Division Initiatives - 2008/2009 Progress and Statistics

Vapor Intrusion Initiative

"Vapor intrusion" (VI) is the process where chemical vapors move from a subsurface source into the indoor air of overlying buildings. Although DEC has historically evaluated soil gas pathways at remedial sites, improvements in analytical techniques and the knowledge gained from remedial activities has increased the understanding of how vapor intrusion occurs. If it is determined that vapor poses a health risk to residents or workers in a building, the building is fitted with a vapor barrier of the same type used to prevent naturally occurring radon from entering structures. Acting together, DEC and the New York State Department of Health are leading the State's proactive approach to vapor intrusion. They have developed a joint strategy to evaluate the vapor intrusion pathway at all of the sites in the State's remedial programs.

DEC identified 421 sites (legacy sites) where remedies were selected prior to the VI initiative. Progress in addressing VI at these legacy sites can also be found on the Status of Vapor Intrusion Evaluations at Legacy Sites page on DEC's website.

Vapor intrusion pathways.

Status of Vapor Intrusion Legacy Sites as of March 31, 2009
Action	Total
Sites Evaluated	160
Sites with Evaluations Underway	261
Sites Awaiting Evaluation	0
Total Legacy Sites	421

Manufactured Gas Plant Initiative

A manufactured gas plant (MGP) is an industrial facility at which gas was produced from coal, oil and other feedstocks. The gas was stored, and then piped to the surrounding area, where it was used for lighting, cooking, and heating homes and businesses. Most of these plants have been closed for 50-100 years, replaced by electricity and natural gas. The sites where MGPs were located however, often contain abandoned underground structures and pipes containing coal tar or other MGP residuals. Some of these waste materials (especially coal tars) may have migrated from existing/former structures and may be present in the subsurface. Impacts to surface water bodies and their sediments are also common since MGPs were typically located near a source of water.

DEC now has one of the most aggressive MGP site investigation and remediation initiatives in the country. Since the problems associated with the former MGP sites were identified, DEC has been working with utilities on a state-wide basis to identify and address the issue of MGP sites for which they may have responsibility. MGP sites are being addressed under the State's remedial programs and are part of their statistics in this report.

Status of Manufactured Gas Plant Sites Currently Identified by DEC as of March 31, 2009
Utility	MGP Sites Currently Identified	Under Order/ Agreement	Awaiting Order/ Agreement	Complete /No Further Action
Central Hudson Gas & Electric	8	7	1	1
Con Edison	53	53	0	14
National Fuel Gas	12	4	8	3
National Grid (KeySpan)¹	43	43	0	3
National Grid (Niagara Mohawk)	53	52	1	10
NYS Electric & Gas	38	36	2	6
Orange & Rockland	7	7	0	1
Rochester Gas & Electric	11	8	3	0
Non Utility/Need Determination	28	4	24	3
Totals	253	214	39	41

_{¹ Former Long Island Lighting Company and Brooklyn Union Gas MGP Sites; does not include non-MGP Sites.)}

More Information

More information about DEC's Manufactured Gas Plant Program. (leaving the Environmental Remediation Annual Report pages)

More information about the Vapor Intrusion Initiative and Guidance. (leaving the Environmental Remediation Annual Report pages)

Back to the Environmental Remediation 2008/2009 Annual Report main page.