November 2013, Vol. 25, No.11

The incredible growing ‘fatberg’

news You might think that the headline-grabbing discovery of a foul-smelling, 13.6-Mg (15-ton) “fatberg” in a London sewer tunnel this past July might persuade locals to rethink where and how they dispose of their used cooking grease and nonflushable wet wipes. 
But just 6 weeks after an eight-member crew worked day and night to dislodge the bus-sized blob, tons of fresh fat were found oozing from the same sewer, according to a release from Thames Water (Reading, U.K.), the city’s water and wastewater utility.

The original mass, which reduced the tunnel to just 5% of its capacity, was discovered after nearby residents complained of being unable to flush their toilets. Had it remained in place, wastewater was at risk of spurting from manholes throughout the Kingston area of southwest London, according to Gordon Hailwood, waste contracts supervisor for Thames Water. As it was, the sheer weight of the fat in the pipes pushed the old brick sewer down into the soft subsoil, creating the need for major repairs. 

The source of the London fat remains under investigation. “This sewer pipe collects the sewage from across most of Kingston, so it could be coming from anywhere,” Hailwood reported. The only thing officials know for sure is that the latest deposit took place in the weeks following the original discovery.  

How did they know? Old, congealed fat is white, according to Hailwood. But the most recently discovered fat is a “fresher” shade of yellow, he said. 

The most recent discovery is not only adding to the cost of repairs, it also is raising questions about the success of an ongoing media campaign to educate residents and businesses on the dangers of disposing wet wipes and fats, oils, and grease (FOG) into the sewers. Officials have been creative in choosing approaches to draw the public’s attention to the problem, from tabloid newspaper-style press releases that graphically describe the problems associated with flushing nondisperables down the toilet, to a parody music video, “Can’t Flush This,” which was produced and posted on YouTube ( www.youtube.com/watch?v=X-FB46km7bo ) by United Utilities Group (Warrington) the largest water company in the United Kingdom. 

   

Wet wipes and grease: A disastrous combo  

You don’t have to live in London to appreciate the challenge Thames Water now faces. One of the most challenging — and often baffling — part of any sewer operator’s job is dealing with the random things that make their way into a city’s sewer system. Prisoner toothbrushes (they have a telltale extra-short handle), tools used for breaking and entering, toys, jewelry, coins, live animals, false teeth, carpeting — all can wreak havoc with a system’s equipment, costing cities tens of thousands of dollars in added maintenance costs a year.  

But t he problems created by the improper disposal of FOG and one-time-use premoistened wipes are eclipsing them all, many operators said.  

No longer reserved for babies’ bottoms, wipes have gained widespread use by travelers, soldiers, hikers, and others who lack ready access to fresh water or are looking for a convenient way to clean a dirty surface. Specialty wipes have been created for everyone from pet owners to those suffering from hemorrhoids. 

“These wipes are not degradable like toilet paper, and that is the problem,” said Michael Seay, an environmental specialist for the City of Dallas (Texas) Water Utilities. “They foul up pumps and cause blockage in the collection systems, increasing the cost of operations.” Put them in proximity to FOG, and the problems snowball like a congealed lump of lard in a sewer.  

To help change consumer habits, t he National Association of Clean Water Agencies and other groups are working with the fabric industry to adjust the directions on products with the “flushable” label. The Water Environment Federation (Alexandria, Va.) has created a webcast on the topic of nondispersables and devoted a session to the issue at last month’s WEFTEC® conference in Chicago.  

  

Could it happen here?  

The question is, could a titanic fatberg like the one in London form in a sewer tunnel on this side of the Atlantic? 

Yes, said Frank Dick, industrial pretreatment coordinator for the city of Vancouver, Wash. “All of the characteristics of the London sewer where the fatberg resided exist in larger cities in the U.S.,” he said. In addition to FOG and wipes, these include the presence of large, old concrete pipes with “sags” or “bellies,” and cool — approximately 15.5ºC (60ºF) — sewer water.  

“The 15-ton berg is particularly impressive, but many of us have seen what we call ‘grease balls,’” Dick said. 

The key is to locate and remove these grease balls before they have a chance to “mate” with the growing number of wipes in the system, said Nick Arhontes, director of Facilities Support Services for the Orange County Sanitation District (Fountain Valley, Calif.). “If [cities] are doing good condition assessments, and spotting grease and debris build-ups early, they will minimize the potential for a similar problem occurring in their system,” he said.  

The city of Vancouver, British Columbia, went even a step further. To track how wet wipes moved through their system, officials recently had sample wipes dyed in different bright colors to see if they would end in the headworks screens at their treatment plant.  

In case there’s any doubt, yes, they did. It’s like the song says: “Can’t flush this.” 

  

— Mary Bufe, WE&T  

  

Bienvenidos to the green frontier   

The world’s largest algae and wastewater project in Spain is showing positive results    

A 5-year project in Southern Spain, billed as the world’s largest project to convert algae into clean energy using wastewater, is starting to bear fruit of an autotrophic kind. The algae crop is producing “outstanding results,” according to a press release by Aqualia (Madrid), a water company that is helping to fund the project. (The European Union and local government of the town of Chiclana are two of the other five partners providing funding.)  

The “biomass obtained shows a particularly high energy potential relative to its digestibility level, with a methane production capacity of around 200–300 litres of gas per kilogram of biomass processed by anaerobic digestion,” according to the release. “The microalgae also allow the purification of wastewater to a high standard.” 

The project is regarded as the largest of its kind because it will encompass 10 ha of cultivation during its final phase. “In New Mexico, there is a 6-hectare biofuel production site — but this uses artificial fertilizer not waste nutrients,” according to the release. “Various other installations around 10 hectares do exist but use food-based crops.” 

  

Responding to a global need  

Frank Rogalla, director of Innovation and Technology at Aqualia and project coordinator, said his team was well aware that algae need both optimal temperature and sunshine to grow, which is why they chose the southern tip of Spain for the location of the project. They are using municipal wastewater from a water resource recovery facility in Chiclana to grow the crop, Rogalla said. 

“The preliminary work is to define the best source of wastewater (primary, secondary, after anaerobic pretreatment) in order to achieve the highest algae productivity, and the best effluent quality, depending on climatic conditions,” Rogalla said. 

The team has made a few other discoveries through the course of the project, namely how to best optimize the energy balance for pond mixing, carbon dioxide injection, and algae harvesting with dissolved air floatation, Rogalla said. 

The goal is to produce enough biofuel by 2016 to power 200 vehicles, according to the news release. By the time the project reaches this phase, the biogas will be used to power public buses and garbage trucks in the region of Cadiz. 

This goal falls in line with the European Union (EU) goal for all EU countries to use 10% biofuels in transportation, Rogalla said. He also noted EU’s parallel goal that “calls for the 20% cut in greenhouse gas emissions compared to the 1990 levels by 2020, a 20% increase in the use of renewable energy by 2020, and a 20% cut in energy consumption through improved energy efficiency by 2020.”  

Rogalla said that after 2 years of preliminary experiments with six 32-m2 areas of cultures, “we are now building the next step, which is a prototype of [two 500-m2 areas] or a total of 10,000 ft2 of culture, including the whole value chain to transform wastewater into bioenergy via algae digestion and biogas production.” He said that once “the prototype phase has confirmed the main design parameters, we will launch the ultimate demo phase to reach the goal, a 10-ha [25-ac] algae farm fed by around 5000 m3/d [1.3 mgd] of wastewater.” 

  

— LaShell Stratton-Childers, WE&T  

  

Preventing an epidemic  

Researchers use wastewater to find the source of diseases and try to prevent the spread of the disease 

For years, scientists have been analyzing microconstituents in wastewater to get a better understanding of the behaviors of a population, specifically drug use rates. Some argue that conducting this research serves an important purpose socially. 

“Estimating the scale of community drug use is important in assessing the needs for law enforcement, public health, and education,” said Kevin Thomas, research manager of ecotoxicology and risk assessment at NIVA in Oslo, Norway.  

Thomas and his team tested in 2010 for the presence of different biomarkers in wastewater from a few Norwegian water resource recovery facilities to analyze the use of cocaine, amphetamines, and MDMA (ecstasy) in surrounding cities. They were able to determine trends in usage both regionally and monthly.  

Now researchers have taken the next step and are using wastewater to serve an even larger social purpose. They are using effluent to detect the presence of diseases in a population and try to thwart future outbreaks and epidemics. Though Israel hasn’t experienced a case of polio since 1988, the World Health Organization (WHO; Geneva) detected the presence of the polio virus in wastewater samples in the country. This led Israel to step up vaccinations to prevent an outbreak. Meanwhile, a report released in August by researchers at the Yale Law School and the Yale School of Public Health (New Haven, Conn.) alleges that United Nations (U.N.) peacekeeping forces caused the deadly cholera outbreak in Haiti after the devastating earthquake on the Caribbean island in 2010. This bacterium entered the local water supply due to inadequate water and sanitation facilities at a U.N. base, the report states.  

  

Using wastewater to try to stymie an outbreak  

Between February and August, WHO detected the same strain of the polio virus in 67 wastewater samples taken from 24 sampling sites in Israel. The wild poliovirus type 1 (WPV1) also had been isolated “in stool samples from 27 healthy children (all under the age of nine years) and one adult, who had been fully immunized for their age as part of ongoing stool sample survey activities,” according to a WHO Aug. 15 news release. “In addition to routine acute flaccid paralysis, public health authorities have expanded the surveillance to all age groups and have increased enterovirus surveillance and are screening aseptic meningitis cases for polio,” according to the release. 

The virus initially was detected only in Southern Israel. To try to prevent its expansion, Israel’s Ministry of Health increased efforts to inoculate children in the southern part of the country with another weakened live polio vaccine. Across Israel, the vaccination rate against polio is 94%, according to WHO. The country also had plans to start a nationwide inoculation campaign in August. 

Unfortunately, these efforts to prevent the spread of the virus outside of the southern region have not been successful. Although no actual cases of paralytic polio have been reported, WPV1 also had been detected in the central district as of August. And though in June WHO initially had assessed the risk of further international spread of the virus strain from Israel as “low to moderate,” by August, the risk had been increased to “moderate to high.” WHO explained in the news release that this “risk assessment reflects evidence of increasing geographic extent of circulation over a prolonged period of time.” 

  

Trying to find the source and access accountability  

In the report, “Peacekeeping without Accountability,” researchers allege that the U.N. bears responsibility for the cholera outbreak in Haiti that has killed more than 8000 people and sickened more than 600,000, according to a Yale Law School Aug. 6 news release. According to the report, U.N. peacekeeping troops inadvertently carried the disease from Nepal to the Haitian town of Méyè. In October 2010, the U.N. deployed these peacekeeping troops to join the MINUSTAH in Haiti to help with earthquake relief efforts. Peacekeepers from Nepal, where cholera is endemic, arrived in Haiti shortly after a major outbreak of the disease occurred in their home country.  

The Méyè base, which was about 40 km from Port-au-Prince, was just a few meters from a tributary of the Artibonite River, “the largest river in Haiti and one [of] the country’s main sources of water for drinking, cooking, and bathing,” according to the report. Sanitation infrastructure at the base was “haphazardly constructed, and as a result, sewage from the base contaminated the nearby tributary,” the report states. “Less than a month after the arrival of the U.N. troops from Nepal, the Haitian Ministry of Public Health reported the first cases of cholera just downstream from the MINUSTAH camp.” 

The report alleges that “cholera spread as Haitians drank contaminated water and ate contaminated food; the country’s already weak and over-burdened sanitary system only exacerbated transmission of the disease among Haitians. In less than two weeks after the initial cases were reported, cholera had already spread throughout central Haiti.” 

The Yale researchers were able to establish several key findings that they say prove the MINUSTAH peacekeeping troops introduced cholera into the country. One of those findings was that “the troops at the MINUSTAH base were exposed to cholera in Nepal, and their feces contaminated the water supply near the base,” according to the report. Also, the outbreak in Haiti is traceable to a single South Asian cholera strain from Nepal. “No compelling alternative hypothesis of the epidemic’s origins has been proposed,” the report states. 

Because the Yale researchers believe the U.N. is the cause of this outbreak, they also believe it is the U.N.’s “legal and moral obligations to remedy this harm,” according to the Aug. 6 news release.  

“While the U.N. has played an important role in the Haitian post-earthquake recovery effort, it has also caused great harm to hundreds of thousands of Haitians,” said Tassity Johnson, a student at Yale Law School and one of the authors of the report, in the news release. “The U.N.’s ongoing unwillingness to hold itself accountable to victims violates its obligations under international law. Moreover, in failing to lead by example, the U.N. undercuts its very mission of promoting the rule of law, protecting human rights, and assisting in the further development of Haiti.” 

  

— LaShell Stratton-Childers , WE&T  

  

  

 Analytical instrumentation set for growth   

Automated instruments can help streamline operations and save on labor costs, but skilled operators still will be needed 

According to a recent report from Frost & Sullivan (Mountain View, Calif.), the U.S. water and wastewater analytical instrumentation market is projected to experience steady growth in the years to come, reaching $330.7 million in 2018, up from $275.3 million in 2012, driven mainly by a need to increase operational efficiency. Continuous analytical instruments increasingly will replace laboratory instruments due to their reliability, the report found, with many larger facilities investing in these instruments as a way to increase analytical efficiency while also reducing operational costs.  

Since the economic downturn, municipalities facing budgetary restrictions have become increasingly interested in adopting strategies that work to enhance or improve operational efficiency and maximize staffing without having to hire more personnel, said Eric Meliton, an energy and environmental industry analyst with Frost & Sullivan. 

“By adopting advanced analytical instruments, utilities can eliminate many of the redundancies associated with laboratory instruments and actually do more work while using less people, cutting labor costs without impacting the testing and monitoring that is required for compliance,” said Meliton. “Long-term, facilities that incorporate continuous automated instrumentation will be able to capture more data and subsequently utilize that data faster, all of which contribute to greater efficiency.” 

The adoption of analytical instrumentation in the water and wastewater sectors represents how some utilities are embracing higher levels of technology and adapting to a landscape that is fast-changing, Meliton said. “This trend is similar to what has taken place in the energy sector, with advanced monitoring and smart grid technology, which has helped greatly improve efficiency, especially on the labor and staffing side,” he said.  

And with advanced instruments coming into this sector, the role of the operator is likely to change, Meliton said, creating more demand for operators and technicians who are comfortable with today’s new technologies.  

  

Operator training is essential  

Analytical instrumentation, while promising in terms of being more cost-effective in the long-term, also carries implications for the municipal workforce — particularly for operators and staff charged with managing instruments. 

It is important for operators to view advances in instrumentation as an opportunity to become educated in the trends taking shape, said Christine Radke, a program manager at the Water Environment Federation (Alexandria, Va.) specializing in operator matters such as training and certification. 

“Despite the growth in instruments that offer greater automation, facilities still will need to rely on properly trained operators and staff who understand the mechanics and use of these tools,” Radke said. “Analytical instruments might be easier and more straightforward in use, but operators also still have to know how to read and work with the data to help optimize operations.” 

The utility of the future will not only be optimized in terms of instrumentation technology, but also in regard to its operators, staff, and personnel, according to Radke.  

Paula Zeller, a senior operator at the Orange County Sanitation District (Fountain Valley, Calif.) said analytical instruments are helpful in terms of increasing efficiency and systemizing tasks, but highly trained operators still will be essential — especially if instruments fail and manual control needs to be taken.  

“In this sense, operators will still be heavily relied on to provide oversight management. They must be capable of making changes or important decisions based on key information,” she said.  

Operators also will play an important role in communicating the different parameters associated with the technology, Zeller said. “Instruments are programmed to simplify tasks and make processes more efficient, but many times the problems that arise require solutions based on human reasoning.”  

  

Optimizing a monitoring system   

While investments in automated analytical instruments that help streamline operations represent one strategy for managing budgetary decreases, another approach recently developed by a U.S. Geological Survey (USGS; Reston, Va.) hydrologist offers potential for addressing cutbacks in spending by enhancing the overall efficiency of an existing network.  

According to research by Jason Fisher with the USGS’s Idaho National Laboratory project office, budget constraints in water resource management agencies often lead to a reduction in the number of wells in a monitoring network. Fisher’s management tool works to determine which wells in a monitoring network add little or no beneficial information and can thus be removed with the least effect to the characterization of the system.  

Fisher studied two water-level monitoring networks within the Eastern Snake River Plain aquifer, developing an algorithm for optimizing an existing monitoring network using an interpolation method to map the water table. By comparing water-table maps based on measurements from the existing and reduced networks, he was able to identify sites giving out redundant data.  

“The goal was to be able to maintain the same level of information with less data, increasing the accuracy of the network, and freeing up money that could be put to use in a different part of the study, making it more robust,” he said. “But if water managers are forced to remove wells from a network, then hopefully they can use this information to make the best decisions possible.”  

Although developed for a groundwater water-level monitoring network, Fisher said the management tool could be applied to most networks using environmental sensors or analytical instruments as long as a spatial component also is present.  

Next, Fisher aims to adapt the management tool to water quality monitoring networks. “And, if the algorithm can be tweaked to better handle temporal data, then the information that could be collected would be the same as in a wastewater treatment plant,” he said.  

  

Jeff Gunderson, WE&T