Conservation Commission Regular Meeting Materials (linked)

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Date: 
May 24, 2022 
 
To: 
Waterford Conservation Commission 
From: Maureen FitzGerald, Environmental Planner 
 
Re:  
Inland Wetland Application #22-04: 934, 940 Hartford Turnpike 
 
Proposed Self-Storage Facility 
 
Findings for Consideration 
 
Proposed Activity: 
The application is for construction of 2 two-story self-storage buildings and associated paved access 
drives, parking spaces, a paved parking area for RV storage and construction of a stormwater detention 
/treatment basin on lands up-gradient of inland wetlands and Jordan Brook, a perennial Class A quality 
stream supporting brook trout.  All permanent site improvements are located beyond the 100 ft. Upland 
Review Area of wetlands with the exception of grading at the west side of the northern building and 
within the abandoned roadbed under the power lines parallel to Harford Turnpike.   
 
Regulated Activities: 
 
 
Clearing, grading and excavation for construction of two buildings and associated parking area 
and a stormwater detention/treatment basin up-gradient of inland wetlands and watercourses; 
 
 
Fill and grading of 3,700 ft.2 +/- within the 100 ft. upland review area to re-grade a portion of the 
utility line access road and the fill slope west of Hartford Turnpike.   
 
 
Discharge of site stormwater run-off up-gradient of Jordan Brook.   
 
Wetland Resources: 
The on-site wetlands are part of the Jordan Brook mainstem corridor (JCM-1), ranked as very high quality 
wetlands in the watershed and a wetland of special significance.  The Jordan Brook watershed 
management plan (2000) recommendations for this wetland are to protect water quality, treat stormwater 
run-off to attain no net increase in pollutant loading, control post-development stormwater discharge, 
support groundwater recharge and maintain a minimum 100 ft. width vegetated buffer between the 
riparian wetland corridor along the perennial stream and adjacent development.   
 
Two wetland pockets also occur on site.  One ponded containment is located between Rte 85 and the old 
roadway bed which serves as an access way to the overhead utility lines.  The other is an isolated pocket 
of forested wetland located at the southeastern end of the property. This wetland forest pocket lies within 
the right-of-way of the 2 water mains which traverse the property.  According to the wetland report, these 
two areas are not viable vernal pool habitats. 
 
Wetland Impacts: 
No direct wetland fill, excavation, grading or other alteration of inland wetlands or watercourses is 
associated with the proposed development.  Temporary impacts to soils within the upland review area 

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include fill and grading of 3,700 ft.2 +/- to re-grade a portion of the utility line access road and the fill 
slope west of Hartford Turnpike.  The wetland assessment report submitted for the application identifies 
concerns for potential impacts to on-site and downstream wetland resources from construction and post-
construction storm water.   
 
Mitigation for these potential impacts consists of implementing an erosion and sediment control plan 
during construction and the treatment of post-construction stormwater discharge through a water quality 
basin designed as a wet pond.  The basins outlet discharges 100 ft. up-gradient of the inland wetlands 
associated with the mainstem corridor of Jordan Brook. 
 
The Conservation Commission determined at their April 28, 2022 scheduled meeting that the proposal 
does not involve significant impact activity and that a public hearing is not required. 
 
Application & Plan Revisions 
Revised plans were submitted on May 19, 2022 to address staff and Commission comments. 
The revisions included additional details in the erosion and sediment control narrative and plans, timing 
of construction for the permanent stormwater basin, inclusion of an oil/water separator and a maintenance 
access way to the stormwater pond.   An addendum to the hydrology report was submitted showing 
results of the SCS TR-55 run-off model for the site in addition to written responses to staff and 
Commission comments.   
 
To demonstrate the development will not increase pollutant loadings to Jordan Brook, the applicant’s 
agent submitted a response referencing research conducted by the University of New Hampshire 
Stormwater Center on the efficiency removal of stormwater practices for pollutants of concern such as 
Nitrogen, Phosphorus, Total Suspended Solids and Zinc.  The written response notes that if a 2 inch depth 
of run-off from the impervious surface area is contained and infiltrated by the stormwater control, the 
reduction of these pollutants in site stormwater is 99-100%. It was indicated that the forebay of the basin 
can hold that amount of run-off. 
 
Considerations For Decision: 
 
The following findings have been developed for the Commission’s consideration of this application in 
accordance with SECTION 10.2 - Considerations For Decision. 
 
1. The proposed activity does not have direct impacts to wetlands or watercourses.  Permanent 
construction improvements are located a minimum distance of 100 feet from the adjacent wetland 
boundary. 
 
2. The stormwater treatment system as designed will capture and treat up to 5 times the calculated water 
quality volume from impervious surface areas and reduce the peak rate of surface run-off prior to 
discharge to the receiving wetland.  The TR-55 run-off calculations indicate the project will decrease 
peak discharge to receiving wetlands for the 2-yr through 100-yr storm event, and retain site run-off 
(no discharge to ground surface) up to the 25-yr storm event.   
 
3. The stormwater basin design incorporates a wet pond that increases residence time of stormwater in 
the pond to attenuate pollutant and thermal loadings prior to discharge to shallow sub-surface flow. 
 
4. The site design is consistent with the recommendations of the Jordan Brook Watershed Management 
Plan for stormwater quality treatment, groundwater recharge, and protection of wetland vegetated 
buffer areas between the wetland resource and adjacent development.  Monitoring of the basin 
stabilization and wetland plantings is proposed for 2 years following project completion. 
 

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5. Short-term impacts are minimized through the implementation of a detailed erosion and sediment 
control plan, a phased construction sequence and required monitoring of construction erosion and 
sediment control measures.   
 
6. Long-term impacts are mitigated by the stormwater treatment basin in controlling water quality 
impacts, maintaining groundwater recharge and detaining peak flows.   
 
The following conditions of approval are proposed for consideration: 
 
Recommended Conditions 
 
a. 
The limit of permanent clearing and disturbance shall be identified as the wetland non-encroachment 
boundary.  No activity, including but not limited to clearing, grading, filling or removal of 
vegetation shall be conducted within the non-encroachment area without specific authorization from 
the Conservation Commission.  The purpose of the non-encroachment area is to protect inland 
wetland resources from direct and indirect impacts associated with adjacent land development. 
 
b. 
The wetland non-encroachment boundary shall be located in the field prior to the start of site 
clearing and approved by the Commission’s agent.  Following construction, the non-encroachment 
boundary shall be permanently marked at 50 ft. intervals with identification markers provided by the 
Conservation Commission affixed to trees or 4x4 wooden posts. 
 
c. 
During construction, the stormwater treatment basins shall be inspected by the design engineer to 
verify the specified type, depths, and permeability of the fill materials applied are consistent with the 
approved plans.  Accumulated construction sediments shall be removed from the basin and the basin 
grading and planting completed and stabilized prior to receiving site stormwater run-off.   
 
d. 
An as-built survey of the stormwater treatment system components shall be submitted to the 
Commission’s agent with written verification from a licensed engineer that the system was 
constructed in accordance with the approved design plans.  This submittal shall be completed prior 
to the issuance of a Certificate of Compliance for the building. 
 
e. 
Monitoring of the stormwater basin plantings, slope stabilization and substrate stabilization shall be 
conducted by a wetland scientist or other qualified professional for a period of two (2) years 
following completion of the basin to document vegetation establishment and functioning of the 
stormwater basins.  Total herbaceous cover of the basin bottom shall equal or exceed 80% at the end 
of the second monitoring year.  Eroded side-slopes and basin substrate areas shall be repaired and re-
seeded as required. The outlet control structures shall be inspected and cleaned of sediment, trash 
and debris.  Invasive plant species such as Lythrum and Phragmites shall be removed from the basin.   
 
f. 
A monitoring report shall be submitted to the Commission’s agent by October 30th of each 
monitoring year documenting basin soil stabilization, vegetation establishment, ponded depth and 
basin discharge and corrective actions taken or required to maintain basin functionality. 
 
g. 
At all times during site construction, temporary diversion swales and sediment traps shall be 
installed and maintained to control construction run-off and prevent sediment discharge to wetlands. 
 
 
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