Basement sump pump smell

[MattN03]

I get a mildew type odor in my basement from a sump pump hole. There is nothing that empties into it, but it is tied into our septic line in case the hole was to fill. The hole has a dirt/rock floor, so it's not concrete. After using the shop-vac to clean out all the water from the hole, I noticed water back in the hole after a large rain. I'm thinking water is coming up from the ground and sitting in this hole causing a mildew type smell. Could I put plastic down & then a 1"-2" of concrete in the bottom of the hole to prevent water from "leaching" back into the hole?

Has anyone else had a similar issue? The house is about 30 years old and we've owned it for around 6 months. The smell has always been there-sometimes worse then others. I have attached a couple pics of what the sump pump hole & waste lines look like. The washer dumps into this waste line & then it runs into a main discharge that runs to the septic system (just the other side of the hot water heater).

[cacher_chick]

Sounds like you have a two part problem.
If there were a lot of rain and the ground was saturated the pit might work like a regular sump pit to keep water from coming up though the floor. This would be a good thing. But- you can't pump this volume of clear water to the septic system. I think you need to live there longer to really see how much ground water is coming in when things are seriously wet out. You might need that sump pump.

If that is the case, your laundry should run to a separate basin that is hooked to your septic system. You should also consider that lint from a washing machine will greatly shorten the life of a sump pump. Grey water should be pumped with a pump that is approved for solids.

Meanwhile you might consider using some of the natural enzyme products that are used for septic maintenance. A small dose in the pit may take care of your smell. In a place with city sewer, bleach is king.

[MattN03]

Sounds like you have a two part problem.
If there were a lot of rain and the ground was saturated the pit might work like a regular sump pit to keep water from coming up though the floor. This would be a good thing. But- you can't pump this volume of clear water to the septic system. I think you need to live there longer to really see how much ground water is coming in when things are seriously wet out. You might need that sump pump.

If that is the case, your laundry should run to a separate basin that is hooked to your septic system. You should also consider that lint from a washing machine will greatly shorten the life of a sump pump. Grey water should be pumped with a pump that is approved for solids.

Meanwhile you might consider using some of the natural enzyme products that are used for septic maintenance. A small dose in the pit may take care of your smell. In a place with city sewer, bleach is king.

The washer waste water doesn't get pumped out via the sump pump-it drains out directly through the waste water line shown in the first pic. We had the enzyme product a couple times a month by flushing it down a toilet. You're suggesting putting a small amount of that same stuff into the sump pump pit to ease the smell? I have added bleach to the pit, and that helped a lot (the smell is pretty much gone actually).

[vitaminj]

You may not be able to get rid of the smell, but sealing the sump cover might help keep the smell in the pit. I've seen some radon sumps that have a peace of plexiglass caulked to the floor to seal the pit. Just my .02.

[MattN03]

Can I add a vent to the sump pump pit and run it into the main waste stack for ventalation? The main waste stack should be vented to the roof-correct?