Category Archives: Professional Perspectives

The Trouble with Food Scraps

The recent publication of GMWEA’s first “Don’t Flush It!” brochure sparked a lively discussion about food scraps among wastewater and solid waste management professionals.  Should be they be flushed or processed in in-sink disposal units — and thus allowed into septic tanks or municipal wastewater systems?

The brochure, “Cloggers!”, identifies materials that typical households flush or pour into their septic/sewer systems – fats, oils, and greases, along with solid items – that clog tanks, pumps, and pipes.

Food scraps proved to be the most nuanced of these materials, due to two, contradictory, characteristics:

1. They are valuable!  They contain sequestered nutritional value, energy, and money, and their value can still be recovered even after the scraps leave your kitchen. (The average American household throws away about $1,600 worth of food every year!) 

2. They are problematic!  Stored improperly, they can grow pathogens, stink, attract  pests, and generate greenhouse gases; flushed, they contribute to clogs in private septic systems and  municipal wastewater plants.

The issue is especially urgent in that Act 148, Vermont’s Universal Recycling & Composting Law, bans the disposal of food in landfills as of July 1, 2020.

What are we to think? Chittenden Solid Waste recently offered this view:

“. . . Don’t look at your garbage disposal for answers—Just ask the folks who manage wastewater treatment plants and witness the repercussions of putting the wrong things down the drain.

“’Organic overload is a concern in septic tanks as well as in wastewater treatment systems,’ says Jim Jutras, Water Quality Superintendent at the Water Resource Recovery Facility in Essex, Vt. ‘Another concern is “hydraulic overload,” where home septic systems and municipal systems . . . accumulate material that can cause trouble, such as “flushable” wipes, grease, and food scraps. This can result in costly repairs or sewage overflows.’

“Some residences don’t have their own system, but do connect directly to a municipal wastewater treatment plant, via pump stations, which require regular maintenance due to the increase in food scraps and ‘flushables’ that can hang up in the pump and cause backups and sewer overflows.

“. . . The bottom line: Drains and garbage disposals are not the solution for handling your food scraps. Public and private water systems, especially older ones, are not designed to handle much more than human waste from your toilet, rinse water from the kitchen sink, or bath/shower water. Even items marketed as ‘flushable’ can cause problems.”

However, Jeff Wennberg, Commissioner of Public Works in Rutland, offers this cautionary “minority report”:

“One-half of the dwelling units in Rutland City are rental units. The vast majority are multi-family homes and most of those do not have the homeowner residing in the home. In nearly all of these cases there is no yard to speak of (Rutland is only 7 square miles and 85% developed). The idea that absentee landlords are going to persuade renters to use composters in the apartment or on-site is totally unrealistic. Compliance with mandatory on-site composting will be 20% to 25% City-wide at best.”

Wennberg’s concern for compliance rates – and for petroleum used in transporting food waste to centralized composting or biodigestion facilities – is validated by past Vermont experiences in Zero Waste and post-consumer food-waste value optimization. 

What’s a householder to do?Fortunately, there are ways to avoid flushing food waste and to soften the edges of our hard choices. Again, thanks are due to CSWD for articulating some alternatives.

1. Store food better – buy smart and fine-tune your fridge

2. Donate food – plan your consumption, give excess to Vermont’s many hunger-fighting programs

3. Feed animals – get to know your local chicken and pig farmers

4. Digest it – compost it yourself, or find a neighbor who does

5. Recover energy – not yet an option in Vermont, but rather a systemic goal to strive for.

CSWD offers more excellent advice at  www.cswd.net/reduce-and-reuse/reducing-food-waste/

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