HomeMy WebLinkAboutCT 99-11; Rancho Carrillo Village L; Tentative Map (CT) (28)uU
August 13, 1999
Mr. Stefan LaCasse
D.R. Horton San Diego
1010 S. Coast Highway 101, Suite 101
Encinitas, CA 92024-5065
Reference: Wall Heights on Village L - Rancho Carrillo (RECON Number 3168N)
Dear Mr. LaCasse:
We have reviewed the noise analysis for Village L of Rancho Carrillo to determine the wall heights
necessary to meet a 60 A-weighted decibel community noise equivalent level (dB[A] CNEL) exterior
noise level for first-floor receivers. Based on this review walls would have to be as high as 11 feet to
meet this standard for all exterior useable areas on the project site. In addition, it would be necessary
to extend the wall across the emergency access opening off Melrose. Without this wall element,
noise enters the property and certain receivers could not be brought to 60 dB(A) CNEL.
In our noise report of May 28, 1999, we concluded that:
With the construction of six- to eight-foot-high noise barriers along the top of the
slope adjacent to Melrose Drive (pads 3 through 5), noise levels at all ground-floor
usable areas on those pads will be at or below 65 CNEL. Wivh the construction of
noise barriers varying from three to six feet in height at the top of the slope along
the northern project boundary, noise levels at all ground-floor usable areas along
the northern boundary will be below the City's 60 CNEL standard. All other
usable exterior areas within the project are anticipated to be at or below 60 CNEL
(Page 18).
In order to gain the additional insertion loss, higher barriers are needed, and the access gap needs to
be closed. The enclosed map shows the location and heights of walls needed to meet 60 dB(A)
CNEL. Table 1 provides resulting noise levels at specific receivers illustrated on the enclosed map.
The detailed computer modeling results are also provided.
I hope this information is what you need. If I can answer any questions, please call.
Charles Bull
President
CSB:sh
Enclosure
TABLE 1
CNEL NOISE LEVELS
WITH CONSTRUCTED BARRIER
Receiver
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
CNEL
56
57
58
59
58
59
60
60
60
60
59
54
52
54
54
58
58
59
59
59
60
60
59
60
60
60