September 2013, Vol. 25, No.9

Measuring success by the half-inch


Milwaukee introduces green infrastructure plan 

When it rains, it pours — except in Milwaukee. 



At least that’s the hope of the Milwaukee Metropolitan Sewerage District (MMSD), which has unveiled an ambitious plan to use green infrastructure to capture the first 12.7 mm (0.5 in.) of rainfall that hits its service region’s impervious surfaces. This amounts to about 2.8 million m³ (740 million gal) of stormwater every time it rains, or almost 1.5 times the storage capacity of the deep-storage tunnel the district completed two decades ago. 

MMSD’s new Regional Green Infrastructure Plan, which provides the blueprint for achieving this goal by 2035, is a key component of the utility’s overall vision to eliminate overflows and backups while improving local water quality. MMSD serves Milwaukee and 27 other municipalities in an area covering 1065 km(411 mi2). 

The plan  

The district’s “first half-inch” goal may be new, but its efforts to support local businesses and communities that implement green infrastructure best management practices (BMPs) date back more than a decade. “The difference now is that we can track the volume of water these BMPs are capturing,” said Karen Sands, manager of sustainability at MMSD.  

This is possible because MMSD collected data on and mapped the 236 km2 (91 mi2) of roads, buildings, parking lots, airports, and other impervious surfaces within its seven watersheds. Its green infrastructure plan includes, among other things, an analysis of how this land is used, the costs and benefits of the BMPs that might be used to capture runoff from it, and the volume of stormwater each type of BMP is designed to retain. 

All this information is helpful as the district goes about the business of prioritizing future projects and making funding decisions, Sands said. 

The district’s analysis, for example, compares the capital costs of various BMPs relative to the storage capacity they create. It found that native landscaping and soil amendments deliver the most bang for the buck, with storage costing an average of only $0.05/L ($0.19/gal) and $0.07/L ($0.28/gal), respectively, compared to green roofs ($1.25/L [$4.72/gal]), cisterns ($1.19/L [$4.51/gal]), and stormwater trees ($1.29/L [$4.89/gal]), according to the plan. Porous pavement, rain barrels, rain gardens, and bioswales all cost less to implement than the existing deep-tunnel storage system, which cost $0.64/L ($2.42/gal). 


Off to a running start  

While the 2035 goal is voluntary, MMSD has at least some regulatory incentive to make these investments. Earlier this year, it became the first wastewater utility in the nation to have green infrastructure included in its pollution discharge permit. To comply, it must add 3785 m3 (1 million gal) in green infrastructure capacity each year for the next 5 years.  

To reach its 2035 goal, the district knows it will have to go well above and beyond the permit requirements. In July, it announced a proposal to contribute $1.2 million toward the construction of cisterns, porous pavement, and other stormwater runoff controls on 13 public and private projects designed to capture more than 12,500 m3 (3.3 million gal) of stormwater. The project owners also bear part of the cost. 

“So far, our green infrastructure program is based on ‘carrots,’ and it only applies to developments of a certain size,” Sands said.  

Current rules require developers to limit runoff to predevelopment levels on projects that increase impervious surfaces by 0.2 ha(0.5 acre) or on any development of 0.8 ha(2 ac) or larger.  

“Now we have to start asking if we should broaden our reach to smaller developments and also to look at ‘sticks’ for noncompliance,” Sands said. An ad hoc committee is being formed to establish these policies, she said.   

“Municipalities here are excited about green infrastructure but worry that the upfront costs and maintenance are sometimes higher [than more traditional approaches],” Sands said. “Our triple-bottom-line analysis shows terrific benefits — but the benefits don’t always go back into the same pocket that the upfront costs came from. Our job now is to figure out how to achieve economies of scale and change the culture so that these approaches become more affordable and accepted.” 

                                                                        Mary Bufe, WE&T 


If Frankenstein knew about wastewater …  

Former graduate student builds an artificial colon to simulate how bacteria in wastewater would behave in a natural environment 

Ian Marcus, a former graduate student at the University of California–Riverside, knew that if he wanted to understand the impact bacteria in wastewater have on groundwater and how bacteria behave in microbial communities with microorganisms, he had to replicate the natural environment in which the bacteria exist. In the past, scientists typically studied bacteria in an isolated environment under ideal growing conditions, but Marcus knew this wasn’t the best approach. He knew it in his gut, which is why for his experiment he built a human gut, incorporating a synthetic human colon, a septic tank, and groundwater.   

A fellow graduate student at the university, Alicia Taylor, was inspired by Marcus’s research and is using the same system to determine how nanoparticles behave in a similar environment. 


It’s all in the gut   

“The first thing I did was background reading,” Marcus said, explaining how he built the synthetic colon. “I’m not a gastroenterologist. I needed to know what the colon does and how it functions.” 

After doing research, Marcus said he knew a few major processes had to be included in his synthetic colon: dehydration along the pathway so that waste can become solid and the water could be redistributed, microbial ability to metabolize metabolites, and facilitated transport of these metabolites to the body. 

The microbes in the colon were taken from a human fecal sample, Marcus said. And three times a day, he “fed” the colon. 

“I used colon media found in literature that would replicate a close approximation to the Western diet,” Marcus said. It was composed of 20 different ingredients, “stuff that’s not digested by the body before it heads to the colon,” he said. 

After conducting his experiment, Marcus found that the Escherichia coli strain in the microbial community may be less mobile in aquatic environments and more prone to forming biofilm than the same E. coli strain in an isolated environment, according to a University of California news release.  

The E. coli therefore could remain longer in the environment, since biofilm provides a refuge for all microorganisms within it, the release says. When the biofilm matures, it sends out bacteria to colonize another surface. Thus, the bacteria could survive in the environment for longer periods.  

“This means that pathogens could potentially linger longer, and over a long period of time travel greater distances in the groundwater,” Marcus said in the release. 

Marcus published his findings in the journal Applied Environmental Microbiology and has since graduated. “I’m headed to France to study synthetic biology,” he said.  


Analyzing a booming industry  

Meanwhile, back at the University of California, Taylor is continuing to work with the system Marcus helped create. She is conducting her own research. She said she also is interested in microorganisms and also thought it was important to study them in the actual microbial communities rather than in isolation. But instead of focusing on bacteria, Taylor chose nanoparticles as her area of study.  

“Nanotech is really booming business,” Taylor explained, and nanoparticles are in many consumer products, from makeup to cereal. She said she was interested in seeing how they affect microbial communities inside the gut. 

For her experiment, Taylor is using titanium oxide, zinc oxide, and cerium oxide nanomaterials. Titanium oxide and zinc oxide are anticipated to be prevalent in groundwater, she said. 

Taylor ran the nanoparticles through the artificial colon. Also, using the same system, she will conduct a study of what happens to microbial communities in septic tanks when nanoparticles go down the drain, much like makeup in the shower.  

Taylor said she wants to see if nanoparticles affect the microbial communities in septic tanks. If they do, “you could then postulate that the septic tank can’t adequately function,” she said. “The contaminated water could enter the groundwater.” 

Taylor says she still has to conduct a few more control studies before she finishes her research. She said she would be ready to publish her findings by next spring.  


LaShell Stratton-Childers, WE&T  



Where’s the green for blue?  

Innovative financing structures hold promise for attracting private capital, but some investors see higher risks 


Capital shortfalls in the water sector are continuing to limit the ability of communities to initiate new projects and complete needed water and wastewater upgrades, causing ever-widening infrastructure and regulatory gaps and creating higher demand for new financing sources. With options limited from the federal level and municipal budgets squeezed, private equity increasingly is seen as a real solution for filling this need and is anticipated to play a much larger role in the future for water infrastructure investing.  

In line with this projection, public–private partnerships have been a growing trend in the water quality industry, but now — beyond financing new facilities through these arrangements — entire programs are being structured around alternative financing models that make use of private capital. However, despite the significant emerging opportunities for private equity to participate in the water sector, some investors are growing cautious in regard to expanding risks facing water utilities.  


A new approach to public–private partnerships  

Prince George’s County, Md., has developed a new public–private partnership model based on a long-term programmatic approach for facilitating stormwater management retrofits. The initiative is being implemented in response to a regulatory mandate to meet Chesapeake Bay total maximum daily load regulations and retrofit approximately 3200 ha (8000 ac) of uncontrolled urban development for improving water quality by 2025.  

The model incorporates an innovative design–build–operate–maintain–finance structure in which program responsibilities, risk, and upfront program financing will be transferred to the private partner.  

“We turned to this type of public–private partnership structure because of the scale and time constraints associated with our mandate,” said Larry Coffman, deputy director of the Prince George’s County Department of Environmental Resources. “A traditional governmental approach to implementing this type of capital program would be too inefficient to complete on time.”  

Under the programmatic model, private partners would provide all initial capital costs and act as general contractors in partnership with the county, which would then pay private partners a monthly fee that would include debt service and operations and maintenance costs.  

In seeking private capital, Coffman said the county is not simply looking for large equity institutions but also is exploring opportunities to work with local lenders, including social–economic financing groups that invest in sustainably orientated businesses. “We are not interested in working with equity groups that are after quick high-rate returns,” Coffman said. “Instead, we want to attract investors that are more in line with pension funds, with reasonable long-term rates. These standards are important in establishing a sustainable financing model.”  

An added benefit of this approach is the opportunity to create an economic stimulus, including new jobs and business development. “We want to use the program to benefit the local community. It is difficult to see the potential for economic development through the typical government procurement process,” Coffman said.  


Higher risks in water investments?   

Although the municipal water sector, including water utility bonds, traditionally has been regarded as a relatively safe, longer-term investment, issues associated with water security, drought, and aging infrastructure are triggering increased concerns about the future stability of this market.  

A recent report by nonprofit organization Ceres (Boston) urged caution and warned of future potential risks to water infrastructure investors because of intensifying water stress, declining revenues, and uncertain water demand.  

The report, Water Ripples: Expanding Risks for U.S. Water Providers, recommends that utilities revise the way they project future water demands and that they move carefully before embarking on pipelines, reservoirs, and other major water infrastructure projects that could create financial risks for investors. 

“Many investors still view this sector as an essential service provider and lower-risk, but over the last couple of years, more water utilities have had their credit ratings downgraded or put on negative watch due to water stresses and supply issues stemming from drought,” said Sharlene Leurig, senior manager of insurance and water programs at Ceres and the report’s author.  

Declining water demand was cited as another risk factor. “Across the country, water systems are seeing a persistent drop in household water consumption,” Leurig said. “This is a very challenging environment to operate in, especially with the knowledge that utilities need to finance the improvement of their infrastructure networks.”  

Leurig recently helped prepare a letter on behalf of a group of investors managing $40 billion in assets that was sent to the National Federation of Municipal Analysts (Pittsburgh), requesting that water utilities be held to more-stringent disclosure requirements on issues relating to supply security, demand management, asset management, and water quality.  

Matt Diserio, president of Water Asset Management LLC (New York), one of the investment groups signed to the letter, said the fact that these water-related risks are starting to be more broadly recognized represents an opportunity to improve water supply reliability and infrastructure quality. “Increased transparency is an important aspect to the 21st century economy,” Diserio said. “Other industries are held to these higher standards, and the water sector should not be any different. Many companies and assets will stand to benefit from a higher degree of transparency in this market.”  

While water-related stresses and infrastructure liabilities pose significant risks to financers, these same issues also can represent investment opportunities, said Steven Kloos, a partner at venture-capital firm True North Venture Partners (Chicago), which focuses on early-stage investment opportunities in such industries as water, energy, and waste.  

“Water scarcity can be [a] driver for a young company with a unique water solution,” Kloos said.  

Due to the declining state of many water infrastructure and delivery systems, Kloos also is seeing higher demand for “smart water solutions that can do things like detect leaks before they become bursts, helping municipalities avoid huge capital expenses,” he said. “These data-driven solutions target water system inefficiencies and reduce losses from nonrevenue water.” 


— Jeff Gunderson, WE&T  


The next $100 billion  

As U.S. drinking water needs loom, experts mull best ways to focus future investments 

Drinking water infrastructure throughout the U.S. will require $384.2 billion in improvements through 2030, according to the results of the fifth Drinking Water Infrastructure Needs Survey and Assessment released in June by the U.S. Environmental Protection Agency (EPA). Meanwhile, the Johnson Foundation (Racine, Wis.) recently asked a panel of experts about ways to rethink existing approaches to water infrastructure in light of climate change. Specifically, the experts were asked the question, “How to spend the next $100 billion?”   


Water needs through 2030  

Conducted every 4 years, the EPA assessment documents the 20-year capital investment needs of the roughly 52,000 community water systems and 21,400 not-for-profit noncommunity water systems that are eligible to receive funding from the Drinking Water State Revolving Fund (DWSRF). The current assessment, which covers the period from 2011 through 2030, only addresses infrastructure needs eligible to receive assistance from DWSRF and so excludes capital expenses associated with such projects as dams, raw-water reservoirs, future growth, and fire protection. The overall total of $384.2 billion tracks closely the results of EPA’s last assessment, which found that water providers would require $379.7 billion from 2007 through 2026.  

By far, the greatest demands pertain to transmission and distribution projects, which require $247.5 billion, or 64% of the total national needs, according to the assessment. Treatment-related infrastructure is the next largest category, representing $72.5 billion, or 19% of total needs, followed by storage ($39.5 billion, or 10%) and source requirements ($20.5 billion, or 5%). As for needs among water providers, the assessment notes that medium-size community water systems — those serving 3301 to 100,000 people — have the greatest needs, totaling $161.8 billion. Large community water systems serving more than 100,000 people have the next largest needs, amounting to $145.1 billion. Small community water systems serving fewer than 3300 people require $64.5 billion through 2030. 


New paradigms  

To ensure their sustainability well into the future, water providers must account for climate change when deciding how to invest in their systems in the future, said Kala Vairavamoorthy, professor and dean of the Patel College of Global Sustainability at the University of South Florida (Tampa). He was one of the experts who responded to the question from the Johnson Foundation about the next $100 billion. 

“The strength and frequency of extreme weather events, coupled with increased variability and unpredictability in the availability and reliability of water resources, is turning our old models and assumptions on their heads,” Vairavamoorthy said. Therefore, a “new vision of water management” that “adapts human demands and structure to the dynamics of natural systems” is needed, he said. 

To this end, water systems must be resilient, reliable, efficient, and flexible, Vairavamoorthy said. However, smaller, decentralized systems are more likely to embody these traits than are the large, centralized systems that predominate in urban areas today. For this reason, “we need to upend the current paradigm and invest more in smaller, distributed urban water systems,” Vairavamoorthy said. Because they are more diverse in nature and able to contain failures to more localized areas, distributed infrastructure decreases risk and vulnerability to extreme events while reducing energy requirements, he said. 

Keeping the risks associated with climate change in mind, water systems should employ a “portfolio strategy” to guide future investment decisions, said Paul Fleming, manager of the climate resiliency group at Seattle Public Utilities, in response to the Johnson Foundation’s question. 

Under this method, “nonstructural approaches are evaluated on par with traditional, structural approaches to determine what mix of strategies best addresses climate risks in an interconnected world,” Fleming said. “This requires investing in improved planning and assessment methods and evaluation techniques to help identify and analyze the varying costs and benefits of a broad array of approaches and to assemble them into viable and implementable portfolios.” 


More planning needed  

G. Tracy Mehan, principal at The Cadmus Group (Boston) and a former assistant administrator of EPA’s Office of Water, agreed on the need for improved planning of infrastructure spending. 

“Some portion of that $100 billion should go to developing and implementing top-notch asset management plans to guide investments over time in a cost-effective and timely manner, including the most basic question as to what assets does a given utility need,” Mehan said in an interview with WE&T. 

Infrastructure improvements that enable water providers to better tailor the quality of water to the intended use should receive serious consideration as part of any discussion of optimizing water systems, said Alan Vicory Jr., principal at Stantec (Edmonton, Alberta), in an interview with WE&T. 

For example, as communities develop new infrastructure or upgrade existing systems, they should try to avoid having to treat all water to drinking water standards, regardless of how the end product is likely to be used, Vicory noted. “We have to get away from that,” he said.  


— Jay Landers, WE&T