MassDOT T has created a dedicated p program to as

NPDES Storm Water
nt Plan
BMP 7U: Water Qualiity Impaired Waters Assessment and Mitigation Pllan
T has created a dedicated program to asssess 303(d) listed impaired
d waters (“303
3(d) waters”) and
n measures, in
ncluding retroffits and other structural BM
MPs where neccessary, to co
to implement mitigation
s of concern in
n 303(d) wate
ers and ensure
e that stormw
water discharges from
discharges of pollutants
T’s urbanized roadways willl not cause insstream excee
edances of wa
ater quality sta
andards. Thiss
program (hereinafter the “Impaired Waters Progra
am”) covers bo
oth 303(d) wa
aters for which
h MassDEP ha
m Daily Load (“TMDL”) reports for all imp
pairments (“C
Category 4a” waters), and th
finalized Total Maximum
s either have not been finalized or do nott cover all imp
pairments affe
ecting the 303
for which TMDL reports
ategory 5” waters). MassD
DOT will assesss its complian
nce with TMD
DL reports und
der the proced
water (“Ca
MDL Watershe
ed Review.
outlined in
The Impaiired Waters Program will co
over a total off 684 impaired
d waters, whicch includes alll 303(d) waterrs
b-basins conttain some porttion of MassD
DOT’s urbanizzed area roadw
ways. In orde
er to compile this
whose sub
DOT analyzed
d the water bo
odies listed in Appendix A of its Stormwa
ater Managem
ment Plan
list, MassD
ates Geological Survey (“USGS”). The new
(“SWMP”)) with new watershed data prepared by the United Sta
d layers permitted mapping
g of more deta
ailed sub-basin
n watersheds and, in turn, allowed for more
odies that havve a potential to receive sto
ormwater disccharges from
accurate identification of the water bo
T’s urbanized roadways. Th
he analysis ussed to develop the original Appendix A used larger
ds that often in
ncluded multip
ple water bod
dies, some of which were no
ot impaired. As Appendix A
listed all waters where such larger watersheds inccluded some portion of MasssDOT’s urbanized roadwa
ays, it
ed an over-inc
clusive listing of 303(d) watters with potential discharges from MasssDOT roads.
T will prioritize
e its review of the 303(d) wa
aters describe
ed above by geographical fa
actors to identify
ers on which MassDOT’s urbanized road
dways may ha
ave the highe
est impact. Sp
those wate
T will place hig
ghest priority on those wate
ers that lie with
hin 500 feet of at least one stormwater outfall
dway, and will prioritize this group by the total numberr of outfalls witthin this 500-ffeet
from an urrbanized road
ew of the remaining water bodies will be prioritized byy the number of urbanized
area. MasssDOT’s revie
ane miles exis
sting within th
he sub-basins of such waters. A compre
ehensive list of the 303(d) waters
roadway la
essed under the Impaired Waters Progra
am, prioritized
d by the geogrraphical factorrs above, app
to be asse
dix L-1.
in Append
The specific steps that MassDOT willl use to assesss 303(d) watters are as follows:
Step 1. Id
dentify Impaiirments Related to Highw
way Stormwatter Runoff
As an initial step, MassDOT will revie
ew the underlying impairme
ents affecting the 303(d) wa
aters to identify
aired by pollutants
ed in highway stormwater ru
unoff. In completing this step,
those thatt may be impa
T will rely on existing data (ssuch as USGS data provided to MassDO
OT in 2009, which surveyed
pollutants in highway ru
unoff from Massachusetts highways) to assess whether highway ru
unoff may be
he impairmentt in question. If existing data
t support a potential link be
etween the im
mpairment and
causing th
highway runoff, MassDOT will proceed with step 2. If not, MasssDOT will document the basis for this
n and will conduct no furthe
er assessmen
nt of the waterr body at issue
Step 2. Map Location
ns of MassDO
OT Outfalls Relative to 303(d) Waters
T will perform a desktop revview of the sub
b-basin of the
e 303(d) waterr body to dete
ermine the spe
heir receiving waters. This procedure wiill help determ
mine whether
locations of MassDOT outfalls and th
T’s outfalls in fact are poten
ntially discharg
ging into the water body at issue, and will identify the
d through a miitigation plan. If MassDOT concludes ba
number off outfalls that may need to be addressed
pping that Mas
ssDOT’s outfa
alls clearly are
e not discharg
ging to the 303
3(d) water, it will documentt the
on its map
n and will con
nduct no furthe
er assessmen
nt of the waterr body at issue
e. However, if
basis for this conclusion
NPDES Storm Water
nt Plan
T concludes th
hat MassDOT
T outfalls are potentially disccharging to a 303(d) water body, then it will
o Step 3.
proceed to
Step 3. Conduct Site Survey of Diischarge Points and Drain
nage Infrastrructure
If a 303(d)) water is iden
ntified under Step 2 as pote
entially receiviing dischargess from MassD
DOT’s urbanizzed
harge points to the water bo
ody and the
roadways, MassDOT will conduct a site visit to survey the disch
ng drainage in
nfrastructure. This survey will identify wa
ater flows to th
he water bodyy, confirm the
utfalls, identifyy any addition
nal outfalls, an
nd identify anyy existing BMP
Ps or other
existence of mapped ou
at may have the effect of re
emoving or tre
eating pollutan
nts before the
ey reach the
structuress at the site tha
e appropriate,, MassDOT will combine this site visit witth its illicit disccharge detecttion
receiving water. Where
hich will identiffy non-stormw
water pollutantts that may be
e causing the impairment at
program (BMP 3D), wh
Step 4. Id
dentify Contrrol Measures
s and BMPs to Ensure tha
at Stormwate
er Discharges
s Will Not Ca
nces in Water Quality Sta
Once the site visit in Step 3 is completed, MassDO
OT will assesss whether add
ditional contro
ol measures and
Ps may be needed to ensure that stormw
water discharg
ges from MasssDOT’s urban
nized roadwayys will
other BMP
s of water qua
ality standardss.
not cause exceedances
“EPA’s po
olicy recognize
es that becausse stormwate
er discharges are due to sto
orm events tha
at are highly
n frequency an
nd duration an
nd are not eassily characterized, only in ra
are cases willl it be feasible
e or
variable in
h numeric limitts for . . . storm
mwater discha
arges.” EPA Memorandum
m, “Establishin
appropriatte to establish
LAs) for Storm
mwater Source
es and NPDES
Total Maxximum Daily Load (TMDL) Wasteload Allocations (WL
Permit Re
equirements Based on Thosse WLAs” (No
ov. 22, 2002) (the “2002 Me
emorandum”). As stated in
n the
morandum: “T
The variability in the [Nation
nal Pollutant Discharge Elim
mination] [S]ysstem and min
2002 Mem
erally available
e make it difficcult to determine with precission or certain
nty actual and
d projected
data gene
or individual dischargers orr groups of disschargers. Th
herefore, EPA
A believes that in these
loadings fo
d as BMPs, an
nd that numerric limits will be used only in
n rare
situations,, permit limits typically can be expressed
In light of the EPA’s guiidance on the
e “rare” use of numeric stan
ndards, MassD
DOT will rely on an iterative
adaptive approach to id
dentify and implement addittional control measures or BMPs at particular sites. As
e data on polllutants in high
hway stormwa
part of thiss approach, MassDOT will consider currrently available
ards, to assesss whether
runoff, inccluding USGS data and anyy applicable numeric water quality standa
er runoff from MassDOT’s urbanized roa
adways has a reasonable potential to cau
use an
uality standards.
T will place prriority in its asssessment and
d mitigation plan
exceedance of water qu
ere the existin
ng data sugge
est that the concentration off the constitue
ent of concern
n in
on those pollutants whe
ay exceed the
e applicable numeric water quality standa
ard. MassDO
OT also will
highway stormwater ma
ncluding guida
ance issued by the EPA an
nd MassDEP, and where
consider any available information, in
e, specific inpu
ut from the EP
PA, regarding
g the types of BMPs that are
e considered effective for
ment at issue (including whe
ere the impairment
is goverrned by non-n
numeric, narra
addressing the impairm
ality standards
s). Where app
propriate, MasssDOT will co
onsider recommendations in
n TMDL reporrts
water qua
e to the same or similar imp
pairments. Ma
assDOT will seek to comple
ete its assesssments as
that relate
efficiently as possible, so that any required control measures orr other BMPs can be implemented witho
undue dellay.
In assessiing the need for additional BMPs at partiicular sites, MassDOT will consider the pollutant remo
es of any existing
BMPs or other
r that may have
the effect
c of removing or treating
eiving water. MassDOT willl also conside
er additional fa
actors, includiing
pollutants before they reach the rece
e magnitude of any potentia
al exceedance
e of water qua
ality standardss, in assessing
g the
site constrraints and the
ent of additional BMPs. Ma
assDOT will do
ocument the basis for its re
precise sccope and exte
NPDES Storm Water
nt Plan
and will de
escribe how such recomme
endations will ensure that stormwater disscharges from
m MassDOT’s
d roadways will not cause exceedances of water qualitty standards. Where the po
otential impacct on
aters from Mas
ssDOT’s urba
anized roadwa
ays is greater and site cond
ditions allow fo
or more
303(d) wa
on in surround
ding areas, MassDOT is co
ommitted to devoting substtantial resourcces to implement
ng retrofits or other structurral BMPs, to mitigate storm
mwater effects at those
effective BMPs, includin
Step 5. Design and Im
mplement BM
For those 303(d) waters
s that require additional BM
MPs, MassDO
OT will create conceptual de
esigns of any
Ps and develo
op protocols fo
or the impleme
entation of no
on-structural BMPs. MassD
required structural BMP
mplement BMPs, including structural BM
MPs, on a rollin
ng basis as th
he need is iden
ntified and fun
plans to im
is secured
In selectin
ng the specific
c structural BM
MPs to be imp
plemented at particular sitess, MassDOT will rely on its BMP
elated tables, attached as L-2 to L-4. Th
hese tables list a variety of structural BMP
Summary Matrix and re
sider for particcular sites, alo
ong with estim
mated pollutan
nt removal rate
es for each BM
that MassDOT will cons
d to particular pollutants and
d types of site
e conditions. The tables alsso prioritize th
he menu of BM
as applied
or the listed pollutants and site condition
ns. As reflecte
ed in the BMP
P Summary Matrix
in order off preference fo
and relate
ed tables, Mas
ssDOT will rely on standard
d pollutant rem
moval efficienccies set forth in EPA and
P guidance to measure the effectiveness of existing an
nd additional BMPs. MassD
DOT will cond
or its external designers and
d contractors to encourage the use of the
e most effective and sitetraining fo
appropriatte BMPs.
Step 6. Documentatio
T will include in each annua
al report an up
pdate on its prrogress in asssessing and mitigating 303((d)
nd will provide
e a semi-annu
ual report to th
he EPA during
g the first yea
ar of the Impaired Waters
waters, an
Program (by Decemberr 8, 2010). MassDOT will document its progress in a standardized format, which
includes th
he name of th
he 303(d) wate
er body, the underlying imp
pairment(s), th
he applicable numeric or
narrative water quality standard(s), a summary of MassDOT’s assessment and mitigation plan , and a report
atus of any pla
anned implementation of ad
dditional contrrol measures or BMPs. The
ese reports will
on the sta
asis of any co
onclusions rea
ached by MassDOT regarding the need or lack of nee
ed for
clearly doccument the ba
BMPs at specific sites.
Measurable Goals: 1) Asse
ess all water listed in Appe
endix L-1 using
g the processs described in this
ng assessmen
nt of at least 25 water bodie
es within the first
i quarter off the Impaired
BMP includin
ogress reportss to EPA durin
ng the first yea
ar of the Impa
Waters Progrram 2) Submiti quarterly pro
For instance, interstate roa
ads represent one example
e of a location where the po
otential impactt on
ng water bodie
es is greater and site conditions generallly allow for more construction. By contra
ge over a 303((d) water placces difficult space constrain
nts on any BM
MP design, and
d will
the existence of a bridg
e redevelopme
ent project. MassDOT inte
ends to aggresssively seek
likely warrrant a more co
g construction
n projects to im
mplement stru
uctural BMPs that would be
e impracticable
e as
opportunitties in pending
ne projects.
MassDOT will later include in this BMP a more detaile
ed schedule fo
or the implementation of
e new funding is secured,
structural BMPs and a plan for securring new funding. Howeverr, even before
T is prepared to begin desig
gn and construction, using its existing co
ontracts, of any additional BMPs
e first quarter of the Impaire
ed Waters Pro
ogram. MasssDOT also hass begun the
that are prroposed in the
o additional co
ontracts of $1 million each for dedicated design consu
ultants who wiill be
process of securing two
ng retrofits and other structtural BMPs ass soon as the need is identified through the
responsible for designin
ent procedures described above.
NPDES Storm Water
nt Plan
Waters Progrram and semii-annually therreafter.3) Provide documen
ntation describ
bed in step 6 in
annual reportts to the EPA..