What tests are undertaken to establish the safety of drinking water and what the outcomes of these tests have been in each year since 1997,…

The Water Supply (Water Quality) (Scotland) Regulations 2001 set out the standards and testing frequencies for 51 different parameters to establish the safety of public drinking water supplies. Additional sampling is also undertaken for cryptosporidium.
There are similar requirements for private water supplies, which serve approximately 3% of the population, and these are set out in the Private Water Supplies (Scotland) Regulations 2006.
Both the public and private water supply regulations are publicly available on the OPSI website at http://www.opsi.gov.uk/legislation/scotland/ssi2001/20010207.htm and http://www.opsi.gov.uk/legislation/scotland/ssi2006/20060209.htm respectively.
A summary of all water quality results is published each year by the Drinking Water Quality Regulator for Scotland in the Drinking Water Quality in Scotland series of publications. Copies are available in the Scottish Parliament Information Centre, and Bib. numbers are listed in the following table:

| Bib. Number

Drinking water quality in Scotland 1997
| 19165

Drinking water quality in Scotland 1998
| 19163

Drinking water quality in Scotland 1999
| 17148

Drinking water quality in Scotland 2000
| 20065

Drinking water quality in Scotland 2001
| 26009

Drinking water quality in Scotland 2002
| 31063

Drinking water quality in Scotland 2003
| 34052

Drinking water quality in Scotland 2004
| 37158

Drinking water quality in Scotland 2005
| 40187

Drinking water quality in Scotland 2006
| 43430

Drinking water quality in Scotland 2007
| 46426

Drinking water quality in Scotland 2008
| 51377

Prior to 2002, the data is not broken down by local authority, but by water authority area.