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environmental safety question

updated sun 30 jun 96


Tamsin A. Whitehead on thu 27 jun 96

I have fairly recently started a little studio in my house (basement, no
windows, no views, but plenty of incentive to concentrate!) and have been
wondering about where the waste goes and what it does there! I am
installing a special trap in my sink, but I know that really just stops
blockage. We have our own septic system, tank and leachfield etc, and I
am wondering about how glaze waste (heavy metals etc) might affect the
pump mechanisms etc. and what happens to it in the leachfield and after?
Does anybody know?

Also, I have heard that some people collect all their glaze waste and
fire it into pots as a means of disposal. Is there a recommendation as to
type of clay, firing temp, amount of glaze in any one pot? Generally I am
firing stoneware to ^6 with corresponding glazes but occasionally to ^10.
Would it be a good idea to keep glaze wastes seperate according to ^
temp, or doesn't it matter? It seems to me to be a neat way of dealing
with the problem and I would be really grateful for any info that anyone
has to share.

Bill Aycock on sat 29 jun 96

At 11:12 PM 6/27/96 EDT, Tamsin A. Whitehead wrote: *** in parts ***
>----------------------------Original message----------------------------
.. We have our own septic system, tank and leachfield etc, and I
>am wondering about how glaze waste (heavy metals etc) might affect the
>pump mechanisms etc. and what happens to it in the leachfield and after?
>Does anybody know?

Tamsin- you really have two problems here, one having to do with stopping
the clay and glaze materials before they go into the system, and; " what to
do with the stuff you collect"

First- it is very important to keep the glaze materials, and ESPECIALLY the
clay from the septic system. A septic tank is a biological digestive
system and anything you put into it that does not process to liquid state to
go to the field just fills the tank. In the natural, normal use, there is a
certain amount of that anyway, which is why the tanks have to be pumped out
every few years. There is no point in filling it early and having the
scrap glaze materials be pumped out at a greater expense than taking care of
it a little bit at a time, your self.

Second- re clay- Clay is a natural sealer and can stop up a leach field if
it gets that far in the very slow flow in the system. In other words, if it
gets only as far as the tank, and settles, it needs pumping; if it get
past the tank, it tends to seal the natural path the water normally takes to
be dispersed into the soil.

I, too, have a septic system. What I use is a medium size plastic garbage
can on castors, just beside the sink. EVERY container used for glazes is
rinsed in the water in the can before going to the sink for a real
cleaning. My hands (covered with throwing slip) are rinsed in a bucket
before final cleaning. This procedure stops all but a small amount of the
scrap from getting to the drains.

One problem many people overlook is the disposal of the clay that gets into
the towels most potters use so many of. ( I use LOTS of towels) In most
modern residential systems, the water from the laundry goes to a separate
field, without a septic tank. There are two reasons for this, one of which
is almost obsolete. First, the water is not full of organic matter that
needs anerobic disgesting (it's called "grey water"); second ( not so bad
these days), the Phosphorous compounds in laundry detergents need to be kept
separate. The laundry disposal field is very susceptible to sealing by
clay, because there is no settling tank ahead of the entry to the field.
New fields cost money and they mess up your yard when they dig new trenches.

I keep my used towels in a mesh bag and periodically rinse them all out in a
5 gallon bucket, which I allow to setttle before decanting. This gets rid of
most of the clay, but it takes time. The towels rinse out easier if they
are allowed to dry before re-wetting. (Really !)

Like they say- it's your money, it's your choice. (It's also your health)

Final disposal of the residue is dependant on too many factors to cover as
easily. I have a clay lined pit that needs to be filled to put mine into,
but I have no lead or Barium compounds to worry about.

Bill- recovering from a five day trip with a bad airconditioner, happy to be
back on Persimmon Hill.

Clayton Bailey on sat 29 jun 96

>----------------------------Original message----------------------------
Concerning the disposal of glaze and clay sediments: Do not fill-up your
septic system with sediment, nor pour the waste glaze into a hole.. In the
Cal State- Hayward Art Department,the Art Department Technician, William
Roan, uses all of the toxic waste of the ceramic shop to make a useful
product. Floor sweepings and sediment from the sinks of the ceramic studios
are mixed together to make a glaze-clay body (approx 50-50 mixture) which
is pressed into plaster molds.The molded products are fired to 2000 degrees
to vitrify the material, making safe and useful art products from otherwise
toxic waste materials.