During his U.S. Senate confirmation hearing to become the No. 2 official at the Justice Department, Todd Blanche suggested that he had no direct knowledge of the decision to abandon a criminal corruption case against the mayor of New York City.

But in a draft letter unsealed on Tuesday, the interim U.S. attorney in Manhattan wrote that a top department official, Emil Bove III, had suggested otherwise before ordering her to seek the case’s dismissal.

The U.S. attorney, Danielle R. Sassoon, wrote that when she suggested that department officials await Mr. Blanche’s Senate confirmation so he could play a role in the decision, Mr. Bove informed her that Mr. Blanche was “on the same page,” and that “there was no need to wait.” The draft was written by Ms. Sassoon earlier this year, as she fought for the case’s survival.

The draft letter was among a cache of communications, including emails and texts, submitted under seal to a judge, Dale E. Ho, by Mr. Bove and Mr. Blanche, after his confirmation, to support their argument for dismissal of the corruption indictment against the mayor, Eric Adams. Judge Ho has yet to rule.

The draft sheds additional light on the circumstances surrounding the explosive decision by top officials in the Justice Department to halt the prosecution of Mr. Adams. The decision set off a political crisis in New York City, where the mayor immediately faced questions about his indebtedness to the Trump administration, which sought the dismissal in part so that Mr. Adams could aid its deportation agenda in New York City.

A Justice Department spokesman said in a statement that Mr. Blanche had no role in decisions at the agency before he was confirmed.

“Todd Blanche was not involved in the Department’s decision-making prior to his confirmation,” the statement said.

During the confirmation hearing, Mr. Blanche was questioned about the Justice Department’s decision making in seeking the dismissal of the Adams case.

When Senator Peter Welch, a Vermont Democrat, asked Mr. Blanche about whether the decisions in the case had been directed by officials in Washington, Mr. Blanche suggested that he had no direct knowledge.

“I have the same information you have,” he said. “It appears it was, yes, I don’t know.”

Reached for comment on Tuesday, Senator Welch said, “If this is true, it clearly indicates Blanche ‘misled’ — in plain English, lied — to the committee.”

It was not immediately clear when Ms. Sassoon drafted the letter. When it was originally filed, under seal, Mr. Bove wrote that Ms. Sassoon sent it to herself on Feb. 12. But the unsealed documents show that Ms. Sassoon sent herself an email that appeared to include the drafted letter as an attachment on Feb. 11 — the day before Mr. Blanche’s hearing.

This is a developing story and will be updated.

Emma G. Fitzsimmons contributed reporting. Susan C. Beachy contributed research.

Road salt is leaching into the reservoirs that hold New York City’s tap water and could make some of it unhealthy to drink by the turn of the century, according to a new study commissioned by city environmental officials.

The study, released last week by the city’s Department of Environmental Protection, found that while salt was edging upward throughout New York’s vast watershed, it was especially pronounced in the New Croton Reservoir, just north of the city.

In that supply, which provides about 10 percent of the city’s drinking water, levels of chloride — a chemical found in salt and an indicator of salinity — tripled over the last 30 years.

If the trend continues, drinking water from the New Croton Reservoir may not meet current safety standards by 2108, according to the report.

While road salt is a main driver of salinity levels in drinking water throughout the United States, other contributing factors include wastewater treatment plant discharges and agriculture, according to the report. Elevated salt levels in fresh water can contribute to health issues like high blood pressure and can also damage the ecosystem, the study said.

Reducing salinity levels throughout New York City’s water system should start with more prudent use of road salt, said Rohit T. Aggarwala, the head of the environmental protection department, which manages the water supply and commissioned the report.

“We just need people who operate roads to start realizing that this is a chemical that we are adding to our environment, and we have to take that seriously,” Mr. Aggarwala said.

Road salt is cheap and plentiful, but it is also dangerous for the environment and corrosive for infrastructure.

In general, local municipalities, and often the state’s Department of Transportation, make the decision to use salt on roadways — a crucial safety measure that melts ice.

“We understand that there is a delicate balance between protecting the environment and maintaining safe highways for motorists,” said Joseph Morrissey, a spokesman for the Department of Transportation. The department minimizes salt usage, Mr. Morrissey said, with methods that include adhering to prescribed application rates, calibrating equipment throughout the winter, training drivers on best practices and using brine, a liquid version of salt that is less concentrated but more expensive.

Officials are focused on curbing the use of salt, while continuing to explore other affordable alternatives, like beet juice — which lessens salt’s corrosive qualities when mixed with brine — and sand, which does not melt ice but provides traction.

Recently, Pete Harckham, a Democratic state senator who represents parts of Westchester County and the Hudson Valley, introduced legislation to create a city and state task force that would explore the issue. “We’ve got to use this as a teachable moment and rethink how we do things,” Mr. Harckham said.

New York City’s pristine tap water is a source of pride among residents and local leaders. Most of it, about 90 percent, comes from rural areas in the Catskill Mountains, a range that extends more than 125 miles north of New York City. It represents the largest unfiltered water supply in the United States.

The remaining 10 percent from the New Croton Reservoir, a collection of 11 smaller reservoirs and three lakes, is filtered, but not for chloride. New Croton is in Westchester County, a relatively dense suburban area, which offers less of an opportunity for the natural environment to absorb runoff from salt on the road. In the less populated Catskills, more vacant land surrounds the water supply, and there have been only marginal increases of chloride levels, Mr. Aggarwala explained.

Last fall, the city temporarily relied on the Croton reservoir for more of its drinking water when half the Catskills supply went offline for repairs to a major aqueduct. An unexpected drought halted the repairs.

Should salinity levels continue to rise in the Croton reservoir, the city could lose a valuable resource, Mr. Aggarwala said.

“One of New York’s greatest strengths is the fact that we have so many different sources of water, 19 reservoirs,” he said. “If we lose the Croton system, that just makes New York City’s water supply much less resilient, and that makes it much less reliable.”

For several suburban towns that draw water directly from smaller reservoirs that feed into the New Croton, the salinity levels are more of an immediate concern. Somers, Yorktown and the City of Peekskill, all in Westchester, draw water from one of those smaller reservoirs, the Amawalk, where chloride levels could exceed safety standards in about 30 years, the study said.

“While I was alarmed by the report, I was not surprised in any way, because we’ve been dealing with this for some years now,” said Mr. Harckham, who represents many of these towns.

Several private wells in the area have had to be taken offline because of salinity levels, he said.

Methods that can help with over-salting roads, Mr. Harckham said, include thermal devices that can take a road’s temperature, to avoid unnecessary applications.

The solution, Mr. Harckham said, “is an equation of knowledge, technology, best practices and money.”

Fred Eversley, a sculptor who used a technique dating back to Isaac Newton to make otherworldly discs of tinted resin, died on March 14 in Manhattan. He was 83.

His death, in a hospital, was confirmed by his wife, Maria Larsson, who said that he died after a brief illness.

Mr. Eversley was a Brooklyn schoolboy of 12 or 13 when he first learned, from an issue of Popular Mechanics, that the centrifugal force created by spinning a vessel of liquid will push its surface into a parabola. Newton did this with a bucket and a rope; Mr. Eversley, working in his parents’ basement, used a pie plate of Jell-O on a turntable.

When he returned to the idea nearly three decades later, after giving up a career as an engineer, he was a fledgling sculptor in the busy artists’ community of Venice Beach, Calif., experimenting with plastics and dye. Using liquid polyester, which he called “the cheapest, the least toxic and the most transparent” resin available, he worked out a process for casting separate layers of resin colored violet, amber and blue in a spinning cylindrical mold.

The result was a form he stuck to for the next 55 years: a translucent disc, somewhat bigger than a vinyl record and much thicker, displayed vertically on a pedestal. Each disc has a highly polished parabolic concavity on one side that creates optical effects like a lens, sharpening and minimizing the view behind it. At the same time, the colors sparkle and change dramatically, according to the light in a given room and a viewer’s movements; as Mr. Eversley liked to say, it becomes a kind of kinetic sculpture without kinetic elements.

Over the years, Mr. Eversley produced opaque as well as translucent discs, worked at different scales, and made other parabolas by slicing through resin rings and tubes at sharp angles. Steadily successful at winning public commissions, he installed soaring curves of futuristic steel or glowing polyurethane at Miami International Airport, in West Palm Beach, Fla., and at the southern end of Central Park.

A charming and self-possessed man, he also acquired friends, mentors and patrons wherever he went. He used the sculptor Charles Mattox’s lathe to spin his first mold, was introduced to the gallerist Leo Castelli by Robert Rauschenberg and, according to his wife, became close friends with the influential collector Hans Heinrich Thyssen-Bornemisza after encountering him in an elevator.

Early on, he showed his work with other members of what became known as the Light and Space movement, an ethereal California spin on Minimalism. He was also associated with Finish Fetish, a movement that emphasizes new materials and the labor-intensive perfection of surfaces, and he was occasionally grouped with the Black Arts Movement, though some other Black artists found his work insufficiently political. (He made his first opaque disc after the sculptor John McCracken jokingly handed him a can of black pigment with which to make some “black art.”)

Still, with his engineering background, Mr. Eversley thought about what he was doing differently from how his peers did. His abiding interest was energy, in the scientific sense. And his abiding love was the only shape that, whatever hits it, whether light or sound, throws everything back into a single focal point: the parabola.

Frederick John Eversley was born in Brooklyn on Aug. 28, 1941. His father, Frederick William Eversley Jr., was an aerospace engineer and a contractor; his mother, Beatrice (Syphax) Eversley, taught at an elementary school. His paternal grandmother was Jewish, and his maternal grandmother was a member of the Shinnecock Nation.

In addition to his wife, he is survived by three younger siblings, Rani, Donald and Thomas Eversley.

As a child, Mr. Eversley liked to listen in on his father’s conversations with other engineers and to experiment with his grandfather’s camera equipment. He attended the progressive Camp Kinderland in Massachusetts; worked at the Folklore Center in Greenwich Village as a teenager as well as for his father’s aviation company; graduated from Brooklyn Technical High School; and met jazz greats like John Coltrane and Ella Fitzgerald at the Putnam Central Club, which his grandfather had founded, in the Bedford-Stuyvesant neighborhood of Brooklyn.

He was the first Black man to live on campus at Carnegie Mellon University in Pittsburgh, then known as the Carnegie Institute of Technology. In his senior year, the father of a fraternity brother offered him a job at Wyle Laboratories in El Segundo, Calif. He had already been accepted to medical school. But then he began dating a painting student with plans to spend the summer in San Miguel de Allende, Mexico.

“It’s a long story,” he recalled in a 2022 interview with the art historian Danielle O’Steen for the monograph “Fred Eversley: Parabolic Lenses,” “but my liberal parents suddenly turned on me and thought my idea was too wild. They refused to help out with money, so I figured the only way to spend the summer of ’63 in Mexico with Suzanne was to accept the job at Wyle and ask for advance payment.”

That fall he moved to Venice Beach and began running tests for NASA, private companies and the Department of Defense, like designing a special test chamber that bombarded the Apollo space capsule with high-intensity noise.

His plans were derailed again by a serious automobile accident in January 1967 that left him temporarily unable to work. By then he was surrounded by artists like James Turrell, whose studio was down the block; Richard Diebenkorn, whose studio was visible from his apartment; and Mr. McCracken, who moved in next door. Many of them came to him for help with engineering problems.

“Since I was on disability payment,” Mr. Eversley explained in the monograph, “I could play freely, without any pressure around staying out of the Army or making my living. I guess I felt like, if others can make art, I can, too. I really had nothing to lose.”

He started with photographic transparencies attached to the sides of plastic cubes illuminated by fluorescent bulbs. But soon, with the encouragement of friends like Mr. Mattox, John Altoon and Robert Rauschenberg, he dropped the photographs and focused on the plastic, casting and polishing luminous rectangles and cones. In 1969, when Mr. Altoon died, Mr. Eversley took over his studio, which had been designed by Frank Gehry.

Soon Mr. Eversley was enjoying a debut few artists could dream of. On a single day in 1970 he sold two pieces directly to the painter and influential gallerist Betty Parsons and was offered a solo show at the Whitney Museum of American Art by Marcia Tucker, with whom he had worked at the Folklore Center. That year he also had several solo shows at commercial galleries in New York, Chicago and Newport Beach, Calif., and appeared in more than a dozen group shows, including one at Pace Gallery in New York and one in Tokyo as well as several in California.

Despite this explosive beginning, for much of his career Mr. Eversley was, and had to be, his own best salesman. Fortunately, though he might have downplayed it, he had a talent for it.

“I really don’t believe, perhaps contrary to popular opinion, that my business techniques are that aggressive,” he said in a 1980 interview with Ocular magazine.

In 2018 he signed with David Kordansky Gallery, which has locations in Los Angeles and New York. The next year, after a yearslong dispute with his Venice Beach landlord, he returned to New York, where he owned a five-story loft building in SoHo. In 2023 Kordansky staged his first New York solo show since 1976, “Fred Eversley: Cylindrical Lenses.” For that show, he made a series of brilliantly colored seven- to nine-foot-tall monoliths, realizing an idea he first had decades earlier. Amanda Gluibizzi described them in The Brooklyn Rail as “megalithic and space-age at the same time.”

Shortly before his death, said Ms. Larsson, an architect who also managed her husband’s studio, Mr. Eversley was talking about what a charmed life he had had. If he did, it must have been at least partly because he came forward so eagerly to meet every opportunity.

“Fred showed up,” Ms. Larsson said. “He showed up everywhere. He used to say, ‘Maria, we need to show up.’”