I-10 Twin Peaks Traffic Interchange, Environmental Assessment

Affected Environment and Environmental Impacts October 2005
Conclusion
Construction of the preferred alternative would require that one or more of the 138
kv TEP transmission line towers be relocated or raised. Close coordination with
TEP would minimize interruptions and inconvenience to customers. While setting
the proposed Twin Peaks Road bridge deck over the UPRR, temporary impacts to
train traffic may occur; however, UPRR would review the plans and would be
involved in the sequencing of construction to ensure that temporary disruptions to
train traffic would be minimized. Some private wells and septic tanks may be
affected by the proposed improvements. The preferred alternative would modify
the CMID canal, but the proposed improvements would not interfere with the
supply of irrigation water during critical periods. Utility coordination would be
maintained throughout the course of the project and schedules for any utility
adjustments would be coordinated closely to minimize interruptions and
inconvenience to utility users. If asbestos-containing water lines are moved or
replaced during the roadway construction, precautions would be implemented to
ensure that the asbestos-containing material would be handled safely.
Material Sources and Waste Materials
Quantity of Borrow
The preferred alternative would construct Twin Peaks Road, the Santa Cruz River
bridges, Twin Peaks Road bridge over I-10 and the UPRR on elevated
embankments. Although the preferred alternative would generate excavation
material from the widening of the low flow channel of the Santa Cruz River, the
project would still require approximately 640,000 cubic yards of borrow material.
Availability
Sand and gravel mining operations operate within the study area. An existing sand
and gravel mining operation (I-10 Avra Valley Mining and Development) is
located on the west side of the Santa Cruz River south of Avra Valley Road, which
is north of the project area. Another active sand and gravel mining operation
(Rinker Materials) is located in the southern project area immediately south of the
south access road.
Status of Clearance of Sites
Any material sources required for this project outside of the project area would be
examined for environmental effects, by the contractor, prior to use, through a
separate environmental analysis in accordance with Arizona Department of
Transportation’s Standard Specifications for Road and Bridge Construction,
Section 1001 Material Sources (2000 Edition) (Stored Specification 1001.2
General), unless the facility has received prior clearance from the EEG of ADOT.
According to Rinker Materials, their materials pit has received environmental
clearance to provide materials to ADOT; therefore, materials from this site could
Interstate 10 Traffic Interchange at
Twin Peaks/Linda Vista
4-100
Project No.: NH-010-D (AIW)
TRACS No.: 10 PM 236 H5838 01D