Current through Register Vol. 48, No. 38, September 20, 2024
a) The
requirements of this Subpart Z are NPDWRs. The regulations in this Subpart Z
establish or extend treatment technique requirements in lieu of maximum
contaminant levels for Cryptosporidium. These requirements are in addition to
requirements for filtration and disinfection in Subparts B, R, and X of this
Part.
b) Applicability. The
requirements of this Subpart Z apply to all Subpart B systems, which are PWSs
supplied by a surface water source and PWSs supplied by a groundwater source
under the direct influence of surface water.
1) A wholesale system supplier, as defined in
Section
611.102,
must comply with the requirements of this Subpart Z based on the population of
the largest system in the combined distribution system.
2) The requirements of this Subpart Z for
filtered system suppliers apply to a supplier required by NPDWRs to provide
filtration treatment, whether or not the supplier is currently operating a
filtration system.
3) The
requirements of this Subpart Z for an unfiltered system supplier apply only to
an unfiltered system supplier that timely met and has continued to meet the
filtration avoidance criteria in Subparts B, R, and X of this Part, as
applicable.
c)
Requirements. A supplier subject to this Subpart Z must comply with the
following requirements:
1) The supplier must
conduct an initial and a second round of source water monitoring for each plant
that treats a surface water or groundwater under the direct influence of
surface water source. This monitoring may include sampling for Cryptosporidium,
E. coli, and turbidity as described in Sections
611.1001
through
611.1006,
to determine what level, if any, of additional Cryptosporidium treatment the
supplier must provide.
2) The
supplier that plans to make a significant change to its disinfection practice
must develop disinfection profiles and calculate disinfection benchmarks, as
described in Sections
611.1008
through
611.1009.
3) A filtered system supplier must determine
its Cryptosporidium treatment bin classification as described in Section
611.1010,
and provide additional treatment for Cryptosporidium, if required, as described
in Section
611.1011.
An unfiltered system supplier must provide treatment for Cryptosporidium as
described in Section
611.1012.
A filtered or unfiltered system supplier must implement Cryptosporidium
treatment according to the schedule in Section
611.1013.
4) A supplier whose system has uncovered
finished water storage facilities must comply with the requirements to cover
the facility or treat the discharge from the facility as described in Section
611.1014.
5) A supplier required to provide additional
treatment for Cryptosporidium must implement microbial toolbox options that are
designed and operated as described in Sections
611.1015
through
611.1020.
6) The supplier must comply with the
applicable recordkeeping and reporting requirements described in Sections
611.1021
and
611.1022.
7) The supplier must address significant
deficiencies identified in sanitary surveys performed by USEPA or the Agency,
as described in Section
611.1023.
BOARD NOTE: Derived from
40 CFR
141.700(2006).
