View report page

101
ENVIRONMENTAL HEALTH SERVICE
WATER SUPPLY
Apart from a small area in the extreme south-west part of the district
which is supplied by the Rickmansworth and Uxbridge Valley Water
Company, the Borough is supplied by the Colne Valley Water Company.
Nearly all the water supplied by them is obtained from a series of wells fed
from gathering grounds in the Chilterns.
The supply has been satisfactory in quantity and quality and no
adverse reports were received.
Throughout the year samples were taken by the Colne Valley Water
Company and in every case the report received was satisfactory. In addition,
eight samples were taken by the department and the following is a copy of
the report received on a sample submitted for chemical analysis during
December, 1966:—
Chemical Results in parts per million
Suspended Matter absent
Appearance clear and bright
Colour less than 5 Hazen Units
Taste normal
Odour absent
Total solid residue dried at 105°C 526 parts per million
Chlorides as Chlorion 49 „ „ „
Nitrate Nitrogen 2 „ „ „
Nitrite Nitrogen absent
Ammoniacal Nitrogen 0.02 „ „ „
Albuminoid Nitrogen 0.01 „ „ „
Oxygen absorbed, 4 hrs. at 27°C. 0.43 „ „ „
Total Hardness as CaC03 222 „ „ „
Non-Carbonate Hardness as CaC03 76 „ „ „
Alkalinity as CaC03 146 „ „ „
Poisonous Metals absent
Reaction pH 7.0
"This is a water with a moderate hardness, about a quarter of which is
permanent. It is, however, satisfactory from a chemical point of view and is
suitable for domestic purposes."
There are no houses in the Borough supplied with water by a stand
pipe, all the dwellings in the district having a supply direct from the
Company's main.
No evidence exists that the water is plumbo-solvent and before
distribution the new water is chlorinated and partially dechlorinated. The
fluoride content of the water supplied is consistently less than 0.1 p.p.m. (F).