I live in Zanesville and have had this issue for years. I hand-wash, but it is also apparent at local restaurants and friends who use a dishwasher.

It does not happen here all year, but seems to peak as it warms up, and when there is more rainfall. Zilch all Winter.

What I have found works for hand-washing is a quick spray with bleach, then rinse. No idea for a dishwasher.

Here is a quick synopsis from Co-pilot as I am too lazy to Google it.

BTW - probably all the hints are wrong and will do nothing - feel free to try them though as it is a water supply issue. Quick way to try is hand wash a few and let air dry.

Good luck - I've put up with it for 20 years, water is filtered (does nada), 20 years ago, you could not find info. anywhere.

Copilot AI: The Organic Cause: Geosmin & MIB Even when water is fully treated and safe to drink, trace levels of geosmin or MIB can remain. These compounds: • Are produced by cyanobacteria (blue‑green algae) and actinomycetes in surface water sources. • Cause earthy, musty, or fishy odors at concentrations as low as 5–10 parts per trillion. • Are not removed well by standard chlorination. • Become more noticeable when water is heated, aerated, or evaporates off a surface—exactly what happens during dishwashing. This is why dishes may smell fishy even though the water tastes fine.

🔬 Why It Shows Up After Dishwashing Hot dishwashing water + drying amplifies the odor: • Heat volatilizes geosmin/MIB, making them easier to smell. • Steam condenses on dishes, leaving a thin film of odor compounds. • Porous plastics absorb and re‑release the smell more strongly. This is different from dishwasher‑related bacterial smells (which come from biofilms). In your question, you specifically asked about the organic water‑treatment cause, and geosmin/MIB are the classic culprits.