The Wyckoff property occupies approximately 57 acres, including a spit with about 0.8 miles of shoreline extending northward into Eagle Harbor on the eastern side of Bainbridge Island, Washington.  The spit was extended and filled at least twice prior to the 1950s, and was the location of wood treatment activities that have caused the current soil and groundwater contamination.

In late summer 2005, Bainbridge Island residents reported the presence of creosote odors and orange staining along the beach in the western portion of the Wyckoff site that had been opened for public recreational use.  Upon inspection, USEPA found evidence of residual contamination and sheen on the beach in the area where the Wyckoff Company had built bulkheads at the shoreline.  A pipeline linking the creosote unloading dock with the creosote tank on the property was also located within the bulkhead area.  In 2000, USEPA had removed the bulkheads and creosote pipeline, as well as contaminated soils and sediments behind the bulkheads and added clean sand to create the current beach.  Based on historical operation information, field observations and analytical results for samples collected in late 2005, it appears that some contaminated materials were not removed from the area when the bulkheads were removed and the beach was constructed.  These materials because exposed when the layer of sand added during beach construction was eroded and redistributed over time.  The primary visibly contaminated area is about 150 feet long by 50 feet wide and extends from the midpoint of the beach to the zero foot mean lower low water (mllw) contour line.  No active creosote seeps have been identified in the area.  The visibly contaminated portion of the beach was roped-off and warning signs were posted in September 2005 to restrict access to this area.

Soil and groundwater at the Wyckoff site are contaminated primarily with creosote and pentachlorophenol (PCP) that were used as wood preservatives.  Free-phase product is known to exist in the subsurface soil as well as dissolved contaminants in groundwater and absorbed contaminants on the soil matrix.

Prior to 1904, the Wyckoff property was owned by a sand mining operation, a brickyard and an oxen yoke-manufacturing business.  From 1904 through 1988, the site was used for the treatment of wood products (e.g. railroad ties and trestles, utility poles, pilings, docks, and piers) by a succession of owners and companies.  Chemicals used at the site include creosote, pentachlorophenol, solvents, gasoline, antifreeze, fuel, waste oil and lubricants.  These chemicals were stored in aboveground storage tanks, conveyed through above-and belowground piping, disposed in sumps, and spilled and buried on site.

EPA began an investigation of the property in 1971, and the site was subsequently placed on the National Priority List.  In 1988, the Wyckoff Company ceased all operations on the property.  In 1993, EPA assumed management of the soil and groundwater operational units (OU’s) and in 1994 the assets of the former Wyckoff Company (now Puget Sound Resources) were placed into an environmental trust.

All wood-treatment structures in the lowland portion of the site, including buildings, foundations, tanks, pipelines and sumps, were removed between 1988 and 1997.  A groundwater treatment plant, monitoring and extraction wells, and a conveyance piping system for groundwater remediation are in place and in use.

The main source of contamination has been the direct release at the ground surface of materials containing polycyclic aromatic hydrocarbons (PAHs and PCP) and dioxins/furans from former wood-preserving operations, and the subsequent migration of these contaminants.

Specific sources of contamination include:

• Discharge of wood preservatives directly onto the ground and into unlined sumps and pits.
• Leaks from former aboveground tanks and associated surface and subsurface piping that contained creosote and pentachlorophenol wood-preserving mixtures.
• Buried sludge that originated from on-site process operations.
• Crystalline naphthalene found buried in (and subsequently removed from) vadose zone soil.
• Drippings from treated logs, poles, and railroad ties.

The wood preservant at this site used the preservatives creosote and PCP.  Creosote is a blend of various coal tar distillates that may contain up to 90 percent PAHs mixed with other hydrocarbons.  Technical-grade PCP contains 85 to 95 percent PCP; the remainder is a mix of other polychlorinated phenols and about 0.1 percent dioxins and furans.  Both creosote and PCP were mixed with an aromatic carrier oil such as No. 2 fuel oil prior to use for wood preservation.  (Note: metals have not been contaminants of interest at this site because there is no record that they were used as part of the wood-preserving process.)

Chemicals detected in light nonaqueous-phase liquid (LNAPL) and dense nonaqueous-phase liquid (DNAPL) are consistent with the products historically used on site (i.e., creosote, pentachlorophenol and aromatic carrier oils).  These two liquid phases generally contain varying concentrations of PAHs, polychlorinated phenols and various other semi volatile and volatile organic compounds.  Detected chemical concentrations in LNAPL and DNAPL are similar, except that PCP is more prevalent in LNAPL.

LNAPL is associated with upper-aquifer groundwater and has been detected beneath the former process area.  LNAPL has been measured at a maximum thickness of 1.2 feet around operating extraction wells.  NAPL associated with inter tidal seeps has also been observed along the eastern and northern shoreline, and appears to coincide with onsite observations of LNAPL in groundwater.

DNAPL associated with the upper aquifer has also been primarily detected beneath the former process area.  It has been measured at a maximum thickness of approximately 10 feet in the extraction wells.