The 20-foot thick overburden consists of various amounts of fill, alluvium, glaciolacustrine clay and till. It is underlain by the Lockport Dolomite. There are three fracture zones of interest in the Lockport at the site. The D zone is the uppermost and extends from the top of the rock to about 40 feet into it. About 22% of the water flow of the three zones is carried by it. The C zone begins about 60 feet below top of rock and is about 28 feet thick. It carries approximately 74% of the groundwater flow. The B zone is immediately below the C zone and while approximately 37 feet thick carries only 4 % of the groundwater flow.

• Dense Non-aqueous Phase Liquids (DNAPLs)
• Fractured Bedrock

The bedrock plume is 1,800 feet long where it intercepts an historic unlined sewer tunnel. The upper 125 feet of the bedrock is contaminated.

• Benzoic acid (150,000 µg/L)
• Hexachlorocyclopentadiene (12,000 µg/L)
• Trichloroethene (140,000 µg/L)
• Chlorobenzene (150,000 µg/L)
• 2-Chlorotoluene (98,000 µg/L)
• Benzene (33,000 µg/L)
• Tetrachloroethene (20,000 µg/L)
• 1,4-Dichlorobenzene (19,000 µg/L)
• 1,2-Dichlorobenzene (12,000 µg/L)
• Arsenic (11,000 µg/L)

• Pump and Treat

Containment.

The hydraulic and chemical monitoring results show that the extraction system is operating effectively. The hydraulic monitoring data show that hydraulic containment along the plant boundary has been achieved in the bedrock D, C and B Zones, and in some cases extends well beyond the plant boundary. The chemical monitoring data obtained from the off site monitoring wells since pumping began in April 1996 have shown that there has been a decrease in the level of organic compounds in the groundwater; a decrease attributable to the groundwater containment and extraction.

http://www.epa.gov/region02/waste/fsoccide.htm