3.15.3 Affected Environment
3.15 Air Quality
3.15.1 Introduction
This section addresses potential impacts
on air quality resulting from the
construction, operation, and maintenance
of features associated with the Preferred
Alternative and other alternatives of the
proposed project. The analysis focuses on
the regulations promulgated to protect the
health, welfare, and environmental quality
of the project area and its residents, as well
as the potential for exceeding federal air
quality standards. Mitigation measures are
identified that would minimize or avoid
adverse impacts.
3.15.2 Description of Area of
Influence
Unlike many of the other resources
analyzed in this chapter, air quality is not
limited by physical boundaries. Instead, air
quality is influenced by air basins that are
generally affected by factors such as
mountains, valleys, vegetation, and large
water bodies. For these reasons, the area of
influence for air quality includes the entire
area depicted on Map 1.3-1 in Chapter 1,
General Overview.
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Except for El Paso’s metropolitan area, air
quality within the project area is generally
good. El Paso, however, consistently
exceeds National Ambient Air Quality
Standards (NAAQS) that have been
designated by the EPA under the Clean
Air Act (Parkhill, Smith & Cooper, Inc.
and CH2M HILL 1997). El Paso is one of
only three metropolitan areas in Texas to
be designated by the Texas Natural
Resource Conservation Commission
(TNRCC) as a “non-attainment” area,
which fails to meet or attain the NAAQS.
Poor air quality in the El Paso area has
been associated with industrial practices
and with transportation and vehicular
effects originating in the larger El
Paso/Cd. Juárez region. Categories of nonattainment for El Paso have included
respirable particulate matter and PM10,
defined as particles with an aerodynamic
diameter less than or equal to a nominal
10 micrometers. Other categories of nonattainment are ozone, with a federal
violation classification of serious, and, in a
portion of El Paso County, carbon
monoxide, with a federal violation
classification of moderate. Carbon
monoxide and particulate levels are
typically very high in the lower Rio
Grande Valley. High particulate levels
have been attributed to the many unpaved
streets and roads in the lower valley
(Parkhill, Smith & Cooper, Inc. and
CH2M HILL 1997).
Categories of air quality attainment for El
Paso include sulfur dioxide, nitrogen
dioxide, and, since 1986, lead. Also, data
indicate that carbon monoxide pollution is
improving, and that El Paso may soon be
categorized as an attainment area for this
pollutant. A number of programs have
been implemented by El Paso to control
the amounts of carbon monoxide, ozone,
and particulate matter in the air and,
therefore, to mitigate the effects of the
growing population. These programs
include the oxygenation of automobile fuel
during winter, a vapor recovery system at
gas stations, the use of pressure control
devices on gasoline pumps during
summer, wood burning restrictions when
particulate levels are high, paving alleys
and streets, and yearly vehicle inspections
and testing for carbon monoxide and
ozone (Parkhill, Smith & Cooper, Inc. and
CH2M HILL 1997).
3.15.4 Environmental
Consequences and Mitigation
3.15.4.1 Issues Eliminated from
Further Analysis
None of the air quality issues identified
during this assessment were eliminated
from analysis. No specific air quality
issues were identified during the public
scoping process.
3.15.4.2 Issues Addressed in the
Impact Analysis
1. The NAAQS are exceeded because of
project construction activities.
2. The NAAQS are exceeded because of
project operation and maintenance
activities.
3.15.4.4 No Action Alternative
Trends and future conditions for air
quality in the project area under the No
Action Alternative would probably be
similar to existing conditions. Air quality
would likely continue to be good in the
project area, except in and near El Paso
where non-attainment of NAAQS for
ozone and PM10 would probably
continue. Fugitive dust generated from
traffic and wind on unpaved streets and
roads would continue to impact air quality.
City of El Paso programs designed to
control the amounts of ozone, particulate
matter, and carbon monoxide may
contribute to reduced levels of these
particulates in the future. Carbon
monoxide levels may come into
compliance with the NAAQS if the trend
of declining levels for this pollutant
continues.
3.15.4.5 Preferred Alternative–River
with Local Plants
The following issues are addressed in the
impact analysis:
3.15.4.5.1 Construction Impacts and
Mitigation. Primary air pollutants
1. Potential temporary impacts on air
quality from construction activities.
typically generated during construction
activities include fugitive dust and
particulate matter. Fugitive dust would be
generated during earth-moving activities
associated with the construction of project
features, particularly water treatment
plants, aqueducts, and water transmission
pipelines, and from the operation of
construction vehicles. Moving earth in dry,
windy weather especially has the potential
to cause dust problems. Particulate matter
would be generated if vegetation from
2. Potential impacts on air quality from
postconstruction operation and
maintenance activities.
3.15.4.3 Significance Criteria
Potential impacts on air quality would be
considered significant if the following
conditions exist:
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land-clearing operations is disposed of by
burning. Both of these potential
construction-related impacts would be
temporary and would occur primarily
during Phase 1 of the project when most
construction activities are scheduled.
Any possible adverse effects would be
minimized or avoided by following
mitigation measures for air pollution
prevention listed in Appendix A, SOPs,
and summarized as follows:

Contractors will comply with all
applicable laws and regulations
concerning prevention of air pollution.

Contractors will use reasonably
available methods and devices to
control, prevent, and reduce the
emission of atmospheric contaminants.

Contractors will obtain appropriate air
quality permits for regulated
atmospheric emissions.


As described previously, El Paso has been
categorized by the EPA as in serious nonattainment for this air quality pollutant.
Ozone can potentially escape into the
atmosphere from the ozone contact basins
at conventional WTPs and then further
degrade air quality. However, with the use
of ozone destruction units, ozone levels
can be kept below 0.1 parts per million by
volume and in compliance with TNRCC
requirements. Other potential air quality
effects during project operation and
maintenance are associated with minor
amounts of vehicle traffic to and from the
project features. This would not be
expected to cause an adverse effect
because of the City of El Paso’s programs,
summarized in Section 3.15.3, Affected
Environment, that are designed to mitigate
for population growth by controlling the
amounts of the three non-attainment air
pollutants (carbon monoxide, ozone, and
particulate matter).
3.15.4.5.3 Unavoidable Adverse
Impacts. There would be no significant
Contractors will obtain necessary
burning permits and comply with all
terms and conditions.
unavoidable adverse impacts on air quality
from construction, operation, or
maintenance of the Preferred Alternative
because of mitigation measures that would
be followed and because of the City of El
Paso’s air quality programs already in
place.
Fugitive dust from exposed soils and
roads will be controlled by wetting or
other methods to prevent it from
damaging dwellings or causing a
nuisance to people
3.15.4.5.4 Cumulative Impacts.
3.15.4.5.2 Operation Impacts and
Mitigation. No potential long-term
Because of the nature of the proposed
project features and the mitigation
measures for minimizing or avoiding
adverse effects, no significant cumulative
air quality impacts would result from the
combination of the Preferred Alternative
with any other reasonably foreseeable
projects in the area of influence.
adverse effects on air quality from project
operation and maintenance have been
identified. Water treatment plants with
conventional filtration facilities, such as
those at the Jonathan Rogers WTP, use
ozone to disinfect raw water against
pathogens, a process known as ozonation.
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3.15.4.6 River with Year-Round Lower
Plants Alternative
Potential air quality impacts and
mitigation for this alternative would
generally be the same as described for the
Preferred Alternative. No significant
unavoidable or cumulative adverse air
quality impacts would be expected.
3.15.4.7 River with Combined Plant
Alternative
Potential air quality impacts and
mitigation for this alternative would
generally be the same as described for the
Preferred Alternative. No significant
unavoidable or cumulative adverse air
quality impacts would be expected.
3.15.4.8 Aqueduct with Local Plants
Alternative
Potential air quality impacts and
mitigation for this alternative would
generally be the same as described for the
Preferred Alternative. No significant
unavoidable or cumulative adverse air
quality impacts would be expected.
3.15.4.9 Aqueduct with Combined
Plant Alternative
Potential air quality impacts and
mitigation for this alternative would
generally be the same as described for the
Preferred Alternative. No significant
unavoidable or cumulative adverse air
quality impacts would be expected.
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