Emissions to Air

All U.S. environmental engineers are required to be CHMM (Certified Hazardous Materials Managers) certified and have had specialized training to manage air emissions.  These experts have a thorough knowledge of the applicable regulations and have designed programs that review current emissions levels and establish goals for reducing them.  GM is committed to reducing ambient air emissions from the manufacturing process.  This section highlights how this occurs and gives some examples of the innovative engineering practices that have been ‘designed into' GM facilities.

Painting operations are the main source of Volatile Organic Componds (VOC) and Hazardous Air Pollutant (HAP) emissions from automotive assembly plants.  The main source of other air pollutant emissions from facility operations, such as nitrogen oxides (NOx), sulfur oxides (SOx) and carbon monoxide (CO), is from burning fuel to supply heat and power.

In the U.S., GM established an Air Steering Committee that shares lessons learned across the Corporation with an emphasis on reducing facility air emissions.  The committee examines past, present, and future air management programs and aligns them with evolving regulatory demands.  The Committee discusses the Best of the Best (BOB) programs and initiatives, and encourages its members to apply these BOB practices at their own facilities.  For example, the Committee focused on the best practices to reduce Hazardous Air Pollutant chemicals.

During the past decade, GM has decreased emissions from heating and power operations by reducing the use of coal and oil-burning systems in favor of cleaner-burning natural gas, and reducing fuel use by improving the energy efficiency of GM facilities.  Older coal-burning systems have been replaced with smaller, higher-efficiency systems.

Environmental engineers in the Powertrain Components and Casting operations use the Casting Emission Reduction Program (CERP) to drive the use of new core resin systems and mold-making operations to reduce emissions to air and water.  The Foundry Environmental Issues Team has developed business plans with key objectives to reduce emissions from melting, pouring, cooling, and shakeout operations at our casting plants.

Ozone Depleting Gases

GM has taken major steps towards eliminating ozone-depleting substances from our products, processes, and operations.  None of our products contain ozone-depleting substances (ODS).  We continue to maintain some stationary equipment, such as process cooling or air conditioning systems, that contain ODS.  The refrigerant-containing systems will be replaced as required and the ODS refrigerants will be recovered and recycled.

Hazardous Air Pollutant (HAP) Emissions

The EPA identifies 189 Hazardous Air Pollutants (HAP) to be regulated.  During 2000, an extensive effort was initiated with the paint suppliers to minimize the amount of HAPs contained in coating materials.  As of November 2006, nearly all of the paint shop coatings used in the U.S. had been reformulated to reduce HAP emissions to below the standards set by the Maximum Available Control Technology (MACT) requirements.

Criteria Air Pollutant Emissions

The major source of criteria air pollutant emissions (other than VOCs) is from burning fuel to supply heat and power to our facilities.  GM has cut emissions from these sources by reducing the use of coal-burning systems, increasing the use of cleaner-burning natural gas, and improving the energy efficiency of facilities.  GM continues to participate in the EPA's Landfill Methane Outreach Program and has converted facility boilers at several different GM operations to burn landfill gas.  Doing so reduces criteria pollutant emissions.  For more on the Landfill Methane Outreach Program, see the Energy section of this report.

The following graph shows criteria air pollutants emitted from our North American facilities since 2003.  The data is derived from fuel usage and calculated using generalized emission factors from EPA Document A.P.-42.  Combined total emissions of TSP, NOx, CO, and SOx are down eight percent over the previous year (2004) and 17 percent since 2003.  On a GMNA production-adjusted basis, these emissions dropped four percent between 2003 and 2005.

• See unit conversion factors at ts.nist.gov, a non-GM site, please check privacy policy.

Emissions to Water

GM strives to use water as efficiently as possible.  Plant wastewater is treated before being discharged to either municipal wastewater treatment plants or other receiving bodies of water, all while meeting applicable permit requirements.  In locations where there are no clear wastewater discharge criteria, GM applies its own requirements and guidelines as defined by the Environmental Performance Criteria (EPCs), which apply globally.

GM facilities operate in accordance with local, regional, and national air and wastewater regulatory requirements.  All manufacturing facilities are required to be certified to the ISO14001 environmental management system.

Wastewater quality tests measure levels of various parameters such as Biological Oxygen Demand (BOD5), Total Suspended Solids (TSS), Chemical Oxygen Demand (COD), nitrogen, phosphorus, oil, grease, and heavy metals.  Global data is not available for these indicators due to the differing data collection systems and variations in analytical processes. The challenge with wastewater is to ensure that on-site wastewater treatment facilities remain efficient and up to date to comply with local discharge regulations in a cost-effective way.

GMNA's Wastewater Facility Containment program maintains safety, reliability, and compliance with relevant regulations and GM Environmental Performance Criteria.