Rinsing out sodium hypochlorite tank concerns.

[ringfinger]

In a few days I will need to clean/rinse out our current 1000 gallon sodium hypochlorite tank. The plan laid out by risk management is cut the tank in half and use the bottom as a backup catch basin for 2 smaller tanks that will sit inside of it.

So far the plan is to use a transfer pump to remove the 200 gallons that currently remain in the tank and store them in another container until later. This should leave only a small amount in the bottom. Right now I'm thinking that I will dilute it with water and then transfer that to the pool, rinsing and pumping it into the pool a few times until it's clean. Even if 10 gallons of sodium hypo remain in the bottom, that would only increase FC by roughly 2 ppm.

Is there anything I'm missing? Will there be fumes when I add rinse water to the tank? Will neutralizing it as I rinse help anything as far as fumes and safety are concerned?

It's been difficult to get information online about this kind of project. The local water authority just wants the tank rinsed out thoroughly, but I don't know how knowledgeable they are on sodium hypo.

Thanks a ton for any information anyone can offer.

 

[Bama Rambler]

What strength is the hypo?

If it's 10% or less you can just pump, drain it, or wash it to the pool.

Once you ave all the actual hypo out you can then rinse it several times to get any residual out. If there isn't a big hurry in getting it cleaned out I'd rinse it a few times a day for a few days, then let it set a day and use the 25 ml FAS-DPD chlorine test to check for any FC.

 

[ringfinger]

Thanks Bama. It's 12.5% hypo. I dug into this project yesterday. Fortunately the pump we used was able to get all but a very small amount out of the tank. I then used a respirator for the initial rinse and will then continue to rinse the tank over the next couple days like you suggested.