Environmental Engineering Reference
In-Depth Information
foul smelling. The numerous mines that provided the coal, coke and ganister
needed by the metal industries pumped untreated metal-rich mine water into
local rivers resulting in them turning an ochreous yellow and the industries
themselves discharged a cocktail of pollutants (e.g., metals, oil, acid) into
surface waters, reducing water quality further.
The River Don and its tributaries used to support a diverse fishery with 31 fish
species, including salmon and trout, being recorded pre- 1850. Fish populations
began to decline rapidly from the beginning of the nineteenth century, initially
due to physical modifications, but then compounded by declining water quality.
Weirs and dams impeded the movement of fish and changes in water flow altered
habitat characteristics. Fish were unable to reach upstream spawning sites.
Sedimentation occurring upstream of weirs produced conditions suited for
roach, bream and perch whereas scouring downstream of weirs produced habitat
more suited to dace, chub, barbel and grayling. Fish populations continued to
decline as water quality deteriorated, and by 1860 the River Don flowing through
Sheffield and downstream to Rotherham was virtually fishless. Fish populations
persisted in the headwaters and tributaries of the Don, although several of these
received waste water from mines that had, and still have, a negative impact on
fish, invertebrate, algal and microbial communities (e.g., Bermingham et al.
1996
;
Ashton
1997
;Amisah&Cowx
2000a
). By 1974, the Don fishery had been reduced
to a small number of brown trout in a few upstream reaches.
The effects of Sheffield's industrial development on the River Don were not
confined to aquatic species. During the height of the manufacturing industry,
the River Don flowing through Sheffield ran at a constant 20
C, the water
having been used for cooling purposes. This warmwater provided suitable condi-
tions for the germination of wild fig (Ficus carica) seeds that entered the river
via sewage works. As a result, more than thirty 80- to 90-year-old fig trees can be
found growing along the River Don in the eastern end of the city (Gilbert
1990
).
Industrialisation in the Don catchment changed the river from a provider of
power, food (fish), drinking water and recreational space to a recipient of
domestic and industrial waste that presented a serious risk to human health.
The abundant local resources (oak woodlands, coal, iron ore and ganister) that
underpinned the development of the metal industries were overexploited
resulting in mine closures and importing of raw materials. By the mid twenti-
eth century, the population of Sheffield had peaked at 577 050 (1951 census)
and the River Don had obtained a reputation for being one of the most polluted
rivers in Europe (Firth
1997
).
Industrial decline and environmental improvement
Sheffield experienced a massive deindustrialisation in the 1980s, beginning
with the steel workers' strike in 1980, and followed 4 years later by the miners'
strike. Between 1975 and 2005, the UK production of coal and steel decreased
