Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Section 3.9. Hazardous Substances and Waste
Impact HAZ-2: Exposure of Humans, Plants, or Wildlife to
Contaminants as a Result of Black Point Sports Club
Remediation Activities – Excavation
Proposed Project
Studies by Northgate Environmental Management and Camp Dresser and
McKee, Inc. in 2003 and 2004, respectively, estimated approximately 8,300 tons
of soil on the Black Point Sports Club may need to be excavated from an area
approximately 300 feet by 650 feet within the shooting range perimeter
(Northgate Environmental Management 2006).
A preliminary and limited soil investigation was performed at the Sports Club by
Harris & Lee Environmental Sciences in 2003 (Harris & Lee 2003). This
investigation identified the occurrence of lead, arsenic, and polynuclear aromatic
hydrocarbons (PAHs) in the soil in the shallow zone extending from the surface
to five inches downwards. (Northgate Environmental Management 2006).
A comprehensive soil and groundwater investigation was conducted by
Northgate in 2006 to assess the distribution of chemicals at the shooting range.
The results of this study verified that soils in the vicinity of the Black Point
Sports Club contain lead, arsenic, and various PAHs primarily derived from
shotgun lead shot and clay targets (Wetlands and Water Resources 2007). 13 out
of 25 samples contained elevated (above background) levels of lead. Four
samples contained lead in high enough concentrations (above 1,000 mg/kg) to be
considered hazardous waste. Arsenic concentrations were found to be consistent
with regional background concentrations, and therefore are not of concern
(Northgate Environmental Management 2006).
The Water Board requested development of a Corrective Action Plan for
remediating the skeet range to address residual lead and PAHs that are contained
in shallow soil at the Sports Club. A Corrective Action Plan (Northgate
Environmental Management 2006) characterizing soil contaminant levels and
outlining appropriate remediation within the context of restoration was submitted
to the San Francisco Bay RWQCB in December 2006 and was approved in
November 2008.
The Corrective Action Plan showed soil contamination levels in the skeet range
to be beneath the legal threshold for contamination when averaged across 12,000
cubic yards of material at the skeet range. While this level is not considered a
threat to animals and wildlife, there is the potential for the transport of
contaminants into more sensitive wetland areas as a result of the Project that
requires the excavation and isolation of contaminated sediments.
In total, the volume of affected soil proposed for removal is approximately
12,000 cubic yards (measured as in-place volume). This is a potentially
significant impact. To reduce this impact to a less than significant level, SLT
would implement will Mitigation Measures HAZ-MM-2 and HAZ-MM-5a.
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
3.9-12
April 2012