Biosolids Consultant Shares Energy Savings Trends

John Donovan has devoted a long career to helping communities make the most of biosolids – with ample assistance from plant operators.
Biosolids Consultant Shares Energy Savings Trends
John Donovan, left, senior vice president for Biosolids and Energy Recovery with CDM Smith, and Richard Weare, capital projects manager at the Greater Lawrence Sanitary District, discuss plant operations.

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John Donovan, P.E., started on the ground floor in a long career as a biosolids consultant.

Graduating from college just as the environmental movement began, he put his civil engineering degrees to work with CDM Smith (then known as Camp Dresser McKee). Forty years later, he can look back on numerous biosolids management projects across the country that he helped conceive and design.

Along the way, he had an inside track to explore emerging technologies, traveling widely to tour treatment plants where new processes were deployed. He counts operators of those and other plants as some of his best teachers. “I have a wealth of experience, and a lot of it is what I have learned from operators over the years,” he says. “Every time I walk onto a treatment plant site, I want the operators to tell me everything they can about their situation. By listening, I can get a strong sense of what the real issues are.”

Operators return the respect: Last year, Donovan received the New England Water Environment Association’s first-ever Biosolids Management Award. It recognized his work on trend-setting projects for the Massachusetts Water Resources Authority (MWRA), the Lewiston-Auburn (Maine) Water Pollution Control Authority and others.

Starting young

Going to high school in the Boston area, Donovan took an interest in math and life sciences, and teachers and guidance counselors steered him toward engineering. He earned a bachelor’s degree in civil engineering from Northeastern University in Boston, along the way gaining work experience through the school’s extensive cooperative programs.

“I had varied experiences working for a municipal government, an environmental consulting firm and a land surveyor, where I learned that working outside in winter perhaps was not what I wanted to do,” Donovan recalls.

By the time he finished undergraduate studies in 1972, he was a U.S. Army Reserve second lieutenant. The Vietnam War was winding down, and the U.S. EPA had just been created. “I had an opportunity to get a graduate degree because the EPA saw a big need to train environmental engineers. I was in the right place at the right time.”

With a newly minted master’s degree in civil engineering, he joined CDM, then a firm with a strong international reputation and about 1,000 people on board. Today the company is five times that size.

“Like a lot of engineers, I didn’t know much coming out of school,” he says. “The firm had taken a number of large assignments involving what at the time we called sludge management. Some of our people were very well respected in that field. Assignments in Boston and New York City and in Florida, Texas and elsewhere were putting stress on the firm’s resources. So as a young graduate, I was assigned to some really challenging projects.”

Out of the ocean

In the late 1970s and early 1980s, cities in the Northeast were under EPA orders to end the long-standing practice of dumping biosolids in the ocean. The orders affected more than 80 cities, many in New York and New Jersey but also Philadelphia, Washington, D.C., and Boston.

“Boston had anaerobic digesters and discharged the digested material to the ocean twice a day on the outgoing tide,” Donovan says. “That practice continued until the 1990s. When I was in school, my master’s work was to study water-quality conditions in the Boston harbor. I was pleased in the 1980s to get involved in the Boston harbor cleanup, which turned out to be one of the most successful environmental programs in the country.”

The demand for better management of residuals opened numerous opportunities for CDM and Donovan to work with municipalities to improve thickening, dewatering and other biosolids processes. The federal construction grants program was in full swing, ensuring that funds were available for major projects.

Eye on innovation

The EPA was also active in research, largely through its Municipal Environmental Research Laboratory in Cincinnati, Ohio. Thanks to mentors in his firm, Donovan won an assignment to work on an EPA contract to monitor and assess emerging biosolids technologies.

“During the construction grants program, the EPA was putting a fair amount of money into analysis of emerging technologies,” says Donovan. “CDM, because of our stature in the industry, got several assignments in that area that I worked on through the 1980s and 1990s. We looked at everything from anaerobic thermophilic digestion to autogenous incineration to vermicomposting, which is making compost using earthworms.

“I gained a lot of insight into what was coming out, and of course there was a lot of interest within our industry because managing solids was so expensive. It was a great opportunity. I got to tour a lot of treatment facilities around the country. There were about two dozen European in-vessel composting facilities built in the 1980s, and I did a study for EPA on that. And CDM Smith had about 40 offices around the country, so I assisted them as part of a team of experts brought in to solve local problems. I have been to most of the states as a result.”

Big towns and small

As the century turned, Donovan’s focus shifted to deep involvement with major projects. He’s especially proud of work for the MWRA at Boston’s Deer Island Sewage Treatment Plant, a 350 mgd (average) facility with 12 large egg-shaped anaerobic digesters. The digested material is pumped 7 miles under the harbor to another facility, where it is centrifuge dewatered and thermally dried to make a pellet product (Bay State Fertilizer). “I had the opportunity to work on the planning for the treatment plant and biosolids facilities and to help design the digesters,” Donovan says.

More recently, the MWRA hired CDM Smith to evaluate the biosolids facilities and recommend improvements. One outcome is a plan to replace the existing combined heat and power (CHP) system with a new gas turbine CHP system that will allow the authority to generate up to one-half of its power needs.   
On a smaller scale, Donovan has worked extensively with the Lewiston-Auburn Water Pollution Control Authority and its 14 mgd (design) treatment plant. In the 1990s, CDM Smith helped the authority establish a highly successful composting facility and end landfilling of biosolids.

Several years ago, with CDM Smith’s help, the authority became the first of Maine’s roughly 120 treatment plants to use anaerobic digestion. Previously, the authority lime-stabilized a portion of its primary and waste activated sludges for application to pasture land as belt-pressed cake. Two mesophilic digesters now yield a higher-quality product that does not require liming and so is more compatible with local soils.

Digestion also produces biogas that fuels a CHP system with two engine-generators rated at a combined 500 kW. The electric output can exceed the plant’s needs during low-flow night hours, and surplus power is sold to the utility grid under a net metering program.

Spotting trends

Diverse experience on biosolids projects gives Donovan good insight to trends in the industry. One of the most important is an emphasis on energy: “There’s a lot of momentum and public sentiment toward ways to reduce energy consumption or produce more energy, especially at facilities that have digesters. I believe we’re going to see a lot more co-digestion, digestion pretreatment, advanced digestion and CHP.

“Every plant would like to be off the grid, but at present only about a quarter of the plants that have digesters use the biogas for anything besides heating their digesters and buildings. So there is a long way to go.

“There’s a lot of talk about bringing in different digester feedstocks. That’s fine, but of course there’s a need to make sure such materials don’t carry contaminants that will affect the plant’s basic mission, which is to clean the wastewater. It’s also important to be mindful of proper equipment selection and proper gas treatment, because certain methods of converting gas to power require higher or lower gas quality.”

Donovan also sees a trend toward producing higher-quality biosolids, despite the added expense, to address public concerns that go with beneficial use. “The biggest complaint from the public is odor,” he says. “Many in the public are dumbfounded when they learn that there is no odor standard per se in federal regulations. There are vector attraction reduction requirements, but you can meet those and still have an odorous product.

“In rural areas, particularly for small generators, if farmers are willing and the sites are well buffered, there is nothing wrong with land application. But across the country we’re seeing people moving to rural and semirural areas who want nothing to do with the odor, or the trucks, or even the thought of biosolids. I don’t see that ever turning around, and so I think the industry needs to move toward more publicly acceptable products.

“Another thing we’re seeing is more regional cooperation. In New Jersey, for example, Hurricane Sandy caused significant long-term outages for some major biosolids processing facilities, and there was a mad scramble to find other outlets, whether dewatering facilities or landfills. We’re starting to see more cooperation at the utility level and even among private-sector service providers. For example, two large companies at a regional level might have a contractual arrangement to use each other’s facilities in the event of some major problem. There isn’t a lot of that yet, but it’s a good trend.”

Ample rewards

These trends unfold as Donovan winds down his career. He now works part time from CDM Smith’s main office in Boston and continues his long involvement with the Water Environment Federation’s Residuals Committee.

“Biosolids management is a key part of our industry, and there has been insufficient investment in that area,” he says. “In biosolids management, there are no cookie cutters. There are about 16,000 wastewater treatment plants in this country. You see a lot of wastewater treatment technologies repeated, but you hardly ever see a solids processing train repeated. The solids side is very much site- and region-specific.

“In working on many biosolids projects over the years and trying to come up with solutions that are reasonable in cost and sustainable, I’ve come to believe that, in taking the long view, you usually make the right choice. As I look back on my career, I have strong sense of accomplishment for helping craft the solutions that CDM Smith has brought to our clients. I greatly appreciate the opportunities I’ve been given to contribute to this industry.”  


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