The South Coast Air Quality Management District (SCAQMD) recently held a public workshop announcing their proposed new Rule 1472—Requirements for Facilities with Multiple Stationary Emergency Standby Diesel-Fueled Internal Combustion Engines. Rule 1472 is a new rule which seeks to regulate diesel particulate emissions at facilities with multiple emergency diesel engines. Diesel particulate emissions were declared as toxic by the state back in 1998. The district estimates that there are approximately 550 facilities that will be impacted by the proposal.
The SCAQMD proposal will add the contaminant to the list of toxic air contaminants subject to regulation under Rules 1401 and 1402. Rule 1401 applies to new, modified, or relocated permit units. It establishes risk-based thresholds for cancer and non-cancer toxic air contaminants (TACs). As a result, emissions from Rule 1472 engines would be evaluated for compliance with Rule 1401. Rule 1402 applies to facility-wide TAC emissions and sets risk-based thresholds for cancer and non-cancer impacts for purposes of notification and risk reductions. It implements the AB2588 Air Toxics Hot Spots program. Compliance with proposed Rule 1472 will typically satisfy Rule 1402 risk reduction requirements. Facilities that exceed the “significance” level of 100 in one million must comply with Rule 1402. Likewise, facilities with non-emergency diesel engines are subject to Rule 1402 requirements.
Proposed Rule 1472 would apply to engine groups of three or more engines (rated at 50 bhp or greater) within 150 meters of one another and having an Engine Group Index greater than 1.0 (one). Facilities with three or more engines within 150 meters of one another must file compliance plans. Compliance plans are to include engine information, locations, identification of engine groups and the Engine Group Index for each engine group. The Engine Group Index is defined as the sum of indices for each engine in the group at the facility for the nearest residential/sensitive receptor.
Engine Group Index = Si (EFi x Operating Hoursi x Distance Factori)
EF = PM emission factor for the engine (grams/bhp-hour)
Operating Hours = Rule 1470 allowable or maximum permitted annual operating hours for testing and maintenance (hours), whichever is less
Distance Factor = Factor from Table 1 of the rule corresponding to the engine rating (bhp) and distance to the nearest receptor. Distance to the nearest receptor is measured from the exhaust stack of the engine to the nearest receptor location. When the engine rating is not listed on the tables, the closest engine size shall be used.
Facilities are to notify SCAQMD whenever engines are added or removed.
Facilities where an Engine Group Index exceeds 1.0 will need to:
- Reduce the Engine Group Index to less than or equal to 1.0; or
- Emit diesel PM at a rate less than or equal to 0.15 g/bhp-hr for each engine; or
- Emit diesel PM at a weighted average rate of less than or equal to 0.15 g/bhp-hr for all applicable engines within an engine group calculated by the following formula:
|Weighted Average =
||Si (Ratingi x Operating Hoursi x Emission Ratei)
|Si (Ratingi x Operating Hoursi)
Weighted Average = The weighted average for diesel PM emission rates
Rating = Engine rating (bhp)
Operating Hours = Maximum permitted annual operating hours for testing and maintenance (hours)
Emission Rate = Diesel PM emission rate (g/bhp-hr)
Facilities are allowed the flexibility to choose one of the compliance options and determine how to meet the emission requirements. Table 1 shows the compliance schedule facilities are subject to under Rule 1472.
Table 1 - Rule 1472 timelines
The following are exempt from the requirements of Rule 1472:
- Facilities which comply with all applicable requirements of Rule 1402.
- Facilities which can demonstrate that each emergency standby diesel-fueled engine at the facility is greater than 150 meters from the nearest receptor.
- Direct-drive emergency standby fire pump engines fueled by diesel. A direct-drive emergency standby fire pump engine is an engine directly coupled to a pump exclusively used in a water-based fire protection system.
- Subdivision (f) of the rule will not apply to facilities with an exemption approved by the Executive Officer.
Facilities which are unable to meet the emission levels required by the rule due to some extreme circumstance must include, as part of their compliance plan, a request for exemption and details of why they will not be able to comply. The rule is scheduled for final adoption in February 2008.