Guidance on Controlling Corrosion in Drinking Water Distribution Systems

Table of Contents

• Background on guidance documents
• Part A. Guidance on corrosion control
• A.1 Introduction and background
• A.2 Corrosion control programs and protocols
  • A.2.1 Monitoring program for residential sites: option 1 (two-tier protocol)
    • A.2.1.1 Tier 1 sampling protocol
    • A.2.1.2 Tier 2 sampling protocol
    • A.2.1.3 Follow-up sampling
  • A.2.2 Monitoring program for residential sites: option 2 (lead service line residences)
    • A.2.2.1 Sampling protocol
  • A.2.3 Frequency of sampling for residential monitoring
  • A.2.4 Number and selection of sites for residential monitoring
  • A.2.5 Monitoring program for non-residential sites (two-tier protocol)
    • A.2.5.1 Tier 1 sampling protocol
    • A.2.5.2 Tier 2 sampling protocol
    • A.2.5.3 Selection of monitoring sites and monitoring frequency
• A.3 Responsabilites
• A.4 Sampling protocols and action levels for lead
  • A.4.1 Initial monitoring for residential sites: option 1 (two-tier protocol)
  • A.4.2 Initial monitoring for residential sites: option 2 (lead service line residences)
  • A.4.3 Initial monitoring for non-residential sites (two-tier protocol)
• Part B. Supporting information
• B.1 Principles of corrosion in drinking water distribution systems
  • B.1.1 Main contaminants from corrosion of drinking water distribution systems
  • B.1.2 Sources of contaminants in distribution systems
    • B.1.2.1 Lead pipes, solders and fittings
    • B.1.2.2 Copper pipes and brass fittings
    • B.1.2.3 Iron pipes
    • B.1.2.4 Galvanized pipes
    • B.1.2.5 Cement pipes
    • B.1.2.6 Plastic pipes
• B.2 Challenges in measuring corrosion
  • B.2.1 Levels of contaminants at the tap
  • B.2.2 Factors influencing levels of contaminants at the tap
    • B.2.2.1 Age of the plumbing system
    • B.2.2.2 Stagnation time of the water
    • B.2.2.3 pH
    • B.2.2.4 Alkalinity
    • B.2.2.5 Temperature
    • B.2.2.6 Calcium
    • B.2.2.7 Free chlorine residual
    • B.2.2.8 Chloramines
    • B.2.2.9 Chloride and sulphate
    • B.2.2.10 Natural organic matter
• B.3 Methods for measuring corrosion
  • B.3.1 Corrosion indices
  • B.3.2 Coupons and pipe rig systems
  • B.3.3 Lead monitoring at the tap
• B.4 Treatment/control measures for lead, copper and iron
  • B.4.1 Materials in drinking water distribution systems
  • B.4.2 Controlling pH and alkalinity
  • B.4.3 Corrosion inhibitors
    • B.4.3.1 Phosphate-based inhibitors
    • B.4.3.2 Silicate-based inhibitors
  • B.4.4 Flushing and maintenance
  • B.4.5 Drinking water treatment devices
• B.5 Rationale for monitoring programs for assessing corrosion
  • B.5.1 Residential monitoring programs
  • B.5.2 Determination of sampling protocols and action level for residential monitoring program: option 1 (two-tier protocol)
    • B.5.2.1 Tier 1 sampling protocol
    • B.5.2.2 Tier 2 sampling protocol
  • B.5.3 Determination of sampling protocols and action levels for residential monitoring program: option 2 (lead service line residences)
    • B.5.3.1 Limitations
  • B.5.4 Determination of residential monitoring sites
  • B.5.5 Determination of sampling protocols and action levels for non-residential monitoring programs
    • B.5.5.1 Tier 1 sampling protocol
    • B.5.5.2 Tier 2 sampling protocol
  • B.5.6 Determination of non-residential monitoring sites
• Part C. Acronyms, tables and references
• C.1 Acronyms
• C.2 Guidance on determination of 90th percentile
• C.3 Principal factors influencing the corrosion and leaching of lead, copper, iron and cement
• C.4 Conditions favouring lead leaching and indicators of lead leaching in drinking water distribution and plumbing systems
  • C.4.1 At the treatment plant
  • C.4.2 Within the distribution system
  • C.4.3 Within the plumbing system
  • C.4.4 At the tap
• C.5 Guidance on prioritizing residential monitoring sites
• C.6 Plumbing profile determination
• C.7 References