In the spirit of interjecting facts into the debate:

Rutgers has some good solid data on sewage sludge and bio-solids. There
are eight fact sheets filled with generally good information in PDF
format. For heavy metals See:

http://www.rce.rutgers.edu/pubs/pdfs/fs956.pdf

This has a nice table showing heavy metal levels in various soil
amendments (rock phosphate, muncipal leaves, various manures etc.).
Rock phosphate is worse than sewage sludge in several categories. Of
course you do not use it in the same amounts but this is just to show
that things people consider innocuous are not so. This fact sheet also
has a table showing predicted soil levels after 100 years of application
of the various ammendments. Again, levels are not alarming for sewage
sludge and not really all that different from several other manures etc.

Another good summary from the scientific perspective in PDF format is:

http://www.eawag.ch/publications/eaw...rinter/en53e_s
tadelm_p.pdf

or

http://tinyurl.com/42953

They are generally balanced and put facts into perspective. For example
they state:

³In Switzerland only 12 % of the heavy metal input into the soil is
contributed by sewage sludge; 38 % originate from manures, 25 % from
atmospheric deposition, 14 % from mineral fertilizers, 6 % from
fungicides, 4 % from compost and 1 % from wood ash
[1]. Many kinds of organic pollutants, e.g. PAK (Fig. 3), get into the
soil to a larger extent by deposition and manure than by sewage sludge
[1]. The annual pollution of the agricultural soil in Switzerland by PCB
is composed by 1000 kg from deposition, 70 kg from manure, 8 kg from
sewage sludge and 3 kg from compost²


Roland