Re: radioactivity in sewer sludge

["Charles Meyer" <Charles.Meyer@tdh.state.tx.us>]

> Date:          Thu, 29 Jul 1999 08:16:10 -0500 (CDT)
> Reply-to:      radsafe@romulus.ehs.uiuc.edu
> From:          scott dennerlein <sdennerlein@radsci.com>
> To:            Multiple recipients of list <radsafe@romulus.ehs.uiuc.edu>
> Subject:       radioactivity in sewer sludge

> People are correct in assuming the majority of the radioactivity input
> to Publicly Owned Treatment Works (POTW's) is from drinking
> water/irrigation, however this material is by nature soluble, i.e. it
> entered the system as water and it leaves as water. The POTW's job is to
> remove biosolids, kill pathogens, and let as much water as possible pass
> through the system. The problem is insoluble material being "screened
> out" in settling ponds and clarifiers,  reconcentrated, and removed as
> dewatered sludge. Hence, the NRC'c prohibition on insoluble,
> non-dispersible discharges. The sludge is either ashed and landfilled,
> or applied to land as fertilizer.
> 
>     The NRC's "Site Decommissioning Management Plan" (NUREG-1444) has a
> good summary of the contamination at the NE Ohio Sewer District. Levels
> of Co-60 in soil ranged up to 9,000 pCi/g. Nothing to sneeze at for
> those of us working to attain levels of 5 pCi/g at many environmental
> sites! There has been ten to fifteen incidents of contamination at
> POTW's over the last few decades, most of which were readily traced back
> to the "offending" company. This may or may not be alot depending on
> your point of view. However, all of these sites were discovered by
> "accident" setting of alarms at the landfill, or during remediation of
> nearby licensed sites. That is why a nationwide screening program is a
> good proactive approach to determine the extent of the problem.
> 
> As far as regulatory control is concerned, regards the Ohio incident,
> the contaminee? was a manufacturor of Co-60 therapy units. The
> requirements for their decommissioning fund may have been too low.
> Rather than lower discharge limits, perhaps requiring greater amounts of
> money to be set aside for decommissiong, to include cleanup of the local
> POTW, may be appropriate.
> 
> Scott Dennerlein
> Radiation Science Inc.
> sdennerlein@radsci.com
> 
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There are not that many of the types of facilities which would have 
the quantity of loose radioactive material to contaminate sewage 
sludge to the extent that it " was allowed " to occur in Ohio.  If 
these facilities are regulated properly, i.e., the regulator reviews 
discharge records and takes independent samples, this kind of 
situation should not develop. 
<><><><><><><><><><><><><><><><><>            
<>    Charles R. (Russ) Meyer                  <>
<> Email:charles.meyer@tdh.state.tx.us 
<>     Phone:(512)834-6688                       <>
<>        Fax:(512)834-6654                        <>
<><><><><><><><><><><><><><><><><>
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