GREEN BUILDINGS THAT include water
conservation measures are becoming
more prevalent. However, there may be
unintended consequences to water quality associated with these buildings, including those associated with high water age.
Water age is equivalent to water residence
time (i.e., detention time), measured from
the entry point of a pipeline distribution
system to its point of use.
Project #4383, Green Building Design:
Water Quality Considerations (Rhoads et al.
2015), identifies water age as a factor that
will play an increasingly important role in
water quality and public health, especially
as water conservation and water efficiency
strategies are adopted. This project identi-
fied a number of concerns that are impor-
tant to consider in green building design
to protect public health and water qual-
ity, including loss of residual disinfectant,
corrosion, taste and odor issues, microbial
regrowth, and opportunistic pathogens
such as Legionella. Real-life examples of
such occurrences are provided, and three
field-site case studies were developed.
Recommendations to reduce issues with
high water age were developed in a fact
sheet (#4383b) for specific stakeholders
including water utilities, building and
home owners, plumbing system designers,
plumber, building occupants, code organi-
zations, and green building organizations
and device manufacturers.
Green Building Design: Water
FILTER CLOGGING EPISODES, equipment
damage, and aesthetic or regulatory
water quality issues are common results
of nuisance algal blooms or zooplankton
population expansions in source water
reservoirs. Among drinking water provid-
ers in the Pacific Northwest, there is a per-
ception that the frequency and severity
of these events have increased in recent
years. There is also growing concern over
invasive species and the specific risks
that they pose to drinking water systems.
Project #4364, Management of Nuisance
Aquatic Species at Pacific Northwest
Drinking Water Utilities (McFadden et al.
2015), describes the management strat-
egies that will guide decision-makers
faced with nuisance species challenges
throughout the industry. Water supply
managers considering development of
predictive capability can take into account
the case study experiences, as well as the
associated requirements for data collec-
tion and organization discussed in the
final report. The procedures for invasive
species risk assessment, through the use
of a risk assessment tool, will allow utilities
to assess their own system vulnerabilities
and improve their understanding of the
specific impacts that a range of potentially
invasive species might bring about.
Nuisance Aquatic Species