Liz McKercher elizabeth.mckercher@deq.virginia.gov Craig Lott ...

Liz McKercher
elizabeth.mckercher@deq.virginia.gov
Craig Lott
craig.lott@deq.virginia.gov

�Definition �Definition and Background
�TMDL development process
�Incorporating �Incorporating Construction Stormwater
Discharges: Past and Present
�TMDL �TMDL-Stormwater Stormwater Universe in Virginia
�Presentation �Presentation Goal: Provide the RAP with
sufficient information to construct
regulatory language

�� Federal Clean Water Act, Act Section 303(d)
• List impaired waters, develop TMDLs
� 40 CFR Section § 130.7
• Water Quality Planning and Management
• TMDLs shall take into account critical conditions for
stream t flow, fl lloading, di and d water t quality lit parameters t
� Code of Virginia,
• §62 §62.1-44.15 1-44 15 (10) & (23) and §62 §62.1-44.19:4 1-44 19:4 and 19:8
� Water Quality Management Planning
Regulation egu at o (9 VVAC-25-720) C 5 0)

1972 1999 2010 2014-15
Clean Water
Act 303(d)
•Each State shall
establish for the
waters identified
...the total maximum
daily load
Settlement by
EPA, Consent
Decree (CD)
•To meet the CD,
Vi Virginia i i completed l t d
TMDLs covering
approximately 225
shellfish and 333
non-shellfish
impairments
TMDL
development
continues
post-CD
• Over 1,100
additional waters
require TMDLs
• 100 TMDLs per
biennium
expected
2002
Clarification from EPA on NPDES-
regulated storm water discharges as
wasteload allocation
EPA modifies
watershed
cleanup
performance
measures
• Begin giving
credit for non-
TMDL solutions
• TMDLs still one
watershed t h d clean- l
up tool

�Maximum load of a specified pollutant
that a water body can assimilate and
attain water quality standards
�Includes a wasteload allocation (point
sources), load allocation (non-point
sources) and a margin of safety.

�TMDL �TMDL = WLA + LA + MOS

�40 �40 CFR '122 122.44(d)(1)(vii)(B), 44(d)(1)(vii)(B) “Effluent Effluent
limits developed to protect a narrative
water quality criterion, criterion a numeric water
quality criterion, or both, are consistent
with assumptions and requirements of
any available WLA for the discharge
prepared by the State and approved by
EPA pursuant to 40 CFR '130.7.”

� Benthic Impairment
• Water body not fully supporting its uses due to water
quality violations of the general aquatic life (benthic)
standard.
�� Aquatic Life Standard
• Based on the aquatic, benthic (or bottom‐dwelling)
macroinvertebrates (organisms without backbones
that t atca can be seen see with w t the t enaked a ed eye) tthat at form o tthe e
foundation of a stream’s food chain.
� The aquatic life water quality standard
states that all state waters should support a
healthy and diverse community of bugs and
fish.

EVALUATE WATERSHED AND
IMPAIRMENT
Water quality data, stressors/sources, climatic conditions, soils,
watershed land use, model existing conditions.
Stakeholder Input
IDENTIFY ENDPOINT
St Stakeholder k h ld IInput t
Water Quality Standards or Reference Condition
MODEL SCENARIOS
Determine allocation of the load among point sources and non-
point i t sources and d allow ll for f a margin i of f safety, f t and d future f t growth. th
Identify reductions.
Stakeholder Input

�Model framework:
• General Watershed Loading Function (GWLF) or
Hydrologic Simulation Program Fortran (HSPF)
�Source Assessment:
• Quantify Construction Storm Load from permits
queried and stakeholder input
�Waste load allocation

�Construction �Construction loads – not clearly
distinguished as a point source (~2004)
�Future �Future activities not explicitly discussed

� Identify y Construction Stormwater as a ppoint
source
• Some TMDLS aggregate the construction load with
that of the MS4
� Allow for future growth in Construction
Stormwater permitted activities (~2011)
�� Differentiate between in-stream loads and
land-based
� Often differentiate between activities within
and d outside t id of f MS4 boundary b d
� By 2011, 48 TMDLs for sediment, 9 for
Phosphorus p , ,pplus the Bay ywatershed

�Many �Many point source permits listed
�Some point sources given an individual
WLA (e.g. (e g waste water treatment plant)
�Others given an aggregated WLA by
source category (e.g. (e g construction)

� Benthic TMDL Watersheds Sediment,
Nitrogen, Phosphorus, including TSS for
the Chesapeake Bay
� Local watershed TMDLs in Virginia where
th the equation ti address dd TSS and d TDS have h
addressed mining sources
� pH TMDL studies to date result in
recommendation for swamp waters
designation designation, or there are co co-pollutants pollutants

Six TMDLs Requiring Additional Measures
TMDL Name Pollutant Total Reductions*
Goose Creek Sediment 70%
Mossy Creek Sediment 74.9%
Mill Creek Watershed Sediment 69‐73%
Bull Run Sediment 77 77.37% 37%
Rivanna River Watershed Sediment 0/59.3%
Outside of MS4/Inside MS4
Difficult Run Sediment 73%
*Reductions to a site with no management/no E&S.

2003 TMDLs - Interpreted to Require
Additional Measures
TMDL Name Pollutant Total Reductions*
Blacks Run Watershed sediment 70%
Cooks Creek Watershed
sediment & Phosphorus 90%
Mill Creek Watershed sediment 70%
Pleasant Run Watershed sediment 80%
Pleasant Run Watershed Phosphorus 80%
Holmans Run sediment 70%
*Reductions to a site with no management/no g /
E&S.

http://www.deq.virginia.gov/ConnectWithDEQ/VEGIS/VEGISDatasets.aspx

http://www.deq.virginia.gov/Programs/Water/WaterQualityInformationTMD
Ls/TMDL/TMDLDevelopment/ApprovedTMDLReports.aspx

http://www.deq.virginia.gov/Programs/
Water/WaterQualityInformationTMDLs/T
MDL/TMDLImplementation/TMDLImple
mentationPlans.aspx

� B.Limitation on coverage. g
� TMDL limitation. Discharges to waters for which a
wasteload allocation (WLA) for a pollutant has
been established in a "total maximum daily y load"
(TMDL) approved by the State Water Control
Board that would apply to stormwater discharges
from o a co construction st uct o act activity v ty are a enot ot eligible e g b e for o
coverage under this permit unless the
stormwater pollution prevention plan (SWPPP)
developed by the operator is consistent with the
requirements related to TMDLs contained in
Section II D 6.

�� 6. Total maximum daily loads. A total
maximum daily load (TMDL) approved by
the State Water Control Board may include a
wasteload allocation to the regulated
construction activity that identifies the
pollutant for which stormwater control
measures are necessary f for the h surface f
waters to meet water quality standards. The
pollutant po uta t identified de t ed in a wasteload waste oad allocation a ocat o
as of the effective date of this permit must
be specified in the SWPPP……

� The SWPPP shall include strategies g and control
measures to ensure consistency with the
assumptions and requirements of the TMDL WLA
that apply to the operator's discharge. In a
situation i i where h a TMDL has h specified ifi d a general l
wasteload allocation applicable to construction
stormwater discharges, but no specific requirements
for construction sites have been identified in the
TMDL, the operator shall consult with the state or
federal TMDL authority to confirm that meeting
permit requirements will be consistent with the
approved TMDL. If the TMDL specifically precludes
such discharges, the operator is not eligible for
coverage under the general permit.

� Erosion and Sediment Control Plans and
Stormwater Management Plans required under
the general permit (with the exception of those
plans p for sites previously p y covered under a
previous version of the general permit) shall
include a written explanation demonstrating that
the t epa plan addessest addresses these eseccritical tca po points tsoof
interest in addition to the basic elements
included in those plans:
� i. Protection measures for discharges to the
� i. Protection measures for discharges to the
Chesapeake Bay or impaired waters or
� waters with an established TMDL.

� Part V. CONSISTENCY WITH TOTAL MAXIMUM
DAILY LOADS
� If the discharge covered by this permit enters a
water with an established or approved Total
MMaximum i
� Daily Load (TMDL), the permittee must implement
measures to ensure that the discharge of pollutants
�� from the site is consistent with the assumptions and
meets the requirements of the approved TMDL,
� including any specific wasteload allocation that has
been established that would apply to the discharge discharge.