If you need to drain the pool where can you put the water? If an oil man drops salt water on the ground there will be hell to pay.
It's not that high of a concentration of salt. I lived in an HOA who enforced teh city policy of no run-off in the storm drains. I drained the completely once when I lived there and I built an adapter to put on the sanitary sewer (legal in my city) to drain the pool. Back washes I dumped out to the gravel on the side of the house.
http://www.csgnetwork.com/poolsalinitycalc.html
The average ocean and sea water salinity is 35PPT, also known as 3.5%
The Red Sea is the saltiest at 4.25%
The Baltic Sea is the least salty at .7%
The Great Salt Lake in Utah varies in locations from 11 to 33%
The Dead Sea (really a lake) varies from 26 to 35%
The Salton Sea in southern California is 4.5% on average
Fresh water is less than 1PPT
Brackish water is 1 to 25PPT
Hypersaline water is greater than 40PPT
Human tears are 9PPT
Current saline swimming pool systems are 2800 to 4000PPM
Older saline swimming pools and therapeutic systems are 3500 to 6500PPM