Selling Sewer Disposal

[Sue Dupre <DUPRE%PUCC.bitnet@vmd.cso.uiuc.edu>]

We are gritting our teeth, biting the bullet and preparing to present a plan to
allow sewer disposal as the primary means of getting rid of our radioactive
liquids.  Until now, sewer disposal was prohibited although our Radiation Safe-
ty Guide had a clause which recognized that some release of radioisotopes to
the sewer was inevitable (due to rinsing of contaminated glassware, etc.).

For our decay-in-storage operation, which is about to become fully operational,
we plan to store liquds until the concentration in the bottle meets the NRC's
sewer release limits and then dispose to the sewer.  We also plan to permit the
disposal of H-3 and C-14 to the sewer, using certain designated sinks and re-
quiring the notification of my office prior to disposal.  Additionally, we want
to allow researchers to dispose of certain low concentration liquids directly
to the sewer without going through decay-in-storage (e.g., sequencing buffer
solutions).

We need to sell our proposal to our Facilities Dept, to the Radiation Safety
Committee, to the University's higher level Committee on Occupational Health &
Safety and finally to the local sewer authority (which has made noises in the
past about prohibiting radioactive material release entirely).  Do any of you
have advice for me based on your own experience about what sort of arguments
and analyses have been most successful in convincing others that sewer disposal
should be allowed?  For instance, someone told me that they had to prove to
their sewer authority that releases would not exceed the EPA drinking water
standard.  Have any of you tried to get sewer disposal approved but failed?

I'm doing various worst case analyses:  e.g., what if all H-3 ordered last year
went into the sewer in one day in the building with the lowest water usage, etc
Any other types of analyses that have worked for you?

If it's more convenient or privacy is an issue, please respond directly to me
via e-mail or call me at (609)258-6252.  As always, your help and comments are
greatly appreciated.

Sue Dupre/Health Physicist/Princeton University