GI In Seattle: The Importance of Pilot Project Success For All Green Infrastructure

4 01 2012

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Ballard Roadside Rain Gardens, Credit: Seattle Public Utilities

The City of Seattle was one of the early pioneers of utilizing green infrastructure as a stormwater best management practice with projects primarily concentrated on reducing stormwater flows in various creek basins. Over the last few years, the City has turned its attention to using green infrastructure for controlling Combined Sewer Overflows (CSOs) within the city. While there is currently no consent decree, the City has established a control target of one untreated overflow per outfall per year for CSO discharged based on a 5-year rolling average (Washington Administrative Code (WAC) 173-245). The highest priority for these efforts has been overflows within Lake Washington. Green infrastructure practices are estimated to contribute to this target by controlling 12% of the 16 million gallons needed to be addressed to achieve the City’s goal. The remaining portion will be controlled by conventional grey infrastructure strategies.

The Ballard Roadside Rain Gardens was the first green infrastructure project designed specifically for controlling CSOs. The $1.4 million pilot project was funded by an American Reinvestment and Recovery Act (ARRA) loan and involved installing a series of rain gardens in the right-of-way along eight blocks in the Ballard neighborhood. The rain gardens were installed in December of 2010 and with the expectation that they would reduce discharge volumes by 59,000 gallons or 1% of the the total within the specic NPDES basin. Unfortunately, many of these rain gardens did not perform as anticipated. As a result, over the last few months the project has received negative press and vocal neighborhood opposition over their performance.

The City conducted an extensive post-construction analysis, and determined  a third of the rain gardens were not draining and another third were underperforming. The main shortcoming identified was that the geotechnical analysis conducted prior to construction was not specific to each rain garden location and therefore could not account for subtle changes in their infiltration rates. As a result, the underperforming rain gardens did not have sufficient infiltration rates to drain within twenty-four hours and underdrains were not used.

After the post-construction evaluation and a comprehensive community outreach effort, the City took corrective action. The public’s main issues included the dangers of standing water (i.e. drowning, mosquito habitat, smell), steep side slopes of the rain gardens, and their overall aesthetics. The corrective action included removing several of the rain gardens, reducing the depths and steepness of side slopes of others, and adding underdrains where they were effective. These changes resulted in reducing the original estimated CSO volume control by 36%.

The City went further and identified recommendations to improve future implementation of green infrastructure projects. Some examples of their recommendations included the following:

Community Engagement

  • Get out into the community early
  • Introduce the problem you are trying to solve, before you present the solution
  • Utilize several communication media to disseminate information and get feedback.

Planning

  • Develop a Project Management Plan (PMP) that outlines roles and responsibilities, schedule, budget, and risks that is approved by management.

Geotechnical

  • Integrate geotechnical engineers into all phases of the project and empower them to speak up.
  • If the corrected (design) infiltration rate is between 0.25 and 0.5 inches per hour, build a redundant system into the design, such as an underdrain.

Design

  • Provide the design for the flow control/bypass plan and erosion and sediment control plan. Do not leave it to the contractor.
  • Review project design, how it functions, and the critical project components with Construction Management ahead of time.

Construction

  • Balance funding sources with the ability to course correct during construction and the documentation requirements.
  • Involve geotechnical engineers in construction to field verify that the excavated or exposed soil look as anticipated.
  • Maintain an open dialogue between contractor, construction management, project manager, designer, and geotechincial engineer.

The City of Seattle should be commended for recognizing the shortcomings of the project and taking quick corrective action. The project serves as a reminder of how important the success of pilot projects are to the future of green infrastructure not only locally but also nationally. News travels fast and high profile failures can cast doubt on the effectiveness of these types of systems and fuel future opposition to projects. When approaching any green infrastructure project, the details and execution are crucial to a project’s success, but when the project is intended to set the standard and introduce the public to green infrastructure practices, it becomes even more critical.

-Brian Phelps

Sources:
Email interview with Shanti Colwell, Environmental Engineer with Seattle Public Utilities
Seattle Public Utilities Case Study
Ballard Roadside Raingardens, Phase I-Lessons Learned





479 Green Infrastructure Case Studies Released

30 09 2011

The American Society of Landscape Architects recently released 479 Green Infrastructure Case Studies. The case studies provide an informative snapshot of the type of green infrastructures are being implemented across the country. We are excited the two projects we submitted (The Pinnacle at Symphony Place green roof and Deaderick Green Street) were included in the list. You can check out the entire list here.

-Brian Phelps





Philly Recieves Approval for Green Infrastructure Plan

3 06 2011

Philadelphia’s Green City, Clean Waters Plan ,submitted to the EPA last September, has been signed by the PA Department of the Environmental Protection (PADEP) and the Philadelphia Water Department (PWD). According to PDW’s press release, it happened on June 1st. The approval of the plan is a big step in furthering green infrastructure’s legitimacy as a tool to address stormwater issues. The following are links to past post about the plan:

Triple Bottom Line of Green Infrastructure

Philadelphia Green Infrastructure Video

-Brian Phelps





Interview with Green Roof for Healthy Cities Founder Steven Peck

20 05 2011

Pinnacle at Symphony Place Green Roof , Nashville, TN

The following is a brief email interview we conducted with Steven Peck, founder and president of Green Roofs for Healthy Cities, a non-profit industry association promoting the planning, designing and building of green roof, and green walls.

GrID: It was good news to hear the green roof market continued to expand in 2010. We hope the trend continues. You were recently quoted in The Dirt, stating this expansion constituted an addition of 8-9 million square feet of green roofs. Can you provide more detail into what characterized this expansion (i.e. type of green roofs, clients, project types, etc)?

Steven Peck: We just posted a report on the industry survey at www.greenroofs.org that contains more detailed information about what types of buildings are green roofs being implemented on, the types of green roofs being installed, locations etc.   It is a free, downloadable report that contains all of this information.

GrID: You acknowledge a lot of this growth is taking place in cities that are encouraging the development of green roofs through  “significant public policy support”. What best policy or program practices are you seeing used most effectively in the United States? Any others you would like to see instituted?

Steven Peck: Most of the policy tools being used in the United States are economic in nature, in the form of tax incentives, increases in floor area for new developments, and grants averaging $5 per square foot.  There are also procurement requirements for government buildings – a good place to start – as well as for any building that is receiving some for of government financial assistance.  For publicly owned buildings, the fact that green roofs, if properly design, installed and maintained by a Green Roof Professional (GRP)  extend the life expectancy of the waterproofing by two times or more, is a significant economic benefit for tax payers.  Billions of square feet of flat roofs are torn off and replaced each year at enormous public and private cost.   

The new versus retrofit markets are different, and the nature of the incentives to encourage green roofs varies from building type to building type, because the economics are very different.  This makes it difficult to generalize about effectiveness.  In buildings where green roofs can provide more direct benefits to the building owner – like condomiums, buildings that are air conditioned, schools and hospitals, the economic case is stronger.  In buildings that are very cheaply constructed, not air conditioned, and the roofs are innaccessable to the occupants or public, greater government incentives are likely to be required owing to the fact that the benefits are more in the public realm.  For example, green roofs are widely regarded as a best management practice by governments in dealing with the need to reduce and slow down stormwater, which in many cities results in significant water quality problems.  So building owners can meet regulatory requirements by installing green roof systems.  

In Canada, two jurisdictions, the City of Toronto and the City of Coquitlam have made green roofs a requirement in various classes of new development.  The Green Roof By-Law in Toronto requires that all buildings over 2,000 square meters of floor area (with the exception of new industrial buildings) must install a green roof.  This policy has already resulted in an estimated 1 million square feet of new green roofing that is now in the planning phase.  It also levels the playing field and provides the design community with the opportunity to skip the ‘justification’ of the green roof and move right to ‘how do we get the most benefit’ from the green roof stage. 

GrID: The new ANSI Fire and Wind standards seem to potentially have a big impact on the aesthetics of green roof design. Can you give us some insight into why and how they were developed? What has been the reaction to the new standards from the design side of the industry? Are they being widely used?

Steven Peck: The standards were developed because of largely unfounded concerns about these issues, but we need to address them in order to remove a potential regulatory barrier.   During the development of the standards, we tried to maintain as much flexibility as possible in terms of design.  It remains to be seen how widely these standards will be adopted, and ultimately what effect they will have on the aesthetics.

GrID: Green roofs can be initially significantly more expensive than traditional commercial roofing. As the green roof market has matured, are you seeing pricing coming down and/or seeing creative financing mechanisms that make it easier for property owners to choose to build a green roof on a new or existing building?

Steven Peck: Generally speaking, as a market begins to mature prices drop as a result of competitive pressures, more efficient implementation, and innovation in product and service delivery.   This has happened in mature markets like Germany, and it is happening in more mature markets in North America.  There is a danger however – buyer beware – that in just using price as a determinant, you may end up with a green roof system that fails to work effectively.  These are engineered systems and all of the parts have to work together to achieve water tightness, structural integrity and the long term health of the plants.   We’ve spent 10 years developing professional training programs in order to establish and promote best practices in the industry.  This has culminated in the development of an occupational standard for a Green Roof Professional.   There are more than 450 GRPs in the marketplace, so make sure that you are working with a GRP to help to ensure that your green roof doesn’t disappoint you.   

GrID: What trends are you seeing in the green roof industry? What will the future of green roofs look like?

Steven Peck: We have recently developed three new courses that reflect some of the trends in the industry.  Advanced Maintenance we launched in April in Washington to provide more detailed information on how to design, budge and implement effective maintenance practices.  Maintenance neglect is one of the main causes of problems on a green roof.   In November of last year, we launched a half day course on Urban Rooftop Food Production, a hot topic these days.  We’ll be providing training in Toronto and New York this summer, two jurisdictions where there is a strong urban food movement.   Water.  In many regions, water shortage is already a problem, and only likely to get worse.  Last year we developed an introductory course on Integrated Building and Site Water Management, in partnership with the American Society of Irrigation Consultants.   This half day course will be available online, in our Living Architecture Academy, in June.   Increasingly, green roofs will be integrated with other forms of green infrastructure, like green walls, and be designed to perform multiple functions – cool cities, biodiversity, food, improve photo-voltaic efficiency.   We’ve still only scratch the surface of the full potential of these technologies. 





Quantifying the Financial Value of the Soft Benefits of Green Roofs

6 05 2011

Steven Peck, Hon. ASLA, and Founder and President of Green Roofs for Healthy Cities was recently interviewed by The DIRT while in Washington D.C. for the Living Architecture Symposium, (“Despite the Economy, Green Roofs Bloom“). In the interview, Mr. Peck quoted a recent survey of the green roof industry  which reported that 8-9 million square feet of green roofs were built last year. This figure represented a 30% increase in market growth. Most of this expansion was focused in cities that have public policies in place that encourage and support green roof installation. The most intriguing statements in the article are those that helped quantify the economic impact of green roofs.

The post included some assertions that quantified the financial value of some of the soft benefits of green roofs. These included

“…average stormwater mitigation benefit is $4.26/sf” and  a view of a green roof improves property values of nearby buildings by 11%”

These figures are based on research by Smart Cities Research Services, Montreal.  “The Monetary Value of the Soft Benefits of Green Roofs” report prepared by Ray Tomalty, Ph.D. and Bartek Komorowski, MUP with the assistance of Dany Doiron, published last year. The report includes research on developing heuristic methods for quantifying seven soft benefits of green roofs: including: change in property values, marketing benefits, food production and food security, sound attenuation, stormwater retention, air quality, and green house gas (GHG) sequestration. The following is a summary of their findings:

I did not include the marketing figures in the table above, due the complexity of their findings.

Since there is little to no research specific to green roofs, the heuristic methods described in the report rely on other related research. Examples include:

Supply and demand play a critical role in determining one values and this is not any different for green infrastructure. For urban areas that may incorporate little to no green infrastructure (i.e. parks, green roofs, street trees) and are predominantly unsightly parking lots and roofs, projects that include green roofs should be more valuable and those properties surrounding it should benefit in some way as well. The report provides a great starting point for financially quantifying the soft benefits of green roofs. Over time, data specific to green roofs will eventually become available and we will be able to more accurately quantify their specific benefits.

-Brian Phelps





Valuing Green Infrastructure

23 03 2011


Earlier this year the Center for Neighborhood Technology (CNT) released the publication “ The Value of Green Infrastructure: A Guide to Recognizing Its Economic, Environmental and Social Benefits”. The publication is a great summary of the benefits of Green Infrastructure and goes a step further by providing data to help communities quantify many of its benefits.

The document includes two example demonstration projects. The first is for a green roof project on a single site and the other seeks to illustrate the benefits of the green roof site if expanded to a neighborhood scale. The authors point out that full life-cycle analysis was not a part of the scope of the analysis included in these demonstrations.

In addition, they offer a series of considerations and limitations of the data included. These points are helpful to consider when applying the information within the report. These include considering the full life-cycle analysis, local performance and level of benefits realized, spatial scaling and thresholds, temporal considerations and scale discounting, operation and maintenance, price variability, and double counting.

The concept of “discounting” described in the report was interesting. It recognizes that society typically values present benefits over future benefits. The following is an excerpt describing this concept:

“The term “discounting” refers to the adjustment one makes to account for future uncertainty (or the opportunity cost of money: a dollar today is not worth the same as a dollar five years down the road). Our society generally values what an investment gives us in the present more than what we might get for it in the future. The reason for this is future uncertainty, and as such, the future value or benefit of an investment must be adjusted or discounted. It is a technique widely used in benefit-cost analyses to understand and compare a project’s implications (its rate of return) over a given temporal scale.”

Overall the report is a helpful resource in quantifying the benefits of green infrastructure. The additional external links and resources provide additional tools and are worth exploring. You can find the full report on CNT’s website.

-Brian Phelps





NYC’s Green Infrastructure Plan

18 11 2010

Last week, the Economist in an articled titled “Trees grow in Brooklyn” reported on U.S. cities implementing green infrastructure strategies to address the pollution of their waterways from storm water runoff. The article focused primarily on New York City and Philadelphia.

According to the article nearly 27 billion gallons of untreated water overflows into the New York harbor each year. NYC’s recently released green infrastructure plan seeks to address run-off from 10% of the impervious surfaces in the City with green infrastructure storm water strategies that range from rain barrels to pervious pavements to green roofs.

The plan estimates that on average the cost per gallon of Combined Sewer Overflow (CSO) avoided ranges between $1 to $2 per gallon. In addition, the City calculates that over a twenty-year period, it will receive between $139 million and $418 million in additional triple-bottom line benefits (i.e. energy savings, increase in property values, health) from the green infrastructure.

While NYC’s strategy is also employing grey infrastructure, they see the combination of the two costing less than a grey only approach. The cost of the green-grey strategy is approximately $5.3 billion of which $2.4 billion makes up the cost of the green infrastructure. This is $1.5 billion less than the grey only solution.

Chris Strickland, a deputy commissioner with the New York’s Department of Environmental Protection sums it up in the article saying that this (green infrastructure plan) is a way of achieving more than one thing with tax dollars.

Link to NYC Green Infrastructure Plan

-Brian Phelps








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