Gerald, 

Allen is right, The U code does =E2=80=8Bnot apply since the material has been through a process and is no longer reagent grade, it=E2=80™s considered a spent. Allen also raises a good point about oxidizing properties of the solution. You can do a quick and dirty test with potassium iodide starch paper. If it has the D001 characteristic, then it's easy, profile the waste with you disposal facility with a D001&D002 and ship it in bulk.

If it doesn't "OX" and you are seriously considering perform elementary neutralization and releasing this to the sanitary drains, you must consider the ultimate environmental fate (Ol=E2=80™ Man River in your case and beyond). I'd start with what (SWBNO) & (LADEQ) stipulate on [fluoride and/or nitrate/nitrite] effluents. Consider the need for a lab analytical to document the composition and properties of the waste stream unless you have well documented generator knowledge. If it is still looking benign and you think the municipality can handle it, maybe send a letter on letterhead to your local municipal water office a letter requesting interpretation and permission to release this material to their system and see if you get a response. If after all that, it is determined suitable for release to the public sewer, I would be at a comfortable level to put in writing that this stream is suitable to release to the lab drains. If this is long term, it might be worth doing the work.

On the other hand, some are from the school of thought that lab wastes should never be released to the environment. Also consider the effort to perform neutralization (purchase and store neutralizer, man hours to neutralize, risk) If using calcium carbonate (marble chips) there can be a considerable standing time for the pH to change. SO, If the material does not OX and this is truly a heavy, regular waste stream that does not change, it can be cost effective and a sound practice to profile the material with your vendor/end disposal facility and bulk into DOT rated shippable 5, 16, 30, 55 gallon drums. We need to be good stewards of the environment. In the research lab, waste disposal fees are the cost of doing business.

However you decide to manage this material, I wish you luck!

Be Well,

James Saccardo, CHMM