Sludge Watch ==> Pennsylvania - proposal to dry sludge and burn in cement kiln

[Maureen Reilly]

Sludgewatch Admin:

Here are four problems with burning sludge in cement kilns.

1.  There are no emissions controls for mercury on cement kilns.  Sewage 
sludge has high levels of mercury...(generally 1.7 - 3.3 ppm) and the sewage 
digestion process has turned the mercury into the more dangerous methylated 
form.  All the mercury in the sludge is emitted into the air when the sludge 
is used as fuel in the kiln.  If it was a modern gasifier there would be 
scrubbers to remove the mercury, but these are not available on kilns.

2.  Sewage sludge has high levels of phosphoric acid. Phosphoric acid can 
corrupt the quality of the cement...slowing down the set up time of the 
cement and reducing strength.

3.  Sludge as an 'alternative fuel' requires different process conditions, 
different air quantities and cement kilns cannot operate under continually 
changing fuels.  This means more 'upset' conditions and emissions.

4.  Kiln workers are not trained to work with pathogenic septic wastes, and 
the sewage sludge can pose health hazards in both storage and use.

....................................................................


Exeter says drying facility would save on sludge disposal costs
Sharon Spohn, Special to The Mercury
02/17/2007

EXETER -- Township officials are considering the construction of a regional 
biosolids drying facility that would save Exeter and other municipalities on 
sludge disposal costs.


Exeter officials and the Berks County Commissioners learned the results 
Monday of a feasibility study authorized by the county commissioners and the 
township.


Exeter’s wastewater treatment plant would be the site of the sludge drying 
facility that would cost $7.5 million and take 2½ years to construct.

The sludge drying facility would dry the sludge, which could then be sold to 
a concrete company that uses the dried biosolids as an alternative fuel.

Surveys sent to other municipalities determined that nearly 30 other 
municipalities would be interested in using the sludge drying facility. 
Those responding to the survey included Amity and New Hanover townships, 
Bally and Boyertown boroughs, Oley and the Daniel Boone Homestead. Limerick 
Township expressed interest and Pottstown was contacted also.

Exeter would make money from neighboring municipalities using the facility 
which would help pay for the debt service on the project.

Exeter Township and Berks County can both apply for grants to help fund the 
project, making it more economical.

Berks County Commissioners’ Chairwoman Judith L. Schwank said the county at 
the very least could dedicate grant funding for the project through its 
$1.75 million Growing Greener II grant.

"We see this as a project of regional importance," Schwank said after the 
meeting.

Berks County Commissioner Thomas W. Gajewski praised the township for its 
work on the proposal.

"We need to find ways to dispose of solid waste without putting it into the 
ground," Gajewski said.

Exeter currently spends $700,000 a year to dispose of sludge into the 
landfill from its wastewater treatment facility.

Without factoring in grants to help pay for the project or income from other 
municipalities using the drying facility, it would cost the township about 
3.5 cents per gallon of wastewater to cover operating expenses and debt 
service. Currently, disposal through Exeter’s hauled waste program costs 
about 4.5 cents per gallon.

The study also determined that Lehigh Cement of Allentown, one of the top 
producers of cement in the country, according to its Web site, is willing to 
sign a long-term contract to take dried biosolids at no cost. Lehigh Cement 
currently uses dried biosolids for an alternative fuel in its plant in 
Maryland. The company is in the planning and permitting process to accept 
dried biosolids at facilities in Pennsylvania and New York.

Paul A. Herb, superintendent of the township’s sewer authority, is expected 
to make recommendations regarding the sludge drying facility project to the 
board of supervisors at the Feb. 26 meeting.

http://www.pottstownmercury.com/site/news.cfm?newsid=17863455&BRD=1674&PAG=461&dept_id=18041&rfi=6