Northumberland County, Pennsylvania in the context of Columbia County, Pennsylvania

Northumberland is a borough in Northumberland County, Pennsylvania, United States. The population was 3,911 at the 2020 census.

The Coal Region is a region of Northeastern Pennsylvania. It is known for being home to the largest known deposits of anthracite coal in the world with an estimated reserve of seven billion short tons.

The region is typically defined as comprising five Pennsylvania counties, Carbon County, Lackawanna County, Luzerne County, Northumberland County, and Schuylkill County. It is home to 910,716 people as of the 2010 census.

Sunbury (/ˈsʌnbɛri/ SUN-berr-ee) is a city and the county seat of Northumberland County in Pennsylvania, United States. Located in the Susquehanna Valley, Sunbury is positioned on the east bank of the Susquehanna River.

Sunbury's roots stretch back to the early 18th century. As of the 2010 census, it had a population of 9,905. The city is one of the three principal cities in the larger Bloomsburg–Berwick metropolitan area.

A spoil tip (also called a boney pile, culm bank, gob pile, waste tip or bing) is a pile built of accumulated spoil – waste material removed during mining. Spoil tips are not formed of slag, but in some areas, such as England and Wales, they are referred to as slag heaps and sometimes as pit heaps. In Scotland the word bing is used. In North American English the term is mine dump or mine waste dump.

The term "spoil" is also used to refer to material removed when digging a foundation, tunnel, or other large excavation. Such material may be ordinary soil and rocks (after separation of coal from waste), or may be heavily contaminated with chemical waste, determining how it may be disposed of. Clean spoil may be used for land reclamation.

Acid mine drainage, acid and metalliferous drainage (AMD), or acid rock drainage (ARD) is the outflow of acidic water from metal mines and coal mines.

Acid rock drainage occurs naturally within some environments as part of the rock weathering process but is exacerbated by large-scale earth disturbances characteristic of mining and other large construction activities, usually within rocks containing an abundance of sulfide minerals. Areas where the earth has been disturbed (e.g. construction sites or highway construction) may create acid rock drainage. In many localities, the liquid that drains from coal stocks, coal handling facilities, coal washeries, and coal waste tips can be highly acidic, and in such cases it is treated as acid rock drainage. These, combined with reduced pH, have a detrimental impact on the streams' aquatic environments.