THE TULLY VALLEY BRINE FIELD/MUDBOIL HYDROGEOLOGIC CONNECTIONS PROJECT

A mudboil is an artesian-pressured feature that discharges fine-grained sediment and water (fresh or brackish) to the land surface which, in time, can cause land-surface subsidence. The mudboils found in the Tully Valley of central New York, near Syracuse, have been a constant problem since the 1950's. In the southern part of this valley, solution brine mining of thick halite deposits (~150 feet or 45.7 meters thick) from the late 1800's through the 1980's caused land surface subsidence in the brine field area. This subsidence was caused by collapse in the brine-field cavities about 1,100 feet (335 meters) below land surface. This collapse in the bedrock eventually worked its way to the land surface along the valley walls. Fractures in the bedrock are currently capturing surface water streams and redirecting the water into a confined aquifer. The increased hydraulic head in the aquifer is believed to be a contributing factor to an increased level of mudboil activity.

Through the use of GPS, water monitors and on site measurements, evidence has been found for both a losing and a gaining stream, ongoing mudboil activity, as well as fairly active land movement. The presence of these features indicates the dynamic nature of the groundwater/surface water in the study area and its affect on the region in the immediate vicinity. This information is being analyzed to produce a remediation project to divert the surface water from the fractures which will hopefully slow the impact on the valley.