Sewage-like smell in kitchen that comes and goes
I am hoping that you might be able to help us with an issue we are having in our kitchen. (It is driving us a bit nuts!) :-) We moved into a new construction home almost two years ago, but the house is on the original basement foundation. The basic gist is that we have a sewage-like small in our kitchen that comes and goes. Sometimes it smells as if it is coming from our main sink, sometimes from our prep sink and sometimes from an in-between spot. The dishwasher itself smells fine, and we have checked the filter in there on a few occasions. When we first called our plumber, he suggested dumping some bleach down each sink drain. We tried doing that a few weeks ago, but the smell still seemed to come and go. At first we thought it was worse when we ran our dishwasher, but more recently it seems to happen randomly. It might be worse on hot days, but we aren't sure. My husband checked for mice, etc. in the basement and underneath the sinks, but he didn't see any sign (and we have never had rodents in the past....) In addition, we have a second bad smell that is coming from our center island (where the prep sink is located.) That spot has a musty odor that is like our basement smell, but my husband thinks this is separate from the sewage-like odor.
A bit of background...Since the house is super tight/energy efficient, we had some early issues with mold in the unfinished concrete basement. We had to toss all of the wood/organic items down there and buy a super strength dehumidifier plus clean the space. We then had some issues with a main sewage line back-up into our basement, but we had that snaked in early September (and it has been fine ever since.) Since the house is so super tight, we decided to put in two ERV systems (heat recovery ventilators) to bring in fresh air. Those were installed in early October, and it is possible that the smell coincides with when those were installed. We had the ERV guys come back to take a look, but they said that everything was sealed up tight. (We do have a vent that comes out right underneath our main kitchen sink.)
Today we called back our plumber, and he told me to try three things: put citrus in both garbage disposals, wipe out both garbage disposals and run Pine Sol (diluted in warm water) through our dishwasher. I will try these things, although I would rather use vinegar than Pine Sol in the dishwasher. (Would this be similar?)
We welcome any input from the wonderful GardenWeb community. We are feeling uncertain about who can help with this smell, and we don't want it to cause any toxic issues for our kids.
Thanks so much,