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SIP: Introduction

General information about air quality state implementation plans (SIP). The Texas SIP, like that of all states, is required by federal law.

Download SIP 101 for an introduction to basic SIP elements and the  NAAQS/SIP update which provides a good overview of the current NAAQS and latest SIP activities across the state. (Help with PDF.)

What is a SIP?

A SIP is an enforceable plan developed at the state level that explains how the state will comply with air quality standards according to the federal Clean Air Act. In order to understand SIPs, you should understand the role of the following:

Federal Clean Air Act

The federal Clean Air Act (FCAA) is the legal foundation for the national air pollution control program. The FCAA requires each state to produce and regularly update a SIP. The FCAA also requires that SIPs include a description of control strategies, or measures to deal with pollution, for areas that fail to achieve national ambient air quality standards (NAAQS). Finally, this Act grants powers of enforcement to the EPA.

United States Environmental Protection Agency (EPA)

The FCAA grants the EPA power to establish national air quality standards, to approve or reject SIPs, to replace SIPs with federal implementation plans (FIPs) when deemed necessary, and to monitor achievement of goals laid out in SIPs and FIPs.

National Ambient Air Quality Standards (NAAQS)

NAAQS are established by the EPA as directed by the FCAA. These standards measure six outdoor air pollutants:

These "criteria pollutants" are commonly occurring air pollutants that can injure health, harm the environment and cause property damage. The NAAQS set nationally acceptable levels of concentrations of these pollutants. Since SIP revisions are mandatory in nonattainment areas, or areas that fail to meet (or attain) the NAAQS, the need for SIP revisions is based on NAAQS.

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What does the Texas SIP contain?

Texas' SIP consists of fourteen sections:

  • Section I: Introduction
  • Section II: Regional Classification
  • Section III: Public Participation/Intergovernmental Coordination
  • Section IV: Preliminary Review
  • Section V: Legal Authority
  • Section VI: Control Strategy*
  • Section VII: Compliance Schedule
  • Section VIII: Texas Air Pollution Emergency Episode Contingency Plan
  • Section IX: Air Quality Surveillance Plan
  • Section X: Review of New Sources and Modifications
  • Section XI: Source Surveillance
  • Section XII: Resources
  • Section XIII: Intergovernmental Cooperation
  • Section XIV: TCEQ Adopted Rules and Regulations

The most frequently revised section of the SIP is Section VI: Control Strategy. This section details the state's effort to meet NAAQS by describing the targets, plans, and control strategies for each area designated nonattainment. The implementation plans of specific control strategies required by the EPA are also addressed in this section.

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What are SIP revisions?

Only one SIP exists for each state. For Texas, this document was initially approved in May 1972. Rather than rewriting the entire SIP regularly, parts of the SIP are simply revised as needed.

Revisions are necessary when new federal or state requirements are enacted, when new data improves modeling techniques, when a specific area's attainment status changes, or when an area fails to reach attainment.

Revisions are typically prepared for a specific area (e.g., "Houston-Galveston-Brazoria SIP" or "Dallas-Fort Worth SIP"); however, sometimes SIP revisions are prepared for a particular control strategy. For example, in October 2001, an "Inspection/Maintenance SIP" was adopted. This revision affected the vehicle inspection/maintenance (I/M) programs of Houston-Galveston-Brazoria, Dallas-Fort Worth, and El Paso.

SIP revisions typically include an assessment of the problem and measures to fix the problem. Assessments of the situation include monitoring data, emissions inventory, and photochemical modeling; measures to "fix" problems are known as control strategies.

SIP revisions typically consist of the following elements: a narrative, rules, and agreements:

  • Narrative: The SIP narrative describes the state's plan, the need for control strategies, and the current proposed strategies.
  • Rules: Rules are the formal declaration of the TCEQ to commit to implementing the adopted control strategy. Once the TCEQ adopts a SIP revision and the associated set of rules, they become state law immediately.
  • Agreements: In some cases, the control strategy applies to a specific plant or business. When this occurs, "agreements" are made with the particular emitter instead of establishing a more general rule.

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How are SIP revisions developed?

SIP revisions must first go through an intense period of research in which data is collected and modeled, control strategies are proposed and tested, and the revision is drafted. This initial phase may take years to complete. The SIP revision is then sent through the TCEQ's formal rulemaking process, which involves publication of the proposal, public meetings, hearings, review of public comments, and finally adoption by TCEQ's commissioners. This process takes about six months. Once a SIP revision is adopted by the commission, it is legally binding and enforceable under state law. After adoption, the revision is submitted to the EPA for review and approval. The SIP revision is federally enforceable after it has been approved by the EPA.

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What is the history of the Texas SIP?

The history posted here provides a broad overview of the SIP revisions that have been submitted to the EPA by the State of Texas. Some sections may be obsolete or superseded by new revisions, but have been retained for the sake of historical completeness. Last updated May 1, 2007. (Help with PDF.)

For a complete list of Texas SIP revisions and other air quality plans, visit the Texas SIP Revisions webpage.

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Why do we need the SIP?

There are numerous reasons why the SIP is necessary and important.

  • The SIP protects our air: The SIP plays a key role in attaining good air quality and protecting citizen's health.
  • The SIP is required by law: The FCAA requires states with counties failing to meet NAAQS to produce a SIP.
  • Failure to produce a SIP has consequences: If a state fails to submit or implement SIP revisions, or if it submits a SIP revision that is unacceptable to the EPA, the EPA has the power to impose sanctions or other penalties on that state. Possible sanctions include cutting off federal highway funds and setting more stringent pollution offsets for certain emitters. Offsets are the reduction of current emissions at a rate equal to or greater than the amount of emissions expected to be produced in a new project.

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How does the SIP affect me?

Texas' SIP affects you in numerous ways.

As an individual

  • Protect your health: The SIP aims to implement air quality standards, which are created to protect human health, including your health. Therefore, SIP revisions aim to improve air quality to a degree that is beneficial for the health and well-being of you and your family.
  • Regulations: Rules set requirements that may affect your everyday life. In some cases, rules may place restrictions on you by creating requirements that may affect the operation, design and emissions level of your property (i.e. your motor vehicle). In other cases rules may offer you incentives to choose technologies that further the SIP's goal.

As a business

  • Regulations: Rules set requirements that may apply to your industry. Regulations may place restrictions on activities and equipment used in your business that affect quality levels. Other regulations may provide incentives that your firm may be able to take advantage of.

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