Faced with a problem here at work

[John Wright]

Part of my duties here at work involve dealing with storm water compliance, and I've successfully managed to get our storm water discharge headed in the right direction and is showing drastic improvements over previous years...with the exception of our aluminum numbers. This is headed upward and I can't figure it out.

Does anyone here have any experience in treating storm water and removing aluminum?

[John Wright]

I've been trying to accomplish this with low buck solutions that don't require alot of maintenance....tons of silt from storm water run-on via the state highway is my biggest obstacle so far regarding maintenance.

[TonyHuntimer]

Sorry. Nothing from me on this topic.

Tony Huntimer
RaceHome.com

[John Wright]

Thanks Tony...figured it was worth a shot to ask, as there is a very diverse group of folks who hang out around here.

[NOT A TA]

More info? Is this a manufacturing facility? Institution? Corporate? Are there lift stations or other pumps involved? Piping age and type? Any relatively new exterior changes? Gutters, roof mounted AC units etc. Anything noticably decaying?

Have you done testing in several parts of the system during normal and high flow periods to try and pinpoint the origin of the aluminum? Tested for aluminum in the base of any sedimentation basins? Any chance of contamination from an outside source? Could be something as simple as a truck that picks up aluminum shavings from a neighboring manufacting operation having shavings blow off on the road by where you are, then getting into your system during high flow runoff periods.

[John Wright]

More info? Is this a manufacturing facility?

Sorry, I left all of that info out, didn't I.

I'm the QC/Safety Mgr. for a medium sized structural steel fabricator(med to high-rise buildings). We have two creeks on two side of our plant and we are located in the bottom between these creeks, so everything runs downhill to us. All of our operations(fabricating/welding/coating) are enclosed within the building and vents have filters to keep it all inside. The only reason we fall under a storm water permit requirement is that we store steel, raw and fabricated on flatbed trailers outside. This constitutes "industrial activity" requiring our SW permit. Our permit states that we will monitor our stormwater at all of the point source discharges. I have records dating way back and when we had our first permit, the numbers were horrible, but we have taken huge strides in reducing those numbers to respectable levels...except for aluminum. There is not an ounce of aluminum in any of our operations, just tons and tons of structural steel. The benchmark for aluminum is .75 ug/l and we struggle at meeting that. I have swimming pool filter sand in bags to use as filters for the stormwater run-off. This has shown to really help with everything except the aluminum.

I took some run-on samples, (but not enough to collect enough historical data) to show that we are actually treating the water as it crosses our property. It leaves us better than when it was when it came from off the highway.....LOL

[John Wright]

I guess what I would love to have an answer for is....how do you filter the aluminum out? Is there a chemical that I can add to my filter media to get the aluminum to drop out of suspension? What makes the aluminum so hard to get rid of?

[NOT A TA]

First I'll ask if the testing indicates Alum or Aluminum since Aluminum bisulfides (Alum) used in processing is tested for and may be what the test results are showing.

If it is aluminum. You can drop the aluminum by lowering the PH with an acid and raise up the Ph after the drop with a caustic. How big are the aluminum particles? Have you been using any chemicals to treat the water? Are there any sections of aluminum pipe that have chemicaly treated water moving through them? If treated water with low PH is run through aluminum pipes it may be causing the problem.

My initial questions were aimed at discovering the possible sources of the aluminum. Long term, it would probably be more cost effective to snub the source than continually treat for something that might be easy to eliminate at the source.

[69496]

I would contact a water treatment company and ask there advice. Out in the west we have companies like Aqua Serve and others. They should be able to give you information on what you can do to remove it. If you can wait a couple weeks I will ask our Service rep from the company we use and see if he has any suggestions.

[Andrew McBride]

contact your state DEQ. They are their to provide the information you need to make your facility compliant. http://www.deq.state.va.us/

I am a safety consultant and somewhat familiar with this stuff, but your deq should provide you the best information.

[Takid455]

I did a lab experiment in college attempting to reduce particular metals in the water. We did a few test, each have pluses and minuses.

anyhow

I would take samples at random locations on the property to locate the source. Quite possible your gutters, A/C units or building siding are slowly corroding. also test the rain water and find the AL content. compare that to your POD. A few other options are electrolysis to get the AL to ionize to an electrode and remove it from the water. Another would be to use a chemical/ filtration device that does similar to the above and them filters it out. I would first test the rain water and them various points on the property and try to get it at the soruce. that would be the most economical in the long run.

[John Wright]

We have an Enviromental consultant that we use to help us, but as of right now they are stumped too. As someone stated above, they are requesting that we sample the rain directly into the jar and see what the levels of Aluminum are in that. As for the size of the particles? Hmmm, they simply state in the lab reports "total recoverable aluminum" and it is shown in units of micrograms per liter(ug/l). The benchmark is .75ug/l. The storm water samples look perfectly clear, you can't see anything with the naked eye.

Aluminum can be naturally occuring in the soil so this may be a tough item to deal with.