August 2022 - Sally Brown Research Library & Commentary

Provided for consideration to MABA members by Sally Brown, PhD., University of Washington
Travel Season
Summer time and summer vacations are back. The Omicron delta 5 variant aside, many of us are raring to hit the road. That may mean long days in the park, a drive to the coast, or even a trip on a plane. Whatever a summer vacation means to you it will likely involve using a toilet far from home. Summer also means light reading material. The beach book or its equivalent is typically a hot romance novel or perhaps a gripping who done it?

For this crowd however, light summer reading is focused on toilet seats. We are away from home, on the road and unless there is a convenient bush in site, quite likely forced to take advantage of public restrooms.
Is that toilet seat safe?
At home in the privacy of your own privy, the germs that may inhabit the bathroom are those that you share with your loved ones. Known germs don’t keep you up at night. In the great wide world however, you are sharing that seat with who knows how many people and how many pathogens. It just isn’t possible to keep your legs crossed for an entire trans- Atlantic flight or a 7 hour car ride. Let’s turn to the experts to see just how hazardous public restrooms are. Perhaps the first and foremost expert on the topic is Chuck Gerba, a colleague of Ian Pepper and a professor at the University of Arizona. He is a co-author of the first article in the library: Toilet hygiene—review and research needs.
This paper confirms your darkest fears- the threat is real! The paper focuses on whether cleaning toilets is an effective means to control the spread of pathogens. It is- a clean toilet is a safe toilet. However, in those public restrooms you don’t know how often or how well they’ve been cleaned. The primary pathway that pathogens travel in the bathroom is during the flush.
If you hang around during the flush aerosols can be inhaled. They can also land on surfaces in the restroom. The paper details the presence and concentration of different pathogens in poop. It notes that diarrhea can be highly effective at spreading pathogens. The authors also note presence of certain pathogens in pee. While many of these die off quickly on dry surfaces Salmonella (9 days), Escherichia coli (8 days) and Shigella (5 days) can persist on toilet seats and other surfaces. The authors report on a case of norovirus outbreak on a plane that infected people sitting near the bathroom. More examples are provided. These pathogens tend to lurk in the biofilm in the toilet bowl just below the water line. Flushing is not enough to make these critters go away. Experiments where toilets were seeded with pathogens show persistence over time. Cleaning can help but it can also contaminate the cleaning utensil. Beware the toilet brush! Continuous release cleaning products are your best option. Look for that blue toilet bowl water.

The next paper in the library Microbial Biogeography of Public Restroom Surfaces offers the equivalent of a travel guide to what you’ll find in public restrooms. Think of this as a TripAdvisor for the bathroom.

The authors sampled 10 surfaces in each of 12 public restrooms all at the University of Colorado at Boulder. They used DNA sequencing to see what was where. They found a wide variety of organisms. Some lived on or near the toilet, others on the floor and others on surfaces touched by hands (think flush lever and sink). The gut associated taxa- those likely to give you stomach trouble- were most commonly found in the area in and around toilets. Women’s rooms had their own special set of organisms, derived from vaginal secretions. The floors had the most diverse grouping of organisms, many derived from soil. If only bacteria could talk, the tales they would tell….
From here we focus on the toilet seat. First taking you away from stomach ailments to flesh eating bacteria. Article #3: Are toilet seats a vector for transmission of methicillin-resistant Staphylococcus aureus? looks at the potential for MRSA transmission from toilet seats. The authors tested toilet seats in a children’s cancer hospital for the presence of MRSA, an antibiotic resistant bacteria that effectively eats your flesh. This bacteria was found in 3% of the toilet seats sampled. Good news is that wiping down the seat with alcohol was sufficient to get rid of the bugs. A 50 fold reduction was seen with appropriate wipe down. Take home from this is to use those toilet seat covers when available and/ or wipes before you sit on a public throne.
Next we focus on the flush. Article #4: Potential for aerosolization of Clostridium difficile after flushing toilets: the role of toilet lids in reducing environmental contamination risk tested the persistence and spread of C. diff after flushing with and without the lid down. The authors tested spiked toilets with two types of toilet seats. The flush is a powerful thing and it sent C. diff almost a foot into the air. Concentrations decreased by 8x within 60 minutes and continued to decline over time. Put the lid down and the droplets crash land on the lid. Take off is aborted. This tells you to avoid the stalls where the flush is fresh.

Our last article takes us to the air. In Metagenomic analysis of viruses in toilet waste from long distance flights—A new procedure for global infectious disease surveillance, the authors report findings from an analysis of toilet water from 19 international flights. The focus was on viral loads. Remember that Covid is a virus. It turns out that Covid is just one of many. The authors found that different regions, even different cities, have their own special viral signature. Fly from SE Asia if you want the best airline food and the highest viral species richness. If you are looking for rotaviruses, make sure you depart from Islamabad. The point here is to make sure you put the seat down when you flush on a plane. Donning your mask may also be prudent both inside and out of the airplane loo.

To sum up here- have a wonderful summer vacation. Enjoy a trip if you have one planned. While this library has highlighted the hazards- remember that public toilets are a wonderful thing and only rarely a cause for concern. If this has gotten you worried, wipe the seat and close the lid. I would bet that you still have plenty of masks around. Between public toilets and Delta 5- it might not be a bad idea to use them now and again.
Sally Brown is a is a Research Associate Professor at the University of Washington, and she is also a columnist and editorial board member for BioCycle magazine.
Do you have information or research to share with MABA members? Looking for other research focus or ideas?
Contact Mary Firestone at [email protected] or 845-901-7905. |
SPOTLIGHT on COMPOST
Composting is an enduring process for transforming biosolids into a Class A EQ product. Compost facilities in the mid-Atlantic region span a full array of sizes, technologies, and ownership models. The region has facilities located both at small water reclamation plants and at large treatment plants. It has windrow systems, enclosed static pile, and in-vessel agitated beds. Composting is done with various amendments -- purchased wood chips, yard debris, and organic matter recovered from solid waste. The region has various ownerships -- municipally-owned and operated composting, municipally-owned and contract-operated, and privately-owned merchant facilities. The common element to all of this variety is a product that is has a firm place in the landscape market for use in residential and commercial landscaping, as a component in soil blending, and as a specialty amendment for agriculture. Biosolids compost is a well-tested and well-accepted soil product. What is more, at least two more biosolids composting facilities are in permitting within the region. Below are several of the branded biosolids compost products made by MABA members
McGill SoilBuilder Premium Compost
 For more than 30 years, McGill Environmental Systems has designed, built, and operated state-of-the-art indoor facilities for industrial-scale production of McGill SoilBuilder Premium Compost. It manufactures this premium compost product through the processing and recycling of non-hazardous, biodegradable by-products and residuals from municipal, industrial, and agribusiness sources. The McGill Regional Composting Facility at Waverly (McGill-Waverly) opened in 2008. It is in Sussex County, Virginia, near the town of Waverly. Its primary service area includes the coastal mid-Atlantic region. This encompasses the District of Columbia south through Richmond-Tidewater to northeastern North Carolina. McGill-Waverly accepts all types of biodegradable materials including food waste and compostable plastics. It is designed to receive and process source-separated wastes transported in roll-off containers, tractor-trailer rigs, and other commercial vehicles that can safely tip into the receiving bunker. Located on a former timber tract, the operation processes in both banked and encapsulated bays with aerated curing. Aerated curing eliminates the need for windrow turners at this facility.
For more information, contact Sean Fallon, Business Development Manager, [email protected], 919-406-4270. The Waverly facility is located at 5056 Beef Steak Rd, Waverly, VA 23890.
WeCare Compost
WeCare Denali, a division of Denali Water Technologies, operates 24 composting facilities around the United States, two of which are county-owned biosolids composting plants. The Burlington Biosolids Composting Facility is a 300 ton per day capacity composting facility in Columbus, NJ, owned by Burlington County, but operated by WeCare Denali, serving about 20 agencies in the county and beyond. It is the largest biosolids facility in New Jersey under contract operations. The Rockland Green Co-Composting Facility, owned by the Rockland County Solid Waste Authority, recycles biosolids from wastewater plants in Rockland County, NY. At both plants, biosolids are mixed with clean wood waste and then composted in in-vessel agitated bed composting systems. The finished product is used on golf courses, flower gardens, and landscaping projects, and are also ingredients in topsoil This plant is adjacent to the Authority's Materials Recovery Facility and Transfer Station in Hillburn, NY. WeCare Denali markets a suite of WeCare Compost products under its WeCare Compost, Mulch, & Soil line.
For more information, contact national sales manager, Ryan J. Cerrato, [email protected], 315-575-4595. The Burlington facility address is 800 Coc-co Lane, PO Box 318, Columbus, NJ 08022. The Rockland facility is 1988420 Torne Valley Road, Hillburn, NY 10931.
ORGRO High Organic Compost
ORGRO is a product of the Baltimore City Compost Facility, a facility owned and operated by Veolia, under contract with the city of Baltimore Department of Public Works. This facility, which was first built in 1984, processes a 45 dry ton per day portion of the anaerobically digested biosolids from the Back River Wastewater Treatment Plant, the balance made into a thermally dried product. The compost plant produces about 35,000 cubic yards of compost in through in vessel composting and extended curing. This facility is one of the original national examples of a public-private partnership, and one of the original programs for commercial marketing of biosolids to commercial landscapers.
For more information, contact Tom Fantom, project manager, [email protected], 410-354-1636. The facility address is 5800 Quarantine Road, Baltimore, MD, 21266.
Landscaper’s Advantage
Landscaper’s Advantage is the product of the A&M Compost Facility, a large enclosed static pile composting plant owned and operated in Manheim, Pennsylvania by the J.P. Mascaro company. It is a merchant plant, accepting biosolids from a wide reach of plants in the mid-Atlantic. The facility is nearly 15 acres under roof. Its website offers a “ virtual tour” slide deck describing the components of its operation and its environmental controls, which includes under one cover both aerated composting and biofiltration. A&M is managed by a registered professional engineer, Ryan Inch, PE, and a compost specialist, Mark Hubbard.
For more information, contact Matt Mascaro, [email protected], 267-228-5288. The facility is located at 2022 Mountain Rd, Manheim, PA 17545.
earthlife Compost
 The Hawk Ridge Composting Facility, New England’s largest compost facility, is owned and operated by Casella Organics, a MABA Board member This facility uses an in-vessel tunnel system (the Gicom Tunnel) to compost a blend of biosolids with woodchips and sawdust, producing a screened compost with the tradename earthlIfe. Recently, Hawk Ridge reached the distinction of delivering its one-millionth cubic yard of compost. Its wholesale customers include golf courses, nurseries, garden centers, and athletic facilities.
For more information, contact John Leslie, [email protected], 207-461-1000. The facility is located at 3 Reynolds Road, Unity, ME 04988. |
|
Important Update for MABA Members: Results from the 2nd National Survey of Biosolids Regulation, Quality, End Use and Disposal in the U.S.

The National Biosolids Data Project (NBDP) has been recently unveiled. You are invited to its comprehensive, user-friendly, data-rich website: http://biosolidsdata.org. This website provides both a national overview of biosolids generation and utilization/disposal in the target year 2018, but, importantly and most usefully for practitioners in the mid-Atlantic region, the NBDP also includes state summary reports. Your MABA staff and volunteers are assembling a webpage which will allow quick access to the state reports in our region.
This NBDP data site was prepared over a two-year period. It was accomplished on a shoe-string budget of about $60,000, with a small EPA grant and some financial contributions from WEF, NACWA and public agencies, and with many hours of volunteer time. The focus is comprehensive, with details on technologies, particularly the distinction of Class A and Class B levels of pathogen treatment, with categories of utilization outlets and products (compost versus pellets), with capture of landfill and incineration disposal, and with an overview of each state’s regulations.
A key feature of the project was the survey of water resource recovery facilities (WRRFs), generators of biosolids. The survey had 452 valid and representative responses from WRRFs in 43 states and DC. This is a set that comprises a flow of about 12,000 MGD, or 34% of total municipal effluent flows in the United States. When generously supplied by public agencies, surveys provided in addition to mass of biosolids and uses, information on pollutant concentrations, program costs and points of view on hurdles and barriers. In a few cases, the surveys of state officials were able to elicit information on septage management. The EPA biosolids records for 2018 in ECHO (Enforcement and Compliance History Online) was also brought into the analysis.
Every effort was made to provide comparable data across all states, but this goal was elusive. In the end, the data reports of 32 states were judged of high confidence, 12 were of moderate confidence and 4 of low confidence. Every state office responsible for biosolids management was afforded an opportunity to review and correct its state’s data and description.
While this richly compiled database might clearly have commercial value, the results are freely available and are intended to aid in the transparency of biosolids programs to the public.
Ned Beecher, for 20 years executive director of NEBRA and then special projects coordinator for the early PFAS response, is the principal investigator for this “second” survey. He was the principal designer of the two surveys (one for state officials and the other for public agencies) and of the database, though with much feedback along the way, Ned had been also the leader of the first survey, which was released fifteen years ago, July 2007, based on biosolids generation and use in 2004, which explains in part the ambitious goals of the current survey.
Many biosolids practitioners over the years had come to rely on this first survey. It was clear to all who used it recently that the first survey had become dated. Ned took on this herculean project, and now with its completion, we can give hearty kudos to Ned for his vision and persistence. Today you will note from Ned’s email communications that he is now the “former” special project manager for NEBRA and available for hire. But updates to the second survey, whether to correct or amplify it, or to change it to reflect new developments, will need to be shouldered by others, and we await these folks to emerge and step forward.
The survey year of 2018 may have the feel of “historical” today. But, at the opening of the project in mid-2020, this was the year most likely to be complete in its data set from federal, state, and municipal sources. The project was intended to be completed by Spring 2021, but whether a victim of pandemic staffing challenges or from competing issues for biosolids practitioners, data collection for this new survey was a slog. In the mid-Atlantic region, the year 2018 had an atypical influence of large rainfall volumes, and in the Northeast region the discovery of perfluoroalkyl substances disrupted programs.
Here is the big reveal! Total biosolids used or disposed of in the U. S. in 2018 was 5,823,000 dry metric tons (dmt). This compares to 6,132,000 dmt reported in the 2004 survey. This decline in total biosolids was a surprise to the NBDP team. The decline may reflect less double counting than in 2004 of solids hauled from small to larger plants for treatment, or in some locations it may reflect a shift from alkaline stabilization to digestion, the latter technology reducing total dry solids. The 2018 database involved fewer estimations, particularly of biosolids production at small WRRFs. With the estimation in this second survey of the sewered population served, the total national average per capita production of biosolids annually is 37 pounds. That agencies and states show a wide range around this average suggests other aspects at play, perhaps the proportion of combined sewer systems and the acceptance of septage from unsewered areas.
Here is the second big reveal. Fifty-three percent of biosolids produced in the United States in 2018 were beneficially used. Within this number are some important findings. More Class A EQ biosolids are being produced in 2018 than in 2004. Despite policies for organics diversion from municipal waste landfills in some states and regions, the same percentage of biosolids are commingled with municipal waste in 2018 as in 2004. The percentage of biosolids fed to incinerators has declined, with a fewer number of sewage sludge incinerators in operation. The survey showed, too, decreased full time equivalent (FTE) employees regulating biosolids at state and federal agencies. As our industry has asserted in the past, the proportion of our nation's croplands receiving biosolids as a nutrient source is very small, less than 1%.
The Mid Atlantic Biosolids Association participated in the NBDP project. It reviewed electronic record reports to the EPA and state environmental agencies, and also surveyed state officials and larger public agencies. In the work covering the 7 states and one district in this region, the NBPD documented that the over 1,800 significant POTWs serve 50 million “sewered” customers, producing 1.3 million dry tons of biosolids annually. Sixteen WRRFs in the region produce over 10,000 dmt. NYCDEP is largest agency (~100,000 dmt), and in descending order are Philadelphia Water Department, DC Water, Passaic Valley Water Commission, Middlesex County Utility Authority, Baltimore Department of Public Works, ALCOSAN (Allegheny County, PA), Hampton Roads Sanitation District (VA), City of Rochester (NY), DELCORA, Bergen County Utility Authority (NJ), Suffolk County (NY), Arlington County (VA), Nassau County (NY), and Fairfax County (VA). The average per capita annual biosolids production in the MABA region is 54 dry pounds.
The NBDP state reports include narratives describing notable facilities and programs that serve to treat and use biosolids. In the MABA region report are these distinctive points. Composting is a major treatment technology in the region (e.g., Burlington Co, Rockland Co, Baltimore, A&M Composting, Natural Soils, Spotsylvania (VA) and many small facilities). Two new, large compost facilities under development in reach of Philadelphia. DELCORA and ALCOSAN are large utilities with sludge Incinerators; others in NY (Rochester), NJ (ACUA) and VA have upgraded to meet new MACT standards. The US’s principal service companies, Synagro and Denali, have main offices in the MABA region and serve hundreds of agency clients NYC is the sole large facility in the US without a pathway to Class A EQ products. PVSC is the exclusive example of a long-tested Zimpro wet oxidation solids treatment, and this agency accepts solids from dozens of agencies. Co-digestion with high strength organic waste has great reference facilities in the MABA region (Rahway Valley SA, Lehigh County Authority, and Hermitage, PA). Landis Sewerage Authority in Vineland NJ is arguably the “greenest” WRRF, with zero effluent discharge and wholly onsite biosolids use.
The narrative also sets the stage for understanding how Pennsylvania, producer of significant biosolids, is also a destination for biosolids from other states. The nature of Pennsylvania’s “accommodative” regulation of biosolids, and similarly restrictive rules in New Jersey, Delaware, and Maryland, ensures that the transport of biosolids regionally and in the direction of Pennsylvania is a significant part of the story of biosolids management regionally. This role is only indirectly revealed in the NBDP. That is because the survey was structured to discuss for each state the mass of biosolids production and the utilization outlets for those state-generated biosolids.
Though the NBDP is the latest information source available to us biosolids practitioners, in a way it is already outdated. Since the 2018 target year for data collection, pressures on two major categories, landfill disposal and land application, have increased. Important issue areas of PFAS contamination worries, risks of new regulations of soil phosphorus, and the experience of inadequate seasonal storage have underscored the challenges of maintaining farmland for biosolids applications. But landfill owners have tightened access by biosolids generators to municipal landfills. This is not only a challenge to Pennsylvania agencies, but more widely to agencies in adjoining states in the mid-Atlantic, which have been reliant on Pennsylvania destinations.
The other side of this “challenges” coin with biosolids in the MABA region is the opportunities for development of merchant facilities and innovative technologies. These include existing innovative facilities, such as regional composting (A&M Composting, Burlington Co-Composting and Rockland County Composting), thermal hydrolysis combined with mesophilic digestion (DC Water and HRSD), co-digestion plants (e.g., Hermitage Food Waste to Energy Facility) and drying processes (Synagro in Philadelphia and Baltimore). Indeed, the MABA region is a landing place for emerging thermal biosolids solutions, such as pyrolysis (BioForceTech), hydrothermal carbonization (SOMAX Bioenergy ), PA and gasification (EarthCare, EcoRemedy and Aries Clean Energy) -- solutions that seem to be particularly urgent in this time of PFAS.
The National Biosolids Data Project demonstrates that the mid-Atlantic region, responsible for nearly a quarter of the nation’s biosolids generation. It is your foundation for understanding future opportunities for biosolids management. Go use it: http://biosolidsdata.org. And, we who helped to assemble the database also will welcome corrections and updates as you find them worthwhile for keeping the information current and accurate, and you can do so by contacting Mary Firestone at [email protected].
|
|