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for Triennial Review of Groundwater Standards
Every three years the DWQ CSU will review the NC 2L groundwater quality
standards and interim maximum allowable concentrations as required by 15A
NCAC 02L.0202(f) to determine if changes are needed. This review process is
referred to as the Groundwater Triennial Review (GWTR).
The DWQ's Standard Operating Procedure for Reviewing Groundwater
Standards (GWSOP) will be used to provide consistency and transparency in the
review process (http://portal.ncdenr.org/web/wq/ps/csu/gwtrirev).
2. All relevant toxicological and epidemiological data, study results, and
calculations used to establish a groundwater standard in accordance with .0202(d)
will be documented as follows and archived in the Classifications and Standards
Unit:
Groundwater Standard Worksheet - A Microsoft Excel worksheet will be
developed and maintained for each standard and will include the numerical values
and references for each of the six criteria used to establish a standard in
accordance with .0202(d). The Groundwater Standard Worksheet calculates a
non cancer systemic threshold concentration and a concentration corresponding to
a I x 10-6 (one -in -a -million) cancer risk according to 2L requirements. It also
contains the numerical values found in the literature for taste and odor thresholds,
federal MCLs and secondary drinking water standards. The worksheets will be
updated as necessary as part of the groundwater triennial review and worksheets
will be developed for new or proposed standards.
Groundwater Standards Table - A Microsoft Excel Table which summarizes
the information used to calculate each groundwater standard will be developed for
easy review of all proposed changes as a result of the triennial review.
Once the GWTR is complete, any proposed changes, additions or deletions to the
groundwater standards will be summarized in a Groundwater Standards Table and
submitted to the Department of Health and Human Services (DHHS) Division of
Public Health (DPH), the Division of Waste Management (DWM) and the DWQ
Aquifer Protection Section for review and comment as provided in the DWQ
standard operating procedure for reviewing groundwater standards
(http://portal.ncdenr.org/web/wq/ps/csu/gwtrirev).
4. The DWQ will attempt to reach consensus with DPH and DWM on appropriate
groundwater standards.
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5. Any needed changes to the groundwater standards as a result of the triennial
review will be presented first as an information item to the Environmental
Management Commission (EMC) Groundwater Committee (GWC) for feedback.
6. Any feedback from the GWC will be incorporated into the GWTR and draft rules
and a draft fiscal analysis will brought back to the GWC at a later date for
approval to go before the full EMC.
7. Results of the GWTR, draft rules and a draft fiscal note will be presented to the
full EMC for approval to proceed to public notice to begin the rulemaking
process.
8. Hard copies of supporting information for the GWTR are available in the file
cabinet located in room 71 IH. Electronic copies of supporting information are
archived on the CSU shared drive at S:/Groundwater Stds-2L/ GWTRs.
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