Home built in 1990 on a sewer system. Strong odor from trap smells like sewer. Plenty of water in trap. The water drains perfectly when shower is in use. We use it every day. Had plumber check it and is has pleanty of wter in the trap. Odor comes and goes. I extracted a table spoon of water from trap and it smells like rotten eggs. Scrubbed sides and bottom of trap. Poured a ton of bleach in and let sit over night. Still smells like sewer water but now with under-tones of bleach. What would make the water constantly smell so toxic?
Thanks for any help.
Guy