Dangerous levels of arsenic at Chapman Field Park, the 560-acre park where county officials closed baseball diamonds on Wednesday, is more than 20 times normal levels in some areas, the county’s chief of environmental monitoring said Thursday.
The findings are puzzling because workers found no other chemicals at elevated levels, said Wilbur Mayorga, chief of Miami-Dade County’s Division of Environmental Monitoring and Restoration. At other parks in and around Miami that closed over the last year after residents began complaining about contamination from an old municipal incinerator in Coconut Grove, samples showed a toxic mix of heavy metals linked to ash.
“Some readers may be concerned with the results because of the city of Miami parks and the concerns with lead and ash. And this is not the case,” Mayorga said. “There was no evidence that this was like some of the other parks.”
Officials are now looking into the park’s history for clues about what generated the arsenic. Melted glass and other bits of solid waste were found in parks where officials believe incinerator ash was either used to fill former quarries, or just dumped. So far, they have found no indication that Chapman Field, a waterfront park just south of Coral Gables and mostly covered by mangrove forests, was either a dump or quarry.
Slightly elevated levels of arsenic are not uncommon in places such as Miami, where soil is rich with marine sediment and fossils. Soil on the county’s barrier islands averages about five milligrams per kilograms in the upper two feet, Mayorga said. That’s just above acceptable limits of about two milligrams.
South of Kendall, the average jumps to about seven milligrams per kilogram, he said. So while officials expected to see higher levels in Chapman Field, they were surprised at the levels first reported in May that showed dramatically high levels that got higher the farther west workers sampled. A second round of testing completed Tuesday turned up one sample with 102 milligrams per kilogram in the top six inches of soil, he said.
“We responded immediately,” he said, explaining he called a meeting with park officials about 11 a.m. Tuesday to recommend closing baseball diamonds where the concentrations were found.
The sampling was done as part of a review of all 263 county parks triggered in 2011 after federal officials found contamination around Olinda Park, built on an old dump in northwest Miami-Dade County. So far, the county has tested 192 of 263 park properties and only found contamination at Brothers to the Rescue Park, which sits next to the site of an old Coral Gables municipal incinerator just off Coral Way. Testing has focused on parks with public access, Mayorga said.
“We’re basically going down the list,” he said.
Workers will return to Chapman Field on Monday and Tuesday to do additional testing, he said. They also will test outside park limits to try to find the boundaries of the contamination. Once those tests are complete, he said, the county can come up with a plan to clean it up.