Columbia subject headings:
Hydrology--Research--United States.
Hydrology--United States--Information services.
Water quality--Research--United States.
Water quality--United States--Information services.
Water-supply--Research--United States.
Water-supply--United States--Information services.
Harvard subject headings:
Information storage and retrieval systems--Water quality
Information storage and retrieval systems--Water resources development
Water quality--Research--United States.
Water resources development--Research--United States.
Princeton subject headings: