Document ID: EPA-R03-RCRA-2010-0132-0028
Agency: epa
Document Type: Supporting & Related Material
Title: 
Posted Date: 2010-10-07T04:00Z

1.  Radiological issue – Does the currently generated sludge have a
radiological component (i.e., is this sludge a mixed waste)?  In the FR
notice for the proposed delisting of the currently generated sludge (64
FR 42320) we wrote, based on information that you submitted, that “In
June 1990, the filter cake was found to contain trace levels of special
nuclear material (i.e., uranium at typically less than 30 picocuries per
gram).  As of October 1991, this special nuclear material contamination
was eliminated from the filter cake.”

In the description of waste streams in the delisting petition, the low
level radioactive treatment system receives small quantities of
radioactive materials including uranium and radioactive materials
contained in storm water from building roofs.  Does precipitation and
microfiltration sufficiently remove the radioactive component in this
waste so that subsequent sludge formation is not a mixed waste?

2.  How is the current delisted filter cake disposed of?  The delisting
for this waste includes a condition requiring it be disposed in a
Subtitle D landfill.

3.  All Federal delistings granted are conditional exclusions which
include several conditions including a condition prescribing permissible
disposal.  For a typical delisted waste, this condition has been
disposal in a Subtitle D landfill.  What disposal options are available
for management of this material under NRC regulations?  Does NRC
regulation of the sludge continue indefinitely, or does it end if the
radiation levels drop below some limit?  We’ve been assuming that
disposal in a Subtitle D landfill is not an option.

4.  Fluoride in groundwater – Based on recent analysis of Final
Effluent Pond (FEP) groundwater monitoring samples, has the
concentration of fluoride in the groundwater changed since the sampling
events of the 2001/2002 timeframe?

5.  Fluoride in sludge – Fluoride concentration (both total and
leachate) were determined on filter cake for the January 14, 2000
delisting of the (then) currently produced sludge. Fluoride
concentrations were determined on sludge samples (not dewatered filter
cake) collected from the FEPs for the pending delisting petition.  

Do you have analytical results that show total and leachable fluoride
concentrations for dewatered FEP sludge?  Perhaps you collected some
fluoride data on filtered samples when you did the recent FEP sludge
removal project.

6.  Active life of the FEPs – Do you have a revised estimate of how
many years you expect to utilize the FEPs until they are decommissioned
and closed?