&EPA

United States
Environmental Protection
Agency

ARSENIC IN DRINKING WATER
COMPLIANCE SUCCESS STORIES

Seattle, WA: Arsenic in Public Schools

Case Study Contact Information

Ron English

(rengli sh@seattleschool s. org)

Seattle Public Schools
(206)252-0651

Seattle Public Schools investigated arsenic levels in school drinking water after finding
high levels at several new drinking water fountains. Monitoring results show that regular
use of drinking water fountains and periodic flushing significantly reduce arsenic to safe
levels.

Lessons Learned

A comprehensive program of monitoring drinking water taps and fountains in Seattle
Public Schools (SPS) indicates that regular use of the school drinking water fountains
helps to prevent accumulation of arsenic, and that flushing is an effective approach to
reducing arsenic levels.

Background

Seattle Public Schools (SPS) provides educational opportunities to approximately 47,000
students in more than 100 schools and administrative buildings. SPS purchases water
exclusively from Seattle Public Utilities (SPU) for drinking water, other potable uses, and
fire protection service. There is no indication that water from the SPU is the source of the
arsenic.

In April 2006, SPS measured high levels of arsenic at several school drinking water
fountains while testing new fountains for lead and other standard water quality
parameters. Although the fountain samples did not have elevated lead levels, several
samples were found to have arsenic levels in the range of 10 to 50 parts per billion (ppb).
All but one of these samples represented fountains that had recently been replaced and
that contained water that had been stagnant for 1 week to 3 months. Arsenic levels were
<10 ppb or below the detection limit for over 99 percent of samples collected from new
fountains containing water with a standing time of 12 to 18 hours.


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Strategy to Address Arsenic Problem

SPS turned off all school drinking water
fountains and taps on May 1, 2006, and
provided bottled water for students and staff as
an interim measure until the source and extent
of the arsenic problem could be identified.

From May to August 2006, SPS measured
arsenic levels in water from every drinking
water tap and fountain at all District schools. Of
more than 3,500 samples tested to date, 21
samples had arsenic levels greater than 10 ppb.

Only 2 of these samples represented school water sources that were active at the time of
sampling. Of these 21 samples, eight were in a single school with recently repaired
fountains that exhibited galvanic corrosion from newly created iron/brass connections
(see photo). These same causative factors apply at some but not all of the other sources
where arsenic was found at levels >10 ppb. Test results consistently indicate that regular
use of the school drinking water fountains helps to prevent accumulation of arsenic, and
that flushing is an effective approach to reducing arsenic levels. At this time, SPS has
returned regular water service to all but one of the affected buildings (one building has
not been tested yet).

SPS has adopted the EPA standard of 10 ppb as a maximum allowable level for all
drinking water sources where water has been flushed and then held for 12 to 18 hours.
Any school drinking water tap or fountain found to have an arsenic level >10 ppb in a
water sample that represents these conditions (standing overnight sample) will remain
out-of-service until the source of arsenic is found.

SPS consultants tested and investigated every possible arsenic source including piping,
fixtures, and materials used in plumbing and cleaning and concluded that the concern is
limited to new fixtures that have not been adequately flushed and remain stagnant for
extended periods. Brass/iron connections will be removed where found, but no additional
remedial action will be taken beyond compliance with the existing SPS protocols for
flushing and testing. Follow-up testing will be performed to confirm the absence of
arsenic.

SPS has worked with local and state health departments, Seattle Public Utilities,
scientists, and other experts to share results and identify possible health impacts. The
school district's Water Quality Oversight Committee has provided guidance on actions
needed to ensure the health and safety of students and staff. SPS has also communicated
directly with parents, staff, and students about water quality. Fact sheets, testing results,
and other resources were posted on the Seattle Public Schools Web site exit Disclaimeri ;
and information was sent to all principals, SPS staff, and community members. The
district frequently updates their Web site as more information becomes available.

Typical iron/brass connection linked
to elevated arsenic levels at some
Seattle Public School drinking water
fountains.


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