If this is the aquifer Wendover and West Wendover uses as a source for drinking water, this is an argument we're not likely to win.
Harold's idea of bringing salt in by train from Salt Lake is starting to look . . . viable.
Another potential is to encourage the state of Utah to cycle some of the very saline water in the great salt lake (120 miles to the east of Bonneville) carried in tanker cars to be deposited on Bonneville salt flats. Some of the costs could be borne by Intrepid as it would assist in their "potash recovery". The state of Utah most assuredly wants to keep the salt flats salty! This type of cycling would enhance halide production on the flats as it would help momma nature speed up the natural deposition of salt on the surface of the flats. Note where the railroad goes making the process fairly direct. There are probably even some tax advantages in there for Intrepid as they could write off some of the efforts as "public interest" items.
Now would be a good time to try this approach, in that due to lower oil prices, there are currently a lot of tanker cars sitting idle, and the cost of transport would be low. Additionally, it could be done off season to Intrepid's operation, run 24/7, and be adjustable to seasonal conditions. A 200 car train running 4 trips a day, 25,000 gallons per car, puts 20 million gallons of salt water on the flats per day without risking the current fresh water resource.
The downside would be the EIS hurdle necessary to get started.