View report page

53
SHELL FISH.
One of your Inspectors has regularly visited Leigh Creek, and he reports
that he has not found any cockles laid in the creek, and that the arrangement
mentioned in my last Annual Report still continues, namely, that the cockles
are brought direct from the gathering grounds on the Maplin Sands, and are
cooked forthwith.
RIVER THAMES WATER.
In my last Annual Report, I wrote at some length on the condition of the
River Thames, and gave the results of a number of analyses of samples of
water which had been taken from various parts of the River Thames and its
estuary, situated within the jurisdiction of the Port Sanitary Authority.
I showed that the main sources of pollution were various storm outfalls
from the main sewerage system of the London County Council—the discharge
of sewage effluents at Barking and Crossness—the discharge of crude
sewage at Southend and Sheerness-on-Sea.
I give the rainfall for each month collected at Greenwich, and also for each
quarter of the year in the London District, and showing the difference from
the average for each quarter, and for the whole year, extracted from the
Quarterly Reports of the Registrar-General.
Quarter. Difference Month. Inches.
from. Average.
January 1.09
February 1.27
March 0.91
3.04 -2.01 3.27
April 3.14
May l.47
June 2.65
7.28 +1.61 7.26
July 0.97
August 1.92
September 0.62
4.16 -2.91 3.51
October 3.25
November 2.23
December 2.73
8.59 +1.58 8.21
23.07 +1.58 above average. 22.25
The purification of the Thames largely depends upon the amount of water
flowing over Teddington Weir, and into the tributaries of the Thames.
The sewage effluent discharged into the Thames from the County Council
outfalls at Barking and Crossness oscillates upwards and downwards with the
flow and ebb of the tide, and is finally oxidised and carried to sea, the process
being practically completed at the Chapman Lighthouse, about twelve miles
below Gravesend.