,.
-ï
‘
«
…? ,‘.‘
www J …» «
J
,
,l
,
,…
l
_
.
”?"”
_
_
fi“î"'
s’
;—
__
ar
_
__
,,; ; ”Î’L
"
:
—,‘
—_, .,:v_ ,
_
_
J‘
'
_
_
—_ .,:
…
.
};…—
%°‘——
“*
.…
.
…
-—
…
,.
'
«
«:»
……î:—;-,. :: '
'
…“
—f
?
%.… ‘
‘
;
»…
.
_
.
__
…
'
f
'
_.
»”
-Ï“; . .
_
»
_
_
\_i
_
_
__
'«ÇÊ;
__
&
.
__
g
”î“.=i
'
‘
l’—
»
!
"
2:—
'
—«:°
Ï—
».
—
"
'
‘»
-—__
»
_
—
.
…
*
»°—'—‘
wuu:°‘-_ -
\_
_
A
.
.
_
«___
___
.
\
}
_,
“‘;—…
»
…,
»
'“'°——
,
:
Ê“‘
"'
:s‘Α°l
“!
i\î
'
_
'
.
……
—
w
«
……»—
,!..
—.a
Æ\”'W
3_
‘gæ_
_
_
__
».
.
._. _
_
_
_
_
,
_
__
\
! _ ——
î_
.
……
'
'
““““
=
b
A
Ë
..
!
The modern method of feeding cattle, emphasizing highly concentrated feed and
small confinement areas, intensifies water pollution, while the manure that used to
return to the land must now be replaced by chemical fertilizers. At the next stage in
'
moving the meat to market—the packing houses—another water pollution problem is
created.
In addition to increasing the direct discharge of animal wastes, current ag—
ricultural practices tend to pollute more than older farming methods because
today farmers rely more heavily on chemical fertilizers and pesticides (both
of which are discussed elsewhere). At this point, it is sufcient to add agricul—
ture to our tally of the major human activities in Which new technology goes
hand in hand with intensied water pollution.
Pressures for Change in Water Treatment
Generally, this intensication has steadily increased the pressure on industrial
and municipal waste treatment systems, since more fundamental changes to
reduce the pollution capacity of modern technology have been so limited. In
some cases such as steelmaking, canning, chemical manufacturing, and farm—
ing, the changes that have been made actually have increased the pollution
load or toxicity. Reliance on waste treatment systems to purify the efuent,
,
however, has” been disappoinüng for two reasons: (1) the science of waste
treatment has lagged far behind the capacity to produce complex and voluminoüs industrial pollutants, and (2) available control devices, imperfect as
they may be, are very expensive to install and operate.
'
'
Pressures for Change in Water Treatment
107
-ï
‘
«
…? ,‘.‘
www J …» «
J
,
,l
,
,…
l
_
.
”?"”
_
_
fi“î"'
s’
;—
__
ar
_
__
,,; ; ”Î’L
"
:
—,‘
—_, .,:v_ ,
_
_
J‘
'
_
_
—_ .,:
…
.
};…—
%°‘——
“*
.…
.
…
-—
…
,.
'
«
«:»
……î:—;-,. :: '
'
…“
—f
?
%.… ‘
‘
;
»…
.
_
.
__
…
'
f
'
_.
»”
-Ï“; . .
_
»
_
_
\_i
_
_
__
'«ÇÊ;
__
&
.
__
g
”î“.=i
'
‘
l’—
»
!
"
2:—
'
—«:°
Ï—
».
—
"
'
‘»
-—__
»
_
—
.
…
*
»°—'—‘
wuu:°‘-_ -
\_
_
A
.
.
_
«___
___
.
\
}
_,
“‘;—…
»
…,
»
'“'°——
,
:
Ê“‘
"'
:s‘Α°l
“!
i\î
'
_
'
.
……
—
w
«
……»—
,!..
—.a
Æ\”'W
3_
‘gæ_
_
_
__
».
.
._. _
_
_
_
_
,
_
__
\
! _ ——
î_
.
……
'
'
““““
=
b
A
Ë
..
!
The modern method of feeding cattle, emphasizing highly concentrated feed and
small confinement areas, intensifies water pollution, while the manure that used to
return to the land must now be replaced by chemical fertilizers. At the next stage in
'
moving the meat to market—the packing houses—another water pollution problem is
created.
In addition to increasing the direct discharge of animal wastes, current ag—
ricultural practices tend to pollute more than older farming methods because
today farmers rely more heavily on chemical fertilizers and pesticides (both
of which are discussed elsewhere). At this point, it is sufcient to add agricul—
ture to our tally of the major human activities in Which new technology goes
hand in hand with intensied water pollution.
Pressures for Change in Water Treatment
Generally, this intensication has steadily increased the pressure on industrial
and municipal waste treatment systems, since more fundamental changes to
reduce the pollution capacity of modern technology have been so limited. In
some cases such as steelmaking, canning, chemical manufacturing, and farm—
ing, the changes that have been made actually have increased the pollution
load or toxicity. Reliance on waste treatment systems to purify the efuent,
,
however, has” been disappoinüng for two reasons: (1) the science of waste
treatment has lagged far behind the capacity to produce complex and voluminoüs industrial pollutants, and (2) available control devices, imperfect as
they may be, are very expensive to install and operate.
'
'
Pressures for Change in Water Treatment
107