Texas Houston/Galveston Area Ozone 15% Rate-of-Progress (ROP) Plan Summary

Purpose of Plan: To reduce emissions of Volatile Organic Compounds (VOCs) by 15% before November 15, 1996.

Area Covered: Houston/Galveston area (Brazoria, Chambers, Fort Bend, Galveston, Harris, Liberty, Montgomery, and Waller counties).

Type of Pollutant: Ozone (caused by reactions between VOCs and nitrogen oxides (NOx)).

Background:
In 1990, the Houston/Galveston area in Texas (Houston) had a one-hour ozone design value of .22 ppm.  As a result, it was designated a severe nonattainment area for violation of the ozone National Ambient Air Quality Standards (NAAQS).  The Clean Air Act requires states with areas designated moderate and above (including severe) for ozone nonattainment to submit, for EPA approval, revisions to their State Implementation Plans (SIPs).  These revisions must show how the state will reduce ozone-causing emissions by 15% within six years of enactment of the 1990 Clean Air Act Amendments, and are referred to as 15% Rate Of Progress plans, or 15% ROP plans.

Texas submitted 15% ROP plans for Houston in two phases.  Phase I was submitted on November 13, 1993, and phase II was submitted May 9, 1994.  On May 22, 1997, the EPA finalized limited approval and limited disapproval of the 15% ROP.  Limited approval was given because the measures included would strengthen the SIP.  Limited disapproval was given because Texas predicted greater emission reductions than the EPA believed could actually occur.

On August 9, 1996, Texas submitted revisions to the 1990 base year emissions inventory and predictions of emission reductions.  The new emission numbers better reflected local conditions instead of relying on national or statewide statistics.  On November 10, 1998, the EPA finalized conditional interim approval of the 15% ROP plan with revised emissions data.  The approval was conditional because Texas did not yet have complete legal authority to implement its motor vehicle inspection and maintenance program, projected to be a significant source of emission reductions.  The approval was also interim because emission reductions credited to the inspection and maintenance program were to be evaluated and readjusted after an 18-month period.  The conditional interim approval of the 15% ROP plan was converted to final approval on November 14, 2001.

Texas was found temporarily exempt from the NOx control requirement (VOCs and NOx can react together to form ozone) on April 19, 1995 because Texas demonstrated that reducing NOx emissions would not help Houston achieve attainment.  This exemption was later extended from December 31, 1996 to December 31, 1997.  Consequently, the 15% ROP plan deals only with VOC emissions reduction.

Pollution Data:
The 1996 revisions to the 1990 base year emissions inventory decreased calculated emission levels, resulting in a lower 1996 target and a lower level of required emission reductions.  The revisions calculated 1990 emissions levels at 1063.72 tons per day.  This emissions inventory is adjusted to not include emissions from biogenic sources and those outside of the Houston area.  The inventory is further adjusted to not include emissions that are expected to be eliminated by federal regulations, such as the Federal Motor Vehicle Control Program, that were adopted before 1990.  The adjusted 1990 base year inventory was found to be 975.39 tons per day resulting in a 1996 emissions target level of 812.77 tons per day.

Pollution Control Measures:
In the tables below, the “Regulation” column displays the name or number of the regulation.  “FR citation” is the reference number for the Federal Register Notice announcing the EPA’s approval of those SIP revisions.  The Federal Register is an official government publication for rules and proposed rules of federal agencies.  It gives more detailed descriptions and explanations of the Houston SIP than are found here.  The first number represents the volume number - 59 represents the 1994 volume, 60 1995, and so on.  “FR” stands for federal register.  The number after “FR” is the page number.  Federal Register notices can found at https://www.govinfo.gov/app/collection/FR

RACT Catch-up: The Clean Air Act requires that all nonattainment areas adopt regulations requiring facilities to use Reasonably Available Control Technology (RACT) to control emissions.  Houston area counties Chambers, Fort Bend, Liberty, Montgomery, and Waller were newly designated as nonattainment for ozone under the 1990 Clean Air Act Amendments.  New nonattainment areas had to adopt regulations to “catch-up” to the RACT requirement.  The Texas RACT Catch-up was approved by the EPA on March 7, 1995 and is expected to contribute significant VOC reductions to the Houston nonattainment area.  The regulations revised as part of the Texas RACT Catch-up are listed in the table below.

RACT Catch-up

State Regulations:  The table below lists other state regulations expected to result in emissions reductions that will count toward the necessary 15%.

State Regulations

RE Improvements: Texas also expected a decrease in emissions due to improved Rule Effectiveness  (RE).  RE is the percentage of facilities actually in compliance with a given regulation.  Texas plans to increase the number of enforcement staff, resulting in an increase in facilities obeying the emission control regulations and greater reductions in VOC emissions.

Federal Regulations:  Texas also relied on some federal regulations to achieve the 15% decrease in VOC emissions.  These are listed in the table below.

Federal Regulations

Contingency Measures:
States with moderate and above ozone nonattainment areas are required to submit contingency plans along with their 15% ROP plans.  Houston’s was to be triggered if it failed to meet the 15% ROP.  Contingency measures, if implemented, are to further reduce VOC emissions by 3%.  The contingency measures included in the Houston 15% ROP are listed below.
 

The contingency section of the 15% ROP plan also relies on emission reductions from the Federal Non-road Small Engine Standards requiring reductions in emissions from small engines such as lawn and logging equipment.  Houston contingency measures also include excess emission reductions from the 15% percent measures to make the required 3% reduction.

Subsequent Action and Events:
Post-1996 Rate of Progress Plan: (see Houston Ozone Post-1996 Rate of Progress Plans Summary)
After 1996, ozone nonattainment areas are required to reduce ozone-causing emissions by 3% each year, averaged over 3 years.  The plan detailing how the state will achieve these emission reductions between 1996 and 1999 is referred to as the Post-1996 Rate of Progress (ROP) plan.  Houston’s Post-1996 ROP plan was given final approval by the EPA on April 25, 2001.

Post-1999 Rate of Progress Plans: (see Houston Ozone Post-1999 Rate of Progress Plans Summary)
The Post-1999 ROP plans reduce emissions in Houston by an additional 9% between 1999-2001, 9% between 2002-2005, and 6% between 2006-2007.  The EPA issued final approval of the Post-1999 ROP plans on November 14, 2001.

Attainment Demonstration:  (see Houston Ozone Attainment Demonstration Summary)
Texas submitted an attainment demonstration for the Houston ozone SIP, including modeling analysis projecting ozone levels in 2007 (Houston’s deadline for achieving NAAQS) and several enforceable commitments.  The EPA approved this attainment demonstration through parallel processing on November 14, 2001.

Texas had planned to fund TERP with taxes on out-of-state vehicle registrations, this tax was found to be unconstitutional in February of 2002, leaving Texas without the funds it needed to achieve the projected emission reductions.  In August of 2002, the EPA proposed to find that Texas was not complying with the terms of the attainment demonstration.  However, funding for TERP was restored by Texas House Bill 1365, signed by the state Governor June 22, 2003.


Federal Register Actions:

EPA Region 6 Contacts:
     Bill Deese or Joanne Sum-Ping at 214-665-7253 or deese.william@epa.gov

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This SIP Citation Was Last Modified on: 08/15/2003