EPA proposes waiving Federal requirements for stations to capture gasoline vapors when vehicles refuel beginning in 2013
11 July 2011
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| Diagram of Stage II VRS and ORVR. Source: EPA. Click to enlarge. |
The US Environmental Protection Agency (EPA) is issuing a proposed rule under the Clean Air Act (CAA) that would waive requirements beginning in 2013 for systems used at gas station pumps to capture potentially harmful gasoline vapors while refueling cars. The result of the proposal would potentially save affected gas stations more than $3,000 annually, according to EPA.
The Clean Air Act allows EPA to waive certain requirements of the Stage II vapor recovery program—a vapor recovery system (VRS) that prevents the discharge to the atmosphere of volatile organic compounds (VOCs) displaced during the dispensing of gasoline into a motor vehicle fuel tank at service stations—when the EPA Administrator determines that onboard refueling vapor recovery (ORVR) systems are in widespread use in the vehicle fleet.
Stage I VRS apply to the gasoline distribution industry; Stage II to service stations. Stage I VRS at gasoline dispensing facilities (GDFs) route gasoline vapors into the tanker truck without releasing them into the atmosphere. Stage II systems consist of special nozzles and coaxial hoses at each gasoline pump that capture vapors from the vehicle’s fuel tank and route them to the station’s underground or aboveground storage tank(s) during the refueling process.
The CAA requires states to implement Stage II gasoline vapor recovery systems in areas classified “Serious,” “Severe,” or “Extreme” for nonattainment of the ozone national ambient air quality standard (NAAQS).
There are generally two types of Stage II VRS: balance systems that passively draw vapors back into the storage tank and vacuum assist systems that use a vacuum pump to draw vapors back into the tank. Most VRS are vacuum assist, according to EPA.
This action proposes to establish 30 June 2013 as the date by which the Administrator determines that ORVR is in widespread use. An estimated 72% of vehicles on the road are expected to have ORVR by that date. ORVR systems are carbon canisters installed in vehicles to capture gasoline vapors evacuated from the gasoline tank before they reach the pump nozzle.
Gasoline-rich vapors in an empty automobile fuel tank are forced out when liquid gasoline is pumped into the tank. Stage II vapor recovery systems capture these vapors at the gasoline pump nozzle and carry them back into the underground storage tank at the service station. Since 1994, gas stations in certain areas have been required to use these gasoline vapor recovery systems.
However, as required by the Clean Air Act, automobile manufacturers began installing onboard refueling vapor recovery (ORVR) technologies in 1998, making gas stations’ systems redundant. Since 2006, all new automobiles and light trucks (pickups, vans, and SUVs) are equipped with ORVR.
Vapor emissions from refueling, if allowed to escape, can contribute significantly to ground-level ozone, sometimes called smog, as well as to other types of harmful air pollution. Ground-level ozone can cause acute respiratory problems, aggravated asthma, temporary decreases in lung capacity in healthy adults and inflammation of lung tissue. Children and the elderly are most at risk. Gasoline vapors also contain toxic air pollutants associated with a variety of health threats.
EPA will accept comment on the proposal for 60 days after publication in the Federal Register.
Resources
Stage II Vapor Recovery Systems Issues Paper (EPA, 2004)
Stage II Vapor Recovery Systems (VRS) and Underground Storage Tanks (Tom Driscoll, EPA)
(ORVR) technologies in 1998
This seems to assume that there are very few cars made before 1998 still on the road. I do not think that is the case and it makes NO sense to backslide on this.
Posted by: SJC | 11 July 2011 at 01:12 PM
Right. (stage II) VRS are the very thing that dramatically cleaned up the air in LA basin. Even though gas pumps will begin to be retired this year - the toxicity of gasoline has not diminished.
Keep these regs. Get rid of CO2 regs. Doh!
Posted by: Reel$$ | 11 July 2011 at 06:37 PM
It makes sense to assume they have data on which to base this decision with regard to cars made before 1998.
Are the underground tanks cooler or cooled? They must be, else why would vapors be generated in the auto's tank but absorbed in the station's tank.
Likewise for the vapors in the underground tank being pumped into the truck, only to push the vapors in the truck outside.
I hardly think they compress the vapors back into the tank or truck.
I am not too surprised that the post 1998 on-board system actually keeps the tank purged of vapors (and stores them in the charcoal) so that as the new fuel goes in only air comes out, however the fuel going in, and air coming out, partly share the same passage, so some (a lot?) vapors will come out anyway.
And this single tankful of vapor amounts to what? 1 teaspoon of liquid? 2?
Rather than assuming the EPA would ever surrender mandating a system due to cost, I wonder; did it ever work?
Posted by: ToppaTom | 11 July 2011 at 11:16 PM
VRS used in California puts a seal over your fill spout and negative pressure in the fill line prevents vapor escape during fueling.
Surprising this is not implemented in green-conscious States. It's very effective.
Posted by: Reel$$ | 12 July 2011 at 07:59 AM
I thought that was what all VRS do.
But they say they can eliminate the VRS because the ORVR eliminates vapor escape during fuelling . ?
Posted by: ToppaTom | 12 July 2011 at 09:16 PM
There's some data that indicates that the ORVR plus Stage II recovery at the stations don't work well together and that you're better off only having ONE recovery system. So it was fairly easy for EPA to sign off on the idea that Stage II can be phased out, the only question is when the right time to make the transition.
Vapor recovery is very effective as a control measure for ground-level ozone, but only in areas where VOC emissions are the dominant factor controlling ozone levels. The major issue with the Clean Air Act now is that it was written under the assumption that all areas worked that way, and that's since been disproved for significant portions of the country (where NOx is the limiting reactant, and VOC is in excess thanks to biogenic sources alone). That's the #1 target that the state/local air quality regulators would like updated in the Clean Air Act- right now in some areas they are being forced to implement ozone control measures by statutory triggers in the Act that do not serve the intended purpose in their particular jurisdiction. They need more NOx controls, rather than to spend money on VOC controls that aren't achieving anything.
Vapor recovery is used in more places than you might realize because it's mostly just California that uses the big rubber bellows over the spout. In other areas the system can be present without much sign to the driver that it's there (the vacuum system doesn't necessary require the bellows).
Posted by: Wes | 13 July 2011 at 05:03 AM
Of course this becomes less of an issue with the expansion of alcohol blending and EVs. The day when we can return the corner gas station to a corner grocery store is highly anticipated.
As is the return of dammed rivers to their original wild states. And dismantle the high voltage transmission lines that cut unsightly swaths through wilderness. And tear down coal fired power plants. And mothball the radiative nukes.
Satchmo sang: "What a Wonderful World" - and it will be.
Posted by: Reel$$ | 13 July 2011 at 11:42 AM
Vapors are generated during fuelling because pumps add bubbles to the fuel for the sake of the automatic shutoff systems.
Posted by: Engineer-Poet | 15 July 2011 at 08:15 PM