« Previous | Contents | Next »
Listen
water
Drinking Water Quality: 1991-2005
| 1991 | 1995 | 2000 | 2003 | 2004 | 2005 |
|---|
Number of samples taken: all parameters (000's) | 227 | 231 | 152 | 155 | 152 | 153 |
|---|
Percentage failure for total coliforms | 7.0 | 2.6 | 1.1 | 0.9 | 0.9 | 1.0 |
|---|
Percentage failure for faecal coliforms | 3.0 | 1.0 | 0.2 | 0.1 | 0.1 | 0.2 |
|---|
The coliform group of organisms is present in large numbers in the gut of all warm-blooded animals and is also widely distributed in the environment. Their presence in tap water indicates a breach in the integrity of the water supply system.
Scottish Water is required to analyse samples taken from water treatment works, service reservoirs and consumers' taps. The Water Supply (Water Quality)(Scotland) Regulations 2001 set strict standards for compliance for a wide range of parameters. The major centres of population in Scotland are served by modern water treatment works, which are generally well equipped to achieve the standards set. In recent years improvements have been made to some of the small, rural treatment works, many of which were previously unable to consistently treat water to the standard required by the Regulations.
Between 1991 and 2005 the percentage of samples from consumers' taps containing coliforms fell from 7% to 1% and the percentage failure for faecal coliforms fell from 3% to 0.2%. Between 2004 and 2005 the failure rate for both total and faecal coliforms increased by 0.1 percentage points.
SOURCE: SCOTTISH EXECUTIVE DRINKING WATER QUALITY DIVISION 2
« Previous | Contents | Next »