Sd. Lennox et al., A COMPARISON OF AGRICULTURAL WATER-POLLUTION INCIDENTS IN NORTHERN-IRELAND WITH THOSE IN ENGLAND AND WALES, Water research, 32(3), 1998, pp. 649-656
Agricultural pollution incidents in Northern Ireland declined by 51% b
etween 1987 and 1995. This decline resulted from a steady decrease in
the largest category of farm pollution, silage effluent, which decline
d by 78%. The decline in silage pollution was most evident in the mont
hs of May and June and may be related to an observed increase in grass
wilting, which reduces silage effluent volumes, and favourable weathe
r during these months. Non-silage related incidents were 49% greater i
n 1995 than in 1987 and showed no particular trend with time nor the d
istinct annual cycle that was observed for silage pollution. Silage ef
fluent represented 51% of all pollution sources, followed by a general
category of farm effluent (27%) and cattle slurry (12%). No other sou
rce contributed more than 4% of the total. An analysis of pollution ca
ses showed that, while incidents associated with leaking and overflowi
ng effluent tanks and leaking silos all declined, incidents where no e
ffluent collection facilities were found increased. This increase was
considered to be the result of a change in detection efficiency rather
than an absolute increase in the number of farms without effluent col
lection facilities. Farm pollution statistics from Northern Ireland an
d England and Wales demonstrated similar trends for both silage and no
n-silage related incidents, with no evidence to suggest that increases
in financial penalties for causing pollution or different levels of g
rant aid had impacted or? long-term trends. Trends in pollution statis
tics from catchments in Northern Ireland targeted for pollution advice
by agriculture advisory staff did not differ from the area as a whole
. (C) 1998 Elsevier Science Ltd. All rights reserved.