RE: Water Irradiation?

["Tony Harrison" <Tony.Harrison@state.co.us>]

Doses for sterilization of food, medical products etc. usually range

from 10 - 50 kGy.  To kill Bacillus sp. spores requires 18 - 25 kGy.  So

a water treatment plant would essentially have to add a medical products

type irradiator - a fiscal and regulatory nightmare for most plants.  



Another thought: would people who object to chlorination not also

object to irradiation?  





-----Original Message-----

From: Kai Kaletsch [mailto:info@eic.nu] 

Sent: Friday July 05, 2002 9:35 AM

To: Franta, Jaroslav; RadSafe

Subject: Re: Water Irradiation?





Both gamma and UV irradiators have to be on 100% of the time because,

unlike

chlorine, they do not kill downstream of your unit and any bugs that

get by

are home free. If UV irradiators need power to run, then they also

need

backup power and an operator 24/7 who knows how to run the system. 

 

How do you deliver the UV? It doesn't go through a steel pipe. If the

water

needs to be open to the atmosphere, that brings some more challenges. 

 

There are some advantages to passive systems.

 

Kai

 

----- Original Message ----- 

From: Franta, Jaroslav 

To: Kai Kaletsch ; RadSafe 

Sent: Friday, July 05, 2002 7:22 AM

Subject: RE: Water Irradiation?





That's an interesting idea, but I'm pretty sure its impractical from

the

economic point of view, since such an irradiator would have to compete

with

a variety of commercial UV sterilizers of all sizes already on the

market.

The one advantage a gamma sterilizer would have over a UV one is that

the

water would not need to be clean for the former to be effective -- UV

sterilizers typically have reduced effectiveness in turbid water, as

the

bugs are shielded by bits of dirt.

Jaro 

----- Original Message ----- 

From: Kai Kaletsch 

To: RadSafe 

Sent: Thursday, July 04, 2002 9:07 PM 

Subject: Water Irradiation? 





Not sure how aware the rest of the world is about this, but here in

Canada

there have been some issues with people getting sick or dying from bugs

in

the drinking water over the last couple of years. Water treatment has

been a

municipal issue but now the feds and provinces are getting more

involved. 



Some communities absolutely refuse to chlorinate their water. I was

wondering if anyone knew what kind of dose it would take to kill the

bugs in

the water. Could that be achieved by putting some Cs-137 or Co-60 next

to a

water pipe? Would it cause the pipe to fall apart? Any side effects to

the

water?



I would just love to see someone propose that to one of these

communities:) 

  

Kai 



Tony Harrison, MSPH

Colorado Dept. of Public Health & Environment

Laboratory and Radiation Services Division

(303)692-3046

tony.harrison@state.co.us



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