I'm mid-DIY on this one but putting it out there in case it's helpful for anyone.
I'm not specifically looking for advice, but if you have personal experience with iron ochre and are willing to share, I would welcome it.
I live in a swamp. I have basement foundation drains that we got replaced when we moved in a few years ago. We mostly wanted battery backups on the pumps, but we ended up getting a new drainage system too. This got us super acquainted with our drains.
There is a type of microbe living in the soil that consumes iron and leaves behind something called iron ochre. We use chemical treatment to help keep the drains running (cleating agent, keeps the iron soluble) but are at the point where the pumps need to be cleaned.
We have a water treatment system (iron/sulphur filter) that backwashes every few days. It is overwhelming the pumps and causes the sump pit alarm to go off (at 4:45 am).
Our pumps are not easy to disconnect from the discharge hose, so I took a first go at cleaning out the pit and making sure the material isn't building up at the pump inlet. There was also a lot of ground water that day, so I wouldn't want to have pulled the pumps in the first place. I am sharing the photos of what it looks like inside a sump pit to help demystify the system.
link to video of the rate of water into the pit 😬
This is a photo of the sump pit:
There are three pumps. On the left you see the first pump (above the green hose), to the right of that you see the second pump, and then the red thing is the ~~emergency pump~~ (edit: float for the emergency pump which you can't see from this angle) which is on a battery back up. On the far right you see the drain and build up of iron ochre, as well as the white hose which is the backwash drain.
The first pump get stuck running dry and I think it has to do with how it is positioned in the pit. The pumps turn on and off via a hardwired float. When the water level rises, the float well...floats and pump turns on. When the water level drops, the float will also move down and eventually reach the off position. When there are more than one pump in a pit, the floats are set at different positions so that a second pump can kick in when the first is unable to keep up.
The float must be getting stuck in the up position. It doesn't do that when the cover is open, but when it is closed it shifts a little bit. It is also not properly sealed, and shoots water out of the sleeve connection to the discharge hose you can see on the left. The strap is facing away ands can't be tightened without taking the pump out.
How I attempted to clean the pit and hopefully flush some of the buildup off the pump internals:
- I forced the pumps to run as long as they could by holding up a float (with a plastic coat hanger, lol - don't put your hands in the pit!)
- After unplugging the pumps, I used a shop vac to clean up the iron ochre buildup on the side of the pit (at the drain) and anything I could get on the bottom, below the pump stands. You can see the contents of the shop vac here
- I put some cleating agent (Iron out) into the pit and left the pumps unplugged to allow the pit to fill with water, keeping as much retention time as possible with the chemical rich water. Once the pit got very full I then plugged in the pumps and let pumps discharge the water. I repeated a few times.
- I flushed the pit using the green hose in the above image. It is connected to my water heater and is only accessible tap in the basement (I have taps for the washing machine but no other plumbing). I opened it to the put and let the pumps keep up.
- After I was satisfied that the pit had been sufficiently flushed, I poured a little bit of bleach into the pit and repeated the process of soaking the pumps. Please never mix bleach with other household chemicals. Bleach is not compatible with the active ingredients in Iron out. The use of bleach in the first place was somewhat questionable. I was trying to kill any iron bacteria in the pit, but I likely didn't use enough to manage that. It's not something I will be doing again.
I think the clean out helped a bit - the pumps seemed to be running quite well, but I have no way to quantify it. Unfortunately, it didn't help enough, and we are still be awoken by the alarms. The next step is to get brave and pull the pumps.
One thing I want to add to this system is something to measure and record the amps draw on the pumps. This would let me know how often they are running and help track issues with their performance.
Once I figure out how to disconnect the pumps and am able to take them out of the pit to clean, I will be sure to take photos of the process to share.