From: Oz <Oz@upthorpe.demon.co.uk>
Newsgroups: sci.agriculture
Subject: Re: Reported on NBC. Oceans are at risk.
Date: Fri, 9 Jan 1998 14:09:48 +0000

This sounds like a re-run of the UK situation. For DECADES uk farmers
were blamed for causing the eutrophication of British rivers due to
phosphate leaching. The fact that this statement came from the (then
publically owned) Water Boards, who were also responsible for sewage
treatment was notable. Now the fact is that in almost all UK soils the
pH is 6.6 to 7.5+ and phosphate is rapidly locked up in these soils.
Even plants need symbiotic rhizofungi to extract adequate amounts. The
amount of phosphate leaching through soils is absolutely minute.

Sewage, however, is a great source of phosphate. I know, about 2,000,000
gallons of sewage sludge gets spread on my farm every year. Bear in mind
that this is just the sludge, most of the treated water (complete with a
lot of nutrients including soluble phosphate) is returned to the river
for re-use. This is under normal circumstances. When periods of wet
weather occur the plant cannot hope to process all the (now very dilute)
waste and so after a brief filtration it has to go straight into the
river. This (combined with the steady pollution of the outflow) causes a
plume of phosphate to enrich river valleys for miles (tens of miles)
downstream.

However when it comes to a publicity war, do not expect farmers to win.
The publicity agents of water companies will make mincemeat of farmers
and nobody likes the increased sewage charges that would be required for
better treatment and storage. It was only some years after the Water
Boards were separated from the River Authority (independent &
responsible for river quality) that the pollution caused by sewage
plants 'suddenly' came to light. The cost of new plant and refurbishment
of sewage plant equipment cost (and is costing) billions.

In article <34B5AF3C.C64@mindspring.com>, JMH <jmhinds@mindspring.com>
writes
>qad@kih.net wrote:
>>
>> Tonites news on NBC was a long report on
>> redtides and other environmental hazards
>> beginning to be felt heavily in our planets
>> oceans.
>
>> I truly hate to see happen the events that are being
>> reported. We really have to lay a lot of this at the
>> doorstep of over fertilization and the runoff of mega
>> hog and poultry farming. Particularily in the sounds
>> and bays of N. Carolina and Louisana delta.
>
>
>NC Hog farmers, disgusted with the bad PR they were getting, retaliated
>with radio ads pointing out that cities along the Nuese River dump more
>human sewage during one bad storm than the entire hog farming industry
>does in a year. Most cities across the US with substandard water
>treatment facilities must often make the difficult decision whether to
>dump raw sewage into the water supply rather than risk worse damage to
>structures during heavy rainfalls/storms.  So, don't lay this blame
>solely at the feet of the farming industry.

--
Oz

From: Oz <Oz@upthorpe.demon.co.uk>
Newsgroups: sci.agriculture
Subject: Re: Reported on NBC. Oceans are at risk.
Date: Sat, 10 Jan 1998 06:53:32 +0000

In article <6967dk$32i$1@solaris.cc.vt.edu>, "Adriana C. Bruggeman"
<jeaan@vtaix.cc.vt.edu> writes

>Did they really blame it on phosphate leaching?

Yes. Politically convenient.

>Because phosphorus is
>indeed highly adsorptive, phosphorus pollution from agricultural sources
>occurs mainly through surface runoff (attached to sediment) not trough
>leaching.

The UK has essentially zero soil runoff. Our idea of really heavy rain
is 1/2" in half an hour in arable areas, or two inches in one day.
Tropical areas can have 12" in an hour, this is 'heavy rainfall'!

On occasionally sees photographs of severe UK erosion. This comprises a
150mmx150mm gully at the bottom of the hill. In parts of the US and Asia
they *really* do have erosion where significant amounts of soil get
washed into watercourses.

It is possible to have surface run-off of nitrates, phosphates and bugs
from soil applied dung on hillsides (or low-lying fields surrounded by
ditches) if really heavy rain washes the neat dung into watercourses.



--
Oz