air quality officials, Logan residents, seek ways to
curb PM 2.5 pollution
February 6, 2009 | LOGAN -- Officials from the State
Division of Air Quality met with concerned Cache Valley
residents Feb. 3 in a public meeting to discuss the
state implementation plan (SIP) that will help Cache
Valley attain the EPA standards for the air pollutant
known as PM 2.5.
PM 2.5 stands for particle matter suspended in the
air that is less than 2.5 microns in size. According
to Bill Reiss, implementation plan coordinator for the
Division of Air Quality, these are particles that can
cause health problems.
The point of reducing these particles is to "protect
the most sensitive in the population, health wise,"
explained Reiss. These include young and older people,
as well as those who may have pulmonary problems.
These particles are small enough to get into the lungs
and blood, and are difficult for the body to expunge
from its systems, he said, adding he was reluctant to
answer medical specifics, because he is not a physician.
The EPA keeps track of PM 2.5 levels for two specific
time periods. One is a yearly average while the other
is a 24-hour period. While Logan does not have a problem
with the yearly average, Reiss said it often fails to
meet requirements for the 24-hour periods.
Revisions made in December 2006 to the EPA's air quality
regulations require that, for a one-day period, there
be fewer than 35 particles sized 2.5 microns or less
per cubic meter of air. At levels higher than this,
health issues appear in the population, Reiss said.
Periods when the levels exceed this limit are the
so-called "red days."
"Weather and topography is a major issue here," explains
Reiss. Because Cache Valley is surrounded by mountains,
pollution has no place to go or dissipate because of
winds. To add to this complication, during the winter
inversion periods small particles in the air accumulate,
which are the periods when we have problems.
These particles "start as gas, and combine with compounds
to become a particle," Reiss said. Gases such as sulfur
dioxide and nitrogen oxide combine with other elements,
and eventually become ammonium sulfate or ammonium nitrate.
Under EPA regulations, it is required that a SIP be
prepared in order to implement regulations and standards
to bring down PM 2.5 levels in the Cache Valley area,
which includes the northern end of Cache county and
the southern part of Franklin county in Idaho.
As part of the process, the Division of Air Quality
will take several steps to draft and implement the SIP.
Among them, they will use a complex mathematical model
that can aid them to measure the pollution in the area,
and will tell them how different regulations may affect
particle level in the valley. In order to have accurate
models, large amounts of date have been and are still
being collected in the valley.
"We have to make these improvements on the face of
a growing population," said Reiss, explaining that as
part of the model, the expected growth in the valley
has to be taken into account, adding to the complications
of these models.
The SIP will also set forth regulations and administrative
measurements that will have to be implemented locally
to reduce the levels of PM 2.5. Reiss said that while
the model will "Shoot for the best," the main goal of
the SIP is only intended to keep levels of particles
"Under the line" of 35 microns per cubic meter.
Reiss explained that there are three types of sources
that cause this kind of pollution in the air: point,
area, and mobile sources. Point sources are places like
large smoke stacks, while area sources are smaller sources
in an area. Mobile sources are the many vehicles in
"Vehicle inspections may make the most significant
impact. A few vehicles pollute the most," he said, explaining
that inspections are a way to both bring these vehicles
back to standard, as well as a way to provide funding
for the program. He adds that while federal regulations
required local areas to med these standards, no funding
aid is provided to accomplish this standards.
"It is not going to solve the problem," said Reiss
about the SIP, reiterating however that the intention
of the SIP process is only to reduce levels of PM 2.5
in the area, and bring Cache Valley "under attainment