Triclosan in Biosolids – No Cause for Concern

In recent years, there has been much concern and scrutiny regarding the microconstituents found in biosolids and whether or not they present a human health risk.  Several research projects have focused on one type of microconstituent – antimicrobial compounds.  In particular, many studies have looked at the antimicrobial Triclosan (TCS), a common ingredient in many household and personal care products. TCS is routinely detected in treated biosolids and wastewater effluents.  But what exactly does this mean to human health?  Is it harmful in the amounts found?  Does it get into the food grown on biosolids-amended farm fields?  If so, is that a problem?  Researchers have looked at these issues and concluded that there is a negligible risk to human health in any of these circumstances.

Let’s clear one thing up first: antimicrobials are not the same as antibiotics.  While “all antibiotics are antimicrobials…not all antimicrobials are antibiotics.”[i]  Antibiotics are molecular substances produced by a microorganism.  Antimicrobials, on the other hand, may be natural or synthetic.  They also tend to have a narrow window of effectiveness for specific microorganisms and are thus less likely to cause bacterial resistance with repeated use.

Now, back to the antimicrobial, Triclosan, whose primary use is in antibacterial soaps and washes.  Research focused on TCS has been reported on by the Food and Drug Administration (FDA) and Water Environment Research Foundation (WERF) as well as in several industry journals.[ii]  All reports conclude that there is a minimal risk to humans from TCS in land-applied biosolids or in its presence in crops grown in fields amended with biosolids.  The FDA had first reviewed TCS in 2010 and again in 2013, concentrating only on antibacterial soaps and body washes that are used with water, not hand sanitizers, wipes, or antibacterial soaps used in health care settings.  In both studies, they concluded that the presence of TCS in biosolids was not hazardous to humans, but did warrant further study because it was so prevalent in household products.

A fascinating result of the FDA’s research was the finding that the benefits of using antibacterial soap products are unproven and that “…no evidence that OTC (over the counter) antibacterial soap products are any more effective at preventing illness than washing with plain soap and water.”[iii]  This raises the question of the need for antibacterial soaps and washes for the general public and whether TCS and other antimicrobials are necessary in consumer products at all.  Might it not be more efficacious to launch a public education campaign to discourage the use of antibacterial products while promoting more thorough hand-washing?  A novel thought, indeed!  In this way, less TCS and other microconstituents would find their way into biosolids while the health and well-being of the human race would not be compromised by avoiding antibacterial products.  Sounds like a win-win!

That being said, because of this particular antimicrobial’s ubiquitous nature in products worldwide and its inefficient removal during wastewater treatment, some researchers have recommended that TCS be placed on the priority list of emerging microconstituent contaminants and its use in products regulated.[iv]

In other words…keep an eye on it.

________________________________________________________________________________________________  [i] “Antimicrobials: An Introduction” Antimicrobial Resistance Learning Site for Veterinary Students. Michigan State University, East Lansing, MI. 2011.
[ii] Versylcke, T; Mayfield, D. B; Tabony, J. A; Capdevielle, M; Slezak, B. “Human health risk assessment of triclosan in land-applied biosolids.” Environmental Toxicology and Chemistry. 14 January 2016.
[iii] Versylcke, T; Mayfield, D. B; Tabony, J. A; Capdevielle, M; Slezak, B. “Human health risk assessment of triclosan in land-applied biosolids.” Environmental Toxicology and Chemistry. 14 January 2016.
[iv] Versylcke, T; Mayfield, D. B; Tabony, J. A; Capdevielle, M; Slezak, B. “Human health risk assessment of triclosan in land-applied biosolids.” Environmental Toxicology and Chemistry. 14 January 2016.


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Regulatory Update and WEFTEC 2016

The Department of Environmental Protection, through an announcement in the Pennsylvania Bulletin dated March 26, 2016 (46 Pa.B. 1611 and 1612), stated that the General Permits for the Beneficial Use of Biosolids by Land Application (PAG-08), the Beneficial Use of Exceptional Quality Biosolids by Land Application (PAG-07), and the Beneficial Use of Residential Septage by Land Application (PAG-09) have been extended until April 2, 2017 to allow DEP more time to review and update the Permits. The DEP is most likely going to propose changes that will include language to bring the General Permits into compliance with PA Nutrient Management Regulations.

IN OTHER NEWS:  We will be presenting a paper in September, 2016 at the WEFTEC conference in New Orleans.  The title is, “Biosolids Hydrolysis Process and High Solids Liquid Fertilizer Reduces Land Application Costs and Complies with Nutrient Management Regulations.”  The solution?  Over the last eight years, a number of biosolids producers in Canada have made use of a biosolids hydrolysis process to overcome stakeholder concerns. This process produces a high solids EQ biosolids liquid that can be land applied in a way that offers a number of benefits to the ratepayer, the public, environmental regulators, and the farmer.  We will be presenting data showing how the benefits of the biosolids hydrolysis process and how its use can help farmers comply with Nutrient Management Regulations while reducing land application costs.

Three take-away points from this presentation include: #1 – All states will be impacted by the Natural Resource Conservation Service Nutrient Management requirements and biosolids recycling programs must make adjustments to remain viable.  #2 – Thermal hydrolysis may take place before or after digestion. In addition to producing Class A biosolids fertilizer product, it greatly reduces the odors at the processing and land application sites.  #3 – There are advantages to the handling, transportation, storage and land application of high solids liquid biosolids product.



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Investigative Reporter “Discovers” Biosolids!

The Mid Atlantic Biosolids Association (MABA) recently reported on a three-part, “so-that’s-how-it’s-done!”  video presentation outlining the cycle of human waste management in New York City.  The video, produced by VICE Media LLC, is entitled, “You Don’t Know S…,” and tracks the human sewage waste output of the residents of Manhattan’s West Side from flush to flow.  Despite the scatological title (and annoying overuse of the word throughout the presentation), these videos do provide the general public with an idea of what happens to human waste after the flush.

The “investigative reporter” who appears on the videos is a bit over-the-top and seems determined to dramatize the process and act like this is amazing news and was a big, dark secret until now!  But wastewater treatment plants (now known as “water resource recovery facilities”) have been processing human waste for decades.  They were engineered for this purpose.  For thousands of years, human waste was left to decompose on its own or was used as is for fertilizer.  However, as cities grew, so did the need to process large quantities of waste material.  Wastewater treatment plants were developed to mimic and speed up the process of bacterial breakdown of the organic material in waste.  But today’s plants go further than simple decomposition.  Since 1992, when ocean dumping was banned, the wastewater treatment sector has grown and continues to develop new methods for dealing with our waste, turning raw sewage into reusable biosolids and clean water.  Treated biosolids are often disposed in landfills, but that is not a sustainable practice.  So other methods of treatment are used to turn biosolids residuals into various types of products that can be used as fertilizer and, in some cases, fuel.

The video shows the steps that must be taken to process waste, including transporting waste via municipal infrastructure to treatment plants, separating liquids from solids, and the subsequent treatment of each of these products.  In cities, this can be a major engineering and logistical feat.  The VICE video follows the sewage sludge as it is pumped to, and then processed in, a new state-of-the-art, $4B treatment plant at Newtown Creek in Brooklyn.  The sludge is then transported by boat to a dewatering plant on Ward’s Island.  Here, the sludge undergoes further processing into wastewater and biosolids that are then available for beneficial use as a fertilizer.  The videos concentrated on the use of biosolids as fertilizer and didn’t explore the other creative uses for biosolids.

It seems that the shock value of a four-letter-word for human waste was used to attract an audience other than those in the wastewater sector in order to then explain the treatment process.  It’s unfortunate that this language is used since this video could be a valuable educational tool for schools to begin the dialogue about issues surrounding our waste production and how we are handling it.  Biosolids use is the ultimate in recycling and discussions of waste treatment and disposal could easily be incorporated into an environmental curriculum.  It’s important to make students realize the critical nature of sewage treatment.  Human waste is a resource that is never-ending.  We will need engineers in the future to develop new ways of treatment and disposal.  The aging infrastructure in our cities is going to need constant upgrading and, with the average age of workers in the wastewater treatment sector at 55, new jobs will be coming available.  It would be a benefit to show students that careers in the waste management field are not only essential to the welfare and health of all communities, they will pretty much guarantee job security.

Judging from the comments, the reaction to these videos was favorable overall, but often with reservations.  Waste treatment tends to be a hidden process, not one that is obvious to most people or even talked about.  We flush and forget about it.  Some commenters expressed a need for the general public to be aware of the consequences of our actions and take responsibility for recycling our waste products, whatever they may be.  The fact that someone actually told this story and showed the steps of the processing of human waste was praised by many teachers as an important educational step.  While some comments wholeheartedly endorsed the treatment process and beneficial use of biosolids as illustrated in the videos, others were conditionally supportive, expressing concerns about the presence of hormones and pharmaceutical products in a material that is being used as a fertilizer.  The public awareness of these types of emerging contaminants (EC’s) may need to be addressed by the biosolids sector.  Viewers asked questions about the presence of heavy metals, hormones, contraceptives, bacteria, and viruses, among other things.  With a rise in public awareness comes a sector need to explore and explain what is being done to evaluate the impacts of and, if necessary, eliminate these EC’s.  What was once out of sight is becoming more transparent so those in the sector must be prepared to answer questions that arise as a result of this growing awareness.

Other areas of concern expressed in viewers’ comments were: that Europe is more stringent in its regulations than the US; where biosolids that can’t be reused end up; whether or not biosolids can be used as fuel; what happens to waste in countries (or states) who can’t afford wastewater treatment plants; whether we can capture methane during the treatment process; and where the waste from airplanes and ships goes.

In the end, how biosolids are ultimately used will depend on the treatment process.  There are very strict regulations regarding what is allowed to be present in biosolids before land application.

If nothing else, the video will help raise awareness about the crucial yet complicated nature of waste management.

Here are the links to view the three parts of the video:

Part 1: is the basics of the liquid treatment at NYC DEP’s Newtown Creek

Part 2: is the haul of liquid digestate by barge to Ward’s Island for dewatering

Part 3: is the composting of biosolids at WeCare’s composting facility in Burlington County.


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Top Soil Blending with EQ Biosolids

Recent enforcement action by PADEP against a biosolids processor and topsoil blender using Exceptional Quality (EQ) biosolids warrants review of State and Federal regulations, as well as interpretation of the regulations and permit conditions. One little known regulatory interpretation in particular affects processors who are involved with top soil blending.

An EPA publication, “Control of Pathogens and Vector Attraction in Sewage Sludge,” is incorporated by reference into the EPA regulation covering biosolids: 40 CFR Part 503. This document states that EQ standards must be maintained as long as the processor maintains control of the material. Therefore, if the biosolids processor is responsible for top soil blending, “…the new product must undergo pathogen and vector attraction reduction processes and be analyzed for Part 503 parameters including pathogens, vector attraction reduction and heavy metals.”

If, however, the EQ product has left the control of the processor (for example, the WWTP or privately owned composting facility sells the EQ biosolids), then the material falls out of the jurisdiction of federal regulations and any subsequent blending of the material with other products is not covered by the Part 503 regulations.

For biosolids processors in Pennsylvania, there are additional specific requirements in the PADEP General Permit for Beneficial Use of Exceptional Quality Biosolids (PAG-07) that should also be reviewed. These permit conditions are summarized below:

  1. The permittee (preparer of EQ biosolids) must provide the following information in writing to the person(s) responsible for the blending operations.
  2. Storage of the EQ biosolids intended for blending and the final product cannot be stored for longer than 1 year.
  3. The amount of EQ biosolids at the blending site cannot exceed 1000 cubic yards and the final product (blended topsoil) stored by the blending operation cannot exceed 7500 cubic yards. Otherwise, a processing permit is required.
  4. Blending and storage activities cannot be conducted in a manner that will create conditions that are conducive to the harboring, breeding, or attraction of vectors. This means no standing water.
  5. Storage must be designed to prevent discharges into surface or groundwater.
  6. Measures must be taken to minimize and control odors and dust emissions.
  7. Best management practices must be implemented to minimize run-on and runoff.
  8. Trucks must be tarped to prevent the potential for dust or spillage.
  9. Trucks/trailers used to transport EQ biosolids or topsoil cannot be used to transport food or feed without proper cleaning.
  10. The blending and storage activities cannot be conducted within 100 feet of a perennial stream, within 33 feet of an intermittent stream, within 11 inches of a seasonal high water table, or within 50 feet of a property boundary.
  11. The person responsible for the blending operations must keep daily records of the weight or volume of exceptional quality biosolids received and final products sold, given away, or otherwise distributed.

Biosolids processors and topsoil blenders need to be aware of these regulations and permit conditions and their interpretations.

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Land Applier’s Compliance Checklist

If you are a biosolids manager who land applies biosolids to farmland, or utilizes a contractor to land apply your biosolids, the spring is a great time to check for compliance.  The following is not a complete list, but it does include the most common compliance problems that are found when PADEP conducts inspections: 

Maintain proper set back distances

Biosolids should not be applied within;

100 feet of a perennial stream

33 feet of an intermittent stream,

100 feet of a sink hole

300 feet of an occupied dwelling (unless owner signs a waiver)

300 feet of a well

100 feet of an Exceptional Value wetland

Flag areas where biosolids will be applied

Even if the field borders woodland, when biosolids is spread up to the woodland, flags must be in place when the land application takes place.

Fully Implemented Farm Conservation Plan or Sedimentation and Erosion Control Plan

Most plans contain an Implementation Schedule.  The PADEP inspectors will find your facility in compliance as long as this plan is being implemented on schedule.

Laboratory Accreditation

The lab you use to run tests for metals, PCBs and nutrients, fecal coliform or salmonella, helminth ova, and enteric virus must be accredited by PADEP Bureau of Laboratories for those tests on biosolids.  Accreditations must be renewed periodically so it is wise to check the PADEP Laboratory Accreditation website to verify that the lab doing your testing is up to date.

Holding time for fecal coliform samples

Both Exceptional Quality and non-Exceptional Quality biosolids are subject to 6 + 2 hour holding times.[1]  This means the sample must be delivered to the lab within 6 hours of sampling and the lab must start the analysis within 2 hours.

Exceptional Value Watersheds

The watershed where you have been land applying for years could be proposed as an Exceptional Value Watershed at some point.  If so, land application should be discontinued until the final designation is made as either Exceptional Value or High Quality.  If the final designation is High Quality you may resume land application.  However, if the final designation is Exceptional Value, you would either have to stop land application in that watershed, or apply for an Individual Permit for Land Application of Biosolids with PADEP.

Check the Nutrient Balance Sheets

If the farm mechanically land applies manure, they should have a Nutrient Management Plan, or a Manure Management Plan.  These plans will contain a nutrient balance sheet which shows the demand for nitrogen and/or phosphorus and the amount of nutrients available from manure, biosolids, other residuals, and fertilizer.  Be sure the farmer is not over-applying nutrients.

Test for Phosphorus Source Coefficient

This is not a regulatory requirement.  However, if you can provide the farmer with a phosphorus source coefficient, he may be able to utilize biosolids on more fields.  If you are sending a sample to Penn State AASL for metals and PCBs you can check the box on the Sample Submittal form to request the PSC.  The additional cost is $15.  [For more information on nutrient management see the Biosolids Corner article in the July August September, 2012 issue of Keystone Water Quality Manager.]

[1] The exception is Class A compost, Class B aerobically digested, and Class B anaerobically digested biosolids which has a 24 hour holding time when EPA Method 1680 or 1681 is used.

Posted in Agriculture, agronomic rates, beneficial use, benefits to farmers, biosolids as fertilizer, biosolids management, compliance issues, EQ biosolids, Exceptional Quality Class A biosolids, indicator organisms, land application, Nutrient management, Phosphorus | Tagged , , , , , , , , , , , , | Leave a comment

An Update on Regrowth, Odors, and Sudden Increase in Biosolids Research

Recently, a WERF-sponsored research study addressed the challenge of developing effective ways for utilities to manage the issues of regrowth, odors, and sudden increase (ROSI) of indicator and pathogenic bacteria in biosolids.  A draft of the study’s final report entitled, “Wastewater Treatment Plant Design And Operation Modifications To Improve Management Of Biosolids Regrowth, Odors And Sudden Increase (ROSI) In Indicator Organisms” (WERF SRSK4T08), was released on June 8, 2012.  The principal investigators for this project were Matthew J. Higgins, Ph.D. from BucknellUniversity and Sudhir N. Murthy, Ph.D., P.E. from DC Water.  Garvey Resources was one of several team members who worked on this project.

Matthew J. HIggins, Ph.D.

Sudhir Murthy, Ph.D., P.E.

A previous WERF study in 2005 had suggested that, after thermophilic treatment/anaerobic digestion, some indicator organisms in biosolids were not destroyed but had actually entered a non-culturable state.  It was postulated that this “suspended animation” could be reversed by centrifuge dewatering, resulting in a “sudden increase” (SI) in bacterial densities to a level often exceeding regulatory requirements for acceptable levels of Class A biosolids.

Based on an additional observation that SI occurs with fecal coliform (a primary indicator organism) but not Salmonella, the new testing focused on E. coli, the main fecal coliform organism.  The researchers found that tests using higher temperatures and longer time frames than are currently recommended were able to eliminate SI.  Indicator organisms were much more robust than actual pathogens.

The other focus of the current ROSI study is on reducing odors, which are mainly associated with primary sludge, rather than waste activated sludge.  The main persistent odorants in centrifuged biosolids were compounds identified as the breakdown products of organics such as proteins, carbohydrates and fats.  It was suggested that eliminating these precursors would help reduce odors.  Field tests in which several amendments were added to the solids either during or after the dewatering process resulted in significantly reduced odors with the added benefit of reduced regrowth in the biosolids.  Also, incubating digested biosolids with protein degrading enzymes reduced odor after dewatering.  This technique had the added benefit of an increase in gas production, which could be recovered for reuse.  However, these results are preliminary and more research is needed in this area.

The beneficial reuse of biosolids is often a key component in biosolids management plans.  The demand for beneficial reuse methods is expected to grow as wastewater treatment plants incorporate more sustainable practices into their management plans. With this in mind, the recently reported results of the ongoing WERF study addressing the problem of ROSI after anaerobic digestion are important for biosolids managers who are dealing with issues of public acceptance, especially in the areas of odor control and the perceived safety risk of biosolids reuse.  The researchers hope is that the newly developed approaches can be easily implemented for better biosolids management.

NOTE:  This blog was based on the final report of the WERF ROSI study.  At the time of publication of this blog, the final report may be available online.  To view the final report, go to

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There has been a shift in how PADEP is implementing the biosolids land application program.  Due to Act 38, related to manure management, this will affect both wastewater treatment plant managers and farmers who land apply biosolids.

What will these changes mean?  What action needs to be taken?

Well, for instance, if Class B biosolids are being land applied to farms permitted for biosolids and the farmer land applies manure, the farm should have a manure management plan or, if they have livestock, they may need a nutrient management plan.  The plans should be reviewed by the biosolids producer and/or land application contractor to verify that there is not a surplus of manure or nutrients overall.

If the wastewater treatment plant is delivering Exceptional Quality (EQ) biosolids to farmers, they should also check the manure management plan to verify that biosolids is not being applied in excess of agronomic rate.  However, if a wastewater treatment plant produces EQ biosolids and the end users come and pick the product up, then the plant is only required to provide a user information sheet.  This sheet will enable the farmer to determine agronomic rate and to comply with any required management practices.

Garvey Resources, Inc. provides Nutrient Management Specialist services and can assist wastewater treatment plants and farmers in the development and implementation of Nutrient Management Plans, Manure Management Plans and Odor Management Plans.  If you are interested in this service that we offer, please feel free to call or email us.  You can reach Diane Garvey at 215-36-24444 or

Posted in Agriculture, agronomic rates, beneficial use, biosolids as fertilizer, biosolids management, compliance issues, disposal of biosolids, Exceptional Quality Class A biosolids, land application, Nutrient management, recycling, resource recovery facility, service offered by Garvey Resources | Tagged , , , , , , , , , , | Leave a comment