The last time we had to do this I went to a drum recycler place and bought 50 gallon plastic drums for $10. each. I forget how many now but it was a large trailer load. Then we stored the brine, re-installed it, and then returned the drums for $4. each. Say it was 25 drums - so $350. for "drum rental fee". <g>
The conventional view serves to protect us from the painful job of thinking.
I have had to call our water treatment plant about this too. They said what others here have, that we could but only a couple hundred gallons a day so as not to foul their microbiological processes that break down the sewage there.
we had to drain two 250hp boilers @north Attleboro,state of mass considers straight boiler water as a pollutant thanks to barney frank,so glycol is also considered toxic and must be documented,,,,,,good luck,,,the plastic barrel deal works good.