April 09, 2011 (rt23 news) - (11/P50) TRENTON - The DEP has been awarded a $267,000 grant from Federal Emergency Management Agency (FEMA) to study the problem of ground instability and subsidence, or surface depressions, associated with abandoned mines in the northern part of the State, Commissioner Bob Martin announced today.

The New Jersey Geological Survey, which will provide matching funds of nearly $90,000, was awarded the federal grant to provide accurate GPS locations for abandoned mines and to develop a scientific database of information to be used to prioritize the risk of subsidence or ground collapse.

"Identifying these sites is very important to public safety,’’ said Commissioner Martin. "This effort will provide counties and towns in former mining areas with valuable information to better understand what literally lies beneath them, to help remediate unstable sites and recondition tracts for potential safe residential and business redevelopment.’’

"This effort will help us provide needed facts and science to make important decisions on future safe development in this region,’’ Commissioner Martin added.

Subsidence hazards due to abandoned mines are identified in the current New Jersey Multi-Hazard Mitigation Plan prepared by the New Jersey State Police Office of Emergency Management. This hazard is the result of natural forces such as rain events, freezing and thawing and gravity that causes voids and shallow filled areas of historic underground mining to collapse.

In this new study, DEP scientists will review historical mining maps and documents - some dating back a century or more - and then will head out into the field across North Jersey to match up that data with the current situation. The result should be creation of an up-to-date database that can guide State, county and local planners in making future decisions. Also included will be an educational outreach to county and local emergency responders.

Nearly 600 abandoned copper, graphite, iron, lead, mica, manganese, sulfide, uranium and zinc mine locations have been identified in North Jersey. The majority are located in Morris, Sussex, Warren, Hunterdon and northern Passaic counties, with a small number also found in Bergen, Essex, Hudson, Middlesex and Union counties.

Periodically, significant rain events have caused mine shafts or filled areas to collapse, damaging residential and commercial buildings, school yards, and infrastructure. The grant will provide funds to more accurately inventory and evaluate the subsidence hazard related to historic mines in northern New Jersey.







New Jersey Geological Survey


Digital Geodata Series
DGS03-2 Abandoned Mines of New Jersey (1:24,000 scale)

(updated 6-21-2006)

Abstract

This Geographic Information System (GIS) point layer, Abandoned Mines of New Jersey contains locations and attributes for abandoned mines. The shapefile has locations for nine types of abandoned mines which are Copper, Graphite, Iron, Lead, Mica, Manganese, Sulfide, Uranium and Zinc. There are 588 abandoned mine locations in the database and they are mapped at a scale of 1:24,000.

This updated version of the data has undergone significant changes in two USGS quadrangles since the previous version of this data, dated July 29, 2005, was published. Previously, Bloomsbury, Blairstown, Easton and High Bridge USGS quadrangles were updated. In this update, field work by geologists was conducted to improve the locational information of the mines in the Franklin and Riegelsville USGS quadrangles. Some of the mines in these quadrangles were located using the global positioning system (GPS). Certain mines in these quadrangles were mapped for the first time and appear in this data but not in the previous versions of the data. Some known mine locations in the previous versions of the data have been more accurately mapped and the points have been relocated.

The GIS point layer (ESRI™ shapefiles) and metadata are compressed as a .zip file for download.

"The potential hazard of collapse from abandon mines is great in many North Jersey communities,’’ said State Geologist Karl Muessig. "We hope to be able to better identify problem areas.’’

Muessig noted that several North Jersey towns have passed ordinances that require the issuance of a certification that no dangers exist from an abandoned mine before a building permit can be approved. However, in most towns there are no such ordinances. In some cases, he said, old mines have been bulldozed and construction of homes, businesses and even public roads has occurred over these sites, prior to local awareness of the historic situation.

"The information gathered in this new study could be invaluable to towns in the former mining region,’’ said Muessig.

There have been 77 collapses due to abandoned mines issues in North Jersey over the past 30 years. Towns such Rockaway Township, North Arlington and Mine Hill have spent hundreds of thousands of dollars apiece to remediate a single collapse.

For example, North Arlington, in Bergen County, has spent about $250,000 per shaft to remediate old copper mines within its boundaries. Rockaway Township, in Morris County, has remediated collapses along the route of the former White Meadow Mine many times. The most recent occurred in 2005 and 2007, with remediation costs exceeding $500,000.

The grant to the New Jersey Geological Survey came through a national competition for $10 million in 2010 FEMA Pre-Disaster Mitigation grants.

For more information on abandoned New Jersey mines, visit: http://www.state.nj.us/dep/njgs/geodata/dgs03-2.htm