US Customs and Border Protection Ajo Housing Development ... - GSA

washes. Other than the native vegetation along the two washes that border the site, the remaining
vegetation on the site is limited, and much is associated with landscaping. For this reason and
because there are no plans to remove the native vegetation that line the two washes, native plant
removal resulting from implementation of the Preferred Alternative would be limited.
No threatened or endangered plants are known to occur at the Preferred Alternative site.
Removal of mature native tree and cactus species would be subject to the Arizona Native Plant
Law administered by the Arizona Department of Agriculture (AZDA) and the Pima County
Protected Plant Ordinance. Native plant removal would be minimized to the extent practicable.
The construction contractor would be required to contact AZDA at least 60 calendar days prior
to construction to arrange for proper native plant treatment. The Preferred Alternative is expected
to have no adverse impacts to any threatened or endangered plants.
Wildlife
Clearing and grading of the Preferred Alternative site is likely to result in some displacement of
small reptiles, mammals, and birds, and could injure or kill small reptiles and mammals if
present during these activities. Species likely to be displaced, injured, or killed are common and
widely distributed and, as a result, construction of the Preferred Alternative would not
appreciably impact the size or future viability of their populations. The Preferred Alternative is
unlikely to alter existing wildlife movement patterns or result in substantial fragmentation of
habitat.
Table 4.
Other special status species occurring within 3 miles of the project area and
the potential effects of the Preferred Alternative on these species.
Species Habitat Potential Occurrence Potential Effect
Reptiles
Sonoran
Desert
tortoise
Gopherus
agassizii
Prefer terrain above
the valley floor on
rocky bajadas and
hillsides within
Sonoran desertscrub
where natural shelter
sites (caves, rock piles,
pack rat nests, dense
vegetation) provide
suitable retreats and
hibernation sites.
(Brennan and
Holycross 2006).
Elevation: 500–5,300
feet.
The project area lies in foothill
paloverde–triangle-leaf bursage–
brittlebush–dominated rolling to low
mountainous terrain within the
known distribution of the species.
AGFD (2010) indicates that HDMS
has numerous records of desert
tortoises within 1 mile of the subject
property. Peter Holm (OPCNM,
personal communication), whose
residence in Ajo lies within one-half
mile of the project area, has observed
tortoises on undisturbed BLM lands
southwest of Ajo. He estimates that
adjacent BLM lands support a
“normal” population
(i.e., sufficiently dense to support a
reproductive population) of desert
tortoises right up to the edge of town.
The Preferred Alternative is
highly disturbed and would not
be expected to support desert
tortoises. However, the
proximity of the property
immediately adjacent to
undisturbed BLM land where
tortoises are known to occur
indicates the potential that
foraging tortoises could travel
from adjacent habitat to the
Preferred Alternative site,
perhaps using natural and
artificial objects and structures
as shelter sites. Project
construction may impact
individual desert tortoises but
will not lead to a trend toward
federal listing or loss of
viability.
Environmental Assessment 21 Ajo Housing Development Project