understood. Understanding the ground water environment, with an assesment of the resource, is necessary before it can be adequately protected and efficiently utilized. This is critical because ground water serves as the principal source of domestic water supply throughout rural areas of the basin and also makes an important contribution to public systems. Past and present efforts within the basin have focused on ensuring the quality of ground water for public consumption as a prerequisite for managing ground water quality. Largescale, general data on ground water quality have been compiled by New Hampshire. Information is slightly more refined in the Massachusetts portion of the basin because of hydrologic studies performed by the U.S. Geological Survey. Studies indicate that ground water quality conditions are generally the same in Massachusetts as in New Hampshire (Hanley, 1990).
The runoff of the Merrimack Basin flows through the interconnected system of surface water and ground water. Although surface water is the most visible manifestation of runoff, it is derived primarily from ground water via subsurface flow. The Merrimack mainstem is the axis in the basin, connecting five principal tributaries and ultimately channeling an average flow of 4.9 billion gallons per day to the Atlantic Ocean.
The water quality of the Merrimack River has gradually improved, and the readily observable contamination has vanished. Although the projections of expected continued improvement in water quality for years 1990 through 2020 may be well founded for Class-B water characteristics, the increased population in the basin and subsequent activity along the river will inevitably affect the attainment of public drinking water standards. It is clear that improvements in the river have been achieved through a combination of local, state, and federal efforts. In addition, the cooperation and financial assistance of private industry have helped bring the Merrimack River to health.
According to the October 1988 bulletin of the Merrimack River Watershed Council, current policies affecting the water resources of the Merrimack include the following:
The Clean Water Act of 1977 and its recent reauthorization, which reflect strong commitment to support water quality programs that improve or maintain water resources at fishable and swimmable quality.
Implementation of the Anadromous Fish Restoration Program in the U.S. Fish and Wildlife Service.