Teach me how to revive it!

[Ashton]

So here's the situation:

I just started a new job in Raleigh, NC this week. The building, when being constructed, needed a place to drain water when they cleaned out the HVAC system and all that because they're near a train track and will get in trouble for dumping water on their land. So they dug this pit and layered it with concrete. It collects rainwater, and all the icky-ness that goes with it. The guy who worked here before me had made it his personal project to turn it into a pond of sorts. He used to have fish in it, but when they cleaned out the HVAC system, the chemical dumped killed all but 2, the plants are still alive though. I have been given this project with no money, few tools, and literally no clue how to even begin. I've attached pictures of what I'm working with here.



Everything I've read online so far doesn't help much for my current situation. Obviously, I can't do a whole lot with it, but is there ANYTHING I can do to revive this thing?
(Note: I also learned that I will be notified ahead of time when they come to clean out the HVAC system, so I can get the fish out ahead of time. We have a small indoor pond we can keep them in if need be while I fix the mess the HVAC dump made)

 

[DutchMuch]

Neat project.
Good luck

 

[Lisak1]

Hmmm... well, that IS a project! I would first consider the aeration - it looks like you have some going, but adding more would certainly help. Next - plants. Can you add some potted water lilies, marginals, or some floating plants? Then fish would help close the circle - the ecosystem would be complete.

My only concern would be that every time they dump into your system, you'll be starting all over. Pond water matures over time and it's not ideal to have to start fresh over and over again. But it's definitely do-able if you're dedicated!

 

[sissy]

It should work look at streams and ponds they get fresh water every time it rains but they get lots of aeration from moving water so maybe an aerator with just a weighted air hose at the bottom .Air always your friend in a pond .It also helps keep mosquito's away

 

[Meyer Jordan]

Since "chemicals"? were introduced to this pond as a result of the HVAC cleaning. I would suggest a complete drain and clean. The residuals of some chemicals can last for years.

 

[Faebinder]

Second what Meyer said.

Is this an isolated system or is this pond getting water from somewhere constantly.

 

[Ashton]

I can't drain it. It has no drainage system and I'll run into the problem that inspired them to dig this pit in the beginning; dumping water onto the surrounding land will get the company in trouble. That's why I'm not sure if I can revive this or how to do so

 

[sissy]

Why would they have to drain your hvac system .The old freon can't be dumped and water from an air conditioner is just water that dumps all the time .I have a heat pump but in NJ had traditional heat and air .The water from it should be clean water and should have nothing in it bad that I know of My drain from my heat pump dumps straight into a flower bad and no harm to it

 

[Ashton]

Why would they have to drain your hvac system .The old freon can't be dumped and water from an air conditioner is just water that dumps all the time .I have a heat pump but in NJ had traditional heat and air .The water from it should be clean water and should have nothing in it bad that I know of My drain from my heat pump dumps straight into a flower bad and no harm to it

I think it's HVAC? I might have misheard/misunderstood. What I was told was that these big machines next to the hole get flushed out every once in a while, and the last time they did, all but two of the fish died. I have only managed to catch snippets of the story at a time. My manager for my department is fairly new to the location himself and only knows part of the story. I've heard the rest in passing from people I've just met who've been there longer

 

[adavisus]

find out what chemicals are being dumped. If it is something simple like clorox you know what you are up against.. When cleaned that muck could be dumped NOT in the pond

 

[moby]

Where does any overflow go to when the system is next flushed, there must be some provision for excess water as it looks pretty full to capacity at present? How often does the system get flushed into it?

 

[sissy]

Can you get a pic of the things that dump the water

 

[MitchM]

I imagine that they are flushing the HVAC condensation collection containers from accumulated condensation.
The collection containers can harbor bacteria such as legionella, so depending on what material the containers are made of and if they are using any cleansers, that's what would be winding up in that pool.
Your best friends are going to be aeration, algae and plants that can absorb whatever toxins wind up in that pool.
You might want to start out with testing the water with a basic freshwater test kit and trying various plants like duckweed, water hyacinth and water lettuce.
You'll really just need to harvest whichever plants grow the most.
That would be a starting point I would recommend anyways.

 

[moby]

There seems to be quite an amount of algae of some kind already flourishing in the tank, and water hyacinth too. I'm not clued up on what parameters water plants need to be able to grow in, but the fact that they surviving/growing, can it be very toxic? Not sure about fish obviously as they would be more susceptible. Do you ever see any animal life, insects using it etc?
When the system gets flushed, what % of water gets changed at that time do you think?It could be something simple such as the sudden change in water temp, pH, if a large volume of water is being added that has knocked the other fish out rather than a chemical change....maybe? Just a few further thoughts.

 

[IPA]

Frankly this scares the heck out of me. I worked for someone that rebuilt radiators and they were required by the EPA to treat the waste water (chemical baths used for cleaning) before releasing into the sewer system. Is this cistern used to avoiding properly treating waste water? And if it can't be dump what is happening as it already seems full when more waste water is added to it or it rains? To the OP, what are the chemicals and how harmful are these to the environment and humans?