Development and Operation of Groundwater, Surface-Water, and Water-Quality Monitoring Networks in Richmond, New York, and Bronx Counties, New York

Previous hydrologic studies have indicated that there may be sufficient water resources underlying Richmond, New York, and Bronx Counties for use as a supplemental water supply by the New York City Department of Environmental Protection (NYCDEP) in times of a drought or other water shortage. Unfortunately, comprehensive data on the quantity and quality of the Counties' water resources are not available to make an accurate assessment. In order to evaluate the availability and suitability of these resources, representative and timely data on the ground-water and surface-water resources of these three Counties are needed.

Objectives

The primary objective is to develop, operate, and maintain long-term monitoring networks on ground-water elevation, pond or lake level, stream discharge, and water quality in Richmond, New York, and Bronx Counties to provide a comprehensive, uninterrupted foundation of hydrologic data. These data are essential for addressing future management and development scenarios for New York City's water resources including: assessment of supplemental water-supply scenarios, ground-water modeling, urban development planning, water-quality and salt-water encroachment studies, wetlands management, and other water-management problems.

Approach

1. Compilation of Records: Records of past observation wells and stream-gaging sites in Richmond, New York, and Bronx Counties were compiled.
2. Field Reconnaissance and Surveying: The location, condition, and site accessibility of the wells and stream-gaging sites found in the data search were determined by USGS personnel in the field.
3. Ground-Water- and Surface-Water-Station Installation: The USGS installed 19 shallow ground-water observation wells in Richmond County, 4 in New York County, and 5 in Bronx County. In Richmond County an additional 8 privately drilled monitoring wells were added to the USGS network. Additionally, 4 streams in Richmond and Bronx Counties are being monitored with continuous stream-gaging equipment. The USGS also installed two lake-level gages at lakes determined to be in hydrologic contact with the local water-table aquifer.
4. Equipment Installation: Continuous ground-water-level recorders are installed at 9 observation wells and 2 pond-level gages; continuous stream-stage recorders are installed at the 4 stream-gaging stations. The 4 stream-gaging stations, and 2 of the 9 selected observation wells are instrumented with satellite- or telephone-telemetry equipment, enabling data collected and transmitted from these sites to be made available in near real-time. All stations will be visited regularly by USGS personnel to perform equipment maintenance and quality assurance
5. Network Monitoring: Water-level elevation, pond level, stream discharge, and ground-water- and surface-water-quality data were collected routinely at selected sites in Richmond, New York, and Bronx Counties. Ground-water sampling was performed on a 2-year rotating schedule of 25 wells per year, so each site in the network was sampled every other year. Samples were analyzed at the USGS's National Water Quality Laboratory for a broad range of constituents, including selected nutrients, major ions, trace metals, volatile organic compounds, semi-volatile organic compounds, organochlorine pesticides, and wastewater indicators.
6. Database Management: All ground-water elevation, pond level, stream discharge, and water-quality data were verified for accuracy and archived in the USGS's National Water Information System (NWIS).
7. Dissemination of Data (Deliverables): Data collected by the study were compiled and published annually in the USGS's Water Resources Data Report. A USGS Fact Sheet or Open File Report describing the hydrogeology and the water-level contours of the local aquifer systems will also be published every two years. Selected data will be available via the Internet.