WEF's membership newsletter covers current Federation activities, Member Association news, and items of concern to the water quality field. WEF Highlights is your source for the most up-to-the-minute WEF news and member information.  



May 2011, Vol. 48, No. 4

Top Story

Nature’s Hard-Shelled Filtration Systems
Organizations work to restore bivalves, nature's water filter, to waterways
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Nature’s water filtration system comes in a small, hard-shelled package. Bivalves, such as oysters, mussels, and clams, naturally remove suspended sediment and nutrients from waterways.

As filter feeders, bivalves filter water to find food. In the process, bivalves remove nitrogen from the water and pull suspended sediment from the water column to deposit on the waterbody floor, said Stephanie Westby, National Oceanic and Atmospheric Administration (NOAA) Oyster Coordinator and Environmental Engineer. Removing nutrients from water reduces the algal blooms that can reduce lowered levels of dissolved oxygen. Removing sediments reduces clouded water and enables sunlight that is needed for the health of aquatic ecosystem to penetrate the water.

A freshwater mussel. Photo courtesy of Eric Engbretson, U.S. Fish and Wildlife Service. Click for larger image. 


Oyster Populations in Decline
Research on oyster ecology and biology began years ago, primarily because of their commercial value, said Catherine Gatenby, project leader at the U.S. Fish and Wildlife Service (FWS) White Sulphur Springs National Fish Hatchery.

One area of focus for oyster research and restoration has been Chesapeake Bay, where the oyster population has declined to about 1% of its historic levels, Westby said. The oyster variety populating saltwater and brackish water along the East Coast is Crassostrea virginica. Overfishing, oyster disease, and poor water quality all have contributed to decline of this oyster in the bay and continue to threaten remaining populations.

Like other bivalves, the oyster cannot swim to avoid a plume of polluted water and will die if dissolved-oxygen levels drop too low or if levels of sediment overwhelm and bury the reefs. And as the oysters decline, the ecological benefits they provide decline as well, Westby said. “And interestingly, the oysters can be a part of the solution,” she said. “They’re a victim of the water quality, but can also be a help if we get to some critical mass.”

Quantifying Benefits of Oysters
“One adult oyster can filter up to about 50 gallons [189 L] of water a day,” Westby said. In addition to filtration, an oyster reef provides habitat for other aquatic species, increasing diversity and health of ecosystems, she added.

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Spat on shell restoration efforts by the Chesapeake Bay Foundation (CBF; Annapolis, Md.). Photo courtesy of CBF. Click for larger image.

A recent study by researchers from the Virginia Commonwealth University (Richmond) measured oysters’ filtration capacity. Researchers measured nutrient contents in the oysters’ tissues and shells at various sizes, according to an American Society of Agronomy (Madison, Wis.) news release.

The study, funded by the U.S. Environmental Protection Agency and administered by the National Fish and Wildlife Foundation, determined that commercial oyster farms harvesting 1 million 76-mm Crassostrea virginica oysters can remove 132 kg of nitrogen, 19 kg of phosphorus, and 3823 kg of carbon. While these amounts are only “a small percentage of the total nutrient reductions needed to achieve Bay water-quality goals,” these offsets on a per-area basis remove a large quantity of nutrients compared to agriculture best management practices and other efforts to control nonpoint source pollution, the study report says.

Numerous Efforts To Restore Oyster Populations
“There is a strong understanding of [oysters’] true ecological value, the water filtration and habitat function,” Westby said. “The focus of the oyster restoration effort is to try to get them back in the water as the natural filters that they are.” There also is a hope to create a sustainable harvest for oysters, primarily through the oyster farms that provide both the economic and environmental benefits.

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“There’s an extensive restoration effort going on in the sanctuary areas to rebuild the reefs, plant them with oysters and not fish them,” Westby said. NOAA distributes funding to rebuild and restock reefs with oysters and has created a benthic mapping program that maps the floor of various tributaries to help determine locations suitable for oyster restoration, she added.

Left, concrete reef structures, called reef balls, are coated with oyster larvae and planted in sanctuaries as a part of CBF’s oyster restoration efforts. Right, one of CBF’s reef balls coated with oysters after being in the water several months. Photos courtesy of CBF. Click for larger images. 

The Chesapeake Bay Foundation (CBF; Annapolis, Md.) is another organization working on oyster restoration in the bay. CBF plants juvenile oysters that have attached to shells and concrete reef structures containing oyster larvae in sanctuaries, creates intertidal oyster shoreline, engages volunteers, and promotes aquaculture. The organization involves the community by collecting shells for its program from local restaurants and involving citizens in an oyster gardening program in which members of the public are provided with cages containing spat to help grow the oysters off their waterfront property.

“Restoration is slow but moving in the right direction,” said Tommy Leggett, Chesapeake Bay Foundation Virginia Oyster Restoration and Fisheries scientist. “Oysters are developing disease tolerance, the oyster fishery is somewhat stabilized in Virginia, and oyster aquaculture is assuming more of the role in production, taking pressure off of the wild resource.” 


Another Powerful Bivalve
The freshwater mussel is another notable bivalve, providing many of the same ecological services and facing many of the same threats as oysters.

Freshwater mussels filter 1 to 3 L of water an hour every day, Gatenby said. And mussels located in an 8-km (5-mi) stretch of river in southeastern Pennsylvania were estimated to remove 24 ton (26 Mg) of silt from the waterway a year, she said.

There are about 300 species of mussels in North America, but 70% of these are in decline, and many are endangered because of chronic and excess sediment in rivers, pollution and excess nutrients, and habitat loss from building dams, Gatenby said. In areas such as the Great Lakes, the invasive zebra mussel also is a concern because it outcompetes local species for food.

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Fish and Wildlife Service employees on a gravel island in the Ohio River study samples of freshwater mussel shells. Photo courtesy of John and Karen Hollingsworth, U.S. Fish and Wildlife Service. Click for larger image.
Working To Restore Mussel Species
Restoration efforts for mussels include habitat restoration by rebuilding the riparian zone, cleaning pollution, conducting additional research about mussels to find the best ways for restoration, and propagating mussels in hatcheries, and reintroducing them in the wild, Gatenby said. The goal of restoration efforts is to create “a self-sustaining system” where the mussels naturally recolonize waterways and reproduce in the wild.
 
 Bivalves- Ohio River Small For one restoration project, 16,000 mussels were rescued from an Allegheny River bridge demolition. More than 5000 of these mussels were taken to the White Sulphur Springs National Fish Hatchery while the others were relocated to different portions of the Allegheny River, as well as the Monongahela, Elk, and Ohio rivers. After the bridge was replaced and the waterway was deemed suitable habitat, some of those mussels were placed back under the bridge. Even though the mussels were moved far offsite for broader-scale conservation, they are thriving and recolonizing other areas.

“We’re working with all of our partners to raise awareness and educate folks that it’s not just about endangered species,” Gatenby said. “It’s about ecological function.”   
The Ohio River, running between Ohio and West Virginia, provides habitat for endangered mussels. Photo courtesy of Craig Stihler, U.S. Fish and Wildlife Service. Click for larger image.  
Jennifer Fulcher, WEF Highlights
Surprisingly Walkable Los Angeles
WEFTEC lands just a short walk from cultural points, restaurants, landmark sites, and more

Ask some long-time residents of Los Angeles, and they’ll respond that not having a car is not an option for living in the most populated metropolis in the United States. But for visitors to downtown L.A. — the site of the 84th Annual Water Environment Federation (WEF; Alexandria, Va.) Technical Exhibition and Conference, WEFTEC® 2011 — immense changes have made this once desolate neighborhood one of the most walkable areas in the country.

“The downtown has really improved tremendously,” said Jim Clark, senior vice president and managing director of Black & Veatch (Overland Park, Kan.) and local resident of more than 35 years. Clark is on the WEFTEC Advisory Committee and serves as the California WEF member of the planning committee. Fifteen years ago, “nobody even wanted to walk in that part of town,” but locals are now referring to it as a “mini Times Square,” Clark said.

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WEFTEC® 2011 will be held at the Los Angeles Convention Center. Photo courtesy of Tom and Michele Grimm. Click for larger image.
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“Los Angeles has more walkable neighborhoods than people think,” said Matt Lerner, chief technical officer of Seattle-based WalkScore.com, an online search tool used for analyzing the pedestrian-friendly attributes of any physical address. Three million scores are generated daily, and more than 6000 Web sites use WalkScore, which ranks downtown Los Angeles the most walkable of all neighborhoods in the metropolis — despite preconceived notions about the city as a whole.

When WalkScore launched in 2007, “Los Angeles was one of the most commented on and discussed cities,” Lerner said. “Myth is stronger than reality.”

“You don’t have to have a car to move around Los Angeles now,” said Gary Lee Moore, city engineer with the Los Angeles Bureau of Engineering.

According to Moore, “any type of food is within a mile” of downtown Los Angeles, and it’s “the infusion of restaurants” that has made the neighborhood vibrant. “The diversity of Los Angeles is reflected in the one-of-a-kind unique restaurants,” he said.

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Above, a view of the L.A. Live campus and the downtown Los Angeles skyline. Photo courtesy of LA Inc., the Los Angeles Convention and and Visitors Bureau. Left,view of downtown Los Angeles from the Los Angeles Department of Water and Power. Photo courtesy of David Giron. Click for larger images.
All that Jazz
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Los Angeles Convention Center. Photo courtesy of LA Inc., the Los Angeles Convention and and Visitors Bureau. Click for larger image.

For those attending WEFTEC 2011, the WalkScore.com’s ratings and testimonials are sure to hold water. Landmarks populate the Convention Center and financial district area, where most of the city’s hotels are situated.

Clark noted that the Grammy Museum and the Walt Disney Concert Hall are a short walk from downtown. There also is the Our Lady of Angels Catholic Church, which has numerous “well-knowns” interred in the basement, and the Dorothy Chandler Pavilion — the former site of the Academy Awards.

The new concert hall is actually part of the Music Center, a pivotal feature of the new L.A. LIVE campus and what inspires thoughts and sentiments of Times Square. A mecca of dining, nightlife, and entertainment, L.A. LIVE features clubs, theaters, concert venues, and the Staples Center, home of the L.A. Lakers basketball games.
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A view of downtown Los Angeles and the Staples Center at night. Photo courtesy of LA INC., the Los Angeles Convention and and Visitors Bureau. Click for larger image.

Buzzing With Amenities
The whole downtown area “is a beehive,” according to Carol Martinez, vice president of communications for LA INC., the Los Angeles Convention and Visitors Bureau. There are numerous one-of-a-kind coffee shops, Starbucks, ATMs, and great opportunities for fueling up. Conveniences of note include The Colburn School Café on South Grand Avenue, Ralph’s Grocery Store on Flower Street, and The Original Pantry restaurant, open 24 hours, on Figueroa Street. This “coffee shop of yesterday” boasts a line on weekend mornings, Martinez said. 

There’s also great shopping — the 100 block Fashion District is nearby — and for aesthetic enthusiasts, access the Downtown Art Walk, a free, self-guided public art tour. Those who arrive in town before the conference begins, take note: The Art Walk Lounge offers complimentary refreshments, giveaways, and a special art exhibit on Thursdays.

Visitors who are craving outdoors-time on a break or in between tours of the Orange County Water District’s Groundwater Replenishment System (former Water Factory 21), Hyperion Treatment Plant, the West Basin’s Water Recycling Facility, and the City of Los Angeles’ Terminal Island Water Reclamation Plant, can find diversions on South Olive Street. A short walk from hotels on South Olive Street or a $0.35 DASH bus from the Convention Center, is Angel’s Knoll, a manicured park featured in the film “500 Days of Summer.” The funicular railway Angel’s Flight, for a $0.25 fare, will take passengers to the Grand Central Market, where there are meals, fruit, and more for putting together a picnic in this scenic pocket park overlooking the city’s majestic buildings, Martinez said.

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The funicular railway Angel's Flight will take passengers to the Grand Central Market in Los Angeles. Photo courtesy of LA INC., the Los Angeles Convention and and Visitors Bureau. Click for larger image.
Have an interest in the downtown’s municipal features? Next to the Walt Disney Concert Hall in L.A. LIVE is a large fountain that actually is part of the Department of Water and Power’s air-conditioning system.

But if it’s urban exploration and other neighborhoods visitors want to see, and they would rather a have quick lift, a short ride on a Downtown DASH to Olvera Street will bring conference-goers to L.A. City Hall, which is featured in countless films and widely used in television production. There also are bazaarlike market stalls in this area, which is the oldest part of town. Buses also go to Chinatown, Little Tokyo, and other famous neighborhoods.

Moore credits the Business Improvement District, as well as the city’s Community Redevelopment Agency, for all of the pedestrian-friendly improvements. “It’s all about a great visitor experience … we continue to evolve and want to do more,” he said, noting that the future of L.A. includes greater ”bikeability” and redevelopment of public access and recreation along the Los Angeles River, where the City of Angels was originally founded.

 

Andrea Fox, WEF Highlights
WEF MOP Series: Detailing the Science Behind Nutrient Removal in MOP 34
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The Water Environment Federation (WEF; Alexandria, Va.) released a new Manual of Practice (MOP) last year that provides in-depth scientific information on nutrient removal topics. Nutrient Removal, MOP 34 includes information taken from a previous WEF special publication published in 1998 that has been improved and built on, according to Bruce Johnson, task force chair for the MOP and project manager at CH2M Hill (Englewood, Colo.).

“This [book] is meant to be more of a scientific basis for nutrient removal,” Johnson said. “The main use of this is understanding the theory behind nutrient removal so that people can be more effective at designing nutrient removal systems.”


While several state regulations and recommendations exist for achieving nutrient removal, they often are not much use for utilities. Different wastewater treatment facilities have different challenges and need different solutions. The new MOP provides the science behind nutrient removal solutions, so readers can understand risks and benefits of providing their own solutions, which is different from the “cookbook approach,” Johnson explained.

To find the best solution, Johnson recommends using a typical set of approaches as a basis and then modifying that solution to find one’s own unique approach, he said. Having an understanding of the processes and science behind nutrient removal is important when people are looking to optimize facilities and trying to achieve low levels of nutrients in wastewater effluent. This book provides this understanding, Johnson said.

The publication devotes one chapter each to two new topics, side-stream nitrogen-removal technologies and nutrient-removal modeling.

The peer-reviewed publication “was almost entirely written by practicing engineers,” Johnson said. “So they have stated these scientific principles in a way that engineers and, hopefully operations people, can understand and use a lot more directly.” Johnson estimates that 40 reviewers went through the publication to make sure everyone agreed on the content, which gives the publication credence and supports the fact that “what we’re talking about in here is the best accepted practices in our industry right now.”
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Bruce Johnson, the task force chair for Nutrient Removal, Manual of Practice 34. Photo courtesy of Johnson.


“This is one of the first books that … holistically describes how engineers approach nutrient removal,” Johnson said. The book details the best tools available for approaching nutrient removal for a comprehensive and complete strategy, he added. “I think it’s applicable to everyone who wants to really understand how nutrient removal [is accomplished] — whether it’s a utility trying to optimize its plant, an engineer trying to figure out the best approach to designing a facility, or a student trying to understand the basics behind nutrient removal,” he said.

The publication was a best-seller at WEFTEC® 2010. Purchase your own copy today.   

Jennifer Fulcher, WEF Highlights