Lacq is a commune

Communes of France

The commune is the lowest level of administrative division in the French Republic. French communes are roughly equivalent to incorporated municipalities or villages in the United States or Gemeinden in Germany...

 in the Pyrénées-Atlantiques

Pyrénées-Atlantiques

Pyrénées-Atlantiques is a department in the southwest of France which takes its name from the Pyrenees mountains and the Atlantic Ocean.- History :...

 department in south-western France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

.

It lies just northwest of the local capital of Pau.

Economy

In modern times it has been based around the industrial uses of subsurface petroleum

Petroleum

Petroleum or crude oil is a naturally occurring, flammable liquid consisting of a complex mixture of hydrocarbons of various molecular weights and other liquid organic compounds, that are found in geologic formations beneath the Earth's surface. Petroleum is recovered mostly through oil drilling...

 reserves, and since 1951 on the extraction and development of a very large natural gas

Natural gas

Natural gas is a naturally occurring gas mixture consisting primarily of methane, typically with 0–20% higher hydrocarbons . It is found associated with other hydrocarbon fuel, in coal beds, as methane clathrates, and is an important fuel source and a major feedstock for fertilizers.Most natural...

 reservoir underneath the city. Processing of the large quantities of hydrogen sulfide

Hydrogen sulfide

Hydrogen sulfide is the chemical compound with the formula . It is a colorless, very poisonous, flammable gas with the characteristic foul odor of expired eggs perceptible at concentrations as low as 0.00047 parts per million...

 in the gas have made Lacq a center of sulfur

Sulfur

Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...

production.