Landfills play a vital role in California's total integrated waste management system. We will need landfills for the foreseeable future for those wastes which cannot be reduced, reused, or recycled. And California leads the nation in its standards for state-of-the-art, environmentally safe landfills.
- Ensuring Environmentally Safe Landfills
- Protection and Quality
- Daily Operations
- When a Landfill is Closed
- Enforcement Team
California's landmark Integrated Waste Management Act of 1989 (AB 939) set an ambitious goal for our cities and counties: Divert 50 percent of all solid waste from landfills by January 1, 2000, through source reduction, recycling and composting. CalRecycle supports this goal through many activities, such as providing technical information to both public and private sectors on waste prevention practices, stimulating markets for recyclable materials, developing new waste prevention technologies, and providing low-interest loans to new recycling industries.
By 1995, our citizens, businesses, and local governments together had achieved a 25 percent statewide diversion rate, and prospects are good for meeting the year-2000 goal. But even when this goal is reached, we will still have more than 22 million tons of waste per year to dispose in our state's landfills.
AB 939 established another important goal for all California counties: provide at least 15 years of ongoing landfill capacity. At a rate of 22 million tons per year, this means that in the year 2000 we will have to identify landfill capacity, statewide, for 330 million tons of solid waste. This much garbage would fill a canyon 15 miles long, a quarter of a mile wide, and as deep as a 20-story building. And, of course, there is the next 15 years, and the next, and so on. It is clear, then, that California will need landfills for the foreseeable future.
Today, 21 of the state's 58 counties, having 41 percent of the population, will exhaust their disposal capacity within 15 years. Of these, 17 have 8 years or less capacity. It takes 7 to 10 years to plan, design, and permit a new landfill. Recognizing this problem, CalRecycle has worked with other concerned agencies to expedite siting and streamline the permit process, while still protecting the environment.
CalRecycle has also initiated regulations, studies, and demonstration projects designed to encourage a more efficient use of our landfills through landfill mining, space-saving cover materials, and baling or shredding of wastes.
Ensuring Environmentally Safe Landfills
Adequate landfill capacity alone, without first-rate environmental protection, is not enough. California will never again tolerate the garbage dumps of the past. We must have state-of-the-art, environmentally safe landfills. To achieve this goal, CalRecycle oversees a comprehensive regulatory system in cooperation with other responsible environmental agencies and landfill operators. This regulatory system starts with the planning and construction of a landfill, continues through its operation, and remains in effect for 30 years after closure. Before construction begins on a new or expanded landfill, the proposal must undergo a rigorous scrutiny, consisting of the following major steps:
- Site Selection: The operator must analyze and test alternative sites to show that site geology and topography will prevent water pollution, flooding, earthquake hazards, and other adverse effects. Also, the site must be remote enough from homes, schools, airports, and other sensitive human activities so as not to cause any adverse effects.
- Environmental Review: An environmental analysis, and in most cases a full environmental impact report, must be prepared to show how all possible adverse environmental impacts will be mitigated.
- Engineering: A detailed engineering design must be prepared, covering every aspect of the landfill site, its construction and operation, and its environmental protection systems.
- Land Use Approval: The local planning agency must certify that the site is in conformance with the city or county general plan, the local zoning code, and the county or regional integrated waste management plan.
- Air Quality Permit Approval: The local or regional air quality management must certify that accurate measures will be taken by the operator to monitor and control all anticipated emissions.
- Water Quality Control Approval: The Regional Water Quality Control Board must adopt waste discharge requirements that the operator must follow to protect surface and ground water quality.
- Solid Waste Facility Permit Approval: Only after all of the foregoing approvals have been obtained may this permit be issued by the solid waste local enforcement agency, with the concurrence of the California Integrated Waste Management Board. It must also be shown that the landfill can meet all state operating standards and has an approved closure plan, a post-closure maintenance and monitoring plan, and proof of financial responsibility in the event of any liability.
Public hearings are held before any of the above approvals and permits are granted. The result is today's modern, state-of-the-art landfill.
Protection and Quality
Leachate Collection and Removal System: Leachate is liquid generated from moisture brought in with the waste, from rainfall which percolates into the landfill, and from the waste decomposition process. It contains dissolved and insoluble chemicals. A network of perforated pipes within the landfill collects the leachate, which then is pumped to a treatment plant.
Leachate Treatment Plant: Leachate may be treated on site for reuse (e.g., to control dust) or may be piped to a treatment plant off site for safe disposal.
Composite Liner System: The composite liner extends entirely beneath the landfill, like a bowl, to contain any leachate. It consists of at least 2 feet of compacted clay, on top of which is a heavy sheet of tough, 60-80 mil HDPE plastic and a protective geo-textile cushion. Over this is a two-foot layer of crushed rock or gravel, within which are the perforated leachate collection pipes.
Groundwater Monitoring Wells: These wells are installed around the perimeter of the landfill and are sampled periodically to detect any possible migration of leachate off the site.
Protection of Air Quality
Landfill Gas Removal System: Landfill gas, mostly methane and carbon dioxide, is formed as the waste decomposes. A grid system of perforated pipes connected to vacuum blowers collects and removes the gas.
Flare Station or Electrical Generator:The landfill gas is either burned off in a flare, or used to generate electricity in a gas turbine.
Gas Monitoring Wells: Gas monitoring wells are placed all around the site, and sampled frequently, to make certain that there is no migration of the gas beyond the site boundaries.
Protection Against Off-Site Flooding
Drainage and Erosion Control System: This system consists of carefully graded decks, surface channels, down drains and holding basins to prevent off-site flooding. The system must be able to control flows resulting from a 100-year-frequency, 24-hour storm.
Daily operations at a landfill are carried out under stringent state regulations designed to protect the environment, public health, and safety. Environmental control systems are required by state laws and regulations to protect the environment and people.
Each incoming refuse vehicle is weighed to make sure that the landfill does not exceed its permitted daily tonnage limits. The weight figures are also used to compute the community's waste diversion progress, and to determine the proper disposal charges to users.
Unloading and Load Checking
The refuse vehicles are directed to the operations area for the day. Unloading must be confined to the smallest area possible in order to control birds, dust, and blowing litter. Specially trained site workers then check for hazardous or unpermitted wastes. If present, these wastes are safely removed for disposal at a facility approved for such wastes.
Spreading and Compacting
Bulldozers quickly spread and compact the waste in layers of about 2 feet. This process eliminates voids where rodents might seek harborage, and conserves valuable landfill volume. It is repeated until the compacted waste reaches a height of 8 to 10 feet.
Waste Cells and Lifts
Each day's deposit of covered waste is called a cell. A continuous row of cells is called a lift. The landfill is made up of many lifts.
At the end of each day's operation, bulldozers spread and compact at least 6 inches of earth over all of the waste. An approved alternative cover, such as shredded green waste, may also be used. The daily cover prevents the emergence of flies and other insects, and controls odors, blowing litter and the infiltration of rainfall.
During all of these steps, site workers in water trucks spray the interior roads and operations areas to control dust. Wires are strung between high poles to discourage birds. Earthen sound barriers are used to control noise.
This is done to ensure proper surface drainage and slope stability, to measure in-place volumes and densities of the wastes, and to control the height and extent of the fill area.
Many landfills salvage wood, metal objects, broken paving, and green wastes. Some landfills are operated in conjunction with a materials recovery facility for recycling glass, paper, plastics, aluminum, and other materials. Unauthorized salvaging, or scavenging, is strictly prohibited.
A security fence or topographic barrier must be maintained around the perimeter of the site to prevent unauthorized entry.
All site operations must be supervised by qualified personnel trained in safety, health, environmental controls, and emergency procedures. During all of these steps, site workers in water trucks spray the interior roads and operations areas to control dust. Wires are strung between high poles to discourage birds. Earthen sound barriers are used to control noise.
What a Landfill is Closed
When a landfill is closed it may look like a park, a golf course or a range of tree-covered hills. But there's much more than a pleasing appearance to a closed landfill. Rigorous environmental standards must be met, including the following:
Engineered Final Cover
The final cover consists of a two-foot compacted soil foundation layer, over which is placed one foot of re-compacted clay to prevent water infiltration, and one foot of soil for the planting of vegetation.
Erosion of the surface of the closed landfill is prevented by planting trees, grasses, and other ground cover, and by the use of terracing, mulching, or a strong geo-textile net.
The slope of the final site face must be no greater than 30 degrees and must be engineered to withstand the maximum probable earthquake for the area.
Postclosure Land Uses
Postclosure uses of the site must not pose a hazard to health, safety, or the environment, and open space must be graded and landscaped to harmonize with the setting.
Seeing that all of the many complex landfill requirements are implemented is a team effort. It is carried out by several state and local agencies under a coordinated inspection program established by state law and designed to eliminate duplication and conflict.
These agencies include:
- Solid Waste Local Enforcement Agencies
- State Water Resources Control Board
- Regional Water Quality Control Boards
- California Air Resources Board
- Regional Air Quality Management Districts
- State Department of Fish & Game
- Department of Occupational Safety & Health
- State Fire Marshall
- Local Fire Department
- Local Zoning & Planning Agency