Scottish Government Research Opportunity
Tenders are sought for this research project no later than noon on Thursday 29 October 2009
THE EFFECT OF DISCONTINUING PHOSPHATE DOSING OF WATER SUPPLIES ON LEAD CONCENTRATIONS IN DRINKING WATER
TENDER REF: CR/2009/07
Visit RESEARCH SPECIFICATION for additional information on the requirements of the project.
The project will commence in November 2009
Should you wish to tender for this work the tender documents can be obtained by e-mailing one of the following quoting the tender reference above:
Mrs Audrey Watson e-mail: audrey.watson@scotland.gsi.gov.uk
Tel: 0131 244 6057 Fax: 0131 244 6566
Mrs Jacqui DiCarlo e-mail : jacqui.dicarlo@scotland.gsi.gov.uk
Tel: 0131 244 6269 Fax 0131 244 6566
Mrs Bridget McGee e-mail: bridget.mcgee@scotland.gsi.gov.uk
Tel: 0131 244 6050 Fax: 0131 244 6566
Schedule 2
RESEARCH SPECIFICATION
THE EFFECT OF DISCONTINUING PHOSPHATE DOSING OF WATER SUPPLIES ON LEAD CONCENTRATIONS IN DRINKING WATER
TENDER REF: CR/2009/07
Introduction
1. This specification sets out the terms of reference for the research project 'The effect of discontinuing phosphate dosing of water supplies on lead concentrations in drinking water'. The project will consider how water quality in waters of different chemistries will be affected in the event of phosphate dosing stopping.
2. Currently, Scottish Water uses phosphate dosing in some of its supply zones, in the form of either orthophosphoric acid or monosodium phosphate, to reduce the solubility of lead from lead pipes which connect mains pipework to consumers' properties. Phosphate dosing can be an effective method of reducing lead exposure to consumers, but is costly, unsustainable and is dosed to all properties fed from the point dosed, and not just those which have lead pipes. Additionally, phosphate which is dosed into drinking water may have to be removed at Scottish Water's waste water treatment works to prevent environmental damage.
3. Ultimately, lead pipes should be replaced, but there is concern that not all pipes will be; for example Scottish Water may eventually replace all communication pipes in their ownership, but if consumers do not replace lead supply pipes (which are within the boundary of consumers' properties), this would continue to present a potential health risk. One option currently being considered is to discontinue phosphate dosing in supply zones where all communication pipes have been replaced and consumers have been notified of the risks from lead in case they wish to consider replacing their pipework.
The Study
Aims
4. The aim of this research project is to determine the impact on water quality if phosphate dosing is stopped. Specifically, the study will aim to:
- Understand the impact on water quality if phosphate dosing was stopped.
- Understand whether consumer exposure to lead could be significantly and/or suddenly increased by stopping phosphate dosing.
Objectives
5. The research objectives for this project are as follows:
- Understand the impact on any remaining lead pipes within a water distribution zone, taking into account the amount of phosphate that has been dosed, the length of time that it has been dosed, and also the different chemistries of different supplies.
- Determine what happens to the coating of insoluble lead phosphate on the surface of the pipes on removal of the phosphate dosing, and determine the different factors which may impact on its stability.
- Understand whether consumer exposure to lead could be significantly and/or suddenly increased by stopping phosphate dosing.
- Determine whether there are any practical actions that could be taken to minimise detrimental effects.
6. Potential Contractors should note that Scottish Water may have beneficial information, and it is expected that the project will require liaison with Scottish Water.
Methods
7. It is anticipated that this exercise will comprise of a literature review to determine the extent of previous studies, and laboratory trials using different water types over an appropriate length of time, probably two to three years, taking into account the potential impact of different seasons. Additionally, the work could use lead pipes removed from a Scottish Water phosphate dosed supply or from a lead test rig. Careful consideration will need to be given as to how representative laboratory trials on exhumed pipe lengths would be.
Potential contractors are encouraged to expand on the methodology and/or propose alternative methods that achieve the same research outcome.
Research Output
8. At the end of the contract, the successful contractor will provide the Scottish Government with the following outputs:
- A final report which should contain an executive summary. Six copies of the draft and final reports should be supplied in hard copy and a disc copy of the final version in a format compatible with Microsoft Word. Potential contractors should indicate in their tender who will have the main responsibility for writing the report.
- A research summary. This should be a 2-4 page summary of the main findings of the research and should be produced separately from the final report. This summary should not be simply a bulleted version of the points in the main report, but should be a wider look at what the findings mean in a wider policy context and may be edited by the Scottish Government.
- An oral presentation of their research findings to the Scottish Government.
Timing
9. It is envisaged that the study will begin in November 2009 and will be completed by November 2012.
Project Management
10 A Steering Group will be set up to allow technical discussions to take place with the contractor, Scottish Water and the Scottish Government and to enable cooperation between relevant parties.