Conservation Commission / IWWA Minutes 10/20/2015
CONSERVATION COMMISSION/INLAND WETLANDS
AND WATERCOURSES AGENCY MINUTES
OCTOBER 20, 2015
REGULAR MEETING
I. CALL TO ORDER
Margery Winters, Chairperson, opened the Regular Meeting of the Conservation Commission at 7:32 p.m. in the Main Meeting Room at the Town Offices. Other members and alternates in attendance were Andrew O’Connor, Darren Cunningham, Jim Morrison, Donna Beinstein, and Donald Rieger. Also present were Michael Glidden, Assistant Town Planner; Janis Prifti, Commission Clerk; and other interested parties.
II. APPOINTMENT OF ALTERNATES
Chairperson Winters seated Commissioner Beinstein for the vacancy.
III. ADMINISTRATIVE APPROVALS
None.
IV. PUBLIC HEARING(s)
Application #15-39 of Town of Simsbury Water Pollution Control, for the stabilization of the river bank from a manhole station 62+70 to 56+90 on the sewer easement located on the property from Winslow Place to Tamarack Lane along the Farmington River Bank.(received 09/15/2015; decision must be rendered by 11195/2015)
Application #15-39 was read into the record.
The Director of Public Works reviewed that WPCA works to protect the river by taking all of the Town’s wastewater utilizing plant capacity of 3.8 million gallons with 5 pump stations in an 85-mile collection system with 2000+ manholes, serving 4500 residential/non-residential accounts, and also serving portions of plant co-owners - Granby and Avon, and providing plant administrative operation services. The Director focused discussion on the 30-inch south interceptor installed in the late ‘60’s/early ‘70’s, which at that time commonly followed natural river terrain; on a typical day this pipe processes about 1 million gallons of waste water, and up to 5 times as much during wet weather; and the pipe serves 2000+ homes/businesses.
The Director noted this pipe is a critical piece of the Town’s collection system with a long history of issues beginning with stream bank instability as a result of 1982 flooding, which was followed by an area study begun in 1984 and completed in 1988 calling for armoring the entire area reach to protect the pipe due to fine silt in the area, with a particularly silty layer near the pipe. The Director indicated that in 1984 about 900 feet of bank was armored, which was less than recommended in the report. The Director noted there was additional damage to the area in 2011 with a narrow section failing and emergency repairs completed in 2012 using rip rap armoring; in 2013, they began actively seeking approvals to armor this proposed section, rather than waiting for an emergency.
The Director showed the pipe location on the south side of Town on the river bank behind Hazel Meadow with a red line indicating the interceptor sewer line and pipe exit area where it moves away from the bank. The Director noted that issues include: protected and endangered species; determining the appropriate method for slope stabilization; removal of woody debris; and site access. The Director indicated 2 mussel surveys were done; in the 2006 survey, they found the Federally-endangered Dwarf Wedge Mussel and also some non-native Asian Clams; in the 2014 survey, they did not find any Federally-endangered species nor Dwarf Wedge Mussels, but did find 22 Eastern Pod Mussels which are of special concern to Connecticut DEEP, and the non-native Asian Clams had become well-established. The Director noted the program includes that 2 weeks prior to construction a biologist would photograph/tag the indicated mussels found 50 meters upstream and 100 meters downstream, relocating them upstream at least 300 meter,s and each would be GPS located in their new location and the biologist would check on them 1 month later and then 1 year later to review growth/mortality with interim reports submitted to DEEP.
Regarding slope protection, the Director indicated the slopes are very steep with poor soils, and the river current is fast resulting in limited alternatives; natural/vegetative solutions would not support 12.5 feet/second flow velocity so 15-inch diameter rip rap was proposed, following standard DOT specifications, as the best method of slope protection with rip rap having been used successfully in past area repairs; and no rip rap would be smaller than 6 inches or more than 30 inches. The Director showed the Commissioners photos of the woody debris in the river and proposed hiring the same biologist to determine the appropriate removal limit and the best method to manage wildlife in that area of the river.
Regarding access to the area, the Director proposed using the 2 existing access routes with tracking pads so that debris is not brought in/out of the site. The Commissioners were shown a recent photo of the area with intermediate-size rip rap currently visible due to low river flows; they would use organic coconut husk netting under this rip rap with some stone on the eroded soil allowing light vegetation including shrubs. The Commissioners noted a discrepancy on the rip rap bank in the Application; the Director confirmed the slope was 2:1 with 1½ horizontal to 1 vertical.
Regarding other alternatives, the Director noted that they looked at relocating the interceptor sewer which would have cost $2.5 million 20 years ago and there is also the issue of where locating that size pipe would be acceptable; and their design consultant indicated rip rap is the best alternative with no other reasonable and prudent alternative available. The Director confirmed this would complete the sewer area proposed to be armored in the original study.
Regarding the sequence/process for putting stone down and removing woody debris, the consultant explained all the woody debris would be flagged by the biologist and then removed/hauled off site at once for disposal with a turbidity curtain around the area to prevent anything getting into the river; then they would proceed with grading the bank for the rip rap working in increments each day leaving nothing exposed working from upstream to downstream. The Director believed an excavator would be used to remove the debris in a very controlled operation so nothing goes into the river, as required by the Army Corp, with the equipment’s reach extending at least a couple of feet into the river and not to woody debris beyond that reach; and debris balance would be determined by the biologist to safeguard fish and mussel habitat.
Regarding project timing, it would begin next May when the mussels emerge from their deep mud hibernation.
Regarding washing the material prior to its placement, the Director indicated it would be staged onsite in small loads in a day’s work, as they do not want to disturb the top of the bank and would work from there downward. The Commissioners noted the Erosion & Sediment Control Plan mentioned de-watering and the consultant indicated when they work on the drainage that de-watering may be required. The Director indicated they would prefer to keep the option open in the permit for which entrance would be used, as the contractor may prefer one-way traffic flow.
Town Staff provided the Commissioners with comments received from Farmington River Watershed Association; the Commissioners noted there were some good points, including whether the Town would re-site this sewer line in the future. The Commissioners also discussed moving to establish native plants/shrubs along the line sooner, rather than waiting for re-vegetation to occur over time, which could allow invasive species entry in in the meantime.
The Commissioners discussed that armoring a bank with rip rap potentially redirects the erosive power of the river to another bank section; the Superintendent responded that ¾ of the section has already been rip rapped with no evidence of any issues elsewhere on the bank. Regarding a post-construction monitoring plan and any catastrophic events, the Director indicated their operation monitors rights of way annually looking for any issues they need to react to and personnel are conscientious in reporting any problems they see and people walking in the area also commonly report any problems to the Town; it was noted a small 40-yard area about 25’ wide was repaired following Hurricane Irene. It was agreed plantings/tublings would be incorporated in bank stabilization.
Chairperson Winters invited public comment.
Martha Hickey of 7 Mathers Crossing asked for the project timeframe length and Town Staff estimated 2 months. Ms. Hickey asked what would happen if there was a wet spring with significant flooding and Town Staff responded they would hold off in high water conditions – the work needs to be done at the right time, and not during an elevated water situation.
Commissioner Rieger made a motion to close the Public Hearing.
Commissioner Cunningham seconded the motion, and it was passed unanimously
Commissioner Rieger made a motion the Commission finds that this is a regulated activity as it involves construction work on the banks of a watercourse.
Commissioner Cunningham seconded the motion, and it was passed unanimously.
Commissioner Rieger made a motion the Commission finds that this is a significant activity as it involves quite a considerable construction on the banks of the watercouree and offers the potential for impacts on the river and wetlands.
Commissioner Cunningham seconded the motion, and it was passed unanimously.
Commissioner Rieger made a motion, recognizing that there is no reasonable and prudent alternative to this approach, that the Commission grant the requested Application noting conditions in Staff’s memorandum, which the Commission and Applicant have seen, and the Commission has discussed proposed modifications to that: 1) in the 2nd Special Condition item regarding woody debris, the Commission proposed debris removal to the extent reasonably feasible and consistent with guidance from the bio-diversity consultant; 2) the 3rd Special Condition item that the rip rap material be reasonably clean in order to avoid sedimentation being introduced; 3) adding a 10th Special Condition that immersion tolerant native plants be considered more feasible and be used on the project; and 4) noting Connecticut DEEP’s request that another NDBD Survey be done if the work is performed after December 2015.
Commissioner Morrison seconded the motion, and it was passed unanimously.
2. Application #15-40 of Terri-Ann Hahn, LADA, P.C., Agent; Richard D., Jr., and Madeline F. Wagner Special Trust, Owners; for a Wetlands Map Amendment to a wetland on the property located at 152 Old Farms Road (Assessor's Map C07, Block 303, Lot 010). Zone R-80. (received 10/06/2015; public hearing must open by 12/102015)
Application #15-40 was read into the record. Commissioner Rieger noted for the record that the Simsbury Land Trust is an abutter to this property and some Commissioners are involved with the Land Trust; however, it was agreed that did not require any Commissioners to be recused from hearing this Application.
The Agent introduced the property located on Old Farms Road composed of 3 parcels totaling 20 acres owned by the Wagner family. The Agent indicated they surveyed and flagged the wetland limits shown in green on the Town map. The soil scientist flagged the wetlands on 12/04/2014, which were not snow covered nor frozen. The scientist noted a south wetland area was sequentially flagged (W1-25) and is seasonally inundated and near a narrow adjacent course of wetland; the NRCS map soils move north into the well-drained Hinckley series; and dominant species included Slippery Elm, White Cedar, Winterberry, Holly, Elderberry, Silky Dogwood, sphagnum moss, etc. The soil scientist did not find evidence of wetland soils in the connecting northern area to the wetland area off the property. The soil scientist indicated the northerly wetland area designated W40-46 has seasonal high ground water within 8 inches of the surface; dominant species included Red Maple, American Elm, Irish Blueberry, Royal Fern, and Cinnamon Fern; and the property appears to drain toward farm fields to the north. The soil scientist looked at the entirety of the site and noted a low portion where culverts were installed which may have enhanced drainage over time with no wetland soils found; another low point was looked at and found to not hold water long enough to develop wet soil conditions; and other areas investigated did not have wetland soils. The scientist noted the areas where augers were placed in reaching her conclusions.
Chairperson Winters invited public comment.
Commissioner Cunningham made a motion to close the Public Hearing
Commissioner Beinstein seconded the motion, and it was passed unanimously.
Commissioner Cunningham made a motion to amend the map as described by the Applicant based on the testimony presented here today and the further comments submitted.
Commissioner Rieger seconded the motion, and it was passed unanimously.
V. DISCUSSION AND POSSIBLE ACTION
1. Application #15-42 of Kimberly Steele, Owner, for filling and grading of a wetland behind the residence on the property located at 22 Neal Drive (Assessor's Map B18, Block 501, Lot 010). Zone R-40. (received 10/06/2015; decision must be rendered by 12/10/2015)
Application #15-42 was read into the record.
The Applicants environmental designer reviewed the proposal for grading and filling of the property’s rear yard abutting a wetland; they would fill/grade to maintain water flow and gain useable yard space. The designer noted plans submitted provide a cross-section of materials to be used, as well as a layout of the activity area. The designer indicated the peat/muck soils would be mildly dredged using rip rap as the most environmentally friendly/financially feasible method and also allowing the ebb/flow of water below the surface; the 4-8-inch rip rap would be topped with a sand base with filter fabric below to separate organic material from the rip rap and prevent invasive phragmites with seeded top soil placed above that would expand the lawn and rear yard reclaiming about 10 feet of lawn from the phragmites.
The Commissioners asked if the former lawn area, before the phragmites, was very wet. The Applicant indicated most of the lawn previously was dry and mowed, but over the years the phragmites growth continued and now when they step off the deck stairs the second step is wet due to a higher water level. The designer explained that the rip rap would allow the water to flow below with more impermeable materials on top, with the plan being to maintain the water level below and the lawn above. The designer provided photos showing the progress over the summer of the phragmites which also cover most of the adjacent wetland area and continue expanding onto dryer lawn areas.
Town Staff noted the house was built in the early ‘70’s, and the higher water level and subsequent phragmites growth is largely attributed to a substantial beaver lodge in the area; the Town hired a beaver trapper and there are beaver deceivers onsite, but no beaver has been captured to date. Regarding maintaining the lawn on top of the rip rap, the cross-section design showed a shelf where it would be secured with filter fabric separating out organic material and it would all be appropriately compacted. Regarding the peat/muck soils, the designer indicated they would be under the rip rap following mild dredging to remove surface lawn, followed by compacted rip rap; and they did not believe it necessary to dig test holes.
The designer noted phragmites would be removed first using a shelf to move in stages with a mini-excavator and building up rip rap in stages. The designer did not believe the mini-excavator sinking in to the soil/grass was a concern due to their buildup plan with fill and access road; they would work across the whole back of the house – 100 feet long x 10-feet wide tapering the fill in the Applicant’s yard on the ends before reaching neighboring back yards. The Commissioners noted DOT does not allow transport of wet soil and suggested they develop a plan for dealing with wet soil. Regarding erosion and sediment control in the wetland, the Commissioners noted phragmites would make a good filter.
The designer proposed beginning the project this fall, if approval is granted. The Applicant clarified her septic tank is to the left of the garage and not near the project area.
Commissioner Cunningham made a motion that this is a regulated activity since it involves filling and grading of a wetland.
Commissioner Morrison seconded the motion, and it was passed unanimously.
Commissioner Cunningham made a motion that this is not a significant activity because of the overall area of disturbance being not significant and the proposed activity should not affect the function of the subject wetland complex.
Commissioner Morrison seconded the motion, and it was passed unanimously.
Commissioner Cunningham made a motion to grant the Application subject to the 5 Special Conditions contained in Staff’s memorandum dated 10/12/2015, and adding a 6th Special Condition that Staff be satisfied with their wet soil transport plan.
Commissioner Morrison seconded the motion, and it was passed unanimously.
Application 15-43 of Marshall Greenberg, Owner, for an addition off the rear of the existing residence on the property located at 15 Banbury Drive (Assessor's Map A14, Block 404, Lot 033). Zone R-40. (received 10/06/2015; decision must be rendered by 12/10/2015)
Application #15-43 was read into the record.
The Applicant proposed removal of a current structure deck replacing it with a similar size deck and adding a stone patio. The Applicant’s contractor indicated the current 14’x20’ deck would be replaced by a 16’x24’ deck with ½ screened in and steps down to a 365 sq. ft. natural stone patio and no change in grade; 6 inches would be excavated with processed stone installed/compacted and the patio laid on that; and a small amount of top soil graded into the lawn off the patio. The Applicant confirmed the patio is 46 feet from the wetland and the deck is 65 feet from the wetland at the closest point.
Regarding lot topography, the Applicant responded that the deck area is about 3-5 feet above the wetland with the area gradually sloping toward the wetland. The contractor indicated the patio would be about 2 inches above the existing lawn with a small amount of top soil tying it into the lawn; the current deck is framing on the ground held up by concrete blocks and ends at the lawn. The contractor confirmed no grading would be required for the patio, only seeding to tie into the lawn; the Commissioners noted Staff’s Special Condition that no grading is permitted. The contractor confirmed that excavated material would be removed; and for erosion/sediment control, they will install silt fence before the tree line in front of the wetlands.
Regarding timing, the contractor confirmed they plan to perform the work as soon as possible.
Commissioner Morrison made a motion that this is a regulated activity because it takes place in the Upland Review Area.
Commissioner Cunningham seconded the motion, and it was passed unanimously.
Commissioner Morrison made a motion that it is a significant activity because it appears there will be no direct impact to the wetlands.
Commissioner Cunningham seconded the motion, and it was passed unanimously.
Commissioner Morrison made a motion to approve the Application subject to the conditions in Staff’s 10/12/2015 report.
3. Application 15-44 of James R. Poitras, Applicant; Harvey Moger, Owner; for the installation of a standby power generator within the upland review area to a wetland adjacent to the existing residence on the property located at 16 Richard Road (Assessor's Map F07, Block 110, Lot 109). Zone R-15. (received 10/06/2015; decision must be rendered by 12/10/2015)
Application #15-44 was read into the record. Commissioner Rieger noted for the record that he was acquainted with Mr. Moger; however, that acquaintance was not believed to require recusal.
The Applicant is planning to put in an automatic standby generator on the property. The Commissioners were provided with a layout showing that main utility service comes into the northwest corner of the house. The contractor described the basement as fully sheetrocked, and the breezeway near the garage is slab, so they prefer to set the 24-inch wide x 48-inch long generator 18 inches off a house chimney which is adjacent to a steep sloped area with a lot of pachysandra, and so they would need to level an area in which to place the recommended stone base for the generator.
The contractor clarified that the gas company suggests placing a 120-gallon tank a minimum of 10 feet away from the generator and the owner would like it in the back up on blocks with a hand shoveled 18-inch deep trench for the line dug to the generator. The contractor believed a concern was they are about 30 feet away from the stream, with the whole house within the 100-foot upland review area.
The contractor was requesting Commission approval for placement/location of the tank in the corner, not too close to the field. Town Staff confirmed the wetland is off site but about 30 feet to the generator and an issue is where the utilities enter the property, so the steep wetland side of the house is the only feasible location for the generator, and the issue for the Commission relates to digging the trench and placing the pad. The contractor confirmed there would be no trench from the generator to the house, but the connection would run along the wood siding and not touch the ground using flexible connections to the generator.
Commissioner Morrison made a motion that this is a regulated activity because it occurs within the Upland Review Area.
Commissioner Cunningham seconded the motion, and it was passed unanimously.
Commissioner Morrison made a motion that this is not a significant activity because it does not appear there will be any impact to the wetlands.
Commissioner Cunningham seconded the motion, and it was passed unanimously.
Commissioner Morrison made a motion to approve Application #15-44 subject to the conditions in Staff’s 10/12/2015 memorandum.
Commissioner Cunningham seconded the motion, and it was passed unanimously.
4. Application #15-38 of Royce Palmer, Owner; Mansour Prime Properties, LLC, Applicant; for Chapter 128 review of the erosion & sedimentation control plan for development on the property located at 80 Climax Road (Assessor's Map D20, Block 608, Lot 001). Zone R-40. (continued from 09/15/2015 and 10/06/2015)
Application #15-38 was read into the record.
The Applicant’s engineer indicated they have returned to provide the Commission with additional requested information about erosion controls and to show separately the roadway grading phase of construction. In addition to information provided in the Commission packet, the engineer provided additional larger 11”x17” copies and a blowup of the narrative. The engineer noted some important steps in the narrative sequence of construction, including: 1) notification of the Town’s agent; 2) staking clearing limits prior to construction with 3.7 acres to be cleared now indicated on the plan and review by the Town prior to construction; 3) separation of the lot construction from the roadway so the stumps/grubbing for the lots will not take place until the roadway construction is at least at the gravel base of construction minimizing the amount of surface area exposed during construction, which is called out in the Stumping/Grinding Phase; 4) on sheet B2, separate erosion control measures are shown during roadway construction and draining, with minimal roadway grading; 5) construction of a diversion swale/berm upgradient from the road to collect any southerly runoff – the ½% swale allows siltation to drop out given the prolonged period of travel within the swale and check dams within the swale divert away from the proposed underground water storage system; 6) a perimeter silt fence would be installed as part of the roadway construction phase, but the idea is for the swale to intercept/redirect site runoff; and 7) construction of individual houses would include and E&S Plan for each one, which would be submitted for review with each building permit.
The engineer noted they worked closely with Staff and have received a letter from the Town Engineer. Regarding Commission concerns that the Town Engineer required a detailed review of the reconfiguration of the stormwater management system, including maintenance and access, Town Staff confirmed that has been completed. The Applicant’s engineer described planned reconfiguration of the system to the front area in an easement away from the homes with easy access from the road, and while the Town Engineer seemed satisfied with this location, final review is reserved for the planning stage at the time of the subdivision permit.
Regarding the start date, the engineer indicated they would like to begin in the spring, depending on the approvals of commissions.
Regarding the narrative clearing sequence order, the building and septic system would be cleared first, then tree clearing, and then a construction entrance would be established with anti-tracking pad and erosion control; the engineer explained the logistics relate to the entrance with the existing driveway providing a construction entrance for demolition with little call for E&S controls; the existing drive would be used to access the site for tree clearing and silt fence put up after clearing; and then they would shift from the drive to the construction entrance where the anti-tracking pad would be installed. The engineer noted their plan was to clear the entrance area to make room for the anti-tracking pad, but they were not opposed to reversing the order, if required. The engineer confirmed the asphalt drive would be removed with the driveway temporarily re-seeded immediately; similarly, all disturbed areas would be re-seeded throughout the project; the house basement about 6-7 feet deep would be removed - their 7-foot test pits on the property found no groundwater on the site and there were no known septic issues or water in the basement.
Regarding what the temporary swale along the road feeds into, the engineer indicated its flow on the map moving through a series of check dams, across a non-disturbed area, through tree stumps providing filtration, bypassing the underground system, and not through the permanent stormwater system during construction; following construction of an inlet, it would pass through a pipe system and into the stormwater system after filtration. Regarding utility lines in the road, they would be part of the roadway phase with Eversource taking about a 15-foot easement on either side of the right of way and power going in before the pavement process, and once subgrade is established on the 450-foot road, all the utilities would go in before paving – all in less than a 6-month period.
Town Staff noted Applications for Intervenor Status were received from Jeremy Vearil and Mrs. Shelly Perron with the Commission needing to determine whether to accept those intervenor applications under 22A-19 of the General State Statutes. Attorney Richard Case, representing both intervenors, indicated they have now fulfilled the requirement to broaden the scope and state factually their environmental concerns; and he noted the Town Attorney previously recommended accepting their intervenor status. Attorney Lou Wise, representing the Applicant, indicated they would not oppose the intervention applications, but he believed on page 2 of the applications that of the four items alleging damage to State natural resources that only one has to do with the Erosion and Sediment Plan before the Commission, and he believed the other items to be beyond the Commission’s jurisdiction. Attorney Wise believed testimony before the Commission should be limited to the issue under 22A-19 and also requested an opportunity to prepare a response. Town Staff clarified separate intervenor status is required for each applicant.
Commissioner Cunningham made a motion to grant intervenor status to Jeremy Vearil.
Commissioner Rieger seconded the motion, and it was passed unanimously.
Commissioner Cunningham made a motion to grant intervenor status to Mrs. Shelly Perron.
Commissioner Beinstein seconded the motion, and it was passed unanimously.
Attorney Chase provided the Commissioners and Applicant with additional color photos of their report and introduced their soil scientist, George Logan, who submitted a copy of his professional resume for the record. The soil scientist believed the Commission should focus on the Erosion and Sediment Control Plan and added that drainage issues are pertinent to the E&S Plan because the Connecticut 2002 Guidelines for Erosion and Sediment Control, which will be revised in the near future, deal with both temporary and permanent erosion controls – the temporary controls have to do with the construction period with the silt fence in during construction and then removed with permanent erosion controls in place post-construction. The soil scientist noted 3.7 acres would be cleared with the clearing limits shown, there are impervious surfaces, earth excavation, filling, etc., so that during the construction phase there are internal sub-phases for the road and lots. The scientist indicated the issue has to do with the post-construction phase where the drainage system ties in; when a different cover type and impervious surfaces on a site are introduced, the dynamics change and the system must be designed to accommodate increased flow velocities, peak rates, and volume. The scientist noted the storm water management system is designed for detention and to reduce peak flow velocities and volume off site. The scientist indicated the site’s natural drainage is southerly and they are capturing it and diverting it to Ethan Drive to a catch basin and cross culvert at a stream which increases the watershed to that particular Ethan Drive point by about 3.5 acres, which does not go there today and resulting in about 77 total acres going there post construction; therefore, it is almost impossible to not have an increase of volume to that point with diversion of 3.5 acres from impervious and other surfaces just up the street. The scientist added in order to accommodate the volume issue, the Applicant has constructed galleys in the soil with stone below/around and performed calculations to show that below the pipes going out from the galley bottoms that there is storage in the stone surrounding and underneath the galleys allowing them to say the volume would not increase, but the compact glacial til soils have a high proportion of silt and fine sediments and a compact horizon down to about 72 inches; they did 2 test pits, one nearby the old system, and the another test pit location was noted in the report. The scientist confirmed he has reviewed all plans submitted to date. The scientist indicated where the densic horizon shows up in the closest pit to the system, he calculated for the south array - the system would be about 2 feet into the densic horizon; and for the north array, about 1 foot into the densic horizon, which means the storage they hoped to have is not practically available. The scientist explained that the densic horizon is compacted til with very, very slow permeability, so that the horizon above it has very permeable soils and putting the galley creates a bath tub with storage not available during storms. The scientist believed they may have been aware of the problem because they originally had an underdrain which was removed from the plan.
The scientist provided the Commissioners with reference manual material regarding watershed protection techniques, which discuss that with increased volume leaving a site that is not being infiltrated or retained going to a stream channel, combined with an additional 3.5 acres of flow, conditions of bankful and sub-bankful flow increase for a prolonged period of time resulting in the channel enlarging and eroding with sediment moving down and eventually impacting the stream channel and associated wetlands. The scientist indicated the erosion and sediment control related problem is that the permanent drainage in the post-construction phase does not accommodate the additional volume resulting in erosion and sediment to the stream and down gradient, and he pointed out that there are an additional 3 phases. The scientist added that the solution would be for the storm water management system to be lifted above the densic horizon by reconfiguring the site and bringing in more fill, which would add to costs. The scientist noted a 2004 manual calling for a couple of test pits for each system, which would provide more specific information they could bring to the Commission. The scientist confirmed his professional opinion of the current plan that there would be post-construction erosion and sedimentation over time which would impact a resource with destruction and pollution of State natural resources. Regarding the scientist calculation of the difference between the densic horizon and the overlying more permeable area, the scientist indicated in the densic horizon for the closest test pit it would be less than .5 inches/day and much better in the B horizons above. The scientist dug some test pits on the neighboring property of an intervenor with similar soils, which were well drained but the densic horizon comes further up.
Regarding the significance of the soil differences, the scientist provided the Commissioners with hydrologic soil analysis information and noted e.g., that C soils have a slow infiltration rate when thoroughly wet …impeding the downward movement of water in soil of fine texture; however, a permeability test would need to be performed in the field and analyzed in the lab to get an exact number. The scientist explained some of the methodology he uses and that the issue with these soils is not only their high silt content, but also that they are structurally compressed and layered so the bottom of the basins will always be filled with water and not provide volume control so when it rains the water goes off site; and although the rates are controlled, the stream will still erode and two lots on Ethan Drive and two lots below will experience long saturation in side yards and erode over time, which could potentially cause flooding. The scientist indicated the abutting intervenors do not need to be directly affected, but proof has to be provided for the record that there is a likelihood of reasonable pollution impairment and destruction of any natural resource specifically. The scientist confirmed that current drainage is toward the south and that the Applicant is trying to do a good thing, but questioned why they haven’t studied the true flow volume and why they are bypassing going down Climax Road to the next street section adding 3.5 acres of flow. While it is a complex project, the scientist believed a better job could be done. Regarding the NRCS maps, the scientist indicated he mostly relied on test pit data.
Attorney Wise reiterated that the Commission’s jurisdiction is limited to the proposed Erosion and Sediment Control Plan and stated from regulations that the Commission “has jurisdiction over erosion and sedimentation on any land which is used in a manner which exposes earth materials to erosion…construction activities where there is exposed earth susceptible to erosion and sedimentation.” Attorney Wise noted that the soil scientist discussed issues following construction and re-vegetation and potential drainage plan defects, which they have now resolved with the Town Engineer. Attorney Wise indicated the project engineer could respond to the soil scientist’s comments, if required, including impacts on a water course or wetland; however, he did not believe the Commission was sitting in its Inland/Wetlands capacity and intervening under 22A-19 meant to raise environmental issues does not expand any agency’s jurisdiction. Town Staff clarified it is valid that the Commission is limited to its jurisdiction pursuant to Chapter 128 to review the Erosion and Sediment Control Plan for the site’s construction or development, but the Commission could hear the project engineer’s response to the soil scientist’s comments limited to that jurisdictional scope. Attorney Wise added that the Commission regulations discuss items involved in an appropriate Erosion and Sediment Control Plan and noted some essential elements. Town staff confirmed this project would go before the Zoning Commission for a zone change, special exception, and site plan, and if approved, would then go to the Planning Commission for subdivision approval, which by statute approves the layout, subdivision of land, and public improvements, including water, sewer, and stormwater systems, which may be a more appropriate venue for utilities normally associated with the subdivision, but because of the nature of the special exception before the Zoning Commission, it is somewhat tied together. Attorney Wise noted the intervenors have also filed with the Zoning Commission to intervene at next month’s meeting, which is where it may belong and the Town Attorney has been involved in the review. The Commissioners suggested efforts to improve the plan would be worthwhile.
Regarding the swale controlling stormwater, the engineer responded that the swale would go in after the road is paved and as lots on one side are developed then some of the swale water would be allowed to enter the storm drainage system, although there would still be inlet protection until the entire site is vegetated and stabilized.
The soil scientist indicated he is looking to narrowly focus and make the project better and noted that Chapter 128 receives its authority from State statute which refers to the 2002 Guidelines for Erosion and Sediment Control where the preamble talks about construction, post-construction, drainage, and resources that could be affected if the temporary or permanent practices are put into place. Attorney Chase agreed with the soil scientist that both the construction and post-construction phases impact this project, which will not work because of the nature of the soils and requires the Commission in this limited capacity to take a look at both. Attorney Wise did not believe that the soil scientist talked about soils interfering with functioning of the construction E&S Plan, but rather talked about post-construction, and noted the Commission’s authority is governed by its regulation to review erosion and sedimentation plans for construction activities and did not believe the Commission typically designs drainage systems for construction.
Town Staff initially confirmed the project would not be returning to this Commission for further review. However, the Commissioners clarified while they agree with the Applicant on the scope of their ordinance, under Commission regulations the Commission is not limited to the 100-foot upland review area as an Inland Wetlands and Watercourses Agency if it is believed actions being taken will have a detrimental impact on a wetland or watercourse removed from the site. The Commissioners confirmed their interest in what will happen downstream from any development so that adjustments can be made early on. Town Staff corrected the initial statement and clarified that if a zone change special exception is granted and goes to the Planning Commission for subdivision approval, the Conservation Commission in its advisory capacity to the Planning Commission could claim jurisdiction at that time to review the Application with an appropriate discussion of the drainage system as the Conservation Commission and/or Inland Wetlands Agency. Attorney Wise noted that only one type of Workforce Housing allows single-family homes, which legally requires both Zoning Commission and Planning Commission approval. The Commissioners noted their vote regarding this E&S Plan is not conditioned on the project returning to this Commission. Town Staff clarified that the proposed Erosion and Sediment Control Plan and both intervenor applications must all be acted on, requiring a total of 3 votes; the Commission must decide, within its jurisdiction, whether there would be significant damage to the environment based on the expert testimony. Attorney Wise indicated it must be kept within the Commission’s jurisdiction noting the Applicant has not yet responded; Attorney Chase agreed with the response being limited to the Commission’s jurisdiction.
An intervenor asked through the soil scientist that during the construction phase when the system is not operational what will happen to the water coming off the site? The Applicant’s engineer responded there is a divide on the property between 2 watersheds with about 2/3 of the property having an existing depression along Climax Road for which they modeled large 25 or 100-year storm events, and the remaining portion of the property flows southerly to another depression on a private residence with other depressions noted along Climax Road acting to infiltrate all the storm water; in summary, to the north, water would go into the diversion swale and to the south, drainage volume/velocity should remain the same as currently. The engineer added they take the highly respected soil scientist’s comments seriously and will address them. Mr. Vearil, an intervenor, expressed skepticism that clear cutting 75% of the trees on this property would not result in water coming through his driveway toward his neighbor’s property in a much greater flow, as it already continually washes out with the existing trees in place; he asked if there was a plan to pool the water before it reaches his driveway. The engineer responded that the intent of the diversion swale is to cut off water moving in that direction, and as each house is built and adds impervious area, each roof water collection system adds to the stormwater management system. Mr. Vearil felt that the 1/3 near his driveway would continue draining the same way with clear cutting of large trees increasing water volume issues. The engineer responded that they could offer during construction to submit weekly reports to address issues that come up so that measures could be added during construction to immediately address issues, e.g. if there is a need for a temporary sediment basin in an area; it would be done as part of the review and they would make sure the contractor does that, which would also relieves the Town of the pressure for inspections – they have been doing this for many towns. Regarding construction of the swale without stumping, the engineer responded that it is constructed at the limit of the roadway construction envelope at the edge.
Commissioner Rieger made a motion regarding Mrs. Perron’s intervention that the Commission finds the points made in her intervention, within the four corners of the Commission’s jurisdiction in this Section 128 matter, do not indicate an environmental impact inconsistent with proof.
Commissioner Morrison seconded the motion, and it was passed unanimously.
Commissioner Rieger made a motion regarding Mr. Vearil’s intervention that the Commission finds the points made in his intervention, within the four corners of the Commission’s jurisdiction in this Section 128 matter, do not indicate an environmental impact inconsistent with proof.
Commissioner Morrison seconded the motion, and it was passed unanimously.
Commissioner Rieger made a motion that Application #15-38 having been amended to provide weekly inspections and reports and whatever remedial practices are implied by those in the judgment of Town Staff, the Commission finds that while there might be drainage questions of broader implication, again within the four corners of Chapter 128 jurisdiction, the Commission finds that the sedimentation and erosion control plan meets the requirements of the ordinance in form and in substance and approves the plan accordingly.
Commissioner Morrison seconded the motion, and it was passed unanimously.
VI. RECEIPT OF NEW APPLICATIONS
Town Staff noted receipt of two applications: one for modifications to the dock at the crew building on Drake Hill which is an Eagle Scout project; and second project for Flower Bridge plants with cut sheets related to an irrigation system.
VII. CORRESPONDENCE/ANNOUNCEMENTS
Town Staff provided correspondence from Representative Hampton regarding a Kinder Morgan 14.8 pipeline extension from East Granby to Farmington due to major community concerns, including 5.7 miles through MDC property. The Commissioners noted it does not occur within Simsbury and is an early-stage FERC jurisdictional matter, although it does cross the river in Simsbury.
VIII. APPROVAL OF MINUTES of the October 6, 2015 Regular Meeting
Chairperson Winters accepted into the record the October 6, 2015 minutes, as written.
IX. ADJOURNMENT
Commissioner O’Connor made a motion to adjourn the meeting at 10:10 p.m.
Commissioner Beinstein seconded the motion, and it was passed unanimously.