Watercapes Spring 2006

• Year: 2006
• Title: Waterscapes
• Author: Water Group of HDR
• Description: The Value of Applied Research
• Publications - Doc Type: Other

Development
Optimization
By Melinda J. Friedman, P.E.
of Distribution S stem Water Quality
Plans, An Awwa4 Project
risking water distribution systems have
been receiving increased attention over
the past few years, with regard to both
physical integrity and water quality. More and
more regulations have been promulgated, or are
in the process of being developed, that directly
focus on water quality conditions in the distribution
system. It is more important than ever for
utilities to have a good understanding of the
microbial, physical and chemical reactions
occurring throughout their distribution systems.
Much of the effort and expense allocated to
treating source water can be wasted if the water
quality significantly degrades by the time it reaches
the customer's tap.
The Distribution System Water Qua IhOptimization
Plan (DSOP) is a tool utilities can use to evaluate
and improve programs that affect distribution
system water quality; evaluate conditions within
the distribution system to reduce the potential
for contamination; create better documentation;
and enhance communication between the various
utility functions that impact water quality in the
distribution system. A DSOP addresses both
regulatory compliance issues and issues related to
aesthetic properties of drinking water.
Optimizing distribution system water quality
management can assist utilities in:
• Reducing the potential for waterborne
pathogens to reach customer's drinking
water,
• Improving distribution system water quality
above and beyond regulatory requirements,
• Preparing for future revisions of the Total
Coliform Rule and the potential Distribution
System Rule that may focus on distribution
system operation and maintenance, instead
of numeric evaluation of coliforms or other
contaminants,
• Identifying and addressing water quality
concerns that can be attributed to the
distribution system,
• Identifying infrastructure improvements
needed to ensure compliance with existing
or future regulations, and incorporating
improvements into the Master Planning process,
Addressing customer expectations above
and beyond meeting drinking water
regulatory requirements, and
Developing programs and practices as
recommended in AWWA Standard G200 -04
for Distribution Systems Operation and
Management (AWWA 2004).
Steps for Conducting a DSOP
Utilities can develop individual DSOPs in the
following manner:
1. Develop water quality and operating goals for
the distribution system
2. Identify ongoing utility programs that
may contribute valuable information related
to the condition of the distribution system
and distribution system water quality.
3. Conduct a distribution system audit using
these steps:
a. Form an audit team.
b. Establish goals /objectives of audit.
c. Gather and review in -house data and
reports.
d. Interview utility personnel.
4. Compare audit findings to industry best
management practices, regulations and
customer expectations.
5. Develop a list of utility needs (DSOP
elements) to be addressed for optimizing
distribution system water quality.
6. Prioritize DSOP elements according to:
a. Relative contribution toward
enhancing and /or improving water
quality conditions throughout the entire
distribution system.
b. Potential benefits for helping to preclude
quality degradation or contamination in
localized areas of the system.
c. Available resources.
7. Develop and implement programs outlined
by DSOP elements.
8. Periodically review programs developed as
part of the DSOP and goals for water
quality and distribution system management.
Additionally, refresher audits will likely be
necessary.
AwwaRF Project 2875, Development of
Distribution System Water Quality Optimization
Plans (Friedman, et al., 2005), was conducted as
tailored collaboration between AwwaRF and
several participating utilities including Greater
Cincinnati Water Works in Ohio, Calgary
Waterworks in Canada and the City of Everett,
Washington. The project was funded in part
by the participating utilities and work products
were developed to benefit the participating
utilities and AwwaRF members. The utilities that
participated in this project all proactively
manage their distribution systems and comply
with drinking water quality regulations.
However, each recognized that there were
ways to improve the quality of water reaching
their customers and enhance their distribution
system operations. The three utilities were also
concerned with addressing customer expec-
tations and assembling and documenting
Best Management Practices for their respective
drinking water distribution systems.
Each utility conducted an audit and field
investigations to assess the conditions
and operating status of their distribution
systems. The audits were used to identify strong
points as well as areas that needed to be
improved to meet industry standardsfordistribution
systems. Water quality and operating goals
were established and documented for each
system. These goals were used to determine which
programs the participating utilities would focus
on for their DSOP. Individual distribution system
programs were then developed at each utility
and these elements were field- tested and refined
at each utility location. The following program
elements were developed for the participating
utilities:
• Distribution system water quality goals.
• A comprehensive distribution system water
quality monitoring program.
• Distribution system biofilm control measures.