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HomeMy WebLinkAboutConservation Commission - 06/13/2006 APPROVED MINUTES EDEN PRAIRIE CONSERVATION COMMISSION TUESDAY,JUNE 13, 2006 7:00 PM, Environmental Learning Center (ELC) 14100 Technology Drive, Eden Prairie, MN ELC Laboratory COMMISSION MEMBERS: Eapen Chacko (Chair), Jan Mosman (Vice Chair), Ray Daniels, Rita Krocak, Geneva MacMillan, David Seymour GUESTS: Peter MacDonagh , Kestrel Design Group; Lyn Jerde, Sun newspapers; and Daniel Woolsey COMMISSION STAFF: Leslie A. Stovring, Staff Liaison Allison Burr, Recording Secretary I. ROLL CALL Vice Chair Mosman called the meeting to order at 7:05 p.m. Eapen Chacko was excused from the meeting. II. APPROVAL OF AGENDA Daniels stated he would like to add an item under Reports from Commission Members regarding wind turbines. MOTION: Daniels moved, seconded by Krocak, to approve the agenda as amended. Motion carried 5-0. III. APPROVAL OF MINUTES A. May 9, 2006 Stovring clarified minute corrections should be limited to typos or substantive items that was forgotten or incorrectly summarized. Editorial language and sentence structure comments will not be incorporated into the final minutes, which will assist in keeping staff time down. She noted minutes standards are being worked on because staff has been told that the minutes have been too long on some occasions. Mosman requested the word "some" be deleted before the sentence beginning "Mosman stated some teachers have their students do research" on page 6. Mosman noted one misspelling of Terry Sticha's name in the minutes (Picha). MOTION: Seymour moved, seconded by Daniels, to approve the original set of minutes, as amended by Mosman. Motion carried 5-0. IV. REPORTS OF STAFF A. Stormwater Pollution Prevention Program (SWPPP) Application Stovring stated that the SWPPP application was completed on time. The new Best Management Practices (BMPs) are online as well as the new SWPPP. Stovring recommended commission members read sections 1, 2, and 3 of the BMP as they Eden Prairie Conservation Commission June 13, 2006 Page 2 focus on public education and public outreach. She noted she is currently writing the annual report for 2005. Next month the Commission can look at projects that can be pulled out of the SWPPP to do. Stovring stated she is also working on the website to add a conservation page to it that links and items of interest generated by the Commission can be added to. V. SPEAKER A. Peter MacDonagh, Kestrel Design Group MacDonagh explained many European countries push green roofs and other types of water and energy conservation practices as they have hit the resources ceiling in terms of energy and water. Therefore, they are forced to have more complex systems to manage these resources. MacDonagh stated there are two kinds of green roofs, those with more than 6 inches of media (intensive) and those with less than 6 inches (extensive.) Extensive roofs can be used for stormwater management, thermal envelope, and increased life span or duration of the roof. A green roof typically lasts two or three times longer than a traditional roof. They are very good for stormwater quality improvement, rate control, and volume control. MacDonagh explained what he meant by thermal envelope. On a 90 degree day last July, he did some measurements around noon on the Central Library's green roof downtown. On the asphalt it was 170 degrees; on the white reflective pavement it was 125 degrees, and the green roof area was at 92 degrees. He stated many large buildings have air conditioning on the roof, so the temperature where air is drawn into the AC is between 145 and 170 degrees while the internal temperature is set between 72 and 78 degrees. He stated 40 percent of a total electric bill for the year is peak demand, so there is a potential there for big savings with green roofs. MacDonagh explained there can be a jump from 170 degrees in the summer to negative 26 degrees in the winter. With a green roof, the jump is only from 92 degrees to minus 26 degrees. MacDonagh explained there is also UV protection on the roof. These reasons explain why there is an increased lifespan of the roof. MacDonagh said the goal for a green roof is to be 30 pounds per square foot saturated, about what a four foot snow load would carry on a traditional roof. He explained there are three layers of shingles on a typical commercial roof, which is about 12 pounds per square foot. Every roof in Minnesota is designed to carry 4 feet of snow load. He recalled the Central Library wanted to add a green roof. They have one acre of roof, and it cost them $1/square foot of additional reinforcement to incorporate the green roof. He noted his firm has also done green roofs on residential garages as a retrofit with little or no structural improvements needed. MacDonagh explained the quality and volume components of stormwater and green roofs. He noted Minnesota is a great place to have these kinds of systems. The state has relatively low precipitation, and most of the rain is concentrated in quick cloud Eden Prairie Conservation Commission June 13, 2006 Page 3 bursts. He noted that about 3/4 inches of rainfall can be held on the roof. He explained a traditional stormwater system is a very expensive, land-intensive system. A green roof is a good way to hold water up in the landscape. Krocak asked if the roof has to be flat in order to incorporate the green roof. MacDonagh responded no, it does not. He has done green roofs on a standard pitched roof on a garage. MacDonagh presented four case studies of green roofs and explained the process to begin planning a green roof. The first step is to review the plants that have the skill set to be on a green roof. He stated because restoration ecology is strong in this region, there are a lot of plants available. MacDonagh discussed the Phillips Eco-Enterprise Center Green Roof and the way it was constructed. He noted there are about 20 varieties of plants on this green roof. A rich variety of animal species (such as butterflies and birds) are often seen on the roofs as well because there tends to be very limited human traffic on the roofs. MacDonagh displayed a series of photos showing the growth and development of the plantings on the Phillips Eco-Enterprise Center Green Roof. He noted there are educational and interpretive signs on the roof, which are available for the public to view. MacDonagh showed slides illustrating the Central Library green roof and noted the green roof will help clean stormwater discharges to the Mississippi River. MacDonagh displayed a concept plan for the future Lund's Grocery Store green roof, which will be implemented in spring 2007. He noted the green roof will go on the 5,000 square foot addition. MacDonagh also discussed the green roof under construction at the Edgewater condominiums. They have a very small site, and do not have a lot of options for their stormwater treatment so the green roof is one piece they are using. MacDonagh explained his firm will be doing 40- and 50-foot green halls on the City Hall project as well. He noted some plants were found growing on the City Hall property that will be re-incorporated into the roof. MacDonagh concluded currently that the cost for green roofs can be high. No matter how many benefits there are, they are still costly. The systems will need to become more popular in order to reduce the cost of the medium. That is the factor blocking getting the roofs into the marketplace. Right now the cost runs from $12/square foot to $28/square foot; that cost can include the membrane or exclude the membrane. Research is being done on growing mediums in an effort to get the cost down. MacDonagh stated Japan is also building tall green walls, 20 or 30 stories tall. The nation has to import nearly all its resources so is very open to these kinds of energy savings. MacMillan asked how the green walls work. MacDonagh responded green walls grow on a media and there is a superstructure off of which they are hung. He Eden Prairie Conservation Commission June 13, 2006 Page 4 explained the various options for the green walls. There can be a massive amount of coverage on the wall. The vines can grow to about 50 feet. He noted in Japan the walls can go up 20 or 30 stories. Daniels asked if there is a fire danger since prairie grasses are utilized. MacDonagh responded there is a fire break, a vegetation-free zone all the way around the green roof that would have to be approved by the fire marshall. Daniels asked if the grasses would ever be burned. MacDonagh responded that maybe in 20 years or so, but not necessarily. MacDonagh stated he knows possibilities for green roofs include the community center's new addition or the new fire station. He suggested another idea is to incorporate one around an air conditioning unit because it will cool the air around the intake. It is important that people see that the green roof has some value in terms of green space. He added these kinds of sustainable models favor long-term landowners, such as a governmental body. These kinds of things make sense for cities or landowners that will be around for a long time. He noted it is always of value if people can look down on the green space. Seymour stated the community may buy into the idea of a green roof if they can get up on the roof and observe it. He suggested making it accessible to the public at the community center, perhaps with an observation area. Stovring stated the biggest hurdle will be the cost. Mosman added it will be important to focus on the long-term cost savings of the green roofs. Daniels asked how long the roof will last at the library. MacDonagh responded 50 to 100 years for a green roof that is constructed properly. The lifespan for a typical roof is 25 to 30 years. MacDonagh stated the Gap headquarters in California has a green roof, and they initially calculated the return on the investment would be 10 years. However, the employees' use of sick days and absenteeism plummeted because employees wanted to be in the building, look at the green spaces outside their windows and breathe the air. As a result, the return on investment turned into about 11 months due to these unforeseen benefits. Seymour asked about the benefits seen in Chicago with the green roof at City Hall. MacDonagh responded in 1995 there were heat storms, with 6,000 people dying in the tops of tall buildings. Mayor Daly convened a study to look at how to cool the tops of the buildings without putting air conditioners in. He put a green roof at the top of City Hall as a way to encourage new businesses to use green roofs as well. As it is now, businesses above a certain size have to have green roofs. They did find that the buildings were cooler during hot spells, even without air conditioning. They felt the investment in saving lives was worth the cost. The City of Minneapolis has also indicated it is a priority in the future. MacMillan asked about the experience of hospitals and green roofs. Eden Prairie Conservation Commission June 13, 2006 Page 5 MacDonagh stated Abbott Northwestern has an abandoned helipad and is considering putting in a green roof. He noted in Europe green roofs on hospitals are very popular, as the length of hospital stays and patients' medication have significantly decreased since the incorporation of the roofs. Seymour suggested providing the minutes of this meeting to the City Council and opening a dialogue between MacDonagh's firm and the City. Stovring stated Paul Sticha is in favor of looking further into using green roof technology. Perhaps the next step would be to present something at the next Parks and Recreation Commission meeting; the community center expansion may be the best option to pursue. Then possibly a meeting could be set up with the fire chief. Seymour asked if it is feasible that MacDonagh, Sticha, and he visit some of the local green roofs. Stovring suggested he talk to Sticha and see what he recommends. Mosman suggested if a presentation is done for the Park and Recreation Commission, it should be taped so it can be shown to other staff members or the Council. Stovring suggested a short letter or document be handed out that highlights the costs and benefits and how the roof is constructed. Mosman suggested some commission members begin work on the idea of a green roof on the community center expansion. Seymour and Mosman indicated they will work on it together and send something to Stovring. The meeting recessed at 8:46 p.m. The meeting reconvened at 8:59 p.m. VI. FUTURE EVENTS A. Eden Prairie Clean Up—Saturday,June 17, 2006Nolunteer Tasks MacMillan and Krocak indicated they will volunteer the morning of the clean up. Stovring stated there are copies of the new fee schedule to hand out while people are waiting in line as well as information to hand out regarding where to take yard waste and the Hennepin County drop-off center. Volunteers should arrive at 8:00 a.m. Environmental Fair - Daniels suggested a theme for the environmental fair in January: Energy Efficiency, Energy Conservation. VII. NEXT MEETING A. July 11, 2006 VII. ADJOURNMENT The meeting was adjourned at 9:08 p.m.