YORK — A public interest program, “Protecting Our Well Water,” will be held on Sunday, Oct. 5 at 7 p.m. at the York Public Library.

The program offers an opportunity to learn about the geology of southern Maine, the sources of well water, threats to drinking water, and what can be done to protect wells from the effects of pollution and extraction.

Speakers will include Dr. Robert Marvinney, director of the Maine Geological Survey, and Gail Darrell, director of the New England office of the Community Environmental Legal Defense Fund. Marvinney and Darrell will talk about the origins of groundwater and threats to the quality of that water, like runoff, fertilizer, arsenic and other pollutants.

Marvinney has been director of the Geological Survey and state geologist since 1995. The agency’s scope includes geologic mapping of Maine’s coastal geology, groundwater investigations, and maintaining a database that tracks the characteristics of wells. He has been involved with many studies of arsenic and its effects on Maine’s groundwater.

Darrell has been a community organizer for the nonprofit public interest firm CELDF for eight years. She worked with New Hampshire residents to create the Community Rights Network to secure the right to local self-government and the right to protect groundwater.

There will be refreshments, and all are welcome.