Apopka officials describe sinkhole, liner failures at Golden Gem reclaimed‑water ponds; tests show no drinking‑water contamination

City utility staff told the Apopka City Council on Feb. 7 that the Golden Gem reclaimed‑water storage complex suffered a sinkhole last year and subsequent liner damage that rendered the larger pond inoperable.

Utility design manager Da Huo said the project, built under a multi‑year agreement with the St. Johns River Water Management District, includes two lined cells — a western cell of about 50 million gallons and an eastern cell of roughly 300 million gallons — and that heavy 2023 rains and inflows contributed to water elevations that exposed a design vulnerability. He said the sinkhole was discovered via satellite imagery and field inspection in January 2024 and phase‑one repairs to plug the sinkhole were completed in September 2024.

Da Huo said consultants conducted drinking‑water testing at three residential wells on May 15 and that results came back within normal regulatory ranges. The city also reviewed continuous daily monitoring from Rock Springs, a downstream recreational spring, and reported no detectable spikes in parameters such as dissolved oxygen, pH or nitrate that would indicate a degradation of groundwater quality tied to the incident. "We are confident at this point that the drinking water of our citizens in the area was not compromised by this incident," he said.

Council members pressed staff on a timeline and costs. Da Huo said the city had requested an extension of permit deadlines through April 2025 but expected it would be difficult to meet that target without more time; he said the pond cannot be returned to service until repairs and additional investigations — including geophysical subsurface scanning — are finished. He recommended a subsurface geophysical examination to map underground voids, removal of the geomembrane liner and installation of a compacted clay bottom, and consideration of partially abandoning the northern cell by building an earthen closure if investigations support that approach.

Blanche Sherman, the city's finance director, said about $950,000 had been authorized for initial phase work and that only about $16,000 remained unobligated from that under‑funded appropriation; preliminary estimates presented earlier to the council placed full repair costs between $10 million and $15 million, though staff and consultants said a detailed, itemized cost estimate is needed before the city can select a funding strategy. Sherman said some pump‑station or larger pump needs might be funded from a separate fund (403) or via transfers from the general fund if necessary.

Council members and staff acknowledged the public‑policy tradeoffs ahead: Golden Gem currently supplies reclaimed water storage that can be returned to distribution for public use, and repairs must balance technical risk, regulatory approval from FDEP and the St. Johns district, and fiscal capacity. Several commissioners asked staff to return with a timeline, a detailed cost estimate, and the city's formal extension request status with state regulators. The city noted the incident was reported to state authorities (FDEP) on Jan. 30, 2024, and that construction repairs have to be reconciled with permit conditions before the pond can resume receiving reclaimed flows.