Distribution Systems:
A Best Practices Guide
Introduction
Purpose This Guide discusses the importance of maintaining your distribution system.
Target This Guide is intended for owners and operators of all public water systems
A u d i e n ce serving fewer than 10,000 persons.
Distribution Systems
Distribution Systems usually consist of:
Piping and fittings Pumps and pump stations Meters
Storage tanks Backflow prevention devices Hydrants and valves
Importance of Maintaining Your Distribution System
A properly maintained distribution system is important for ensuring that you can: provide high
quality water to your customers, continue operating in the event of an emergency, help
minimize property damage as a result of responding to an emergency, and help prevent
contamination events. A properly maintained distribution system can also extend equipment
life-cycles and minimize problems related to minor or major equipment failures.
Distribution System Routine and Preventative Maintenance Tasks
The following table provides suggested frequencies of routine and preventative maintenance
tasks for systems under normal operation. However, any time a system experiences water
quality issues, the appropriate tasks should be performed as frequently as needed. Contact
your state for more information.
Task Benefits Suggested Frequency
Improves reliability.
Familiarizes crews with valve
location.
Valve exercising Identifies inoperable valves. Annually.
Locates obstructed valve boxes.
Ensures isolation of distribution
system sections when necessary.
Removes aged water from the
pipeline. Annually for all piping.
Reduces buildup of biofilms and More often in areas with
Flushing pipelines
sediments. water quality issues
(e.g., dead ends).
Restores disinfectant residual.
Detects vandalism.
Identifies defects.
Daily or weekly for
Storage tank Ensures that access hatches are vandalism. Annually for
inspections locked. other items.
Ensures that vents, overflows, and
drains are screened.
Distribution System Routine and Preventative Maintenance Tasks
(continued)
Task Benefits Suggested Frequency
Improves protection against Every 3 years for
Storage tank sources of contamination. cleaning. Painting and
maintenance Extends the useful life of the repairs as dictated by
equipment. inspection.
Provides information on potential
contamination of raw and finished
water.
Routine water quality Will vary depending on
monitoring (e.g., pH, Helps determine effectiveness of water quality and state
temperature) treatment. regulations.
Helps assure the compatibility of
the water with the materials.
Ensures that hydrants and valves
are operable and that no water
Inspecting and flushing losses occur. Once or twice per year.
hydrants and valves
Ensures that hydrants and valves
are not susceptible to tampering.
Reduces the risk of backflow
contamination.
Helps your system provide better
Maintaining operating
pressure range of service to customers. Continuously.
distribution system Reduces damage to infrastructure
due to excess pressure.
Provides adequate fire flow.
Can reduce pumping and treatment Daily at the source.
Tracking unaccounted costs. Monthly or during
for water Helps identify leaks, breaks, stolen routine meter reading at
water, and inaccurate meters. customer connections.
Indicates a presence of inadequate
Monthly in conjunction
Testing for presence of chlorine residual, possible high
with Total Coliform
excess biofilms disinfection byproduct levels, and
sampling.
water stagnation.
Identifies the need to modify
Monitoring corrosion Annually.
treatment or conduct flushing.
Checking for normal Can extend the useful life of
wear (such as in infrastructure components. According to the
mechanical parts found manufacturer's
in pumps and control Helps avoid unnecessary recommendations.
valves) replacement or operational costs.
For additional information:
Call the Safe Drinking Water Hotline at 1-800-426-4791, visit the EPA Web site at
www.epa.gov/safewater/smallsys.html, or contact your State drinking water representative.
Office of Water September 2006 EPA 816-F-06-038
