Monthly Archives: December 2013

A Pilot Study for Retrospective Evaluation of Cured-in-Place Pipe (CIPP) Rehabilitation of Municipal Gravity Sewers

Pipe rehabilitation and trenchless pipe replacement technologies have seen a steadily increasing use over the past 30 to 40 years. Despite the massive public investment in the rehabilitation of the US water and wastewater infrastructure, there has been little formal and quantitative evaluation of whether rehabilitation technologies are performing as expected and whether rehabilitation is indeed cost-effective compared to replacement. This paper describes the results of a pilot project for the retrospective evaluation of cured-in-place pipe (CIPP) liners. The pilot testing used CIPP samples from both large and small diameter sewers in two cities: Denver, CO and Columbus, OH. Testing on the liners included: thickness, annular gap, ovality, density, specific gravity, porosity, flexural strength, flexural modulus, tensile strength, tensile modulus, surface hardness, glass transition temperature, and Raman spectroscopy. In addition, environmental data was gathered as appropriate to each retrieval process including: external soil conditions and pH, and internal waste stream pH. Summaries of the test results and a discussion of their implications for CIPP performance are provided in this paper. All of the samples retrieved from the four locations involved in the pilot study testing were in excellent condition after being in use for 25 years, 23 years, 21 years and 5 years, respectively. Overall, it is concluded that there is no reason to anticipate that the liners evaluated in this pilot study will not last for their intended lifetime of 50 years and perhaps well beyond.

Recommendations following a multi-laboratory comparison of microbial source tracking methods

Microbial source tracking (MST) methods are under development to provide resource managers with tools to identify sources of fecal contamination in water. Some of the most promising methods currently under development were recently evaluated in the Source Identification Protocol Project (SIPP), in which 27 laboratories compared methods for their ability to identify sources of fecal pollution from blinded water samples containing either one or two different fecal pollution sources. This paper details lessons learned from the SIPP study and makes recommendations for research necessary to further advance MST. Results from the SIPP study demonstrate that methods are available that can identify whether particular host sources, including humans, cows and gulls, have contributed to contamination in a body of water. Fecal
source allocation to predict the percent contribution of contamination from various pollution sources proved to be more problematic. Although additional research is needed to field validate and determine the robustness of findings, it is clear that MST can be a useful tool for resource managers tasked with bringing water bodies into compliance with State standards. Furthermore, it is apparent that the field of MST will continue to evolve and improve. Technological advances including high throughput DNA sequence analysis and field deployable detection systems will likely improve our ability to identify and apportion source-associated microbes in water.

Characterization of fecal concentrations in human and other animal sources by physical, culutre-based, and quantitative real-time PCR methods

The characteristics of fecal sources, and the ways in which they are measured, can
profoundly influence the interpretation of which sources are contaminating water. Although
feces from various hosts are known to differ, it is not well understood how those differences compare across fecal types and how differences depend on characterization methods. This study investigated how nine different fecal characterization methods provide different impressions of fecal concentration in water, and how those impressions varied across twelve fecal pollution sources. Fecal sources investigated included chicken, cow, deer, dog, goose, gull, horse, human, pig, pigeon, septage and sewage. A fecal stock was prepared for each source by mixing feces from 6-22 individual samples with artificial freshwater. Fecal concentrations were estimated by physical (wet fecal mass added and total DNA mass extracted), culture-based (E. coli and enterococci by membrane filtration and defined substrate), and quantitative real-time PCR (Bacteroidales, E. coli, and enterococci) characterization methods. The characteristics of each fecal stock and the relationships between physical, culture-based and qPCR-based characteristics
varied within and among different fecal sources. An in silico exercise was performed to assess how different characterization methods can impact identification of the dominant fecal pollution source in a mixed source sample. A comparison of 10:90 mixtures, using enterococci by defined substrate as a benchmark characteristic, predicted a dominant source reversal in 27% of all possible combinations. This potential for disagreement in dominant source identification based on fecal source characterization method implies that, depending on how a fecal source is defined,highly variable impressions of that host?s fecal content as a water contaminant may result.

Enterococcus and Escherichia coli fecal source apportionment with microbial source tracking genetic markers – is it feasible?

Fecal pollution is measured in surface waters using culture-based measurements of
enterococci and Escherichia coli bacteria. Source apportionment of these two fecal
indicator bacteria is an urgent need for prioritizing remediation efforts and quantifying health risks associated with source-specific pathogens. There are a number of quantitative real-time PCR (QPCR) assays that estimate concentrations of host-associated genetic markers; however, their concentrations are not necessarily amenable to source apportionment because the markers may differ in prevalence across sources. Here we mathematically derive and test a method that utilizes the ratios of fecal host-associated genetic markers and culture and molecular measurements of general fecal indicators to apportion enterococci, E. coli, and Bacteroidales. The source contribution is approximately equal to the ratio of the host-associated and the general fecal indicator concentrations in a water sample divided by the ratio in the source material, so long as cross-reactivity is negligible. We illustrate the utility of the ratio method using samples consisting of mixtures of various fecal pollution sources. Although source apportionment works well with these artificial samples, application to aged samples can confound source allocation predictions. In particular, culturable enterococci and E. coli, the organisms presently regulated in the United States and much of the world, decay at different rates compared to host-associated markers and as a result cannot be apportioned using this method. However, limited data from a previous study suggest a similar decay rate between host-associated and QPCR-measured Enterococcus, E. coli and Bacteroidales genetic markers suggesting that apportionment may be possible for these organisms, however further work is needed to confirm.

Campbell Recalls 300 Cases of Prego Traditional Italian Sauce Due to a Risk of Spoilage

Campbell Soup Company is voluntarily recalling approximately 300 cases of 24-ounce jars of Prego Traditional Italian sauce because of a risk of spoilage. The affected product was manufactured on December 15, 2013 and can be identified by the Best By date of June 16, 2015 and a four-digit, military time code ranging from CT BJ ZV 0330 through CT BJ ZV 0449.

Comparison of PCR and quantitative real-time PCR methods for the characterization of ruminant and cattle fecal pollution sources

The state of California has mandated the preparation of a guidance document on the application
of fecal source identification methods for recreational water quality management. California
contains the fifth highest population of cattle in the United States, making the inclusion of cow50
associated methods a logical choice. Because the performance of these methods has been shown
to change based on geography and/or local animal feeding practices, laboratory comparisons are
needed to determine which assays are best suited for implementation. We describe the
performance characterization of two end-point PCR assays (CF128 and CF193) and five real
time quantitative PCR (qPCR) assays (Rum2Bac, BacR, BacCow, CowM2, and CowM3)
reported to be associated with either ruminant or cattle feces. Each assay was tested against a
blinded set of 38 reference challenge filters (19 duplicate samples) containing fecal pollution
from 12 different sources suspected to impact water quality. Blinded reference challenge filters
contained either a single fecal source or a mixture of two different sources. Ruminant- and cow
associated genetic markers were detected in all filters containing a cattle fecal source. However,
some assays cross-reacted with non-target animal sources. The abundance of each host
associated genetic marker was measured for qPCR-based assays in both target and non-target
animals and compared to quantities of total DNA mass, weight mass of fecal material, as well as
Bacteroidales, and enterococci determined by 16S rRNA qPCR and culture-based approaches
(enterococci only). Experiments indicate that all assays offer precise estimates of respective
DNA target concentrations, but show differences in specificity and abundance of genetic markers
in non-target fecal pollution sources.

Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study

A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent
comparative testing. Here, we evaluated ten of these methods (BacH, BacHum-UCD, B.
thetaiotaomicron (BtH), BsteriF1, gyrB, HF183 endpoint, HF183 SYBR, HF183 Taqman,
HumM2, and M. smithii nifH (Mnif)) using 64 blind samples prepared in one laboratory. The
blind samples contained either one or two fecal sources from human, wastewater or non-human
sources. The assay results were assessed for presence/absence of the human markers and also
quantitatively while varying the following: 1) classification of samples that were detected but not
quantifiable (DNQ) as positive or negative; 2) reference fecal sample concentration unit of
measure (such as culturable indicator bacteria, wet mass, total DNA, etc); and 3) human fecal
source type (stool, sewage or septage). Assay performance using presence/absence results was
found to depend on the classification of DNQ samples. The assays that performed best
quantitatively varied based on the fecal concentration unit of measure and laboratory protocol.
All methods were consistently more sensitive to human stools compared to sewage or septage in
both the presence/absence and quantitative analysis. Overall, HF183 Taqman was found to be the
most effective marker of human fecal contamination in this California-based study.

Performance of forty-one microbial source tracking methods: A twenty-seven lab evaluation study

The last decade has seen development of numerous new microbial source tracking (MST)
methodologies, but many of these have been tested in just a few laboratories with a
limited number of fecal samples. This method evaluation study examined the specificity and sensitivity of 43 MST methodologies by analyzing data generated in 27 laboratories. MST methodologies that targeted human, cow, ruminant, dog, gull, pig, horse, and sheep were tested against sewage, septage, human, cow, dog, deer, pig, chicken, pigeon, gull, horse, and goose fecal samples. Each laboratory received 64 blind samples containing a single source (singletons) or two sources (doubletons), as well as diluted singleton samples to assess method sensitivity. Laboratories utilized their own protocols when performing the methods and data were deposited in a central database before samples were unblinded. Between one and seven laboratories tested each method. The most sensitive and specific assays, based on an analysis of presence/absence of each marker in target and non-target fecal samples, were HF183 endpoint and HF183 SYBR (human), CF193 and Rum2Bac (ruminant), CowM2 and CowM3 (cow), BacCan (dog), Gull2SYBR and LeeSeaGull (gull), PF163 and pigmtDNA (pig), HoF597 (horse), PhyloChip (pig, horse, chicken, deer), Universal 16S TRFLP (deer), and Bacteroidales 16S TRFLP (pig, horse, chicken, deer); all had sensitivity and specificity higher than 80% in all or the majority of laboratories. When the abundance of MST markers in target and non-target fecal samples was examined, some assays that performed well in the binary analysis were found to not be sensitive enough as median concentrations fell below a minimum abundance criterion (set at 50 copies per colony forming units of enterococci) in target fecal samples. Similarly, some assays that cross-reacted with nontarget fecal sources in the binary analysis were found to be acceptable in a quantitative analysis because the cross-reaction occurred at very low levels. Based on a quantitative analysis, the best performing methods were HF183Taqman and BacH (human), Rum2Bac and BacR (ruminant), LeeSeaGull (gull), and Pig2Bac (pig); no cow or dogspecific assay met the quantitative specificity and sensitivity criteria. While this study evaluated the marker performance in defined samples, further field testing as well as development of frameworks for fecal source allocation and risk assessment are needed.

Establishment and Early Succession of Bacterial Communities in Monochloramine-Treated Drinking Water Biofilms

Monochloramine is increasingly used as a drinking water disinfectant because it forms lower levels of regulated disinfection by-products. While its use has been shown to increase nitrifying bacteria, little is known about the bacterial succession within biofilms in monochloramine-treated systems. The microbial composition of biofilm and drinking water was examined by analyzing 16S rRNA gene clone libraries generated from a pipe-loop over a period of eight months. No significant differences in community structure were observed between biofilm capturing devices or coupon material used. However, differences in community structure were evident when samples were grouped by month, suggesting that all biofilm communities that developed on different devices underwent similar successions over time. Early stages of biofilm formation were dominated by Serratia (29%), Cloacibacterium (23%), Diaphorobacter (16%), and Pseudomonas (7%), while Mycobacterium-like phylotypes were the most predominant populations (>27%) in subsequent months. The Mycobacterium-like sequences identified were closely related to members of the nontuberculous mycobacteria, often isolated from potable water supplies, of which some have been implicated in outbreaks targeting individuals with predisposing conditions. In addition, planktonic communities appeared to share different distribution of members compared to biofilms. Overall, 90% of the diversity in all the clone library samples was associated with the phyla Proteobacteria, Actinobacteria and Bacteroidetes. These results are consistent with the view that monochloramine-treated drinking water provides favorable conditions for mycobacteria and other potential opportunistic pathogens (e.g. P. aeruginosa), which may be encouraged by the development of nitrifiers and other community members.

Presidential Proclamation: National Slavery and Human Trafficking Prevention Month 2014

Over a century and a half after President Abraham Lincoln issued the Emancipation Proclamation, millions remain in bondage — children forced to take part in armed conflict or sold to brothels by their destitute families, men and women who toil for little or no pay, who are threatened and beaten if they try to escape. Slavery tears at our social fabric, fuels violence and organized crime, and debases our common humanity. During National Slavery and Human Trafficking Prevention Month, we renew our commitment to ending this scourge in all its forms.

Because modern-day slavery is a global tragedy, combating it requires international action. The United States is shining a spotlight on the dark corners where it persists, placing sanctions on some of the worst abusers, giving countries incentives to meet their responsibilities, and partnering with groups that help trafficking victims escape from their abusers’ grip. We are working with other nations as they step up their own efforts, and we are seeing more countries pass anti-human trafficking laws and improve enforcement.

At home, we are leading by example. My Administration is cracking down on traffickers, charging a record number of perpetrators. We are deploying new technology in the fight against human trafficking, developing the Federal Government’s first-ever strategic action plan to strengthen victim services, and strengthening protections against human trafficking in Federal contracts. During the past year, the White House has hosted events on combating human trafficking, bringing together leaders from every sector of society. Together, we came up with new ideas to fight trafficking at the national and grassroots levels.

As we work to dismantle trafficking networks and help survivors rebuild their lives, we must also address the underlying forces that push so many into bondage. We must develop economies that create legitimate jobs, build a global sense of justice that says no child should ever be exploited, and empower our daughters and sons with the same chances to pursue their dreams. This month, I call on every nation, every community, and every individual to fight human trafficking wherever it exists. Let us declare as one that slavery has no place in our world, and let us finally restore to all people the most basic rights of freedom, dignity, and justice.

NOW, THEREFORE, I, BARACK OBAMA, President of the United States of America, by virtue of the authority vested in me by the Constitution and the laws of the United States, do hereby proclaim January 2014 as National Slavery and Human Trafficking Prevention Month, culminating in the annual celebration of National Freedom Day on February 1. I call upon businesses, national and community organizations, faith-based groups, families, and all Americans to recognize the vital role we can play in ending all forms of slavery and to observe this month with appropriate programs and activities.

IN WITNESS WHEREOF, I have hereunto set my hand this thirty-first day of December, in the year of our Lord two thousand thirteen, and of the Independence of the United States of America the two hundred and thirty-eighth.

– Cross posted from whitehouse.gov

2014 United States Mint America the Beautiful Quarters Proof Set™ Available January 7

WASHINGTON – Sales will open at noon Eastern Time (ET) on January 7 for the 2014 United States Mint America the Beautiful Quarters Proof Set (product code Q5E).  This year's set contains proof versions of quarters with reverse (tails side) designs honoring Great Smoky Mountains National Park (Tennessee), Shenandoah National Park (Virginia), Arches National Park (Utah), Great Sand Dunes National Park (Colorado), and Everglades National Park (Florida).  The obverse (heads side) of each coin features John Flanagan's 1932 portrait of George Washington.