Closed, Illegal and Abandoned (CIA) Disposal Sites

Problems and Hazards

CIA sites can present a variety of potential hazards to the health and safety of the public as well as adverse impacts to the environment.  Some specific effects of CIA sites are described below.

Vector and pest breeding

Newer illegal sites may provide attractants, such as food wastes, for pest vectors; breeding areas, such as old tires and other open containers, that can attract mosquito breeding; or shelter for rodents and other pests.

Physical hazard and injury to public and wildlife

Exposed and/or inadequately covered wastes can pose a potential hazard to human health and safety as well as a danger to wildlife or domestic animals. Human visitors to a disposal site may injure themselves by sharp objects in the refuse (for example, fencing, rebar, broken glass). Containers of hazardous materials may be present on-site. Wildlife attempting to graze, forage, scavenge, or browse can injure themselves or ingest potentially hazardous materials or be fouled or entangled in certain waste materials such as wire, cording, or mesh.

Potential hazardous materials

Unregulated sites can serve as attractant sites for illegal disposal of hazardous materials, both contained or non-contained. These can become a danger to future visitors to a site, as well as be damaging to the environment.

• Lead exposure—Exposed burn ash can contain statistically significant levels of lead which exceed California definitions for hazardous waste (for example, exceed the total threshold limit concentration (TTLC) of 1000 milligrams/kilogram for lead).
• Dioxins and furans—Exposed burn ash can contain combustion byproducts containing dioxins and furans, which are known carcinogens.
• Radiological hazards—Disposal sites operating in the 1920s–1940s may contain low-level radiological waste from medical equipment and other equipment using radioactive sources (instrument dials).
• Military waste—Disposal sites at former Department of Defense installations may contain hazardous wastes, ordnance, and other wastes from military equipment maintenance and operations.

Adverse impacts to the environment

Nonaqueous liquid or water-soluble solid substances may permeate the underlying soil and invade underlying aquifers, or drain into adjacent watersheds and cause surface water, groundwater, and/or soil contamination. Possible airborne impacts include volatilization to the atmosphere and inhalation (fugitive dust and waste particulates). Liquid or soluble materials can be assimilated through vegetation and migrate into the food chain from herbivores to predators or possibly to humans. Landfill gas can adversely impact plant development.

Adverse impact of interference with future land uses (economic feasibility)

As local development continues in more rural locations, some activities may eventually encroach upon existing illegal sites. Cleanup, or its potential costs, may reduce the prospect of considering a CIA site for development. Furthermore, migration of landfill gas can limit potential uses.

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	Typical gas migration routes (16 KB)	Impact of differential settlement and gas migration on building structures (20 KB)

Attractants for future illegal disposal activities

When a CIA site is continually used for illegal disposal activities, it attracts future parties and repeat users to continue illegally dumping their waste.

	Illegal Dump Sites are an  "attractive nuisance" (22 KB)

Loss of usable or recyclable materials

Disposal of larger materials or white goods and other recyclables potentially puts these items out of the recycling loop. If a site is too difficult to clean out and recover these materials, they may be left in place and covered.

Adverse visual impact

Illegal sites or abandoned sites can pose a negative visual impact, especially in more remote areas where recreational visitors may come across a site. Sites located along roads present immediate impacts to all who pass by.

	Legacy municipal site (28 KB)

Expense

CIA sites can present a significant financial burden on the unsuspecting party or regulating agency, municipality, or county that discovers a site. Cleanup typically involves field investigation, testing, and evaluation of the waste materials for classification for waste disposal, as well as for determining remedies and risk assessment to determine the institutional controls to be applied (for example, land-use and deed restrictions).

Costs for clean closure or consolidation and capping often can exceed the market value of the property. For most private responsible parties, the economic burdens associated with a CIA site are difficult to offset unless a revenue-producing beneficial use (storage, parking, golf driving range, etc.) for the property can be implemented to offset capital remedial costs, maintenance, and monitoring.

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Last updated: April 18, 2008