"Joseph Gwinn" wrote in message
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In article ,
"Ed Huntress" wrote:
"Joseph Gwinn" wrote in message
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In article , "." wrote:
On 7/11/2011 7:49 PM, Ed Huntress wrote:
"Joseph wrote in message
...
In ,
"Ed wrote:
[snip]
look at it this way - would you rather have healthy rivers and cloudy
drinking glasses or nice clean drinking glasses and dead rivers? I
choose the former. And, I wash by hand so there has never been an
issue
anyway.
This is a false dichotomy, and in addition fails back-of-the-envelope
reasonableness calculations.
The false dichotomy is the claim that we can have either clean rivers
or
clean glasses. Actually, there is no reason not to have both, as
discussed next.
The main use of phosphate chemicals is fertilizer: "About 95% of the
phosphate rock mined is used to produce fertilizers, animal feeds and
pesticides." [1]
This leaves 5% for everything else, including dishwasher detergents.
Modern dishwashers use a few ounces of detergent per wash, while farms
use phosphate fertilizer by the ton. The difference is thus orders of
magnitude.
So even if we stopped washing dishes altogether, nothing much would
change.
Yeah, except when it does. Cumulative phosphate use from washing clothes,
in
densly populated areas, can be a much higher percentage of the phosphate
load on rivers. I haven't seen the numbers for a while but I recall that
it
was a high percentage in the Delaware at one time. There isn't as much ag
runoff in that river as in many others.
There are a few problems here.
First, we are talking about dishwashing, not clothes washing, which
makes for a big difference in detergent use, at least a factor of ten.
Right. I'm just comparing total househeld use versus the runoff. I didn't
even know there were phosphates in dishwasher detergent until you brought it
up.
I don't know about others, but I have not been having any problems with
clothes washing detergents. The problem is with dishwashing detergents.
I don't think I would have noticed except that I had Oakite as a client
while it was happening, and their engineers brought it up in discussion. But
I noticed as soon as I tried adding some TSP, per their suggestion, to
really dirty loads of clothes.
Second, Delaware is an outlier, being a very small state with a very
large fraction of non-farming households. The Delaware River promptly
flows into the Atlantic Ocean, joining the outflow from the rest of the
Eastern Seaboard. What matters is the aggregate.
Ok. As I said, I'm involved with the Delaware Estuary Project (I wonder what
the mailman thinks when he delivers my copy of _Delaware Estuary News_ every
month? g) The river has been important to me for most of my life. So I'm
concerned specifically with the issues involved there.
We've had some discussion here about the fact that phosphates are difficult
to remove in sewerage treatment, and I just followed up last night by
reading up on it, trying to refresh my slight memory of it and to learn
something. We apparently have poor sequestration of phosphates in much of
the Delaware watershed. And, as you say, it's an outlier, with very high
population in the watershed and relatively less agriculture. The lower
Hudson is in a similar situation.
Third, animals (including humans) excrete phosphorus in their excrement:
"However, where used, detergent phosphates contribute only 5 - 20% of
phosphates in sewage (most phosphate in sewage comes from human bodily
functions and food wastes), and sewage itself is only a minority source
of phosphate to the environment compared to agriculture." [2]
Overall, I don't doubt that.
To summarize, 95% of phosphate goes into agriculture, and thus to
phosphate runoff. Of the remaining 5%, detergents are a fraction of
that 5%. Of detergents, something like 90% was for clothes washing, and
maybe 10% was for dishwashing. This was before the effort to remove
phosphates from detergents was undertaken, but even then only (5%)(10%)=
0.5% went into dishwashing detergents. After the removal effort, this
has been reduced to a fraction of 0.5%.
The amelioration efforts in the Delaware watershed have been studied, and
isolated to the degree that was possible. As I stated earlier, eliminating
phosphates in clothes-washing detergent had a (claimed) measurable effect on
oxygen levels in the lower Delaware. Consumer education programs about lawn
and garden fertilizing and runoff did not. Commercial agriculture efforts
and regulations also had a measurable effect.
So, the focus would have to be on agriculture. The problem is that crop
plants cannot be convinced that they don't need phosphorus to grow.
Not having any background in this, I can't address the individual issues.
But my understanding is that fertilizing timing is an issue; release rates
are an issue; plowing practice is an issue; quantities are an issue. All are
being addressed by one institution or another.
It's better than sitting around and sucking our thumbs, but I don't know the
numbers.
--
Ed Huntress
Joe Gwinn
As I said above, The basic problem [with the EPA] is that they don't
know when to just stop, to just declare victory and move on.
Joe Gwinn
http://en.wikipedia.org/wiki/False_dilemma
[1] "World Phosphate Production: Overview and Prospects", L. CISSE and
T. MRABET, World Phosphate Institute, 3, Rue Abdelkader Al Mazini,
20001
Casablanca, Morocco, in Phosphorus Research Bulletin Vol. 15 (2004) p.
21-25, www.imphos.org/download/jena/cisse_prb-15.pdf.
[2] "Questions and Answers on the use of phosphate in detergents", 10
February 2011, CEEP (Centre Européen d¹Etudes sur les Polyphosphates),
http://www.ceep-phosphates.org/Files...%20detergent%2
0proposal%2010%20February%202011.pdf.