To control landfill gas, the department's Air/Gas Section designs, permits, operates, and maintains landfill gas collection and flare stations, and performs air quality monitoring.
At the large active landfills, the gas collection system is continuously expanded to keep up with the fill operations by adding both horizontal and vertical gas collection wells and piping to convey the gas to the control system.
Horizontal collection wells can be constructed using Tire Derived Aggregate (TDA) in lieu of two and three in rock aggregate material. The Department of Resources Recycling and Recovery (CalRecycle) has helped fund these horizontal gas collection well projects by awarding Riverside County the following TDA grants:
- TDA2-12-0022: $150,748 (130,070 California tires diverted)
- TDA5-15-0003: $133,584 (110,122 California tires diverted)
- TDA9-17-0006: $157,205 (126,205 California tires diverted)
- TDA15-19-0007: $148,908
CalRecycle encourages the use of TDA rather than conventional aggregate in various civil engineering applications by offering these grants. Besides the environmental benefits of diverting used tires from landfills and reducing the need to mine gravel, TDA is cost-effective, drains well, and is lighter than conventional processed gravel making it easier to transport and handle.