Written by Nora Lough

March 20, 2023

Paul Derosiers has made a great career in the clean-water business, and along the way has used skills he acquired in his early years as a teacher.

An economic downturn gave Paul Desrosiers his start in wastewater. At the time, a few decades ago, he thought his detour away from teaching would be temporary.

Desrosiers is technical advisor for operations with the Narragansett Bay Commission in Rhode Island. Until two years ago he was superintendent of the commission’s Field’s Point Wastewater Treatment Plant, one of two that collect wastewater from Providence and surrounding communities.

Desrosiers enjoyed the superintendent’s job, yet there was a strong in-house candidate to succeed him. To nurture talent and take advantage of Desrosiers’ experience, his superiors created the technical advisor position for him. “I’ve kind of got the best of both worlds: assist with decision-making but no midnight phone calls,” he says.

He was the winner of a 2019 Carmine J. Goneconte Award from the Rhode Island Clean Water Association and a 2019 Regional Wastewater Treatment Plant Operator of the Year award from the U.S. EPA New England office.

Downsized for the better

That economic decline that changed Desrosiers’ career course came in the late 1970s. Desrosiers graduated from the University of Rhode Island with a degree in education and had taught elementary school for a couple of years. When schools were consolidated because of the downturn, Desrosiers, having little seniority, was among the first to be let go.

After a few months he hired on as a counselor under the Comprehensive Employment and Training Act in the town of West Warwick, where he helped unemployed people return to the workforce. During five years there he also worked in the town’s personnel department, helping set up eligibility lists for jobs in the police, fire and public works departments.

When his CETA contract was about to end, he put his name on the eligibility lists for public works and wastewater treatment. The wastewater job had rotating shifts that would allow him to interview for teaching jobs, in 1983 he was hired at the West Warwick treatment plant.

“The day I started was the same day the town hired a company to do contract management of the facility,” he says. He worked there for about six months while his supervisor talked about cutting staff. He took a job with the contract company as an operator at the wastewater plant in Fall River, Massachusetts, but it was a midnight shift about 30 miles from his home. So after six months he joined the Rhode Island Department of Environmental Management as a wastewater treatment plant inspector.

When he saw an opening for a training specialist at the Narragansett Bay Commission (then a state agency, now a quasi-government agency), he saw an opportunity to use his education degree. He got the job, and when one of the wastewater plant supervisors left, Desrosiers asked if he could fill in two days a week. In 1992, he became assistant superintendent at Field’s Point.

Acquisition and change

About 1995, the commission took control of the Bucklin Point wastewater plant, and that brought a change for Desrosiers. His boss, Carmine Goneconte took on the job of putting the Bucklin Point plant, which had deteriorated for lack of funds, into good condition. In 2015, He assigned Desrosiers to oversee the Field’s Point plant.

Now, in his adviser position, Desrosiers can support to the superintendents of both plants and ensure that institutional knowledge is preserved and transmitted. Many questions that come to him concern the biological treatment system at Field’s Point.

“We have the largest IFAS system in the world,” Desrosiers says. “That’s integrated fixed-film activated sludge.” When the Kruger-designed system was installed in 2012, plants using the technology treated about 1 mgd, Desrosiers says. Field’s Point today is a 77 mgd plant, with a 123 mgd wet-weather capacity.

Given the restricted space on the Field’s Point site, the compact IFAS meant the aeration system, including HSi turbo blowers and multistage blowers from Atlas Copco, APG-Neuros Turbo Blowers and Howden single stage blowers, wouldn’t have to be expanded. “We could create zones within each tank and adequately remove nitrogen. That was the driving factor,” Desrosiers says.

From May 1 to Oct. 31, effluent nitrogen must be less than 5 mg/L because the algae that thrive on nitrogen are most active in warmer weather, which is also when the breakdown of dead algae can create hypoxic conditions in Narragansett Bay.

The IFAS system uses floating artificial media to increase treatment surface area in a sequence of pre-anoxic, aerobic, post-anoxic and re-aeration zones. When water flows out of the IFAS tank, the artificial media are stopped by cylindrical wedge-wire screens.

Two opposites

For the past four years Field’s Point has not had to add alkalinity or carbon to support nitrogen removal. “If I had to describe our system, I would say we had an undersized aeration system and an overabundance of final clarifiers,” Desrosiers says.

There are nine clarifiers (ClearStream Environmental), each holding 1.3 to 1.4 million gallons. But if an aeration tank is taken offline when flows are high, the plant may struggle to meet permit limits, Desrosiers says. The needs of IFAS also required the plant team to be creative.

Screw lift pumps (Lakeside Equipment) move water about 16 feet up from the primary clarifiers to the IFAS tanks. The team knew the pumps would introduce air to the water, which then flows into the first IFAS anoxic zone. To correct that, the team recommended adding some of the return activated sludge upstream of that zone to use up some of the dissolved oxygen.

Aside from IFAS, Field’s Point is a standard activated sludge plant; it disinfects with chlorine. Bucklin Point is also activated sludge but uses UV for final disinfection (TrojanUV4000 from Trojan Technologies). In wet weather there is disinfection with sodium hypochlorite followed by dechlorination with sodium bisulfite.

Bucklin Point (46 mgd design and 116 mgd wet-weather flow) is the opposite of Field’s Point in that it has more aeration capacity, using Roots single stage blowers (Howden) and APG-Neuros turbo blowers,  but only six final clarifiers (Hi-Tech Environmental), four of which are shallow and sometimes require polymer to aid settling. Two more clarifiers are planned.

During the seasonal nitrogen restriction, Bucklin operators use a four-stage process with anoxic, aerobic, post-anoxic and re-aeration zones. During winter, operators repurpose tanks to use a modified Ludzak-Ettinger process with a single anoxic zone followed by three aerobic zones.

The collection system is equipped with tide gates, custom-made in-house, for the outlets of combined sewer overflows. That is necessary for an ocean coastal system where high tides can push water back into the treatment plant, Desrosiers says. The collection system also includes is a 3-mile-long, 26-foot-diameter, 65-million-gallon deep tunnel to store wet-weather flows for later treatment.

Good boss

For most of his time with the Narragansett Bay Commission, Desrosiers worked under Goneconte and was the first recipient of the state award named for him. Goneconte died in October 2016 at age 60, only a year after he made Desrosiers Field’s Point superintendent.

“We lost him way too young,” Desrosiers says. “Carmine had a background very similar to mine. He was a teacher. He went to Rhode Island College and couldn’t find a job coming out of school. The economy was tough. He ended up getting a job in the laboratory for the old city of Providence treatment plant before the Narragansett Bay Commission took it over.”

Goneconte was active in the Rhode Island Clean Water Association and the New England Water Environment Association. He was among the people who came up with the idea for the Water Environment Federation Operations Challenge.

“He was just a great guy to work for, and we had a complementary skill set,” Desrosiers says. “He loved dealing with people and personnel issues, and I was more the process guy. It was a great relationship for 22 years.”

When Goneconte passed, Desrosiers asked the Rhode Island Clean Water Association to create a plaque in his memory and rename the groups Operator of the Year Award in his honor. “If you were to put a face on the Narragansett Bay Commission, it would have been Carmine Goneconte’s,” he says.

Surprising career

Although Desrosiers never got back to full-time teaching, he likes where he is, and he did teach a bit as a training specialist for the commission and at the Community College of Rhode Island, where he taught the treatment class for entry-level operators.

Although he has personal awards, Desrosiers says one that he likes best came in 1995, when the EPA gave the commission its National Excellence Award for having the best-operated and maintained large secondary wastewater treatment plant in the country.

“To tell you the truth, I love what I do,” Desrosiers says. “Teaching is a lot of intangibles. You hope that you get through to people. You hope that they learn. But with wastewater, you’ve got a finished product every day. You can look at that effluent and say, ‘Wow, this is great.’”