Smelly water coming into sump pit - NEED Help!

Old 04-25-18, 05:26 PM
Thread Starter
Join Date: Apr 2018
Location: United States
Posts: 1
Received 0 Votes on 0 Posts
Smelly water coming into sump pit - NEED Help!


Hopefully, someone has experienced something similar to what we are going through, because three plumbers, one home inspection company, and a sewer specialist company could not pinpoint the problem.

We recently bought a home that has a basement with a sump pit. The sump pit has a terrible smell that has taken over the entire house. We were told that we needed a new sump pump and that would drain out the stagnant water in the pit, that was inaccurate. After multiple video scopes of all lines, we found that the perimeter drains that feed into the sump pit are completely full of water. The water coming from these lines smells terrible (rotten eggs), so it seems this water is stagnant and has been in there for who knows how long. It does look like there was heaving in the basement at some point and this may have caused the sump pit to lift. Based on the video scope, it looks like the drains that feed into the pit were also lifted, causing the water to get stuck in the lines and preventing them from draining properly. The main issue is the smell. The water coming into the pit smells awful and when the HVAC is turned on it picks up the smell and spreads it through the entire house.

A few questions I have are, has anyone dealt with something similar before? Is having a lot of standing (smelly) water in the perimeter drains normal? Would lowering the sump basin also lower the drain lines so water can properly flow into the pit?

One company told us that lowering the sump pit would also help to lower the drain lines and solve the issue. Another company said we need to dig up everything (entire perimeter drain lines) and replace, $10k+ worth of work. After getting the runaround for almost a month, hopefully, we can get some proper guidance.

Thank you in advance
Old 04-25-18, 06:45 PM
Join Date: Mar 2010
Location: USA
Posts: 4,508
Received 139 Votes on 128 Posts
Water stagnating in the drain pipes is not always bad. The hydrodynamics of the sump pump and perimeter drain pipes is different for each system and also is different at different times of the year. Under some conditions it is more efficient to let water stagnate.

Usually the perimeter drain pipes are nested in gravel as opposed to simply buried in dirt. If there is a bed of gravel, then adjusting the pit liner (pit basin) to be a few inches lower and the last 3 feet worth of drain pipes approaching the pit angled down a little more will let more water drain out of the pipe system.

You might be able to drill some 2 inch holes in the floor every 8 feet or so above and following the route of the drain pipes around the perimeter. Then put down chlorine based or other sanitizing or disinfecting chemicals to break up any organic matter such as biomat that formed throughout the system over the years.
Old 04-25-18, 08:46 PM
XSleeper's Avatar
Group Moderator
Join Date: Dec 2004
Location: USA
Posts: 27,362
Received 997 Votes on 908 Posts
Sounds to me like you need a sealed sump pump system, not an open one. The problem is the rotten odor from the mucky ground and ground water, so the solution is keeping that air from entering the conditioned space. Answer: sealed sump pump system.
Old 04-26-18, 05:21 AM
Group Moderator
Join Date: Mar 2003
Location: NC, USA
Posts: 25,579
Received 970 Votes on 891 Posts
I agree with the sealed sump. You probably need something like is used when creating a sump pit for a basement bathroom. The sump has a sealed and gasketed lid and provision for a vent to the outside. This completely seals off what's inside the pit from the inside of the home.
Old 04-26-18, 05:48 AM
Join Date: Nov 2012
Location: USA
Posts: 2,085
Received 166 Votes on 145 Posts
Stagnant water should usually smell "swampy" not "rotten egg"...

First question - is the house on a septic system or public sewer?

Well, here are some scenarios.

A) The dishwasher is diverted to the sump pump, or into an old well / cistern, which is leaking back through the perimiter drain.

B) The seller cleared away lots of shubbry and trees, and the plant roots were removed with a stump-grinder. The rotting roots and ground up stumps will be "sour" for a year or two while they decompose.

C) Seller put down raw woodchips around the house, they'll be "sour" for a year until they age.

D) The seller had a pest control company out to deal with a groundhog / ground squirrel / rats digging around the foundation, they laid bait, and there's a deceased critter underground. Will clear up in a few more months.

E) You have a well and septic system, and the well has a high sulphur content.
You're doing lots of laundry, the septic system / sandmound is full to overloaded, and the sulpher laced water is soaking back into the perimeter drains.

Best short term solution is
1) a cover over the sump pit,
2) lower the trigger settign for the sump pump to move more water out
3) a fan in the basement.window
4) check the grading around the house to make sure sump water moves out beyond the perimeter drain.

Last edited by Hal_S; 04-26-18 at 06:08 AM.

Thread Tools
Search this Thread
Ask a Question
Question Title:
Your question will be posted in: