The City contracts ASC Geosciences, Inc. (ASC) to test the South Street property for lime sludge and finds approximately 25,000 cubic yards of sludge on the site. FDEP recommends testing for arsenic and aluminum. ASC tests 44 test pits at varying depths. Aluminum concentration is well below soil cleanup target level of 80,000 mg/kg in all 44 pts. Only one of the 44 test pits is found to have arsenic levels exceeding soil cleanup target levels for commercial/industrial of 12 mg/kg. Test pit #14 is found to have a concentration of 16 mg/kg, eight feet below the ground surface. All other pits are tested at or below target level.
ASC suggests several remediation scenarios, including:
• Excavating all of the sludge and replacing with clean fill.
• Excavating the top two feet of material and replacing with clean fill. (would likely require a deed restriction for the type of structures/foundations allowed)
• Excavating the top two feet of material, and chemically fixating the land with cement or other technique. (would likely require a deed restriction for the type of structures/foundations allowed)
A 2017 Estimate of the costs of each potential remediation strategy are estimated from $3 million to $17 million, depending on the strategy utilized and site-specific factors that cannot be determined at the current time.