View report page

RIVER POLLUTION
The attempt to improve the condition of the rivers in the Borough continues and in addition
to the regular checks which are carried out to control oil pollution from the Uxbridge Industrial
Estate, a concentrated effort was made to improve the condition of the Grand Union Canal at Harefield
and where it flows west-east across the southern part of the Borough from West Drayton to Hayes.
The first volume of "River Pollution Survey 1970" classified all the rivers in this Borough as grade
class I, except for the canal and the River Colne where it flows with the canal at Harefield which
were grade II. A survey of the canal was made to check all points of discharge into the canal including
the effluent discharges and the points where water is abstracted from and returned to the canal for
industrial purposes. A number of points of pollution were noted and with the exception of discolouration
caused by the effluent discharged from the West Herts Main Drainage Works the persons
were contacted and the pollution prevented. In volume II of "River Pollution Survey 1970" reference
was made to the pollution of the River Colne by unsatisfactory effluent from a sewage disposal
works.
A total of 875 visits were made in connection with pollution of rivers, ponds and water courses
and some of the matters dealt with are listed below:
A plastic storage tank containing 1,500 gallons of sulphuric acid burst, and as the tank was
not bunded, discharged into the surface water drainage. The company by the use of caustic soda
and with assistance from the London Fire Brigade attempted to neutralise and dilute the discharge.
There was serious contamination of the river and damage could have resulted to the sewers. There
is no authority to require the provision of "bund" walling to enclose a storage tank and thus prevent
the escape of chemical, including oil, if a tank burst. The British standard specification for the installation
of oil storage tanks recommends the provision of a bund wall capable of retaining the tank
capacity plus 10% i.e. to allow for any rain water which may be trapped within the bund, but this is a
recommendation and cannot be enforced. Action can be taken to secure a penalty for contaminating
both the Council's sewers or the river but it is not possible to enforce the provisions of works necessary
to safeguard against the possibility of pollution in the event of an accident of this kind occurring.
Oil pollution into Yeading Brook was traced back to a factory at Eastcote where apprentices were
cleaning engineering equipment and pouring the waste into a surface water drain. This source of
pollution has now ceased. It should be stressed that the expression "was traced back" is a brief
and accurate description of what in practice is several hours work and a number of other possibilities
had to be eliminated if the fish in the rivers were to be protected. A drum of chemicals spilled from a
lorry at London (Heathrow) Airport and burst. The driver, a police officer and a passer-by all suffered
from the effects of fumes and had to receive hospital attention but, fortunately there were no serious
or lasting effects. It was again necessary for the fire brigade to hose down and pollution although
heavily diluted would have got into the rivers. The chemical involved was only labelled by a trade
name and there was some difficulty in locating the actual chemicals used in the preparation.
Contamination of the surface water sewage system also occurred when a bulk tanker carrying
perchloroethylene sprang a leak while parked in a car park in the West Drayton area. Investigation
of the pollution of a stream in the Ruislip area revealed that foul water from the sinks in a nearby
factory was being discharged into the stream. The main foul water drainage from the factory discharged
into a cesspool. The cesspool which was emptied by the Council would have had to be
enlarged. A contribution to the cost was made by the Council and all the foul drainage from the
premises connected direct to the foul sewer. Regular and systematic patrolling of rivers and water
courses by the environmental health staff is not possible and information from the public concerning
pollution of the rivers is always welcome.
LECTURES
During the year groups of student midwives from Hillingdon group of hospitals visited the
department to spend a day with the public health inspectors.
Assistance was given with an in-training course for staff from the Health Control Unit at
London Airport.
Food hygiene lectures were given to domestic science pupils, members of women's organisations,
and in connection with a special training course for food handlers which was organised in
collaboration with the St. John Ambulance Association (Hillingdon Centre).
101