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HomeMy WebLinkAboutmin of conservation com 12/5/2005 Yo ,-.. / Conservation Commission Meeting December 5. 2005 Tn'\J~.1 RrE~EIVEO , " I::. ~,L r.RKS OFF ICt 06 JUN - 6 AM": 3 6 NANSFlELD MASSACHUSETTS Present: Colin Cauldwell, Chair; Paul Boyden, Vice Chair; Carole Matthew; Jack Smith; Marc Marcussen; Jerry 81. Hilaire; Cindy Ostrowski; Michele Grenier, Conservation and Environmental Planner. Ann McMenemy, ERM, Louis Masiello, WS Development, Dave White, Civil Engineer for ESS, Jeff Bridge, Mason & Associates, Mark Beaudry, Meridian Associates and Jeff Heidelberg were present. Lou Masiello told the Commission that the project received ZBA approval this past summer for the parking ratio. Mass Electric power lines will need to cross a small portion of the zoning code landscape buffer and the ZBA approved. Also there was an issue with some on-site soils in areas where construction will be in close proximity to but is no longer an issue-this will have no impact environmentally. r- Lou said they had received unanimous approval of the site plan on a special permit application in November from the Planning Board (the appeal period has run out). He also said they have received the final certification from Mass Environmental Policies Act Unit/Secretary of Environmental Affairs in late summer-this process is complete and the appeal period has run out. The Department of Environmental Protection issued a sewer connection/extension permit for the public sewer infrastructure that the applicant is building at their expense. The new sewer extension will service this project and will have the ability to service Cabot, Cabot and Forbes as well as future projects. This is part of the Town's master plan for sewer improvements in this area. The Army Corps of Engineering has issued their approval for both the environmental issues related to the wetlands and the relocation of the Stearns White house. They have received a Memorandum Of Understanding (Mansfield Historical Society and Mass Historical Society were also involved with this process). r" Ann McMenemy summarized the project from the initial filing, May 24, 2004, thru the many changes that have occurred. The latest plans, dated 9/212005, include modifications to ihe access to Route 140, relocated utility easement, the redesigned berm and spillway and additional.mitigatin&measures and increases in wetland impacts. ,--. Ann McMenemy wanted the Commission to know that the Federal Wetlands Permit has been issued and as soon as she receives the corrected permit she will send a copy to Michele for our files. She told the Commission they are waiting for the 401 Water Quality Certification. The DEP performed a site review in July and had requested some additional analysis information. She wanted the Commission to know that all the boundaries were legally established in an ORAD before the applicant became involved. The ORAD is still valid for another year. Impact Area #3-Mass Electric Easement: Colin wanted to know where the Mass Electric easement goes, where the proposed easement will be and the width. Ann told him that it was 50 ft. for both the existing and proposed. Paul wanted to know who proposed the relocation. Lou said that the relocation was done at the applicant's request in order to develop the shopping center. r Paul wanted to know what the process was for moving the poles. Lou said the arrangement with Mass Electric involves paying them to build new poles and signing an amended easement that moves the existing easement from its present location to the perimeter of the site. This needs to be done so WS can develop the central portion of the site. He does not feel the work to install these poles causes a wetland impact but if Mass Electric comes back in the future and uses their ability, under the easement, to clear the vegetation so it does not interfere with their power lines, this will clearly result in an impact. So they have incorporated those areas into their permit even though they do not think this will happen. They have provided mitigation for these areas. Lou told the Commission that up to this time, Mass Electric has only cleared a small portion of the easement, usually only 25 ft., not the 50 ft. Lenny Flynn is concerned that the same thing will happen with this easement that has happened in Great Woods. Mass Electric went off the easement in Great Woods along the hiking trials. Paul agreed with Lenny and said there has been a problem like this on Oak Street. Lou feels they have accounted for the worst case scenario-assuming MECO does what Lenny has seen at Great Woods-with the permit and mitigation. Lenny also wanted to know why they couldn't put the electric underground. r- r Lou said that MECO would not allow this because of the large number people it services and the added time needed to bring the people up to service. Colin said it was a maintenance issue. Paul asked if the Planning Board needs to get involved with the relocation and Lou said they have reviewed the location of the line and its interplay with landscaping buffers intended to screen the property from the roadway to make sure there isn't a conflict. Lenny wanted to know why it is better around the periphery instead of right straight thru. Lou told him they would be building where the existing lines are (the lines presently bi- sect the upland area). Cindy asked why the lines couldn't go over this area. Lou explained that you can"t build or put a parking lot under power lines. Landscaping (trees) and site lighting is also an issue when you have overhead lines. Paul wanted to know if Mass Electric would be supplying the electricity for the project. Mansfield Electric will service the site; the only interaction with Mass Electric will be the easement. Carole wanted to know why MECO has the right to govern where these lines go. Because they own the easement rights, they have that right. r- Colin asked Jeff Bridge if he had any comments. Jeff said he would like to acknowledge the applicants for their professionalism. They have been extremely receptive, very cooperative and respectful on every issue, even though they haven't always agreed during this process. (The first letter in June of comments and questions resulted in a meeting in July. The applicant addressed these comments and Mason & Associates formulated a ~ response in September. In response to the Sept. comments, the applicant addressed those comments and further revised the plans, addressing the Route 140 issues and changes that were made to the mitigation and buffer zone enhancement areas) Jeff questioned the clearing of the 50 ft. easement. If only 25 ft. were cleared, it would reduce substantially the impact on the wetland. Ann said they had gone back to MECO and were told they had to work within the 50 ft. Lou agreed with Jeff about clearing the 25 ft. and reducing the impact but MECO has the fmal say. He explained that to ask MECO to take the 25 ft. instead of the 50 ft. is asking them to take a narrower easement in this portion and in the future not having the rights they have today in the 50 ft. ,,-- Ann said that the impact numbers are for the assumption that the full width of the easement will be cut at these wetlands impact areas. In most areas, only a small portion (" of the full easement width is actually maintained. She said that Wetland 1 has the most value and function of all the wetlands and that the relocation of the existing poles from this wetland will allow this area to revert back to wooded wetlands. The Commission wanted to know the height of the poles. Lou said the parking lot poles are 35 ft. but the pedestrian areas are shorter. Lou reminded the Commission that over-all, the project respects the 25 ft. Ann said that there is a greater than 2 to I mitigation ratio for wetland impacts on the site. Impact # 13: Cindy wanted to know why Mass Highway only granted a right-in and not a right-out for Route 140. Lou explained it would compromise the safety on Route 140 and the 495 southbound off ramp because of inadequate sight distance. Cars needing to get to 495 southbound would have to cross lanes of traffic to get into the left lane and cars in the left lane would need to get into the right lane to get to 495 northbound. r- Colin wanted to know if Ann had accounted for the wetland under the parking lot-will it still function? Ann said they are relocating the wetland and it will function, it will still drain and flow toward the intermittent stream. She said that when she filed with the Army Corps of Engineering/40 1 Water Quality that this wetland was counted as a Federally Jurisdictional Wetland and is included in the mitigation numbers (the Federal Wetland Impact number is higher than the state number). Paul asked if soundings had been taken of the pond. Lou said there is information on record that indicated its depth is between 16 ft. and 20 ft. Colin asked the Commission if they had any questions or comments. Michele said she would like to thank WS for working with Mason & Associates to get to where this project is today. A lot of things have been change for the good of the project and for Conservation. They have answered everything Jeffhas addressed and his recommendations have been incorporated. Jeff again said that all comments that Mason & Associates made have been addressed. Colin wanted to know if they have been adequately addressed. r Jeff said the only issue remaining, stated in the June and September letters and referenced again in November, is the use of the pond for stormwater management. Jeff's position is that it is an isolated water body- "we are going to be using the pond for stormwater management purposes. Weare filling wetlands at the downstream end as a means to be able to hold water in that basin. This is a change-stormwater isn't going there today". (' This will result in a minor increase in the water surface elevation during a storm event for a short duration of time. Jeff said his interpretation of the regulation is that it is an activity under taken by the applicant that will result in an alteration of a resource area. The applicant's position is that it is not. Jeff said they did a Stormwater Alternatives Analysis in July, looking at other alternatives (sub-surface, surfitce detention, putting stormwater below ground under the parking lot) to see what could be done to avoid using the pond for stormwater management. These alternatives were evaluated in depth and determined by the applicant to be economically not viable. r" Jeff explained that Land Under Water has a threshold of 5000 sq. ft. The Commission can permit an alteration in excess of that threshold as long as it doesn't have an adverse impact on the wildlife habitat. Jeff's position is that it is an activity, there is an alteration, although it may be negligible and of short duration. Procedurally it should come under Conservation's jurisdiction. He said the applicant feels the discharge of stormwater runoff into the pond is not a regulated activity resulting in an alteration to LUW. Mason & Associates continue to maintain that use of the existing pond for stormwater management, regardless of it being the preferred alternative, constitutes a regulated activity resulting in an alteration of a resource area. If it is actually an activity/alteration, it should have an application fee (for activities resulting in the raising and lowering of the water level in the pond) and a wildlife evaluation. A wildlife evaluation was done for the streams but not the pond. The Commission would like an evaluation done for the pond and its banks. Ann agreed and this will be done next spring. This should be added to the Conditions. Jeff said that Mason & Associates in not in a position to evaluate the financial viability of the alternatives. With the exception of the use of the pond for stormwater management, all the comments have been adequately addressed and incorporated into the plan. Colin asked Ann if the use of the pond would alter the capacity as well as the water quality. She said that the water (most of the runoff to the pond is from the School Street improvements) is going to be treated. She said there would be an elevation in the pond, amounting to 3 n for a 2 to 5 hour period during large storm events. Ann believes this will not change the capacity of the LUW to provide important wildlife habitat functions because the area will not change as a result of the temporary minor increases in the water level in the pond after storm events. Colin wanted to know if the crossing of the intermittent stream has been designed yet. Ann told him the design of the stream crossings associated with the proposed project was conceived almost a year ago, prior to the federal stream crossing guidelines that were adopted in January of this year. When the Army Corps of Engineering issued the permit, they did not hold the applicant to the new guidelines. r . y ,.,...-- Jeffwanted to point out to the Commission that the applicant deferred their response to Mason & Associates comment to provide additional information regarding irrigation and its effect on the pond. It was always purposed as an activity-to put in-take structures in the pond for irrigation purposes but was never described in detail or defined. Lou agreed. Ann said there is a proposal for irrigation. Lou explained that the Selectmen administer the Water Conservation Policy rules. They want to minimize development usage of the public water system. WS has an application before the Selectmen now. The Selectmen are waiting for all the other permits to be issued before they hear WS. Lou thinks the irrigation system from the pond is a great idea. Colin wanted to know if the Commission has some input on what type of system is installed. Ann-This can be added to the special conditions of the permit. Lou- The Commission has the authority to specify constraints such as the irrigation system shall never drain the pond below a certain elevation and if it does it will automatically shut off-applicant must design the system this way to prevent a draw down. Colin asked the Commission members their thoughts on the project. r Jerry feels it is a well thought out project but he has questions concerning the discharge to the pond and the wildlife habitat. Lou feels the even though a wildlife study has not been done, Ann has address this topic extensively in the March 25th submittal. Paul wanted to know if there was a sampling program set up to monitor the water quality of the pond. Ann told him the water quality should not be an issue. Michele said the Commission could require monitoring. Carole thought the project was well thought out but she is stuck on the pond issues. She also feels the buffer zone should have been 50 ft.-the project should not have gone forward on a verbal conversation with Dick Lewis or a draft. Colin would also have liked the 50 ft. set back on this project but the project was too far along before the Commission said they would require the 50 ft. Marc felt it was presented well and seemed to have the Mansfield residents in mind. r- Ann thanked Marc for his comment on the residents and said that the Commission can write the Order of Conditions permit to make sure all the commitments made are satisfied. Lou said this helps them, having a set of rules. r Paul is not sure if it is a good or bad idea discharging into the pond. He said that you have to maintain the water table, some control devise, somewhere. He would like the Commission and Lou to draft a letter to DEP, the Utilities Commission and MECO, in regards to what we want as far as the easement is concerned. It would go a long way in straightening out the easement mess. Also to let them know the things that have occurred have been detrimental to this site, Great Woods and Oak Street. Paul thinks there should be a monitoring program for the water quality. How do you maintain water quality when you don't know the source of the water going into the pond? Ann said they are going on the assumption that the standards have been met (800.10) therefore you will not have an adverse effect on the wetland resource areas from the stormwater discharges to them. Ann said the monitoring program is not an unreasonable consideration. She will get a base line before construction begins. Paul would like this written in the Order of Conditions. Colin wanted to know if there is a spray/low level toxicity program for invasive species. Maybe this also should be written in to the Order. Lou agreed that it should be included in the Order. r Ann said an invasive species management plan has been prepared for the wetland replacement and buffer enhancement areas to control the purple loosestrife and reed canary grass. An annual monitoring program will be implemented and based on the assessment, management options will be considered and implemented. She told the Commission that there is some mechanical pulling and that herbicides are used (a spot targeted treatment-cut the stem and injecting the herbicide into the stems, very spot specific). The Army Corps monitoring plans are for 5 yrs. The Commission requires 2 yrs. Marc asked Ann about the chemical and biological functions of the pond. She told him she does not know if the pond stratifies but she suspects that it does. She will go out this spring to document this factor about the pond as part of understanding the way it functions. She feels the health of the pond should be evaluated post construction to see if the system is working as predicted-if not we need to figure out why and make corrections. Cindy -the 50 ft. set back should have been acknowledged. She said that as a Commission member, she would make sure that any new construction follows the 50 ft. no touch. She would like to see a wildlife assessment done for the pond. The electric easement-there has to be a better way to do this, instead of going around the perimeter. She agrees with Paul about getting DEP, the Utilities Commission along with MECO involved. There has to be a better way, maybe a combination of above and underground. She would rather see it underground. r '. r- Lou told her that he has spent a lot of time with MECO about this. The Planning Board has weighed in extensively, specifically for underground. There is no way MECO will put the electric underground, they will say no to this project. Lenny would like the 50 ft. tree buffer to be part of the Order of Conditions. Dave White summarized the control devise and how the discharge will enter the pond. The stormwater enters the site in 3 locations off School Street. Three Stormceptors will be located along School Street to treat the stormwater prior to discharge into wetlands 4 & 5, thru the drainage ditch adjacent to the pond and then will enter the pond. The stormwater management system does not rely on the use of any wetland resource area as a stromwater basin. Peak discharge rates to all resource areas are at or below the proposed normal water elevation. The elevations in the pond will remain the same as the present level. They will not be lowering the pond. They are simply going to be holding the water a little longer than normal and then releasing it. This will not increase the peak discharge rate of runoff The stormwater will be treated to 8001'0 TSS removal prior to discharge into the intermittent stream. The TSS removal will actually be higher because of the addition of the 4 detention ponds proposed for the site (they were not counted). r A manhole will be constructed on the existing pipeline, approximately 50 ft. from the current outlet. Paul wanted to know what the function of the manhole would be. Dave said it is a means to provide a change in direction. All the retention basins are out of the 25 ft. and outside the wetlands. Mark summarized the 4 remaining comments of the 1215/2005 letter. He said that the issues have not necessarily gone away but they have been addressed, resulting in plan and document changes, some of which were done today. Comment #l-Alternatives Analysis-the change to the pond will result in the water table fluctuating from 2 to 3.5 inches for the more frequent 2 year storm. Water is going into the pond that wasn't going in before. The peak flow rates that are going into the pond are actually less than the existing flow rates. The difference is that the water stage of the pond is going up. This is not a result of an increase flow to the pond; it is the change to the outlet structure and in the berming around the downstream end. The Alternatives Analysis was suggested to look at what could be done so the pond level would not mcrease. Alternative 5-increase the amount of runoff from School Street, enlarge detention basin I and adding 3 additional opened basins, allowing no increase to the pond. This alternative would result in a loss of30,000 sq. ft. The reduction would make the project financially not viable. r r- Alternative 6-replaces 2 of the opened basins with 2 subsurface detention basins, in combination with 1 surface basin. This would be a combination of pipe and stone storage. The cost to construct the two additional subsurface detention basins represents a significant increase in the overall construction costs, an increase between 23% and 30%, making this alternative financially infeasible. Comment #2 is in regards to the hydraulic calculations for School Street and Route 140 drainage improvements. The applicant has not really designed the stormwater management system hydraulically for the School Street improvements. It is Mark's understanding that the applicant has agreed to a potential condition of approval that would require that John Sullivan review the hydraulic system when the design evolves to the point that they can submit. Comment #3-Basin 2 outlet structure currently is an orifice-basically a hole was cut thru the concrete wall of the outlet structure. It is located on the very bottom of the basin, which over time would be subject to flooding, etc. Mark: suggested a sump be constructed in front of the orifice to manage any debris that might be collecting there. The plan was change this evening to reflect this. r- Comment #4 concerns project phasing. Mark feels there is a need for more of a response from the applicant as to how the phasing might be dealt with. The concern is that the complete stormwater management system for a particular building phase, including its associated detention basin, may not be fully installed as part of that phase if some of the piping and the basin are located in a future phase area. Mark would like to make sure that the plans state that the "stormwater management basins will be fully constructed, and runoff from the work area will be temporarily or permanently routed to the completed basin, prior to the construction on a phase that is proposed to contribute runoff to a given basin". The Commission might want to have additional information in the conditions of approval as well as documentation of the Stormwater Pollution Prevention Plan for the project. Mark also said that a comprehensive Stormwater Pollution Prevention Plan should be prepared for the project (because the project is disturbing more than a acre of land). The applicant has prepare a good solid draft but the Commission may want to require, as a condition, that when it is prepared and finalized, and when a contractor is on board (this only has to occur 48 hours prior to the start of construction) that it be submitted to the Commission for our records and review (when the Notice of Intent is sent to the EPA, you only have to certify that a plan has been prepared, you don't actually submit the plan to the EP A for review). He said that this is basically an instruction manual for how erosion control and everything else is going to occur on this project. This will help ensure that no short-term impacts will occur as the project is built. He also said that in the June letter, it was stated that the erosion control was somewhat limited on the plans. He wanted the Commission to know that the applicant has provided additional information. r .. r- Colin asked the Commission members to write the Orders that they feel should be conditioned and at the next meeting the conditions will be discussed with input from the applicant. Lou asked that he and Ann be kept informed of the conditions bye-mail. The meeting will be scheduled for December 12th at 6:30. A motion was made to adjourn (Jerry-Carole) at 10: 10. Next meeting will be December 12, 2005 at 6:30. fcLflJ~ j5t 2~ ~ , r- r T