Hazardous Waste Sites

Hazardous waste sites affect thousands of communities across the country. These include abandoned dumpsites, municipal landfills, industrial ponds, storage piles, military base waste sites, and similarly designated areas. Sites that are inactive (not receiving hazardous waste) are generally listed and ranked for cleanup under the Federal Superfund legislation or State cleanup programs, while active sites are regulated under RCRA.

Only the most dangerous sites are eligible for Superfund, which ranks qualified sites on the National Priorities List (NPL). A site is placed on the NPL after a preliminary assessment and a more thorough site investigation demonstrate that a potentially serious health threat exists. While approximately 22,000 hazardous waste sites are identified in EPA’s inclusive Emergency Response and Remedial Information System (ERRIS), less than 1% of this number is included on the NPL.

A score assigned to the site by the State and reviewed by EPA usually determines the NPL ranking. The score reflects the severity of the contamination, and the vulnerability of residents and the environment to damage from any of the pathways of exposure. Careful testing is required to establish concentrations of pollutants at various points.

State and local officials have been taking an active role in the hazardous waste discovery process. Many local officials have actively sought out these sites with the aid of local citizens. Ideally, the “responsible party” who left the waste assists in cleanup, but in some cases, the polluting company no longer exists or responsibility cannot be proven. The State or local area may be left with extremely large cleanup costs in such cases—which is why prevention of poor waste disposal practices is by far the best option.

Unfortunately, “cleanup” is not as “clean” a process as the name implies. There are basically three approaches to cleaning contaminated soil:
  1. Containment. The objective of this approach is to leave the waste in place and try to keep it from moving into the soil, air, or groundwater. Unfortunately, natural forces have triumphed in many landfills to date, and systems expected to last decades have made it only a few years before leaking.
  2. Off-Site Disposal. Under this approach, hazardous materials are removed to a RCRA site. Often, risks are transferred rather than eliminated; a number of RCRA landfills have begun to leak and have been added to the NPL for cleanup.
  3. Treatment. Numerous technologies are available or are currently being explored to chemically treat waste so that it is no longer harmful. The best method varies according to the waste. Some waste can be biodegraded by adding microorganisms specifically bred to “eat up” the chemicals; organic chemicals can sometimes be forced to break down when high temperatures are applied.
Decontaminating groundwater is an even lengthier process. Since groundwater moves slowly through the soil, as long as 20 years may be needed to complete decontamination once pollution has occurred. Three water treatment approaches are currently in use:
  1. Air Stripping/Aeration. Water is brought to the surface and agitated or sprayed into the air to accelerate the evaporation of organic compounds. Citizens near a site using this method need to ask questions about the rate at which toxic elements are released into the atmosphere, particularly if residential areas are located near the stripping tower.
  2. Activated Carbon. This treatment passes water through columns containing activated carbon, leaving many chemicals attached to the carbon particles. A sensitive issue in this type of treatment is how to dispose of the contaminated carbon.
  3. Chemical Precipitation. In this approach, primarily used to remove metals such as lead and arsenic, chemicals are added which can convert metals to insoluble particles. These particles then settle out of the water as sludge. The controversial issue with this method is the disposal of the toxic sludge.