Merging Gray and Green Infrastructure with Triple Bottom Line Analysis

A Triple Bottom Line (TBL) Approach Across the country, cities and towns are giving green infrastructure techniques a hard look, but evaluating their very different benefits can be daunting. While traditional gray infrastructure is proven and dependable, it is usually expensive and rarely adds beauty to the landscape. Green infrastructure is better at addressing pollutant sources, but is still often considered experimental. Which should be used? The decision is important, because while a storm may last an afternoon, stormwater management issues can have lasting consequences, not just to a municipality?s bottom line, but to a city?s look, vibe and environment.

Every community has its own reasons to consider green infrastructure. It may start with a compliance mandate or a desire to build more sustainably or economically. With its broader scope and array of options, the integration of green infrastructure can open up the planning process to more complex advantages such as open space expansion or green job creation. Since green infrastructure benefits don?t always fit a financial/engineering model, proving that green can do the job alone is often challenging.
The way forward, as it so often does, lies in the middle: A strategy that marries the strengths and successes of both gray and green infrastructure while overcoming the weaknesses. And getting to the right mix can still feel like an uphill climb as decision-makers attempt to align apples-and-oranges criteria, such as:

  • How do we define the value of a project?
  • How do we compare dissimilar infrastructure?
  • Which is the better solution ? the culvert or the bioswale?

Balancing Cost, Environment and Social Factors

A Triple Bottom Line (TBL) approach has successfully helped city and utility leaders weigh the full spectrum of considerations and select the sustainable path. More a concept than a process, Triple Bottom Line integrates the softer social and environmental factors with the hard economic facts of green and gray infrastructure planning to provide holistic input to the decision-making process. When developed well, Triple Bottom Line becomes a neutral tool that rates infrastructure on the degree to which it matches the culture, based on the characteristics, performance and impact of the project.

Why does Triple Bottom Line planning work? Because it applies measurable criteria consistently across the entire infrastructure project. Triple Bottom Line is a value-added proposition for utilities because it:

  • Recognizes the value of differing views;
  • Builds consensus;
  • Expands the point of view to include neighbors, the city, the environment, plant life, the cityscape; and
  • Tells the stories that go beyond the capital dollars to common sense.

As a concept, the Triple Bottom Line model balances economic analyses with community and environmental needs. The most successful projects engage all three aspects of utility management.?

Factoring in Culture and Context

Frequently, the concept of a Triple Bottom Line analysis feels abstract, when in actuality, it is simply flexible. Highly customizable, the framework contains a balanced amount of economic, environmental and social criteria that are well defined and measurable, enabling application over a broad array of projects. Indeed, this characteristic is a key reason for the success of the TBL analysis as developing and prioritizing capital projects cannot be considered out of context. For municipal work, context consists of:

  • Details of project work;
  • The utility?s experience and skill with the technology;
  • Funding;
  • Priorities of the general public;
  • Priorities of the business community;
  • Priorities of politicians;
  • Requirements of any judicial actions; and
  • Tolerance for trial-and-error.

The context of the project work reflects the culture of the community and utility, which in turn drives where the sweet spot is on the gray-to-green spectrum. It is important to recognize that culture is dynamic. Today, doors are open to us that not only were closed a decade ago ? they didn?t even exist.

In New York City, green infrastructure is an important means to advancing the city?s stormwater management goals. In the New York City Department of Environmental Protection Annual Report for 2013, the EPA notes, ?Investing in green infrastructure is a cost-effective way to improve the quality of New York City?s waterways while bringing multiple benefits to local communities, including improved air quality, increased shade and cooler temperatures during the summer. Green infrastructure also enhances the aesthetics of New York City?s neighborhoods and provides economic opportunities for green jobs.? The report goes on to note, ?Social co-benefits include opportunities for workforce development and improved quality of life, and economic co-benefits include reduced wastewater treatment needs… DEP?s Green Infrastructure Program will continue to contribute to a greener, more sustainable city.?

Our most urban city centers are working to balance the necessities of modern life with the traditional values of sustainability. In such applications, Triple Bottom Line analysis is an effective tool to prioritizing the most effective capital projects. The flexibility of the tool also means it can be adapted to where a utility needs it most ? planning, design and post-construction evaluation.?

For example, Fort Wayne, Ind., turned to a Triple Bottom Line Analysis as a planning tool to recognize capital projects that advanced the goals of sustainable stormwater management, improved quality of life, revitalizing downtown, reducing stormwater into the combined sewer system and instituting alternatives to gray infrastructure. Eight sewer basin studies used TBL to competitively evaluate 29 options consisting of asset management only, gray infrastructure, green infrastructure or gray/green hybrid. Criteria evaluated included reduction in basement and street flooding (social), job creation (social), local Total Suspended Solids (TSS) reduction (environmental) and combined sewage overflow (CSO) cost per gallon removed (economic). The analysis showed the best values to be associated with three asset management projects, one green infrastructure project and three hybrid gray/green projects. The biggest takeaway was finding there was always a cost-effective option to make gray infrastructure better.

The City of Chattanooga, Tenn., used Triple Bottom Line to support a paradigm shift needed to meet the requirements of the Municipal Separate Storm Sewer System (MS4) permit. Detention ponds used for stormwater control had proven to be ineffective, missing the mark in controlling erosion downstream. However, developers unfamiliar with green infrastructure and Low Impact Development (LID) expected that alternative methods would increase costs. Yet when they compared the costs and benefits of two demonstration projects ? designed both traditionally and as LID ? they observed that traditional methods could not do the job, but that LID was both effective and economical, with tangible and lasting benefits that increased the value of the project. The results of the analysis supported changes in City Code that by mid-2014 will make LID the new way of doing business.

A Triple Bottom Line (TBL) Approach

Defining, Measuring and Scoring Criteria

Triple Bottom Line Analysis is performed using spreadsheets that allow for the definition of criteria, calculation or assignment of a score based how well the project satisfies the criteria, a weighting of the criteria for importance and a calculation of a score. The challenging part of using a TBL analysis is defining criteria in a measurable way. It is simple to say, for example, that job creation is a priority. It is challenging to measure job creation in a manner that is accurate and timely. Do only new jobs count? What about beefing up workload of a soft labor force? Not all jobs are created equal. Do we differentiate between higher-wage jobs with benefits and seasonal jobs without benefits? What period of time do we wait before ?measuring? the change? What metric do we use? Unemployment statistics? Income tax? Can we monetize it? For use in planning, how do we project job creation? Each community can set its own standards within the Triple Bottom Line structure.

These are just a few examples of the type of thinking that goes into developing a Triple Bottom Line analysis. Table 1 provides an example of how a criterion ? reduced basement flooding ? can be defined and measured in different ways and shows how each community can set its own standards within the Triple Bottom Line structure.

Here are a few strategies to consider when creating a TBL structure:

  1. What do we want to accomplish? Spell out the purpose of using an approach that goes beyond dollars. Is it a livable community? Is it satisfying a grassroots movement? Is it lowering costs? Be honest. You will come back to this time and time again when your team gets stuck in the weeds.
  2. Include many points of view when brainstorming criteria. Balance is key. A process skewed by a vocal minority works for no one. Have a broad skill set represented and engage internal staff, stakeholders and trusted advisors.
  3. Keep criteria meaningful. There are going to be a lot of great ideas ? too many, in fact. To work, the number and weight of each criterion has to be meaningful. Prevent dilution by eliminating redundant or closely related criteria. Look for criteria that are differentiators. A ?yes? (or ?no?) across the board does nothing for making a decision.
  4. Define how you are going to measure it. Maintain a relative accuracy to avoid overly complex or detailed calculations that do not offer an advantage. Decide between quantitative (dollars, pounds of pollutants, labor hours) and qualitative (significant advantage, neutral, disadvantage). Defining how to measure criteria can serve as a good screening tool of the criteria themselves.
  5. Test it. Apply your TBL protocol to one or two past projects you consider a success. Does the TBL application need to be tweaked? Could your good project have been better?
  6. Use a facilitator. Whether internal or external, a facilitator is important to keeping the process on track. Done in a truly collaborative manner, it can take six months from the start until the TBL is ready for use. A lot of discussion, thought and debate happens. A good facilitator keeps the dialogue focused, productive and respectful.

Case after case shows the TBL concept to be fair and balanced, structured but not rigid, flexible but consistent. It digests dissimilar data to produce an easy-to-understand, bottom line statement. Triple Bottom Line Analysis is a powerful tool for utility managers wanting to integrate the factors that affect everyday people into the infrastructure planning processes.?
Peter Glus is vice president and director of business development, NYC, ARCADIS.

Leave a Reply

Your email address will not be published. Required fields are marked *