond in a boat with a trolling motor.
I would like to permanantly eradicate the milfoil. Sonar sounds like a good choice, but I have 2 exit tiles feeding into a creek that runs south of the pond. I was wondering about using 2,4-D. My reading on other sites tells me that it is pretty much specific for milfoil. The pond is 15 years old and stocked with largemouth bass, hybrid bluegills, black crappie, yellow bullheads, channel catfish, and a variety of bluegill that resembles the georgia giant.
Any help or suggestions for the eradication will be greatly appreciated, as well as the application rate or total amount per acre needed. The average depth of the pond is 6 feet as determined by a Purdue Extension Agent.
Thanks in advance for your knowledge!!!