Tag Archives: biosolids

The PFAS Predicament II

This is the second post on poly- and perfluoroalkyl substances (PFAS), those problematic “contaminants of emerging concern.”

Writing about PFAS is difficult because the landscape is changing so fast.  During the last year, this family of 5,000 human-made chemicals has caused increasing consternation among drinking water and wastewater professionals and regulators.  As awareness of their prevalence — in our bodies, food, consumer goods, industrial products, and water – grows, at least 20 alarmed state legislatures have crafted policies to confront the problem.

Above: Firefighting foam is among the most concentrated sources of localized PFAS contamination.

In the last couple of months, national and regional water and wastewater organizations have jumped into the issue with member advisories and Congressional testimonies. As GMWEA’s Government Affairs committee members can attest, water quality professionals’ inboxes are often jammed with PFAS-related bulletins from the National Association of Clean Water Agencies (NACWA), Water Environment Federation (WEF), American Water Works Association (AWWA), and many others.

Coherent, consistent policy related to PFAS is hard to establish for a number of reasons:

  • The scientific and regulatory issues are complex — and hard to quickly convey to preoccupied policy-makers.
  • There are so many PFAS, with so many vehicles for human exposure; their sources, transport and persistence characteristics, and health effects vary widely.
  • Their health effects have, for the most part, not been confidently ascertained.  As WEF states about H.R. 2500 (see below), “With limited research into the health effects of the 5,000 PFAS compounds and no established analytical methods and treatment methods for wastewater effluent, this amendment is bad policy.”
  • Misconceptions abound, sometimes prompting hasty decisions in attempts to protect the public health.

Above: PFAS foam on a Michigan lake, residual from mining operations. Photo thanks to the Detroit Free Press.

Where things stand in the U.S. Congress:

In July, both houses of Congress passed legislation on PFAS as part of the National Defense Authorization Act – but the House and Senate versions differed.  As of this writing, the House bill, H.R. 2500, has provisions that would regulate PFAS under CERCLA, the Superfund legislation passed in 1980. CERCLA has strict stipulations about retroactive liability, which WEF says “could place the burden on FPAS ‘receivers,’ such as wastewater and drinking water agencies.'” 

The Senate version, S.1790, does not include these provisions, and the various water associations are advocating for terms more like the Senate’s; the bills will have to be reconciled in conference during September.  However, to add to the confusion, President Trump has signaled he’ll veto the bill in either form!

Key points:

The national and regional drinking water and wastewater associations strongly support government action to protect public health, but warn of “unintended consequences” of legislation.  The sheer lack of information about PFAS and the risk of local liability are their chief concern.

  • Of particular concern is the misconception that wastewater treatment plants generate or add PFAS. They don’t — treatment facilities only convey what they receive from influent.
  • The best solution is to prevent PFAS from entering the wastewater stream — to identify sources, prohibit certain commercial uses, and focus on origin-specific mitigation.
  • Wastewater treatment plants — that is, the communities that they serve — are unable to afford the expense of measuring, monitoring, and removal of PFAS arriving at facilities.
  • Trace amounts of PFAS in wastewater plant effluent, and in biosolids, could potentially enter groundwater and thus drinking water sources. However, according to the North East Biosolids and Residuals Association (NEBRA), except in “a few worst-case scenarios” when treatment plants have received exceptionally high concentrations from industrial and other points of origin, impact on drinking water sources is not likely to exceed established concentration limits.  NEBRA stresses that PFAS do not “originate” with biosolids but from sources higher up the wastewater stream – the best place to intercept them.

Next: PFAS regulation in Vermont and indications — or lack thereof — of the likelihood that PFAS show up in public drinking water systems.

To return to GMWEA’s website, click here.


A New Hampshire Operator’s Visit to Vermont

Looking at my blank computer screen now, I am wondering what I can say that would be different.  How can I describe my wastewater operator exchange experience in Vermont?

Before June of 2017, I had no idea this program existed — until my plant superintendent shared an e-mail from New Hampshire Dept. of Environmental Services, asking if we were interested in sending an operator. I corresponded with N.H. contact Mike Carle, and he got my name submitted as an alternate with Sean Greig.

Later, my exchange confirmed, Chris Robinson — water quality superintendent of Shelburne, Vermont — contacted me with a final itinerary for my visit, Nov. 6, 7, and 8, 2018.  Chris was also gracious enough to take me around to the plants on the second day of my tour.  He explained the processes these plants use and the type of work they do to avoid having a negative impact on the environment.  

The author, third from front on left, with co-conspirators at the DoubleTree Hotel in Burlington, Vermont, during his exchange.

The treatment plant tours, on the first two days, were very interesting. I was led through plants by operators with experience ranging from two months to over 30 years. In every case, they explained each step of their process with me and shared insights about how they keep things running — in some cases, while dealing with storm flows and equipment failures.

During my tour, I also spoke with lab techs at each plant, asking what types of tests they run and where they grab samples when they do checks on equipment. There was even time to look through the microscope on the Shelburne tour and talk about the installation of DO and ORP monitoring probes.

I was also lucky enough to meet a local farmer and ride along on a land application of treated liquid fertilizer fresh from the plant.

Spreader tank taking on biosolids for land application at the Essex Junction plant.

I discovered that plants use disk filters to polish effluent before it passes through UV lights for disinfection; operators explained that the filters help extend the service life between cleanings on light racks.

All of the plants running digesters were using the methane gas for heating and power generation, and some, coupled with solar, were able to greatly cut power costs.                    

Some plants were not set up for sludge thickening and have to truck the material to other plants to process.  The plant where I work is in the same situation, so our town is considering upgrades to add machinery that will eliminate trucking costs.  In the past, our facility was rarely used by haulers, but recently surrounding towns have set limits on daily amounts being accepted. Along with rate changes, this results in an increase in truck traffic.

My Vermont tour allowed me to ask people about maintenance issues with the septage receiving units, as I noticed we all share the same brand of equipment. There are so many different thoughts on septage; some plants are able to handle the loads better, while others are limited in capacity.

I spent my final day at GMWEA’s trade show, where I was able to meet with sales reps and get information on all of the newest technology for treatment plants. The event  also included trainings for operators; I went to the morning Basic Math class and was pleasantly surprised at how much information they got across in an hour, with a very good instructor who understood how to keep it simple. Later, I sat in on the polymer course, and I was pleased to walk away with useful information that I can share with coworkers.

If I had to pick out one thing that stuck with me from the exchange program, it’s how well every one worked together between the different towns and operators.  You get the sense that everyone is working toward the same goal: protecting the environment and producing skilled professional operators.

As operators we need to take time to thank groups like Green Mountain Water, who are willing to invest in us.  Consider signing up and being a part of something that can make a difference!

Submitted by Ernie Smalley