The purpose of this report is to summarize data on groundwater quality in the major aquifiers of the Highlands and Valley and Ridge Physiographic Provinces in New Jersey. This information will provide all interested parties with concentration ranges for many water quality parameters.Chemical analyses of samples collected from105 wells in the major bedrock aquifers of the Highlands and Valley and Ridge Physiographic Provinces in New Jersey indicate that groundwater quality is very good for most purposes. Locally though, it may require treatment for undesirable characteristics and constituents.The most common quality problems are associated with the state recommended secondary drinking water standards