HomeMy WebLinkAbout091024 - 05.1 ATTACHMENT C“Small Town Atmosphere
Outstanding Quality of Life”
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DRAFT MITIGATED NEGATIVE DECLARATION OF ENVIRONMENTAL
SIGNIFICANCE
LEAD AGENCY: Town of Danville -- (Fred Korbmacher)
NAME OF PROJECT: SUB22-0006 (SD 9264)
PROJECT DESCRIPTION: The subdivision of an existing 8.49-acre parcel into
seven single family residential lots
ENVIRONMENTAL EFFECTS/MITIGATION MEASURES:
1.GEOLOGY AND SOILS: Will the Project:
a)Expose people or structures to potential substantial adverse effects, including
the risk of loss, injury, or death involving:
ii)Landslides? Less Than Significant Impact with mitigations Incorporated.
Existing landslide on the subject properties could be subject to seismically
induced deformation and will require corrective grading to improve slope
stability as discussed in the report prepared by ENGEO Incorporated.
MITIGATION MEASURE 1: Landslides removals are depicted in Section 4.2.3 in the ENGEO
Incorporated report, which will require field inspections to make recommendations for adjusting
the depth and extents of removals based on revealed conditions.
b)Result in substantial soil erosion or the loss of topsoil? Less than
Significant Impact with mitigations Incorporated. Per the report prepared by
ENGEO Incorporated, recommend additional sulfated testing at the
completion of finished grading.
MITIGATION MEASURE 2: Erosion Control is outlined in Section 4.8 in the ENGEO
Incorporated report. The applicant shall be required to follow the recommendations to include
revegetation of graded slopes with organic-rich stripping’s and spreading these materials in a thin
layer (approximately 6 inched thick) on graded slopes prior to winter rains and following rough
grading. All landscape slopes shall be maintained in a vegetated state after project completion. The
use of drought-tolerant vegetation requiring infrequent drip irrigation during summer os
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recommended. No pressurized irrigation lines should be placed on or near the tops of graded
slopes.
c) Be located on a geologic unit or soil that is unstable, or that would become
unstable as a result of the project, and potentially result in on- or off-site
landslide, lateral spreading, subsidence, liquefaction or collapse? Less than
Significant Impact with mitigation Incorporated. According to the
Geotechnical report prepared by ENGEO Incorporated, it is recommending to
design improvements to mitigate these concerns.
MITIGATION MEASURE 3: Removals for General Subexcavation, Existing Fill, Landslide
Removals are outlined in Section 4.2 of the ENGEO Incorporated report.
d) Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building
Code (1994), creating substantial risks to life or property? Less than
Significant Impact with mitigations Incorporated. Landslides and expansive
soil hazards exist throughout the Danville area. Expansive soil can be mitigated
by proper foundation design and grading measures. These mitigation
measures are detailed in the report prepared by ENGEO Incorporated.
MITIGATION MEASURE 4: The applicant shall follow the recommendations of the soils report
prepared by ENGEO Incorporated Section 5.0 FOUNDATION RECOMMENDATIONS.
2. NOISE: Would the project result in:
d) A substantial temporary or periodic increase in ambient noise levels in the
project vicinity above levels existing without the project? Less than
Significant Impact with Mitigation Incorporated. Noise levels would
temporarily be increased due to noise associated with the construction of
the project. The noise impact will be less than significant given required
standard conditions of approval which define and limit hours of
construction.
MITIGATION MEASURE 5: The applicant shall require their contractors and subcontractors
to the period between the weekday hours of 7:30 a.m. to 5:30 p.m. (Mondays through Fridays),
unless otherwise approved in writing by the City Engineer for general construction activity and
the Chief Building Official for building construction activity. Prior to any construction work on
the site, including grading, the applicant shall install a minimum 3’ x 3’ sign at the project entry
which specifies the allowable construction workdays and hours, and lists the name and contact
September 3, 2024
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person for the overall project manager and all contractors and sub-contractors working on the job.
3. UTILITIES AND SERVICE SYSTEMS: Would the project result in:
c) Require or result in the construction of new storm water drainage facilities
or expansion of existing facilities, the construction of which could cause
significant environmental effects? Less Than Significant with Mitigation
Incorporated. The project will be required to comply with all stormwater
quality requirements. The project proposes self-retaining pervious areas
and a bio-retention basin. Calculations were computed on the Contra Costa
Clean Water Program’s IMP calculator to determine C3 compliance.
MITIGATION MEASURE 6: Stormwater and surface water runoff shall be directed into the
property’s public storm drain system. The applicant shall be required to pay the Excavation
Mitigation Fee to Contra Costa County Flood Control.
DETERMINATION: Based upon the above identified mitigation measures, no
significant environmental impacts are anticipated to be
associated with the subject project. A Draft Mitigated
Negative Declaration of Environmental Significance has been
prepared.
The Initial Study was prepared by the Planning Department, Town of Danville. Copies
of the Initial Study may be obtained at the Town offices located at 500 La Gonda Way,
Danville, California 94526.
ATTEST:
Fred Korbmacher
Development Service Coordinator