Download 30 Years of River Quality A Retrospective and Prospective View

30 Years of River Quality
A Retrospective and Prospective View
EPA National Water Event
Galway Bay Hotel 12-13 June 2013
John Lucey
Presentation Outline
• Overview of past 30 years’ river quality
• Problems solved and those remaining
• Future challenges and possible solutions
Alien Species
Alien Species
• Are alien species a real problem in water
quality?
• Or can the cure be worse than the disease?
Glyphosate and Triclopyr being applied to control
Gunnera on Achill and Dichlobenil - highly toxic to
zooplankton and moderately toxic to fish - being used
to control Lagarosiphon in Lough Corrib.
Siltation
A study of suspended sediment (suspended solids) results
(2010, 2011 and January-March 2012: n=960) for designated
salmonid rivers in the south-east, which also support pearl
mussels, showed a mean concentration of 9 mg/l (annual
average guideline standard of 25 mg/l). The study concluded
that, despite siltation being a problem at some sites, current
nitrate levels in south-east Irish rivers would appear to be a
more widespread risk for pearl-mussel survival.
http://www.epa.ie/pubs/reports/water/rivers/riversedimentstud
ies.html
The EPA has commissioned, under the STRIVE programme,
a large-scale project Measurement of silt flux in rivers and
benefits of enhancement measures (SILTFLUX).
Acid Rain
Acid rain has come and gone!
Worldwide reductions of sulphur dioxide.
In Ireland some waters were impacted in the
past, e.g. Lugaduff River (Glendalough) and
is now much reduced. Investigations began 30
years ago show little change in acid status of
other waters.
The global problem is now CO2 rather than
SO2
Native Woodland Establishment Scheme
Forest Service proposal to plant native trees
within designated acid-sensitive areas will
help greatly.
Will return to topic of trees and rivers later in
presentation.
Rivers 30 years Ago
40 years ago we joined the EU (then EEC).
30 years ago CAP had kicked in leading to an
agricultural revolution.
Fertiliser use increased in both pasture and
tillage areas. Large increase in animal
numbers led to slurry and silage waste
reaching rivers - in rural areas - already
polluted in towns.
River Quality 30 Years Ago
In or below many towns were grossly or
moderately polluted for a short stretch which
dissipated with travel downstream as the river
acted as a WTP breaking down the sewage.
Some Rivers 30 years Ago
Fish Kills – Some Attitudes
At a meeting on river quality with farmers in
the 1980s an IFA local rep asked ‘what is the
difference between us killing a few fish and
anglers doing the same?’
The only thing more expensive than education is ignorance
Benjamin Franklin
Fish Kills
A marked upsurge in fish kills had occurred in
Irish rivers in the 1970s coinciding with the
intensification of agriculture. In response to
this situation, a nationwide public information
campaign was launched and an enforcement
strategy was put in place by the then Regional
Fisheries Boards and Local Authorities.
There were 127 fish kills in 1987 and ‘only’
10 in 2012 - the lowest on record.
Fish Kills
Sources: CFB, RFBs and IFI (Fiona Kelly)
Seriously Polluted River Sites
Trends in River Water Quality
High Status River Sites
Water Quality Management Plans
There is nothing new in the concept of
catchment management in Ireland. The first
such Plan was published 30 years ago in 1983
for the Barrow catchment with others
following.
One of the main outcomes of the Plans was
the commissioning of new WTPs. These
would now need upgrading after 30-year lifespan.
Integrated Catchment Management
Is a process of decision making and action
involving multiple interests aimed at
integrating the different uses of land, water
and related environmental resources.
A planned pilot project with Kilkenny County
Council on small River Nore sub-catchment
(Nuenna).
Constructed Wetlands
• ICWs seen as the panacea for all our ills!
• Adequate for polishing - nutrient removal but certainly not for treating municipal or
agricultural waste.
• Unless they are lined the groundwater may
be contaminated.
• If discharging to watercourse then should be
licenced.
Constructed Wetlands
Riparian Buffer Zones
Intercept sediments and nutrients.
Reduce erosion/bank stabilization.
Reduce flooding.
Carbon sinks.
Riparian Buffer Zones
Zone 1 functions mainly to shade the water source and act as
a bank stabilizer. Should include large native tree species that
grow fast.
Zone 2 should be an important transition between grassland
and wood. Should include native shrub species. Acts to slow
and absorb contaminants missed in Zone 3.
Zone 3 serves primarily to slow water runoff and begin to
absorb contaminants before they reach the other zones.
Should consist mostly of native grass species.
Riparian Buffer Zones
Source: http://www.dep.wv.gov/WWE/Programs/nonptsource/Pages/BMPs.aspx
Riparian Buffer Zones
Teagasc study summary
Study on farmers’ attitudes to riparian buffer zones:
Buckley et al., 2012. Supply of an ecosystem service—Farmers’ willingness to adopt
riparian buffer zones in agricultural catchments. Environmental Science & Policy 24
http://t-stor.teagasc.ie/handle/11019/328
Tree-lined River 1800s
Tree-lined River 1900s
Tree-lined River 1900s
Tree-lined River 2000s
Future Challenges and Possible Solutions
• To meet objectives of WFD
Some progress but not enough - almost 30% of river
channel remains polluted to some degree.
• To preserve at least the status quo ante –
with Food Harvest 2020 coming on stream
Has Anaerobic Digestion a Role?
• Riparian Buffer Zones?
• Integrated Catchment Management?
• Nutrient Management
Artificial Fertiliser Use.
River Quality - Overall Situation
The problem in Ireland is largely low-level river
pollution of enrichment with nutrients.
Other EU MS would be quite happy to have this type
of river-quality problem as a challenge.
Rivers where anglers would expect trout and hope
for salmon.
Best Mayfly fishing recorded on Lough Sheelin in over forty years with more than 1,000
trout recorded.
We have come a long way in the past 30 years and
the prime task now should be to restore those
enriched sites to at least good ecological quality
while at least also preserving the existing high
quality habitats.