23-Jun-2011
Fresh water has been released from the River
Welland, near Spalding, into the South Holland
Main Drain to reduce salinity levels after
a number of fish died as a result of salt
water entering the
watercourse.
The Environment Agency stepped in on Friday,
17 June, with assistance from South Holland
Internal Drainage Board, to prevent further
deaths after receiving reports of dead fish
in the drain.
South Holland Main Drain is a freshwater
watercourse that can become salty during
warm and low-flow conditions.
The recent long period of dry weather and
ongoing drought has meant less water in
the drainage system and a higher concentration
of salt water entering from the Tidal River
Nene or possibly from groundwater.
Manfai Tang, Environment Management Team
Leader, said: “Since receiving reports about
dead fish in South Holland Main Drain, we
have taken action to reduce the salinity
of the water. This has included repairing
a sluice and pumping in fresh water.
“We are continuing to monitor the situation
and expect it to improve with fresh water
entering the drain. It is important for
people to tell us if they spot distressed
fish so that we can take action quickly.
The new fishing season is now underway and
we are asking anglers and other river-users
to help us keep an eye on our waterways.”
The fresh water was
pumped from the River Welland and across
the drainage system with assistance from
South Holland Internal Drainage Board. Holbeach
and District Angling Club has been kept
updated and has been supporting the Environment
Agency by providing information and informing
the local fishing community.
Oxygen levels in the water are high, however,
the salinity levels in South Holland Main
Drain means that conditions are not favourable
to some fish such as pike, which is the
main fish species seen to be affected by
the salt.
Environment Agency officers will continue
to monitor the situation and the Environment
Agency’s fisheries team is on stand-by.
+ More
Environment Agency taking
action after central London fish kill
20-Jun-2011
Pollution on the River Thames causes fish
to die.
Environment Agency officers are supervising
the clean up of the River Thames in west
London following the discharge of over 450,000
tonnes of storm sewage over the weekend.
Large numbers of dead fish including flounder,
bream, roach, eel, dace and other aquatic
life such as water shrimps have been spotted
along the river along with sewage detritus.
The incident happened
after the heavy rain over the weekend caused
the release of more than 250,000 tonnes
of storm sewage into the river from combined
sewer overflows (CSOs) and at least 200,000
tonnes of storm sewage from the Mogden Sewage
Treatment Works in Isleworth. These discharges,
combined with the current warm dry weather
and low river flows, resulted in the low
oxygen levels and fish deaths along a kilometre
stretch of the river
Oxygen levels are being studied by Environment
Agency monitoring stations along the river.
Thames Water has dosed the polluted water
with hydrogen peroxide from three different
locations to add oxygen to the water. Its
oxygenation vessels have also been deployed
to the area and can inject 30 tonnes of
oxygen a day into the water.
Howard Davidson, the Environment Agency’s
Director, South East said: “This is a major
sewage pollution incident which has caused
the death of a huge number of fish. Discharges
from combined sewers happen 50 to 60 times
a year and can be caused by as little as
2 mm of rainfall, and on Sunday more than
30mm fell over west London.
“We are currently monitoring
Thames Water’s clean up efforts and assessing
the full impact but unfortunately we may
never know the exact numbers of fish that
have died.”
The Environment Agency has worked with Thames
Water and other partners to find a solution
to these discharges. The London Tideway
Improvements Programme which will reduce
such storm sewage discharges to the Thames,
involves upgrades to all the major tidal
sewage treatment works to increase their
capacity, and the proposed London Tideway
Tunnels which recently underwent a public
consultation.
Members of the public can report pollution
incidents by calling the Environment Agency’s
emergency hotline on 0800 80 70 60.
Ends
All media enquiries: 0118 953 5555
Please ask for the duty press officer
Environment Agency news releases, both national
and regional, can be found on its web site:
www.environment-agency.gov.uk
Notes to Editor
Storm sewage is foul sewage diluted with
rainwater. This occurs where you have a
combined sewage network which takes both
sewage from homes and businesses and rainfall
run-off from roads and other hard surfaces.
The sewage treatment
works, pumping stations and combined sewer
overflows (CSOs) along the River Thames
have legally permitted discharges and are
in place to prevent sewage backing up into
peoples homes and properties when the sewer
network or sewage treatment works have reached
full capacity.
The London Tideway Tunnels
involves construction of a Lee Tunnel and
a Thames Tunnel. Once completed, these huge
tunnels running under London will intercept
and store combined sewer overflows and transfer
the effluent to Beckton sewage treatment
works. The scheme will address 36 unsatisfactory
combined sewer overflows, many of which
will be intercepted, and will provide a
much-needed upgrade to a sewerage system
that has not seen major changes since early
last century.
London Tideway Tunnels,
along with major upgrades to 5 of London’s
sewage treatment works will, once complete,
protect the river from regular pollution
from storm discharges.
The Environment Agency has informed the
London Port Health Authority which protects
public health in the London Port area.
For enquiries about
risks to human health please contact the
London Port Health Authority directly.
