2018
WORKING GROUP DRAFT
Imperial County – Mexicali Air Quality Work Plan
to Improve Air Quality in the Border Region

December 5, 2018

 The Imperial County – Mexicali
Air Quality Work Plan would
not have been possible without
the support, collaboration,
involvement, and ideas on
strategies from the following
agencies and stakeholders:

Working Group Participants
United States Environmental Protection Agency Region 9
California Environmental Protection Agency Border Program
California Air Resources Board
Imperial County Air Pollution Control District
Imperial County Public Health Department
The Coalition of Labor, Agriculture and Business
Calexico Unified School District
Comite Civico del Valle
Imperial Irrigation District
Office of Assemblyman Eduardo Garcia
Imperial Valley Childhood Asthma Program
Imperial County Transportation Commission
Secretariat of Environment for Baja California
The Directorate of Environmental Protection for the City of Mexicali
OBSER BC

 The Imperial-County Mexicali Air Quality Work Plan is a blueprint of
priority actions recommended to improve air quality in the border region.
The work plan reflects the input of a broad coalition of government
agencies, industry representatives, and environmental groups on both
sides of the California-Mexico border. The goal of this document, and the
working group that informed its development, is to foster ongoing
collaboration and solution building so that one day all residents in this
cross-border region can breathe healthy air.

 Table of Contents
Introduction and .....................................................................................................................................5
Background ..............................................................................................................................................5
Imperial County-Mexicali Border Region ............................................................... 5
Air quality concerns in Imperial County and Mexicali........................................... 5
Other Border Region Air Quality Programs ........................................................... 6
Background on the Development of the Imperial County – Mexicali
Air Quality Work Plan ............................................................................................. 8
Levels of Air Pollution Authority in California ....................................................... 8
Levels of Air Pollution Authority in Mexico ............................................................ 8
Working Group .....................................................................................................................................10
Overview of Group .................................................................................................. 10
Non-Governmental Organization Involvement .................................................... 10
Working Group Meetings and Topics Discussed ................................................... 10
Work Plan Priorities for Imperial County and Mexicali ............................................................12
Discussion of Priorities for Work Plan .................................................................. 12
Importance of Increasing Support at the State and Local Level in Mexicali ...... 12
Work Plan Priorities............................................................................................... 12
Education and Outreach ....................................................................................................12
Agricultural and Waste Burning ......................................................................................16
Monitoring.........................................................................................................................19
Collaboration ......................................................................................................................20
Off-Highway Vehicles........................................................................................................20
Vehicle Emissions and Border Traffic................................................................................21
Unpaved Roads ..................................................................................................................23
Regulating Mexicali Sources .............................................................................................23
Other Priorities ..................................................................................................................23
Enforcement .......................................................................................................................24
Future Updates ......................................................................................................................................27

4

 Mexicali, in part due to farmers in the United States
moving business into Mexicali to take advantage of the
lower labor cost and decreased regulation. As a result of
extensive production and industrial activities, as well as
the burning of garbage, tires, and agricultural material,
Mexicali has some of the worst air quality in Mexico.

Introduction and
Background

Cities in Imperial County are not highly populated. The
three largest cities in Imperial County - Brawley, El
Centro, and Calexico are similar in size with
populations of 26,000, 44,000, and 40,000 people,
respectively. Mexicali has more than four times the
population of Imperial County and more than 18 times
the population of the City of Calexico, located on the
Imperial-Mexicali border. Although Imperial County
and Mexicali have different populations, they share a
common airshed that affects the health and livelihood of
people on both sides of the border.

Imperial County-Mexicali Border Region
The Imperial County-Mexicali border region is located in
the southeast corner of California and is home to
approximately one million people. Imperial County’s
population is around 180,000 people with most of its
population located in the City of El Centro (~44,000
residents). Imperial County has a bustling agriculture
industry with close to half a million farmable acres. Cattle,
fruits, vegetables, hay, nuts, and seeds produced in
Imperial County help feed the nation and the world.
Imperial County consistently ranks in the top ten
agricultural producing counties in California.

Air quality concerns in Imperial County and
Mexicali
Border communities such as Calexico and Mexicali are
unique areas where many different people come
together and cross-geopolitical boundaries. Residents on
both sides of the border share a common environment
and have similar exposures to pollutants. While it would
seem that the most exposure to air pollution along the
Calexico-Mexicali border relates to traffic emissions,
particulate matter (PM) emissions are generated from
other sources such as agricultural burning, industrial
sources, unpaved roads, windblown dust, and cultural
practices to name a few. Despite the challenges of
geography, climate, and proximity to Mexico, air quality
in Imperial County has improved but less improvement
has been observed in the border area closest to Mexico.

Imperial County shares its southern border with the
metropolitan area of Mexicali, Baja California, Mexico
(Mexicali). Two major ports of entry (POE) are located at
the Calexico-Mexicali border. The Calexico West POE is
the third busiest land port in the State processing about
20,000 northbound vehicles and 12,500 pedestrian
crossings per day. 1 In contrast, the Calexico East POE,
located approximately 7 miles to the east of Calexico West,
is the principal gateway for heavy-duty commercial trucks
into the Imperial Valley. It is the second busiest
commercial POE along the California-Mexico border,
processing nearly a thousand heavy-duty trucks each day. 2
Over the past 20 years, Mexico has become California’s top
trading partner and the United States’ second largest
trading partner, which has resulted in a significant
increase in traffic and congestion.

PM contains a variety of microscopic solid and liquid
particles in the air including aerosols, dust, smoke,
fumes, ash, and pollen. The size of the particle, PM10 or
PM2.5, determines how long the particle typically stays
airborne and the different health effects that would be
experienced from exposure. PM10 usually originates
from natural sources such as windblown dust and
human activity such as driving on paved and unpaved
roads, off-highway vehicles (OHV), agricultural field
preparation and harvest, etc. PM10 emissions do not
tend to remain in the air for long periods and usually
settle out of the air within a few hours.

Mexicali is the capital of the state of Baja California,
Mexico and its main economic industries are agriculture
production and industry, mainly assembly plants
(maquiladoras). The maquiladoras are tax-free factories
where parts from other countries are imported, assembled,
and then exported as finished products. The Mexicali
Valley is a very fruitful agricultural region much like the
Imperial Valley, with around 150,000 farmable acres
(2017). Farmed acreage has increased over the years in

PM2.5 is also known as fine PM and is more hazardous
than PM10 since it can penetrate deeper into the

1

U.S. General Services Administration; Fact Sheet: Calexico West
Land Port of Entry; August 2016.

2

5

California State Transportation Agency; California Freight Mobility
Plan, Appendix B-5-3; December 2014.

 respiratory system and can even get into the blood and
reach the brain and heart. PM2.5 is made up of sulfate and
nitrate particles, elemental and organic carbon, geological
dust, and other organic compounds mainly generated from
anthropogenic (i.e. manmade) sources. PM2.5 can be
formed directly and secondarily through chemical
reactions in the atmosphere. PM2.5 can stay in the air for
days to weeks and can travel long distances.

Recent analysis of the chemical composition of PM2.5
particles collected at the California Air Resources Board
(CARB) air monitoring station at Calexico indicates that
combustion, such as produced from motor vehicles or wood
and waste burning, are a major source of particulate
matter in Imperial County. The analysis of chemical
composition data also indicated that elements such as
chromium, lead, and zinc, normally measured at very low
levels throughout Imperial County and the rest of the state
were significantly higher at the Calexico air-monitoring
site. The potential sources of these elements include the
burning of garbage or other non-biomass materials and
industry that does not exist in Imperial County. In
addition, correlations between wind direction and these
source signatures indicated that the origin of these
pollutants was south-southeast of the monitoring site in
the direction of the border and Mexicali. Recent PM2.5
monitoring data collected in Mexicali between April of 2016
and April of 2018 showed that PM2.5 concentrations in
Mexicali were much higher than concentrations measured
in Calexico and that days with high concentrations in
Mexicali directly impacted the Calexico monitor. In
previous State Implementation Plans 3 (SIP) submitted for
Imperial County, the evidence supports the international
cross-border impact of Mexicali air pollution sources on the
residents in Imperial County, and more specifically in
Calexico.

Imperial County’s air quality ranks as among the worst in
the state of California, being nonattainment for the federal
24-hour PM10 standard of 150 ug/m3, the annual PM2.5
standard of 12 ug/m3, and the 8-hour ozone standard of 70
ppb. Cities in Imperial County are not highly populated but
the County shares its border with the City of Mexicali,
which has more than four times the population of Imperial
County. In addition, Mexicali’s population is more than 18
times the population of the City of Calexico, which is
located on the Imperial-Mexicali border.
The Imperial County PM2.5 nonattainment area is
bordered by mountain ranges to the west, east, and
southwest. These ranges act as barriers and channel
airflow within the Imperial and Mexicali Valleys.
Mountain valleys often enhance the formation of
temperature inversions, resulting in stagnant air
conditions and trapping of air pollution for extended
periods, especially in the wintertime. This is common in
the Imperial Valley, particularly near the international
border on nights with light winds. Inversions often occur
over multiple days during the winter months resulting in
considerable increases in PM2.5 concentrations. The
geography, topography, climate, and similar meteorology
throughout the area does not restrict airflow between the
Imperial and Mexicali Valleys which results in a shared
airshed for the region.

Existing Border Region Air Quality Programs and
Agreements
La Paz Agreement
Collaboration on environmental issues in the border region
has been ongoing between the United States, California,
and Mexico for many years. In 1983, the United States and
Mexico entered into the United States–Mexico Agreement
on Cooperation for the Protection and Improvement of the
Environment in the Border Area, also known as the La Paz
Agreement. The sole purpose of the La Paz agreement is to
protect and conserve the environment along the border and
the agreement lays out the responsibilities of both parties
to prevent and control air, water, and land pollution in the
border area.

Imperial County contains relatively few major industrial
sources, with unpaved road dust and fugitive windblown
dust emissions representing the largest emission sources
of PM10 and PM2.5. Other significant emission sources of
PM emissions include off-road vehicles, farming
operations, and agricultural burning. In contrast, the city
of Mexicali, with a population of nearly 700,000, has a large
number of industrial, mobile, and area sources. These
sources are generally subject to less stringent air pollution
regulations than similar sources in California.
Consequently, emissions from comparable source
categories in Mexicali are significantly higher than in
Imperial County for PM2.5, nitrogen oxides (NOx), sulfur
oxides (SOx), reactive organic gases (ROG) and ammonia
(NH3).

North American Development Bank/ Border Environment
Cooperation Commission
In 1994, the North American Development Bank
(NADBANK) and the Border Environment Cooperation
Commission (BECC) was created to provide financing, as
well as technical and other assistance, to support the
development and implementation of infrastructure

3

A SIP is a comprehensive plan that describes how a nonattainment area
will attain an air quality standard.

6

 projects that help preserve, protect and enhance the
environment of the border region.

California and Baja California, Mexico Air Quality
Implementation Plans
States on both sides of the border continue to identify
measures they can take to improve air quality in their
region by developing State Implementation Plans (SIPs) in
the U.S. and ProAires in Mexico. SIPs are comprehensive
plans that describe how a nonattainment area will attain
national ambient air quality standards (NAAQS). SIPs are
a compilation of new and previously submitted plans,
programs (such as monitoring, modeling, permitting, etc.),
district rules, state regulations and federal controls.

North American Free Trade Agreement/Commission for
Environmental Cooperation
Also in 1994, the North American Free Trade Agreement
(NAFTA) and Commission for Environmental Cooperation
(CEC) were formed. The CEC facilitates collaboration and
public participation to conserve, protect and enhance the
North American environment, by increasing economic,
trade, and social links among Canada, Mexico, and the
United States.

In the State of Baja California, Mexico, the government
develops the Mexico ProAire, which is a program to
improve air quality in Baja California. The most recent
ProAire for Baja California (2018-2027) includes goals to
reduce emissions from vehicles at border crossings, expand
dust control, and replace agricultural burning with more
sustainable practices. SIPs and the ProAire have a
common goal of identifying and implementing measures to
improve air quality in a region over time.

California-Mexico Border Relations Council
The California-Mexico Border Relations Council (CMBRC)
was created in 2006
(AB 3021, Núñez) and coordinates
cross-border
programs,
initiatives,
projects
and
partnerships along the California-Mexico border. The
CMBRC serves as a representative body of the State of
California whose goal is to continue to develop and enhance
cross-border relations between California and Mexico. The
CMBRC provides an annual update on California–Mexico
activities and programs to the Legislature and has the
potential to identify new Border priorities and fundable
projects in the areas of infrastructure, trade, environment,
health and security while supporting current and ongoing
activities.

California-Mexico 2014 Climate Change and Environment
Memorandum of Understanding
In July 2014, California and Mexico signed a Memorandum
of Understanding (MOU) to Enhance Cooperation on
Climate Change and the Environment. This joint effort
aimed to improve and protect the environment while
ensuring sustainable use of natural resources to improve
quality of life and increase trade and investment
opportunities. The MOU was a four-year effort that ended
in July of 2018 and contained four priority action areas:
climate change, air quality, wildfires and clean vehicles.

U.S. EPA/SEMARNAT Bi-National Programs
Since 1996, there have been three programs between U.S.
EPA and SEMARNAT to address the bi-national
environmental issues (the Border XXI program (1996), the
Border 2012 program (2003), and the Border 2020 program
(2012)). The Border 2020 program includes efforts to
improve air and water quality, reduce waste, strengthen
emergency
preparation
and
response,
promote
environmental stewardship, and address environmental
health. The Border 2020 program contains five objectives
to reduce air pollution in the border region and
achievement of these goals are developed through input
from states, local governments, and citizens.

The air quality goals in the MOU were to: 1. Coordinate air
quality planning efforts for airsheds along the border; 2.
Share technical knowledge and information needed to
support development of robust air quality planning and
mitigation efforts; and 3. Improve the comparability of data
collected in Mexico and California.
Although many programs exist to address the air quality
problems in the U.S.-Mexico border region, it is necessary
to increase the participation and actions from these
programs to ensure air quality continues to improve in the
border region.

Imperial Valley/Mexicali Air Quality Task Force
As part of the Border 2020 program, the Air Quality Task
Force (AQTF) for Imperial Valley/Mexicali was formed to
address issues unique to the border region. The AQTF
includes representatives from federal, state and local
governments from both sides of the border, as well as
representatives
from
academia,
environmental
organizations, and the public. The AQTF was created to
promote regional efforts to improve the air quality
monitoring network, emission inventories and air pollution
transport modeling development, as well as the creation of
programs and strategies to improve air quality.

7

 Background on the Development of the Imperial
County – Mexicali Air Quality Work Plan

Levels of Air Pollution Authority in California
The Federal Clean Air Act (CAA) provides the basis for the
air pollution control effort in the United States. The CAA
includes: national ambient air quality standards (NAAQS)
for criteria air pollutants (carbon monoxide, ozone,
particulate matter of PM10 and PM2.5, nitrogen dioxide,
sulfur dioxide, and lead) and hazardous air pollutants;,
state attainment plans; motor vehicle emissions standards;
stationary source emissions standards and permits; acid
rain control measures; stratospheric ozone protection; and
enforcement provisions. The United States Environmental
Protection Agency (U.S. EPA) sets nationwide air quality
and emissions standards and oversees state efforts and
enforcement. States can enforce stronger air pollution
laws, but they cannot have weaker pollution limits than
those set by
U.S. EPA.

On May 25, 2018, CARB staff presented the 2018 Annual
PM2.5 SIP for the 12 ug/m3 PM2.5 standard to the CARB
Board for approval. The SIP demonstrated that the
Calexico monitor would be in attainment of the annual
PM2.5 standard “but for” emissions impacting the site from
Mexicali. Although the Board approved the Annual PM2.5
SIP for Imperial County, the Board also acknowledged that
there are major air quality concerns in the border region
and more needs to be done to improve air quality to protect
the health of residents on both sides of the border.
The CARB Board directed staff to develop a work plan in
coordination with the Imperial County Air Pollution
Control District (ICAPCD) and appropriate stakeholders in
California and Mexico to explore additional measures that
could be taken to improve air quality in the border region.
Measures to be considered on the U.S. side of the border
include assessing how the ICAPCD’s enforcement protocols
might be strengthened and how they compare to other
similar local air districts in California. Other measures
include assessing the ICAPCD’s fugitive dust regulations
and opportunities for improvement. On the Mexican side of
the border, the aim of the work plan is to address crossborder air pollution impacts and how to provide assistance
within the limits of CARB’s jurisdictional authority to
Mexican government agencies in mitigating air emissions
that ultimately impact Imperial County.

CARB is the agency responsible for coordination and
oversight of state and local air pollution control programs
in California and for implementing the Federal and
California Clean Air Act. CARB sets the state’s own
stricter emissions standards for a range of statewide
pollution sources including vehicles, fuels and consumer
products. CARB is also responsible for monitoring the
regulatory activity of California's 35 local air districts.
Other CARB duties include but are not limited to
monitoring air quality, setting emissions standards for new
motor vehicles, and reviewing district input for the SIP.
California's 35 local air districts are responsible for
regulating emissions from businesses and stationary
facilities such as oil refineries, auto body shops, and dry
cleaners. The ICAPCD is the local air district for Imperial
County.

With this direction, CARB staff began working
immediately to assemble a working group of members and
agencies to provide feedback on what priorities are most
important to include in the work plan. This work plan is
an initial assessment of priority areas that the work group
members proposes that CARB and other government
agencies focus on in both Imperial County and Mexicali to
improve air quality in the border region. Priority areas
include: increasing the education and awareness of PM air
quality and health impacts; improving regulatory
authority, enforcement protocols, and rule stringency;
enhancing air monitoring; and identifying funding
mechanisms to achieve these goals.

Levels of Air Pollution Authority in Mexico
In Mexico, the federal government has the jurisdiction to
regulate all air pollution sources. The General Law of
Ecological Balance and Environmental Protection
(LGEEPA), states that the Secretariat of Environment and
Natural Resources (SEMARNAT) must provide the general
guidelines for regulated sources. SEMARNAT is
authorized to regulate emissions by establishing emissions
limits, monitoring, and setting standards through Official
Mexican Standards (NOMs), developing programs with
state and local authorities, and imposing penalties. NOMs
are technical standards established for products,
processes, facilities, systems, activities, services and other
methods of production. NOMs establish maximum
allowable pollutant limits for contaminants in air, water
and soil, and list hazardous waste, substances, and
endangered species.

This work plan is a living document that will be used to
gauge progress over time on implementing priority actions
and recommendations as well as to determine where course
corrections need to be made based on critical lessons
learned.

8

 The Office of the Federal Prosecutor for Environmental
Protection (PROFEPA) is the enforcement arm of
SEMARNAT and it has the authority to carry out
inspection
visits,
prosecute
environmental
noncompliance,
apply
sanctions,
generally
enforce
environmental laws and regulations, and perform
inspections and sanction the entities and individuals
subject to air emissions reports. PROFEPA also oversees
the federal voluntary environmental audit program.
Mexican states have jurisdiction to apply their state laws
and to prevent and control atmospheric pollution from
industries and mobile sources not under federal
jurisdiction. For Mexicali, the state authority is the
Secretariat for Environmental Protection State of Baja
California (SPA BC). SPA BC also develops plans similar
to SIPs in California, called the ProAire. The ProAire lays
out specific strategies and actions that the state will take
to reduce air pollutant emissions in the state. SPA BC has
a ProAire Mexicali (2011-2020) and a State ProAire (20182027) plan to further reduce emissions. The Directorate of
Environmental Protection for the City of Mexicalihas
jurisdiction to prevent and control emissions by merchant
and services point sources, such as restaurants, with the
collaboration of state authorities when state law requires
it.

9

 Non-Governmental Organization Involvement

Working Group

Overview of Group
To better understand the source impacts and opportunities
to improve air quality in the border region, CARB staff
included stakeholders in the working group that have a
direct relationship with air quality work in Imperial
County and Mexicali. The Imperial County-Mexicali Air
Quality working group (working group) was comprised of a
number of individuals with various concerns and
backgrounds to provide a broader context of the air quality
issues in the border region.
Working group participants include the: U.S. EPA Region
9, California Environmental Protection Agency Border
Program (Cal EPA), CARB, ICAPCD, Imperial County
Public Health Department, Coalition of Labor Agriculture
and Business (COLAB) Calexico Unified School District,
the Directorate of Environmental Protection for the City of
Mexicali, the Secretary of Environmental Protection of
Baja California (SPABC), Baja California Epidemiology,
Comite Civico del Valle, OBSER BC, Office of
Assemblyman Eduardo Garcia, Imperial Irrigation District
(IID), Imperial County Transportation Commission, the
Imperial Valley Childhood Asthma Program, and other
community participants.
Beginning with the formation of the working group,
participants continually stressed the importance of
cooperation and collaboration to address local air quality
issues and the need for agencies to approach these issues
from a binational perspective rather than one exclusive to
Imperial County. Through this working group, the
binational cooperation and collaboration needed for a
successful work plan was built. It became clear that there
is no single solution for improving PM air quality in the
border region since Imperial County and Mexicali are
unique areas with varying challenges, barriers, and
solutions. Thus, the work plan was assembled with
acknowledgement
of
the
differing
regulations,
governments, resources, funding, and legislation between
California and Mexico but also opportunities for
collaboration and leveraging of resources.

It is important to highlight the role that non-governmental
organizations (NGOs) play in helping to tackle
environmental issues in the Imperial County-Mexicali
border region. NGO involvement for this bi-national work
group is key to ensuring greater international cooperation
by gaining public support and bringing increased
awareness of local environmental problems in the
communities.
NGOs can promote environmental
legislation, advocate for regulations, and increase
education and awareness of existing environmental laws.
Overall, the participation of NGOs in the workgroup is
important to ensure that citizens and local businesses are
involved in helping Imperial County and Mexicali tackle
air quality issues more effectively.

Working Group Meetings and Topics Discussed
From July through October of 2018, the working group met
four times in Calexico, California to discuss priorities for
the work plan. A general overview of each of the working
group meetings is provided below.

First Working Group Kick-Off Meeting –
July 9, 2018
On July 9, 2018, CARB held the first working group
meeting at the San Diego State University campus in
Calexico, California. The purpose of this initial meeting
was to introduce the Imperial-Mexicali Air Quality Work
Plan concept, agree on common expectations and goals for
the working group, and identify an initial set of priorities
that the working group thought would be most important
to include in the work plan. Also discussed was the
tentative schedule for the work plan and the commitment
needed from the working group members to participate in
meetings on a monthly basis until the final work plan was
available for public release and CARB Board consideration.

Second Working Group Meeting – August 9, 2018
CARB held the second working group meeting on August
9, 2018 at the Workforce Center in Calexico, California.
This meeting focused on discussing barriers,
opportunities, concerns, and recommendations to improve
air quality in both Imperial County and Mexicali. The
focus of this meeting was on regulation of air pollution
sources in Mexicali and collaboration between agencies to
ensure a successful work plan and follow through on the
priorities identified.

Third Working Group Meeting –
September 13, 2018
CARB held the third working group meeting on September
13, 2018 at the Kiki Camarena Library in Calexico,

10

 California. This meeting focused on discussing barriers,
concerns, and recommendations specifically regarding
vehicle emissions in the border region and the ports of
entry, and enforcement in the border region. The timelines
for the draft work plan, comment period, and potential
town hall meetings were discussed. The working group was
also asked to fill out a table listing their priorities,
concerns, strategies, and metrics to track progress that
they felt were most important to include in the work plan.
The input from the group was considered in the final work
plan.

Fourth Working Group Meeting –
November 7, 2018
CARB held the fourth working group meeting on
November 7, 2018 at the Kiki Camarena Library in
Calexico, California. The purpose of this meeting was to
discuss comments on the draft work plan. Discussion and
comments were shared at the meeting regarding: the
winter media campaign “Ambientalizate”, the low-cost PM
sensor network planned for Mexicali, vehicle emissions at
the ports of entry, the Smog Check program in Imperial
County, the Vehicle Verification program in Baja
California, agricultural burning, unpaved roads, and
regulating stationary sources in Mexicali. Working group
participants were asked to submit formal comments to
CARB by November 16, 2018 to ensure incorporation into
the draft final work plan.

11

 Work Plan Priorities for
Imperial County
and Mexicali

Discussion of Priorities for Work Plan
The main priorities identified by the working group for
incorporation into the work plan are listed below. These
priorities were discussed with the working group and were
considered efforts that would help to achieve the greatest
emission reduction benefits for PM2.5 and PM10 in the
border region. Some priorities identified by the working
group only applied in one region so not all actions are
addressed in both areas. The priorities below are further
broken down into individual sources or focus areas. The
actions under each priority are also listed as either shortterm or long-term efforts. For purposes of this work plan,
short-term actions include those measures that can be
completed in the next 12 months while long-term actions
are those that will take longer than one year to complete.
The list below summarizes the Imperial County - Mexicali
Air Quality Work Plan Priority Areas that were identified
as being most important to improving air quality in the
border region.
-

Education/Outreach
Monitoring
Unpaved Roads
OHV Rules
Regulating Mexicali Sources
Agricultural Burning
Waste Burning
Collaboration
Vehicle Emissions and Border Traffic
Enforcement

CARB worked closely with the ICAPCD, the Directorate of
Environmental Protection for the City of Mexicali, and SPA
BC to develop actions that can be taken in Imperial County
and Mexicali to help improve air quality in the Imperial
County – Mexicali border region. Although CARB lacks
authority over implementation of suggestions in this work
plan that would take place in Mexicali, CARB believes it is
important to report on the recommendations developed by
the working group and hopes to continue collaborating
with Mexicali to see them through.

Importance of Increasing Support at the State and
Local Level in Mexicali
For the majority of the actions identified in this work plan
to come into fruition in Mexicali, it is essential that funding
and support of the implementation of the air quality
regulations be provided from Mexico’s national
government to the state of Baja California and city
authorities in Mexicali. Building up the administrative and
regulatory environmental capacity at the state and city
level in Mexico is an essential component to ensuring the
actions are possible, with the lower levels of government
being able to achieve greater financial independence for
managing the air pollution in Mexicali. The working group
recommends an expansion of environmental education
programs and an increase in the level of environmental
investment in order to achieve these actions. State and city
authorities in Mexico would also need increased staffing
and financial resources from Mexico’s federal government
for the permitting and inspection of facilities.

Work Plan Priorities

Education and Outreach
Short Term Actions - Imperial County
Improved Winter Media Campaign
Mexico is known for its varied customs and traditions. As
part of Mexico’s traditions, the use of fireworks and the
burning of tires and wood during festivities is
commonplace. To educate the public on the health hazards
associated with the burning of these materials, the media
campaign “Ambientalizate” was created in 2011 with
funding from U.S. EPA. The main objective of this
campaign is to educate the public, especially the sensitive
groups such as the elderly and children, of the hazardous
health and environmental impacts these sources cause in
the Mexicali region as well as the border town of Calexico,
California. U.S. EPA continues to provide funding to
ICAPCD in support of this important outreach campaign
to reduce sources of PM impacting communities in the
border region.
The campaign provides education and awareness in
Calexico and Mexicali by airing four separate public
service advertisements that all have different focus topics
for air quality. The campaign is also broadcasted on nine
high frequency radio stations and six television stations
approximately 1,500 times from November through
January. The public service advertisements illustrate the
impacts fire, wood, and tire burning have on our health and
the environment with hope to develop a “no burn”
mentality and ultimately break these traditions.

12

 The good news about this campaign is that awareness is
growing regarding the air quality in the Imperial-Mexicali
border region. In the beginning of the media campaign in
2011, there were only 48 subscribers to the Imperial Valley
air
quality
alerts
and
forecast
website
www.imperialvalleyair.org. As of 2018, the number of
email subscribers has increased to 1,500, with 3,500
subscribers of the mobile application.

relationships. This research, if approved, would be very
valuable to the ICAPCD’s understanding of source
contributions to windblown dust emissions in the County.

Currently the ICAPCD, the Directorate of Environmental
Protection for the City of Mexicali and SPA BC are working
on revising the public service advertisements as they are
outdated and need a new, modern, more captivating
message that resonates with communities. The thought is
to have a message that engages the community on the
consequences of open burning. In the past, the message has
been focused on making the public more aware of mainly
the health consequences. However, the new message will
also bring increased awareness of the consequences such
as new sanctions implemented in 2018 that are being
enforced for the first time should people continue to burn
fireworks, tires, trash, or wood. Over 700 police officers
were trained on how to enforce this new ordinance.
Penalties can reach 16,000 pesos (or roughly $850 U.S.
dollars).

Staff has provided initial comments to the ICAPCD on the
adequacy of their Regulation VIII fugitive dust rules and
continues to investigate opportunities for rule
strengthening. CARB staff will continue to work with the
ICAPCD to evaluate the District’s dust control rules. Some
potential areas for improvement include, but are not
limited to: requiring the stabilization of OHV disturbed
surfaces during periods of inactivity when high wind
conditions can entrain loose soil particles and produce
significant plumes of windblown dust; amending Rule 800
applicability to coincide with the OHV activity season,
which runs from late-October to mid-April of each year;
and requiring submittal and approval of dust control plans
for construction and earthmoving projects together with
conservation management plans for agricultural
operations. Additionally, we suggest the ICAPCD map the
emissivity of soil types within the Imperial Valley and
tailor the number and/or effectiveness of Conservation
Management Practices to the uncontrolled emissivity
levels of soils on which agricultural operations are
conducted.

Regulation VIII Fugitive Dust Rules Evaluation

Salton Sea Dust Mitigation

The ICAPCD has adopted and implemented a set of rules
to regulate sources of fugitive dust within its jurisdiction.
These rules address agricultural operations, unpaved and
paved road travel, OHV recreational vehicle activities,
construction activities, and open areas, among others.
Enforcement of these rules is important for the protection
of public health as Imperial County periodically
experiences exceedances of federal and state PM10 air
quality standards. In Imperial County, more than 80
percent of the PM10 and PM2.5 emissions are from open
area windblown dust, with the main sources areas being
unpaved roads, agricultural lands, pasturelands, and
desert lands. Imperial County experiences the highest
rates of pediatric asthma hospitalization and emergency
room visits in the state, making it even more important
that the ICAPCD does all that it can to control dust
emissions.

Imperial County residents have raised concerns about
future air quality in Imperial County as Salton Sea water
levels decline due to the cessation of mitigation water
flows. As the surface level of the Salton Sea drops over the
next three decades, the lakebed – or playa – will become
exposed and become a potential new source of PM2.5 in the
northern portion of Imperial County. Unless prevented or
controlled, windblown PM2.5 could reverse some of the air
quality gains proposed in the 2018 PM2.5 SIP. To address
this, CARB has been collaborating with other state, as well
as federal and local, agencies since 2003 in the monitoring,
planning, and control of PM emissions at the Salton Sea.
CARB staff were instrumental in the design and
construction of a six-station network of shoreline PM and
meteorological monitoring stations at the Salton Sea in
2009. These stations collect baseline air quality data and
serve as an early warning system for changes in exposed
playa dust emissivity. The continuous hourly data collected
since February 2010 provide a rich database for
assessment of air quality impacts and development of
mitigation measures by researchers and regulatory
agencies alike.

Essential to any control program is the accurate
quantification source emissions, including spatial and
temporal variability. For this reason, CARB staff
submitted a research proposal that would quantify the
windblown dust emissions in Imperial County on a more
accurate level by plotting soil types, measuring soil
emissivity, quantifying the control benefits of vegetation
and soil moisture, and refining emission-wind speed

By requirement of the 2003 water transfer agreement, the
IID has been the principal agency involved in Salton Sea
windblown dust research and control measure testing for

13

 the past 15 years. Using funds pooled by the water agencies
involved in the transfer, IID has retained a team of air
quality consultants who participate in dust control
research and testing at Owens Lake to conduct similar
activities at the Salton Sea. CARB staff is closely
coordinating with this team of air quality consultants on
technical aspects of windblown dust research at the Salton
Sea.
In the past two years, new dust plume visualization
systems have been adapted to ongoing analyses of playa
emissions. These new systems include 360-degree images
recorded during daylight hours at elevated locations at Red
Hill Bay and Anza Borrego Desert State Park, as well as
images captured by new GOES-R geostationary satellites.
These systems are useful in identifying windblown dust
source areas and dust plume density and trajectory. IID’s
team of air quality consultants has been researching the
design, control effectiveness, and costs of alternative playa
dust control measures since 2013. Early findings from this
research include discovery of a three-year lag between the
playa first becoming exposed and the onset of windblown
dust generation. Dust control research has also found that
deep tilling is an effective short-term control measure that
does not require the use of water.
In 2016 and 2017, U.S. EPA granted funds to CARB for the
assessment of toxic constituents in windblown Salton Sea
playa dust and the measurement of soil emissivity during
high wind events, respectively. The grant for toxic
constituent assessment was channeled under a subaward
agreement to the IID to complement playa dust monitoring
being conducted by their air quality consultant team. A
final report of this assessment is due to be released by
December 31, 2018. The grant for soil emissivity testing
was passed through to the ICAPCD and requires the
acquisition, training use, and application of a PI-SWERL
portable wind tunnel by District staff to measure the
emissivity of disturbed and undisturbed desert soils,
agricultural lands, vacant parcels, and Salton Sea
shoreline areas to inform future refinement of District
windblown dust emission control rules. Grant-funded
activities related to soil emissivity testing are scheduled to
be completed by September 30, 2019.
CARB staff will continue collaborating with U.S. EPA,
ICAPCD, South Coast Air Quality Management District,
IID, and the Torres Martinez Desert Cahuilla Indians in
playa dust control research and testing activities. Staff will
also continue to communicate the findings and
implications of these research activities to the affected air
quality agencies and the many community groups
concerned about future Salton Sea emissions. These
research activities will help establish the most costeffective controls to mitigate playa dust that affects
Imperial County.

Increased Outreach and Support for Border,
Environmental Justice, and Salton Sea Issues
ICAPCD has added two special project managers with
dedicated staff to work specifically on border, the Salton
Sea, and related environmental justice involvement.
Additionally, a staff person at ICAPCD will focus on social
media and a webpage for the Salton Sea, border activities,
and all related environmental justice matters valley-wide
to further educate and bring awareness to the public on
these important air quality matters.

Short Term Actions - Mexicali
PM2.5, PM10, and Ozone Air Quality Alerts and
Forecasts for Mexicali
It is very important for the residents in Mexicali to be able
to have continuous and readily available access to the air
quality data in the region. The Imperial County air quality
website has been able to provide local air quality
information, alerts, and forecasts to residents in Imperial
County over the years and we think providing this same
type of information to Mexicali would be very beneficial for
residents in the border region.
As a result of this work plan, the City of Mexicali will be
added to the next air quality alert and forecast contract
that will include air alerts, a mobile application, and
forecasting services. These alerts and forecasts will be
available to residents in Mexicali starting in the winter of
2018/2019. The website will utilize the monitoring
information currently provided by SPA BC but will later be
able to include other stations as they are added to the
network. Future monitoring sites will need to have
reliable, accurate, and permanent locations to ensure that
accurate forecasting of air quality can be provided. The
website is available in Spanish and English and will
provide users with forecasts by 9:30 a.m. each day of
ambient ozone levels during the ozone season and
particulate matter (PM10 and PM2.5) levels year-round for
Mexicali and Imperial County. As a direct result of this
work plan, this work is expected to be completed as part of
the next website and forecasting contract with CARB and
the ICAPCD, which already includes website development
(www.imperialvalleyair.org) and forecasting services for
Imperial County.
The public may register to receive notifications via email
or text when the air quality is expected to reach unhealthy
levels. The contract will also ensure that both Mexicali and
Imperial County residents have access to the “Imperial
Valley Air Quality” mobile app to further enhance public
access to air quality information in the border region. This

14

 mobile application will also have Global Positioning
System (GPS) capability that will allow residents to see the
air quality nearest to where they are located. This free app
will provide the current Air Quality Index (AQI) levels,
current AQI forecasts, and the forecast discussion (in
English) for Mexicali.
Once the contract is finalized, CARB will coordinate with
the ICAPCD, SPA BC, and the website developer to
evaluate accessibility and air quality forecasts in Imperial
County and Mexicali to ensure that timely air quality
information is provided to the public. Since ImperialCounty and Mexicali share the same airshed it is
important that this air quality information is available to
residents on both sides of the border.
This capability will also prove helpful for establishing burn
days in Mexicali if an agricultural burn program is
instituted in the future. The forecasts will allow authorities
in Mexicali to establish which days should be considered
burn or no-burn days and will help to educate the farmers
on the meteorological criteria that is best to burn under to
ensure proper dispersion of the air pollution. This
information can also help prevent sensitive groups (such as
children and the elderly) from being overly exposed to air
pollution on bad air quality days, by limiting the time spent
outdoors when the air quality is unhealthy. Overall, this
capability for Mexicali can prove helpful in many other
instances and can be used in schools and for the public to
bring more awareness to the serious health issue going on
in Mexicali with air pollution.

Northern Baja California Emission Inventory
Improvements
Accurate emission inventories are needed to help
determine significant sources of air pollution in an area
and to target regulatory actions to reduce that
pollution. Emissions inventories are also essential for air
quality modeling to estimate an areas air quality in the
future and which reductions will have the greatest benefit
to air quality. Inventories also can be used to raise the
public’s awareness regarding sources of pollution nearby.
CARB has not been able to accurately model Mexico’s air
quality, and specifically Mexico’s impact on U.S. border
cities, due to reliability issues with Mexico’s air quality
data and emissions inventory. In response to the needs
described above, in 2018, U.S. EPA Region 9 provided
grant funding to CARB to contract for improvements to the
emission inventory for Northern Baja California.
This inventory effort will result in an updated 2014, 2020,
and 2025 emissions inventory for the Baja California
municipalities (i.e., Mexicali, Tecate, Tijuana, Playas de
Rosarito, and Ensenada) located within the Northern Baja

California (CARB modeling domain). Emissions estimates
will be prepared for point, area, mobile, and nonroad
sources for NOx, Sulfur dioxide (SO2), Volatile organic
compounds (VOC) Carbon monoxide (CO), PM10, PM2.5,
and NH3. The contractor will make the following
improvements to the latest inventory generated for Baja
California (2014 MNEI):
-

-

Revise the point source and area source emissions.
Estimate emissions from missing criteria
pollutants.
Estimate on-road motor vehicle emissions at the
six U.S.-Mexico border crossings (Calexico West,
Calexico East, Andrade, Tecate, San Ysidro and
Otay Mesa).
Estimate agricultural burning emissions in
Mexicali (both field and orchard pruning).
Estimate brick kiln emissions in Mexicali
Estimate windblown dust from agricultural lands
for Mexicali and Tecate.

The contract will end on September 30, 2019 and will
provide beneficial information to CARB, agencies in
Mexico, and the public by providing updated and new
emission estimates for sources in the Northern Baja
California modeling domain region. This inventory effort
will be used by CARB in future air quality models and
nonattainment area planning.

Short Term Recommendations - Mexicali
Increase Education and Awareness of Air Quality
Because many of the harmful air pollution activities
occurring in Mexicali are considered traditional cultural
practices, it is even more important to ensure that
increased education and awareness is provided to the
public. Recognizing the meteorological conditions in the
region and the public health impacts, it should no longer
be culturally acceptable to burn wood to cook food in the
yard, to burn tires to stay warm, and to use firecrackers for
Independence Day, Christmas, and New Year’s
celebrations. By increasing education and awareness of the
air quality in Mexicali, and with the recent City of Mexicali
Ordinance to apply sanctions for such burning practices,
progress in reducing the air pollution in Mexicali will
occur.
However, in order to have an effective education and
awareness program, the city, state, and federal
governments in Mexico must work together to ensure an
impactful program. The agencies need to look at the needs
of the community in terms of the air quality and gain a
better understanding of what sources are producing the

15

 most pollution in different areas of Mexicali.
A
communication campaign in addition to the one discussed
above should also be developed such as advertising
information and air quality on a Facebook page or other
media avenues. It is also important to ensure that
education and awareness of air quality and air pollution is
brought into the schools in Mexicali. It is important for
children to know about air quality and pollution because
when they are familiar with what it is, knowledgeable
about its consequences, and informed about how they can
reduce or eliminate their own (or families) actions that
produce emissions, they can help prevent it. A school flag
program would be great to implement in Mexicali, as it
would involve the children, schools, teachers, and
community in learning about air quality and being aware
of the air quality in their city.
In addition, the working group recommends that Mexicali
work with the mass media’s community representatives to
dedicate a short segment of the news to discuss the region’s
air quality for that day. This would bring even more
awareness on air quality to those watching television in
addition to the media campaign discussed above.
Increasing the public’s awareness of the Imperial-Mexicali
Air Quality Task Force meetings to ensure that
participation forums are available to the public to discuss
air quality in the border region would also be very
beneficial. In addition, the governments in Mexico should
increase the support for University research that is
devoted exclusively to environmental health associated
with air pollution and disease prevention.

Long-Term Actions - Imperial County
Further Evaluation of Dust Emissions
In 2017, U.S. EPA issued a grant to CARB, which was subawarded to the ICAPCD, to procure and operate one
miniature portable wind tunnel (PI-SWERL) to assess soil
emissivity levels on lands in and around central Imperial
Valley communities impacted by windblown dust. As a
part of this grant, the ICAPCD will receive training for up
to 10 staff at a two-day session on the use and maintenance
of the PI-SWERL from the manufacturer, and then will
receive additional training from IID air quality consultants
in soil type characterization, surface stability, PI-SWERL
data management, and soil emissivity data uploading to an
IID database designed for public access.
Under the contract, Formation Environmental LLC, IID’s
lead air quality consultant, will provide this latter training
at five test sites in or near populated areas impacted by
windblown dust from areas that may include the Salton
Sea. The primary goal of this grant is to build capacity
within the ICAPCD to develop and implement protocols for

the use of the PI-SWERL as a fugitive dust regulatory
compliance tool and to inform future revisions to the
ICAPCD’s fugitive dust regulations applicable to
windblown dust.

Agricultural and Waste Burning
Short Term Actions - Imperial County
In Imperial County, after vegetative material is harvested,
the fields and stubble are burned to prepare for the next
planting. This burning helps prevent the spread of plant
diseases and controls weeds and other pests. Title 17 of the
California Code of Regulations provides agricultural and
prescribed burning guidelines for each area in California.
Title 17 specifically requires the ICAPCD to have rules in
place that minimize smoke from agricultural burning.
ICAPCD Rule 701 prohibits agricultural burning on any
day declared to be a no-burn day by CARB, a fire control
agency, or the ICAPCD’s Air Pollution Control Officer.
On a daily basis, the ICAPCD reviews meteorological
reports from various airport operators, the National
Weather Service, state fire agencies, and CARB to help
determine whether the day is a burn day. Burn/no burn
days are declared for the entire county. The ICAPCD uses
a detailed map of Imperial County to ensure that burns are
allocated correctly to ensure minimal-to-no smoke impacts
on the public. Daily burn authorizations specify the
amount, timing, and location of each burn event. ICAPCD
also considers local air quality as part of the daily burn
determination and can decide it is not a burn day even if
CARB authorized that day as a burn day.
The ICAPCD submits an annual agricultural burn report
to CARB in January of each year. The report includes the
amount of acres and the type of crops that were burned
during the previous calendar year. The most recent report
for 2017 indicates significant reductions in burning since
2003 in Imperial County. Open burning in Imperial County
has been reduced in quantity as well as the types of crops
burned. Emphasizing public health and safety, Imperial
County has successfully reduced burning from a total of
40,221 acres of all crops in 2003 to 10,220 acres in 2017,
primarily consisting of grass crops (e.g., alfalfa, klein,
bermuda). This represents a 75 percent reduction since
2003. Due to fluctuations in agricultural production, there
have been increases and decreases in agricultural burning
between years. However, agricultural burning on average
has been declining.
To
estimate
the
impact
of
agricultural
and
open/miscellaneous burning on ambient concentrations on
an annual basis, the average PM2.5 concentrations in
Calexico, El Centro, and Brawley were compared on burn

16

 days to those recorded on no-burn days. As shown in Table
1 below, on no-burn days, the average PM2.5
concentrations at Calexico, El Centro, and Brawley for
2015 through 2017 were 13.3 µg/m3, 8.7 µg/m3, and 11.0
µg/m3, respectively. On burn days, the averages were 11.4
µg/m3 at Calexico, 7.8 µg/m3 at El Centro, and 8.1 µg/m3
at Brawley.
Table 1. PM2.5 Average Comparison on
Burn and No Burn Days at Calexico
Calexico

El Centro

Brawley

Burn Day

11.4

7.8

8.1

No Burn Day

13.3

8.7

11.0

For all PM2.5 sites, the average PM2.5 concentrations
were lower on burn days, which suggests that when
burning did occur, meteorological conditions allowed
pollutants to disperse. Days with PM2.5 concentrations
over 12.0 µg/m3 did occur on agricultural burn days, but
occurred more frequently on days when burning is
prohibited in Imperial County. Between 2015 and 2017,
there were a total of 715 days (2/3 days) where either
agricultural or miscellaneous burns took place in Imperial
County. Of these days, there were five days at the Calexico
monitoring station where the PM2.5 concentration was
over 35 ug/m3 but none of the burns occurred in Calexico.
These concentrations also occurred in the winter (1/2/15,
1/14/16, 1/18/16, 12/11/16, and 12/3/17) when stagnation
and PM2.5 emissions are highest in Imperial and Mexicali.
Under stagnant meteorological conditions when winds are
low, pollutants within Calexico and Mexicali tend to
accumulate and increased PM2.5 concentrations occur
with greater frequency.
Difficulties on declaring a burn or no burn day may arise
such as times when early air quality forecasts and
parameters call for a burn day but winds increase a couple
of hours later. In this case, the increased winds would
affect the burns and smoke direction negatively and during
those occasions the ICAPCD attempts to contact those that
were given permission to burn (agricultural fields and/or
residential burns) and request that they do not burn.
Although the ICAPCD’s program has not been perfect in
preventing all burning from occurring on high PM2.5 days
in Calexico, overall, the ICAPCD’s agricultural burn
program effectively limits burning on forecasted high
PM2.5 days.
To further protect the public from the health impacts
associated with agricultural burning, ICAPCD commits to
amend the Agricultural Burn Procedures (Policy 34) by
expanding the special burn buffer from 1.5 miles to 2 miles.
This will require that an inspector be present when
burning occurs within 2 miles of a residential area, rural
school, or near heavily traveled roads. ICAPCD will also

look at revising Policy 34 to prioritize smaller acreage
burns of wheat to reduce potential for, and duration of,
smoke impacts. This would allow growers to choose to cut
a field in half or in quarters in order to move up on the
priority list to burn. ICAPCD has also started providing
daily burn determinations on their website to increase
transparency and awareness to the residents and farmers
in Imperial County.

Short Term Actions - Mexicali
Recent City Ordinance to Deter Burning
In August of 2018, a city ordinance reform began that
allowed the agents of the Municipal Public Security
Bureau (DSPM) of Mexicali to issue fines when residents
were caught throwing garbage on public roads,
contaminating water, drains, and vacant lots and burning
garbage, tires or any other waste or scrap in public places,
vacant lots, or any third-party properties or
buildings. Over 700 officers received training on how to
enforce
this
ordinance.
The main idea of the implementation of these fines is to
raise awareness of the damage to the environment that
residents are causing when they litter or pollute the air,
water, and land. Penalties can range from 40-200 days of
Unit of Measurement and Update (UMA) , reaching 16
thousand pesos (or roughly $850 U.S. dollars). Every two
months DSPM will send the Directorate of Environmental
Protection for the City of Mexicaliinformation that includes
how many citations were issued, the reason for the citation.
The city intends to track the progress by monitoring the air
quality and by analyzing the complaints of the citizens. If
fewer complaints are received by the city, it could mean
that the enforcement of the new ordinance is helping to
decrease the number of people burning, littering and using
fireworks in Mexicali.
The City of Mexicali has also been working to get waste
tires and wood off the streets to prevent further burning
emissions in the City. The "Clean Air for Mexicali 2018"
Program was coordinated by the Secretary of the City
Council, and involved the Fire Department, Public
Security Directorate, Directorate of Civil Protection, Street
Commerce and the Directorate of Environmental
Protection with the aim of preventing bad practices such as
open burning of garbage, tires, wood, firewood and other
fuels that have generated very high levels of air pollution
in Mexicali. As part of this effort, the city was able to
confiscate over 40,000 pounds of wood and over 500 pounds
of pyrotechnic material. This effort involved 106 public
servants from different agencies in Mexicali. In addition,
the city collected over 58,000 waste tires and took them to
tire disposal centers. The sale of fireworks was also banned

17

 in Mexicali in the winter of 2016. Although the ban of
selling fireworks within the city limits of Mexicali is not
permanent, it will apply during the current
Administration, which ends in 2019. The local police
department enforces the fireworks ban.
This effort was reinforced by the Environmental Protection
Directorate with more environmental dissemination
(consisting of nine media tours to both radio and television
stations) to call the general public to join the "Clean Air
Program for Mexicali" by avoiding purchasing and burning
pyrotechnic material, as well as conducting open burning.
Positive steps are being taken to reduce the amount of
waste burning that occurs in Mexicali. However, more
needs to be done to reduce sources of waste burning in the
city. The progress made on the new environmental
ordinance will be trackable and is expected to show a
reduction in burning in Mexicali from these efforts. In
addition, increasing education and awareness of the areas
air quality and the health impacts from different types of
burning will help to make people think twice before
burning waste in the city.

Short Term Recommendations - Mexicali
Agricultural Burning
The practice of agricultural burning generates air
pollutants such as carbon monoxide, NOx, VOC, and PM.
Mexicali does not restrict or have a permitting program for
agricultural burning. Agricultural material is often burned
in Mexicali at night to avoid being “seen.” Although these
emissions are less visible, the impact to air quality the
following morning is much worse and causes serious health
affects due to the typical inversion in the morning in
Mexicali that traps pollutants to the ground. Another issue
with agricultural burning in Mexicali is that
approximately 85% of the acres farmed are rented,
therefore owners and renters show little interest to invest
in any kind of initiative to reduce agricultural burning for
other practices, such as no-till, or using the agricultural
material to mitigate dust impacts at nearby feedlots. These
agricultural burns sometimes contain more than just
biomass material, including tires and trash, further
increasing the air pollution in the region.
One sustainable method to deal with the biomass, without
having to burn it, is no-till, which is a tillage system that
sows on the surface of the soil, still covered with the
residues from the previous crop, which retain moisture and
reduce soil loss caused by rain or wind and risk of erosion.
This system also helps to reduce fugitive windblown dust
emission levels from these lands. This technique helps soil
conservation and reduces emissions of air pollutants.

Recently, the Municipality of Mexicali with the support of
the Secretary of Agricultural Development (SEDAGRO)
and the Secretary of Environmental Protection (SPA), both
of the State of Baja California, developed educational
posters on the health impacts from agricultural burning
along with a discussion on the cleaner ways to burn by
taking into consideration the appropriate time of day to
burn (10:00 am to 3:00 pm) and meteorological conditions
like wind speed (10-15 km/hr), temperature (less than or
equal to 40c), and relative humidity (not greater than 40
percent). The posters also discuss the importance of
watching the fire until it is completely extinguished,
having fire breaks to prevent fire spreading, and how
agricultural waste should be free from other types of waste
such as plastic, tires, paper, and rope, and should not
contain soil or moisture. It is also important that farmers
consider the air quality in the region before burning. If
farmers are going to burn, they need to look around for
existing smoke or haze first. If the visibility is degraded,
farmers should not burn until the particulates clear.
Recently, ICAPCD has requested to expand the scope of
their CAA 103 grant without additional costto add a media
campaign focusing on the months with the highest
agricultural burning in Mexicali to increase education
about the health effects from agricultural burning and
alternative methods to agricultural burning that could be
used. The City Council of Mexicali, the SPA, and
SEDAGRO will work with the Directorate of
Environmental Protection to establish a rule to control and
permit agricultural burning. Currently, the authority to
regulate agricultural burning in Mexicali lies at the State
level. The regulation should require that farmers looking
to burn agricultural material must obtain an agricultural
burn permit from the city or state prior to initiating any
burns. The Directorate of Environmental Protection for
the City of Mexicali will participate with the State in the
development of the actions that are approved in the Plan
for agricultural burning. Agricultural burning should also
utilize the air quality data and forecasts issued by the
contractor for the Imperial Valley Air Quality website to
determine which days should be authorized burn or noburn days. The ICAPCD and CARB could also work with
authorities in Mexicali to disseminate the daily burn call
authorizations based on air quality forecasts for the day.
It is also important to search for alternatives for
management of agricultural waste and avoid burning by
placing new value on the waste (ex: biomass to control dust
from feedlots). If possible, another idea would to be to
create an incentive program for farmers to choose to not
burn their residue in return for a monetary incentive. City
and state authorities should concentrate their initial
efforts to reduce agricultural burning near “ejidos” in
Mexicali (small towns in Mexicali surrounded by
agricultural fields that are burned) as these towns are most

18

 affected by the pollution affects from agricultural burning.

Monitoring
Short Term Actions - Mexicali
Continuation of PM2.5 monitoring in Mexicali
On January 15, 2015, the Calexico monitor, located within
one mile of the international border with Mexicali and was
designated nonattainment for the 2012 PM2.5 annual
standard. Due to its proximity to Mexicali, Calexico is
impacted daily by emissions from Mexicali. The Clean Air
Act includes special provisions for areas located next to an
international border which allows states to take into
consideration the impacts of cross border transport of
pollutants. Consistent and reliable air quality data are
needed on both sides of the border in order to analyze the
degree to which the transport of pollutants from Mexico
affects the PM2.5 concentrations at the Calexico monitor.
In June 2015, CARB entered into a contract with SCS
Tracer Environmental to install and operate PM2.5
monitors at two sites in Mexicali. PM2.5 data was collected
from April 2016 - April 2018. With funding support from
U.S. EPA, CARB is working to develop a contract that
would continue the monitoring efforts at the University
Autónoma de Benito Juárez (UABC) and Colegio de
Bachilleres (COBACH) monitoring stations in Mexicali.
This would provide reliable PM2.5 mass and speciation
data for residents in Mexicali and would have a dual
benefit by linking the data to the alerts/forecasting mobile
application and website already in place for the Imperial
Valley. This monitoring contract would run for two
additional years pending available funding. In addition,
the contractor has agreed to provide SPA monitoring staff
on the maintenance and operation of the monitors to crosstrain so in the future SPA would be able to take over these
sites when the next contract ends.
In addition, the SPA BC is currently seeking funding to
refurbish existing Mexicali monitors. SPA BC applied for a
$500k grant from the Council of Science and Technological
Innovation (COCIT) of Baja California and is awaiting
approval. Effective monitoring is very important to have
in Mexicali to allow research to look into the causes of the
air pollution in the region, how the pollution is transported
through the atmosphere, and the health and
environmental effects. Monitoring can also be useful to
support the strengthening of regulatory standards and
NAAQS and to be able to monitor the results of new or
increased stringency regulations. Most importantly, the
monitoring data will be provided to the public so they know
the level of air pollution that they are breathing, and can

take precautions to prevent going outside when pollution
is unhealthy.

Enhanced PM2.5 Monitoring in Mexicali
In recent years, increased attention has been brought to
various environmental problems in Mexicali, especially
related to air quality. Air pollution in Mexicali can be easily
perceived, especially in more populated communities or
cities, due to the decreasing visibility and the fact that air
pollution causes serious health problems.
Faced with this situation, the environmental and health
authorities in Mexicali agree that it is necessary to
quantitatively assess air quality further, by measuring the
concentrations of the contaminants that are present in the
environment, and likewise, by keeping a record of the
measurements of pollutants present in the air Mexicali
residents breathe. Knowing the air quality throughout the
city of Mexicali will be very useful since this will allow the
public and government agencies to gain an increased
understanding on the sources that could be generating the
PM2.5 pollution in the area, which would ultimately lead
to further regulation, increased enforcement, and
protection of the health of the population.
As a result of this work plan, the Directorate of
Environmental Protection for the City of Mexicali and
CARB have been working together on a project to establish
a more robust PM2.5 monitoring network in Mexicali. This
project includes adding 50 instantaneous PM2.5 sensors
throughout various locations in Mexicali. Having a better
idea of the air quality throughout different areas of
Mexicali will be very useful since this will allow the public
and government agencies to gain an increased
understanding of the sources that are generating the
PM2.5 pollution in the area. This monitoring will also
provide the environmental and health authorities with a
historical record of air quality in Mexicali, by region and at
different times of the year. Perhaps the most important
benefit of having instantaneous PM2.5 air quality
information available to authorities in Mexicali, is that this
data will allow authorities to investigate sources of high
PM2.5 and increase enforcement where needed.
The PM2.5 sensors will be loaned to the City from CARB
with a commitment to involve government agencies and
Universities to assume the tasks of guarding and
maintaining the monitoring equipment. The majority of
sensors will be placed in police stations, fire stations, and
City buildings. The rest of the sensors will be used to
monitor the air quality in the Valley of Mexicali, which is
seriously affected by emissions from agricultural burning.
CARB staff will transfer their knowledge of sensor

19

 installation, operation, and the retrieval of data by
providing a training to the City and University staff after
the signing of the Memorandum of Cooperation.
This government agreement will allow enhanced PM2.5
monitoring to occur in Mexicali. CARB will loan the sensor
equipment to the City in two phases to ensure that the first
set of sensors will operate correctly in the conditions
present in Mexicali. As part of this agreement, the
Directorate of Environmental Protection for the City of
Mexicali will send CARB quarterly reports on the
inspections that were performed from the monitoring of the
air quality data. This will ensure that actions are being
taken to investigate and enforce the air quality regulations
in Mexicali and that the sensors are benefiting the City and
its residents.

Short Term Recommendations - Mexicali
Training on Monitoring, Maintenance, and
Submittal of Air Quality Data
To monitor, maintain, and submit air quality data is a
complex job that requires full time staff to make sure data
is accurate and reliable. All monitoring instruments must
also be calibrated to ensure the data is accurate and can be
used to identify future air quality trends. In addition, the
massive amount of information produced by the monitoring
network must be received, decoded, organized, and stored
in a retrievable database for agencies and the public to
access.
For these reasons, running and maintaining a monitoring
network is no simple task. In Mexicali specifically, an
insufficient budget and lack of staff to keep up with the
maintenance of the air quality equipment is the biggest
roadblock to providing an effective and accurate
monitoring network. In addition, there is not a proper
independent environmental fund to support the
functioning of the monitoring system in Mexico. If local and
state environmental agencies in Mexicali and Baja
California were to receive more funding and staff for
specifically this purpose, the state and city could have a
much more robust system.
CARB as well as the Contractor for the Mexicali PM2.5
monitoring project commit to helping the City of Mexicali
and SPA BC further to educate site operators on the
operation, maintenance, and submittal of air quality data
when needed. Training could include how to keep the
monitoring stations in optimal operation including
maintenance and submittal of data. It would also be
advantageous for the City of Mexicali and SPA BC to apply
for grants to get financing for new equipment, accessories,

and parts needed to ensure reliable and effective
monitoring data are being recorded for public consumption.

Collaboration
Short Term Actions - Mexicali
MOU with Mexico
In July 2014, California’s Governor Edmund G. Brown Jr.
and Mexico's Ministry of Environment and Natural
Resources Undersecretary Rodolfo Lacy and National
Forestry Commission General Director Jorge Rescala
Pérez signed the Memorandum of Understanding (MOU)

to Enhance Cooperation on Climate Change and the
Environment. The purpose of this four-year agreement was

to promote and carry out cooperative activities related to
environmental issues. The working groups (Climate
Change, Air Quality, Clean Vehicles, and Wildfires) each
made substantial progress, with leads from California and
Mexico working together on a regular basis. CalEPA and
SEMARNAT coordinated working group efforts. With the
MOU expiring in 2018, and new administrations taking
office in 2019, a new MOU would be advantageous to
continue cooperative efforts to improve air quality in the
California-Mexico border region.

Off-Highway Vehicles
Long Term Actions – Imperial County
OHV Rules
The ICAPCD has been in discussions with the Bureau of
Land Management (BLM) and the California State
Department of Parks and Recreation (DPR) on how to best
address and further mitigate windblown dust emissions
from OHV parks in Imperial County. In addition, the
ICAPCD has been working closely with the Sheriff’s
Department to address issues with trespassing of OHV’s
into Salton Sea Shoreline, surrounding areas not
designated for OHV riding, and open areas in general that
need enforcement per Rule 804. The ICAPCD in
conjunction with the County Council has been working on
two County Ordinances to facilitate enforcement related to
OHV trespassing. To meet this goal, the ICAPCD in
conjunction with multiple agencies, has been working on
budget augmentation for the Imperial County Sheriff’s
Office to ensure implementation of enforcement on this
source. The County will continue discussions with BLM
and DPR into the future to come up with strategies to
reduce fugitive dust emissions generated and increased by
OHV usage in Imperial County, specifically on the west
side of the Valley.

20

 Vehicle Emissions and Border Traffic
Long-Term Recommendations – Imperial County
Evaluating Vehicle Emissions at the Ports of Entry
It is very well understood that vehicles are not necessarily
operating where they are registered. Currently, CARB’s
on-road mobile source emissions inventory tool (EMFAC)
utilizes data from the Department of Motor Vehicle (DMV)
registration addresses with some spatial adjustments
using data from past studies to estimate emissions and
activity at the county level. However, no data currently
exists to spatially allocate at a more localized level.
Automated license plate readers (ALPRs) are high-speed,
computer-controlled camera systems that can be setup on
highway overpasses, street poles, streetlights, or mobile
trailers, and can capture all license plate numbers that
come into their view. License plate data acquired using
ALPR cameras will provide the necessary information to
establish fleet characteristics and activity at the localized
level through registration databases (DMV and
International Registration Plan (IRP)). These data will
also improve CARBs ability to assess and track the
compliance of in-use diesel regulations (e.g., Truck and Bus
Regulation) and support agency’s efforts to enforce existing
and future mobile source regulations such as heavy duty
Inspection and Maintenance (I/M) program.
Given the issues with the data sources described above,
new sources of data are crucial for developing mobile
source inventories at the local scale.
A large,
representative sample of license plates from vehicles
operating within different regions, communities, and
passing through border weigh stations in California will
provide the necessary linkage to fleet characteristics
through registration databases (DMV and IRP). These
data will also improve CARB’s ability to assess and track
vehicle and fleet compliance with our in-use diesel
regulations, hence supporting CARB’s efforts to enforce
existing mobile source regulations, such as the Truck and
Bus regulation and Periodic Smoke Inspection Program,
and potential future regulations, such as a comprehensive
Heavy-Duty Vehicle Inspection and Maintenance program.
The solicitation is out for this contract now and to provide
two camera systems at the Calexico-East port of entry to
evaluate northbound truck traffic.
To build upon the ALPR system to get a better idea of the
fleet and vehicle emissions at the Calexico East port of
entry, a study is needed to utilize CARB’s recently
developed Portable Emissions AcQuisition System
(PEAQS). This study would include the ALPR technology
discussed above, and PEAQS would be used to measure the

emissions of black carbon and oxides of nitrogen of
individual heavy-duty vehicles entering California from
Mexico. The study should begin with an initial deployment
of PEAQS at the Calexico-East port of entry to obtain
baseline information on the age, emissions profile, and
origin of heavy-duty vehicles crossing into the United
States. The study should also involve an informational
outreach program for heavy-duty vehicles, followed by
focused enforcement activities on the highest emitting
vehicles and characterize fleet emissions after the
implementation of mitigation measures. Collecting heavyduty vehicle emission information before, during, and after
intervention and mitigation activities will allow regulators
to assess the effectiveness of focused outreach and
enforcement in reducing heavy-duty vehicle emissions and
help develop new approaches to reducing emissions from
mobile sources. ALPR and PEAQS technologies should be
utilized at the POE’s in Calexico to determine a more
accurate estimate of emissions generated at the border.

Smog Check Program
Currently, Imperial County residents only have to smog
their vehicles when there is a change in ownership.
Although the area is nonattainment for ozone, the original
designations of the Smog Check Program were based on
population data from 1990. If an area had a population of
less than 200,000, the area did not have to implement a
basic or enhanced Smog Check Program, which ensures
that cars are checked for emissions every 1-2 years.
With the population of Imperial County approaching
200,000, Imperial County should consider volunteering to
increase their Smog Check Program to the basic program,
which would require that all cars that operate in the
County would have to pass emissions inspections every
other year. It is important that Imperial County does what
it can to reduce vehicle emissions, particularly those at the
POE’s which impact the PM2.5 levels at the Calexico
monitor.

Long-Term Recommendations – Mexicali
Enhanced Vehicle Verification Program
In 2017, the Secretary of Planning and Finance reported
that 1.1 million vehicles were registered in Baja California,
of which ~378,000 of those are registered in Mexicali,
Mexico. Roughly, 30% of the vehicles in Mexicali that are
registered went through the vehicle verification program
in 2017. The vehicle verification program in Mexico is to be
completed every year. Although the environmental law in
Mexico establishes that all vehicles must be smogged, since
2012 when the program was implemented, there has been
no enforcement of the requirement because there are no

21

 penalties associated with non-compliance. Because the
vehicle verification program in Mexico is sticker and not
registration based, it is important that inspection and
surveillance be done and complemented with fines to
ensure more people comply with the requirement. The
main reason that participation in the vehicle verification
program is so low in Mexico is because vehicle owners are
not penalized in any way when they fail to comply with the
verification requirement. To increase participation in the
vehicle verification program, fines for noncompliance
should be added to the program.
In addition, many vehicles enter Mexico without going
through the proper importation process. Vehicles that are
more than 10 years old are not supposed to be imported
into Mexico. However, many vehicles are driven over the
border without registration and legal documentation but
are able to cross the border and are used in Mexico.
“Chocolate vehicles” are vehicles that come from outside
Mexico without any registration and to which probably did
not pass smog in the State from which they came. There is
a problem of vehicles crossing the border without proper
importation and a lack of authority in Mexico to enforce the
regulations against these polluting vehicles.
California should also share information on the California
registered vehicles with Mexico to allow SPA to check if
those vehicles are now operating in Mexico and if those
vehicles had a valid smog check in California before moving
across the border. CARB and the Bureau of Automotive
Repair (BAR) can also provide Mexicali vehicle verification
program officials with training and recommendations on
how to make better use of the onboard diagnostic (OBD)
data that they collect for a greater level of inspection
stringency. Overall, the main recommendation is for
Mexico’s vehicle verification program to add fines to the
program to increase participation.

Vehicle Idling Emissions
The Baja California emissions inventory shows that motor
vehicles are the principal source of NOx, VOC, and carbon
monoxide emissions. From 1980 to 2015, the number of
vehicles operating in Baja California rose from 347
thousand to 1.1 million (Figure 1). One of the main
contributors for increased motor vehicle emissions in the
border region is the continuous starting and stopping in
traffic and at the POE’s. This vehicle traffic occurs at the
POE checkpoints that control the passage of motor vehicles
between Baja California and California. While cars are
waiting to go through the checkpoint, they keep the engine
running as the line slowly advances. This results in
increased gas consumption and air pollutant emissions.

Figure 1. Growth trend of the vehicle fleet in the
State of Baja California (1980 - 2015).

It is very important to understand the magnitude of the
emissions coming from the vehicles at the POE’s. For this
reason, the license plate capture system (ALCP) discussed
previously to understand the age distribution of the vehicle
fleet at the border is critical to tracking emissions at the
POEs. In addition, the recent emission inventory
improvement contract will focus on border area emissions
by using wait time and volume statistics. Once emissions
are quantified, it is important that environmental and
transportation agencies in California and Mexico work
together to create emissions reductions scenarios that will
benefit both countries by reducing vehicle wait times at the
crossings.
Concerning the emissions generated from the commercial
truck POE (Calexico-East) in the border region, additional
projects should be considered to reduce the times for cargo
inspection by authorities. Currently, U.S. EPA is funding
the North American Research Partnership (NARP)
through a Border 2020 grant awarded through the North
American Development Bank to quantify emissions
reduction benefits from the Nogales Unified Cargo
Processing Facility. The project will analyze the emission
reduction benefits resulting from unified cargo inspections
and help to improve our understanding of the relationship
between wait-times, and emissions at the Mariposa Land
POE. This project will also help to educate border agencies
on the additional infrastructure investments that could be
made to mitigate wait-time and emissions at the border. If
this project is successful and wait times are reduced for
commercial trucks, the working group recommends that a
similar program be implemented at the Calexico-East
POE.
In recent years, some actions have been taken to reduce the
wait times at the POE’s, including increasing the number
of checkpoints, reducing the number of administrative
procedures, having preferential faster lanes for certain
vehicles etc. However, given the constant increase in the
flow of vehicular traffic and border crossings, it is

22

 necessary to evaluate new alternatives for more efficient
vehicle border crossing.

Unpaved Roads
Long-Term Recommendations – Mexicali
Reduce Emissions from Unpaved Roads
Mexicali is an arid desert region with lots of open natural
areas. Dust emissions from paved and unpaved roads in
Mexicali are intensified due to winds passing over exposed
areas. These emissions are transported to other areas of
Mexicali including areas where the majority of the
population resides. With the increase in population and
transportation comes an increase in windblown dust
emissions. Windblown dust emissions negatively affects
the residents in Mexicali by exacerbating respiratory
ailments due to high PM levels.
Baja California’s emissions inventory for anthropogenic
sources shows that unpaved roads are the principal source
of PM10 emissions in the region. If natural emissions are
considered in addition to anthropogenic emissions, wind
erosion contributes to 80% of PM10 in Mexicali. Only
Tijuana and Tecate mention eroded soils in their
environmental protection rules, so it is important that the
rest of the municipalities update their rules to regulate this
land type. The working group recommends that Mexicali
update its environmental protection rules to include
regulation of unpaved and open areas.
The working group recommends that the City of Mexicali
and SPA BC work to reduce PM emissions from unpaved
roads in Mexicali. The agencies should work to oversee
compliance with residential and commercial development
permits with regard to dust control, train on construction
techniques and practices that support reducing PM
emissions, emphasize the importance of the impact of PM
generated by construction and demolition, develop a
program for collection of construction waste, develop an
inventory of eroded areas and unpaved roads inside urban
areas in Baja California, evaluate surface coating
techniques to reduce uncovered land areas and unpaved
roads, and apply surface coating techniques to reduce
uncovered land areas and unpaved roads.
The city and SPA BC should also seek additional funding
mechanisms to pave additional unpaved roads into the
future. NADBANK loans and consulting with the
Economic Development Council in Mexicali are viable
options to seeking additional funding to pave unpaved
roads in the future. Although paving would be the best
long-term option to combating windblown dust emissions

from unpaved roads, the city and state should also look into
other alternatives to stabilizing roadways such as watering
and soil stabilization on heavily traveled roadways. To
most effectively reduce the number of unpaved roads in
Mexicali, it is primarily important to prioritize where the
paving should take place to ensure that the highest
emitting roadways are paved first.

Regulating Mexicali Sources
Long-Term Recommendations – Mexicali
Improve Emissions Inventory Data, Increase
Inspection, Surveillance, and Regulation on Industry
In the most recent emissions inventory for Baja California,
the commerce and services source category contributes
mainly to VOC, CO and PM2.5 emissions based on the use
of products such as solvents, burning of biomass like wood
and carbon for food processing, and water heating used in
activities of the sector.
It is important for the city to update the municipal
environmental regulation on commerce and services. The
list of commerce and service businesses should be updated
on an annual basis to ensure that business permits are up
to date and that an inspection and surveillance system
exists. The commerce and service businesses should also be
trained on the guidelines to which they are held to reduce
their impact on the air pollution in the region. The
emissions from these service industries should also be
accurately reflected in the emissions inventory for
Mexicali. Dust control plans should be required for
construction sites to build in Mexicali. There are many
agreements that need to be made in Mexicali between the
local, state, and federal governments to ensure that an
effective enforcement and permitting process is occurring
on regulating sources in Mexicali. A realistic timeline that
also incorporates the change in state and federal
government will also be needed.

Other Priorities
Long-Term Recommendations - Mexicali
Program to Control Emissions from Livestock
Farming
Both PM and NH3 emissions from livestock in feedlots is a
definite air pollution concern in Mexicali. There is
currently no dust control on large feedlots in Mexicali. An
inventory of PM and NH3 emissions from livestock farming
in Mexicali should be generated to gain a better
understanding of the magnitude of emissions generated by
feedlots. The city and SPA BC should meet with the

23

 feedlots to see if they would be agreeable to controlling dust
and NH3 from their feedlots since theses feedlots are not
regulated to control these emissions. Previously, a program
was administered by SPA BC with agricultural owners and
a large feedlot in Mexico where wheat stubble from
agricultural fields was used by the feedlots to incorporate
the stubble into animal pens with manure and was sold.
This effort had a dual benefit of reducing agricultural
burning and feedlot dust emissions. When the SPA BC
went through a change in government, this program ended.
The working group recommends that SPA BC look at
reinstating this program, promote the use of better
practices for animal waste management, provide training
to the livestock companies in the use of new practices of
handling the livestock waste, and most importantly, for
SPA BC or SEMARNAT to establish and enforce a
regulation on livestock farming to control emissions of PM
and NH3.

Enforcement
Long-Term Action – Imperial County
Strengthening Enforcement
Rules are only effective when there is compliance with
requirements, and enforcement often becomes necessary
when industry, or the public, do not meet those
requirements. The ICAPCD is the regulatory agency that
has the primary responsibility for controlling air pollution
from stationary and area sources within Imperial County,
but also enforces state and federal rules. CARB has the
responsibility for controlling air pollution from mobile
sources and for reviewing district enforcement
practices. As such, both agencies share a role in ensuring
the enforcement of air pollution regulations in the County.
To ensure effective enforcement, CARB and ICAPCD staff
will evaluate enforcement programs, protocols, and results
to strengthen enforcement programs and maximize
compliance with existing requirements.

businesses, such as geothermal power plants, are inspected
multiple times each year. When a violation has been
found, the ICAPCD requires the business to return to
compliance, and may assess penalties or pursue legal
actions, if necessary, to deter future violators.
CARB has an extensive mobile source enforcement
program, with efforts focused on trucks in the border
region and particularly at the border crossing at Calexico.
CARB also enforces programs focused on diesel-fueled offroad equipment, such as construction equipment and
Transportation Refrigeration Units (TRU).
Diesel
enforcement is conducted through investigations / audits,
administrative actions, and field inspections. CARB’s goal
is to achieve compliance through effective implementation
and enforcement of regulatory requirements. The diesel
rules, with a large number of regulated entities across the
state, are challenging to enforce.
Working together, CARB and the ICAPCD will collect and
evaluate permitting, enforcement, and complaint policies
and procedures that describe how staff conducts
inspections, investigates complaints, and resolves
violations and statistics for key stationary and mobile
source programs that can measure the effectiveness of
these programs.
Results from this evaluation will be
compared to similar statistics in other similar regions and
the South Coast Air Quality Management District.
Using the findings from the evaluation described above,
and the comparison of statistics in ICAPCD to other
Districts, CARB and ICAPCD staff will work together to
develop a work plan that will strengthen permitting and
enforcement efforts within the ICAPCD boundaries. This
may include updating policies and procedures, developing
and implementing innovative methods for enforcement,
and/or conducting more frequent enforcement on sources
that have been non-compliant in the past in order to
identify and deter future non-compliance.

ICAPCD has an extensive program designed to control
emissions from stationary sources within the County. For
example, ICAPCD has adopted more than 100 rules that
set emission limits and operational restrictions on
stationary sources, and sets a high priority on permitting
and enforcement. Nearly half of the air district staff works
on permitting and enforcement at the district, issuing,
maintaining, and enforcing 800 operating permits issued
to more than 350 businesses and facilities subject to air
pollution rules in Imperial County. The district also issues
more than 200 agricultural burning permits each year.
The ICAPCD’s goal is to inspect each permitted source at
least one time each year to verify compliance; some

24

 Recommendations and Actions for Imperial
County
ICAPCD:
- Continue to work with agencies in Mexicali on media
campaigns that relate to the border region.
- Continue to investigate opportunities for Regulation
VIII rule strengthening.
- Map the emissivity of soil types within the Imperial
Valley and tailor the number and/or effectiveness of
Conservation Management Practices to the uncontrolled
emissivity levels of soils on which agricultural
operations are conducted.
- Continue collaboration with IID and CARB in playa
dust control research and testing activities at the Salton
Sea to help establish the most cost-effective controls to
mitigate playa dust that affects Imperial County.
- Develop and implement protocols for the use of the
portable wind tunnel as a fugitive dust regulatory
compliance tool and to inform future revisions to the
ICAPCD’s fugitive dust regulations applicable to
windblown dust.
- Amend Policy 34 (Agricultural Burn Procedures) to
increase the buffer zone for special burns from 1.5 to 2
miles, and prioritize smaller acreage burns of wheat to
reduce potential for, and duration of, smoke impacts.
- Continue discussions with BLM and DPR to come up
with strategies to reduce fugitive dust emissions
generated and increased by OHV usage in Imperial
County, specifically on the west side of the Valley.
- Continue working closely with the Sheriff’s Department
to address issues with trespassing of OHV’s into Salton
Sea Shoreline.
- Continue working on County Ordinances to facilitate
enforcement related to OHV trespassing.

CARB and Imperial County:
- The ALPR and PEAQS technologies should be utilized
at the POE’s in Calexico to determine a more accurate
estimate of emissions generated at the border.
- Volunteer to increase the Smog Check Program in
Imperial County to a basic program, which would
require that all cars that operate in the County would
have to pass emissions inspections every other year.
- Working together, CARB and the ICAPCD will collect
and evaluate permitting, enforcement, and complaint
policies and procedures that describe how staff conducts
inspections, investigates complaints, and resolves
violations. CARB and ICAPCD staff will work together
to develop a work plan that will strengthen permitting
and enforcement efforts within the ICAPCD
boundaries.

25

 Recommendations and Actions for Mexicali,
Baja California
SPA BC:
- Once the Mexicali PM2.5 monitoring stations are
added to the alert/forecasting website contract for
Imperial Valley, SPA BC should work with CARB,
ICAPCD, and the website developer to warrant that
air quality data is maintained and made available to
ensure forecasts in Mexicali can be provided to the
public.
- Work with CARB to educate site operators on the
operation, maintenance, and submittal of air quality
data when needed.
- Work with California to check if vehicles that were
previously operated in California, but are now
operating in Mexico, had a valid smog check in
California before moving across the border.
- Seek training and recommendations from CARB and
BAR for how to make better use of the onboard
diagnostic (OBD) data that is collected for a greater
level of inspection stringency for the smog check
program.
- Look at reinstating the wheat stubble to feedlots
program, promote the use of better practices for
animal waste management, provide training to the
livestock companies in the use of new practices of
handling the livestock waste, and establish and
enforce a regulation on livestock farming to control
emissions of PM and NH3.

The Directorate of Environmental Protection for the
City of Mexicali and SPA BC:
- Continue to work with ICAPCD and CARB to improve
the winter and summer media campaigns.
- Gain a better understanding of what sources are
producing the most pollution in different areas of
Mexicali.
- Establish a communication campaign such as
advertising information and air quality on a Facebook
page or other media avenues.
- Bring education and awareness of air quality and air
pollution into the schools in Mexicali.
- Work with the mass media’s community
representatives to dedicate a short segment of the
news to discuss the region’s air quality for that day.
- Increase support for University research that is
devoted exclusively to environmental health
associated with air pollution and disease prevention.
- Apply for grants to get financing for new equipment,
accessories, and parts needed to ensure reliable and
effective monitoring data.
- Establish a rule to control and permit agricultural
burning. Sign an agreement with the federal
government to allow enforcement of the regulation.
Create an incentive program for farmers to choose to
not burn their residue in return for a monetary
incentive.
- Reduce PM emissions from unpaved roads in
Mexicali.
- Develop an inventory of eroded areas and unpaved
roads inside urban areas in Baja California
- Evaluate stabilization techniques to reduce emissions
from uncovered land areas and unpaved roads.
- Seek additional funding mechanisms to pave
additional unpaved roads into the future.
- Prioritize where the paving should take place to
ensure that the highest emitting roadways are paved
first.
- Require dust control plans for construction sites to
build in Mexicali.
- To increase participation and compliance with the
vehicle verification program, fines should be added to
to the program.

The Directorate of Environmental Protection for the
City of Mexicali:
- On agreement to receive PM2.5 monitors from CARB,
send quarterly reports to CARB on the inspections
that were performed from the monitoring of the air
quality data and the associated enforcement actions
that were taken.
- Update the municipal environmental regulation on
commerce and services, ensure an inspection and
surveillance system exists, and update the list of
commerce and service businesses on an annual basis.

26

 Future Updates

This work plan was developed by CARB in collaboration
with the various Imperial County and Mexicali
stakeholders and reflects the input and expertise of a range
of state and local government and community
organizations. The set of actions from this work plan will
be presented to the CARB board on December 13, 2018. The
actions identified in this work plan will help to move the
Imperial County – Mexicali border region towards cleaner
air quality.
Many of these actions are new and ambitious while others
are more recent and already underway. Collectively, these
actions are evidence of California and Mexico’s ability to
show that it is possible to tackle air pollution in the border
region by working together and continue operating to see
these actions come to fruition. Some of the actions are
short-term, while others are focused on longer-term efforts
that will provide major benefits well into the future.
Success of this work plan will require the creation of new
policies and regulations in some areas, and expanding and
refining existing policies and regulations in others. Staff
envisions that this work plan will continue to have
quarterly in person working group meetings, with
conference calls occurring more frequently to ensure that
these actions are followed through on. Staff also
recommends that this work plan be brought to the Board
as a yearly update until all actions have been completed.
The metrics to track progress table on next page provides
more details as to how CARB and the working group will
track the success of these actions and who will be
accountable for which actions.

27

 Metrics to Track Progress
Priority Area

Short Term (<12 months) Work Plan Actions and Recommendations
Work Plan Actions and Recommendations

Agencies
Involved
Actions - Education and Outreach - Imperial County

Improved Winter
Media Campaign

Continue to work with agencies in Mexicali on the "Ambientalizate"
media campaigns in the border region.

Regulation VIII
Fugitive Dust
Rules Evaluation
Salton Sea Dust
Mitigation

Continue to investigate opportunities for Regulation VIII rule
strengthening.

PM2.5, PM10, and
Ozone Air Quality
Alerts and
Forecasts for
Mexicali
Increase Education
and Awareness of
Air Quality

Proposed Timeline

SPA BC
Municipality
ICAPCD
CARB
ICAPCD
CARB

Winter 2018 - new media
campaign will be completed.

Continue collaboration with IID and CARB in playa dust control
research and testing activities at the Salton Sea to help establish
the most cost-effective controls to mitigate playa dust that affects
Imperial County.

ICAPCD
IID
CARB

Ongoing. IID, CARB, and
ICAPCD have already been
working together on playa dust
control research.

Once the Mexicali PM2.5 monitoring stations are added to the
alert/forecasting website contract for Imperial Valley, SPA BC should
work with CARB, ICAPCD, and the website developer to guarantee that
air quality data is maintained and made available to ensure forecasts in
Mexicali can be provided to the public.
Gain a better understanding of what sources are producing the most
pollution in different areas of Mexicali.

SPA BC
CARB
ICAPCD
Contractor

Winter 2018/2019. Contract is
expected to begin around
Jan/Feb of 2019.

CARB
SPA BC
Municipality

Establish a communication campaign such as advertising information
and air quality on a Facebook page or other media avenues.
Bring education and awareness of air quality and air pollution into the
schools in Mexicali.

SPA BC
Municipality
SPA BC
Municipality

Ongoing but certain sources will
be estimated in 2019 through
CARB contract. SPA BC and
Municipality should seek
additional inventory
improvements.
Summer of 2019.

Work with the mass media’s community representatives to dedicate a
short segment of the news to discuss the region’s air quality for that
day.
Increase support for University research that is devoted exclusively to
environmental health associated with air pollution and disease
prevention.

SPA BC
Municipality

Recommendations - Education and Outreach - Mexicali

28

SEMARNAT
SPA BC
Municipality

Ongoing. This evaluation is
already underway.

Start to develop educational
material for schools in Q1 of
2019.
Work with media to see if
segment is possible by Q2 of
2019.
Ongoing. Negotiations with
SEMARNAT to see if additional
funding can be allocated for this
effort.

 Agricultural
Burn Program
Effectiveness

Actions - Agricultural Burning - Imperial County

ICAPCD will amend the Agricultural Burn Procedures to increase the
special burn buffer zone from 1.5 to 2 miles and prioritize smaller
acreage burns of wheat to reduce potential for, and duration of, smoke
impacts.

ICAPCD

Winter of 2018/2019.

Establish a rule to control and permit agricultural burning. Sign an
agreement with the federal government to allow enforcement of the
regulation.
Create an incentive program for farmers to choose to not burn
agricultural residue in return for a monetary incentive.

SEMARNAT
SPA BC
Municipality

2019.

SPA BC
Municipality

The City of Mexicali should develop metrics to track progress of the city
ordinance on burning to see if the ordinance is causing a change in the
air quality of Mexicali.
.

Municipality

2019. If regulation above is
successful, see if incentive
money would also be available
to reduce burning further.
Start November 2018. City
could analyze data quarterly
after reports are received.

On agreement to receive PM2.5 monitors from CARB, send quarterly
reports to CARB on the inspections that were performed from the
monitoring of the air quality data and the associated enforcement
actions that were taken.
Work with CARB to educate site operators on the operation,
maintenance, and submittal of air quality data when needed.
Apply for grants to get financing for new equipment, accessories, and
parts needed to ensure reliable and effective monitoring data.

Municipality

Begin Summer 2019.

SPA BC
Municipality
SPA BC

Ongoing. Support is available
when requested.
SPA BC is seeking funding
now. If funding is not provided,
SPA BC should continue to
seek grants.

Recommendations - Agricultural and Waste Burning - Mexicali

Agricultural
Burning

Waste Burning

Recommendations - Monitoring - Mexicali

Enhanced PM2.5
Monitoring in
Mexicali
Training on
Monitoring,
Maintenance, and
Submittal of Air
Quality Data

29

 Priority Area
Further Evaluation of
Dust Emissions

OHV Rules

Long Term (>12 months) Work Plan Actions and Recommendations
Work Plan Actions and Recommendations

Agencies
Involved
Actions - Education and Outreach - Imperial County

Proposed Timeline

Map the emissivity of soil types within the Imperial Valley and tailor the
number and/or effectiveness of Conservation Management Practices to the
uncontrolled emissivity levels of soils on which agricultural operations are
conducted.
Develop and implement protocols for the use of the portable wind tunnel as
a fugitive dust regulatory compliance tool and to inform future revisions to
the ICAPCD’s fugitive dust regulations applicable to windblown dust.

ICAPCD

Continue discussions with BLM and DPR to come up with strategies to
reduce fugitive dust emissions generated and increased by OHV usage in
Imperial County, specifically on the west side of the Valley.

ICAPCD
CARB
BLM
DPR
ICAPCD
IC Sheriff’s
Dept.
ICAPCD
IC

2019/2020.

ICAPCD

Actions - Off-Highway Vehicles – Imperial County

Continue working closely with the Sheriff’s Department to address issues
with trespassing of OHV’s into Salton Sea Shoreline.
Continue working on County Ordinances to facilitate enforcement related
to OHV trespassing.

2019/2020.

Recommendations - Vehicle Emissions and Border Traffic – Imperial County

Evaluating
Vehicle
Emissions at the
Ports of Entry
Smog Check
Program

Utilize the ALPR and PEAQS technologies at the POE’s in Calexico to
determine a more accurate estimate of emissions generated at the border.

CARB
ICAPCD
CBP
ICTC

2019/2020. CARB should work
with CBP and ICTC to
establish stations at the POE’s
in Calexico.

Increase Smog Check Program to the basic program to require that all cars
that operate in the County would have to pass emissions inspections every
other year.

ICAPCD
IC

2019/2020.

Enhanced Vehicle
Verification
Program

California could share information on the California registered vehicles
with Mexico to allow SPA to check if those vehicles are now operating in
Mexico and if those vehicles had a valid smog check in California before
moving across the border.
Fines should be added to the vehicle verification program for noncompliance.
Seek training and recommendations from CARB and BAR for how to make
better use of the onboard diagnostic (OBD) data that is collected for a
greater level of inspection stringency for the vehicle verification program.

SPA BC
CARB

Work could begin in 2019.

SPA BC
Municipality
SPA BC
CARB
BAR

Work could begin in 2019.

Recommendations - Vehicle Emissions and Border Traffic - Mexicali

30

Ongoing but CARB and BAR
are available to train and offer
recommendations now.

 Strengthening
Enforcement

Reduce Emissions
from Unpaved Roads

Actions - Enforcement – Imperial County

CARB and the ICAPCD will collect and evaluate permitting, enforcement,
and complaint policies and procedures that describe how staff conducts
inspections, investigates complaints, and resolves violations, and statistics
for key stationary and mobile source programs that can measure the
effectiveness of these programs.
CARB and ICAPCD staff will work together to develop a work plan that
will strengthen permitting and enforcement efforts within the ICAPCD
boundaries.

CARB
ICAPCD

2019/2020.

CARB
ICAPCD

2019/2020.

Reduce PM emissions from unpaved roads in Mexicali.

SPA BC
Municipality
Mexicali
Public Works
SPA BC
Municipality
SPA BC

Ongoing after prioritization of
most emissive unpaved roads is
established.

SPA BC
Municipality
SPA BC
Municipality

2019/2020.

2019/2020.
2019/2020
2019/2020.

Recommendations - Unpaved Roads - Mexicali

Develop an inventory of eroded areas and unpaved roads inside urban
areas in Baja California.
Evaluate stabilization techniques to reduce emissions from uncovered land
areas and unpaved roads.
Seek additional funding mechanisms to pave additional unpaved roads into
the future.
Prioritize where the paving should take place to ensure that the highest
emitting roadways are paved first.

Recommendations - Regulating Mexicali Sources - Mexicali

2019/2020.
2019/2020.

2019/2020.

Regulating Mexicali
Sources

Update the municipal environmental regulation on commerce and services.
Ensure an inspection and surveillance system exists
Update the list of commerce and service businesses on an annual or biannual basis.

Municipality
Municipality
Municipality

Program to
Control
Emissions from
Livestock
Farming

Look at reinstating the wheat stubble to feedlots program.
Promote the use of better practices for animal waste management.
Provide training to the livestock companies in the use of new
practices of handling the livestock waste.
Establish and enforce a regulation on livestock farming to control
emissions of PM and NH3.

SPA BC
SPA BC
SPA BC

2019/2020.
2019/2020.
2019/2020/

SPA BC

2019/2020.

Recommendations - Other Priorities - Mexicali

31