Connie Brower
NC DENR Division of Water Resources
Triennial Review of Standards
 For the US EPA to approve modifications to
a state’s standards, criteria must be
sufficient to maintain protection of
human health and aquatic life
 The Triennial Review is toxicity based
Proposed Changes:
Human Health standards
Aquatic life metals standards
Clarifications/reorganization of water
quality standards regulations
2,4 D: chlorophenoxy herbicide
Incorporation of updated
non-cancer information provided
through US EPA IRIS
Manganese
 The current water quality standard for
Manganese is proposed to be removed
from the regulations
 Naturally occurring levels of
Manganese in North Carolina waters
are elevated
Proposed Changes to Aquatic Life
Standards
Review of National Criteria
and Science
 Since 1980’s - US EPA has published revisions
to several metals
 To date, North Carolina has not adopted those
recommended changes
 Metals standards are proposed for
modification to reflect current science
15A NCAC 02B .0211 and .0220
Aquatic Life Standards
Acute Criterion
 For Metals:
 Acute standards are proposed (along w chronic)
 Exceptions: Selenium & Mercury (chronic only)
 Duration information is proposed
 96 hour average - chronic
 1 hour average - acute
Flow Design Criterion
 1Q10 flow criterion for implementation
of the acute standards
 Flow design based upon federal guidance
 Currently in use by NPDES permit
writers (daily max)
Metals Toxicity
 Toxicity of metals is influenced by factors such
as….
 Form and speciation of the metal
 pH, TSS, DOC, TOC, water hardness, etc…
 EPA’s national criteria take some of these
factors into account
 Dissolved metals
 Hardness-based criteria with equations
 Cu Biotic Ligand Model (10 co-parameters)
Dissolved Metals
 With the exception of Mercury and
Selenium, DWR proposes the use of
dissolved metals water quality standards
 Dissolved metals standards better
represent the bioavailable fraction
Hardness-Dependent Metals

For some metals:
↓ water hardness is associated with
↑ aquatic toxicity
Metal specific equations that include
provisions for localized hardness
applications are proposed
Hardness-Dependent Metals
 Equation-based instream standards are proposed
Formula for Cadmium (chronic):
{1.101672-[ln hardness](0.041838)} ∙ e^{0.7998[ln hardness]-4.4451}
 Numerical instream standards illustrated using a hardness of
25 mg/l are presented in proposed rules for clarification
purposes
Applicable Cadmium (chronic) illustrated standard
at an instream hardness of 25 mg/l (or lower)
= 0.15 ug/l
Flexibility of Applicable Instream
Hardness Values
 The ability to use applicable instream
hardness concentrations between
25 mg/l to 400 mg/l
 To assess compliance with the equation
based standard, hardness is sampled
with metals analysis
Dissolved Metal Standards:
Implementation in Ambient Monitoring
 Collect instream sample for metal & hardness
analysis
Filter in field (to capture the dissolved portion)
Routine metals analysis by laboratory
 Enter lab reported hardness into the equation(s)
from 2B rules to calculate each metal standard
 Compare reported dissolved metals instream
concentration to the sample specific metal standard
to determine compliance.
Dissolved Metal Standards
Implementation in NPDES permits
 40 CFR 122.45 (c): permits are written as
total recoverable metals
 NPDES will employ EPA published
translators for this purpose
 Translator answers the question:
What fraction of metal in the effluent
will be dissolved in the receiving water?
Hardness-Dependent Metals
NPDES Implementation
 Permits will incorporate protective metals levels that
consider in-stream and effluent water hardness

In-stream hardness for NPDES use:
Median percentile of local 8 digit HUC data

Effluent hardness for NPDES use:
Median percentile of effluent hardness data
Metal
Current Total
Freshwater
Aquatic Life Standard
Proposed Dissolved Standard at
25 mg/l hardness (ug/L)
Chronic at
50 mg/L Hardness
Chronic
25 mg/L
Acute
25 mg/L
Arsenic
50
150
340
Beryllium
6.5
6.5
65
Cadmium*
2 / 0.4 trout
0.15
0.82 / 0.51 trout
Chromium (total)
50
Chromium III *
none
24
180
Chromium VI
none
11
16
Copper *
7 (AL)
2.7 (AL)
3.6 (AL)
Iron
1 mg/L (AL)
Lead *
25
Manganese
** current WS std
Proposed for removal
Proposed for removal
0.54
14
**Proposed for removal
Nickel *
88
16
140
Silver
0.06 (AL)
0.06 (AL)
0.30 (AL) *
Zinc *
50 (AL)
36 (AL)
36 (AL)
Biological Confirmation
 Assessment of the biological integrity of the
stream will supersede instream metal
sampling results when determining
attainment of aquatic life use
 Exceptions: Mercury and Selenium
Variances
In accordance with 15A NCAC 02B .0226 – variances
from the state water quality standards may be
approved by the Commission on a case-by-case
basis.
Comments received with respect to the applicable
variances will be forwarded to the Surface Water
Protection Section for evaluation during the next
permit cycle review
Fiscal Impact (NC GS 150B)
 Fiscal impacts detailed
 Fiscal analysis prepared & submitted to Office of State
Budget Management (OSBM)
 OSBM has certified that proposed rules & fiscal note meets
the requirements of NC GS 150B-19.1
 Alternatives considered:
 No action
 Adoption of revised Total vs Dissolved Metals
Fiscal Impacts
 Projected outcomes (~2950 permittees):
 ~96% wastewater dischargers not affected
 ~106 facilities get new limits for metal(s)
 ~21 facilities revert to monitoring only
 Estimated impact:
 $181 m in costs over 30 year period, Net Present Value
 $195 m in benefits over 30 year period, Net Present Value
Projected Timeline
 November 19, 2013
 January 3, 2014
 March 13, 2014
 March–April 2014
 May 2014


Public Hearing
End of Comment Period
Hearing Officer’s Report
Complete Fiscal Note
Draft proposed regulations
WQC review of proposals
Request approval for Public
Hearings
**** Request to proceed to EMC
Summer 2014
Public Hearings
Fall / Early winter 2015 EMC approval request
Request to Proceed to EMC to Ask for
Permission to Proceed to Public
Hearing with Surface Water Quality
Standards Rule Amendments to
15A NCAC 02B and
Approval of the Fiscal Note in
accordance with NC GS 150B-19.1(e).
(WQC may request a “30-day waiver” to
proceed to EMC the next day)
Questions?
Connie Brower
Classifications and Standards/ Rules Review Branch
Connie.Brower@ncdenr.gov
919-807-6416
http://portal.ncdenr.org/web/wq/ps/csu/swtrirev