Report No FR0448

LAYING POTABLE WATER PIPELINES IN CONTAMINATED GROUND -
GUIDANCE NOTES

FR0448

Nov 1994

SUMMARY

I BENEFITS

The availability of simple, structured guidelines for the assessment of contaminated sites and the preliminary choice of pipe materials and installation techniques will enable water supply engineers to approach the development of mainlaying schemes on contaminated land with increased confidence.

II OBJECTIVES

To collate existing information and guidance on the selection and installation of pipeline materials in contaminated land.

To review recent research on the effects of ground contaminants on pipeline materials.

To prepare structured guidelines for the selection and installation of pipeline materials in contaminated land situations for use by water supply engineers, and to provide an input to the revision of the Pipe Materials Selection Manual for water supply applications.

III REASONS

Local authorities are facing growing pressure for the redevelopment of existing and derelict sites in urban areas, in order to restrain the demand for greenfield sites in more rural areas. Many such redevelopment sites have a history of prior industrial use, and so many be associated with a wide range of ground contaminants, the nature and extent of which may be more or less well defined. In this situation, there is a need for simplified guidance which will enable a water supply engineer to be aware of the most common hazards to be encountered on a particular redevelopment site, and to identify the pipeline materials and installation methods most likely to provide effective solutions on such sites, in terms of avoiding permeation and contamination of supply, and premature pipeline structural failure.

IV CONCLUSIONS

Simplified guidance is presented on the classification of contaminated sites according to prior use and likely risk of contamination, contaminated site investigation procedures, key contaminant threshold (trigger) levels, and the resultant initial pipeline materials choices for a range of common prior site uses.

Guidance is also given on appropriate pipeline installation measures which can be used to reduce or eliminate the potential effects of ground contaminants on water supply pipelines.

V RECOMMENDATIONS

The present simplified guidelines should be used by water supply engineers as an initial basis for developing their final choice of water supply pipeline materials and/or installation techniques for mainlaying on former industrial sites where ground contamination may be present.

VI RESUME OF CONTENTS

The report contains a summary of the responsibilities of the site developer and water supply utility in relation to the redevelopment of contaminated sites; a classification of sites according to the likely risk and consequence of contamination; outline site inspection guidance and investigation procedures; summaries of threshold (trigger) levels for some commonly-encountered inorganic and volatile organic compounds; a simple look-up guide giving the preliminary choice(s) of pipeline materials likely to be suitable for a wide range of common former industrial site uses; and guidance on complementary site installation procedures to minimise the risk of pipeline permeation and/or structural failure by site contaminants.

Copies of the report are available from FWR, price 15.00, less 20% to FWR Members.