"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 ,
"Ed Huntress" wrote:

"Joseph Gwinn" wrote in message
...
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.

Yes. A lot depends on the composition of the local water. People with
water softeners seem to have far less trouble.


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.

Is the Delaware Estuary News that heavy?

g It's not the weight. It's the weirdness. Aside from people I've met at
meetings of the group, I've known only one other person who subscribes.

The mailman probably thinks I'm a card-carrying Green Peacer. Actually, I'm
just a fisherman and a boater who's watched the effects of pollution on my
favorite waters for about 58 years, up close and personal. It's gotten a LOT
better.



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.

I thought you lived in New Jersey.

I do. I'm between the middle Delaware and the lower Hudson. The mouth of the
Hudson estuary is about fifteen miles from where I'm sitting right now.



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.

Are these measurable effects also significant? We can measure such
things to parts per billion, orders of magnitude below anything worth
worrying about.

I don't know. I'm sure you could find out. As I said, I was remarking about
a couple of reports published years ago about eutrification of the lower
Delaware. They were measuring oxygen levels.



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.

Really? Given the considerable effort and cost yielding trivial impact,
perhaps the same effort would yield far greater return elsewhere.

Maybe. If you're interested enough, there's plenty of information around.
I'm mostly interested in the marine life in the local estuaries, and the
rivers above them. I don't follow the issues closely. I've only read a
couple of reports about local efforts to keep phosphates out of the
Delaware.


This is the proof that the EPA doesn't know when to stop.

I don't think that this one example is "proof" of anything about the EPA.
The proof I'm most interested in is how effective they are, and there's
plenty of that. You can find people, I'm sure, who can discuss their
efficiency. You might even find one who knows enough to talk about it, but
don't count on that happening on Usenet. d8-)

My general take on the EPA is that they have a very big job, with
pathetically meager resources to do it. So they paint a lot of things with a
broad brush, out of necessity, and they're constrained in every direction by
our principles of equal treatment and so on. I don't envy their position. I
do admire many of their results.

--
Ed Huntress



Joe Gwinn