Conservation Commission

MINUTES OF THE MEETING Tuesday January 20, 2015 LACONIA CONSERVATION COMMISSION Approved at the March 4, 2015 meeting PRESENT- Dean Anson, Hillary May, Lisa Morin, Mike Foote, and D. Williams. ABSENT- Marnie Schulz OTHERS PRESENT- Steve Smith, Steven Smith & Associates and Daniel Coons, Soil & Wetland Scientist and Gretchen Gandini, WOW trail Executive Director I. Call To Order: Review of the minutes from the January 7, 2014 meeting Tabled until the next meeting II. New Business: a. Appl#PL2015-0001SP, 0002 CUP (wetland) 93 Lexington Dr. MBL 376-324-5 Proposal to construct 47,520 addition to existing building The original conceptual Titeflex plans were introduced to the Conservation Commission last fall. Steve Smith thanked the Conservation Commission for suggesting the use of porous pavement. The porous pavement idea was introduced when Titeflex could not meet the City’s green space requirements. D. Anson asked how the depth of groundwater would impact the porous pavement. D. Cooms said the groundwater was approximately 80 inches down. S. Smith described how porous pavement deals with excess water. Underdrains are included in the design to capture and divert excess water toward the treatment swales. D. Williams asked about winter maintenance. Porous pavement does not require the application of salt or sand. The technology enables melting and filtration therefore reducing the rare need to apply salt. Since the parking lot is free of salt and sand any snow plowed on the new site will be free of these two major contaminants. The pavement must be vacuumed from time to time depending on any offsite sand or salt infiltration. S. Smith explained they are in process of adding the snow storage areas on the plan. All excess snow will be shipped off site. The access drive and other non-porous areas will be equipped with oil water separators to further cleanse any off site runoff. The Con Com was concerned about the amount of trees that will be cut. S. Smith reminded the Con Com the elimination of the retention pond reduces impacts to wetlands and their buffers. Taking this action has now saved many trees that were originally targeted for removal. Requests were made to reduce the amount of parking spaces at the facility to preserve more trees. S. Smith said that is not possible due to current and future parking demands. The Con Com questioned the need to use grass on the down slope area after the porous pavement ends. A conservation mix could be added in its place eliminating the need to add chemical fertilizers.  Roof runoff will be controlled by a sand filter system. Water then will flow into the drainage system located under the non-porous pavement. The Con Com recommended that Oil water separators be placed at the end of each drainage line. A question arose about a previously delineated wetland that would now be partially covered under the porous pavement. S. Smith clarified the older wetland report referred to a wetland near Primrose. D. Coons explained he evaluated the area and determined it was not a wetland. D. Anson was extremely concerned about the lack of a reading for the depth of the water table in the spring. He also questioned the wetlands evaluation report if no readings occurred in the spring. He requested this comment be added to the wetlands report as part of the Con Com comments to be made to NHDES. S. McPhie reminded the owners that they must be very careful not to allow sediments to leave the property and fill wetlands. The city owns the abutting wetland parcel. If sediments accumulate in any wetland on the city’s parcel they will be obligated to report that infraction to NHDES. Only clear non- turbid water should exit the site. D. Anson asked about impacts to wildlife. D. Coombs indicated there was no significant wildlife on the property. No vernal pools existed. D. Anson asked if any other green building techniques would be used. He then suggested a green roof. S. Smith still felt a green roof in a cold climate is too costly and not fully accepted yet as a viable solution. S. Smith did add all water used in the manufacturing process will be recycled onsite Maintenance plans will be the key to assuring all innovative drainage devises function properly. Proper installation and supervision of the porous pavement installation is critical. A wetland permit will be filed containing the information provided to you tonight along with a SWPP plan that will make all those responsible for maintenance activities accountable. D. Anson reviewed the TRC comments provided to him and asked for any other additional comments. H. May praised the use of porous pavement. L. Morin asked about the drainage pattern changes. S. McPhie explained flows appear to move toward Lake Opechee reaching the Fuller Conservation Easement first. Flows then culvert under Route 106 into the city owned Tardiff open space lands finally flowing under North Main Street and into Lake Opechee. M. Foote made a motion to pass their positive recommendations to the Planning Board including the additional comments mentioned tonight. Those comments will be added to the existing TRC comments. The motion was seconded by H. May. The motion passed 5-0-0. b. Review and Comment on NHDES wetlands Permit for Phase II of the WOW trail. The project will extend along the railroad corridor from the Laconia City Station to the Belmont Town Line S. Smith presented the wetland permit for Phase II of the WOW trail. He reviewed the four wetland impacts and drainage improvements. The Con Com had questions concerning the presence of a vernal pool. The vernal pool was indicated in an earlier wetland study provide to them. L. Morin said since the site has not changed over the past few years the pool must still exist. S. Smith believed P. Schauer was able to evaluate the wetland again and determined it was not a vernal pool. He would provide an updated determination and add it to the current report. If the area shows any signs of a vernal pool it probably would not be as productive as one located in an area that was not disturbed today due to hundreds of years of railroad use. Either way this is a city project so local vernal pool regulations are optional. The overall benefit of the project is to provide safe public access in areas where traffic is heavy and streets can be dangerous to children. Many precautions have been taken to be sensitive to all the wetland areas so overall impacts have been minimized.  L. Morin made a motion to clarify if the wetland in question is a vernal pool as indicated in the earlier SEC report. If a letter can be provided by a soil scientist indicating it is not then there will be no need to send any comments to NHDES. M. Foote seconded the motion. The motion passed 5-0-0. c. Conservation Commission yearly nominations M. Foote made a motion to nominate D. Anson as Conservation Chairman. The motion was seconded by D. Williams. The motion passed 4-0-1. D. Anson abstained and accepted the nomination. M. Foote made a motion to nominate H. May as Assistant Chair. L. Morin seconded the motion. The motion passed 4-0-1. H. May abstained and accepted the nomination. d. Black Brook presentation handout S. McPhie provided D. Anson with an updated copy of the standard Black Brook Power Point presentation and requested feedback from him. Upon receipt and payment of our final water testing bills for 2013- 2014 we should target the presentation at that time. III. Old Business: a. Brook Subcommittee updates D. Anson reported they had not yet received notification on the Bank of New Hampshire application for Black Brook funding. He will update everyone at the next meeting. No additional information or bills have been provided by DuBois and King. Stay tuned for the spring season! b. Follow up on changes to the State Wetland ordinance No additional comments. IV. Liaison & Sub-Committee Reports: Permit Sub-Committee review and updates All permits have been reviewed and updated. V. Other Business: - Subdivision/ Site Plan update - Commissioners Comments - Staff Comments VI. Adjournment: M. Foote made a motion to adjourn the meeting. The motion was seconded by L. Morin passing 5-0-0.