HomeMy WebLinkAboutCT 99-01; Carlsbad Beach Estates; Tentative Map (CT) (41)DOUGLAS EILAR & ASSOCIATES
ACOUSTICAL & ENVIRONMENTAL CONSULTING
October 22, 1998
Merit Group
Attention: David Buckmaster
2172 El Camino Real #202
Oceanside, CA 92054
SUBJECT: REPORT OF RAILROAD NOISE EVALUATION FOR
PROPOSED CARLSBAD BEACH ESTATES
Dear David:
At your request, we have conducted an evaluation of railroad noise levels at the site of
your proposed Carlsbad Beach Estates, a residential development, on Chinquapin in
Carlsbad. This report is prepared for you to submit to the City of Carlsbad to satisfy city
requirements for a noise analysis prior to discretionary approval of your project.
Summary
Field noise measurements at the project site were made to determine noise levels caused
by passing trains. The train schedules and other relevant information with a bearing on
noise were obtained. An analysis of total noise exposure throughout different period of
the typical weekday was conducted. The results indicate a noise exposure of less than 50
decibels (dB), CNEL, worst case, at the northeast property corner, and lower noise levels
elsewhere on subject property, from noise caused by passing trains. There are no other
significant noise sources impacting subject property.
This noise level is substantially less than the 60 CNEL desired noise limit for residential
land uses in the City of Carlsbad. Thus, there is no significant adverse impact from
noise, and no mitigation is required.
Project Setting
Subject property is located on Chinquapin Avenue in the City of Carlsbad. It is
approximately 500 feet west of the coastal railroad route and a quarter mile inland from
the Pacific Ocean. Less than a quarter mile south is the Agua Hedionda Lagoon. Subject
property is located in an older residential neighborhood consisting of single family and
multi-family units. Most residential properties in the area are single story or two-story.
Filar K A«nriptp<: - ^91 N Willmvsnrino Dr Fnrinitas CA Q?ft?4 - 76(1/7^-
Merit Group - Carlsbad Beach Estates Noise Analysis
October 22, 1998
Page Two
Noise Sources
There are no significant noise sources affecting subject property. The closest identified
potential noise source is the coastal railroad, which is used by Amtrak for passenger
trains, by the North County Transit District for commuter trains, and by Burlington
Northern Railway for freight trains. The departure pattern for the McClellan-Palomar
Airport is more than one mile south. Other than these, the only other sources of noise are
light traffic on nearby residential streets, an occasional plane or helicopter in the distance,
residential noises such as lawnmowers, and animals including birds and dogs. The only
source with a potential for significance at this property is the railroad, which is the
subject of this evaluation.
Railroad Operations
The current railroad schedules for Amtrak and the Coaster for the nearby stretch of track
were obtained. We also contacted a representative of the North County Transit District
that owns the railroad right-of-way. He provided additional relevant information about
the operations and schedules of all users of the tracks, including the freight trains.
Information about the number of cars, train speed, and stops was also obtained. No
significant change in future operations is anticipated at this time, so current operations
were used as a guide to this analysis.
The Coaster operates nine commuter trains in each direction on a typical weekday, for a
total of 18. Amtrak operates ten similar trains in each direction nearly every day, for a
total of 20. Burlington Northern normally operates an average of four freight trains per
day, usually one in each direction during the day and one in each direction late at night.
The passenger trains normally run with a single engine and five to eight cars. The freight
trains usually have several engines and have from 50 to 100 cars; 75 cars was estimated
to be an average.
The passenger trains can reach speeds of 60 to 80 mph on open stretches. In this vicinity,
however, speeds are less. The Coaster stops to the north at Carlsbad Village and to the
south at Poinsettia, so is does not gather much speed here, and passes by at an estimated
speed of 25-40 southbound, and somewhat less northbound. The nearest Amtrak stops
are in Oceanside and Solana Beach, so these trains do not stop nearby. Their speeds in
this area are estimated at 35-50 mph in this area. The freight trains do not stop nearby
and are slower, with an estimated speed of 25-30 mph.
Filar K A<:<;nHatp« - ~\~>\ N Willmvsnrina T> Fnrinitns PA Q7f)74 - 760/7S'?-! RfiS
Merit Group - Carlsbad Beach Estates Noise Analysis
October 22,1998
Page Three
Since Tamarack Avenue, a block north of Chinquapin, has a railroad crossing,
northbound trains sound their horn as they approach and pass Chinquapin, since
Tamarack is just ahead. Southbound trains do not, since they have already made their
nearest crossing. Consequently, the northbound trains are louder due to the additional
noise source of the horn.
The approximate times for train pass-bys, based on their current schedules, are:
Amtrak -
Southbound
08: 10a.m.
09:15
10:32
12:24 p.m.
02:18
04:02
06:03
06:55
09:13
11:41
Amtrak -
Northbound
06:57 a.m.
08:53
10:14
11:09
01:01 p.m.
03:43
04:43
06:23
08:28
10:55
Coaster -
Southbound
05:29 a.m.
06:13
06:48
07:19
07:48
11:05
03:40 p.m.
05:00
05:30
Coaster -
Northbound
07:29 a.m.
08:39
03:08 p.m.
04:32
05:10
05:42
06:14
06:58
07:32
Noise or Sound Level Descriptors
All noise level or sound level values presented herein are expressed in terms of decibels (dB),
with A-weighting to approximate the hearing sensitivity of humans. Time-averaged noise
levels are expressed by the symbol L,, for a specified duration. The Community Noise
Equivalent Level (CNEL) is a 24-hour average, where sound levels during evening hours of 7
p.m. to 10 p.m. have an added 5 dB weighting, and sound levels during night-time hours of 10
p.m. to 7 a.m. have an added 10 dB weighting. This is similar to the Day-Night sound level,
Ld«, which is a 24-hour average with 10 dB added weighting on the same night-time hours but
no added weighting on the evening hours. These metrics are used to express noise levels for
both measurement and municipal regulations, for land use guidelines and enforcement of
noise ordinances.
Filar * A«<:rvriatp<5 -N Willnw«;nrino Dr Fnrinitas PA 97094 - 760/7S1-
Merit Group - Carlsbad Beach Estates Noise Analysis
October 22, 1998
Page Four
Field Measurements
On Friday, October 16, 1998, simultaneous noise level measurements during train pass-
bys were conducted by two technicians from Douglas Eilar & Associates. The
measurements were conducted during the late morning, with fair weather and a very light
breeze. The noise level of a southbound Coaster train was measured at approximately
11:07 a.m., and the noise from a northbound Amtrak train was measured at
approximately 11:15 a.m. Freight train operations are few and are not on a
predetermined schedule, so no freight train measurements were made.
Two measurement positions were used, at locations shown in the attached site plan.
Position A was near the northeast property corner, at the fence on the eastern property
line, about five feet inside the sidewalk. Position B was about five feet inside the
southeast property corner. The microphones were at a height of four to five feet above
the ground.
The instruments used for noise measurements included two type 1 (precision) sound level
meters: a GenRad Model 1988 and a Quest Model 1800. Both were calibrated just prior
to and immediately after the noise measurements. Both have also been calibrated within
the past 12 months by an independent metrology service, in compliance with ANSI
standards. During the noise measurements, both units were mounted on tripods and
equipped with windscreens. A distance measuring wheel was used to measure all
distances.
At Position A, the southbound Coaster train at 11:07 a.m. was measured to have a noise
level (Leq) of 55.6 dB during the brief passby duration of 20 seconds. The simultaneous
measurement of this train from Position B yielded an average noise level during the peak
10 seconds of the passby of 50.3 dB (Leq).
At Position A, the northbound Amtrak train at 11:15 a.m. was measured to have an
average noise level (Leq) of 61.4 dB over a duration of 40 seconds. It was louder and
audible over a longer period in large part to the use of the horn as the train approached
the Tamarack Avenue crossing. The simultaneous measurement of this train from
Position B yielded an average noise level during the peak 10 seconds of passby at 53.2
dB (Leq).
Ambient noise levels at both measurement positions, with no distinctive noises in the
background, were approximately 44 dB. All measurements were rather brief for two
reasons - the train passbys were quick, and shorter duration measurements minimized the
chance of other occasional interfering sound from affecting the results.
TVmolac Filar* A««r>Hatp<; - W N Willnwsnrino Dr Rnrinitas PA Q?fP4 -
Merit Group - Carlsbad Beach Estates Noise Analysis
October 22, 1998
Page Five
Analysis
The above noise measurements and the frequency, timing, direction and type of train
operations were subject to analysis for all operations to arrive at a value for CNEL from
the total of all railroad activities. The worst case of the northeast corner of subject
property, at Position A was first considered. The noise level of 55.6 dB for 20 seconds
per pass for the 14 southbound passenger trains during the 12 daytime hours (between 7
a.m. and 7 p.m.) was averaged, with the result being an hourly average of 34 dB (Leq).
(This is based on the general principle in which a 3 dB reduction is applied to convert a
given sound intensity to the equivalent intensity over a period twice as long.) The same
procedure for the 16 northbound passenger trains (at 61.4 dB per 40-second passby)
during this 12-hour period yielded an hourly average of 44 dB (Leq). Freight train noise
was estimated to be the worse case of 61.4 dB in each direction, and the duration of a
typical freight train was conservatively estimated to be five minutes. Based on this, the
two daily passes (one in each direction) during daytime hours yielded an hourly average
on 44 dB (Leq). The addition of these three sources results in an hourly average of 47 dB
(CNEL) during the 12 daytime hours.
In evening hours there is one southbound passenger train and two northbound trains. By
similar computation, the hourly average during the three evening hours (7 p.m. to 10
p.m.) is 41 dB (Leq). For CNEL determination, a 5 dB penalty is added to evening noise,
resulting in a figure of 46 dB.
For the nine night-time hours (between 10 p.m. and 7 a.m.), there are four southbound
passenger trains, one northbound passenger trains, and one freight train in each direction.
The combined noise level for these operations results in an hourly average of 45 dB
(Leq). For CNEL computation, a 10 dB penalty is added, which resulting in a figure of
55 dB. The CNEL for all operations during the 24-hour day is 49.9 dB, as follows:
(12 hours x 47 dB + 3 hours x 46 dB + 9 hours x 55 dB) / 24 hours - 49.875 dB
Carlsbad Noise Regulations
The desirable limit for noise for residential land uses in the City of Carlsbad is 60 dB,
CNEL. This figure is used as a guide for the City to determine compatibility of proposed
new land uses or developments with existing or anticipated noise levels from
transportation of other noise sources. A higher noise level is allowed in certain
circumstances, such as within the airport noise contours or in existing areas which
already are exposed to high noise levels. When a proposed project is exposed to less
than 60 dB, CNEL, it is reasonable to assume that interior noise levels will be less than
45 dB, CNEL.
nnnolai Filar # A««nHatp<: - "PI N Willnwsnrino Dr F.nrinitas TA Q7074 -
Merit Group - Carlsbad Beach Estates Noise Analysis
October 22,1998
Page Six
Conclusions
The noise levels from railroad operations were calculated for the location on subject
property where noise exposure would be loudest. The noise level at. Position B was
demonstrated to be less, by measurement, and the noise level elsewhere would also be
less, due to the presence of other residential structures between the these locations and
the railroad. Since the noise exposure at subject property from railroad activities is
determined to be no more than 50 dB, CNEL, at any location on the site, the noise is well
below the limit of 60 CNEL stated in the Noise Element to the General Plan for the city
of Carlsbad. Thus, there is no adverse impact from railroad noise, and no mitigation is
necessary.
Please do not hesitate to contact me if you have any questions concerning this analysis.
Sincerely,
Douglas Eilar & Associates
Douglas K. Eilar, Acoustician
Principal Investigator
DKEielm
References and Contacts:
1) City of Carlsbad Noise Element to the General Plan.
2) City of Carlsbad Noise Guidelines, September 1995.
3) North County Transit District, Chris Schmidt, 760/967-2828
4) San Diego Transit Corp, Automated Travel Information System, Eric Anderson
Attachments:
1) Assessor's Map showing property location and approximate CNEL contours
2) Reduced site plan, showing sound level measurement locations
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