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80th WEFTEC® Is Biggest Ever
Sustainability Moves to the Forefront
Stockholm Water Prize Laureate outlines problems, solutions for water professionals
Indirect Potable Reuse: Easing Public Concern
California collection systems meet new requirements with help from state, member association partnership
WEFTEC.07, held Oct. 13–17 in San Diego, was the largest event in the conference’s 80-year history. This year’s event drew 19,929 attendees and 1017 exhibitors that occupied 268,405 ft2 of floor space — breaking the previous exhibit space record set at WEFTEC.06 in Dallas and the attendance record set at WEFTEC.02 in Chicago, the host city for WEFTEC.08.
The conference program featured 119 technical sessions, 25 workshops, and eight facility tours. Sessions on membrane bioreactors, asset management, nutrient removal, and renewable energy were especially popular with attendees. WEFTEC.07 also marked the 35th anniversary of the Clean Water Act, recognized with a session devoted to “The Next 35 Years of the Clean Water Act”; the 20th annual Operations Challenge competition, won by the Commode Commandos from the Rocky Mountain Water Environment Association; and the first meeting of the Water Environment Federation’s (WEF; Alexandria, Va.) Sustainability Community of Practice.
The Opening General Session officially kicked off the conference on Oct. 14. This year’s keynote speaker, 2007 Stockholm Water Prize Laureate Perry L. McCarty, received a standing ovation after his presentation on sustainable water resources. The Opening General Session also featured remarks from WEF’s immediate past president, Mohamed Dahab; incoming president, Adam Zabinski; San Diego Mayor, Jerry Sanders; as well as a presentation by National Geographic (Washington, D.C.) underwater photographer David Doubilet.
After traveling to Chicago in 2008, WEFTEC will be hosted by Orlando, Fla., in 2009, and New Orleans in 2010.
WEFTEC.07 Scavenger Hunt Winner
Congratulations to Wendy Anderson, process engineer for the Metro Wastewater Reclamation District (Denver), who won a new iPod nano for visiting the WEF Publications Booth and completing the WEFTEC.07 Scavenger Hunt.
“The Scavenger Hunt was an excellent idea,” Anderson said. “It compelled me to read over the WEF Awards display a little more closely, and I discovered Eric Wahlberg had won the Morgan Operational Solutions Medal. I work with Eric frequently. And two directors from my workplace — Steve Rogowski and Mitch Costanzo, one from my department — were recognized for their work with the National Biosolids Partnership Environmental Management System. Thank you and WEF for the wonderful prize.”
Stockholm Water Prize Laureate outlines problems, solutions for water professionals
Although the water and wastewater sectors face both new and long-standing challenges, sustainable solutions are available to protect water resources, according to Perry L. McCarty, 2007 Stockholm Water Prize Laureate and the keynote speaker at the Opening General Session of WEFTEC®.07.
“Each of us must do our part if the overall problem is to be solved,” McCarty said. “Water is such a precious resource, something we often forget unless we are forced to do without.”
The Opening General Session kicked off the 80th annual WEFTEC Conference, which was held Oct. 13–17 in San Diego. The session focused on sustainability, a subject that affects all aspects of the water and wastewater community.
McCarty was the recipient of the 2007 Stockholm Water Prize from the Stockholm International Water Institute (Sweden). McCarty was honored for his pioneering work in developing the scientific approach for the design and operation of water and wastewater systems and establishing the role of fundamental microbiology and chemistry in the design of bioreactors.
In his address, McCarty discussed some of the innovations in wastewater treatment that have emerged in the last 50 years, and suggested how past advances might help solve current and future problems.
McCarty highlighted four major problem areas in wastewater treatment: pathogens, dissolved oxygen deficiency, industrial waste, and eutrification.
“We have addressed the first quite well with drinking water, but we are just beginning to get serious about addressing the latter three,” he said.
McCarty cited problems that water and wastewater professionals have faced in the past, such as the burning Cuyahoga River in Ohio, U.S. dependence on oil, treatment plants turning into bubble baths, and rivers running dry.
“We were in need of solutions,” he said. “Fortunately, research to address this need was crisply instigated and solutions came about rapidly.”
For example, McCarty said, the South Tahoe Public Utility District began advanced treatment in 1956 to remove nitrogen and metals. The processes used at South Tahoe were then applied to Windhoek, Namibia, when the capital city ran out of fresh water. By 1968, the technologies used at South Tahoe solved the problems created by water shortage in Windhoek, McCarty said.
He also discussed the growing use of reverse osmosis technology, which he said was just a “laboratory curiosity in the early 1960s.” Later on, Water Factory 21, a full-scale reverse osmosis plant, was built in Orange County, Calif. Although the plant has since been torn down to make way for the new Groundwater Replenishment System, the legacy of this groundbreaking plant lives on.
“Thirty years later, this technology is being widely applied in California and throughout the world,” McCarty said. “Water Factory 21 was an apt name for this 21st century concept.”
McCarty, who first attended WEFTEC 50 years ago when it was held in Boston, also touched on the challenges posed by pesticides, improper waste disposal, and soil and groundwater pollution, citing the problems at Love Canal in Niagara Falls, N.Y. He said the handling of exposed drums of hazardous chemicals was the easy problem to solve. The more difficult problem, according to McCarty, was remediating soil and groundwater contaminated by pesticides, polychlorinated biphenyls, and petroleum hydrocarbons.
“Better living through chemistry certainly greatly increased our use of synthetic chemicals, creating problems with hundreds of billions of dollars of costs,” he said. “Our precious groundwaters have been severely contaminated. Prevention has become a must.”
McCarty went on to discuss the effects of climate change as it pertains to water professionals. He alluded to the consequences of rising ocean levels and their effect on coastal aquifers, as well as the significant effect of climate change on water distribution systems throughout the world.
He emphasized the energy aspect of wastewater treatment and how it affects climate change. Waste handling and treatment represents 4% of the world’s greenhouse gas emissions, according to McCarty. Because chemicals produced during the handling and treatment of waste — such as methane and nitrous oxide — contribute to climate change, water professionals are directly associated with the cause of climate change and the need for sustainable solutions, he said.
McCarty also believes the wastewater sector is one of the easiest and most cost-effective to control in terms of greenhouse gas emissions. While methane is a greenhouse gas, it also is a biofuel that can be used for energy.
“Its collection and use as a fuel can offset the use of fossil fuels,” McCarty said, referring to methane.
Outside of methane, wastewater treatment creates greenhouse gas emissions in other areas, McCarty said. Energy use throughout the wastewater system, such as the electricity needed for the transport and treatment of wastewater, creates more greenhouse gas emissions.
For example, water is pumped considerable distances to provide for the water needs of Southern California. This leads to large consumption of electricity and, as a result of the abundance of electricity used, more greenhouse gas emissions. To alleviate these energy concerns, McCarty suggested capturing the methane produced from anaerobic digestion, and using it as an energy source.
“Treatment plant design can have a major impact on greenhouse gas emissions,” he said.
WEF President Mohamed Dahab echoed McCarty, stressing the importance of sustainability in the face of climate change and the world’s growing population. He said water scarcity is the next world water crisis, and while finding solutions will be difficult, human imagination, persistence, and ingenuity can solve these problems.
“We must be serious about sustaining our environmental resources, and we must learn to live as responsible members of the human family,” Dahab said.
David Doubilet, an underwater photographer for National Geographic (Washington, D.C.), followed McCarty. Doubilet has photographed more than 60 stories for National Geographic, and said that he has spent a great deal of his life underwater. This has given him a unique view of the world, as well as an appreciation for the beauty of unspoiled water.
“Clear water is one of the greatest gifts our planet has to offer,” Doubilet said.
Doubilet displayed an impressive array of his photographs from around the world, including the Okavango River in southwest Africa, the Galapagos Islands, the Grand Cayman Islands, Cuba, French Polynesia, New Zealand, Florida, and Hawaii. Doubilet also has photographed a wide variety of life in the water environment, including crocodiles, buffalo, hippopotamuses, elephants, frogs, sharks, barracudas, dolphins, and jellyfish.
San Diego Mayor Jerry Sanders welcomed attendees to San Diego and highlighted the city’s needed infrastructure upgrades.
“We’re in the midst of our own water and wastewater infrastructure upgrades,” Sanders said, noting that there had been no infrastructure upgrades in San Diego for quite some time. The city has state and taxpayer support for upgrades, and San Diego has big plans.
“We’re setting out to spend $1.4 billion over the next 4 years, making sure that facilities and pipes … are in great shape,” he said.
Incoming WEF president Adam Zabinski closed the Opening General Session. He highlighted the 35th anniversary of the Clean Water Act and the successes the Act has helped achieve. Zabinski said the new charge for water professionals is to create a truly sustainable water environment. Energy management issues, microconstituents, and greenhouse gas emissions also are concerns, he said.
To address these emerging problems, “We need a national effort, similar to that of 35 years ago, to assess not only our water needs of today, but also for future generations,” Zabinski said.
Despite the difficulty of these obstacles, Zabinski believes they can be overcome.
“The challenges we face are truly great,” he said. “But we have always risen to our challenges.”
— Michael Bonsiewich, WE&T
The lack of effective strategies to address microconstituents is one of the main impediments to more widespread use of indirect potable recharge, said Jörg Drewes, associate professor of environmental science and engineering at the Colorado School of Mines (Golden, Colo.). Drewes was the speaker at the annual Association of Environmental Engineering and Science Professors (AEESP) Scientist’s Luncheon at WEFTEC®.07 in San Diego.
Drewes defined indirect potable reuse (IPR) as “the intentional introduction of reclaimed water into a raw drinking water supply.” He also defined the need for its increased use by citing how climate change has coincided with reduced flows in the Colorado River, which supplies drinking and irrigation water to much of the western United States.
For example, the 190-ML/d (50-mgd) Prairie Waters Project in Aurora, Colo., will provide 30% of the area’s future water supply, according to Drewes. “It’s important to note that this plant is downstream of Denver on the South Platte River and carries 90% wastewater,” he said.
Drewes said that the science and technology underlying IPR are sound, but the challenge is in gaining public support for the practice. Microorganisms, aesthetics, and inorganic and organic chemicals are all well-handled by current water reuse practices, he said. However, unregulated and unidentified contaminants are what cause the public to worry.
These compounds have been called by many different names: pharmaceuticals and personal care products, endocrine-disrupting compounds, pollutants of potential concern, and microconstituents, to list a few. Drewes jokingly suggested a new term, compounds of emerging publicity.
More and more of these compounds are detected as laboratory methods become more sensitive, but what that detection means is still up for debate, he said. “What we know about the occurrence of these compounds in secondary treated wastewater effluent is highly biased. It’s biased because it depends on the analytical method you apply to qualify these compounds,” he said.
The results of what microconstituents are present are also biased by regional uses of the source compounds. For example, diclofenac, a nonsteroidal anti-inflammatory drug, is not very popular in North America, but highly used in Europe. And, for pharmaceuticals that are used commonly in both places, European wastewater shows residual concentrations that are double or triple North American levels, Drewes said. However, the reason for that discrepancy is that on average Europe’s per capita water use rates are one-half or one-third of North American rates; there is simply less water to dilute the compounds, he explained.
On the other side of that equation, there are many commonly used chemicals for which the environmental effects have not been tested. He said that 43% of the 3000 high production volume chemicals used in the United States have never been tested for their environmental effects. “There’s a tremendous volume generated, but we have little idea of their toxicity,” he said. “If you look at these chemicals that reflect different household chemicals like preservatives, you see them reaching the micrograms-per-liter range in raw sewage,” he said.
As more research is completed, more of these compounds will be identified, he said. “The key question is really: What does it all mean? When communicating with the public, how will they receive this? What the public really wants are zero [concentrations].”
The question then becomes “What is zero for microconstituent chemicals?” It’s difficult to communicate with the public exactly what the results of highly sensitive methods mean, Drewes said.
In fact, a recent study of microconstituents reported a high percentage of common microconstituents such as caffeine and tricolsan in the laboratory blanks. “These compounds are widely used, and it’s very difficult to keep them out of the lab environment. So by pushing detection limits further into this noise, you run into the problem of whether the detection is real or an artifact.”
Regardless of how small a number is, Drewes said, “if you see compounds detected, and you report a number, then what the public assumes is that there are adverse health effects.”
Multiple Barriers, Multiple Approaches
Of the various treatment schemes used to reclaim wastewater for IPR, none rely on a single treatment or barrier. Rather, a series of process steps provides various means of treatment. “It’s a sequence of barriers providing diversity and redundancy,” he said. “We want to have multiple barriers that can deal with different types of compounds.”
These barriers are as varied as the compounds they remove. Some barriers include biodegradation, chemical oxidation, photolysis, and physical separation. “The question becomes, how can we design a system where we assure absence of these emerging contaminants to provide a water source undistinguishable from existing supplies?”
To achieve that goal, Drewes compared empirical and mechanistic approaches to effectively removing microconstituents.
The empirical approach relies on continual laboratory monitoring to track the presence of indicator chemicals or surrogate measurements. Indicators are chemicals that occur at quantifiable levels and represent certain physicochemical and biodegradable characteristics of a family of microconstituents. If the indicator is removed, the assumption is that the other microconstituents associated with it have been removed, he said. For example, ibuprofen might be monitored as an indicator of several microconstituents.
A surrogate, on the other hand, is a bulk parameter, such as total organic carbon or conductivity, that serves as a performance measure for the removal of a certain type of microconstituent from a specific process, Drewes said. For biodegradation, for example, a certain change in total organic carbon could indicate that certain microconstituents had been treated.
To ensure good removal of all represented compounds, an indicator or surrogate that was difficult to remove or effect in relation to the other microconstituents would be chosen. This would ensure that if the indicator or surrogate were affected, most if not all of the other compounds would be as well.
Drewes outlined the pros and cons of the empirical approach. On the plus side, it simplifies the analytical effort for analysis and provides conservative estimates of removal. The downside, however, is that the indicator compound may change over time as consumer practices change. Because indicators may need to change, indicators and surrogates would need to be reviewed regularly. This also would be a site-specific approach that would require each facility to establish its own practices, he said.
The second model Drewes presented was a mechanistic approach. A mechanistic approach seeks to build a model that shows which treatment processes by their nature remove certain classes of compounds.
Drewes used membrane treatment to highlight the operation of this method. He explained that membranes prevent microconstituents — or any other compounds — from passing through by three functions: size exclusion, adsorption, and electrostatic repulsion. Because of these functions, ionic compounds are readily removed by membranes. However, there is currently no method for predicting the removal efficiency for non-ionic microconstituents due to limitations in determining appropriate solute size. For example, a linear molecule with a very large molecular weight could pass through a pore while a much smaller cyclic molecule would be excluded.
The advantages of the mechanistic approach for membrane systems is that it considers operational conditions and works well for certain classes of compounds. However, it is difficult to find the proper solute size descriptor, and due to the intense research needed to validate removal, it is not user-friendly.
Drewes also described a hybrid empirical–mechanistic method that seeks to use solute properties, such as shape, hydrophobicity, and polarity, to predict orientation angle and, thus, shed light on solute size.
“There are multiple ways to design an indirect potable reuse scheme,” Drewes said. “There is not an industry standard that says you need to use MF/RO [microfiltration/reverse osmosis] to do it right.”
“Planned IPR can provide drinking water supplies that are indistinguishable from conventional sources,” he said.
— Steve Spicer, WE&T
California collection systems meet new requirements with help from state, member association partnership
Approximately 150 WEFTEC®.07 attendees gathered to hear Nicholas Pinhey, public works director for the City of Modesto, Calif., speak at the WEF Collection Systems Luncheon. Pinhey’s Oct. 15 presentation recapped new waste discharge requirements recently set in place by the California State Water Resources Control Board (SWRCB), and explained how the California Water Environment Association (CWEA) partnered with SWRB to help agencies comply.
Pinhey opened the presentation by noting the decrease in California’s per capita infrastructure spending. In the 1950s, Pinhey said, Californians spent $180 per capita on infrastructure; today, a mere $25 per capita. Lack of funding combined with an aging infrastructure and growing population led California to take a closer at its collection systems management. Pinhey noted “virtually all collection systems [in California] have SSOs.”
An increase in the number of SSOs reported led the state to question whether there truly were more SSOs, or if there was just an increase in SSO reporting. Thus, it was decided that reporting and data collection had to be improved; standardized SSO reporting and regulatory measures would benefit water quality and extend the life of the collection systems infrastructure, Pinhey said.
California’s program, adopted in May 2006, requires all agencies within the state with sanitary sewer systems 1.6 km (1 mi) or greater in length to comply with requirements under the new, statewide Sewer System Management Plan (SSMP), and to report SSOs electronically. But getting utilities and agencies throughout California to make the appropriate changes and learn how to electronically report SSOs was not simple, Pinhey explained. CWEA’s involvement became instrumental in getting the collection systems up to speed.
Nick Arhontes, a CWEA member and director of the Orange County Sanitation District (OCSD; Fountain Valley, Calif.) operations and maintenance and regional services department, attended Pinhey’s presentation and noted that how easily agencies comply has much to do with their past performance.
“I think it depends on the agencies’ past practices in managing their assets properly. Those that are doing a good job — in that they have adequate enterprise funds or dedicated revenue streams — I think they’ll adapt to this very easily,” Arhontes said. “Those that are challenged by not having good maintenance programs and not having good knowledge of their assets will probably struggle with this program.”
OCSD was fortunate, getting a jumpstart in that in 2002 the regional board for North and Central Orange County issued an order to agencies to meet certain waste discharge requirements. So now that the statewide order is in effect, OCSD can focus on revamping some aspects of their system. “We’re doing very well. We’re using [the state ordered plan] as an opportunity to refresh,” Arhontes said.
On the Same Page
To roll out the SWCRB program, an SSO Guidance Committee was formed, comprised of SWRCB staff, industry representatives, and staff from nongovernmental organizations. The committee established the Waste Discharge Requirement (WDR), which created the basic requirements for all agencies to meet. The WDR was set up with the knowledge that SSOs are preventable, and that with guidelines in place to enforce systemwide operation, maintenance, and management plans, SSOs in California could be reduced.
Pinhey listed the program requirements:
- All public-operated sewer collection systems must apply for coverage under the WDR.
- All covered collection systems must report SSOs online.
- All covered collection systems must develop a SSMP.
The WDR also includes time frames for SSO reporting based on the category of overflow. A Category 1 SSO would need to be reported as soon as possible, but no more than 3 business days from the date of occurrence. A final certified report on Category 1 SSOs must be completed within 15 days of conclusion of response and remediation. Category 2 SSOs must be reported within 30 days of the end of the month in which the SSO occurred. Private lateral SSOs may be reported at the enrollee’s discretion, and a zero occurrence of SSOs also must be reported within 30 days of the month’s end.
“You report no matter what,” Pinhey said. He noted that online reporting also makes public access to SSO information easier. “We’re in a greater fish bowl than we were” prior to online reporting, he said.
Arhontes noted the importance of standardizing reporting. “Consistent notification allows the local stakeholders, including health care agencies and the public, to be aware of potential problems,” he said. “Reporting allows data to be collected and gathered in order to understand the issue and the magnitude of sewer spills — whether they are from publicly operated systems or private property.”
To get all agencies to report these SSOs in the appropriate time frame, CWEA and SWRCB reached out to them with training.
Pinhey explained that training on reporting SSOs to a state database and meeting the regulations under the SSMP is provided to all regions through the state and member association partnership. Previously, each region was handling implementing and reporting requirements for SSOs slightly differently, explained Pinhey. The program will put the entire state on a single database for reporting.
The consistent reporting of SSOs is important to know “what’s really happening out there,” Pinhey said. In June 2007, the online reporting system went live.
Partners in SSOs
By partnering with California, CWEA was able to make some adjustments that benefited agencies throughout the state.
“CWEA’s work with the state to help with outreach and training — just to help spread the word on this order — was very important,” Arhontes said. “What this allowed the state to do was to leverage CWEA’s members in order to help spread the word faster.”
Together, CWEA and SWRCB formed a memorandum of agreement (MOA), which Arhontes described as “a very simple but precedent-setting agreement.” Both the state and the member association had deliverables to produce under the MOA. For example, CWEA had to develop and execute a work plan to meet training objectives and offer periodic training at conferences. They also had to develop a training manual, create an evaluation tool, and provide feedback to the state, among other things. The state, on the other hand, had to review the training materials CWEA created and provide timely feedback, post CWEA training announcements online, and provide access to an online reporting database simulation.
The MOA, Arhontes said, is a document from which other member associations could benefit. “Other member agencies could better work with their regulators on forming alliances” based on the CWEA–SWRCB partnership, he said.
Pinhey noted that there were additional benefits to the state and member association working together. “First, we were able to get the schedule for the implementation of the WDR lengthened,” he explained. “Essentially, the compliance deadlines were moved out to more reasonable time frames. Second, we were able to get the state to agree that the proper training needed to be conducted prior to implementation. Basically, give agencies the [training] tools and the time to implement the requirements to help ensure success.”
— Meghan H. Oliver, WE&T