188.8.131.52. Hazardous Air Pollutants Early Reduction
In December 1992, EPA issued final rules for the early reduction of hazardous air pollutants. If a facility qualifies by reducing hazardous air pollutants by 90 percent (95 percent in the case of hazardous particulate emissions) prior to EPA proposing MACT regulations on the source category, the facility may defer compliance with the new maximum available control technology standards (MACT) for up to six years. Because participation in the program is voluntary, a source must anticipate cost savings or it would not have an incentive to participate. Once a source is accepted into the program it becomes legally obligated to meet the 90 (or 95) percent emission limitation. Trading exists intertemporally in that sources exchange their early reductions for their later reductions. Two NESHAP rules are discussed here.
Petroleum Industry NESHAP
The petroleum industry NESHAP rule, promulgated on August 18, 1995, establishes MACT requirements for process vents, storage vessels, wastewater streams and equipment leaks tanks at refineries. The rule specifically includes marine tank vessel loading activities and gasoline loading racks. The rule excludes distillation units at pipeline pumping stations and certain process vents that EPA determined to be subject to future NESHAP rules: catalyst regeneration on cracking units, vents on sulfur recovery units, and vents on catalytic reforming units. The rule achieves VOC reductions at a modest cost of less than $600 per ton; however, without the VOC credits the rule would fail a stand-alone benefit-cost test on the air toxics component.
On September 19, 1995 EPA issued a final NESHAP rule for marine vessel tank loading operations that affects new and existing marine bulk loading and unloading facilities that emit 10 tons or more of a hazardous air pollutant (HAP) or 25 tons of any aggregate HAPs. Affected facilities must install a vapor collection system to collect VOC displaced from marine tank vessels during loading. The vapor recovery system must achieve a 95 percent reduction in emissions (98 percent if combustion is used).
Both rules permit the use of emissions averaging among marine tank vessel loading operations, bulk gasoline terminal or pipeline breakout station storage vessels and bulk gasoline loading racks, and petroleum refineries. Emissions averaging gives the owner the opportunity to find the most cost-effective control strategies for its situation. The owner may over-control at some emission points and under-control at others to achieve the overall required level of emissions control.
Hazardous Organic Chemical NESHAP
The Hazardous Organic Chemical NESHAP (or "HON") affects more than 400 facilities of the Synthetic Organic Chemical Manufacturing Industry (SOCII). The final rule requires sources to limit emissions of organic HAPs to apply "reference control" or equivalent technology at MACT. In recognition of the high costs of some MACT controls in this industry, the rule allows emissions averaging. Under this alternative method of compliance, sources engaging in pollution prevention measures that over-control at some points earn credits that can be used to offset debits for under-control at other points.
By mid-1993 over 60 chemical plants had asked to participate so as to avoid for 6 years the synthetic organic chemical MACT standard. Other types of facilities also had applied to join the program. (Novello and Martineau)