Conservation Commission Meeting Agenda/Materials 109R and 131 Clark Lane Exhibit List (linked)

Connecticut Watershed Response Plan
for Impervious Cover ——
FEB 06 2023
Planning & Development
Town of Waterford, CT
Effects of Stormwater on Water Quality
@ Impervious Cover > 12%
Connecticut Department of Bureau of Water Protection and Land Reuse
79 Elm Street
ENERGY & Hartford, CT 06106-5127
os ENVIRONMENTAL (860) 424-3704
PROTECTION Robert Idee, Commissioner
C-22-14
109R & 131 CLARK LANE
PUBLIC HEARING
EXHIBIT # 24

Connecticut Watershed Response Plan
for
Impervious Cover
Effects of Stormwater on Water Quality
Betsey Wingfield, Chief
Bureau of Water Protection and Land Reuse
Connecticut Department of Energy
& Environmental Protection
Prepared by:
FB Environmental Associates, Inc.
97A Exchange Street, Suite 305
Portland, Maine 04101
Revised by:
Planning and Standards Division
Bureau of Water Protection and Land Reuse
Connecticut Department of Energy & Environmental Protection

Connecticut Watershed Response Plan for Impervious Cover 2015
Table of Contents
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B. Waterbody Description...
C. Pollutant of Concern and Pollutant Sources ....csscccssscsessscssesssssessscesecsssssscsssessesscsessesseaseessssecessnseees 5
D. Applicable Surface Water Quality Standards...
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F, Implementation to. Reduce the Effect: of UC ssisisisssssaisssnsiansecsncsananrereinnnemnannaiansaasasinnies 9
G, Water Quality MOmitoring ssscssscssssscesssessnisssissesnasisesscassseasonsscsseasseasncseasaseabassassssnesascavaansasabedeasacessaase 11
H. Implementation ASSurance .......sssesesesssesssssessseneseseencesscsssssenssneeesencseseesseeessesseeseaceeseseessesseneeeeesesseeee 13
J. Public Participation s.csissccssscssiesrssesssceesssccansssssasscsaccsesusisescacssencessuscissisivensssisssnsssvesesauissciesestsensieverevsees 14
List of Figures
Figure 1: Areas in Connecticut with greater than 12% impervious cover.
Figure 2: The Connecticut Biological Condition Gradient Model. ccc cseeseseeeseenenseeeees 7
List of Tables
Table 1: Applicable Water Quality Standards 0... ccceeeeeeeeseeeseseneneneeseeserssseseseneeneseeteseneeeneeees 6
List of Appendices
Appendix 1: Additional Resources for Implementation
Appendix 2: Percent Impervious Cover as a Surrogate Target for TMDL Analyses in CT
Appendix 3: Impervious Cover in Connecticut Municipalities
Appendix 4: Responding to an Impervious Cover-Based TMDL
Appendix 5: Case Studies: Examples of Action in Connecticut Watersheds
a) Eagleville Brook, Mansfield — Collaboration Success Story
b) Jordan Cove, Waterford — Residential LID Monitoring Project
c) Hole in the Wall, Niantic — Outdoor Stormwater Classroom Project
Appendix 6: Impaired Segment Summaries

Connecticut Watershed Response Plan for Impervious Cover
2015
Appendix 6-1: Sub-Regional Basin CT2000: Southeast Shoreline
Appendix 6-2: Sub-Regional Basin CT4403: Trout Brook
Appendix 6-3: Sub-Regional Basin CT4500: Hockanum River
Appendix 6-4: Sub-Regional Basin CT5200: Quinnipiac River
Appendix 6-5: Sub-Regional Basin CT5203: Misery Brook
Appendix 6-6: Sub-Regional Basin CT5205: Sodom Brook
Appendix 6-7: Sub-Regional Basin CT5206: Harbor Brook
Appendix 6-8: Sub-Regional Basin CT5207: Wharton Brook
Appendix 6-9: Sub-Regional Basin CT5302: Mill River
Appendix 6-10: Sub-Regional Basin CT5306: Indian River
Appendix 6-11: Sub-Regional Basin CT6000: Housatonic River
Appendix 6-12: Sub-Regional Basin CT6600: Still River
Appendix 6-13: Sub-Regional Basin CT7000: Southwest Shoreline
Appendix 6-14: Sub-Regional Basin CT7105: Pequonnock River
Appendix 6-15: Sub-Regional Basin CT7403: Noroton River
ii

Connecticut Watershed Response Plan for Impervious Cover 2015
A. Introduction
The Connecticut Department of Energy and Environmental Protection (CT DEEP) has conducted
studies on the relationship between impervious cover (IC) in the upstream watershed and the
aquatic life in adjacent surface waters (http://www.ct.gov/deep/imperviouscoverstudies). IC refers
to landscape surfaces such as pavement or buildings (hard surfaces) that no longer absorb rain and
can direct large volumes of stormwater runoff. The amount of IC affects both the quality and
quantity of water resources by disrupting the natural hydrological cycle. IC prevents precipitation
from infiltrating into the ground thus increasing surface runoff (quantity) and pollutant transport
to the receiving water (quality).These studies indicate that as the amount of IC exceeds 12%,
unacceptable impacts to aquatic life can be predicted to occur in surface waters. From these studies,
stormwater pollution has also been identified as probable contributing cause to the impairment
through the Stressor Identification (SI) process - a method to identify stressors causing biological
impairments in aquatic ecosystems.
The waterbodies included in this Connecticut Watershed Response Plan for Impervious Cover
document have been assessed as not meeting the designated use criteria for Habitat for Fish, Other
Aquatic Life and Wildlife contained within the regulations for Connecticut Water Quality
Standards (CT DEEP, 2013). The waterbodies were included on the 2012 List of Connecticut
Waterbodies Not Meeting Water Quality Standards (Impaired Waters List). These waterbodies
were selected as examples of impairments, but the impairment relationship of stormwater pollution
and impervious cover is not exclusive to these waterbodies.
Research on impervious cover and stormwater frequently report pollution impacts from issues such
as nutrients, metals, polycyclic aromatic hydrocarbons (PAHs), bacteria, temperature and
hydrology. The impacts from impervious cover and stormwater pollution are also not a recent
problem. As early as the 1960s, impervious cover was reported to effect the urban hydrology
compared to the natural environment (Leopold, 1968).
Regardless of whether or not a waterbody is impaired, any watershed with high levels of
impervious cover is predicted to contribute to degraded water quality because of stormwater
pollution. It is recommended that management measures for waterbodies be planned and
implemented in areas that have high levels of impervious cover.
The Plan presents percent reductions of watershed IC for a subset of impaired surface waters and
provides recommendations for managing stormwater and impervious cover to support water
quality improvements. The target percent impervious cover (%IC) are not regulatory limits but are
intended to guide the application of Best Management Practice (BMP) and Low Impact
Development (LID) techniques to reduce the impact of impervious surfaces. The target also does
3

Connecticut Watershed Response Plan for Impervious Cover 2015
not represent an actual required reduction in the amount of hard surfaces.
B. Waterbody Description
Connecticut is an urbanizing state, increasing its development footprint by almost 5% from 1985
to 2006, and urbanization is a major cause of water quality impairment in the State (Arnold, et al,
2010). Urban watersheds are characterized by a mosaic of hard surfaces, such as parking lots and
rooftops, which do not allow rain to infiltrate. Traveling over these impervious surfaces, large
volumes of rapidly moving stormwater can carry a complex array of pollutants and cause other
impacts, such as streambank erosion, flooding, and unnatural characteristics of volume and
velocity. As shown in Figure 1, urban areas with significant IC are scattered throughout
Connecticut, and concentrated within interstate highway corridors of I-395, I-84, I-91 and I-95.
N Data Source: CT DEEP
. Created by:
@ impervious Cover > 12% oo 20 ao tmes A FB Environmental,
June 2012
Figure 1: Areas in Connecticut with greater than 12% impervious cover.
Developed watershed characteristics promote excessive erosion and sedimentation from
4

Connecticut Watershed Response Plan for Impervious Cover 2015
stormwater runoff that can degrade stream habitat. In these watersheds, streams suffer from what
has been called urban stream syndrome, a complex and synergistic combination of hydrologic
alteration and multiple pollutant stressors (Walsh et al. 2005 and Arnold et al, 2010). Studies by
CT DEEP across small Connecticut watersheds indicate that as little as 12% IC has the potential
to affect the magnitude, frequency, timing, and duration of the hydrograph as well as the speed,
volume and quality of runoff to a stream. From 2005-2006, CT DEEP conducted statewide
research comparing stream health, as indicated by metrics for the benthic macroinvertebrate
communities, to watershed IC estimates based on 30-meter remotely sensed data (Chabaeva et al.,
2007 and Arnold et al., 2010). A total of 125 stream segments were studied, and the results were
compelling, in keeping with the literature on the impacts of impervious cover: no stream with over
12% impervious cover in its immediate upstream catchment area met the State’s aquatic life
criteria for a healthy stream (Bellucci, 2007; see Appendix 2).
The streams identified in Appendix 6 are included on CT’s 2012 Impaired Waters List for not
meeting criteria of Habitat for Fish, Other Aquatic Life and Wildlife. Designated Use assessments
conducted by CT DEEP indicated that aquatic life use support goals are not being met in these
streams, but the cause of the impairment was determined to be unknown. Given that many of these
watersheds are urbanized, reported with a cause unknown, and contain IC levels known to cause
impairments to aquatic life, these waterbodies were identified for further study to determine if an
IC stressor would be accurate given that stormwater pollution could be contributing to the observed
water quality impairment. Therefore CT DEEP performed a screening-level Stressor Identification
(SI) on each stream’s watershed incorporated in this Plan in order to support application of %IC
target reduction. Important watershed characteristics included size of the upstream drainage area
(<50 square miles), impaired location beyond 1 mile of a sewage treatment plant discharge, and
an upstream drainage area containing a significant amount of IC that exceeded 12%.
The streams in Appendix 6 represent impaired waterbodies where a percent reduction in IC is
applicable given the impairment and watershed characteristics. Site-specific information on each
stream segment is included beginning with Appendix 6-1 of this report.
C. Pollutant of Concern and Pollutant Sources
An impairment to the aquatic life in these streams was identified using bioassessment protocols as
outlined in Connecticut's Consolidated Assessment and Listing Methodology (Chapter 1 of the
Connecticut Integrated Water Quality Report, CT DEEP, 2012). Although bioassessments can
identify impaired aquatic communities, they often do not identify the cause of impairment. Such
is the case with these streams where the cause of the aquatic life impairment was unknown. As
described above, a screening level analysis was conducted to identify the potential stressor(s) and
determine the most likely candidate cause. Watersheds were evaluated to identify potential
5

Connecticut Watershed Response Plan for Impervious Cover 2015
pollutant sources such as industrial discharges, landfills and sources of potential groundwater
contamination. Waterbodies were selected for inclusion in this Plan if these potential sources did
not predominate other landscape level stressors associated with stormwater pollution within the
watershed. It is possible that additional stressors contributing the observed impairments in addition
to the aggregate impacts of stormwater pollution may be identified in the future which may require
additional management measures. CT DEEP determined that one most probable cause of the
aquatic life impairment in these streams is a complex array of pollutants transported by stormwater.
There is a strong correlation between pollutant loads and stormwater runoff from impervious land
cover in the watershed (Appendix 2). Therefore, it is reasonable to rely on the surrogate measure
of %IC to represent impacts from stormwater pollution (the effect of stormwater runoff on
pollutant loads and hydrology) that ultimately contributes to aquatic life impairment in the streams.
D. Applicable Surface Water Quality Standards
Connecticut's Water Quality Standards (WQS) assign all fresh surface waters to one of three
classes (Table 1); each classification is defined by the most sensitive designated uses to be
Table 1: Applicable Water Quality Standards
Surface Water Class Designated Use
e Existing or proposed drinking water supply;
Habitat for fish and other aquatic life and wildlife;
Recreation; and
Water supply for industry and agriculture.
Potential drinking water supply;
Habitat for fish and other aquatic life and wildlife;
Recreation;
Navigation; and
Water supply for industry and agriculture.
Habitat for fish and other aquatic life and wildlife;
B e Recreation;
e Navigation; and
e Water supply for industry and agriculture.
AA
Surface Water Class Biological Condition Criteria
Sustainable, diverse biological communities _of indigenous taxa shall be
AA, present. Moderate changes, from natural conditions, in the structure of the
A biological communities, and minimal changes in ecosystem function may be
, evident; however, water quality shall be sufficient to sustain a biological
B condition within the range of Connecticut Biological Condition Gradient
Tiers 1-4 (See Figure 2 below).

Connecticut Watershed Response Plan for Impervious Cover 2015
protected. Biological Condition criteria are used to assess the biological integrity of surface waters
in the State. These criteria describe the expected health and composition of aquatic communities
inhabiting waters of a given designated use, based on measurements in unimpaired waters (CT
DEEP, 201 1a). Biological Condition criteria and designated uses for Classes AA, A, and B waters
are listed below in Table 1. The Surface Water Classification for each impaired stream segment is
listed in Table 2 of Appendices 6-1 thru 6-15.
411 Native Condition
Native
Minimal Changes in Structure of the
Biotic Community and Minimal Changes
Ih Ecosystem Function
Evident Changes In Structure of the
Biological Blotic Community and!Minimal
Changes in Ecosystem Function
Condition Moderate Changes in Structure
of the Biotic Community and
Minimal Changes in Ecosystem
Function
oho era ame Set Fant 029 ET EE ae Gh or a hn EO EY SERS EY SEP EE OS Se CTY Pales}=trveltel
Major Changes In Structure of the
Blotic Community and Moderate 5
Changes in Ecosystem Function
Severe Changes In Structure of the Biotic
Degraded Community and Major Loss of Ecosystem Function
Stressor Gradient
The Connecticut Biological Condition Gradient Model illustrates the relationship between the amount
of stress on the environment and its effect on biological communities. According to the model, as the
level of stress gets progressively greater, biological communities, which start out in a natural condition
(Tier 1), begin to change as they respond to the stress (CT DEEP, 201 1a).
Figure 2: The Connecticut Biological Condition Gradient Model.
E. Water Quality Target
The reduction targets in the Plan for the impaired streams were developed using percent IC as a
surrogate for a complex array of stormwater pollution that impacts aquatic life. The goal of the
Plan is to reduce impacts from stormwater pollution on the aquatic life in these streams addressed.
Meeting the goals will be assessed by measuring the aquatic life directly and not by measuring the
IC reduction. The aquatic life criteria are referenced in Connecticut's WQS (see previous section),

Connecticut Watershed Response Plan for Impervious Cover 2015
and assessment of attainment of aquatic life criteria is described in Consolidated Assessment and
Listing Methodology (CT DEEP, 2006). A target of 12% IC represents the level of impervious
cover in the contributing watershed, below which a stream is likely to support a macroinvertebrate
community that meets aquatic life use goals in Connecticut Water Quality Standards. The 12% IC
target is within the range of % IC values generally reported in the literature (ENSR, 2005; CWP,
2003; Arnold et al., 2006) and, more specifically, in other New England states such as Maine
(Maine DEP, 2005; see Appendix 2 for further information).
Stormwater pollution is categorized under two types of pollutant loads: point and non-point
sources. Point sources are permitted a waste load allocation (WLA) and regulated under the
National Pollutant Discharge Elimination System (NPDES), but a load allocation (LA) is also
contributed by non-point sources where no regulations are applicable. It is not feasible to draw a
clear distinction between stormwater pollution originating from point and non-point sources
because insufficient data are available for each parcel in the watershed and the fact that stormwater
pollution is highly variable in frequency and duration. Consequently, a Margin of Safety (MOS)
is incorporated into the %IC target in order to account for uncertainties regarding the relationship
between water quality and sources (point and non-point), Therefore, a 1% MOS was subtracted
from the %IC target to account for uncertainty in the analysis, resulting in a combined WLA and
LA target of 11%. The 11% IC target applies to all drainage areas involving both point and non-
point sources in the watershed (WLA=LA=11% IC), in order to reduce pollutant loads and restore
hydrologic and biological integrity of the watershed as a whole.
All of the streams highlighted in this document are within an Urban Area regulated under
Connecticut's Municipal Separate Storm Sewer Systems (MS4) general permit. However, the %IC
target reductions are not permit limits or an explicit requirement to reduce or eliminate the actual
amount of hard surfaces within a watershed. The IC target solely focuses on the effect of
impervious surfaces on water quality and should not be construed to require a literal reduction in
actual amount of road and building surfaces. These percentages are provided to serve as a guideline
to reduce the impact of stormwater pollution for waterbodies that are within a watershed with 11%
or greater IC. Following these guidelines would lead to improvements in the aquatic life
community of a watershed.
This 11% IC target for WLA and LA can also be expressed as a percent reduction in the effect of
the existing impervious cover compared to current conditions, and can provide a benchmark for
implementation of best management practices (BMPs) to reduce the impacts of impervious cover
on aquatic biota living in the stream. The WLA and LA % IC target, and any percent reduction in
the effect of IC to achieve the target, can be applied to both the WLA and LA because of the
practical difficulty of separating stormwater pollution contributed by background, nonpoint, and
point sources.

Connecticut Watershed Response Plan for Impervious Cover: 2015
To calculate the percent reductions for the effect of IC on water quality required to achieve the
WLA and LA target:
Percent IC reduction = ((IC Current Condition - IC Target)/IC Current Condition) x 100
where IC Target = 11%
To calculate the Current Condition, % IC values for each stream section were derived from the
National Land Cover Database 2006 percent imperviousness estimate layer for the conterminous
United States (http://www.mrlc.gov/). This 30 meter resolution data is based primarily on the
unsupervised classification of 2006 Landsat Enhanced Thematic Mapper satellite data (Fry et al.,
2011). The analyses for each of the streams addressed by this Plan are provided in the site-specific
appendices. The percent reduction of IC to achieve the IC target is calculated for informational
purposes only, to describe the percent reduction needed in the effect of the existing IC on the
watershed, and should only be used as an implementation guide.
F. Implementation to Reduce the Effect of IC
As emphasized earlier in this document, IC can be used as a surrogate for the impacts that
pollutants and other stressors from stormwater pollution have on the aquatic life community in
streams. In order to minimize the effects from a complex array of stormwater pollution to the
waters of the State, including those that are impaired, NPDES stormwater permittees can aid in
the implementation of control measures which would reduce impacts from stormwater pollution
to offset the negative effect of IC. Future development activities have the potential to increase
impervious cover, and should be constructed and operated to limit the effect of stormwater
pollution due to impervious cover on the aquatic life in these streams.
Permitted Stormwater Sources
The control of stormwater pollution from regulated sources is a significant means of addressing
the impairment to aquatic life. Regulated stormwater discharges consist of those authorized under
the General Permit for the Discharge of Stormwater from Municipal Separate Storm Sewer
Systems (MS4 GP), General Permit for the Discharge of Stormwater and Dewatering Wastewaters
from Construction Activities (Construction GP), General Permit for the Discharge of Stormwater
Associated with Industrial Activity (Industrial GP), and General Permit for the Discharge of
Stormwater from Commercial Activities (Commercial GP). Each of these general permits requires
the implementation of control measures, water quality monitoring and some type of a stormwater
management plan.
MS4 GP discharges
MS4 dischargers must implement the Stormwater Management Plan (SMP) required by the MS4
9

Connecticut Watershed Response Plan for Impervious Cover 2015
permit reissued on January 9, 2011, and as amended. The SMP includes best management practices
(BMPs) grouped into six Minimum Control Measures, which consist of Public Education and
Outreach, Public Involvement/ Participation, Illicit Discharge Detection and Elimination,
Construction Site Stormwater Runoff, Post Construction Stormwater Management in New
Development and Redevelopment, and Pollution Prevention/Good Housekeeping. Compliance
with the MS4 GP, as amended, includes implementation of the SMP and six Minimum Control
Measures.
Construction GP discharges
The Construction GP regulates the runoff from construction with 5 or more acres of soil
disturbance for projects with municipal land use approvals and with 1 or more acres of soil
disturbance for projects without municipal land use approvals. The Construction GP requires
controls to reduce the discharge of sediment during construction and includes measures to address
the long term impacts related to post-construction stormwater discharges. These post-construction
discharges require the retention and/or infiltration of stormwater using LID and runoff reduction
methods. Although the proposed post-construction performance standards are not based on the
percentage of impervious cover, the runoff retention standards specified will serve to reduce and/or
disconnect impervious area.
Industrial GP discharges
Industrial facilities are required to develop and implement a Stormwater Pollution Prevention Plan
(SWPPP). The SWPPP must include control measures (similar to BMPs) to reduce or eliminate
the discharge of pollutants from the site. Typically, industrial sites are highly impervious. However
site constraints, and cost considerations will complicate the reduction of impervious cover. To
address the effect of IC, industrial sites where site expansion or redevelopment is planned should
focus on the reduction and minimization of impervious area. The industrial facility can consider
which BMPs may be appropriate for the site as well as those to address specific sources.
Commercial GP discharges
The Commercial GP regulates commercial sites with impervious surfaces exceeding 5 acres, such
as malls and “big box” stores. The plan to address the control of stormwater pollutants from these
sites is called a Stormwater Management Plan (SMP). The commercial site can consider which
BMPs are appropriate for the site as well as those to address specific sources.
Non-Regulated Discharges
Approximately one-third of the municipalities in the State do not fall under the MS4 permit. Non-MS4
municipalities can voluntarily implement the BMPs within the MS4 permit and this document. Any
facilities that discharge non-regulated stormwater can update their Pollution Prevention Plans to
10

Connecticut Watershed Response Plan for Impervious Cover 2015
include BMPs that can reduce pollutants from entering surface waters. These BMPs could include
revised housekeeping procedures to reduce pollutants or techniques that increase infiltration to reduce
runoff. Additionally, sites or areas that are not regulated by a NPDES permit (such as small scale
commercial and construction sites, residential sites, etc.) should consider implementation
measures to minimize and/or disconnect impervious areas. Improving water quality within the
community to address nonpoint source pollution requires actions, large and small, by the
community.
Apart from of these discharge categories, successful implementation will be best accomplished
through incorporating an adaptive management strategy on a watershed basis. Additional
investigation is necessary for all watersheds in order to fully document problem areas and begin
the restoration process. The implementation strategy should include: 1) conducting parcel-level
field work to locate directly connected impervious cover; 2) reducing IC where practical; 3)
disconnecting IC from the surface waterbody; 4) minimizing additional disturbance to maintain
existing natural buffering capacity; and 5) installing engineered BMPs and LID practices to reduce
the impact of IC on receiving water hydrology and water quality. Appendices 4 and 5 provide
some appropriate strategies and case studies for reducing stormwater pollution on a case by case
basis.
G. Water Quality Monitoring
Monitoring is a valuable tool where its design can be tailored for decision-maker or scientific
objectives. Common techniques for water quality monitoring include analyses of biological and
chemical samples. The information from these analyses can provide strong empirical evidence for
determining status, developing models and identifying trends of water quality. However, these
techniques are not necessarily required to inform every decision. Monitoring can be a simple
technique such as tracking project implementation or land use changes in the watershed. This
gathered information can drive decisions at the local level which can provide cost-savings by
focusing resources and increasing BMP effectiveness. Data from analyses, tracking or other
techniques can be used to further refine efforts to improve water quality. The following provides
some background on the development of a monitoring plan strategy.
CT DEEP Monitoring Plan
Surface water chemistry and benthic macroinvertebrate data will be collected by CT DEEP Bureau
of Water Protection and Land Reuse as described in the Rotating Basin Ambient Monitoring
Strategy (CT DEEP, 1999). Benthic macroinvertebrates will provide the primary metric to measure
the progress of meeting the criteria of Habitat for Fish, Other Aquatic Life and Wildlife Use
11

Connecticut Watershed Response Plan for Impervious Cover 2015
support. The Bureau of Water Protection and Land Reuse may also coordinate with the CT DEEP
Inland Fisheries Division to collect fish population data. Fish population data can provide an
additional measure for aquatic life use support.
Permittee Monitoring Plans
A comprehensive water quality monitoring program is beneficial to help guide implementation
efforts and at a minimum should be designed to accomplish two major objectives: source detection
and tracking water quality improvements. Monitoring is crucial to identify specific sources of
stormwater runoff which will, in turn, direct BMP implementation efforts.
Progress in BMP implementation can be gauged through implementing a fixed station ambient
monitoring program. Supplemental samples can be collected at other key locations within the
watershed, such as above and below potential contributing sources or areas slated for BMP
implementation. Since watershed borders do not follow town borders there is a possibility CT
DEEP did not sample locations in your town. If this is the case then collecting a sample where the
waterbody enters your town and another where the waterbody leaves your town maybe helpful to
determine how stormwater pollution in your town influences water quality.
Non-regulated Monitoring Plans
Non-regulated areas or sites are not required to develop discharge monitoring plans, but simple
tracking techniques can still be beneficial towards water quality improvements. Tracking
improvements can help identify areas of concern and assist in future planning. Tracking
implementation is simple to establish by noting an area or a total of actions, such as disconnecting
rain gutters, stormwater retrofits or installing porous pavement. In some cases, this information is
helpful to secure funding or get connected to shovel-ready projects. Tracking information can be
used to calculate areas that have implemented BMPs which points to reducing the impact of hard
surfaces and showing progress towards reducing pollution. Tracking any activity can assist with
defining improvements in water quality, documenting implementation actions and achieving
restoration goals.
Recommended Monitoring Parameters
All pollutant parameters should be analyzed using methods prescribed in the Code of Federal
Regulations’. Electronic submission of data to CT DEEP is highly encouraged. Results of
monitoring that indicate unusually high levels of contamination or potentially illegal activities
should be forwarded to the appropriate municipal or State agency for follow-up investigation and
enforcement. As these parameters are found in the MS4 permit, the following are strongly
recommended in any monitoring program:
° pH (SU)
12

Connecticut Watershed Response Plan for Impervious Cover 2015
e Temperature
e Dissolved Oxygen (mg/l)
e Hardness (mg/l)
e Conductivity (umos)
e Chloride (mg/l)
e Magnesium (mg/l)
e Cyanide (mg/l)
e Surfactants as MBAS (mg/l)
e Total Petroleum Hydrocarbons (mg/l)
e Oil and grease (mg/l)
e Chemical Oxygen Demand (mg/l)
e Total Suspended Solids (mg/l)
e Total Phosphorous (mg/l)
e Ammonia (mg/l)
e Total Kjeldahl Nitrogen (mg/l)
e Nitrate plus Nitrite Nitrogen (mg/l)
e Total Copper (mg/l)
e Total Lead (mg/l)
e Total Zinc (mg/l)
e E.coli and Total Coliform (col/100ml) (for Class AA, A and B surface waters)
e Fecal coliform and Enterococci (col/100ml) (for Class SA and SB surface waters)
CT DEEP is committed to providing technical assistance in monitoring program design and
establishing procedures for electronic data submission.
H. Implementation Assurance
The Department can work with watershed partners, including towns and conservation
organizations to implement better stormwater management in the impaired streams and
watersheds. Additionally, there is a combination of regulatory and non-regulatory program support
in Connecticut, including: regulatory enforcement requirements, availability of financial
incentives, and local, State, and federal programs for pollution control. Enforcement of regulations
controlling non-point source discharges includes local implementation of Connecticut’s Enhanced
State Nonpoint Source Management Program (www.ct.gov/deep/nps).
CT DEEP continues to work with watershed stakeholders to draft Watershed Based Plans (WBPs)
under the CWA 319 program. As part of these WBPs, watershed stakeholders investigate
impairments and promote the implementation of nonpoint source pollution best management
13

Connecticut Watershed Response Plan for Impervious Cover 2015
practices and stormwater management practices in the watershed. CT DEEP approves various
WBPs, including those that recommend watershed-wide and place-based management measures
to reduce nonpoint source pollution and source mitigation. These recommended WBP projects
may be eligible for CWA 319 funding, as long as such projects are not used for permit compliance.
I. Public Participation
Public participation plays an important role in water quality restoration, and this Plan will be posted
on the Department website (www.ct.gov/deep) for public access. This Plan is intended to serve an
advisory role to regulatory programs such as the NPDES permitting. The Department welcomes
public feedback to assist with the implementation process that will involve the cooperation of
citizens, local government and CT DEEP.
14

Connecticut Watershed Response Plan for Impervious Cover 2015
References
Arnold, C.L. and C.J. Gibbons (2006). Impervious Surface Coverage: The Emergence of a Key
Environmental Indicator, Journal of the American Planning Association, vol. 62, no. 2,
Spring 1996, pages 243-258.
Amold, C.L., Bellucci, C.J., Collins, K., and R. Claytor (2010). Responding to the first impervious
cover-based TMDL in the nation. Watershed Science Bulletin. Fall 2010, pp. 11-18.
Bellucci, Christopher (2007). Stormwater and aquatic life: making the connection between
impervious cover and aquatic life impairments for TMDL development in Connecticut
streams. Proceedings of the Water Environment Federation TMDL Conference, Bellevue,
WA, 1003-1018.
Center for Watershed Protection (2003). Watershed Protection Research Monograph No.1,
Impacts of Impervious Cover on Aquatic Systems, March 2003.
Chabaeva, A., Hurd, J., Civco, D. (2007). QUANTITATIVE ASSESSMENT OF THE
ACCURACY OF SPATIAL ESTIMATION OF IMPERVIOUS COVER. ASPRS 2007
Annual Conference Tampa, Florida. May 7-11, 2007.
CT DEEP (1999). Ambient monitoring strategy for rivers and streams rotating basin approach.
State of Connecticut, Department of Environmental Protection, Bureau of Water
Management, 79 Elm Street, Hartford, CT 06106-5127.
CT DEEP (2006). Connecticut Consolidated Assessment & Listing Methodology for 305 (b) and
303(d) Reporting. 7 CT Dept. of Energy & Environmental Protection, Bureau of Water
Management, Planning Division, Hartford, CT. 34 pp.
CT DEEP (2007). Stressor Identification for Eagleville Brook in TMDL for Eagleville Brook,
Mansfield, CT. CT Dept. of Energy & Environmental Protection, Hartford, CT.
CT DEEP (2013). Regulations for Connecticut Water Quality Standards. CT Dept. of Energy &
Environmental Protection, Bureau of Water Management, Planning Division, Hartford,
CT. http://www.ct.gov/deep/lib/deep/regulations/22a/22a-426-1through9.pdf
CT DEEP (2012). 2012 State of Connecticut Integrated Water Quality Report. CT Dept. of Energy
& Environmental Protection, Bureau of Water Protection and Land Reuse, Hartford, CT.
http://www.ct.gov/deep/iwar
ENSR Corporation (2005). Pilot TMDL applications using the impervious cover method. ENSR
International, Westford, MA.
Fry, J., Xian, G., Jin, S., Dewitz, J., Homer, C., Yang, L., Barnes, C., Herold, N., and Wickham,
J. (2011). Completion of the 2006 National Land Cover Database for the Conterminous
15

Connecticut Watershed Response Plan for Impervious Cover 2015
United States, PE&RS, Vol. 77(9):858-864.
Leopold, L. (1968). Hydrology for Urban Land Planning — A Guidebook on the Hydrologic Effects
of Urban Land Use. United States Geological Survey, Reston, Va. Geological Survey
Circular 554.
Maine Department of Environmental Protection (2011). Percent Impervious Cover Targets for
Stream Restoration and Watershed Management. Maine Department of Environmental
Protection, Bureau of Land and Water, Augusta, Maine. DEPLW July 2011.
Plafkin, J.L., M.T. Barbour, K.D. Porter, S.K. Gross, and R.M. Hughes (1989). Rapid
bioassessment protocols for use in streams and rivers: Benthic macroinvertebrates and fish.
EPA 440/4-89/001. USEPA, Washington, DC.
Walsh, C., Fletcher, T., and Ladson, A. (2005) Stream restoration in urban catchments through
redesigning stormwater systems: looking to the catchment to save the stream. J. N. Am.
Benthol. Soc., 2005, 24(3):690-705.
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