OPERATIONS
After years of careful evaluation of data provided by CA-NV AWWA and industry professionals, the NSF standards review board, which performs
testing and establishes the criteria for American National Standards Institute ANSI Standard 61 (Drinking water system components Health
effects (61i127)), has modified the standard with respect to concrete in contact with drinking water.
www.ca-nv-awwa.org 17
ANSI/NSF Standard 61 Finally Finalized
By Joy Eldredge
Shown: 1.0 MG prestressed concrete tank in California’s Central Valley. Courtesy of DN Tanks.
History
In December 2012, NSF International proposed an increase
in the testing requirements for concrete and other items. As a
representative of the drinking water industry, CA-NV AWWA
commented on the process for changing the standard and
requested the data and rationale that drove the proposed
changes. The issue had been a recurrent subject at CA-NV
AWWA’s annual spring and fall conferences because California
Water Regulations require all items in contact with drinking
water to be in compliance with ANSI/NSF 61.
The proposed changes posed a significant challenge to CA-NV
members, and an ad hoc subcommittee was established in
the Water Quality Division to develop guidance on complying
with existing California regulations. The committee engaged
California’s State Water Resources Control Board’s Division of
Drinking Water (DDW) about the challenges of complying with
the requirements as written.
Over a five-year time period, the Ad Hoc Subcommittee on
Standard 61, DDW regulators, NSF joint committee members,
and NSF staff were able to compile data, conduct analysis and
collectively develop modified language for concrete compliance.
The following provides an overview of the changes to the ANSI/
NSF 61 with regard to concrete.
Section 3.3.2 Minimum Test Batteries
Uncoated concrete storage tanks of 350,000 gallons or larger are
exempt from ANSI/NSF 61.
Uncoated concrete with a diluted surface area-to volume ratio less
than or equal to 0.8 in2/L for static conditions or 0.08 in2/L for
flowing conditions are exempt.
In both exemptions, individual admixtures still need to be
certified for compliance with ANSI/NSF 61. The requirement for
admixtures to comply with Standard 61 has not been an obstacle
to the drinking water industry since products that have been