Information Letters

Information letters are used by DWI to communicate any changes in regulatory matters, guidance or procedures to the water industry and relevant stakeholders. They are automatically sent to named contacts within the industry but are available on request to anyone.

The list below includes only those letters that contain current information. Many older letters have been superseded. However, copies of such letters are available by contacting dwi.enquiries@defra.gsi.gov.uk

These documents are in PDF format. The Adobe® Acrobat Reader® can be freely downloaded here.

 

2017

REF

TITLE

Annex

01/2017

The Water Industry (Suppliers’ Information) Direction 2017(PDF 75KB)

Information Direction (PDF 87KB)

2016

REF

TITLE

Annex

07/2016
(Dec 16)

Approved products for use in public water supplies in the United Kingdom – improvements to the Secretary of State’s list and notice of intention to revoke approvals of some products (PDF 234KB)

N/A

06/2016
(Jul 16)

Catchment management undertakings (PDF 159KB)

N/A

05/2016
(Jul 16)

Changes to the procedures for radioactivity Notices (PDF 182KB)

N/A

04/2016
(Jun 16)

New drinking water quality legislation (2016) (PDF 152KB)

N/A

03/2016
(Apr 16)

List of approved products for use in public water supplies in the United Kingdom (PDF 107KB)New drinking water quality legislation (2016)

Products removed from the list of approved products (PDF 101KB)

02/2016
(Mar 16)

Legislative changes relating to the DWI cost recovery scheme (PDF 61KB)

N/A

01/2016
(Jan 16)

Code of practice on technical aspects of fluoridation of water supplies 2016 (PDF 113KB)

Code of practice (PDF 306KB)

2015

REF

TITLE

Annex

05/2015

Publication of research: Understanding the implcations of the European requirements relating to Radon in Drinking Water (PDF 80KB)

N/A

04/2015

Publication of a research report on the significance of Chromium in drinking water (PDF 114KB)

N/A

03/2015

Regulation 31 approval of products and substances intended for disinfestation, disinfection or cleaning agents of waterworks apparatus and distribution systems (PDF 110KB)

N/A

02/2015

Legal Instruments - Processes for reporting on, agreeing changes to and closure/revocation (PDF 113KB)

1 - Undertaking progress (PDF 102KB)
2 - Distribution consumer acceptability and discolouration schemes (PDF 71KB)
3 - Notice progress (PDF 103KB)
4 - Justification of proposed changes (PDF 73KB)
5 - Undertakings completion report (PDF 55KB)
6 - Notice completion report (PDF 113KB)

01/2015

Regulation 28 reporting requirements (PDF 115KB)

A - Specification (PDF 266KB)


2014

REF

TITLE

Annex

05/2014

List of approved products for use in public water supplies in the United Kingdom (PDF 109KB)

A - Products removed from the list of approved products (PDF 253KB)

04/2014

Cryptosporidium monitoring in water supplies (PDF 139KB)

N/A

03/2014

Drinking water quality improvement programmes – changes to progress reporting requirements (PDF 111KB)

N/A

02/2014

Regulation 28 reporting requirements (PDF 110KB)

A - General requirements
Updated in annex A of IL 01/2015
B - Specification
Updated in annex A of IL 01/2015
C - Parameter/Hazard list (XLS 138KB)
D - Example tables (Zip file 173KB)
Updated September 2014
E - Query log (XLS 125KB)
Updated 12 November 2014

01/2014

Metaldehyde and other pesticides (PDF 134KB)

N/A


2013

REF

TITLE

Annex

06/2013

New European requirements for monitoring for radioactivity in drinking water supplies (PDF 75KB)

N/A

05/2013

Drinking water analysis and the regulatory requirements (PDF 95KB)

N/A

04/2013

Collection of data under the Private Water Supplies Regulations 2009 and the Private Water Supplies (Wales) Regulations 2010 (PDF 107KB)

1 - Return template (excel 440KB)
Updated September 2015
2 - Example return (excel 448KB)
Updated September 2015
3 - Specification (PDF 210KB)
Updated September 2015
FAQ (PDF 252KB)

03/2013

Cost recovery: publication of fees (PDF 95KB)

Schedule of fees
Updated October 2015

01/2013

The 2014 Periodic Review of prices – Guidance on drinking water quality requirements (PDF 287KB)

N/A


2012

REF

TITLE

Annex

09/2012

The Water Industry (Suppliers' Information) Direction 2012 (PDF 137KB)

Information Direction (PDF 196KB)
Changes to tables (PDF 60KB)
(Data specification)

08/2012

Outline of the Drinking Water Inspectorate cost recovery regime (PDF 112KB)

N/A

07/2012

Publication of further research on nitrosamines in water treatment coagulants and drinking water (PDF 102KB)

N/A

06/2012

Regulation 15 compliance arrangements (PDF 180KB)

N/A

04/2012

Water supply hygiene – summary findings of technical audits of distribution depots and associated network operations between July and November 2011 (PDF 144KB)

N/A

03/2012

Publication of research report on human pharmaceuticals in raw and treated river water to inform regulatory risk assessment methodology (PDF 96KB)

Link to report

02/2012

Arrangements for demonstrating that reporting of analytical results meet regulatory requirements (PDF 70KB)

N/A

01/2012

Update of the Inspectorate’s structure (PDF 143KB)

A - DWI structure (PDF 45KB)
updated January 2017
B - Cascade list (PDF 18KB)
updated January 2017


2011

REF

TITLE

Annex

10/2011

Guidance to local authorities in England on charging arrangements under the Private Water Supplies Regulations 2009

10a/2011 - sent to local authorities in England that have private water supplies and sent a data return to DWI for 2010 (PDF 92KB)
10b/2011 - sent to local authorities in England that have no private water supplies or did not send a data return to DWI for 2010 (PDF 92KB)
10c/2011 - sent to local authorities in Wales for information (PDF 93KB)

N/A

08/2011

Publication of report: Objectionable taste and odour in water supplies in North-East London between January and March 2010 (PDF 91KB)

Report
(PDF 1.6MB)

07/2011

Implementation of the new SCA blue book 233: The determination of taste and odour in drinking waters (2010) (PDF 50KB)

N/A

06/2011

Technical Audit of Water Companies under Section 86 of the Water Industry Act 1991: Publication of the report following the audit of STS Analytical Services at Bridgend (PDF 94KB)

Audit report (PDF 513KB)

05/2011

Production, delivery, receipt and control of water treatment chemicals (PDF 101KB)

N/A

04/2011

Guidance on the general provisions for monitoring of parameters relevant to radioactivity (PDF 106KB)

N/A

03/2011

Publication of World Health Organisation (WHO) document entitled 'Water safety in buildings' (PDF 80KB)

N/A

02/2011

DWI Enforcement Policy (PDF 88KB)

Enforcement policy (PDF 169KB)

01/2011

Amendment to The Water Supply (Water Quality) Regulations 2010 (Wales) (PDF 92KB)

N/A


2010

REF

TITLE

Annex

13/2010

Collection of data under the Private Water Supplies Regulations 2009 (PDF 99KB)

Please see IL 04/2013

11/2010

Guidance to local authorities in England on charging arrangements under the Private Water Supplies Regulation 2009 (PDF 106KB)

A - Letter (PDF 702KB)
B - Extract from guidance (PDF 55KB)

10/2010

Guidance on using contractors to deliver Local Authority duties under the Private Water Supplies Regulations (PDF 113KB)

N/A

09/2010

Revised DWI Guidance on the Water Supply (Water Quality) Regulations (PDF 153KB)

1 - Regulations (PDF 896KB)
2 (PDF 1.29MB)
3 - Regulations for Wales (PDF 251KB)
4 - Guidance for Regulations for Wales (PDF 1.29MB)

08/2010

Changes to the process for assessment of drinking water quality event notifications (PDF 93KB)

N/A

06/2010

Consultation on update DWI guidance on the Water Supply (Water Quality) Regulations (PDF 116KB)

Annex A - Draft guidance (PDF 1.4MB)

04/2010

New drinking water quality legislation (2010) (PDF 247KB)

A - The Water Supply Regulations 2010 (PDF 69KB)
B - The Water Supply Regulations 2010 for Wales (PDF 251KB)
C - Amendments to Regulations (PDF 48KB)

03/2010

Better Regulation Executive : Report on the Hampton implementation review of the Drinking Water Inspectorate (PDF 76KB)

N/A

02/2010

Revision of guidance on the regulatory responsibilities of new (inset) appointees in relation to public water supplies (PDF 76KB)

Guidance for inset appointments (282KB)

01/2010

Guidance on the use of ultraviolet (UV) irradiation for the disinfection of public water supplies (PDF 75KB)

Guidance on UV irradiation (181KB)


2009

REF

TITLE

Annex

10/2009

Revision of guidance on the water supply (water quality) regulations 2000/2001 specific to PFOS (perfluorooctane sulphonate) and PFOA (perfluorooctanoic acid) concentrations in drinking water (PDF 140KB)

PFOS guidance(5MB)

9/2009

Drinking water safety - Guidance to health and water professionals (PDF 140KB)

Drinking water safety publication (5MB)

8/2009

Reappointment of Chief Drinking Water Inspector and further update on the restructuring of the Drinking Water Inspectorate (PDF 93KB)

For up to date cascade list see Info letter 01/2012

5/2009

Guidance on the reporting and investigation of taste and odour detections (PDF 159KB)

N/A

4/2009

Submission of raw water monitoring data to the Drinking Water Inspectorate (PDF 138KB)

A - Table format for reporting raw water (PDF 34KB)
B - Parameter code list (PDF 232KB)
B Parameter code list (excel 140KB)
Updated Jan 2017

3/2009

Further guidance on changes within the operations team and the inspector liaison role (PDF 141KB)

N/A

2/2009

Changes to the process for assessment of drinking water quality event notifications (PDF 101KB)

N/A

2008

REF

TITLE

Annex

10/2008

Guidance on the Water Supply (Water Quality) Regulations 2000 (England) & 2001 (Wales) incorporating the Water Supply (Water Quality) (Amendment) Regulations 2007 (PDF 85KB)

Guidance on the Regulations (PDF 827KB)

09/2008

Publication of research report on N-Nitrosodimethylamine (NDMA) in drinking water and associated guidance to the industry (PDF 80KB)

N/A

08/2008

Changes to the approval of disinfectants for emergency use (PDF 93KB)

N/A

07/2008  

Guidance on the requirement to submit a risk assessment under regulations 27 and 28 of the Water Supply (Water Quality) Regulations 2000 (2001 in Wales) (Amendment) Regulations 2007 (PDF 93KB)

Guidance notes (PDF 123KB)

06/2008 

Audit of Regulations 35(1) (PDF 69KB)

Final report (PDF 1.5MB)

05/2008 

Concessionary supplies - further guidance (PDF 109KB)

N/A

04/2008 

Regulation 31 (PDF 101KB)

N/A

01/2008 

The Water Supply (Water Quality) Regulations 2000 as amended - Publication of an unofficial consolidated version of the Regulations (PDF 129KB)

N/A

2007

REF

TITLE

Annex

10/2007 

Updated guidance on the notification of events (PDF 71KB)

N/A

09/2007 

The Water Supply (Water Quality) Regulations 2000 (Amendment) Regulations 2007 - Changes to water company data tables (PDF 299KB)

N/A

08/2007 

Guidance on interpretation of Regulation 16(2)(d)(i) of the Water Supply (Water Quality) Regulations 2000 (2001 in Wales) (PDF 87KB)

Guidance on implementation of Regulation 16(2)(d)(i) (PDF 130KB)

07/2007 

Outcome of the consultation exercise on amendment to the Water Supply (Water Quality) Regulations 2000 - Publication of the amendment regulations and the government response to the consultation (PDF 126KB)

N/A

06/2007 

Outcome of the consultation exercise on amendment to the Water Supply (Water Quality) Regulations 2000 - Requirements for raw water monitoring (PDF 89KB)

N/A

05/2007  

Guidance on the Water Supply (Water Quality) Regulations 2000/2001 specific to PFOS (Perfluorooctane Sulphonate) AND PFOA (Perflourooctanoic Acid) concentrations in drinking water (PDF 79KB)

N/A

01/2007  

Technical audit of Water Companies under section 86 of the Water Industry Act 1991: Summary report for the vertical audits for pesticide parameters (PDF 72KB)

Summary audit report (PDF 249KB)

2006

REF

TITLE

Annex

11/2006

Technical Audit of Water Companies under section 86 of the Water Industry Act 1991: Summary report for the vertical audits for non-microbiological parameters, 2005 (PDF 102KB)

N/A

10/2006 

Cryptosporidiosis in England and Wales (PDF 98KB)

A - Report summary (PDF 14KB)
B - Report conclusions and recommendations (PDF 27KB)

06/2006

DWI Drinking Water Quality Improvement Programmes - Process for agreeing changes to improvement programmes associated with legal instruments (PDF 164KB)

N/A

05/2006 

Control of Water Treatment Chemicals (PDF 86KB)

N/A

03/2006 

Issues relating to 2006 monthly data submissions to the Drinking Water Inspectorate, and information required for inclusion in the chief Inspector's Report (PDF 260KB)

N/A

02/2006 

Concessionary Supplies: Reporting of compliance results and the calculation of Operational Performance Indices (PDF 81KB)

N/A

01/2006 

Annual Provision of Information on Consumer Contacts (PDF 172KB)

Example return (PDF 67KB)

2005

REF

TITLE

Annex

17/2005

Cryptosporidiosis in England and Wales (PDF 141KB)

N/A

15/2005

Distribution Operation and Maintenance Strategies (DOMS) - Update to DWI requirements and expectations (PDF 29KB)

N/A

14/2005

List of water treatment works in England and Wales (PDF 75KB)

List (PDF 279KB)

12/2005

Guidance on sample and sample extract stability trials and the preservation and preparation of samples for metals analysis (PDF 135KB)

A - Guidance on sample and sample extract stability trials (PDF 169KB)
B - Sample preservation and preparation for metals analysis of drinking water (PDF 102KB)
C - Stability trial worked example (PDF 10KB)

08/2005

Technical audit of water companies under Section 86 of the Water Industry Act 1991: Summary report for the vertical audits for non microbiological parameters, 2004 (PDF 107KB)

Summary report (PDF 269KB)

05/2005

Code of Practice on technical aspects of Fluoridation of water supplies 2005 (PDF 77KB)

Code of practice (PDF 64KB)

03/2005

Guidance on the calibration and analytical quality control for residual chlorine measurements (PDF 76KB)

Guidance (PDF 169KB)

02/2005

Issues relating to the submission of sample data to the Drinking Water Inspectorate (PDF 204KB)

N/A

01/2005

Requirements for monitoring radioactivity in water supplies (PDF 85KB)

N/A

2004

REF

TITLE

Annex

13/2004

Common Carriage: Guidance on the drinking water quality aspects (PDF 82KB)

Guidance (PDF 214KB)

11/2004

Information requirements following notification of an exceedence of a regulatory standard (PDF 80KB)

A - Pro forma (PDF 70KB)
B - Format for the submission of additional information (PDF 104KB)

10/2004

Monitoring drinking water at establishments where water is supplied to the public (PDF 91KB)

Categories and estimate of numbers (PDF 37KB)

05/2004

Commencement of Part 3 Provisions of Water Act 2003 (PDF 82KB)

N/A

04/2004

Water Supply (Water Quality) Regulations 2000: Report on the results of the survey of analytical performance for the measurement of lead (PDF 128KB)

N/A

2003

REF

TITLE

Annex

18/2003

Monitoring for conservative parameters in water supply zones supplied by bulk supplies of treated water (PDF 86KB)

Template for applications (PDF 98KB)

17/2003

Section 19 Undertakings continuing beyond 31 December 2003 and the frequency of monitoring requirements (PDF 98KB)

N/A

16/2003

The Water Supply (Water Quality) Regulations 2000 and the Water Supply (Water Quality) Regulations 2001 - Monitoring for Clostridium perfringens (including spores) (PDF 139KB)

N/A

12/2003

Procedures for the Delivery of Water Treatment Chemicals (PDF 82KB)

N/A

09/2003

Authorised and Automatic Supply Point Authorisations (PDF 46KB)

1 - Parameters for which Regulation 8(1) is applicable (PDF 86KB)
2 - Parameters unlikely to be granted supply points authorisations (PDF 89KB)
3 - Parameters for which supply point authorisations are likely to be granted (PDF 64KB)
4 - Application for authorised supply point monitoring (PDF 74KB)

06/2003

The Water Undertakers (Information) Direction 2003 - Format for provision of certain information (PDF 88KB)

A - Information Direction (PDF 40KB)
B - File specification (PDF 129KB)
C- Parameter code list* (PDF 257KB) *Updated Oct 2014

03/2003

Water Supply (Water Quality) Regulations 2000 - Authorised Departures under Regulations 42 and 20 (PDF 88KB)

List of parameters (PDF 50KB)

2002

REF

TITLE

Annex

15/2002

Distribution Operation and Maintenance Strategies (DOMS) - DWI Requirements and Expectations (PDF 175KB)

Expanatory notes (PDF 141KB)

03/2002

Cryptosporidium in water supplies: guidance on low-pressure membrane integrity monitoring (PDF 99KB)

Criteria to be included in membrane integrity proposals (PDF 34KB)

2001

REF

TITLE

Annex

13/2001

Water Supply (Water Quality) (Amendment) Regulations 2001 (SI 2001/2885)  (PDF 23KB)

N/A

11/2001

The Water Supply (Water Quality) (Amendment) Regulations 1999: Cryptosporidium in Water Supplies - Listing of products capable of removing or retaining particles greater than 1 micron diameter (PDF 113KB)

N/A

03/2001

Further Guidance on Requirements to Meet New Lead Standards (PDF 231KB)

N/A

02/2001

Water Supply (Water Quality) Regulations 1989: Guidelines for Calibration in Laboratories (PDF 251KB)

N/A

01/2001

Radon and Uranium in Drinking Water Supplies (PDF 98KB)

A - Draft letter (PDF 104KB)
B - Assessment of the effects of uranium in drinking water (PDF 42KB)
C - Controlling levels of radon (PDF 103KB)

2000

REF

TITLE

Annex

16/2000

Review of procedures for operation and maintenance of the distribution network (PDF 77KB)

Summary report (PDF 47KB)
Checklist 1 (PDF 19KB)
Checklist 2 (PDF 18KB)
Checklist 3 (PDF 15KB)
Checklist 4 (PDF 16KB)
Checklist 5 (PDF 23KB)
Checklist 6 (PDF 14KB)
Checklist 7 (PDF 14KB)
Checklist 8 (PDF 18KB)
Checklist 9 (PDF 12KB)
Checklist 10 (PDF 14KB)

09/2000

Distribution System Undertakings: Investigations, Pre- and Post-Renovation Assessment (PPRA) and New Undertakings (PDF 89KB)

A - Appraisal of results of pre- and post-renovation assessment (PDF 120KB)
B - Levels of investigation (PDF 63KB)

1999

REF

TITLE

Annex

18/1999

Further guidance on analytical quality control (AQC) and analytical reporting limits (PDF 81KB)

Guidance (PDF 157KB)

1998

REF

TITLE

Annex

14/1998

Disinfection After Mains Bursts and Repairs and Other Mains Activities (PDF 24KB)

N/A

1997

REF

TITLE

Annex

15/1997

S19 distribution system undertakings: customer questionnaires for assessing discoloured water problems (PDF 41KB)

N/A

13/1997

Incidents involving discoloured or 'dirty' water supplies (PDF 36KB)

N/A

1996

REF

TITLE

Annex

04/1996

Monitoring of distribution system undertakings (PDF 66KB)

N/A

 

 

Page reviewed: 13 February 2017
Page modified: 13 February 2017

Drinking Water Inspectorate