HomeMy WebLinkAbout3184; CANNON ROAD WEST; MITIGATION MONITORING RESULTS; 1999-09-03Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 /619-640-0763 San Diego, CA 92108-4003 www.ise-advantage.com
September 3, 1999 RECEIVED
Mr. Doug Gettinger SEP - 7 1999
Ogden Environmental and Energy, Inc
5510 Morehouse Drive ENGINEERING
San Diego, CA 92121 DEPARTMENT
Re: Cannon Road Mitigation Monitoring Results - Week #22 (9-2-99)
(ISE Report #99-009v, 035)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on September 2, 1999. The results of that
survey are presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at I-S to El Camino Real. The Cannon
Road extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek' are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the banks. of P'e Agua Hedionda Creek.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #22 (9-2-99)
ISE Report #99-009v, 035
September 3, 1999
Page 2
KIA
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L ( /
Project AllQnmen
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s
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Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
Acoustical Definitions
Airborne sound is a rapid fluctuation of air pressure above and below
atmospheric levels. The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level
of zero '0" dB is scaled such that it is defined as the threshold of human hearing and
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level.
Most of the sounds we hear in the environment do not consist of a single -
frequency, but rather a broad band of frequencies differing in sound level. The
intensities of each frequency add to generate the sound we hear. The method
commonly used to quantify environmental sounds consists of determining all of the
frequencies of a sound according to a weighting system that reflects the nonlinear
response characteristics of the human ear. This is called "A" weighting, and the decibel
level measured is called the A-weighted sound level (or dBA). In practice, the level of a
noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve.
- Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -. Week #22 (9-2-99)
ISE Report #99-009v, 035
September 3, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the L10 typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be//ii
push/us) and the southwestern willow flycatcher (Empidonax trail/ii extnmus) and the
federally threatened California gnatcatcher (Polio pt/la California).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species. Management Plan for the least Bell's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #22 (9-2-99)
lSE Report #99-009v, 035
September 3, 1999
Page 4
M. Analysis Methodology
Existing Conditions Field Survey
Four Larson Davis Model 700 ANSI Type 2 integrating sound level meters were
used as the data collection devices. The meters were positioned at the locations shown
below in Figure 2 and the accompanying matrix.
VIL
gua 30
/EvapPInt
'\ P
. .ç Agua
V 357
..:.)..., •. -e .
,.
N.
/9 rM*Iy,TkT 0 1/2 I MILE I 11 IMII I 11340 1000 0 1000 2000 3000 4000 FEET
1 I I'I rM,H
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS L.at GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
ML #4 n/a 330 08.194 N 1170 18.401 W Macario Canyon Area
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #22 (9-2-99)
ISE Report #99-009v, 035
September 3, 1999
Page 5
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Findings
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to excavating, bridge fabrication, light grading and associated ancillary
activities. To date, the least Bell's vireo has been predominantly located between
station markers 103+00 and 108+00. These station markers correlate with ISE
monitoring locations 1 and 2. Additionally, as of August 31, 1999, USFWS has officially
released the habitat within Macario Canyon from any further mitigation monitoring. As a
result, no noise monitoring was performed at ISE monitoring location ML 4 during the
Week #22 monitoring period.
During the Week #22 monitoring period, construction activities associated with
the Cannon Road West Project were associated with the dismantling of the temporary
noise wall along El Camino Real and erection of a new temporary wall to be located
along the stretch of habitat adjacent to station marker 110+00.
Testing conditions during the monitoring intervals were clear with an average
barometric pressure reading of 29.95 in-Hg, an average westerly wind speed of 0 to 5
miles per hour (MPH), and an approximate mean temperature of 75 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and.Lmin), and the statistical indicators L10, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #22 (9-2-99)
ISE Report #99-009v, 035
September 3, 1999
Page
Table 1: Measured Construction Levels - Cannon Road Alignment
Site Leg
1-Hour Noise Level Descriptors in dBA
.Lmax. Lmin LIO L50 L90
9:00 a.m.
ML 1 55.0 66.0 46.0 57.5 54.0 50.5
ML 2 55.5 75.0 43.0 58.0 54.0 48.5
ML 3 54.0 77.0 39.5 53.5 43.0 41.0
ML 4 n/a n/a n/a n/a n/a n/a
10:00 a.m.
ML 1 56.0 69.5 44.0 59.0 54.5 51.0
ML 2 55.0 62.5 42.5 58.0 54.5 50.0
ML 3 58.5 69.0 40.5 61.5 57.5 42.5
ML 4 n/a n/a n/a n/a n/a n/a
11:00 a.m.
ML 1 56.5 77.0 43.5 57.5 55.5 50.5
ML 2 48.5 66.5 40.5 51.0 43.0 41.5
ML 3 55.5 64.0 43.5 58.5 55.0 49.5
ML 4 n/a n/a n/a n/a n/a n/a
12:00 p.m.
ML 1 57.5 74.5 44.0 60.0 56.0 49.5
ML 2 53.5 49.5 45.5 41.5 37.5 33.5
ML 3 56.0 76.5 40.5 57.5 44.0 42.0
ML 4 n/a n/a n/a n/a n/a n/a
1:00 P.M.
ML 1 57.0 76.5 44.5 59.0 56.5 51.5
ML 2 55.5 76.0 40.5 57.0 45.0 41.5
ML 3 58.0 72.0 43.0 59.5 56.0 51.0
ML 4 n/a n/a n/a n/a n/a n/a
ML 4 released per USFWS memo dated 8/31/99
Measurements collected at monitoring locations, ML 1 through ML 3, reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. All monitoring stations were below the 60-dBA
Leq-h impact threshold during the Week #22 monitoring period. The highest hourly.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results Week #22 (9-2-99)
ISE Report #99-009v, 035
September 3, 1999
Page 7
energy equivalent sound level (Leq-h) recorded for monitoring locations ML 1 through 3
was 58.5 dBA and was due entirely to traffic activity along El Camino Real.
Recommendations
All monitoring locations were observed to be below the 60-dBA Leq impact
threshold throughout the duration of the Week #22 monitoring period. ISE recommends
no further mitigation at this time.
Since no further construction is planned within the Cannon Road West
Extension alignment until 9/16/99 (the release date for noise mitigation requirements),
ISE recommends closure of the noise-monitoring plan at this time. This report will
constitute the final report for this monitoring plan.
Should you have any questions regarding the above, please do not hesitate to
contact me at (619) 640-9379.
Sincer
Rick Tavares, REA, INCE
Project Principal
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
8 (v%t)
RECEIVED
Investigative Science and Engineering .1111 091999
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 / 619-640-0763
San Diego, CA 92108-4003 www.iseadp4 R ING
DEPARTMENT
July 8, 1999
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc.
5510 Morehouse Drive
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #15 (7-7-99)
(ISE Report #99-0090)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (lSE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on July 7, 1999. The results of that survey are
presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the banks of the Agua Hedionda Creek.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #15 (7-7-99)
ISE Report #99-0090
July 8, 1999
Page 2
I, tf I
9
..*. -. ". . '.. .:
PA
*
Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
Acoustical Definitions
Airborne sound is a rapid fluctuation of air pressure above and below
'atmospheric levels. The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level
of zero "0" dB is scaled such that it is defined as the threshold of human hearing and
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level.
Most of the sounds we hear in the environment do not consist of a single
frequency, but rather a broad band of frequencies differing in sound level. The
intensities of each frequency add to generate the sound we hear. The method
commonly used to quantify environmental sounds consists of determining all of the.
frequencies of a sound according to a weighting system that reflects the nonlinear
response characteristics of the human ear. This is called "A" weighting, and the decibel
level measured is called the A-weighted sound level (or dBA). In practice, the level of a
noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve.
Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results Week #15 (7-7-99)
ISE Report #99-0090
July 8, 1999
Page
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in-which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors LIO, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the LIO typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be/Ill
push/us) and the southwestern willow flycatcher (Empidonax trail/ii extrimus) and the
federally threatened California gnatcatcher (Polioptila california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Bell's vireo"
theoretically estimated that {traffic) noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is. typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #15 (7-7-99)
lSE Report #99-0090
July 8, 1999
Page 4
EB Analysis Methodology
Existing Conditions Field Survey
Four Larson Davis Model 700 ANSI Type 2 integrating sound level meters were
used as the data collection devices. The meters were positioned at the locations shown
below in Figure 2 and the accompanying matrix.
Counti
30 gua
lML#2r"' .. .
ML #1
41
Agua
...- ,-.
0 1/2 1MILE TN 11V ---- I
13W 1000 0 1000 2000 3000 FEET
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No.. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195 W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
ML #4 n/a 330 08.194 N 1170 18.401 W Macario Canyon
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #15 (7-7-99)
ISE Report #99-0090
July 8, 1999
Page
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field, deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to excavating, bridge fabrication, light grading and associated ancillary
activities. To date, the least Bell's vireo has been predominantly located between
station markers 103+00 and 108+00. These station markers correlate with ISE
monitoring locations I and 2.
Additional sightings of the least Bell's vireo have been observed within Macarlo
Canyon (approximately 1-mile southwest of ISE monitoring location #1). As 'a result of
new grading activities adjacent to the habitat,' an additional meter (ML 4) has been
placed at this location (refer to Figures 3a through c).
During the Week #15 monitoring period, construction activities associated with
the Cannon Road West Project were concentrated near monitoring location #3
(adjacent to El Camino Real). Activities and equipment observed at this location were
primarily affiliated with excavating and trenching for the proposed sewer line, and
relocation of materials used for the falsework bridge supports. Equipment utilized
during this monitoring period included a single CAT dozer (model D6R, CAT excavator
(model 345BL), CAT forklift (model TH83), Skytrak forklift (model 9038), and a truck
mounted crane.
Activities and equipment observed at Macario Canyon were associated with the
proposed alignment of Faraday Road (to connect with Cannon Road) and included
three CAT scrapers 'working in a continuous short haul cycle (model 657E), two CAT
dozers (model D9R), a CAT dozer (model D9L), and a CAT tractor (model 950B).
Testing conditions during the monitoring intervals were clear with an average
barometric pressure reading of 29.90 in-Hg, an average westerly wind speed of 0 to 3
miles per hour (MPH), and an approximate mean temperature 'of 70 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and' Lmin), and the statistical indicators LIO, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #15 (7-7-99)
ISE Report #99-0090
July 8, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
I 1 -Hour Noise Level Descriptors in cIBA
Site Leq Lmax Lmin LID L50 L90
9:30 am.
ML 1 47.5 64.5 . 41.0 50.5 43.5 42.0
ML 52.0 73.5 41.0 52.0 46.5 43.0
ML 3., 54.5 68.0 42.5 57.0 53.5 50.0
ML 4 66.0 76.5 44.0 70.0 63.5 52.5
10:30 a.m.
ML 1 46.5 61.5 40.0 50.0 43.5 41.5
ML 2. 49.0 64.0 40.5 . 52.0 47.0 43.5
ML 3 56.0 64.5 44.5 58.5 55.5 52.5
MIL 64.0 76.0 43.0 68.0 61.5 51.5
11:30 a.m.
ML 1 50.0 70.5 40.0 50.5 43.5 41.5
MIL 49.5 68.5 38.5 49.5 44.0 41.0
MI-3 54.5 72.5 40.0 57.0 53.5 48.5
ML j4 61.5 74.0 405 6625 51.5 42.0
12:30 p.m.
ML 1 48.5 64.0 40.0 51.5 43.0 41.0
MIL 47.5 55.5 42.0 51.5 45.0 43.0
MI-3 55.5 65.5 42.0 58.0 55.0 51.0
MI-4 61.5 77.0 41.0 66.0 53.0 45.5
1:30 p.m.
ML 1. 50.5 . 70.0 41.0 51.0 44.0 42.0
ML 50.0 69.0 39.0 49.5 44.5 41.5
ML 54.0 72.0 39.5 56.5 53.0 48.0
MI-4 61.0 73.5 41.5 66.0 51.0 43.0
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #15 (7-7-99)
ISE Report #99-0090
July 8, 1999
Page 7
Measurements collected at monitoring locations, ML I through ML 4, reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. With the exception of ML 4 (Macano Canyon), all
monitoring locations were below the 60-dBA Leq impact threshold during the Week #15
monitoring period. Monitoring location #4 (ML 4) showed an exceedance throughout the
duration of the monitoring period. The highest hourly energy equivalent sound level
(Leq-h) at this monitoring location was 66.0-dBA and was recorded during the 9:30 am.
monitoring interval. Additionally, the background noise level (L90), for Macario Canyon,
did not exceed 52.5-dBA thus enabling vireo communication within the affected areas
90 percent of the time.
ES Recommendations
With the exception of ML 4 (Macario Canyon), All monitoring locations were
observed to be below the ..60-dBA Leq impact threshold throughout the duration of the
Week #15 monitoring period. The exceedances recorded at ML 4 were attributed to the
close proximity of grading activities pertaining to the proposed alignment of Faraday
Road to the habitat boundary. The following mitigation measures are recommended.
Equipment utilized for grading activities close to the habitat should be fitted with
shielded exhaust stacks (i.e., modified stacks that are positioned away from the
habitat area).
If item # 1 is not feasible, grading and hauling routes should be organized in a
fashion as to have exhaust stacks positioned away from the habitat at their
closest point to the area of concern.
Utilize excavated material to create an earthen berm along the western limits of
the alignment in order to attenuate construction noise entering the habitat area.
Such berms can reduce noise levels up to 14-dBA for practical construction
heights.
Idling of equipment should be kept to a minimum.
Staging and maintenance of equipment should be performed away from the
habitat boundary.
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Mr. Doug Gethnger
Cannon Road Mitigation Monitoring Results - Week #15 (7-7-99)
ISE Report #99-0090
July 8, 1999
Page 10
Figure 3c: Earth-moving activities associated with the proposed Faraday Road alignment.
J/•
Investigative Science and Engineering
3511 Cam/no Del Rio South, Suite 302 Phonel4aPA91 93709719-640-0763
San Diego, CA 92108-4003 .' www.ise-advantage.com
ENGINEERING
DEPARTMENT
June 1, 1999
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc.
5510 Morehouse Drive
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #12 (5-27-99)
(ISE Report #99-0091)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on May 27, 1999. The results of that survey
are presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure. 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 175 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua. Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
4..
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-27-99)
SE Report #99-0091
June l,1999
Page 2
KIM
1
126:?..4
4 <j
'ProjectAignmen
4' 4?
Op -N.
Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
Acoustical Definitions
Airborne sound is a rapid fluctuation of air pressure above and below
atmospheric levels. The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level
of zero 0" dB is scaled such that it is defined as the threshold of human hearing and
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level.
Most of the sounds we hear in the environment do not consist of a single
frequency, but rather a broad band of frequencies differing in sound level. The
intensities of each frequency add to generate the sound we hear. The method
commonly used to quantify environmental sounds consists of determining all of the
frequencies of a sound according to a weighting system that reflects the nonlinear
response characteristics of the human ear. This is called "A" weighting, and the decibel
level measured is called the A-weighted sound level (or dBA). In practice, the level of a
noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve. .
Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-2799)
ISE Report #99-0091
June 1, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured:
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the L10 typically describe transient or short-tern, events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be/Ill
pusillus) and the southwestern willow flycatcher (Empidonax trailill extnmus) and the
federally threatened California gnatcatcher (Polioptila california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Bell's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results — Week #12 (5-27-99)
ISE Report #99-0091
June 1, 1999
Page
EM Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
::. •:?/ :,>,/
4i? .71
.11ilA.t ,
cr II
' t
intorosa
Country Cit
30j
/ #2
NIMN 0 1
1
v 1 fl
4
MILE
9.4 a
rn..wa__1
000 FEET
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor. Sta. Eng. Sta. No. GPS Lät GPS' Lon•• Description
ML #1 102+00 330 08.780 N 1170 18.195W. Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-27-99)
ISE Report #99-0091
June 1, 1999
Page
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Findings
Field Monitorina Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. To date, the least Bell's vireo
sightings have been predominantly located between station markers 103+00 and
108+00. These station markers correlate with ISE monitoring locations I and 2. ISE
verified the completion of the temporary construction noise wall along these sensitive
areas of the project alignment. The as-built design can be seen in Figures 3a through -
g at the end of this report.
During the Week #12 monitoring period, construction activities associated with
the Cannon Road West Project were concentrated near monitoring location #3
(adjacent to El Camino Real). Activities and equipment observed at this location were
primarily affiliated with the pouring of cement to create the bridge deck of the Cannon
Road I El Camino Real bridge. Equipment observed at this location consisted of
multiple cement haulers, which would deposit their load into a cement "hopper" located
adjacent to monitoring location #3. The cement haulers worked in a continuos cycle,
entering and exiting the project site via El Camino Real. Additional equipment being
utilized during this monitoring period included a single CAT dozer (model D9R), a
Bidwell cement "smoother", and a model 9038 turbo forklift.
Testing conditions during the monitoring intervals were clear with an average
barometric pressure reading of 30.00 in-Hg, an average westerly wind speed of 0 to 5
miles per hour (MPH), and an approximate mean temperature of 70. 5 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the statistical indicators L10, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-27-99)
ISE Report #99-0091
June 1, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
1-Hour Noise Level Descriptors in dBA
Site Leq Lmax Lmin LIO L50 L90
6:30 am.
ML 1 48.5 80.5 40.0 48.0 44.5 42.5
ML2 54.5 66.5 47.5 57.0 54.0 51.0
ML3 63.0 72.0 49.5 66.5 61.0 55.0
7:30 a.m.
ML 1 53.5 67.0 40.0 55.5 45.0 42.0
ML 2 55.0 65.0 48.5 57.0 54.5 52.0
ML3 65.0 71.0 54.5 67.5 64.5 59.0
8:30 am.
ML 1 46.5 63.0 40.0 48.0 43.5 41.5
ML 2 52.5 59.5 47.0 55.0 51.5 48.5
ML3 65.0 76.5 51.0 67.5 64.5 59.5
9:30 p.m.
ML 1 49.5 69.0 40.5 54.0 44.0 42.0
ML2 51.0 80.5 42.0 52.0 49.0 47.5
ML3 64.0 74.0 52.5 67.0 64.0 57.0
10:30 p.m.
ML 1 51.0 69.5 41.0 51.0 46.0 43.5
ML2 51.0 66.0 43.0 53.0 50.0 47.5
ML3 62.5 59.0 51.5 66.0 62.5 55.5
11:30 p.m.
ML 1 50.0 70.5 42.5 51.0 46.0 44.0
ML2 52.5 74.0 47.5 53.5 50.0 48.5
ML3 63.5 70.5 52.0 66.0 63.5 57.0
12:30 p.m.
ML 1 49.0 67.0 42.5 51.0 46.0 44.0
ML 2 52.5 70.0 47.5 54.5 51.0 49.0
ML.3 64.5 74.0 52.5 66.5 64.0 59.0
1:30 p.m.
ML 1 47.5 62.5 42.0 50.0 45.5 43.5
ML2 52.0 66.5 47.5 54.0 51.0 49.0
ML3 62.5 69.5 52.5 65.5 62.0 57.0
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-27-99)
ISE Report #99-0091
June 1, 1999
Page 7
Measurements collected at monitoring locations ML I through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Monitoring location #3 showed a slight
exceedance of the 60-dBA Leq impact threshold throughout the duration of the Week
#12 monitoring period. This exceedance was a direct result of cement pumping
activities associated with the El Camino' Real Bridge over crossing. Additional
acoustical mitigation and onsite monitoring was implemented to reduce impacts as
much as possible (see Figure 4). Consequently, the background noise level (L90), for
all monitoring locations, did not exceed 59.5 dBA thus enabling vireo' communication
within the affected areas. This. record of 59.5 dBA was recorded at ML 3 and should be
noted as being slightly lower than pre-construction levels (due to the adjacency of El
Camino Real).
Recommendations
Monitoring Location #3 was found to have an energy average sound level (Leq-
h) in excess of 60 dBA during the Week #12 monitoring period. The exceedance
observed at ML 3 was due to construction activities associated with the construction of
the Cannon Road access bridge. Construction activities associated with this phase of
construction were scheduled to be complete within one day's time.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
0ENTA.
Rick Tavares, EIT, REA, INCE
Project Principal No. 06
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #12 (5-27-99)
ISE Report #99-0091
Junel, 1999
Page
TTT
j - 4 /
MW w
ar - 3,-..Ono • ''s • 7 ' .',' ' . ?-.. .. 4. .-
3
3 + -
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-27-99)
ISE Report #99-0091
June 1, 1999
Page 10
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-27-99)
SE Report #99-0091
June 1, 1999
Page 12
Figure 3e: Completed Noise Wall - End View Facing West (Stations 96+00 to 108+00)
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-27-99)
ISE Report #99-0091
June 1, 1999
Page 13
Figure 3f: Completed Noise Wall - Interior End View Facing West
(Stations 96+00 to 108+00)
wk
-
WAR r 131 , G
its to MIT G-
--• - •: 4
2
' I
t. - .- .- -- -- I •- 1& -' lot - II
'I
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #12 (5-27-99)
SE Report #99-0091
June 1, 1999
Page 15
. ..... . . . .• . .
. •.
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c
1 1
c ' f •
• r.......................... .........•. .,
, 4
:i
Figure 4a: Additional Mitigation Effort for Concrete Pumping Operations
(El Camino Real Bridge Crossing)
-\-. ~ rl~ '.
-
J L!
-
. . -.
-
--
__--.p.
-.
-..--.-
Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 / 619-640-0763
San Diego, CA 92108-4003 www.ise-advantage.com
RECEIVED
May 21, 1999
Mr. Doug Gethnger
Ogden Environmental and Energy, Inc.
5510 Morehouse Drive
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #11(5-20-99)
(ISE Report #99-009k)
Dear Mr. Gettinger:
MAY 2 It 1999
ENGINEERING
DEPARTMENT
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on May 20, 1999. The results of that survey
are presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations fdr the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #11(5-20-99)
lSE Report #99-009k
May 21, 1999
Page
01
40,
'ProjectAUgnmen 4'l -4a a i:••
.. Wj.'.. -in
APA
Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
Acoustical Definitions
Airborne sound is a rapid fluctuation of air pressure above and below ,
atmospheric levels. The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level
of zero "0" dB is scaled such that it is defined as the threshold of human hearing and
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level.
Most of the sounds we hear in the environment do not consist of a single
frequency, but rather a broad band of frequencies differing in sound level. The
intensities of each frequency add to generate the sound we hear. The method
commonly used to quantify environmental sounds consists of determining all of the
frequencies of a sound according to a weighting system that reflects the nonlinear
response characteristics of the human ear. This is called "A" weighting, and the decibel
level measured is called the A-weighted sound level (or dBA). In practice, the level of a
- noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve.
- Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #11(5-20-99)
ISE Report #99-009k
May 21, 1999
Page '3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the LIO typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirableto know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be//il
pusillus) and the southwestern willow flycatcher (Empidonax trail/ii extrimus) and the
federally threatened California gnatcatcher (Polio ptila california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Bell's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #11 (5-20-99)
lSE Report #99-009k
May 21, 1999
Page 4
Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
"\
intorosa
ountry Ch
30
INL#2fl 1r
N/MN rJP r 1 MILE
Iiaio 1000 0 1000 2000 3000 4000 FEET / I ,AcaI r*xI r,aansv4,, ü?.
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #11(5-20-99)
ISE Report #99-009k
May 21, 1999
Pages
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Findings
Field Monitorina Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. To date, the least Bell's vireo
sightings have been predominantly located between station markers 103+00 and
108+00. These station markers correlate with ISE monitoring locations I and 2.
During the Week #11 monitoring period, construction activities associated with
the Cannon Road West Project were concentrated near the ML 3 location (adjacent to
El Camino Real). Activities and equipment observed at this location were primarily
affiliated with the fabrication of the Cannon Road / El Camino Real Bridge deck and
pipe trenching. Equipment observed at this location consisted of a CAT model 950B
dozer (1), CAT model 773B hauler (2), CAT model 345BL excavator (1), and a model
9038 turbo forklift (1).
Project related activities were also observed at monitoring location #2 and were
affiliated with the fabrication of the new noise wall located adjacent to station marker
108+00. The progress of the noise wall, as of the date of this report can be seen in
Figure 3 at the end of this report.
Testing conditions during the monitoring intervals were clear and cool with an
average barometric pressure reading of 30.05 in-Hg, an average westerly wind speed
of 3 to 7 miles per hour (MPH), and an approximate mean temperature of 68.7 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the'statistical indicators LIO, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #11 (5-20-99)
ISE Report #99-009k
May 21, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
1-Hour Noise Level Descriptors in dBA
Site Leq -Lmax Lmun LIO -L50.L90
9:00 a.m.
ML 1 53.0 79.5 43.0 55.5 47.0 45.0
ML 50;5 71.0 41.5 52.0 46.0 43.5
ML 58.5 71.0 50.5 60.5 57.5 54.5
10:00 a.m.
ML 1 49.5 67.5 40.0 51.5 45.0 42.0
MI-2 54.0 74.5 42.5 56.0 46.5 44.0
MI-3 58.5 72.0 50.5 61.0 58.0 54.5
11:00 a.m.
MI-1 51.0 70.5 40.0 53.0 45.5 42.0
ML 2 59.5 77.0 42.5 62.5 50.0 45.5
ML 3 57.5 76.0 48.0 60.0 57.0 53.0
12:00 p.m.
ML 1 49.5 68.5 40.0 51.0 44.5 41.5
ML 69.0 89.0 42.0 67.5 54.0 46.5
MI-3 57.0 69.0 44.5 59.5 56.0 52.0
1:00 P.M.
ML 1 52.0 73.5 41.0 54.5 46.5 42.5
ML 58.5 76.5 43.0 61.0 54.5 47.5
ML 3 57.0 67.0 49.5 59.5 56.5 53.5
2:00 p.m.
ML 1 52.0 73.5 41.0 54.0 46.5 42.5
MI-2 56.0 77.0 42.5 57.0 49.0 45.0
MI-3 57.5 68.0 49.5 59.5 57.0 53.5
3:00 p.m.
ML 1 50.0 74.5 39.5 51.0 44.5 41.5
MI-2 50.0 70.0 41.0 52.0 46.5 43.0
MI-3 57.5 65.5 47.5 59.5 57.0 53.5
4:00 p.m.
ML 1 54.5 76.5 40.0 55.5 46.0 42.0
ML 53.5 70.5 41.5 55.0 47.5 43.5
ML 3 58.0 70.5 47.0 60.0 57.5 52.5
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #11 (5-20-99)
ISE Report #99-009k
May 21, 1999
Page 7
Measurements collected at monitoring locations ML 1 through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Monitoring location #2 showed an exceedance of
the 60-dBA impact threshold during the. 12:00 p.m. monitoring interval. This
exceedance was a direct result of construction related activities pertaining to the
erection of a temporary noise wall located approximately at station marker 108+00. The
duration of these activities was short enough such that the background noise level
(1-90), for all monitoring locations, did not exceed 54.5 dBA. This record of 54.5 dBA
was recorded at ML 3, which currently experiences noise levels below pre-construction
values due to the presence of the as-built noise wall. The completed noise wall at ML 3
can be seen below in Figure 4.
Recommendations
Monitoring Location #2 was found to have an energy average sound level (Leq-
h) in excess of 60 dBA during the Week #11 monitoring period. The exceedance
observed at ML 2 was due to construction activities associated with the fabrication of
the new noise wall along a small section of the northern project limit (station marker
108+00). Construction activities associated with this noise wall are not considered long-
term and are expected to be complete within one day's time.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
TAVA
Rick Tavares, EIT, REA, INCE LU
Project Principal No. 06
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #11(5-20-99)
lSE Report #99-009k
May 21, 1999
Page 8
,,
4 1
.
• - , .-
_? •$' 'I
.
-
I.____ •- -. - •- -
-Flit
lo
vo
r
Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 1619-640-0763
San Diego, CA 92108-4003 wwwise-advantage.com
May 14, 1999
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc.
5510 Morehouse Drive
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #10 (5-13-99)
(ISE Report #99-009j)
Dear Mr. Gettinger:
MAY 17 1999
ENGINEERING
DEPARTMENT
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on May 13, 1999. The results of that survey
are presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
Mr. Doug G
Cannon Ro
ISE Report
May 14, 19
Page 2
126 \-'' -. f.• I174.•
34
'PAL
c;
.•
___________ \ .• \ .'
#4 OWN
Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
Acoustical Definitions
Airborne sound is a rapid fluctuation of air pressure above and below
atmospheric levels. The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level
of zero 0" dB is scaled such that it is defined as the threshold of human hearing and
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level.
Most of the sounds we hear in the environment do not consist of a single
frequency, but rather a broad band of frequencies differing in sound level. The
intensities of each frequency add to generate the sound we hear. The method
commonly used to quantify environmental sounds consists of determining all of the
frequencies of a sound according to a weighting system that reflects the nonlinear
response characteristics of the human ear. This is called "A" weighting, and the decibel,
level measured is called the A-weighted sound level (or dBA). In practice, the level of a
noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve.
Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #10 (5-13-99)
ISE Report #99-009j
May 14, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the LIO typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be//il
push/us) and the southwestern willow flycatcher (Empidonax traillii extnmus) and the
federally threatened California gnatcatcher (Poliopti/a california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Be/I's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results —Week #10 (5-13-99)
ISE Report #99-009j
May 14, 1999
Page 4
Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
:1b if f ci intorosa C 1 Country CI
30) gu
/ ../
/ . • 6
/ .. /..
0 1/2 1MILE
fNt /MN
lia,o 1000 0 1000 2000 3000 4000 FEET
j • VISS41 ECd noa,jj,,'.wx4M
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #10 (5-13-99)
ISE Report #99-009j
May 14, 1999
Page
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, LIO, L50, and
L90.
Findings
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. To date, the least Bell's vireo
sightings have been predominantly located, between station markers 103+00 and
108+00. These station markers correlate with ISE'monitonng locations I and 2. During
the Week #10 monitoring period, construction activities associated with the Cannon
Road West Project were concentrated near the ML 3 location '(adjacent to El Camino
Real). Activities and equipment observed at this location were primarily affiliated with
the fabrication of the Cannon Road / El Camino Real Bridge foundation and deck.
Equipment observed at this location consisted of a CAT model 950B dozer (1), CAT
model 773B hauler (1), CAT model 345BL excavator (1), and a model 9038 turbo
forklift (1). Construction activities associated with the unrelated housing project
adjacent to the south were appreciable at Monitoring Location #1.
Testing conditions during the monitoring intervals were cool and cloudy with an
average barometric pressure reading of 29.90 in-Hg, an average westerly wind speed
of 1 to 5 miles per hour (MPH), and an approximate mean temperature of 68.5 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the statistical indicators LIO, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #10 (5-13-99)
ISE Report #99-009j
May 14, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
jTT::Ti1. -Hour Noise Level Descriptors ifl'dBA"..; .,:. .
Site Leq Lmax Lm in LIO L50 L90
7:30 a.m.
ML 1 45.5 70.0 35.5 45.5 40.0 37.5
ML2 57.0 '69.5 42.5 , 61.0 55.5 46.5
ML 67.0 90.5 50.5 67.5 56.5 53.5
8:30 a.m.
ML 1 46.5 71.0 35.0 46.0 40.5 38.0
ML2 57.5 70.5 42.0 61.5 55.0 46.0
ML3 67.5 90.0 50.0 68.0 56.0 53.0
930 a.m.
ML 1 46.5 69.0 36.5 46.5 41.0 38.5
ML2 57.5 79.0 40.5 58.5 50.0 45.5
MIL 66.0 86.0 47.5 . 67.0 55.5 52.0
10:30 a.m.
ML 1 52.0 80.0 37.5 48.5 42.5 40.0
ML 2 54.5 78.0 40.0 56.0 48.0 ' 43.0
ML3 71.0 91.0 49.0 73.5 57.0 ' 53.5
11:30 a.m.
ML 1 44.0 60.5 38.0 46.5 41.5 39.5
ML 2 58.0 87.0 39.5 53.5 46.5 43.0
ML 3 69.0 92.0 45.0 71.5 57.5 53.5
12:30 p.m.
ML 1 46.5 64.0 38.5 50.0 42.5 39.5
ML2 50.5 69.0 40.5 52.5 46.0 43.0
ML 63.0 , 84.5 43.0 63.5 58.5 55.0
1:30 p.m.
ML 1 44.5 65.5 37.5 45.0 41.0 39.5
ML 2 48.0 62.0 41.0 50.5 46.0 . 43.0
ML 58.5 71.0 50.5 61.0 57.5 54.0
2:30 p.m. '
ML 1 ' 65.0 85.5 38.5 63.0 42.5 39.5
ML 2 55.0 64.5 , 43.5 59.0 52.0 46.5
ML 57.0 69.5 51.5 59.5 56.0 53.0
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #10 (5-13-99)
ISE Report #99-009j
May 14, 1999
Page 7
Measurements collected at monitoring locations ML I through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Two monitoring locations, ML I and ML 3,
showed an exceedance of the 60-dBA impact threshold throughout the duration of the
monitoring intervals. During the 2:30 p.m. monitoring interval, ML 2 showed and
exceedance due to traffic (supply transporting) associated with 'the adjacent project to
the south and is not project related. The exceedance observed at ML 3 from 7:30 a.m.
through 12:30 p.m. was due to the construction of a temporary noise wall along the
northern project limit (from El .Camino Real to the western limits of the Cannon Road /
El Camino Real Bridge). The duration of these activities was short enough such that the
background noise level (L90) for all monitoring locations did not exceed 55.0 dBA. This
level of 55.0 dBA was recorded at ML 3.
EN Recommendations
Monitoring Locations I and 3 were found to have an energy average sound
level (Leq-h) in excess of 60 dBA during the Week #10 monitoring period. The
exceedance observed at ML I was due to transport activities associated with the
adjacent project to the south, and is not project related.
Due the construction of the noise wall along the northeastern project limit, ML 3
showed an exceedance throughout the duration of the 7:30 a.m. to 12:30 p.m.
monitoring intervals. The activities associated with the fabrication of this noise wall are
not long term and should be completed within one day's time.
Should you have any questions regarding the above conclusion, please do not
hesitateto contact me at (619) 640-9379.
Sincerely,
Rick Tavares, EIT, REA, lNCE
Project Principal
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, lSE
c 5' Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 /619-640-0763
San Diego, CA 92108-4003 v'.ww.ise-advantage.com
RECE WED
May 6, 1999
MAY 10 1999
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc. ENGINEERING
5510 Morehouse Drive DEPARTMENT
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #9 (5-5-99)
(ISE Report #99-0091)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (lSE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on May 5, 1999. The results of that survey are
presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #9 (5-5-99)
SE Report #99-009i
May 6, 1999
Page 2
Rlvk~ql ~_-11
/ AW
..rojectAhgnmen 17,
xea\'vw.
/\
; '.'. ..
'
&
Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
Acoustical Definitions -
Airborne sound is a rapid fluctuation of air pressure above and below
atmospheric levels. The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level
of zero "0" dB is scaled such that it is defined as the threshold of human hearing and •
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level. • .,.
Most of the sounds we hear in the environment do not consist of a single
frequency, but rather a broad band of frequencies differing in sound level. The
intensities of each frequency add to generate the sound we hear. The method . ... -
commonly used to quantify environmental sounds consists of determining all of the •
frequencies of a sound according to a weighting system that reflects the nonlinear •
response characteristics of the human ear. This is called "A" weighting, and the decibel *
level measured is called the A-weighted sound level (or dBA). In practice, the level of a • - * •
noise source is conveniently measured using a sound level meter that includes a filter: • - . •
corresponding to the dBA curve. . -, •,
Although the A-weighted sound level may adequately indicate the level of.
environmental noise at any instant in time, community noise levels *vary continuously. '
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #9 (5-5-99)
ISE Report #99-009i
May 6, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L1 1 L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the L10 typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be//ii
pusillus) and the southwestern willow flycatcher (Empidonax trail/ii extrimus) and the
federally threatened California gnatcatcher (Polio ptila california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Bell's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
/: •-2(
cy- 'L-i Li
tVi;"• r1 ,.i
_
/Agua
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results — Week #9 (5-5-99)
ISE Report #99-009i
May 6, 1999
Page 4
ES Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
AD
9fr .:••
intorosa
Country CI
riE 10:21
/
0 1/2 1MILE [N T ,MN r...,&....*r.
/13Y0 1000 0 1000 2000 3000 4000 FEET
/ S I R.NY4I LWSI I*c..w-.
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #9 (5-5-99)
ISE Report #99-0091
May 6, 1999
Page 5
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Findings
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. To date, the least Bell's vireo
sightings have been predominantly located between station markers 103+00 and
108+00. These station markers correlate with ISE monitoring locations I and 2. During
the Week #9 monitoring period, construction activities associated with the Cannon
Road West Project were concentrated at the ML 3 location (adjacent to El Camino
Real). Activities and equipment observed at this location were primarily affiliated with
the fabrication of the Cannon Road I El Camino Real Bridge foundation and deck.
Equipment utilized at this location consisted of a CAT model 834B dozer (1), CAT
model 773B hauler (2), CAT model 988B dozer (1), CAT model D9R earthmover (1),
and a model 9038 turbo forklift (1). Construction activities associated with the unrelated
housing project adjacent to the south were appreciable at Monitoring Location #2.
Testing conditions during the monitoring intervals were overcast with an average
barometric pressure reading of 29.95 in-Hg, an average westerly wind speed of 1 to 5
miles per hour (MPH), and an approximate mean temperature of 71.5 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the statistical indicators L10, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #9 (5-5-99)
ISE Report #99-009i
May 6, 1999
Page
Table 1: Measured Construction Levels - Cannon Road West Alignment
I 1-Hour Noise Level Descriptors in dBA
Site Leq Lmax Lmin LIO 1-50 L90
7:30 a.m.
ML 1 58.0 85.0 44.0 59.5 52.0 47.0
ML 2 56.5 73.0 45.0 58.5 53.0 49.5
MI-3 67.5 82.5 57.0 70.5 67.0 63.0
8:30 am.
ML 1 59.0 85.5 44.5 60.0 52.5 47.5
ML 2 56.0 73.5 45.5 58.0 52.0 48.5
MI-3 68.0 83.0 56.5 71.0 66.0 62.5
9:30 am.
ML 1 58.5 77.0 41.0 58.0 45.5 42.5
ML 2 57.0 75.0 44.0 59.0 50.5 46.5
MI-3 69.0 86.5 55.5 71.5 65.0 60.5
10:30 am.
ML 1 57.0 77.0 41.5 58.0 45.5 43.0
ML 58.5 71.0 48.0 62.5 56.0 50.5
MI-3 71.5 93.5 61.0 74.0 69.5 66.0
11:30 a.m.
ML 1 52.5 71.5 41.5 53.5 46.5 43.5
MI-2 58.5 76.5 48.0 59.0 54.0 50.5
MI-3 81.0 95.0 51.5 85.0 77.0 66.0
12:30 p.m.
ML 1 52.0 70.5 41.5 52.5 45.5 43.0
MI-2 61.5 80.0 47.5 62.5 58.5 55.0
69.0 82.0 49.0 74.0 59.0 53.0
1:30 p.m.
ML 1 50.5 68.5 41.5 52.0 45.5 43.0
ML 55.5 73.5 47.0 59.0 51.5 48.5
ML 68.0 85.5 57.0 71.0 65.0 61.0
2:30 p.m.
ML 1 55.5 71.5 42.0 54.5 46.5 43.5
ML 2 52.0 79.0 47.0 54.0 49.5 48.0
69.5 77.0 62.0 72.0 69.0 65.5
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #9 (5-5-99)
ISE Report #99-009i
May 6, 1999
Page 7
Measurements collected at monitoring locations ML 1 through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Two monitoring locations, ML 2 and ML 3,
showed an exceedance of the 60-dBA impact threshold throughout the duration of the
monitoring intervals. The exceedance recorded at ML 2 was due to traffic and grading
activities associated with the adjacent project to the south and are not project related.
With the exception of ML 3, the duration of these activities was short enough such that
the background noise level (L90) for monitoring locations 1 and 2 was 55.0 dBA or less.
This record of 55.0 dBA was recorded at ML 2.
Background noise levels obtained at monitoring location #3 exceeded the 60.0
dBA threshold for all but one of the monitoring intervals. Excluding the 12:30pm interval
(approximate break time), L90 noise levels for ML 3 ranged from 60.5 to 66.0 dBA.
Recommendations
Monitoring Location #2 was found to have an energy average sound level (Leq-
h) in excess of 60 dBA during the 12:00pm interval; however, this exceedance was due
to the close proximity of construction activities associated with the adjacent project to
the south, and are not project related.
Project related activities associated with the fabrication of the Cannon Road I El Camino Real Bridge foundation and deck produced Leq-h noise levels as high as 81.0
dBA and L90 noise levels up to 66.0 dBA. The noise levels recorded at ML 3 indicated
that noise produced at this location exceeds the 60.0 dBA threshold established by
USFWS and therefore, will require appropriate mitigation. The mitigation
recommendations outlined in the Week #7 report (ISE Report #99-009g, 4-21-99)
would still be applicable.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
eick avares, ElT, REA, INCE
Project Principal
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
OtA~AENTk 4,S,
No. 067,75
4'x8'x5/8" Construction Grade Plywood
Single Panel - Nailed Direct
Repeat Sections As Necessary
To Finish Length
GROUND LEVEL
Concrete Base ri'.'.jr , 1LiL
8
GROUND J1VEL
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4"x4"x12' Fir 4"x4"x12' Fir 4"x4"x12' Fir
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TOP PROFILE
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Cannon Road Noise Wall Detail
REVI SIZE
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33008.563', 117018.598' .33008.563', 117017.1191'
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IIi-,i.'o 1000 0 1000 2000 3000 4000 FEET
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Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 / 619-640-0763
San Diego, CA 92108-4003 www.ise-advantage.com
April 28, 1999 RECEIVED
Mr. Doug Gettinger APR 2 91999
Ogden Environmental and Energy, Inc. ENGINEERING 5510 Morehouse Drive DEPARTMENT San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #8 (4-28-99)
(ISE Report #99-009h)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on April 28, 1999. The results of that survey
are presented in this letter report.
Ej Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
4' 4: 1
4.944 ( '1•'' '4 2 / <
r '4 4 1 1
6 .2'4 •
I
I'
-. :' ;' Ri
' . ' .
Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107) •
r •
.
••
I . . . •... . .4
. • '.
.• - - . . .4•• ,. ' . -
4
- . . . . -.
.
. . . . '4.. .
..
... I Ac
.
oustical Definitions . '
Airborne sound is a rapid fluctuation of jair pressure above and below
atmospheric levels. The loudest sounds the human ear can, hear conformably is . . ......'
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect. Because of this vast range, any-attempt to represent the .'
- • acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of: ' '-' ':
.. . this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level , •,,
of zero "0" dB is scaled such that it is defined as the threshold of human hearing and '•
:.. '
... . would be barely audible to a human of normal hearing under extremely quiet listening It conditions and would correspond to a sound pressure level equal to the reference level. •
Most of the sounds we hear in the environment do not consist of a'single ,.,•.
frequency, but rather a broad band of frequencies differing in sound level: The -'!' i.'-
intensities of each frequency add to generate the sound we hear. .4The method '... , ''..'' .• 1•4
'. commonly used to quantify environmental sounds consists of determining all of the ••
frequencies of a sound according to a weighting system that reflects the nonlinear. .
.4 ..
response characteristics of the human ear. This is called "A" weighting, and the decibel •• ...
level measured is called the A-weighted sound level (or dBA). In practice,-the level of a ,, 1' •
noise source is conveniently measured using a sound level meter that includes a filter . •. . .
corresponding to the dBA curve
Although the A-weighed sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously. L
4/. . S . • . 4
• . . I, • . . , . •- $ IS.. '4'.
.1 .. .,' 4
. 2.•
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #8 (4-28-99)
ISE Report #99-009h
April 28, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the LIO typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be//ii
push/us) and the southwestern willow flycatcher (Empidonax trail/ii extrimus) and the
federally threatened California gnatcatcher (Polio ptila california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Bell's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
I-
C
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71.Country CI
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. 11
#3
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #8 (4-28-99)
SE Report #99-009h
April 28, 1999
Page 4
EN Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
H 9
0 1/2 I MILE N j MN I Iit,o 1000 0 1000 2000 3000 4000 FEET / I t.i nr.i t*w,.t*4
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #8 (4-28-99)
ISE Report #99-009h
Apnl28 1999
Page 5
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Findings
Field MonitonnQ Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. During the week #8 monitoring
period, construction activities associated with the Cannon Road West Project were
primarily concentrated near the ML 3 location (adjacent to El Camino Real). Activities
and equipment observed at this location were primarily affiliated with the fabrication of
the Cannon Road I El Camino Real bridge supports. Equipment utilized at this location
consisted of a CAT model 950B dozer (1), CAT model 773B hauler (1), CAT 345BL
excavator (1), a single truck mounted hoist crane, and a model 9038 turbo forklift (1).
Construction activities associated with the unrelated housing project adjacent to the
south were appreciable at Monitoring Location #2.
Testing conditions during the monitoring intervals were overcast with an average
barometric pressure reading of 30.05 in-Hg, an average westerly wind speed of 1 to 5
miles per hour (MPH), and an approximate mean temperature of 70.5 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the statistical indicators L10, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #8 (4-28-99)
ISE Report #99-009h
April 28, 1999
Page
Table 1: Measured Construction Levels - Cannon Road West Alignment
I 1 -Hour Noise Level Descriptors in dBA
Site Leq Lmax Lmin LIO L50 L90
7:30 a.m.
ML 1 48.5 62.0 41.5 51.0 46.5 44.0
MI-2 64.0 75.0 46.0 69.5 63.0 51.5
MI-3 58.5 71.5 52.0 61.0 58.0 55.0
8:30 a.m.
ML 1 49.5 63.5 42.0 52.0 47.0 44.5
ML 66.0 77.0 47.5 70.5 64.0 52.5
MI-3 58.0 71.0 51.5 60.5 57.5 54.5
9:30 a.m.
ML 1 55.0 72.5 420 58.0 50.0 44.5
MI-2 66.0 74.0 46.5 69.0 65.0 57.0
MI-3 58.5 70.5 51.0 60.5 57.5 54.5
10:30 a.m.
ML 1 54.0 67.0 42.0 58.0 49.0 44.0
ML 2 61.0 73.5 49.5 66.0 57.0 53.0
ML 58.0 68.0 51.0 60.5 57.5 54.0
11:30 a.m.
ML 1 56.0 74.0 42.0 60.5 50.5 44.5
MI-2 63.0 80.5 43.0 65.5 58.0 49.0
MI-3 57.5 71.0 46.5 60.0 57.0 53.0
12:30 p.m.
ML 1 56.0 72.0 42.5 59.5 50.0 44.5
MI-2 63.5 84.0 52.5 66.5 62.0 57.5
MI-3 58.5 71.0 51.0 61.0 58.5 55.0
1:30 p.m.
ML 1 54.0 73.0 43.0 58.0 49.0 45.0
ML 61.0 74.5 46.5 64.5 58.5 52.0
MI-3 58.5 66.0 51.0 60.5 58.0 55.5
2:30 p.m.
ML 1 53.0 72.5 42.5 57.0 50.0 45.5
ML 2 59.5 75.0 46.0 65.0 59.0 53.5
MI-3 57.5 65.5 51.5 60.0 58.5 55.0
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #8 (4-28-99)
ISE Report #99-009h
April 28, 1999
Page 7
Measurements collected at monitoring locations ML I through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Only one Monitoring Location, ML 2, showed an
exceedance of the 60-dBA impact threshold throughout the duration of the monitoring
intervals. The exceedance recorded at ML 2 was due to traffic and excavation activities
associated with the adjacent project to the south and are not project related. The
duration of these activities was short enough such that the background noise level
(1-90) for all monitoring locations was 57.5 dBA or less. This record of 57.5 dBA was
recorded at ML 2.
Recommendations
Monitoring Location #2 was found to have an energy average sound level (Leq-
h) in excess of 60 dBA; however, this exceedance was due to the close proximity of
construction activities associated with the adjacent project to the south, and are not
project related. The mitigation measures proposed within monitoring report #1 are still
applicable.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
Rick Tavares, EIT, REA, INCE
Project Principal
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379/619-640-0763
San Diego, CA 92108-4003 www.ise-advantage.com
RECEIVED
April 27, 1999
APR 281999
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc. ENGINEERING
5510 Morehouse Drive DEPARTMENT
San Diego, CA 92121
- Re: Cannon Road Mitigation Monitoring Results - Week #7 (4-21-99)
(lSE Report #99-009g)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (lSE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on April 21, 1999. The results of that survey
are presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
1A
ON
'ProjectAIignme
' t'&.. ' .' "i eaj"NallIS
4 ,, Q V(
944
, , ,. i, 4. '.
,
All
'
.4 .4 &.FIX,4I /
' ' - . S ,. _5 •' . ,'4'_. 4'I 14i y
•.:,' -'Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107) :
-
. Acoustical Definitions , . ....
4.'
..
5. .. . . . . .. .. ..'..
. . .' Airborne sound is a rapid fluctuation of air pressure above and below
'. atmospheric levels. The loudest sounds the human ear can hear conformably , is''. '• .:
approximately one trillion (a one with 12 zeros following it) times the acoustic energy', ,'
•
-. " - .. • that the ear, can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of / ' •'
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level .
of zero 0 dB is scaled such that it is defined as the threshold of human heanng and
would be barely audible to a human of normal hearing under extremely quiet listening conditions and would correspond to a sound pressure level equal to the reference level
Most of the sounds we hear in the environment do notconsist of a single','' .'.
frequency, but rather a broad band of frequencies' differing in sound level. The .
intensities of each frequency add to generate the sound we hear. The method
commonly used to quantify environmental sounds consists of determining all of the
- frequencies of a sound according to a weighting system that reflects • the nonlinear.
response characteristics of the human ear. This is called "A" weighting, and the decibel.
.
level measured is called the A-weighted sound level (or dBA). In practice, the level of a. .
noise source is conveniently measured using a sound level meter that includes a filter'IT
,'corresponding to the dBA curve.
Although the A-weighted sound level may adequately, indicate the level. of,• :, :. environmental noise at any instant in time, community noise levels vary continuously. • .
7'. . •, • . ,: ,
4 1
.4, 4
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #7 (4-21-99)
ISE Report #99-009g
April 27, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors LIO, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the L10 typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be/Ill
pusi//us) and the southwestern willow flycatcher (Empidonax trail/ii extrimus) and the
federally threatened California gnatcatcher (Polioptlla california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Be/I's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results — Week #7 (4-21-99)
ISE Report #99-009g
April 27, 1999
Page 4
ER Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
f 2#3 ; Country ci
/ 0 I
±ffTiCrN IvL#1
- I i,•.
in 1/
0 1/2 1MILE
/13L10 1000 0 1000
aL1n'as'w
2000 3000 4000 FEET
f I IWI 7iUW L!1 n aT I
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195 W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #7 (4-21-99)
ISE Report #99-009g
April 27, 1999
Page 5
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Findings
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. During the week #7 monitoring
period, construction activities associated with the Cannon Road West Project were
primarily concentrated near the ML 3 location (adjacent to El Camino Real). Activities
and equipment observed at this location were primarily affiliated with the fabrication of
the Cannon Road / El Camino Real bridge supports. Equipment utilized at this location
consisted primarily of a single dozer and digger. Construction activities associated with
unrelated properties to the north and south were appreciable at Monitoring Location #2.
Testing conditions during the monitoring intervals were clear and sunny with an
average barometric pressure reading. of 29.85 in-Hg, an average westerly wind speed
of 1 to 5 miles per hour (MPH), and an approximate mean temperature of 78.5 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the statistical indicators LIO, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #7 (4-21-99)
ISE Report #99-009g
April 27, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
1-Hour Noise Level Descriptors in dBA
Site Leq Lmax Lmin LIO L50 L90
7:30 a.m.
ML 1 51.5 71.0 43.0 54.0 48.5 45.5
ML 67.0 81.0 53.5 69.0 65.5 59.0
MI-3 66.5 77.5 55.5 71.0 63.5 60.5
8:30 a.m.
ML 1 53.0 66.0 42.5 56.5 50.5 46.0
L1L2 64.5 80.0 54.0 66.5 63.0 58.5
MI-3 65.5 77.5 55.0 68.5 63.5 60.5
9:30 a.m.
ML 1 56.5 68.5 44.5 60.5 53.5 49.0
MI-2 66.5 83.5 52.5 68.0 61.5 57.0
ML 3 64.0 77.5 55.5 66.5 62.0 59.5
10:30 a.m.
ML 1 57.5 74.0 42.5 61.5 53.5 46.5
WLL2 64.5 92.5 51.5 65.5 60.5 57.0
MI-3 63.0 77.0 53.0 65.0 60.5 56,5
11:30 a.m.
ML 1 57.0 72.5 42.0 61.0 53.5 46.5
ML 2 63.5 80.0 48.5 67.0 57.5 52.0
MI-3 59.0 74.5 49.0 61.5 57.0 53.5
12:30 p.m.
ML 1 59.5 76.5 42.5 62.5 55.5 48.5
MI-2 64.0 80.5 50.0 66.0 60.5 55.5
ML 62.5 74.0 51.0 65.0 61.0 57.0
1:30 p.m.
ML 1 55.5 71.0 42.5 59.5 50.5 45.0
ML 62.0 79.0 46.0 64.5 59.0 54.0
ML. 61.0 75.5 51.0 64.0 59.5 55.5
2:30 p.m.
ML 1 52.0 65.0 41.0 56.0 47.0 44.0
MI-2 60.0 80.5 47.5 60.0 54.5 51.0
ML 3 62.5 71.5 54.0 65.0 61.0 58.0
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #7 (4-21-99)
ISE Report #99-009g
April 27, 1999
Page 7
Measurements collected at monitoring locations ML I through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Two locations, ML 2 and ML 3, showed an
exceedance of the 60-dBA impact threshold throughout the duration of the monitoring
intervals. At ML 2, this exceedance was due to the close proximity of grading activities
associated with the adjacent property to the south and are not project related. For ML
3, this exceedance was due to the close proximity of construction activities associated
with the prospective Cannon Road I El Camino Real bridge. The duration of these
activities was short enough such that the background noise level (L90) recorded at
Monitoring Locations #2 and #3 was 60.5 dBA.
Recommendations
Monitoring Locations #2 and #3 were found to have an energy average sound
level (Leq-h) in excess of 60 dBA. Of these two, only ML 3 was directly project related.
This exceedance was due to the close proximity of construction activities associated
with the prospective Cannon Road I El Camino Real bridge. The mitigation measures
proposed within monitoring report #1 are still applicable, thus,
I. It is recommended that a temporary 8-foot-heigh-plywood noise barrier be
constructed along the habitat periphery near the bridge construction area to
shield the habitat from construction-related noise. Details of the temporary
barrier will be forwarded to Ogden and the City.
2. Idling of equipment near habitat (especially adjacent to ML #2 area) should
be kept to a minimum.
In addition, Ogden's biological staff has informed ISE that least Bell's vireo were
present near Station 99+00 and 108+00. Mitigation Item #1 identified above should
also be applied to these areas as well.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
Rick Tavares, EIT, REA, INCE
Project Principal
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 / 619-640-0763
San Diego, CA 92108-4003 wwwise-advantage.com
'DECEIVED
April 16, 1999
APR 19 1999
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc.
5510 Morehouse Drive
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #6 (4-16-99)
(ISE Report #99-0090
Dear Mr. Gettinger:
ENGINEERING
DEPARTMENT
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on April 16, 1999. The results of that survey
are presented in this letter report.
Introduction and Definitions
Site Characterization
I
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road -
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher. -
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda , . .
• , m"' -v
-,
•
tt
JJ 'r .
)I42 4*Il r
.-
126
rA L
17127
'
4Projecl Aiignrnen 'i
- l.I3 1 MR11,
4 I•13
// 3 ••.'
I , , ,
-'. IU./I..:/w..
J13 1c
--.'I -'- .- 3' .- p'.r1
?
. .3'.;p\i..
' 41 Il eII'
'1
gmm
.......... .,..........
I
I
Figure 1 Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 11 07),
Acoustical Definitions
- .. 1 • • ' ,- -
Airborne sound is a rapid fluctuation of air pressure above and below
-I.. - I_ -
' atmospheric levels The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect Because of this vast range any attempt to represent the
- acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a loganthmic ratio known as the decibel (dB) is commonly employed .,,A sound level
• of zero 0 dB is scaled such that it is defined as the threshold of human hearing and -
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level -----
- -
Most of the sounds we hear, in the environment do not consist of a single
frequency, but rather a broad band of frequencies differing in sound level The
intensities of each frequency add to generate the sound we hear.'The method
* commonly used to quantify environmental sounds consists of determining all of the
frequencies of a sound according to a weighting system that reflects the nonlinear
response characteristics of the human ear. This is called "A" weighting and the decibel *
level measured is called the A-weighted sound level (or dBA) In practice the level of a 4 ,' *
noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve
-
3 1 1
II
Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously.
4 - 1
1 I 4 I •
'p
4, I,
I I'-
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #6 (4-16-99)
ISE Report #99-009e
April 16, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the L10 typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be//ii
push/us) and the southwestern willow flycatcher (Empidonax trail/ii extrimus) and the
federally threatened California gnatcatcher (Poiopti/a california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Bell's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California :
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #6 (4-16-99)
ISE Report #99-009e
April 16, 1999
Page 4
Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
ID
<
intorosa
IVIL #3 ...Country CIt
gua
10 7 (4j
—. IvL#2
.J IvL #1 JI /t
,1
0 1/2 1MILE TN T / MN •._,,. i,cc,t r.s*g..tg,..sq I /iie 1000 0 1000 2000 3000 4000 FEET / I Fk.'IbI R6W,I
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #6 (4-16-99)
ISE Report #99-009e
April 16, 1999
Page 5
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. During the week #5 monitoring
period, construction activities associated with the Cannon Road West Project were
primarily concentrated near the ML 3 location (adjacent to El Camino Real). Observed
equipment utilized at this location consisted primarily of a single truck-mounted crane.
Construction activities associated with an adjacent property to the north were
appreciable at Monitoring Location #2.
Testing conditions during the monitoring intervals were clear and sunny with an
average barometric pressure reading of 29.99 in-Hg, an average westerly wind speed
of 1 to 5 miles per hour (MPH), and an approximate mean temperature of 79.5 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the statistical indicators LIO, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #6 (4-16-99)
lSE Report #99-009e
April 16, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
I 1-Hour Noise Level Descriptors in dBA
Site Leq Lmax Lmin LIO L50 L90
7:30 a.m.
ML 1 51.5 69.0 44.0 52.5 50.5 49.0
ML 59.5 79.5 51.5 60.5 56.0 54.0
ML 3 56.0 68.5 49.0 57.5 56.0 52.0
8:30 am.
ML 1 51.5 70.0 44.0 52.0 48.5 47.5
ML 59.0 79.0 52.5 61.5 56.5 55.0
MI-3 57.0 71.0 50.0 59.5 56.0 53.0
9:30 a.m.
ML 1 52.5 71.0 45.0 53.0 49.5 48.0
MI-2 60.0 83.0 53.0 62.0 57.0 54.5
MI-3 57.0 71.0 50.0 59.5 56.0 53.0
10:30 a.m.
ML 1 50.0 68.0 43.0 51.5 47.5 45.5
MI-2 61.0 76.0 51.0 65.0 57.5 54.5
ML 3 56.5 67.0 50.0 59.0 56.0 53.0
11:30 a.m.
ML 1 52.0 73.5 43.0 54.0 48.0 46.0
MI-2 59.5 73.0 48.5 62.5 55.0 52.0
MI-3 57.0 71.0 49.5 59.0 56.0 53.0
12:30 p.m.
ML 1 50.0 62.0 45.0 53.0 48.5 46.5
MI-2 62.0 82.0 49.5 60.5 54.0 52.0
MI-3 56.5 71.5 49.5 58.5 56.0 53,0
1:30 p.m.
ML 1 52.0 62.5 42.0 55.5 50.0 46.0
ML 2 58.5 70.0 50.5 61.5 56.5 53.0
MI-3 . 56.0 65.0 49.5 58.0 55.5 52.5
2:30 p.m.
ML 1 51.5 62.0 44.5 54.0 50.5 47.5
ML 59.5 70.5 51.5 62.5 58.0 . 54.5
MI-3 59.0 72.5 50.0 62.0 56.0 53.0
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #6 (4-16-99)
ISE Report #99-009e
April 16, 1999
Page 7
Measurements collected at monitoring locations ML I through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Only one location, ML 2, showed an exceedance
of the 60-dBA impact threshold throughout the duration of the monitoring intervals. This
exceedance was due to the close proximity of grading activities associated with the
adjacent property to the north and are not project related. The duration of these
activities was short enough such that the background noise level (1-90) was 55.0 dBA or
less enabling vireo communication over 90% of the time.
60 Recommendations
Monitoring Location #2 was found to have an energy average sound level (Leq-
h) in excess of 60 dBA. This exceedance was due to adjacent grading operations of an
unrelated project north of the western Cannon Road extension. The mitigation
measures proposed within monitoring report #1 are still applicable.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
Rick Tavares, EIT, REA, INCE
Project Principal
Investigative Science and Engineering
Cc: Shem Howard, City of Carlsbad
Glen Laube, ISE
Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 /619-640-0763
San Diego, CA 92108-4003 www.ise-advantage.com
April 8, 1999 APR 121999
ENGINEERING
Mr. Doug Gettinger DEPARTMENT
Ogden Environmental and Energy, Inc.
5510 Morehouse Drive
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #5 (4-8-99)
(ISE Report #99-009e)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on April 8, 1999. The results of that survey are
presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #5 (4-8-99)
ISE Report #99-009e
April 8, 1999
Page 2
to k i1
)> \\ -
..:.
':,
. .-
:• i•I
:i4 ', ,', .., ;1.i'•
AUZA
Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
Acoustical Definitions
Airborne sound is a rapid fluctuation of air pressure above and below
atmospheric levels. The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level
of zero "0" dB is scaled such that it is defined as the threshold of human hearing and
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level.
Most of the sounds we hear in the environment do not consist of a single
frequency, but rather a broad band of frequencies differing in sound level. The
intensities of each frequency add to generate the sound we hear. The method
commonly used to quantify environmental sounds consists of determining all of the
frequencies of a sound according to a weighting system that reflects the nonlinear
response characteristics of the human ear. This is called "A" weighting, and the decibel
level measured is called the A-weighted sound level (or dBA). In practice, the level of a
noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve.
Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #5 (4-8-99)
ISE Report #99-009e
April 8, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the L10 typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be/Ill
pusillus) and the southwestern willow flycatcher (Empidonax fraillll extnmus) and the
federally threatened California gnatcatcher (Poliopti/a california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Be/I's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results —Week #5 (4.8-99)
ISE Report #99-009e
April 8, 1999
Page 4
Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
..,/ •;,.-' .
J. K
ML #31 .*Y.Country CR1
J Ila p
- M, #2
•- ) r-1
7 IVL #1
S :..•.<_:_/'•. : S
/ /
t aPnt
Ne/MN 1/2 1 MILE
1000 0 1000 2000 3000 4000 FEET
J I W'flSWnflJ
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
S (ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #5 (4-8-99)
ISE Report #99-009e
April 8, 1999
Page 5
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. During the week #5 monitoring
period, construction activities associated with the Cannon Road West Project were
primarily concentrated near the ML 3 location (adjacent to El Camino Real). Observed
equipment utilized at this location consisted of dozers, scrapers, diggers, and a single
chainsaw. In addition, construction activities associated with the adjacent property to
the north were appreciable at Monitoring Locations 1 and 2.
Testing conditions during the monitoring intervals were partly cloudy with an
average barometric pressure reading of 29.85 in-Hg, an average westerly wind speed
of 5 to 10 miles per hour (MPH), and an approximate mean temperature of 69.5
degrees Fahrenheit. The results of the sound level monitoring are shown below in
Table 1. The values for the energy equivalent sound level (Leq), the maximum and
minimum measured sound levels (Lmax and Lmin), and the statistical indicators LIO,
L50, and L90, are given for each monitoring location. Areas in excess of the 60-dBA
Leq-h impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #5 (4-8-99)
ISE Report #99-009e
April 8, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
1-Hour Noise Level Descriptors in dBA
Site Leq Lmax Lmin . LIO L50 L90
7:30 a.m.
ML 1 51.0 72.5 38.0 52.5 45.0 41.5
ML 55.0 89.5 44.0 55.0 51.0 47.5
ML 3 58.5 69.5 45.5 62.0 59.0 53.5
8:30 a.m.
ML 1 51.5 68.0 37.5 1 54.5 46.0 41.5
ML 2 56.5 72.0 44.5 58.5 53.5 48.5
MI-3 55.5 68.5 44.0 58.0 54.5 50.0
9:30 a.m.
ML 1 51.5 75.0 37.0 51.5 43.5 39.5
MI-2 55.5 71.5 42.5 58.5 52.0 46.0
MI-3 62.5 80.0 54.0 67.5 60.5 56.5
10:30 a.m.
ML 1 52.5 73.5 39.5 52.5 45.5 42.0
MI-2 58.5 73.5 46.0 62.0 52.5 49.0
MI-3 83.5 79.5 53.0 66.5 61.0 57.0
11:30 am.
ML 1 52.0 71.0 39.0 54.0 46.0 42.0
MI-2 59.0 79.5 45.5 61.0 54.5 49.5
MI-3 61.5 79.0 49.0 63.5 57.0 54.0
12:30 p.m.
ML 1 49.5 72.5 39.0 51.5 45.0 41.5
ML 2 57.0 75.0 46.0 59.0 54.0 49.0
MI-3 64.5 81.0 53.0 68.0 61.5 57.5
1:30 p.m.
ML 1 50.5 69.5 40.5 53.5 45.5 42.0
ML 2 56.0 74.0 47.5 58.0 53.5 50.0
MI-3 .64.5 85.5 56.0 67.0 62.0 59.5
2:30 p.m.
ML 1 53.0 72.0 39.5 55.0 46.5 43.0
MI-2 59.0 81.0 46.5 59.5 55.5 50.0
ML 3 64.5 81.0 53.0 68.0 61.5 57.5
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #5 (4-8-99)
lSE Report #99-009e
April 8, 1999
Page 7
Measurements collected at monitoring locations ML 1 through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Only one location, ML 3, showed an exceedance
of the 60 dBA impact threshold throughout the duration of the monitoring intervals. This
exceedance was due to the close proximity of grading activities associated with the
adjacent property to the north and are not project related. In addition, noise from
adjacent El Camino Real Road was found to be a significant noise contributor at this
monitoring location. The duration of these activities was short enough such that the
background noise level (1-90) was 59.5 dBA or less enabling vireo communication over
90% of the time.
Recommendations
Monitoring Location #3 was found to have an energy average sound level (Leq-
h) in excess of 60 dBA. This exceedance was due to adjacent grading operations of an
unrelated project north of the western Cannon Road extension and traffic activity along
El Camino Real. The mitigation measures proposed within monitoring report #1 are still
applicable.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
Rick Tavares, EIT, REA, INCE No. 06
Project Principal
Investigative Science and Engineering
kOF
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
-I,tJ1
Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302
San Diego, CA 92108-4003
April 5, 1999
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc.
5510 Morehouse Drive
San Diego, CA 92121
PhoneFax: 619-640-9379 / 619-640-0763
www.ise-advanfage.com
RECEIVED
APR 0.6 1999
- ENGINEERING
* DEPARTMENT..
Re: Cannon Road Mitigation Monitoring Results - Week #4 (4-1-99)
(ISE Report #99-009d)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat.
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on April 1, 1999. The results of that survey are
presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings. and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher,
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to-,.the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda . . -.
4
S -
C '
p - - - c
p.
-.
- ,
5458
S
5! S•
S
-S c
3A 5àj
, kt
:1211 FR
* PwjectAhgnmen
NO
-' 0 ~Jtl -
WA
N
tsp
44
NN RP 0
i4s'p . 4
Ou P$P
p ?-4 -c p ¼W p-
- -.
PiI4
•
4T4
. P•''*i P
-P 7 * S P44q•1f5p 1 ---1 4c -. c__P
7.
S. 4 Figure 1 Project Alignment Area Map (Thomas Guide Pages 11 26, 1127, and 1107)
Acoustical Definitions
Airborne sound is a rapid fluctuation of air pressure above and below
atmospheric levels The loudest sounds the human ear can hear conformably is
approximately one trillion (a one with 12 zeros following it) times the acoustic energy
that the ear can barely detect Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this, a logarithmic ratio known as the decibel (dB) is commonly employed A sound level
of zero '0' dB is scaled such that it is defined as the threshold of human hearing and
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level
5, 4,
Most of the sounds we hear in the environment do not consist of a single
frequency, but rather a broad band of frequencies differing, in sound level The
intensities of each frequency add to generate the sound we hear. The method
commonly used to quantify environmental sounds consists of determining all of the
frequencies of a sound according to a weighting system that reflects the nonlinear
response charactenstics of the human ear. This is called "A" weighting, and the decibel
level measured is called the A-weighted sound level (or dBA) In practice the level of a
noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve
Although the A-weighted sound level may adequately indicate the level of
'S
8.
environmental noise at any instant in time community noise levels vary contino uusly
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #4 (4-1-99)
ISE Report #99-009d
April 5, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors LIO, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the L10 typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be//ii
push/us) and the southwestern willow flycatcher (Empidonax trail/ii extrimus) and the
federally threatened California gnatcatcher (Polioptila california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
temtones. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Be/I's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
41
ffl
IvL#3
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #4 (4-1-99)
ISE Report #99-009d
April 5, 1999
Page 4
Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
intorosa
.-,,Country Clt
,
VVi
0 1/2 1MILE LITJWLi'l lt8I l'rJ f'I I
13 8 1000 0 1000 2000 3000 4000 FEET /
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 w Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
r
el
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #4 (4-1-99)
ISE Report #99-009d
April 5, 1999
Page 5
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, LIO, L50, and
L90. x- u
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. Due to adverse weather
conditions, no construction activities associated with the Cannon Road West Project
were observed during the week #4 monitoring period. Construction equipment was
operational at an unrelated project adjacent to the north (across Agua Hedionda
Creek).
Testing conditions during the monitoring intervals were cloudy (heavy
precipitation) with an average barometric pressure reading of 29.25 in-Hg, an average
northwesterly wind speed of.4 to 10 miles per hour (MPH), and an approximate mean
temperature of 68 degrees Fahrenheit. The results of the sound level monitoring are
shown below in Table 1. The values for the energy equivalent sound level (Leq), the
maximum and minimum measured sound levels (Lmax and Lmin), and the statistical
indicators 1-10, L50, and L90, are given for each monitoring location. Areas in excess of
the 60-dBA Leq-h impact threshold are underlined.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #4 (4-1-99)
ISE Report #99-009d
April 5, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
I 1 -Hour Noise Level Descriptors in dBA
Site Leq Lmax Lmin LIO L50 L90
7:30 a.m.
ML 60.5 77.5 44.0 65.0 55.5 49.0
ML2 57.5 76.5 46.0 61.0 54.0 50.0
ML 3 69.5 81.5 61.5 71.5 69.5 67.0
8:30 a.m.
ML 1 60.5 . 75.0 46.0 64.0 56.5 50.0
ML2 57.5 74.0 46.5 61.0 54.0 49.5
ML3 67.0 74.0 56.0 69.5 67.0 62.5
9:30 a.m.
M'L1 62.5 79.5 43.0 66.5 57.5 50.0
ML2 56.5 71.0 46.5 60.0 53.0 49.5
ML 3 62.0 73.0 52.5 65.0 60.5 58.0
10:30 a.m.
.4L .J. 64.0 83.5 44.0 67.5 58.0 51.0
L2 64.5 87.5 46.0 63.0 54.5 50.0
ML.3 65.0 77.0 54.5 67.5 64.0 60.5
11:30 a.m.
ML 67.5 81.5 42.0 72.0 62.5 54.0
ML2 73.0 91.0 48.5 74.0 64.0 55.5
ML3 61.5 76.0 50.0 64.0 60.0 56.0
12:30 p.m.
ML 1 62.0 79.0 42.5 66.0 58.0 47.0
62.0 83.5 46.0 65.0 56.0 49.0
ML 3 62.0 73.5 49.0 66.0 59.5 55.0
1:30 p.m.
ML 65.0 81.5 45.0 68.5 62.0 55.5
.L2 67.5 81.5 49.0 71.0 65.0 59.0
ML 60.0 74.0 48.5 62.0 59.0 55.0
2:30 p.m.
ML 70.0 87.0 46.0 74.0 64.5 56.5
ML2 73.0 90.5 48.5 77.5 68.5 59.5
ML 62.0 75.0 49.5 64.5 61.5 57.0
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #4 (4-1-99)
ISE Report #99-009d
April 5, 1999
,' Page 7
Measurements collected at monitoring locations ML 1 through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. All locations showed an exceedance of the 60-
dBA Leq-h impact threshold at some period within the monitoring interval. This
exceedance was due entirely to construction activities associated with the adjacent
property to the north and the heavy rain conditions present during the entire monitoring
day. The duration of offsite construction activities was short enough such that the
background noise level (i.e., L90) was 59.5 dBA or less enabling vireo communication
over 90% of the time Monitoring Locations #1 and #2. Monitoring Location #3, which is
adjacent to El Camino Real, had the highest background readings. This again was
directly attributable to traffic noise along the wet pavement.
Recommendations
All Monitoring Locations (i.e., ML 1, ML 2, and ML 3) were found to have an
energy average sound level (Leq-h) in excess of 60 dBA. This exceedance was due to
adjacent grading operations of unrelated projects located to the north. The mitigation
measures proposed within monitoring report #1 are still applicable.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
Rick Tavares, ElT, REA, INCE
Project Principal
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
H
Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 PhonelFax: 619-640-9379-1619-640-0763
San Diego, CA 92108-4003 www.ise-advantage.com
March 26, 1999
MAR 29 1999
Mr. Doug Gettinger
Ogden Environmental and Energy Inc. ENGINEERING
5510 Morehouse Drive DEPARTMENT
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #3 (3-25-99)
(ISE Report #99-009c)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on March 25, 1999. The results of that survey
are presented in this letter report.
Introduction and Definitions
*
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles-east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings .and traverses through and adjacent to -
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
- -:.i;'• - L..'- ., -
4.-
.0 , ..0 to - / . •*,c./¼.:
-
¼ ¼
-c
12
MR
¼4 ¼ 14
,o ç
- -
-it..
-. - - -
Mr. Doug Gettinger .. . .;-.
= . Cannon Road Mitigation Monitoring Results - Week #3 (3-25-99
,s J
)
. . ISE Report #99-009c
March 26, 1.999 ..
,0 .Page2 - -
-. .
ii
-...-
Figure 1 Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
........-
¼ ¼
0) . . . - --
4
0 . . ¼ • - •-
- -•-- . . r - . . - . ;.,-.- 4 - T - *
Acoustical Definitions ¼
0
+ 4. 4 0_
Airborne sound is a rapid fluctuation of air pressure above and below
atmospheric ' levels. The 010udest sountds the human ear can hear conformably is - • ¼
0 approximately one trillion (a one with 12 zeros following it) times the acoustic energy,
that the ear can barely detect Because of this vast range any attempt to represent the r
acoustic intensity of a particular sound on a linear scale becomes unwieldy Because of
this a logarithmic ratio known as the decibel (dB) is commonly employed A sound level
of zero '0 dB is scaled such that it is defined as the threshold of human hearing and
would be barely audible to a human of normal hearing under extremely quiet listening
conditions and would correspond to a sound pressure level equal to the reference level -
)
Most of the sounds we hear in the environment do not consist of a single
¼4 4/ 4
- frequency, but rather a broad band of frequencies differing insound level. The . ¼
- intensities of each frequency add to generate the sound we hear. The method -'
-
commonly used to quantify environmental sounds consists of determining all of the , - 1 frequencies of a -sound according to a weighting system that reflects the nonlinear -
- response characteristics of the human ear. This is called "A" weighting and the decibel
¼ level measured is called the A-weighted sound level (or dBA) In practice, the level of a
noise source is conveniently measured using a sound level meter that includes a filter
corresponding to the dBA curve ¼
- Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary, continuously '
4-
1 ¼
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #3 (3-25-99)
ISE Report #99-009c
March 26, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors LIO, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the LIO typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lrnin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
JB Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be/Ill
pusillus) and the southwestern willow flycatcher (Empidonax trailill extnmus) and the
federally threatened California gnatcatcher (Polioptila california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Bell's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #3 (3-25-99)
ISE Report #99-009c
March 26, 1999
Page 4
go Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
ID
.../L::77- Awr- " I
",----------1 I fiT I
:11: ii 7 \• c K 4W/bffltorosa I
Qqu.ntr.y CIII
\, "/ o Agua
\ ... .f. ....
ij , ..- (1 o NIL #2
., :J :
-10 0.
Ne/MN 0 !12 - 1MILE
1000 — 0 10 _j00 30 _0O FEET
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #3 (3-25-99)
lSE Report #99-009c
March 26, 1999
Page
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, 1-10, L50, and
L90.
Findings
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. Due to adverse weather
conditions, no construction activities associated with the Cannon Road West Project
were observed during the week #3 monitoring period. Construction equipment was
operational at unrelated projects adjacent to the north (across Agua Hedionda Creek)
and south of the western Cannon Road extension.
Testing conditions during the monitoring intervals were cloudy (with moderate to
heavy precipitation) with an average barometric pressure reading of 29.85 in-Hg, an
average northwesterly wind speed of 0 to 5 miles per hour (MPH), and an approximate
mean temperature of 68 degrees Fahrenheit. The results of the sound level monitoring
are shown below in Table 1. The values for the energy equivalent sound level (Leq),
the maximum and minimum measured sound levels (Lmax and Lmin), and the
statistical indicators LIO, 1-50, and L90, are given for each monitoring location. Areas in
excess of the 60-dBA Leq-h impact threshold are underlined.
II
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #3 (3-25-99)
ISE Report #99-009c
March 26, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
I 1 -Hour Noise Level Descriptors in dBA
Site Leq Lmax Lmin LIO L50 L90
8:00a.m.
MU. 67.5 79.0 50.5 71.0 66.0 59.0
ML2 60.5 81.5 44.5 64.0 51.5 48.0
ML3 57.5 76.0 43.5 60.5 56.5 51.0
9:00a.m.
MU. 68.0 81.5 51.0 71.5 66.5 58.5
ML2 59.0 83.5 44.0 60.0 50.5 47.5
4
ML 3 . 55.5 68.0 44.5 58.5 54.5 50.0
10:00a.m.
ML 65.5 84.0 38.5 70.0 58.5 43.5
ML2 61.0 83.0 43.0 62.0 51.5 47.0
ML 3, 56.5 . 71.0 44.5 59.0 55.0 50.5
11:00 a.m.
ML 1 58.0 81.0 38.0 59.0 47.5 42.0
ML2 60.5 82.0 45.0 63.5 52.0 47.5
ML 3 • 58.5 77.5 48.0 60.0 56.5 53.0
12:00 p.m.
ML 1 59.5 77.0 41.5 64.0 52.5 45.0
ML2 64.5 82.5 . 45.5 69.0 58.0 50.0
ML 61.5 75.0 51.5 64.5 59.5 56.0
1:00 P.M.
ML 62.5 76.0 45.5 65.5 60.5 52.5
ML2 67.0 . 85.0 47.0 70.5 64.5 55.0
ML3 63.5 78.5 53.5 66.0 63.0 60.0
2:00 p.m.
ML.1 60.0 76.0 46.0 63.5 58.0 52.5
MU 61.0 75.0 48.0 64.0 60.0 55.0
ML 63.0 76.5 52.5 65.0 62.5 58.0
3:00 p.m. .
ML 62.5 86.5 48.0 64.0 59.5 55.0
ML2 66.0 87.0 53.5 66.0 62.0 58.5
ML 63.0 71.5 56.5 65.0 62.5 ' 59.0
Mr. Doug Gethnger
Cannon Road Mitigation Monitoring Results - Week #3 (3-25-99)
ISE Report #99-009c
March 26, 1999
Page
£
Measurements collected at monitoring locations ML I through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. All locations showed an exceedance of the 60-
dBA Leq-h impact threshold at some period within the monitoring interval. This
exceedance was due to construction activities associated with the adjacent properties
to the north and south. The duration of these activities was short enough such that the
background noise level (1-90) was 60.0 dBA or less enabling vireo communication over
90% of the time.
Recommendations
All Monitoring Locations (i.e., ML 1, ML 2, and ML 3) were found to have an
energy average sound level (Leq-h) in excess of 60 dBA. This exceedance was due to
adjacent grading operations of unrelated projects located to the north and south of the
western Cannon Road extension. The mitigation measures proposed within monitoring
report #1 are still applicable.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
Rick Tavares, EIT, REA, INCE
Project Principal
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
41
a
I
1-4
&gative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379 / 619-640-0763
San Diego, CA 92108-4003 www.ise-advantage.com
March 18, 1999
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc.
5510 Morehouse Drive
San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #2 (3-17-99)
(lSE Report #99-009b)
Dear Mr. Gettinger:
MAR 19 1999
ENGINEERING
DEPARTMENT
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the npanan habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on March 17, 1999. The results of that survey
are presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
- located adjacent to the north and commercial developments are present to the west.
Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
approximately 5 feet above MSL along the Agua Hedionda
f-..',4 '541•'4.• 4'ç . • 5.:c ...
'4 '' :' "4i '' ' "..''• '4", . 1 J
;- 2 '
F '4' F
/ -Ill'5 I 4454. 4L / / '44._4554 L'4
P;octAhgnmen 44
0 FL
, .4, 4.4.4, I '44i :I '4
, •
'555k
I "• '44 4 , 544'4-I~' I/f'4)4., '4 '4' 4 '444 '4.'
" •' .'
0111L 4 54'
1
1'
t 1•_.t
4 '5 4,$ W. 4' '444
.4' . . 4... ',i '4.•
.4 ',... • '.'
•• 4 . . •5 .4 •
Mr Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #2 (3-17-99)
ISE Report #99-009b
March 18, 1999
Page .2
-
.4 4 . •4' -.5
Figure 1 Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107)
,,i_.i
.
Acoustical Definitions - f,, 4
•• ti . s- . ' '. '4 - * - •• r , - . . . - 'I
i ,'
-4
. • . S
. .• Airborne' sound is a rapid fluctuation of air pressure above and below, -
atmospheric levels The loudest sounds the human ear can hear conformably is -.
- •- 4'
.-.
approximately. one trillion. (a one with 12 zeros following it) times the acoustic energy
-. that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of
this a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level • - ." '.;
of zero "0" dB is scaled such that it is defined as the threshold of human hearing and - - .
would be barely audible to a human of normal hearing under extremely quiet listening .
'4
conditions and would correspond to .a sound pressure level equal to the reference level
,' , -
- • .
- - . 5,.
Most of the sounds we hear in the environment do not consist of a single
.•
' - •' -
- frequency, but rather a broad band of frequencies differing in sound level. The
of each frequency add to generate the sound we hear. The method intensities ' •
--
f'." -. commonly used -to quantify environmental sounds consists of determining all of the
'frequencies of a sound according to a weighting system- that reflects the ,nonlinear -'- -
* response charactenstics of the human ear. This is called "A" weighting and the decibel
-
- - '4:lev6l measured is called the A-weighted sound level (or dBA). In practice, the level of a - - -
- noise source is conveniently measured using a sound level meter that includes a filter 1
'4 corresponding to the dBA curve
S * - •' •'0 - - - . . - . . - I .-' . . '._.. ---"St - -,
Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time, community noise levels vary continuously
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #2 (3-17-99)
ISE Report #99-009b
March 18, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable..
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the' fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the LIO typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
ES Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be/Ill
pusillus) and the southwestern willow flycatcher (Empidonax trail/fl extrimus) and the
federally threatened California gnatcatcher (Polio ptila california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
territories. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Bell's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval of
the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #2 (3-17-99)
ISE Report #99-009b
March 18, 1999
Page
EB Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
1"
tntorosa
-7,Country CI
4g ua
J /7. it / . ...• I 0
____ .•
,' j IVIL #1
,
rN/MN 1/2 1 MILE
1/13%' 1000 0 1000 2000 3000 4000 FEET - -
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195 W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position Error = 49'
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #2 (3-17-99)
ISE Report #99-009b
March 18, 1999
Page
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, L10, L50, and
L90.
Field Monitoring Results
A field survey was performed to ascertain construction noise levels within the
habitat area due to light grading and ancillary activities. No construction activities
associated with the Cannon Road West Project were observed during the week #2
monitoring period; however, scrapers and dozers were operational at an unrelated
project to the south.
Testing conditions during the monitoring intervals were partly cloudy with an
average barometric pressure reading of 29.85 in-Hg, an average westerly wind speed
of 8 to 15 miles per hour (MPH), and an approximate mean temperature of 70 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the statistical indicators L10, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h .
impact threshold are underlined. .
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #2 (3-17-99)
ISE Report #99-009b
March 18, 1999
Page 6
Table 1: Measured Construction Levels - Cannon Road West Alignment
-Hour Noise Level Descriptors in dBA
Site Leq Lmax Lrnin LIO L50 L90
7:30 a.m.
ML 1 50.0 71.5 37.0 51.5 44.0 40.5
ML 2 55.5 80.5 45.0 56.0 52.0 48.5
MI-3 58.5 68.5 44.5 61.0 58.0 52.5
8:30 a.m.
ML 1 51.0 68.5 37.0 54.0 45.0 40.0
ML2 55.0 71.5 43.0 58.0 52.5 47.5
ML 3 55.5 68.5 44.0 58.0 54.5 50.0
9:30 a.m.
ML 1 51.5 75.0 37.0 51.5 43.5 39.5
ML2 55.5 71.5 42.5 58.5 52.0 46.0
ML 3 57.0 68.0 45.0 59.5 55.5 51.5
10:30 a.m.
ML 1 52.0 71.5 37.5 54.5 46.0 40.0
ML2 57.0 73.0 43.0 61.5 53.0 46.5
ML 3 55.5 67.0 44.5 58.0 54.5 50.5
11:30 a.m.
ML 1 52.5 68.5 37.5 55.0 46.0 ' 39.5
ML2 57.0 72.5 41.0 61.5 52.5 44.5
ML3 56.5 70.0 45.0 59.0 55.5 51.0
12:30 p.m.
ML 1 55.5 77.0 38.0 57.5 48.0 ' 41.5
ML2 57.5 74.5 42.0 60.5 51.5 45.5
MI-3 56.5 67.5 43.5 59.0 56.0 51.5
1:30 p.m.
ML 1 54.0 72.5 39.0 56.5 48.0 42.5'
ML2 58.5 77.5 43.5 62.0 54.5 48.5
ML 3 57.0 72.0 44.0 59.5 56.5 52.0
2:30 p.m.
60.5 67.0 49.0 63.5 59.5 54.5
ML2 67.5 77.0 54.5 74.0 61.5 56.5
ML 3 - - - - - -
* 2:30 p.m. interval data unavailable for ML 3.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #2 (3-17-99)
ISE Report #99-009b
March 18, 1999
Page 7
Measurements collected at monitoring locations ML I through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. Two locations showed an exceedance of the 60
dBA impact threshold (during the 2:30 p.m. monitoring period). These locations were
ML 1 and ML 2. This exceedance was due to grading activities associated with the
adjacent property to the south and not project related. The duration of these activities
was short enough such that the background noise level (1-90) was 56.5 dBA or less
enabling vireo communication over 90% of the time.
go Recommendations
Monitoring Locations #1 and #2 were found to have an energy average sound
level (Leq-h) in excess of 60 dBA. This exceedance was due to adjacent grading
operations of an unrelated project south of the western Cannon Road extension. The
mitigation measures proposed within monitoring report #1 are still applicable.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
/-, e-,- 61 ~ ;~—O e ~ ~
Rick Tavares, EIT, REA, INCE
Project Principal
Investigative Science and Engineering
Cc: Sherri Howard, City of Carlsbad
Glen Laube, ISE
017 CAL%!
Investigative Science and Engineering
3511 Camino Del Rio South, Suite 302 Phone/Fax: 619-640-9379/619-640-0763
San Diego, CA 92108-4003 www.ise-advantage.com
March 15, 1999 RECTD
MAR 16
Mr. Doug Gettinger
Ogden Environmental and Energy, Inc. ENC' 3 5510 Morehouse Drive DEPA1thJT San Diego, CA 92121
Re: Cannon Road Mitigation Monitoring Results - Week #1(3-10-99)
(ISE Report #99-009a)
Dear Mr. Gettinger:
Pursuant to U.S.F.W.S. permit approval requirements, Investigative Science
and Engineering (ISE) has examined potential noise impacts to the riparian habitat
along the proposed Cannon Road extension alignment located in Carlsbad, California.
A field survey of the site was performed on March 10, 1999. The results of that survey
are presented in this letter report.
Introduction and Definitions
Site Characterization
The Cannon Road West Project is located in the City of Carlsbad in San Diego
County, California (refer to Figure 1). This project will extend Cannon Road
approximately 2 miles east from its terminus at 1-5 to Camino Real. The Cannon Road
extension consists of two bridge crossings and traverses through and adjacent to
habitat for the federally endangered/threatened least Bell's vireo, southwestern willow
flycatcher, and California gnatcatcher.
The predominate land use of the' project area is undisturbed open space.
Wetlands originating from the Agua Hedionda Lagoon and Agua Hedionda Creek are
located adjacent to the north and commercial developments are present to the west.
V Elevations for the project area have been altered due to construction activities;
however, pre-construction elevations range from approximately 100 feet above mean
sea level (MSL) along the terrace over looking Agua Hedionda Lagoon down to
V approximately 5 feet above MSL along the Agua Hedionda V
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Figure 1: Project Alignment Area Map (Thomas Guide Pages 1126, 1127, and 1107) .
Acoustical Definitions - . . • . • -.
Airborne sound is a rapid fluctuation of air pressure above and below — atmospheric levels. The loudest sounds the human ear can hear conformably is
:-
- approximately one trillion (a one with 12 zeros'following it) times the acoustic energy"..
,
- that the ear can barely detect. Because of this vast range, any attempt to represent the
acoustic intensity of a particular sound on a linear scale becomes unwieldy. Because of '
this, a logarithmic ratio known as the decibel (dB) is commonly employed. A sound level
of zero "0" dB is scaled such that it is defined as the threshold of human hearing and -
would be barely audible to a human of normal hearing under extremely quiet listening
-
I . conditions and would correspond to a sound pressure level equal to the reference level.
1. . . . . . Most of the sounds we hear in the environment do, not consist of a single.':-
— - frequency, but rather a broad band of frequencies differing in sound level. The . .
- intensities of each frequency add to generate the sound we hear. The method . .,.
commonly used to quantify environmental sounds consists of determining all of the.,.. -
•- . .i; - frequencies of a sound according to a weighting system that reflects the nonlinear .. .. . ..
response characteristics of the human ear. This is called "A" weighting, and the decibel .
5
.
level measured is called the A-weighted sound level (or dBA). In practice, the level of a
noise source is conveniently measured using a sound level meter that includes a filter , . . .
.5
corresponding to the dBA curve.' • . •' .5-
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Although the A-weighted sound level may adequately indicate the level of
environmental noise at any instant in time community noise levels vary continuously ',
.,. .
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Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #1(3-10-99)
ISE Report #99-009a
- March 15, 1999
Page 3
Environmental noise includes a conglomeration of sounds from distant sources that
create a relatively steady background noise in which no particular source is identifiable.
For this type of noise, a single descriptor called the Leq (or equivalent sound level) is
used. Leq is the energy-mean A-weighted sound level during a measured time interval.
It is the 'equivalent' constant sound level that would have to be produced by a given
source to equal the fluctuating level measured.
To describe time-varying character of environmental noise, the statistical noise
descriptors L10, L50, and L90 are commonly used. They are the noise levels equaled
or exceeded during 10 percent, 50 percent, and 90 percent of a stated time. Sound
levels associated with the L10 typically describe transient or short-term events, while
levels associated with the L90 describe the steady state (or most prevalent) noise
conditions. In addition, it is often desirable to know the acoustic range of the noise
source being measured. This is accomplished through the maximum and minimum
measured sound level (Lmax and Lmin) indicators. The Lmin value obtained for a
particular monitoring location is often called the acoustic floor for that location.
Applicable Significance Criteria
Wildlife Habitat Regulations
Construction and operational noise generated by this project is regulated by the
United States Fish and Wildlife Service (U.S.F.W.S.) and the California Department of
Fish and Game for its effect on federally endangered least Bell's vireo (Vireo be/Ill
push/us) and the southwestern willow flycatcher (Empidonax trail/ii extrimus) and the
federally threatened California gnatcatcher (Poliop ti/a california).
Resource agencies have theorized that elevated noise levels can potentially
mask songs of the least Bell's vireo which are used to attract mates and defend
temtones. The San Diego Association of Governments (SANDAG) in a 1990 study
entitled "Comprehensive Species Management Plan for the least Be/I's vireo"
theoretically estimated that {traffic} noise levels above 60 dBA Leq in vireo breeding
areas may sufficiently mask the vireo's song and potentially reduce the reproductive
success of this species during their breeding season that occurs from March 1 to
September 1. Since sustained noise exposure (indicated by the L90 metric) produces
greater masking effects than intermittent peak levels, this report will analyze both
effects. The SANDAG report conclusions were unclear as to the specific time interval
of the measurement, but it is typically taken as one hour. Although research is on going
regarding similar noise impacts to the southwestern willow flycatcher and California
gnatcatcher, in the absence of species-specific data, these same study results are
applied by the Service to this bird species as well.
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results - Week #1(3-10-99)
ISE Report #99-009a
March 15, 1999
Page 4
ES Analysis Methodology
Existing Conditions Field Survey
Three Larson Davis Model 700 ANSI Type 2 integrating sound level meters
were used as the data collection devices. The meters were positioned at the locations
shown below in Figure 2 and the accompanying matrix.
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Country CI
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rNT,MN 0 1/2 1 MILE
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10
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00 0 1000 2000 3000 4000 FEET f i4L ,.ttI
Figure 2: Project Area Topography (USGS 7.5 San Luis Rey Quadrangle 1:12000)
Monitor Sta. Eng. Sta. No. GPS Lat GPS Lon Description
ML #1 102+00 330 08.780 N 1170 18.195W Western end of alignment
ML #2 113+00 330 08.826 N 1170 18.011 W Central point of alignment
ML #3 n/a 330 08.952 N 1170 17.895 W Eastern end of alignment
(ECR bridge crossing)
ECR = El Camino Real Rd.
EPE = Estimated Position En-or = 49'
Mr. Doug Gettinger
Cannon Road.Mitigation Monitoring Results -Week #1(3-10-99)
ISE Report #99-009a
March 15, 1999
Page 5
The meters were mounted on tripods roughly 5 feet above the ground and were
calibrated before and after each field deployment. Each station was programmed to
record and log the following noise metrics each hour: Leq-h, Lmax, Lmin, LIO, L50, and
L90.
Field Monitoring Results
A minimal field survey was performed to ascertain construction noise levels
within the habitat area due to light grading and ancillary activities. Several graders and
dozers were observed during the monitoring period principally adjusting the rough
grade of the roadway alignment.
Testing conditions during the monitoring intervals were partly cloudy with an
average barometric pressure reading of 29.85 in-Hg, an average northerly wind speed
of 3 to 5 miles per hour (MPH), and an approximate mean temperature of 68 degrees
Fahrenheit. The results of the sound level monitoring are shown below in Table 1. The
values for the energy equivalent sound level (Leq), the maximum and minimum
measured sound levels (Lmax and Lmin), and the statistical indicators L10, L50, and
L90, are given for each monitoring location. Areas in excess of the 60-dBA Leq-h
impact threshold are underlined.
Table 1: Measured Construction Levels - Cannon Road West Alignment
I
Site Leq
1-Hour Noise Level Descriptors
Lmax Lmin LIO
in dBA
L50 L90
11:30 am.
ML 1 54.0 77.5 41.0 57.0 44.0 42.5
M.L2 60.5 77.5 43.5 64.0 54.5 47.0
ML 3 56.5 73.0 44.0 58.5 55.5 50.5
12:30 p.m.
ML 1 49.5 71.5 40.5 51.0 43.5 42.0
ML 64.0 85.0 45.0 64.5 57.0 50.5
ML 3 56.0 67.0 44.0 58.5 55.0 50.5
1:30 p.m.
ML 1 54.5 70.0 41.5 56.5 45.5 43.0
69.0 87.0 46.5 70.0 59.5 53.5
ML 3 56.5 73.0 44.5 59.0 55.5 51.5
Mr. Doug Gettinger
Cannon Road Mitigation Monitoring Results -Week #1(3-10-99)
ISE Report #99-009a
March 15, 1999 -
Page
Measurements collected at monitoring locations ML 1 through ML 3 reflect
typical sound levels associated with the community setting observed and the
topography of the surrounding terrain. The only location that showed an exceedance
was ML #2. This exceedance was due to the relatively close pass-bys of the grader.
The duration of each pass-by was short enough such that the background noise level
(L90) was 53 dBA or less enabling vireo communication over 90% of the time.
Recommendations
Monitoring Location #2 was found to have an energy average sound level (Leq-
h) in excess of 60 dBA. This exceedance was due to grading operations close to the
habitat boundary. The following mitigation measures are required:
Grading or other operations close to the habitat boundary should utilize
equipment with shielded exhaust stacks (i.e., modified exhaust stacks that point
away from the habitat area). A plywood shielding enclosure readily constructed
on-site would suffice to this end.
If Item #1 is not implementable (as would be the case for non-standard
equipment) then a temporary plywood noise barrier should be constructed near
the working area.
Idling of equipment near habitat should be kept to a minimum.
Should you have any questions regarding the above conclusion, please do not
hesitate to contact me at (619) 640-9379.
Sincerely,
Rick Tavares, EIT, REA, INCE 9 No. 06 9
Project Principal
Investigative Science and Engineering 0.
4OFcu_'o,,,.
Cc: Shem Howard, City of Carlsbad .
Glen Laube, ISE