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HomeMy WebLinkAboutWetlands Assessment Wetland Delineations Wetland Evaluations Soil Evaluations 1 ____________________________________________________________________ Ian T. Cole Professional Registered Soil Scientist / Professional Wetland Scientist PO BOX 619 Middletown, CT 06457 Itcole@gmail.com 860-514-5642 November 10, 2021 Ms. Aisha Khan Company Operations & Acquisitions Shahani Inc. 53 E Industrial Road, Unit C1 Branford CT 06405 RE: Wetland Delineation and Impact Assessment, Shahani Dist., LLC, 612-Norwich Salem Turnpike (aka Intersection of Rte. 82 & Rte. 163), Oakdale (Montville), Connecticut. Dear Ms. Khan: At Shahani Inc.’s request, I completed a delineation of the jurisdictional wetlands and watercourses on the above referenced parcel. Additionally, I have reviewed the subject site plans and I offer the following comments relative to assessing impacts to the inland wetlands and watercourses due to the proposed regulated activities. Delineation Methodology A wetland survey was completed in accordance with the standards of the Natural Resources Conservation Services (NRCS) National Cooperative Soil Survey and the definitions of inland wetlands and watercourses as found in the Connecticut General Statutes, Chapter 440, Sections 22a-36 through 22a-45 as amended. Wetlands, as defined by the Statute are those soil types designated as poorly drained, very poorly drained, floodplain or alluvial in accordance with the NRCS National Cooperative Soil Survey. Such areas may also include disturbed areas that have been filled, graded, or excavated and which possess an aquic (saturated) soil moisture regime. Watercourses means rivers, streams, brooks, waterways, lakes, ponds, marshes, swamps, bogs, and all other bodies of water, natural or artificial, vernal, or intermittent, public, or private, which are contained within, flow through or border upon the Town of Montville or any portion thereof not regulated pursuant to sections 22a-28 through 22a-35, inclusive, of the Connecticut General Statutes. Intermittent watercourses are defined permanent channel and bank and the occurrence of two or more of the following Wetland Delineations Wetland Evaluations Soil Evaluations 2 characteristics: (a) evidence of scour or deposits of recent alluvium or detritus, (b) the presence of standing or flowing water for duration longer than a particular storm incident, and (c) the presence of hydrophytic vegetation. Wetland Findings The on-site soil survey and wetland delineation was completed on October 28, 2021. The wetland delineation was completed under blue sky conditions. Those areas meeting the wetland criteria noted above were marked in the field with sequentially numbered pink and blue flagging. The original delineation completed in 2020 by Environmental Planning Services is substantially correct and accurately represents the limits of the jurisdictional wetlands on the subject property. I recovered the original flagging which was still readily identifiable and I re-tied new pink and blue survey flagging to easily identify the wetland boundary in the field. The on-site wetlands are characterized as a well-defined forested wetland corridor associated with hillside seepage wetland that drains southerly, conveying seasonal flows towards Whittle Brook. Along the flagged boundary the wetland exhibits wooded swamp vegetation with red maple (Acer rubrum) dominating the forest overstory, and a moderately dense shrub stratum of various species including but not limited to spicebush (Lindera benzoin), winterberry (Ilex verticillata), with patches of multiflora rose (Rosa multiflora) and Japanese Barberry. Pockets of sphagnum moss ground cover can be observed in the lowest-lying depressions within the wetland boundary. Photo 1: Forested Wetland Wetland Delineations Wetland Evaluations Soil Evaluations 3 Soil Survey The soils identified on the site are a refinement of the Natural Resources Conservation Service (NRCS) Websoil survey. The wetlands soils are classified as Walpole poorly drained sandy loams. A typical soil profile along the wetland boundary consists of approximately 2”-0” of intermediately decomposed organic material (Oi), followed by 0”-6” of a thick dark topsoil horizon (A), underlain by 6”-16” of a wet weakly developed grayish subsoil horizon (Bg) with common redoximorphic features (Common medium distinct strong brown mottles, masses) ranging from fine sandy loam to very fine sandy loam. This subsoil is underlain by a saturated sandy loam to fine sandy loam gray substratum (2Cg). The naturally occurring upland soil in the wooded portion of the property are mapped and classified as Sudbury sandy loams. Sudbury series consists of very deep, moderately well and somewhat poorly drained soils on outwash plains. They are nearly level through strongly sloping soils in slight depressions and on terraces and foot slopes in areas of outwash or glaciofluvial deposits. The northern limits of the property occur at the interface of where outwash meets the glacial till landscape. In the northern portions of the property are inclusions of Charlton-Chatfield sandy loams. These soils are typically associated with shallow depth to bedrock. The upland soils within the bulk of the proposed activities are classified as Udorthents / Urban land complex which contains miscellaneous soil types that are present on the landscape in a complex pattern that is not practical or necessary to sperate. Urban land is used to denote moderately-well to well-drained an earthen material which has been so disturbed by cutting, filling, or grading, that the original soil profile can no longer be decerned and are co-associated with buildings, roads, parking lots and landscaping of highly developed areas. Wetland Delineations Wetland Evaluations Soil Evaluations 4 Proposed Activities The applicant is seeking approval from the Town of Montville to improve the existing gas station with a new addition to the convenience store, improvements to existing infrastructure including pumps, canopy, underground storage tanks and associated re- paving. Site drainage will be directed to a new 1500-gallon oil and water /grit separator, hydrodynamic separator unit and a new compliant subsurface sewage disposal system will service the renovated store. The proposed development will not result in any direct permanent wetland impact. Due to the needs of the proposed development and the location and proximity of the wetland resources, part of the activities is proposed within Town regulated Upland Review Area (URA). Except for some minimal clearing, and surficial grading to support the new septic, all proposed activities are more than 50’ from the wetland boundary. For all practical purposes apart from the proposed septic area the proposed improvements are within the existing developed envelope of the site. Photo 2: Area of proposed on-site subsurface sewage disposal system Wetland Delineations Wetland Evaluations Soil Evaluations 5 Photo 3: Example of existing conditions Wetland Delineations Wetland Evaluations Soil Evaluations 6 Impact Assessment The planned improvements will largely occur within the limits of pre-disturbed man- made manufactured lands. The proposal does not include any filling, discharges, excavation, or removal of vegetation within the wetlands. The uneven topography along the wetland boundary and excavated cuts and fills in combination with the vegetation of secondary growth is evidence of past clearing and earth work had occurred in preparation for the original development. Currently there is no existing stormwater management system on the property and untreated runoff from paved areas of the adjacent developments direct runoff discharge to the southeast corner of the lot paralleling the southbound lane of Route 163, eventually making it to Whittle Brook. The site improvements will provide an engineered stormwater management system that will attenuate and treat stormwater including an oil and water separator / hydrodynamic separator unit. Short-term impacts during construction will be reduced through measures to control sedimentation and erosion. These measures will minimize the chance that siltation and sedimentation will encroach beyond the limits of disturbance or into the regulated wetlands. The site plans provide a narrative of the erosion and sediment control plan, which follows the requirements of the 2002 Connecticut Guidelines for Erosion and Sediment Control. There is minimal erosion hazard due to the generally level landscape. These controls as well as compliance with permit approvals will assure that no permanent adverse effects will impact the receiving wetlands. The proposed site grades will not measurably change the existing drainage patterns. The proposed drainage system will be equipped with an oil and water separator water quality unit (WQU) to catch and hold oils from the pavement. The proposed impervious area is nearly equal to the existing impervious area; therefore, the proposed improvements will not measurably increase the rate of runoff of the site. The WQU will follow the manufactures recommended maintenance plan which outlines inspection, reporting and cleanout requirements. Additionally, the management and operation of the site will include a spill prevention and contingency cleanup procedure. Conclusion The proposed site improvements and modifications provide upgraded industry and regulatory standards and best management practices to provide a better functioning commercial property that is more environmentally sensitive than what is existing. Based on my review, if the actions are adopted and implemented as detailed above, it is my professional judgement that with the regulated activities will not have a negative effect on the natural capacity of the wetland system or the functions and services it provides If you have any questions or comments, please do not hesitate to contact me at itcole@gmail.com or (860) 514-5642 Sincerely, Ian T. Cole Professional Registered Soil Scientist / Professional Wetland Scientist #2006