Author: Jamie Frye

Field Trip: Anaerobic Digester

On Friday, August 2, Eco-Ambassadors visited Jordan Dairy Farms Heifer Facility in Spencer, MA to learn about organics to energy anaerobic digestion. Jordan Dairy Farms partners with Vanguard Renewables, a company that engineers and operates anaerobic digesters, to repurpose food waste and manure as bedding and fertilizer. The trip demonstrated how closing the waste cycle can be cost effective and energy efficient.

John Hanselman, Executive Chairman of Vanguard Renewables, explains anaerobic digestion to the group.

Inputs: Vanguard Renewables’ food industry customers, including manufacturers, breweries, and grocery stores, send their depackaged food waste to Jordan Dairy Farms. The farm receives about 120 tons of food waste each day, between five and ten truckloads. The food waste is added to the first anaerobic digester, along with manure produced by the farm’s cows.

What Happens: Incoming organic waste is filtered for plastic and other solid contaminants, then mixed with waste already inside the first digester. The methanogens, or digesting bacteria, can only survive a 0.5 degree temperature change in a period of 12 hours, so convection keeps the mixture at a steady 104 degrees. Waste air passes through three successive filters– cedar chips, activated carbon, and carbon– to eliminate odors.

Above: Technicians conduct regular chemical tests to ensure correct pH and microbe levels.
Below: Pressurized tubes control digester heating and cooling.

After five days in the first digester, the mixture is transferred to the second digester, where it will spend 25 days. The organic waste is mixed at various heights throughout the digester to ensure uniform temperature and pH. 200 different sensors monitor the digester at all times. The biogas produced in the second digester is about 65% methane, with some carbon dioxide and hydrogen sulfide. The gas is captured in two membranes stretched above the digester.

Membranes capture the methane gas given off by digestion.

Outputs: The gas is sent to a combustion engine connected to a generator, producing one megawatt of power every hour. The liquid is extracted from the digested waste and becomes organic fertilizer for crops, while the leftover solids become soft, dry bedding for cows. As part of their partnership, Vanguard Renewables shares all digestion products with Jordan Dairy Farms.

John shows the group handfuls of soft, dry bedding material produced from digestion.

Vanguard Renewables operates five anaerobic digesters on small, family dairy farms across Massachusetts, and receives food waste from 65% of Massachusetts food manufacturers. Anaerobic digestion diverts organic waste from the landfill and reduces greenhouse gas emissions from said waste by more than 85%. Anaerobic digestion shows that renewable technologies both protect the environment and stimulate the economy.

Summer Compost Tips

Composting is a great way to divert waste from the landfill, fertilize local gardens and agriculture, and increase awareness of food waste. However, during the hot and humid summer months, unpleasant smells and pesky bugs can discourage even the most committed composters. The following tips help address common summer composting problems.

Photo by Jan Kopřiva on Unsplash

1. Store food scraps in the fridge or freezer

Does your compost pile up faster than you can take it out? Try keeping it in the fridge or freezer between collection days, if you are on a curbside pick up program, or until you can take it to your regular drop-off site. The cooler temperatures slow decomposition, reducing odors. Designate a food storage container or a reusable, sealable plastic bag for compost. Just don’t forget about your compost in the fridge or freezer!

2. No fridge space? Use a smaller compost bin and empty it daily

Our office compost is temporarily being collected in a sugar dish!

In our office, we switched from collecting compost in a 2 gallon bucket to a re-purposed sugar dish. It fills up fast so we take it out daily, instead of once a week. Taking turns makes this sound much less daunting! Plus, our food scraps don’t have time to get smelly, and the ants and fruit flies stay away. We will switch back to the larger bin when temperatures cool. Almost anything can be used as a compost bin, just make sure it has a lid and doesn’t leak.

3. Set a trap for fruit flies and gnats

Photo from

Pesky fruit flies and gnats invading your kitchen space? Try trapping them in a jar or glass with a mixture of equal parts apple cider vinegar, dish soap, and water. You can make a funnel out of paper and tape it to the container so it points down, but does not get wet. Fruit flies will be attracted to the sweet smells and fly down into the jar, but they won’t be able to get back out!  Read the full instructions here.

4. Change out the compost bag or liner more often

Programs Intern Jennifer Frye setting a recurring reminder on her phone

Every three to four days, or when your compost starts to get smelly, replace the bag or liner in your compost container. You can put the old food scraps in a new bag, transfer them to the fridge or freezer, or keep them outside in a cool, dry place until collection day or until you can bring the scraps offsite. Try setting a recurring reminder on your phone to change the compost liner. 

5. Clean out the bin after emptying it

It only takes a few minutes to wash out your compost bin with soap and water. You can even wipe it out with spray cleaner and a rag. Cleaning your bin gets rid of any spills or leaks that might build up and cause odors. Make sure to let the bin dry before putting a new bag or liner in!

6. Add paper towels, napkins, and coffee grounds

Remember that compost is more than just food scraps! Adding paper towels and napkins to your compost absorbs liquids, and adding coffee grounds decreases unpleasant odors. Tea bags will also work if you’re not a coffee drinker. All paper towels and napkins can be composted, even bleached paper.

7. Bring the entire bin outside

If you use a compostable bag as a bin liner and it leaks, bring your kitchen bin outside and transfer the contents of the bag there. This way you avoid dripping smelly liquid everywhere. To avoid leaks, try double bagging, or line your compost bin with a BioBag and paper towels. While the bin is outside, you can even take the opportunity hose it out and let it dry in the sun.

2019 Sustainability Champions Ceremony and Reception

On Thursday, July 11, the Tufts Office of Sustainability hosted the 2019 Sustainability Champions Ceremony and Reception. Guests gathered in the historic Coolidge Room of Ballou Hall to recognize newly trained Eco-Ambassadors and recently certified Green Offices. This year, two new awards were also presented: Sustainability Champion and Eco-Rep of the Year. 

Sustainability Program Director Tina Woolston speaks at the event.

Tina Woolston, Sustainability Program Director, opened the event by welcoming guests and introducing the new Executive Vice President, Mike Howard. He brings experience promoting sustainability at Smith College and MIT to his role at Tufts.  

Education and Outreach Program Administrator Shoshana Blank speaks before the awards are presented.

Shoshana Blank, the Education and Outreach Program Administrator, then explained the Green Office Certification and Eco-Ambassador programs. She spoke on the importance of individual efforts in creating an institutional culture of environmental responsibility. Faculty, staff, and student sustainability actions are vital alongside university policies.

President Tony Monaco speaks on sustainability efforts across the university in the last year.

President Monaco attended the ceremony to personally congratulate the Green Offices, Eco-Ambassadors, Sustainability Champions, and the Eco-Rep of the Year. He remarked on the many ways Tufts has demonstrated its commitment to the environment in the past year since the 2018 reception. 

Attendees check out posters featuring university Green Fund projects in 2018 and 2019. Learn more about the program on our website.

Notably, the Green Fund provided $40,000 to finance eight projects across all four campuses. Information about each Green Fund project was displayed on posters along the wall. Guests enjoyed learning about the projects, and were hopefully inspired to propose sustainability projects of their own.

The Tufts Center for Engineering Education and Outreach (CEEO) receives a Platinum level Green Office certification.

The ceremony continued with the presentation of the awards. Twenty-three Green Offices received certificates in frames made of recycled circuit boards. Eight were certified at the Bronze Level, six at the Silver Level, seven at the Gold Level, and two at the Platinum Level. The 22 Eco-Ambassadors trained in June 2019 also received certificates. Each award recipient posed for a photo with President Monaco.

Inaugural Sustainability Champion Whitney Stiehler of the Tufts Wildlife Clinic receives her award from President Monaco.

Sustainability Champion awards were given to JP Beaulac of Tufts Dining, Whitney Stiehler of the Tufts Wildlife Clinic, Lynne Ramsey of the Center for Engineering Outreach and Education (CEEO), and the Tufts Technology Services Green Team, as a whole group. These individuals demonstrate an outstanding commitment to sustainability at Tufts.

Rising senior Elyssa Anneser speaks as Eco-Rep Coordinator for the upcoming 2019-20 academic year. She presented Carla Giannattasio, A20, with the inaugural Eco-Rep of the Year award.

Elyssa Anneser, A20 and Eco-Rep Coordinator for AY 2019-2020, awarded Carla Giannattasio, A20, Eco-Rep of the Year. The new awards were designed by summer Programs Intern Jennifer Frye and created by Communications Intern Michaela Morse. They made use of old records donated to the Office of Sustainability during Spring residence hall move-out and utilized the laser cutter in the Advanced Production Lab at the SMFA to cut plexiglass and circular plywood frames.

Over 80 people attended the event. It is open to the whole Tufts community.

After the awards ceremony, guests mingled and enjoyed finger foods and beverages. Discussions turned to various ways to improve university sustainability. Eco-Ambassadors encouraged coworkers to undergo training, and Green Office members promised to certify at a higher level. Guests left motivated to work towards even bigger sustainability goals. Their achievements will be celebrated at next year’s Sustainability Champions Ceremony and Reception.

To see all the photos from this year’s event, visit the Office of Sustainability’s Facebook page.

Below is a list of all the Green Offices, Eco-Ambassadors, and Sustainability Champions that were acknowledged at this year’s reception. 

Newly certified Green Offices, all of which all successfully participated in and completed the 2019 Green Office Certification Challenge–

Bronze Certified offices:

  • Tufts Technology Services – TAB 301
  • Department of Sociology
  • Department of Biomedical Engineering – 4 Colby Street
  • Sackler School of Graduate Biomedical Sciences Dean’s Office
  • Tufts Music Department
  • Tufts Hillel
  • Tufts Comparative Medicine Services
  • Tufts Technology Services –TAB Basement

Silver Certified offices:

  • Center for the Enhancement of Learning and Teaching / Educational Technology Services
  • Tufts Center for the Study of Drug Development & Tufts Dental IT
  • Tufts Technology Services –Information Security
  • Fletcher Global Master of Arts Program
  • Cummings School Dialysis Department
  • Department of Public Health and Community Medicine – The SUPPER Project

Gold Certified offices:

  • University Chaplaincy
  • Department of Biomedical Engineering – Black Lab
  • Human Resources
  • Tufts Technology Services -16 Dearborn Road
  • Fletcher Office of Admissions and Financial Aid
  • Office of Institutional Research
  • Foster Hospital for Small Animals -The Client Service Team

Platinum Certified offices:

  • Center for International Environment and Resource Policy (CIERP)
  • Tufts Center for Engineering Education and Outreach (CEEO)

Newest members of the Tufts Eco-Ambassador program, who were trained in June 2019:

  • Liam Curry – Facilities/Engineering
  • Kristen Dabney – Student Accessibility Services
  • Jillian DeMair – CIERP, Fletcher
  • Kim Ellwood – Office of the Graduate Dean for the School of Engineering
  • Branden Etheridge – Facilities/Engineering
  • Austin Fuller – Strategy & Program Development
  • Caroline Harrison – International Literary and Cultural Studies
  • Peter Loeb – Hillel
  • Doris Pfaffinger – International Literary and Cultural Studies
  • Jaime McSkimming – Tisch Library 
  • Monica Morin – Biology
  • Katie Mulroy – Fletcher Student Affairs
  • Liza Reed – Fletcher, Communications & PR Specialist
  • Melissa Weikart – Music Department
  • Jenna Whitney – University Advancement Special Events
  • Janice Willson – Office of the President 
  • Rebekah Plotkin – Gordon Institute
  • Justin Cronin – Chemistry
  • Karin Wiedemann – Office of Career Services, Fletcher
  • Gina O’Connor – Film and Media Studies
  • Zara Konarski Rudenauer – Counseling & Mental Health
  • Bruce Johnson – Eliot-Pearson/Child Study & Human Development

Sustainability Champions, who are individuals that go above and beyond what the traditional person (who doesn’t have sustainability in their job title) might do to help make Tufts more sustainable–

Inaugural Sustainability Champions:

  • Lynne Ramsey – Center for Engineering Education and Outreach (CEEO)
  • Whitney Stiehler – Tufts Wildlife Clinic Coordinator
  • The Tufts Technology Services Sustainability Team
  • JP Beaulac – Associate Director of Residential Dining
  • Carla Giannattasio – Inaugural Eco-Rep of the Year Award

Where does Boston’s wastewater go?

This June, the Office of Sustainability organized a field trip to the Deer Island Wastewater Treatment Plant. Current and future Eco-Ambassadors spent a cloudy Friday morning touring the plant and learning about the life cycle of their wastewater, from the drain to Boston Harbor. The field trip encouraged mindfulness about water consumption and showed how wastewater treatment is engineered to maximize efficiency, providing wastewater management for decades to come.

In 1972, the Environmental Protection Agency (EPA) passed the Clean Water Act. The act, among other things, required cities to process wastewater with both primary and secondary treatment. In 1987, Massachusetts created the Massachusetts Water Resource Authority (MWRA) with the goal of updating Boston’s wastewater treatment to comply with the new EPA standards. In 2000, after a decade of planning and construction, the current Deer Island Wastewater Treatment Plant was completed.

Deer Island services 2.5 million people in the Metropolitan Boston area and processes an average of 370 million gallons of wastewater daily. How does wastewater “influent” make it to Deer Island? Gravity drives influent through conveyance tunnels underneath the city.  Massive pumps lift the influent 80 to 150 feet up into the plant. Deer Island has a wastewater capacity of 1.3 billion gallons per day, and on rainy days more pumps are brought online to accommodate increased influent. 

Process Control Project Manager Timothy Beaulieu explains primary treatment to the group

After arriving at Deer Island, influent undergoes primary treatment. Grit is removed and disposed of at landfills, then clarifiers remove pollutants. At this stage, about 60% of suspended solids and 50% of pathogens and toxic chemicals are removed. Gravity separates sludge and scum from the wastewater – scum sits on top of the water while sludge sinks to the bottom.

Once primary treatment is complete, wastewater continues to secondary treatment. Mixers, reactors, and clarifiers remove remaining solids through biological and gravitational processes. Deer Island manufactures oxygen to feed microorganisms which consume dissolved organic matter. After secondary treatment, 85% of pollution has been removed from the wastewater.

Effluent is disinfected and then dechlorinated before diffusing into Massachusetts Bay

The final step before wastewater “effluent” is discharged is disinfection. Effluent is treated with sodium hypochlorite to kill any remaining pathogens, then sodium bisulfite is added to dechlorinate the water. Effluent is released into the Massachusetts Bay through over 50 individual diffuser pipes, ensuring rapid and thorough mixing with ocean water. The effluent is monitored for appropriate chemical and oxygen levels to protect the local ecosystem.

Egg-shaped digestors use bacteria to break down sludge and scum to produce fertilizer

But what happens to the sludge and scum leftover from primary treatment? The solids are first thickened in centrifuges, then added to egg-shaped anaerobic digestors. The digestors are huge, 90 feet wide and 130 feet tall, and carefully maintain a pH and temperature that mimic the human body. Bacteria already present in the waste break down the sludge and scum into methane gas, carbon dioxide, and water vapor. The methane is captured and converted into 95% of Deer Island heating needs and 20% of electricity needs.

Digestion reduces sludge and scum quantities by 55%, and the remaining solids are pumped to the MWRA pelletizing facility in Quincy. The resulting organic nitrogen fertilizer, meeting strict EPA and MA Department of Environmental Protection requirements, is used in agriculture and forestry. Additionally, air from Deer Island is scrubbed of sulfur using filters and activated carbon to prevent sulfur dioxide emissions.

After visiting Deer Island, it’s clear that the plant is designed to operate in the most sustainable way possible. Every output – water, air, gas, solids – is either cleaned to meet environmental standards or repurposed as energy or fertilizer. Residents can rest assured that their wastewater is properly treated thanks to the care and effort of Deer Island planners, engineers, and operators.