WRF Tailored Collaboration project #4509, Metals Accumulation
and Release Within the Distribution System: Evaluation and
Mitigation (Friedman et al. 2016), was sponsored by Park City
Municipal Corporation (PCMC), in Park City, UT. Two of PCMC’s
water supplies contain naturally occurring heavy metals such as
arsenic (As), thallium ( Tl), and lead (Pb), along with co-occurring
iron (Fe) and manganese (Mn). Treatment and blending are pro-
vided to remove and dilute metals at the sources, but over many
TIC concentrations that far exceed point-of-entry (POE) levels,
and in some cases exceed maximum contaminant levels (MCLs)
or action levels, have been measured within distribution systems.
It should be noted that no MCLs or action levels for TICs apply
to the utility-owned portion of the distribution system. Thus,
although excursions (defined as a measurement greater than an
MCL or action level) have been observed, regulatory violations
have not occurred.
and Release Within the
Melinda Friedman and Andrew Hill, Confluence Engineering Group, LLC; Laurie McNeill,
Utah State University; Michelle De Haan, Park City Municipal Corporation
The potential for accumulation and intermittent release of trace inor- ganic contaminants (TICs) within drinking water distribution sys- tems has gained considerable attention over the past several years.