Sludge Watch ==> Charottetown 'sterilizes' its sewage sludge - want some?

[Maureen Reilly]

sludgewatch admin:

Once again we see a reporter who understands very little of what he was told 
on the sewer tour.
This story states that the Charlottetown sewer waste will be heated and 
'cooked' in such a way that bad bacteria die and good bacteria remain.

Ummm...say what?

If you kill all the pathgenic bacteria, you have killed all the 
non-pathogenic bacteria, too.
And leaving the material temporarily 'pasturized' means that just like your 
pasturized milk, it is free to regrow pathogenic bacteria later, since all 
the nutrient is still sitting there.

Interesting that the resulting material is classed as meeting the USA 
criteria for Class A sludge. This is Canada...Canada has a different 
regulatory framework.   This Canadian sewage stuff doesn't claim to meet the 
Canadian Federal Fertilizer Act which is the Canadian standard for 
fertilizer sold for agricultural or home use.

The Canadian criteria is much much more stringent than the US Class A 
standard, but it equally lax in its inspection and enforcement standards.  A 
few years ago a random test of sewage sludge based 'fertilizers' in Canada 
found 23% non compliance with the bacterial standards (BOTH fecal coliform 
AND salmonella criteria must be met at all times in the material .... at the 
plant, at the truck, in storage, as applied...etc).

If you can imagine taking the chemicals from your garage and under the sink, 
mixing it with the poo from the critical care unit down the road,  and 
baking the mixture into crumbled cookies....then you can imagine how happy 
you would be to plunge your hand into the mixture and use it in the veggie 
garden out back.


And here's the big thing...Prince Edward Island (PEI) is intensely planted 
to potatoes.  Private agreements between growers and processors state that 
sewage sludge is not to be used on protatoes.   Even the local island paper 
cardboard sludge compost is not to be used on potato crops.


Where is this crumbly crap supposed to go?  You want it on your lettuce and 
carrots?

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Monday, October 23, 2006

Sterilizing sewer sludge

Expensive expansion to Charlottetown waste water treatment plant nearly 
complete.

By Nigel Armstrong
The Guardian - Charlottetown, Prince Edward Island, Canada

Charlottetown is about to lead Canada in a process of sterilizing and drying 
sewer sludge.

“The process we are putting place for sludge management here is the first of 
its kind in Canada,” said Craig Walker, utility manager with the 
Charlottetown Water and Sewer Department. “It’s a pasteurization of the 
sludge material. It will be what is called an EPA class-A bio-solid. It will 
be a dried organic matter that you can shove your hand into and go spread it 
on your garden at home.”

It is the last step in a $22.5 -million upgrade to the Charlottetown waste 
water treatment plant scheduled to begin startup in a few weeks and be fully 
operational by January. Only two other places in the U.S. use such a system.

The process is an import from Denmark. Gas from early stages in the 
treatment process is gathered and burned. The heat pasteurizes the sludge 
but allows good bacteria to survive. The liquid then goes to first one, then 
a second digester which is already on the site as part of the original 1974 
treatment plant.

In the final step, the sludge is spun in centrifuges and the resulting 
powdery material stored.

“There is opportunities in the future with that material,” said Walker. “It 
could be pelletized. We are looking at some of those other opportunities.”

For agriculture, it would compete well with chemical soil enhancers because

the sludge breaks down at a slower pace and is not as soluble and does not 
get into the water table as easily, said Walker.

“There is a bit of a public relations component that will need to happen, 
and maybe even some marketing but that is further down the road. We want to 
be sure everything is working and want to be able to characterize (the 
complete chemical makeup) of this material.”

One area of uncertainty is smell. The site will become a disposal centre for 
commercial septic tank cleaning companies and Walker said it is not known to 
what degree if any smell will increase.

“We have made provisions to add odour controls if needed,” he said

While sludge treatment is leading edge, the waste water going back into 
Charlottetown Harbour is still not completely clean.

“It is probably a couple of steps away from what would be considered 
ultimate treatment but when you look at (the top) systems there is other 
reasons for them needing to do that . . . such as releasing the water back 
into a lake,” said Walker.

A higher level of water treatment would require huge investments of land and 
money that is not required for discharge into a tidal river, he said.

The new treatment plant will eliminate chlorine treatment of waste water and 
instead use ultraviolet light.

“That is a huge improvement,” said Philip Brown, chair of the water and 
sewer utility.

“$22 million well spent.”

http://www.theguardian.pe.ca/index.cfm?sid=4373&sc=2