Long Island’s most precious resource is its water. The aquifer below Long Island is the sole source of drinking water for residents of Suffolk County, while surface waters are used for food production, bathing and recreation. It is therefore the policy of Suffolk County to maintain its water resources as near to their natural condition of purity as reasonably possible for the safeguarding of the public health. As defined in the Suffolk County Sanitary Code, the county requires the use of all available practical methods to prevent water pollution from sewage, industrial and other wastes, toxic or hazardous materials, and storm-water runoff.

The Department of Health Services enforces local, state and federal laws regulating water supply and promotes the extension of public water supply to all areas of the county. The department also maintains a process of groundwater planning, carries out research and development in the field of alternatives to community water supply, and promotes education and acceptance of the importance of groundwater management and protection.