BLACKSTONE (2006): PERMEABLE PAVING – Permeable paving, used for the first time on campus in Blackstone’s courtyard, reduces runoff by over 37% by allowing water to drain between gaps in the paving material. Blackstone uses recycled EcoStone pavers.

 

BLACKSTONE (2006): BIOSWALE – Blackstone’s 34’ x 154’ bioswale is designed to filter stormwater runoff from an adjacent parking lot. The system works by using plants for sedimentation, filtration, adsorption, and microbial action. Components include a grass filter strip, sand bed, crushed stone overflow, planting bed, and perforated pipes. Designed to manage two to ten year storm events, the bioswale is able to filter water at a rate of approximately one inch per hour, draining completely within 48-72 hours of a storm, with 6” or less of ponding. No runoff is drained to the municipal sewer system, instead the treated stormwater is released directly into the Charles River. It was designed by Michael Blier/Landworks Studio. [Bioswale diagram by Bruner Cott]

 

[Blackstone bioswale, Bruner Cott]

 

According to Harvard's Joe Griffin and Tim Baird (20 August 2004), operation and maintenance is as follows:

• The bioswale should be inspected about twice per year, and after each major storm event.
• The crushed stone diaphragm (~3/4” diameter stone) may require changeout every three to four years, depending on debris accumulation.
• The overflow system employs a Stormceptor system to filter out sediment accumulation.
• Planting soil that may require periodic aeration of sedimentation impacts its capacity as a biofilter.
• In the wintertime, freezing will reduce infiltration and may cause ponding to the level of the overflow drain.

 

 

175 NORTH HARVARD STREET (2005): RAINWATER HARVESTING – Rainwater Recovery, Inc., installed an underground rainwater recovery vault-type system for washing Harvard's transportation fleet at 175 North Harvard Street. Demand for washing these vehicles is approximately 300 to 400 gallons of water per day. The system captures about half of the stormwater that falls on the 5,000 square foot roof. Rainwater is diverted through two downspouts into the 1,200 gallon holding tank, where it is filtered. About one inch of water is enough to fill the crate, while excess is diverted into a 2,500 gallon dry well. The payback is approximately ten years based on current (2007) Cambridge water costs. See Rainwater Recovery's cost sheet for more information. The crate (pictured below) is wrapped in filter fabric and EPDM, with inlets cut into it. About two inches of topsoil (7 psi) are needed to cover the crate. The crates can withstand approximately 37 psi. The crates also contain 80% post-consumer recycled content. In addition to conserving water, the systems also recharge local groundwater supply and reduce polluted stormwater runoff into local bodies of water. In New England, these rainwater recovery systems can be used for irrigation, sanitation, and HVAC make-up water. Rainwater Recovery can work with the civil engineer, landscape architect, and contractor, starting early in the design process. To size a system for your project, see Rainwater Recovery Tools and their Sample Project Questionnaire. Contact Philip Reidy, P.E., Principal, at 781-647-9500 for an estimate.

 

 

ZERO ARROW STREET (2006): RAINWATER HARVESTING – CISTERN – A 2000 cubic foot stormwater cistern collects water in the basement to provide 100% of the water used for irrigation on the site. Water is collected from the roof and area drains located at impervious areas. The tank has the capacity to accommodate at least 25% of the 100-year storm level.

 

 

OTHER

60 Oxford Street was originally a 95% impervious parking lot. Site improvements, including a roof garden and vegetation, have decreased the site to 60% imperviousness. The City of Cambridge would not allow the project to sheet flow any stormwater into the city sewer system. 

 

 

HAMILTON HALL, HBS (2006) uses Rain Bird 1800-PRS Spray Heads connected to a central control system and weather station. It is predicted to save 65% in potable water in total gallons per year over a conventional irrigation system. See Hamilton's WEc1.1 submittal for a narrative on the system. A savings calculator for this system can be found here.

60 OXFORD STREET (2004) uses Rain Bird Controllers, PESB Valves, Matched Precipitation Rate Nozzles, Hunter Multi-Clik Rain Sensors to reduce potable water consumption.

HARVARD BUSINESS SCHOOL uses a Rain Bird System to achieve a reduction of 4,795,000 gallons of water per year. The project used Green Campus Loan Funds. The total project cost was $243,429, with annual savings of $50,756 with a payback of 4.8 years.

The Rain Bird System is a computer controlled irrigation system used at Harvard Business School that determines irrigation rates based on data from an on-site weather station. Computer technologies are achieving impressive resource and financial savings in previously low-tech facility and landscaping. Features of this system include:

• A weather station that collects temperature, wind speed, solar radiation, and humidity data

• Site rain counter

• Zone programmability that allows each irrigation zone to be designated a specific water need parameter

• Automatic flow shutoff to zones of excessive flow

• Remote access to schedule system via cell phone

• Site monitor log

The Rain Bird system creates run schedules to keep desired moisture levels in perfect balance. Provisions had to be made to integrate the computer irrigation system with the existing irrigation infrastructure and intranet system. Also, provisions were made for a weather station to be installed on the HBS campus.

 

LESSONS LEARNED

	HARVARD PROJECT(S)	PLANTS	PLANT ATTRIBUTES
	BLACKSTONE	Planting Narrative	Native, drought-resistance, hardy
	90 MOUNT AUBURN ST.	Planting Narrative	Native, drought-resistance, hardy

 

Plant species native to New England require no more water than is provided during an average regional rainfall. Planting adapted or native species that are able to survive solely on regional rainfall amounts is a long-term, environmentally responsible decision, and a tenet to the fourth Harvard University Sustainability Principle.  It enhances the health of campus ecosystems and increases the diversity of native species. The surprisingly rich and varied ecosystem found on Harvard’s urban campus is supported when landscape designers and architects develop planting plans and irrigation strategies that both enhance the campus' flora and fauna and eliminate the need for a permanent irrigation system and consumption of potable water.

The native, drought-tolerant, and hardy species found at Blackstone include a "no-mow mix" grass, and Red Maple, River Birch, Honey Locust, and Scarlet Oak trees. These low-maintenance trees and shrubs are hardy enough to withstand the urban and various weather conditions. Shading provided by the trees will further reduce the need for additional irrigation.

Considering that Cambridge landscapes are irrigated with a weekly average of 10-15 gallons per acre per week, specifying native plants yields significant cost savings while protecting a valuable resource.

 

 

HARVARD BUSINESS SCHOOL: WYSS HALL, HAMILTON HALL, ALDRICH HALL (2006)

Harvard Business School (HBS) is committed to a campus that is pleasant and safe for its students, faculty, staff and visitors. HBS is also committed to a sustainable campus that uses resources efficiently and minimizes its negative impacts on the environment. HBS believes these commitments compliment one another and has attempted to develop a Campus Exterior Lighting Master Plan that addresses safety and comfort as well as energy efficiency and minimal environmental impact. Specifically, HBS has developed the following guidelines for the exterior lighting master plan:

 

Uniform Lighting

HBS strives for exterior lighting that aids in protecting property from theft and vandalism and provides a safer environment for student, faculty and staff. Proper illumination is a combination of even distribution, good color, and visual comfort.  Lighting should be uniform, without shadows or sharp contrast between light and dark, and should reduce glare. Too much light or contrast reduces visibility. The Illuminating Engineering Society of North America (IESNA) recommends at least 0.2 footcandles to avoid dark areas for public safety. The HBS campus goal is a uniform 1.0 footcandles for sidewalks, pathways and building entrances, and 0.2 footcandles for areas surrounding sidewalks and pathways. 

Energy-Efficient Lighting

HBS recognizes that there are many options for providing the recommended level of light to its campus. Whenever selecting new lighting, HBS will consider energy efficiency amongst its criteria, comparing the efficacy or lumens per watt of each option. Specifically, HBS will look to replace its incandescent and halogen lighting with more efficient options. The campus is currently retrofitting its halogen building mounted and post mounted lamps with more efficient high pressure sodium lamps. The school will use the ASHRAE/IESNA Standard 90.1-2004, Exterior Lighting Section to recommend lighting power densities. The HBS campus, located in Boston, MA, is included in ASHRAE/IESNA Lighting Zone 3, Commercial/Industrial, High-Density Residential. The school will attempt to find lighting alternatives that allow at least a 20% energy reduction below the lighting power densities for exterior areas and 50% below those for building facades and landscape features. This will be done while keeping the safety and comfort of the campus top priority.

Minimal Up-Lighting

The HBS campus is located within a dense urban surrounding and the amount of up-lighting or light pollution from Boston and its suburbs is significant. Nonetheless, HBS strives to reduce its contribution to light pollution. In accordance with ASHRAE/IESNA Lighting Zone 3 recommendations, no more than 5% of the total initial designed fixture lumens will be emitted at an angle of 90 degrees or higher. When possible, new or retrofitted lamps will emit less up lighting than the recommendations. The campus has recently worked with a lighting designer to retrofit many of the existing building mounted and pole mounted lamps around campus to reduce up-lighting.  This 50 watt, 4000 lumen lamp has been sent to a laboratory in Pennsylvania and had a complete photometric analysis. Testing results show that the retrofitted lamps are classified as cutoff with 0.7% of the lumens emitted at an angle greater than 90 degrees.

Minimize Light Trespass

HBS will minimize the light trespass from its campus onto neighboring properties. Consistent with ASHRAE/IESNA Lighting Zone 3 recommendations, HBS will maintain an initial illuminance value no greater than 0.20 horizontal and vertical footcandles at the exterior site boundaries as noted on the Lighting Master Plan Site Map. HBS lighting will emit no greater than 0.01 horizontal footcandles 15 feet beyond the site. For much of the HBS campus this site boundary is the curb line with the public street surrounding the campus.

HBS will utilize this Exterior Lighting Master Plan when making all decisions regarding exterior lighting additions or alterations. The campus will also analyze existing lighting and evaluate the feasibility of retrofit lighting to further align existing lighting with the master plan of the campus.

 

Wyss Hall SSc8 LEED submittal

 

BLACKSTONE (2006) Blackstone is using light fixtures that reduce light tresspass, but did not attempt LEED SSc8: Light Pollution Reduction.

 

 

Light pollution reduction refers to designing lighting that projects downward, rather than skyward  The Advanced Buildings Energy Benchmark Section 5.10 describes optimal performance criteria for Outdoor Lighting. Others:

90 Mount Auburn SSc8 LEED submittal

60 Oxford SSc8 LEED submittal

 

Advanced Lighting Guidelines: 2003 Edition 

Outdoor Lighting Research, California Outdoor Lighting Standards, 6 June 2002 

IESNA RP33-99 Lighting for Exterior Environments and RP-20-98 Lighting for Parking Facilities

International Energy Conservation Code: 2000 Edition