Conservation Commission Regular Meeting Materials (linked)

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Indigo Land Design, LLC          
860.388.9343 Phone 
40 Elm Street, 2nd Floor           
860.391.8854 Fax 
Old Saybrook, CT 06475           
jwren@Indigo-Land.com E-mail 
 
www.Indigo-Land.com 
 
 
 
 
September 2, 2022  
 
 
Maureen FitzGerald 
Environmental Planner 
Town of Waterford 
15 Ropes Ferry Road 
Waterford, CT 06385 
 
RE: Application #C-22-07: 48 Great Neck Road 
       Residential Condominium Development 
       Responses to Application Review Comments 
 
Dear Maureen, 
 
Please find below our responses to your plan review regarding this application. 
 
1) At the August 11th meeting, we discussed Alternatives A & B and provided color-coded 
sketches of disturbance areas and also provided reasons supporting proceeding with 
Alternative A. The estimated wetland disturbance areas are as follows: 454 s.f. (0.0104 
ac.) of permanent disturbance and 1,460 s.f. (0.0335 ac.) of temporary disturbance for a 
total of 1,914 s.f. or 0.044 acres.  
 
2) The grading and clearing at the toes of slopes for all stormwater management basins 
is the minimum required for construction and implementation of e&s controls. In all cases, 
temporarily cleared and disturbed areas along the fringes of the 50-foot buffer will be 
replanted per the project planting plan and full 50-foot (min.) vegetated buffers will be 
provided. 
 
3) Details for the proposed bridge that is comprised of pre-cast footings, abutments, 
voided beam slabs, and wingwalls are enclosed. A supplemental construction sequence 
for the crossing has been added to the plans. Construction mats will be utilized over the 
existing woods road/farm crossing to provide construction access to the crossing site. 
 
4) Dewatering details and specifications have been added to the plans. Dewatering pump 
discharges with silt sack will be placed within either temporary sediment traps (for e&s) 
and/or within roughly graded WQV basins for infiltration into the sandy soil substrate. 

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5) Alternative A has a single 20-foot bridge span crossing proposed. In the vicinity of the 
proposed crossing, there are large boulders that will be retained in place and/or 
temporarily relocated for construction and then replaced to maintain the natural surface 
substrate and also provide scour protection for the bridge. Per Jim Cowen ~ Substrate 
consisting of stones and gravel disturbed during construction will be used at the edges of 
the bridge and retaining walls to stabilize and restore the streambed and banks. There 
are 2 large boulders one on each side of the streambank at the southern edge of 
the proposed bridge. These boulders stabilize and define the stream channel banks. 
Leave them in place or reposition them if needed so that they continue to function. 
 
6) Sediment forebay areas that provide a minimum of 10% WQV are included on the 
plans within the two main stormwater basins. Callouts including sizing information are 
provided as well. 
 
7) Four soil test pits were recently conducted on site. Generally, the subsoil and parent 
material are sandy with no shallow restrictive layers and favorable permeability rates. The 
results of that testing including descriptions, sieve analyses, and permeabilities are 
enclosed herewith. 
 
8) The 18-inch layer of biofiltration soil mix as recommended in the planting plan has been 
added to the stormwater management basin details. Due to favorable soil conditions on 
site, it will be possible to utilize native materials for the biofiltration mix. 
 
9) These basin storage elevations and WQV volumes are included within the project 
drainage report. 
 
10) Per Jim Cowen ~ The stormwater basins are designed to be biofiltration basins which 
will drain between storm events. In all 4 test pits, there was no indication of seasonal high 
groundwater well below the bottom of the proposed basins. The underlying parent soil 
was medium loamy sand. No restrictive layer or water table was observed. This is 
consistent with the mapped soil units (Canton & Charlton) Both soil units have a depth to 
a root restrictive layer greater than 60 inches and the natural drainage class is well 
drained. The soils excavated to create the basins are suitable to use in the biofiltration 
soil mix. 
 
11) The watershed model would need to be reconfigured and reanalyzed to extrapolate 
this information. We will provide this information at or before the September 8, 2022 
Conservation Commission meeting.  
 
12) As previously discussed and reviewed, we have revised the plans in this area to 
regrade a portion of the roadway to promote overland flow and reduce flow and 
impervious area to the catch basins. Also, due to favorable soil conditions, we have added 
four new WQV biofiltration basins at drainage outfalls to handle runoff from the roadway 
areas and other point discharges. 
 

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13) The trail will be constructed of woodchips generated from site clearing. The path will 
be located in such a manner to minimize grading, clearing and tree removal. Minimal 
ground disturbance is anticipated for trail construction. Due to a mountain laurel 
understory throughout the site, some mountain laurel will need to be cut for the trail but 
then will be transplanted on slopes and buffer areas. 
 
14) The plans have been updated to include the signature of James Cowen, CPSS who 
is the project soil and wetland scientist and flagged the wetland boundaries on site. 
 
Please contact me if you have any questions or need any additional information. 
 
Sincerely, 
 
 
 
Joe Wren, P.E. 
Principal  
Indigo Land Design, LLC