2013 Water System Plan, Volume II - Seattle City Clerk's Office - City ...

sampling, or reduce the amount of samples required. The State issued waivers for SPU for
Volatile Organic Chemicals (VOCs) and Synthetic Organic Chemicals (SOCs) for the 2008 to
2010 monitoring period. SPU will apply for waivers for the 2011 to 2013 monitoring period.
There are also several area-wide waivers in effect for several of the SOCs. These waivers apply
to all systems within the designated area.
SPU operates its own State-certified laboratory for a majority of the parameters monitored. This
includes total coliform, fecal coliform, HPC, most inorganic chemicals, trihalomethanes,
haloacetic acids, lead, copper, VOCs, and all SWTR parameters. Samples for SOCs, asbestos,
some inorganics, and Cryptosporidium and Giardia are sent to other laboratories certified by the
state or EPA for the analysis.
Adjustments to monitoring are often required based on operational considerations, detection of
organic chemicals, construction projects, or as required by the state based on a public health
concern. SPU will work with the State to determine appropriate changes to the monitoring
program to address any concerns that may arise.
2.0 Monitoring Requirements
The following summarizes the monitoring requirements for existing and future regulations.
Existing regulations include those finalized by EPA and published in the Federal Register under
40 CFR Part 141. Any regulation the state has adopted into Chapter 246-290 WAC with changes
or additions are also discussed under existing regulations. Future regulations include those
currently proposed by EPA.
2.1 Existing Regulations
The existing regulations discussed below are organized by their common name with a reference
to the appropriate federal and state section numbers.
Total Coliform Rule (40 CFR 141.21 and WAC 246-290-300 (3))
SPU collects and analyzes coliform samples from representative points throughout the direct
service area as outlined in SPU’s Coliform Monitoring Plan (attached without appendices).
These samples are collected at designated sample stands according to established routes assigned
by the Senior Water Quality Analyst or designee. Routes are designed to cover both the Cedar
and Tolt service areas each day; with most sample stands being sampled weekly. To meet
regulatory requirements, SPU must collect at least 189 coliform samples from its direct service
area each month. The chlorine residual is also analyzed in the field at the time of coliform
sample collection as required by state regulations. Temperature is also measured, although not
required.
For any sample found to be positive for total coliform, or invalidated, follow-up action is taken
according to state and federal regulations, as described in SPU’s Coliform Monitoring Plan. This
follow-up action may include additional sample collection, additional analyses such as fecal
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