It is not necessary to remove the tanks, in fact, the tanks in the vehicle stay in the vehicle. To refuel the vehicle, the operator simply raises the hood and connects a high-pressure hose to a "quick disconnect" fitting. Natural gas storage tanks and a compressor, located at the facility, enable GSA to repressure the entire fleet each evening. Vehicles which operate on a 24-hour basis can be "quick loaded" in a matter of minutes. The entire fleet can be mass-loaded in 3 hours.

The West Coast Field Testing Laboratory is conducting the pollution-testing portion of the General Services Administration dualfuel project. The laboratory is a part of the Public Health Service under the Department of Health, Education, and Welfare.

Before the GSA vehicles were put on the road, all 24 were tested by the testing laboratory, including the 12 control vehicles and those actual equipped with the dual-fuel system.

An electronic instrument called the infrared spectrophotometer was used to measure the degree of hydrocarbon and carbon monoxide emission from the exhaust of each vehicle. Twelve of the vehicles will be retested approximately every 4,000 miles. And that retest will now occur around March 1.

This I think, Mr. Chairman, is a rather dramatic demonstration of what this system achieves in the area of pollution reduction.

The three filters pictured in this slide are a graphic example of the clean-burning properties of natural gas.

They are the results of actual exhaust emission tests of GSA vehicles conducted by the West Coast Field Testing Laboratory for the Natural Air Pollution Control Administration. The tests conducted in that laboratory were shown in the previous slide. The upper left disc shows the deposit on a filter which came from the exhaust of a 1960 111⁄2 ton truck. Its gasoline-powered 264-cubic-inch engine did not contain smog control equipment.

This antedated the pollution control devices required now by Federal law. The upper right shows the deposits on a filter which came from the exhaust of a 1969 1/2-ton pickup truck. Its gasoline-powered 250-cubic-inch engine was equipped with smog control devices.

The bottom filter shows the clean-burning properties of natural gas. The exhaust of a 1969 1-ton pickup truck, running on natural gas, produced only a slight discoloration. These filters are part of the sevencycle HEW test which is routinely run at this laboratory. Each of these filters were subjected to the identical seven-cycle test and show the identical passage of exhaust fumes over the filter in the test.

Our test program at the West Los Angeles Veterans' Administration Hospital calls for an analysis by the HEW laboratory of the exhaust emissions of our test vehicles, both gasoline and natural gas, on March 1 or after 4,000 miles, on each vehicle. This information will then be compared, both as to reduction and amount of air pollution emitted at the beginning of the test, and the relative pollutants produced by the test and control vehicles. For this reason, we, at this time, do not have available for the committee precise test information to indicate the reduction in air pollution which results from use of natural gas fuel in GSA vehicles.

The slide which you are now viewing shows the reduction achieved by this system on test vehicles operated by the Pacific Lighting Co.

That company has, by the way, operated approximately 35 vehicles for more than a year using this system. All indications at this time are that the GSA test vehicles will meet or exceed the results achieved by Pacific Lighting.

Although I apologize for the state of this slide, I think you can see the dramatic reductions that are achieved in the three principal pollutants carbon monoxide, oxides of nitrogen, and hydrocarbonsby this fuel.

We do have some preliminary information concerning economy in miles per gallon of fuel. As this slide shows, the natural-gas-powered vehicles depicted by the solid bars achieved better fuel mileage than their counterpart control vehicles. Natural-gas-powered vehicles averaged 10.5 miles per gallon. The gasoline-fueled vehicles averaged 7.1 miles per gallon. These mileages are low. That is, there is a high fuel consumption. This is another indication of the value of this test at the VA hospital because these vehicles are heavy stop-and-go and slowspeed vehicles. They operate within the confines of a hospital area at low speeds, and there is a great deal of engine-idling time on the engines. This accounts for the low mileage both with gasoline and natural gas. Specific data on maintenance, labor, and material costs are not available since the project has only been in operation a short while. Our dual-fuel drivers have noted significant benefits in quick engine starts, smooth low-speed operation, and reduced odors and noxious fumes. Refueling is easy, clean, and efficient.