Areas with low seismic activity such as the eastern United States or eastern Canada provide numerous examples of water loss in the local wells as a direct result of seismic activity. One example, the Cornwall Massena earthquake (centered between Massena, New York and Cornwall, Ontario) of 1944 had a magnitude of 5.8 (on the Richter magnitude scale) and had clear hydrological effects on the area. For instance, a large number of wells were left dry in St. Lawrence County causing acute hardship; however, the number of wells and the size of the affected population were not reported (Stover and Coffman, 1993).
In 2002, a 5.0 magnitude earthquake in Essex County, New York resulted in two counties being declared in a state of emergency due to the significant amount of damage that occurred as a direct result from the earthquake, including loss and contamination of well water. The New York State Department of Health was called on to intervene in the aftermath and to assist local governments to ensure the safety of drinking water supplies in both Clinton and Essex counties. However, the number of privately owned wells affected by the earthquake was not reported (Office of the Governor Press Release, 2002).
The most dramatic example of water loss in the area with low seismic risk is the Pymatuning Earthquake of 1998 in northwestern Pennsylvania. The earthquake had a magnitude of 5.2 and resulted in the disruption of more than 120 household supply wells in an area of approximately 50 miles2 (129.5 sq. km) (Fleeger et al., 1999). In the report published by the United States Geological Survey (USGS) an official observed that ‘the most important result of the earthquake was water well damage.’ In one well, the water level was documented to have decreased by 40 ft (12.2 m) overnight; this was followed by a sustained period of decline over approximately two months where the level dropped by an additional 55 ft (16.7 m).
Furthermore, water level decline by as much as 100 ft (30.48 m) was reported and the affected wells never gained original water levels. As a result, more than 120 homes were left without water after the earthquake and wells had to be subsequently re-drilled. It took more than one month to drill new wells which were to provide the communities of Greenville and Jamestown with water. In the case of homes that lost well water, most homeowner’s insurance policies did not cover water loss, so residents had to drill new wells at their own expense and the process took more than three months (Armbruster et al., 1998).
Apart from earthquakes described in New York, Pennsylvania, and Maine, other states in low seismic risk areas reported similar incidents of wells becoming dry as a result of earthquakes. These included the states of Idaho, Montana, Ohio, and Georgia (USGS, 2003, USGS, 2006; Ohio Department of Natural Resources, 1986; Whitehead et al., 1984). In all of these cases, the assessment of earthquake impact on wells was insufficient, mainly because seismic and hydrogeologic studies were usually conducted separately.
Areas with high seismic activity provide many more examples of water supply disruption by earthquakes. California is a high-seismic activity region and it is one of the most affected states. One of the earliest earthquakes mentioned in relation to the loss of well water in California was the Fort Tejon earthquake on January 5, 1857, which registered a 7.9 magnitude. Hydrological alterations as a result of the Fort Tejon earthquake occurred throughout the region, and changes in well water flow were reported as far north as the Santa Clara Valley (Yewell, 2007).
The 1906 San Francisco earthquake had hydrologic effects similar to those of 1989 Loma Prieta earthquake, including the drying up of many wells in the Pajaro River area of Santa Cruz County (USGS, 1994). The 1989 Loma Prieta earthquake in northern California, magnitude 7.1, left dry wells for residents of San Mateo and Monterey counties (Municipal Services Review for the North County Area of Monterey County, 2004; The South Skyline Association, 2003).
Most recently, in 2003 the San Simeon earthquake (magnitude 6.5) affected California’s central coast and resulted in the drying and collapsing of wells, among many other hydrological changes in the region. One of the severely affected was San Luis Obispo County, where cattle is one of the top two commodities produced. In the aftermath of the earthquake, ranchers were forced to trim their herds because of uncertainty in water supply (California Farm Bureau Federation, 2004).
Apart from the incidents described above, where earthquakes have resulted in the drying of wells, changes in well water levels and water quality occur on a widespread basis; they can be associated with earthquakes whose epicenters are located at various distances from wells. For example, multiple earthquakes in Alaska, as well as the earthquake that generated the 2004 Asian tsunami, caused well water fluctuations in the continental United States (Rozell, 2004; USGS, 2005). Changes in water levels in a USGS observation well in Virginia were recorded in association with approximately 50 earthquakes worldwide (usually greater than 6.0 in magnitude) within a 16 month period between 2005 and 2007 (USGS, 2007). In addition to changes in water levels, increased turbidity in wells is also associated with earthquakes and is important because water can be rendered unsafe for drinking.
Unfortunately, lack of data on the location of wells in relation to the topography and the wells’ water conditions (i. e. ‘dry’ wells or ‘wet’ wells) prevents more substantial research on the effect of earthquakes on wells. The described cases of water supply loss in the US (except the Pymatuning earthquake case) contained no data on wells’ water conditions (i. e. ‘dry’ vs. ‘wet’) or the location of wells with respect to topography. Moreover, only USGS wells that have monitoring functionality are mentioned in most studies published by hydrogeologists dealing with earthquake effects on groundwater (e. g. Montgomery and Manga, 2003; Roeloffs et al., 1995; Rojstaczer and Wolf, 1992; Rojstaczer and Wolf, 1994). No household wells that lost water due to earthquake activity in the US have been mapped or assessed in a comprehensive way by the specialists.
World History
