Now that we have some time to digest what we found, I can share.
We took 2 sediment samples from one point off of Todd's Point and one in Stamford harbor.
Both reasonably deep water (30 feet)
They were black and heavy, they did not smell of Hydrogen Sulfide.
The initial test I forgot to take a pH, we will do that again.
Adding acid released a lot of H2s and CO2.
When I did the actual test one came back with 2 mg/L (they were suspended in Sound water) and the other 5 mg/L
They were trapped in the carbonate material which was released during the first part of the test.
Sulfate (SO4) was 2,000 mg/L and 4,300 mg/L respectfully.
The H2S smoking Gun did not prove itself.