Timeline
Three hundred years, and three decades of quiet
Every entry below is dated and sourced. Where an agency document and a news report disagree, both appear. Highlighted rows are the four moments that changed what was officially known.
The shape of the record
Nineteen dated entries across three hundred and forty-seven years. Almost all of them fall in the last four decades, and one stretch is empty.
The shape of the recordNineteen dated entries across three hundred and forty-seven years. Almost all of them fall in the last four decades, and one stretch of twenty-eight years carries nothing at all. Hover or tap a band to read it.
Bands mark periods with documents on the record, not continuous activity
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1679
Le Griffon
The location is believed to be where René-Robert Cavelier, Sieur de La Salle, built the barque Le Griffon, the first sailing vessel to work the upper Great Lakes. A commemorative rock at Griffon Park, on the mainland shore, marks the story.7
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early 1900s
The west end is first extended with fill
DEC’s account: the western end of Cayuga Island was extended into the Niagara River using fill.1
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1958–1962
Extended again, this time with industrial material
DEC: the western end was extended again between 1958 and 1962 “using fill that included industrial material.”1 This is the origin of everything that follows.
The Niagara Gazette reports the extension pushed roughly 240 yards into the river, and gives wider date ranges for the fill activity — 1950 to 1980 in one account, 1960 to 1982 in another.45 DEC’s published range is the narrower one used here.
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1984
A joint EPA and USGS report
Per the Niagara Gazette, a joint EPA/USGS report that year confirmed toxic chemicals at the site, and the DEC investigation of that era was completed in 1984.4 DEC’s own 2026 fact sheet does not mention 1984 and points instead to assessments in 1992 and 1993. The two accounts have not been reconciled publicly.
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1 May 1988
Phase I report, Griffon Park
The first investigation document in DEC’s file for Griffon Park — site 932081, on the mainland shore across the Little River.8
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1992 & 1993
DEC and DOH assess the island, and notify every owner
DEC, working with the Department of Health, conducted site assessments and sampling. The assessments “identified sporadic contamination of mercury, pesticides, and other contaminants in surface and subsurface soils.”1
Notices detailing the contaminant levels were provided to each property owner, and owners were told to contact DEC or DOH before doing ground-intrusive work on their properties.1 This is the fact that makes the 2025 discovery a rediscovery.
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1 Nov 1993
Preliminary Site Assessment, Griffon Park
A two-volume PSA is filed for site 932081.8
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1993–2021
The gap
No investigation document for the Cayuga Island site appears in DEC’s public folder for this period; the folder’s earliest posted item is the February 2026 fact sheet.9 The Gazette describes attention as having waned “for roughly two decades” until testing resumed in autumn 2025.4 An environmental attorney, Christen Civiletto, called the delay “alarming” and “inexcusable,” noting that families lived above the material without knowing.4
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23 Feb –
23 Mar 2022Griffon Park: five monitoring wells, and fill 5 to 17 feet down
Under DEC’s Inactive Landfill Initiative, five new monitoring wells were installed, developed and sampled at Griffon Park. Fill material was identified in five borings at depths between 5 and 17 feet below ground surface, including clear and brown glass, metal, cloth, brick fragments, cinder and wood.10
This is across the Little River from the island, not on it — but it is the most specific published description of what mid-century fill in this neighbourhood actually contains.
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Mar 2023
Griffon Park field and summary reports posted
DEC posts the Inactive Landfill Initiative summary report (1 March) and field activities report (9 March) for site 932081.8
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Oct 2025
A crew smells something in the right-of-way
A contractor working for the Niagara Falls Water Board drills soil borings in the West Rivershore Drive right-of-way ahead of water-main placement and reports a chemical odour in the ground. Subsurface samples submitted to DEC show “elevated levels of several contaminants related to industrial material.”1
Local reporting identifies the firm as CPL Engineering and says two borings were involved.5 DEC follows up by collecting its own soil samples from the same right-of-way.1
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early Dec 2025
Results come back above residential screening levels
DEC receives its results. They are “consistent with historical data” and show “exceedances of DEC screening levels in residential settings for several contaminants.”1
DEC cites three reasons for acting now: the new data, the historic use of fill in creating the island, and revised requirements for addressing contamination.1 The standards changed, not only the evidence.
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Feb 2026
DEC contacts property owners on the westernmost tip
Outreach begins to potentially impacted owners, offering a three-part sampling programme: surface soil, sub-slab soil vapour with indoor air, and sump water.1
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9 Feb 2026
First public fact sheet
DEC posts “Investigation” to the site 932008 document folder — the first public document in the file.9
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spring 2026
Sampling at properties that granted access
DEC’s contractor collects soil, sub-slab soil vapour, indoor air and sump water samples at properties whose owners provided voluntary access. Results are “provided directly to the property owners.”1 DEC had anticipated completing this phase in spring 2026.5
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Jun 2026
A community meeting, and a public disagreement
Roughly 22 affected property owners attend a meeting at the LaSalle branch library.5 Mayor Robert Restaino says of the state: “The New York State DEC is on this project, and I am sure they will do all they can to attend to what is there and have remediation of what is there.”5 DEC Region 9 Director Chad Staniszewski confirms the agencies are evaluating potential health risks.5
Assemblyman Angelo J. Morinello asks residents to cooperate. Property owner and former FBI agent J. Gary DiLaura publicly disputes that any danger exists.6
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17 Jun 2026
Griffon Park samples reach the laboratory
Soil, sediment and groundwater samples from Griffon Park are received by Pace Analytical Services in East Longmeadow, Massachusetts, submitted by LaBella Associates of Rochester on DEC’s behalf. The analytical suite covers volatile and semivolatile organics, 1,4-dioxane, organochlorine pesticides, PCBs, total metals, anions and general chemistry.11
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23 & 29
Jul 2026Griffon Park results posted — and labelled unvalidated
DEC posts a July 2026 analytical report explicitly marked unvalidated, and a sampling summary memo.8 Because DEC itself has not validated that data, no findings from it are summarised on this site.
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1 Sep 2026
Impacts confirmed indoors; a second phase begins
DEC posts West Cayuga Island — Site Investigation Update. Findings from participating properties to date “confirmed some impacts to indoor air and soil.” Property-specific mitigation plans are “underway.” DEC and DOH “are beginning a second phase of investigations,” with offers to be extended to additional properties along West Rivershore Drive. All work is “at no cost to the homeowner.”1
Sources on this page
- NYSDEC, West Cayuga Island — Site Investigation Update (1 September 2026). Primary
- Mark Scheer, “Two decades since DEC last probed Cayuga Island contaminants”, Niagara Gazette, 20 June 2026. Reporting
- Mark Scheer, “DEC: chemical sampling underway on west end of Cayuga Island”, Niagara Gazette, 15 June 2026. Reporting
- Dave McKinley, “Investigation into Cayuga Island contaminants continue”, WGRZ, 17 June 2026. Reporting
- Niagara Falls USA, Griffon Park & Boat Dock; Wikipedia, Cayuga Island. Background
- NYSDEC document folder, site 932081, Griffon Park. Primary
- NYSDEC document folder, site 932008, Cayuga Island. Primary
- NYSDEC, Field Activities Report — Inactive Landfill Initiative, Griffon Park, 9 March 2023. Primary
- NYSDEC / Pace Analytical Services, Griffon Park July 2026 Analytical Report (unvalidated), 23 July 2026. Primary