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

RECEINED
Carya Ecological Services, LLC
FEB 08 2023
183 Guinevere Ridge
t
Planning estar, CT Cheshire, CT 06410
Town of Wat erford, C| } (203) 271-1949
sigrun.gadwa@sbcglobal.net
February 7, 2023
Conservation Commission, Town of Waterford
15 Rope Ferry Road
Waterford, Connecticut 06385 - 2886
ATTN: Chairman Dimmock and Environmental Planner, Maureen Fitzgerald
RE: Application Review, Part 2, Impacts Assessment: App. # C22-15. 47-Unit
Residential Subdivision, including affordable units; 141 Clark Lane. Owners: L & M
Archambault; Applicant: Kingstown Properties, LLC
Carya Job No.: 23- WFD 3
Dear Commissioners:
Part 2 of the Carya Review focuses on the likely adverse impacts on the regulated resources
from the proposed project. Several concerns have already been expressed orally on January
26" by Carya and by local residents. Part 1 of the report, dated January 26, 2023, focused on
existing conditions, in the Fenger Book headwaters wetland system, and included figures at
several scales. Part 1, with its attachments, was resubmitted electronically on January 29, 2023.
Our concerns are further explained in this report, and their relevance to your commission is
clarified. The list of materials we have reviewed is at the start of Part 1, the Existing Conditions
report; several storm water resources in that list are attached to Part 2 of our review (Impacts
Assessment), dated February 7, in Attachment B. They were referenced in the oral
presentation on January 26".
Additional field observations of on-site conditions within the regulated resources took place
on February 2", 2023, supplementing the perimeter inspection on January 25, 2023. I was
permitted to go onto the property for several hours, accompanied by Project Surveyor/Engineer
David Held and Mark Branse, the attorney for the applicant.
Multifaceted and interrelated environmental problems are associated with this application.
Based on our review, the major expected adverse impacts to wetland/watercourse resources,
and also to human health and safety, can be linked 1) to the redistribution of runoff and
C-22-14
109R & 131 CLARK LANE
PUBLIC HEARING
EXHIBIT # 32

groundwater into the excessively large stormwater management system at the south end of
the site, and 2) to the extensive anticipated impacts to mature trees as a result of excessive
density/impervious surface. We suggest changes, consistent with LID (Low Impact Design)
principles, that would substantially reduce these impacts.
Significantly reducing the volume treated by the two basins will allow multiple
improvements to the bioretention basin and the wet-bottom detention basin. The 13.736-acre
drainage area for the retention basin includes 5.29 acres of impervious surface, partly along a
915-foot section of Clark Lane, and partly within the proposed development envelope.
Substantial reduction in the volume of stormwater entering the southern basins (by over
30%) could be achieved without adversely impacting riparian wetlands or water quality in
Fenger Brook.
1.0 Clark Lane runoff through buffer to Fenger Brook.
“» First, we recommend continuing to allow the existing upland buffer to filter and treat
the 15” discharge pipe between House #’s 113 and #115. This would require
extending the pipe to the base of the new fill bank and installing a simple level
spreader. Although the buffer is narrow (just over 50 feet) along much of the western
perimeter of this property, the gentle northwesterly flow path, below the Clark Lane
discharge pipe is ~300-feet long, from the fill slope between Units #14 and #15 to the
wetland boundary. The flow path proceeds northeasterly, perpendicular to contour lines.
The Clark Lane stormwater discharge spreads out and infiltrates into the deep Watchaug
soils largely before reaching the downgradient vegetated riparian buffers. It is renovated
naturally by sorption to soil particles, degradation and transformation by soil microbes,
and uptake by vegetation. The moderate infiltration rate of the Watchaug soil series is
preferred for stormwater filtration by soil.
“» Multiflora rose thicket is the dominant cover type along the flow path. It is a tough
species, not sensitive to disturbance, although it is valuable nesting habitat for
songbirds and mice and provides good wildlife cover. Atty Branse stated incorrectly
on January 26" that the post-agricultural habitat in the area to be developed offers poor
quality wildlife habitat. In fact, the woodland cover type, with scattered tall trees, and
dense shrub cover and herbs, is a declining and valuable habitat type. It is a valuable
complement to red maple-dominated wooded swamp; it provides insect food and nest
sites for songbirds and rabbit and rodent hunting habitat for owls, hawks, foxes, and
bobcats, that reside mostly in the adjacent wetlands.
“* We inspected the downgradient resources on 2-3-23, and found no evidence of
impairment from Clark Lane runoff. Fenger Brook was inspected several hundred feet

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downgradient of the flow path to the brook from the discharge pipe. Low specific
conductivity (151.3 us/cm) and salinity (0.1 ppt), and excellent instream habitat quality
with no evidence of erosion, embeddedness, nutrient enrichment, or sedimentation,
show that Clark Lane runoff is currently not degrading the stream. Adjacent riparian
forested wetlands are also non-impaired on the stream banks, covered with moss and
low herbs.
Currently, just below the outfall, a ~ 80 foot-long, 2-foot deep, scoured channel
traverses the proposed development footprint, before flow begins to spread out within
a mature tree cluster. Those trees would be eliminated by the proposed filling. Site-
specific planning to choose an appropriate spreading structure will be needed to prevent
formation of a new scoured channel.
A key question: How much will removing the Clark Lane drainage reduce the volume
entering the detention and bioretention basins for the design storms? Without additional
LED measures, will it address the anticipated adverse impacts?
Note that the applicant has just (afternoon of 2-6-23) submitted a brief alternative to the town,
for this application: to allow the Clark Lane Drainage to continue, as currently, to flow
through the existing upland buffer to Fenger Brook, by extending the discharge pipe to the
eastern limits of the subdivision, with no mention of a spreader of any sort.
2.0
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Hydrologic Impacts from Reduced Infiltration
The applicant has provided the total impervious cover (IC) draining into the retention
basin (5.29 acres), but not the IC from the Clark Road drainage versus that from the
development. Based on Sheet 3 of the plans, we measured 1.75 acres (43%) of IC
within the narrow, northern 4-acre portion of the development; no infiltration will take
place where IC is present. Some of the rainfall infiltrating into the remaining pervious
soil in this area, will be diverted into the gravel utility trenches and the gravel beds
beneath the pavement, necessary to prevent road damage from frost heave. The trenches
and gravel beds will also intercept much of the east-flowing groundwater from
precipitation onto the residential properties along Clark Lane (mostly pervious). We
estimate that over fifty percent of the rainfall falling in the development area will be
diverted, as well as additional groundwater from the west. It will not reach the
groundwater that flows westerly towards the wetlands, which are only about fifty feet
away along the northern section; the buffer is only 38 feet wide adjacent to Unit #6.

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With climate change droughts are becoming more severe and frequent; loss of such a
large fraction of infiltration will exacerbate the situation. When the water supply to a
wetland is significantly diminished, wetland soil becomes drier, organic soil is
mineralized and diminishes, and pools dry up earlier. These are all clear-cut physical
impacts. Hydrophytic plant species are replaced by more upland species, and there are
losses of aquatic fauna needing flooded areas to breed, including spring peepers, toads,
and gray tree frogs, as well as vernal pool amphibians. Often few invertebrates remain
other than mosquitos, which need only five days and very shallow water to breed, and
may become abundant in the absence of predators. Production export and nutrient
cycling functions are diminished, as are wildlife and aquatic habitat functions.
Infiltrating roof runoff from the proposed manufactured homes in the northern and
central portions of the project and eliminating units would provide additional reduction
in the runoff volume to be handled by the two southern basins. Lowering home density
and replacing their footprints with pervious green spaces would achieve a similar
reduction in stormwater runoff volume, and increase in infiltrated volume, for each
home eliminated. We note that the applicant has not provided groundwater recharge
calculations. Each roof is 1283 square feet in area. Infiltrating the runoff from fifteen
roofs would increase area available for infiltration by about 19,250 square feet (0.44
acres). Taking out 15 homes would eliminate about 25,660 square feet (0.59 acres) of
impervious surface, including the shared parking areas.
3.0 Indirect wetlands impacts from tree mortality and dieback
These suggested changes to reduce IC would augment groundwater flow to the wetlands.
Instead of being diverted to the southern basins, precipitation could continue to maintain
existing hydrology and tree health to the west of the development in the upland review area.
Drought-stressed trees are more vulnerable to infection by fungi, and insect attack and tree tips
are more likely if root systems are weak. Even non-pathogenic fungal species can cause
mortality in combination with drought stress (or stress due to excess water). How would
adverse impacts to these trees also be adverse impacts to the wetland?
Wetland trees and trees to the south or west of a wetland help to maintain its moist,
cool microclimate, a physical characteristic needed especially by amphibians and by
the more northern-affinity wetland species.
Foliage volume is reduced by drought stress and disease, such that transpiration and
uptake of nutrients and dissolved metals would diminish. Note that attenuation of

nutrients and toxicants is a function that is active both in wetlands and in their upland
review areas, a major reason that Upland Review Area’s (URA) are protected.
“» Likewise, healthy trees in the upland review area provide complementary and
supplemental habitat and food for wetland-dependent wildlife.
“» They shade streams and pools and are the source of the leaf litter at the base of the
aquatic food chain.
“» Downgradient of the northern half of the proposed development, substantial reduction
of the volume of groundwater feeding the forested wetland and its URA will have an
adverse impact on wildlife support and aquatic habitat functions, as well as on human
use values, for citizens recreating in Bates Forest Park and adjoining forest.
4.0 Potential Rain Garden (s)
Another potential way to help prevent adverse hydrologic impacts and effectively treat the
metals and toxic hydrocarbons in a portion of the pavement runoff would be to construct one
or more small biofiltration basin(s) (aka raingardens), each taking the place of one house. A
rain garden could replace Unit #6, where the fill slope is only 38 feet from the wetland
boundary. Filtered groundwater, and overflow during major storms would discharge easterly
into the forested upland buffer, where upland buffer vegetation would extract the remaining
nutrients, since biofiltration BMP’s do not remove more than 50% of the nutrients in
stormwater. No underdrain would be necessary. Soils are suited to Low Impact Density (LID).
The raingarden would also serve as a green space, reducing community density and improving
quality of life.
Note that a long term study by the UNH Stormwater Center is comparing raingardens with
different vegetation types; per the 2012 biennial report, contrary to expectation, meadow type
vegetation, with grass and forbs fully retained its initial infiltration rate; infiltration declined
with all other vegetation types. Apparently this is due to macropores formed by dying roots.
Grass thatch did not reduce infiltration as feared; the CT manual erroneously recommends
avoiding grass cover for that reason. Mulch does not need to be regularly replenished, and
maintenance is limited to mowing a few times a season. The meadow raingarden should
include patches of preferred flowering plants for pollinators and patches of some of the more
graceful and attractive, heavy-seeding grass and sedge species.
5.0 Bioretention Basin
“ . The bioretention basin is very large, about 0.35 acres in area with a 24” ponding
capacity.

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The design of the large southern bioretention basin can be brought into
conformance with University of New Hampshire guidance, with a forebay, an
adequately thick flayer of filter media (24” to 30”, not 18”), and dense, healthy
vegetative cover.
There will be less clogging over time by the fine particulate fraction of Total
Suspended Solids (TSS), which is unavoidably poorly removed by all kinds of
hydrodynamic separators, including Stormceptor, as explained at the meeting
on January 26th by David Held, the Project Engineer.
Dewatering by the proposed 6” diameter underdrain can be also reduced, with a
smaller size perforated pipe, such that the groundwater table in the nearby
wetlands to the west is not significantly lowered.
Reducing amplitude and duration of flooding will allow much better
development of vegetation.
Perhaps the compost component of the media mix (usually 10%) was omitted
to encourage faster drainage of high water volumes (ponding up to 24” deep)?
Compost is important for healthy, vigorous vegetation growth and to support
microbe populations.
Note that the applicant has already modified the bioretention design and added
“submerged gravel wetland” component to the system in response to oral comments
and the referenced UNH guidance. We are unable to review these changes if this report
is to be submitted a few days before the next meeting.
6.0 Retention Basin
“» The application proposes redistribution of most of the property’s water to this one
location. Rain falling on the development rectangle had previously soaked into the
gently sloping ground and then proceeded as groundwater towards the Fenger Brook
and its associated wetlands. The discharge from the large detention basin will reach
28.85 cfs in larger storms per the applicant’s drainage report. Per this report the basin
will hold 127,579 cubic feet during a 100 year storm. The interior of the large
stormwater basin is 250 feet X ~130 feet, 0.97 acres. Maximum outflow is 28.85 cfs.
We were told on January 26 that the basin will drain within one day, and the ten inch
pipe set five feet below the seasonal water table is expected to flow nearly continuously.
dewatering the area, lowering the water table to the west and the south of the basin.
This will stress trees whose root systems are adjusted to existing hydrology, especially
during droughts, which have become more frequent due to climate change.

“» Tree mortality ona large scale will result from the large and continuous water inputs to
the level red maple forest just past the level spreader. In this portion of the forested
wetland, over an acre in area, the soil is already saturated to the surface and micro-
topography is limited.
“» With constant seepage as well as constant inflow from the underdrain of the detention
basin, the current basin design is poorly suited to establishment of wetland vegetation.
Seeds and poorly rooted seedlings will wash off the lower slopes, and seedling
establishment is often poor on saturated soil.
** Most woody wetland plants do need aerated soil for their roots, and grow on hummocks
and mounds. The plans do not include any woody plantings for the large detention
basin. Nor does the plan does not incorporate micro-topography, micro-pools, or large
woody debris to foster establishment of a diverse wetland community that would
include sufficient mosquito predators. Atty. Branse emphasized that a wetland was
being created. However, a stormwater wetland of this size without a woody component
in the vegetation cannot approach the level of function of a natural wetland. Inland
emergent wetlands are bordered by trees or shrub thickets.
¢* Mosquitos need minimal water depth to breed, and only five days to complete their life
cycle. This basin, like any flat graded area will have local elevation differences where
water collects. Even deer hoof prints would make depressions large enough for
mosquito reproduction. Fully draining stormwater ponds are known to have more issues
with mosquitos breeding in shallow residual puddles than constructed stormwater
wetlands. They have enough plant and hydrologic diversity to support assorted
mosquito predators. These predators include invertebrates like predaceous midges and
dragonflies and amphibians like bullfrogs. The anticipated increase in mosquito
breeding is a serious matter because of the immediately adjacent middle school.
Mosquitos also feed on naked nestling songbirds, including wetland-associated species.
** Steep saturated lower basin slopes (2.3:1) will also be prone to erosion during intense
rain events. This will be an adverse impact on water quality discharged into the
wetland, undoing prior successful nutrient removal, due to the high phosphorus content
of eroded sediment. Erosion Control Matting is usually required for slopes steeper than
3:1,
“» The steep, slopes, up to 10 feet high, will also be slippery and dangerous, for children
and for maintenance personnel collecting litter and doing other maintenance.

“» If volume entering the basin is significantly reduced, the basin can be less deep, and the
diameter of the discharge pipe can be reduced. The duration and volume of between-
storm flows will be lower, as will the peak discharges during major storms. Likewise
volume reduction will improve vegetative cover in the large detention basin, and shrubs
can also be planted. This will improve vegetative uptake of nutrients and dissolved
pollutants, less well filtered by the bioretention basin than the metals and hydrocarbons.
Fine sediment will also be better filtered. No amendments to the excavated subsoil are
proposed to foster plant growth. Organic matter also fosters N-nitrate transformation to
nitrogen gas by microbes through denitrification. Organic matter will build up slowly
under vegetation over time, but a compost amendment to the basin bottom during basin
construction is suggested.
7.0 Threat of scour and channel formation along flow path to Fenger Brook
¢* Very importantly, a significant reduction in the proposed flow volumes and velocities
from the retention basin will reduce the likelihood that discharge flows will form
channels and ditches downgradient of the level spreader, resulting in scour, erosion,
and additional nutrient loading en route to Fenger Brook, and also within the Brook.
The Channel Protection Criteria in the CT Stormwater Manual have not been met. The
flow path from the detention basin to Fenger Brook was inspected on February 3, 2023,
and the contour are also informative. (See handout). Much of the flow path has a gentle
slope but there is a steeper section about 200 feet upgradient of the brook, where flow
concentration is likely to occur, if flows are not largely infiltrated before that point.
Flow will enter a small feeder tributary before reaching the main brook.
o,“* As noted above, a tree stand is at risk in an already very wet and level portion of the
forested wetlands, about an acre in size, beginning just downgradient of the large level
spreader, east of the stone wall. The roots of trees, red maples included, need sufficient
oxygen. In an old growth forest with irregular micro-topography, woody plants are
usually rooted on the better aerated hummocks and mounds. This level forest was
farmed in the past, likely over 100 years ago.
2%*» Channel erosion would occur during a large storm event, that had saturated the soil in
the somewhat poorly drained wetlands, as well as in the very wet swamp forest at the
start of the flow path. A deeper, narrow, eroded channel provides less contact with the
substrate than sheet flow and is less effective at polishing the residual pollutants that
leave the basins. The commissioners should remember that pollutant concentrations,
including metals and toxic polycyclic hydrocarbons, are high in runoff from busy
streets in dense neighborhoods like the proposed development. See the table of
pollutant concentrations by land use in the excerpt from the NYS Stormwater

Management Manual, one of the stormwater resources entered into the record. Even
with acceptable removal percentages, retention basin discharge should be “polished”
by passing diffusely through a wetland buffer, not short-circuiting in an eroded channel.
Reconcentration in a channel is a highly likely significant adverse impact with the
currently proposed excessive discharge volume. Even a very broad stream buffer, such
as this one, is vulnerable to scour from large flows, where the water table is already
near or at the surface or when multiple recent rain events have reduced infiltration
capacity of the upper soil horizon. Other projects with which I have been involved
have stipulated regular repairs of incipient channels downgradient of level spreaders, a
long term, and expensive maintenance task.
Substantially reduced discharge volumes at this location (e.g. by 40% or more) during
the higher frequency storms are much more likely to be well-accommodated, without
channel formation and accompanying erosion. Although the wetland boundary will be
just ten feet downgradient of the level spreader, the distance to Fenger Brook is almost
500 feet. Large portions of the buffer, past the saturated swamp, are drier spectrum
forested wetlands with considerable capacity for infiltration and pollutant filtration and
nutrient uptake. By significantly reducing the volume of discharge from the large
detention basin, over an acre of tree “drowning” will be averted or at least much
reduced.
Indirect Tree-related Adverse Impacts
Impacts to trees will occur both within wetlands and upgradient of wetlands; during
project construction and post construction. Manufactured homes will be placed on both
sides of a central road in a long narrow rectangle (1300 feet by 187 feet). The proposal
calls for flattening the currently gently sloping land, by cutting up to six feet along the
west side of the proposed development and by filling up to eight feet along the east
side, with the central road at grade. Significant soil disturbance up to the property line
is allowed because the normally required setbacks to the property lines are waived for
this affordable housing development. Conventional homes can be built on a gentle
slope, but a manufactured home requires a level, concrete platform. Cut and fill
quantities have not been provided. This will eliminate at least 390 trees on the north
side of the project, conservatively assuming about fifteen trees in each 50-foot x 187-
foot section. See the bullets in Section 3.0 for a list of wetland-related ecosystem
services provided by trees.

*» Soil will be compacted during construction, becoming less pervious. As discussed
above, runoff will be directed from impervious surfaces into the drainage system
causing drought stress, and some groundwater will also be diverted along the gravel
roadbed and gravel utility trenches. Less groundwater will flow easterly. Many root
systems of trees still standing will be truncated by cuts or partially buried by fill and
deprived of oxygen. This will include trees at the base of the fill slope, in the upland
review area, and trees at the rear of neighbor’s properties, whose root systems extend
onto the subject property. Within a few years, drought stress or damage to root
systems stress is typically followed by disease, such as pathogenic fungal infections or
bark beetle attacks, which will kill additional trees. We noted that heavy bittersweet
vines are also stressing trees in the upland review area, mostly on town land. The
applicant has not indicated any intention to cut and treat the bittersweet vines with
triclopyr , using the very safe, highly effective, and efficient “cut-and-paint” technique.
¢* Trees in the proposed development rectangle are concentrated along its eastern and
western perimeter where they screen the wetland and forest URA to the east from
outdoor lighting nearer to Clark Lane. The tree screen reducing the broad array of
adverse ecological impacts from artificial night-time illumination, of which large-scale
mortality of night flying moths and beetles is most significant. Travis and Longcore
(2000) prepared a thorough literature review on this topic. Many insect species
unfortunately fly hundreds of feet from wetlands to a distant outdoor light source,
“sucked” away from their natural habitat even if just a speck of light is visible. Foraging
by nocturnal animals is inhibited by elevated light levels, an instinct to avoid predation
on moonlit nights. The proposed light posts are low enough to be screened by building
from many angles, but loss of the tree screen to the west will increase adverse light
impacts within the URA.
“+ Indirect adverse impacts on wetland functions will also ensue from the loss of so many
mature tall trees, including oaks, cottonwoods, tulip trees, and red maples: a substantial
loss of insect gleaning habitat, nest sites, and perches for species with home ranges that
encompass several hundred feet of adjacent upland habitat. The 2020 report by the
Forest Subgroup of the GC3 (Governor’s Council on Climate Change is a
comprehensive treatment of trees’ benefits to the environment and human society. See
https://portal.ct.gov/DEEP/Climate-Change/GC3/GC3-Working-group-reports.
9.0 Nutrient Releases to Groundwater
“> Quality of groundwater flowing into the adjacent wetland will decline for two reasons:
loss of the felled trees’ nutrient and metals uptake function, and substantial nutrient
inputs to groundwater as the root systems of the felled trees decompose, especially

those felled on the west side of the development. In particular, concentrations of
dissolved phosphorus (normally very low in forested streams) have been shown to spike
after substantial logging has taken place within the watershed of a forest stream
(Binkley 2004). This finding is based on a very large data set published by USGS. Most
invasive plants have been observed to grow and spread more rapidly in soil enriched
by decomposing roots.
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In the southwestern portion of the site, substantial nutrient discharge into the north-
west-flowing groundwater that feeds Fenger Brook will follow tree mortality in the
wetland downgradient of the large level spreader. As explained above, tree mortality is
expected there due to the much wetter soil conditions, as a result of the high volume of
discharge from the detention basin.
10.0 Ecojustice and Stormwater Maintenance Issues
“* Multiple issues related to tree losses will harm the existing modest Clark Lane
neighborhood, including declining home values and high cost of tree removal. Stressed
trees growing near the cut or fill zones will be safety hazards. Tree losses will mean
less shade and evaporative cooling, and diminished filtration of air pollution and noise
from the busy road. These impacts will apply to residents of the new neighborhood as
well as to the Clark Lane neighbors.
“* These ecojustice issues related to tree loss join others pointed out in oral testimony on
January 26, 2023: the safety threats from steep fill banks just behind homes and from
steep stormwater basin banks, especially just after large storms when water will be
deep enough for drowning; and a project layout inviting littering and dumping. These
would all seem initially to be non-wetlands issues, but in fact there will be relevant long
term adverse effects. Neglect of stormwater facility maintenance will ensue if what
could have been an attractive well-kept community becomes a depressed, low-rent
neighborhood. It is reasonably likely that the landlord will cut corners on stormwater
facility maintenance or sell the project to a new owner who does not understand their
rationales.
CONCLUSION
It is our professional opinion that the impacts to regulated resources explained in this report
are sufficiently serious, that the commission will not be able to permit this application. We
suggest that the applicant prepare an alternative design with less impervious surface and
substantially more infiltration and less volume entering the southern stormwater management
system. Our goal is to increase infiltration on the project site. Reducing housing density will

accomplish this and this is recommended. We want to minimize changes to the existing
hydrology. These are all established LID goals.
Thank you for the opportunity to provide input.
Respectfully submitted,
CARYA ECOLOGICAL SERVICES, LLC
Sup. Gob
Sigrun N. Gadwa, MS, PWS
Ecologist, Professional Wetland Scientist
Registered Soil Scientist
REFERENCES
Allan, J. David. 1995. Stream Ecology: Structure and Function of Running Waters. Chapm,an & Hall,
London. 388 pp.
Bennie, J., Davies, T. W., Cruse, D., Gaston, K. J., & Swenson, N. (2016). Ecological effects of
artificial light at night on wild plants. Journal of Ecology, 104(3), 611-620.
https://doi.org/10.1111/1365-2745.12551
Barling, R.D. and I. D. Moore. 1994 Role of Buffer strips in Management of Waterway Pollution: A
Review. Environmental Management. 18(4): 543-558.
Binkley, Dan, Geroge G. Ince, Jason Kaye, and Christopher Williams. October 2004. Nitrogen
and Phosphorus Concentrations in Forest Streams of the United States. Journal of the
American Water Resources Association. 1277 to 1291.
Brinson, Mark. 1993. Changes in the Functioning of Wetlands along Environmental Gradients.
Wetlands, 13(2): 65-74.
CT DEP. 1991. Policy Statement: Riparian Corridor Protection. Department of Environmental
Protection, Inland Fisheries Division. Hartford, CT.
CT DEP. 1997. Guidelines: Upland Review Area Regulations; Connecticut’s Inland Wetlands &
Watercourses Act. Department of Environmental Protection, Wetlands Management Section,
Bureau of Water Management. Hartford, CT.
CTDEEP. 2004. Stormwater Quality Manual. __ https://ctstormwatermanual.nemo.uconn.edu

DeGraaf, R,M. and D.D. Rudis. 1987. New England Wildlife Habitat, New England Wildlife
Habitat Distribution and Natural History. General Technical Report NE 108. NE Forest
Experiment Station., Amherst, Mass.
Fuss & O’Neill. 1996. Fenger Brook Watershed Management Study, New London and Waterford,
1996. Prepared for Coastal Resources Management, Sea Grant Marine Advisory Program
, New Haven, CT.
CTDEEP. 2015. Report on Fenger Brook (CT 2000-30-01) as an impaired portion of the Southeast
Shoreline Drainage Area (CT 2000).
Gadwa and Logan. 2006, revised 2011. The Scientific Basis for Wetland & Watercourse Buffer
Zones. Prepared For the Berlin Land Trust. _https://caryaecological.com/publications/
Gaston, K. J., Bennie, J., Davies, T. W., & Hopkins, J. (2013). The ecological impacts of
nighttime light pollution: a mechanistic appraisal. Biological Reviews, 88(4), 912-927.
https://doi.org/10.1111/brv.12036
GC3 Final Report [Governor’s Council on Climate Change]. 2020. Report of the Forest
Subgroup of the Working & Natural Lands Working Group.
https://portal.ct.gov/DEEP/Climate-Change/GC3/GC3-Working-group-reports.
Hefting, M.M. and J.M. de Klein. 1998. Nitrogen removal in buffer strips along a lowland stream
in the Netherlands: a pilot study. Environmental Pollution 102: S1(1998) 521-526.
Hemmond and Fisher. 1994. Chemical Fate and Transport in the Environment. Academic Press,
San Diego. 337 pp.
Meyer, Judy; Kaplan, Louis; Newbold, Denis; Strayer, David; Woltemade, Christopher; Zedler,
Joy, Beilfuss, Richard; Carpenter, Quentin; Semlitch, Ray; Watzin, Mary; and Zedler, Paul.
September 2003. Where Rivers are born. The Scientific Imperative for Defending Small
Streams and Wetlands. American Rivers and Sierra Club. 23 pp.
Moreschi, P and E. Mas, Fuss & O'Neill, Inc., 2001. Jordan Brook Watershed Management
Plan. In. Bridging the Gap: Meeting the World's Water and Environmental Resources
Challenges Published on Line in 4-26-2012. https://doi.org/10.1061/40569(2001)185
NY State DEC Stormwater Management Design Manual. 2020.
Oberts, Garry. 2000 Influence of Snowmelt dynamics on Stormwater runoff quality. Article #3
in The Practice of Watershed Protection, 2000, ed T. Schueler and H. Holland.
Perkin, E. K., Hélker, F., & Tockner, K. (2014). The effects of artificial lighting on adult aquatic
and terrestrial insects. Freshwater Biology, 59(2), 368-377.
https://doi.org/10.1111/fwb.12270

Phillips, Jonathon. 1989. An Evaluation of the Factors Determining the Effectiveness of Water
Quality Buffer Zones. Journal of Hydrology. 107: 133-145.
Reijnen, Rien and Ruud Foppen. 1997. Disturbance by Traffic of breeding birds: evaluation of
the effect and considerations of planning and managing road corridors. Biodiversity and
Conservation. 6:567-581 (197).
Rich, C., Longcore, T. (2006). Ecological consequences of artificial night lighting. Island Press
Ridolfi, L, P. D’Odorico, & F. Laio. 2006. Effect of vegetation-water table feedbacks on the
stability and resilience of plant ecosystems. Water Resources Research. 42 (wo 1201)
Trettin, Carl C. et al. 1997. Northern Forested Wetlands: Ecology & Management. CRC Press,
Taylor & Francis Group pp 239-247.
Schueler, T and H. Holland. 2000. The Practice of Watershed Protection.
Straka TM, von der Lippe M, Voigt CC, Gandy M, Kowarik I, Buchholz S. Light pollution
impairs urban nocturnal pollinators but less so in areas with high tree cover. Sci Total
Environ. (2021) 778:152980. 10.1016/j.scitotenv.2021.146244
University of New Hampshire Stormwater Center. 2009 Biennial Report.
https://www.unh.edu/unhse/
University of New Hampshire Stormwater Center. 2012 Biennial Report.
https://www.unh.edu/unhse/
Virginia DEQ . 2017. VVA DEQ Stormwater Design Specification No. 9: Bioretention.
Virginia Stormwater BMP Clearinghouse. https:/Awww.swbmp.vwrre.vt.edu
Wise, S. (2007). Studying the ecological impacts of light pollution on wildlife: amphibians as
models. StarLight Common Herit. C Marin J Jafari EdsCanary Isl. Spain StarLight
Initiat. Palma Biosphere Reserve Inst. Astrofisica Canar. Gov. Canary Isl. Span. Minist.
Environ. UNESCO-MaB, 107-116.
Appendix 1: Critique/Discussion of the Bioretention Basin Design
A. A correctly sized forebay can be added. It will settle out some of the fine sediment
not removed by the Stormceptor (per the size class distribution in the specifications
information included in the applicant’s drainage report, corroborated verbally by the
engineer Mr. Held, on 1-26-23. Per the NHS, fine sediment deposition is the primary
reason that infiltration rates often decline over time in bio-infiltration basins.

. A sufficiently thick media layer (24” to 48”) is recommended by the 2009 UNH SWC,
and also by the Virginia DEQ. A thick filter can be used instead of the proposed 18”,
which is not thick enough to achieve the removal rates expected for this BMP, about
44% for nitrogen See Biofilter row in UNH pollutant Removal Efficiency Table.in
Attachment B. None of the four variants undergoing long-term testing have a filter
layer as thin as 18”. The need to drain the basin quickly is likely the reason that the
plan calls for the thinner layer, as drainage is faster through a thinner filter, and the
current plan calls for draining a very large volume, ponding up to 24” deep.
. One aspect of the proposed media mix does not conform to biofilter media specs.
Although proportions vary a good deal recommended media mixes all include: wood
or bark chip mulch, sand, soil, and ~ 10% compost. The applicant’s mix has no
compost, which supports plant growth better than decomposed wood or bark chips.
Compost could slightly slow down infiltration, but fostering vegetation is more
important because plant roots and the macropores created by rootlet death each year,
are highly beneficial for sustainable infiltration.
. Ifvolume to be treated is significantly reduced, meadow vegetation in the bioretention
basin will not be compromised as it would be by the proposed plan. Ponding depth will
be up to 24” deep (per the detail on Sheet 17), with a moderate rate of drainage through
the media, resulting in conditions more suited to marsh vegetation. Bioretention basins
function best when set several feet above the water table, with relatively fast-draining
underlying soils. Use of underdrains is an acceptable approach, but the proposed plan
has excessive water inputs.
One other question is whether the device to be used to separate the first flush from
cleaner runoff from rainfall in the later portions of rain events may divert some of the
first flush runoff from very high intensity storms because water depth will may be
greater than the height of the weir. This would cause some of the first flush runoff to
bypass the bioretention basin. With a smaller total runoff volume this issue would be
less likely to be a problem. Filter media in bioretention basins are certainly more
efficient at removing toxic metals and hydrocarbons in the first flush of pavement
runoff, than the detention basin.
Finally, the bioretention basin would not need to be set so deep, and the underdrain
could be smaller with less flow. This would reduce the dewatering hydrologic impact
on the adjacent wetlands and upland review area, and the ongoing flow through the
detention basin and level spreader.