A third-party expert review of the proposal to redevelop the former School Sisters of Notre Dame property on Belden Hill Rd. has not yet concluded that the plan meets Wilton’s stormwater management requirements, as key questions remain unresolved before the reviewer can offer a recommendation to the Inland Wetlands Commission (IWC) on whether to allow the project to proceed.
At the same time, experts retained by the project’s intervenor — an abutting neighbor challenging the project — are raising a more fundamental concern: that the wetland system the developer aims to manage is already stable and functioning — and that the proposed changes could disrupt it.
During a Thursday, Apr. 9 public hearing, Joe Canas, principal engineer with Tighe & Bond, the firm hired by the IWC to conduct an independent review, said the applicant (Hines SL Wilton Associates LP) has made significant progress but has not yet demonstrated compliance.
“The applicant has been responsive to our comments, and they’ve been moving forward in a positive direction toward compliance,” Canas said. “That said, … we can’t make a determination at this time that the proposed application is compliant with the town’s stormwater management requirements.”
Canas noted that Redness & Mead, the engineering firm developing the stormwater management plan for Hines, submitted “a significant volume of [new] materials” shortly before the hearing, leaving insufficient time for review by the commission, its consultants Tighe & Bond, or Cramer & Anderson, lawyers retained by intervenor Kari Roberts. Canas said he expects to provide an updated assessment at the next public hearing on Apr. 23.
Editor’s note: Roberts, whose property abuts the School Sisters site, is a member of Wilton’s Board of Finance. She is participating in this proceeding as a private property owner.
While the town’s consultant focused on technical gaps that could potentially be addressed with additional data and analysis, the experts representing the intervenor challenged the underlying premise of the proposal itself.
George Logan, a senior ecologist with Rema Ecological Services, said available evidence indicates the wetland ecosystem is already “stable and resilient,” and argued that the proposed stormwater systems are “attempting to solve a problem that does not exist.”
Logan and other experts retained by Roberts — whose property abuts the site — cited concerns including altered groundwater patterns, reduced natural stormwater “pulses,” and insufficient baseline data to support the developer’s conclusion that the project would not adversely impact the wetland.
“At a minimum, what we need is additional site-specific data analysis, and those should be required before any determination can be made,” Logan said.
Proposal Overview
As GOOD Morning Wilton previously reported, Hines is proposing to redevelop the 38-acre site into a senior living community with 280 residential independent living, assisted living and memory care units.
Most of the units would be located in a building roughly overlaying the footprint of the existing structure, while preserving the chapel as a common-use space. The design also calls for the construction of two below-grade parking garages.
The site’s 18 acres of wooded land — including 10 acres of wetlands — would be preserved and restored with improved drainage, removal of invasive vegetation, and the introduction of native plants.
IWC’s Independent Review Identifies Outstanding Technical Issues: More Detailed Modeling, Resized Sediment Traps, Invasive Species Management Plan
The town’s independent reviewer focused primarily on technical aspects of the proposal that require further validation before a compliance determination can be made.
Canas and other Tighe & Bond engineers outlined several areas where additional information is needed, particularly related to stormwater management sediment and erosion control, and wetlands management.
While the Hines proposal aims to recreate the site’s natural hydrological cycle of the using underground chamber systems, rain gardens, permeable pavement and separators, Canas said key details remain incomplete. He recommended additional water infiltration testing and soil analysis to verify assumptions used in the design, as well as confirming the groundwater table levels for the proposed underground infiltration systems.
Regarding sediment erosion controls, Canas noted that temporary sediment traps planned for the construction phase may not have sufficient capacity to prevent overflow during heavy rain events. He requested detailed calculations and methodology for determining volume for independent verification.
Tighe & Bond engineer Matt Regan also recommended evaluating the condition of the existing stormwater outfalls and the wetland’s pond outlet, and called for an invasive species management plan to address what he described as the “dominance” of invasive vegetation on the site.
Despite those concerns, Regan said that the proposed project “generally avoids direct wetland impacts and concentrates site redevelopment away from existing wetlands. Most of the development occurs outside of the jurisdictional upland review area, so therefore the impacts are minimal in extent.”
Canas concluded by noting that the applicant has addressed 90-95% of the questions Tighe & Bond raised earlier in the review process.
Commissioners asked Canas and Regan about the stormwater permit process, the potential impact of underground construction on water and sediment flow to the wetland, and how water levels are assessed — questions that may already be answered in the materials submitted by the applicant or, if not, can be addressed at the next public hearing.
Intervenor’s Experts Challenge Need for Proposed Wetland System
Experts retained by the intervenor offered a more sweeping critique, questioning whether the proposed stormwater systems are even necessary — or potentially harmful.
Logan argued that the wetland ecosystem functions as a stable and resilient system, and warned that installing engineered stormwater management systems the applicant would be “removing what makes the system work.”
He cited concerns including interrelated changes to the wetland ecosystem as well as incomplete water quality analysis and a lack of sufficiently detailed baseline data — that, taken together, do not support the developer’s argument that there will be no adverse impact on the wetland from the development and its associated wetland management plan.
Steven Trinkaus of Trinkaus Engineering, LLC focused on water quality, arguing that the requirements of Connecticut Department of Energy and Environmental Protection (CT DEEP) — and cited by the developer — do not fully address contaminants like nitrogen and phosphorous, and that catch basins and pretreatment systems planned by the developer would be inadequate.
“An analogy I like to use is if you take a bathtub with six inches of water, if you put a foot of water in your bathtub, do you get any cleaner?” Trinkaus said “You don’t, you simply have more water to let down the drain.”
Trinkaus also said that the proposed underground systems are too close to sources of seasonal groundwater, and he questioned the developer’s estimates for roof runoff and challenged Redniss & Mead’s pollutant loading analysis technique.
“The bottom line is, these systems are not going to address water quality,” Trinkaus said.
Attorney Perley Grimes Jr., representing Roberts, reiterated the legal requirement for the IWC to consider “feasible and prudent alternatives” to the Hines proposal, including a lower density of residential units. Citing a case in New Milford that involved a similar application to conduct a Significant Regulated Activity in a wetland, Grimes noted that feasible alternatives included reductions in impervious cover and natural vegetation, and designing the property in conformance with current zoning requirements, thereby reducing the effects of runoff on wetlands.
Residents Raise Concerns About Private Wells, Lighting Disruption and Impacts on Migration and Mating Patterns of Wildlife
Public comment reflected a range of concerns about the proposal’s potential environmental and neighborhood impacts.
Thomas Banahan of 5 Twin Ponds Ln. urged the IWC to deny the application, arguing that the underground parking garages are likely to redirect groundwater flow, which could affect neighboring private wells and possibly cause subsidence that could damage buildings. Banahan said that the disruption could also create a pathway for surface contaminants to reach groundwater.
Nicki LaMonica of 296 Belden Hill Rd. expressed concerns about the potential use of pesticides and herbicides to both control the invasive species and help new plantings take root.
“As a homeowner very near the SSND property, who obtains her family’s drinking water from a private well and uses well water to grow organic food for her family, I can tell you that this elicits a deep fear and distrust of the applicant,” LaMonica said.
Alissa Brady of 302 Belden Hill Rd. expressed concern over the potential loss of natural habitats as a result of new plantings. She said she believes the applicant’s biological assessments were insufficient to understand the site’s wildlife, migratory patterns and biological activity. She also recommended that Wilton’s Water Pollution Control Authority (WPCA) reexamine its decision to allow the new development to have the same amount of flow into the sewer system as the existing SSND facility given that there will be significant new structures including the underground garages.
Linda Gance of 400 Belden Hill Rd. said she strongly supports the Hines proposal. “It will significantly improve wetlands and stormwater management compared to the 1960s development, enhance the neighborhood, and, for a nearly 40-acre site, likely generate the least amount of traffic possible,” she said.
John Brady, also of 302 Belden Hill Rd., said he was “extremely concerned” that the developer was minimizing the potential impacts of the construction on the adjacent wetland and its associated upland review area. Noting that half of his property is protected wetland, he said the IWC would be “very, very concerned” if he proposed to remove trees and vegetation to the same extent as what Hines is proposing for the SSND property. He also expressed concern that the sewer system could be overwhelmed by a major rain event.
Eileen Corsalo of 36 Borglum Rd. said she is concerned about the potential effects of light pollution on the wetland’s ecology. She argued that lighting could disrupt natural breeding, feeding and hunting patterns of mammals, amphibians and birds, as well as affect the quality of life for neighbors, and urged the IWC to reject the proposal.
Jennifer Malloy of 364 Belden Hill Rd. asked the commissioners to consider the potential environmental impacts on Miller-Driscoll School, which is located across Belden Hill Rd. from the School Sisters property. The Hines proposal does not propose any mitigation of noise, dust or construction vehicle exhaust from disrupting outdoor learning and play spaces during the 39-month construction period, Malloy said.
“The steady stream of heavy construction equipment will deposit oil and other pollutants to the surface of the construction site,” Malloy said. “There is no mention in the application of collecting pollutants in catch basins or treating them before surface flows across the property and onto the Miller-Driscoll school boundaries.”
Responding to questions from commissioners, IWC Counsel Pete Gelderman said that the issues of light pollution and the impact of the underground garages could be considered within the IWC’s purview if it can be proven that they would have an effect on the wetland or watercourses, for example through expert testimony or detailed studies. Canas and Regan said Tight & Bond would review the potential impacts of the underground construction and light disturbances on the wetland.
What’s Next?
The public hearing for the School Sisters proposal will continue through the next IWC meeting on Apr. 23.
IWC Chair Jason Terry requested that the applicant and intervenor submit all documents to be considered by the commissioners no later than Apr. 21 to ensure enough time to review.
At the next meeting, Tighe & Bond will present its final recommendations, followed by questions and comments by representatives of both the intervenor and applicant, which will be granted the final word. The public will have another chance to comment following those discussions. At that point, the public hearing will be closed and the IWC will begin its deliberations.
Terry emphasized that it should not be expected that the IWC will take a final vote at the Apr. 23 meeting, but rather the vote will be taken at a subsequent meeting.