Environmental Impact Statement - Sonoma Land Trust

California Department of Fish and Game
U.S. Fish and Wildlife Service
Section 3.3. Water Quality
c. waters to exceed the following quality limits at any time during
construction activities:
i) Dissolved oxygen: 5.0 mg/l minimum. When natural factors cause
lesser concentrations, then this discharge shall not cause further
reductions in the concentration of dissolved oxygen.
ii) Dissolved sulfide: 0.1 mg/l maximum.
iii) pH: A variation of natural ambient pH by more than 0.5 pH units.
iv) Toxic or other deleterious substances: None shall be present in
concentrations or quantities which may cause deleterious effects on
aquatic biota, wildlife, or waterfowl, or which render any of these unfit
for human consumption either at levels created in the receiving waters or
as a result of biological concentrations.
2. The concentrations of chemicals of concern, as found in grab samples taken
no more than 100 feet beyond the Project Boundary, shall not exceed the
Receiving Water Limits unless it can be shown that site conditions are not
significantly different from ambient concentrations of those chemicals (as
measured in the open waters of San Pablo Bay.
Monitoring – SLT or its contractors shall monitor background turbidity, total
suspended solids, dissolved oxygen, dissolved sulfide, pH and temperature levels
once daily at a location at least 300 yards from dredging activity. Monitoring
during dredging for these constituents shall be done every two hours at a point
no more than 100 feet outside the Project Boundary to ensure water quality
concentrations do not exceed the receiving water standards. Two turbidity
meters shall be used: one no more than 100 feet beyond the Project Boundary
and one in a suitable reference location located at least 300 yards from
construction activity.
Remedial Action – Where monitoring indicates exceedance of the receiving
water standards above for more than four hours continuously or for 8 hours in
any one week, then dredging activity shall be suspended until turbidity levels fall
below exceedance levels for a minimum of 4 hours. Additionally, SLT or its
contractors shall take efforts to avert the repeat of the exceedance. This may
require changing the pace of dredging or reconfiguration of silt curtains or other
measures, as necessary.
Alternative requirements established in conditions of permits issued by USACE
and RWQCB that are certified as protective of water quality by these agencies
will be considered the functional equivalent of the requirements listed above.
Conclusion: Less than Significant with mitigation.
Sears Point Wetland and Watershed Restoration
Project Final Environmental Impact
Report/Environmental Impact Statement
3.3-22
April 2012