Former manufactured gas plant sites are not unique to Columbia Gas of Virginia, nor to other NiSource subsidiaries and utilities around the country.

	Byproduts of manufactured gas plants
	Evaluating sites
	Health risks
	Cleanup

Byproducts of manufactures gas plants
The technology used to produce manufactured gas resulted in byproducts such as coal tar and oil. Much of this material is black or dark blue in appearance, either oily or granular and often smells like mothballs. In the past this material was either sold for use by other industries for things like asphalt or was shipped offsite for disposal. However, some of the byproduct materials remained on the land where MGPs operated (when the plants were active, byproducts were stored on site).

Before cleanup can begin, extensive testing is done at the surface and below the ground to determine exactly where contaminated areas are located.

Site evaluation
NiSource's former manufactured gas plant sites have a variety of uses today. Many are on company property, many others are in commercial or industrial use; some are vacant land; a few are residential property.

As with many former industrial properties, manufactured gas plant sites have the potential to contribute to economic development and community revitalization efforts. All over the country, sites are being cleaned up and turned in to new office buildings, residences, parks and nature areas. In other cases, actions are being taken to make sure a property can continue its current use. These include utility service centers, restaurants, athletic fields, churches and parks.

Columbia Gas of Virginia has taken on the responsibility of conducting a voluntary program to evaluate sites that once were used to produce or distribute gas manufactured from coal and/or oil.

The program to evaluate former manufacture gas plants is thorough and systematic. The program includes a review of historical information, assessment of current uses of the property and visual inspections.

The sites are ranked according to potential risk to health and the environment, then scheduled for an intensive investigation performed by a qualified environmental engineering firm. The investigation involves collecting soil and water samples for laboratory analysis. The results are used to determine if a site needs to be cleaned up and what actions should be taken to make sure it is safe to use.

Other factors that may affect when a site undergoes a thorough investigation are a property sale or plans for changing the current use.

Health risks
Investigations have found no sites that are considered immediate health risks and measures are in place to prevent potentially unsafe exposures. For example, we are asking people not to do any digging without contacting our environmental staff.

If conditions were such that people were considered to be at serious risk, Columbia Gas of Virginia would take steps to correct the situation.

We continue to check on all sites as we proceed with the systematic program of investigations. If conditions were to change at a site, we would take action to make sure the risk remains low.

Cleanup
Columbia Gas of Virginia is working with the Virginia Department of Environmental Quality and other environmental agencies in cases when a site is being investigated or cleaned up. In all cases, actions taken to make sure sites are safe comply with relevant environmental laws and regulations.

There are several alternatives that meet environmental laws that can be utilized to make sure a site is safe to use. Some of the options for cleaning up, or remediating, sites are: removal for offsite thermal treatment, removal for land disposal, bioremediation (using bacteria to "eat" the chemical compounds), stabilization of impacted soil at the site and creating barriers to prevent contact with residues that remain below ground. The sites are dealt with individually, based on the results of the investigation and plans for property use.

Investigating and cleaning up a site may require that hazardous materials be uncovered. Dozens of sites have been cleaned up around the U.S. with little or no off-site impact because measures are taken to make sure that it is a safe operation, both for the workers at the site and the surrounding area. Some actions include the use of devices to monitor the chemical compounds in the air; foams and plastic sheeting to cover contaminated material; fabric-draped fences to minimize vapors and odors; and remedies that stabilize and/or contain impacted soil without having to excavate.

Media coverage of environmental projects too often fails to differentiate between hazard and risk. Some of the chemicals found in manufactured gas plant residues can indeed be harmful, but where they are located or how they are used determines if they are a health risk. In many cases, there is little risk of exposure to the public because materials are below the ground surface where contact is unlikely.

People may be exposed to a hazardous substance but still not be considered at undue risk. Treated lumber, often used to landscape our homes, contains many of the same hazardous chemicals found in gas manufacturing byproducts. The government has not taken any actions to ban this product because exposure to the chemicals is considered an acceptable risk. Another example is unleaded gasoline, which contains benzene. While people who pump their own gas inhale benzene, it is an acceptable risk because the exposure is limited.

Ferrocyanide, one of the cyanide compounds, may be present at former manufactured gas plant sites in gas purifier residues. This compound is in a stable form that presents little health risk. It could be released to the environment only in rare circumstances if there were very acid or very alkaline conditions.