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  • OCTA Environmental Programs from A to Z

  • Clean Fuel

    All of OCTA’s buses run on clean natural gas (CNG, LNG, and hydrogen). As required by the California Air Resource Board, all future bus purchases will be powered by CNG fuel with low NOx engines, hydrogen, or other zero-emission fueled technology.


    The OC Bus contingency fleet (20 buses) is operated by diesel. The remaining diesel buses have been retrofitted with Level 3 Diesel Particulate filters that reduce diesel soot by more than 85 percent. The contingency fleet is only deployed for long- term emergencies when OCTA cannot fuel CNG or LNG. All diesel buses in the fleet use ultra-low sulfur diesel that has been shown to improve air quality. Opacity tests are performed annually for all diesel contingency buses.

    Engine Replacement / Repower

    OCTA is replacing older CNG engines with 2016 compliant Cummin ISL-G engines that will reduce NOX and particulate emissions by 99 percent. OCTA’s coach operators use CNG-powered Honda Civic vehicles when conducting coach operator relief.

    Fleet Emissions

    OCTA has exceeded all CARB and SCAMQD emission requirements for an urban bus fleet as well as for transit fleet vehicles. Compared to 2002 baseline emissions, OCTA reduced its particulate matter emissions by 97 percent and NOX emissions by 99 percent.

    Freon Recovery

    OCTA recycles refrigerants using a reclaim machine. More than 97 percent of OC Buses use R-407C in their air conditioning systems. The EPA regards R-407C as one of the best refrigerants to minimize environmental impact.

    HVAC Energy Efficiency Study

    In 2013, OCTA completed a facility study for energy conservation at all bus maintenance bases resulting in an equipment payback analysis for the HVAC and air compressor systems. OCTA is actively pursuing cost and energy efficient replacements and upgrades to its aging systems.

    LED Upgrades

    OCTA has been upgrading facilities with LED lighting since 2012, including: 12 lights at the Brea Park and Ride in 2012, 19 lights at the bus operations employee parking lot and 64 parking lot lights at the Fullerton Park and Ride in 2013, 62 parking lot lights at the Irvine Construction Circle Base in 2015, 390 lights at the Fullerton Park and Ride, Laguna Hills Transportation Center, and Newport Beach Transportation Center in 2016, and 295 lights at the Goldenwest Transportation Center, Garden Grove, Irvine Construction Circle, and Santa Ana bases in 2017.

    Parts Cleaning System

    OCTA has replaced the solvent parts cleaning system with aqueous cleaning units that have water-based solutions. These solutions are nonflammable and contain little or no volatile organic compounds. As a result, OCTA has eliminated significant hazardous waste generated from its parts cleaning systems.

    Open Space

    As of January 2014, OCTA has acquired approximately 1,300 acres of open space property that will be permanently designated as wilderness preserves as part of the OC Go Freeway Environmental Mitigation Program.
    See more about Open Space here


    OCTA has an active recycling program that diverts paper, metals, cardboard, plastic and aluminum cans from landfills.

    Spill Kits

    All maintenance road call service trucks are equipped with spill kits. Spill kit supplies are stocked at all of the OCTA maintenance bus bases. These kits allow employees to immediately clean up accidental spills of antifreeze or oil from buses.

    Stormwater Management

    Stormwater is water from rain or snowfall that flows across the land and ultimately into rivers, creeks, lakes, and ditches. Other sources of water include over-irrigation, automobile wash water, or any other activity that results in water flowing into the storm drainage system. This water runoff carries debris, trash, sediment, pollutants, etc. from sidewalks, streets, and parking lots through storm drains and eventually into the rivers, creeks, and lakes. Fertilizers, paint, antifreeze, oil, fuel, and other materials may also be carried from urbanized areas to the waterways. These pollutants can add to or create problems in bodies of water.

    Stormwater goes directly from the storm drainage system into local lakes, rivers, and streams with no water quality treatment.

    The Santa Ana Regional Water Quality and Control Board regulates stormwater runoff for OCTA’s facilities and activities. To comply with stormwater permits, OCTA implements robust Stormwater Pollution Prevention Plans (SWPPP). The SWPPP describes actions OCTA should take to ensure stormwater leaving our facilities have no pollutants.


    To save water, OCTA switched to low-maintenance, low-water usage xeriscape landscaping at several facilities. The switch helped OCTA facilities like the Fullerton Park and Ride, Santa Ana base, and Garden Grove maintenance and operation bases cut irrigation water consumption in half.

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