Documents & Resources

Frequently Asked Questions


What is the origin of the contamination from the Bay Shore former MGP site?

Historical gas manufacturing activity has affected the soil and groundwater at the former MGP site. This includes the areas in which operations were located, as well as two off-site groundwater plumes emanating from the main site. Some of these materials have the potential to affect human health or the environment. A remediation program is in progress to clean up the site to protect the nearby community.

What is the status of the cleanup at the Bay Shore former MGP site?

Major remedial activities have been completed in each of the OUs. In the Spring and Summer of 2011 the excavation of remaining contamination in the upper ten feet was completed in designated areas throughout OU4. Site restoration activities were completed in Spring 2012.

Health & Safety:

How can people be exposed to contaminants from former MGP sites?

In general, people can be exposed to MGP wastes through three major routes:

  • breathing (also called inhalation)
  • eating or drinking (also called ingestion)
  • skin contact (also called dermal contact)

People can be exposed to MGP contamination through contact with tar, tar-contaminated soils, purifier waste, contaminated groundwater or surface water, contaminated dust and contaminated air. However, it is important to note that if there is no contact with wastes, there is no exposure.

More details on potential exposure risks are available at the NYSDEC website.

Are members of my community at risk for exposure to potentially hazardous contamination?

No evidence of human exposure has been found in Bay Shore or Brightwaters and as remedial measures continue to reduce contaminant levels, the risk of human exposure continues to drop.

Is my drinking water safe?

Yes. Studies have shown that the contaminated groundwater found at and around the former MGP site has had no impact on the community's drinking water supply. Additionally, water companies must supply drinking water that meets state and federal quality standards and water supplies are tested on a regular basis to ensure the water is in compliance with these standards.

Read more information on the drinking water supply in Suffolk County.


What does ppm mean?

Most contaminants are expressed as parts per million (ppm).This means that the concentration of a particular substance is very low even though the regulatory agency may consider it a significant amount. One ppm is one part in one million. For example, one ppm is equivalent to one inch in 16 miles or one second in 11.5 days.

What does ppb mean?

An even smaller concentration measurement than ppm is parts per billion (ppb). For example, one ppb is equivalent to one second in nearly 32 years.

A detailed explanation of both ppm and ppb can be found on this National Environmental Services Center fact sheet.

What is BTEX?

BTEX is an abbreviation for a group of chemical compounds: benzene, toluene, ethylbenzene and xylene. BTEX compounds are commonly found in MGP wastes and are used as anti-knock compounds in gasoline. They are commonly found as groundwater contaminants near gas stations, MGP sites and other industrial facilities.

What are PAHs?

PAH is an abbreviation for polycyclic aromatic hydrocarbons. PAHs are made up of several semi-volatile compounds also found in many petroleum products, such as fuel oil and asphalt. PAHs tend to be denser than water and are not readily dissolved or broken down in the environment.

View a complete glossary of MGP terms.