Sludge Watch ==> Hamilton unveils sewage sludge 'masterplan' tonight

[maureen.reilly at sympatico.ca]

Sludgewatch Admin:

Hamilton sewage sludge, what to do, what to do?  Hamilton is one of the 
great old factory towns of Toronto...home to some of the world's biggest 
steel mills.  And the high heavy metals in its sewage sludge are an artifact 
of its industrial base.

So is it bury, spread, sell, or burn?

Well, lets rule out sell right off the get go. Sources at Hamilton 
Wastewater have explained that the sludge is too contaminated with heavy 
metals to legally sell as fertilizer...so there would be no point in 
undertaking the expense to pelletize it.

And if it is too contaminated to sell as fertilizer...why would farmers want 
it to fertilize their fields as a waste soil ammendment? Why would the 
public want to eat crops from or milk/beef from animals grazed on those 
fields?

An additional concern is raised about pathogens in Hamilton sludge.  Since 
it is anaerobically digested and centrifuged it may be one of the sludges 
that undergoes pathogen reactivation after centrifuging.

According to recent studies undertaken by the Water Environment Research 
Foundation, many sewage plants digesters don't actually kill pathogens, they 
just put the fecal coliform in a non detectable state. Then 20 minutes after 
dewatering the sludge fecal coliform counts go throught the roof.  That is 
to say the fecal coliform levels might go from 1,000 fecal coliform per gram 
to 1,000,000,000 (one billion) per gram.



Those bacteria would then proceed to double every 20 minutes during the two 
hour truck drive out to farm fields.   This has huge public health 
implications.

see reference below (after the Hamilton story)

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Meeting tonight on city's sludge removal plans

By Eric McGuinness
The Hamilton Spectator
(Sep 19, 2006)
Rural Haldimand and Niagara residents may be as interested as Hamiltonians 
in meetings tonight and Thursday night to outline options for getting rid of 
the city's sewage sludge over the next 20 years.

That's because Hamilton pays to spread thousands of tonnes of the waste on 
farmland in both neighbouring jurisdictions, a practice widespread in North 
America despite concerns about toxic heavy metals, viruses and other 
pathogens.

Consultants and city staff who have spent a year looking at what to do with 
what they call biosolids worry urban growth in southern Ontario will result 
in sludge production outstripping the supply of available farmland. They 
also expect regulations to tighten.

As a result, they recommend the city also look at burning sludge to produce 
electricity and/or treating it to make a higher-quality fertilizer, even 
though land availability for its use would still be a concern.

Tonight's public information centre will be at the former Stoney Creek City 
Hall, 777 Highway. 8. Thursday's will be at Woodward Avenue Public School, 
575 Woodward Ave. Both run from 7 to 8:30.

Public input will be used in drafting a master plan to be presented to city 
council early next year.

Phil Sidhwa of American Water, which spreads the sludge, says the 35,600 wet 
tonnes Hamilton produced last year is enough to fill 1,000 trucks or about 
three per day.

Jim Harnum, senior director of water and wastewater, says it may make sense 
to diversify, rather than rely entirely on applying untreated biosolids to 
farmland. Treatment options include adding lime to stabilize it, as Niagara 
does, or heating it to kill potentially harmful organisms.

"Both thermal reduction (incineration) and land application have gotten a 
bad rap. There are pros and cons to both. Thermal reduction results in air 
emissions on site, but recovers energy, while trucking to rural areas uses 
energy and also creates air pollution.

"We want to look at the total, overall environmental impact, using the 
triple bottom line approach (environment, energy, economy)."

California-based Liberty Energy wants to build an east Hamilton power plant 
fuelled by wood waste and sludge. Harnum said that plant, if approved, could 
be used, but the city would also look at building its own facility if 
burning is a chosen solution.

Maureen Reilly, an environmental activist who opposes land application of 
sludge, says taxpayers should be concerned because disposal is becoming more 
difficult and expensive.

"I find cities don't make good decisions when the public isn't looking. ... 
Taxpayers should understand farmers can't take all of it or won't take all 
of it, and foreign landfills don't want to take it. The public has to get 
educated about the whole realm."

emcguinness at thespec.com

905-526-4650

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http://www.hamiltonspectator.com/NASApp/cs/ContentServer?pagename=hamilton/Layout/Article_Type1&c=Article&cid=1158617413269&call_pageid=1020420665036&col=1014656511815..............................


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Examination of Reactivation and Regrowth of Fecal Coliforms in Anaerobically 
Digested Sludge
WERF Report: Biosolids and Residuals (03-CTS-13T)

Author(s): MJ Higgins, S Murthy

In a recent study of anaerobically digested solids from seven wastewater 
treatment facilities, counts of fecal coliform bacteria increased after 
dewatering at four of the facilities tested. Immediately after 
centrifugation, fecal coliform counts increased from very low or 
nondetectable levels, often by as much as several orders of magnitude, at 
the four facilities where increases were observed. This study only looked at 
seven facilities and only facilities using anaerobic digestion and 
high-solids centrifugation for dewatering; numerous other stabilization and 
dewatering processes are also widely used.

The study identifies some potential control methods and mitigation 
strategies that utilities could use to reduce coliform levels.

The title belongs to WERF Report Series

Publication Date: October 2006 · Pages: 72 · ISBN: 1843397366 · Paperback · 
Publication Type: WERF
http://www.iwapublishing.com/template.cfm?name=isbn1843397366