2010-06-22_PERMIT FILE - M2010019

• Permit No: M2010019
• IBM Index Class Name: PERMIT FILE
• Doc Date: 6/22/2010
• Doc Name: Written objection
• From: Various
• To: DRMS
• Email Name: DMC
• Media Type: D
• Archive: No

Eagle Mountain Major Gravel Operations
High Level HSE Review
A t ,r It moderately conservative assumption, since a conservative assumption of no attenuation credit is
being taken for foliage (discussed above).
Equipment Assumptions. The basic type of equipment to be used is anticipated to excavators,
scrapers, front end loaders, rock crushers and a screening system. Sound levels taken a distance
of approximately 17 in for similar pieces of equipment are shown in the table below. For this
study, the levels in Table 1 below are assumed to be at the plant boundary.
Table 1- Typical Equipment Sound Levels
Equipment Type Sound Level (dB @
approx. 17m)

j John Deere 690D Typical Excavator F:::73::
j John Deere 862B Typical Scraper ( 80

G
John Deere 644E Typical Loader s
80

Dump Truck 68
!
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j
1 Typical Rock Crusher 94

Typical Screening System 86
To determine the sound level due at any particular receiver location, we will assume that at a
given time there is one piece of excavation equipment, one dump truck, front-end loader, a
screener and a crusher operating simultaneously at the plant site. These noise sources are the
components of the plant noise sources. If we combine the sound levels of these pieces of
equipment according to the discussion above, we will have a sound level at approximately 17m
(assumed to be the plant fence line) of 95 decibels. In addition, another off-site dump truck is
considered at a source dB of 94. The results are summarized in Table 2 below.
Attenuation from air was not included as the EEMUA calculations take into account standard
atmospheric conditions/data. Both hemispherical and spherical calculations were performed.
Attenuation for grass was considered for the hemispherical as reported in the table below. For the
spherical calculations attenuation for grass absorption was not added as spherical calculation are
for elevated surfaces and do not consider the reflective/hardness of the ground. The difference in
the results for hemispherical and spherical were nominal, therefore only the hemispherical results
are reported in Table 2 below. Attenuation for grass was not considered for the off-site dump
truck/traffic noise as the type of road surfaces, etc. is unknown. However, theoretically there
would be some attenuation from the grass lands.
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