On Jan 25, 10:07*am, Gz wrote:
On Jan 8, 2:37*pm, Oren wrote:




There is heavy metals in sludge and sometimes you
will find tomatoes seeds growing in it at the plant. Also marijuana.


Any seed growing in this sludge is from the organic material they use
for soil mix, not from the sewage treatment process

As for heavy metals, Class A is the only one approved for home lawn
and gardens and should contain levels less than most background
levels There is also another type of biosolids above the class A
called Exceptional Quality. This is preferable to use. Again you can
research the max allowable levels of heavy metals in each class. The
Exceptional Quality is recommended bt the many Master Gardener
Association here in the PNW, still as a safety precaution I do not
recommend it for anyone with a compromised immune system or other
health problems.

http://water.epa.gov/polwaste/wastew...lids/genqa.cfm


Having said that you need to beware that many sand/gravel places will
use lesser classes of biosludge to make their compost mix, further
mixing that with other soil to make their top greade garden mix or
they gather up the waste from a cut site that was previously sprayed
with lesser quality sludge.

I also do not recommend adding sand to desert soils. Never have seen
it to work well even with drip irrigation expect for melons. They
were a desert plant to start with.
http://www.artistic-arborist.com/june_2004.htm