The Texas construction industry will face new environmental air quality control in 2005. The use of dieselpowered construction equipment >50 hp will be restricted during the morning hours throughout the ozone season in both the Dallas/Fort Worth (DFW) and Houston/Galveston (HG) nonattainment areas. Work with these equipment may begin after 10:00 a.m. in DFW and after noon in HG. Texas is currently the only state with such controls in its State Implementation Plan. The Texas Natural Resource Conservation Commission’s (TNRCC’s) inputs for the U.S. Environmental Protection Agency’s (EPA’s) NONROAD model used construction equipment inventory and equipment activity data to improve and reduce NONROAD’s emission estimates by two-thirds from its default inputs. The equipment inventory from HG was then scaled and applied to DFW.
As a result of this rule, TxDOT operations will be significantly affected in terms of additional project costs and delayed project schedules. Interviews with TxDOT staff and private contractors in the affected nonattainment areas were used to estimate the budgetary and schedule impacts from the rule. The budgetary impact from both nonattainment areas is estimated to be $116 million annually, or an estimated $350,000 per ton NOx reduced. Project schedules are estimated to increase 5 to 28 percent. Alternative emission control technologies are available that can reduce NOx and particulate matter. These technologies are typically aftermarket products used to retrofit equipment. The diesel engine emission control technology is generally less than the cost of the construction equipment restriction rule and provides greater NOx emission benefits. Some states have government incentive programs to encourage repower, retrofit, or purchase of cleaner equipment by paying the incremental cost for equipment exceeding a baseline NOx reduction. This report synthesizes the work performed for this project and documented in other research and letter reports. The purpose of the project was to review TNRCC-modeled results, assess the impacts to TxDOT of the construction equipment restriction rule, assess the cost-effectiveness of alternative control measure technology, and assess mobile source emission changes due to work zone lane closures.