In May 2019, the Leslie Science & Nature Center’s friends, supporters, and staff were exuberant: the long-anticipated outdoor “Nature Playscape” was set for groundbreaking. The City of Ann Arbor, the Michigan Council for Arts and Cultural Affairs, and Toyota Research and Development all helped to fund it. Rusty Keeler of Earthplay had a draft plan, and Michigan Recreational Construction Inc. was set to build it. A decades-long dream was coming true.

Until it wasn’t.

Instead of an invitation to the groundbreaking, the LSNC website announced in June that, effective immediately, all programming would be relocated off-site, including day camp for hundreds of kids. “Our contractor found an unnatural depression in the woods [where the Playscape would be] with an unnatural looking material at the base of the depression,” the release revealed. Soil testing uncovered “elevated levels of heavy metals and other contaminants … Out of an abundance of caution we have decided to relocate programming effective immediately.”

Those familiar with the bucolic LSNC site–adjacent to Leslie Park, Leslie Golf Course, and Black Pond Woods Nature Area along Traver Rd. in northeast Ann Arbor–might wonder how such a visually pristine site could contain elevated levels of arsenic, cadmium, chromium, copper, lead, zinc, selenium, silver, and mercury, plus volatile and semi-volatile organic compounds. Levels of arsenic and lead at the Playscape site were “above residential direct contact criteria,” according to the report from engineering consultants at the Ann Arbor office of Tetra Tech.

Susan Westhoff, LSNC’s executive director, says that the center’s office, the Leslie farmhouse, and the Critter House were tested, as were the air and soil around the raptor cages, and all “were fine.” However, she says, the DTE Energy House requires air-quality improvements.

That building, which showcases energy systems, building techniques, and recycled materials, is home to many of LSNC’s camps and most of its educational programming. It also is used for special events and rented to other organizations.

Westhoff says the DTE Energy House “sits roughly where the laboratory building of Leslie Laboratories was.” In a September letter, Tetra Tech put it more precisely: “The western half of the current DTE Energy Nature House sits over the former laboratory.”

“Leslie Laboratories” is the answer to the question: how did such a “pristine” site become so contaminated?

Eugene H. Leslie (1892-1976) and his wife Emily Hebner Leslie (1890-1976) met at Columbia University, where Emily studied home economics and Eugene earned a doctorate in chemical engineering in 1916. He then served as chief chemist at the General Petroleum Corporation in Los Angeles and later as assistant to the president of the U.S. Industrial Alcohol Company in New York. In 1919 he joined the U-M engineering faculty. There, based on his doctoral research and work experience, he wrote a hefty tome, Motor Fuels: Their Production and Technology, in 1923.

While Dr. Leslie was researching and teaching at the U-M, Mrs. Leslie made a place for herself in the broader community with a focus on gardening. She was involved in the Woman’s National Farm and Garden Association and was president of the Ann Arbor Garden Club, winning several awards at its 1957 Festival of Flowers.

In 1923, the Leslies bought a house and four acres of land at 1831 Traver Rd. Eventually they acquired a total of 229 acres, operating a 200-acre farm around the house and on what is now Leslie Golf Course. They established an apple orchard with more than 400 trees, grazed cattle and hogs, and raised a variety of crops. Neighborhood children could play, fly model planes, hold ball games, and build forts on the homestead. According to an LSNC history, the Leslies cherished their open space, feared development of it after their deaths, and wanted to provide for “an awful lot of youngsters in this area who need a playground.”

Dr. Leslie stayed at the university until 1928. Then, according to the Regents’ Proceedings, he resigned to “meet the increasing demand made upon him for professional services in the petroleum industry.” The LSNC history quotes him as saying that the university “told me to choose between teaching and consulting.”

Leslie Laboratories’ main building was not far from the couple’s house. Earlier in his career, Dr. Leslie had improved toluene and acetone, essential in World War I as components of trinitrotoluene, also known as TNT. During World War II, he discovered a substitute for natural rubber.

Most of Leslie’s career, however, was devoted to finding ways to extract more gasoline from crude petroleum and to improve gasoline so that cars got better mileage. By 1924, he and other researchers had raised the percentage of gasoline derived by a given volume of crude oil from 20 percent to 70 percent, enabling the continued growth of the nation’s auto industry.

Leslie also experimented with a wide variety of gasoline additives. He may well have worked with Phillips Petroleum on the discovery that tetraethyl lead and toluene improved the performance of aircraft and automobile engines. Leslie’s papers at the Bentley Historical Library include two folders of Phillips Petroleum Company material and documents from two dozen other petroleum and refining companies. From the mid-1940s to the mid-1960s, he also used the lab for research related to his farming.

Both the Leslies died in 1976, leaving the buildings and 229 acres to the city. On that property, the city developed Leslie Golf Course, Leslie Woods, Leslie Park, and the Leslie Science Center.

The science center opened in 1986 under the management of the city Parks and Recreation Department, which had written a master plan for it. In 2007, LSC separated from the city as a 501(c)3 organization with a board of directors. The city continued to own the property, but, according to the group’s history, letting an independent nonprofit manage it was “the best option for a sustainable future in the face of dwindling municipal dollars.” To better reflect its mission, the organization’s name was expanded to the Leslie Science & Nature Center.

The city knew in 1977, as it began to implement the Leslies’ wishes, that Dr. Leslie had two laboratories on the property: the one near the house and another on what is now Leslie Golf Course. The golf course lab, used by Leslie’s U-M students, had burned down earlier. The lab near the house was filled with chemicals used for both petroleum and farm-related research.

The city removed all the chemicals from the remaining lab in March 1977, informed by a six-page inventory dated July 22, 1946. Parks superintendent George Owers consulted with William Joy, of the U-M Department of Occupational Safety and Environmental Health, writing that the “City did not want responsibility for … liabilities … [from] accidental spillage of these chemicals.”

Apparently speaking of that 1977 removal, the Leslies’ former housekeeper, Helen Bezzeg, said in a 1985 interview: “The city was alarmed to find that the lab had some dangerous chemicals in it … One of the city guys said ‘he [Leslie] had enough out there to blow the city off the map.'” She added that the tiny red house just next to the lab held “a lot of sprays, poison, and so on.”

Bezzeg also said that Dr. Leslie did “not really” ever say that he had been wrong about anything, or made a terrible mistake. On the other hand, “Mrs. Leslie insisted that the chemicals that they’d been using was wrong [sic]. And she was always preaching to him that you are going to defeat your own purpose … and if you don’t go ahead and take care of [the property] you’re going to wear it out.”

Environmental concerns surfaced again in 1991. After neighbors successfully fought a proposed development nearby, the city ended up buying the property, which is now the Black Pond Woods Nature Area. Gardeners from a Project Grow parcel found barrels leaking liquid with a strong petroleum odor in the woods and reported that to the city.

In January 1992, the city ordered the razing of a shed behind the lab. It also hired consultants Atwell-Hicks to do site evaluation and environmental testing at the Black Pond Woods and the Leslie Science Center properties.

In November 1992, the consultants reported finding thirty-five drums and elevated levels of tetrachloroethylene in the soil. They recommended the city discuss these results with legal counsel, have a qualified contractor dispose of the drums, and conduct an investigation at the Leslie Science Center to evaluate the vertical and horizontal extent of soil contamination.

The report identified four locations to investigate for contaminants: a depression north of the road surrounding the orchard; a concrete pit next to the spray house; the former laboratory; and the orchards, which ran along Traver Rd. and wrapped around the east, north, and west sides of what are now the LSNC buildings.

Was the investigation to evaluate the soil contamination ever done? Tetra Tech’s report to the city includes an Oct. 2, 1995 letter from Gerald Clark of the city Parks & Recreation department to the Michigan Department of Environmental Quality that refers to the Atwell-Hicks recommendations this way: “No further investigation of the soils has taken place.” The letter has a handwritten note at the top saying: “Nancy: We must follow up on soils testing and cleanup.”

“I haven’t come across anything that indicates what the follow-up was to that memo,” says city community services area administrator Derek Delacourt. Patti McCall at Tetra Tech also drew a blank: “I reviewed the documents that were available in both the city and state’s records. Based on what was available I cannot determine if additional work was completed.” But judging from last summer’s findings, it was not.

According to Delacourt, last year’s discoveries set off “a very cooperative process” to identify the contamination and then plan, carry out, and pay for its remediation. The city is leading the way because it owns the buildings and the land.

Delacourt says “they are poking holes all over the property,” have examined its history, and have removed some contaminated soil and replaced it with clean soil. They found nothing in the groundwater, he adds. Because testing found all buildings other than the DTE Energy House were safe, the staff, birds, and animals can remain where they are. But the DTE building needed a vapor intrusion mitigation system to prevent volatile organic compounds such as tetrachloroethylene–listed in Dr. Leslie’s 1946 inventory–from entering the building. And before programs can return, the contamination in other areas must also be remediated.

Delacourt says the Washtenaw County Brownfield Redevelopment Authority (WCBRA), the Ann Arbor planning department, and the city council have all approved a remediation plan. The WCBRA will cover the estimated $535,438 cost, using a revolving fund of money normally used for “tax increment financing.” Delacourt says that will “reduce the potential for impacts to the city parks funding.”

TetraTech’s Patti McCall emails that the floor of DTE Energy House “was sealed in November and a mitigation system was installed, which is working effectively.” But in February, the company was still testing the air there, as well as new soil samples. Delacourt says that the city is working with the Michigan Department of Environment, Great Lakes, and Energy (EGLE) to establish the cleanup criteria for the site, particularly for arsenic. That needs to be resolved before the remediation can be completed.

Last summer, LSNC found new venues for programs that included 900 summer campers, who went to Buhr Park. They’ll be relocated again this year. “At this time we have moved all of our programming off-site through the summer,” Westhoff emails, “and await more information to be able to know what next steps look like.”

The dislocation has affected the LSNC’s ability to provide programs, which in turn affects its finances. Westhoff praises the “flexibility, fortitude, and passion shown by” the staffs of Leslie and partner organization the Hands-On Museum, city parks staff, and LSNC’s many volunteers. However, she writes, LSNC “continues to see a shortage of normal programs.” She says that the loss of indoor and outdoor space means no weekend overnights at all, no birthday parties, and no more field trips for eighty or ninety kids–with the DTE Energy House closed, forty is the new maximum.

The LSNC’s 2019-20 budget is $913,342. “We have absorbed about $87,949 in additional expenses, on top of lost revenue of $32,000 in summer camp, and 38 percent of our regular fall programs,” Westhoff writes, adding that more campers cancelled than were added from the wait list. She underlines that LSNC needs extraordinary additional support: money, space, and expanded partnerships to “ensure the organization is sustainable well into the future, regardless of our site.”

This unfolding story, which Delacourt called “most unfortunate,” holds a lesson being learned across the country. Innovative work in science such as Dr. Leslie’s may appear to provide a miraculous improvement in agricultural and industrial productivity but later be found to be an environmental nightmare. Mrs. Leslie’s warning about chemicals could have included adding tetraethyl lead to gasoline to improve a car’s performance and using lead arsenate spray to prevent codling moths on apple trees–both of which are now banned.

The city apparently did not connect the dots between Leslie’s profession as a chemical engineer, the chemicals in the laboratory on the property, and potential environmental damage.

Paradoxically, the legacy of Dr. Leslie’s science is, at least for now, preventing children from experiencing the nature he so wanted them to enjoy. And the much longed-for Nature Playscape is on hold, at least for now.