I also don't know. I asked some people in field (awaiting responses). I see this quote on page 17 of the meeting notes:

"The dose estimate assumes a uniform radioactive contamination concentration in these waters equal to 4.44E-2 uCi/ml"

I'm curious what "assumes" means, has someone measured the tritium levels, or is it actually a blind assumption.

Edit: Thanks for posting some content with details, the original article seems biased, but I am curious about the topic from better sources. Also I'm on a phone and having a difficult time typing properly today.